Carbody of railcar
A carbody of a railcar includes an underframe, a side bodyshell, and a roof bodyshell. At least one of the underframe, the side bodyshell, and the roof bodyshell includes: an outer plate portion facing a car outside; and a reinforced portion joined 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 communicating with the internal space is formed on the outer plate portion.
1. A carbody of a railcar, the carbody comprising:
an underframe;
a side bodyshell; and
a roof bodyshell,
wherein:
at least one of the underframe, the side bodyshell, and the roof bodyshell is entirely formed of a double skin bodyshell having a truss structure section, the double skin bodyshell including:
an outer plate portion facing an outside of the railcar, and
a reinforced portion connected to an inside surface of the outer plate portion such that at least one internal space is formed between the reinforced portion and the outer plate portion,
the reinforced portion includes (i) an inner plate portion disposed at an inside of the railcar relative to the outer plate portion so as to be spaced apart from the outer plate portion, and (ii) a plurality of coupling rib portions coupled to the outer plate portion and the inner plate portion, the plurality of coupling rib portions forming a plurality of triangles in a truss shape together with the outer plate portion and the inner plate portion,
at least one sound absorbing hole is formed at the outer plate portion, the at least one sound absorbing hole communicating with the at least one internal space, and
upon the underframe being entirely formed of the double skin bodyshell, the underframe is configured to attach to underfloor devices at the outer plate portion.
2. The carbody according to claim 1 , wherein the sound absorbing hole is formed on the side bodyshell and arranged above the underframe and under a window opening of the side bodyshell.
3. The carbody according to claim 1 , wherein a plurality of sound absorbing holes is formed at the outer plate portion, the plurality of sound absorbing holes including the at least one sound absorbing hole.
4. The carbody according to claim 1 , wherein:
the at least one internal space includes a first internal space and a second internal space;
the at least one sound absorbing hole includes at least one first sound absorbing hole communicating with the first internal space and at least one second sound absorbing hole communicating with the second internal space; and
at least one of a hole diameter, an opening ratio, a hole length, and an arrangement is different between the first sound absorbing hole and the second sound absorbing hole.
5. The carbody according to claim 4 , wherein:
a generated stress of a first region included in the outer plate portion and facing the first internal space is greater than generated stress of a second region included in the outer plate portion and facing the second internal space; and
an opening ratio of the first region is less than an opening ratio of the second region.
6. The carbody according to claim 4 , wherein:
the sound absorbing hole is formed on the side bodyshell;
the first internal space is arranged closer to the underframe than the second internal space; and
an opening ratio of a first region included in the outer plate portion and facing the first internal space is less than an opening ratio of a second region included in the outer plate portion and facing the second internal space.
7. The carbody according to claim 4 , wherein:
the sound absorbing hole is formed on the side bodyshell;
the first internal space is formed closer to a window opening of the side bodyshell than the second internal space; and
an opening ratio of a first region included in the outer plate portion and facing the first internal space is less than an opening ratio of a second region included in the outer plate portion and facing the second internal space.
8. The carbody according to claim 1 , wherein the at least one sound absorbing hole includes a drain hole communicating with a lower end of the internal space.
9. The carbody according to claim 1 , wherein a sound absorbing material is disposed in the at least one internal space.
10. A carbody of a railcar, the carbody comprising:
an underframe;
a side bodyshell; and
a roof bodyshell,
wherein:
at least one of the underframe, the side bodyshell, and the roof bodyshell includes an outer plate portion facing a car outside, and a reinforced portion connected to an inside surface of the outer plate portion such that at least one internal space is formed between the reinforced portion and the outer plate portion;
the reinforced portion includes:
a head portion,
a pair of leg portions extending from respective ends of the head portion toward the outer plate portion, and
a pair of flange portions extending from the corresponding leg portions in respective directions opposite to each other and joined to the outer plate portion; and
at least one sound absorbing hole is formed at the outer plate portion, the at least one sound absorbing hole communicating with the at least one internal space.
11. The carbody according to claim 10 , wherein the sound absorbing hole is formed on the side bodyshell and arranged above the underframe and under a window opening of the side bodyshell.
12. The carbody according to claim 10 , wherein a plurality of sound absorbing holes is formed at the outer plate portion, the plurality of sound absorbing holes including the at least one sound absorbing hole.
13. The carbody according to claim 10 , wherein:
the at least one internal space includes a first internal space and a second internal space;
the at least one sound absorbing hole includes at least one first sound absorbing hole communicating with the first internal space and at least one second sound absorbing hole communicating with the second internal space; and
at least one of a hole diameter, an opening ratio, a hole length, and an arrangement is different between the first sound absorbing hole and the second sound absorbing hole.
14. The carbody according to claim 13 , wherein:
a generated stress of a first region included in the outer plate portion and facing the first internal space is greater than a generated stress of a second region included in the outer plate portion and facing the second internal space; and
an opening ratio of the first region is less than an opening ratio of the second region.
15. The carbody according to claim 13 , wherein:
the sound absorbing hole is formed on the side bodyshell;
the first internal space is arranged closer to the underframe than the second internal space; and
an opening ratio of a first region included in the outer plate portion and facing the first internal space is less than an opening ratio of a second region included in the outer plate portion and facing the second internal space.
16. The carbody according to claim 13 , wherein:
the sound absorbing hole is formed on the side bodyshell;
the first internal space is formed closer to a window opening of the side bodyshell than the second internal space; and
an opening ratio of a first region included in the outer plate portion and facing the first internal space is less than an opening ratio of a second region included in the outer plate portion and facing the second internal space.
17. The carbody according to claim 10 , wherein the at least one sound absorbing hole includes a drain hole communicating with a lower end of the internal space.
18. The carbody according to claim 10 , wherein a sound absorbing material is disposed in the at least one internal space.