Abstract The fuel supply of fuel injection pump is adjusted on the test bench. After installation, there is still uneven supply of oil. The main reason is the difference between the state of commissioning and the conditions of use, the uneven supply of oil during commissioning, Valve spring failure; injection pump installed and then adjust the method. Key words: Fuel pump fuel supply and then adjust the fuel supply advance angle CLC number U262.11 document identification code Fuel injection pump diesel fuel supply system is an important component, usually in the test bench to adjust the amount of fuel installed after use, even if there will be occasional lack of power, exhaust black smoke, speed instability abnormalities. Mainly due to fuel injection pump debugging and the actual amount of fuel into the cylinder does not match or uneven supply of fuel caused by each cylinder, a direct impact on the dynamic performance of diesel engines, economy and reliability. First, the reason for uneven fuel injection pump 1. Different debugging conditions and conditions of use Fuel injection pump is tested on the test bed at room temperature, while the installed use is in cylinder compression end, the cylinder temperature of 500 ~ 700 ℃, pressure 3 ~ 5MPa conditions, the difference between the two larger. Locomotive operation, the injection pump and injector temperatures are up to about 90 ℃, can also cause diesel viscosity decreased, so the plunger and needle valve leakage increased, the amount of oil back more than debugging. It has been determined that the amount of fuel actually injected into the cylinder by the fuel injection pump is only about 80% of that of the test rig. Although the pump commissioning staff will consider this factor, it is impossible to know exactly. In addition, due to the wear and tear of the cylinder piston and valve mechanism, the compression temperature and pressure of each cylinder will be different. Even if the test bench debugging a good injection pump, installed capacity, the cylinder fuel supply will have uneven. 2. There is uneven fuel supply when debugging Fuel injection pump test bench debugging, the requirements of the cylinder at rated speed of the fuel supply unevenness should be <3%. The actual commissioning process, due to the test bench dedicated injector and high-pressure tubing length, shape, diameter, etc. can not be exactly the same with the original machine, coupled with the difference of debugging technology, injection pump installed, the actual injection of oil in the cylinder The amount of non-uniformity is often> 3%. 3 parts caused by uneven fuel supply Long-term use of locomotives, fuel injection pump drive coupling loose or clearance is too large, wear gear drive, backlash increases, will also affect the cylinder fuel supply uniformity. In addition, high-pressure hose fittings due to frequent vibration or tight leakage of leakage, as well as the tightening force Ambassador joint metal off and plug the tubing, the same will cause the uneven supply of fuel for each cylinder. In addition, in the fuel pump and governor spring, where the force is strong, large deformation, high frequency of the work belongs to the plunger spring. So its breaking frequency is higher. The light of reducing the amount of fuel injection, the cylinder fuel injection uneven, each cylinder fuel injection interval time difference, fuel injection start time delay; severe intermittent fuel supply can not even. Second, after the adjustment of the fuel pump installed 1 injection pump to adjust the basis According to the exhaust temperature of each cylinder, pressure or smoke color to determine the actual working conditions and the degree of combustion of the diesel engine to determine the cylinder oil supply too much or too little fuel supply too early or too late, and then readjust . By properly adjusting the fuel supply and fuel supply time for each cylinder, the fuel injection pump can supply oil to each cylinder of the diesel engine according to the principle of on-demand distribution so as to eliminate the actual differences among cylinders. 2. Fuel pump readjustment of the operation of technology (l) After the fuel injection pump is installed, adjust the oil supply time according to the specified standard and remove the exhaust manifold to observe the working condition of each cylinder. (2) Start the diesel engine, idling idle 2 ~ 3min, touch each cylinder exhaust port and near the fuel injector cylinder head, if a cylinder temperature is too high, it can be concluded that the cylinder fuel supply too much. (3) When the engine temperature exceeds 50 ℃, increase the throttle, let the engine run at rated speed, at the same time check the color of the exhaust port, pay attention to listen to the sound of the cylinder. If a cylinder of black smoke, indicating the fuel supply is too large, with more mechanical equipment used in the 135 series diesel engine, for example, the pump can adjust the gear rod to the direction of stopping oil, release the locking screw on the adjustment gear , Take a thin iron rod into the hole of the oil control sleeve, tap with a hammer, turn it to the right, you can reduce the fuel supply, and vice versa increased. When a cylinder has a crisp percussion, and difficult to start, indicating the fuel supply too early; if a cylinder temperature is too high, or even a flame jet, it may be the oil supply started too late. Such as the 135 series diesel engine, each cylinder fuel supply start time adjustment, is determined by the position of the pump plunger. When the fuel supply start time is too late, the timing adjustment nut should be screwed out with some screws, the fuel supply start time is too early, then tighten the screws. (4) check the fuel supply advance angle General oil spill method can be used to check the fuel supply advance angle, the pump will be a high-pressure pipe fittings loosened, will be connected to the fuel injector at one end of the connector removed, the tubing turned to the horizontal position, and then tighten the pump high-pressure tubing joints, the throttle pulled The maximum position, open the decompression of the car until a few drops of diesel emerge from the outlet of the high-pressure tubing. Wipe the diesel at the exit of the tubing and turn the flywheel slowly. At the same time pay attention to observe the high-pressure tubing at the exit of the oil surface, at the beginning of the moment it started to stop rotating flywheel. At this point, the engraving of the tank or the body should be aligned in the flywheel top dead center between 16 ~ 20 °. If the two have been in alignment before the oil spilled, indicating too much fuel advance angle, oil supply too early; if more than the oil overflow, the fuel supply advance angle is too small, too late. It is noteworthy that, for multi-cylinder diesel engine, the need to install a dedicated glass tube and pointer to measure the first cylinder compression top dead center and start the fan when the fan between the two symbols between the arc length to determine the fuel supply advance is it right or not. At the same time also check each monomer pump intermittent fuel supply is the same, if different, can adjust the gap between the plunger and tappet or gasket between the pump and the body thickness, so that the oil interval to achieve the same. When the fuel supply advance angle is too small or too large, it needs to be adjusted. Different types of fuel supply advance angle adjustment methods are different. The new 195 and 190 diesel engine, is through the increase and decrease of the copper gasket between the pump and the body to adjust the fuel supply advance angle. Increasing gasket supply time becomes late, otherwise it is earlier. 190-1 and 1105 diesel engine is to adjust the adjustment screw on the fuel injection pump servo column to adjust the fuel supply advance angle, screw in (outside), the oil supply time becomes late (early). 4115 diesel engine is by adjusting the relative position of the spline access plate and the injection pump gear to change the fuel supply advance angle, spline dial with the fuel pump spline sleeve turn a hole clockwise, the fuel supply advance angle increased by 3 ° , So that oil supply earlier, on the contrary, turning a hole counterclockwise, the fuel supply advance angle reduced 3 °, so that the oil supply time becomes late. After the above initial adjustment, check the exhaust temperature of each cylinder is consistent, if you can not restore the normal work of the engine, you should measure the cylinder pressure is within the allowed range, if necessary, replace the piston ring or grinding valve, check the injector The atomization situation and the opening pressure is normal.