Drum type washing machine

Abstract

To provide a drum type washing machine which includes a ball balancer in which a rolling element can properly move in an annular container even in the case where the amount of liquid sealed inside the annular container is reduced.SOLUTION: A drum type washing machine includes: an outer tub; a drum constituted so as to rotate around an axis line extending in a horizontal direction or in an oblique direction in the outer tub; and an annular container mounted on the drum, and for storing a plurality of rolling elements and a liquid. The rolling element has a spherical shape. The annular container is an annular circular pipe, and a protrusion part protruding toward the inside on an outer peripheral wall is formed. In a drum rotation state where the rolling elements are pressed toward the outer peripheral wall by a centrifugal force generated by the drum rotating, the outer peripheral surface of the rolling element and the outer peripheral wall come into point-contact at two point-contact parts, and a liquid passing part is formed between the two point-contact parts.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a drum-type washing machine installed in, for example, a coin-operated laundry shop. [Background technology]

[0002] In conventional drum-type washing machines, when the spin cycle begins, if laundry becomes unbalanced inside the drum, which is rotatably arranged inside the housing, the drum may vibrate, making it impossible to start the spin cycle. For this reason, some drum-type washing machines are equipped with ball balancers at the front and rear ends of the drum to counteract the imbalance (see Patent Document 1).

[0003] A ball balancer typically has an annular container (a tubular guide member) attached around the side periphery of a drum, multiple rolling elements (metal balls) that fit inside the annular container and roll, and a liquid (a viscous fluid such as oil) stored inside the annular container to suppress sudden movement of the rolling elements. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2011-125401 Summary of the Invention [Problem to be solved by the invention]

[0005] First, we will briefly explain how the ball balancer reduces drum vibration. When clothes become unbalanced inside the drum during spin drying, the center of vibration of the outer tub moves to a position closer to the clothes unbalance than the center of rotation of the drum. Meanwhile, during spin drying, centrifugal force acts on the rolling elements and liquid due to the rotation of the drum, causing them to move farther away from the center of vibration of the outer tub. When the rolling elements and liquid begin to gather in a position symmetrical to the clothes unbalance, the clothes unbalance is canceled out and the outer tub vibration decreases, so the movement of the rolling elements stops, allowing spin drying to be performed with the vibration canceled out.

[0006] In conventional ball balancer 530, annular container 531 has a rectangular cross section. Therefore, when a centrifugal force acts on rolling elements 532 toward outer peripheral wall 535 of annular container 531 due to the rotation of the drum, rolling elements 532 come into contact with outer peripheral wall 535, as shown in Fig. 9(c). At this time, a relatively large gap is formed at a corner near the outer peripheral wall of annular container 531 (between the outer peripheral surface of rolling elements 532 and outer peripheral wall 535), and a large amount of liquid 533 is stored in the gap.

[0007] In order to reduce the amount of liquid 533 sealed in a conventional ball balancer 530, the inventors of the present invention have considered a new ball balancer 630 in which the cross-sectional shape of the annular container 531 of the conventional ball balancer 530 has been changed to a circular (round) shape.

[0008] However, if the cross-sectional shape of the annular container 631 in the ball balancer 630 is changed to a circular shape (round shape), and a centrifugal force toward the outer peripheral wall 635 of the annular container 631 acts on the rolling elements 632 due to the rotation of the drum, the rolling elements 632 come into contact with the outer peripheral wall 635, as shown in Fig. 10(c). At this time, almost no gap is formed between the outer peripheral surface of the rolling elements 632 and the outer peripheral wall 635 near the outer peripheral wall 635 of the annular container 631. The range of the outer peripheral wall 635 is a portion that connects the front end 631a and the rear end 631b of the annular container 631 on the outer periphery of the annular container 631. The inventors of the present invention have discovered that when a gap is formed between the outer peripheral surface of the rolling body 632 and the outer peripheral wall 635, the gap becomes a liquid passage portion through which the liquid 633 passes as the rolling body 632 moves, but if the liquid passage portion becomes small, the rolling body 632 will no longer roll properly within the annular container 631, resulting in a technical problem in that clothing imbalance cannot be properly counteracted.

[0009] As a result of extensive research conducted by the inventors of the present invention to solve the above-mentioned technical problem, they found that in order for the rolling elements in the annular container to properly move to a position that offsets the clothing imbalance, it is necessary to displace the liquid in the direction of the rolling elements' movement. In other words, when the cross-sectional shape of the annular container is conventionally square, when the rolling elements in the annular container move to a position that offsets the clothing imbalance, the liquid in the direction of the rolling elements' movement flows from the corners on the outer periphery of the rolling elements to the rear of the rolling elements. The inventors of the present invention found that if the cross-sectional shape of the annular container is circular (round), the gap (liquid passage) through which the liquid in the direction of the rolling elements' movement flows behind the rolling elements becomes narrower, and the liquid in the direction of the rolling elements' movement acts as a resistance to the ball's movement. As a result, the inventors of the present invention found that by increasing the gap (liquid passage) through which the liquid in the direction of the rolling elements' movement flows behind the rolling elements, the rolling elements in the annular container can properly move to a position that offsets the clothing imbalance.

[0010] Therefore, an object of the present invention is to provide a drum-type washing machine equipped with a ball balancer that allows the rolling elements to move properly within the annular container even when the amount of liquid sealed inside the annular container is reduced. [Means for solving the problem]

[0011] A drum-type washing machine according to one aspect of the present invention comprises an outer tub, a drum configured to be rotatable within the outer tub around an axis extending horizontally or inclined, and an annular container attached to the drum and containing a plurality of rolling elements and a liquid, wherein the rolling elements are spherical, and the annular container is an annular tube having an outer peripheral wall on which a protrusion protruding inward or a recess recessed outward is formed, and when the drum is in a rotating state in which the rolling elements are pressed toward the outer peripheral wall by centrifugal force generated by the rotation of the drum, the outer peripheral surfaces of the rolling elements and the outer peripheral wall are in point contact at two point contact portions, and a liquid passage is formed between the two point contact portions.

[0012] In this case, even if the annular container is a circular tube, by forming a protrusion or recess on its outer wall, the outer surface of the rolling element and the outer wall come into point contact at two point contact points when the drum is rotating, forming a liquid passage between the two point contact points. This prevents liquid in the direction of the rolling element's movement from creating resistance to the movement of the rolling element. As a result, even if the annular container is a circular tube, the rolling element inside the annular container can be moved appropriately to a position that offsets clothing imbalance, thereby appropriately reducing drum vibration.

[0013] According to another aspect of the present invention, there is provided a drum-type washing machine comprising: an outer tub; a drum configured to be rotatable within the outer tub about an axis extending horizontally or inclined; and an annular container attached to the drum and containing a plurality of rolling elements and a liquid, wherein the rolling elements are spherical; and the annular container is an annular circular tube having an outer peripheral wall on which a protrusion protruding inward or a recess recessed outward is formed, and when the diameters of the rolling elements and the circular tube are the same, when compared in a cross section perpendicular to the axial center of the circular tube, in a drum rotating state in which the rolling elements are pressed toward the outer peripheral wall by centrifugal force generated by the rotation of the drum, a liquid passage formed between the outer peripheral surface of the rolling elements and the outer peripheral wall is larger than a liquid passage formed between the outer peripheral surface of the rolling elements and the outer peripheral wall when the protrusion or the recess is not formed on the outer peripheral wall of the annular container, where the diameters of the rolling elements and the circular tube are the same.

[0014] In this case, even if the annular container is a circular tube, by forming a protrusion or recess on its outer wall, the liquid passage formed between the outer surface of the rolling element and the outer wall becomes relatively large, and liquid in the direction of movement of the rolling element flows behind the rolling element through the liquid passage. This prevents liquid in the direction of movement of the rolling element from acting as resistance to its movement. As a result, even if the annular container is a circular tube, the rolling element inside the annular container can be moved appropriately to a position that offsets clothing imbalance, and drum vibration can be appropriately reduced.

[0015] The protrusion has two flat surfaces whose distance decreases toward the tip, and the angle between the two flat surfaces is preferably 160 degrees or less.

[0016] In this case, the liquid passage formed between the outer peripheral surface of the rolling element and the outer peripheral wall becomes sufficiently large, allowing the rolling element in the annular container to move appropriately to a position that offsets the clothing imbalance.

[0017] The protrusion has a cross section whose width decreases as it approaches the tip, and the tip and two base portions are each formed in an R-shape, and it is preferable that in the cross section, the angle between the tangent at the connection between the R-shape of the tip and the R-shape of one of the base portions and the tangent at the connection between the R-shape of the tip and the R-shape of the other of the base portions is 160 degrees or less.

[0018] In this case, the liquid passage formed between the outer peripheral surface of the rolling element and the outer peripheral wall becomes sufficiently large, allowing the rolling element in the annular container to move appropriately to a position that offsets the clothing imbalance. [Effects of the Invention]

[0019] In the drum type washing machine according to the present invention, even when the amount of liquid sealed inside the annular container is reduced, the rolling elements can be moved appropriately. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a cross-sectional view of a drum-type washing machine 1 according to a first embodiment of the present invention. [Figure 2] FIG. 2(a) is a plan view of the ball balancer 30 of the first embodiment, FIG. 2(b) is a cross-sectional view taken along line II-II in FIG. 2(a), and FIG. 2(c) is an enlarged view of the area surrounded by the dotted line in FIG. 2(b). [Figure 3] 10 is a diagram illustrating the shape of a protrusion 36. FIG. [Figure 4] 10 is a diagram illustrating the distance between two protrusions 36. FIG. [Figure 5] 10A and 10B are diagrams illustrating a method for reducing vibration of the drum 5 by the ball balancer 30. [Figure 6] FIG. 6(a) is a plan view of the ball balancer 30 of the second embodiment, FIG. 6(b) is a cross-sectional view taken along line VI-VI in FIG. 6(a), and FIG. 6(c) is an enlarged view of the area surrounded by the dotted line in FIG. 6(b). [Figure 7]FIG. 7(a) is a plan view of the ball balancer 30 of the third embodiment, FIG. 7(b) is a cross-sectional view taken along line VII-VII in FIG. 7(a), and FIG. 7(c) is an enlarged view of the area surrounded by the dotted line in FIG. 7(b). [Figure 8] 10A and 10B are diagrams illustrating modified shapes of the protrusion 36. FIG. [Figure 9] FIG. 9(a) is a plan view of a conventional ball balancer 530, FIG. 9(b) is a cross-sectional view taken along line IX-IX in FIG. 9(a), and FIG. 9(c) is an enlarged view of the area surrounded by the dotted line in FIG. 9(b). [Figure 10] FIG. 10(a) is a plan view of a ball balancer 630 studied by the inventors of the present invention, FIG. 10(b) is a cross-sectional view taken along line XX in FIG. 10(a), and FIG. 10(c) is an enlarged view of the area surrounded by the dotted line in FIG. 10(b). DETAILED DESCRIPTION OF THE INVENTION

[0021] (First embodiment) A drum type washing machine 1 according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a cross-sectional view of a drum type washing machine 1 according to the first embodiment of the present invention.

[0022] The drum type washing machine 1 of this embodiment is used in, for example, a coin laundry shop, and is operated in the order of a washing process, a rinsing process, and a spin-drying process.

[0023] As shown in FIG. 1, a drum-type washing machine 1 has a box-shaped housing 2. An outer tub 3 having a substantially cylindrical inner circumferential surface is disposed inside the housing 2. A drum 5 having a substantially cylindrical inner circumferential surface for storing clothes is disposed inside the outer tub 3. An opening 5a is formed at the front end of the drum 5, and an annular loading port 3a is formed at the front end of the outer tub 3 and is disposed in front of the opening 5a of the drum 5. The drum 5 is supported by a main shaft 6 extending in the front-to-rear direction and is rotatable about a horizontal axis.

[0024] An operation panel 2a is provided on the upper front surface of the housing 2, and a front panel 10 is detachably attached below the operation panel 2a on the lower front surface of the housing 2. An operation unit 2a1 for user operation is arranged on the operation panel 2a. A clothing insertion opening 11 is formed on the front panel 10, facing the insertion opening 3a formed at the front end of the outer tub 3.

[0025] A door 12 for opening and closing the loading opening 3a is provided at the front end of the outer tub 3. When the front panel 10 is attached to the housing 2, the door 12 is located inside the clothes loading opening 11 of the front panel 10. In the drum type washing machine 1, opening the door 12 allows clothes (laundry) to be put into and taken out of the drum 5.

[0026] The main shaft 6 is rotatably supported by a bearing 6a attached to the rear wall of the outer tub 3, and a main pulley 13 is attached to the tip of the main shaft 6 that protrudes further rearward. A motor 14 is installed at the bottom of the housing 2, and a motor pulley 15 is attached to the rotating shaft of the motor 14. The rotational power of the motor pulley 15 is transmitted to the main pulley 13 via a timing belt 16. As a result, when the motor 14 is driven, the drum 5 rotates around the main shaft 6.

[0027] A water supply pipe 20 with a water supply valve 20a installed midway is connected to the upper part of the rear wall of the outer tub 3, and when the water supply valve 20a is opened, water supplied from outside is supplied to the outer tub 3 via the water supply pipe 20. A drain pipe 21 with a drain valve 21a installed midway is connected to a drain outlet installed at the bottom of the outer tub 3, and when the drain valve 21a is opened, the water in the outer tub 2 is discharged outside the machine through the drain pipe 21.

[0028] A ball balancer 30 is provided near the opening 5a at the front end of the drum 5. Fig. 2(a) is a plan view of the ball balancer 30, Fig. 2(b) is a cross-sectional view taken along line II-II in Fig. 2(a), and Fig. 2(c) is an enlarged view of the area surrounded by the dotted line in Fig. 2(b).

[0029] 2(a), the ball balancer 30 has an annular container 31. The annular container 31 is formed from an annular pipe, and contains a plurality of rolling elements 32 as moving elements and a liquid 33 inside the annular container 31. The annular container 31 is installed inside the drum 5, closer to the opening 5a of the drum 5, so that its rotation axis coincides with the rotation axis of the drum 5.

[0030] In the drum-type washing machine 1 of this embodiment, a metal ball having a diameter of, for example, 30 mm is used as the spherical rolling element 32 that rolls within the annular container 31. The material of the rolling element 32 is, for example, carbon steel. The weight of the rolling element 32 is, for example, 110 g. However, the diameter and weight of the rolling element 32 are not limited thereto. In this embodiment, the weight of the rolling element is, for example, 110 g to 510 g, and preferably 110 g to 340 g. Furthermore, the diameter of the rolling element is, for example, 30 mm to 50 mm, and preferably 30 mm to 45 mm. The liquid 33 is, for example, silicone oil. While oils such as silicone oil can be used as the liquid 33, the type of liquid is not limited thereto. The cross-sectional shape of the circular tube forming the annular container 31 is, for example, a circular shape having a diameter of 34 mm. However, the diameter of the cross-sectional shape of the annular container 31 is not limited thereto. As will be explained later, since the protrusions 36 are formed on the circular pipe forming the annular container 31, the cross-sectional shape of the circular pipe with the protrusions 36 formed thereon is not exactly circular, but the cross-sectional shape of the circular pipe without the protrusions 36 formed thereon is the same as the cross-sectional shape of the annular container 631 shown in Figure 10(c) when the cross-sectional shape is changed to a circular shape (round). In Figure 2(c), the rolling elements 32 are illustrated as spherical with a diameter N1 mm, and the annular container 31 is illustrated as a circular pipe with a diameter N2 mm with the protrusions 36 formed thereon, and this is also shown in Figures 6(c), 7(c), and 10(c).

[0031] As shown in FIG. 2(c), the outer periphery of the annular container 31 is provided with an outer peripheral wall 35 that is curved convexly outward. In FIG. 2(c), the outer peripheral wall 35 is curved convexly downward in the drawing, and this is also the case in FIGS. 6(c), 7(c), and 10(c). The outer peripheral wall 35 covers a portion of the outer periphery of the annular container 31 that connects the front end 31a and the rear end 31b of the annular container 31. Two protrusions 36 that protrude inward are formed along the entire periphery of the outer peripheral wall 35. That is, the two protrusions 36 are each formed in an annular shape and are provided on the outer peripheral wall 35 with a gap between them. The two protrusions 36 are provided symmetrically with respect to the outermost portion 35T of the annular container 31. The cross-sectional area of ​​the protrusions 36 decreases as they approach the tip.

[0032] The shapes of the two protrusions 36 formed on the outer peripheral wall 35 will be described with reference to Fig. 3. Since the two protrusions 36 have substantially the same shape, only the protrusion 36 shown on the right side of Fig. 2(c) will be described.

[0033] 3, in a cross section perpendicular to the axial center of the annular container 35, the protrusion 36 has an upper curved portion t1, a flat portion t2, and a lower curved portion t3 that are arranged above a straight line C that passes through the tip end (point contact portion 36a) of the protrusion 36, and an upper curved portion t4, a flat portion t5, and a lower curved portion t6 that are arranged below the straight line C. The upper curved portion t1 and the upper curved portion t4 are symmetrical with respect to the straight line C, the flat portion t2 and the flat portion t5 are symmetrical with respect to the straight line C, and the lower curved portion t3 and the upper curved portion t6 are symmetrical with respect to the straight line C.

[0034] The flat surface portions t2 and t5 are flat surfaces, whereas the upper curved surface t1, the lower curved surface t3, the upper curved surface t4, and the lower curved surface t6 are formed in an R-shape with a predetermined curvature. The flat surface portions t2 and t5 are inclined so that the distance between them decreases as they approach the tip of the protrusion 36. In this embodiment, the angle θ between the plane extending from the flat surface portion t2 and the plane extending from the flat surface portion t5 is 108 degrees. The angle θ is 160 degrees or less, and preferably 110 degrees or less.

[0035] In this embodiment, the diameter of the circular tube of the annular container 31 (the diameter of the circular tube when the protrusions 36 are not formed) is the same as the diameter of the annular container 631 shown in Figure 10, and the diameter of the rolling element 32 is the same as the diameter of the rolling element 632 shown in Figure 10.Therefore, the ball balancer 30 of this embodiment differs from the ball balancer 630 shown in Figure 10 in that two protrusions 36 are formed on the outer wall 35 of the annular container 31.

[0036] The inventors of the present invention found that when the cross-sectional shape of the annular container 631 is changed to a circular shape (round shape) as shown in Figure 10, the gap (liquid passage portion) formed between the outer surface of the rolling body 632 and the outer wall 635 becomes smaller, and the rolling body 632 no longer rolls properly within the annular container 631. Therefore, they formed two protrusions 36 that protrude inward on the outer wall 35 of the circular tube of the annular container 631.

[0037] In this case, when the drum 5 is rotating and the rolling elements 32 are pressed toward the outer peripheral wall 35 by centrifugal force generated by the rotation of the drum 5, the outer peripheral surfaces of the rolling elements 32 and the outer peripheral wall 35 are in point contact at two point contact portions 36a, which are the tip ends of the two protrusions 36, as shown in FIG. 2(c). At this time, a liquid passage 40 through which the liquid 33 passes along the circumferential direction of the annular container 31 is formed between the outer peripheral surfaces of the rolling elements 32 and the outer peripheral wall 35. Specifically, the liquid passage 40a is formed closer to the front end than the two protrusions 36, the liquid passage 40b is formed between the two protrusions 36, and the liquid passage 40c is formed closer to the rear end than the two protrusions 36. The liquid passage 40b formed between the two protrusions 36 is the liquid passage formed between the two point contact portions 36a.

[0038] In this embodiment, Figure 2(c) and Figure 10(c) are compared, that is, the size of the liquid passage section 40 and the size of the liquid passage section 640 are compared when the diameter N1 of the rolling body 32 and the diameter N1 of the rolling body 632 are the same and the diameter N2 of the circular tube of the annular container 31 and the diameter N2 of the annular container 631 are the same.

[0039] 10(c), as described above, when a centrifugal force generated by the rotation of drum 5 acts on rolling element 632 toward outer peripheral wall 635, rolling element 632 comes into contact with outer peripheral wall 635. At this time, liquid passage portion 640, through which liquid 633 passes along the circumferential direction of annular container 631, is formed between the outer peripheral surface of rolling element 632 and outer peripheral wall 635. Specifically, liquid passage portion 640a is formed on the front end side, and liquid passage portion 640b is formed on the rear end side.

[0040] Comparing cross sections perpendicular to the axial center of the annular container 31 as shown in Figures 2(c) and 10(c), the liquid passage portion 40 formed between the outer peripheral surface of the rolling element 32 and the outer peripheral wall 35 in Figure 2(c) is larger than the liquid passage portion 640 formed between the outer peripheral surface of the rolling element 632 and the outer peripheral wall 635 in Figure 10(c). In other words, when the protrusion 36 is formed on the outer peripheral wall 35 of the annular container 32 as shown in Figure 2(c), the size of the liquid passage portion is larger than when no protrusion is formed on the outer peripheral wall 635 of the annular container 632 as shown in Figure 10(c).

[0041] That is, if the area of ​​the liquid passage section 640 (the sum of liquid passage section 640a and liquid passage section 640b) formed between the outer peripheral surface of the rolling body 632 and the outer peripheral wall 635 in the cross-sectional view of Figure 10(c) is T0, the area of ​​the liquid passage section 40 (the sum of liquid passage section 40a, liquid passage section 40b, and liquid passage section 40c) formed between the outer peripheral surface of the rolling body 32 and the outer peripheral wall 35 in the cross-sectional view of Figure 2(c) is larger than T0.

[0042] As shown in FIG. 2( c), the two protrusions 36 are formed on the outer peripheral wall 35 at a distance (circumferential distance) such that, in a drum rotation state in which the rolling element 32 is pressed against the outer peripheral wall 35, the outer peripheral surface of the rolling element 32 and the outer peripheral wall 35 are in point contact at the tips of the two protrusions 36, and the outer peripheral surface of the rolling element 32 does not come into contact with the outer peripheral wall 35 between the two protrusions 36. For example, if the distance (circumferential distance) between the two protrusions 36 is too large, as shown in FIG. 4, in a drum rotation state in which the rolling element 32 is pressed against the outer peripheral wall 35, the outer peripheral surface of the rolling element 32 comes into contact with the outer peripheral wall 35 between the two protrusions 36. Therefore, the two protrusions 36 are formed on the outer peripheral wall 35 at a distance such that, in a drum rotation state in which the rolling element 32 is pressed against the outer peripheral wall 35, the outer peripheral surface of the rolling element 32 does not come into contact with the outer peripheral wall 35 between the two protrusions 36.

[0043] A brief description will now be given of how the ball balancer 30 of this embodiment reduces vibration of the drum 5. If clothes become unbalanced in the drum during spin-drying, the center of vibration of the outer tub 3 moves to a position closer to the clothes unbalance than the center of rotation of the drum 5, as shown in FIG. 5. Meanwhile, during spin-drying, centrifugal force acts on the rolling elements 32 and liquid 33 due to the rotation of the drum 5, causing them to move farther away from the center of vibration of the outer tub. When the rolling elements 32 and liquid 33 begin to gather at positions symmetrical to the clothes unbalance, the clothes unbalance is canceled out and the outer tub vibration decreases, so the movement of the rolling elements 32 stops, allowing spin-drying to be performed with the vibration canceled out.

[0044] As described above, the drum-type washing machine 1 of this embodiment comprises an outer tub 3, a drum 5 configured to be rotatable around an axis extending horizontally or inclined within the outer tub 3, and an annular container 31 attached to the drum 5 and containing a plurality of rolling elements 32 and a liquid 33, wherein the rolling elements 32 are spherical, and the annular container 31 is an annular circular tube having a protrusion 36 formed on its outer peripheral wall 35 that protrudes inward, and when the drum is in a rotating state in which the rolling elements 32 are pressed toward the outer peripheral wall 35 by centrifugal force generated by the rotation of the drum 5, the outer peripheral surfaces of the rolling elements 32 and the outer peripheral wall 35 are in point contact at two point contact portions 36a, and a liquid passage portion 40b is formed between the two point contact portions 36a.

[0045] In this case, even if the annular container 31 is a circular tube, by forming the protrusions 36 on its outer wall 35, the outer surface of the rolling elements 32 and the outer wall 35 come into point contact at two point contact areas 36a when the drum 5 is rotating, and a liquid passage 40b is formed between the two point contact areas 36a. This prevents the liquid 33 in the direction of the rolling elements' movement from acting as a resistance to the movement of the rolling elements 32. As a result, even if the annular container 31 is a circular tube, the rolling elements 32 inside the annular container 31 can be moved appropriately to a position that offsets the imbalance in the clothes, and the vibration of the drum 5 can be appropriately reduced.

[0046] Furthermore, the drum-type washing machine 1 of this embodiment includes an outer tub 3, a drum 5 configured to be rotatable around an axis extending horizontally or inclined within the outer tub 3, and an annular container 31 attached to the drum 5 and containing a plurality of rolling elements 32 and a liquid 33, wherein the rolling elements 32 are spherical and the annular container 31 is an annular circular tube having a protrusion 36 protruding inward on its outer wall 35. When the diameters of the rolling elements 32 and the diameters of the circular tubes are the same, when comparing cross sections perpendicular to the axial center of the circular tubes, in a drum rotation state in which the rolling elements 32 are pressed toward the outer wall 35 by centrifugal force generated by the rotation of the drum 5, the liquid passage 40 formed between the outer surface of the rolling elements 32 and the outer wall 35 is larger than the liquid passage portion formed between the outer surface of the rolling elements 32 and the outer wall 35 when the protrusion 36 is not formed on the outer wall 35 of the annular container 31.

[0047] In this case, even if the annular container 31 is a circular pipe, by forming the protrusions 36 on the outer wall 35, the liquid passages 40 formed between the outer surfaces of the rolling elements 32 and the outer wall 35 become relatively large, and the liquid 33 in the direction of movement of the rolling elements 32 flows behind the rolling elements 32 through the liquid passages 40. This prevents the liquid 33 in the direction of movement of the rolling elements 32 from acting as a resistance to the movement of the rolling elements 32. As a result, even if the annular container 31 is a circular pipe, the rolling elements inside the annular container 31 can be moved appropriately to positions that cancel out the imbalance in the clothes, and the vibration of the drum 5 can be appropriately reduced.

[0048] In the drum type washing machine 1 of this embodiment, the protrusion 36 has two flat surfaces t2 and t4 whose distance decreases toward the tip, and the angle between the two flat surfaces t2 and t4 is 160 degrees or less.

[0049] In this case, the liquid passage 40 formed between the outer surface of the rolling body 32 and the outer wall of the outer periphery 35 becomes sufficiently large, allowing the rolling body 32 inside the annular container 31 to move appropriately to a position that offsets the clothing imbalance.

[0050] (Second embodiment) The drum type washing machine 101 of this embodiment differs from the drum type washing machine 1 of the first embodiment in the shape of the annular container of the ball balancer. Other configurations of the drum type washing machine 101 of this embodiment are similar to those of the drum type washing machine 1 of the first embodiment, and therefore detailed description thereof will be omitted.

[0051] In the ball balancer 130 of the drum-type washing machine 101 of the second embodiment, as shown in FIG. 6(c), an outer peripheral wall 135 that is curved convexly outward is provided on the outer periphery of the annular container 131. The outer peripheral wall 135 covers a portion of the outer periphery of the annular container 131 that connects the front end 131a and the rear end 131b of the annular container 131. A single protrusion 136 that protrudes inward is formed along the entire periphery of the outer peripheral wall 135. That is, the protrusion 136 is formed in an annular shape and is provided on the rear end 131b side of the outermost portion 135T of the outer peripheral wall 135 of the annular container 131. The cross-sectional area of ​​the protrusion 136 decreases as it approaches the tip. The shape of the protrusion 136 is the same as the shape of the protrusion 36 of the first embodiment.

[0052] In this embodiment, the diameter of the circular tube of the annular container 131 (the diameter of the circular tube when the protrusion 136 is not formed) is the same as the diameter of the annular container 631 shown in Fig. 10, and the diameter of the rolling element 132 is the same as the diameter of the rolling element 632 shown in Fig. 10. Therefore, the ball balancer 130 of this embodiment differs from the ball balancer 630 shown in Fig. 10 in that one protrusion 136 is formed on the outer peripheral wall 135 of the annular container 131.

[0053] The inventor of the present invention found that when the cross-sectional shape of the annular container 631 is changed to a circular shape (round shape) as shown in Figure 10, the gap (liquid passage portion) formed between the outer surface of the rolling body 632 and the outer wall 635 becomes smaller, and the rolling body 632 no longer rolls properly within the annular container 631.Therefore, he formed a single protrusion 136 that protrudes inward from the outer wall 35 of the circular tube of the annular container 31.

[0054] In this case, when the drum 5 is rotating and the centrifugal force generated by the rotation of the drum 5 presses the rolling elements 132 toward the outer peripheral wall 135, the rolling elements 132 come into point contact with the outermost portion 135T of the outer peripheral wall 135 of the annular container 131 at a portion 135Ta on the front end side end 131a side and at the tip of the protruding portion 136, as shown in FIG. 6(c). At this time, a liquid passing portion 140 through which the liquid 133 passes along the circumferential direction of the annular container 131 is formed between the outer peripheral surface of the rolling elements 132 and the outer peripheral wall 135. Specifically, a liquid passing portion 140a is formed on the front end side of the portion 135Ta of the outer peripheral wall 135, a liquid passing portion 140b is formed between the portion 135Ta of the outer peripheral wall 135 and the protruding portion 36, and a liquid passing portion 140c is formed on the rear end side of the protruding portion 36.

[0055] In this embodiment, Figure 6(c) and Figure 10(c) are compared, that is, the size of the liquid passage section 140 and the size of the liquid passage section 640 are compared when the diameter N1 of the rolling body 132 and the diameter N1 of the rolling body 632 are the same, and the diameter N2 of the circular tube of the annular container 131 and the diameter N2 of the cross-sectional shape of the annular container 631 are the same.

[0056] Comparing cross sections perpendicular to the axial center of the annular container 131 as shown in Figures 6(c) and 10(c), the liquid passage portion 140 formed between the outer peripheral surface of the rolling element 132 and the outer peripheral wall 135 in Figure 6(c) is larger than the liquid passage portion 640 formed between the outer peripheral surface of the rolling element 632 and the outer peripheral wall 635 in Figure 10(c). In other words, when the protrusion 136 is formed on the outer peripheral wall 135 of the annular container 132 as shown in Figure 6(c), the size of the liquid passage portion is larger than when no protrusion is formed on the outer peripheral wall 635 of the annular container 632 as shown in Figure 10(c).

[0057] That is, if the area of ​​liquid passage section 640 (the sum of liquid passage section 640a and liquid passage section 640b) formed between the outer peripheral surface of rolling body 632 and outer peripheral wall 635 in the cross-sectional view of Figure 10(c) is T0, the area of ​​liquid passage section 140 (the sum of liquid passage section 140a, liquid passage section 140b, and liquid passage section 140c) formed between the outer peripheral surface of rolling body 132 and outer peripheral wall 135 in the cross-sectional view of Figure 6(c) is larger than T0.

[0058] As described above, drum type washing machine 101 of this embodiment includes outer tub 3, drum 5 configured to be rotatable around an axis extending horizontally or in an inclined direction within outer tub 3, and annular container 131 attached to drum 5 and accommodating a plurality of rolling elements 132 and liquid 133, rolling elements 132 being spherical, annular container 131 being an annular circular tube and having protrusions 136 formed on its outer peripheral wall 135 so as to protrude inward, and rolling elements 132 having the same diameter. and the diameter of the circular pipe is the same, when comparing cross sections perpendicular to the axial center of the circular pipe, the liquid passage portion 140 formed between the outer surface of the rolling body 132 and the outer peripheral wall 135 in the drum rotating state in which the rolling body 132 is pressed toward the outer peripheral wall 135 by the centrifugal force generated by the rotation of the drum 5 is larger than the liquid passage portion formed between the outer surface of the rolling body 132 and the outer peripheral wall 635 when the protrusion 136 is not formed on the outer peripheral wall 135 of the annular container 131.

[0059] In this case, even if annular container 131 is a circular pipe, by forming protrusion 136 on its outer circumferential wall 135, liquid passing portion 140 formed between the outer circumferential surface of rolling element 132 and outer circumferential wall 135 becomes relatively large, and liquid 133 in the direction of movement of rolling element 132 flows behind rolling element 132 through liquid passing portion 140. This prevents liquid 133 in the direction of movement of rolling element 132 from acting as resistance to the movement of rolling element 132. As a result, even if annular container 131 is a circular pipe, the rolling element inside annular container 131 can be appropriately moved to a position that cancels out the imbalance in the clothes, and vibration of drum 5 can be appropriately reduced.

[0060] (Third embodiment) The drum type washing machine 301 of this embodiment differs from the drum type washing machine 1 of the first embodiment in the shape of the annular container of the ball balancer. Other configurations of the drum type washing machine 301 of this embodiment are similar to those of the drum type washing machine 1 of the first embodiment, so detailed description thereof will be omitted.

[0061] In a ball balancer 330 of a drum-type washing machine 301 of the third embodiment, as shown in FIG. 7( c), an outer peripheral wall 335 that is curved in a convex shape toward the outside is provided on the outer periphery of the annular container 331. The range of the outer peripheral wall 335 is a portion that connects a front end 331a and a rear end 331b of the annular container 331 on the outer periphery of the annular container 331. A single recess 336 recessed toward the outside is formed along the entire periphery of the outer peripheral wall 335. That is, the recess 336 is formed in an annular shape and is provided so as to correspond to an outermost portion 335T of the outer peripheral wall 335 of the annular container 331. Note that because the recess 336 recessed toward the outside of the outer peripheral wall 336 forms a liquid passage portion 340b, resistance from the wall surface is reduced, and the liquid 333 flows more easily than when a protrusion that protrudes toward the inside is formed on the outer peripheral wall.

[0062] In this embodiment, the diameter of the circular tube of the annular container 331 (the diameter of the circular tube when the recess 336 is not formed) is the same as the diameter of the annular container 631 shown in Fig. 10, and the diameter of the rolling element 332 is the same as the diameter of the rolling element 632 shown in Fig. 10. Therefore, the ball balancer 330 of this embodiment differs from the ball balancer 630 shown in Fig. 10 in that one recess 336 is formed in the outer peripheral wall 335 of the annular container 331.

[0063] The inventors of the present invention found that when the cross-sectional shape of the annular container 631 is changed to a circular shape (round shape) as shown in Figure 10, the gap (liquid passage portion) formed between the outer surface of the rolling body 632 and the outer wall 635 becomes smaller, and the rolling body 632 no longer rolls properly within the annular container 631.Therefore, for the circular tube of the annular container 631, a single recess 336 recessed outward in the outer wall 335 is formed.

[0064] In this case, when the drum 5 is rotating and the centrifugal force generated by the rotation of the drum 5 presses the rolling elements 332 toward the outer peripheral wall 335, the rolling elements 332 come into point contact at two point contact portions 336a, which are both edge portions of the recessed portion 336 in the outer peripheral wall 335 of the annular container 331, as shown in FIG. 7(c). At this time, a liquid passage 340 through which the liquid 333 passes along the circumferential direction of the annular container 331 is formed between the outer peripheral surface of the rolling elements 332 and the outer peripheral wall 335. Specifically, the liquid passage 340a is formed on the front side of the recessed portion 336 in the outer peripheral wall 335, the liquid passage 340b is formed within the recessed portion 336 in the outer peripheral wall 335, and the liquid passage 340c is formed on the rear side of the recessed portion 336 in the outer peripheral wall 335. The liquid passage 340b formed between both edge portions of the recessed portion 336 is the liquid passage formed between the two point contact portions 336a.

[0065] In this embodiment, Figure 7(c) and Figure 10(c) are compared, that is, the size of the liquid passage section 340 and the size of the liquid passage section 640 are compared when the diameter N1 of the rolling body 332 and the diameter N1 of the rolling body 632 are the same and the diameter N2 of the circular tube of the annular container 331 and the diameter N2 of the cross-sectional shape of the annular container 631 are the same.

[0066] Comparing cross sections perpendicular to the axial center of the annular container as shown in Figures 7(c) and 10(c), liquid passage portion 340 formed between the outer peripheral surface of rolling element 332 and outer peripheral wall 335 in Figure 7(c) is larger than liquid passage portion 640 formed between the outer peripheral surface of rolling element 632 and outer peripheral wall 635 in Figure 10(c). In other words, when recess 336 is formed in outer peripheral wall 335 of annular container 332 as in Figure 7(c), the size of the liquid passage portion is larger than when no recess is formed in outer peripheral wall 635 of annular container 632 as in Figure 10(c).

[0067] That is, if the area of ​​liquid passage section 640 (the sum of liquid passage section 640a and liquid passage section 640b) formed between the outer peripheral surface of rolling body 632 and outer peripheral wall 635 in the cross-sectional view of Figure 10(c) is T0, the area of ​​liquid passage section 340 (the sum of liquid passage section 340a, liquid passage section 340b, and liquid passage section 340c) formed between the outer peripheral surface of rolling body 332 and outer peripheral wall 335 in the cross-sectional view of Figure 7(c) is larger than T0.

[0068] As described above, the drum-type washing machine 301 of this embodiment includes an outer tub 3, a drum 5 configured to be rotatable around an axis extending horizontally or inclined within the outer tub 3, and an annular container 331 attached to the drum 5 and containing a plurality of rolling elements 332 and a liquid 333, wherein the rolling elements 332 are spherical, and the annular container 331 is an annular circular tube having an outer peripheral wall 335 on which a recess 336 recessed outward is formed, and when the drum is in a rotating state in which the rolling elements 332 are pressed toward the outer peripheral wall 335 by centrifugal force generated by the rotation of the drum 5, the outer peripheral surface of the rolling elements 332 and the outer peripheral wall 335 come into point contact at two point contact portions 336a, and a liquid passage portion 340b is formed between the two point contact portions 336a.

[0069] In this case, even if the annular container 331 is a circular tube, by forming a protrusion 336 on its outer peripheral wall 335, the outer peripheral surface of the rolling element 332 and the outer peripheral wall 335 come into point contact at two point contact portions 336a when the drum 5 is rotating, and a liquid passage portion 340b is formed between the two point contact portions 336a. This prevents the liquid 333 in the direction of the rolling element's movement from acting as a resistance to the movement of the rolling element 332. As a result, even if the annular container 331 is a circular tube, the rolling element 332 inside the annular container 331 can be moved appropriately to a position that offsets the imbalance in the clothes, and the vibration of the drum 5 can be appropriately reduced.

[0070] Furthermore, the drum-type washing machine 1 of this embodiment includes an outer tub 3, a drum 5 configured to be rotatable around an axis extending horizontally or inclined within the outer tub 3, and an annular container 331 attached to the drum 5 and containing a plurality of rolling elements 332 and a liquid 333. The rolling elements 332 are spherical, and the annular container 331 is an annular circular tube having an outer peripheral wall 335 on which a recess 336 recessed outward is formed. When the diameters of the rolling elements 332 and the diameters of the circular tubes are the same, when comparing cross sections perpendicular to the axial center of the circular tubes, in a drum rotation state in which the rolling elements 332 are pressed toward the outer peripheral wall 335 by centrifugal force generated by the rotation of the drum 5, the liquid passage portion 340 formed between the outer peripheral surface of the rolling elements 332 and the outer peripheral wall 335 is larger than the liquid passage portion formed between the outer peripheral surface of the rolling elements 332 and the outer peripheral wall 335 when the recess 336 is not formed in the outer peripheral wall 335 of the annular container 331.

[0071] In this case, even if the annular container 331 is a circular tube, by forming a recess 336 in its outer wall 335, the liquid passage 340 formed between the outer surface of the rolling element 332 and the outer wall 335 becomes relatively large, and the liquid 333 in the direction of movement of the rolling element 332 flows behind the rolling element 332 through the liquid passage 340. This prevents the liquid 333 in the direction of movement of the rolling element 332 from acting as a resistance to the movement of the rolling element 332. As a result, even if the annular container 331 is a circular tube, the rolling element inside the annular container 331 can be appropriately moved to a position that offsets the imbalance in the clothes, and the vibration of the drum 5 can be appropriately reduced.

[0072] Although the embodiments of the present invention have been described above, the specific configurations of the various components are not limited to the above-described embodiments.

[0073] For example, in the first to third embodiments, examples of liquid passages formed between the outer peripheral surfaces of the rolling elements and the outer peripheral wall when the drum is rotating and the rolling elements are pressed toward the outer peripheral wall by centrifugal force generated by the rotation of the drum have been described, but the liquid passages are not limited to these. The number, size, shape, and arrangement of liquid passages formed between the outer peripheral surfaces of the rolling elements and the outer peripheral wall are arbitrary. Furthermore, the number, size, shape, and arrangement of protrusions or recesses for forming liquid passages between the outer peripheral surfaces of the rolling elements and the outer peripheral wall are arbitrary.

[0074] 8, in a cross section perpendicular to the axial center of the annular container 35, the protrusion 36 has an upper curved portion t1 and a lower curved portion t3 arranged above a straight line C passing through the tip end (point contact portion 36a) of the protrusion 36, and an upper curved portion t4 and a lower curved portion t6 arranged below the straight line C. The upper curved portion t1 and the upper curved portion t4 have shapes symmetrical with respect to the straight line C, and the lower curved portion t3 and the upper curved portion t6 have shapes symmetrical with respect to the straight line C.

[0075] The upper curved portion t1, the lower curved portion t3, the upper curved portion t4, and the lower curved portion t6 are formed into an R-shape with a predetermined curvature. In this embodiment, the angle θ between the tangent to the connection portion Ta between the upper curved portion t1 and the lower curved portion t3 and the tangent to the connection portion Tb between the upper curved portion t4 and the lower curved portion t6 is 108 degrees. The angle θ is 160 degrees or less, and preferably 110 degrees or less. Therefore, the protrusion 36 does not need to have two inclined flat portions whose distance decreases as it approaches the tip of the protrusion 36.

[0076] In the first to third embodiments, a large drum-type washing machine installed in a coin-operated laundry shop has been described, but the present invention is not limited thereto. The drum-type washing machine of the present invention can be applied to a drum-type washing machine for home use.

[0077] In the above first to third embodiments, a drum type washing machine having a ball balancer has been described, but the present invention is not limited to this, and the drum type washing machine of the present invention may also be a drum type washer-dryer. [Explanation of symbols]

[0078] 1. Drum washing machine 2. Case 3 Outer tank 5 Drums 30 Ball Balancer 31 Annular container 32 rolling elements 33 liquid 35 Outer wall 35T outermost part 36 Protrusion 40 Liquid passage section 101 Drum washing machine 130 Ball Balancer 131 Annular container 132 rolling elements 133 Liquid 135 Outer wall 136 Protrusion 140 Liquid passage section 301 Drum washing machine 330 Ball Balancer 331 Annular container 332 Rolling elements 333 Liquid 335 Outer wall 336 Recess 340 Liquid passage section

Claims

1. The outer tank and a drum configured to be rotatable around an axis extending horizontally or in an inclined direction within the outer tub; an annular container attached to the drum and configured to contain a plurality of rolling elements and a liquid; The rolling elements are spherical, the annular container is an annular circular tube having an outer circumferential wall on which a protrusion protruding inward or a recess recessed outward is formed, a drum-type washing machine, characterized in that, in a drum rotation state in which the rolling bodies are pressed toward the outer peripheral wall by centrifugal force generated by the rotation of the drum, the outer peripheral surfaces of the rolling bodies and the outer peripheral wall are in point contact with each other at two point contact portions, and a liquid passage portion is formed between the two point contact portions.

2. The outer tank and a drum configured to be rotatable around an axis extending horizontally or in an inclined direction within the outer tub; an annular container attached to the drum and configured to contain a plurality of rolling elements and a liquid; The rolling elements are spherical, the annular container is an annular circular tube having an outer circumferential wall on which a protrusion protruding inward or a recess recessed outward is formed, When the diameters of the rolling elements and the diameters of the circular pipes are the same, and when a cross section perpendicular to the axial center of the circular pipe is compared, a liquid passage formed between the outer peripheral surface of the rolling body and the outer peripheral wall when the drum is rotating and the rolling body is pressed toward the outer peripheral wall by centrifugal force generated by the rotation of the drum, the liquid passage formed between the outer peripheral surface of the rolling body and the outer peripheral wall is larger than a liquid passage formed between the outer peripheral surface of the rolling body and the outer peripheral wall when the protrusion or the recess is not formed on the outer peripheral wall of the annular container.

3. The protrusion has two flat surfaces whose distance decreases as the protrusion approaches a tip thereof, 3. The drum-type washing machine according to claim 1, wherein the angle between the two planes is 160 degrees or less.

4. The protrusion has a cross section whose width decreases as it approaches a tip, and the tip and two base portions are each formed in an R-shape, 3. The drum-type washing machine according to claim 1, wherein, in the cross section, an angle between a tangent at a connection between the R-shaped tip portion and one of the R-shaped base portions and a tangent at a connection between the R-shaped tip portion and the R-shaped base portion on the other side is 160 degrees or less.

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