Rail vehicles

Abstract

To provide a rail vehicle for achieving both pressure loss and noise reduction in a duct without violating vehicle limits.SOLUTION: In a rail vehicle in which a sound-absorbing insulation material is installed adjacently to a duct for air conditioning provided in a vehicle body, aiming at noise reduction and an insulation effect from the outside of the vehicle body to the inside of the vehicle, the sound-absorbing insulation material is acoustically exposed in the duct by purposely removing an air duct constituting the duct, and noise in the duct is prevented from increasing even if a sound absorption material in the duct is removed in order to reduce pressure loss in the duct by giving not only the noise reduction and the insulation effect from the outside of the vehicle to the inside of the vehicle but also a noise reduction effect in the duct to the sound absorption insulation material.SELECTED DRAWING: Figure 3

Description

【Technical Field】 【0001】 The present invention relates to a track vehicle. 【Background Art】 【0002】 Towards the realization of carbon neutrality, efforts towards decarbonization are accelerating globally, and further reduction of environmental impact is required. In track vehicles including railway vehicles, specific efforts to reduce environmental impact are being promoted, and one of them is the effort to improve energy efficiency of air conditioners. 【0003】 In order for an air conditioner to flow air into a duct, it is necessary to send air from the air conditioner into the duct at a pressure [Pa] (which can also be expressed as energy per unit volume [J / m 【0005】 , , , , , , hereinafter referred to as energy) greater than the pressure loss occurring in the duct. In other words, by reducing the pressure loss occurring in the duct, the energy required for the air conditioner to flow air into the duct can be reduced, and the energy efficiency improvement of the air conditioner is promoted. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2002-178739 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 One factor that increases pressure loss within a duct is the narrowing of the flow path due to the installation of sound-absorbing material within the flow path. However, if the sound-absorbing material is removed to avoid this, the noise inside the duct increases, and consequently, the noise inside the vehicle increases. To compensate for this, one option is to widen the outside of the duct to create new space for installing sound-absorbing material, or to enlarge the duct itself. However, in railway vehicles, for example, the placement of components is meticulously designed so that equipment, piping, and wiring fit within the vehicle clearance limits, making it difficult to expand the installation space without interfering with surrounding components. 【0006】 In contrast, Patent Document 1 discloses an automobile technology that integrates sound-absorbing materials used in the engine compartment with those used in the face duct, with the aim of improving the efficiency of the mounting space for air conditioning ducts such as face ducts. However, even if one tries to apply such technology to railcars, it is difficult to integrate the sound-absorbing materials used in the engine compartment with those used in the ducts. Furthermore, electric railcars do not have an engine compartment in the first place. 【0007】 This invention was made in consideration of the above-mentioned problems, and aims to provide a rail vehicle that can achieve both pressure loss reduction and noise reduction within the duct. [Means for solving the problem] 【0008】 To solve the above problems, one representative rail vehicle of the present invention is a rail vehicle having an air conditioning duct provided on the vehicle body and a sound-absorbing and heat-insulating material installed adjacent to the duct, A flexible thin film material is placed inside the duct, with at least a portion of the sound-absorbing and heat-insulating material. Exposed via, The exposed surface of the sound-absorbing and heat-insulating material is covered with the acoustically transparent wall, which is the flexible thin film material. The sound-transmitting wall extends from the roof structure of the rail vehicle to the interior panel, with its end sandwiched between the upper surface of the sound-absorbing and heat-insulating material and the roof structure, and between the lower surface of the sound-absorbing and heat-insulating material and the interior panel. This is achieved by doing so. [Effects of the Invention] 【0009】 According to the present invention, it is possible to provide a rail vehicle that can achieve both pressure loss reduction and noise reduction within the duct. Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing] 【0010】 [Figure 1] Figure 1 is a cross-sectional view of a conventional railway vehicle duct perpendicular to the direction of the rails. [Figure 2] Figure 2 is a cross-sectional view of a conventional railway vehicle duct, perpendicular to the direction of the sleepers. [Figure 3] Figure 3 is a cross-sectional view relating to Embodiment 1 of the present invention, showing a railway vehicle duct perpendicular to the rail direction. [Figure 4] Figure 4 is a cross-sectional view relating to Embodiment 2 of the present invention, showing a railway vehicle duct perpendicular to the rail direction. [Figure 5] Figure 5 is a cross-sectional view relating to Embodiment 3 of the present invention, showing a railway vehicle duct perpendicular to the rail direction. [Figure 6] Figure 6 is a cross-sectional view relating to Embodiment 4 of the present invention, showing a railway vehicle duct perpendicular to the direction of the sleepers. [Modes for carrying out the invention] 【0011】 Here, "rail-track vehicles" refer to vehicles that operate along laid tracks, including railway cars, monorail cars, new transit system vehicles, and trams. Below, we will explain using railway cars as a representative example of rail-track vehicles. 【0012】 [Embodiment 1] Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a structure in which an air conditioning duct is installed on the roof will be described as an example, but the installation location of the duct is not limited to this, and for example, the duct may be installed under the floorboards, etc. 【0013】 Figure 1 shows a cross-section of a conventional railway vehicle duct perpendicular to the direction of the rails. The duct 1 for air conditioning is composed of an air duct 2, an air outlet 3a, a sound-absorbing material 4a, a perforated metal 11a, and a dew prevention material 5, and is attached to the structure 7 of the railway vehicle via a mounting metal 6a. 【0014】 The sound-absorbing material 4a is covered with a perforated metal 11a which is a plate material with pores so as not to move by the wind pressure during air conditioning operation. As shown in Fig. 2 (a cross-sectional view perpendicular to the sleeper direction of the railway vehicle duct) showing the cross-section A - A of Fig. 1, the perforated metal 11a is fixed by riveting 60 to the air duct 2 on the side surface of the duct 1. 【0015】 Here, an example of riveting the perforated metal 11a is shown, but the fixing method of this embodiment is not limited to this. For example, it may be screwed or brazed. In addition, in this embodiment, a rectangular parallelepiped sound-absorbing and heat-insulating material is described as an example, but the shape of the sound-absorbing and heat-insulating material is not limited to this, and it may be shaped with a slope so as to eliminate a sudden change in the cross-sectional shape of the duct, which is one of the factors increasing the pressure loss in the duct. 【0016】 In addition, in this embodiment described later, since the duct on the roof part is taken as an example, the air conditioner 8 is installed above the upper part of the structure 7 (above the roof structure), but the installation position of the air conditioner is not limited to this. For example, the installation position of the air conditioner may be under the floor. 【0017】 The air conditioner 8 and the duct 1 shown schematically are connected via the opening 7a of the structure 7. The temperature and humidity inside the vehicle are adjusted by sending the conditioned air from the air conditioner 8 into the duct 1, dividing the air flow by the flow dividing plate 9 into the front and rear positions of the vehicle, and discharging it into the vehicle from the air outlet 3a shown in Fig. 1. In addition, a cross-flow fan 20 is attached to the structure 7 via a mounting metal 6b, and by flowing air from the air outlet 3b, the air inside the vehicle is stirred so that the temperature of the space inside the vehicle becomes uniform. 【0018】 Furthermore, sound-absorbing and heat-insulating material 4b is installed between the structure 7 and the interior panel 30. This is intended to reduce noise transmitted from outside the vehicle to the interior and to provide heat insulation. Figure 1 shows the cross-section BB of Figure 2, with reference numeral 50 indicating a lighting fixture and reference numeral 51 indicating a lighting cover. 【0019】 Figure 3 is a cross-sectional view of a railway vehicle duct perpendicular to the rail direction, relating to an embodiment of the present invention. Note that in Figures 3 and beyond, explanations of components common to Figures 1 and 2 will be omitted. The difference from the conventional structure shown in Figure 1 is that the sound-absorbing material 4a, the perforated metal 11a covering the sound-absorbing material 4a, and a portion of the air duct 2 adjacent to the sound-absorbing material 4a have been removed, and instead, the sound-absorbing and heat-insulating material 4b is directly exposed inside the duct 1. 【0020】 This configuration aims to reduce pressure loss within the duct by deliberately removing the air duct 2 that constitutes the duct 1. By removing the sound-absorbing material 4a inside the duct 1, the noise reduction effect lost is attributed to the sound-absorbing and heat-insulating material 4b, which was previously installed adjacent to the duct 1 for other purposes (reducing noise transmitted from outside to inside the vehicle and providing heat insulation). This achieves both pressure loss reduction and noise reduction within the duct 1. In this embodiment, the configuration is described as being applied to the side of the duct, but the application location is not limited to this, and may be, for example, the top surface of the duct. 【0021】 It is generally known that in order for sound-absorbing or sound-insulating materials to exert their full noise reduction effect, a thickness equivalent to one-quarter wavelength of the noise frequency is required. By applying this configuration, by removing a portion of the perforated metal 11a and the air duct 2, it is possible to use a sound-insulating material 4b that is thicker than the sound-absorbing material 4a conventionally installed in the duct. As a result, a noise reduction effect can be obtained even for lower frequency noise than before, and in duct noise where the operating noise of the air conditioning system (low frequency noise) is dominant, noise can be reduced compared to conventional structures. In addition, by constructing the inner wall of the duct with sound-insulating material, the air duct and perforated metal can be reduced, making it lighter than conventional structures. 【0022】 According to this embodiment, in a railway vehicle in which a sound-absorbing and heat-insulating material sealed between the body structure and interior panels of the vehicle body and an air conditioning duct provided on the vehicle body are installed adjacent to each other, the air duct that constituted the duct is deliberately removed so that the sound-absorbing and heat-insulating material is acoustically exposed inside the duct. This provides the sound-absorbing and heat-insulating material not only with noise reduction and heat insulation effects from outside to inside the vehicle, but also with noise reduction effects inside the duct. As a result, even if the sound-absorbing material inside the duct is removed for the purpose of reducing pressure loss inside the duct, an increase in noise inside the duct can be prevented. 【0023】 [Embodiment 2] Even if the sound-absorbing and heat-insulating material 4b is used on the inner wall of the duct as in Embodiment 1 above, airtightness is ensured by the flow resistance of the sound-absorbing and heat-insulating material. However, if concerns about airtightness cannot be eliminated, the surface of the sound-absorbing and heat-insulating material 4b exposed inside the duct 1 may be covered with an acoustically transparent wall 10, as shown in Figure 4. 【0024】 The acoustically transparent wall 10 refers to a wall that allows sound to pass through but not airflow, and examples include thin films and screens used in movie theaters (collectively called flexible thin film materials). For more information on "acoustically transparent walls," see, for example, "Research on Noise Reduction Using Acoustically Transparent Walls (Theoretical Analysis of Reflectivity of Acoustically Transparent Walls)" by Tomonori Matsuda et al., Proceedings of the Japan Society of Mechanical Engineers, No. 115-1, [11'-3, Chugoku-Shikoku Branch 49th General Meeting and Lecture]. By covering the sound-absorbing and heat-insulating material 4b with the acoustically transparent wall 10, it is possible to ensure the airtightness of the duct 1 while giving the sound-absorbing and heat-insulating material 4b a noise reduction effect inside the duct 1. 【0025】 In the example shown in Figure 4, the acoustic permeable wall 10 extends from the roof structure to the interior panel 30, wrapping around the upper and lower surfaces of the sound-absorbing and insulating material 4b, with its end sandwiched between the upper surface of the sound-absorbing and insulating material 4b and the roof structure, and between the lower surface of the sound-absorbing and insulating material 4b and the interior panel 30. This allows the surface of the sound-absorbing and insulating material 4b to be covered with the flexible acoustic permeable wall 10 without wrinkles or creases. 【0026】 [Embodiment 3] If the inner wall of the duct is constructed solely of sound-absorbing and heat-insulating material, as in Embodiment 1 described above, there is a concern that the sound-absorbing and heat-insulating material will gradually fall or protrude into the duct due to its own weight on the top and sides of the duct. As a structure to solve this, as shown in Figure 5, the inner wall of the duct where the sound-absorbing and heat-insulating material 4b is exposed (exposed surface) is covered with perforated metal 11b with an opening ratio (the ratio of the total area of ​​openings punched out by the punching process) of 30% or more. In this case, a portion of the sound-absorbing and heat-insulating material 4b will be directly exposed into the duct 1 through the openings in the perforated metal 11b. 【0027】 It is generally known that perforated metal becomes acoustically transparent (without impairing the sound-absorbing function of the sound-absorbing and insulating material) when the perforation ratio is 30% or more. By using perforated metal with such a configuration, it is possible to provide the sound-absorbing and insulating material 4b with a noise reduction effect inside the duct 1 while preventing the sound-absorbing and insulating material from falling into or protruding into the inside of the duct. 【0028】 In this embodiment, the sides and top of the duct are made of perforated metal, but the scope of application is not limited to this, and the bottom of the duct may also be made of perforated metal depending on the duct structure of the target duct. Furthermore, it may be combined with the acoustically transparent wall shown in Embodiment 2. 【0029】 [Embodiment 4] In the above embodiment 3, the entire inner wall of the duct is made of perforated metal. However, using perforated metal requires strength analysis and additional sheet metal processing, so it is desirable to use it only to the minimum extent necessary depending on the purpose. For example, in the upstream part of the duct, which is close to the air conditioning unit, the operating noise of the air conditioning unit (low-frequency noise) is dominant, so in order to obtain a noise reduction effect even for low-frequency noise, the thicker parts of the sound-absorbing and insulating material (sides in Figure 6) are made of perforated metal 11c. Also, in the downstream part of the duct, the area where a large area can be obtained for noise reduction by the sound-absorbing and insulating material (sound absorption area) (top surface in Figure 6) is made of perforated metal 11d. In this way, by considering the frequency at which noise reduction is to be achieved, the sound absorption area to be secured, and the structure of the duct in question, the application range of perforated metal may be configured to differ depending on the part of the duct, such as making the inner wall of the duct of perforated metal. It is preferable that the perforation ratio of the perforated metal 11c and 11d is 30% or more. 【0030】 According to the present invention, in addition to the noise reduction and heat insulation effects from outside the vehicle to inside the vehicle that were targeted by conventional vehicle body structures, it is possible to provide a noise reduction effect within the duct without increasing the pressure loss within the duct. Furthermore, by utilizing the effects of the present invention, it is possible to reduce the amount of sound-absorbing material in the duct and reduce pressure loss while keeping noise levels below conventional levels, thereby achieving both pressure loss reduction and noise reduction within the duct. Compared to conventional technology, the present invention can newly provide a noise reduction effect within the duct to the sound-absorbing and heat-insulating materials that were installed in conventional vehicle body structures for the purpose of noise reduction and heat insulation. 【0031】 This specification includes disclosures of the following inventions. (First form) In a rail vehicle having an air conditioning duct provided on the vehicle body and a sound-absorbing and heat-insulating material installed adjacent to the duct, A rail vehicle characterized in that at least a portion of the sound-absorbing and heat-insulating material is exposed inside the duct via a flexible thin film material or directly. 【0032】 (Second form) In the first form of rail vehicle, A rail vehicle characterized in that the exposed surface of the sound-absorbing and heat-insulating material is covered with an acoustically permeable wall as the flexible thin film material. 【0033】 (Third form) In the second form of rail vehicle, A rail vehicle characterized in that the sound-transmitting wall extends from the roof structure to the interior panel, and its end is sandwiched between the upper surface of the sound-absorbing and heat-insulating material and the roof structure, and between the lower surface of the sound-absorbing and heat-insulating material and the interior panel. 【0034】 (Fourth form) In any of the first to third forms of rail vehicles, A rail vehicle characterized by covering the exposed surface of the sound-absorbing and heat-insulating material with perforated metal having an open-hole ratio of 30% or more. 【0035】 (Fifth form) In the fourth form of rail vehicle, A rail vehicle characterized in that the application range of the perforated metal is configured to differ depending on the part of the duct, according to at least one of the frequency at which noise of the duct is to be reduced and the sound absorption area to be secured. 【0036】 (Sixth form) In any of the rail vehicles of the first to fifth forms A rail vehicle characterized in that an air conditioning system that supplies air to the duct is located above the roof structure. [Explanation of Symbols] 【0037】 1...Duct, 2...Air conduit, 3a, 3b...Air outlet, 4a...Sound-absorbing material, 4b...Sound-absorbing and heat-insulating material, 5...Condensation prevention material, 6a, 6b...Mounting bracket, 7...Structure, 8...Air conditioning unit, 9...Flow divider plate, 10...Acoustic transparent wall, 11a, 11b, 11c, 11d...Perforated metal, 20...Cross-flow fan, 30...Interior panel, 50...Lighting fixture, 51...Lighting cover, 60...Rivet

Claims

[Claim 1] In a rail vehicle having an air conditioning duct provided on the vehicle body and a sound-absorbing and heat-insulating material installed adjacent to the duct, At least a portion of the sound-absorbing and heat-insulating material is exposed inside the duct via a flexible thin film material. The exposed surface of the sound-absorbing and heat-insulating material is covered with the acoustically transparent wall, which is the flexible thin film material. The sound-transmitting wall extends from the roof structure of the rail vehicle to the interior panel, and its end is sandwiched between the upper surface of the sound-absorbing and heat-insulating material and the roof structure, and between the lower surface of the sound-absorbing and heat-insulating material and the interior panel, characterized in that the rail vehicle. [Claim 2] In the rail vehicle described in claim 1, A rail vehicle characterized in that an air conditioning system that supplies air to the duct is located above the roof structure.

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