CN113661286B

CN113661286B - Damper and washing machine with same

Info

Publication number: CN113661286B
Application number: CN202080025652.4A
Authority: CN
Inventors: 真保宙史; 仲岛崇博; 西冈由行; 铃木裕一; 森一志
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-06-05
Filing date: 2020-05-29
Publication date: 2023-09-01
Anticipated expiration: 2040-05-29
Also published as: KR20200140699A; JP2020197277A; CN113661286A

Abstract

A washing machine includes a tub disposed within a housing and a damper mounted between the housing and the tub for damping vibration of the tub. The damper includes: a plunger having one end supported on the housing; a lever having one end supported on the water tub and the other end movably inserted into the plunger; a housing arranged to surround some of the plunger and the rod and including a friction member arranged between the housing and the plunger to contact an outer circumferential surface of the plunger; and a switching device configured to be in a first state in which the lever is coupled to the housing and movable with the housing within the plunger, and a second state in which the lever is separated from the housing and is individually movable within the plunger.

Description

Damper and washing machine with same

Technical Field

The present disclosure relates to a damper and a washing machine having the same.

Background

With the conventional washing machine, it is suggested to increase the damping force of the damper in the resonance frequency band of the tub (water tank) at a low rotation number in an initial stage of the spin-drying process while reducing the damping force of the damper for high-speed rotation of the tub.

For example, the washing machine disclosed in JP publication No. 2006-29585 is equipped with a damper cylinder, a shaft inserted from an end of the damper cylinder to move back and forth in a length direction of the damper cylinder, and a friction member provided so that the shaft damps vibration by friction with an inner wall of the damper cylinder and so that the shaft is movable in a direction perpendicular to the length direction of the damper cylinder.

Disclosure of Invention

Technical problem

The present disclosure provides a damper for suppressing vibration of a tub of a washing machine with a simple structure.

The present disclosure also provides a damper for suppressing not only vibration of a washing machine but also vibration of at least one of two members moving relative to each other with a simple structure.

The present disclosure also provides a damper for suppressing vibration with a simple structure and a washing machine having the same.

Technical proposal

According to one aspect of the present disclosure, a washing machine includes a housing; a water tub disposed in the housing and having a spin dryer tub rotatably installed therein; and a damper installed between the housing and the tub for damping vibration of the tub, wherein the damper includes: a plunger having one end supported on the housing; a lever having one end supported on the water tub and the other end movably inserted into the plunger; a housing arranged to surround an outer circumferential surface of some of the plunger and the rod, and including a friction member arranged between the housing and the plunger to contact the outer circumferential surface of the plunger; and a switching device having a first state in which the lever is coupled to the housing and movable together with the housing within the plunger while the friction member is in contact with the outer circumferential surface of the plunger, and a second state in which the lever is separated from the housing and is individually movable within the plunger.

The switching apparatus may include a coupling member coupled to the lever to allow the housing and the lever to be coupled to each other, and a driving member to displace the coupling member to be coupled to or decoupled from the lever.

The coupling member may include a rectangular parallelepiped portion, a protrusion protruding from the rectangular parallelepiped portion, and a plurality of protrusions protruding from the rectangular parallelepiped portion toward the lever.

The driving member may include: a housing fixed to the housing; a working lever having one end received in the housing and fixed to the protrusion and the other end protruding from the housing to move the coupling member; the supporting component is arranged at the other end of the working rod; and a coil spring having one end supported on the housing and the other end supported on the support member.

When a voltage is applied to the driving member to generate an urging force to the working lever, the working lever may enable the coupling member to move toward the lever, coupling the plurality of protrusions to the lever, and thus coupling the housing and the lever to each other.

When the damper is extended or contracted while the housing and the rod are in the coupled state, the rod and the housing may be moved together to or from the plunger, so that the damping force of the damper is increased due to the frictional force generated between the friction member and the outer circumferential surface of the plunger.

When the voltage applied to the driving member is stopped, the working lever may move the coupling member in a direction away from the lever, the plurality of protrusions are separated from the lever, and thus the housing and the lever are separated from each other.

When the damper is extended or contracted while the housing and the rod are in a separated state, the rod may be individually moved to or from the plunger, so that a friction force is generated between the plunger and the rod, and when the friction force is smaller than a friction force generated between the friction member and an outer circumferential surface of the plunger, the damping force of the damper may be smaller than that in a coupled state in which the housing and the rod are coupled to each other.

The plunger may include a tube in the form of a cylinder into which the rod is inserted, and a base provided at one side of the tube and supported on the water tub.

The stem may include a stem portion inserted into the plunger and a base portion disposed on one side of the stem portion and supported on the housing.

The rod-shaped portion may include a plurality of concave portions recessed from an outer circumferential surface of the rod-shaped portion and engaged and coupled with the plurality of protrusions.

The housing may include a cover member surrounding an outer circumferential surface of some of the plunger and the rod and accommodating the friction member, and a restricting member disposed at an end of the cover member for restricting movement of the friction member.

The cover member may include a first cylindrical portion provided with a restriction member and having an inner diameter smaller than an outer diameter of the friction member to accommodate the friction member fitted between the plunger and the first cylindrical portion, a second cylindrical portion having an inner diameter smaller than the inner diameter of the first cylindrical portion to restrict movement of the friction member in a direction opposite to the restriction member, and a third cylindrical portion having an inner diameter smaller than the inner diameter of the second cylindrical portion and larger than the outer diameter of the rod to allow the rod to slide therein.

The rod may include a protrusion arranged to protrude from an outer circumferential surface of the rod for restricting movement of the rod by being caught by the third cylindrical portion when the damper is extended.

To prevent damage by collision of one end of the housing with the base of the plunger when the damper is contracted, the protrusion may be positioned such that when the damper is extended and the protrusion is captured by the third cylindrical portion, one end of the rod is closer to the base of the plunger than one end of the housing.

According to another aspect of the present disclosure, a damper may include: a plunger having one end supported on one of the two members for relative movement; a rod having one end supported on the other of the two members and the other end movably inserted into the plunger; a housing arranged to surround an outer circumferential surface of some of the plunger and the rod, and including a friction member arranged between the housing and the plunger to contact the outer circumferential surface of the plunger; and a switching device having a first state in which the lever is coupled to the housing and movable together with the housing within the plunger while the friction member is in contact with the outer circumferential surface of the plunger, and a second state in which the lever is separated from the housing and is individually movable within the plunger.

The coupling member may include a rectangular parallelepiped portion, a protrusion protruding from the rectangular parallelepiped portion, and a plurality of protrusions protruding from the rectangular parallelepiped portion toward the lever to be coupled to or separated from the lever.

The drive member may include a housing fixed to the housing; a working lever having one end received in the housing and fixed to the protrusion and the other end protruding from the housing to move the coupling member; a support member mounted at the other end of the working rod; and a coil spring having one end supported on the housing and the other end supported on the support member.

According to another aspect of the present disclosure, a damper may include: a plunger having one end supported on one of the two members for relative movement; a rod having one end supported on the other of the two members and the other end movably inserted into the plunger; a housing arranged to surround an outer circumferential surface of some of the plunger and the rod, and including a friction member arranged between the housing and the plunger to contact the outer circumferential surface of the plunger; and a switching device that switches between a state in which the lever is coupled to the housing and a state in which the lever is decoupled from the housing to change a damping force due to a friction force generated when the lever moves within the plunger.

Advantageous effects of the application

According to the embodiments of the present disclosure, a damper of vibration suppressed with a simple structure and a washing machine having the same may be provided.

Drawings

Fig. 1 shows a schematic view of a washing machine according to an embodiment of the present disclosure;

FIG. 2 shows a schematic view of a damper;

fig. 3 shows an example of a coupled state;

FIG. 4 shows an example of an extension damper in a coupled state;

FIG. 5 shows an example of a contraction damper in a coupled state;

FIG. 6 shows an example of an extension damper in a detached state;

FIG. 7 shows an example of a contraction damper in a detached state;

fig. 8 shows an example of a relationship between the rotation speed of the motor and the vibration of the water tub; and

fig. 9 shows a diagram for describing the position of the protrusion arranged in the shaft portion of the lever.

Detailed Description

Figures 1 through 9, discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will appreciate that the principles of the present disclosure may be implemented in any suitably arranged system or device.

The embodiments and features described and illustrated in this disclosure are examples only, and various modifications of alternative embodiments and figures are possible at the time of filing the present application.

Like reference numerals refer to like parts or features throughout the drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. It should be understood that the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Terms including ordinal numbers such as "first" and "second" may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure. When items are described using the conjunctive terminology "… and/or …" and the like, the description should be understood to include any and all combinations of one or more of the associated listed items.

The terms "front", "rear", "upper", "lower", "top" and "bottom" as used herein are defined with respect to the drawings, but these terms may not limit the shape and location of the corresponding components.

Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings.

Fig. 1 shows a schematic view of a washing machine 1 according to an embodiment of the present disclosure. Specifically, fig. 1 shows a sectional view of the washing machine 1 as seen from the right side. In fig. 1, the left direction is the forward direction of the washing machine 1, the right direction is the backward direction of the washing machine 1, the upper direction is the upward direction of the washing machine 1, and the lower direction is the downward direction of the washing machine 1.

In the embodiment of the present disclosure, the washing machine 1 may include a tub 10, a spin dryer tub 20 as an example of a rotating body rotatably installed in the tub 10, and a housing 30 for accommodating the tub 10 and the spin dryer tub 20.

The rotation shaft 21 of the spin basket 20 extends in the front-rear direction, and the spin basket 20 rotates leftward, for example, the spin basket 20 rotates counterclockwise when the washing machine 1 is viewed from the front.

The case 30 is substantially shaped like a rectangular parallelepiped, and includes a frame 30a made of steel and an iron plate 30b having a lower hardness than that of the frame 30 a. An opening is formed at a front portion of the housing 30 through which laundry is put, and a door 31 is mounted on the housing 30 to open or close the opening.

The washing machine 1 may further include a motor 40, a conveyor 50 for transmitting a rotational force of the motor 40 to the rotation shaft 21 of the spin basket 20, and a control device 60 for controlling the operation of the motor 40.

The motor 40 may be, for example, a three-phase brushless motor including a rotation angle detector 41, such as a rotary transformer, rotary encoder, or the like, for detecting the rotation angle of the motor 40.

The conveyor 50 may include a pulley mounted on the rotation shaft 21, a belt surrounding the pulley, or the like.

The control device 60 is an arithmetic and logical operation circuit including a Central Processing Unit (CPU), a Read Only Memory (ROM), a Random Access Memory (RAM), a backup RAM, and the like. The control device 60 may include at least one processor. The control device 60 may receive an output signal from the rotation angle detector 41 of the motor 40. The control device 60 may set a target current that needs to be applied to the motor 40 based on, for example, an output signal from the rotation angle detector 41, and perform feedback control based on the target current.

The washing machine 1 may further include a spring 70 mounted between the frame 30a of the housing 30 and the tub 10. For example, there may be a plurality of springs 70.

The washing machine 1 may further include a damper 100 mounted between the frame 30a of the housing 30 and the tub 10 for damping vibration of the tub 10. For example, the washing machine 1 may include four dampers 100 connected between four bottom corners of the tub 10 and the frame 30a on the bottom of the housing 30. Further, the washing machine 1 may include two dampers 100 connected between the front and rear portions of the left top of the tub 10 and the frame 30a of the upper left portion of the housing 30, and two dampers 100 connected between the front and rear portions of the right top of the tub 10 and the frame 30a of the upper right portion of the housing 30. One of the eight dampers 100 may be omitted, or additional dampers 100 may be added to the eight dampers 100.

Fig. 2 shows a schematic diagram of a damper 100 according to an embodiment of the present disclosure.

The damper 100 may include a plunger 110 as an example of a supporting member whose one end is supported on the housing 30, and a lever 120 as an example of a rod-shaped member whose one end is supported on the tub 10 and whose other end is inserted into the plunger 110. Further, the damper 100 may include a housing 130 to cover around some of the plunger 110 and the rod 120. The damper 100 may further include a switching device 140, the switching device 140 being an example of a switching device that switches between a first state in which the lever 120 and the housing 130 are combined to allow the housing 130 to move with the lever 120 to the plunger 110 or out of the plunger 110, and a second state in which the lever 120 is separated from the housing 130. One end of the plunger 110 may be supported on the water tub 10, and one end of the lever 120 may be supported on the housing 30.

The plunger 110 may include a cylindrical tube 111 and a base 112 for holding the tube 111. A pin hole 111a may be formed in the base 112 for passing a pin therethrough to couple the plunger 110 to the tub 10. For example, the shape of the pin hole 111a is similar to a cylinder.

The stem 120 may include a stem portion 121 and a base portion 122 for holding the stem portion 121.

The shaft 121 may have a cylindrical form, for example. The outer diameter of the rod-shaped portion 121 is equal to or smaller than the inner diameter of the tube 111 of the plunger 110, and the other end of the rod-shaped portion 121 opposite to the base 122 is inserted into the tube 111 of the plunger 110. As the plunger 110 slides within the tube 111 of the plunger 110, the damper 100 extends or contracts.

In the following description, the direction of the center line of the shaft 121, i.e., the direction in which the shaft 121 moves toward or from the plunger 110, is simply referred to as the "extending and contracting direction". Further, in the extending and contracting directions, one side of the water tub 10 is referred to as one side, and one side of the housing 30 is referred to as the other side.

A concave portion 121a depressed from the outer circumference may be formed at an end of the rod-shaped portion 121 on the side of the base 122. For example, the concave portion 121a may have a spiral shape. However, the form of the concave portion 121a is not limited thereto. The concave portion 121a may extend in a direction perpendicular to the extending and contracting directions. In some cases, a plurality of (e.g., 5) concave portions 121a may be formed in the extending and contracting directions. Further, the concave portion 121a may be formed around the entire outer circumference of the rod-shaped portion 121, or two concave portions 121a may be formed on the circumference at intervals of 180 degrees.

Further, a protrusion 121b protruding from the outer circumference of the rod-shaped portion 121 may be formed at a position closer to the central portion of the rod-shaped portion 121 than the recess portion 121a. The position and size of the protruding portion 121b will be described later.

A pin hole 122a may be formed in the base 122 for passing a pin therethrough to couple the lever 120 to the housing 30. For example, the shape of the pin hole 122a is similar to a cylinder.

The housing 130 may include a friction member 131, a cover member 133 for covering the friction member 131, and a restricting member 132 for restricting movement of the friction member 131, the friction member 131 being an example of a contact body arranged around the tube 111 to contact the outer circumference of the tube 111 of the plunger 110.

The friction member 131 is shaped like a cylinder. When the lever 120 is coupled to the housing 130 through the switching device 140, the lever 120 may be capable of moving with the housing 130 within the plunger 110 when the friction member 131 contacts the outer circumference of the plunger 110. When the lever 120 is separated from the housing 130 by the switching device 140, only the lever 120 can move within the plunger 110.

The friction member 131 may be formed of any material having good wear resistance. For example, the friction member 131 may be made of urethane resin or urethane rubber. In another example, the friction member 131 may be made of nitrile rubber (NBR), hydrogenated NBR (H-NBR), ethylene propylene rubber (e.g., EPDM), styrene Butadiene Rubber (SBR), or natural rubber. In still another example, the friction member 131 may be made of a thermosetting resin or a thermoplastic resin. Thermosetting resins may include, but are not limited to, for example, phenolic resins and epoxy resins. The thermoplastic resin may include, but is not limited to, for example, polyamide resins, polyimide resins, and polycarbonate resins. Alternatively, the material of the friction member 131 may be metal. The metal may include, for example, copper and brass.

The cover member 133 has the form of three cylindrical portions having different inner diameters and outer diameters, namely a first cylindrical portion 136, a second cylindrical portion 137, and a third cylindrical portion 138, which are sequentially arranged from side to side in the extending and contracting directions.

The first cylindrical portion 136 is longer than the friction member 131 in the extending and contracting directions. The inner diameter of the first cylindrical portion 136 is smaller than the outer diameter of the friction member 131. The first cylindrical portion 136 positions the friction member 131 between the first cylindrical portion 136 and the tube 111 of the plunger 110. The inner diameter of the first cylindrical portion 136 and the thickness of the friction member 131 are set such that the inner circumferential surface and the outer circumferential surface of the friction member 131 are held in contact with the outer circumferential surface of the tube 111 and the inner circumferential surface of the first cylindrical portion 136, respectively, and friction is generated between the inner circumferential surface of the friction member 131 and the outer circumferential surface of the tube 111 and the outer circumferential surface of the friction member 131 and the inner circumferential surface of the first cylindrical portion 136.

The inner diameter of the second cylindrical portion 137 is smaller than the outer diameter of the friction member 131. The end of the second cylindrical portion 137 on one side in the extending and contracting directions restricts the movement of the friction member 131 to the other side. The inner diameter of the second cylindrical portion 137 is greater than the outer diameter of the tube 111 of the plunger 110. The housing 130 is movable relative to the tube 111.

The inner diameter of the third cylindrical portion 138 is smaller than the inner diameter of the second cylindrical portion 137 and larger than the outer diameter of the shaft portion 121 of the shaft 120. The rod portion 121 of the rod 120 is capable of sliding within the third cylindrical portion 138.

The distance from the centerline of the stem 120 to the protrusion 121b of the stem portion 121 is less than the inner diameter of the second cylindrical portion 137 and greater than the inner diameter of the third cylindrical portion 138. This causes the protrusion 121b of the rod-shaped portion 121 to collide with the end of the third cylindrical portion 138, thereby restricting the movement of the housing 130 to the other side of the rod 120.

A mounting portion 138a in which the switching device 140 is mounted is formed in the third cylindrical portion 138. The mounting portion 138a has a cylindrical portion to support a coupling member 150 (which will be described later) of the switching device 140 to be slidable.

The restriction member 132 is installed in the first cylindrical portion 136 to close the opening of the end of the first cylindrical portion 136 of the cover member 133. For example, the restriction member 132 is fixed to the first cylindrical portion 136 by a fastening member such as a screw. In another example, the restraining member 132 may be forcibly fitted into the first cylindrical portion 136. Further, the restriction member 132 may have a sealing function to prevent foreign matter such as dust from invading the housing 130.

The switching device 140 may include a coupling member 150 and a driving member 160 for moving the coupling member 150, the coupling member 150 having a protrusion 151a coupled to a recess portion 121a formed at the lever 120. The coupling member 150 may be coupled to the lever 120 to allow the housing and the lever 120 to be coupled to or decoupled from each other. The driving member 160 may displace the coupling member 150 to be coupled to the lever 120 or to be decoupled from the lever 120.

The coupling member 150 includes a rectangular parallelepiped portion 151 and a protrusion 152 protruding from the rectangular parallelepiped portion 151, and moves in a direction perpendicular to the extending and contracting directions.

The rectangular parallelepiped-shaped portion 151 includes projections 151a (for example, three projections 151a in this embodiment of the present disclosure) projecting toward the lever 120 from a side facing the lever 120 in the extending and contracting directions at regular intervals. The projection 151a extends in a direction perpendicular to the paper of fig. 2.

On the other side opposite to the side of the rectangular parallelepiped portion 151 on which the projection 151a is formed, there is a projection 152 formed in a direction perpendicular to the extending and contracting directions. In the following description, a direction perpendicular to the extending and contracting directions is sometimes referred to as a vertical direction.

For example, the driving member 160 is a so-called solenoid actuator that converts electric energy into mechanical energy using electromagnetic force.

The driving member 160 may include a coil, a magnetic core 161, and a working rod 162 guided to the magnetic core 161. The driving member 160 may further include a housing 163 covering the coil, the magnetic core 161, and the working rod 162, and a coil spring 164 disposed around the housing 163.

The working lever 162 has one end received in the housing 163 facing the coupling member 150 and the other end protruding from the housing 163 opposite to the coupling member 150. The supporting member 165 may be installed at the other end of the working rod 162 protruding from the housing 163 to support one end of the coil spring 164. Further, an end of the working rod 162 facing the coupling member 150 may be fixed to the protrusion 152 of the coupling member 150.

The housing 163 may be secured to the housing 130. For example, the housing 163 may be fixed to the third cylindrical portion 138 of the housing 130 by fastening members such as bolts or screws. The housing 163 may support one end of the coil spring 164.

For example, the support member 165 may have the form of a disk.

Fig. 3 shows an example of the coupled state.

In the switching device 140 as described above, when a voltage is applied to the driving member 160 and a current flows in the coil of the driving member 160 through the lead wire, a propulsive force in the vertical direction is generated to the operating lever 162. Then, the working lever 162 moves toward the lever 120, and the coupling member 150 fixed to the working lever 162 also moves to the lever 120. This allows the protrusion 151a of the coupling member 150 to be fitted into the recess 121a formed on the lever 120. The state in which the projection 151a is fitted into the concave portion 121a will also be referred to as a coupled state. The coupling state is an example of the aforementioned first state.

When the voltage applied to the driving member 160 is stopped, there is no pushing force on the working lever 162, and thus the working lever 162 moves in the opposite direction away from the lever 120 according to the elastic force of the coil spring 164, and the coupling member 150 also moves in the opposite direction. This causes the protrusion 151a of the coupling member 150 to fall out of the recess portion 121a formed on the lever 120, i.e., in a state of not being fitted to the recess portion 121a. The state in which the projection 151a is not fitted to the concave portion 121a is also referred to as a separated state. Fig. 2 shows an example of the separated state. The detached state is an example of the aforementioned second state.

The voltage applied to the driving member 160 may be controlled by the control device 60. When the rotation speed N of the motor 40 is within the predetermined rotation speed range Nt, the control device 60 applies a voltage to the driving member 160. On the other hand, when the rotational speed N of the motor 40 exceeds the predetermined rotational speed range Nt, the control device 60 does not apply a voltage to the driving member 160. For example, the control device 60 may determine the rotational speed N of the motor 40 based on the rotational angle of the motor 40 detected by the rotational angle detector 41 (e.g., a resolver mounted on the motor 40). In another example, the control device 60 may determine the rotational speed N of the motor 40 based on a target value of the current applied to the motor 40.

Fig. 4 shows an example of an extension damper in a coupled state, and fig. 5 shows an example of a contraction damper in a coupled state. Fig. 6 shows an example of an extension damper in a separated state, and fig. 7 shows an example of a contraction damper in a separated state.

In the washing machine 1 having the above-described structure, when the rotational speed N of the motor 40 falls within the predetermined rotational speed range Nt, the protrusion 151a of the coupling member 150 of the switching device 140 is fitted into the recess 121a formed on the lever 120, i.e., in the coupled state, when the control device 60 applies a voltage to the driving member 160. Referring to fig. 4 and 5, in the coupled state, the rod 120 and the housing 130 may be combined and moved to the plunger 110 or moved from the plunger 110. Specifically, the housing 130 and the plunger 110 move relative to each other while the friction member 131 of the housing 130 is in contact with the outer circumferential surface of the plunger 110. Accordingly, a damping force is generated to the damper 100 by the friction force generated between the friction member 131 and the plunger 110.

The frictional force generated between the friction member 131 and the plunger 110 may vary according to the force applied to the friction member 131 to press and contact the outer circumferential surface of the plunger 110 through the first cylindrical part 136 of the housing 130. The frictional force may also vary depending on the thickness of the friction member 131, i.e., the difference between the outer radius and the inner radius of the friction member 131 and the difference between the outer diameter of the friction member 131 and the inner diameter of the first cylindrical portion 136. In addition, the friction force may also depend on the material of the friction member 131. Accordingly, the damping force of the damper 100 may depend on the thickness or material of the friction member 131, or the difference between the outer diameter of the friction member 131 and the inner diameter of the first cylindrical portion 136.

For example, the predetermined rotation speed range Nt may include a rotation speed N of the motor 40 resonating with the washing machine 1, for example, about 100rpm to about 300rpm.

When the rotation speed N of the motor 40 exceeds the predetermined rotation speed range Nt, since the control device 60 does not apply a voltage to the driving member 160, the protrusion 151a of the coupling member 150 of the switching device 140 is in a separated state not fitted into the recess portion 121a formed on the lever 120. Referring to fig. 6 and 7, in the separated state, the rod 120 and the housing 130 are not united but separated from each other, and thus, the rod 120 can be moved relative to the plunger 110 while the housing 130 is not moved to the plunger 110 or from the plunger 110. Therefore, a damping force caused by a friction force generated between the friction member 131 and the plunger 110 may not be generated on the damper 100. Since the frictional force generated between the plunger 110 and the rod 120 is insignificant compared to the frictional force generated between the friction member 131 and the plunger 110, the damping force at speeds exceeding the predetermined rotational speed range Nt is weak.

Fig. 8 shows an example of a relationship between the rotation speed N of the motor 40 and the vibration of the water tub 10. The solid line represents the vibration of the tub 10 of the washing machine 1 according to the embodiment of the present disclosure, and the dotted line represents the vibration of the tub 10 of the washing machine having the comparative structure. Unlike the washing machine 1 according to the embodiment of the present disclosure, the washing machine having the comparative structure is not equipped with the damper 100.

As shown in fig. 8, when the rotation speed N of the motor 40 does not fall within the predetermined rotation speed range Nt, a damping force due to a friction force generated between the friction member 131 and the plunger 110 is not generated to the damper 100, and vibration of the washing machine 1 according to the embodiment of the present disclosure and the washing machine having the comparative structure is substantially the same. Otherwise, when the rotation speed N of the motor 40 falls within the predetermined rotation speed range Nt, a damping force generated due to a friction force generated between the friction member 131 and the plunger 110 appears on the damper 100, and the vibration of the washing machine 1 according to the embodiment of the present disclosure is smaller than that of the washing machine having the comparative structure.

Further, in comparison with a washing machine (hereinafter also referred to as a washing machine having another comparative structure) on which a damping force generated, for example, due to a friction force generated by the friction member 131 occurs at a speed exceeding the predetermined rotation speed range Nt, vibration of the tub 10 at a speed exceeding the predetermined rotation speed range Nt is hardly transmitted to the housing 30 in the washing machine 1 according to an embodiment of the present disclosure. Therefore, the washing machine 1 according to the embodiment of the present disclosure has less vibration of the casing 30 than that of the washing machine having another comparative structure at a speed exceeding the predetermined rotation speed range Nt.

The vibration of the washing machine 1 according to the embodiment of the present disclosure is smaller than that of the washing machine having the comparison structure or having another comparison structure, and the vibration of the casing 30 of the washing machine 1 or the vibration on the floor on which the washing machine 1 is mounted is also reduced. Noise due to vibration is also reduced.

Accordingly, with the washing machine 1 according to the embodiment of the present disclosure, interference between the tub 10 and the iron plate 30b of the housing 30 due to vibration of the tub 10 or the housing 30 can be suppressed. Even when vibration occurs, the distance between the tub 10 and the iron plate 30b of the case 30 is not narrower than that in the washing machine having the comparative structure or having other structures, and thus the washing machine 1 may have the tub 10 of a larger size in the case of the same-sized case 30. As a result, the washing machine 1 according to the embodiment of the present disclosure can accommodate more laundry amount without increasing the external dimension defined by the outer surface of the casing 30.

Further, with the damper 100 as described above, the above-described effects can be obtained without complicating the structure. Specifically, with the damper 100, the friction member 131 is disposed within the housing 130 that is covered around the plunger 110 or the rod 120 to generate a friction force between the friction member 131 and the outer circumferential surface of the plunger 110. Such a structure of the damper 100 is simpler than a structure having a member equipped with a friction member provided in the plunger 110 or the rod 120, for example. Furthermore, it is also simpler than, for example, another structure in which a member equipped with a friction member is provided between the housing 130 and the plunger 110 or the rod 120 separately from the housing 130.

With the damper 100 in the embodiment of the present disclosure, when the size of the friction member 131 is constant, the friction force between the friction member 131 and the outer circumferential surface of the plunger 110, further, the damping force of the damper 100 may be changed by changing the inner diameter of the first cylindrical portion 136 of the housing 130. Thus, for example, when it is desired to change the damping force of a certain type of washing machine, the damping force may be changed simply by changing the inner diameter of the first cylindrical portion 136 of the housing 130 without changing the size of the friction member 131.

In the damper 100 of the embodiment of the present disclosure, the lever 120 and the housing 130 having the friction member 131 may be combined by coupling the protrusion 151a of the coupling member 150 to the recess formed on the outer circumferential surface of the lever 120 from the outside. The coupling member 150 moves in a direction perpendicular to the extending and contracting directions to couple the protrusion 151a to the recess portion 121a. Accordingly, the damper 100 has a simpler structure than a structure in which a member having the friction member 131 (corresponding to the housing 130 of the damper 100) is rotated to combine the member and the lever 120.

The coupling member 150 moves in a direction perpendicular to the extending and contracting directions. Further, the frictional force between the friction member 131 and the outer circumferential surface of the plunger 110 is generated by a force applied to the friction member 131 to press and contact the plunger 110, not by the driving member 160 to determine the inner diameter of the first cylindrical portion 136 of the housing 130. That is, the driving member 160 may generate a force to such an extent that the protrusion 151a of the coupling member 150 can be coupled to the concave portion 121a formed on the outer circumferential surface of the lever 120 or separated from the concave portion 121a. For example, instead of the structure in which the lever 120 and the housing 130 are united using the coupling member 150, a structure in which a friction member is pressed against the outer circumferential surface of the lever 120 and the housing 130 are united using a friction force generated between the friction member and the outer circumferential surface of the lever 120 (hereinafter referred to as a second comparative structure) may be considered. With the second comparative structure, in order to generate friction force to move the friction members in the vertical direction for coupling, electromagnetic force of the driving member 160 may be increased, and for this, the coil or the magnetic core 161 may be larger. In contrast, with the damper 100 in the embodiment of the present disclosure, a small solenoid actuator may be used as the driving member 160. The solenoid actuator has good response characteristics and can be instantaneously switched between the coupled state and the decoupled state, thereby allowing the damping force to be changed with high accuracy according to the rotation speed N of the motor 40. With the second comparison structure, when it is desired to change the damping force of a certain type of washing machine, the electromagnetic force of the driving member 160 may be changed, and the driving member 160 may be larger to increase the damping force. In contrast, with the damper 100 of the embodiment of the present disclosure, the damping force can be changed by changing only the inner diameter of the first cylindrical portion 136 of the housing 130.

Further, when a voltage is applied to the driving member 160 for the coupled state, since the washing machine 1 vibrates, even if the position of the protrusion 151a of the coupling member 150 does not match the position of the recess portion 121a of the lever 120 and the protrusion 151a contacts the outer circumferential surface of the lever 120, the lever 120 moves to the coupling member 150 and thus the protrusion 151a is coupled to the recess portion 121a. Therefore, with the damper 100 according to the embodiment of the present disclosure, the coupled state can be obtained at a desired timing. The moving direction of the coupling member 150 may not be perpendicular to the extending and contracting directions. For example, the moving direction of the coupling member 150 may be inclined with respect to the extending and contracting directions and the directions perpendicular to the extending and contracting directions.

Further, since the damper 100 of the embodiment of the present disclosure has a structure that generates a damping force using the friction force of the friction member 131, the damper 100 is smaller than a damper that generates a damping force using, for example, a Magnetorheological (MR) fluid. In particular, the MR fluid-based damper tends to increase due to its own filling with MR fluid, but the damper 100 according to embodiments of the present disclosure may be reduced in size because it does not need to be filled with a fluid such as MR fluid. In addition, a damper that generates a damping force using an MR fluid needs to change its design, for example, the amount of the MR fluid, to change the damping force for a certain type of washing machine. In contrast, with the damper 100 of the embodiment of the present disclosure, the damping force can be simply changed by changing the inner diameter of the first cylindrical portion 136 of the housing 130.

Further, as described above, the damper 100 according to the embodiment of the present disclosure may reduce vibration of the water tub 10 even in the case of a simple structure. This is because the damper 100 is disposed not only between the bottom of the tub 10 and the bottom of the housing 30, but also between the top of the tub 10 and the left and right ends of the housing 30, so that it is in a coupled state even at the rotation speed N resonating in the left-right direction of the tub 10.

Fig. 9 shows a diagram for describing the position of the protrusion 121b formed on the shaft portion 121 of the lever 120.

The protrusion 121b formed on the lever 120 is provided at a position where a distance Lh from a hole center of the pin hole 122a formed on the base 122 as an example of a support end supported on the water tub 10 to an end of the housing 130 is smaller than a distance Lr from the hole center of the pin hole 122a to a front end of the lever 120.

The reason will be described below. When one end of the housing 130 collides with the base 112 of the plunger 110 in a coupled state in which the lever 120 and the housing 130 are combined, the switching device 140 may be damaged. Specifically, in the coupled state, when the damper 100 has a large stroke and the end of the housing 130 collides with the base 112 of the plunger 110, impact power from the collision may be transmitted to the switching device 140 and may damage the switching device 140. With the damper 100 according to the embodiment of the present disclosure, when the protrusion 121b formed on the rod 120 is positioned such that the distance Lh is smaller than the distance Lr, the rod 120 collides with the base 112 of the plunger 110 when the damper 100 is contracted. Accordingly, the switching device 140 can be prevented from being damaged due to collision of one end of the housing 130 with the base 112 of the plunger 110.

Specifically, in order to prevent damage caused by collision of one end of the housing 130 with the base 112 of the plunger 110 when the damper 100 is contracted, the protrusion 121b may be positioned such that one end of the rod 120 is closer to the base 112 of the plunger 110 than one end of the housing 130 when the damper 100 is extended and the protrusion 121b is caught by the third cylindrical portion 138.

In the embodiment of the present disclosure, the damper 100 is applied to the washing machine 1 such that one end of the plunger 110 supports a member on one side of the housing 30 or the tub 10 and one end of the lever 120 supports a member on the other side of the housing 30 or the tub 10, but the structure is not limited thereto. For example, the damper 100 may be disposed between two members that are movable relative to each other. Specifically, one end of the plunger 110 may support one of the two members that move relative to each other, while one end of the rod 120 may support the other of the two members, while the other end of the rod 120 is inserted into the plunger 110.

Claims

1. A washing machine, comprising:

a housing;

a water tub disposed within the housing and including a spin dryer tub rotatably installed within the water tub; and

a damper installed between the housing and the water tub and configured to damp vibration of the water tub,

wherein the damper comprises:

a plunger having one end supported on the housing;

a lever having one end supported on the water tub and the other end movably inserted into the plunger;

a housing arranged to surround an outer circumferential surface of some of the plungers and the rod, the housing including a friction member arranged between the housing and the plungers to contact the outer circumferential surface of the plungers; and

a switching device configured to be:

a first state in which the lever is coupled to the housing,

the lever is configured to move together with the housing within the plunger while the friction member is in contact with the outer circumferential surface of the plunger in the first state, and

a second state in which the lever is separated from the housing,

the rod is configured to move independently within the plunger in the second state.

2. The washing machine as claimed in claim 1, wherein the switching device comprises:

a coupling member coupled to the lever, the coupling member configured to couple the housing and the lever to each other; and

a driving member configured to displace the coupling member to be coupled to or decoupled from the lever.

3. The washing machine as claimed in claim 2, wherein the coupling member includes:

a rectangular parallelepiped-shaped portion;

a protrusion protruding from the rectangular parallelepiped-shaped portion; and

a plurality of projections protruding from the rectangular parallelepiped portion toward the lever.

4. A washing machine as claimed in claim 3, wherein the driving member comprises:

a case member fixed to the housing;

a working lever having one end received in the housing member and fixed to the protruding portion, and the other end protruding from the housing member and configured to move the coupling member;

a support member mounted to the other end of the working rod; and

a coil spring having one end supported on the case member and the other end supported on the support member.

5. The washing machine as claimed in claim 4, wherein when a voltage is applied to the driving member to generate an urging force to the working lever, the working lever is configured to move the coupling member and the plurality of protrusions toward the lever to couple the plurality of protrusions to the lever, and thus couple the housing and the lever to each other.

6. The washing machine as claimed in claim 5, wherein when the damper is extended or contracted while the housing and the lever are in a coupled state, the lever and the housing are configured to move together to or from the plunger, so that a damping force of the damper is increased due to a friction force generated between the friction member and an outer circumferential surface of the plunger.

7. The washing machine as claimed in claim 6, wherein when the application of the voltage to the driving member is stopped, the working lever is configured to move the coupling member and the plurality of protrusions in a direction away from the lever to separate the plurality of protrusions from the lever, and thus separate the housing and the lever from each other.

8. The washing machine as claimed in claim 7, wherein when the damper is extended or contracted while the housing and the lever are in a separated state, the lever is configured to be moved to or from the plunger alone, causing a friction force to be generated between the plunger and the lever, and when the friction force generated between the plunger and the lever is smaller than the friction force generated between the friction member and an outer circumferential surface of the plunger, the damping force of the damper is smaller than the damping force in the coupled state in which the housing and the lever are coupled to each other.

9. A washing machine as claimed in claim 3, wherein the lever comprises:

a rod-shaped portion inserted into the plunger; and

a base portion disposed on one side of the shaft portion and supported on the housing.

10. The washing machine as claimed in claim 9, wherein the shaft includes a plurality of recess portions recessed from an outer circumferential surface of the shaft, and fitted and coupled with the plurality of protrusions.

11. The washing machine as claimed in claim 1, wherein the plunger includes:

a tube having a cylindrical form into which the rod is inserted; and

a base disposed at one side of the pipe and supported on the water tub.

12. The washing machine as claimed in claim 1, wherein the housing comprises:

a cover member surrounding an outer circumferential surface of some of the plunger and the rod and configured to accommodate the friction member; and

a restricting member disposed at an end of the cover member and configured to restrict movement of the friction member.

13. The washing machine as claimed in claim 12, wherein the cover member includes:

a first cylindrical portion provided with the restriction member and having an inner diameter configured to accommodate the friction member fitted between the plunger and the first cylindrical portion such that friction is generated between the friction member and an inner circumferential surface of the first cylindrical portion;

a second cylindrical portion having an inner diameter smaller than an inner diameter of the first cylindrical portion to restrict movement of the friction member in a direction opposite to the restriction member; and

a third cylindrical portion having an inner diameter smaller than the inner diameter of the second cylindrical portion and larger than the outer diameter of the rod to allow the rod to slide therein.

14. The washing machine as claimed in claim 13, wherein the lever includes a protrusion arranged to protrude from an outer circumferential surface of the lever and configured to limit movement of the lever by being caught by the third cylindrical portion when the damper is extended.

15. The washing machine as claimed in claim 14, wherein, in order to prevent one end of the housing from being damaged by collision with a base of the plunger when the damper is contracted, the protrusion is positioned such that one end of the rod is closer to the base of the plunger than the one end of the housing when the damper is extended and the protrusion is caught by the third cylindrical portion.