Drum brake type electric parking brake apparatus

Patent metadata

Field	Value
Publication number	US-9440626-B2
Application number	US-201213710671-A
Country	US
Kind code	B2
Filing date	Dec 11, 2012
Priority date	Dec 14, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

There is provided a drum brake type electric parking brake apparatus includes an electric actuator unit, a backing plate and a knuckle. The electric actuator unit includes an electric motor and a decelerator, and expands a gap between one end portions of the brake shoes based on activation of the electric motor. The electric actuator unit is separately provided from the backing plate. The electric actuator unit is arranged at an inner-side surface of the knuckle, and the backing plate is arranged at an outer-side surface of the knuckle. The backing plate and the electric actuator unit are supported and fixed to the knuckle.

First claim

What is claimed is:

1. A drum brake electric parking brake apparatus comprising:
a knuckle, configured to perform as a suspension of a vehicle, formed with a concave portion at an inner-side surface thereof;
a backing plate, supported and fixed to the knuckle;
a pair of brake shoes, supported to an outer-side surface of the backing plate, and configured to be displaced in a direction in which the brake shoes are separated from each other;
a drum, provided to surround the brake shoes, and configured to rotate together with a wheel that is rotatably supported to an outer-side surface of the knuckle;
an anchor, fixed between one end portions of the brake shoes in a circumferential direction of the drum at a part of the outer-side surface of the backing plate, and configured to receive a brake torque applied to the brake shoes due to a friction between linings of the brake shoes and an inner circumferential surface of the drum; and
an electric actuator unit, including an electric motor and a decelerator, and configured to expand a gap between the one end portions of the brake shoes based on activation of the electric motor, wherein
the electric actuator unit is supported and fixed to the inner-side surface of the knuckle and the knuckle is entirely arranged at an inner-side surface of the backing plate such that the electric actuator unit is not directly fixed to the backing plate,
the backing plate and the knuckle are formed with respective first through holes through which a fixing member is inserted to fix the backing plate to the knuckle, and
the first through holes are disposed at a bottom surface of the concave portion.

2. The drum brake electric parking brake apparatus according to claim 1 , wherein
the anchor, the backing plate, the electric actuator unit and the knuckle are formed with respective second through holes, and
a bolt is inserted through the second through holes to fix the anchor, the backing plate and the electric actuator unit to the knuckle.

3. The drum brake electric parking brake apparatus according to claim 2 , wherein
the backing plate and the knuckle are formed with respective third through holes, and
an output member which is inserted through the third through hole connects an output part of the electric actuator unit to an input part of an expansion and contraction mechanism configured to expand and contract the gap between the one end portions of the brake shoes.

4. The drum brake electric parking brake apparatus according to claim 2 , wherein
one of the second through holes is a screwed hole having a female screw, and
the bolt is screwed with the female screw to fix the anchor, the backing plate and the electric actuator unit to the knuckle.

Assignees

• Akebono Brake Ind

Inventors

• Akada Hironori
• Ishikawa Hiroyasu
• Suzuki Michio

Classifications

• F16D2125/68

  Lever-link mechanisms, e.g. toggles with change of force ratio · CPC title

• F16D2125/34

  acting in the direction of the axis of rotation · CPC title

• F16D2125/48

  with parallel stationary axes, e.g. spur gears · CPC title

• F16D2051/005

  Protective covers · CPC title

• F16D51/48 Primary

  with two linked or directly-interacting brake shoes · CPC title