1. Adjustment of valve foot space: valve arrangement in normal operation, with the wear of parts, the valve foot space will change. If the cam, valve rod end face and tappet contact surface wear, the open space will become larger, while the valve head and valve seat wear, the open space will become smaller. Therefore, the base value of open space should be taken in the adjustment. If the rule is 0.2 ~ 0.25 mm, the actual value can be 0.22 mm. This not only takes into account the actual situation of the change of the open space, but also considers the question of the measurement error, which can fully ensure the completion of the air gap effect of the valve foot.

2、氣門座的鉸削：氣門座鉸削通常為手作業(yè)業(yè)，應(yīng)格外重視三個疑問：一是在消除凹陷、斑駁，能鉸出無缺錐面的基礎(chǔ)上，鉸削量越小越好；二是鉸削時用力要均勻，起刀收刀要輕，少鉸多調(diào)查，以保證較少的鉸削量和較高的光潔度;三是與氣門試配，判定好作業(yè)面方位和寬度。方位應(yīng)調(diào)整到氣門錐面的中下部，偏上或偏下可用上、下口鉸刀進行調(diào)整。作業(yè)面寬度，進氣門可掌握在0.9mm(規(guī)矩為1~2.2mm)，排氣門可掌握在1.4mm(規(guī)矩為1.5~2.5mm)。實踐證明上述寬度在氣門與氣門座研磨后，進氣門可達1mm,排氣門可達1.5mm,均在規(guī)矩寬度的下限，能大大提高其運用壽數(shù)。

2. Valve seat reaming: valve seat reaming is usually a manual operation, and three questions should be paid special attention to: first, on the basis of eliminating depression and mottling, and reaming out no missing cone surface, the smaller the reaming amount is, the better; second, the force should be even when reaming, and the knife should be lifted and closed lightly, and more investigation should be carried out to ensure less reaming amount and higher smoothness; The third is to match with the valve to determine the working face orientation and width. The orientation should be adjusted to the middle and lower part of the valve cone surface, and the upper and lower reamers can be used to adjust the position. The width of working face can be controlled within 0.9mm for inlet valve and 1.4mm for exhaust valve (1.5-2.5mm). Practice has proved that after grinding the valve and valve seat, the inlet valve can reach 1 mm and the exhaust valve can reach 1.5 mm, which are both within the lower limit of the regular width, which can greatly improve the service life of the valve.

3、攪拌車修補質(zhì)量差在修補作業(yè)中出色的疑問是氣門與氣門座作業(yè)面加工質(zhì)量達不到懇求，構(gòu)成作業(yè)面燒蝕、凹陷而前期損壞；凸輪軸軸承在刮削中其協(xié)作空地、接觸面積、各軸承同心度達不到懇求，加速磨損，呈現(xiàn)異響構(gòu)成前期損壞；氣門導(dǎo)管在更換新件時，鉸削質(zhì)量達不到規(guī)矩懇求，直接影響氣門及氣門座運用壽數(shù)。

3. The repair quality of mixer truck is poor. In the repair operation, the outstanding question is that the processing quality of valve and valve seat working surface can not meet the requirements, which constitutes ablation and depression of working surface, and early damage; camshaft bearing in scraping, its cooperation space, contact area, bearing concentricity can not meet the requirements, accelerate wear and appear abnormal noise, which constitutes early damage; when valve guide is replaced with new parts, hinge Cutting quality can not meet the requirements, which directly affects the service life of valve and valve seat.

4、凸輪軸軸承的刮削：凸輪軸軸承的刮削歸于手作業(yè)業(yè)，保證質(zhì)量有一定難度。為刮削便利，又通常在氣缸體外加工，因此應(yīng)格外留意四個疑問：一是要判定好軸承刮削后內(nèi)孔的直徑;二是刮削中要盡量留意堅持軸承內(nèi)孔與外圓的同軸度;三是邊刮削邊與軸頸試配，并保證接觸印痕分布均勻;四是將軸承壓入座孔時，應(yīng)留意對正油孔。刮削后裝入凸輪軸，翻滾數(shù)圈，視情進行恰當修整，接觸面積應(yīng)抵達75%以上并分布均勻，空地符合規(guī)矩。

4. Scraping of camshaft bearing: scraping of camshaft bearing belongs to manual operation, so it is difficult to ensure quality. For the convenience of scraping, it is usually processed outside the cylinder. Therefore, we should pay special attention to the following four questions: first, determine the diameter of the inner hole of the bearing after scraping; second, pay attention to the coaxiality between the inner hole and the outer circle of the bearing; third, try to fit the bearing with the journal while scraping, and ensure that the contact marks are evenly distributed; fourth, when pressing the bearing into the seat hole, pay attention to aligning the oil hole. After scraping, install the camshaft, roll it for several turns, and properly trim it according to the situation. The contact area should reach more than 75% and be evenly distributed. The open space should meet the regulations.