Sanitary washing apparatus

Abstract

A nozzle of a sanitary washing apparatus includes a first cylindrical part, a second cylindrical part, and a lid part. The second cylindrical part has an inflow hole and an air supply hole which are communicated with a gap between the first cylindrical part and the second cylindrical part. The first cylindrical part has an inflow hole having a sectional area smaller than a sectional area of an upper internal space above the inflow hole and smaller than a sectional area of a passage hole of the lid part. The sectional area of the passage hole of the lid part increases upward.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application is based upon and claims the benefit of priority to Japanese Patent Application No. 2024-207686, filed on Nov. 28, 2024, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to a sanitary washing apparatus that washes a local area of a seated human body.BACKGROUND ART

[0003] In a sanitary washing apparatus that washes a local area of a seated human body, it is known that intermittently spraying warm water, even in a relatively small volume, can give a so-called “wash feeling”, which is a feeling of being washed well, to the human body as compared with continuously spraying the warm water to the local area of the human body.

[0004] Patent Literature 1 (JP 2024-50194 A) describes a sanitary washing apparatus that can selectively discharge an intermittent water stream and a continuous water stream including air bubbles mixed therein from a nozzle without using a pump.

[0005] In the sanitary washing apparatus, pulsation action of a water stream is stabilized when the intermittent water stream is generated. However, in the sanitary washing apparatus, The water stream pulsates also when the continuous water stream including the air bubbles mixed therein is generated, and the continuous water stream is thus likely to change into the intermittent water stream, and therefore, the continuous water stream including the air bubbles mixed therein is difficult to be generated.SUMMARY

[0006] It is an object of the present disclosure to provide a sanitary washing apparatus configured to selectively and stably generate the intermittent water stream and the continuous water stream including air bubbles mixed therein without using a pump.

[0007] A sanitary washing apparatus of an aspect of the present disclosure includes a nozzle configured to discharge a water stream toward a local area of a seated human body. The nozzle includes a first cylindrical part; a second cylindrical part; and a lid part. The first cylindrical part has a central axis extending in one direction. The second cylindrical part has a central axis coincident with the central axis of the first cylindrical part and surrounding an outer peripheral surface of the first cylindrical part. The lid part closes an upper end which is one end in the one direction of the second cylindrical part. The first cylindrical part has a part in one direction in which a first inflow hole is formed, the first inflow hole formed as a through hole penetrating the part in the one direction. The lid part has a passage hole formed as a through hole penetrating the lid part in the one direction. Between the outer peripheral surface of the first cylindrical part and an inner peripheral surface of the second cylindrical part, a first gap is provided. The first gap has a lower end which is a remaining one end in the one direction and which is closed. Between the first cylindrical part and the lid part, a second gap communicated with the first gap is provided. The first cylindrical part faces the lid part. The second cylindrical part has a second inflow hole formed as a through hole and an air supply hole formed as a through hole, the second inflow hole and the air supply hole being communicated with the first gap. The first inflow hole has a sectional area smaller than a sectional area of an internal space of an upper portion of the first cylindrical part, the internal space being at an upper portion of the first cylindrical part and being above the first inflow hole. The sectional area of the first inflow hole is smaller than a sectional area of the passage hole. The sectional area of the passage hole increases upward. A central axis of the first inflow hole and a central axis of the passage hole are on an identical straight line. The first cylindrical part has an upper end located above the second inflow hole. The sanitary washing apparatus is configured to change a flow ratio of a first flow rate to a second flow rate during operation to switch the water stream between at least two states including a first state and a second state. Here, the first flow rate is a flow rate of water flowing into the first inflow hole. The second flow rate is a flow rate of water flowing into the second inflow hole. In the first state, a continuous water stream passing through the passage hole with a gap between the continuous water stream and an inner peripheral surface of the passage hole is discharged from the passage hole, and the continuous water stream then changes to an intermittent water stream in a space. In the second state, a continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface of the passage hole is discharged from the passage hole.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The figures depict one or more implementation in accordance with the present teaching, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.

[0009] FIG. 1 is a perspective view of a sanitary washing apparatus attached to a toilet according to a first embodiment;

[0010] FIG. 2 is a circuit diagram of a water circuit included in the sanitary washing apparatus according to the first embodiment;

[0011] FIG. 3 is an exterior perspective view of a nozzle according to the first embodiment;

[0012] FIG. 4 is a sectional view of the nozzle taken along line A-A of FIG. 3;

[0013] FIG. 5 is an enlarged view of a main part of the nozzle shown in FIG. 4;

[0014] FIG. 6 is a sectional view of action 1 which is a situation where a water stream in a first state is discharged from the nozzle;

[0015] FIG. 7 is a sectional view of action 2 which is a situation where the water stream in the first state is discharged from the nozzle;

[0016] FIG. 8 is a sectional view of action 3 which is a situation where the water stream in the first state is discharged from the nozzle;

[0017] FIG. 9 is a sectional view of action 4 which is a situation where the water stream in the first state is discharged from the nozzle;

[0018] FIG. 10 is a sectional view of action 5 which is a situation where the water stream in the first state is discharged from the nozzle;

[0019] FIG. 11 is a sectional view of action 6 which is a situation where the water stream in the first state is discharged from the nozzle;

[0020] FIG. 12 is a view of state 1 of the water stream in a space after the water stream is discharged from the nozzle;

[0021] FIG. 13 is a view of state 2 of the water stream in the space after the water stream is discharged from the nozzle;

[0022] FIG. 14 is a view of a state of a water stream in a space after a water stream in a second state is discharged from the nozzle;

[0023] FIG. 15 is a sectional view of action 1 which is a situation where a water stream in a second state is discharged from the nozzle;

[0024] FIG. 16 is a sectional view of action 2 which is a situation where the water stream in the second state is discharged from the nozzle;

[0025] FIG. 17 is a sectional view of action 3 which is a situation where the water stream in the second state is discharged from the nozzle;

[0026] FIG. 18 is a sectional view of action 4 which is a situation where the water stream in the second state is discharged from the nozzle;

[0027] FIG. 19 is a sectional view of action 5 which is a situation where the water stream in the second state is discharged from the nozzle;

[0028] FIG. 20 is a sectional view of action 6 which is a situation where the water stream in the second state is discharged from the nozzle;

[0029] FIG. 21 is a sectional view of a situation where a water stream in a third state is discharged from the nozzle; and

[0030] FIG. 22 is a sectional view of a situation where a water stream in a fourth state is discharged from the nozzle.DETAILED DESCRIPTION

[0031] An embodiment of a sanitary washing apparatus 1, a nozzle 2, and a water stream generating method according to the present disclosure will be described below with reference to the drawings. The embodiment described below is an example with which the present disclosure is described, but the embodiment described below is not intended to limit the present disclosure. For example, shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulae, respective contents of steps in, and respective orders of, the method, and the like shown in the embodiment below are mere examples. The present disclosure may include contents not described below. Moreover, in the following description, geometric expressions, such as parallel and orthogonal, may be used, and these expressions do not indicate mathematical precision but include substantially acceptable errors, shifts, and the like. Further, expressions, such as simultaneous and identical, also include a substantially acceptable range.

[0032] Moreover, the drawings are schematic views accordingly provided with emphasis, omission, or adjustment in ratio to illustrate the present disclosure and do not show actual shapes, positional relationships, and ratios.

[0033] Further, a plurality of inventions may be comprehensively described as one embodiment below. Furthermore, some of contents described below are explained as optional components relating to the present disclosure.First Embodiment

[0034] FIG. 1 is a perspective view of a sanitary washing apparatus 1 attached to a toilet 3. FIG. 2 is a circuit diagram of a water circuit 4 included in the sanitary washing apparatus 1. The sanitary washing apparatus 1 is attached to the toilet 3. The sanitary washing apparatus 1 is an apparatus that discharges water generated by a heating device 45 from a nozzle 2 to a local area of a person seated on a seat 30. The sanitary washing apparatus 1 includes the seat 30 openable / closeable with respect to the toilet 3. The nozzle 2 is provided to a tip end of a nozzle body 20. The nozzle 2 can appear and be hidden together with the nozzle body 20. The sanitary washing apparatus 1 may be provided with a toilet cover openable / closeable with respect to the toilet 3. In the present specification and claims, “water” includes warm water.

[0035] The configuration of the water circuit 4 included in the sanitary washing apparatus 1 is not limited to a particular configuration but is the configuration described below. The water circuit 4 includes a feed-water connection port 40, a strainer 41, a water stop solenoid valve 42, a pressure reducing valve 43, a vacuum breaker 44, a heating device 45, a flow control valve 46, and a switching device 47 in this order from upstream.

[0036] The feed-water connection port 40 is a member that is connected to a water pipe by, for example, an adapter. The feed-water connection port 40 includes the strainer 41 integrally incorporated in the interior thereof. The strainer 41 prevents inflow of trash included in tap water.

[0037] The water stop solenoid valve 42 is a valve that is opened and closed by being controlled by a control device 31 (see FIG. 1) to be able to stop a flow of water from the water pipe. Opening the water stop solenoid valve 42 enables water to be discharged from the nozzle 2, and closing the water stop solenoid valve 42 enables discharging the water from the nozzle 2 to be stopped.

[0038] The pressure reducing valve 43 is a valve that reduces a water pressure of water supplied from the water pipe such that the water pressure of water after passing through the pressure reducing valve 43 is kept constant.

[0039] The vacuum breaker 44 prevents water in the interior of the water circuit 4 from flowing back to the water pipe, for example, when the water pipe connected to the feed-water connection port 40 has a negative pressure due to, for example, water outage. The vacuum breaker 44 is connected to a vent pipe 48. The vent pipe 48 extends to a toilet bowl 32 (see FIG. 1) of the toilet 3. The vent pipe 48 is a supply path of external air supplied to the vacuum breaker 44 when the vacuum breaker 44 operates. Moreover, the vent pipe 48 has a function as a water release path that releases water instantaneously released during operation of the vacuum breaker 44 into the toilet 3.

[0040] The heating device 45 is a device that heats tap water supplied from the water pipe to generate warm water. The heating device 45 is not limited to a particular device but is a heat exchanger that instantaneously heats tap water supplied from the water pipe. The heating device 45 integrally includes a buffer tank 450 that makes the temperature of the water heated by the heating device 45 uniform.

[0041] The flow control valve 46 is a valve that is controlled by the control device 31 to adjust the volume of water supplied to the nozzle 2.

[0042] The switching device 47 separates the water heated by the heating device 45 into first water W1 and second water W2 and supplies the first water W1 and second water W2 to the nozzle 2. The switching device 47 is configured to switch a flow ratio of a first flow rate of the first water W1 to a second flow rate of the second water W2.

[0043] FIG. 3 is an exterior perspective view of the nozzle 2. FIG. 4 is a sectional view of the nozzle 2 taken along line A-A of FIG. 3. FIG. 5 is an enlarged view of a main part of the nozzle 2. FIG. 5 is a sectional view and a broken line is added to distinguish components from one another to facilitate the understanding.

[0044] The nozzle 2 is a nozzle 2 that discharges warm water heated by the heating device 45 toward a local area of the body of a person seated on the seat 30. As shown in FIGS. 3 to 5, the nozzle 2 includes a first cylindrical part 5, a second cylindrical part 6, and a lid part 7. The nozzle 2 further includes a first connection part 8 and a second connection part 9.

[0045] The first cylindrical part 5 has a central axis 50 extending in one direction D1. In the following description, one end side in the one direction D1 is referred to as an upper side, and the other end side in the one direction D1 is referred to as a lower side. The first cylindrical part 5 has a part in one direction D1 (in the Z-axis direction in the figure) in which a first inflow hole 51 is formed. The first inflow hole 51 is formed as a through hole penetrating the part in the one direction D1. The first water W1, which is one of two parts of the water generated by the heating device 45 and separated by the switching device 47, flows into a lower end opening of the first cylindrical part 5, passes through the first inflow hole 51, and flows into an internal space of the first cylindrical part 5, the internal space being at an upper portion 52 of the first cylindrical part 5 and being above the first inflow hole 51. As shown in FIG. 5 and FIG. 6, a sectional area S1 of the first inflow hole 51 and a sectional area S2 of the internal space of the upper portion 52 are in such a relationship that the first water W1 flowing from the first inflow hole 51 into the internal space can be ejected from an upper end opening of the first cylindrical part 5 without coming into contact with an inner peripheral surface of the upper portion 52. Specifically, S2>S1. The shape of the first cylindrical part 5 is not limited to a particular shape but is a circularly cylindrical shape. The shape of the first inflow hole 51 is not limited to a particular shape but is a circular shape when viewed in the one direction D1, and the first inflow hole 51 is arranged at the center of the first cylindrical part 5 in a radial direction. The sectional area shows the area (size of a region) surrounded by an inner peripheral surface of a cylinder in a cut plane of the cylinder when the cylinder is cut orthogonally to the central axis thereof.

[0046] The second cylindrical part 6 has a central axis 60 which coincides with the central axis 50 of the first cylindrical part 5. The second cylindrical part 6 is a cylindrical part surrounding an outer peripheral surface of the first cylindrical part 5. Between the outer peripheral surface of the first cylindrical part 5 and an inner peripheral surface of the second cylindrical part 6, a first gap 21 is provided, and the first gap 21 has a lower end which is closed. The inner peripheral surface of the second cylindrical part 6 faces the outer peripheral surface of the first cylindrical part 5. The lower end of the first gap 21 is closed by part of the first cylindrical part 5. The first gap 21 has a radial length G1 narrower than an inner diameter L1 of the first inflow hole 51. The second cylindrical part 6 protrudes upward beyond an upper end of the first cylindrical part 5 in the one direction D1. Thus, the second water W2 flowing into the first gap 21 between the first cylindrical part 5 and the second cylindrical part 6 climbs over the upper end of the first cylindrical part 5 and flows into the first cylindrical part 5. The shape of the second cylindrical part 6 may be rectangularly cylindrical but is not limited to a particular shape. The second cylindrical part 6 has a circularly cylindrical shape similar to the first cylindrical part 5 and is arranged coaxially with the first cylindrical part 5.

[0047] The lid part 7 includes: a lid part body 70 having a circularly annular shape; and a cylindrical part 71 provided to extend upward from a surface on a front side (i.e., upper side) of the lid part body 70. The cylindrical part 71 is arranged at a location which is on an opposite side (i.e., upper side) of the first cylindrical part 5 from the first inflow hole 51 and which is apart from the first cylindrical part 5. The cylindrical part 71 is a cylindrical part arranged coaxially with the first cylindrical part 5. That is, the first cylindrical part 5, the second cylindrical part 6, and the cylindrical part 71 are arranged to have an identical axis. The shape of the cylindrical part 71 is a circularly cylindrical shape similar to the first cylindrical part 5.

[0048] The lid part 7 is disposed to close an upper end of the second cylindrical part 6. The lid part 7 includes: the lid part body 70 closing the upper end of the second cylindrical part 6; and the cylindrical part 71 protruding upward from a center part of the lid part body 70 in the radial direction. The lid part 7 has a passage hole 72 formed as a through hole penetrating the lid part 7 in the one direction D1. The passage hole 72 is formed in the lid part body 70 and the cylindrical part 71. The lid part 7 does not have to include the cylindrical part 71 but may consist of the lid part body 70. A central axis of the first inflow hole 51 and a central axis of the passage hole 72 are located on the same straight line.

[0049] The passage hole 72 has a sectional area increasing upward. The passage hole 72 has a circular truncated cone shape. The lid part 7 surrounding the passage hole 72 has an inner peripheral surface 720 tilted in a tapered shape. The inner peripheral surface 720 has an angle larger than 0 degrees and smaller than 10 degrees to the central axis of the passage hole 72.

[0050] A diameter L2 of an upper end opening 721 of the passage hole 72 is larger than a diameter L3 of a lower end opening 722 of the passage hole 72. A sectional area S3 of the upper end opening 721 is larger than a sectional area S4 of the lower end opening 722.

[0051] For example, the diameter L3 is 1.35 mm, and the diameter L2 is 1.45 mm. In this case, an angle of the inner peripheral surface 720 to the central axis of the passage hole 72 is 3.57 degrees.

[0052] Between the first cylindrical part 5 and the lid part 7, a second gap 22 communicated with the first gap 21 is provided. Therefore, the first cylindrical part 5 faces the lid part 7.

[0053] The second cylindrical part 6 has a second inflow hole 61 formed as a through hole and an air supply hole 62 formed as a through hole such that the second inflow hole 61 and the air supply hole 62 are communicated with the first gap 21. The second inflow hole 61 penetrating part of a peripheral wall of the second cylindrical part 6 in a circumferential direction is a through hole through which the second water W2, which is the other of the two parts of the water separated by the switching device 47, flows into the first gap 21. The second inflow hole 61 penetrates the peripheral wall at a portion which is part of the second cylindrical part 6 and which overlaps the outer perimeter of the first cylindrical part 5. That is, the upper end of the first cylindrical part 5 is located above the second inflow hole 61. The second water W2 flowing into the second inflow hole 61 hits the outer peripheral surface of the first cylindrical part 5.

[0054] The air supply hole 62 is a through hole through which air outside the second cylindrical part 6 is supplied to the first gap 21. The air supply hole 62 is provided in a lower portion of the second cylindrical part 6 and is communication with a lower end part of the first gap 21. The number of air supply hole(s) 62 may be one or more, but one air supply hole 62 is provided for the second cylindrical part 6 as shown in FIG. 3.

[0055] A positional relationship between the air supply hole 62 and the second inflow hole 61 is not limited to a particular relationship, but the second inflow hole 61 is disposed above the air supply hole 62 as shown in FIG. 5. The second inflow hole 61 and the air supply hole 62 are arranged such that an inflow direction of the second water W2 from the second inflow hole 61 and an inflow direction of air from the air supply hole 62 are parallel to each other. The air supply hole 62 and the second inflow hole 61 are arranged at locations apart from each other by 180 degrees centered on the central axis 60 of the second cylindrical part 6.

[0056] Through the passage hole 72, the first water W1 flowing from the first inflow hole 51 passes alone, or the second water W2 filled in the inner side of the second cylindrical part 6 passes together with the first water W1. The sectional area S4 of the lower end opening 722 of the passage hole 72 is larger than the sectional area S1 of the first inflow hole 51. In other words, the relationship that S4>S1 is satisfied. Thus, the first water W1 flowing from the first inflow hole 51 into the passage hole 72 in a state where the second water W2 does not flow into the inner side of the first cylindrical part 5 (i.e., in a state where the interior of the first cylindrical part 5 is filled with air) can pass through the passage hole 72 without coming into contact with the inner peripheral surface 720 of the passage hole 72. The relationship between S2 and S4 may be that S4≥S2. Alternatively, the relationship may be that S2>S4 (where S4>S1).

[0057] The upper end of the second cylindrical part 6 is disposed above the upper end of the first cylindrical part 5, and the lower end of the second cylindrical part 6 is disposed at the same location as the lower end of the first cylindrical part 5 in an up / down direction.

[0058] As shown in FIG. 4, the first connection part 8 is a portion to which a tube is connected. The tube guides the first water W1, which is the one of the two parts of the water separated by the switching device 47. The first connection part 8 has an outer peripheral surface having a bamboo sprout-like retaining shape. The first connection part 8 is cylindrical and is integral with the first cylindrical part 5. An internal space of the first connection part 8 and the internal space of the first cylindrical part 5 are continuous in a straight line. The first cylindrical part 5 and the first connection part 8 are configured as one cylindrical member. The first cylindrical part 5 and the first connection part 8 are a resin molded piece.

[0059] The second connection part 9 is a portion to which a tube is connected. The tube guides the second water W2, which is the other of the two parts of the water separated by the switching device 47. The second connection part 9 has an outer peripheral surface having a bamboo sprout-like retaining shape. The second connection part 9 has a cylindrical shape extending in a direction (in an X-axis direction in the figure) orthogonal to the one direction D1 and is integral with the second cylindrical part 6. An internal space of the second connection part 9 and the second inflow hole 61 of the second cylindrical part 6 are continuous in a straight line. The second cylindrical part 6, the lid part 7, and the second connection part 9 are configured as one member. The second cylindrical part 6, the lid part 7, and the second connection part 9 are a resin molded piece.

[0060] The switching device 47 is a device for switching a flow ratio of the first flow rate, which is the flow rate of water flowing into the first inflow hole 51 of the nozzle 2, to the second flow rate, which is the flow rate of water flowing into the second inflow hole 61 of the nozzle 2. The switching device 47 has no pump function but is capable of switching the flow ratio by a water path configuration operated by a motor 470. The switching device 47 is provided to be able to implement five switching modes different from one another in terms of flow ratio.

[0061] In a first switching mode, the switching device 47 switches the flow ratio such that the flow rate of water flowing into the second inflow hole 61 of the nozzle 2 is about 25% of the flow rate of water flowing into the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 3:1 to 7:1. When the switching device 47 is in the first switching mode, a water stream which changes to an intermittent water stream in a space after being discharged as a continuous water stream is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “first state”, see FIG. 13).

[0062] In a second switching mode, the switching device 47 switches the flow ratio such that the flow rate of water flowing into the second inflow hole 61 of the nozzle 2 is about 40% of the flow rate of water flowing into the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 2.0:1 to 3.0:1. When the switching device 47 is in the second switching mode, a continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein is discharged from the passage hole 72 of the nozzle 2 as shown in FIG. 14 (hereinafter referred to as a “second state”). The switching device 47 switches the flow ratio such that the second flow rate in the second state is higher than the second flow rate in the first state.

[0063] In a third switching mode, the switching device 47 causes substantially the same volumes of water to flow into the first inflow hole 51 and the second inflow hole 61 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 1.0:1 to 1.5:1. When the switching device 47 is in the third switching mode, a jet stream which is a continuous water stream as shown in FIG. 15 or 21 is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “third state”).

[0064] In a fourth switching mode, the switching device 47 switches the flow ratio such that water flows into only the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 1:0. When the switching device 47 is in the fourth switching mode, a continuous and narrow water stream as shown in FIG. 22 is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “fourth state”).

[0065] In response to an operation given to a rear wash button provided to the control device 31 (see FIG. 1), the switching device 47 enters a switching mode corresponding to the button to which the operation has been given.

[0066] A situation where the intermittent water stream (i.e., a water stream in the first state) is generated in a space will be described below. At the time of generating the water stream in the first state, a first discharge state and a second discharge state are repeated as general actions. In the first discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51 passes through the passage hole 72 and is discharged from the passage hole 72, but the second water W2 flowing into the first gap 21 through the second inflow hole 61 is not discharged from the passage hole 72. In the second discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51 passes through the passage hole 72. The second water W2 flowing from the second inflow hole 61 into the first gap 21 passes through the second gap 22 and the passage hole 72. Thus, the first water W1 and the second water W2 are discharged together from the passage hole 72.

[0067] With reference to FIGS. 6 to 13, generation of a water stream in the first state is sequentially given in detail. As shown in FIG. 6, the first water W1 in an injection state flows from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51. The first water W1 flowing into the upper portion 52 passes through air in the upper portion 52 and air in the passage hole 72 without coming into contact with the inner peripheral surface of the upper portion 52 or the inner peripheral surface 720 of the passage hole 72 and is discharged from the passage hole 72. This state is the first discharge state. In the first discharge state, the second water W2 flows from the second inflow hole 61 into the first gap 21 and accumulates in the first gap 21. The second water W2 does not flow out through the air supply hole 62 due to the surface tension of the water. Thus, in the first discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 is discharged from the passage hole 72, but the second water W2 flowing from the second inflow hole 61 into the first gap 21 is not discharged from the passage hole 72. In the first discharge state, the second water W2 flowing from the second inflow hole 61 into the first gap 21 accumulates in the first gap 21 and does not reach the second gap 22, and air is in the second gap 22.

[0068] Then, when the second water W2 fills the first gap 21, as shown in FIGS. 7 and 8, the second water W2 passes through the second gap 22, and the second water W2 climbs over the upper end of the first cylindrical part 5 and flows into the interior of the first cylindrical part 5. The second water W2 flows into the inner side of the first cylindrical part 5 from at least part in the circumferential direction of the upper end of the first cylindrical part 5.

[0069] At this time, the second water W2 collides with the first water W1, is pulled in a flow direction of the first water W1, and flows into the interior of the first cylindrical part 5, and the interior of the first cylindrical part 5 is filled with the first water W1 and the second water W2. Then, as shown in FIG. 9, water which is a mixture of the first water W1 and the second water W2 is discharged from the passage hole 72. The water, which is a mixture of the first water W1 and the second water W2, is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the lower end opening 722 of the passage hole 72, and thus, there is a gap between the water and the inner peripheral surface 720 of the passage hole 72. This state is the second discharge state.

[0070] In the second discharge state, a first condition and a second condition are satisfied, and thus, an ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at a downstream end of the first inflow hole 51, and thereby, air is sucked through the air supply hole 62.

[0071] As shown in FIG. 10, the air sucked through the air supply hole 62 passes through the first gap 21 and the second gap 22, flows into the interior of the first cylindrical part 5 by being pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51, and flows into the interior of the passage hole 72 by being pulled by the flow of the first water W1.

[0072] Next, the air flowing into the interior of the upper portion 52 of the first cylindrical part 5 and the interior of the passage hole 72 spreads to surround the first water W1 as shown in FIG. 11 and blocks the flow of the second water W2 into the first water W1. Further, when a state where the interior of the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2 is released, the ejector effect is inactivated, and an air sucking action ends, returning to the first discharge state. Thus, a flow which is a thick jet stream formed by merging of the second water W2 with the first water W1 is switched to a thin jet stream of only the first water W1. In this way, the first discharge state and the second discharge state are repeated.

[0073] FIG. 12 is a view of state 1 of a water stream in a space after the water stream is discharged from the nozzle 2. FIG. 13 is a view of state 2 of the water stream in the space after the water stream is discharged from the nozzle 2. A first flying water W10 shown in each of these figures is water which is in the first discharge state and which corresponds to only the first water W1 discharged from the passage hole 72 to air. A second flying water W12 is water which is in the second discharge state and which correspond to the first water W1 and the second water W2 discharged together from the passage hole 72. The flow speed of the first flying water W10 is higher than the flow speed of the second flying water W12. Therefore, the first flying water W10 separates from a subsequent second flying water W12 and forms a water mass together with a preceding second flying water W12 as shown in FIG. 13. In this way, water discharged from the nozzle 2 forms an intermittent water stream in the space.

[0074] Subsequently, a situation where a continuous water stream (i.e., a water stream in the second state) shown in FIG. 14, having a jet stream diameter narrowing in a certain cycle, and including air bubbles mixed therein is generated will be described. The second flow rate in the second state is higher than the second flow rate in the first state.

[0075] In the generation of the water stream in the second state, actions shown in FIGS. 6 to 8 are first of all caused in a similar manner to the generation of the water stream in the first state. The generation of the water stream in the second state may be started with the action shown in FIG. 9.

[0076] At the time of generating the water stream in the second state, the second flow rate is higher than the second flow rate in the first state. Therefore, water which is a mixture of the first water W1 and the second water W2 spreads in the interior of the passage hole 72 to the inner peripheral surface 720 and fills the interior of the passage hole 72 as shown in FIG. 15. The water, which is the mixture of the first water W1 and the second water W2, is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the upper end opening 721 of the passage hole 72.

[0077] In this discharge state, the first condition and the second condition are satisfied, and thus, the ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at the downstream end of the first inflow hole 51. Also, a third condition and a fourth condition are satisfied, and thus, the ejector effect is generated. The third condition is that the flow speed in the lower end opening 722 of the passage hole 72 is higher than the flow speed in the upper portion above the lower end opening 722 of the passage hole 72 to cause a speed difference. The fourth condition is that the passage hole 72 is filled with the first water W1 and the second water W2. This generates a negative pressure in the lower end opening 722 of the passage hole 72. That is, at the time of generating the water stream in the second state, negative pressures are generated at two locations, namely the downstream end of the first inflow hole 51 and the lower end opening 722 of the passage hole 72, and thereby, air is sucked through the air supply hole 62.

[0078] As shown in FIG. 16, the air sucked through the air supply hole 62 passes from the air supply hole 62 through the first gap 21 and the second gap 22, and flows into the interior of the upper portion 52 of the first cylindrical part 5 by being pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51. Then, the air sucked through the air supply hole 62 collides with the water stream of the first water W1 by being pulled to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72. Then, the air sucked through the air supply hole 62 flows into the interior of the passage hole 72 by being pulled by the flow of the first water W1.

[0079] In the air flowing to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72, air bubbles are crushed by the water stream of the first water W1 into fine air bubbles, which are mixed overall in the first water W1 and the second water W2 in the passage hole 72.

[0080] Then, as shown in FIGS. 17 and 18, the air pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51 reaches the downstream end of the first inflow hole 51, thereby canceling negative pressure generation at the downstream end of the first inflow hole 51. Then, the air pulled to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72 and the air pulled by the flow of the first water W1 enter the passage hole 72, Thereby canceling negative pressure generation at the lower end opening 722 of the passage hole 72. This achieves a state where only the first water W1 is discharged from the passage hole 72.

[0081] When the negative pressure generation at the two locations, namely, the downstream end of the first inflow hole 51 and the lower end opening 722 of the passage hole 72 is canceled, the second water W2 flows into, and fills, the interior of the upper portion 52 of the first cylindrical part 5 and the interior of the passage hole 72 as shown in FIGS. 19 and 20. Thus, the negative pressures are generated again at the two locations, namely, the downstream end of the first inflow hole 51 and the lower end of the passage hole 72, thereby generating a water stream shown in FIG. 14 and obtained by mixing air as the fine air bubbles overall in the first water W1 and the second water W2 in the passage hole 72.

[0082] At the time of generating the water stream in the second state, the second flow rate is higher than the second flow rate in the first state. Therefore, at the time of generating the water stream in the second state, a state shown in FIG. 18 where the negative pressure generation at the two locations is canceled is switched to a negative pressure generation state shown in FIG. 20 in a shorter time than an interval between the release and the generation of the negative pressure in the first state. Therefore, at the time of generating the water stream in the second state, the intermittent flow as shown in FIG. 13 is not generated but a continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein is generated.

[0083] At the time of generating the water stream in the second state, repeating actions shown in FIGS. 17 to 20 generates a continuous water stream shown in FIG. 14, having a jet stream diameter narrowing in a certain cycle, and including air bubbles mixed therein.

[0084] Subsequently, a situation where a jet stream (i.e., water stream in the third state) which is a continuous water stream shown in FIG. 21 is generated will be described. The second flow rate in the third state is higher than the second flow rate in the first state and is lower than the second flow rate in the second state. In the third state, the first flow rate and the second flow rate are substantially equal to each other.

[0085] In the generation of the water stream in the third state, actions shown in FIGS. 6 to 9 are first of all occur in a similar manner to the generation of the water stream in the first state. The generation of the water stream in the third state may be started with the action shown in FIG. 9.

[0086] At the time of generating the water stream in the third state, the first condition and the second condition are satisfied in the action shown in FIG. 9, and thus, the ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at the downstream end of the first inflow hole 51. However, at the time of generating the water stream in the third state, the second flow rate is significantly higher than the second flow rate in the first state, and therefore, the air sucked through the air supply hole 62 due to the pressure of the second water W2 can be prevented from reaching the first water W1. Thus, at the time of generating the water stream in the third state, actions shown in FIGS. 10 to 13 do not occur, and a jet stream which is the continuous water stream shown in FIG. 15 or 21 and including no air bubbles mixed therein can be generated. The water stream in the third state keeps its continuous flow in a space after being discharged from the passage hole 72.

[0087] The second flow rate in the third state can accordingly be set within a range in which a flow ratio of the first flow rate to the second flow rate is 1.0:1 to 1.5:1. When the second flow rate in the third state is higher than a certain value, a jet stream shown in FIG. 15 can be generated, and when the second flow rate in the third state is lower than the certain value, a jet stream shown in FIG. 21 can be generated.

[0088] Subsequently, a situation where a continuous narrow water stream (i.e., a water stream in the fourth state) shown in FIG. 22 is generated will be described. At the time of generating the water stream in the fourth state, only the first water W1, but no second water W2, is supplied to the nozzle 2.

[0089] At the time of generating the water stream in the fourth state, the first water W1 in an injection state flows from the first inflow hole 51 into the upper portion 52 of the first cylindrical part 5. The first water W1 flowing into the upper portion 52 of the first cylindrical part 5 passes through air in the upper portion 52 of the first cylindrical part 5 and air in the passage hole 72 without coming into contact with the inner peripheral surface of the upper portion 52 of the first cylindrical part 5 or the inner peripheral surface 720 of the passage hole 72 and is discharged from the passage hole 72. The first water W1 is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the first inflow hole 51.

[0090] With the sanitary washing apparatus 1 described above, changing the flow ratio of the first flow rate to the second flow rate by the switching device 47 enables four types of water streams to selectively be discharged from the passage hole 72 of a single nozzle 2. Thus, it is possible to delicately respond to preferences of a user seated on the seat 30.

[0091] Moreover, in the sanitary washing apparatus 1, the inner peripheral surface 720 of the passage hole 72 is less likely to be wetted with water at the time of generating the water streams in the first state, the third state, and the fourth state, and therefore, the ratio of water adhering to the inner peripheral surface 720 can be suppressed from increasing. Thus, the sanitary washing apparatus 1 can suppress a continuous water stream spreading to the inner peripheral surface 720 of the passage hole 72 and including air bubbles mixed therein from being changed to an intermittent water stream by pulsation of this water stream when the continuous water stream is generated, and thereby, the continuous water stream including air bubbles mixed therein can stably be generated. Therefore, the sanitary washing apparatus 1 enables the intermittent water stream and the continuous water stream including air bubbles mixed therein to be selectively and stably generated without using a pump.Variations

[0092] Subsequently, variations of the sanitary washing apparatus 1 described above will be described. The variations described below may accordingly be combined with each other.

[0093] The sanitary washing apparatus 1 may be configured to selectively discharge only the water streams in the first state and the second state and does not have to be able to discharge all or some of the water streams in the third state and fourth state. In other words, the switching device 47 may be disposed to be able to switch the flow ratio only between the first switching mode and the second switching mode.

[0094] The inner peripheral surface 720 of the passage hole 72 may have an angle larger than or equal to 10 degrees to the central axis of the passage hole 72.

[0095] The structure of the nozzle 2 is not limited to the structures shown in FIGS. 3 and 4, and the nozzle 2 is at least configured such that the water stream is switched between at least two states including the first state and the second state in accordance with the flow ratio of the first flow rate to the second flow rate.Summary

[0096] A sanitary washing apparatus 1 of a first aspect according to the present disclosure has the following configurations.

[0097] A sanitary washing apparatus (1) of a first aspect includes a nozzle (2) configured to discharge a water stream toward a local area of a seated human body. The nozzle (2) includes a first cylindrical part (5), a second cylindrical part (6), and a lid part (7). The first cylindrical part (5) has a central axis (50) extending in one direction (D1). The second cylindrical part (6) has a central axis (60) coincident with the central axis (50) of the first cylindrical part (5) and surrounding an outer peripheral surface of the first cylindrical part (5). The lid part (7) closes an upper end which is one end in the one direction (D1) of the second cylindrical part (6). The first cylindrical part (5) has a part in the one direction (D1) in which a first inflow hole (51) is formed, the first inflow hole (51) formed as a through hole penetrating the part in the one direction (D1). The lid part (7) has a passage hole (72) formed as a through hole penetrating the lid part (7) in the one direction (D1). Between the outer peripheral surface of the first cylindrical part (5) and an inner peripheral surface of the second cylindrical part (6), a first gap (21) is provided. The first gap (21) has a lower end which is a remaining one end in the one direction (D1) and which is closed. Between the first cylindrical part (5) and the lid part (7), a second gap (22) communicated with the first gap (21) is provided. The first cylindrical part (5) faces the lid part (7). The second cylindrical part (6) has a second inflow hole (61) formed as a through hole and an air supply hole (62) formed as a through hole, the second inflow hole (61) and the air supply hole (62) being communicated with the first gap (21). The first inflow hole (51) has a sectional area smaller than a sectional area of an internal space of an upper portion of the first cylindrical part (5), the internal space being at an upper portion of the first cylindrical part (5) and being above the first inflow hole (51). The sectional area of the first inflow hole (51) is smaller than a sectional area of the passage hole (72). The sectional area of the passage hole (72) increases upward. A central axis of the first inflow hole (51) and a central axis of the passage hole (72) are on an identical straight line. The first cylindrical part (5) has an upper end located above the second inflow hole (61). The sanitary washing apparatus (1) is configured to change a flow ratio between a first flow rate and a second flow rate during operation to switch the water stream between at least two states including a first state and a second state. Here, the first flow rate is a flow rate of water flowing into the first inflow hole (51). The second flow rate is a flow rate of water flowing into the second inflow hole (61). In the first state, a continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and an inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole, and the continuous water stream then changes to an intermittent water stream in a space. In the second state, a continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72).

[0098] In the sanitary washing apparatus (1) of the first aspect, to generate the intermittent water stream in the first state, the continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole. Therefore, in the sanitary washing apparatus (1) of the first aspect, the chances that the inner peripheral surface (720) of the passage hole (72) is wetted with water can be reduced, and a ratio of the water adhering to the inner peripheral surface (720) can be suppressed from increasing. Thus, in the sanitary washing apparatus (1) of the first aspect, when the continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72), the continuous water stream can be suppressed from changing to the intermittent water stream. Therefore, the sanitary washing apparatus (1) of the first aspect enables the intermittent water stream and the continuous water stream including air bubbles mixed therein to be selectively and stably generated without using a pump.

[0099] A sanitary washing apparatus (1) of a second aspect according to the present disclosure further has the following configuration in addition to the configuration of the first aspect.

[0100] The sanitary washing apparatus (1) of the second aspect includes a switching device (47) configured to change the flow ratio. The switching device (47) is configured to change the flow ratio such that the second flow rate in the second state is higher than the second flow rate in the first state.

[0101] In the sanitary washing apparatus (1) of the second aspect, In generating the water stream in the second state, the volume of inflow to the second inflow hole (61) increases, and therefore, a flow rate via the first gap (21) and the second gap (22) to the passage hole (72) can be increased. Thus, in the sanitary washing apparatus (1) of the second aspect, water easily spreads in the passage hole (72) to the inner peripheral surface (720), and the continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is easily discharged from the passage hole (72). Therefore, the sanitary washing apparatus (1) of the second aspect facilitates stable generation of the water stream in the second state.

[0102] A sanitary washing apparatus (1) of a third aspect according to the present disclosure further has the following configuration in addition to the configuration of the first or second aspect.

[0103] In the sanitary washing apparatus (1) of the third aspect, the inner peripheral surface (720) of the passage hole (72) has an angle greater than 0 degrees and less than 10 degrees with respect to the central axis of the passage hole (72).

[0104] In the sanitary washing apparatus (1) of the third aspect, the inner peripheral surface (720) of the passage hole (72) has a relatively small tilt, and therefore, at the time of generating the water stream in the second state, water easily spreads to the inner peripheral surface (720) of the passage hole (72), and thereby, the water stream in the second state is easily generated.

[0105] A sanitary washing apparatus (1) of a fourth aspect according to the present disclosure further has the following configuration in addition to the configuration of any one of the first to third aspects.

[0106] In the sanitary washing apparatus (1) of the fourth aspect, the at least two states include a third state. In the third state, a continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole and then keeps a continuous flow in the space.

[0107] In the sanitary washing apparatus (1) of the fourth aspect, also at the time of generating the continuous water stream in the third state, the continuous water stream passing through the passage hole (72) with the gap between the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole. Therefore, in the sanitary washing apparatus (1) of the fourth aspect, the chances that the inner peripheral surface (720) of the passage hole (72) is wetted with water can be reduced, a ratio of the water adhering to the inner peripheral surface (720) can be suppressed from increasing, and the continuous water stream including air bubbles mixed therein can stably be generated.

[0108] A sanitary washing apparatus (1) of a fifth aspect according to the present disclosure further has the following configuration in addition to the configuration of any one of the first to fourth aspects.

[0109] In the sanitary washing apparatus (1) of the fifth aspect, the at least two states include a fourth state. In the fourth state, a water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) and a water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface (720) of the passage hole (72) are alternately and continuously discharged from the passage hole (72).

[0110] In the sanitary washing apparatus (1) of the fifth aspect, the water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) and the water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface (720) of the passage hole (72) are alternately and continuously discharged from the passage hole (72)). Therefore, the sanitary washing apparatus (1) of the fifth aspect enables the continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein to be discharged, and therefore, a water stream which gives a strong shock and a feeling of washing as compared with the water stream in the second state can be applied to a local area of a user.

[0111] The present disclosure is not limited to the embodiments described above. For example, another embodiment implemented by combining the constituent elements described in the present specification as desired or by removing some of the constituent elements may also serve as an embodiment of the present disclosure. In addition, the present disclosure also encompasses a modification obtained by making various alterations, to the foregoing embodiments, that a person skilled in the art can conceive of within the spirit of the present disclosure, namely, within the scope that does not depart from what is construed by the wordings set forth in the claims.

Examples

first embodiment

[0034]FIG. 1 is a perspective view of a sanitary washing apparatus 1 attached to a toilet 3. FIG. 2 is a circuit diagram of a water circuit 4 included in the sanitary washing apparatus 1. The sanitary washing apparatus 1 is attached to the toilet 3. The sanitary washing apparatus 1 is an apparatus that discharges water generated by a heating device 45 from a nozzle 2 to a local area of a person seated on a seat 30. The sanitary washing apparatus 1 includes the seat 30 openable / closeable with respect to the toilet 3. The nozzle 2 is provided to a tip end of a nozzle body 20. The nozzle 2 can appear and be hidden together with the nozzle body 20. The sanitary washing apparatus 1 may be provided with a toilet cover openable / closeable with respect to the toilet 3. In the present specification and claims, “water” includes warm water.

[0035]The configuration of the water circuit 4 included in the sanitary washing apparatus 1 is not limited to a particular configuration but is the configura...

CROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The present application is based upon and claims the benefit of priority to Japanese Patent Application No. 2024-207686, filed on Nov. 28, 2024, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to a sanitary washing apparatus that washes a local area of a seated human body.BACKGROUND ART

[0003] In a sanitary washing apparatus that washes a local area of a seated human body, it is known that intermittently spraying warm water, even in a relatively small volume, can give a so-called “wash feeling”, which is a feeling of being washed well, to the human body as compared with continuously spraying the warm water to the local area of the human body.

[0004] Patent Literature 1 (JP 2024-50194 A) describes a sanitary washing apparatus that can selectively discharge an intermittent water stream and a continuous water stream including air bubbles mixed therein from a nozzle without using a pump.

[0005] In the sanitary washing apparatus, pulsation action of a water stream is stabilized when the intermittent water stream is generated. However, in the sanitary washing apparatus, The water stream pulsates also when the continuous water stream including the air bubbles mixed therein is generated, and the continuous water stream is thus likely to change into the intermittent water stream, and therefore, the continuous water stream including the air bubbles mixed therein is difficult to be generated.SUMMARY

[0006] It is an object of the present disclosure to provide a sanitary washing apparatus configured to selectively and stably generate the intermittent water stream and the continuous water stream including air bubbles mixed therein without using a pump.

[0007] A sanitary washing apparatus of an aspect of the present disclosure includes a nozzle configured to discharge a water stream toward a local area of a seated human body. The nozzle includes a first cylindrical part; a second cylindrical part; and a lid part. The first cylindrical part has a central axis extending in one direction. The second cylindrical part has a central axis coincident with the central axis of the first cylindrical part and surrounding an outer peripheral surface of the first cylindrical part. The lid part closes an upper end which is one end in the one direction of the second cylindrical part. The first cylindrical part has a part in one direction in which a first inflow hole is formed, the first inflow hole formed as a through hole penetrating the part in the one direction. The lid part has a passage hole formed as a through hole penetrating the lid part in the one direction. Between the outer peripheral surface of the first cylindrical part and an inner peripheral surface of the second cylindrical part, a first gap is provided. The first gap has a lower end which is a remaining one end in the one direction and which is closed. Between the first cylindrical part and the lid part, a second gap communicated with the first gap is provided. The first cylindrical part faces the lid part. The second cylindrical part has a second inflow hole formed as a through hole and an air supply hole formed as a through hole, the second inflow hole and the air supply hole being communicated with the first gap. The first inflow hole has a sectional area smaller than a sectional area of an internal space of an upper portion of the first cylindrical part, the internal space being at an upper portion of the first cylindrical part and being above the first inflow hole. The sectional area of the first inflow hole is smaller than a sectional area of the passage hole. The sectional area of the passage hole increases upward. A central axis of the first inflow hole and a central axis of the passage hole are on an identical straight line. The first cylindrical part has an upper end located above the second inflow hole. The sanitary washing apparatus is configured to change a flow ratio of a first flow rate to a second flow rate during operation to switch the water stream between at least two states including a first state and a second state. Here, the first flow rate is a flow rate of water flowing into the first inflow hole. The second flow rate is a flow rate of water flowing into the second inflow hole. In the first state, a continuous water stream passing through the passage hole with a gap between the continuous water stream and an inner peripheral surface of the passage hole is discharged from the passage hole, and the continuous water stream then changes to an intermittent water stream in a space. In the second state, a continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface of the passage hole is discharged from the passage hole.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The figures depict one or more implementation in accordance with the present teaching, by way of example only, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements.

[0009] FIG. 1 is a perspective view of a sanitary washing apparatus attached to a toilet according to a first embodiment;

[0010] FIG. 2 is a circuit diagram of a water circuit included in the sanitary washing apparatus according to the first embodiment;

[0011] FIG. 3 is an exterior perspective view of a nozzle according to the first embodiment;

[0012] FIG. 4 is a sectional view of the nozzle taken along line A-A of FIG. 3;

[0013] FIG. 5 is an enlarged view of a main part of the nozzle shown in FIG. 4;

[0014] FIG. 6 is a sectional view of action 1 which is a situation where a water stream in a first state is discharged from the nozzle;

[0015] FIG. 7 is a sectional view of action 2 which is a situation where the water stream in the first state is discharged from the nozzle;

[0016] FIG. 8 is a sectional view of action 3 which is a situation where the water stream in the first state is discharged from the nozzle;

[0017] FIG. 9 is a sectional view of action 4 which is a situation where the water stream in the first state is discharged from the nozzle;

[0018] FIG. 10 is a sectional view of action 5 which is a situation where the water stream in the first state is discharged from the nozzle;

[0019] FIG. 11 is a sectional view of action 6 which is a situation where the water stream in the first state is discharged from the nozzle;

[0020] FIG. 12 is a view of state 1 of the water stream in a space after the water stream is discharged from the nozzle;

[0021] FIG. 13 is a view of state 2 of the water stream in the space after the water stream is discharged from the nozzle;

[0022] FIG. 14 is a view of a state of a water stream in a space after a water stream in a second state is discharged from the nozzle;

[0023] FIG. 15 is a sectional view of action 1 which is a situation where a water stream in a second state is discharged from the nozzle;

[0024] FIG. 16 is a sectional view of action 2 which is a situation where the water stream in the second state is discharged from the nozzle;

[0025] FIG. 17 is a sectional view of action 3 which is a situation where the water stream in the second state is discharged from the nozzle;

[0026] FIG. 18 is a sectional view of action 4 which is a situation where the water stream in the second state is discharged from the nozzle;

[0027] FIG. 19 is a sectional view of action 5 which is a situation where the water stream in the second state is discharged from the nozzle;

[0028] FIG. 20 is a sectional view of action 6 which is a situation where the water stream in the second state is discharged from the nozzle;

[0029] FIG. 21 is a sectional view of a situation where a water stream in a third state is discharged from the nozzle; and

[0030] FIG. 22 is a sectional view of a situation where a water stream in a fourth state is discharged from the nozzle.DETAILED DESCRIPTION

[0031] An embodiment of a sanitary washing apparatus 1, a nozzle 2, and a water stream generating method according to the present disclosure will be described below with reference to the drawings. The embodiment described below is an example with which the present disclosure is described, but the embodiment described below is not intended to limit the present disclosure. For example, shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulae, respective contents of steps in, and respective orders of, the method, and the like shown in the embodiment below are mere examples. The present disclosure may include contents not described below. Moreover, in the following description, geometric expressions, such as parallel and orthogonal, may be used, and these expressions do not indicate mathematical precision but include substantially acceptable errors, shifts, and the like. Further, expressions, such as simultaneous and identical, also include a substantially acceptable range.

[0032] Moreover, the drawings are schematic views accordingly provided with emphasis, omission, or adjustment in ratio to illustrate the present disclosure and do not show actual shapes, positional relationships, and ratios.

[0033] Further, a plurality of inventions may be comprehensively described as one embodiment below. Furthermore, some of contents described below are explained as optional components relating to the present disclosure.First Embodiment

[0034] FIG. 1 is a perspective view of a sanitary washing apparatus 1 attached to a toilet 3. FIG. 2 is a circuit diagram of a water circuit 4 included in the sanitary washing apparatus 1. The sanitary washing apparatus 1 is attached to the toilet 3. The sanitary washing apparatus 1 is an apparatus that discharges water generated by a heating device 45 from a nozzle 2 to a local area of a person seated on a seat 30. The sanitary washing apparatus 1 includes the seat 30 openable / closeable with respect to the toilet 3. The nozzle 2 is provided to a tip end of a nozzle body 20. The nozzle 2 can appear and be hidden together with the nozzle body 20. The sanitary washing apparatus 1 may be provided with a toilet cover openable / closeable with respect to the toilet 3. In the present specification and claims, “water” includes warm water.

[0035] The configuration of the water circuit 4 included in the sanitary washing apparatus 1 is not limited to a particular configuration but is the configuration described below. The water circuit 4 includes a feed-water connection port 40, a strainer 41, a water stop solenoid valve 42, a pressure reducing valve 43, a vacuum breaker 44, a heating device 45, a flow control valve 46, and a switching device 47 in this order from upstream.

[0036] The feed-water connection port 40 is a member that is connected to a water pipe by, for example, an adapter. The feed-water connection port 40 includes the strainer 41 integrally incorporated in the interior thereof. The strainer 41 prevents inflow of trash included in tap water.

[0037] The water stop solenoid valve 42 is a valve that is opened and closed by being controlled by a control device 31 (see FIG. 1) to be able to stop a flow of water from the water pipe. Opening the water stop solenoid valve 42 enables water to be discharged from the nozzle 2, and closing the water stop solenoid valve 42 enables discharging the water from the nozzle 2 to be stopped.

[0038] The pressure reducing valve 43 is a valve that reduces a water pressure of water supplied from the water pipe such that the water pressure of water after passing through the pressure reducing valve 43 is kept constant.

[0039] The vacuum breaker 44 prevents water in the interior of the water circuit 4 from flowing back to the water pipe, for example, when the water pipe connected to the feed-water connection port 40 has a negative pressure due to, for example, water outage. The vacuum breaker 44 is connected to a vent pipe 48. The vent pipe 48 extends to a toilet bowl 32 (see FIG. 1) of the toilet 3. The vent pipe 48 is a supply path of external air supplied to the vacuum breaker 44 when the vacuum breaker 44 operates. Moreover, the vent pipe 48 has a function as a water release path that releases water instantaneously released during operation of the vacuum breaker 44 into the toilet 3.

[0040] The heating device 45 is a device that heats tap water supplied from the water pipe to generate warm water. The heating device 45 is not limited to a particular device but is a heat exchanger that instantaneously heats tap water supplied from the water pipe. The heating device 45 integrally includes a buffer tank 450 that makes the temperature of the water heated by the heating device 45 uniform.

[0041] The flow control valve 46 is a valve that is controlled by the control device 31 to adjust the volume of water supplied to the nozzle 2.

[0042] The switching device 47 separates the water heated by the heating device 45 into first water W1 and second water W2 and supplies the first water W1 and second water W2 to the nozzle 2. The switching device 47 is configured to switch a flow ratio of a first flow rate of the first water W1 to a second flow rate of the second water W2.

[0043] FIG. 3 is an exterior perspective view of the nozzle 2. FIG. 4 is a sectional view of the nozzle 2 taken along line A-A of FIG. 3. FIG. 5 is an enlarged view of a main part of the nozzle 2. FIG. 5 is a sectional view and a broken line is added to distinguish components from one another to facilitate the understanding.

[0044] The nozzle 2 is a nozzle 2 that discharges warm water heated by the heating device 45 toward a local area of the body of a person seated on the seat 30. As shown in FIGS. 3 to 5, the nozzle 2 includes a first cylindrical part 5, a second cylindrical part 6, and a lid part 7. The nozzle 2 further includes a first connection part 8 and a second connection part 9.

[0045] The first cylindrical part 5 has a central axis 50 extending in one direction D1. In the following description, one end side in the one direction D1 is referred to as an upper side, and the other end side in the one direction D1 is referred to as a lower side. The first cylindrical part 5 has a part in one direction D1 (in the Z-axis direction in the figure) in which a first inflow hole 51 is formed. The first inflow hole 51 is formed as a through hole penetrating the part in the one direction D1. The first water W1, which is one of two parts of the water generated by the heating device 45 and separated by the switching device 47, flows into a lower end opening of the first cylindrical part 5, passes through the first inflow hole 51, and flows into an internal space of the first cylindrical part 5, the internal space being at an upper portion 52 of the first cylindrical part 5 and being above the first inflow hole 51. As shown in FIG. 5 and FIG. 6, a sectional area S1 of the first inflow hole 51 and a sectional area S2 of the internal space of the upper portion 52 are in such a relationship that the first water W1 flowing from the first inflow hole 51 into the internal space can be ejected from an upper end opening of the first cylindrical part 5 without coming into contact with an inner peripheral surface of the upper portion 52. Specifically, S2>S1. The shape of the first cylindrical part 5 is not limited to a particular shape but is a circularly cylindrical shape. The shape of the first inflow hole 51 is not limited to a particular shape but is a circular shape when viewed in the one direction D1, and the first inflow hole 51 is arranged at the center of the first cylindrical part 5 in a radial direction. The sectional area shows the area (size of a region) surrounded by an inner peripheral surface of a cylinder in a cut plane of the cylinder when the cylinder is cut orthogonally to the central axis thereof.

[0046] The second cylindrical part 6 has a central axis 60 which coincides with the central axis 50 of the first cylindrical part 5. The second cylindrical part 6 is a cylindrical part surrounding an outer peripheral surface of the first cylindrical part 5. Between the outer peripheral surface of the first cylindrical part 5 and an inner peripheral surface of the second cylindrical part 6, a first gap 21 is provided, and the first gap 21 has a lower end which is closed. The inner peripheral surface of the second cylindrical part 6 faces the outer peripheral surface of the first cylindrical part 5. The lower end of the first gap 21 is closed by part of the first cylindrical part 5. The first gap 21 has a radial length G1 narrower than an inner diameter L1 of the first inflow hole 51. The second cylindrical part 6 protrudes upward beyond an upper end of the first cylindrical part 5 in the one direction D1. Thus, the second water W2 flowing into the first gap 21 between the first cylindrical part 5 and the second cylindrical part 6 climbs over the upper end of the first cylindrical part 5 and flows into the first cylindrical part 5. The shape of the second cylindrical part 6 may be rectangularly cylindrical but is not limited to a particular shape. The second cylindrical part 6 has a circularly cylindrical shape similar to the first cylindrical part 5 and is arranged coaxially with the first cylindrical part 5.

[0047] The lid part 7 includes: a lid part body 70 having a circularly annular shape; and a cylindrical part 71 provided to extend upward from a surface on a front side (i.e., upper side) of the lid part body 70. The cylindrical part 71 is arranged at a location which is on an opposite side (i.e., upper side) of the first cylindrical part 5 from the first inflow hole 51 and which is apart from the first cylindrical part 5. The cylindrical part 71 is a cylindrical part arranged coaxially with the first cylindrical part 5. That is, the first cylindrical part 5, the second cylindrical part 6, and the cylindrical part 71 are arranged to have an identical axis. The shape of the cylindrical part 71 is a circularly cylindrical shape similar to the first cylindrical part 5.

[0048] The lid part 7 is disposed to close an upper end of the second cylindrical part 6. The lid part 7 includes: the lid part body 70 closing the upper end of the second cylindrical part 6; and the cylindrical part 71 protruding upward from a center part of the lid part body 70 in the radial direction. The lid part 7 has a passage hole 72 formed as a through hole penetrating the lid part 7 in the one direction D1. The passage hole 72 is formed in the lid part body 70 and the cylindrical part 71. The lid part 7 does not have to include the cylindrical part 71 but may consist of the lid part body 70. A central axis of the first inflow hole 51 and a central axis of the passage hole 72 are located on the same straight line.

[0049] The passage hole 72 has a sectional area increasing upward. The passage hole 72 has a circular truncated cone shape. The lid part 7 surrounding the passage hole 72 has an inner peripheral surface 720 tilted in a tapered shape. The inner peripheral surface 720 has an angle larger than 0 degrees and smaller than 10 degrees to the central axis of the passage hole 72.

[0050] A diameter L2 of an upper end opening 721 of the passage hole 72 is larger than a diameter L3 of a lower end opening 722 of the passage hole 72. A sectional area S3 of the upper end opening 721 is larger than a sectional area S4 of the lower end opening 722.

[0051] For example, the diameter L3 is 1.35 mm, and the diameter L2 is 1.45 mm. In this case, an angle of the inner peripheral surface 720 to the central axis of the passage hole 72 is 3.57 degrees.

[0052] Between the first cylindrical part 5 and the lid part 7, a second gap 22 communicated with the first gap 21 is provided. Therefore, the first cylindrical part 5 faces the lid part 7.

[0053] The second cylindrical part 6 has a second inflow hole 61 formed as a through hole and an air supply hole 62 formed as a through hole such that the second inflow hole 61 and the air supply hole 62 are communicated with the first gap 21. The second inflow hole 61 penetrating part of a peripheral wall of the second cylindrical part 6 in a circumferential direction is a through hole through which the second water W2, which is the other of the two parts of the water separated by the switching device 47, flows into the first gap 21. The second inflow hole 61 penetrates the peripheral wall at a portion which is part of the second cylindrical part 6 and which overlaps the outer perimeter of the first cylindrical part 5. That is, the upper end of the first cylindrical part 5 is located above the second inflow hole 61. The second water W2 flowing into the second inflow hole 61 hits the outer peripheral surface of the first cylindrical part 5.

[0054] The air supply hole 62 is a through hole through which air outside the second cylindrical part 6 is supplied to the first gap 21. The air supply hole 62 is provided in a lower portion of the second cylindrical part 6 and is communication with a lower end part of the first gap 21. The number of air supply hole(s) 62 may be one or more, but one air supply hole 62 is provided for the second cylindrical part 6 as shown in FIG. 3.

[0055] A positional relationship between the air supply hole 62 and the second inflow hole 61 is not limited to a particular relationship, but the second inflow hole 61 is disposed above the air supply hole 62 as shown in FIG. 5. The second inflow hole 61 and the air supply hole 62 are arranged such that an inflow direction of the second water W2 from the second inflow hole 61 and an inflow direction of air from the air supply hole 62 are parallel to each other. The air supply hole 62 and the second inflow hole 61 are arranged at locations apart from each other by 180 degrees centered on the central axis 60 of the second cylindrical part 6.

[0056] Through the passage hole 72, the first water W1 flowing from the first inflow hole 51 passes alone, or the second water W2 filled in the inner side of the second cylindrical part 6 passes together with the first water W1. The sectional area S4 of the lower end opening 722 of the passage hole 72 is larger than the sectional area S1 of the first inflow hole 51. In other words, the relationship that S4>S1 is satisfied. Thus, the first water W1 flowing from the first inflow hole 51 into the passage hole 72 in a state where the second water W2 does not flow into the inner side of the first cylindrical part 5 (i.e., in a state where the interior of the first cylindrical part 5 is filled with air) can pass through the passage hole 72 without coming into contact with the inner peripheral surface 720 of the passage hole 72. The relationship between S2 and S4 may be that S4≥S2. Alternatively, the relationship may be that S2>S4 (where S4>S1).

[0057] The upper end of the second cylindrical part 6 is disposed above the upper end of the first cylindrical part 5, and the lower end of the second cylindrical part 6 is disposed at the same location as the lower end of the first cylindrical part 5 in an up / down direction.

[0058] As shown in FIG. 4, the first connection part 8 is a portion to which a tube is connected. The tube guides the first water W1, which is the one of the two parts of the water separated by the switching device 47. The first connection part 8 has an outer peripheral surface having a bamboo sprout-like retaining shape. The first connection part 8 is cylindrical and is integral with the first cylindrical part 5. An internal space of the first connection part 8 and the internal space of the first cylindrical part 5 are continuous in a straight line. The first cylindrical part 5 and the first connection part 8 are configured as one cylindrical member. The first cylindrical part 5 and the first connection part 8 are a resin molded piece.

[0059] The second connection part 9 is a portion to which a tube is connected. The tube guides the second water W2, which is the other of the two parts of the water separated by the switching device 47. The second connection part 9 has an outer peripheral surface having a bamboo sprout-like retaining shape. The second connection part 9 has a cylindrical shape extending in a direction (in an X-axis direction in the figure) orthogonal to the one direction D1 and is integral with the second cylindrical part 6. An internal space of the second connection part 9 and the second inflow hole 61 of the second cylindrical part 6 are continuous in a straight line. The second cylindrical part 6, the lid part 7, and the second connection part 9 are configured as one member. The second cylindrical part 6, the lid part 7, and the second connection part 9 are a resin molded piece.

[0060] The switching device 47 is a device for switching a flow ratio of the first flow rate, which is the flow rate of water flowing into the first inflow hole 51 of the nozzle 2, to the second flow rate, which is the flow rate of water flowing into the second inflow hole 61 of the nozzle 2. The switching device 47 has no pump function but is capable of switching the flow ratio by a water path configuration operated by a motor 470. The switching device 47 is provided to be able to implement five switching modes different from one another in terms of flow ratio.

[0061] In a first switching mode, the switching device 47 switches the flow ratio such that the flow rate of water flowing into the second inflow hole 61 of the nozzle 2 is about 25% of the flow rate of water flowing into the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 3:1 to 7:1. When the switching device 47 is in the first switching mode, a water stream which changes to an intermittent water stream in a space after being discharged as a continuous water stream is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “first state”, see FIG. 13).

[0062] In a second switching mode, the switching device 47 switches the flow ratio such that the flow rate of water flowing into the second inflow hole 61 of the nozzle 2 is about 40% of the flow rate of water flowing into the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 2.0:1 to 3.0:1. When the switching device 47 is in the second switching mode, a continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein is discharged from the passage hole 72 of the nozzle 2 as shown in FIG. 14 (hereinafter referred to as a “second state”). The switching device 47 switches the flow ratio such that the second flow rate in the second state is higher than the second flow rate in the first state.

[0063] In a third switching mode, the switching device 47 causes substantially the same volumes of water to flow into the first inflow hole 51 and the second inflow hole 61 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 1.0:1 to 1.5:1. When the switching device 47 is in the third switching mode, a jet stream which is a continuous water stream as shown in FIG. 15 or 21 is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “third state”).

[0064] In a fourth switching mode, the switching device 47 switches the flow ratio such that water flows into only the first inflow hole 51 of the nozzle 2. At this time, the flow ratio of the first flow rate to the second flow rate is 1:0. When the switching device 47 is in the fourth switching mode, a continuous and narrow water stream as shown in FIG. 22 is discharged from the passage hole 72 of the nozzle 2 (hereinafter referred to as a “fourth state”).

[0065] In response to an operation given to a rear wash button provided to the control device 31 (see FIG. 1), the switching device 47 enters a switching mode corresponding to the button to which the operation has been given.

[0066] A situation where the intermittent water stream (i.e., a water stream in the first state) is generated in a space will be described below. At the time of generating the water stream in the first state, a first discharge state and a second discharge state are repeated as general actions. In the first discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51 passes through the passage hole 72 and is discharged from the passage hole 72, but the second water W2 flowing into the first gap 21 through the second inflow hole 61 is not discharged from the passage hole 72. In the second discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51 passes through the passage hole 72. The second water W2 flowing from the second inflow hole 61 into the first gap 21 passes through the second gap 22 and the passage hole 72. Thus, the first water W1 and the second water W2 are discharged together from the passage hole 72.

[0067] With reference to FIGS. 6 to 13, generation of a water stream in the first state is sequentially given in detail. As shown in FIG. 6, the first water W1 in an injection state flows from the first inflow hole 51 into the upper portion 52 above the first inflow hole 51. The first water W1 flowing into the upper portion 52 passes through air in the upper portion 52 and air in the passage hole 72 without coming into contact with the inner peripheral surface of the upper portion 52 or the inner peripheral surface 720 of the passage hole 72 and is discharged from the passage hole 72. This state is the first discharge state. In the first discharge state, the second water W2 flows from the second inflow hole 61 into the first gap 21 and accumulates in the first gap 21. The second water W2 does not flow out through the air supply hole 62 due to the surface tension of the water. Thus, in the first discharge state, the first water W1 flowing from the first inflow hole 51 into the upper portion 52 is discharged from the passage hole 72, but the second water W2 flowing from the second inflow hole 61 into the first gap 21 is not discharged from the passage hole 72. In the first discharge state, the second water W2 flowing from the second inflow hole 61 into the first gap 21 accumulates in the first gap 21 and does not reach the second gap 22, and air is in the second gap 22.

[0068] Then, when the second water W2 fills the first gap 21, as shown in FIGS. 7 and 8, the second water W2 passes through the second gap 22, and the second water W2 climbs over the upper end of the first cylindrical part 5 and flows into the interior of the first cylindrical part 5. The second water W2 flows into the inner side of the first cylindrical part 5 from at least part in the circumferential direction of the upper end of the first cylindrical part 5.

[0069] At this time, the second water W2 collides with the first water W1, is pulled in a flow direction of the first water W1, and flows into the interior of the first cylindrical part 5, and the interior of the first cylindrical part 5 is filled with the first water W1 and the second water W2. Then, as shown in FIG. 9, water which is a mixture of the first water W1 and the second water W2 is discharged from the passage hole 72. The water, which is a mixture of the first water W1 and the second water W2, is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the lower end opening 722 of the passage hole 72, and thus, there is a gap between the water and the inner peripheral surface 720 of the passage hole 72. This state is the second discharge state.

[0070] In the second discharge state, a first condition and a second condition are satisfied, and thus, an ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at a downstream end of the first inflow hole 51, and thereby, air is sucked through the air supply hole 62.

[0071] As shown in FIG. 10, the air sucked through the air supply hole 62 passes through the first gap 21 and the second gap 22, flows into the interior of the first cylindrical part 5 by being pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51, and flows into the interior of the passage hole 72 by being pulled by the flow of the first water W1.

[0072] Next, the air flowing into the interior of the upper portion 52 of the first cylindrical part 5 and the interior of the passage hole 72 spreads to surround the first water W1 as shown in FIG. 11 and blocks the flow of the second water W2 into the first water W1. Further, when a state where the interior of the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2 is released, the ejector effect is inactivated, and an air sucking action ends, returning to the first discharge state. Thus, a flow which is a thick jet stream formed by merging of the second water W2 with the first water W1 is switched to a thin jet stream of only the first water W1. In this way, the first discharge state and the second discharge state are repeated.

[0073] FIG. 12 is a view of state 1 of a water stream in a space after the water stream is discharged from the nozzle 2. FIG. 13 is a view of state 2 of the water stream in the space after the water stream is discharged from the nozzle 2. A first flying water W10 shown in each of these figures is water which is in the first discharge state and which corresponds to only the first water W1 discharged from the passage hole 72 to air. A second flying water W12 is water which is in the second discharge state and which correspond to the first water W1 and the second water W2 discharged together from the passage hole 72. The flow speed of the first flying water W10 is higher than the flow speed of the second flying water W12. Therefore, the first flying water W10 separates from a subsequent second flying water W12 and forms a water mass together with a preceding second flying water W12 as shown in FIG. 13. In this way, water discharged from the nozzle 2 forms an intermittent water stream in the space.

[0074] Subsequently, a situation where a continuous water stream (i.e., a water stream in the second state) shown in FIG. 14, having a jet stream diameter narrowing in a certain cycle, and including air bubbles mixed therein is generated will be described. The second flow rate in the second state is higher than the second flow rate in the first state.

[0075] In the generation of the water stream in the second state, actions shown in FIGS. 6 to 8 are first of all caused in a similar manner to the generation of the water stream in the first state. The generation of the water stream in the second state may be started with the action shown in FIG. 9.

[0076] At the time of generating the water stream in the second state, the second flow rate is higher than the second flow rate in the first state. Therefore, water which is a mixture of the first water W1 and the second water W2 spreads in the interior of the passage hole 72 to the inner peripheral surface 720 and fills the interior of the passage hole 72 as shown in FIG. 15. The water, which is the mixture of the first water W1 and the second water W2, is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the upper end opening 721 of the passage hole 72.

[0077] In this discharge state, the first condition and the second condition are satisfied, and thus, the ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at the downstream end of the first inflow hole 51. Also, a third condition and a fourth condition are satisfied, and thus, the ejector effect is generated. The third condition is that the flow speed in the lower end opening 722 of the passage hole 72 is higher than the flow speed in the upper portion above the lower end opening 722 of the passage hole 72 to cause a speed difference. The fourth condition is that the passage hole 72 is filled with the first water W1 and the second water W2. This generates a negative pressure in the lower end opening 722 of the passage hole 72. That is, at the time of generating the water stream in the second state, negative pressures are generated at two locations, namely the downstream end of the first inflow hole 51 and the lower end opening 722 of the passage hole 72, and thereby, air is sucked through the air supply hole 62.

[0078] As shown in FIG. 16, the air sucked through the air supply hole 62 passes from the air supply hole 62 through the first gap 21 and the second gap 22, and flows into the interior of the upper portion 52 of the first cylindrical part 5 by being pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51. Then, the air sucked through the air supply hole 62 collides with the water stream of the first water W1 by being pulled to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72. Then, the air sucked through the air supply hole 62 flows into the interior of the passage hole 72 by being pulled by the flow of the first water W1.

[0079] In the air flowing to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72, air bubbles are crushed by the water stream of the first water W1 into fine air bubbles, which are mixed overall in the first water W1 and the second water W2 in the passage hole 72.

[0080] Then, as shown in FIGS. 17 and 18, the air pulled to the location where the negative pressure is generated at the downstream end of the first inflow hole 51 reaches the downstream end of the first inflow hole 51, thereby canceling negative pressure generation at the downstream end of the first inflow hole 51. Then, the air pulled to the location where the negative pressure is generated at the lower end opening 722 of the passage hole 72 and the air pulled by the flow of the first water W1 enter the passage hole 72, Thereby canceling negative pressure generation at the lower end opening 722 of the passage hole 72. This achieves a state where only the first water W1 is discharged from the passage hole 72.

[0081] When the negative pressure generation at the two locations, namely, the downstream end of the first inflow hole 51 and the lower end opening 722 of the passage hole 72 is canceled, the second water W2 flows into, and fills, the interior of the upper portion 52 of the first cylindrical part 5 and the interior of the passage hole 72 as shown in FIGS. 19 and 20. Thus, the negative pressures are generated again at the two locations, namely, the downstream end of the first inflow hole 51 and the lower end of the passage hole 72, thereby generating a water stream shown in FIG. 14 and obtained by mixing air as the fine air bubbles overall in the first water W1 and the second water W2 in the passage hole 72.

[0082] At the time of generating the water stream in the second state, the second flow rate is higher than the second flow rate in the first state. Therefore, at the time of generating the water stream in the second state, a state shown in FIG. 18 where the negative pressure generation at the two locations is canceled is switched to a negative pressure generation state shown in FIG. 20 in a shorter time than an interval between the release and the generation of the negative pressure in the first state. Therefore, at the time of generating the water stream in the second state, the intermittent flow as shown in FIG. 13 is not generated but a continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein is generated.

[0083] At the time of generating the water stream in the second state, repeating actions shown in FIGS. 17 to 20 generates a continuous water stream shown in FIG. 14, having a jet stream diameter narrowing in a certain cycle, and including air bubbles mixed therein.

[0084] Subsequently, a situation where a jet stream (i.e., water stream in the third state) which is a continuous water stream shown in FIG. 21 is generated will be described. The second flow rate in the third state is higher than the second flow rate in the first state and is lower than the second flow rate in the second state. In the third state, the first flow rate and the second flow rate are substantially equal to each other.

[0085] In the generation of the water stream in the third state, actions shown in FIGS. 6 to 9 are first of all occur in a similar manner to the generation of the water stream in the first state. The generation of the water stream in the third state may be started with the action shown in FIG. 9.

[0086] At the time of generating the water stream in the third state, the first condition and the second condition are satisfied in the action shown in FIG. 9, and thus, the ejector effect is generated. The first condition is that the flow speed of the first water W1 in the first inflow hole 51 is higher than the flow speed of the first water W1 and the second water W2 in the upper portion 52 of the first cylindrical part 5 to cause a speed difference. The second condition is that the upper portion 52 of the first cylindrical part 5 is filled with the first water W1 and the second water W2. This generates a negative pressure at the downstream end of the first inflow hole 51. However, at the time of generating the water stream in the third state, the second flow rate is significantly higher than the second flow rate in the first state, and therefore, the air sucked through the air supply hole 62 due to the pressure of the second water W2 can be prevented from reaching the first water W1. Thus, at the time of generating the water stream in the third state, actions shown in FIGS. 10 to 13 do not occur, and a jet stream which is the continuous water stream shown in FIG. 15 or 21 and including no air bubbles mixed therein can be generated. The water stream in the third state keeps its continuous flow in a space after being discharged from the passage hole 72.

[0087] The second flow rate in the third state can accordingly be set within a range in which a flow ratio of the first flow rate to the second flow rate is 1.0:1 to 1.5:1. When the second flow rate in the third state is higher than a certain value, a jet stream shown in FIG. 15 can be generated, and when the second flow rate in the third state is lower than the certain value, a jet stream shown in FIG. 21 can be generated.

[0088] Subsequently, a situation where a continuous narrow water stream (i.e., a water stream in the fourth state) shown in FIG. 22 is generated will be described. At the time of generating the water stream in the fourth state, only the first water W1, but no second water W2, is supplied to the nozzle 2.

[0089] At the time of generating the water stream in the fourth state, the first water W1 in an injection state flows from the first inflow hole 51 into the upper portion 52 of the first cylindrical part 5. The first water W1 flowing into the upper portion 52 of the first cylindrical part 5 passes through air in the upper portion 52 of the first cylindrical part 5 and air in the passage hole 72 without coming into contact with the inner peripheral surface of the upper portion 52 of the first cylindrical part 5 or the inner peripheral surface 720 of the passage hole 72 and is discharged from the passage hole 72. The first water W1 is discharged from the passage hole 72 to have a substantially the same thickness (in other words, sectional area) as the first inflow hole 51.

[0090] With the sanitary washing apparatus 1 described above, changing the flow ratio of the first flow rate to the second flow rate by the switching device 47 enables four types of water streams to selectively be discharged from the passage hole 72 of a single nozzle 2. Thus, it is possible to delicately respond to preferences of a user seated on the seat 30.

[0091] Moreover, in the sanitary washing apparatus 1, the inner peripheral surface 720 of the passage hole 72 is less likely to be wetted with water at the time of generating the water streams in the first state, the third state, and the fourth state, and therefore, the ratio of water adhering to the inner peripheral surface 720 can be suppressed from increasing. Thus, the sanitary washing apparatus 1 can suppress a continuous water stream spreading to the inner peripheral surface 720 of the passage hole 72 and including air bubbles mixed therein from being changed to an intermittent water stream by pulsation of this water stream when the continuous water stream is generated, and thereby, the continuous water stream including air bubbles mixed therein can stably be generated. Therefore, the sanitary washing apparatus 1 enables the intermittent water stream and the continuous water stream including air bubbles mixed therein to be selectively and stably generated without using a pump.Variations

[0092] Subsequently, variations of the sanitary washing apparatus 1 described above will be described. The variations described below may accordingly be combined with each other.

[0093] The sanitary washing apparatus 1 may be configured to selectively discharge only the water streams in the first state and the second state and does not have to be able to discharge all or some of the water streams in the third state and fourth state. In other words, the switching device 47 may be disposed to be able to switch the flow ratio only between the first switching mode and the second switching mode.

[0094] The inner peripheral surface 720 of the passage hole 72 may have an angle larger than or equal to 10 degrees to the central axis of the passage hole 72.

[0095] The structure of the nozzle 2 is not limited to the structures shown in FIGS. 3 and 4, and the nozzle 2 is at least configured such that the water stream is switched between at least two states including the first state and the second state in accordance with the flow ratio of the first flow rate to the second flow rate.Summary

[0096] A sanitary washing apparatus 1 of a first aspect according to the present disclosure has the following configurations.

[0097] A sanitary washing apparatus (1) of a first aspect includes a nozzle (2) configured to discharge a water stream toward a local area of a seated human body. The nozzle (2) includes a first cylindrical part (5), a second cylindrical part (6), and a lid part (7). The first cylindrical part (5) has a central axis (50) extending in one direction (D1). The second cylindrical part (6) has a central axis (60) coincident with the central axis (50) of the first cylindrical part (5) and surrounding an outer peripheral surface of the first cylindrical part (5). The lid part (7) closes an upper end which is one end in the one direction (D1) of the second cylindrical part (6). The first cylindrical part (5) has a part in the one direction (D1) in which a first inflow hole (51) is formed, the first inflow hole (51) formed as a through hole penetrating the part in the one direction (D1). The lid part (7) has a passage hole (72) formed as a through hole penetrating the lid part (7) in the one direction (D1). Between the outer peripheral surface of the first cylindrical part (5) and an inner peripheral surface of the second cylindrical part (6), a first gap (21) is provided. The first gap (21) has a lower end which is a remaining one end in the one direction (D1) and which is closed. Between the first cylindrical part (5) and the lid part (7), a second gap (22) communicated with the first gap (21) is provided. The first cylindrical part (5) faces the lid part (7). The second cylindrical part (6) has a second inflow hole (61) formed as a through hole and an air supply hole (62) formed as a through hole, the second inflow hole (61) and the air supply hole (62) being communicated with the first gap (21). The first inflow hole (51) has a sectional area smaller than a sectional area of an internal space of an upper portion of the first cylindrical part (5), the internal space being at an upper portion of the first cylindrical part (5) and being above the first inflow hole (51). The sectional area of the first inflow hole (51) is smaller than a sectional area of the passage hole (72). The sectional area of the passage hole (72) increases upward. A central axis of the first inflow hole (51) and a central axis of the passage hole (72) are on an identical straight line. The first cylindrical part (5) has an upper end located above the second inflow hole (61). The sanitary washing apparatus (1) is configured to change a flow ratio between a first flow rate and a second flow rate during operation to switch the water stream between at least two states including a first state and a second state. Here, the first flow rate is a flow rate of water flowing into the first inflow hole (51). The second flow rate is a flow rate of water flowing into the second inflow hole (61). In the first state, a continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and an inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole, and the continuous water stream then changes to an intermittent water stream in a space. In the second state, a continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72).

[0098] In the sanitary washing apparatus (1) of the first aspect, to generate the intermittent water stream in the first state, the continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole. Therefore, in the sanitary washing apparatus (1) of the first aspect, the chances that the inner peripheral surface (720) of the passage hole (72) is wetted with water can be reduced, and a ratio of the water adhering to the inner peripheral surface (720) can be suppressed from increasing. Thus, in the sanitary washing apparatus (1) of the first aspect, when the continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72), the continuous water stream can be suppressed from changing to the intermittent water stream. Therefore, the sanitary washing apparatus (1) of the first aspect enables the intermittent water stream and the continuous water stream including air bubbles mixed therein to be selectively and stably generated without using a pump.

[0099] A sanitary washing apparatus (1) of a second aspect according to the present disclosure further has the following configuration in addition to the configuration of the first aspect.

[0100] The sanitary washing apparatus (1) of the second aspect includes a switching device (47) configured to change the flow ratio. The switching device (47) is configured to change the flow ratio such that the second flow rate in the second state is higher than the second flow rate in the first state.

[0101] In the sanitary washing apparatus (1) of the second aspect, In generating the water stream in the second state, the volume of inflow to the second inflow hole (61) increases, and therefore, a flow rate via the first gap (21) and the second gap (22) to the passage hole (72) can be increased. Thus, in the sanitary washing apparatus (1) of the second aspect, water easily spreads in the passage hole (72) to the inner peripheral surface (720), and the continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) is easily discharged from the passage hole (72). Therefore, the sanitary washing apparatus (1) of the second aspect facilitates stable generation of the water stream in the second state.

[0102] A sanitary washing apparatus (1) of a third aspect according to the present disclosure further has the following configuration in addition to the configuration of the first or second aspect.

[0103] In the sanitary washing apparatus (1) of the third aspect, the inner peripheral surface (720) of the passage hole (72) has an angle greater than 0 degrees and less than 10 degrees with respect to the central axis of the passage hole (72).

[0104] In the sanitary washing apparatus (1) of the third aspect, the inner peripheral surface (720) of the passage hole (72) has a relatively small tilt, and therefore, at the time of generating the water stream in the second state, water easily spreads to the inner peripheral surface (720) of the passage hole (72), and thereby, the water stream in the second state is easily generated.

[0105] A sanitary washing apparatus (1) of a fourth aspect according to the present disclosure further has the following configuration in addition to the configuration of any one of the first to third aspects.

[0106] In the sanitary washing apparatus (1) of the fourth aspect, the at least two states include a third state. In the third state, a continuous water stream passing through the passage hole (72) with a gap between the continuous water stream and the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole and then keeps a continuous flow in the space.

[0107] In the sanitary washing apparatus (1) of the fourth aspect, also at the time of generating the continuous water stream in the third state, the continuous water stream passing through the passage hole (72) with the gap between the inner peripheral surface (720) of the passage hole (72) is discharged from the passage hole (72)passage hole. Therefore, in the sanitary washing apparatus (1) of the fourth aspect, the chances that the inner peripheral surface (720) of the passage hole (72) is wetted with water can be reduced, a ratio of the water adhering to the inner peripheral surface (720) can be suppressed from increasing, and the continuous water stream including air bubbles mixed therein can stably be generated.

[0108] A sanitary washing apparatus (1) of a fifth aspect according to the present disclosure further has the following configuration in addition to the configuration of any one of the first to fourth aspects.

[0109] In the sanitary washing apparatus (1) of the fifth aspect, the at least two states include a fourth state. In the fourth state, a water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) and a water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface (720) of the passage hole (72) are alternately and continuously discharged from the passage hole (72).

[0110] In the sanitary washing apparatus (1) of the fifth aspect, the water stream including air bubbles mixed therein and spreading to the inner peripheral surface (720) of the passage hole (72) and the water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface (720) of the passage hole (72) are alternately and continuously discharged from the passage hole (72)). Therefore, the sanitary washing apparatus (1) of the fifth aspect enables the continuous water stream having a jet stream diameter narrowing in a certain cycle and including air bubbles mixed therein to be discharged, and therefore, a water stream which gives a strong shock and a feeling of washing as compared with the water stream in the second state can be applied to a local area of a user.

[0111] The present disclosure is not limited to the embodiments described above. For example, another embodiment implemented by combining the constituent elements described in the present specification as desired or by removing some of the constituent elements may also serve as an embodiment of the present disclosure. In addition, the present disclosure also encompasses a modification obtained by making various alterations, to the foregoing embodiments, that a person skilled in the art can conceive of within the spirit of the present disclosure, namely, within the scope that does not depart from what is construed by the wordings set forth in the claims.

Examples

first embodiment

[0034]FIG. 1 is a perspective view of a sanitary washing apparatus 1 attached to a toilet 3. FIG. 2 is a circuit diagram of a water circuit 4 included in the sanitary washing apparatus 1. The sanitary washing apparatus 1 is attached to the toilet 3. The sanitary washing apparatus 1 is an apparatus that discharges water generated by a heating device 45 from a nozzle 2 to a local area of a person seated on a seat 30. The sanitary washing apparatus 1 includes the seat 30 openable / closeable with respect to the toilet 3. The nozzle 2 is provided to a tip end of a nozzle body 20. The nozzle 2 can appear and be hidden together with the nozzle body 20. The sanitary washing apparatus 1 may be provided with a toilet cover openable / closeable with respect to the toilet 3. In the present specification and claims, “water” includes warm water.

[0035]The configuration of the water circuit 4 included in the sanitary washing apparatus 1 is not limited to a particular configuration but is the configura...

Claims

1. A sanitary washing apparatus comprising a nozzle configured to discharge a water stream toward a local area of a seated human body,the nozzle includinga first cylindrical part having a central axis extending in one direction,a second cylindrical part having a central axis coincident with the central axis of the first cylindrical part and surrounding an outer peripheral surface of the first cylindrical part, anda lid part closing an upper end which is one end in the one direction of the second cylindrical part,the first cylindrical part having a part in the one direction in which a first inflow hole is formed, the first inflow hole formed as a through hole penetrating the part in the one direction,the lid part having a passage hole formed as a through hole penetrating the lid part in the one direction,between the outer peripheral surface of the first cylindrical part and an inner peripheral surface of the second cylindrical part, a first gap being provided, the first gap having a lower end which is a remaining one end in the one direction and which is closed,between the first cylindrical part and the lid part, a second gap communicated with the first gap being provided,the first cylindrical part facing the lid part,the second cylindrical part having a second inflow hole formed as a through hole and an air supply hole formed as a through hole, the second inflow hole and the air supply hole being communicated with the first gap,the first inflow hole having a sectional area smaller than a sectional area of an internal space of an upper portion of the first cylindrical part, the internal space being at an upper portion of the first cylindrical part and being above the first inflow hole,the sectional area of the first inflow hole being smaller than a sectional area of the passage hole,the sectional area of the passage hole increasing upward,a central axis of the first inflow hole and a central axis of the passage hole being on an identical straight line,the first cylindrical part has an upper end located above the second inflow hole,the sanitary washing apparatus being configured to change a flow ratio between a first flow rate and a second flow rate during operation to switch the water stream between at least two states including a first state and a second state,the first flow rate being a flow rate of water flowing into the first inflow hole,the second flow rate being a flow rate of water flowing into the second inflow hole,in the first state, a continuous water stream passing through the passage hole with a gap between the continuous water stream and an inner peripheral surface of the passage hole being discharged from the passage hole, and the continuous water stream then changing to an intermittent water stream in a space,in the second state, a continuous water stream including air bubbles mixed therein and spreading to the inner peripheral surface of the passage hole being discharged from the passage hole.

2. The sanitary washing apparatus of claim 1, further comprising a switching device configured to change the flow ratio, whereinthe switching device is configured to change the flow ratio such that the second flow rate in the second state is higher than the second flow rate in the first state.

3. The sanitary washing apparatus of claim 1, whereinthe inner peripheral surface of the passage hole has an angle greater than 0 degrees and less than 10 degrees with respect to the central axis of the passage hole.

4. The sanitary washing apparatus of claim 1, whereinthe at least two states include a third state, andin the third state, a continuous water stream passing through the passage hole with a gap between the continuous water stream and the inner peripheral surface of the passage hole is discharged from the passage hole and then keeps a continuous flow in the space.

5. The sanitary washing apparatus of claim 1, whereinthe at least two states include a fourth state, andin the fourth state, a water stream including air bubbles mixed therein and spreading to the inner peripheral surface of the passage hole and a water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface of the passage hole are alternately and continuously discharged from the passage hole.

6. The sanitary washing apparatus of claim 4, whereinthe at least two states include a fourth state, andin the fourth state, a water stream including air bubbles mixed therein and spreading to the inner peripheral surface of the passage hole and a water stream including no air bubbles mixed therein and being at a gap from the inner peripheral surface of the passage hole are alternately and continuously discharged from the passage hole.

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