EP2907431B1

EP2907431B1 - Shower head

Info

Publication number: EP2907431B1
Application number: EP13846077.9A
Authority: EP
Inventors: Yasunari Maeda; Yoshihiro Itou; Naoki Shibata; Tomohiro Akita
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2012-10-11
Filing date: 2013-10-08
Publication date: 2018-06-27
Anticipated expiration: 2033-10-08
Also published as: CN104703520B; EP2907431A1; CN104703520A; EP2907431A4; WO2014057660A1

Description

Technical Field

The present invention relates to a shower head that discharges warm or cold water including microbubbles from spray apertures.

Background Art

Microbubbles of 50 µm diameter or smaller, which are mixing in warm or cold water, have relatively large specific surface areas and therefore the microbubbles can absorb and remove a considerable amount of pollutants such as sebum of a human body. The smaller the diameter of microbubbles is, the larger the specific surface areas are. Minimization of the diameter of microbubbles is desirable in order to improve such a cleansing function as above-mentioned.
JP 2009-178661 A discloses an apparatus for discharging liquid which can generate microbubbles efficiently and at high densities. The apparatus disclosed in JP 2009-178661 A can be applied to a shower head.
EP 2 260 945 A1 discloses a shower head comprising a casing and a suction pipe for the suction of air in a distribution chamber. The shower head allows to evacuate residual water from the distribution chamber after use of the shower.
CN 202 087 441 U discloses a distribution-type shower head wherein water is directly distributed individually and alone into water outlet chambers in different regions, which ensures stable and uniform water distributions at individual water outlets to achieve good water-spraying effects with low flow rate and high efficiency.
In the apparatus, a passage for liquid such as warm or cold water is formed by a liquid introducing path, a liquid swirling path connected to an upstream side of the liquid introduction path, a flow reducing path connected to an upstream side of the liquid swirling path, and a flow expanding path connected to an upstream side of the flow reducing path. A liquid swirling blade is disposed in the liquid swirling path. A diameter of the flow expanding path is larger than that of the flow reducing path. The flow expanding path communicates with a liquid discharge port.
Further, the apparatus has a gas introducing path. The gas introducing path communicates with an outside of the apparatus and is open to a downstream side in the liquid swirling path or the flow reducing path. In addition, a tapered flow scattering plane is provided with the apparatus. The flow scattering plane is facing in the flow expanding path and is disposed opposite to an open area of the flow reducing path.
In the apparatus disclosed in JP 2009-178661 A , a swirling flow occurs in the liquid introduced through the liquid introducing path within the flow swirling path. A gas such as air is mixed in the swirling flow through the gas introducing path by pressure reduction accompanied by the swirling flow and then a gas-liquid mixed fluid generates. When the gas-liquid mixed fluid passes through the flow reducing path, a flow rate and swirling frequency increase and microbubbles gradually generate by a shear force in the gas-liquid mixed fluid. After that, destruction of swirls takes place by scattering of the swirling flow accompanied by a centrifugal force in the flow expanding path. Subsequently, bubbles included in the gas-liquid mixed fluid are minimized and a plurality of microbubbles generate. At the same time, a part of the gas-liquid mixed fluid collides with the flow scattering plane. As a result, the swirling flows are completely destructed and microbubbles generate. The liquid including a plurality of microbubbles discharges into the outside of the apparatus through the liquid discharge port.

Summary of Invention

Technical Problem

JP 2009-178661 A discloses that the apparatus above-mentioned can promote reduction of cost of parts, assembly of parts, and suppression of manufacturing cost. However, the apparatus has a defect that the structure for generating microbubbles is a little complicated. For example, it is pointed out that a flow swirling path is necessitated and provision of the liquid swirling blade is essential for formation of the swirling flow. It is also pointed out that the flow scattering plane is essential. A simple structure is strongly demanded for realization of a shower head with versatility.
The present invention was made in the circumstances above-mentioned and has one of the objects to provide a shower head with a simple structure, which can promote generation of microbubbles by suppressing merger of bubbles.

Solution to Problem

In order to accomplish the object above-mentioned, the main aspect of the present invention provides a shower head includes a head main body provided with a gas-liquid mixing portion, the gas-mixing portion being disposed at an upstream side of an introducing path for warm or cold water which is formed in the head body and mixing a gas absorbed by pressure reduction during introducing the warm or cold water in the warm or cold water as a bubble, a spray plate having a flat portion and a plurality of spray apertures formed at the flat portion by piercing in a thickness direction of the flat portion, the spray plate being disposed at an outside of an exit of the introducing path and attached to the head main body, and a discharge path formed between the head main body and the spray plate, disposed parallel to the spray plate, and communicated with the introducing path. The gas-liquid mixing portion has a compression portion and a decompression portion at a second introducing path, the warm or cold water introduced in the second introducing path of the gas-liquid mixing portion is once pressurized when passing the compression portion and the pressure of the warm or cold water is subsequently reduced when passing the decompression portion, accompanied by the pressure reduction, a gas is absorbed in a gas path of a gas-introducing pipe through an entrance, the absorbed gas is mixed as a bubble in the warm or cold water introduced in the second introducing path through a communication path from an exit. In the shower head, the introducing path has an enlarged path at a side of the exit of the introducing path, a cross-sectional area of the enlarged path continuously enlarging toward the exit, and the discharge path is disposed perpendicular to the side of the exit of the introducing path and an entrance of the discharge path has a cross-sectional area at which a volume of the warm or cold water flowing into the discharge path per unit time is equal to or less than a volume of the warm or cold water passing a portion except the enlarged path of the introducing path per unit time or less.
In the shower head, it is preferable that each of cross-sections in a length direction of the enlarged path of the introducing path has a cross-sectional area so that the volume of the warm or cold water passing per unit time is similar to one another every cross-section
In the shower head, it is preferable that the spray apertures formed in the spray plate have a compression portion at a side of an entrance and a decompression portion at a side of the exit, respectively.
In the shower head, it is preferable that a plurality of ribs are provided in the discharge path along a flow of the warm or cold water in the discharge path and the discharge path is partitioned by the ribs.
In the shower head, it is preferable that each of the ribs is disposed between adjacent two of the spray apertures.
In the shower head, it is preferable that a swirl path for swirling the warm or cold water is concavely shaped at an upstream side of the spray apertures in the spray plate, and the swirl path communicates with both the discharge path and expands outwardly from the discharge path.
In the shower head, it is preferable that a length in a discharging direction of the warm or cold water flowing toward the spray apertures is shorter than a length in an introducing direction of the warm or cold water in the swirl path, and the former length and the latter length cross at right angles each other.
In the shower head, it is preferable that a microbubble forming unit is formed by the discharge path and the swirl path and a plurality of the microbubble forming units are provided side by side in a direction of a length of the shower head.
In the shower head, it is preferable that the adjacent two swirl paths communicate with each other by a communicating portion in the adjacent two microbubble forming units.

Effects of Invention

The shower head of the present invention realizes a simple structure and promotes generation of microbubbles by suppressing merger of bubbles.

Brief Description of Drawings

Figs. 1(a) and 1(b) are a front view showing a first embodiment of a shower head of the present invention and a cross-sectional view taken from line A-A of Fig. 1(a), respectively.
Fig. 2 is a perspective view of the shower head shown in Figs. 1(a) and 1(b).
Fig. 3 is a cross-sectional view similar to Fig. 1(b), showing a second embodiment of the shower head of the present invention.
Fig. 4 is an enlarged cross-sectional view of an essential portion, showing a third embodiment of the shower head of the present invention.
Fig. 5 is a cross-sectional view showing a fourth embodiment of the shower head of the present invention.
Fig. 6 is a cross-sectional view showing a fifth embodiment of the shower head of the present invention.
Figs. 7(a) and 7(b) are a front view showing a sixth embodiment of the shower head of the present invention and a cross-sectional view taken from line A-A of Fig. 1(a), respectively.
Fig. 8 is a cross-sectional view showing a seventh embodiment of the shower head of the present invention.
Fig. 9 is a sectional view showing an eighth embodiment of the shower head of the present invention in a length direction of the eighth embodiment.
Figs. 10(a) and 10(b) are a front perspective view of and a perspective view of a rear essential portion of the shower head shown in Fig. 9, respectively.
Fig. 11 is a perspective view of a spray plate seen from a rear side in the shower head shown in Fig. 9.
Figs. 12(a) and 12(b) are a rear view of the spray plate shown in Fig. 11 and a sectional view of an essential portion of the shower head in a width direction of the shower head shown in Fig. 9, respectively.
Figs. 13(a), 13(b), and 13(c) are a perspective view of an essential portion showing a ninth embodiment of the shower head of the present invention, a cross-sectional view taken from line A-A of Fig. 13(a), and a cross-sectional view taken from line B-B of Fig. 13(a), respectively.

Embodiments

Figs. 1(a) and 1(b) are a front view showing a first embodiment of a shower head of the present invention and a cross-sectional view taken from line A-A of Fig. 1(a), respectively. Fig. 2 is a perspective view of the shower head shown in Figs. 1(a) and 1(b).
A shower head 1 includes a head main body 2, a spray plate 3, and a discharge path 4 for warm or cold water.
The head main body 2 is provided with a gas-liquid mixing portion 11. The gas-liquid mixing portion 11 is disposed at an upstream side of an introducing path 30 for the warm or cold water. The introducing path 30 is formed in the head main body 2. The gas-liquid mixing portion 11 mixes a gas absorbed by pressure reduction during introducing the warm or cold water in the warm or cold water as a bubble.
The spray plate 3 has a flat portion. A plurality of spray apertures 31 are formed at the flat portion of the spray plate 3. The spray apertures 31 are formed at the flat portion by piercing in a thickness direction of the flat portion. The spray plate 3 is disposed at an outlet 28 of the introducing path 30 and attached to the head main body 2.
The discharge path 4 is formed between the head main body 2 and the spray plate 3. The discharge path 4 is disposed parallel to the spray plate 3 and communicated with the introducing path 30.
In the shower head 1, the introducing path 30 has an enlarged path 29 at a side of an exit 28 of the introducing path 30. A cross-sectional area of the enlarged path 29 is continuously enlarging toward the exit 28. The discharge path 40 is disposed perpendicular to the side of the exit 28 of the introducing path 30. An entrance 35 of the discharge path 4 has a cross-sectional area at which a volume of the warm or cold water flowing into the discharge path 40 per unit time is equal to or less than a volume of the warm or cold water passing a portion except the enlarged path 29 of the introducing path 30 per unit time.
Specifically, a base 5 and overlapping portion 6 both of which has a disk-shape are provided with the head main body 2 of the shower head 1. The base 5 is a relatively thick part and a first introducing path 7 of which a cross-section has a round shape is formed in the base 5. The first introducing path 7 introduces the warm or cold water and sends the warm or cold water to the overlapping portion 6. The first introducing path 7 has an entrance 8 at a side end portion of the base 5 and an exit 9 at a center portion of the base 5. The introducing path 7 is bent in an L shape. In other words, the first introducing path 7 straightly extends from the entrance 8 to a central axis of the base 5 and has a bent portion 10 by being bent in the L shape near the central axis. A gas-liquid mixing portion 11 is provided with the base 5 near the entrance 8 of the first introducing path 7.
A second introducing path 12 a cross-section of which is a round shape is formed in the gas-liquid mixing portion 11. The second introducing path 12 introduces the warm or cold water in the gas-liquid mixing portion 11 and sends the warm or cold water to the entrance 8 of the base 5. The second introducing path 12 has a compression portion 14 at a side of an entrance 15. An inside diameter of the compression portion 14 sharply decreases in a length direction of the second introducing path 12. The second introducing path 12 also has a decompression portion 16 at a side of an exit 15. The decompression portion 16 communicates with the compression portion 14. An inside diameter of the decompression portion 16 gradually increases toward the exit 15. The exit 15 of the second introducing path 12 coincides with the entrance 8 of the first introducing path 7 formed in the base 5 so that the second introducing path 12 communicates with the first introducing path 7.
A gas-introducing pipe 18 a cross-section of which is a round shape is orthogonally connected to the gas-liquid mixing portion 11. The gas-introducing pipe 18 is disposed at around a connecting portion of the compression portion 14 and the decompression portion 16 of the second introducing path 12 and has a gas path 17 for passing a gas such as an air, oxygen, carbon dioxide, or ozone. The gas-introducing pipe 18 extends outwardly from the gas-liquid mixing portion 11. The gas-introducing pipe 18 has an entrance 19 at a tip portion of the gas introducing portion18 and also has an exit 20 at a nearest portion to the gas-liquid mixing portion 11. A communicating path 21 a cross-section of which is a round shape is formed between the second introducing path 12 and the exit 20 of the gas-introducing pipe 18 in the gas-liquid mixing portion 11. The gas path 17 of the gas-introducing pipe 18 communicates with the second introducing path 12 through a communicating path 21.
In the gas-liquid mixing portion 11, an end portion of a side of the exit 15 of the second introducing path 12 is secured by fitting a recess 22 formed at a side end portion of the base 5 and protrudes outwardly from the base 5. An O-ring 23 is interposed between the base 5 and the gas-liquid mixing portion in the recess 22 and thereby tightness between the base 5 and the gas-liquid mixing portion 11 is secured. A position of the gas-liquid mixing portion 11 is not limited to an upstream of the first introducing portion 11 of the base 5 but may be an arbitrary portion from the entrance 8 of the first introducing path 7 to the bent portion 10.
A plurality of connecting bores 24 piercing the base 5 in a thickness direction of the base 5 are formed at outer peripheral portion of the base 5. The connecting bores 24 are used for connecting the spray plate 3 with the base 5 and are disposed at a prescribed interval at the outer peripheral portion of the base 5.
A size of the overlapping portion 6 is less by one size than that of the base 5. The overlapping portion is a disk-shaped part with a certain amount of thickness. The third introducing path 15 a cross-section of which is a round shape is formed in the overlapping portion 6. The third introducing path 25 introduces and sends the war or cold water. The third introducing path 25 is disposed at a central axis of the overlapping portion and pierces the overlapping potion 6 in a front and rear direction. The overlapping portion 6 overlaps the base 5 by coinciding an entrance 26 of the third introducing path 2 with the exit 9 of the first introducing path 7 of the base 5 and forms the head main body 2 with the base 5. In a portion which the overlapping portion 6 overlaps the base 5, an O-ring 27 is interposed at a portion where the exit 9 of the first introducing path 7 comes close to the entrance 26 of the third introducing path 25. Tightness between the base 5 and the overlapping portion 6 is secured by the O-ring 27.
The third introducing path 25 formed in the overlapping portion has an enlarged path 29 at a side of an exit 28. An inside diameter of the enlarged path 29 is continuously enlarged and a cross-sectional area of the enlarged path 29 gradually increases. An inner surface of the enlarged path 29 is curved so as to extend outwardly as the enlarged path 29 is advanced to the exit 28.
In the shower head main unit 2, the first introducing path 30 is formed by the first introducing path 7, the second introducing path 12 and the third introducing path 25. The war or cold water introduced in the introducing path 30 and flowing out from the introducing path 30 is discharged from the spray apertures formed in the spray plate 3.
A plurality of the spray apertures 31 are formed between a central portion and an outer peripheral portion in the spray plate 3. At least a portion where the spray apertures 31 are formed in the spray plate 3 has a thinly and flatly disk-shape. The spray apertures pierce the disk-shaped portion in a thickness direction of the disk-shaped portion. Adjacent three spray apertures form a basic pattern of arrangement of the spray apertures 31. In the basic pattern, each of the three spray apertures is apart from one another at a constant interval from a central side to an outer peripheral side. The basic patterns are repeatedly disposed along a periphery of the spray plate 3. Arrangement of the spray apertures 31 in the spray plate 3 is spiral.
A cylindrical barrel 32 with a thickness protrudes at an outer peripheral portion of the spray plate 3. The cylindrical barrel 32 is disposed from an outside of the spray aperture 31 which is positioned closest to a peripheral of the spray plate 3 to a side peripheral end of the spray plate 3. An inside diameter of the barrel 32 coincides with an outside diameter of the overlapping portion 6 of the head main body 2. A plurality of attachment bores 33 pierce in a length direction of the barrel 32 and in a width direction of the spray plate 3. The shower head 1 is assembled by connecting the spray plate 3 with the base 5. The assembly of the shower head 1 is accomplished by coinciding the attachment bore 33 with the connecting bore 24 formed in the base 5, overlapping the spray plate 3 with the base 5, and screwing a fastener such as a screw from the attachment bore 33 to connecting bore 24. The spray plate 3 is disposed at an exit of the introducing path 30 formed in the head main body 2, in other word, at an outside of the exit 28 of the third introducing path 25 formed in the overlapping portion.
It is possible that the overlap of the overlapping portion 6 and the base 5 by fitting the overlapping portion 6 in the barrel 32 of the spray plate 3 when connecting the spray plate 3 with the base 5, for example. Of course, it is possible that the overlapping portion 6 is overlapped with the base 5 and secured by the fastener before attachment to the spray plate 3. An O-ring 34 is interposed between the barrel 32 and the overlapping portion and tightness between the overlapping portion 6 and the barrel 32 is secured.
In the shower head 1 assembled in the manner above-mentioned, the discharge path 4 of the warm or cold water is formed between the head main body 2 and the spray plate 3. Specifically, a narrow clearance between the overlapping portion 6 of the head main body 6 and the spray plate 3 is the discharge path 4. The discharge path 4 is disposed parallel to the spray plate 3 and communicates the introducing path 30 of the head main body 2. The discharge path 4 also communicates with the spray apertures 31 of the spray plate 3.
The discharge path 4 is disposed perpendicular to a portion of an exit side of the introducing portion 30, i.e., a portion from the bent portion 10 of the first introducing path 7 to the exit 9 and the third introducing path 25. The entrance 35 which is an exit of the introducing path 30 and coincides with a downstream end of the enlarged path 29 has the cross-sectional area with the following relationship. The cross-sectional area of the entrance 35 is set to realize that a washer-like shaped volume of the warm or cold water flowing into the discharge path 4 per unit time, for example, about 0.1 second is equal to or less than disk-shaped volume of the warm or cold water passing the portion of the introducing portion 30 except the enlarged path 29 per unit time. The cross-sectional area of the entrance 35 is an area of a cross-section perpendicular to a flow direction of the warm or cold water flowing in the introducing path 30.
The shower head 1 can discharge warm or cold water including a plurality of microbubbles of 50 µm or less in a diameter from the spray apertures 31. The shower head 1 is connected with a water pipe such as a hose at the entrance 13 of the gas-liquid mixing portion 11. The warm or cold water introduced in the second introducing path 12 of the gas-liquid mixing portion 11 by way of the water pipe is once pressurized when passing the compression portion 14 and the pressure of the warm or cold water is subsequently reduced when passing the decompression portion 16. Accompanied by the pressure reduction, a gas such as an air, oxygen, carbon dioxide or ozone is absorbed in the gas path 17 of the gas-introducing pipe 18 through the entrance 19. The absorbed gas is mixed as a bubble in the warm or cold water introduced in the second introducing path 12 through the communicating path 21 from the exit 20. As a result, the warm or cold water is introduced as a gas-liquid mixing fluid in the first introducing path 7 from the exit 15 of the second introducing path 12 through the entrance 8.
The warm or cold water introduced in the first introducing path 7 changes a flow direction to a perpendicular direction at the bent portion 10, flows out from the exit 9 of the first introducing path 7 and is introduced in the third introducing path 25 through the entrance 26. The warm or cold water introduced in the third introducing path 25 extends outwardly and flows along the inner surface of the enlarged path 29 when passing the enlarged portion 29 and is introduced in the discharge path 4 from the exit 28 of the third introducing path 25 through the entrance 35. Since the enlarged portion 29 is curved such that the inner surface extends outwardly, generation of turbulence such as a spiral in the warm or cold water flowing out from the exit 28 is suppressed. Collision of bubbles accompanied by generation of the turbulence is suppressed and coalescence of bubbles is also suppressed.
As above-mentioned, the exit 35 of the discharge path 4 has the cross-sectional area which realizes that the washer-like shaped volume of the warm or cold water flowing into the discharge path 4 per unit time is equal to or less than a disk-shaped volume of the warm or cold water passing the portion of the introducing portion 30 except the enlarged path 29 per unit time. Accordingly, the warm or cold water introduced in the discharge path 4 is pressurized. Subsequently, the pressure of the warm or cold water is gradually reduced since the cross-sectional area of the downstream side portion from the entrance 35 is larger than that of the entrance 25. As a result of the pressurization and reduction of the pressure, the bubbles in the warm or cold water are also crushed near the entrance 35 and almost all of the bubbles become microbubbles. The warm or cold water containing a plurality of microbubbles almost radially flows toward the outer peripheral portion from the entrance 35 because generation of turbulence is suppressed as above-mentioned. The warm or cold water containing a plurality of the microbubbles is discharged to an outside of the shower head 1 through the spray apertures 31. Since a diameter of the microbubble is much smaller than an inner diameter of the spray aperture, the microbubbles can easily pass the spray apertures 31. The warm or cold water containing a plurality of microbubbles, which is discharges from the shower head 1, has a high washing function by a large specific surface area of the microbubbles.
As above-mentioned, the shower head 1 is substantially formed by the head main body 2 in which the introducing path 30 and with which the gas-liquid mixing portion 11 is provided at the upstream side of the introducing path 30, the spray plate 3 in which a plurality of spray apertures 31 are formed, and the discharge path 4 formed between the head main body 2 and the spray plate 3. Accordingly, the shower head not only promotes production of the warm or cold water containing a plurality of the microbubbles but also has a simple structure. The shower head 1 is expected to have versatility.
Fig. 3 is a cross-sectional view similar to Fig. 1(b), showing a second embodiment of the shower head of the present invention.
With respect to a shower head 1a, several portions and parts which are common to those of the shower head 1 as shown in Fig. 1 (b) are put same reference numbers in Fig. 3 and explanations of those portions and parts are abbreviated.
The shower head 1a having an enlarged path 29a of the introducing path 30 is different from the shower head 1 compared with the enlarged path 29. Each of cross-sections in a length direction of the enlarged path 29a, i.e., each of cross-sections perpendicular to the flow of the warm or cold water, has a cross-sectional area so that the volume of the warm or cold water passing per unit time is similar to one another every cross-section. The shower head 1a can suppress slowdown of flowing rate when the warm or cold water passes the enlarged path 29a and therefore collision of the bubbles in the warm or cold water is more preferably suppressed and coalescence of bubbles is also more preferably suppressed. Expansion of the bubbles and decrease of the number of the bubbles accompanied by the expansion are suppressed.
Fig. 4 is an enlarged cross-sectional view of an essential portion, showing a third embodiment of the shower head of the present invention.
With respect to a shower head 1b, several portions and parts which are common to those of the shower head 1 as shown in Fig. 1 (b) are put same reference numbers in Fig. 4 and explanations of those portions and parts are abbreviated. Fig. 4 shows a periphery of a spray aperture 31a formed in the spray plate 3 provided with the shower head 1b.
In the shower head 1b, a spray aperture 31a has a compression portion 37 an inner diameter of which is drastically reduced at a side of an entrance 36 facing the discharge path 4 as shown in Fig. 1 (b) and has a decompression portion 39 an inner diameter of which continuously increases at a side of an exit 38 discharging the warm or cold water to an outside of the shower head 1b. The compression portion 37 and the decompression portion 39 communicate with each other in a middle of a length direction of the spray aperture 31a.
In the shower head 1b provided the spray plate 3 in which the spray aperture 31a is formed, the warm or cold water containing a plurality of the microbubbles is pressurized in the compression portion 37 when the warm or cold water passes the spray aperture 31a and subsequently the pressure is reduced in the decompression portion 39. The microbubbles contained in the warm or cold water are more preferably crushed and the diameters become much smaller by such fluctuation of pressure. The specific surface areas of the microbubbles become much larger and the washing function of the warm or cold water containing p plurality of the microbubbles, which is discharged from the shower head 1b, is advanced.
An angle α formed by opposing inner surfaces of the decompression portion 39 is preferably in a range from 10° to 20° in view of efficiency for crushing the microbubbles and is around 15° in general.
Fig. 5 is a cross-sectional view showing a fourth embodiment of the shower head of the present invention.
Fig. 5 shows a shower head 1c, which corresponds to a cross section taken from line B-B of the shower head 1 shown in Fig. 1(b). With respect to a shower head 1c, several portions and parts which are common to those of the shower head 1 as shown in Fig. 1 (b) are put same reference numbers in Fig. 5 and explanations of those portions and parts are eliminated.
A plurality of ribs 40 are provided with the shower head 1c along a flow of the warm or cold water in the discharge path 4 as provided with the shower head 1 sown in Fig. 1, i.e., along a direction from a central portion to a outer peripheral portion of the spray plate. The ribs 40 are protruded at the spray plate, extend in a length direction of the barrel 32, and are radially disposed at a constant interval. The ribs 40 partitions the discharge path 4 by insertion of ribs 40 in the discharge path 4 when the spray plate 3 provided a plurality of ribs 40 is attached to head main body 2.
The shower head 1c easily forms a radial flow of the warm or cold water introduced in the discharge path 4 from the entrance 35 toward an outer peripheral portion of the discharge path 4. Generation of a flow of the warm or cold water in a peripheral direction of the discharge path 4 is suppressed and generation of turbulence is also suppressed. Accordingly, the collision of the microbubbles contained in the warm or cold water and coalescence brought about the collision is furthermore preferably suppressed. It is possible to discharge the warm or cold water which contains a plurality of the microbubbles and the washing function of which is more advanced.
The ribs 40 are disposed corresponding to every basic arrangement pattern of the spray apertures 31 formed in the spray plate 3 as above-mentioned. However, disposition of the ribs 40 is not limited to the disposition corresponding to every basic arrangement pattern of the spray apertures 31.
Fig. 6 is a cross-sectional view showing a fifth embodiment of the shower head of the present invention.
Fig. 6 shows a shower head 1d in a similar manner to Fig. 5. With respect to a shower head 1d, several portions and parts which are common to those of the shower head 1 as shown in Fig. 1 (b) are put same reference numbers in Fig. 6 and explanations of those portions and parts are abbreviated.
In the shower head 1d, every rib 40 shown in Fig. 5 is disposed between adjacent two spray apertures 31. The disposition of the ribs 40 helps to more easily form the radial flow of the warm or cold water introduced in the discharge path 4 as in shown in Fig. 1 from the entrance 35 toward the outer peripheral portion of the spry plate 3. The flow of the warm or cold water in the peripheral direction of the discharge path 4 is effectively suppressed and generation of the turbulence is also effectively suppressed. It is possible to discharge the warm or cold water containing a plurality of microbubbles, the washing function of which is effectively advanced.
Figs. 7(a) and 7(b) are a front view showing a sixth embodiment of the shower head of the present invention and a cross-sectional view taken from line A-A of Fig. 1(a), respectively.
With respect to a shower head 1e, several portions and parts which are common to those of the shower head 1 as shown in Fig. 1 (b) are put same reference numbers in Fig. 7 and explanations of those portions and parts are abbreviated.
In the shower head 1e, a swirl path 41 for swirling the warm or cold water is concavely shaped at an upstream of the spray apertures 31 formed in the spray plate 3. The swirl path 41 is formed as a round channel notched in a thickness direction of the spray plate 3. The swirl path 41 has a relationship of 1 < d. "l" is a length of a discharging direction of the warm or cold water flowing toward the spray apertures 31. "d" is a length in an introducing direction of the warm or cold water. "d" is perpendicular to "l". Specifically, the length l in the discharging direction toward the spray apertures 31 is shorter than the length d of the introducing direction of the warm or cold water in the swirl path 41. The lengths l and d cross at right angles each other. The swirl path 41 expands outwardly and is disposed at an outside from the discharge path 4. In the swirl path 41, the length 1 of the discharging the warm or cold water is longer than a clearance between the head main body 2 and the spray plate 3, specifically, between the overlapping portion 6 and the spray plate 3, which forms the discharge path 4.
In addition, the barrel 3 protruded at the outer peripheral portion of the spray plate 3 is disposed from an outside of the swirl path 41 to an outer peripheral end of the spray plate 3 in the shower head 1e.
The shower head 1e can discharge the warm or cold water containing a plurality of microbubbles with a diameter of less than 50 µm or less from the spray apertures 31. The warm or cold water introduced in the swirl path 41 collides the inner surface of the barrel 32 during introduction in the swirl path 41 and a flow of the warm or cold water is orthogonally bent. As a result, a swirl flow temporarily generates in the warm or cold water introduced in the swirl path 41. However, the swirl flow soon collapses by a shear force generated ascribe to difference between a flow of the warm or cold water toward the spray apertures 31 and a flow of the warm or cold water flowing in the swirl path 41 from the discharge path 4. There is possibility that large bubbles a diameter of each of which is relatively large are contained in the warm or cold water and the large bubbles are trapped in a central portion of the swirl flow. However, the large bubbles are free from constraint due to collapse of the swirl flow and are changed to the microbubbles by being crushed by the shear force. Crushing the bubbles contained in the warm or cold water is promoted by the swirl flow generated in the swirl path 41 and the collapse of the swirl flow, resulting in production of the warm or cold water containing a plurality of microbubbles.
Additionally, when there is a relationship of 1 < d where "l" is the length 1 of the discharging direction toward the spray apertures 31 and "d" is the length d of the introducing direction, which is perpendicular to the length "l" , difference of a force affecting the warm or cold water between a spraying direction and the introducing direction of the warm or cold water is enlarged. The shear force obtained by the swirl flow generated in the swirl path 41 becomes larger according to the difference of the force above-mentioned, resulting in promotion of crushing the bubbles. The promotion effectively functions for producing microbubbles. A density of the microbubbles is higher and the warm or cold water discharged from the spray apertures 31 has good quality. In addition, shortening of the length 1 of the spraying direction of the warm or cold water contributes to minimization of a size of the shower head 1.
Fig. 8 is a cross-sectional view showing a seventh embodiment of the shower head of the present invention.
With respect to a shower head 1f, several portions and parts which are common to those of the shower head 1e as shown in Fig. 7 (b) are put same reference numbers in Fig. 8 and explanations of those portions and parts are abbreviated.
The shower head 1f is different from the shower head 1e shown in Fig. 7 (b) on enlarged path 29a of the introduction path 30 compared with the enlarged path 29 of the shower head 1e. Specifically, each of cross sections in a length direction of the enlarged path 29a, i.e., a cross section perpendicular to a flow of the warm or cold water, has a cross-sectional area that a volume passing warm or cold water per unit time is equal ever cross-section. The shower head 1f having such the enlarged path 29a can suppress slowdown of a flow rate when the warm or cold water passes the enlarged path 29a. As a result, the collision of the bubbles in the warm or cold water is furthermore suppressed and the coalescence of the bubbles is furthermore suppressed. The expansion of the bubble and the decrease of the number of the bubbles are suppressed.
Fig. 9 is a sectional view showing an eighth embodiment of the shower head of the present invention in a length direction of the eighth embodiment. Figs. 10(a) and 10(b) are a front perspective view of and a perspective view of a rear essential portion of the shower head shown in Fig. 9, respectively.
With respect to a shower head 1g, several portions and parts which are common to those of the shower head 1 as shown in Figs. 1 (a) and 1 (a) put same reference numbers in Figs. 9, 10(a), and 10(b).
In the shower head 1g, the head main body 2 has a longitudinal shape. The first introducing path 7 a cross-section of which is a round shape is formed in the head main body 2. The first introducing path 7 which introduces the warm and cold water has the entrance 8 at a lower end portion of the head main body 2 and the exit 9 at an upper end portion. The first introducing path 7 extends in a length direction of the head main body 2 and two exits 9 are provided at an upper portion and a lower end portion of the first introducing path 7. The gas-liquid mixing portion 11is connected near the entrance 8 of the first introducing path 7.
The second introducing path 12 a cross section of which is a round shape is formed in the gas-liquid mixing portion 11. The second introducing path 12 introduces the warm or cold water and sends the entrance 8 of the first introducing path 7. The second introducing path 12 has the compression portion in a lower end portion of the second introducing path 12 and has the decompression portion 16 which communicates with the compression portion 14 at the side of the exit 15. The inner diameter of the compression portion 14 drastically reduced in the length direction of the second introducing path 12. The inner diameter of the decompression portion 16 continuously increases toward the exit 15. The exit 15 of the second introducing path 12 coincides with the entrance 18 of the first introducing path 7 and the second introducing path 12 communicates with the first introducing path 7.
The gas-introducing pipe (not shown) having the gas path for a gas such as an air, oxygen, carbon dioxide, or ozone in the gas-introducing pipe is orthogonally connected with the gas-liquid mixing portion 11 near the connecting potion of the compression portion 14 and the decompression portion 16 of the second introducing path 12. The gas-introducing pipe extends outwardly from the gas-liquid mixing portion 11. The gas-introducing pipe also has the entrance at the tip portion of the gas-introducing pipe and the exit at the nearest portion of the gas-liquid mixing portion 11. The communicating path (not shown) is formed in the gas-liquid mixing portion 11 between the second introducing path 12 and the exit of the gas-introducing pipe. The gas path of the gas-introducing pipe communicates with the second introducing path 12 through the communicating path.
The disposition of the gas-liquid mixing portion is not limited to the upstream side from the first introducing path 7 but may be the middle portion of the first introducing path 7.
The two third introducing paths 25 each of cross sections of which is a round shape are formed in the head main body 2. The third introducing path 25 sends the warm or cold water introduced in the first introducing path 7 to the discharge path 4. One of the third introducing paths 25 is disposed at the upper portion of the head main body 2 and the other of the third introducing paths 25 is disposed at the lower portion of the head main body 2. Each of the third introducing paths 25 communicates with the first introducing path 7 by coinciding the entrances 26 with the exit 9 of the first introducing path 7. The each of the third introducing paths 25 is disposed perpendicular to the first introducing path 7.
The each of the third inflow channels 25 has the enlarged portion 29 at the side of the exit 28. The inner diameter of the enlarged portion 29 is continuously enlarged toward the exit 28 and the cross-sectional area of the enlarged portion 29 is gradually enlarged. The inner surface of the enlarged portion 29 is bent so as to expand outwardly toward the exit 28.
The introducing path 30 for warm or cold water is formed by the first introducing path 7, the second introducing path 12, and the third introducing path 25 in the head main body 2. The warm or cold water which is introduced in the introducing path 30 and flows frome the introducing path 3 is discharged from the apertures 32 formed in the spray plate 3.
As shown in Fig. 10 (a), the spray plate 3 has a rectangular shape seem from a front. The spray apertures 31 are lengthwise and widthwise aligned at the spray plate 3. At least portion of the spray plate 3 where the spray apertures 31 are formed has a thin and flat shape. The spray apertures 31 pierce the flat shaped portion in the thickness direction of the flat shaped portion.
The swirl path 41 for generating the swirling flow in the warm or cold water is concavely shaped at the upstream side of the spray apertures 31. The swirl path 41 is formed as a recess having a rectangular shape seen from a front by notching the spray plate 3 in a thickness direction of the spray plate 3. The swirl path 41 has a relationship of 1 < d. "l" is a length of a discharging direction of the warm or cold water flowing toward the spray apertures 31. "d" is a length in an introducing direction of the warm or cold water. "d" is perpendicular to "l". Specifically, the length l in the discharging direction toward the spray apertures 31 is shorter than the length d of the introducing direction of the warm or cold water in the swirl path 41. The lengths 1 and d cross at right angles each other. The swirl path 41 communicates with both of the discharge path 4 and the spray apertures 31.
The spray plate 3 is attached to an upper end portion of the head main body at a side of the front through the O-ring 34. Tightness between the spray plate 3 and the head main body 2 is secured by the O-ring 34.
In the shower head 1g to which the spray plate 3 is attached, the discharge path 4 of the warm or cold water is formed between the head main body 2 and the spray plate 3. Specifically, the narrow clearance between the head main body 2 and the spray plate 3 is the discharge path 4. The discharge path 4 is disposed parallel to the spray plate 3. The discharge path 4 communicates with the introducing path 30 of the head main body and the swirl path 41 of the spray plate 3.
In the discharge path 4, the portion at the exit side of the introducing path 30 is disposed perpendicular to the third introducing path 25. The entrance 35 which is the exit of the introducing path 30 and coincides with the downstream end of the enlarged path 29 has the cross-sectional area with the following relationship. The cross-sectional area of the entrance 35 is set to realize that a washer-like shaped volume of the warm or cold water flowing into the discharge path 4 per unit time, for example, about 0.1 second is equal to or less than a disk-shaped volume of the warm or cold water passing the portion of the introducing portion 30 except the enlarged path 29 per unit time. The cross-sectional area of the entrance 35 is the area of the cross-section perpendicular to the flow direction of the warm or cold water flowing in the introducing path 30.
The swirl path 41 expands outwardly from the discharge path 4. In the discharge path 41, the length 1 in the discharging direction of the warm or cold water is longer than the clearance forming the discharge path 4 between the head main body 2 and the spray plate 3.
A microbubble forming unit 42 is formed the discharge path 4 and the swirl path 41 above-mentioned in the shower head 1g. Two microbubble forming units are provided with the shower head 1f and are disposed side by side in a length direction of the head main body 2.
Fig. 11 is a perspective view of a spray plate seen from a rear side in the shower head shown in Fig. 9. Figs. 12(a) and 12(b) are a rear view of the spray plate shown in Fig. 11 and a sectional view of an essential portion of the shower head in a width direction of the shower head shown in Fig. 9, respectively.
As shown in Fig. 11 and Figs. 12(a) and 12(b), the two microbubble forming units 42 are arranged in upward and downward in the spray plate 3. An upper microbubble forming unit 42a and lower microbubble forming unit 42b is divided by a rib 43 disposed at a boundary portion of the microbubble forming units 42a and 42b. The rib 43 rises from the spray plate 3 and expands in a width direction of the spray plate 3. The rib 43 protrudes at the boundary portion of the swirl paths 41 of the microbubble forming units 42a and 42b. On the other hand, right and left ends of the rib 43 is disposed at an inside from side ends of the swirl paths 41 and a communicating portion 44 is formed between the right and left ends and the side ends of the swirl paths 41. The adjacent swirl paths 41 in the microbubble forming paths 42a and 42b communicate with each other by the communicating portion 44.
The shower head 1g can discharge warm or cold water including a plurality of microbubbles of 50 µm or less in a diameter from the spray apertures 31. The shower head 1g is connected with a water pipe such as a hose at the entrance of the gas-liquid mixing portion 11. The warm or cold water introduced in the second introducing path 12 of the gas-liquid mixing portion 11 by way of the water pipe is once pressurized when passing the compression portion 14 and the pressure of the warm or cold water is subsequently reduced when passing the decompression portion 16. Accompanied by the pressure reduction, a gas such as an air, oxygen, carbon dioxide or ozone is absorbed in the gas path 17 of the gas-introducing pipe 18 through the entrance 19. The absorbed gas is mixed as a bubble in the warm or cold water introduced in the second introducing path 12 through the communicating path 21 from the exit 20. As a result, the warm or cold water is introduced as a gas-liquid mixing fluid in the first introducing path 7 from the exit 15 of the second introducing path 12 through the entrance 8.
The warm or cold water introduced in the first introducing path 7 flows out from the exit 9 and is introduced in the third introducing path 25 through the entrance 26. The warm or cold water introduced in the third introducing path 25 extends outwardly and flows along the inner surface of the enlarged path 29 when passing the enlarged portion 29 and is introduced in the discharge path 4 from the exit 28 of the third introducing path 25 through the entrance 35. Since the enlarged portion 29 is curved such that the inner surface extends outwardly, generation of turbulence such as a spiral in the warm or cold water flowing out from the exit 28 is suppressed. Collision of bubbles accompanied by generation of the turbulence is suppressed and coalescence of bubbles is also suppressed.
As above-mentioned, the exit 35 of the discharge path 4 has the cross-sectional area which realizes that the washer-like shaped volume of the warm or cold water flowing into the discharge path 4 per unit time is equal to or less than a disk-shaped volume of the warm or cold water passing the portion of the introducing portion 30 except the enlarged path 29 per unit time. Accordingly, the warm or cold water introduced in the discharge path 4 is pressurized. Subsequently, the pressure of the warm or cold water is gradually reduced since the cross-sectional area of the downstream side portion from the entrance 35 is larger than that of the entrance 25. As a result of the pressurization and reduction of the pressure, the bubbles in the warm or cold water are also crushed near the entrance 35 and almost all of the bubbles become microbubbles. The warm or cold water containing the microbubbles almost radially flows toward the outer peripheral portion of the discharge path 4 because generation of the turbulence is suppressed as above-mentioned. The warm or cold water containing the microbubbles is subsequently introduced in the swirl path 41.
The warm or cold water introduced in the swirl path 41 collides the side end face of the swirl path 41during introduction in the swirl path 41 and a flow of the warm or cold water is orthogonally bent. As a result, a swirl flow temporarily generates in the warm or cold water introduced in the swirl path 41. However, the swirl flow soon collapses by a shear force generated ascribe to difference between a flow of the warm or cold water toward the spray apertures 31 and a flow of the warm or cold water flowing in the swirl path 41 from the discharge path 4. There is possibility that large bubbles a dimaeter of each of which is relatively large are contained in the warm or cold water and the large bubbles are trapped in a central portion of the swirl flow. However, the large bubbles are free from constraint due to collapse of the swirl flow and are changed to the microbubbles by being crushed by the shear force. Crushing the bubbles contained in the warm or cold water is promoted by the swirl flow generated in the swirl path 41 and the collapse of the swirl flow, resulting in production of the warm or cold water containing a plurality of microbubbles.
The warm or cold water containing a plurality of the microbubbles is discharged to an outside of the shower head 1g through the spray apertures 31. The microbubbles easily pass the spray apertures 31 because a diameter of each of the microbubbles is much smaller than an inner diameter of the spray apertures 31. The warm or cold water containing a plurality of the microbubbles has a high washing function since a specific surface area of the each of the microbubble is large enough.
As above-mentioned, the shower head 1g is substantially formed by the head main body 2 in which the introducing path 30 and with which the gas-liquid mixing portion 11 is provided at the upstream side of the introducing path 30, the spray plate 3 in which a plurality of spray apertures 31 are formed and the swirl path 41 is concavely shaped, and the discharge path 4 formed between the head main body 2 and the spray plate 3. Accordingly, the shower head 1g not only promotes production of the warm or cold water containing a plurality of the microbubbles but also has a simple structure. The shower head 1g is expected to have versatility.
Additionally, in the swirl path 41, when there is a relationship of l < d where "l" is the length 1 of the discharging direction toward the spray apertures 31 and "d" is the length d of the introducing direction, which is perpendicular to the length "l", difference of a force affecting the warm or cold water between a spraying direction and the introducing direction of the warm or cold water is enlarged. The shear force obtained by the swirl flow generated in the swirl path 41 becomes larger according to the difference of the force above-mentioned, resulting in promotion of crushing the bubbles. The promotion effectively functions for producing microbubbles. A density of the microbubbles is higher and the warm or cold water discharged from the spray apertures 31 has good quality. In addition, shortening of the length 1 of the spraying direction of the warm or cold water contributes to minimization of a size of the shower head 1g.
In the shower head 1g, each of cross-sections in a length direction of the enlarged path 29, i.e., each of cross-sections perpendicular to the flow of the warm or cold water, has a cross-sectional area so that the volume of the warm or cold water passing per unit time is similar to one another every cross-section. The shower head 1g having the enlarged path 29 can suppress slowdown of flowing rate when the warm or cold water passes the enlarged path 29 and therefore collision of the bubbles in the warm or cold water is more preferably suppressed and coalescence of bubbles is also more preferably suppressed. Expansion of the bubbles and decrease of the number of the bubbles accompanied by the expansion are suppressed.
The two microbubble forming units 42a and 42b formed by the discharge path 4 and the swirl path 41 are disposed side by side in the length of the head main body 2. The shower head 1g can spray the warm or cold water containing a plurality of the microbubbles in a wide range. Additionally, since the adjacent swirl paths 41 in the microbubble forming units 42a and 42b communicate with each other by the communicating portion 44, difference of pressures between the microbubble forming units 42a and 42b can be suppressed to be little. A power of the warm or cold water containing a plurality of the microbubbles, which is discharged from spray apertures 31, is uniform and a shower with good quality can be realized.
Figs. 13(a), 13(b), and 13(c) are a perspective view of an essential portion showing a ninth embodiment of the shower head of the present invention, a cross-sectional view taken from line A-A of Fig. 13(a), and a cross-sectional view taken from line B-B of Fig. 13(a), respectively. With respect to a shower head 1h, several portions and parts which are common to those of the shower head 1g as shown in Figs. 9 to 12 are put same reference numbers in Fig. 13 and explanations of those portions and parts are abbreviated.
A plurality of spray projections 45 having a cylindrical shape stand on a surface of a planar portion 3 of the spray plate 3 as a flat portion forming the discharge path 4 with the head main body 2. A spray aperture 31 is formed in an inside of the spray projection 45 and a portion of the planar portion 3a corresponding to the inside of the spray projection 45. The spray aperture 31 communicates with the discharge path 4. The spray aperture 31 is disposed at a central portion seen from a tip side of the spray projection 45. The spray plate 3 including the spray projection 45 is made of a material with elasticity such as rubber.
In the shower head 1h, a head cover 46 is provided at an outside of the spray plate 3 and a through holes are formed at portions corresponding to the spray projections 45 in the head cover 46. The spray plate 3 can be attached to a rear side of the head cover 46 with elasticity of the spray plate 3. When the spray plate 3 is attached to the head cover 46, the spray projections 45 protrude to an outside through the through holes. A length of the spray projections 45 is set to be one that tip potions of the spray projections 45 protrude from the surface of the head cover 46.
On the other hand, the surface of the head cover 46 is curved. Accordingly, the whole shape of the shower head 1h has a cylindrical shape. The cylindrical shape includes not only a complete cylinder but also shapes can be visually recognized as a whole with a little deformation from the complete cylinder. Since the surface of the head cover 46 is curved, the shower head 1h has good appearances even though the spray plate 3 has the planar portion 3a.
As the shower head 1h is used, foreign substances such as a scale due to calcium in components solved in water precipitate in the spray apertures 31 near the tip portions of the spray projections 45 and accumulate in turn. As a result, there is possibility that clogging occurs in the spray apertures near the tip portions of the spray projections 45. However, as above-mentioned, the spray projections 45 protrude a little from the surface of the head cover 46 and the spray projections 45 are made of a material with elasticity. Accordingly, when the spray projections 45 are elastically deformed by scrubbing with fingers of a human, the foreign substances can be easily removed by ejection or shredding.
The shower head of the present invention is defined by the claims. Various modifications are possible for the shapes and configurations of the shower head main unit, spray plate, outflow channel, and swirl generating channel as well as details including the configuration and position of the gas-liquid mixing section and the number of microbubble generating unit.

Reference number List

1, 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h shower head
2 head main body
3 spray plate
3a flat portion
4 discharge path
11 gas-liquid mixing portion
29, 29a enlarged path
30 introducing path
31, 31a spray aperture
35 entrance of the discharge path
36 entrance of the spray aperture
37 compression portion
38 exit of spray aperture
39 decompression portion
40 rib
41 swirl path
42, 42a, 42b microbubble forming unit
44 communicating portion
l length in a discharging direction of the swirl path
d length in an introducing direction of the swirl path

Industrial Applicability

The shower head of the present invention has a simple structure and can promote generation of microbubbles by suppressing merger of bubbles.

Claims

A shower head (1) comprising:
a head main body (2) provided with a gas-liquid mixing portion (11), the gas-liquid mixing portion (11) being disposed at an upstream side of an introducing path (30) for warm or cold water which is formed in the head main body (2) and mixing a gas absorbed by pressure reduction during introducing the warm or cold water in the warm or cold water as a bubble,

a spray plate (3) having a flat portion and a plurality of spray apertures (31) formed at the flat portion by piercing in a thickness direction of the flat portion, the spray plate (3) being disposed at an outside of an exit (28) of the introducing path (30) and attached to the head main body (2), and

a discharge path (4) formed between the head main body (2) and the spray plate (3), disposed parallel to the spray plate (3), and communicated with the introducing path (30),

characterized in that the gas-liquid mixing portion (11) has a compression portion (14) and a decompression portion (16) at a second introducing path (12), the warm or cold water introduced in the second introducing path (12) of the gas-liquid mixing portion (11) is once pressurized when passing the compression portion (14) and the pressure of the warm or cold water is subsequently reduced when passing the decompression portion (16), accompanied by the pressure reduction, a gas is absorbed in a gas path (17) of a gas-introducing pipe (18) through an entrance (19), the absorbed gas is mixed as a bubble in the warm or cold water introduced in the second introducing path (12) through a communication path (21) from an exit (20),

the introducing path (30) has an enlarged path (29) at a side of the exit (28) of the introducing path (30), a cross-sectional area of the enlarged path (29) continuously enlarging toward the exit (28), and that

the discharge path (4) is disposed perpendicular to the side of the exit (28) of the introducing path (30) and an entrance (35) of the discharge path (4) has a cross-sectional area at which a volume of the warm or cold water flowing into the discharge path (4) per unit time is equal to or less than a volume of the warm or cold water passing a portion except the enlarged path (29) of the introducing path (30) per unit time or less.
The shower head (1) according to claim 1, each of cross-sections in a length direction of the enlarged path (29) of the introducing path (30) has a cross-sectional area so that the volume of the warm or cold water passing per unit time is similar to one another every cross-section.
The shower head (1a, 1b) according to claim 1 or 2, wherein the spray apertures (31a) formed in the spray plate (3) have a compression portion (37) at a side of an entrance (36) and a decompression portion (39) at a side of the exit (38), respectively.
The shower head (1c, 1d) according to any one of claims 1 to 3, wherein a plurality of ribs (40) are provided in the discharge path (4) along a flow of the warm or cold water in the discharge path (4) and the discharge path (4) is partitioned by the ribs (40).
The shower head (1d) according to claim 4, wherein each of the ribs (40) is disposed between adjacent two of the spray apertures (31).
The shower head (1e, 1f) according to claim 1 or 2, wherein a swirl path (41) for swirling the warm or cold water is concavely shaped at an upstream side of the spray apertures (31) in the spray plate (3), and the swirl path (41) communicates with both the discharge path (4) and the spray apertures (31) and expands outwardly from the discharge path (4).
The shower head (1e, 1f, 1g) according to claim 6, wherein, a length (l) in a discharging direction of the warm or cold water flowing toward the spray apertures (31) is shorter than a length (d) in an introducing direction of the warm or cold water in the swirl path (41), and the former length (l) and the latter length (d) cross at right angles each other.
The shower head (1g) according to claim 6 or 7, wherein a microbubble forming unit (42) is formed by the discharge path (4) and the swirl path and a plurality of the microbubble forming units (42) are provided side by side in a direction of a length of the shower head (1g).
The shower head (1g) according to claim 8, wherein the adjacent two swirl paths (41) communicate with each other by a communicating portion (44) in the adjacent two microbubble forming units (42).