缸蓋加工工藝概述

1、 中文譯文 發(fā)動機缸蓋加工工藝概述一、發(fā)動機缸蓋的功用 氣缸蓋是發(fā)動機的主要零件之一，位于發(fā)動機的上部，其底平面經汽缸襯墊，用螺栓緊固在氣缸體上。主要功用如下：1、封閉氣缸上部，并與活塞頂部和汽缸壁一起形成燃燒室。2、作為定置氣門發(fā)動機的配氣機構、進排氣管和出水管的裝配基體。3、氣缸蓋內部有冷卻水套，其底面上的冷卻水孔與氣缸體冷卻水孔相通，以便利用循環(huán)水帶走發(fā)動機的高溫。二、氣缸蓋的結構特點氣缸蓋應具有足夠的強度和剛度，以保證在氣體的壓力和熱應力的作用下，能夠可靠的工作。氣缸蓋的形狀一般為六面體，系多孔薄壁件，其中我們現(xiàn)在481缸蓋上，加工的數(shù)量多達100個。鑄造最薄處只有4.5毫米。 三、缸

2、蓋材料與毛坯制造1、缸蓋的材料： 缸蓋的材料，現(xiàn)在的發(fā)動機廠家一般選用鋁合金。因為鋁合金導熱性能較好，有利于適當提高壓壓縮比，質量也較輕，可以降低整車、整機的重量。但是鋁合金缸蓋的剛度差，使用過程中容易變形。 缸蓋附件上，以前氣門座材料一般采用耐熱合金鑄鐵，氣門導管一般采用鑄鐵?，F(xiàn)在粉末冶金在氣門閥座和導管上運用的越來越多了，而且很多復雜的形狀也能鑄造成型，不需要再加工了。但耐磨性不如鑄鐵。 裂紋：鑄造應力造成； 冷隔：澆注過程中鋁水冷卻速度不一致造成； 表面疏松：澆注溫度不當或鋁水成分不當； 氣孔：澆注鋁水中夾雜了空氣； 砂眼：澆注鋁水中夾雜了雜質； 沾砂：工件出爐溫度不當或沒有噴丸等。四、

3、缸蓋的加工難點：1、平面加工工藝 缸蓋的頂面、底面和進、排氣面都是大面積平面，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藝過程的基礎，例如480缸蓋就是。 這就對機床的幾何精度和刀具的調整精度要求比較高。 以前缸蓋大平面加工，采用硬質合金刀片加工，并配一個金剛石修光刃?，F(xiàn)在，如果毛坯情況好的話，全部采用金剛石刀片進行加工，可以很好的提高加工后的表面粗糙度。2、高精度孔的加工 氣缸蓋上的氣門閥座、導管孔、挺桿孔和凸輪軸孔等孔系，有配合關系。其尺寸精度、位置精度和表面粗糙度要求極為嚴格。所以這些高精度孔系的加工工序是缸蓋工藝中的核心工序，應給予充分的重視。 1

4、）、缸蓋氣門閥座、氣門導管精加工 缸蓋氣門閥座、氣門導管同時與發(fā)動機氣門配合，所以同軸度要求比較高；另外氣門閥座與氣門錐面進行密封配合，對于圓度要求也非常高。 對于上述部位的加工過程，現(xiàn)在480缸蓋分解如下： 機床主軸快進-工進-主軸重新啟動，加工氣門閥座錐面-主軸停止、并后退一端距離-主軸重新啟動，槍鉸加工氣門導管（干通） -加工完畢-工進退刀-主軸回推。 這樣做的好處，就是一次定位，加工完畢氣門導管和氣門閥座，可以減少重復定位誤差，提高氣門導管和氣門閥座的同軸度。 另外，主軸在重新啟動后，加工氣門閥座的時候，進刀方向如果沿著閥座徑向方向，此種加工方式成為“車”閥座，可以提供加工精度。如果進

5、刀方向沿著閥座軸向方向，稱為“锪”或 “鏜”閥座。 因為氣門閥座和氣門導管材料的變化，加工過程中選用的刀具也在不斷的發(fā)生變化。以前的硬質合金刀片逐漸被CBN刀片所替代，很大的提供了加工效率和加工質量。并且，如果有銅基粉末冶金材料的氣門閥座和氣門導管，還可以采用PCD刀片進行加工。 2）、缸蓋挺桿孔、氣門導管底孔的加工 這些孔的加工，雖然加工精度比較高，但是，只要選好加工余量、參數(shù)和刀具，加工過程基本沒有什么問題。 3）、缸蓋凸輪軸孔的加工 缸蓋凸輪軸孔，就是缸蓋最長的孔，如果分段加工的話，雖然可以保證凸輪軸孔的加工精度，但是無法滿足凸輪軸孔的同軸度要求，所以要求精加工一次加工成型。對于長度為5

6、00mm左右的刀桿而言，如何消除刀桿自身重力所產生的影響？ 對于專機自動線而言，一般都帶有鏜模架以消除影響，對于比較大的發(fā)動機，有可能帶有好幾個鏜模架。 對于加工中心，現(xiàn)在基本已經取消鏜模架，利用刀具的自導向來消除刀桿重力的影響。刀桿的結構特點是：在刀桿的圓周上，均勻布置一個刀刃和三個導向條。刀桿數(shù)量一般是一長一短。 加工過程如下： 先由短刀桿加工一個凸輪軸孔（至半精加工尺寸）-退刀-長刀桿完成所有凸輪軸孔的半精、精加工。 4）、缸蓋加工過程的毛刺 對于鋁合金缸蓋，因為是塑性材料，加工過程中不可避免的產生毛刺。 對于加工過程中的毛刺，除了要合理的選用加工參數(shù)、刀具參數(shù)外，還可以提高工件材料的硬

7、度，也可以弱化加工過程中毛刺的產生。 現(xiàn)在加工過程中，主要有以下幾種方式去除加工毛刺： 一、尼龍毛刷去毛刺，多用于大的加工表面和大的孔系去毛刺； 二、高壓水去毛刺，多用于深油孔去毛刺，也有利用旋轉水柱去大面或大孔的毛刺；三、表面噴丸或表面拋丸：多用于鑄件表面的毛刺、飛邊處理，影響工件的清潔度；四、電火花去毛刺：用于比較難去除的毛刺，比如合金鋼的毛刺，對于不規(guī)則的毛刺，去除比較困難；五、氫氧爆破去毛刺：利用氫氧燃燒產生的壓力和高溫氣流，將附于工件表面產生的毛刺消除，但是對于工件毛坯要求比較高，補焊、裂紋、冷隔都有可能導致工件報廢。 5）、缸蓋的清洗 缸蓋清洗工序是缸蓋的主要輔助工序之一。因為發(fā)動

8、機對缸蓋的清潔度要求非常嚴格（我們現(xiàn)在AVL缸蓋的清潔度指標為：7mg），而缸蓋又是一個多孔型腔組成的復雜鑄造箱體，如清洗不徹底而使砂子和鋁屑等進入發(fā)動機的潤滑系統(tǒng)或汽缸中，則會直接影響發(fā)動機的工作和使用壽命。所以，應該充分重視缸蓋的清洗工序。 對于缸蓋清洗機而言，現(xiàn)在一般都帶有射流清洗工位，相當于預清洗工位，工件在水箱中翻轉，清洗噴嘴帶有壓縮空氣的水流，從而達到工件粗步清洗的效果。 對于有裝配需求或不易清洗干凈之處，清洗機上一般配備有頂點定位清洗工位，就可以將規(guī)定部位清洗干凈了。但會導致機床長度增加、噴嘴布置不方便等，而且還無法滿足柔性清洗的需求。 對于缸蓋水道的清洗，因為受到毛坯鑄造質量的

9、影響比較大，所以也是一個清洗難點。五、典型缸蓋加工工藝流程 下面我們以AVL缸蓋的加工工藝流程為例，了解在加工中心上是如何加工缸蓋零件的： OP10：毛坯上料； OP20：毛坯基準定位，加工缸蓋進、排氣面（除了進氣側面油孔不加工外）； OP30：排氣側面精基準定位，加工缸蓋頂面、前、后端面的加工內容； OP40：排氣側面精基準定位，加工缸蓋頂面、燃燒室面的加工內容；OP60：清洗工序；OP70：缸蓋水道和油道試漏；OP80：缸蓋氣門閥座、氣門導管裝配（常溫裝配）；OP90：缸蓋凸輪軸蓋、定位銷裝配，凸輪軸蓋螺栓自動擰緊；OP100：排氣側面精基準定位，完成缸蓋頂面和燃燒室面的精加工（氣門導管和

10、氣門閥座的精加工）；OP110：排氣側面精基準定位，完成缸蓋凸輪軸孔和前、后端面的精加工；OP120：終清洗工序；OP130：涂膠、壓裝碗形塞、鋼球；OP140：試漏機；OP150：目視檢測；OP160：打號工序；OP170：成品下料。 從上面的工藝流程來看，已經運用了加工中心制造技術、敏捷制造技術等較為現(xiàn)在的生產線制造技術。 另外，為了更好的進行多品種共線生產，缸蓋的設計、工藝基準都在向排氣側轉化，以便更好的進行共線生產。六、缸蓋加工的注意事項：1、缸蓋尺寸較大時，由于內應力重新分布而產生變形，會嚴重影響缸蓋的加工精度。一般的原則就是先面后孔，粗加工和精加工盡量分散，以保證加工應力的釋放。2

11、、為了避免缸蓋結合面劃傷，一般將結合面精加工盡量放在后續(xù)工序。3、振動清理內腔鐵屑雜物工序，應安排在與水腔有關的加工工序以后最為適宜。免得震動清理后，又加工與水腔有關的部位，又有鐵屑掉進去，以后還需要進行清洗。4、加工過程中，特別是自動化大批量加工過程中，最好帶有夾具噴氣檢測和刀具折斷檢測，以減少加工過程中，不必要的損失。七、結束語 以上就是發(fā)動機缸蓋加工工藝的概述，真正的知識來自于現(xiàn)場，來自于時間。英文原文Overview of engine cylinder head machining process First, the function of the engine cylinder

12、head              Cylinder head of the engine of the main parts, the upper part of the engine, the cylinder liner via the bottom plane, with bolts on the cylinder body. The main function is as follows: 1, the closed upper cylinder

13、 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 base. 3, inside the cylinder head cooling water jacket, the bottom surface of the cooling water hole of the cylinder block cooling wa

14、ter hole communicating in order to use the engine temperature circulating water away. Second, the structural characteristics of the cylinder head the cylinder head should have sufficient strength and rigidity to ensure that the gas pressure and under the action of thermal stress, work reliably. cyli

15、nder 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 4.5 mm at the thinnest. Third, the head material and blank manufacturing 1, cylinder head material: Cylinder head material, and now the

16、engine manufacturers generally use aluminum. Because aluminum thermal conductivity is better, is conducive to an appropriate increase in pressure compression ratio, the quality is also lighter, you can reduce the vehicle, the whole weight. But the difference in stiffness aluminum alloy cylinder head

17、, easily deformed during use. cylinder head attachment, previously valve seat material commonly used heat-resistant alloy cast iron, cast iron valve guides commonly used. 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 casti

18、ng, without reprocessing it. However, abrasion resistance than cast iron. Crack: casting stress caused; Cold compartment: aluminum casting process water cooling rate caused inconsistent; loose surface: aluminum water pouring temperature irregularity or improper ingredients; stomatal: casting aluminu

19、m 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 machining difficulties: 1, plane processing the cylinder head top surface, a bottom surface and into the exhaust area planar faces are

20、 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 is. This geometric accuracy of the machine and tool adjustment is relatively high precision. Previous large flat cylinder head machin

21、ing, 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 improve the surface roughness after processing. 2, high-precision machining holes cylinder head valve seat tube hole, holes, etc. tappet cam

22、shaft bore holes and the Department has with the relationship. Its dimensional accuracy, position accuracy and surface roughness requirements are extremely stringent. So these high-precision machining holes of cylinder head technology process is the core process, should be given full attention. 1, c

23、ylinder 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; additional valve seat for sealing engagement with the valve cone, the roundness requirements are very high. For the processing of these

24、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 distance - restart gun reaming valve guides ( QianTong) - finished processing - workers and retract - spindle pushed back. The benefit

25、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 concentricity. In addition, the spindle after the restart, machining the valve seat when the feed direction if the radial direction along

26、the seat, processing methods such as "car" seat, providing precision. If the feed direction along the axial direction of the valve seat, called "countersink" or    "Boring" seat. Because the valve seat and valve guide material change in the selection

27、 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 inserts can also be used for processing. 2, cylinder head tappet hole bottom out

28、let valve guide machining              These 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 machini

29、ng             Camshaft 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 concentrici

30、ty, it requires a finish molding. For the length of the shank is about 500mm, the arbor itself how to eliminate the impact of gravity?              For the purposes of automatic line plane, generally with boring mold to eliminate

31、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-oriented tool to eliminate the effects of gravity Arbor. Arbor structure is characterized by: the circumference of the holder, even

32、ly 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-finished dimen

33、sion) - 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 process

34、ing glitches, in addition to a reasonable selection of machining parameters, tool parameters, but also can improve the hardness of the workpiece material, it can weaken the processing of burrs.          Now the process, mainly in the following severa

35、l ways to remove burr:   A nylon brush deburring, and more for the processing of large surfaces and large holes of deburring;   Second, the high-pressure water deburring, used for deep-hole deburring, there are also a rotating water jet Omo or large burr hole; Third, th

36、e surface shot peening or surface: the surface used for casting burrs processing, affecting the cleanliness of the workpiece; Fourth, the spark deburring: for the more difficult to remove burrs, such as steel burrs, for irregular burr removal more difficult; five hydroxide blasting deburring: the us

37、e of hydrogen combustion pressure and high-temperature air, will be attached to the surface of the workpiece burrs eliminated, but high demand for workpiece blank, patching, crack, cold traps are likely to lead to the workpiece scrapped. 5, cylinder head cleaning Cylinder head cleaning process is on

38、e of the main auxiliary processes. Cleanliness on the head because the engine was very strict (We now head AVL cleanliness indicators: 7mg), while the cylinder head is a complex consisting of a porous cavity casting box, if not thoroughly cleaned leaving the sand and aluminum shavings from entering

39、the engine lubrication system or cylinder, it will directly affect the work and life of the engine. Therefore, we should pay full attention to the cylinder head cleaning process.              For head cleaning machine, it is now g

40、enerally with jet cleaning station, the equivalent of pre-cleaning station, flip the workpiece in the tank cleaning nozzles with compressed air flow from step to achieve the effect of cleaning the workpiece thick. For assembly requirements or difficult to clean the place, generally equipped with a w

41、ashing machine cleaning station vertex positioning, you can clean the parts required. But will cause the machine to increase the length inconvenience nozzle arrangement, but can not meet the needs of flexible cleaning. For head cleaning waterways as being rough casting quality is relatively large, i

42、t is also a cleaning difficult. Fifth, the typical process flow cylinder head               Here we AVL cylinder head machining process, for example, to understand how the machining center machining cylinder head parts: 

43、   OP10: blank feeding;    OP20: rough benchmark positioning, processing cylinder head intake and exhaust side (in addition to the intake side of the hole is not working outside);    OP30: benchmarking exhaust side finishing, processing the top

44、surface of cylinder head, before and after the machining face;    OP40: benchmarking exhaust side finishing, processing cylinder head top surface, the combustion chamber surface machining content; OP60: the cleaning process; OP70: head waterways, and oil leak; OP80: cylinder head

45、 valve seat and valve guide assembly (assembly room temperature); OP90: camshaft cylinder head cover, pin assembly, automatic camshaft cap bolts tightened; OP100: exhaust side finishing benchmarking, complete cylinder head top surface and the combustion chamber surface finishing (valve guides and va

46、lve seat finishing); OP110: exhaust side finishing benchmarking, complete cylinder head camshaft hole and the front and rear end finishing; OP120: Final cleaning process; OP130: gluing, pressing bowl plug, ball; OP140: leak testing machine; OP150: visual inspection; OP160: marking process; OP170: finished cutting. From the above process point of view, have been