真空助力器失效分析及密封檢測(cè)方法

楊平 程小強(qiáng) 程教育

摘 要：某車型售后出現(xiàn)在持續(xù)輕制動(dòng)情況下，偶發(fā)制動(dòng)踏板發(fā)硬，制動(dòng)無助力的故障現(xiàn)象，嚴(yán)重影響駕駛安全。經(jīng)過多樣本實(shí)車進(jìn)行數(shù)據(jù)采集，原因分析，判斷在輕制動(dòng)情況下真空助力器存在泄漏，根據(jù)實(shí)車數(shù)據(jù)轉(zhuǎn)化，在臺(tái)架試驗(yàn)中進(jìn)行故障復(fù)現(xiàn)，對(duì)故障件拆解確認(rèn)根本原因?yàn)榛钊麅?nèi)壁尺寸及表面處理缺陷。通過對(duì)該樣件的失效模式，結(jié)合現(xiàn)有的驗(yàn)證方法，提出并改進(jìn)零部件臺(tái)架試驗(yàn)密封檢測(cè)方法，在零部件級(jí)別識(shí)別故障，提升流入整車和市場(chǎng)的零件良品率，避免售后安全風(fēng)險(xiǎn)及對(duì)車企品牌聲譽(yù)損傷。

關(guān)鍵詞：真空助力器;制動(dòng)踏板發(fā)硬;輕制動(dòng);密封檢測(cè)

中圖分類號(hào)：U467 ?文獻(xiàn)標(biāo)識(shí)碼：B ?文章編號(hào)：1671-7988（2020）19-157-04

Failure Analysis and Sealing Detection Methods of Vacuum Booster

Yang Ping， Cheng Xiaoqiang， Cheng Jiaoyu

（Vehicle Performance & Testing Department， Jiangling Motors Co.， Ltd Product Development Center，

Jiangxi Nanchang 330001）

Abstract： A certain vehicle model After-sales occasionally appears brake pedal hard， brake helplessness of failure in the case of continuous light braking， seriously affecting driving safety. After data collection of multi-sample of complete vehicles， analysis to determine the vacuum booster leakage under the light braking situation， according to the complete vehicles data conversion， failure mode recurrent in the bench test， confirm the root cause of the piston inner wall size and surface treatment defects after failure parts disassemble. A sealing detection method of the component bench test is proposed and improved Through the failure mode of the sample combined with the existing verification method， identify the failure at the component level， improve the rate of qualified parts entering the complete vehicle and the market， avoid the safety risk of the aftermarket and the brand reputation damage to the automobile company.

Keywords： Vacuum booster; Brake pedal hard; Light braking; Sealing detection

CLC NO.： U467 ?Document Code： B ?Article ID： 1671-7988（2020）19-157-04

前言

真空助力器是利用真空（負(fù)壓）增加駕駛員通過制動(dòng)踏板施加于制動(dòng)主缸力的部件，實(shí)現(xiàn)更輕便的制動(dòng)操作性和更好的制動(dòng)性能，廣泛運(yùn)用于當(dāng)今汽車制動(dòng)系統(tǒng)中。真空助力器密封一旦失效，會(huì)出現(xiàn)制動(dòng)無助力、踏板發(fā)硬，從而直接影響制動(dòng)性能，導(dǎo)致事故發(fā)生[1-2]。所以真空助力器的密封性能驗(yàn)證尤為重要，需要覆蓋全面的工況操作，充分驗(yàn)證因設(shè)計(jì)或制造裝配過程中導(dǎo)致的密封失效問題。

本文利用IMC數(shù)采設(shè)備對(duì)售后故障樣車進(jìn)行踏板力及真空度測(cè)試，并依據(jù)整車結(jié)果在臺(tái)架上進(jìn)行換算復(fù)現(xiàn)。確認(rèn)密封失效的實(shí)際使用工況，結(jié)合實(shí)際使用工況和失效模式進(jìn)行根本原因分析，排查出制造過程中的工藝缺陷。……