Artificial rain nozzle and artificial rain generator

Abstract

To provide an artificial rainfall nozzle and an artificial rainfall generation device capable of reproducing artificial rainfall in a range from drizzle to fine rain which could not be reproduced in prior arts.SOLUTION: An artificial rainfall nozzle 10 comprises a nozzle main body 20 and a porous plate 30. The nozzle main body 20 comprises: a flexible tube part 21 formed of a flexible member and connected to a supply source of water; and a tip opening 22 which is provided on a tip of the flexible tube part 21. When jetting the water supplied from the supply source of water from the tip opening 22 through the flexible tube part 21, the flexible tube part 21 is vibrated by self-excited vibration. The porous plate 30 is formed of a porous member having many small holes 31 and is arranged to face the tip opening 22, and divides the water 26 jetted from the tip opening 22 into fine droplets 32 through the small holes 31.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an artificial rainfall nozzle and an artificial rainfall generating device. More specifically, the present invention relates to an artificial rainfall nozzle and an artificial rainfall generating device capable of reproducing a rainfall intensity approximated to natural rainfall and a raindrop size distribution corresponding to the intensity in a space defined by width, depth, and height.

Background Art

[0002] As artificial rainfall nozzles and artificial rainfall generating devices, in addition to general ones using spray nozzles, Patent Documents 1 and 2 by the present applicant are known. The artificial rainfall nozzles of Patent Documents 1 and 2 include a thin tube connected to a water supply source, a flexible tube connected to this thin tube and forming a spray outlet at the tip, and a guide fin fixed to this flexible tube. When water from the water supply source sprays out from the spray outlet at the tip of the flexible tube, it vibrates due to the momentum of the water, and can produce artificial rain with a raindrop size close to natural rain such as light rain. This raindrop size can be adjusted by appropriately setting the inner diameter of the thin tube, the amount of supplied water, the pressure, and the length of the flexible tube. Further, due to the presence of the guide fin, the sway of the flexible tube is restricted, and interference between the flexible tube and nearby members is prevented.

[0003] In addition, one of the uses of the artificial rainfall generating device is to evaluate driving support systems for elderly drivers or for autonomous driving. A sensor for grasping the situation around the vehicle (for example, the presence and position of people, other vehicles, obstacles, signs, etc.) is essential for the driving support system. For such a sensor, for example, a stereo camera or a three-dimensional scanning infrared sensor called LiDAR is used, but there is a problem that the object recognition ability decreases in bad weather such as rain or fog. Therefore, the artificial rainfall generating device reproduces bad weather such as rain or fog, and tests the driving support system in that environment. In such applications, it is required to be able to reproduce from misty rain to extremely light rain (rainfall intensity is 0.1 - 1 [mm / hr] and average rainfall particle size is 0.1 - 0.9 [mm]).

Prior Art Documents

[0004] [Patent Document 1] Patent No. 4711112 [Patent Document 2] Patent No. 5827667 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, conventional technology had the following problems:

[0006] Conventional technology using flexible tubes can reproduce normal rainfall to heavy rain (rainfall intensity of 10-300 mm / hr and average raindrop size of 1.0-4.0 mm), but it could not reproduce drizzle to very light rain (rainfall intensity of 0.1-10 mm / hr and average raindrop size of 0.1-0.9 mm), which resulted in a decrease in the performance of various sensors.

[0007] Conventional technologies using spray nozzles produce fine particles with an average diameter of 0.005 to 0.05 mm, meaning that various sensors can only be evaluated in haze or foggy conditions, not in drizzle or light rain. In addition, the spraying conditions require a high-pressure water pump, resulting in extremely high equipment costs.

[0008] Therefore, the object of the present invention is to provide an artificial rain nozzle and an artificial rain generation device that can reproduce artificial rainfall ranging from drizzle to very light rain, which could not be reproduced with conventional technology. [Means for solving the problem]

[0009] The artificial rain nozzle according to the present invention is An artificial rain nozzle used for artificial rainfall, A nozzle body having a flexible tube section formed of a flexible member and connected to a water supply source, and a tip opening provided at the tip of the flexible tube section, wherein the flexible tube section self-excites when water supplied from the water supply source is ejected through the flexible tube section from the tip opening, A porous plate is formed of a porous member having numerous small holes and is positioned opposite the tip opening, and divides the water ejected from the tip opening into fine water droplets through the small holes, This is an artificial rain nozzle equipped with [a specific feature / feature].

[0010] The artificial rain generation device according to the present invention is Multiple artificial rain nozzles according to the present invention, Multiple mounting members for attaching the artificial rain nozzle, A support mechanism for supporting the aforementioned mounting member, This is an artificial rain generation device equipped with [specific features / features]. [Effects of the Invention]

[0011] According to the artificial rain nozzle of the present invention, water supplied to the nozzle body is passed through a self-excited vibrating flexible tube section and ejected from the tip opening, and the water ejected from the tip opening is passed through small holes in a porous plate to further divide it into finer water droplets, thereby enabling the reproduction of artificial rainfall ranging from drizzle to very light rain, which could not be reproduced with conventional technology.

[0012] According to the artificial rain generation device of the present invention, since it is equipped with multiple artificial rain nozzles according to the present invention, it is possible to reproduce artificial rainfall ranging from drizzle to very light rain over a wider area. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1[A] shows a plan view and Figure 1[B] shows a side view of the artificial rain nozzle of Embodiment 1. [Figure 2] This is a plan view showing the artificial rain nozzle in disassembled form, as shown in Figure 1. [Figure 3]Fig. 1 shows the nozzle body. Fig. 3[A] is an overall perspective view, and Fig. 3[B] is a partial perspective view showing the enlarged tip opening. [Figure 4] Fig. 3 is a partial plan view showing a modification example of the artificial rainfall nozzle of Fig. 1. [Figure 5] Fig. 6 is a front view showing the artificial rainfall generating device of Embodiment 2. [Figure 6] Fig. 9 is a front view showing the artificial rainfall generating device of Embodiment 3.

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described with reference to the drawings. Embodiment 1 is an artificial rainfall nozzle, Embodiment 2 is a first example of an artificial rainfall generating device, and Embodiment 3 is a second example of an artificial rainfall generating device.

[0015] <Embodiment 1> Fig. 1 shows the artificial rainfall nozzle 10 of Embodiment 1. Fig. 1[A] is a plan view, and Fig. 1[B] is a side view. In Fig. 1[B], a part of the porous plate 30 is enlarged to show the small holes 31. Fig. 2 is a plan view showing the artificial rainfall nozzle 10 disassembled. Fig. 3 shows the nozzle body 20. Fig. 3[A] is an overall perspective view, and Fig. 3[B] is a partial perspective view showing the enlarged tip opening 22. Fig. 4 is a partial plan view showing a modification example of the artificial rainfall nozzle 10. Hereinafter, it will be described based on Figs. 1 to 4.

[0016] The artificial rainfall nozzle 10 of the first embodiment is used for artificial rainfall and includes a nozzle body 20 and a porous plate 30. The nozzle body 20 is formed of a flexible member and has a flexible tube portion 21 connected to a water supply source and a tip opening 22 provided at the tip of the flexible tube portion 21. When the water supplied from the water supply source is ejected from the tip opening 22 through the flexible tube portion 21, the flexible tube portion 21 undergoes self-excited vibration. The porous plate 30 is formed of a porous member having a large number of small holes 31 (FIG. 1[B]) and is disposed opposite to the tip opening 22, and divides the water 26 (FIG. 1[A]) ejected from the tip opening 22 into fine water droplets 32 (FIG. 1[A]) through the small holes 31. The water 26 is a water droplet larger than the water droplet 32.

[0017] The nozzle body 20 is connected to a nozzle-side joint 11, and a water supply pipe 13 as a water supply source is connected to a pipe-side joint 12. Therefore, when the nozzle-side joint 11 and the pipe-side joint 12 are fitted together, the nozzle body 20 is connected to the water supply pipe 13. In other words, the nozzle body 20 is detachably connected to the water supply pipe 13, which is a water supply source, via a pipe-side joint 12 and a nozzle-side joint 11, which are connecting members (for example, quick sockets).

[0018] Both ends of the porous plate 30 are fixed to both ends of a support plate 15, and a ring-shaped mounting tool 16 is provided at the center of the support plate 15. When the nozzle body 20 is passed through the inside of the ring-shaped mounting tool 16, the inside of the ring-shaped mounting tool 16 is fitted with the outside of the nozzle-side joint 11. Thereby, the porous plate 30 is attached to the nozzle body 20, and the nozzle body 20 is surrounded by the porous plate 30 and the support plate 15.

[0019] Next, the configuration of the nozzle body 20 will be described in detail mainly based on FIG. 3.

[0020] The nozzle body 20 has a flexible tube section 21 and a tip opening 22, as well as a guide fin section 23, a thin tube insertion section 24, and a thin tube section 25. In the nozzle body 20, the side from which water is discharged will be called the tip, and the side from which water is injected will be called the rear end. From the rear end to the tip of the nozzle body 20, the thin tube section 25, the thin tube insertion section 24, the guide fin section 23, the flexible tube section 21, and the tip opening 22 are located. The tip side of the thin tube section 25 is provided with a thin tube insertion section 24 connected to the thin tube section 25. The tip side of the thin tube insertion section 24 is provided with a guide fin section 23. The guide fin section 23 functions as a thin plate-shaped tube vibration control unit that controls the direction of motion of the self-excited vibration of the flexible tube section 21, and is provided in a shape that protrudes a predetermined length from the thin tube insertion section 24 toward the tip side, enclosing a part of the flexible tube section 21. The flexible tube section 21 is provided on the tip side of the guide fin section 23, and the tip of the flexible tube section 21 is the tip opening 22.

[0021] The narrow tube section 25 is the part connected to the nozzle-side joint 11. The flexible tube section 21, as described above, is made of a flexible material (for example, silicone rubber) and is connected to the narrow tube section 25, guiding the water flowing inside the narrow tube section 25 and ejecting it to the outside. The nozzle-side joint 11 and the narrow tube section 25 may be made of synthetic resin, for example, and may be formed integrally with the nozzle body 20.

[0022] The flexible tube section 21 has an inner diameter of, for example, 1 mm and an outer diameter of, for example, 2 mm. The inner diameter affects the particle size of the water 26 ejected from the tip opening 22, and is therefore determined by the required particle size distribution. The outer diameter can change the state of self-excited vibration and thus affects the watering area. These properties are adjusted by the specific gravity, elasticity, and other physical properties of the resin that constitutes the flexible tube section 21.

[0023] Furthermore, while the inner diameters of the narrow tube section 25 and the flexible tube section 21 are generally in the range of 1 to 2 mm, appropriate diameters are used to achieve the required raindrop particle size distribution and rainfall intensity. For example, several nozzle bodies equipped with flexible tube sections with an inner diameter of 1 mm or more can be prepared and selected as appropriate depending on the intended use. Note that the smaller the inner diameter, the smaller the droplet size of the water 26 ejected from the tip opening 22.

[0024] As mentioned above, the tip of the flexible tube section 21 is a tip opening 22 for ejecting water (liquid) that has flowed inside the flexible tube section 21. Here, the length t of the flexible tube section 21 (Figure 3[A]) is defined as the distance from the base of the guide fin section 23 to the tip opening 22. For example, in a flexible tube section 21 with an inner diameter of 1[mm] and an outer diameter of 2[mm], good self-excited vibration is obtained when the length t is 30[mm].

[0025] As shown in Figure 3[A], the guide fin portion 23 has a planar shape that is an elongated pentagon. The side shape of the guide fin portion 23 is such that at its rear end, it has a wall thickness that is the same as the outer diameter of the narrow tube portion 25, and as it extends toward the tip, it becomes smoothly thinner, and at the portion where the flexible tube portion 21 protrudes, it has a thickness that is approximately the same as the outer diameter of the flexible tube portion 21, thus forming an overall wedge shape.

[0026] Thus, the guide fin portion 23 is a thin, wedge-shaped structure formed axially symmetric with respect to the axial direction of the flexible tube portion 21, and therefore has a tendency to bend in the thickness direction of the wedge. For this reason, the guide fin portion 23 acts to promote vibration of the flexible tube portion 21 generally in the thickness direction, thereby suppressing vibration in the width direction of the wedge. Note that the guide fin portion 23 is not limited to symmetrical shape; it may be twisted, and its thickness and width dimensions may be in the shape of an inverted wedge. The only requirement is that it is given a shape that can control the vibration direction of the flexible tube portion 21 to match the shape of the watering area.

[0027] If the tube insertion section 24, guide fin section 23, and flexible tube section 21 are integrally molded from silicone rubber as described above, the guide fin section 23 does not need to enclose the flexible tube section 21; rather, it is sufficient that a continuous flow path having the inner diameter of the flexible tube section 21 is maintained and opens to the tube insertion section 24. The material of the nozzle body 20 is not limited to silicone rubber; it may also be various rubber materials such as fluororubber or EPDM, or various synthetic resin materials such as polyvinyl chloride, polyethylene, polypropylene, or polyurethane. In short, it is sufficient as long as it is flexible.

[0028] Next, the structure of the porous plate 30 will be explained in detail, mainly based on Figure 1.

[0029] In this embodiment 1, the porous member is a strip-shaped wire mesh, the small holes 31 are the mesh openings, and the porous plate 30 is made by bending the wire mesh into a cylindrical shape so that the short sides of the strip-shaped wire mesh are close together. At this time, the size of the small holes 31 is appropriately set so that the water droplets 32 satisfy the desired rainfall intensity and rainfall particle size. For example, if the small holes 31 are circular, the diameter is adjusted; if they are square, the length of one side is adjusted; and if they are rectangular, the lengths of the long and short sides are adjusted. Alternatively, the void ratio (porosity) of the porous member or the distance X (Figure 4) from each position 221 of the tip opening 22 that moves due to self-excited vibration to the porous plate 30 may be set. Generally, the smaller the small holes 31, the smaller the void ratio, or the shorter the distance X, the smaller the water droplets 32 become.

[0030] The shape of the porous plate 30 when viewed from above is not limited to a circle or an ellipse, but may also be a triangle, square, rectangle, polygon, etc. The porous plate 30 only needs to be positioned opposite the tip opening 22, for example, installed at a certain distance from the tip opening 22, and does not need to surround the nozzle body 20, nor does it need to be attached to the nozzle body 20. The porous member is not limited to wire mesh, but may also be made of perforated metal, expanded metal, grating, wire mesh, porous metal body, porous ceramics, or porous material made of rubber or synthetic resin, etc.

[0031] Furthermore, as shown in Figure 4, the porous plate 30 may be positioned opposite the tip opening 22 such that the distance X from each position 221 of the tip opening 22, which moves due to self-excited vibration, to the porous plate 30 is constant. In this case, the porous plate 30 and each position 221 are concentric when viewed from above.

[0032] Next, the operation and effects of the artificial rain nozzle 10 will be explained.

[0033] (1) With the artificial rain nozzle 10, water supplied to the nozzle body 20 is passed through a self-excited vibrating flexible tube section 21 and ejected from the tip opening 22, and the water 26 ejected from the tip opening 22 is passed through small holes 31 in a porous plate 30 and further divided into finer water droplets 32, thereby making it possible to reproduce artificial rainfall ranging from drizzle to very light rain, which could not be reproduced with conventional technology.

[0034] In the nozzle body 20, water 26 (water droplets) ejected from the tip opening 22 is scattered over a wide area because the flexible tube section 21 vibrates on its own. At this time, even with just the nozzle body 20, it is possible to reproduce everything from normal rainfall to heavy rain by controlling the pressure and flow rate of the supplied water. However, because the water droplets 26 are relatively large, it is necessary to further break down the water 26 to finer particles in order to reproduce everything from drizzle to very light rain. Therefore, by passing the water 26 ejected from the tip opening 22 through the small holes 31 of the porous plate 30 and further dividing it into finer water droplets 32, it becomes possible to reproduce everything from drizzle to very light rain.

[0035] (2) The flexible tube section 21, formed from a flexible member, has low mechanical rigidity, so self-excited vibration occurs with only a very small amount of kinetic energy. Therefore, the water pump that makes up the artificial rain generation device can be made smaller, and the amount of water supplied can also be reduced. In other words, both the device cost and the device operating cost (electricity and water charges) can be kept low.

[0036] (3) As shown in Figure 4, if the porous plate 30 is positioned such that the distance X from each position 221 of the tip opening 22 that moves due to self-excited vibration to the porous plate 30 is constant, then the conditions from the tip opening 22 to the porous plate 30 (for example, deceleration of the water 26 due to air resistance) will be almost the same at all positions 221 that move due to self-excited vibration. As a result, water droplets 32 with a more stable particle size can be dispersed.

[0037] (4) When the porous member is a strip-shaped wire mesh and the small holes 31 are the mesh of the wire mesh, if the wire mesh is bent into a cylindrical shape so that the short sides of the strip-shaped wire mesh are close together to form the porous plate 30, the wire mesh is an easily available material and is easy to bend, so the porous plate 30 can be easily formed. In particular, as shown in Figure 4, the shape of the porous plate 30 can be easily formed to be concentric with respect to each position 221 of the tip opening 22 that moves due to self-excited vibration.

[0038] <Embodiment 2> Figure 5 is a front view showing the artificial rain generation device 50 of Embodiment 2. The following explanation will be based on Figure 5. However, in Figure 5, the same reference numerals are used for parts that are the same as in Embodiment 1, or the reference numerals are omitted, to avoid redundant explanations.

[0039] The artificial rain generator 50 of this second embodiment includes a plurality of artificial rain nozzles 10, mounting members 51 for attaching the artificial rain nozzles 10, and support columns 52-56 as a support mechanism for supporting the mounting members 51. The direction 57 in which the flexible tube section 21 self-excites is perpendicular to the drawing. Note that for direction 57, a circle with an X inside indicates the direction from the front to the back of the paper (screen), and a circle with a · indicates the direction from the back to the front of the paper (screen).

[0040] The mounting members 51 are, for example, the nozzle-side joint 11 and the pipe-side joint 12 shown in Figures 1 and 2. The support column 56 is, for example, the water supply pipe 13 shown in Figures 1 and 2. The support columns 52 and 53 are erected on the floor or ground, with a support column 54 horizontally installed at the upper ends of the support columns 52 and 53, and a support column 56 horizontally installed below the support column 54 via a support column 55. Stabilizing legs (not shown) are provided at the lower parts of the support columns 52 and 53. In this way, multiple artificial rain nozzles 10 are suspended between the support columns 52 and 53, below the horizontal support column 56, via the mounting members 51.

[0041] Furthermore, the multiple mounting members 51 are arranged on the support column 56 with spacing between them so that the multiple tip openings 22 do not interfere with each other. In this embodiment 2, there are four artificial rain nozzles 10, but of course, there can be any number. The support mechanism is not limited to the support columns 52-56, but may be composed of other support members.

[0042] Water supplied to each nozzle body 20 of the multiple artificial rain nozzles 10 is ejected from the tip opening 22 through a self-excited vibrating flexible tube section 21. The water ejected from the tip opening 22 is further divided into finer droplets through the small holes in the porous plate 30. Because the artificial rain generator 50 is equipped with multiple artificial rain nozzles 10, it is possible to reproduce artificial rainfall ranging from drizzle to very light rain over a wider area. Other functions and effects of this embodiment 2 are the same as those of embodiment 1.

[0043] <Embodiment 3> Figure 6 is a front view showing the artificial rain generation device 50 of Embodiment 3. The following explanation will be based on Figure 6. However, in Figure 6, the same parts as in Embodiments 1 and 2 are either denoted by the same reference numerals or omitted, thereby avoiding redundant explanations.

[0044] The artificial rain generator 60 of this third embodiment is used for artificial rainfall and comprises a plurality of nozzle bodies 20, a porous plate 61, mounting members 51 for attaching the nozzle bodies 20, and support columns 52 to 56 as a support mechanism for supporting the mounting members 51.

[0045] Each of the multiple nozzle bodies 20 is made of a flexible material and has a flexible tube section 21 connected to a water supply source, and a tip opening 22 provided at the tip of the flexible tube section 21. When water supplied from the water supply source is ejected through the flexible tube section 21 and out of the tip opening 22, the flexible tube section 21 vibrates on its own. The porous plate 61 is made of a porous material having many small holes and is positioned opposite the multiple tip openings 22, dividing the water ejected from each tip opening 22 into fine droplets through the small holes.

[0046] The porous plate 61 consists of a single flat wire mesh and is installed between the support columns 52 and 53, beneath the multiple nozzle bodies 20. Water supplied by the multiple nozzle bodies 20 is ejected from the tip openings 22 through the self-excited vibrating flexible tube section 21. The water ejected from the tip openings 22 is further divided into finer droplets as it passes through the small holes in the porous plate 61.

[0047] In Embodiment 2, as shown in Figure 5, the same number of porous plates 30 as the number of nozzle bodies 20 are required. On the other hand, in Embodiment 3, only one porous plate 61 is needed for the number of nozzle bodies 20. Therefore, the artificial rain generation device 60 can simplify the overall configuration and can be manufactured easily and at low cost. The other functions and effects of Embodiment 3 are the same as those of Embodiments 1 and 2.

[0048] <Other> Although the present invention has been described above with reference to the embodiments described above, the present invention is not limited to the embodiments described above. Various modifications can be made to the configuration and details of the present invention that will be understood by those skilled in the art. Furthermore, the present invention also includes combinations of some or all of the configurations of the above embodiments as appropriate. [Industrial applicability]

[0049] The artificial rain nozzle and artificial rain generator according to the present invention are not only used for evaluating driving support systems, but are also used in all places where artificial rain is needed, such as car washes, greenhouse cultivation, watering of green areas on building rooftops, fields, vacant lots, and grounds, to prevent dust and sand from rising. They are also used for inspections (or tests) to confirm the durability and water resistance of various structures used outdoors against rainfall, for topsoil erosion experiments, waterproofing tests of buildings and vehicles, development of detectors to detect the start of rainfall, disaster prevention and detector development, and as countermeasures against the heat island phenomenon using the latent heat of vaporization of water. [Explanation of symbols]

[0050] 10 Artificial rain nozzles 11 Nozzle-side fitting 12. Pipe-side fittings 13. Water supply piping 15 Support plate 16. Ring-shaped attachment device 20 Nozzle body 21 Flexible tube section 22 Tip opening 221 each position 23 Guide fin section 24. Capillary insertion section 25. Capillary section 26 water 30 porous plate 31 small hole 32 water drops 50 Artificial Rainmaking Device 51 Mounting member 52,53,54,55,56 Pillar (support mechanism) 57 directions (self-excited vibration) 60 Artificial Rain Generator 61 Porous plate

Claims

1. An artificial rain nozzle used for artificial rainfall, A nozzle body having a flexible tube section formed of a flexible member and connected to a water supply source, and a tip opening provided at the tip of the flexible tube section, wherein the flexible tube section self-excites when water supplied from the water supply source is ejected through the flexible tube section from the tip opening, A porous plate is formed of a porous member having numerous small holes and is positioned opposite the tip opening, and divides the water ejected from the tip opening into fine water droplets through the small holes, The porous plate is positioned opposite the tip opening such that the distance from each position of the tip opening that moves due to the self-excited vibration to the porous plate is constant. Artificial rain nozzle.

2. An artificial rain nozzle used for artificial rainfall, A nozzle body having a flexible tube section formed of a flexible member and connected to a water supply source, and a tip opening provided at the tip of the flexible tube section, wherein the flexible tube section self-excites when water supplied from the water supply source is ejected through the flexible tube section from the tip opening, A porous plate is formed of a porous member having numerous small holes and is positioned opposite the tip opening, and divides the water ejected from the tip opening into fine water droplets through the small holes, The porous member is a strip-shaped wire mesh, and the small holes are the mesh of the wire mesh. The porous plate is formed by bending the wire mesh into a cylindrical shape so that the short sides of the strip-shaped wire mesh are close together. Artificial rain nozzle.

3. A plurality of artificial rain nozzles according to Claim 1, A mounting member for attaching the artificial rain nozzle, A support mechanism for supporting the aforementioned mounting member, An artificial rain generator equipped with [specific features / equipment].

4. A plurality of artificial rain nozzles according to Claim 2, A mounting member for attaching the artificial rain nozzle, A support mechanism for supporting the aforementioned mounting member, An artificial rain generator equipped with [specific features / equipment].

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