JP2024068521A - washing machine - Google Patents

Abstract

[Problem] Achieve both high rigidity of the water tub (drum) for larger capacity and improved vibration reduction effect by the fluid balancer. [Solution] A washing machine S includes an outer tub 10 for holding wash water, a water tub (drum 20) provided inside the outer tub 10 for holding laundry, and a cylindrical fluid balancer 23 disposed inside the water tub and having multiple layers of flow paths in the radial direction in which liquid capable of moving in the circumferential direction is sealed. A plurality of long projections 23b are disposed on the outer periphery 23sb of the fluid balancer, and a plurality of long engagement portions (grooves 20e) are disposed on the inner periphery of the water tub. The fluid balancer and the water tub are fixed by screwing the projections of the fluid balancer into the engagement portions of the water tub. [Selected Figure] Fig. 6

Description

The present invention relates to a washing machine.

Drum-type washing machines are becoming larger in capacity to meet the need to shorten washing times and reduce the number of washes. At the same time, there is a demand to reduce the external dimensions of drum-type washing machines to meet the need to reduce the installation space. When the external dimensions of such drum-type washing machines are reduced, vibrations caused by uneven distribution of clothes during the spin cycle increase, so it is desirable to reduce the vibrations.

Patent Document 1 and Patent Document 2 disclose the structure of a drum-type washing machine. A drum-type washing machine houses a washing tub supported by springs and dampers inside a housing. The washing tub is composed of a drum in which cloths are placed and an outer tub that contains the drum.

A vibration-proof fluid balancer is fixed to the drum with screws. The fluid balancer rotates with the drum during washing. The fluid balancer has a hollow circular tube structure, and liquid that can move in the circumferential direction is sealed inside. About half of the cavity volume of the fluid balancer is filled with liquid. A liquid with a high specific gravity is used as the liquid. This is because the higher the specific gravity of the liquid, the more the centrifugal force of the liquid can offset the centrifugal force caused by the uneven distribution of fabrics, and the more efficiently vibration can be reduced (vibration prevention).

Multiple baffle plates are arranged inside the circular tube of the fluid balancer, with a shape that allows liquid to move circumferentially inside. When the drum is stopped, gravity causes liquid to accumulate in the lower part of the fluid balancer. When the drum starts to rotate, the baffle plates scoop up the liquid. As the rotation speed of the drum is increased, centrifugal force causes the liquid to stick to the inner wall on the outer periphery of the flow path. During the spin cycle, the washing tub vibrates due to uneven distribution of fabrics. This vibration causes the liquid to become unevenly distributed.

When the rotational speed of the drum passes the resonant rotational speed (resonant rotation number) of the vibration system consisting of the washing tub, spring, and damper, the phase of the vibration displacement of the washing tub lags behind the phase of the vibration force caused by the uneven distribution of the fabrics, and eventually becomes the opposite phase. As the liquid flows freely, the liquid is unevenly distributed on the opposite side to the uneven distribution of the fabrics, canceling out the vibration force caused by the uneven distribution of the fabrics and reducing the vibration of the washing tub and housing.

Fluid balancers use a structure that is radially multi-layered by stacking circular tube structures concentrically. This is because the vibration reduction effect increases with the number of layers. The vibration reduction effect is greater for the outer layers of the multi-layer structure. This is because as the rotation radius increases, the centrifugal force of the liquid increases, making it possible to offset the vibration force caused by uneven distribution of fabric.

The structural material used for the fluid balancer in drum-type washing machines is a resin material that can be easily molded into a hollow circular tube structure. The circular tube structure is made thinner to increase the hollow volume of the flow passages in each layer. This allows the liquid to flow freely and increases the amount of liquid, improving the vibration reduction effect.

On the outer periphery of the cylindrical structure, multiple screw fastening parts with sufficient thread engagement length are arranged to firmly integrate and fix the drum and fluid balancer. This allows the drum-type washing machine to suppress deformation of the drum due to the centrifugal force of a large amount of fabric, and improves the rigidity of the cylindrical structure of the large-diameter drum.

JP 2007-167263 A JP 2001-321592 A

The conventional technology described in Patent Document 1 relates to a drum-type washing machine equipped with a fluid balancer, and discloses a technology for ensuring sufficient engagement length of the screws that secure the fluid balancer to the drum. However, in the conventional technology described in Patent Document 1, the screw hole portion is formed to protrude into the flow path of the outermost layer (outermost circumference), which reduces the volume of the flow path of the outermost layer, which has the greatest vibration reduction effect. As a result, the conventional technology described in Patent Document 1 may reduce the vibration reduction effect. Therefore, it is desired that the conventional technology described in Patent Document 1 does not reduce the volume of the flow path of the outermost layer.

The conventional technology described in Patent Document 2 relates to a drum-type washing machine equipped with a fluid balancer, and discloses a technology for expanding the hollow volume of the flow path without protruding the screw hole portion into the outermost flow path. However, in the conventional technology described in Patent Document 2, the fluid balancer has a thin-walled circular tube structure made of a resin material. With such conventional technology described in Patent Document 2, it is difficult to ensure a sufficient thread engagement length to maintain strength, and the configuration makes it difficult to increase the rigidity of the drum to increase capacity. Therefore, there is a demand for the conventional technology described in Patent Document 2 to make it easier to increase the rigidity of the drum to increase capacity.

Therefore, with the conventional technologies described in Patent Documents 1 and 2, it is difficult to achieve both high drum rigidity for larger capacity and improved vibration reduction effect of the fluid balancer.

The present invention has been made to solve the above-mentioned problems, and its main objective is to provide a washing machine that can achieve both high drum rigidity for larger capacity and improved vibration reduction effect by the fluid balancer.

In order to achieve the above-mentioned object, the present invention provides a washing machine comprising an outer tub for holding wash water, a water tub provided within the outer tub for holding laundry, and a tubular fluid balancer disposed within the water tub and having multiple radially-oriented flow paths in which a liquid capable of moving circumferentially is sealed, wherein a plurality of elongated protrusions are disposed on the outer periphery of the fluid balancer and a plurality of elongated engaging portions are disposed on the inner periphery of the water tub, and the fluid balancer and the water tub are fixed together by screwing the protrusions of the fluid balancer into the engaging portions of the water tub.
Other means will be described later.

The present invention makes it possible to achieve both high rigidity of the water tank (drum) for larger capacity and improved vibration reduction effect of the fluid balancer.

1 is a cross-sectional view of a washing machine according to an embodiment, seen from the side. 1 is an external perspective view of a washing machine according to an embodiment; 2 is a block diagram showing the electrical configuration of the washing machine according to the embodiment; FIG. 1A to 1C are diagrams illustrating the operation of a fluid balancer of a washing machine according to an embodiment of the present invention; 6A to 6C are diagrams illustrating the operation of the fluid balancer of the washing machine according to the embodiment (2). 1 is a perspective view of a fluid balancer of a washing machine according to an embodiment; 4 is an enlarged view of the periphery of a protrusion in the fluid balancer of the washing machine according to the embodiment. FIG. FIG. 2 is a perspective view of a drum of the washing machine according to the embodiment. 13A and 13B are explanatory diagrams of a protrusion of a fluid balancer in the washing machine of the first modified example. FIG. 11 is an explanatory diagram of a groove in a drum of a washing machine according to a first modified example. 13 is an explanatory diagram of a protrusion of a fluid balancer in a washing machine of a second modified example. FIG. FIG. 11 is an explanatory diagram of a groove in a drum of a washing machine according to a second modified example. 13 is an explanatory diagram of a protrusion of a fluid balancer in a washing machine according to a third modified example. FIG. 13 is an explanatory diagram of a protrusion of a fluid balancer in a washing machine according to a fourth modified example. FIG. FIG. 13 is an explanatory diagram of a groove in a drum of a washing machine according to a fifth modified example.

Below, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the drawings. Note that each figure merely shows a schematic view to the extent that the present invention can be fully understood. Therefore, the present invention is not limited to the illustrated examples. In addition, in each figure, common or similar components are given the same reference numerals, and duplicate explanations thereof will be omitted.

<Overall configuration of washing machine S>
The present invention relates to a washing machine, and in particular to a fluid balancer provided in a washing machine. Hereinafter, the overall configuration of a washing machine S according to the present embodiment 1 will be described with reference to Figs. 1 and 2. Fig. 1 is a cross-sectional view of the washing machine S according to the present embodiment 1 as seen from the side. Fig. 2 is an external perspective view of the washing machine S. In this embodiment, the washing machine S will be described on the assumption that it is a drum washing machine. However, the washing machine S may be a vertical washing machine.

The washing machine S according to this embodiment is covered by a base 1 and a housing 2. The housing 2, which is made up of a combination of steel plate and resin molded parts to form an outer shell, is installed on top of the base 1 of the washing machine S. The housing 2 is made up of a front panel 2a, a back panel 2b, left and right side panels 2c (see Figure 2), and a top panel 2d. A door 3 for inserting and removing fabrics is provided on the front of the housing 2. A user inserts and removes fabrics by opening and closing the door 3.

An operation panel 4 is provided on the front of the upper part of the housing 2 to allow the user to operate the washing machine S. The operation panel 4 is equipped with operation buttons for turning the power on/off, starting or pausing operation, selecting a course, etc., as well as a screen that displays the time and operating conditions.

A water supply unit 15 to which a water supply hose 15h is connected is provided on the top of the housing 2. The water supply unit 15 and the detergent case 16 are connected via piping 17. The detergent case 16 is connected to the front of the outer tub 10 via piping 18. Water that flows into the water supply unit 15 flows into the outer tub 10 via the detergent case 16.

The washing tub 10S is composed of an outer tub 10 to which washing water is supplied, and a cylindrical drum 20 contained within the outer tub 10. The drum 20 functions as a water tub, and cloths to be washed are placed in the drum 20. Note that although the water tub 10c is shown in FIG. 1, the water tub 10c will be described as referring to a part of the outer tub 10.

<Configuration of outer tank 10>
The outer tub 10 shown in Fig. 1 has a generally cylindrical shape centered on a generally horizontal center line C, and has a front panel and a back panel. An opening 10a is formed in the front panel of the outer tub 10. The opening 10a is used for putting laundry in and taking it out.

The outer tub 10 is composed of a tub cover 10b at the front with an opening 10a, and a water tub 10c at the rear. The tub cover 10b and the water tub 10c can be disassembled at a dividing surface 10d (see Figure 1). The tub cover 10b and the water tub 10c are fastened and fixed with bolts b1. The outer tub 10 contains the drum 20 and serves as a water tub.

As shown in FIG. 1, the opening 10a on the front of the outer tub 10 is connected to the front of the housing 2 via a cylindrical rubber bellows 11. The opening 10a is sealed with water by closing the door 3. The drum 20 is disposed inside the outer tub 10 so as to be rotatable around a substantially horizontal axis of rotation (center line C).

A drain hose 9 (see Figure 2) is attached to the bottom of the base 1. A drain outlet 7 and a drain valve 8 are located at the bottom of the outer tub 10 of the washing tub 10S. The outer tub 10 is connected to the drain hose 9 via the drain outlet 7 and the drain valve 8.

A pair of springs 14 are attached to the upper part of the outer tub 10 on the left and right sides to suspend the outer tub 10 from the housing 2. A pair of front dampers 41 and rear dampers 42 are provided on the lower part of the outer tub 10 on the left and right sides.

<Configuration of front damper 41 and rear damper 42>
The front damper 41 and the rear damper 42 use viscous damping force to damp the vibration force caused by uneven distribution of the clothes inside the drum 20 in multiple directions. The front damper 41 and the rear damper 42 each use a compression coil spring and a fluid damper using a fluid such as hydraulic pressure or pneumatic pressure on which the viscous force of the fluid acts, or a fluid damper using a fluid such as hydraulic pressure or pneumatic pressure on which the viscous force of the fluid acts. Note that the fluid used in the fluid damper may be a fluid other than air or oil.

One end of the front damper 41 is attached to the pedestal 41a of the outer tub 10. The other end of the front damper 41 is attached to the base 1. Similarly, one end of the rear damper 42 is attached to the pedestal 42a of the outer tub 10. The other end of the rear damper 42 is attached to the base 1. The pedestals 41a and 42a may be formed integrally with the outer tub 10 or may be separate parts.

The dividing surface 10d of the outer tub 10 shown in FIG. 1 is provided on the side of the clothes insertion opening 20d, which is forward of the center in the front-to-rear direction in the direction of the substantially horizontal rotation axis (center line C) of the drum 20.

An acceleration sensor 10e capable of detecting vibrations of the outer tub 10 in the up-down, left-right, and front-back directions is attached to the underside of the outer tub 10. When the vibrations of the outer tub 10 are measured by the acceleration sensor 10e during operation, if the vibrations exceed a predetermined value, the control device 5 (see Figure 3) controls the drum 20 to stop rotating.

<Configuration of Drum 20>
A cylindrical drum 20 shown in FIG. 1 has a drum body plate 20a provided with small drainage holes 20c for drainage and ventilation.

A number of lifters 22 for lifting up the fabrics are attached to the inside of the drum 20. The drum bottom plate 20b on the back of the cylindrical drum 20 is a reinforcing member for the drum 20. A vibration-proof fluid balancer 23 is attached to the opening (clothing inlet 20d) at the end of the front of the drum 20. The fluid balancer 23 is a cylindrical object that is placed inside the drum 20 (water tank) and has multiple layers of flow paths in the radial direction in which a liquid that can move in the circumferential direction is sealed. The fluid balancer 23 is fixed to the front side of the drum 20. Line C23 represents the vertical centerline near the center of the fluid balancer 23 in the front-to-rear direction.

The fluid balancer 23 rotates together with the drum 20. During the dehydration operation, the fluid balancer 23 suppresses vibration of the outer tub 10 by moving the liquid contained therein in a direction that counteracts the uneven distribution of the fabrics in the drum 20, that is, to the opposite side of the uneven distribution of the fabrics.

The drum 20 is rotatably supported on the outer tub 10 via a shaft 31 connected to the drum bottom plate 20b and a bearing (not shown). The shaft 31 is directly connected to a pulley 33, for example. The drive motor 32 is fixed to the lower back surface of the outer tub 10. The drive motor 32 is connected to the pulley 33 via a rubber belt 34. The drive motor 32 rotates the drum 20 via the rubber belt 34, the pulley 33, and the shaft 31.

The drive motor 32 is provided with a rotation detection sensor 47 (see FIG. 3). The rotation detection sensor 47 detects the rotation speed of the drive motor 32 during operation. The control device 5 (see FIG. 3) can calculate the rotation speed of the drum 20 using the reduction ratio based on the detection value of the rotation detection sensor 47.

<Configuration of control device 5>
Fig. 3 is a block diagram showing the electrical configuration of the washing machine S. A signal from the operation panel 4 shown in Fig. 2 is input to the control device 5. In addition, a rotation detection signal of the drive motor 32 detected by the rotation detection sensor 47 of the drive motor 32 and a vibration detection signal detected by the acceleration sensor 10e of the outer tub 10 are input to the control device 5.

The control device 5 can acquire the rotation speed of the drum 20 and the vibration displacement of the outer tub 10 by calculations using the reduction ratio, integration, etc. The control device 5 transmits a control signal to the drive circuit 6, which drives the drive motor 32, according to a control program stored based on the acquired information.

<Operation of washing machine S>
When washing clothes with the washing machine S, a user opens the door 3 shown in Fig. 2 and puts laundry into the drum 20 (see Fig. 1). After putting detergent into the detergent case 16, the user inputs an operation signal into the operation panel 4 to start the operation of the washing machine S. When an operation signal is input into the operation panel 4, the control device 5 transmits a control signal to the drive circuit 6 and the like, and the washing machine S performs the operations in the order of the washing process, the spin-drying process, the rinsing process, and the drying process.

In the washing process, first, the water supply valve installed in the water supply unit 15 (see Figure 1) opens, and the supplied water passes through the detergent case 16 and enters the outer tub 10 together with the detergent. The fabrics in the drum 20 are lifted in the direction of rotation by multiple lifters 22 and then dropped. The fabrics are repeatedly agitated, dropping from the height at which they were lifted by the lifters 22, and are beaten to wash. After the beating wash operation is performed for a predetermined time, the washing process ends.

When the dehydration process starts, the drain valve 8 shown in Figure 1 opens first, and the water in the outer tub 10 is drained via the drain hose 9. The drum 20 is then rotated at a constant high speed for a predetermined time, and the water in the fabrics is dehydrated by centrifugal force. After the drum 20 has been rotating at high speed for a predetermined time, the dehydration process ends.

When the rinsing process starts, the water supply valve is opened to supply water, which is then poured into the outer tub 10 via the piping 19 (see FIG. 1) that connects the water supply unit 15 shown in FIG. 1 to the outer tub 10. In the rinsing process, similar to the washing process, the laundry is lifted in the rotational direction by the lifter 22 of the drum 20 and then dropped from that height, repeating the agitation action (beating action). This action dilutes the detergent contained in the fabrics and rinses them out with the supplied water.

After the rinsing step, the spin-drying step is carried out again, and the washing operation is completed.
During the dehydration process, the acceleration sensor 10e is used to measure the vibration of the outer tub 10 during the dehydration operation, and if the amplitude of the vibration of the outer tub 10 exceeds a predetermined value, the control device 5 stops the rotation of the drum 20.

At the initial stage of each process, an operation to detect the amount of laundry is performed by the rotation detection sensor 47 (see Figure 3). In the laundry amount detection operation, for example, the drum 20 is raised to a predetermined rotation speed, and then the rotation of the drum 20 is stopped and the drum 20 is rotated by inertia (rotation due to inertia force) to decrease to the predetermined rotation speed. The control device 5 determines the amount of laundry based on the time required for the rotation speed of the drum 20 to increase and decrease. The control device 5 then controls the rotation speed of the drum 20 with reference to the determined amount of laundry.

In addition, in the initial stage of each process, the rotation detection sensor 47 also detects whether the fabric is shifted to one side. This operation involves rotating the washing tub 10S (drum 20, outer tub 10) at a constant speed between a high rotation speed at which the fabric sticks to the inner surface of the drum 20 due to centrifugal force and a rotation speed that is sufficiently lower than the resonant rotation speed caused by the washing tub 10S (drum 20, outer tub 10) and the members that support it.

During this time, the rotation speed of the drum 20 varies over time due to the influence of fluctuations in torque when the lifter 22 lifts the fabric. Based on this fluctuation in rotation speed, the control device 5 determines the offset 50 of the fabric (see FIG. 5). The control device 5 then references the offset 50 to control the rotation speed of the drum 20 by controlling the rotation of the drive motor 32. In the case of a washing machine S equipped with a drying function, the drying process is carried out after the spin-drying process.

<Configuration of fluid balancer 23>
4 and 5 are explanatory diagrams of the operation of the fluid balancer 23. FIG. 4 shows a schematic internal state of the fluid balancer 23 as viewed from the front (the direction of the arrow I shown in FIG. 1) when the fluid balancer 23 is stopped. FIG. 5 shows a schematic internal state of the fluid balancer 23 as viewed from the front (the direction of the arrow I shown in FIG. 1) when the fluid balancer 23 is rotating. In order to simplify the drawings, the fluid balancer 23 is described as having a single-layer structure. However, the fluid balancer 23 can have a multi-layer structure as shown in FIG. 7, for example, and is not limited to a single-layer structure. In the example shown in FIG. 7, the fluid balancer 23 has a structure having two cavities 23a, an outer cavity 23aaa and an inner cavity 23ab. In addition, the circumferential direction and the radial direction of the fluid balancer 23 may be described as the circumferential direction and the radial direction, respectively.

The fluid balancer 23 is attached to the drum 20 and rotates together with the drum 20. The fluid balancer 23 has a hollow circular tube (ring) structure through which the liquid 51 can move circumferentially. Inside the fluid balancer 23, a cavity 23a is provided that serves as a flow path 53r through which the liquid 51 flows. The fluid balancer 23 is used in a single-layer structure (see Figure 4) or a multi-layer structure (see Figure 7) in which hollow circular tubes are stacked concentrically. The fluid balancer 23 can improve the vibration reduction effect depending on the number of layers.

The circular tube of the fluid balancer 23 is filled with liquid 51, which is about half the volume of the internal cavity 23a. Salt water or the like is used as the liquid 51 in order to increase the specific gravity. The liquid 51 should have a high specific gravity. This is because the centrifugal force acting on the liquid 51 inside the fluid balancer 23 acts against the centrifugal force caused by the uneven distribution of clothing, thus preventing vibration.

Baffle plates 54 are arranged at equal intervals in the circumferential direction in the flow path 53r (cavity 23a) inside the circular tube of the fluid balancer 23. The space between adjacent baffle plates 54 is a space through which the liquid 51 flows.

When the drum 20 is stopped, the liquid 51 accumulates below the fluid balancer 23 due to gravity. The circular tube 53 of the fluid balancer 23 is composed of an inner wall portion 53a provided on the inner circumference side and an outer wall portion 53b provided on the outer circumference side. The inner wall portion 53a on the inner circumference side and the outer wall portion 53b on the outer circumference side form a flow path 53r, which is a circular cavity 23a.

The fluid balancer 23 shown in FIG. 4 has a baffle plate 54 attached to the outer wall portion 53b on the outer periphery of the circular tube 53. When the drum 20 starts to rotate, the baffle plate 54 adjusts the flow while scooping up the liquid 51. The baffle plate 54 extends in the depth direction of the drum 20 in the fluid balancer 23 (to the right side of the paper in FIG. 1) and is formed in a flat plate shape.

As shown in FIG. 5, when the drum 20 rotates, the liquid 51 gradually sticks to the outer wall 53b on the outer periphery of the flow path 53r of the circular tube due to centrifugal force. The uneven distribution of the fabric 50 can be considered as a mass point as shown in the figure. When the washing tub vibrates due to the uneven distribution of the fabric 50, the liquid 51 is unevenly distributed in a direction in which the center O1 of the circular tube when the drum 20 rotates is displaced by the vibration from the center O of the circular tube when the drum 20 is stopped.

The position where the liquid 51 is biased in the fluid balancer 23 changes before and after passing the resonant rotation speed (resonant rotation number) of the vibration system consisting of the outer tub 10 of the washing tub, the drum 20, the spring 14, the front damper 41, and the rear damper 42.

Figure 5 shows a state in which the liquid 51 is biased 51y at a position that has the effect of counteracting the bias 50 of the fabric. In other words, it shows a state in which the liquid 51 is biased 51y at a position opposite the fabric that counteracts the bias 50 of the fabric.

When the drum 20 rotates at a sufficiently high rotation speed after passing the resonant rotation speed (resonant rotation number), the phase of the vibration displacement of the washing tub 10S (drum 20, outer tub 10) lags behind the phase of the excitation force caused by the fabric shift 50, and eventually becomes the opposite phase. In other words, a shift 51y of the liquid 51 is formed at a position opposite the shift 50 of the fabric. As a result, the shift 51y of the liquid 51 acts to balance the shift 50 of the fabric.

In this way, the shift 51y of the liquid 51 cancels out the vibration force caused by the shift 50 of the fabric on the opposite side, thereby reducing the vibration of the washing tub 10S and the housing 2. Under these circumstances, the shift 51y of the liquid 51 does not shift within each of the circular tubes of the fluid balancer 23, and the liquid 51 sticks to the circular tubes of the fluid balancer 23 and rotates almost synchronously.

When the drum 20 rotates at a sufficiently low rotational speed before passing the resonant rotational speed (resonant rotation number), the direction of the vibration displacement of the drum 20 is in phase with the fabric offset 50. In other words, the liquid 51 is on the same side as the fabric offset 50. Therefore, the offset 51y of the liquid 51 does not cancel out the vibration force caused by the fabric offset 50.

In the process of passing through the resonant rotation speed (resonant rotation number), the liquid 51 flows and transitions to the opposite side of the cloth shift 50. The ease with which the liquid 51 flows within the fluid balancer 23 varies depending on the arrangement of the baffle plate 54.

It is desirable for the liquid 51 in the fluid balancer 23 to transition as quickly as possible through the circular tube. The faster the transition of the liquid 51, the shorter the time it takes for the liquid 51 to move to the position opposite the fabric shift 50, and the greater the effect of reducing vibration immediately after passing the resonant rotation speed (resonant rotation number).

The fluid balancer 23 is designed using a resin material that is easy to mold into a hollow circular tube structure. The circular tube structure can be made thin to allow the liquid to flow freely, increase the amount of liquid, and improve the vibration reduction effect, and the hollow volume of the flow path in each layer can be maximized.

<Characteristic configuration of the washing machine S>
The characteristic configuration of the washing machine S will be described below.
Washing machine S generates vibrations due to uneven distribution of laundry during the spin-drying process. In order to increase the capacity of washing machine S, it is important to simultaneously increase the rigidity of drum 20, which is the water tub, and improve the vibration reduction effect of fluid balancer 23. The present invention focuses on the following points of fluid balancer 23 used to dampen vibrations during the spin-drying process.

As described above, the washing machine S has an outer tub 10 and a drum 20 as a washing tub 10S (see FIG. 1). A fluid balancer 23 is disposed at the front side of the drum 20. The fluid balancer 23 is formed in a circular tube (ring) shape centered on a center line C so that the liquid 51 can move in the circumferential direction. The fluid balancer 23 has a multi-layer structure having multiple layers in the radial direction to improve the vibration reduction effect. The innermost diameter, outermost diameter, and flow path dimensions of the circular tube structure of the fluid balancer 23 are set according to the volume of laundry stored in the drum 20.

The fluid balancer 23 is designed from a resin material that is easy to mold into a hollow circular tube structure. In order to allow the liquid to flow freely, increase the amount of liquid, and improve the vibration reduction effect, the circular tube structure is made thin-walled and the hollow volume of the flow path of each layer is maximized. Placing the fluid balancer 23 inside the drum 20 rather than outside the drum 20 makes it less likely for the drum 20 to bend when the drum 20 rotates. This is because placing the fluid balancer 23 inside the drum 20 acts to push open the mounting part of the drum 20, making it less likely for the mounting part of the drum 20 and the storage part connected to the mounting part to bend.

A number of screw fastening parts 21, which ensure sufficient thread engagement length, are arranged on the outer periphery of the cylindrical structure. In order to prevent deformation of the drum 20 due to the centrifugal force of the large amount of fabric and to improve the rigidity of the cylindrical structure of the large diameter drum 20, the drum 20 and the fluid balancer 23 are firmly integrated and fixed by screw fastening.

However, as in the present invention, when the fluid balancer 23 is fixed to the drum 20 in a manner that does not provide a screw hole 21a, not only can the drum 20 and the fluid balancer 23 be firmly integrated, but the volume of the flow path in the outermost tank, which has the greatest vibration reduction effect, can be increased, making it possible to achieve both high rigidity of the drum 20 for larger capacity and improved vibration reduction effect by the fluid balancer 23.

Figure 6 is a perspective view of the fluid balancer 23 of the washing machine S. Figure 7 is an enlarged view of the periphery of the protrusion 23b (ridge) of the fluid balancer 23. In the example shown in Figure 7, the fluid balancer 23 has a two-layer structure, and has a cavity 23aa that functions as the outer flow path 53ra and a cavity 23ab that functions as the inner flow path 53rb. The fluid balancer 23 can also have a layered structure of three or more layers. Figure 8 is a perspective view of the drum 20 of the washing machine S.

As shown in FIG. 6, a plurality of elongated protrusions 23b (ribs) are arranged at equal intervals on the outer peripheral portion 23sb on the rear side of the fluid balancer 23. The protrusions 23b of the fluid balancer 23 are arranged so as to extend toward the outer diameter side. The protrusions 23b of the fluid balancer 23 are arranged so as to be inclined in an oblique direction with respect to the center line C. That is, the protrusions 23b of the fluid balancer 23 are arranged so as to be parallel to each other and inclined with respect to the rotation axis. The protrusions 23b of the fluid balancer 23 are arranged so as not to impair the volume of the cavity 23a inside the fluid balancer 23 shown in FIG. 7. In particular, when the fluid balancer 23 has a multi-layer structure as shown in FIG. 7, the protrusions 23b of the fluid balancer 23 are arranged so as not to protrude into the cavity 23aa that constitutes the flow path 53ra of the outermost layer (outermost circumference). Such a fluid balancer 23 can prevent a decrease in the volume of the outermost layer flow passage 53ra (cavity 23aa), which has the greatest vibration reduction effect. The protrusion 23b of the fluid balancer 23 is formed so that its radial height is lower than the protrusion 23c described below. In other words, the protrusion 23c of the fluid balancer 23 described below is formed so that its radial height is higher than the protrusion 23b.

As shown in FIG. 8, multiple long grooves 20e are arranged at equal intervals on the inner peripheral portion 20sa on the front side of the drum 20. The grooves 20e of the drum 20 are engagement portions that engage with the protrusions 23b (see FIG. 6 and FIG. 7) of the fluid balancer 23. The grooves 20e of the drum 20 are arranged to extend toward the outer diameter side. The grooves 20e of the drum 20 are arranged to be inclined in an oblique direction with respect to the center line C. In other words, the grooves 20e of the drum 20 are arranged to be parallel to each other and inclined with respect to the rotation axis.

In this embodiment, the engagement portion is provided by forming a concave groove 20e on the inner circumference 20sa (see FIG. 8) of the mounting portion of the drum 20. However, the engagement portion may also be provided by forming multiple sets of two equally spaced protrusions on the inner circumference 20sa (see FIG. 8) of the mounting portion of the drum 20, and forming a space between the two protrusions.

The protrusions 23b of the fluid balancer 23 and the grooves 20e of the drum 20 are formed in a direction that tightens when the drum 20 rotates at high speed (during dehydration operation). In this embodiment, the drum 20 is described as being driven by the drive motor 32 (see FIG. 1) and rotating counterclockwise (see arrow A20 in FIG. 8) when rotating at high speed (during dehydration operation). The fluid balancer 23 is described as being driven by the rotation of the drum 20 and rotating counterclockwise (see arrow A23 in FIG. 6). Therefore, in this embodiment, the protrusions 23b of the fluid balancer 23 and the grooves 20e of the drum 20 are formed in an oblique direction so as to rotate clockwise from the front side to the rear side.

As shown in Figs. 6 and 7, the outer peripheral portion 23sb on the front side of the fluid balancer 23 is provided with a protrusion 23c that protrudes toward the outer diameter side. The protrusion 23c of the fluid balancer 23 is provided in a direction perpendicular to the center line C. The protrusion 23c of the fluid balancer 23 is formed so that its radial height is greater than that of the protrusion 23b.

The protrusion 23b (see FIG. 6) of the resin fluid balancer 23 is screwed into the groove 20e (see FIG. 8) of the stainless steel drum 20. In other words, the fluid balancer 23 is attached by being screwed into the drum 20 while being rotated. The fluid balancer 23 is firmly integrated with the drum 20 by screwing the protrusion 23b (see FIG. 6) into the groove 20e (see FIG. 8) of the drum 20. The fluid balancer 23 can be screwed into the drum 20 while being rotated until the protrusion 23c (see FIG. 6), which is formed with a radial height higher than the protrusion 23b, abuts against the tip of the drum 20.

Generally, when the engagement length of the screw that fixes the fluid balancer 23 to the drum 20 is sufficiently secured, the screw hole portion 21a shown in FIG. 1 is formed so as to protrude into the outermost layer (outermost circumference) of the flow path (for example, the flow path 53ra shown in FIG. 1) provided inside the fluid balancer 23. As a result, the volume of the outermost layer of the flow path, which has the greatest vibration reduction effect, is reduced. Therefore, it is desirable to design the fluid balancer 23 so that the screw hole portion 21a does not protrude into the outermost layer of the flow path, so that the volume of the outermost layer of the flow path, which has the greatest vibration reduction effect, is not reduced. However, since the fluid balancer 23 is a thin-walled circular tube structure molded from a resin material, if the screw hole portion 21a is designed so that it does not protrude into the outermost layer of the flow path, it becomes difficult to secure an engagement length of the screw that can maintain the strength of the screw fastening portion 21.

In this embodiment, the washing machine S is configured so that the screw hole portion 21a does not protrude into the outermost layer of the flow path, but instead has multiple long protrusions 23b on the fluid balancer 23 and multiple long grooves 20e (engagement portions) on the drum 20. The washing machine S is configured to fix the fluid balancer 23 and the drum 20 by screwing the protrusions 23b of the fluid balancer 23 into the grooves 20e (engagement portions) of the drum 20.

The washing machine S according to this embodiment is configured so that the screw hole 21a provided on the outer periphery 23sb of the fluid balancer 23 and the multiple long protrusions 23b of the fluid balancer 23 do not protrude into the outermost layer of the flow passage 53ra (cavity 23aa). In this washing machine S, the volume of the outermost layer of the flow passage 53ra (cavity 23aa), which has the greatest vibration reduction effect, is not reduced (i.e., it can be made relatively large). Therefore, the washing machine S can improve the vibration reduction effect of the fluid balancer 23. In addition, the washing machine S can firmly integrate the fluid balancer 23 and the drum 20, so that deformation of the drum 20 due to the centrifugal force of a large amount of cloth can be suppressed. In addition, the washing machine S can improve the rigidity of the drum 20 as a circular tube structure, making it easier to design a drum 20 with a larger diameter.

Therefore, the washing machine S according to this embodiment can achieve both high rigidity of the drum 20 for a larger capacity and improved vibration reduction effect of the fluid balancer 23.

As described above, the washing machine S according to the first embodiment can achieve both high rigidity of the drum 20 for a larger capacity and improved vibration reduction effect of the fluid balancer 23.

The present invention is not limited to the above-described embodiment, but includes various modified examples. For example, the above-described embodiment has been described in detail to explain the present invention in an easy-to-understand manner, and is not necessarily limited to having all of the configurations described. In addition, it is possible to replace part of the configuration of the embodiment with another configuration, and it is also possible to add another configuration to the configuration of the embodiment. In addition, it is possible to add, delete, or replace part of each configuration with another configuration.

<First Modification>
The configuration of the washing machine SA of the first modification will be described below with reference to Fig. 9 and Fig. 10. Fig. 9 is an explanatory diagram of the protrusion 23b1 of the fluid balancer 23c1 in the washing machine SA of the first modification. Fig. 10 is an explanatory diagram of the groove 20e1 of the drum 20c1 in the washing machine SA of the first modification.

As shown in FIG. 9, a plurality of elongated protrusions 23b1 are arranged at equal intervals on the outer peripheral portion 23sb on the rear side of the fluid balancer 23c1. The protrusions 23b1 of the fluid balancer 23c1 are arranged to extend toward the outer diameter side. The protrusions 23b1 of the fluid balancer 23c1 are configured to wrap around the outer peripheral portion 23sb on the rear side of the fluid balancer 23c1 several times by increasing the inclination angle of the protrusions 23b of the fluid balancer 23 shown in FIG. 6. The protrusions 23b1 of the fluid balancer 23c1 are arranged in a shape that imitates the helix of the threads of a male screw. The protrusions 23b1 of the fluid balancer 23c1 are arranged so as not to impair the volume of the cavity 23a inside the fluid balancer 23 shown in FIG. 7 (in the example shown in FIG. 9, the fluid balancer 23c1). In particular, when the fluid balancer 23 has a multi-layer structure as shown in FIG. 7, the protrusion 23b1 of the fluid balancer 23c1 is provided so as not to protrude into the cavity 23aa that constitutes the flow path 53ra of the outermost layer (outermost circumference). Such a fluid balancer 23c1 can prevent a decrease in the volume of the flow path 53ra (cavity 23aa) of the outermost layer, which has the greatest vibration reduction effect. The protrusion 23b1 of the fluid balancer 23c1 is formed so that its radial height is lower than the protrusion 23c. In other words, the protrusion 23c of the fluid balancer 23c1 is formed so that its radial height is higher than the protrusion 23b1.

As shown in FIG. 10, multiple long grooves 20e1 are arranged at equal intervals on the inner peripheral portion 20sa on the front side of the drum 20c1. The grooves 20e1 of the drum 20c1 are engagement portions that engage with the protrusions 23b1 of the fluid balancer 23c1. The grooves 20e1 of the drum 20c1 are provided so as to extend toward the outer periphery. The grooves 20e1 of the drum 20c1 are configured so as to wrap around the inner peripheral portion 20sa on the front side of the drum 20 multiple times by increasing the inclination angle of the grooves 20e of the drum 20 shown in FIG. 8. The grooves 20e1 of the drum 20c1 are arranged in a shape that imitates the helical threads of a female screw.

The protrusion 23b1 of the fluid balancer 23c1 and the groove 20e1 of the drum 20c1 are formed in a direction that tightens when the drum 20c1 rotates at high speed (during dehydration operation). In this embodiment, the protrusion 23b1 of the fluid balancer 23c1 and the groove 20e1 of the drum 20c1 are described as being formed in an oblique direction so as to rotate clockwise from the front side to the rear side.

The protrusion 23b1 of the resin fluid balancer 23c1 is screwed into the groove 20e1 of the stainless steel drum 20c1. In other words, the fluid balancer 23c1 is attached to the drum 20c1 by screwing it while rotating. The fluid balancer 23c1 is firmly integrated with the drum 20c1 by screwing the protrusion 23b1 into the groove 20e1 of the drum 20. The fluid balancer 23c1 can be screwed into the drum 20c1 while rotating until the protrusion 23c, which is formed with a radial height higher than the protrusion 23b1, abuts against the tip of the drum 20c1.

<Second Modification>
The configuration of the washing machine SB of the second modification will be described below with reference to Fig. 11 and Fig. 12. Fig. 11 is an explanatory diagram of the protrusion 23d of the fluid balancer 23c2 in the washing machine SB of the second modification. Fig. 12 is an explanatory diagram of the groove 24e of the drum 20c2 in the washing machine SB of the second modification.

As shown in FIG. 11, the outer peripheral portion 23sb on the rear side of the fluid balancer 23c2 has multiple elongated protrusions 23b arranged at equal intervals, similar to the fluid balancer 23 shown in FIG. 6.

In addition, multiple long protrusions 23d are arranged at equal intervals on the inner peripheral portion 23sa on the rear side of the fluid balancer 23c2. The protrusions 23d of the fluid balancer 23c2 are arranged to extend toward the inner diameter side. The multiple protrusions 23d are arranged to be inclined in an oblique direction with respect to the center line C. That is, the multiple protrusions 23d are arranged to be parallel to each other and oblique to the rotation axis. The protrusions 23d are arranged so as not to impair the volume of the cavity 23a inside the fluid balancer 23 shown in FIG. 7 (fluid balancer 23c2 in the example shown in FIG. 11). In particular, when multiple cavities 23a exist inside the fluid balancer 23 (fluid balancer 23c2 in the example shown in FIG. 11) as shown in FIG. 7, the protrusions 23b are arranged so as not to impair the volume of the inner cavity that becomes the innermost layer of the flow path.

As shown in FIG. 12, the inner peripheral portion 20sa on the front side of the drum 20c2 has a plurality of elongated grooves 20e arranged at equal intervals, similar to the drum 20 shown in FIG. 8.

As shown in FIG. 12, a reinforcing ring 24 is attached to the inner portion of the front side of the drum 20c2. The reinforcing ring 24 is a member for reinforcing the rigidity of the tip of the drum 20c2, which is deformed by the centrifugal force of a large amount of fabric. The reinforcing ring 24 is ring-shaped so that the outer periphery 24sb abuts against the inner periphery 23sa of the fluid balancer 23c2 (see FIG. 11).

Multiple elongated grooves 24e are arranged at equal intervals on the outer periphery 24sb of the reinforcing ring 24. The grooves 24e of the reinforcing ring 24 are engagement portions that engage with the protrusions 23d (see FIG. 11) of the fluid balancer 23c2. The grooves 20e of the drum 20c2 are provided so as to extend toward the inner diameter side. The grooves 24e of the reinforcing ring 24 are provided so as to be inclined in an oblique direction with respect to the center line C. In other words, the grooves 24e of the reinforcing ring 24 are arranged so as to be parallel to each other and inclined with respect to the rotation axis.

The protrusions 23b and 23d (see FIG. 11) of the resin fluid balancer 23c2 are screwed into the grooves 20e and 24e (see FIG. 12) of the stainless steel drum 20c2. In other words, the fluid balancer 23c2 is attached by being screwed into the drum 20c2 while rotating. The fluid balancer 23c2 is firmly integrated with the drum 20c2 by screwing the protrusions 23b and 23d (see FIG. 11) into the grooves 20e (see FIG. 12) of the drum 20c2. The fluid balancer 23c2 can be screwed into the drum 20c2 while rotating until the protrusions 23c (see FIG. 11), which are formed with a radial height higher than the protrusions 23b, come into contact with the tip of the drum 20c2.

<Third Modification>
Hereinafter, the configuration of the washing machine SC of the third modification will be described with reference to Fig. 13. Fig. 13 is an explanatory diagram of the protrusions 23b and 23c of the fluid balancer 23 in the washing machine SC of the third modification. As shown in Fig. 13, the fluid balancer 23 has a gap 25 between the protrusions 23b and 23c, and the radial height of the protrusions 23b can be increased toward the opposite side to the side that fits into the drum 20.

In the example shown in FIG. 13, a gap 25 is provided between the protrusions 23b and 23c. The reason for providing the gap 25 is that the engagement force between the protrusion 23b of the fluid balancer 23 and the groove 20e of the drum 20 can be improved by abutting the corner of the protrusion 23b against the inner periphery 20sa of the drum 20.

When this type of fluid balancer 23 is screwed in, the protrusions 23b push the drum 20 apart, causing the tip of the drum 20 to expand in the circumferential direction. Therefore, the more the fluid balancer 23 is screwed in, the more force is generated that shrinks the fluid balancer 23 in the circumferential direction, allowing the fluid balancer 23 and the drum 20 to be integrated even more firmly.

<Fourth Modification>
The washing machine S according to the embodiment described above may be structured such that the cross section perpendicular to the radial direction of the protrusion 23b of the fluid balancer 23 is non-rectangular, and the protrusion 23b of the fluid balancer 23 is screwed into the groove 20e of the drum 20. Hereinafter, with reference to FIG. 14, the configuration of the washing machine SD of the fourth modified example having such a structure will be described. FIG. 14 is an explanatory diagram of the protrusion 23b of the fluid balancer 23 in the washing machine SD of the fourth modified example. The protrusion 23b of the fluid balancer 23 is not rectangular in shape from the circumferential viewpoint, but is elliptical. That is, the protrusion 23b of the fluid balancer 23 is non-rectangular in shape in the cross section perpendicular to the radial direction. The protrusion 23b of the fluid balancer 23 may be hexagonal, rhombus, or the like.

When the protrusions 23b of the fluid balancer 23 are screwed in while pushing the grooves 20e of the drum 20 apart, the tip of the drum 20 expands in the circumferential direction. As a result, the more the fluid balancer 23 is screwed in, the more tension is generated that shrinks the fluid balancer 23 in the circumferential direction. As a result, the fluid balancer 23 and the drum 20 are fixed together even more firmly.

For example, as shown in FIG. 11, when the protrusions 23b, 23d are arranged on the outer periphery 23sb and the inner periphery 23sa of the fluid balancer 23c2, the protrusions 23b, 23d arranged on either or both of the outer periphery 23sb and the inner periphery 23sa can be configured so that the cross section perpendicular to the radial direction has a non-rectangular shape.

<Fifth Modification>
The washing machine S according to the embodiment described above may be structured such that the groove 20e of the drum 20 has a non-rectangular cross section perpendicular to the radial direction, and the protrusion 23b of the fluid balancer 23 is screwed into the groove 20e of the drum 20. Hereinafter, the configuration of the washing machine SE of the fifth modified example having such a structure will be described with reference to FIG. 15. FIG. 15 is an explanatory diagram of the groove 20e of the drum 20 in the washing machine SE of the fifth modified example. In the example shown in FIG. 15, the groove 20e of the inner periphery 20sa of the drum 20 is arranged in a shape that imitates the helical shape of the thread of a female screw, and is configured so that the interval between the grooves is narrow in the middle part. In other words, the groove 20e of the drum 20 has a non-rectangular cross section perpendicular to the radial direction.

When the protrusions 23b of the fluid balancer 23 are screwed in, they push open the narrow portion of the groove 20e of the drum 20, causing the tip of the drum 20 to expand in the circumferential direction. As a result, the more the fluid balancer 23 is screwed in, the more tension is generated that shrinks the fluid balancer 23 in the circumferential direction. As a result, the fluid balancer 23 and the drum 20 are fixed together even more firmly.

For example, as shown in FIG. 12, when grooves 20e, 24e (engagement portions) are arranged on the inner periphery 20sa of drum 20c2 and the outer periphery 24sb of reinforcing ring 24, grooves 20e, 24e (engagement portions) arranged on either or both of inner periphery 20sa and outer periphery 24sb can be configured so that the cross-sectional shape perpendicular to the radial direction is non-rectangular.

<Other matters>
(1) In the above embodiment, the fluid balancer 23 is formed in a plurality of layers (see FIG. 7). However, the present invention can also be applied to a fluid balancer 23 having a single layer.
(2) In the above embodiment, the washing machine S having a substantially horizontal rotation shaft is described (see FIG. 1). However, the present invention is also applicable to a vertical washing machine having a substantially vertical rotation shaft.
(3) The present invention is not limited to the configurations of the above-described embodiment and modified examples, and various modifications are possible.
(4) The present invention is not limited to being applied to drum-type washing machines, but can also be applied to vertical washing machines. In addition, the present invention can also be applied to drum-type or vertical washing/drying machines that have a drying function.

10 Outer tub 10S Washing tub 20, 20c1, 20c2 Drum (water tub)
20e, 20e1, 24e Groove (engagement portion)
20sa, 23sa Inner circumference 21 Screw fastening portion 21a Screw hole portion 23, 23c1, 23c2 Fluid balancer 23a, 23aa, 23ab Cavity 23b, 23b1, 23c, 23d Protrusion 23sb, 24sb Outer circumference 24 Reinforcing ring 25 Gap 51 Liquid 53 Circular pipe 53a Inner wall portion 53b Outer wall portion 53r, 53ra, 53rb Flow path S, SA, SB, SC, SD, SE Washing machine (drum type washing machine)

Claims (10)

An outer tub for washing water,
A water tub provided in the outer tub and capable of receiving laundry;
A cylindrical fluid balancer is disposed in the water tank and has a plurality of layers of flow paths in a radial direction in which a liquid capable of moving in a circumferential direction is sealed.
A plurality of elongated protrusions are arranged on an outer periphery of the fluid balancer,
A plurality of elongated engagement portions are disposed on the inner periphery of the water tank,
The washing machine, wherein the fluid balancer and the water tub are fixed to each other by screwing a protrusion of the fluid balancer into an engagement portion of the water tub. The washing machine according to claim 1,
The protrusion of the fluid balancer is arranged in a male thread shape,
The washing machine is characterized in that the engagement portion of the water tub is arranged in the form of a female screw. The washing machine according to claim 1,
The washing machine, wherein the protrusion of the fluid balancer has a radial height that is greater on an opposite side to the side where the fluid balancer is fitted into the water tub. The washing machine according to claim 1,
The washing machine, wherein the protrusion of the fluid balancer has a non-rectangular cross section perpendicular to the radial direction. The washing machine according to claim 1,
The washing machine is characterized in that the engaging portion of the water tub has a non-rectangular cross section perpendicular to the radial direction. An outer tub for washing water,
A water tub provided in the outer tub and capable of receiving laundry;
A fluid balancer having a cylindrical shape and including a plurality of layers of flow paths in a radial direction, the fluid balancer being disposed in the water tank and containing a liquid movable in a circumferential direction;
a reinforcing ring disposed in an inner portion of the water tank and formed in a ring shape such that an outer periphery of the reinforcing ring abuts against an inner periphery of the fluid balancer;
A plurality of elongated protrusions are arranged on the outer periphery and the inner periphery of the fluid balancer,
A plurality of elongated engagement portions are disposed on an inner periphery of the water tank and an outer periphery of the reinforcing ring,
The washing machine is characterized in that the fluid balancer and the water tub are fixed together by screwing a protrusion arranged on the outer periphery of the fluid balancer into an engagement portion arranged on the inner periphery of the water tub, and by screwing a protrusion arranged on the inner periphery of the fluid balancer into an engagement portion arranged on the outer periphery of the reinforcing ring. The washing machine according to claim 6,
The protrusions arranged on the outer periphery and the inner periphery of the fluid balancer are arranged in a male screw shape,
A washing machine characterized in that an engagement portion arranged on an inner periphery of the water tub and an engagement portion arranged on an outer periphery of the reinforcing ring are arranged in the form of a female screw. The washing machine according to claim 6,
The washing machine, wherein the protrusions arranged on the outer periphery of the fluid balancer have a radial height that increases toward the opposite side to the side that is fitted into the water tub. The washing machine according to claim 6,
A washing machine characterized in that the protrusions arranged on either or both of the outer circumferential portion and the inner circumferential portion of the fluid balancer have a non-rectangular cross-sectional shape perpendicular to the radial direction. The washing machine according to claim 6,
A washing machine characterized in that an engagement portion arranged on either or both of the inner periphery of the water tub and the outer periphery of the reinforcing ring has a non-rectangular cross-sectional shape perpendicular to the radial direction.

Images