Brake disc for railway vehicle
A brake disc for a railway vehicle includes: a disc plate portion that has a sliding portion of a front face; a plurality of radial fins that are provided on the rear face of a disc plate portion, and that have a shape that extends in the radial direction of the disc plate portion; and a circumferential rib that is provided between each pair of adjacent radial fins, and that has a shape that extends in the circumferential direction of the disc plate portion. A flow path for air is formed between the pair of radial fins, and the flow path for air is narrowed by the circumferential rib. On the circumferential rib, a gradual slope for suppressing fluctuations in an airflow that passes between the pair of radial fins is provided from a base part to a top part.
1. A brake disc for a railway vehicle, the brake disc comprising:
one and only one disc plate portion having a sliding portion on a front face, the disc plate portion having a monolithic annular shape,
a plurality of substantially straight radial fins provided on a rear face of the disc plate portion and having a shape extending in a radial direction from an inner circumferential side to an outer circumferential side of the rear face of the disc plate portion, the disk plate portion being disposed on one side of the plurality of the radial fins so that the brake disk is open on another side opposite to the one side, and
a circumferential rib provided between each pair of radial fins that are adjacent among the plurality of radial fins, and having a shape extending in a circumferential direction of the disc plate portion, along a radius that does not vary, wherein:
a flow path for air that runs from an inner circumferential side to an outer circumferential side of the disc plate portion is formed between the pair of radial fins in a state in which the disc plate portion is fastened to a wheel of the railway vehicle, and the flow path for air is narrowed by the circumferential rib; and
a gradual slope for suppressing fluctuations in an airflow that passes between the pair of radial fins is provided on the circumferential rib on a side face along the radial direction of the disc plate portion.
2. The brake disc for a railway vehicle according to claim 1 , wherein the gradual slope is provided on one side face of the circumferential rib that faces the inner circumferential side along the radial direction of the disc plate portion, or is provided on both side faces of the circumferential rib that face the inner circumferential side and the outer circumferential side, respectively, along the radial direction of the disc plate portion.
3. The brake disc for a railway vehicle according to claim 1 , wherein:
the gradual slope includes a top-part gradual slope that is provided at least at a top part of the circumferential rib, and
the top-part gradual slope is a convex curved face having a radius of curvature of 2 mm, the top-part gradual slope being provided at a side portion facing the inner circumferential side of the disc plate portion, at a first section of 2 mm or more in the radial direction of the disc plate portion, and at a second section of 2 mm or more in a rotational axis direction of the disc plate portion from a vertex of the circumferential rib.
4. The brake disc for a railway vehicle according to claim 1 , wherein:
the gradual slope includes a top-part gradual slope that is provided at least at a top part of the circumferential rib, and
the top-part gradual slope is a convex curved face having a radius of curvature of 5 mm, the top-part gradual slope being provided at a side portion facing the inner circumferential side of the disc plate portion, at a first section of 5 mm or more in the radial direction of the disc plate portion, and at a second section of 5 mm or more in a rotational axis direction of the disc plate portion from a vertex of the circumferential rib.
5. The brake disc for a railway vehicle according to claim 1 , wherein the circumferential rib connects the pair of radial fins, and having a flow path for air between the wheel and the circumferential rib.
6. The brake disc for a railway vehicle according to claim 1 , wherein:
the gradual slope includes a top-part gradual slope that is provided at least at a top part of the circumferential rib, and
the top-part gradual slope is a sloping face which is more gradual than a convex curved face having a radius of curvature of 2 mm, the top-part gradual slope being provided at a side portion facing the inner circumferential side of the disc plate portion, at a first section of 2 mm or more in the radial direction of the disc plate portion, and at a second section of 2 mm or more in a rotational axis direction of the disc plate portion from a vertex of the circumferential rib.
7. The brake disc for a railway vehicle according to claim 1 , wherein:
the gradual slope includes a top-part gradual slope that is provided at least at a top part of the circumferential rib, and
the top-part gradual slope is a sloping face which is more gradual than a convex curved face having a radius of curvature of 5 mm, the top-part gradual slope being provided at a side portion facing the inner circumferential side of the disc plate portion, at a first section of 5 mm or more in the radial direction of the disc plate portion, and at a second section of 5 mm or more in a rotational axis direction of the disc plate portion from a vertex of the circumferential rib.