缸盖加工工艺概述Word文件下载.docx

1、但是铝合金缸盖的刚度差，使用过程中容易变形。 缸盖附件上，以前气门座材料一般采用耐热合金铸铁，气门导管一般采用铸铁。现在粉末冶金在气门阀座和导管上运用的越来越多了，而且很多复杂的形状也能铸造成型，不需要再加工了。但耐磨性不如铸铁。 裂纹：铸造应力造成； 冷隔：浇注过程中铝水冷却速度不一致造成； 表面疏松：浇注温度不当或铝水成分不当； 气孔：浇注铝水中夹杂了空气； 砂眼：浇注铝水中夹杂了杂质； 沾砂：工件出炉温度不当或没有喷丸等。四、缸盖的加工难点：1、平面加工工艺 缸盖的顶面、底面和进、排气面都是大面积平面，精度要求高（平面度0.04，垂直度0.05，位置度0.10），而且有可能是全部工艺过程

2、的基础，例如480缸盖就是。 这就对机床的几何精度和刀具的调整精度要求比较高。 以前缸盖大平面加工，采用硬质合金刀片加工，并配一个金刚石修光刃。现在，如果毛坯情况好的话，全部采用金刚石刀片进行加工，可以很好的提高加工后的表面粗糙度。2、高精度孔的加工 气缸盖上的气门阀座、导管孔、挺杆孔和凸轮轴孔等孔系，有配合关系。其尺寸精度、位置精度和表面粗糙度要求极为严格。所以这些高精度孔系的加工工序是缸盖工艺中的核心工序，应给予充分的重视。 1）、缸盖气门阀座、气门导管精加工 缸盖气门阀座、气门导管同时与发动机气门配合，所以同轴度要求比较高；另外气门阀座与气门锥面进行密封配合，对于圆度要求也非常高。 对于

3、上述部位的加工过程，现在480缸盖分解如下： 机床主轴快进-工进-主轴重新启动，加工气门阀座锥面-主轴停止、并后退一端距离-主轴重新启动，枪铰加工气门导管（干通） -加工完毕-工进退刀-主轴回推。 这样做的好处，就是一次定位，加工完毕气门导管和气门阀座，可以减少重复定位误差，提高气门导管和气门阀座的同轴度。 另外，主轴在重新启动后，加工气门阀座的时候，进刀方向如果沿着阀座径向方向，此种加工方式成为“车”阀座，可以提供加工精度。如果进刀方向沿着阀座轴向方向，称为“锪”或 “镗”阀座。 因为气门阀座和气门导管材料的变化，加工过程中选用的刀具也在不断的发生变化。以前的硬质合金刀片逐渐被CBN刀片所替

4、代，很大的提供了加工效率和加工质量。并且，如果有铜基粉末冶金材料的气门阀座和气门导管，还可以采用PCD刀片进行加工。 2）、缸盖挺杆孔、气门导管底孔的加工 这些孔的加工，虽然加工精度比较高，但是，只要选好加工余量、参数和刀具，加工过程基本没有什么问题。 3）、缸盖凸轮轴孔的加工 缸盖凸轮轴孔，就是缸盖最长的孔，如果分段加工的话，虽然可以保证凸轮轴孔的加工精度，但是无法满足凸轮轴孔的同轴度要求，所以要求精加工一次加工成型。对于长度为500mm左右的刀杆而言，如何消除刀杆自身重力所产生的影响？ 对于专机自动线而言，一般都带有镗模架以消除影响，对于比较大的发动机，有可能带有好几个镗模架。 对于加工中

5、心，现在基本已经取消镗模架，利用刀具的自导向来消除刀杆重力的影响。刀杆的结构特点是：在刀杆的圆周上，均匀布置一个刀刃和三个导向条。刀杆数量一般是一长一短。 加工过程如下： 先由短刀杆加工一个凸轮轴孔（至半精加工尺寸）-退刀-长刀杆完成所有凸轮轴孔的半精、精加工。 4）、缸盖加工过程的毛刺 对于铝合金缸盖，因为是塑性材料，加工过程中不可避免的产生毛刺。 对于加工过程中的毛刺，除了要合理的选用加工参数、刀具参数外，还可以提高工件材料的硬度，也可以弱化加工过程中毛刺的产生。 现在加工过程中，主要有以下几种方式去除加工毛刺： 一、尼龙毛刷去毛刺，多用于大的加工表面和大的孔系去毛刺； 二、高压水去毛刺，

6、多用于深油孔去毛刺，也有利用旋转水柱去大面或大孔的毛刺；三、表面喷丸或表面抛丸：多用于铸件表面的毛刺、飞边处理，影响工件的清洁度；四、电火花去毛刺：用于比较难去除的毛刺，比如合金钢的毛刺，对于不规则的毛刺，去除比较困难；五、氢氧爆破去毛刺：利用氢氧燃烧产生的压力和高温气流，将附于工件表面产生的毛刺消除，但是对于工件毛坯要求比较高，补焊、裂纹、冷隔都有可能导致工件报废。 5）、缸盖的清洗 缸盖清洗工序是缸盖的主要辅助工序之一。因为发动机对缸盖的清洁度要求非常严格（我们现在AVL缸盖的清洁度指标为：7mg），而缸盖又是一个多孔型腔组成的复杂铸造箱体，如清洗不彻底而使砂子和铝屑等进入发动机的润滑系统

7、或汽缸中，则会直接影响发动机的工作和使用寿命。所以，应该充分重视缸盖的清洗工序。 对于缸盖清洗机而言，现在一般都带有射流清洗工位，相当于预清洗工位，工件在水箱中翻转，清洗喷嘴带有压缩空气的水流，从而达到工件粗步清洗的效果。 对于有装配需求或不易清洗干净之处，清洗机上一般配备有顶点定位清洗工位，就可以将规定部位清洗干净了。但会导致机床长度增加、喷嘴布置不方便等，而且还无法满足柔性清洗的需求。 对于缸盖水道的清洗，因为受到毛坯铸造质量的影响比较大，所以也是一个清洗难点。五、典型缸盖加工工艺流程 下面我们以AVL缸盖的加工工艺流程为例，了解在加工中心上是如何加工缸盖零件的： OP10：毛坯上料； O

8、P20：毛坯基准定位，加工缸盖进、排气面（除了进气侧面油孔不加工外）； OP30：排气侧面精基准定位，加工缸盖顶面、前、后端面的加工内容； OP40：排气侧面精基准定位，加工缸盖顶面、燃烧室面的加工内容；OP60：清洗工序；OP70：缸盖水道和油道试漏；OP80：缸盖气门阀座、气门导管装配（常温装配）；OP90：缸盖凸轮轴盖、定位销装配，凸轮轴盖螺栓自动拧紧；OP100：排气侧面精基准定位，完成缸盖顶面和燃烧室面的精加工（气门导管和气门阀座的精加工）；OP110：排气侧面精基准定位，完成缸盖凸轮轴孔和前、后端面的精加工；OP120：终清洗工序；OP130：涂胶、压装碗形塞、钢球；OP140：试

9、漏机；OP150：目视检测；OP160：打号工序；OP170：成品下料。 从上面的工艺流程来看，已经运用了加工中心制造技术、敏捷制造技术等较为现在的生产线制造技术。 另外，为了更好的进行多品种共线生产，缸盖的设计、工艺基准都在向排气侧转化，以便更好的进行共线生产。六、缸盖加工的注意事项：1、缸盖尺寸较大时，由于内应力重新分布而产生变形，会严重影响缸盖的加工精度。一般的原则就是先面后孔，粗加工和精加工尽量分散，以保证加工应力的释放。2、为了避免缸盖结合面划伤，一般将结合面精加工尽量放在后续工序。3、振动清理内腔铁屑杂物工序，应安排在与水腔有关的加工工序以后最为适宜。免得震动清理后，又加工与水腔有

10、关的部位，又有铁屑掉进去，以后还需要进行清洗。4、加工过程中，特别是自动化大批量加工过程中，最好带有夹具喷气检测和刀具折断检测，以减少加工过程中，不必要的损失。七、结束语 以上就是发动机缸盖加工工艺的概述，真正的知识来自于现场，来自于时间。英文原文Overview of engine cylinder head machining process First, the function of the engine cylinder headCylinder head of the engine of the main parts, the upper part of the engine, t

11、he cylinder liner via the bottom plane, with bolts on the cylinder body. The main function is as follows: 1, the closed upper cylinder and the piston and the cylinder wall at the top with a combustion chamber. 2, as a set-valve engine valve train, intake and exhaust pipe and the outlet pipe assembly

12、 base. 3, inside the cylinder head cooling water jacket, the bottom surface of the cooling water hole of the cylinder block cooling water hole communicating in order to use the engine temperature circulating water away. Second, the structural characteristics of the cylinder head the cylinder head sh

13、ould have sufficient strength and rigidity to ensure that the gas pressure and under the action of thermal stress, work reliably. cylinder head shape is generally hexahedral, based porous thin pieces, of which we are now 481 cylinder head, processing up to 100 the number of holes. Casting is only 4.

14、5 mm at the thinnest. Third, the head material and blank manufacturing 1, cylinder head material: Cylinder head material, and now the engine manufacturers generally use aluminum. Because aluminum thermal conductivity is better, is conducive to an appropriate increase in pressure compression ratio, t

15、he quality is also lighter, you can reduce the vehicle, the whole weight. But the difference in stiffness aluminum alloy cylinder head, easily deformed during use. cylinder head attachment, previously valve seat material commonly used heat-resistant alloy cast iron, cast iron valve guides commonly u

16、sed. Powder metallurgy is now the seat of the valve and conduit on the use of more and more, and many complex shapes can also be casting, without reprocessing it. However, abrasion resistance than cast iron. Crack: casting stress caused; Cold compartment: aluminum casting process water cooling rate

17、caused inconsistent; loose surface: aluminum water pouring temperature irregularity or improper ingredients; stomatal: casting aluminum water mixed with air; trachoma: cast aluminum water mixed with impurities; dip sand: improper or no workpiece temperature baked shot and so on. Four, cylinder head

18、machining difficulties: 1, plane processing the cylinder head top surface, a bottom surface and into the exhaust area planar faces are large, high precision （flatness 0.04 0.05 verticality, the position degree of 0.10）, and may be the basis for all of the process, for example, the cylinder 480 Cover

19、 is. This geometric accuracy of the machine and tool adjustment is relatively high precision. Previous large flat cylinder head machining, machining with carbide blade, and with a diamond blade Danxiu Guang. Now, if the situation is good rough, all using diamond blade for processing, may well improv

20、e the surface roughness after processing. 2, high-precision machining holes cylinder head valve seat tube hole, holes, etc. tappet camshaft bore holes and the Department has with the relationship. Its dimensional accuracy, position accuracy and surface roughness requirements are extremely stringent.

21、 So these high-precision machining holes of cylinder head technology process is the core process, should be given full attention. 1, cylinder head valve seats, valve guides finishing cylinder head valve seats, valve guides with both the engine valve, so that the coaxial degree is relatively high; ad

22、ditional valve seat for sealing engagement with the valve cone, the roundness requirements are very high. For the processing of these parts, now 480 head breaks down as follows: Fast Forward - spindle work into - spindle restart processing valve seat cone - spindle stop and back end of the spindle d

23、istance - restart gun reaming valve guides （ QianTong） - finished processing - workers and retract - spindle pushed back. The benefit is that once positioned, processing is complete valve guides and valve seat, positioning error can reduce duplication and improve the valve guides and valve seat conc

24、entricity. In addition, the spindle after the restart, machining the valve seat when the feed direction if the radial direction along the seat, processing methods such as car seat, providing precision. If the feed direction along the axial direction of the valve seat, called countersink orBoring sea

25、t. Because the valve seat and valve guide material change in the selection process of the tool is constantly changing. Carbide inserts before gradually replaced CBN inserts, great processing efficiency and provide quality. And if there is copper powder material valve seat and valve guide, PCD insert

26、s can also be used for processing. 2, cylinder head tappet hole bottom outlet valve guide machiningThese hole machining, although precision is relatively high, however, as long as the selected allowance, and the tool, the process basically no problem. 3, cylinder head camshaft hole machiningCamshaft

27、 cylinder head bore, the cylinder head is the longest holes in the staging process, even though the camshaft hole processing can ensure accuracy, but can not meet the requirements of the camshaft hole concentricity, it requires a finish molding. For the length of the shank is about 500mm, the arbor

28、itself how to eliminate the impact of gravity?For the purposes of automatic line plane, generally with boring mold to eliminate the influence of the relatively large engine, there may be several boring with mold. For machining centers, now has basically been canceled boring mold, the use of self-ori

29、ented tool to eliminate the effects of gravity Arbor. Arbor structure is characterized by: the circumference of the holder, evenly arranged a blade and three guide bars. Arbor quantity is generally a long, one short.Process as follows:First by knife rod processing a camshaft hole （to the semi-finish

30、ed dimension） - retraction - Long shank complete all the camshaft hole semi-intensive, finishing. 4, cylinder head machining process burr For aluminum alloy cylinder head, because it is a plastic material, processing inevitable glitches.For processing glitches, in addition to a reasonable selection of machining parameters, tool parameters, but also can improve the hardness of the workpiece material, it