Diesel generator set maintenance training diesel engine -p121-p125 diesel engine...

Diesel generator set maintenance training diesel engine -p121-p125 diesel engine adjustment

Chapter IV Adjustment of Diesel Generator Diesel Engine Main Content:

1 Introduce how to adjust the fuel supply advance angle of the diesel engine;

2 Introduce the adjusting method of diesel valve clearance;

3 Introduce the check and adjustment methods of diesel engine timing;

4 Introduce the right method of adjusting the oil pressure of diesel 6R6A;

5 Introduction Adjustment Method of Silicon Rectifier Surge Generator Regulator

6 Introduce the adjusting method of diesel belt after wind;

7 Describes how to adjust the decompression when the diesel engine starts.

Diesel generator set diesel engine in the long running process, the friction coefficient of its moving parts will change at any time, especially the new diesel engine is even more so. For example, after a new diesel engine is used for a period of time, the injection advance angle may be changed due to the looseness of two fixing screws on the coupling plate of the high-pressure pump drive shaft, causing an abnormal metal knocking sound in the cylinder, causing the fuel to Deterioration of combustion in the combustion chamber makes it difficult to start the diesel engine and even “reverses” it. In case of oversupply, diesel engine power shortage, exhaust pipe black smoke, diesel engine temperature is too high, and rhythmic unclear deep knocking sound in the cylinder will not occur. Diesel fuel also cannot make diesel well in the combustion chamber. combustion. For another example, the valve clearance changes during the operation of the diesel engine, and the failure of the diesel engine may result in power shortage. Therefore, only by carefully learning to adjust the various methods of diesel engines, and once they are effectively used in practice, can the diesel engine work in the best condition and be safe and reliable.

Diesel Generator Diesel engine maintenance personnel or operators must learn the following adjustment methods.

Section 1 Adjustment of Fuel Supply Advance Angle and Valve Clearance

First, the adjustment of fuel advance angle

In order to obtain the most economical fuel consumption rate or when the injection pump is calibrated and reassembled. Generally, the injection advance angle should be corrected. Methods as below:

In the diesel engine running 800h, the vehicle running 20000km generally should be corrected for injection advance angle. Specific method 1 Remove the high-pressure fuel pipe of the first cylinder of the high-pressure pump, as shown in Figure 4-l.

2 Lock the adjustable speed lever on the regulator to the maximum fuel supply position of the diesel engine, as shown in Figure 4-2.

3 As shown in Fig. 4.3, rotate the crankshaft according to the direction of rotation of the diesel engine. Observe the oil supply of the high pressure oil pump during the rotation. When the first cylinder is found to have just fluctuate, stop cranking.

4 When the angle of oil supply on the flywheel corresponding to the pointer on the flywheel housing does not match the normal specified angle, loosen the two fixing screws on the engaging plate of the high pressure oil pump drive shaft, as shown in Figure 4-4.

5 If it is found that the fuel supply angle is too small, pull the flywheel upwards (counterclockwise) from the lower end of the oil monitoring port to push the specified oil supply angle to the twist pin on the flywheel housing, as shown in Figure 4-5. If it is found that the fuel supply angle is too large, pull the flywheel (clockwise) downwards from the upper end of the oil monitoring port so that the specified oil supply angle is aligned with the needle on the flywheel. Then fasten the two screws on the splice tray. Note: When adjusting the injection advance angle, the system must be filled with fuel, otherwise the adjusted injection advance angle will have a certain error. The advance angle of the 135 series diesel engine is 28°~31°. Please refer to the diesel manual for details.

Before the high pressure oil pump is calibrated, it is best to make a mark when disassembling. If no mark is made, it is necessary to first determine whether the first cylinder of the diesel engine is at the top dead center “o” of the compression stroke. Then remove the high-pressure pump side cover plate, and turn the high-pressure pump drive shaft according to the direction of the diesel engine, so that the first cylinder of the high-pressure oil pump stops when close to the fuel supply, and then the high-pressure oil pump adapter is installed to the transmission shaft. Locating screws. Note that the two set screws should generally be fixed in the middle of each hole.

When determining the top dead center of the gasoline engine, remove the spark plug of the first cylinder, then use the cotton cloth to block the spark cold hole, and rotate the flywheel clockwise. When the cotton cloth is impacted by the compressive force in the cylinder, the piston is in the compression stroke. At this point, the "o" scale is aligned with the pointer. This method can also be used for diesel engines.

Second, the valve clearance adjustment

When the cylinder head, piston ring, or cylinder head gasket is replaced and the cylinder head is tightened according to the specified torque, the valve clearance must be adjusted. This is because the valve clearance is too large or too small to be detrimental to the operation of the diesel engine. Clearance of the clearance will increase the impact and wear of the valve transmission components, and will also cause the valve to open early and close, affecting the intake air and exhaust gas volume, resulting in a decrease in the diesel engine power. When the clearance is too small, the expansion of the valve is hindered by the heat, and the valve will be closed laxly. In severe cases, the valve will be damaged. Take 135 series diesel engine as an example to introduce the valve gap adjustment method.

1 Turn the crankshaft in the direction of rotation of the diesel engine so that the pointer on the flywheel housing is aligned with the “o” mark on the flywheel.

2 Remove the cylinder head cover, then use your hand to move the push rods of the intake and exhaust valves of the first cylinder or the sixth cylinder, as shown in Figure 4-6. If the push rod of the intake or exhaust valve of the first or the sixth cylinder can be shaken and relaxed by hand, the first or the sixth cylinder is at the top dead center of the compression stroke.

3 After confirming the top dead center of the compression stroke, loosen the remote counter lock nut, loosen the rocker arm to adjust the whole screw with a flat-blade screwdriver, and adjust according to the provisions of 0.25 mm of the intake valve and 0.30 mm of the exhaust valve. In the process, the feeler gauge should not be too tight and not too loose, as shown in Figure 4-7. After adjusting, tighten the rocker lock nut. Keep in mind that before adjusting, be sure to pry and the wall weight mat mast is pregnant in the middle of the tappet, otherwise the adjusted valve clearance is incorrect.

When the first cylinder is in the top dead center of the compression stroke, the adjustable sequence is l-2-3-6-7-10- (ie, the first cylinder, inlet and exhaust valves can be adjusted; the second cylinder, adjusted Valve third cylinder, adjust the exhaust m fourth cylinder, adjust the intake lazy fifth cylinder, adjust the exhaust valve). After adjustment, rotate the flywheel according to the direction of rotation of the diesel engine so that the timing “o” on the flywheel is aligned with the pointer of the monitoring port, and then the valve without adjustment can be adjusted again as required.

The valve clearance of the diesel generator set 135 series diesel engine when it is cold is shown in Table 4-1.