Patent Application
20190001998
The present invention relates to a carbody of a railcar.
High speed railcars are subjected to various noise countermeasures, and therefore, a noise level is made lower than a predetermined environmental regulation value. For example, PTL 1 discloses a sound absorbing panel covering an underfloor device from a lower side and a lateral side, the underfloor device being provided under a carbody. According to this, noises reflecting between the car and a ground wall surface (such as a soundproof wall surface or a tunnel wall surface) located beside a permanent way can be absorbed by the sound absorbing panel.
PTL 1: Japanese Patent No. 4286799
In recent years, railcars are further increasing in speed. Since noise is substantially proportional to the square of a car travelling speed or more, further noise countermeasures are desired in some cases. For example, when the sound absorbing panel is provided not only around the underfloor device provided under the carbody but also a side surface of the carbody, a large sound absorbing area can be secured. However, when the sound absorbing panel is provided on a side surface of a side bodyshell of the carbody, the side bodyshell needs to be positioned at an inner side in a car width direction by the thickness of the sound absorbing panel from the viewpoint of car gauge, and this causes a problem that a passenger room space of the carbody narrows. Further, since work of joining the sound absorbing panel to an outer surface of the side bodyshell is necessary, car assembly man-hours increase, and the number of parts of the car also increases.
An object of the present invention is to satisfactorily absorb noise of a railcar without narrowing a passenger room space of a carbody while preventing the number of parts and car assembly man-hours from increasing.
A carbody of a railcar according to one aspect of the present invention a carbody including an underframe, a side bodyshell, and a roof bodyshell, at least one of the underframe, the side bodyshell, and the roof bodyshell including an outer plate portion and a reinforced portion, the outer plate portion facing a car outside, the reinforced portion being connected to an inside surface of the outer plate portion and forming at least one internal space between the reinforced portion and the outer plate portion, at least one sound absorbing hole being formed at the outer plate portion and communicating with the internal space.
According to the above configuration, since a sound absorbing function is given to the carbody itself, sound absorption can be performed by the carbody without providing a sound absorbing panel on an outer surface of the outer plate portion of the carbody. Therefore, the noise of the railcar can be satisfactorily absorbed without narrowing the passenger room space of the carbody while preventing the number of parts and the car assembly man-hours from increasing.
According to the present invention, the noise of the railcar can be satisfactorily absorbed without narrowing the passenger room space of the carbody while preventing the number of parts and the car assembly man-hours from increasing.
Hereinafter, embodiments will be explained with reference to the drawings.
The side bodyshell 5 includes: an outer plate portion 7 facing a car outside; and a reinforced portion 10 connected to an inside surface of the outer plate portion 7 and forming a plurality of internal spaces S between the reinforced portion 10 and the outer plate portion 7. Carbody longitudinal direction end portions of the internal spaces S are closed by lids, not shown (for example, end bodyshells). The reinforced portion 10 includes: an inner plate portion 8 arranged at a car inside of the outer plate portion 7 so as to be spaced apart from the outer plate portion 7; and a plurality of coupling rib portions 9 coupled to the outer plate portion 7 and the inner plate portion 8. The plurality of coupling rib portions 9 form a plurality of triangles in a truss shape together with the outer plate portion 7 and the inner plate portion 8. It should be noted that each of the underframe 4 and the roof bodyshell 6 has the same structure as the side bodyshell 5.
A plurality of underfloor devices 11 (for example, an inverter, a transformer, and the like) attached to the underframe 4 are arranged under the carbody 2. Rails 14 on which the bogie 3 travels are laid on a ground surface 13, and a soundproof wall 15 projects upward from the ground surface 13. The soundproof wall 15 is arranged beside the railcar 1 and projects to a position higher than the underframe 4 and lower than the window opening 5a.
As shown in
As shown in
As shown in
The hole length, a hole pitch (i.e., an inter-hole distance), and the arrangement are the same between the second sound absorbing holes H2 and the third sound absorbing holes H3. However, the hole diameter is different between the second sound absorbing holes H2 and the third sound absorbing holes H3. Specifically, the hole diameter of the third sound absorbing hole H3 is larger than the hole diameter of the second sound absorbing hole H2. The hole diameter, the hole length, the opening ratio, and the arrangement are the same between the third sound absorbing holes H3 and the fourth sound absorbing holes H4. The opening ratio of the first region R1 of the outer plate portion 7 is lower than the opening ratio of the second region R2 of the outer plate portion 7, and the opening ratio of the second region R2 of the outer plate portion 7 is lower than the opening ratio of the third region R3 of the outer plate portion 7. In the present embodiment, regarding the regions R1 to R3 of the outer plate portion 7, generated stress is higher in the region closer to the window opening 5a, and strength decrease tolerance is lower in the region closer to the window opening 5a. Therefore, regarding the regions R1 to R3 of the outer plate portion 7, the opening ratio is set to be lower in the region closer to the window opening 5a. It should be noted that the opening ratio denotes a ratio of opening areas of all the sound absorbing holes in an area of the outer plate portion.
As shown in
Drain holes D are formed in the respective first to twelfth regions R1 to R12 of the outer plate portion 7 so as to communicate with respective lower end portions of the first to twelfth internal spaces S1 to S12. To be specific, the car longitudinal direction end portions of the first to twelfth internal spaces S1 to S12 are closed by lids (not shown), but even when water flows into the first to twelfth internal spaces S1 to S12 through the first to twelfth sound absorbing holes H1 to H12, the water is naturally discharged through the drain holes D. It should be noted that the drain holes D also serve as the sound absorbing holes.
A sound absorbing material A may be inserted into at least one of the first to thirteenth internal spaces S1 to S13. Various types of materials may be used as the sound absorbing material A, and for example, a porous material is used. The sound absorbing material A may be inserted into all the internal spaces with which the sound absorbing holes communicate, or may be selectively inserted into one or more internal spaces. One example is that the sound absorbing material A is not inserted into the internal space corresponding to the region in which the opening ratio is lower than a predetermined value, and the sound absorbing material A is inserted into the internal space corresponding to the region in which the opening ratio is the predetermined value or more.
According to the above explained configuration, a sound absorbing function is given to the side bodyshell 5 itself. Therefore, sound absorption can be performed by the carbody 2 without attaching a sound absorbing panel to an outer surface of the side bodyshell 5. On this account, the noise of the railcar 1 can be satisfactorily absorbed without narrowing the passenger room space P of the carbody 2 while preventing the number of parts and the car assembly man-hours from increasing. To be specific, even if a sound insulation property is reduced by forming the holes H1 to H12 on the side bodyshell 5, the noise outside the carbody 2 is reduced by the sound absorbing holes H1 to H12, so that the total amount of noise entering from the car outside into the car inside through the entire carbody 2 can be suppressed.
Since the sound absorbing holes H1 to H12 are arranged above the underframe 4 and under the window opening 5a, the noise reflecting between the soundproof wall 15 and the carbody 2 can be effectively absorbed. Further, since the sound absorbing holes H1 to H12 include sound absorbing holes among which at least one of the hole diameter, the hole length, the opening ratio, and the arrangement is different, suitable sound absorbing design can be realized in accordance with the characteristics of the noise.
Regarding the regions R11 to R13 of the outer plate portion 7, the opening ratio is set to be lower in the region closer to the underframe 4. Further, regarding the regions R1 to R3 of the outer plate portion 7, the opening ratio is set to be lower in the region closer to the window opening 5a. To be specific, the side bodyshell 5 includes both a portion whose required strength is high and a portion whose required strength is low. Based on this, by providing the sound absorbing holes H1 to H12 at appropriate positions of the outer plate portion 7, both maintaining the strength of the side bodyshell 5 and improving the sound absorbing performance can be realized.
The head portion 29 is arranged at a car inside of the outer plate portion 27 so as to be spaced apart from the outer plate portion 27 and extends in the carbody longitudinal direction. The pair of leg portions 30 extend from both respective ends (i.e., upper and lower ends) of the head portion 29 toward the outer plate portion 27. The pair of flange portions 31 extend from respective end portions of the pair of leg portions 30 in respective directions (i.e., upper and lower directions) opposite to each other, the end portions being located close to the outer plate portion 27. The pair of flange portions 31 are joined to the outer plate portion 27 by laser welding or spot welding. To be specific, the internal space T is surrounded by the outer plate portion 27, the pair of leg portions 30, and the head portion 29. Carbody longitudinal direction end portions of the internal spaces T are closed by lids, not shown (for example, the end bodyshells).
In the wainscot panel region 25b of the side bodyshell 25, a plurality of internal spaces T each having a square section are provided so as to be lined up in the vertical direction. To be specific, in the wainscot panel region 25b of the side bodyshell 25, a first internal space T1, a second internal space T2, . . . are provided in this order from an upper side. A plurality of first sound absorbing holes H21 communicating with the first internal space T1 are formed in a first region Q1 included in the outer plate portion 27 and facing the first internal space T1. A plurality of second sound absorbing holes H22 communicating with the second internal space T2 are formed in a second region Q2 included in the outer plate portion 7 and facing the second internal space T2.
The first sound absorbing holes H21 are arranged in a row in the carbody longitudinal direction, and the second sound absorbing holes H22 are arranged in a row in the carbody longitudinal direction. However, the hole diameter and the hole pitch are different between the first sound absorbing holes H21 and the second sound absorbing holes H22. Specifically, the hole diameter of the first sound absorbing hole H21 is smaller than the hole diameter of the second sound absorbing hole H22, and the hole pitch of the first sound absorbing holes H21 is larger than the hole pitch of the second sound absorbing holes H22. Further, the sound absorbing material A may be inserted into at least one of the internal spaces T1 and T2. As with Embodiment 1, the sound absorbing material A may be inserted into all the internal spaces or may be selectively inserted into one or more internal spaces.
According to the above explained configuration, the noise of the railcar can be effectively absorbed without narrowing the passenger room space of the carbody while preventing the number of parts and the car assembly man-hours from increasing. Further, suitable sound absorbing design can be realized in accordance with the characteristics of the noise. Furthermore, both maintaining the strength of the side bodyshell 25 and improving the sound absorbing performance can be realized. It should be noted that since the other components are the same as those in Embodiment 1, explanations thereof are omitted. In Embodiment 2, the horizontal frame member is used as the reinforced portion forming the internal space with which the sound absorbing holes of the outer plate portion communicate. However, a vertical frame member may be used as the reinforced portion.
Next, Example and Comparative Example will be explained.
Table 1 shows specifications of the side bodyshell of Example 1. The side bodyshell of Example 1 has the same double skin structure as Embodiment 1 but is different in specifications from the example shown in
The present invention is not limited to the above embodiments, and modifications, additions, and eliminations may be made with respect to the configuration of the present invention. The above embodiments may be combined arbitrarily. For example, some of components or methods in one embodiment may be applied to another embodiment. Further, some of components in the embodiment may be separated and extracted arbitrarily from the other components in the embodiment. Although the sound absorbing holes are provided at the region included in the side bodyshell and located between the underframe and the window opening, the sound absorbing holes may also be provided at a region included in the side bodyshell and located above the window opening. The sound absorbing holes may be provided at the underframe and/or the roof bodyshell in addition to or instead of the side bodyshell. The internal spaces with which the sound absorbing holes of the side bodyshell communicate are not limited to the above embodiments. For example, the internal space may be an internal space of a side bodyshell having a double skin structure and have a square section. The shape of the sound absorbing hole is not especially limited and may be a long circular shape, an oval shape, a square shape, a polygonal shape, or the like instead of the circular shape.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-249665 | Dec 2015 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2016/087813 | 12/19/2016 | WO | 00 |
