Disc brake and piston
Provided are a disc brake and a piston whose weights can be effectively reduced. A disc brake includes a piston configured to press a pad against a disc. The piston includes a body member formed into a bottomed cylindrical shape and including a cylinder portion and a bottom portion. The cylinder portion and the bottom portion are approximately equal in wall thickness. The piston further includes a plate-shaped member fixed to an external bottom surface of the body member and disposed within a range of the external bottom surface and in a region including a center of the external bottom surface.
1. A disc brake piston for pressing a pad against a disc, comprising:
a plate-shaped member fixed to an external bottom surface of a body member formed into a bottomed cylindrical shape in which a cylinder portion and a bottom portion are approximately equal in wall thickness,
wherein the plate-shaped member is disposed within a range of the external bottom surface and in a region including a center of the external bottom surface, and
wherein an elastic damping member is placed between the external bottom surface and the plate-shaped member that one whole surface of the plate-shaped member is adhesively fixed via the damping member to the external bottom surface.
2. The disc brake piston of claim 1 , wherein the plate-shaped member is bonded and fixed to the external bottom surface with a phenol-based adhesive.
3. A disc brake comprising the disc brake piston of claim 1 .
4. A disc brake comprising the disc brake piston of claim 2 .
5. A disc brake piston for pressing a pad against a disc, the piston comprising:
a body member and a plate-shaped member,
the body member being formed into a bottomed cylindrical shape in which a cylinder portion and a bottom portion are approximately equal in wall thickness, and
the plate-shaped member being fixed to an external bottom surface of the body portion, and
wherein the plate-shaped member is disposed within a range of the external bottom surface and in a region including a center of the external bottom surface, and
wherein the piston comprises a piston body;
the piston body comprises the body member, the plate member, and an adhesion layer between the body member and the plate member;
an annular seal groove is formed in an outer peripheral portion of the piston body, such that the annular seal groove is located between the body member and the plate member;
the seal groove surrounds the adhesion layer; and
an annular seal member is fitted in the seal groove.
6. The disc brake piston of claim 5 , wherein the plate-shaped member is bonded and fixed to the external bottom surface with a phenol-based adhesive.
7. A disc brake comprising the disc brake piston of claim 5 .