Microbubble generator

Abstract

To efficiently generate fine bubbles while suppressing the lowering of a flow rate.SOLUTION: The fine bubble generator includes a main body portion having a flow path that connects an inlet portion and an outlet portion and through which a liquid can pass, and a colliding portion that generates fine bubbles in the liquid by reducing a cross-sectional area of the flow path, and the colliding portion is configured by a plurality of protruding portions that are formed so as to protrude from an inner peripheral surface of the main body portion toward the inside of the flow path, are provided at intervals along a circumferential direction of the main body portion, and have respective distal ends directly connected to each other.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a microbubble generator. [Background technology]

[0002] Conventionally, there has been known a micro-bubble generator that can generate micro-bubbles by locally reducing the cross-sectional area of ​​a flow path through which a liquid such as water flows, thereby rapidly reducing the pressure of the liquid passing through the flow path and causing dissolved air in the liquid to precipitate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-23936 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional configuration leaves room for improvement in terms of efficiently generating fine bubbles while suppressing a decrease in flow rate.

[0005] Therefore, a micro-bubble generator is provided that can efficiently generate micro-bubbles while suppressing a decrease in flow rate. [Means for solving the problem]

[0006] The micro-bubble generator of the embodiment comprises a main body portion having a flow path that connects an inlet portion and an outlet portion and allows a liquid to pass through, and a collision portion that generates micro-bubbles in the liquid by reducing the cross-sectional area of ​​the flow path, and the collision portion is composed of a plurality of protrusions that are formed to protrude from the inner surface of the main body portion toward the inside of the flow path and are arranged at intervals around the circumferential direction of the main body portion, and whose tips are directly connected to each other. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a longitudinal sectional side view schematically illustrating an example of a drum-type washing machine according to a first embodiment. [Figure 2] FIG. 1 is a partial cross-sectional view showing an example of a state in which the micro-bubble generator according to the first embodiment is incorporated into a water injection case. [Figure 3] FIG. 1 is a perspective view showing a state in which a flow path member is removed from the micro-bubble generator according to a first embodiment; [Figure 4] FIG. 1 is a view of the micro-bubble generator according to the first embodiment, viewed from the upstream side. [Figure 5] 5 is a cross-sectional view of the micro-bubble generator according to the first embodiment, taken along line X5-X5 in FIG. 4, with the flow path member removed. [Figure 6] FIG. 10 is a cross-sectional view showing another example of the collision portion according to the first embodiment. [Figure 7] FIG. 7 is an enlarged cross-sectional view of a portion of the micro-bubble generator according to the first embodiment taken along line X7-X7 in FIG. [Figure 8] FIG. 10 is a partial cross-sectional view showing another example of the state in which the micro-bubble generator according to the first embodiment is incorporated into the water injection case. [Figure 9] FIG. 7 is a cross-sectional view corresponding to FIG. 6, illustrating an example of a collision portion according to a second embodiment. [Figure 10] FIG. 10 is a cross-sectional view corresponding to FIG. 6 showing an example of a collision portion according to a third embodiment. [Figure 11] FIG. 10 is a cross-sectional view corresponding to FIG. 6, showing another example of the collision portion according to the third embodiment. [Figure 12] FIG. 10 is a cross-sectional view corresponding to FIG. 6 showing an example of a collision portion according to a fourth embodiment. [Figure 13] FIG. 10 is a partial cross-sectional view showing an example in which a fine bubble generator is provided upstream of a water supply valve in the fifth embodiment. [Figure 14] FIG. 13 is a longitudinal sectional side view schematically showing an example of a dishwasher according to a sixth embodiment. [Figure 15] FIG. 13 is a top view schematically illustrating an example of a flush toilet device according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, several embodiments will be described with reference to the drawings. Elements that are substantially the same in each embodiment will be given the same reference numerals, and descriptions thereof will be omitted. Furthermore, in each embodiment, the terms "first," "second," etc., attached to components, etc., are used merely to distinguish between similar components, and do not indicate superiority or inferiority among the components or a time element.

[0009] (First embodiment) First, a first embodiment will be described with reference to FIGS. 1 to 8 , illustrating an example in which a fine-bubble generator is applied to a washing machine as a cleaning device. The washing machine 10 shown in FIG. 1 is a drum-type washing machine, either a horizontal-axis type in which the rotation axis of the rotating tub 14 is horizontal, or an inclined-axis type in which the rotation axis of the rotating tub is tilted downward toward the rear. The washing machine is not limited to a drum-type washing machine, but may also be a vertical-axis type washing machine in which the rotation axis of the rotating tub is vertical. The washing machine 10 may or may not have a drying function, such as a heater or heat pump. The washing machine 10 may also be equipped with an automatic treatment agent dispenser that can automatically dispense laundry treatment agents such as detergent and finishing agent. The automatic treatment agent dispenser has a treatment agent tank that can store an amount of laundry treatment agent used for multiple wash cycles, and can automatically dispense a predetermined amount of laundry treatment agent from the treatment agent tank into the water tub for each wash cycle.

[0010] Washing machine 10 includes an outer casing 11, a door 12, a water tub 13, a rotating tub 14, a motor 15, a drainage mechanism 16, and a water injection device 20. Washing machine 10 also includes a well-known operation panel and control devices, etc., although details are not shown. In FIG. 1, the side of washing machine 10 on which washing machine 10 is installed, i.e., the vertically lower side, is referred to as the lower side of washing machine 10, and the side opposite the installation surface, i.e., the vertically upper side, is referred to as the upper side of washing machine 10. Furthermore, the left side of FIG. 1, i.e., the side of door 12 relative to outer casing 11, is referred to as the front side of washing machine 10, and the right side of FIG. 1, i.e., the side opposite door 12 relative to outer casing 11, is referred to as the rear side of washing machine 10.

[0011] Outer box 11 is formed into a rectangular hollow box shape as a whole by combining metals such as stainless steel plates and resin materials, for example. Outer box 11 forms the outer shell of washing machine 10. Outer box 11 also has opening 111 on the front side that connects the inside and outside of outer box 11. Door 12 is provided on the front side of outer box 11 and opens and closes opening 111. With door 12 open, a user can put clothes in or take clothes out of spin tub 14 through opening 111.

[0012] Both water tub 13 and rotatable tub 14 are cylindrical with a bottom. Water tub 13 can store water therein. Water tub 13 is disposed within outer casing 11 and is elastically supported by a suspension (not shown). Rotatable tub 14 is disposed rotatably within water tub 13 and is driven to rotate by motor 15. Motor 15 is provided on the outside of the bottom of water tub 13 and functions to drive and rotate rotatable tub 14 relative to water tub 13.

[0013] Drain mechanism 16 is for draining water in water tub 13 to the outside of washing machine 10. Drain mechanism 16 can be configured to have drain valve 161 and drain hose 162. Drain valve 161 is configured to be able to open and close electromagnetically. One end of drain hose 162 is connected to drain valve 161, and the other end is drawn out to the outside of washing machine 10. When drain valve 161 is opened while water is stored in water tub 13, the water stored in water tub 13 is drained to the outside of washing machine 10 through drain hose 162. In other words, drain valve 161 opens and closes a drain path for draining water stored in water tub 13 to the outside.

[0014] The water injection device 20 is used to inject water supplied from an external water source, such as a water tap, into the water tank 13. The water injection device 20 has a water supply valve 21, a water injection case 22, a water injection hose 23, and a micro-bubble generator 30. The water supply valve 21 is configured to be electromagnetically openable and closable. The water supply valve 21 opens and closes a path leading from the external water source to the water tank 13 via the water injection case 22. As shown in FIG. 2 , the water supply valve 21 has an inlet 211 and an outlet 212. The inlet 211 is connected to an external water source, such as a water faucet (not shown), via a water supply hose 100. The outlet 212 is connected to, for example, the water injection case 22.

[0015] Water injection case 22 has the function of receiving water supplied from an external water source and supplying the water into water tub 13 via water injection hose 23. Water injection case 22 is made of, for example, synthetic resin, and can be formed in a long box shape along the front-to-rear direction of washing machine 10. Water injection case 22 is configured to be able to store laundry treatment agents such as detergent and fabric softener inside. As shown in FIG. 2, water injection case 22 has connection part 221 and communication part 222. Connection part 221 and communication part 222 communicate between the inside and outside of water injection case 22. Connection part 221 is formed in, for example, a cylindrical shape with a step on its inner circumferential surface.

[0016] Connection part 221 connects water supply valve 21 and water injection case 22. Water that passes through water supply valve 21 flows into water injection case 22 through connection part 221. As shown in FIG. 2, outlet part 212 of water supply valve 21 is directly connected to connection part 221. Direct connection means that no other components are interposed between the components that are connected to each other. A seal member 24 is provided between the outer peripheral surface of outlet part 212 and the inner peripheral surface of connection part 221. Seal member 24 is formed, for example, by an O-ring made of synthetic resin. The seal member 24 is pressed by the outer peripheral surface of outlet part 212 and the inner peripheral surface of connection part 221, connecting outlet part 212 and connection part 221 in a watertight state.

[0017] The communicating portion 222 is formed, for example, in a cylindrical shape with a substantially constant inner diameter. The inner diameter of the communicating portion 222 is smaller than the inner diameter of the connecting portion 221, for example. The communicating portion 222 is located downstream of the connecting portion 221. In other words, the connecting portion 221 is located upstream of the communicating portion 222. The downstream side means the downstream side in the direction in which water supplied from an external water source flows. The upstream side means the upstream side in the direction in which water supplied from an external water source flows.

[0018] Water injection hose 23 is used to inject water that has flowed into water injection case 22 from an external water source into water tub 13. As shown in FIG. 1 , one end of water injection hose 23 is connected to water injection case 22, and the other end is connected to water tub 13. When water flows into water injection case 22 with a laundry treatment agent stored in water injection case 22, the laundry treatment agent in water injection case 22 mixes with the water flowing inside water injection case 22, and then passes through water injection hose 23 and flows into water tub 13.

[0019] The fine-bubble generator 30 has the function of generating fine bubbles, including ultrafine bubbles, in a liquid such as water supplied from an external water source as the liquid passes through the fine-bubble generator 30 in the direction of arrow A in Figure 2. Ultrafine bubbles are bubbles with a particle diameter of 50 nm to less than 1,000 nm. Because of their small particle size, ultrafine bubbles can penetrate into intricate areas and provide a cleaning effect that removes dirt from objects that cannot be removed by other fine bubbles such as microbubbles. Furthermore, ultrafine bubbles have the properties of having nano-order particle diameters, low buoyancy, and high hydrophobicity, which makes them difficult to dissolve in water, resulting in a long residence time in liquid.

[0020] The micro-bubble generator 30 is provided downstream of the water supply valve 21 and inside the water injection case 22. As shown in FIG. 2 , the micro-bubble generator 30 is attached in a state in which it is supported between the outflow portion 212 and the connection portion 221. The micro-bubble generator 30 is attached, for example, in a state in which it is sandwiched between the outflow portion 212 and the connection portion 221. A seal member 25 is provided between the outer peripheral surface of the micro-bubble generator 30 and the inner peripheral surface of the connection portion 221. The seal member 25 is formed, for example, by an O-ring made of synthetic resin. The seal member 25 is pressed by the outer peripheral surface of the micro-bubble generator 30 and the inner peripheral surface of the connection portion 221, thereby connecting the micro-bubble generator 30 and the connection portion 221 in a watertight state. The micro-bubble generator 30 may also be configured to be fixed to the outflow portion 212 and the connection portion 221 by press-fitting.

[0021] The micro-bubble generator 30 is made of, for example, synthetic resin, and has a diameter and overall length of, for example, several mm to several tens of mm, specifically, a maximum diameter of approximately 15 mm and a length of approximately 10 mm. As shown in FIG. 2, the micro-bubble generator 30 is formed, for example, in a cylindrical shape with a flange. The micro-bubble generator 30 has a main body 40, a flow path member 50, and a collision section 60. The main body 40 is located on the upstream side of the micro-bubble generator 30, and the flow path member 50 is located on the downstream side of the micro-bubble generator 30. The main body 40 and the flow path member 50 are configured to be separate from each other and can be combined with each other. The main body 40 and the flow path member 50 are not limited to being separate bodies, but may also be configured as an integrated body.

[0022] As shown in Figures 2 and 3, the main body 40 is formed, for example, in a cylindrical shape with a step on the outer circumferential surface. The main body 40 has an inlet 41, an outlet 42, and a flow path 43. The inlet 41 and the outlet 42 are formed, for example, in a cylindrical shape. The inlet 41 is a portion through which water flows from the outside of the main body 40 into the inside. Water that passes through the water supply valve 21 from an external water source is introduced into the main body 40 through the inlet 41. The outlet 42 is a portion through which water flows out from the inside of the main body 40 to the outside. The inner diameter of the outlet 42 is smaller than the inner diameter of the inlet.

[0023] Outlet portion 42 is connected to flow path member 50. Water introduced into main body 40 flows from outlet portion 42 through flow path member 50 into water inlet case 22, then merges with the laundry treatment agent inside water inlet case 22, and is supplied into water tub 13. Outlet portion 42 is formed, for example, in a cylindrical shape with a constant inner diameter. The inner diameter of outlet portion 42 is set to be approximately the same as the inner diameter of communication portion 222 of water inlet case 22. In this embodiment, the inner diameter of outlet portion 42 is set to be approximately 3 mm.

[0024] The flow path 43 is provided inside the main body 40, connects the inlet 41 and the outlet 42, and allows liquid to pass through. As shown in FIGS. 4 and 5 , the flow path 43 includes an upstream throttle section 431, a straight section 432, and a downstream throttle section 433. The upstream throttle section 431, the straight section 432, and the downstream throttle section 433 are provided around the entire inner circumferential surface of the main body 40. The upstream throttle section 431 is provided on the inlet side, i.e., the upstream side, of the main body 40. The upstream throttle section 431 is connected to the inlet 41 and is provided between the inlet 41 and the outlet 42. The upstream throttle section 431 is formed so that the cross-sectional area, i.e., the inner diameter, of the flow path 43 gradually decreases from the inlet 41 to a midpoint in the extension direction of the main body 40. In this embodiment, the upstream tapered section 431 is formed in a tapered pipe shape, so-called a truncated cone, in which the cross-sectional area of ​​the flow path 43, i.e., the inner diameter, gradually decreases continuously. The upstream tapered section 431 may also be configured to gradually decrease the cross-sectional area of ​​the flow path 43 in a stepped manner. Furthermore, the upstream tapered section 431 may be configured integrally with the main body 40 or may be a separate body.

[0025] The straight section 432 is provided downstream of the upstream-side tapered section 431. The straight section 432 is formed in a cylindrical shape, a so-called straight pipe shape, in which the inner diameter does not change, i.e., the cross-sectional area of ​​the flow path 43, i.e., the area through which the liquid can pass, does not change. The inner diameter of the straight section 432 is set to be approximately the same as the minimum inner diameter of the upstream-side tapered section 431.

[0026] The downstream tapered section 433 is provided on the outflow side, i.e., downstream side, of the main body 40. The downstream tapered section 433 is provided between the straight section 432 and the outlet section 42 and is connected to the outlet section 42. The downstream tapered section 433 is provided closer to the outlet section 42 than the upstream tapered section 431. In other words, the upstream tapered section 431 is provided closer to the inlet section 41 than the downstream tapered section 433. The downstream tapered section 433 is formed so that the cross-sectional area, i.e., the inner diameter, of the flow path 43 gradually decreases from the straight section 432 to a midpoint in the extension direction of the main body 40. In this embodiment, the downstream tapered section 433 is formed in a tapered pipe shape, a so-called truncated cone shape, in which the cross-sectional area, i.e., the inner diameter of the flow path 43, gradually decreases continuously. The downstream tapered section 433 may also be configured so that the cross-sectional area of ​​the flow path 43 gradually decreases in a stepped manner. Furthermore, the downstream tapered portion 433 may be configured integrally with the main body portion 40 or may be a separate body.

[0027] The cross-sectional area of ​​the flow path 43 is narrowed in stages by the upstream-side narrowed section 431 and the downstream-side narrowed section 433. The flow of the liquid, which becomes turbulent when passing through the upstream-side narrowed section 431, is rectified by the straight section 432, and then the cross-sectional area of ​​the flow path is narrowed further by the downstream-side narrowed section 433, thereby stabilizing the flow of the liquid and increasing the flow rate. The lengths Lu and Ld of the upstream-side narrowed section 431 and the downstream-side narrowed section 433 can be set to be the same or different. In this embodiment, the length Lu of the upstream-side narrowed section 431 is set to be longer than the length Ld of the downstream-side narrowed section 433.

[0028] Furthermore, the inclination angles θu and θd of the upstream throttle section 431 and the downstream throttle section 433 relative to the horizontal can be set to the same or different angles. The inclination angles θu and θd can be set, for example, in the range of 10° to 30°. In this embodiment, the inclination angle θu of the upstream throttle section 431 relative to the horizontal and the inclination angle θd of the downstream throttle section 433 relative to the horizontal are set to the same angle. When the inclination angles θu and θd are set to different angles, it is preferable to set the inclination angle θd larger than the inclination angle θu. This suppresses an increase in flow velocity in the upstream throttle section 431, thereby suppressing pressure loss.

[0029] As shown in FIG. 2 , the flow path member 50 is formed, for example, in a cylindrical shape with a step on its inner circumferential surface, and has a flow path 51 therein. The overall length of the flow path member 50 is, for example, longer than the overall length of the main body 40. The flow path member 50 communicates between the main body 40 and the communication portion 222 of the water injection case 22. The inner diameter of the upstream portion of the flow path member 50 is slightly larger than the outer diameter of the downstream portion of the main body 40. The downstream portion of the main body 40 is configured to be insertable into the upstream portion of the flow path member 50 in a substantially fitted state. The main body 40 and the flow path member 50 can be combined by inserting the downstream portion of the main body 40 into the upstream portion of the flow path member 50. The inner diameter of the downstream portion of the flow path member 50 is set to be substantially the same as the inner diameter of the communication portion 222 and the inner diameter of the outlet portion 42.

[0030] The collision portion 60 is intended to generate microscopic bubbles in the liquid passing through the flow path 43 by locally reducing the cross-sectional area of ​​the flow path 43. The ratio of the cross-sectional area of ​​the collision portion 60 to the cross-sectional area of ​​the flow path 43 can be set to approximately 25% to 45%. As shown in FIGS. 3 and 5 , the collision portion 60 is provided near the downstream end of the main body portion 40, with at least a portion of it being in the downstream tapered portion 433. In this embodiment, the collision portion 60 is provided in the outlet portion 42 and a portion of the downstream tapered portion 433. The collision portion 60 is formed integrally with the main body portion 40, for example, by injection molding a synthetic resin material. The collision portion 60 need not necessarily be formed integrally with the main body portion 40, but may also be formed separately.

[0031] As shown in FIG. 4, the collision section 60 divides the flow path 43 into a plurality of sections (in this case, three sections) in the radial direction with respect to the center of the flow path 43 along the direction in which the liquid flows. In other words, the flow path 43 is divided into three flow paths 43a when passing through the collision section 60. As shown in FIGS. 4 and 5, the collision section 60 is composed of, for example, three rod-shaped protrusions 61, which protrude from the inner circumferential surfaces of the downstream tapered section 433 and the outlet section 42 toward the inside of the flow path 43. In this embodiment, the protrusions 61 protrude from the inner circumferential surfaces of the downstream tapered section 433 and the outlet section 42 toward the center of the cross section of the flow path 43. The protrusions 61 are connected at their tips to form a generally Y-shape.

[0032] The multiple protrusions 61 are arranged at equal intervals in the circumferential direction of the cross section of the flow path 43. The multiple protrusions 61 are not limited to being spaced at equal intervals, but may be spaced at uneven intervals. The area of ​​the gap formed between each protrusion 61 is the minimum cross-sectional area through which water can pass in the micro-bubble generator 30. The multiple protrusions 61 may be four or more, as shown in FIG. 6. That is, the multiple protrusions 61 may divide the flow path 43 into four or more sections. In the example of FIG. 6, the multiple protrusions 61 form the collision section 60 in, for example, a substantially cross shape as a whole. In this case, the flow path 43 is divided into four flow paths 43b when passing through the collision section 60.

[0033] As shown in FIG. 7 , the protrusion 61 has an upstream wall 611, an expanded diameter portion 612, and a downstream wall 613. The upstream wall 611 forms the upstream end of the protrusion 61. The longitudinal cross-sectional shape of the upstream wall 611 is formed, for example, in a so-called bullet-shaped curved surface that is convex in the opposite direction to the direction of liquid flow in the flow path 43, i.e., toward the upstream side. The longitudinal direction refers to the direction along the direction of liquid flow in the flow path 43. The width direction refers to the direction perpendicular to the direction along the direction of liquid flow in the flow path 43, and is the direction along the up-down direction of the washing machine 10 when the fine-bubble generator 30 is attached to the washing machine 10.

[0034] The cross-sectional shape of the upstream wall portion 611 in the longitudinal direction may be a triangle that is pointed toward the upstream side. The expanded diameter portion 612 is connected to the upstream wall portion 611 and is formed so as to expand in a substantially linear manner from the upstream side to the downstream side. The expanded diameter portion 612 is not limited to a configuration in which the diameter expands in a linear manner, and may also be a configuration in which the diameter expands in a curved manner. In other words, the cross-sectional shape of the protruding portion 61 is smaller on the upstream side in the direction in which the liquid flows in the flow channel 43 than on the downstream side. The cross-sectional shape of the protruding portion 61 in the longitudinal direction changes smoothly in the direction in which the liquid flows in the flow channel 43.

[0035] The downstream wall 613 is connected to the expanded diameter portion 612 and constitutes the downstream end of the protrusion 61. The longitudinal cross-sectional shape of the downstream wall 613 is, for example, substantially rectangular. The downstream end face of the downstream wall 613 is located on the same plane as the downstream end face of the main body 40. The downstream face of the protrusion 61 is configured to be flush with the downstream face of the main body 40. Furthermore, considering only the shape of the downstream end of the protrusion 61, the longitudinal dimension of the downstream wall 613 is smaller than the width dimension of the downstream wall 613. Furthermore, the longitudinal dimension of the downstream wall 613 is set to be substantially the same as the longitudinal dimension of the outlet 42. Therefore, the inner diameter of the gap formed between the outlet 42 and the downstream wall 613 is constant.

[0036] Here, if the longitudinal dimension L of the protrusion 61 is smaller than the widthwise dimension W in the cross section of the protrusion 61, the angle of the surface at which the expanded diameter portion 612 faces the liquid flowing through the flow path 43 becomes large, and the flow resistance of the protrusion 61 to the liquid flowing through the flow path 43 increases, which may result in a decrease in flow rate. Therefore, in this embodiment, as shown in FIG. 7 , the longitudinal dimension L of the protrusion 61 is larger than the widthwise dimension W in the cross section of the protrusion 61. This reduces the flow resistance of the protrusion 61 to the liquid flowing through the flow path 43, thereby increasing the flow rate. In this embodiment, the ratio of the longitudinal dimension L to the widthwise dimension W of the protrusion 61 is set to, for example, approximately 3:2. The longitudinal dimension L of the protrusion 61 is set to, for example, approximately 0.7 mm to 1.1 mm, and the widthwise dimension W of the protrusion 61 is set to, for example, approximately 0.5 mm to 0.7 mm.

[0037] When water flows into the upstream side of the fine-bubble generator 30, the cross-sectional area of ​​the flow path is narrowed at the upstream throttle section 431, which is formed so as to gradually reduce the inner diameter. This narrows the flow path, increasing the flow velocity based on the so-called Bernoulli's principle of fluid dynamics, and cavitation occurs due to reduced pressure. The water flow is then rectified by the straight section 432, and then the flow velocity is further increased by the downstream throttle section 433. When the high-speed water collides with the collision section 60, shear force acts on the water, and negative pressure, for example, -1.0 MPa or less, is generated in the negative pressure region formed near the downstream end face of the collision section 60, generating fine bubbles. As a result, the fine-bubble generator 30 precipitates a large amount of air dissolved in the water passing through the fine-bubble generator 30 as fine bubbles, thereby enabling the supply of fine-bubble water containing a larger amount of fine bubbles than before passing through the fine-bubble generator 30.

[0038] According to the embodiment described above, the micro-bubble generator 30 comprises a main body 40 and a collision section 60. The main body 40 has a flow path 43 that connects an inlet 41 and an outlet 42 and allows liquid to pass through. The collision section 60 generates micro-bubbles in the liquid by reducing the cross-sectional area of ​​the flow path 43. The main body 40 has a downstream throttle section 433. The downstream throttle section 433 is provided so as to be connected to the outlet 42, and gradually reduces the cross-sectional area of ​​the flow path 43. The collision section 60 is provided in the downstream throttle section 433.

[0039] According to this, the flow velocity of the liquid can be effectively increased by narrowing the flow path 43 with the downstream narrowed section 433 and the collision section 60. Then, by increasing the flow velocity of the liquid flowing through the flow path 43 near the outlet section 42, fine bubbles can be efficiently generated. Furthermore, by passing the liquid in a stable flow state through the downstream narrowed section 433 and bringing it into contact with the collision section 60, pressure loss can be reduced, and a decrease in the flow rate can be suppressed.

[0040] The main body 40 further has an upstream throttle section 431. The upstream throttle section 431 is provided closer to the inlet 41 than the downstream throttle section 433, and gradually reduces the cross-sectional area of ​​the flow path 43. This increases the flow rate of the liquid flowing through the flow path 43 through the multiple stages of the upstream throttle section 431 and the downstream throttle section 433, thereby improving the pressure reduction effect on the liquid and increasing the amount of fine bubbles generated.

[0041] Furthermore, the downstream throttle section 433 is provided around the entire inner circumferential surface of the main body 40. This allows the cross-sectional area of ​​the flow path 43 to be continuously throttled, thereby efficiently increasing the flow rate of the liquid flowing through the flow path 43. This increases the amount of microbubbles generated.

[0042] The collision section 60 is composed of a plurality of protrusions 61. The plurality of protrusions 61 are formed to protrude from the inner circumferential surface of the main body 40 toward the inside of the flow path 43, and are provided at approximately equal intervals in the circumferential direction of the inner circumferential surface of the main body 40. The plurality of protrusions 61 are connected within the flow path 43. This allows the plurality of protrusions 61 to be connected and linked together within the flow path, thereby increasing the strength of the collision section 60. This improves the reliability of the micro-bubble generator 30. Furthermore, by connecting the plurality of protrusions 61 within the flow path 43, the flow path 43 can be divided into a plurality of parts. This increases the flow rate of the liquid in the divided flow paths 43. This therefore increases the amount of micro-bubbles generated.

[0043] As shown in FIG. 8, the micro-bubble generator 30 may be configured without the flow path member 50. In this case, the micro-bubble generator 30 is configured by a main body 40 and a collision section 60. The main body 40 is connected to the communication section 222 of the water injection case 22. In other words, the main body 40 is directly connected to the water injection case 22. In the example of FIG. 8, water introduced into the main body 40 flows out from the outlet section 42 into the water injection case 22, then merges with the laundry treatment agent inside the water injection case 22 and is supplied to the water tub 13. This reduces the number of parts in the micro-bubble generator 30, thereby reducing the assembly man-hours. As a result, the manufacturing cost of the water injection device 20 incorporating the micro-bubble generator 30 can be reduced.

[0044] (Second embodiment) Next, a second embodiment will be described with reference to FIG. 9. The second embodiment differs from the first embodiment in the configuration of the collision portion 60. The second embodiment includes a protrusion 62 instead of the protrusion 61 of the first embodiment. Specifically, while the tips of the multiple protrusions 61 are connected in the first embodiment, the multiple protrusions 62 of this embodiment each have a cone-shaped end at the tip, and are not connected but are independent. Therefore, in this embodiment, the flow path 43 is not partitioned by the multiple protrusions 62.

[0045] The protruding portion 62 can be configured with a cross-sectional shape similar to that of the protruding portion 61. The protruding portion 62 has an upstream wall portion 621, an expanded diameter portion 622, and a downstream wall portion 623. The cross-sectional shapes of the upstream wall portion 621, the expanded diameter portion 622, and the downstream wall portion 623 of the protruding portion 62 are similar to those of the upstream wall portion 611, the expanded diameter portion 612, and the downstream wall portion 613 of the protruding portion 61, respectively, and therefore will not be described again.

[0046] The second embodiment also achieves the same effects as the first embodiment. Furthermore, since the multiple protrusions 62 are not connected to each other within the flow path 43, the proportion of the cross-sectional area of ​​the collision portion 60 in the internal cross-sectional area of ​​the main body 40 can be reduced, thereby ensuring the cross-sectional area of ​​the flow path 43. This makes it possible to ensure the flow rate.

[0047] (Third embodiment) Next, a third embodiment will be described with reference to Figures 10 and 11. This third embodiment differs from the first embodiment in that the fine-bubble generator 30 includes a collision section 71 instead of the collision section 60 of the first embodiment. Specifically, whereas the collision section 60 of the first embodiment is made up of multiple protrusions 61, the collision section 71 of this embodiment is made up of a single member. In other words, whereas the collision section 60 is made up of three protrusions 61, the collision section 71 of this embodiment is made up of two protrusions.

[0048] The collision section 71 is formed of, for example, a plate-like or rod-like member, and is provided so as to cross the flow path 43. In other words, the flow path 43 is divided into two flow paths 43c when passing through the collision section 60. In this embodiment, the collision section 71 extends linearly from one point on the inner circumferential surface of the downstream tapered section 433 and the outlet section 42, through the center of the cross section of the downstream tapered section 433 and the outlet section 42, i.e., the center of the flow path 43, to another point on the inner circumferential surface of the downstream tapered section 433 and the outlet section 42, in this case, the opposite surface. Therefore, the cross-sectional areas of the flow paths 43c divided by the collision section 71 are approximately equal and are the minimum cross-sectional areas through which the liquid in the micro-bubble generator 30 can pass.

[0049] The collision portion 71 can be configured with a cross-sectional shape similar to that of the protrusion 61. The collision portion 71 has an upstream wall portion 711, an expanded diameter portion 712, and a downstream wall portion 713. The cross-sectional shapes of the upstream wall portion 711, the expanded diameter portion 712, and the downstream wall portion 713 of the collision portion 71 are similar to those of the upstream wall portion 611, the expanded diameter portion 612, and the downstream wall portion 613 of the protrusion 61, respectively, and therefore will not be described here. As shown in FIG. 10 , the collision portion 71 is provided, for example, substantially horizontally with respect to the installation surface of the washing machine 10. The collision portion 71 is not limited to being substantially horizontal with respect to the installation surface of the washing machine 10, but may be inclined with respect to the horizontal or substantially vertical. The collision portion 71 is not limited to being configured to pass through the center of the flow path 43, but may be configured to cross the flow path 43 without passing through the center of the flow path 43. The collision portion 71 is not limited to being configured to extend linearly, but may be configured to extend in other shapes, such as a curved or bent shape.

[0050] The third embodiment can also achieve the same effects as the above-described embodiments. Furthermore, by minimizing the number of flow paths 43 separated by the collision section 71, the cross-sectional area of ​​the flow paths 43 can be secured, thereby preventing a decrease in flow rate. Furthermore, by having the collision section 71 bridge the inner circumferential surface of the downstream tapered section 433 and the outlet section 42, the strength of the vicinity of the outlet section 42 against external forces can be increased. This improves the reliability of the micro-bubble generator 30.

[0051] 11, a plurality of collision sections 71 may be provided at intervals in the downstream narrowed section 433 and the outlet section 42. In the example of FIG. 11, two collision sections 71 are provided. The number of collision sections 71 is not limited to two, and three or more collision sections 71 may be provided. In this case, the flow path 43 is divided into three or more flow paths 43c by the plurality of collision sections 71. By providing a plurality of collision sections 71, the strength against external forces in the vicinity of the outlet section 42 can be further increased.

[0052] (Fourth embodiment) Next, a fourth embodiment will be described with reference to FIG. 12 . This fourth embodiment differs from the third embodiment in that the fine-bubble generator 30 includes a collision section 72 instead of the collision section 71 of the third embodiment. The cross-sectional shape of the collision section 72 can be configured similarly to that of the collision section 71. The collision section 72 of this embodiment has multiple main body sections 721 and an annular section 722. The main body section 721 is formed, for example, from a plate-shaped or rod-shaped member, and is formed to protrude into the flow path 43 from the inner circumferential surfaces of the downstream tapered section 433 and the outlet section 42. The multiple main body sections 721 are arranged, for example, symmetrically with respect to the center of the flow path 43. The multiple main body sections 721 may also be asymmetric with respect to the center of the flow path 43.

[0053] The annular portion 722 is formed, for example, in a circular ring shape, and is provided between a plurality of main body portions 721. In this embodiment, the center of the annular portion 722 coincides with the center of the flow path 43. The annular portion 722 has a through hole 723. The through hole 723 is provided at the center of the annular portion 722 and is formed by penetrating the collision portion 72 in the thickness direction. In this configuration, the flow path 43 is partitioned into two flow paths 43d and one circular flow path 43e when passing through the collision portion 72. The cross-sectional area of ​​the flow path 43e is set smaller than the cross-sectional area of ​​the flow path 43d.

[0054] 12, the downstream throttle sections 433 are provided at two locations by cutting out a portion of the inner circumferential surface of the main body 40 in the circumferential direction. In this case, the portion of the inner circumferential surface of the main body 40 where the downstream throttle sections 433 are not provided is formed so as to connect the straight section 432 and the outlet section 42. As a result, by providing the downstream throttle sections 433 in a region of the inner circumferential surface of the main body 40 corresponding to the collision section 72, the liquid whose flow rate has been increased can be effectively brought into contact with the downstream throttle sections 433, while ensuring a large cross-sectional area of ​​the flow path 43 in the portion where the downstream throttle sections 433 are not present, it is possible to simultaneously generate fine bubbles and ensure a sufficient flow rate.

[0055] The fourth embodiment can also achieve the same effects as the above-described embodiments. Here, by providing the through-holes 723 in the collision portion 72, the flow path resistance tends to be reduced. Therefore, according to this embodiment, the flow rate can be increased.

[0056] Furthermore, in this embodiment, the through-hole 723 is provided in the center of the flow path 43. The center of the flow path 43 is where the flow velocity is fastest within the flow path 43. Therefore, by providing the through-hole 723 in the center of the flow path 43, the flow velocity of the liquid can be effectively increased. This is expected to increase the amount of microbubbles generated.

[0057] (Fifth embodiment) A fifth embodiment will be described with reference to FIG. 13 . In this fifth embodiment, the installation position of the fine-bubble generator 30 in the washing machine 10 differs from that of the above-described embodiments. Specifically, whereas the fine-bubble generator 30 in the above-described embodiments is provided downstream of the water supply valve 21, the fine-bubble generator 30 in this embodiment is provided upstream of the water supply valve 21. In this embodiment, the water injection device 20 has a cylindrical member 26. The cylindrical member 26 is formed, for example, in a cylindrical shape with a step on its outer circumferential surface. As shown in FIG. 13 , one end of the cylindrical member 26 is connected to the inlet 211 of the water supply valve 21, and the other end is connected to the water supply hose 100. The cylindrical member 26 is detachably attached to the inlet 211 and the water supply hose 100 by, for example, threaded engagement. In this case, the threaded portion formed in the inlet 211 can be positioned above the upper surface 112 of the outer casing 11.

[0058] In this embodiment, the fine-bubble generator 30 is built into the cylindrical member 26. The fine-bubble generator 30 is composed of a main body 40 and a collision portion 60. When the water supply valve 21 is opened, water flows from an external water source into the cylindrical member 26 through the water supply hose 100, passes through the cylindrical member 26, passes through the fine-bubble generator 30, and then flows into the water supply valve 21. This fifth embodiment also provides the same effects as the above-described embodiments. Furthermore, for example, by attaching the cylindrical member 26 between the water supply valve 21 and the water supply hose 100 to an existing washing machine that does not have a fine-bubble generator 30, a fine-bubble generation function can be added to the existing washing machine. Furthermore, for example, if the fine-bubble generator 30 malfunctions, the cylindrical member 26 can be removed from the water supply valve 21 and the water supply hose 100, and the malfunction of the fine-bubble generator 30 can be easily addressed by replacing the part.

[0059] Furthermore, when the fine-bubble generator 30 is provided upstream of the water supply valve 21 as in the fifth embodiment, it is not possible to compensate for the reduction in flow rate caused by the fine-bubble generator 30 by branching the downstream side of the water supply valve 21, which is possible when the fine-bubble generator 30 is provided downstream, and the water supply rate to the washing machine 10 is determined solely by the flow rate of the fine-bubble generator 30. Therefore, the fine-bubble generator 30 of the present invention, which can increase the water supply rate compared to conventional fine-bubble generators, can fully demonstrate its effects in the fifth embodiment as well.

[0060] (Sixth embodiment) Next, a sixth embodiment will be described with reference to FIG. 14 . In this sixth embodiment, the dishwasher 80 is applied to a dishwasher 80 as a washing device. As is well known, the dishwasher 80 includes an outer case 81, a door 82, a washing tub 83, a dish basket 84, a washing nozzle 85, a circulation device 86, a heater 87, and a water supply mechanism 88. The outer case 81 constitutes the outer shell of the dishwasher 80 and is formed, for example, from a stainless steel plate into a rectangular box shape with an opening at the front. The door 82 is provided on the front side of the outer case 81 and opens and closes the opening of the outer case 81. With the door 82 open, a user can place or remove dishes D in or from the washing tub 83 through the opening. The washing tub 83 is provided within the outer case 81 and is formed, for example, from a stainless steel plate into a rectangular box shape with an opening at the front. The dish basket 84 is for storing dishes D. The dish basket 84 is configured to allow access between the inside and outside of the washing tub 83 when the door 82 is open.

[0061] The washing nozzle 85 is provided in the washing tub 83 below the dish basket 84. When a washing liquid, which is a mixture of water and a detergent, is supplied to the washing nozzle 85, the washing liquid is sprayed from the tip of the washing nozzle 85. The circulation device 86 is provided, for example, at the bottom of the outer box 81. The circulation device 86 can be configured to have a switching valve 861 and a pump 862. The switching valve 861 is configured to be electromagnetically openable and closable. The switching valve 861 is configured to be able to selectively switch between a circulation path for circulating the washing liquid stored in the washing tub 83 and a drainage path for draining the water stored in the washing tub 83 to the outside. The pump 862 functions as a circulation pump for circulating the washing liquid in the washing tub 83 through the circulation path, and also functions as a drainage pump for draining the washing liquid in the washing tub 83 through the drainage path.

[0062] The heater 87 is provided, for example, at the bottom of the cleaning tank 83. The heater 87 has the function of heating the cleaning liquid stored in the cleaning tank 83 to turn it into hot water. The water supply mechanism 88 is for supplying water supplied from an external water source, such as a tap, into the cleaning tank 83. The water supply mechanism 88 has a water supply valve 881, a water supply pipe 882, and a water supply inlet 883. The water supply valve 881 is configured to be electromagnetically openable and closable. The water supply pipe 882 is formed, for example, of a metal pipe, and one end is connected to the water supply valve 881 and the other end is connected to the water supply inlet 883. The water supply inlet 883 is provided, for example, at the top of the cleaning tank 83. The water supply inlet 883 is for supplying water supplied from the external water source into the cleaning tank 83. When the water supply valve 881 is opened, water supplied from the external water source is supplied into the cleaning tank 83 from the water supply inlet 883 through the water supply pipe 882. That is, the water supply valve 881 opens and closes the path from an external water source through the water supply pipe 882 to the water supply port 883 .

[0063] The water supply port 883 has an attachment portion 883a. In this embodiment, as shown in FIG. 14, the fine-bubble generator 30 is built into the attachment portion 883a. As a result, the fine-bubble generator 30 generates fine bubbles, including ultrafine bubbles, in water supplied from an external water source as the water passes through the fine-bubble generator 30 in the direction of arrow A in FIG. 14. When the water supply valve 881 is opened with detergent in the washing tub 83, the detergent in the washing tub 83 and the fine-bubble water generated by passing through the fine-bubble generator 30 are mixed in the washing tub 83. Then, the pump 862 and the heater 87 are driven, and the fine-bubble water, which has been mixed with the cleaning liquid and turned into warm water, is sprayed from the washing nozzle 85 toward the dishes D, washing the dishes D. According to the sixth embodiment, in a dishwasher 80 equipped with the fine-bubble generator 30, the washing performance can be improved by the effect of the fine bubbles while suppressing a decrease in flow rate.

[0064] Seventh embodiment Next, a seventh embodiment will be described with reference to Figure 15. This seventh embodiment is applied to a flush toilet apparatus 90 as a flushing device. As is well known, the flush toilet apparatus 90 comprises a toilet bowl 91 and a water supply mechanism 92. The toilet bowl 91 functions as a flushing tank. The toilet bowl 91 has a toilet bowl 911 and a rim 912 provided on the outer periphery of the upper end of the toilet bowl 911.

[0065] The water supply mechanism 92 has a water supply valve 921, a main water supply pipe 922, a toilet bowl water supply pipe 923, a rim water supply pipe 924, and a detergent supply device 925. The water supply valve 921 is configured to be electromagnetically openable. One end of the main water supply pipe 922 is connected to the water supply valve 921, and the other end branches into two, connected to a toilet bowl water supply pipe 923 and a rim water supply pipe 924. The toilet bowl water supply pipe 923 is used to supply water supplied from an external water source into the toilet bowl 911. The toilet bowl water supply pipe 923 has an outlet 923a, which is located at the tip of the toilet bowl water supply pipe 923 and supplies water to the toilet bowl 911. The rim water supply pipe 924 is used to supply water supplied from an external water source to the rim 912. The rim water supply pipe 924 has an outlet portion 924a. The outlet portion 924a is provided at the tip of the rim water supply pipe 924 and is a portion that supplies water to the rim 912.

[0066] When the water supply valve 921 is opened, water supplied from an external water source passes from the main water supply pipe 922 through the toilet bowl water supply pipe 923 and the rim water supply pipe 924 and is supplied into the toilet bowl 91. In other words, the water supply valve 921 opens and closes the path leading from the external water source to the toilet bowl 91 via the water supply pipes 922, 923, and 924. The detergent supply device 925 has the function of automatically supplying a detergent into the toilet bowl 91 via the detergent supply pipe 925a, for example, when the water supply valve 921 is opened and water is supplied into the toilet bowl 91 through the water supply pipes 922, 923, and 924.

[0067] The main water supply pipe 922 also has an attachment portion 922a. In this embodiment, as shown in FIG. 15, the fine-bubble generator 30 is built into the attachment portion 922a. As a result, the fine-bubble generator 30 generates fine bubbles, including ultrafine bubbles, in water supplied from an external water source as the water passes through the fine-bubble generator 30 in the direction of arrow A in FIG. 15. When the water supply valve 921 is opened, the cleaning agent in the toilet bowl 91 and the fine-bubble water generated by passing through the fine-bubble generator 30 are mixed inside the toilet bowl 91. The toilet bowl 91 is then flushed with the fine-bubble water mixed with the cleaning agent. According to this seventh embodiment, in a flush toilet device 90 equipped with a fine-bubble generator 30, cleaning performance can be improved by the effect of the fine bubbles while suppressing a decrease in flow rate.

[0068] In the above-described embodiments, the micro-bubble generator has been described using specific numerical values, but these specific numerical values ​​are merely examples and can, of course, be changed as appropriate. Furthermore, the above-described embodiments can also be implemented by combining them in any desired manner. Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as defined in the claims. [Explanation of symbols]

[0069] 10... washing machine (cleaning equipment), 30... fine bubble generator, 40... main body, 41... inlet portion, 42... outlet portion, 43... flow path, 431... upstream constriction portion, 433... downstream constriction portion, 60, 71, 72... collision portion, 61, 62... protrusion portion, 723... through hole, 80... dishwasher (cleaning equipment), 90... flush toilet device (cleaning equipment)

Claims

1. a main body portion having a flow path connecting the inlet portion and the outlet portion and allowing a liquid to pass through; a collision section that generates microbubbles in the liquid by reducing the cross-sectional area of ​​the flow path, The collision portion is formed by a plurality of protrusions that are formed to protrude from the inner circumferential surface of the main body portion toward the inside of the flow path, are arranged at intervals along the circumferential direction of the main body portion, and have respective tips that are directly connected to each other. Microbubble generator.

2. the main body portion has a downstream tapered portion that gradually reduces the cross-sectional area of ​​the flow path, and an upstream tapered portion that is provided closer to the inlet portion than the downstream tapered portion and gradually reduces the cross-sectional area of ​​the flow path, the collision portion is in contact with the liquid that has passed through the downstream-side narrowed portion; The microbubble generator according to claim 1.

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