Washing machine

Abstract

To provide a washing machine having a large washing capacity and high reliability.SOLUTION: A washing machine includes a tub including a bottom wall and a cylindrical side wall connected to the bottom wall, and a reinforcing member located on a back surface side of the bottom wall, extending outward from a center of the tub when viewed from a direction in which a central axis of the tub extends, and connected to the tub at an outer end portion. The bottom wall includes a protruding portion provided in a portion where the reinforcing member is provided, and a bulging portion provided in a portion where the reinforcing member is not provided and recessed from the protruding portion. An outer end portion of the protruding portion in the radial direction has a wide portion that becomes wider toward the outside in the radial direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to washing machines. [Background technology]

[0002] Patent Document 1 discloses an example of a so-called drum-type washing machine equipped with a washing tub having a horizontally extending rotation axis. Patent Document 1 also discloses a configuration in which the internal volume of the washing tub is increased by an expansion area formed so that the bottom of the washing tub protrudes toward the outside of the washing tub. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2007-526811 Summary of the Invention [Problem to be solved by the invention]

[0004] The washing tub described in Patent Document 1 is formed by press working. The bottom of the washing tub described in Patent Document 1 has larger irregularities than usual, so the metal plate becomes locally thin during press working, which may result in insufficient strength.

[0005] One object of the present disclosure is to provide a washing machine that has a large washing capacity and is highly reliable, for example. [Means for solving the problem]

[0006] In one aspect of the present disclosure, a washing machine includes a tub having a bottom wall and a cylindrical side wall connected to the bottom wall, and a reinforcing member located on the back side of the bottom wall, extending outward from the center of the tub when viewed along the central axis of the tub, and connected to the tub at its outer end. The bottom wall has a protrusion provided in a portion where the reinforcing member is provided and a bulge provided in a portion where the reinforcing member is not provided and recessed further than the protrusion. The radially outer end of the protrusion has a wide portion that widens radially outward. [Effects of the Invention]

[0007] According to the present disclosure, for example, it is possible to provide a washing machine with a large washing capacity and high reliability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a washing machine. [Figure 2] FIG. 2 is a schematic perspective view of a washing tub. [Figure 3] FIG. 2 is a schematic perspective view of a washing tub and a reinforcing member. [Figure 4] FIG. 2 is a schematic plan view of the washing tub. [Figure 5] FIG. 2 is a schematic rear view of the washing tub and the reinforcing member. [Figure 6] FIG. 6 is a schematic cross-sectional view taken along line VI-VI in FIG. 4. [Figure 7] FIG. 7 is a schematic cross-sectional view taken along line VII-VII in FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. 4. [Figure 9] FIG. 9 is a schematic cross-sectional view taken along line IX-IX in FIG. [Figure 10] FIG. 5 is a schematic cross-sectional view taken along line XX in FIG. 4. [Figure 11] FIG. 10 is a schematic cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 5 is a schematic cross-sectional view taken along a line L2 in FIG. 4. [Figure 13]FIG. 10 is a schematic plan view of a washing tub in a first modified example. [Figure 14] FIG. 10 is a schematic plan view of a washing tub in a second modified example. [Figure 15] FIG. 11 is a schematic plan view of a washing tub in a third modified example. [Figure 16] FIG. 13 is a schematic plan view of a washing tub in a fourth modified example. [Figure 17] FIG. 13 is a schematic plan view of a washing tub in a fifth modified example. [Figure 18] FIG. 13 is a schematic plan view of a washing tub in a sixth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] A washing machine 1 according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. In the following description, components having substantially the same functions will be referred to by the same reference numerals, and the description will be used interchangeably. In the following description, the side of the washing machine 1 where the door 12 (see FIG. 1) is provided will be referred to as the front side, and the opposite side will be referred to as the rear side. The front-to-rear direction will sometimes be referred to as the depth direction. The right side and left side are the directions when viewing the washing machine 1 from the front side to the rear side. The left-to-right direction will sometimes be referred to as the width direction. The direction perpendicular to each of the depth direction and width direction will be referred to as the height direction.

[0010] In the present disclosure, the term "washing machine" refers to a general device that performs various processes, such as washing, on items to be washed. Examples of processes that a washing machine can perform on items to be washed include washing, drying, deodorizing, and sterilizing. The items to be washed are not particularly limited. Examples of items to be washed include cloth products. Specific examples of items to be washed include clothing such as clothes, hats, and gloves, personal belongings such as shoes, bags, handkerchiefs, and towels, bedding such as curtains, blankets, towel blankets, and futon covers, carpets, stuffed toys, and the like.

[0011] (Washing machine 1) First, as shown in FIG. 1, washing machine 1 includes housing 11, door 12, water tub 13, washing tub 14, motor 15 as a rotation mechanism, water supply channel 16, and drain channel 17.

[0012] Housing 11 houses each component of washing machine 1. Housing 11 is formed, for example, in a substantially rectangular parallelepiped shape. An upper portion of the front surface, which is one side surface of housing 11, forms inclined surface 11a that extends obliquely upward toward the rear.

[0013] A main opening 11b is formed in the inclined surface 11a of the housing 11. The main opening 11b is used for putting laundry in and taking laundry out. The door 12 is rotatably supported by the housing 11. The door 12 is rotatable between a closed position where the main opening 11b is closed and an open position where the main opening 11b is opened.

[0014] A water inlet 11c is provided at the top of the housing 11. A water outlet 11d is provided at the bottom of the housing 11.

[0015] Water tub 13 stores water used for washing. Water tub 13 is formed with opening 13a that communicates with main opening 11b of housing 11. Water tub 13 also has water supply port 13b and drain port 13c.

[0016] The water supply channel 16 is a channel that runs from the water supply port 11c of the housing 11 to the water supply port 13b of the water tank 13. The drain channel 17 is a channel that runs from the drain port 13c of the water tank 13 to the drain port 11d of the housing 11.

[0017] A washing tub 14 is provided inside water tub 13. Like water tub 13, washing tub 14 is cylindrical and has a bottom. Washing tub 14 and water tub 13 are arranged concentrically. Laundry is placed into washing tub 14. Washing tub 14 accommodates laundry. Washing tub 14 is cylindrical and has an opening 14a at one end and a bottom at the other end. Laundry is placed into washing tub 14 through main opening 11b and opening 14a of washing tub 14.

[0018] The water supplied to water supply passage 16 is supplied into water tub 13 through water supply port 13b, and further supplied into washing tub 14 through a plurality of through-holes formed in washing tub 14.

[0019] The water inside water tub 13 and washing tub 14 is discharged through drain outlet 13c and drainage channel 17 to drain outlet 11d.

[0020] Washing tub 14 is supported rotatably around rotating shaft 15a. Motor 15 rotates rotating shaft 15a to rotate washing tub 14. Motor 15 constitutes a rotation mechanism that rotates washing tub 14, which constitutes a tub. Motor 15 as a rotation mechanism may, for example, rotate washing tub 14 only in one rotation direction around the axis of rotating shaft 15a, or may be configured to rotate in both clockwise and counterclockwise directions. For example, motor 15 may be controlled to repeatedly perform one rotation operation that rotates washing tub 14 clockwise and another rotation operation that rotates washing tub 14 counterclockwise.

[0021] The rotating shaft 15a of the washing tub 14 is inclined relative to the horizontal direction. Therefore, the opening 14a of the washing tub 14 faces diagonally upward. For example, the rotating shaft 15a is inclined at an angle of 3 to 30 degrees relative to the horizontal direction. The angle of inclination of the rotating shaft 15a relative to the horizontal direction is determined based on the water-saving effect, cleaning power, the susceptibility to damage to the laundry, the ease of removing the laundry, and the like. The rotating shaft 15a may also be disposed horizontally. In this case, the washing tub 14 is supported with the opening 14a of the washing tub 14 facing the horizontal direction.

[0022] For example, by driving motor 15 and rotating washing tub 14 relative to water tub 13 when water is stored in water tub 13, laundry in washing tub 14 can be washed or rinsed. Also, by driving motor 15 when there is no water in water tub 13, laundry in washing tub 14 can be dehydrated.

[0023] FIG. 2 is a schematic perspective view of washing tub 14. FIG. 3 is a schematic perspective view of washing tub 14 and reinforcing member 20. FIG. 4 is a schematic plan view of washing tub 14 when viewed from the direction in which central axis A extends. FIG. 5 is a schematic back view of washing tub 14 and reinforcing member 20 when viewed from the direction in which central axis A extends. FIG. 6 is a schematic cross-sectional view taken along line VI-VI in FIG. 4. FIG. 7 is a schematic cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. 4. FIG. 9 is a schematic cross-sectional view taken along line IX-IX in FIG. 4. FIG. 10 is a schematic cross-sectional view taken along line XX in FIG. 4. FIG. 11 is a schematic cross-sectional view taken along line XI-XI in FIG. 4.

[0024] Next, mainly with reference to Figures 1 to 11, washing tub 14 as a tub and reinforcing member 20 fixed to washing tub 14 will be described in detail.

[0025] As shown in FIG. 1, washing machine 1 is provided with water tub 13 capable of storing water. Water tub 13 is generally cylindrical with one end closed. Specifically, water tub 13 has a generally cylindrical side wall (peripheral wall) 13e and a bottom wall 13d that closes the rear end of side wall 13e. Water tub 13 cannot rotate relative to housing 11. Water tub 13 is provided within housing 11 so that it can swing using dampers, springs, etc. (not shown).

[0026] A washing tub 14 serving as a tub is disposed inside water tub 13. Laundry is placed in washing tub 14 and washed. Therefore, the washing capacity (volume of laundry that can be selected) of washing machine 1 correlates with the volume of washing tub 14. The larger the volume of washing tub 14, the larger the washing capacity of washing machine 1.

[0027] For example, as shown in FIGS. 2 and 3, washing tub 14 is substantially cylindrical with a bottom. Specifically, washing tub 14 is substantially cylindrical with one end closed. More specifically, washing tub 14 has bottom wall 14b and side wall (peripheral wall) 14c. Bottom wall 14b is located in front of bottom wall 13d of water tub 13 in the direction in which central axis A extends. Bottom wall 14b and bottom wall 13d are each substantially disk-shaped. Bottom wall 14b and bottom wall 13d are disposed substantially parallel to each other and substantially concentrically. More specifically, when no laundry has been placed in washing machine 1 and washing machine 1 is stopped, bottom wall 14b and bottom wall 13d are disposed substantially concentrically.

[0028] A cylindrical side wall (peripheral wall) 14c is connected to bottom wall 14b. Bottom wall 14b and side wall 14c are fixed to each other by, for example, crimping. More specifically, side wall 14c is connected to the peripheral edge of disk-shaped bottom wall 14b. Side wall 14c extends diagonally forward (in the direction of central axis A) from bottom wall 14b. Washing tub 14 and water tub 13 are arranged to share the same central axis A. Washing tub 14 has a smaller diameter than water tub 13. A clearance is provided between the outer peripheral surface of washing tub 14 and the inner peripheral surface of water tub 13.

[0029] Washing tub 14 is rotatable about central axis A relative to water tub 13 shown in FIG. 1. Washing tub 14 is driven to rotate by motor 15, which serves as a rotation mechanism. When motor 15 is driven, washing tub 14 rotates relative to water tub 13 and housing 11. This agitates the laundry, water, etc. in washing tub 14. This allows the laundry to be washed, rinsed, loosened, dehydrated, etc.

[0030] Specifically, washing tub 14 is connected to rotating shaft 15a of motor 15. Rotating shaft 15a extends along central axis A. Central axis A extends diagonally upward toward the front. Rotating shaft 15a is connected to the center of bottom wall 14b of washing tub 14. When motor 15 is driven, washing tub 14 rotates around central axis A together with rotating shaft 15a.

[0031] In this embodiment, the central axis A extends obliquely upward toward the front, but the present disclosure is not limited to this configuration. The central axis A, which is the rotation axis of the washing tub 14, may extend obliquely upward toward the front, or may extend substantially horizontally.

[0032] As shown in FIGS. 3 and 5, a reinforcing member 20 is provided on the rear side of washing tub 14, specifically, on the back side of bottom wall 14b. Reinforcing member 20 is thicker than bottom wall 14b. Specifically, reinforcing member 20 has a portion that is even thicker than the thickest portion of bottom wall 14b. The average thickness of reinforcing member 20 is greater than the average thickness of bottom wall 14b. Reinforcing member 20 reinforces washing tub 14, which is driven to rotate by motor 15, to improve the rigidity of washing tub 14 and efficiently transmit the rotational force (torque) of rotating shaft 15a to washing tub 14. When viewed from the direction of central axis A of washing tub 14, reinforcing member 20 extends outward from the center of washing tub 14 and is connected to washing tub 14 at its outer end.

[0033] In detail, reinforcing member 20 includes shaft portion 21 and a plurality of support portions 22a, 22b, and 22c. Shaft portion 21 is located in the center of bottom wall 14b. Shaft portion 21 is located on central axis A. Shaft portion 21 is fixed to rotating shaft 15a (see FIG. 1) by fastening members such as bolts and nuts. Shaft portion 21 is fitted into a through-hole formed in the center of bottom wall 14b. Therefore, the surface of shaft portion 21 is located on the inner surface of washing tub 14. Shaft portion 21 is formed with blowing ports 23a and 23b for blowing heated air.

[0034] The plurality of support portions 22a, 22b, and 22c are connected to the shaft portion 21. In this embodiment, specifically, three support portions 22a, 22b, and 22c are provided at intervals (more specifically, at equal intervals) along the circumferential direction centered on the central axis A. The plurality of support portions 22a, 22b, and 22c each extend radially outward from the shaft portion 21. The outer ends of the support portions 22a, 22b, and 22c are connected to the washing tub 14 by fastening members such as bolts and nuts. In this embodiment, the outer ends of the support portions 22a, 22b, and 22c are fixed to the sidewall 14c. Therefore, torque from the rotating shaft 15a is transmitted to the sidewall 14c via the reinforcing member 20.

[0035] For example, as shown in Fig. 1, in washing machine 1, a portion of bottom wall 14b of washing tub 14 bulges rearward in the direction of extension of central axis A in order to increase the washing capacity. For example, compared to when the bottom wall of the washing tub is flat, by bulging bottom wall 14b in the direction opposite to the opening of washing tub 14 as in this embodiment, the volume of washing tub 14 can be increased. Therefore, the washing capacity of washing machine 1 can be increased.

[0036] In detail, as shown in FIG. 4, the bottom wall 14b has a plurality of bulging portions 41 and one or a plurality of protruding portions .

[0037] When viewed in the direction along the central axis A, the protrusion 42 is provided in a region corresponding to the region where the reinforcing member 20 shown in FIGS. 3 and 5 is provided. When viewed in the direction along the central axis A, the protrusion 42 is provided in a portion of the bottom wall 14b that is located in front of the reinforcing member 20. More specifically, when viewed in the direction along the central axis A, the portion where the protrusion 42 is provided is located in front of the multiple support portions 22a, 22b, and 22c of the reinforcing member 20. Therefore, as shown in FIGS. 2 and 4, for example, when viewed in the direction along the central axis A, the protrusion 42 is provided so as to extend outward from the center of the bottom wall 14b. Specifically, when viewed in the direction along the central axis A, the protrusion 42 has multiple linear portions that extend outward from the center of the bottom wall 14b and are spaced apart from one another along the circumferential direction of the central axis A.

[0038] The back surface of protrusion 42 is recessed forward, i.e., toward the opening of washing tub 14, when viewed from the direction in which central axis A extends. In other words, protrusion 42 has a recess on the back surface that recesses toward the opening of washing tub 14. At least a portion of reinforcing member 20 (specifically, multiple support portions 22a, 22b, and 22c) is located in the area provided in protrusion 42. This reduces the thickness of the portion of reinforcing member 20 that protrudes rearward from washing tub 14. This reduces the clearance between bottom wall 14b of washing tub 14 and bottom wall 13d of water tub 13, as shown in FIG. 1. This allows washing tub 14 to be made deeper. In other words, the dimension of washing tub 14 along the direction in which central axis A extends can be increased. This allows the volume of washing tub 14 to be increased.

[0039] As shown in FIGS. 2 and 4 , bottom wall 14b has at least one bulging portion 41. The bulging portion 41 is provided in a portion where reinforcing member 20 is not provided. Specifically, the bulging portion 41 is provided in at least a portion of the bottom wall 14b that does not overlap with reinforcing member 20 when viewed from the direction of central axis A. In this embodiment, bulging portion 41 is provided in each of the regions between adjacent support portions 22a, 22b, and 22c in the circumferential direction, i.e., the regions between adjacent protrusions 42 in the circumferential direction. The bulging portion 41 bulges toward the rear side (rear side when viewed from the direction of central axis A) of the region where reinforcing member 20 is provided. Providing this bulging portion 41 increases the volume of washing tub 14 by the volume of bulging portion 41. Therefore, the washing capacity of washing machine 1 can be increased. From the viewpoint of further increasing the washing capacity of washing machine 1, it is preferable that bulging portion 41 bulges rearward beyond side wall 14c.

[0040] In this manner, in this embodiment, by providing a protrusion 42 in the portion where the reinforcing member 20 is provided, and arranging at least a portion of the reinforcing member 20 within the protrusion 42, and by providing a bulge 41 in the portion where the reinforcing member 20 is not provided, the capacity of the washing tub 14 can be increased, and as a result, the washing capacity of the washing machine 1 can be increased.

[0041] It is known that washing tub 14 is made by joining cylindrically formed side wall 14c to bottom wall 14b, which is formed by press-forming a flat metal plate. For example, when attempting to form bulging portion 41 and protruding portion 42 of bottom wall 14b by press-forming a flat metal plate, portions of the metal plate may have different elongation rates during press-forming. Therefore, for example, undesired deformation such as wrinkles may occur in portions where the elongation rate is likely to be low, such as the outer portion of bottom wall 14b. In a drum-type washing machine 1, bottom wall 14b is visible to the user. Therefore, wrinkles on bottom wall 14b may detract from the aesthetic appearance of washing machine 1.

[0042] In the washing machine 1, an unevenness 50 is provided on the radially outer portion of the bulging portion 41 of the bottom wall 14b. In the radially outer portion of the bottom wall 14b, particularly in the portion near the protruding portion 42, the protruding portion 42 and the bulging portion 41 are arranged close to each other. Furthermore, the portions of the bulging portion 41 where the radial width is smallest are close to each other. This causes the amount of stretch of the metal plate to increase locally, making it prone to being pulled and wrinkling at that location. Furthermore, if the bulging portion 41 is formed deep, the metal is pulled from the radially outer portion of the bulging portion 41. This overlapping of these pulls makes it prone to irregular wrinkles at the radially outer portion of the bulging portion 41. In this embodiment, the unevenness 50 is provided on the radially outer portion of the bulging portion 41. This increases the elongation rate of the relevant portion. Therefore, the unevenness 50 can absorb the localized stretch of the metal, thereby suppressing the occurrence of wrinkles. Moreover, even if wrinkles occur, the appearance is less likely to be marred by the provision of the unevenness 50 in advance. Therefore, the washing machine 1 can achieve both a large washing capacity and excellent appearance.

[0043] When a bulge 41 is provided, wrinkles along the radial direction are likely to occur. In particular, when the bulge 41 is provided along the periphery of the disk-shaped bottom wall 14b so that the bulge 41 deepens from the periphery toward the center of the bottom wall 14b, as in this embodiment, wrinkles along the radial direction are more likely to occur. In this embodiment, multiple irregularities 50 are provided along the circumferential direction on the outer portion of the bulge 41. This increases the elongation rate in the circumferential direction and increases rigidity in the radial direction. As a result, localized elongation of the metal in the radial direction is suppressed, making it more difficult for wrinkles along the radial direction to occur.

[0044] In the washing machine 1, the unevenness 50 is provided as a first convex portion 51 and a second convex portion 52, which respectively protrude from the bottom surface of the bulge portion 41 toward the front side (more specifically, toward the front side when viewed from the direction in which the central axis A extends).

[0045] The first protrusion 51 as the first unevenness is located at approximately the center along the circumferential direction of the outer part of the bulging portion 41. In this embodiment, one first protrusion 51 is provided for each bulging portion 41.

[0046] The second convex portions 52 as second irregularities are located further outward in the circumferential direction than the first convex portions 51. The second convex portions 52 are provided between the first convex portions 51 and the protruding portion 42 adjacent to the first convex portion 51 in the circumferential direction. In detail, a plurality of second convex portions 52 are provided at intervals between the first convex portion 51 and the protruding portion 42 adjacent to the first convex portion 51 in the circumferential direction. The plurality of second convex portions 52 are provided at substantially equal intervals in the circumferential direction.

[0047] In this way, by providing a plurality of irregularities 50 (first convex portions 51 and second convex portions 52) along the circumferential direction, the occurrence of wrinkles can be effectively suppressed over the entire outer portion of the bulging portion 41.

[0048] In this embodiment, an example has been described in which a plurality of mutually independent concave and convex portions (specifically, a plurality of convex portions) are formed as the plurality of concave and convex portions. In this embodiment, a flat surface may be interposed between adjacent convex portions in the circumferential direction. However, the present invention is not limited to this configuration. For example, a plurality of mutually independent concave and convex portions may be formed as the plurality of concave and convex portions. Furthermore, a plurality of convex and convex portions may be formed continuously, for example, in a wave shape.

[0049] The first convex portion 51 is higher and wider than the second convex portion 52. By providing such a large first convex portion 51, a structure similar to the protrusion 42 is disposed in the middle of the radially outer portion of the bulging portion 41. This is equivalent to shortening the circumferential length of the outer portion sandwiched between the protrusions, and it is possible to distribute the areas where the amount of elongation of the metal plate is locally large.

[0050] 4, the width of first protrusion 51 along the circumferential direction increases toward the radially inward direction. Meanwhile, the height of first protrusion 51 along the direction in which central axis A extends decreases toward the radially inward direction. This allows laundry below bottom wall 14b to be lifted upward by the rotation of washing tub 14.

[0051] Since wrinkles extending in the radial direction are likely to occur, it is preferable to provide a plurality of elongated second convex portions 52 extending in the radial direction along the circumferential direction among the concave and convex portions 50. In particular, it is preferable to provide second convex portions 52 adjacent to each other in the circumferential direction on the protrusions 42 and first convex portions 51 that form large steps.

[0052] More specifically, as shown primarily in FIG. 6 , the bulging portion 41 has a bottom portion 41a, an outer portion 41b, a horizontal portion 41c, and a fixing portion 41d. The bottom portion 41a is the portion that bulges most toward the rear surface side. The bottom portion 41a may be flat or curved. Hereinafter, in this embodiment, the bottom portion 41a is curved (for example, bowl-shaped). The outer portion 41b is located radially outward from the bottom portion 41a. The outer portion 41b extends radially outward from the bottom portion 41a. The angle formed by the outer portion 41b and the central axis A is smaller than the angle formed by the bottom portion 41a and the central axis A. The outer portion 41b is provided so as to form a curved surface that is continuous with the bottom portion 41a in a cross section including the central axis A. For this reason, in this embodiment, in a cross section including central axis A, the curvature of outer portion 41b is higher on the horizontal portion 41c side than on the bottom portion 41a side. For this reason, for example, in the process of forming bulging portion 41 by press molding, the amount of extension of the metal plate changes greatly near the boundary between outer portion 41b and horizontal portion 41c. Therefore, wrinkles are likely to occur on the outer periphery of outer portion 41b. In washing machine 1, unevenness 50 is formed on outer portion 41b, where wrinkles are likely to occur, but unevenness 50 is not formed on bottom portion 41a. For this reason, the occurrence of wrinkles is more effectively suppressed.

[0053] The radially outer side of the outer portion 41b is connected to the horizontal portion 41c. The horizontal portion 41c extends radially outward from the outer portion 41b. The horizontal portion 41c is approximately perpendicular to the direction in which the central axis A extends. Therefore, the horizontal portion 41c and the outer portion 41b form an angle.

[0054] The horizontal portion 41c is connected to the fixed portion 41d. The fixed portion 41d has a portion parallel to the side wall 14c on the inner side of the side wall 14c. The fixed portion 41d is fixed to the side wall 14c at this portion.

[0055] In washing machine 1, second convex portion 52 having an elongated shape is formed across horizontal portion 41c and outer portion 41b, which extend in different directions. This enhances the reinforcing effect (rigidity improvement effect) of bottom wall 14b by second convex portion 52. This further effectively prevents wrinkles from occurring. From the viewpoint of effectively preventing wrinkles from occurring, second convex portion 52 is preferably formed so as to extend from the outer end of horizontal portion 41c to the inner end of outer portion 41b.

[0056] In washing machine 1, second convex portions 52 having an elongated shape are provided so as to intersect with the circumferential direction. Specifically, second convex portions 52 are provided so as to extend perpendicular to the circumferential direction, i.e., along the radial direction. Therefore, for example, when washing tub 14 is rotating, laundry pressed against bottom wall 14b is not easily hindered from falling due to gravity by second convex portions 52. This prevents laundry from sticking to bottom wall 14b, and allows the laundry to be suitably agitated in washing tub 14.

[0057] In this embodiment, each of the second protrusions 52 has a linear oval shape with a circumferential width that is substantially constant in the radial direction. However, the present disclosure is not limited to this configuration. For example, each of the second protrusions 52 may have multiple portions with different circumferential widths. For example, each of the second protrusions 52 may have a shape in which the circumferential width increases radially outward. Specifically, each of the second protrusions 52 may have a substantially fan shape or a substantially triangular shape. Furthermore, when viewed from the direction in which the central axis A extends, each of the second protrusions 52 does not necessarily have to be linear. For example, each of the second protrusions 52 may have a curved shape, a bent shape, a zigzag shape, or the like when viewed from the direction in which the central axis A extends.

[0058] As shown primarily in FIG. 4 , the protrusion 42 has an outer end portion 42a on the radially outer side. The outer end portion 42a is aligned circumferentially with the portion where the irregularities 50 are formed. In other words, the outer end portion 42a and the region where the irregularities 50 are formed are substantially the same region in the radial direction. Therefore, the region where the outer end portion 42a is formed is prone to wrinkles, for example, during the process of forming the bottom wall 14b by press molding. The outer end portion 42a, which is provided in this region where wrinkles are likely to occur, has a wide portion 42b that widens radially outward. More specifically, when viewed from the direction in which the central axis A extends, the wide portion 42b is a portion whose width W1 in a direction perpendicular to a line L1 passing through the central axis A and the circumferential center C of the outermost end of the protrusion 42 increases radially outward. In this embodiment, the entire outer end portion 42a constitutes the wide portion 42b. Therefore, the elongation rate of the region where the outer end portion 42a is formed can be increased during press molding. Therefore, the occurrence of wrinkles can be suppressed.

[0059] For example, as shown in FIGS. 4, 8 to 10, etc., the protrusion 42 has a top surface 42A and an inclined surface 42B. The top surface 42A is located on the front side in the direction in which the central axis A extends. The top surface 42A may be, for example, flat, or may be curved and convex toward the front side in the direction in which the central axis A extends. The top surface 42A may include, for example, at least one flat portion and at least one curved portion. The inclined surface 42B connects the top surface 42A to the bulging portion 41. The angle formed by the inclined surface 42B and the central axis A is preferably larger than the angle formed by the top surface 42A and the central axis A. The inclined surface 42B may be flat, or may be curved and convex toward the front or rear side in the direction in which the central axis A extends. The inclined surface 42B may include, for example, at least one flat portion and at least one curved portion.

[0060] While wrinkles during press molding are likely to occur in the circumferentially outer portions of the protrusion 42, the inclined surface 42B is configured so that the width W2 in the direction perpendicular to the line L1 of the wide portion 42b formed by the outer end portion 42a increases radially outward. This allows for a higher elongation rate in the region where the wide portion is located during the process of forming the bottom wall 14b by press molding. As a result, the occurrence of wrinkles during press molding can be more effectively suppressed.

[0061] From the viewpoint of more effectively suppressing the occurrence of wrinkles, it is preferable that the portion of the inclined surface 42B that constitutes the wide portion 42b is concave, and that the radius of curvature of the portion of the inclined surface 42B that constitutes the wide portion 42b on the line L2 that passes through the valley of that portion gradually increases toward the center of the bulging portion 41. This configuration can prevent the inclined surface 42B from having a portion where the curvature changes suddenly. Therefore, for example, the occurrence of cracks during press forming can be effectively suppressed.

[0062] 4 and 12, it is preferable that the angle formed by the first portion 42B1 of the inclined surface 42B, which is the inclined surface 42B located on a line L2 that passes through the recessed portion that forms the wide portion 42b, with the central axis A is larger, i.e., the angle formed by the second portion 42B2 of the inclined surface 42B located on a line L2 that passes through the recessed portion that forms the wide portion 42b is smaller. It is also preferable that the radius of curvature of the connecting portion 42B3 that connects the bottom 41a and the second portion 42B2 gradually increases toward the bottom 41a.

[0063] From a similar viewpoint, it is preferable that inclined surface 42B includes, in a radially outer portion located radially outward, a portion having a normal that is inclined with respect to central axis A in both the radial and circumferential directions when viewed from the direction in which central axis A extends. For example, in the present embodiment, specifically, at least connection portion 42B3 of inclined surface 42B has a normal that is inclined with respect to central axis A in both the radial and circumferential directions when viewed from the direction in which central axis A extends. In this way, since connection portion 42B3 having a normal that is inclined with respect to the direction in which wrinkles that tend to occur extend or the depth direction of wrinkles is provided, wrinkles are less likely to occur during press forming, etc.

[0064] Modifications of the above embodiment will be described below. In particular, modifications having different forms of the irregularities 50 will be described below. Therefore, the description of the above embodiment other than the irregularities 50 will be applied to the following modifications. In the following description, components having substantially similar functions will be referred to by the same reference numerals, and their description will be omitted.

[0065] (First Modification) FIG. 13 is a schematic plan view of washing tub 14 in the first modified example. In the above embodiment, an example has been described in which multiple types of concaves and convexes are provided as the concaves and convexes 50. However, the present disclosure is not limited to this configuration. For example, only one type of concaves and convexes may be provided as the concaves and convexes 50.

[0066] 13, only second protrusions 52 are provided as the irregularities 50. Specifically, a plurality of second protrusions 52 are provided at equal intervals between the outer ends of adjacent protrusions 42 in the circumferential direction. Even with this configuration, it is possible to effectively suppress the occurrence of wrinkles during press molding, for example.

[0067] In addition, the multiple projections 50 (specifically, the multiple second projections 52) provided between the outer ends of adjacent protrusions 42 in the circumferential direction may include projections that are different from each other in at least one of their length along the radial direction and their width along the circumferential direction.

[0068] (Second Modification, Third Modification, Fourth Modification) Fig. 14 is a schematic plan view of washing tub 14 in a second modified example. Fig. 15 is a schematic plan view of washing tub 14 in a third modified example. Fig. 16 is a schematic plan view of washing tub 14 in a fourth modified example.

[0069] In the above embodiment, an example has been described in which each second protrusion 52 has an elongated shape extending along the circumferential direction. However, the present disclosure is not limited to this configuration. For example, as in a second modified example shown in FIG. 14 , each second protrusion 52 may extend in a direction inclined relative to the radial direction. In the second modified example, each second protrusion 52 has an elongated shape extending in a direction inclined relative to both the radial direction and the circumferential direction. Specifically, in the second modified example, each second protrusion 52 is provided in a curved shape that curves inward in the circumferential direction from the outer end in the radial direction. Even with this configuration, for example, the occurrence of wrinkles during press molding can be effectively suppressed.

[0070] Each second protrusion 52 may be provided, for example, in a linear shape extending in a direction inclined relative to the radial direction.

[0071] As in a third modified example shown in Fig. 15, each second protrusion 52 may be provided so as to have a portion perpendicular to the radial direction. Specifically, in the third modified example, each second protrusion 52 is provided so as to extend along the circumferential direction. A plurality of second protrusions 52 extending along the circumferential direction are arranged at intervals along the radial direction. Even with this configuration, it is possible to effectively suppress the occurrence of wrinkles during, for example, press molding.

[0072] In addition, in the third modified example, it is preferable that the length along the circumferential direction of the second protrusion 52 located on the radially outer side is longer than the length along the circumferential direction of the second protrusion 52 located on the radially inner side.

[0073] When providing the second protrusions 52 having an elongated shape extending in the circumferential direction, it is preferable to provide a plurality of second protrusions 52 at intervals along the radial direction.

[0074] As in a fourth modified example shown in Fig. 16, the second protrusions 52 may be arranged in a dot pattern. Specifically, in the fourth modified example, the second protrusions 52 are arranged in a substantially circular shape when viewed from the direction in which the central axis A extends. A plurality of substantially circular second protrusions 52 are arranged in a matrix along both the radial and circumferential directions. Even with this configuration, it is possible to effectively suppress the occurrence of wrinkles during, for example, press molding.

[0075] When dot-shaped second convex portions 52 are provided, the shape of the second convex portions 52 when viewed from the direction in which the central axis A extends is not limited to a circle, and may be, for example, an ellipse, an oval, a polygon, or the like.

[0076] (Fifth and Sixth Modifications) Fig. 17 is a schematic plan view of washing tub 14 in the fifth modified example. Fig. 18 is a schematic plan view of washing tub 14 in the sixth modified example.

[0077] A fifth modified example shown in FIG. 17 is a further modified example of the third modified example shown in FIG. 15. A sixth modified example shown in FIG. 18 is a further modified example of the fourth modified example shown in FIG. 16. As shown in FIGS. 17 and 18, only second convex portions 52 extending in the circumferential direction or dot-shaped second convex portions 52 may be provided as the unevenness 50, and no first convex portions 51 may be provided. Conversely, no second convex portions 52 may be provided, and only at least one first convex portion 51 may be provided. Even with such a configuration, it is possible to effectively suppress the occurrence of wrinkles during press molding, for example. [Explanation of symbols]

[0078] 1: Washing machine 11: Housing 13: Aquarium 14: Washing machine tub 14b:Bottom wall 14c: Side wall 15: Motor 15a: Rotating shaft 20: Reinforcement member 21: Shaft 22a: Support part 22b: Support part 22c: Support part 41 :bulge 41a: Bottom 41b:Outer part 41c:Horizontal part 41d: Fixed part 42:Protrusion 42b: Wide part 42A:Top surface 42B: Inclined surface 42B1 :1st part 42B2 :Second part 42B3: Connection part 42a: Outer end 50: Unevenness 51: First convex part 52: Second convex part

Claims

1. a vessel having a bottom wall and a cylindrical side wall connected to the bottom wall; a reinforcing member located on the rear surface side of the bottom wall, extending outward from the center of the tank when viewed from the direction of extension of the central axis of the tank, and connected to the tank at its outer end; Equipped with The bottom wall is a protrusion provided at a portion where the reinforcing member is provided; and a bulging portion provided in a portion where the reinforcing member is not provided and recessed further than the protruding portion; and The washing machine, wherein the radially outer end of the protrusion has a wide portion that widens radially outward.

2. the protrusion includes a top surface and an inclined surface connecting the top surface and the bulge portion, The washing machine according to claim 1 , wherein the width of the inclined surface increases radially outward in the wide portion.

3. 3. The washing machine according to claim 2, wherein in the wide portion, the radius of curvature of the inclined surface gradually increases toward the center of the bulging portion on a line passing through a valley of the portion of the inclined surface that constitutes the wide portion.

4. the protrusion includes a top surface and an inclined surface connecting an end of the top surface to the bulge portion, The washing machine according to claim 1, wherein the inclined surface has a portion at a radially outer portion thereof, the portion having a normal that is inclined with respect to the central axis in both the radial direction and the circumferential direction when viewed from the direction in which the central axis of the tub extends.

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