行星齒輪式電子駐車煞車及轉向系統之設計

A Novel Design of the Planetary Gear Mechanism for Electric Parking Brake and Steering System

陳齊國(Chi-Kuo Chen)

指導教授 ： 尤正吉

國立臺北科技大學/機電學院/車輛工程系所/碩士(2012年)

摘要

目前的電子駐車煞車系統大多藉由蝸桿蝸輪機構或自鎖型螺桿，將馬達的旋轉運動進而轉為直線運動，並在馬達斷電後維持煞車力。然而，無論是蝸桿蝸輪機構或自鎖型螺桿，二者都因摩擦損失的關係導致低效率。本研究規劃以一組無太陽輪之行星齒輪機構發展出一新型電子駐車煞車系統，並改善其原先機構低效率的問題。若適當配置各齒輪大小，可在行星小齒輪上找到一條近似直線的軌跡且使其軌跡擁有自鎖特性。本研究並以上述基本行星齒輪直線機構為基礎，發展一新型行星齒輪轉向機構。此種新型行星齒輪轉向機構參考方向盤轉角作為依據，提供一種特定可變齒比之特性，減少方向盤打至左右死點之圈數，增加駕駛之便利卻不影響車輛在高速行駛下之直行穩定性，及低速轉向時之操控性。

關鍵字

行星齒輪機構 ； 直線運動 ； 電子駐車煞車 ； 自鎖機構 ； 可變轉向系統

並列摘要

Most current electric parking brake systems use thread and worm gear sets or self-locking screws to transfer the rotational motion of the electric motor into the linear motion, required by a braking actuator and to maintain braking effort, because of the system’s irreversible nature, i.e. the friction angle between the contact surfaces is larger than the lead angle of the worm or the screw; however, worm gear sets and self-locking screws have low transmission efficiency, resulting from the friction force, which consumes more power from the motor. This study proposes a novel parking brake mechanism, which uses a special planetary gear train without a sun gear to improve upon the performance of existing electric parking brake systems. The dimensions of the gear sets are determined through a systematic design process. Kinematic and force analysis demonstrate that an approximately square locus, generated from a specific point on the planet gear, allows transfer of motion and a level of self-locking. Furthermore, in this research, the new straight-line motion mechanism, based on the basic planetary gear mentioned in the last design of electric parking brake, refers to the steering wheel angle to achieve variable-gear ratio in different condition of vehicle, so that the vehicle will steering with smaller steering wheel angle compared with conventional vehicle. With this advantage, the vehicle can reach the ideal of turning radius to minimize the wear of tire.

並列關鍵字

Planetary Gear Set ； Straight-line Motion ； Electric parking brake ； Self-locking Mechanism ； Variable Gear-ratio Steering

參考文獻

[29] 徐培恩，前輪獨立轉向車之運動分析，碩士論文，國立台北科技大學車輛工程研究所，台北，2006。

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