How many engines can't be dismantled

He was panting to remove heavy scrap?

Repair the diesel engine.

The big car is universal, please spread it

A qualified diesel engine repairman

The eight major cards must go through

First pass: "three leakage"

When repairing diesel engines to prevent and solve the "three leakage" problem, the "five word" criterion can be adopted, namely, strict, clean, wiped, grinding and tight.

Yan: for parts disassembly and installation, we must strictly observe the operation rules, strictly prohibit messing and knocking. If we screw the bolts, we must tighten them up in order and tighten several times, so that we do not want to twist the order in order to prevent parts from deforming.

Clean: it must be clean and clean before the parts are assembled, so as to prevent the inclusion of impurities. If the contact belt of the valve and the valve seat is mixed with the tiny sundries, it will not only leak oil, but also directly affect the work of the engine.

Wipe: in applying the sealant leak asbestos pad, paper pad and plug. In the stone cotton to wipe thin and uniform, not too thick, also do not have to pad the whole face with, only apply the local oil spill.

Grinding: the joint surface of grinding or milling parts is to restore the smoothness and accuracy of the surface, so that the oil pipe joints or gaskets can be sealed and oil free after grinding.

Tight: the tightness of the sealing device should be suitable, not too tight or too loose, such as the various contact surfaces and sealing nuts of the diesel engine, and the appropriate tightness must be maintained.

Second pass: cylinder pressure clearance

In order to ensure enough cylinder pressure, the clearance between piston and cylinder liner must meet the requirements of piston ring end and side clearance. Valve and valve seat seal, fuel injector front seal is better, cylinder gasket is better, and thickness meets the requirements.

Third: the volume of the combustion chamber.

Diesel engine repair, often make the volume of the combustion chamber is changed, change the original compression ratio, directly affects the normal operation of diesel engine, combustion chamber volume change factors are: the position of the piston isreversed cylinder pad thickness properly, crank mechanical wear or bending, swirl chamber dislocation, large valve sinkage so, in repair, to respond to these situations of attention.

Fourth pass: normal time

Timing closing including fuel injection timing and valve timing, if the oil supply is not positive, if the gas shortage, will cause the vehicle to start, if you try to start the valve is not tightly closed, or the valve head impact piston, at the same time, with the engine exhaust jitter, the color is not correct.

Fifth: "three"

The bad state of the air filter makes the dust enter the valve.  Accelerating the early wear of the piston ring, cylinder, valve and valve seat, resulting in difficulty in starting and decreasing power.  The technical condition of diesel and oil filter is not good, it will cause impurities to enter between the relevant parts, resulting in early wear and tear of the three major precision parts, and accelerating the wear of crankshaft and bushing, which will result in early abandonment of diesel engine.

Sixth: Diesel atomization

Plunger pair, the oil outlet valve side and injector needle Deputy technical status is not good, will cause atomization adverse, the diesel engine is difficult to start, incomplete combustion, coke increased, resulting in reduction of engine power, fuel consumption increase, therefore, the fuel system, especially the precision coupling of careful check.

Seventh pass: through hole and small hole

(1) the 5 through holes of the bearing and bushing of the pass hole must be correct when they are installed.

A, the main bearings, each of the main bearing oil groove on drill hole, respectively, and the cylinder body, the shaft neck oil is interlinked, when installed, as long as the main bearing flange notch on the quasi steady pin, can prevent the main bearing rotation, ensuring the oil hole alignment, make lubrication smoothly, avoid burn out.

B, rocker bushing. When entering the bushing into the rocker arm, if the hole is not aligned, the rocker shaft and bushing will burn due to lack of lubrication and dry friction, causing the valve clearance to become bigger and produce a serious knocking.

C, connecting rod bushing. The connecting rod small drill has oil collecting holes and the oil hole of connecting rod bushing. When the copper sleeve is sleeved to the connecting rod small head, if two oil holes are not aligned, the copper sleeve and piston pin must be "Dangdang" percussion or even kill.

When D and starting shaft bushing are installed, the two bushing oil holes shall be connected with the oil collecting groove corresponding to the body and the gear cover when installing the starting shaft bushing. Otherwise, the starting shaft and bushing will accelerate the wear, causing the change of oil supply angle and valve timing, resulting in the decrease of the power of the diesel engine.

(2) there are 4 small holes in the small hole.

A, the tank cover hole. After the hole is blocked, the fuel tank no longer communicates with the atmosphere. The upper part of the tank will cause negative pressure due to the decrease of the oil surface, resulting in the interruption of the oil supply. After the fuel is heated, the evaporation will increase the pressure inside the tank, which will cause the oil leakage at the fuel tank switch, so the hole can not be blocked.

After B and crankcase changing holes, the waste gas in the crankcase is accumulated and the air pressure in the crankcase increases. It will cause oil leakage and high waste gas to mix into the oil. It will also speed up the deterioration of the oil and accelerate the wear of the machine parts. Therefore, it is necessary to dredge the hole during maintenance.

C, oil pump discharge hole. The blockage of the oil drain hole on the oil pump will cause a small amount of diesel oil leakage between the push rod and the pipe to enter the fuel injection pump, dilute the lubricating oil in the shell, and accelerate the wear of the parts, so the hole can not be blocked.

D, pump discharge hole, if the hole is blocked, leakage of water can not drain out of the pump body, and enter the bearing seat, it will accelerate the damage of the bearing. Therefore, we must dredge the hole during overhaul.

Eighth pass: grinding and closing

(1) cold grinding. Unload the injector, drive the diesel engine with external force, check the oil pressure and temperature at each part, and listen to the sound of each component. When the temperature is high, the machine will be released.