Patent ID: 8875849

Claim:
A vehicle caliper brake device which is installed in a vehicle that includes a vehicle body and a vehicle wheel having a braking surface to exert a braking force on the vehicle wheel, comprising: a brake pad that exerts a frictional force on the braking surface; a holder that supports the brake pad; a caliper main body supported by the vehicle body; a pair of anchor pins joined to the holder; and a pair of adjusters that support the pair of anchor pins respectively such that the holder is capable of advancing and retreating relative to the braking surface; and an actuator that presses the brake pad against the braking surface via the holder, wherein the actuator comprises: a diaphragm accommodated in the caliper main body; a driving pressure chamber defined by the diaphragm on an inner side of the caliper main body; a piston that transmits a displacement of the diaphragm to the holder; and a joining mechanism including a plurality of screws for fixing the piston to the holder, wherein the piston is a hollow cylindrical member comprising an elliptical tube portion having an elliptical cross-section, a crown plate portion that closes a tip end of the elliptical tube portion, and a partition wall portion that partitions an inside of the elliptical tube portion, an insulation space that blocks heat transfer from the holder to the piston is provided on an inner side of the piston, and the joining mechanism further includes a plurality of screw holes formed in the piston, the screws being inserted through the holder and screwed into the screw holes, wherein the piston comprises a flange that projects sideward from a base end of the elliptical tube portion, and the screw holes include screw holes formed in the flange.