Repair the diesel engine to make a good eight
1, "three leaks" off To prevent and solve the problem of “three leakages†when repairing diesel engines, we can adopt the “five-character†guideline, that is, strict, clean, wiping, grinding, and tight. Yan: For the disassembly and installation of parts, strict requirements must be followed. Observe the operating procedures. It is forbidden to knock and knock. If bolts are tightened, they must be tightened several times in sequence and not tightened in order to prevent deformation of the parts. Clean:Before assembly, be sure to clean and prevent impurities from mixing. If the oil valve and the valve seat contact with the ring zone mixed with very small debris, it will not only leak oil, but also directly affect the engine's work. Wipe: Apply asbestos oil on the asbestos pad, paper pad, and various plugs. When asbestos oil is applied, it should be thin and even, not too thick, and do not apply the entire surface of the pad, just smear the part of the oil spill. Grinding: The surface of the milled or milled part. Its function is to restore the surface finish and precision, so that after the oil pipe joint or gasket is ground, it can keep the seal and not leak oil. Tightness: The tightness of the sealing device should be appropriate, and it must not be too tight or too loose. For example, various contact surfaces of the diesel engine and the seal nut must be maintained in appropriate tightness. 2, cylinder pressure off In order to ensure that there is sufficient cylinder pressure, the clearance between the piston and the cylinder sleeve, the end and edge clearance of the piston ring must meet the requirements, the sealing of the valve and valve seat, the seal of the injector front end is better, the cylinder pad is better, and the thickness Meet the requirements. 3, the volume of the combustion chamber After the diesel engine is repaired, it often causes the volume of the combustion chamber to change, and the original compression ratio is changed, which directly affects the normal operation of the diesel engine. Factors that change the volume of the combustion chamber include: piston position reversed, improper cylinder pad thickness, crank connecting rod machinery Wear or bending, vortex chamber misalignment, valve overhang, etc., should be taken care of during repairs. 4, timing off Timing clearance includes timing of fuel supply and timing of timing. If fuel supply is not correct, S195 and X195 diesel engines can be adjusted by means of spacers between the fuel injection pump and the gear chamber cover, each increasing or decreasing 0.1mm thick shim. Equivalent to a flywheel arc length of 6.3mm. If the gas distribution is insufficient, first check and correct the error on the timing gear installation, and then adjust the valve clearance, the valve clearance changes by 0.1mm, the crank angle changes by 3 degrees, which is equivalent to the flywheel arc length 11.1mm, should pay attention to the piston adjustment When compressed to top dead center, the clearance between the inlet and exhaust valves (cold state) can not be less than 0.2mm, to prevent the machine parts from being heated to expand, the valve closing is not strict, or the valve head hits the piston. 5, "three filter" off The air filter technology is not in a good condition and will cause dust to enter the valve. Accelerated early wear of piston rings, cylinders, valves, and valve seats caused difficulty in starting and power reduction. The poor technical condition of diesel and oil filters will cause impurities to enter between the relevant parts, causing early wear of the three precision coupling parts and accelerating the wear of the crankshaft and the bearing bush. In severe cases, the diesel engine will be scrapped early. 6, diesel atomization shut The poor technical state of the plunger pair, the outlet valve and the injector needle valve pair will cause poor atomization of the fuel injection, which makes the diesel engine start difficult, the combustion is not complete, and the amount of coke increases, resulting in a decrease in engine power and fuel consumption. Therefore, the fuel system, especially precision fittings, must be inspected carefully. 7, through holes and small holes (1) Through-holes The S195 diesel engine is used as an example. The five through-holes of bearings and bushings must be aligned during installation. a. The main bearing, each pair of main bearing oil groove is drilled with oil holes, which are also connected with the oil on the cylinder block and the main shaft respectively. When the installation is completed, the main bearing can be prevented as long as the flange of the main bearing is aligned with the positioning pin. Rotate to ensure that the oil hole is aligned so that the lubricant can be unimpeded and burned. b, rocker bushings. When pressing the bush into the rocker arm, if the hole is not aligned, the rocker arm shaft and bushing will be lack of lubrication, dry friction and burning will cause the valve clearance to become large, resulting in severe knocking noise. c, connecting rod bushings. The connecting rod is drilled with a collecting hole and communicates with the oil hole of the connecting rod bushing. When the copper bushing is connected to the small head of the connecting rod, if the two oil holes are not aligned, the copper bushing and the piston pin are knocked off. Hit the sound and even kill it. d. When starting the shaft bushing and installing the starting shaft bushing, the two bushing oil holes must communicate with the corresponding oil collecting grooves on the body and gear cover, otherwise the starting shaft and bushing will accelerate the wear and cause oil supply. Changes in the angle and valve phase result in a drop in diesel engine power. (2) The small hole is mainly the following 4 holes a, tank cover ventilation holes. After this hole is blocked, the tank is no longer open to the atmosphere. The upper part of the tank will experience negative pressure due to a drop in oil level. This will interrupt the supply of fuel. When the fuel is heated and evaporates, the pressure in the tank will increase, causing oil leakage at the switch of the tank. Therefore, This hole cannot be blocked. b. After the crankcase ventilation hole is blocked and the ventilation hole is blocked, the exhaust gas in the crankcase will accumulate, and the pressure in the crankcase will increase. This will cause the oil to leak. The high-humidity exhaust gas will be mixed with the oil, and the engine oil will be spoiled. Parts are worn, so be sure to clear this hole during maintenance. c. Oil pump drain hole. The plugging of the drain hole on the oil pump can cause a small amount of diesel oil between the push rod and the conduit to leak into the fuel injection pump, dilute the lubricant in the housing, and accelerate the wear of the component. Therefore, the hole cannot be blocked. d. Pump drain hole. If the hole is blocked, the leaking water will not drain out of the pump body. If it enters the bearing seat, it will accelerate the damage of the bearing. Therefore, it must be cleared during the inspection. 8, grinding off (1) cold run-in. Remove the injector, use external force to drive the diesel engine, check the oil pressure and temperature of each part, and pay attention to listening to the sound of each part. After the cold running-in, when the temperature is high, the engine oil will be released, and the oil filter and the oil passage will be cleaned. (2) heat run-in. No load thermal run-in, pay attention to the working condition of the diesel engine and the noise of various parts; heat and wear in accordance with the specified load and time, often pay attention to the sound of various parts and the helium of the oil port, smoke exhaust, fuel injector return oil, etc., and find problems should be promptly eliminated . Rose Flower,Jasmine Flower,Wild Chrysanthemum,Common Bombax Flower Henan Qiancuntang medicial technology co.ltd. , https://www.qctchineseherb.com