A disc brake comprising:
a mounting member attached to a non-rotating portion of a vehicle and having a
5 torque receiving part on both sides of a disc in a rotation direction;
a friction pad movable in an axial direction of the disc;
a caliper supported by the mounting member and pressing the friction pad
against the disc;
a pad support spring attached to the torque receiving part on a disc rotation
10 direction entry side and the torque receiving part on a disc rotation direction exit side of
the mounting member, and having a support part which elastically supports the friction
pad and biases the friction pad outward in a disc radial direction; and
a pad return spring provided at least on the disc rotation direction entry side
between the friction pad and the caliper, including attachment parts at both ends each of
15 which is attached to an outer surface of the friction pad on a disc radial direction outward
side, and a folded part provided between the attachment parts at both ends and coming
into contact with the caliper to bias the friction pad in a direction away from the disc,
wherein
a support biasing force of the support part on the disc rotation direction entry
20 side biasing the friction pad outward in the disc radial direction is equal to or larger than
an acting biasing force of the pad return spring on the disc rotation direction entry side
acting on the friction pad in a direction opposite to the support biasing force.
2. The disc brake according to claim 1, wherein the support biasing force of the support
25 part on the disc rotation direction entry side is larger than the support biasing force of the
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support part on the disc rotation direction exit side.
3. The disc brake according to claim 1, wherein Fs-Fv·sin 8 2:: Fs' provided that
Fs: the support biasing force of the support part on the disc rotation direction
5 entry side,
Fv·sin 8: the acting biasing force due to the pad return spring, and
Fs': the support biasing force of the support part on the disc rotation direction
exit side.
10 4. The disc brake according to claim 2, wherein Fs-Fv·sin 8 2:: Fs' provided that
Fs: the support biasing force of the support part on the disc rotation direction
entry side,
Fv·sin 8: the acting biasing force due to the pad return spring, and
Fs': the support biasing force of the support part on the disc rotation direction
15 exit side.
20
5. The disc brake according to any one of claims 1 to 4, wherein when the pad return
spring is provided on the disc rotation direction exit side and on the disc rotation
direction entry side, Fs-Fv·sin 8 > Fs' -Fv' ·sin 8 provided that
Fs: the support biasing force of the support part on the disc rotation direction
entry side,
Fv·sin 8: the acting biasing force due to the pad return spring on the disc rotation
direction entry side,
Fs': the support biasing force of the support part on the disc rotation direction
25 exit side, and