Clothes treatment device and method for manufacturing drum

Abstract

The present invention relates to a clothing treatment device and a method for manufacturing a drum. According to one embodiment, a clothing treatment device including a drum can be provided, wherein the drum includes a cylindrical portion, a lifter portion that is bent from the cylindrical portion and protrudes inward from the cylindrical portion and has a longitudinal axis in the front-to-rear direction, and a recess portion that is formed by bending the cylindrical portion in a lifter peripheral portion that forms the periphery of the lifter portion, and the recess portion is formed at least partially between a first position that is a position of the lifter peripheral portion and a second position that is a position on the opposite side of the longitudinal axis of the lifter portion.

Description

[Technical Field]

[0001] The present invention relates to a laundry treatment device and a method for manufacturing a drum. [Background technology]

[0002] Clothes processing devices for processing laundry include washing machines, dryers, etc. Clothes processing devices such as washing machines and dryers and methods for manufacturing drums include a rotatable drum. The drum in the clothing processing device and drum manufacturing method contains laundry. The laundry contained in the drum is processed by various operations performed by the clothing processing device.

[0003] The drum may include a lifter disposed on the inner circumferential surface. Korean Patent Publication No. 10-2011-0022359 discloses that the lifter disposed on the inner circumferential surface lifts laundry when the drum rotates.

[0004] The lifter lifts the laundry, which is beneficial for various processes performed by the laundry treatment device. For example, in the case of a washing machine, a lifter can ensure higher friction between the laundry and cleaning power than a machine without a lifter.

[0005] Korean Patent Publication No. 10-2020-0025557 discloses forming a lifter by plastically processing a metal plate that forms a drum. When a drum is manufactured by processing a metal plate to form a lifter, and then rolling the metal plate with the lifter into a cylindrical shape and joining both ends, the part where the lifter is formed may be deformed (or broken) during the rolling process. Furthermore, the rigidity of the part where the lifter is formed is weaker than the other parts of the manufactured drum, which may lead to breakage. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a clothing processing device and a method for manufacturing a drum that can reduce damage (e.g., tearing and collapse) caused by load when a metal plate used to manufacture the drum is bent to form a lifter (hereinafter referred to as a drum with a forming-type lifter structure).

[0007] The present invention provides a clothing treatment device and a method for manufacturing a drum having a forming-type lifter structure that can reduce damage by dispersing stress generated in the lifter.

[0008] The present invention provides a clothing treatment device and a method for manufacturing a drum having a forming-type lifter structure, which can avoid the risk of tearing during the process of winding a metal plate into a cylindrical shape.

[0009] The present invention provides a laundry treatment device and a method for manufacturing a drum that can reduce the risk of damage to the drum due to load during use.

[0010] The problems to be solved by the present invention are not limited to these, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0011] According to one embodiment, a clothing processing device is provided that includes a drum, wherein the drum includes a cylindrical portion, a lifter portion that is bent from the cylindrical portion and protrudes inside the cylindrical portion, and has a long axis in the front-to-back direction, and a recess portion that is formed by bending the cylindrical portion in a lifter peripheral portion that forms the periphery of the lifter portion, and the recess portion is formed at least partially between a first position that is a position on the lifter peripheral portion and a second position that is a position on the opposite side of the long axis of the lifter portion.

[0012] In addition, there is provided a clothing treatment device in which the recessed portion is protruded from the outside of the cylindrical portion.

[0013] Also provided is a clothing processing device, wherein the recess portion includes a first recess portion and a second recess portion that conforms to the shape of the first recess portion but is spaced apart from the lifter portion by the first recess portion.

[0014] In addition, the drum further includes a recess-forming protrusion spaced apart from the lifter portion and formed by bending the cylindrical portion to protrude inward of the cylindrical portion, and the recess is located between the lifter portion and the recess-forming protrusion.

[0015] Also provided is a clothing processing device in which the recess-forming protrusion includes a first recess-forming protrusion formed at a first distance from the lifter portion, and a second recess-forming protrusion formed at a second distance from the lifter portion, and the recess includes a first recess located between the lifter portion and the first recess-forming protrusion, and a second recess located between the first recess-forming protrusion and the second recess-forming protrusion.

[0016] In addition, there is provided a clothes treating device in which the recessed portion is formed in the entire periphery of the lifter.

[0017] In addition, there is provided a clothing treatment device in which the cylindrical portion is formed by winding a metal plate made of a metal material.

[0018] Also provided is a clothing processing device in which a plurality of lifter sections are formed, the plurality of sections forming one set, the plurality of sets being arranged equiangularly.

[0019] In addition, there is provided a clothing processing device in which the plurality of lifter sections constituting each group are arranged offset in the front-to-rear direction.

[0020] In addition, a clothing processing device is provided in which the lifter sections include a plurality of front lifter sections arranged equiangularly, and a plurality of rear lifter sections arranged equiangularly and rearward of the front lifter sections, and the recess sections include a front lifter recess section formed in the front lifter peripheral section that forms the periphery of each of the front lifter sections, and a rear lifter recess section formed in the rear lifter peripheral section that forms the periphery of each of the rear lifter sections.

[0021] In addition, a clothing disposal device is provided in which the front lifter recess is formed at least behind the front lifter periphery.

[0022] In addition, a clothing disposal device is provided in which the rear lifter recess is formed at least in front of the rear lifter periphery.

[0023] The drum is also rotatable.

[0024] The apparatus further includes a tub for receiving the drum therein, the drum being rotatably mounted within the tub.

[0025] According to one embodiment, a method for manufacturing a drum for a clothing treatment device is provided, which includes a bending step of bending a metal plate to form a lifter portion having a first height and a recess portion having a first depth, and a joining step of rolling the metal plate into a cylindrical shape and joining both ends after the bending step.

[0026] There is also provided a method for manufacturing a drum for a clothes treating device, wherein the first height is greater than the first depth.

[0027] Also provided is a method for manufacturing a drum for a clothing treatment device, wherein the recess portion is formed by a recess-forming protrusion formed by bending the metal plate by a second height in the same direction as the protruding direction of the lifter portion.

[0028] Also, there is provided a method for manufacturing a drum for a clothing treatment device, wherein the recessed portion is formed by bending the metal plate by the first depth in a direction opposite to a protruding direction of the lifter.

[0029] The clothing treatment device may be a washing machine.

[0030] The laundry treatment device may be a dryer. [Effects of the Invention]

[0031] According to various embodiments of the clothing processing device and drum manufacturing method of the present invention, when a metal plate used to manufacture the drum is bent to form a lifter (hereinafter referred to as a drum with a forming-type lifter structure), damage due to load (e.g., tearing, collapse) can be reduced.

[0032] According to various embodiments of the present invention, in a drum having a forming-type lifter structure, stress generated in the lifter can be distributed, thereby reducing breakage.

[0033] According to various embodiments of the present invention, in the manufacturing process of a drum with a forming-type lifter structure, the risk of tearing can be avoided during the process of winding a metal plate into a cylindrical shape.

[0034] Various embodiments of the present invention can reduce the risk of drum damage due to loads during use.

[0035] The effects of the present invention are not limited to these, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0036] [Figure 1] 1 is a cross-sectional view schematically illustrating a clothing treatment device according to an embodiment of the present invention.

[0037] [Figure 2]FIG. 2 is an exploded perspective view of a drum 40 according to an embodiment of the present invention.

[0038] [Figure 3] 1 is a front view of a cylindrical portion 41 according to an embodiment of the present invention.

[0039] [Figure 4] This is a plan view of a metal plate 41' for manufacturing a cylindrical portion 41 according to the first embodiment of the present invention, and is an enlarged view of the portion where a lifter portion 1410 and a recess portion 1415 according to the first embodiment are formed.

[0040] [Figure 5] FIG. 5 is an enlarged view of part A in FIG. 4.

[0041] [Figure 6] 6 is a cross-sectional view taken along II' line, which is the minor axis of the front lifter section 1410a in FIG. 5. FIG.

[0042] [Figure 7] 6 is a cross-sectional view taken along line II-II' of FIG. 5, which is the long axis of the front lifter section 1410a.

[0043] [Figure 8] 8 is a diagram for explaining a recessed portion 1415 according to the first embodiment, and is an enlarged view of part B in FIG. 7. FIG.

[0044] [Figure 9] This is a plan view of a metal plate 41' for manufacturing a cylindrical portion 41 according to a second embodiment of the present invention, and is an enlarged view of the portion where a lifter portion 2410 and a recess portion 2415 according to the second embodiment are formed.

[0045] [Figure 10] FIG. 10 is an enlarged view of part C in FIG. 9.

[0046] [Figure 11]11 is a cross-sectional view taken along II', which is the minor axis of the rear lifter section 2410b in FIG.

[0047] [Figure 12] 11 is a cross-sectional view taken along line II-II' of FIG. 10, which is the long axis of the rear lifter section 2410b.

[0048] [Figure 13] 13 is a diagram for explaining a recessed portion 2415 according to the second embodiment, and is an enlarged view of part D in FIG. 12. FIG.

[0049] [Figure 14] FIG. 10 is a plan view of a metal plate for manufacturing a cylindrical portion according to a third embodiment of the present invention, showing an enlarged view of the portion where the lifter portion and recess portion according to the third embodiment are formed.

[0050] [Figure 15] FIG. 15 is an enlarged view of part E in FIG.

[0051] [Figure 16] 16 is a cross-sectional view taken along II', which is the minor axis of the front lifter section 2410a in FIG.

[0052] [Figure 17] 16 is a cross-sectional view taken along line II-II' of FIG. 15, which is the long axis of the front lifter section 2410a.

[0053] [Figure 18] 14 is a stress simulation for a structure in which the recessed portion 1415 is not applied.

[0054] [Figure 19] This is a stress simulation in a structure to which a recessed portion 1415 is applied, when the same conditions (lifter shape, load, etc.) as those in FIG. 18 are applied.

[0055] [Figure 20]20(a) and 20(b) are diagrams showing the flow of fabric induced depending on the rotation speed of the drum 40. Fig. 20(a) is a diagram showing the case where the drum 40 is rotating at a relatively slow speed. Fig. 20(b) is a diagram showing the case where the drum 40 is rotating at a higher speed than in (a). Fig. 20(c) is a diagram showing the case where the drum 40 is rotating at an even higher speed than in (b).

[0056] [Figure 21] 10 is a diagram illustrating a schematic view of stress acting on a drum 141 according to an embodiment of the present invention and how the stress is dispersed at a weakened portion.

[0057] [Figure 22] 10 is a diagram illustrating a schematic view of stress acting on a drum 241 according to another embodiment of the present invention and how the stress is dispersed at a weakened portion. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0058] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0059] The present invention can be realized by various embodiments and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not relevant to the explanation may be omitted. Also, in the drawings, similar parts are designated by similar reference numerals throughout the specification.

[0060] In this specification, explanations that are considered redundant will generally be omitted.

[0061] <Terminology>

[0062] As used in the following description, the term "clothes treatment device" refers to any device capable of washing, drying, refreshing, or otherwise treating clothes.

[0063] The term "clothing processing" used in the following description refers to processing such as washing, sterilizing, bleaching, softening, and drying performed on clothing. Clothing processing can be achieved by processes and courses executed by a clothing processing device. One or more processes are combined to form a course. One or more processes can be arranged in chronological order and combined to form a course. Processes include washing, rinsing, spin-drying, drying, cooling, refreshing, etc. The washing process is a process of separating foreign matter attached to clothing using water and detergent. The rinsing process is a process of separating laundry and foreign matter using water. The spin-drying process is a process of removing water from laundry. The drying process is a process of removing moisture from laundry. The cooling process is a process of lowering the temperature of heated laundry. The refreshing process is a process of deodorizing laundry, removing wrinkles, and sterilizing laundry using air or steam.

[0064] As used in the following description, the term "detergent" refers to any substance used to disinfect, sanitize, or remove impurities from clothing, fabrics, etc. In one embodiment, the detergent may be a powdered solid or liquid, etc.

[0065] As used in the following description, the term "softener" means any substance or agent used to soften clothes, fabrics, etc.

[0066] The term "bleaching agent" used in the following description means any substance or chemical that chemically decomposes and removes colored substances contained in textiles, etc., to whiten the textiles, etc.

[0067] The term "treatment agent" as used in the following description refers to any substance that causes a chemical or physical action to treat clothing. In one embodiment, treatment agents can be used to include detergents, fabric softeners, bleaches, and the like.

[0068] The term "fluid" as used in the following description means any fluid that is mixed with or acts as a solvent for the fabric treatment. In one embodiment, the fluid may be wash water, i.e., water.

[0069] The terms "upper," "lower," "left," "right," "front," and "rear" used in the following description will be understood based on the coordinate system of the referenced drawings. These terms are used for convenience of explanation, to intuitively explain relative positional relationships, and are not intended to limit the invention by the terms themselves. For convenience of explanation, a coordinate system will be referenced, with the upper side being described as Z, the left side as X, and the front side as Y.

[0070] In this specification, when a component is described as being "coupled" or "connected" to another component, it should be understood that the component may be "directly coupled" or "directly connected" to the other component, but there may be other components intervening between them. On the other hand, in this specification, when a component is described as being "directly coupled" or "directly connected" to another component, it should be understood to mean that there are no other components intervening between them.

[0071] The terms used in this specification are used to describe specific embodiments and are not intended to limit the present invention. For example, when a term of a lower concept (e.g., "spring") is used instead of a term of a higher concept (e.g., "elastic member") to make the description of the embodiments easier to understand, this is intended to describe the embodiments and is not intended to limit the present invention to the lower concept.

[0072] In this specification, singular expressions can include plural expressions unless the context clearly indicates otherwise.

[0073] In this specification, the terms "comprise" or "have" and the like are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0074] As used herein, the term "and / or" includes a combination of listed items or any of the listed items. For example, "a and / or b" means "a and b," "a," or "b." Additionally, "a or b" can be interpreted to mean "a," "b," or "both a and b."

[0075] <Example>

[0076] Fig. 1 is a cross-sectional view showing a schematic diagram of a clothing treatment device according to one embodiment of the present invention. The clothing treatment device and drum manufacturing device 1 shown in Fig. 1 and described as one embodiment is a washing machine. The clothing treatment device 1 according to one embodiment will be described with reference to Fig. 1.

[0077] The laundry treatment device 1 includes a cabinet 10, a door 15, a tub 30, a drum 40, a drum drive unit 50, a detergent supply unit 60, a water supply unit 70, a drain / circulation unit 80, and the like.

[0078] The cabinet 10 forms the exterior of the laundry processing device 1. An input opening is formed on the front of the cabinet 10. A door 15 is connected to the input opening. The door 15 is rotatably connected to the cabinet 10. When the door 15 is opened, the inside of the drum 40 can be accessed.

[0079] The tub 30 is disposed inside the cabinet 10. The tub 30 is a water tank that stores wash water as needed. The tub 30 can be supported by various configurations. In this embodiment, the tub 30 is supported by a damper 20. The damper 20 reduces vibrations generated in the tub 30. The front of the tub 30 is open and communicates with the inlet of the cabinet 10.

[0080] The drum 40 is disposed inside the tub 30. The drum 40 is rotatably installed. The drum 40 includes a cylindrical portion 41, a rear portion 42, and a front portion 43. The cylindrical portion 41 is formed by rolling a metal (e.g., stainless steel) plate into a circle and joining both ends. The cylindrical portion 41 has a cylindrical shape as a whole. It should be understood that the term "cylindrical" does not mean a cylinder in the strict mathematical or geometric sense. The rear portion 42 closes the open rear surface of the cylindrical portion 41. The rear portion 42 is connected to the cylindrical portion 41 at its rear. The front portion 43 has an opening to allow laundry to be loaded into the drum 40 and communicates with the loading port of the cabinet 10. The rear portion 42 and the front portion 43, like the cylindrical portion 41, are made of a metal material. A plurality of through holes are formed in the drum 40 to allow washing water to flow between the tub 30 and the drum 40. The washing water contained in the tub 30 flows into the drum 40 or is discharged from the tub 30 through a plurality of through-holes formed in the drum 40. The cylindrical portion 41 of the drum 40 and the inner surface of the tub 30 are spaced apart from each other.

[0081] The drum 40 is coupled to a drum drive 50 that rotates the drum 40. In this embodiment, the drum drive 50 is an electric motor including a stator and a rotor. The drum drive 50 includes a rotating shaft 51. The rotating shaft 51 passes through the back surface of the tub 30 and is coupled to the back portion 42 of the drum 40. More specifically, the back portion 42 of the drum 40 is coupled to a spider that is coupled to the rotating shaft 51.

[0082] The drum 40 is formed with a lifter portion 410. The lifter portion 410 is formed on the cylindrical portion 41 of the drum 40. In one embodiment of the present invention, a plurality of lifter portions 410 are formed along the circumferential direction of the cylindrical portion 41. A plurality of the lifter portions 410 arranged along the circumferential direction constitute one group. In the illustrated embodiment, a front lifter portion 410a and a rear lifter portion 410b are provided to constitute one group. The lifter portion 410 according to one embodiment of the present invention is formed by bending the cylindrical portion 41. The lifter portion 410 will be described in more detail below.

[0083] The detergent supply unit 60 includes a detergent dispenser 61 and a detergent supply pipe 65. The detergent dispenser 61 is configured to store a detergent and / or a fabric softener. The detergent supply pipe 65 is configured to form a flow path for supplying the detergent and / or fabric softener stored in the detergent dispenser 61 to the tub 30.

[0084] The water supply unit 70 is configured to supply water to the tub 30. The water supply unit 70 includes a water supply valve 71 and a water supply pipe 75. When the water supply valve 71 is opened to supply water, water is supplied to the laundry treatment device 1 through the water supply pipe 75. In this embodiment, the water supply pipe 75 is connected to the detergent supply unit 60. The water flowing in through the water supply unit 70 is supplied to the detergent dispenser 61, and can attract the detergent and / or fabric softener contained in the detergent dispenser 61 to the tub 30. The water flowing in to the detergent dispenser 61 through the water supply pipe 75 is mixed with the detergent and / or fabric softener and supplied to the tub 30 through the detergent supply pipe 65.

[0085] The drainage / circulation unit 80 is configured to circulate the water contained in the tub 30 or to drain the water contained in the tub 30 to the outside. In the embodiments, the drainage unit and the circulation unit are collectively described as the drainage / circulation unit 80, but the drainage unit and the circulation unit may be provided separately. The drainage / circulation unit 80 according to one embodiment of the present invention includes a pump unit 81, a discharge hose 82, a circulation hose 83, and a drain hose 84.

[0086] A drain pump and a circulation pump are provided in the pump unit 81. The pump unit 81 may also have a built-in drain filter (not shown).

[0087] The discharge hose 82 connects the tub 30 to the pump unit 81. The discharge hose 82 is connected to the inlet of the pump unit 81. Water in the tub 30 is discharged from the tub 30 through the discharge hose 82 and flows into the pump unit 81.

[0088] The circulation hose 83 connects the pump unit 81 and the tub 30. The pump unit 81 supplies the incoming water to the circulation hose 83 and then to the tub 30 again. In one embodiment, a circulation pump is provided in the pump unit 81, and one end of the circulation hose 83 is connected to the outlet of the circulation pump, and the other end of the circulation hose 83 is connected to the tub 30. When the circulation pump is operated, the wash water stored in the tub 30 is supplied back to the tub 30 via the discharge hose 82, the pump unit 81, and the circulation hose 83. In one embodiment, various functions are performed as the wash water circulates.

[0089] The drain hose 84 connects the pump unit 81 to the outside of the laundry treatment device 1. In one embodiment, the pump unit 81 is provided with a drain pump, and one end of the drain hose 84 is connected to the outlet of the drain pump. The other end of the drain hose 84 is disposed outside the laundry treatment device 1. The other end of the drain hose 84 is positioned at an appropriate drain outlet depending on the installation environment. When the drain pump is activated, the wash water contained in the tub 30 is discharged to the outside of the laundry treatment device through the discharge hose 82, the pump unit 81, and the drain hose 84.

[0090] Fig. 2 is an exploded perspective view of drum 40 according to one embodiment of the present invention. Fig. 3 is a view of cylindrical portion 41 according to one embodiment of the present invention as seen from the front. Drum 40 according to one embodiment of the present invention will be described with reference to Figs. 2 and 3.

[0091] The drum 40 includes a cylindrical portion 41, a rear portion 42, and a front portion 43. The cylindrical portion 41 is formed by rolling a metal (e.g., stainless steel) plate into a hollow cylinder and joining both ends together. Various known processing techniques, such as curling, seaming, and welding, can be applied to join the ends. The cylindrical portion 41 is cylindrical as a whole. It should be understood that "cylindrical" does not mean a cylinder in the strict mathematical or geometric sense. The rear portion 42 closes the open rear surface of the cylindrical portion 41. The rear portion 42 is joined to the cylindrical portion 41 at the rear of the cylindrical portion 41. Various known processing techniques, such as curling, seaming, and welding, can be applied to join the rear portion 42 and the cylindrical portion 41. The front portion 43 has a drum opening 43a that allows laundry to be loaded into the drum 40 and communicates with the loading port of the cabinet 10. Various known processing techniques, such as curling, seaming, and welding, can also be applied to join the front portion 43 and the cylindrical portion 41. The rear portion 42 and the front portion 43 may be made of a metal material, similar to the cylindrical portion 41. A plurality of through holes are formed in the drum 40, allowing the wash water to flow between the tub 30 and the drum 40. The wash water contained in the tub 30 flows into the drum 40 or is discharged from the tub 30 to the outside through the through holes formed in the drum 40. In order to clearly show the lifter portion 410, the through holes formed in the cylindrical portion 41 are not shown in FIG. 2.

[0092] A plurality of lifter portions 410 are formed along the circumferential direction. A plurality of lifter portions 410 constitute one group. In the illustrated example, three groups of lifter portions 411, 412, and 413 are provided, and each group includes two lifter portions. In this embodiment, the first group of lifter portions 411 includes a first lifter portion 411a and a second lifter portion 411b. The second group of lifter portions 412 includes a first lifter portion 412a and a second lifter portion 412b. The third group of lifter portions 413 includes a first lifter portion 413a and a second lifter portion 413b. According to one embodiment of the present invention, the first set of lifter elements 411, the second set of lifter elements 412, and the third set of lifter elements 413 are equiangularly arranged with respect to the rotation axis O (see FIG. 3) of the drum 40. The rotation axis O can be defined by the rotation axis 51. Here, equiangular does not mean equiangular in the strict mathematical or geometric sense, but should be understood to include a range of equality and a margin of error. According to an embodiment of the present invention, each set of lifter elements 411, 412, and 413 includes multiple lifter elements, thereby allowing the length of the major axis of each lifter element 410 to be shortened. If the length of the major axis of the lifter element 410 is long, the center of the lifter element 410 may be damaged. On the other hand, if the length of the lifter element 410 is short, stress may be concentrated at the ends along the major axis, causing the ends where the stress is concentrated to be damaged (see FIGS. 21 and 22).

[0093] According to the definitions in this specification, the first lifter section 411a, the first lifter section 412a, and the first lifter section 413a are the front lifter section 410a. Also, the second lifter section 411b, the second lifter section 412b, and the second lifter section 413b are the rear lifter section 410b. In this specification, the names of the lifter sections are defined based on the front-to-rear direction of the drum 40, and are not intended to limit the scope of the claims.

[0094] 4 is a plan view of metal plate 41' for manufacturing cylindrical portion 41 according to the first embodiment of the present invention, showing an enlarged view of a portion where lifter portion 1410 according to the first embodiment is formed. The description will be made with reference to FIG.

[0095] The metal plate 41' may be embossed to reinforce its strength. According to one embodiment of the present invention, the embossing is performed by bending the metal plate 41' inward or outward relative to its reference portion 41a. The bending of the metal plate 41' can be achieved by plastically processing the metal plate 41'. Hereinafter, the reference portion 41a of the metal plate may also be referred to as the reference portion of the cylindrical portion 41. Because the cylindrical portion 41 is manufactured by rolling the metal plate 41' into a circular shape, the reference portion of the metal plate 41' serves as the reference portion of the cylindrical portion 41.

[0096] A first embossment 41b and a second embossment 41c may be formed on the metal plate 41'. The first embossment 41b and the second embossment 41c may protrude in opposite directions. In an embodiment, the first embossment 41b is a protruding portion of the metal plate 41' protruding toward the outside of the drum 40. The second embossment 41c is a protruding portion of the metal plate 41' protruding toward the inside of the drum 40. The first embossment 41b has a circular plane. The first embossment 41b is formed to have a curved shape as a whole. The first embossment 41b may have a spherical shape. The second embossment 41c has a circular plane. The second embossment 41c is formed to have a curved shape as a whole. The second embossment 41c may have a spherical shape. The first embossment 41b and the second embossing 41c may be formed to have different sizes. For example, the diameters of the planes are different. Also, the protruding heights are different. In the embodiment, the planar diameter of the first embossment 41b is smaller than that of the second embossment 41c. The first embossment 41b and the second embossment 41c can be arranged alternately. In the embodiment, the protrusion that constitutes the second embossment 41c is arranged between the multiple protrusions that constitute the first embossment 41b. A through hole 41d is formed in the portion where the first embossment 41b is formed. The through hole 41d is formed in the center of the first embossment 41b. Since the embodiment describes a washing machine, the through hole 41d will be described, but in the case of a dryer, the through hole 41d is not formed.

[0097] As an example of the lifter unit 410 described above, a lifter unit 1410 according to a first embodiment is provided. The lifter unit 1410 includes a front lifter unit 1410a and a rear lifter unit 1410b. The lifter unit 1410 protrudes to a height higher than the first embossment 41b and the second embossment 41c. The lifter unit 1410 protrudes inward from the cylindrical unit 41. The lifter unit 1410 may be formed by having the metal plate 41' protrude 10 mm or more from its base portion 41a. Meanwhile, the lifter unit 1410 functions to lift laundry contained in the drum 40, and the height of the lifter unit 1410 need only protrude to an appropriate height sufficient to perform this function. The numerical values ​​described herein are intended to facilitate understanding of the lifter unit 1410.

[0098] The lifter portion 1410 has a longitudinal axis extending in the front-rear direction. In this embodiment, the front lifter portion 1410a has a longitudinal axis extending in the front-rear direction, and the rear lifter portion 1410b also has a longitudinal axis extending in the front-rear direction. In this embodiment, the front lifter portion 1410a is positioned on a first axis a, and the rear lifter portion 1410b is positioned on a second axis b. The first axis a and the second axis b are spaced apart by a predetermined distance d. In this embodiment, the rear lifter portion 1410b is formed at a position shifted to one side in the left-right direction from the front lifter portion 1410a in a front view. In other words, the front lifter portion 1410a and the rear lifter portion 1410b are positioned offset from each other in the front-rear direction. The arrangement of the lifter portion 1410 according to the first embodiment can solve the problem of reduced moldability between the front lifter portion 1410a and the rear lifter portion 1410b. In addition, the degree of dispersion of the laundry in the drum 40 during washing can be improved. Furthermore, the penetration rate of dewatering can be improved.

[0099] FIG. 5 is an enlarged view of portion A in FIG. 4. The description will be given taking portion A, where the front lifter portion 1410a is formed, as an example. However, because the front lifter portion 1410a and the rear lifter portion 410b can have similar structures, the description of the front lifter portion 1410a will be used to describe the rear lifter portion 1410b. FIG. 6 is a cross-sectional view taken along line I-I', which is the minor axis of the front lifter portion 1410a in FIG. 5. FIG. 7 is a cross-sectional view taken along line II-II', which is the major axis of the front lifter portion 1410a in FIG. 5. A first embodiment of the present invention will be described with reference to FIG. 5, 6, and 7.

[0100] The front lifter portion 1410a protrudes toward the inside of the drum 40. In FIGS. 6 and 7, the inside of the drum 40 is indicated as the upper side of the drawing. The front lifter portion 1410a protrudes with a cross-section that narrows as it moves away from the reference portion 41a of the metal plate. The front lifter portion 1410a is formed so that its uppermost end protrudes a first height h1 from the reference portion 41a of the metal plate. An inclined surface bend portion 1412 is formed on the inclined surface of the front lifter portion 1410a. In one embodiment, the front lifter portion 1410a is formed with a first inclined surface bend portion 1412a and a second inclined surface bend portion 1412b. The first inclined surface bend portion 1412a and the second inclined surface bend portion 1412b reinforce the strength of the front lifter portion 1410a. In the embodiment, two inclined surface bend portions 1412 are formed, but the number of inclined surface bend portions 1412 can be increased or decreased as needed depending on the design. An upper bent portion 1413 is formed at the upper portion of the front lifter portion 1410a. The upper bent portion 1413 reinforces the rigidity of the upper portion of the front lifter portion 1410a. In this embodiment, the upper bent portion 1413 is formed by bending concavely at the uppermost end.

[0101] In the metal plate 41' that constitutes the cylindrical portion 41, the periphery of the lifter portion 1410 is defined as a lifter periphery A1. The lifter periphery A1 follows the shape of the protruding front lifter portion 1410a. In the illustrated embodiment, the lifter periphery A1 is provided to form the periphery of the front lifter portion 1410a. The lifter periphery A1 may refer to a predetermined distance from the point where the front lifter portion 1410a begins to protrude from the reference portion 41a of the metal plate in a direction away from the front lifter portion 1410a.

[0102] A recessed portion 1415 is formed in the lifter peripheral portion A1. The recessed portion 1415 is formed by processing the metal plate 41'. The recessed portion 1415 is formed by processing to bend the metal plate 41' that constitutes the cylindrical portion 41. If the front lifter portion 1410a is defined as being convex, the recessed portion 1415 is defined as being concave.

[0103] In the illustrated embodiment, recess 1415 is formed entirely around the periphery of front lifter portion 1410a along lifter periphery A1. However, this is not intended to limit the scope of the claims. In this embodiment, recess 1415 is formed in lifter periphery A1, but may be formed in at least a portion A1' between a first position P1, which is a position on lifter periphery A1, and a second position P2, which is a position on the opposite side of the major axis.

[0104] Recess 1415 is also formed around rear lifter portion 1410b. The recess 1415 formed around rear lifter portion 1410b will be replaced with the description of recess 1415 surrounding front lifter portion 1410a. However, because stress concentrates at the portion where front lifter portion 1410a and rear lifter portion 1410b face each other, recess 1415 is preferably formed at least in the portion where stress concentrates. Therefore, the front lifter recess formed around front lifter portion 1410a is formed at least behind the front lifter periphery, and the rear lifter recess formed around rear lifter portion 1410b is formed at least in front of the rear lifter periphery.

[0105] FIG. 8 is an enlarged view of portion B in FIG. 7 to explain the recessed portion 1415. The description will be made with reference to FIG. 8. The recessed portion 1415 has a depth d1 and a width w1. In this embodiment, the inventors have recognized that a greater depth d1 and a narrower width w1 of the recessed portion 1415 are advantageous. However, the depth d1 of the recessed portion 1415 is limited by the distance between the drum 40 and the tab 30. Although the recessed portion 1415 protrudes outward, there is a distance between the portion where the recessed portion 1415 is formed and the inner wall of the tab 30. The recessed portion 1415 is not a component for reinforcing strength or rigidity, but rather a component for dispersing concentrated stress. The recessed portion 1415 is formed in the lifter peripheral portion A1 and is formed along the shape of the lifter portion 1410 protruding from the metal plate 41′. In other words, the recess 1415 is formed in the lifter peripheral portion A1, which is the portion where the lifter portion 1410 begins to protrude from the reference portion 41a of the metal plate. Therefore, by forming the recess 1415 in the portion where stress is concentrated, the area on which the stress acts increases, the stress is dispersed, and the risk of breakage is reduced. FIG. 18 is a stress simulation for a structure in which the recess 1415 is not applied, and FIG. 19 is a stress simulation for a structure in which the recess 1415 is applied under the same conditions as FIG. 18 (lifter shape, load, etc.). Referring to FIG. 19, it can be seen that the stress concentrated in the portion indicated by P3 in FIG. 18 has been dispersed.

[0106] Fig. 9 is a plan view of metal plate 41' for manufacturing cylindrical portion 41 according to the second embodiment of the present invention, showing an enlarged view of a portion where lifter portion 2420 according to the second embodiment is formed. The description will be made with reference to Fig. 9. In Fig. 9, the configuration other than lifter portion 2410 according to the second embodiment is replaced by the description in Fig. 4.

[0107] As an example of the lifter unit 410 described above, a lifter unit 2410 according to a second embodiment is provided. The lifter unit 2410 includes a front lifter unit 2410a and a rear lifter unit 2410b. The lifter unit 2410 protrudes to a height greater than the first embossment 41b and the second embossment 41c. The lifter unit 2410 protrudes inward from the cylindrical unit 41. The lifter unit 2410 is formed by protruding the metal plate 41' from the reference portion 41a of the metal plate by 10 mm or more. Meanwhile, the lifter unit 2410 functions to lift laundry contained in the drum 40, and the height of the lifter unit 2410 is sufficient as long as it protrudes to a height appropriate for performing this function. The numerical values ​​described herein are intended to facilitate understanding of the lifter unit 2410.

[0108] The lifter portion 2410 has a longitudinal axis extending in the front-rear direction. In this embodiment, the front lifter portion 2410a has a longitudinal axis extending in the front-rear direction, and the rear lifter portion 2410b also has a longitudinal axis extending in the front-rear direction. In this embodiment, the front lifter portion 2410a is positioned on a first axis a, and the rear lifter portion 2410b is positioned on a second axis b. The first axis a and the second axis b are spaced apart by a predetermined distance d. In this embodiment, the rear lifter portion 2410b is formed at a position shifted to one side in the left-right direction from the front lifter portion 2410a in a front view. The front lifter portion 2410a and the rear lifter portion 2410b are positioned offset from each other in the front-rear direction. The arrangement of the lifter portion 2410 according to the second embodiment can solve the problem of reduced moldability between the front lifter portion 2410a and the rear lifter portion 2410b. In addition, the degree of dispersion of the laundry in the drum 40 during washing can be improved. Furthermore, the penetration rate of dewatering can be improved.

[0109] FIG. 10 is an enlarged view of portion C in FIG. 9. The following description will be given taking portion C, where the rear lifter portion 2410b is formed, as an example. However, because the rear lifter portion 2410b and the front lifter portion 2410a can have similar structures, the description of the rear lifter portion 2410b will be substituted for the description of the front lifter portion 2410a. FIG. 11 is a cross-sectional view taken along line I-I', which is the minor axis of the rear lifter portion 2410b in FIG. 10, and FIG. 12 is a cross-sectional view taken along line II-II', which is the major axis of the rear lifter portion 2410b in FIG. 10. A second embodiment of the present invention will be described with reference to FIG. 10, 11, and 12.

[0110] The rear lifter portion 2410b protrudes toward the inside of the drum 40. In FIGS. 11 and 12, the inside of the drum 40 is shown as the upper side of the drawing. The rear lifter portion 2410b protrudes with a cross-section that narrows as it moves away from the reference portion 41a of the metal plate. The rear lifter portion 2410b is formed so that its uppermost end protrudes a first height h2 from the reference portion 41a of the metal plate. An inclined surface bend portion 2412 is formed on the inclined surface of the rear lifter portion 2410b. In one embodiment, the rear lifter portion 2410b is formed with a first inclined surface bend portion 2412a and a second inclined surface bend portion 2412b. The first inclined surface bend portion 2412a and the second inclined surface bend portion 2412b reinforce the strength of the rear lifter portion 2410b. In the embodiment, two inclined surface bends 2412 are formed, but the number can be increased or decreased as appropriate depending on the design. An upper end bend 2413 is formed at the upper part of the rear lifter part 2410b. The upper end bend 2413 reinforces the rigidity of the upper part of the rear lifter part 2410b. In the embodiment, the upper end bend 2413 is formed by bending concavely at the uppermost end.

[0111] In the metal plate 41' forming the cylindrical portion 41, the periphery of the lifter portion 2410 is defined as the lifter periphery A2. The lifter periphery A2 follows the shape of the protruding rear lifter portion 2410b. In the illustrated embodiment, the lifter periphery A2 is provided to form the periphery of the rear lifter portion 2410b. The lifter periphery A2 may refer to a predetermined distance from the point where the rear lifter portion 2410b starts to protrude from the base portion 41a of the metal plate in a direction away from the rear lifter portion 2410b.

[0112] A recessed portion 2415 is formed in the lifter peripheral portion A2. The recessed portion 2415 is formed by processing the metal plate 41'. The recessed portion 2415 is formed by bending the metal plate 41' that forms the cylindrical portion 41. In the illustrated embodiment, the recessed portion 2415 is formed entirely along the lifter peripheral portion A2, surrounding the periphery of the lifter peripheral portion A2. However, this is not intended to limit the scope of the claims. In this embodiment, the lifter peripheral portion A2 is formed in the rear lifter portion 2410b, but may be formed in at least a portion A2' between a first position P1, where the recessed portion 2415 is located, and a second position P2, where the recessed portion 2415 is located on the opposite side of the major axis.

[0113] A recess 2415 is also formed around the front lifter portion 2410a. The recess 2415 formed around the front lifter portion 2410a will be replaced with the description of the recess 2415 surrounding the rear lifter portion 2410b. However, because stress concentrates at the portion where the rear lifter portion 2410b and the front lifter portion 2410a face each other, it is desirable that the recess 2415 be formed at least in the portion where stress concentrates. Therefore, the front lifter recess formed around the front lifter portion 2410a is formed at least behind the front lifter periphery, and the rear lifter recess formed around the rear lifter portion 2410b is formed at least in front of the rear lifter periphery.

[0114] Fig. 13 is a diagram for explaining the recessed portion (2415), and is an enlarged view of part D in Fig. 12. Description will be made with reference to Fig. 13.

[0115] The recessed portion 2415 has a depth d2 and a width w2. In an embodiment, the inventors have found that it is advantageous for the recessed portion 2415 to have a greater depth d2 and a narrower width w2. In an embodiment, the protruding height of the recessed portion 2415 defines the depth d2 of the recess-forming protrusion 2416. Meanwhile, the protruding height of the recess-forming protrusion 2416 is less than the height h2 of the lifter portion 2410.

[0116] The recess portion 2415 is formed between the lifter portion 2410 and the recess-forming protrusion 2416. In other words, the recess portion 2415 is defined by the relationship between the lifter portion 2410 and the recess-forming protrusion 2416. The recess-forming protrusion 2416 is formed by bending the cylindrical portion 41. The recess-forming protrusion 2416 is formed by bending the cylindrical portion 41 inward. The recess-forming protrusion 2416 is formed at a position spaced apart from the lifter portion 2410. The recess portion 2415 is defined by the space between the lifter portion 2410 and the recess-forming protrusion 2416. The recess portion 2415 is a concept that includes a sunken and bent shape.

[0117] The recessed portion 2415 is not a component for reinforcing strength or rigidity, but a component for dispersing concentrated stress. The reference portion 41a of the metal plate is formed in the recessed portion 2415, and is formed along the shape of the lifter peripheral portion A2 protruding from the lifter portion 2410. In other words, it is formed in the recessed portion 2415, which is the portion where the metal plate 41' begins to protrude from the lifter peripheral portion A2. Therefore, by forming the lifter portion 2410 in the portion where stress is concentrated, the area on which the stress acts increases, the stress is dispersed, and the risk of breakage is reduced.

[0118] Figure 14 is a plan view of a metal plate 41' for manufacturing a cylindrical portion 41 according to a third embodiment of the present invention, showing an enlarged view of a portion in which a lifter portion 2410 and a recessed portion 3415 are formed. The following description will be made with reference to Figure 14. The lifter portion 2410 shown in Figure 14 has the same configuration as the lifter portion 2410 described with reference to Figures 9 to 12, and therefore the above description will be used instead. A recessed portion 3415 is formed around the lifter portion 2410.

[0119] FIG. 15 is an enlarged view of portion E in FIG. 14. The lifter section 2410 has the same configuration as the lifter section 2410 described in FIGS. 9 to 12. However, for more specific explanation, FIG. 15 will be described based on the front lifter section 2410a. FIG. 16 is a cross-sectional view taken along line I-I', which is the minor axis of the front lifter section 2410a in FIG. 15. FIG. 17 is a cross-sectional view taken along line II-II', which is the major axis of the front lifter section 2410a in FIG. 15. A third embodiment of the present invention will be described with reference to FIG. 15, 16, and 17.

[0120] The front lifter portion 2410a protrudes toward the inside of the drum 40. In FIGS. 16 and 17, the inside of the drum 40 is shown as the upper side of the drawing. The front lifter portion 2410a protrudes with a cross-section that narrows as it moves away from the reference portion 41a of the metal plate. The front lifter portion 2410a is formed so that its uppermost end protrudes a first height h2 from the reference portion 41a of the metal plate. An inclined surface bend portion 2412 is formed on the inclined surface of the front lifter portion 2410a. In one embodiment, the front lifter portion 2410a is formed with a first inclined surface bend portion 2412a and a second inclined surface bend portion 2412b. The first inclined surface bend portion 2412a and the second inclined surface bend portion 2412b reinforce the strength of the front lifter portion 2410a. In the embodiment, two inclined surface bends 2412 are formed, but the number can be increased or decreased as appropriate depending on the design. An upper end bend 2413 is formed at the upper part of the front lifter part 2410a. The upper end bend 2413 reinforces the rigidity of the upper part of the front lifter part 2410a. In the embodiment, the upper end bend 2413 is formed by bending concavely at the uppermost end.

[0121] In the metal plate 41' forming the cylindrical portion 41, the periphery of the lifter portion 2410 is defined as a lifter periphery A3. The lifter periphery A3 follows the shape of the protruding front lifter portion 2410a. In the illustrated embodiment, the lifter periphery A3 is provided to form the periphery of the front lifter portion 2410a. The lifter periphery A3 may refer to a predetermined distance from the point where the front lifter portion 2410a begins to protrude from the base portion 41a of the metal plate in a direction away from the front lifter portion 2410a.

[0122] A recess 3415 is formed in the lifter peripheral portion A3. The recess 3415 is formed by processing the metal plate 41'. The recess 3415 is formed by bending the metal plate 41' that forms the cylindrical portion 41. In the illustrated embodiment, the recess 3415 is formed entirely around the periphery of the front lifter portion 2410a along the lifter peripheral portion A3. However, this is not intended to limit the scope of the claims. In this embodiment, the recess 3415 is formed in the lifter peripheral portion A3, but it may be formed in at least a portion A3' between a first position P1, which is a position on the lifter peripheral portion A3, and a second position P2, which is a position on the opposite side of the major axis.

[0123] A recess 3415 is also formed around the rear lifter portion 2410b. The recess 3415 formed around the rear lifter portion 2410b will be replaced with the description of the recess 3415 surrounding the front lifter portion 2410a. However, because stress concentrates at the portion where the front lifter portion 2410a and the rear lifter portion 2410b face each other, it is desirable that the recess 3415 be formed at least in the portion where the stress concentrates. Therefore, the rear lifter recess formed around the rear lifter portion 2410b is formed at least forward of the rear lifter periphery, and the front lifter recess formed around the front lifter portion 2410a is formed at least rear of the front lifter periphery.

[0124] The recess portion 3415 includes a first recess portion 3415a and a second recess portion 3415b. The first recess portion 3415a is formed around the front lifter portion 2410a. The first recess portion 3415a is substituted for the description of the recess portion 3415 above. The second recess portion 3415b follows the shape of the first recess portion 3415a but has an enlarged planar shape. The second recess portion 3415b follows the shape of the first recess portion 3415a but is spaced further from the front lifter portion 2410a than the first recess portion 3415a.

[0125] According to the illustrated embodiment, the recess portion 3415 is defined by a recess-forming protrusion 3416. The recess-forming protrusion 3416 includes a first recess-forming protrusion 3416a and a second recess-forming protrusion 3416b. The first recess-forming protrusion 3416a is spaced a first distance from the front lifter portion 2410a. The first recess-forming protrusion 3416a is substituted for the description of the recess-forming protrusion 3416 described above. The second recess-forming protrusion 3416b is spaced a second distance from the front lifter portion 2410a. The second distance is greater than the first distance. That is, the second recess-forming protrusion 3416b is spaced further from the front lifter portion 2410a than the first recess-forming protrusion 3416a. According to the embodiment, the second recess-forming protrusion 3416b surrounds the periphery of the first recess-forming protrusion 3416a. According to the embodiment, the first recess 3415a is defined between the front lifter portion 2410a and the first recess-forming protrusion 3416a. The second recess 3415b is defined between the first recess-forming protrusion 3416a and the second recess-forming protrusion 3416b. That is, the first recess 3415a is formed by the relationship between the front lifter portion 2410a and the first recess-forming protrusion 3416a. The second recess 3415b is formed by the relationship between the first recess-forming protrusion 3416a and the second recess-forming protrusion 3416b. By configuring a plurality of recesses 3415 as in the embodiment, the stress distribution effect can be enhanced.

[0126] Unlike the illustrated embodiment, the first recessed portion and the second recessed portion may be provided so as to protrude outward from the cylindrical portion 41, like the recessed portion configurations described with reference to FIGS.

[0127] When interpreting the claims with reference to the various embodiments described above, the widths of the lifter peripheral regions A1, A2, and A3 are not mathematically defined. The lifter peripheral regions A1, A2, and A3 may be defined by the widths of the recessed portions 1415, 2415, and 3415. The portion where the lifter portion 410 begins to protrude based on the height of the reference portion 41a of the metal plate can be defined as the periphery of the lifter portion 410. The lifter peripheral regions A1, A2, and A3 can be defined as a predetermined area occupied by a position spaced a predetermined distance from the periphery of the lifter portion 410. The lifter peripheral regions A1, A2, and A3 can be defined as an area that follows the periphery of the lifter portion 410 and resembles the shape of the periphery.

[0128] 20 shows the flow of fabric induced according to the rotation speed of the drum 40. During the rotation of the drum 40, forces acting on the fabric within the drum 40 include gravity, the support force applied by the lifter section 410, and the centrifugal force induced by the rotation of the drum 40.

[0129] FIG. 20(a) shows a case where the drum 40 rotates at a relatively slow speed. At this time, the fabric m inside the drum 40 is lifted to a predetermined height by the lifter unit 410 and then repeatedly falls. Most of the fabric does not reach the height corresponding to a position rotated 90 degrees from the lowest point of the drum 40 in the direction of rotation of the drum 40, but instead rolls or slides along the inner surface of the drum 40 as it falls. This flow of the fabric m (e.g., (1) → (2) → (3)) is called "rolling." The rotation of the drum 40 that causes the fabric m to roll is defined as "rolling motion." The rotation speed of the drum 40 in the rolling motion is approximately 30 to 43 rpm.

[0130] FIG. 20(b) shows a case where the drum 40 rotates at a higher speed than in FIG. 20(a). At this time, most of the fabric m inside the drum 40 is lifted by the lifter unit 410 to a higher position than in the rolling case (for example, from the lowest point of the drum 40 to half the height of the drum 40, or to a position higher than the position rotated 90 degrees in the direction of the drum 40's rotation), and then repeatedly falls. This flow of the fabric m (e.g., (1) → (2) → (3) → (4)) is hereinafter referred to as "tumbling." The rotation of the drum 40 that causes the fabric m to tumble is defined as a "tumbling motion." The rotation speed of the drum 40 in the tumbling motion is higher than in the rolling motion, e.g., 44 to 48 rpm.

[0131] FIG. 20(c) shows a case where the drum 40 rotates at an even higher speed than in FIG. 20(b). When the drum 40 rotates at a high speed, the cloth m adheres to the inner circumferential surface of the drum 40 due to centrifugal force, and continues to rotate without dropping even at the highest point of the drum 40 (for example, (1) → (2) → (3) → (4)). The rotation of the drum 40 at this time is defined as a "filtration motion." The rotation speed of the drum 40 in the filtration motion is higher than that in the tumbling motion, for example, 70 rpm or higher.

[0132] 21 is a schematic diagram showing the stress acting on the drum 141 according to an embodiment of the present invention and how the stress is dispersed at the weakened portion. The stress dispersion structure of the drum 141 according to an embodiment of the present invention will be described with reference to FIG.

[0133] Drum 141 is provided as an example of drum 40. FIG. 21 shows an enlarged view of a portion of drum 141 where lifter section 410 is formed. In drum 141, front lifter section 410a and rear lifter section 410b are disposed offset from each other with respect to the longitudinal axis. Rear lifter section 410b is formed on line A-A'. Front lifter section 410a is formed on line B-B'. A cross-sectional view of drum 141 where rear lifter section 410b is formed along line A-A' and a load simulation acting on that portion are indicated by arrows. The applied load acts in the direction of centrifugal force. A cross-sectional view of drum 141 where front lifter section 410a is formed along line B-B' and a load simulation acting on that portion are indicated by arrows. According to the load simulation, weak portions where stress concentrates are both ends along the longitudinal axis of rear lifter section 410b and both ends along the longitudinal axis of front lifter section 410a. According to the structure to which the recessed portion 415 according to the embodiment of the present invention is applied, stress concentrated in the direction of the arrow (--→) is dispersed, and thus the weak portion is improved.

[0134] 22 is a schematic diagram showing the stress acting on a drum 241 according to another embodiment of the present invention and how the stress is dispersed at the weakened portion. The stress dispersion structure of the drum 241 according to another embodiment of the present invention will be described with reference to FIG.

[0135] Drum 241 is provided as an example of drum 40. FIG. 22 shows an enlarged view of a portion of drum 241 where lifter portion 410 is formed. In drum 241, front lifter portion 410a and rear lifter portion 410b are coaxially arranged with respect to the longitudinal axis. Front lifter portion 410a and rear lifter portion 410b are formed on line C-C'. A cross-sectional view of line C-C' and a simulation of the load acting on the portion are indicated by arrows. The applied load acts in the direction of centrifugal force. The positions where the highest stress is concentrated on drum 241 are the rear end of front lifter portion 410a along the longitudinal axis and the front end of rear lifter portion 410b along the longitudinal axis. A structure incorporating recessed portion 415 according to an embodiment of the present invention disperses the stress concentrated in the direction of the arrows, thereby improving the weakened portion. 22, recesses 415 are formed at least at the rear end of front lifter section 410a along the longitudinal axis thereof and at the front end of rear lifter section 410b along the longitudinal axis thereof. These are weak areas where stress is most concentrated, and a structure incorporating recesses 415 disperses the stress concentrated in the direction of the arrow (--→), thereby improving the weak areas.

[0136] The drum 40 is formed by winding and joining a metal plate 41'. Because the drum 40 is formed by winding the metal plate 41' and joining both ends, a joining line 41e (see FIG. 2) may be formed. If a long horizontal bend parallel to the winding direction (the circumferential direction of the drum) is formed when winding the metal plate 41', the horizontal bend may tear during the manufacturing process. Furthermore, the horizontal bend may be damaged during use of the drum 40. According to various embodiments of the present invention, the risk of damage during the winding process of the metal plate 41' is reduced compared to forming a long horizontal bend in a weaker portion of the drum 40 to reinforce the rigidity of the drum 40. Furthermore, the risk of damage during use of the drum 40 is reduced.

[0137] The drum 40 is formed by rolling and joining a processed metal plate 41'. The processed metal plate 41' is provided with a lifter portion 410, a recessed portion 415, and embossments 41b and 41c. According to various embodiments of the present invention, the lifter portion 410 is structurally reinforced, the risk of tearing during the manufacturing process is reduced, and formability is improved.

[0138] Although a washing machine has been described as an example of a laundry treatment device, the drum according to the embodiment of the present invention can also be used in a dryer. When the laundry treatment device is a dryer, a heat exchanger that communicates with the interior of the drum and removes moisture from the drum may be provided. Furthermore, the drum according to the embodiment of the present invention can also be used in a washer-dryer that combines the functions of a washing machine and a dryer.

[0139] While the laundry treatment device and drum manufacturing method according to the present invention have been described above using specific embodiments, these are merely examples, and the present invention is not limited thereto and should be construed as having the broadest scope in accordance with the basic concepts disclosed herein. Those skilled in the art may combine or substitute the disclosed embodiments to implement other embodiments not described, which also do not depart from the scope of the present invention. Furthermore, those skilled in the art may easily modify or alter the disclosed embodiments based on this specification, and it is clear that these modifications and alterations also fall within the scope of the present invention.

Claims

1. In a clothing treatment device including a drum, The drum is Cylindrical part, a lifter portion that is bent from the cylindrical portion and protrudes inward from the cylindrical portion, and has a long axis in the front-rear direction; and a recess portion formed by bending the cylindrical portion at a lifter peripheral portion that forms a periphery of the lifter portion, The recessed portion is A clothing processing device formed at least partially between a first position, which is a position on the lifter periphery, and a second position, which is a position on the opposite side of the long axis of the lifter portion.

2. The recessed portion is The clothing processing device according to claim 1 , wherein the cylindrical portion is provided with a protruding portion.

3. The recessed portion is a first recessed portion; and The clothing processing device of claim 1 , further comprising a second recess portion that conforms to the shape of the first recess portion but is spaced further from the lifter portion than the first recess portion.

4. The drum is The cylindrical portion further includes a recess-forming protrusion spaced apart from the lifter portion and protruding toward the inside of the cylindrical portion by bending the cylindrical portion, The recessed portion is The clothing treatment device of claim 1 , wherein the clothing treatment device is located between the lifter portion and the recess-forming protrusion.

5. The recess-forming protrusion is a first recess-forming protrusion formed at a first distance from the lifter portion; and a second recess-forming protrusion formed at a second distance from the lifter portion; The recessed portion is a first recess portion located between the lifter portion and the first recess-forming protrusion; and The clothing treating device of claim 4 , including a second recess portion located between the first recess-forming protrusion and the second recess-forming protrusion.

6. The recessed portion is The lifter is formed around the entire periphery. The clothing treatment device according to claim 1 .

7. The cylindrical portion is The clothing treatment device according to claim 1 , which is formed by winding a metal plate of a metal material.

8. The lifter portion is A plurality of the electrodes are formed, and the plurality of electrodes form one set, and the set is made up of a plurality of electrodes; The clothing treatment device of claim 1 , wherein the plurality of sets are equiangularly arranged.

9. The plurality of lifter sections constituting each group are: The clothing processing device according to claim 8, wherein the clothing processing device is arranged offset in the front-to-rear direction.

10. The lifter portion is a plurality of equiangularly arranged front lifter sections; and a plurality of rear lifter sections are provided, equiangularly arranged, and arranged rearward of the front lifter sections; The recessed portion is a front lifter recess formed in a front lifter periphery that forms a periphery of each of the front lifter portions; and The clothing treatment device of claim 1 , further comprising a rear lifter recess formed in a rear lifter periphery that defines the periphery of each of the rear lifter sections.

11. The front lifter recess portion is The clothing treatment device of claim 10, wherein the front lifter is formed at least rearward of the periphery.

12. The rear lifter recess portion is The clothing treatment device of claim 10, wherein the rear lifter is formed at least in front of the periphery.

13. The laundry treatment device according to any one of claims 1 to 12, wherein the drum is rotatable.

14. a tub for receiving the drum therein; The laundry treating device according to any one of claims 1 to 12, wherein the drum is rotatably mounted inside the tub.

Images