Brake Disc
A brake disc capable of sufficiently absorbing thermal stress associated with thermal expansion and deformation of the braking section. The brake disc includes a mounting section for attachment to a wheel, a braking section located at the outside circumference of the mounting section for brake pads to be brought into sliding contact therewith, and a connecting arm section for connecting each of the plurality of mounting portions of the mounting section and the braking section. Connecting arms in the connecting arm section each extend from their respective ones of the plurality of mounting portions in one side direction different from the radial direction of the braking section to reach the braking section, and adjacent mounting portions are connected to each other at least through a connecting arm.
1. A brake disc comprising:
a mounting section for attachment to a wheel;
a braking section located at an outside circumference of said mounting section for brake pads to be brought into sliding contact therewith; and
a connecting arm section for connecting the mounting section and said braking section;
wherein said connecting arm section comprises a plurality of connecting arms, each said connecting arm extending from a mounting portion formed in said mounting section in a side direction different from a radial direction of said braking section to reach a connecting point with said braking section;
wherein adjacent mounting portions are connected to each other at least through said connecting arms;
wherein the connecting arms and braking section are integrally formed; and
wherein a first distance from a first mounting portion of a first connecting arm to an adjacent mounting portion of an adjacent connecting arm, the adjacent connecting arm being located opposite from the side direction of the first connecting arm, is greater than a second distance from the first mounting portion to the connecting point of the adjacent connecting arm with the braking section.
2. The brake disc according to claim 1 , wherein at least two connecting arms extend from one of said mounting portions to said braking section.
3. The brake disc according to claim 2 , wherein one of said connecting arms extending from said one mounting portion is connected, by a reinforcement arm, to another mounting portion located in the side direction of said one mounting portion.
4. The brake disc according to claim 3 , wherein an opening defined by said mounting portions, said connecting arms and said reinforcement arms, and located centrally of the brake disc, is a polygon.
5. The brake disc according to claim 4 , wherein said polygon is approximately a regular hexagon.
6. The brake disc according to claim 2 , wherein at least one of said connecting arms extending from said one mounting portion is branched to reach a plurality of locations of said braking section.
7. The brake disc according to claim 2 , wherein the at least two connecting arms extending from said one mounting portion include connecting arms of different lengths, at least one of which other than a shortest connecting arm is connected, by a reinforcement arm, to a mounting portion located in the side direction of said mounting portion.
8. The brake disc according to claim 1 , wherein said braking section and said connecting arm section are arranged such that braking force is applied to said braking section producing frictional heat when said brake pads are brought into sliding contact with said braking section, and a whole of said connecting arm section is deformed by thermal expansion during braking of said braking section.
9. The brake disc according to claim 1 , wherein one connecting arm extends from one of said mounting portions to said braking section.
10. The brake disc according to claim 1 , wherein said braking section is formed with a plurality of small holes.
11. The brake disc according to claim 1 , wherein said brake disc is a brake disc for a motorcycle.
12. A vehicle equipped with the brake disc set forth in claim 1 .