Some drivers reported that the same blender they and their friends bought would have engine problems after a period of use, but the engine of their friend's car was OK. What's up? Let's find out.
1. Improper use of mixer maintenance data
攪拌車維修中未科學地選擇維修數據是造成機械零件早期損壞的重要原因之一。例如，閥門與閥座接觸面的寬度規定為進氣閥1-2.2mm，排氣閥1.5-2.5mm。但是，在實際的維護中，很多人認為寬一點總比窄一點好，所以他們習慣于選擇上限值或接近上限值，因為閥面寬度已經接近上限值。例如,閥門間隙,通用汽車提供0.2 - -0.25毫米,但在維護調整也認為有點大間隙比小一些,因此,在使用的上限,事實上,間隙太大,不僅降低發動機功率,還會出現敲門聲音和早期損壞。
The unscientific selection of maintenance data is one of the important reasons for the early damage of mechanical parts. For example, the width of the valve seat contact surface is specified as intake valve 1- 2.2mm , vent valve One point five - 2.5mm 。 However, in the actual maintenance, many people think that a little wider is better than a little narrower, so they are used to choose the upper limit value or close to the upper limit value, because the valve face width is close to the upper limit value. For example, valve clearance, provided by General Motors zero point two -- zero point two five Mm, but in the maintenance adjustment, it is also considered that the clearance is a little larger than a little smaller. Therefore, in the upper limit of use, in fact, the clearance is too large, which not only reduces the engine power, but also causes knocking sound and early damage.
2. Valve polishing
For the maintenance of the mixing truck, if the valve is melted, the pits and dents should be grinded smoothly. Generally, in the smooth grinder, four problems should be paid attention to during the operation: first, make sure that the valve head is concentric with the rod, otherwise it should be straightened; second, on the premise of grinding out the complete cone surface, the light grinding truck should be as small as possible. Third, try to improve the surface finish; fourth, the sagging end of the valve rod should be polished.
3. Hinge pin of valve guide rail
The matching clearance between the valve stem and the valve tube is the key to determine the service life of the valve tube. Therefore, when replacing the new valve pipe, the fit clearance of reaming pin should be strictly controlled. The specified lower clearance limit of each hybrid vehicle can effectively extend its service life.
4. Valve grinding
Valve lapping can be divided into two situations: one is only slight pitting on the valve and valve seat, without light lapping and hinge pin lapping; the other is light lapping and hinge pin lapping on the valve and valve seat. The former is first ground with pure steel sand, then with fine sand stone, and finally with oil agent until the sealing meets the requirements and the width meets the requirements. In the latter case, only when the seal fails to meet the grinding requirements, the operator shall pay attention to the operation and not use too much force. It is strictly forbidden to knock the valve up and down, otherwise concave sand marks will appear, which will affect the maintenance quality.
The failure of the concrete mixer is not terrible, but the maintenance is not correct, and the performance of the engine will only get worse and worse. Mixers are affordable, and it's time to buy them.