Ball-in-ramp brake caliper type parking brake for vehicle

Abstract

In a BIR type brake caliper according to the embodiment of the present invention, when a BIR (Ball in Ramp) type cartridge assembly, which generates an axial force while rotating, presses pads against a disk plate during parking braking, balls provided between input and output ramps of the cartridge assembly move along variable trajectories gradually decreased in a radial direction and increase a force. For this reason, even though an operation force of a parking lever is small, the cartridge assembly generates a force capable of maintaining a parking braking force. As a result, it is possible to obtain characteristic reducing an operation force, which should be applied to a parking handle by a driver.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is based on, and claims priority from, Korean Application Serial Number 10-2007-0088062, filed on Aug. 31, 2007, the disclosure of which is hereby incorporated by reference herein in its entirety.FIELD OF THE INVENTION[0002]The present invention relates to a parking brake for a vehicle, and more particularly, to a Ball-In-Ramp brake caliper type parking brake for a vehicle.BACKGROUND OF THE INVENTION[0003]In general, a parking brake, which is used to temporarily park a vehicle or park a vehicle on an inclined place such as a hill, applies pressure to a wheel by using cables pulled by a hand unlike a brake that applies pressure to a wheel by using oil pressure generated by a general pedal. The parking brake is operated by a parking lever provided near a driver's seat.[0004]The parking brake includes a parking lever, a parking brake cable, and an equalizer. The parking lever is operated by a hand. The parking brake c...

AI Technical Summary

Benefits of technology

[0010]Embodiments of the present invention provide a parking brake capable of reducing a driver's operation force. In the parking brake, an axial force of a BIR (Ball-In-Ramp) type cartridge assembly inserted into a caliper, which provides a liquid pressure chamber filled with brake oil, is increased due to variable movement trajectories of ball provided between the ramps. Accordingly, during braking parking, even though an operation force of a lever is small, a large parking braking force is generated by the cartridge assembly.

[0011]Further, embodiments of the present invention provide a parking brake that reduces a driver's operation force and increases a parking braking force during braking without changing the design and entire structure thereof. In the parking brake, a BIR type cartridge assembly is structured so that balls between Ramps, which move in an axial direction by a parking operation force, have variable movement trajectories.

[0012]Furthermore, embodiments of the present invention provide a parking brake where the structures of ramps and balls of a cartridge assembly are hardly changed. In the parking brake, movement trajectories of the balls of a BIR type cartridge assembly are gradually decreased in a radial direction in the ramps, in which the balls are received, and an axial force is increased.

[0014]The cartridge assembly may include an input ramp, an output ramp, and a ball case housing. The input ramp is rotated by the parking operation force input unit of which one end is connected to the parking cable outside the caliper housing. The output ramp is provided at a side opposite to the input ramp, and generates an axial force pushing the pads toward the disk plate when the input ramp is rotated. The ball case housing is provided in the ball movement grooves having the variable paths formed on the input and output ramps, and gradually increases the axial force of the output ramp as balls having movement trajectories along the ball movement grooves move from the central portions to the ends portions during the rotation of the input ramp.

[0020]According to the embodiment of the present invention, an axial force is significantly increased using ramps and balls of a BIR (Ball-In-Ramp) type cartridge assembly inserted into a caliper, which provides a liquid pressure chamber filled with brake oil. Accordingly, during braking parking, the old, the feeble, and women also can generate an enough parking braking force with a small operation force.

[0021]Further, since the BIR type cartridge assembly according to an embodiment of the present invention increases a parking braking force by using ramps and balls, the designs of a parking brake and a cartridge assembly hardly need to be changed.

Problems solved by technology

For this reason, there is a problem in that a driver's operation force is increased to perform parking braking.

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