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1、发动机维修案例主讲：董永占单位：售后培训部课时：1小时Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.案例一：水温高，气缸垫冲蚀故障现象：北京用户 长城CC6460D，行驶2000Km，
2、水箱总是亏水，发动机水温高，拆检发现气缸垫 冲蚀，4缸缸盖腐蚀严重，出现凹坑。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.原因分析：造成气缸垫冲蚀的原因主要有：气缸盖或汽缸体工作面不平
3、 气缸盖螺栓拧紧力矩或拧紧顺序不当 气缸垫质量过差 燃烧室存有大量积碳，发动机压缩比过大，工作粗 暴 使用低标号燃油，长期处于爆震工作不良状态 缸体或气缸盖水道设计Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Asp
4、ose Pty Ltd.检测： 检查发动机气缸盖，发现气缸盖和缸体工作面平面度在标准范围内，气缸垫的质量也符合要求，且发动机点火正时准确，检测燃油标号也符合要求，但在拆检过程中，感觉4缸缸盖的两个螺栓较其余的缸盖螺栓，拧紧力矩明显小，燃烧室内积碳也较多。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 200
5、4-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.结论：针对以上检查，可以判定：造成水温高、冲蚀缸垫的原因主要有两方面：1、维修或保养期间，缸盖的拧紧力矩不均匀造成，致使缸垫受到的压力不均衡，使水流不均匀，造成局部水温高引起缸垫腐蚀 2、燃烧室积碳过多，发动机压缩比过大，使发动机工作粗暴，导致水温高。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.S
6、lides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.故障分析：故障分析：从市场反馈看，从市场反馈看，4 4缸水温高造成缸垫冲蚀、缸缸水温高造成缸垫冲蚀、缸 盖腐蚀的故障现象是盖腐蚀的故障现象是491491发动机普遍存在的现象发动机普遍存在的现象 ，针对此问题，长城内燃机公司也做了相当多，针对此问题，长城内燃机公司也做了相当多 的工作和各种试验。的工作和各种试验。1 1、气缸盖水道结构改动试验、气缸盖水道结构改动试验气缸盖第
7、气缸盖第4 4缸水道结构进行了优化，通过对缸水道结构进行了优化，通过对 比试验验证，效果比较明显。现在批量生产的比试验验证，效果比较明显。现在批量生产的 缸盖第缸盖第4 4缸水道已经做了改动。缸水道已经做了改动。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd
8、.Copyright 2004-2011 Aspose Pty Ltd.2、汽缸盖螺栓拧紧力矩试验通过对不同车辆（行程不同）的汽缸盖螺 栓力矩进行检测，力矩大多没有在规定范围内 ，且同一发动机的缸盖螺栓拧紧力矩不均衡， 尤其是4缸与其它3个缸的螺栓力矩差别很大。 这样致使缸垫受力不均，最后导致4缸水温高， 缸垫冲蚀。我们要求各服务站，在用户车辆进行保养 维修期间，要求对汽缸盖螺栓按拧紧规定的拧 紧顺序及力矩拧紧。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.
9、0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.维修案例二：保养不及时，造成大小 瓦烧蚀 故障现象： 保定用户 迪尔小双 形驶13000公里后发动 机 发出敲击声，拆检发现大小烧蚀Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.
10、Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.故障判断分析： 对发动机拆解后发现气门室盖内积有5mm厚 油泥，放出的机油呈粘稠状，第四缸曲轴主 轴颈、连杆轴颈严重磨损，大小瓦烧蚀，其 它几道轴瓦均有不同程度磨损。与司机沟通 后得知此车已有1.5万公里未更换过机油， 明 显为保养不当所致。Evaluation only.Evaluation only. Created with
11、 Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose
12、.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspos
13、e Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.事后总结： 此故障为典型使用过程中保养不当所致，所 以要加强对用户正确驾车和保养常识的宣传 。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 200
14、4-2011 Aspose Pty Ltd.维修案例三：连杆弯曲，活塞破损 故障现象： 浙江用户 哈弗两驱 此车在涉水后发动 机 内部发出撞击异响，拆检后发现连杆弯曲， 活塞破损Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2
15、011 Aspose Pty Ltd.故障判断分析：服务站反馈：机油没有进水；主轴承瓦和连杆瓦无异常磨损；司机反馈：行驶中水温正常，水箱未缺水；综合以上信息初步判断为：行驶中不明原因造成缸内进水，在压缩过程中，由于水的不可压缩性，造成连杆弯曲。此后曲轴平衡块撞击活塞销座部位，造成活塞破损。Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.
16、0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0. Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd.事后总结：车辆一方面要注意保养，另一方面要正确驾 驶，以避免不必要损失。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Created with Aspose.Slides for
