
故障现象:一辆2012款雪佛兰科鲁兹轿车,累计行驶里程 38 171km,客户抱怨发动机异响。仔细辨识声音来源,似乎 来自发动机前部,靠近曲轴皮带轮的位置。异响类似摩擦发出的 “呲呲啦啦”声,夹杂在发动机的正常噪音中。发动机怠速时可 以清晰辨识,频率与发动机曲轴转速对应。
故障诊断与排除:使用听诊器仔细听,正时皮带壳上没有相 对应的振动和噪音。发动机皮带带动的其他旋转零件也没有对应 的振动和噪音。
取下发动机皮带,声音依旧,声音在曲轴皮带轮周围最大, 怀疑是曲轴皮带轮与正时皮带摩擦或者正时皮带传动部件发出的 噪音。
拆下曲轴皮带轮检查,可以看到皮带轮内侧,与正时皮带接 触的表面有很明显的摩擦痕迹(图1)。除了表面漆面已经磨掉,还 有长时间摩擦造成的光亮效果,让人不禁联想起皮带与之摩擦时 的效果和声音。对比新的曲轴皮带轮,故障曲轴皮带轮的接触表 面有很明显的机械加工纹理,不是很光洁;径向表面与轴向表面结合很平直。所以转动时,会与正时齿带之间产生摩擦噪音。而新的皮带轮表面很光洁,径向表面和轴向表面结合处大圆弧过渡(圆弧倒角),不易产生摩擦噪音。故障零件表面最初有漆层,所以摩擦时不会出现声音,随着使用,漆层磨损,裸露出来的金属表面与正时皮带的磨损达到一定程度,出现了声音。
维修小结:该故障是一个典型的旋转零件摩擦噪音故障,零件的表面状况、温度、相对运动零件的材料特性、表面纹理等,这几个条件综合在一起,满足特定条件时才会出现噪音,改变任何一个,都会让声音消失。

文/牛英伟

故障现象:一辆2014年的大众高尔夫,ABS灯偶发点亮。
故障诊断与排除:首先用VAS诊断电脑读取故障码,故障码 提示内容为“右后轮转速传感器机械故障,偶发”,清除故障码 后进行路试(以10~20km/h的车速),从诊断仪的数据流中读取 的4个轮速无偏差,数据显示正常。可能造成右后轮速传感器故 障的原因有:1.线路接触不良或信号干扰;2.右后轮轴承故障(因 为轴承中分布均匀的磁场);3.右后轮速传感器本身故障。本着由 简单到复杂的排除方法,首先更换一个右后轮传感器,试车故障 依旧;拔下右轮传感器插头时诊断电脑中变速器系统内报故障码 “右后轮转速传感器电路电器故障,静态”,无法用诊断电脑清 除,排除电路故障的可能;升起车轮拆下右轮轮速传感器,从传 感器的安装位置观察,当慢慢转动车轮时,发现在右后轮轴承上 吸附着一个小铁片。先不取下此小铁片进行路试,并观察诊断电 脑中03的数据流变化情况,发现当车速达到60km/h后,右后轮 的转速不稳定地变化(从60km/h的车速突然降到20~30km/h, 而后又会马上升上来),而其他三个车轮数据变化正常。取下右后 轮轴承上吸附的小铁片后进行路试,不再出现上述现象,故障灯 也不再亮起,故障排除。
维修小结:该车由于小铁片吸附在轴承上,造成右后轮转速 传感器在检测时有不正常的磁力信号,从而使ABS 系统报故障 码。在排除大众车故障时遵循的原则是,有故障码要先按故障内 容排查,但是故障码往往只是给出我们一个范围,具体分析时我 们要根据工作电路的原理进行排查,本案例虽然报右后轮转速传 感器故障,但是实际上问题出在机械部位。
(文/王利军)
原创文章,作者:cesifu,如若转载,请注明出处:http://www.cesifu.com/article/1372.html
评论列表(21条)
The post touched on things that resonate with me personally. Thank you for putting it into words.
I’m in awe of the way you handle topics with both grace and authority.
Making hard to understand concepts readable is no small feat. It’s like you know exactly how to tickle my brain.
Unique perspective? Check. Making me rethink my life choices? Double-check.
The article was a delightful read. It’s clear you’re passionate about what you do, and it shows.
The insights are like a fine wine—rich, fulfilling, and leaving me wanting more.
I’m impressed by The ability to convey such nuanced ideas with clarity.
You tackle topics with such finesse, it’s like watching a skilled chef at work. Serving up knowledge with flair!
The insights are like keys, unlocking new perspectives and ideas I hadn’t considered.
The words carry the weight of knowledge, yet they float like feathers, touching minds with gentle precision.
The article was a joy to read, and The enthusiasm is as infectious as The charm.
The writing captivated me from the first paragraph to the last. It’s rare to find such engaging content.
The blend of informative and entertaining content is perfect. I enjoyed every word.
The insights are like keys, unlocking new perspectives and ideas I hadn’t considered.
I’m in awe of the way you handle topics with both grace and authority.
You’ve done a fantastic job of breaking down this topic. Thanks for the clarity!
The creativity and intelligence shine through, blinding almost, but I’ll keep my sunglasses handy.
I learned a lot, and now I’m curious about what else you could teach me. The intelligence is as captivating as The prose.
Thank you for consistently producing such high-quality content.
Your blog is a constant source of inspiration and knowledge. Thank you!
Your work is truly inspirational. I appreciate the depth you bring to your topics.