Rainfall testing apparatus and method for testing rainfall

Abstract

To run a test with a rainfall intensity of 10 mm / h or less.SOLUTION: A rainfall testing apparatus 10 is a testing apparatus for evaluating characteristics of a test piece for rainfall by causing rain having a rainfall intensity of 10 mm / h or less. The testing apparatus 10 includes a plurality of nozzles 20, each configured to spray water droplets 25. Each nozzle 20 has a structure in which the spread range of the sprayed water droplets 25 varies according to the supplied water pressure. The nozzles 20 are installed such that the water droplets 25 are sprayed upward so that the droplets 25 reach the test piece TP as the traveling direction of the droplets 25 changes from the spraying direction to a downward direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rainfall test device and a rainfall test method. [Background technology]

[0002] Conventionally, as disclosed in Patent Document 1 below, a rainfall test device has been known that artificially causes rain to fall on a test specimen to evaluate the test specimen's resistance to rainfall. The test device disclosed in Patent Document 1 is configured such that a large number of pipes are arranged on the ceiling and a large number of water spray nozzles are arranged at the bottom of each pipe. The water spray nozzles drop water supplied through the pipes. This allows artificial rainfall to be reproduced. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 50-90693 Summary of the Invention [Problem to be solved by the invention]

[0004] The rainfall test device disclosed in Patent Document 1 simply drops water from the nozzles, so if an attempt is made to increase the rainfall intensity (mm / h), the water flowing out of the nozzles does not form droplets but becomes a continuous stream. On the other hand, while it may be possible to make raindrop-like droplets flow out of the nozzles by reducing the amount of water flowing out of the nozzles, a configuration in which water drops are dropped from multiple nozzles arranged along a pipe is not suitable for testing weak rainfall intensities, for example, of 10 mm / h or less.

[0005] To test for weaker rainfall intensity, a configuration that sprays water droplets from fewer nozzles is required, but even in this case, the amount of water sprayed from each nozzle must be reduced. Reducing the amount of water sprayed requires reducing the water supply pressure to the nozzles. However, in this case, the reduced water pressure applied to the nozzles narrows the range over which the water droplets are dispersed when sprayed from the nozzles, resulting in areas where the rain does not fall. Therefore, to reproduce conditions closer to actual rainfall, it is necessary to increase the number of nozzles, but increasing the number of nozzles increases the total amount of water. Therefore, there is a limit to how much rainfall intensity can be reduced simply by reducing the water supply pressure. Furthermore, increasing the number of nozzles increases the cost of the equipment.

[0006] Therefore, the present invention has been made in consideration of the above-mentioned conventional technology, and its object is to provide a rainfall test device and a rainfall test method that can perform tests with weak rainfall intensities of 10 mm / h or less. [Means for solving the problem]

[0007] To achieve the above object, the rainfall test apparatus of the present invention is a test apparatus for evaluating the characteristics of a test specimen against rainfall by injecting rain at a rainfall intensity of 10 mm / h or less, and includes a plurality of nozzles configured to spray water droplets. Each of the plurality of nozzles is configured so that the spread range of the sprayed water droplets changes depending on the supply water pressure. At least one of the plurality of nozzles is installed to spray water droplets above the test specimen so that the flow direction of the water droplets changes from the spray direction to downward so that the water droplets reach the test specimen.

[0008] In the rainfall test apparatus of the present invention, at least one of the multiple nozzles is installed to spray water droplets above the test specimen. The water droplets sprayed from this nozzle reach the test specimen by changing direction from the spray direction to downward. This increases the distance the water droplets travel from the nozzle to the test specimen compared to a configuration in which the nozzle sprays water droplets toward the test specimen. Furthermore, because the water droplets are sprayed from the nozzle in a spreading manner, the longer the travel distance, the greater the water droplets spread. Therefore, even if the water supply pressure is reduced to reduce the water flow rate to the nozzle to obtain a rainfall intensity of 10 mm / h or less, the longer the travel distance to the test specimen, the smaller the water droplets' spread range can be prevented. This makes it possible to reproduce conditions close to actual rainfall. Therefore, it is possible to spray a smaller amount of water droplets over a wider area, making it possible to perform rainfall tests with lower rainfall intensities.

[0009] The at least one nozzle may be installed so that the nozzle faces horizontally or obliquely upward.

[0010] Since there is a distribution in the size of the water droplets sprayed from the nozzle, by installing the nozzle so that the nozzle faces horizontally or diagonally upward, the range that the water droplets reach can be distributed according to the distribution of the water droplet sizes. In addition, the travel distance of the water droplets sprayed from the nozzle can be longer compared to when the nozzle is installed so that the nozzle faces diagonally downward. Therefore, it is possible to conduct tests in which weaker rain falls over a wider area compared to when the nozzle is installed so that the nozzle faces diagonally downward. In addition, compared to when the nozzle is installed so that the nozzle sprays water droplets directly upward, the ceiling of the test chamber can be lowered, which prevents the test chamber from becoming larger.

[0011] At least two of the plurality of nozzles may be positioned to spray water droplets above the specimen so that the direction of the water droplets changes from the spray direction to downward so that the water droplets reach the specimen, and in this case, the at least two nozzles may be positioned on opposite sides of the specimen and laterally offset from facing each other.

[0012] This configuration can prevent uneven distribution of rain compared to when water droplets are sprayed from the same side of the test piece. Also, because the two nozzles are positioned to the side rather than facing each other, water droplets from one nozzle can reach places that are difficult for the other nozzle to reach.

[0013] At least two of the plurality of nozzles may be arranged to spray water droplets above the specimen so that the direction of the water droplets changes from the spray direction to downward so that the water droplets reach the specimen. In this case, the at least two nozzles may be arranged on opposite sides of the specimen and facing each other.

[0014] In this case, the distribution of rain can be prevented from becoming uneven compared to when the water droplets are sprayed from the same side of the test piece, and the water droplets can be evenly distributed on both sides of the test piece.

[0015] The at least two nozzles may be arranged so that at least a portion of the ranges that the water droplets reach overlap each other.

[0016] In this aspect, for example, the range of water droplets sprayed from one of the two nozzles and reaching a longer distance may overlap with the range of water droplets sprayed from the other nozzle and reaching a shorter distance. Furthermore, the range of water droplets sprayed from one nozzle and reaching a shorter distance may overlap with the range of water droplets sprayed from the other nozzle and reaching a longer distance. Because relatively large water droplets reach farther and relatively small water droplets reach closer, overlapping the ranges of water droplets sprayed from the two nozzles as described above reduces bias in the precipitation distribution.

[0017] The at least one nozzle may be positioned so that the water droplets reach an area outside the set test area.

[0018] In this configuration, the amount of water droplets that fall within the test area is reduced compared to when all the water droplets fall within the test area. As a result, it is possible to weaken the intensity of rainfall (reduce the amount of rainfall) within the test area while maintaining the water supply pressure to the nozzle, and therefore it is possible to weaken the intensity of rainfall while preventing the range of spread of the water droplets sprayed from the nozzle from narrowing.

[0019] The rainfall test apparatus may include a ventilation channel for supplying air into the test chamber. In this case, the ventilation channel may have an opening for generating a downflow outside a test area in the test chamber where the specimen is placed, but may not have an opening for allowing the air in the ventilation channel to flow out toward the test area.

[0020] In this embodiment, a downflow occurs outside the test area due to the air flowing out from the opening of the ventilation duct. Therefore, even if there is air flow in the area outside the test area, the downflow makes it difficult for the air inside the test area to be affected by the air flow in the area outside the test area. This prevents the water droplets sprayed from the nozzle from being washed away by the air flow, which could result in failure to obtain the desired rainfall distribution or particle size distribution.

[0021] In order to achieve the above-mentioned object, the rainfall test method of the present invention is a test method for evaluating the characteristics of a test specimen against rainfall by causing rain to fall at a rainfall intensity of 10 mm / h or less, in which water droplets are sprayed from a plurality of nozzles configured so that the spread range of the sprayed water droplets changes depending on the supply water pressure, and at least one of the plurality of nozzles sprays water droplets above the test specimen so that the flow direction of the water droplets changes from the spray direction to downward so that the water droplets reach the test specimen.

[0022] In the rainfall test method according to the present invention, at least one of the multiple nozzles sprays water droplets above the test specimen. The water droplets sprayed from this nozzle reach the test specimen by changing direction from the spraying direction to a downward direction. This increases the travel distance of the water droplets from the nozzle to the test specimen compared to a configuration in which the nozzles are installed to spray water droplets toward the test specimen. Furthermore, because the water droplets are sprayed from the nozzle in a spreading manner, the longer the travel distance, the greater the water droplets spread. Therefore, even if the water supply pressure is reduced to reduce the amount of water to the nozzle to obtain a rainfall intensity of 10 mm / h or less, the longer the travel distance to the test specimen, the smaller the water droplets' spread range can be prevented by increasing the travel distance to the test specimen. This makes it possible to reproduce conditions close to actual rainfall. Therefore, it is possible to spray a smaller amount of water droplets over a wider area, thereby enabling rainfall tests with lower rainfall intensities. [Effects of the Invention]

[0023] As described above, the rainfall test device according to the present invention can perform tests with a weak rainfall intensity of 10 mm / h or less. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a diagram illustrating a rainfall test device according to a first embodiment. [Figure 2] FIG. 1 shows a top view of the test area, illustrating the area where water droplets fall onto the floor. [Figure 3]FIG. 10 is a diagram for explaining that the location where a water droplet falls varies depending on the size of the water droplet. [Figure 4] FIG. 10 is a diagram showing a case where a first nozzle and a second nozzle are arranged in positions facing each other. [Figure 5] FIG. 10 is a diagram showing a case where the nozzle is installed so that the jetting port faces obliquely upward. [Figure 6] FIG. 2 is a diagram illustrating the configuration of a nozzle. [Figure 7] 10A and 10B are diagrams showing an example of a case where the nozzle is installed in a different position and orientation. [Figure 8] FIG. 10 is a diagram schematically illustrating a rainfall test device according to a second embodiment. [Figure 9] 10A and 10B are diagrams for explaining the position of the opening when the outer areas are present only on a pair of opposing side surfaces of the test area. DETAILED DESCRIPTION OF THE INVENTION

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0026] (First embodiment) 1 and 2, the rainfall test apparatus 10 according to this embodiment is a test apparatus for evaluating the characteristics of a test specimen TP against rainfall by causing rainfall of 10 mm / h or less (or 5 mm or less) to fall in a set test area 12. Note that the rainfall test may also be performed at a rainfall intensity of 1 mm / h or more, 2 mm / h or more, or 5 mm / h or more, as long as the rainfall intensity is 10 mm / h or less.

[0027] The test area 12 is an area set as an area where a desired rainfall intensity is obtained on the floor surface of the test area 12 by spraying water from nozzles 20, which will be described later. The test area 12 may be recognized as the entire test chamber 14 for conducting the rainfall test, or, as shown in FIG. 1, a predetermined area within the test chamber 14 may be set as the test area 12.

[0028] The test area 12 is a rectangular parallelepiped area with a rectangular cross section when viewed from above, and the specimen TP (or at least a portion of the specimen TP) is placed within this test area 12. Alternatively, if the specimen TP is a drivable vehicle such as an automobile, the specimen TP may be moved through the test area 12 during the rainfall test. Note that the test area 12 does not have to be rectangular parallelepiped in shape, and may have a circular shape when viewed from above, for example. Furthermore, the test area 12 does not have to be set within the test chamber 14.

[0029] The rainfall test device 10 is equipped with a plurality of nozzles 20, each configured to spray water droplets 25. Each nozzle 20 is connected to a pipe 22, which is connected to a water supply source 21, and configured to spray water supplied from the water supply source 21. The pipe 22 is provided with a valve 22a for adjusting the water pressure or flow rate, and adjusting the opening of this valve 22a changes the amount and speed of water sprayed from the nozzle 20. The valve 22a is adjusted to obtain rainfall intensity of 10 mm / h or less (or 5 mm or less).

[0030] 2 shows an example in which four nozzles 20 are arranged, but more or fewer nozzles 20 may be arranged. Furthermore, a nozzle (not shown) may be arranged in addition to these to spray water droplets 25 onto areas of the test area 12 experiencing less rainfall. This nozzle (not shown) may spray water droplets in a direction different from that of nozzle 20. Furthermore, a nozzle (not shown) may be added that is installed to spray water droplets toward the specimen TP.

[0031] Two of the four nozzles 20 (first nozzles 20a) are arranged on one side of the test area 12, and the remaining two (second nozzles 20b) are arranged on the opposite side. That is, each first nozzle 20a is located on one side (imaginary side) 12a of the test area 12 or its outer side, and each second nozzle 20b is located on the side (imaginary side) 12b opposite to the side 12a or its outer side. In other words, the first nozzles 20a and the second nozzles 20b are arranged on opposite sides of the test piece TP. The numbers of the first nozzles 20a and the second nozzles 20b are not limited to two, and can be set appropriately depending on the size of the test area 12.

[0032] Each first nozzle 20a is fixed to a support 23 (first support 23a) and is disposed at an appropriate height position according to the size of the specimen TP. Each second nozzle 20b is fixed to a support 23 (second support 23b) and is disposed at the same height position as the first nozzle 20a. Note that when the test area 12 is set within the test chamber 14, each first nozzle 20a and each second nozzle 20b may be fixed to the side wall of the test chamber 14 instead of being fixed to the support 23.

[0033] As shown in FIG. 1 , the first nozzle 20a and the second nozzle 20b are each installed to spray water droplets 25 above the specimen TP in the test area 12. Specifically, the first nozzle 20a and the second nozzle 20b are each installed at a position higher than the upper end of the specimen TP and with the nozzle 27 facing horizontally. That is, the nozzle 20 is installed in an orientation such that an extension of the nozzle 27 passes above the specimen TP. In FIG. 1 , because the nozzle 27 faces horizontally, the first nozzle 20a and the second nozzle 20b spray water droplets 25 so that they spread from a horizontal direction. The water droplets 25 reach the specimen TP by changing their flow direction downward in a parabolic curve due to gravity. That is, the first nozzle 20a and the second nozzle 20b are installed so that the water droplets 25 sprayed above the specimen TP change their flow direction downward to reach the specimen TP.

[0034] The water droplets 25 are sprayed so that they spread out from a horizontal direction, but because the size of the water droplets 25 varies, the location where the water droplets 25 fall varies depending on the size of the water droplets 25. That is, as shown in Figure 3, large water droplets 25a reach farther and small water droplets 25b fall closer. Taking advantage of this property, the positions of the first nozzle 20a and the second nozzle 20b are determined according to the spray speed so that the water droplets 25 reach the test piece TP evenly within the test area 12.

[0035] That is, the positions of the first nozzle 20a and the second nozzle 20b are set so that the area where the relatively large water droplets 25a sprayed from the first nozzle 20a fall overlaps with the area where the relatively small water droplets 25b sprayed from the second nozzle 20b fall. However, as shown in Fig. 2, the first nozzle 20a and the second nozzle 20b do not face each other directly, but are positioned at a position shifted to the side from their opposing positions, so the area 31 where the water droplets 25 from the first nozzle 20a fall and the area 32 where the water droplets 25 from the second nozzle 20b fall are shifted in accordance with the positional shift between the nozzles 20.

[0036] The spacing between the first nozzles 20a is set so that the areas 31 onto which the water droplets 25 jetted from each first nozzle 20a fall partially overlap. The spacing between the second nozzles 20b is set so that the areas 32 onto which the water droplets 25 jetted from each second nozzle 20b fall partially overlap. This reduces the area onto which the water droplets 25 do not fall. Note that FIG. 2 is a diagram illustrating the existence of overlapping areas and is merely an example. The overlapping areas may be larger or smaller than this.

[0037] Furthermore, each of the first nozzles 20 a and each of the second nozzles 20 b are installed so that the water droplets 25 reach areas outside the test area 12 .

[0038] When a rainfall test with weak rainfall intensity is performed using the rainfall test device 10, the water supply pressure to each nozzle 20 may be set low to reduce the amount of water sprayed from each nozzle 20. When the water supply pressure to each nozzle 20 is lowered, the amount of water sprayed from each nozzle 20 decreases, and the spread of the water droplets 25 sprayed from each nozzle 20 becomes narrower accordingly. This may make it difficult to spray rain evenly over the test specimen TP.

[0039] To address this concern, in this embodiment, in order to reduce the amount of rainfall within the test area 12 without reducing the water supply pressure to each nozzle 20, the nozzles 20 are positioned so that some of the water droplets 25 sprayed from the nozzles 20 reach outside the test area 12. Note that if the number of nozzles 20 is increased while reducing the water supply pressure, the amount of rainfall will ultimately increase, making it difficult to test light rainfall intensities.

[0040] In FIG. 2, the first nozzle 20a and the second nozzle 20b are arranged in positions offset laterally (in the vertical direction in FIG. 2) from facing each other when viewed from above, but this is not limited thereto. For example, as shown in FIG. 4, the first nozzle 20a and the second nozzle 20b may be arranged in positions facing each other when viewed from above. In this case, water droplets 25 can be evenly dropped onto the specimen TP from both sides. Even in this case, the area 31 onto which the water droplets 25 jetted from the first nozzle 20a fall and the area 32 onto which the water droplets 25 jetted from the second nozzle 20b fall may be arranged to partially overlap. Furthermore, the areas 31 onto which the water droplets 25 jetted from adjacent first nozzles 20a fall are arranged to partially overlap each other, but this is not limited thereto.

[0041] As shown in FIG. 1 , the nozzle 20 is installed so that the nozzle 27 faces horizontally to spray the water droplets 25 above the specimen TP. However, this is not limiting. As shown in FIG. 5 , the nozzle 20 may be installed so that the nozzle 27 faces diagonally upward. In this case, the water droplets 25 are sprayed so that they spread from a direction centered on the diagonally upward direction. Note that the nozzle 20 may be installed so that it faces diagonally downward as long as it is set to spray the water droplets 25 above the specimen TP. For example, the nozzle 20 may be installed so that the extension of the nozzle 27 passes above the specimen TP. In this case, the water droplets 25 are sprayed diagonally downward, but the water droplets 25 are sprayed from the nozzle 20 toward the back of the specimen TP. In other words, the water droplets 25 are sprayed from the nozzle 20 in a direction that would reach a position farther than the specimen TP if the water droplets 25 traveled in a straight line. However, after being sprayed, the direction of the water droplets 25 gradually changes to a more downward direction, and they end up falling on the specimen TP.

[0042] Here, the structures of the first nozzle 20a and the second nozzle 20b will be briefly explained. Both the first nozzle 20a and the second nozzle 20b have the same structure. As shown in FIG. 6, the nozzle 20 includes a main body 35 fixed to a support 23 or the like, and a tube 36 connected to the main body 35 and having an outlet 27 at its tip. The main body 35 is connected to a pipe 22 connected to the water supply source 21, and is configured to circulate water sent through the pipe 22. The main body 35 is attached to the support 23 or the like so that the outlet 27 of the tube 36 faces a predetermined direction.

[0043] The tube 36 ejects water from the nozzle 27 as water flows through the main body 35. The tube 36 is thin and flexible so that it can easily bend in any direction due to the reaction force it receives from the ejected water. Therefore, as the tube 36 continues to eject water, it repeatedly bends and deforms in any direction, with the main body 35 as a support point. As the tube 36 repeatedly deforms, the ejected water breaks up into droplets 25, and these droplets 25 are ejected in a scattering manner. Because the tube 36 is configured to bend due to the reaction force of the ejected water, the amount of deformation changes depending on the supply water pressure. Therefore, the higher the supply water pressure, the larger the range over which the water droplets 25 spread, and the lower the supply water pressure, the smaller the range over which the water droplets 25 spread.

[0044] Although the tube 36 is thin and flexible, it can maintain its posture in its natural state when not spraying water. Therefore, by determining the orientation of the main body 35, the orientation of the nozzle 27 can be determined, for example, horizontally.

[0045] Nozzle 20 is not limited to a configuration that uses the bending of tube 36 to spray water so that water droplets 25 scatter. For example, nozzle 20 may be a nozzle made of a hard material (e.g., metal) and having fine nozzles 27. In this case, the water is broken up into droplets 25 by rapid expansion when sprayed from nozzle 27. Even in this case, the higher the water pressure supplied to nozzle 20, the greater the range over which water droplets 25 spread. However, in the case of metal nozzle 20, water droplets 25 are formed by expansion of water when sprayed from fine nozzles 27, so water is supplied at a higher water pressure.

[0046] As shown in FIG. 1 , the nozzle 20 is fixed to the support 23 so as to spray water droplets 25 horizontally (spraying the water droplets 25 above the test specimen TP). However, when conducting rainfall tests with stronger rainfall intensities, the nozzle 20 can be repositioned and oriented as shown in FIG. 7 . That is, the nozzle 20 in FIG. 1 can be removed from the support 23 and installed so as to spray water droplets 25 downward from the top of the test area 12. In this case, the nozzle 20 is installed so that the nozzle 27 faces the test specimen TP, not above it. This example demonstrates that the nozzle 20 used in the position shown in FIG. 1 can also be used for tests with stronger rainfall intensities. In this case, the nozzle 20 can be attached to the ceiling of the test chamber 14 or to a support member 40 suspended above the test area 12.

[0047] As described above, in the rainfall test apparatus 10 of this embodiment, the multiple nozzles 20 are installed to spray water droplets 25 above the test specimen TP. The water droplets 25 sprayed from the nozzles 20 reach the test specimen TP by changing their flow direction from the spraying direction to downward. Therefore, compared to a configuration in which the nozzles 20 are installed to spray water droplets 25 toward the test specimen TP, as shown in FIG. 7, the travel distance of the water droplets 25 from the nozzles 20 to the test specimen TP is longer. Furthermore, because the water droplets 25 are sprayed from the nozzles 20 in a spreading manner, the longer the travel distance, the wider the water droplets 25 will be. Therefore, even if the water supply pressure is reduced to reduce the amount of water to the nozzles 20 to obtain rainfall with an intensity of 10 mm / h or less, the longer the travel distance to the test specimen TP, the narrowing of the range of the water droplets 25 can be prevented by increasing the travel distance to the test specimen TP. This makes it possible to reproduce conditions close to actual rainfall. Therefore, it becomes possible to make smaller amounts of water droplets 25 fall over a wider area, making it possible to carry out rainfall tests with weaker rainfall intensity.

[0048] Furthermore, since there is a distribution in the size of the water droplets 25 sprayed from the nozzle 20, by installing the nozzle 20 so that the nozzle 27 faces horizontally, the range that the water droplets 25 reach can be distributed according to the distribution of the sizes of the water droplets 25. Furthermore, the travel distance of the water droplets 25 sprayed from the nozzle 20 can be made longer compared to when the nozzle 27 is installed so that the nozzle 27 faces diagonally downward. Therefore, compared to when the nozzle 27 is installed so that the nozzle 27 faces diagonally downward, it is possible to perform a test in which rain with a weaker rainfall intensity falls over a wider range. Furthermore, compared to when the nozzle 20 is installed so that the nozzle 27 sprays the water droplets 25 directly upward, the ceiling of the test chamber 14 can be made lower, thereby preventing the test chamber 14 from becoming larger.

[0049] Furthermore, in this embodiment, the first nozzle 20a and the second nozzle 20b are arranged to spray the water droplets 25 from opposite sides of the specimen TP, which reduces the unevenness of the rain distribution compared to when the water droplets 25 are sprayed from the same side of the specimen TP. Furthermore, the first nozzle 20a and the second nozzle 20b are arranged at positions shifted laterally from facing each other, which allows the water droplets 25 from one nozzle 20 to reach a location that is difficult for the water droplets 25 from the other nozzle 20 to reach. Furthermore, among the water droplets 25 sprayed from the first nozzle 20a and the second nozzle 20b, the water droplets 25 with larger particle sizes fall farther away, and the water droplets 25 with smaller particle sizes fall closer. Therefore, by arranging the first nozzle 20a and the second nozzle 20b as described above, it is possible to reduce the variation in the particle size distribution of the water droplets 25 falling depending on the location.

[0050] In this embodiment, the ranges of the water droplets 25 sprayed from the multiple nozzles 20 are set to at least partially overlap each other. Therefore, for example, the range of the water droplets 25a sprayed from the first nozzle 20a and the range of the water droplets 25b sprayed from the second nozzle 20b can be set to overlap. This has the effect of eliminating bias in the precipitation distribution.

[0051] (Second embodiment) 8, the second embodiment is provided with a blower 50 for blowing air into the test chamber 14. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0052] If an air current is generated in the test chamber 14, the water droplets 25 sprayed from the nozzle 20 may be swept away by the air current in the test chamber 14. For this reason, even if an air current is generated in the test chamber 14, the air blowing means 50 is provided to prevent the water droplets 25 from being swept away by the air current and causing fluctuations in the rainfall distribution or particle size distribution.

[0053] For example, when air-conditioning the test chamber 14, the conditioned air sent out from the indoor unit 55 of the air conditioner circulates within the test chamber 14. In this case, the water droplets 25 sprayed from the nozzles 20 may be swept away by the conditioned air, which may prevent the desired rainfall distribution or particle size distribution from being achieved. In particular, small water droplets 25b are easily swept away by the airflow. For this reason, the air blowing means 50 is configured to generate a downflow outside the test area 12 so that the water droplets 25 sprayed from the nozzles 20 are not affected by the airflow of the conditioned air.

[0054] The air blowing means 50 includes a blower 50a for generating an airflow and an air passage 50b through which the airflow generated by the operation of the blower 50a flows. The air passage 50b is disposed above the area including the test area 12 and the area outside it (outer area 57), along the ceiling 14a of the test chamber 14. The air passage 50b also has a portion that runs along the sidewall 14b of the test chamber 14, and is configured to connect from this portion to the upper portion of the outer area 57.

[0055] The ventilation passage 50b is formed by a plate-like member arranged to form a space between the ceiling 14a and the side wall 14b of the test chamber 14. However, the ventilation passage 50b is not limited to this configuration, and may be formed by a duct arranged along the ceiling 14a of the test chamber 14. The ventilation passage 50b may be provided only above the outer area 57.

[0056] The ventilation passage 50b is provided with an opening 50c that allows the air flowing in the ventilation passage 50b to flow downward. The opening 50c is located above the outer area 57 that surrounds the test area 12, and the air flowing out from the opening 50c creates a downflow around the test area 12. On the other hand, no opening is provided above the test area 12. In other words, no opening is provided that allows the air in the ventilation passage 50b to flow toward the inside of the test area 12. Therefore, even if conditioned air circulates within the test chamber 14, the influence of the flow of conditioned air on the water droplets 25 that fall within the test area 12 is suppressed.

[0057] Although some of the downflow may change direction due to the floor surface 14c of the test room 14 and flow into the test area 12, the opening 50c of the ventilation passage 50b cannot be said to be an opening that allows the air in the ventilation passage 50b to flow out toward the test area 12.

[0058] In this manner, in this embodiment, the air flowing out from the opening 50c of the ventilation passage 50b creates a downflow around the test area 12. Therefore, even if there is a flow of conditioned air in the outer area 57, the downflow makes it difficult for the test area 12 to be affected by the flow of conditioned air. This prevents the water droplets 25 sprayed from the nozzle 20 from being washed away by the air flow, which could prevent the desired rainfall distribution or particle size distribution from being obtained.

[0059] The case where the blower means 50 for generating a downflow is provided is not limited to the case where a flow of conditioned air is generated in the test chamber 14. Even if the flow is not conditioned air, the same effect can be obtained by providing the blower means 50 when an air flow is generated in the test chamber 14.

[0060] Furthermore, openings 50c of ventilation passage 50b are not limited to being arranged so as to surround test area 12. For example, as shown in Fig. 9, if nozzles 20 are provided on each of a pair of opposing side walls 14d of a rectangular test chamber 14 when viewed from above, and if these side walls 14d define a pair of side surfaces 12c of the rectangular test area 12, the space between the other pair of side surfaces 12d of test area 12 and the other pair of side walls 14e of test chamber 14 becomes outer area 57. In this case, openings 50c may be provided in outer areas 57 located above and below test area 12 in Fig. 9.

[0061] Although a description of other configurations, actions, and effects will be omitted, the description of the first embodiment can be applied to the second embodiment.

[0062] (Other embodiments) It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The present invention is not limited to the above-described embodiments, and various modifications and improvements are possible without departing from the spirit of the present invention. For example, in the above-described embodiments, multiple nozzles 20 are installed so as to spray water droplets 25 from opposite sides of the specimen TP, but this is not limiting. Multiple nozzles 20 may also be installed so as to spray water droplets 25 from one side of the specimen TP. [Explanation of symbols]

[0063] 10: Rainfall test equipment 12: Testing area 14: Examination room 20: Nozzle 20a: First nozzle 20b: Second nozzle 25: Water droplets 27: Injection port 50b:Ventilation path 50c: opening TP: Specimen

Claims

1. A test device for evaluating the characteristics of a test specimen against rain by causing rain to fall at a rainfall intensity of 10 mm / h or less, a plurality of nozzles each configured to eject droplets of water; Each of the plurality of nozzles has a configuration in which the spreading range of the sprayed water droplets changes according to the supply water pressure, At least one of the plurality of nozzles is installed to spray water droplets above the specimen so that the direction of the water droplets changes from the spray direction to downward so that the water droplets reach the specimen.

2. The rainfall test apparatus according to claim 1 , wherein the at least one nozzle is installed so that an ejection port faces horizontally or obliquely upward.

3. At least two nozzles of the plurality of nozzles are installed to spray water droplets above the specimen so that the flow direction of the water droplets changes from the spraying direction to downward so that the water droplets reach the specimen, 2. The rain test apparatus of claim 1, wherein the at least two nozzles are positioned opposite each other and laterally offset from an opposing position relative to the specimen.

4. At least two nozzles of the plurality of nozzles are installed to spray water droplets above the specimen so that the flow direction of the water droplets changes from the spraying direction to downward so that the water droplets reach the specimen, The rain test apparatus of claim 1 , wherein the at least two nozzles are positioned opposite each other with respect to the specimen so as to face each other.

5. The rainfall test apparatus according to claim 3 or 4, wherein the at least two nozzles are arranged so that at least a part of the ranges that the water droplets reach overlap each other.

6. 5. The rainfall test apparatus according to claim 1, wherein the at least one nozzle is installed so that water droplets reach an area outside the set test area.

7. It is equipped with a ventilation channel to send air into the test room.

5. A rainfall test apparatus according to claim 1, wherein the ventilation duct has an opening that generates a downflow outside the test area in the test chamber where the test specimen is placed, but does not have an opening that allows the air in the ventilation duct to flow out toward the test area.

8. A test method for evaluating the characteristics of a test specimen against rainfall by subjecting it to rainfall at a rainfall intensity of 10 mm / h or less, comprising: Water droplets are sprayed from a plurality of nozzles configured such that the range of spread of the sprayed water droplets changes in response to the supply water pressure; At this time, at least one of the plurality of nozzles sprays water droplets above the test specimen so that the flow direction of the water droplets changes from the spraying direction to downward, thereby allowing the water droplets to reach the test specimen.

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