Brake control apparatus obtaining braking force by pressing of friction member using motor

• US 6,845,852 B2
• Filed: 03/19/2003
• Issued: 01/25/2005
• Est. Priority Date: 03/20/2002
• Status: Expired due to Fees

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.)
• Inventors: Takeshita, Takayuki, Arakawa, Haruo, Yokoyama, Takahisa
• Primary Examiner(s): Butler, Douglas C.
• Assistant Examiner(s): KING, BRADLEY T
• Application Number:
  US10/391,203
• Publication Number:
  US 20040011603A1
• Time in Patent Office: 678 Days
• Field of Search: 188/72.1, 188/72.7, 188/72.8, 188/71.7, 188/71.8, 188/71.9, 188/158, 188/162, 188/196.D, 188/196.V
• US Class Current: 188/72.8
• CPC Class Codes: B60T 13/741 acting on an ultimate actuator
• CPC Class Codes: F16D 2121/24 using motors
• CPC Class Codes: F16D 2125/26 Cranks
• CPC Class Codes: F16D 2125/36 Helical cams, Ball-rotating ramps
• CPC Class Codes: F16D 2125/48 with parallel stationary axes, e.g. spur gears
• CPC Class Codes: F16D 2125/50 with parallel non-stationary axes, e.g. planetary gearing
• CPC Class Codes: F16D 2127/007 for non-linear operation
• CPC Class Codes: F16D 65/18 adapted for drawing members together , e.g. for disc brakes
• CPC Class Codes: F16D 65/567 for mounting on a disc brake

Abstract

A vehicular brake apparatus, which is provided at a shaft of a motor that revolves due to depression of a brake pedal, has a variable gear mechanism including a non-circular spur gear that changes a reduction ratio from a high gear ratio to a low gear ratio along with revolution. Revolution is converted to linear movement by roller bearings interposed between two ramp portions each having a straight inclined surface, and a friction member is pressed against a disk by a friction material holding portion being moved in a straight direction. Further, a braking force is generated on the disk by the friction member and another friction member provided on the opposite side of the caliper. As a result, it is possible to generate a highly responsive braking force by the high gear ratio when revolution of the motor initially increases, and possible to reduce electric power consumption using a highly efficient motor speed by changing from the high gear ratio to the low gear ratio in accordance with the motor revolution speed.

Claims

1. A vehicular brake apparatus comprising:

a motor that is electrically driven to revolve a shaft thereof;

a reduction portion for reducing a speed of revolution of the shaft of the motor at a predetermined near ratio;

a movement conversion portion for converting the revolution, which has already been reduced in speed by the reduction portion, to a linear movement, and for pressing a friction member to a disc revolving integrally with a vehicle wheel for generating a braking force; and

a press member located between the movement conversion portion and the friction member and having clutch members that can selectively contact a first contact portion provided in a linear movement portion as an output portion of the movement conversion portion or a second contact portion provided in an end portion of the shaft of the motor, the clutch members being located alone a circumferential direction of the shaft and deformable in an axial direction of the shaft;

wherein the press member includes a female screw at a center portion thereof, and a male screw integrally fixed with the friction member at a side of the friction member opposite the disc, the male screw being screwed in the female screw.

2. The vehicular brake apparatus according to claim 1, wherein:

the reduction portion is configured as a cycloid reduction mechanism.

3. The vehicular brake apparatus according to claim 2, wherein:

the movement conversion portion is configured as a ramp mechanism including a ramp portion located on a rotatable ring portion provided in the cycloid reduction mechanism, an anti-rotatable ring portion facing the rotatable ring portion and a revolution member located between the rotatable ring portion and the anti-rotatable ring portion.