Reason and Preventive Measures of Crack of B Type Injection Pump Camshaft

At present, most of the major engineering equipment, such as TY120 bulldozers, ZL series loaders, PY160 road graders and 75KW mobile power plants equipped by our army's Corps of Engineers (sub-teams), most adopt the 6135 diesel engine as the mechanical power source device . As the "heart" type B 6136 diesel injection pump, camshafts often break during equipment training and camping driving, which seriously affected the successful completion of military training and exercise tasks. Combined with teaching and repairing equipment practice, this paper introduces the failure reason, repair method and preventive measures of camshaft fracture of 6135 diesel engine type B injection pump. 1 reason for failure 6135 type diesel engine used in the B-type pump plunger pump, which is fixed to the bracket on one side of the diesel engine body by four bolts from the diesel engine crankshaft driven by the timing gear, fuel injection camshaft and oil pump Drive shaft coupling. The lift of the injection pump cam is 10mm, the center distance of the minute pump is 40mm, and the maximum speed of the pump reaches 1000rpm. Due to the high rotational speed of the fuel injection pump and the installation form of "four-point support", as well as the improper use and maintenance, etc., the abrasion of the circular arc surface of the pump body at the joint of the fuel injection pump and the support (the relative abrasion of the arc surface in the supporter is relatively small) Body down, so that the camshaft and pump drive shaft offset. Fuel injection camshaft by the twisting, bending and swinging and other forces generated additional alternating stress, eventually leading to camshaft fatigue fracture. 2 Repair 6135 diesel engine B-type injection pump camshaft journal surface finish of not less than 8, the hardness of not less than HRC45, cylindricity tolerance of 0.10mm, full-length straightness tolerance of 0.05mm, are precision parts. For the repair of camshaft fracture, the general "replacement repair method", that is, replace the camshaft. However, after the replacement of repair if not ruled out the root causes of camshaft fracture, will inevitably lead to camshaft rupture again. To avoid repeated camshaft fractures, it is common practice to replace a B-type pump body or a B-type injection pump assembly. This approach is neither economical nor difficult to guarantee (the method of replacing the B type pump body with a pump pump test bench pump), especially in field conditions more difficult to protect. After many years of practice, the following three kinds of emergency methods are more suitable for the repair of the 6135 diesel engine B-type injection pump camshaft fracture under field conditions. 2.1 The original cause of repair camshaft rupture is the root cause of pump body wear and tear. Based on this, we can weld the pump body with the "heap fill" welding method, the thickness of the heap compensation and slightly larger than the amount of wear and tear. Welding after the use of methods of cutting and grinding the welding parts polished flat, restore the original geometry of the pump body, cleaning the various parts, installed after commissioning can be used. The original repair method can also use metal glue make up method, repair the pump body pump. That is, the prepared metal glue is coated on the worn area, the thickness and area of ​​the metal adhesive coating is slightly larger than the wear amount. After the metal glue is solidified for 20 to 30 minutes, the area coated with the metal glue is polished and polished, Installed to use after debugging. 2.2 parts dismantling spell 6135 Diesel Engine B-type fuel pump pump material is generally cast iron or aluminum alloy, despite the different materials, the installation of the same size and internal structure. Therefore, can be scrapped 6135 type diesel engine B-type injection pump, according to the need to disassemble available pump body, camshaft and other parts, assembled into a complete B-type fuel pump, installed after debugging qualified use. 2.3 Additional Parts Law In the field conditions, can not use the "original repair law" and "parts removed spell", you can use the "additional parts law." The specific method is: ① with a knife and grinding abrasive cloth to wear and tear parts of the pump grinding (wear parts with the bracket with the surface, and by the end of the pump drive shaft is more serious); ② with a deep caliper after abrasion measured by the pump The depth of the site, the wear depth is generally between 0.5 ~ 1mm; ③ made of copper or iron pieces into additional parts gasket. The thickness of the additional part is determined according to the depth of the worn part measured. The width of the additional part is approximately equal to the thickness of the bracket. The length of the additional part is approximately equal to the arc length of the worn part of the pump body. ④ Attach the prepared gasket to the bracket and the pump Body wear between parts. The number of additional gaskets is determined according to the depth of the worn parts measured, generally not more than three; ⑤ start the test after installation and adjustment, delivery. 3 Precautions 6135 Diesel Engine B-type fuel pump pump body wear is mainly due to the relatively loose body and bracket caused. Therefore, we can prevent it from the following three aspects. 3.1 Installation should be correct Type 6135 Diesel Engine B-type fuel injection pump often due to uneven fuel supply for each cylinder, fuel supply interval angle is not allowed to remove the whole repair and so on, the overall installation after the school pump. Installation should pay attention to the following points: ① fixed bolt diagonal tight. If the first tight outside or on the side of the body by two bolts, on the one hand may result in a good adjustment of the fuel supply advance was destroyed. The first fixed by the body side of the two fixed bolts, advance advance angle of oil supply; first fixed outside the two fixed bolts, fuel supply ahead of schedule in advance. On the other hand, the camshaft axis of the fuel injection pump and the axis of the drive shaft of the oil pump may have deviated during installation. After the engine is started, the camshaft is directly subjected to additional alternating stress and fatigue fracture. ② fixed bolts should be sub-2 to 3 times tight. ③ The tightening torque of the fixing bolt should be between 1.5 ~ 2.5kg (the fixing bolt is M8 × 1 or M10 × 1 fine thread, the tightening torque is too big and easy to damage the thread); ④ The fixing bolt should be tight in place . In practice, two fixing bolts close to one side of the body often appear, which are not tightly fixed due to the limitation of the installation position, but the two fixing bolts on the outside are tightly tightened. 3.2 Maintenance should be appropriate 6135 diesel engine B-type fuel injection pump diesel engine fuel supply system is an important component. In the use of maintenance process should pay attention to the following three points: ① oil pump oil quantity, quality to meet the requirements. Such as poor lubrication, ranging from the pump drive components early wear and tear, heavy bearing stuck, resulting in camshaft was broken. ② camshaft axial clearance should be appropriate. Camshaft axial clearance is generally about 0.03 ~ 0.15mm, the gap is too large, the camshaft wear and tear accelerated, the engine is not running smoothly, causing the pump early wear and tear. Oil pump advance angle and the cylinder oil supply interval angle to meet the requirements. If the fuel supply advance angle and the interval between each cylinder oil supply do not meet the requirements, not only will the engine power, economic deterioration, but also cause the engine start difficult, unstable operation, leading to pump wear and tear accelerated. 3.3 Check to 6135 type diesel engine B-type fuel pump pump and bracket loose situation, usually during the week of maintenance inspection. If you find the engine has abnormal conditions or loose body, should be promptly checked tight. Check the tight method according to the installation requirements.

Vacuum Brazed Carbide Grinding Wheel

Brazed Grinding Wheel,Diamond Brazed Core Drill,Diamond Brazed Grinding Wheel,Vacuum Brazed Carbide Grinding Wheel

DANYANG HANFENG TOOLS CO.,LTD. , https://www.hanfengdiatools.com