Fuel injection pump assembly basic operation points

1. The plunger and the plunger sleeve are matched in a complete set and cannot be exchanged. Before loading the fuel injection pump body, check that their models meet the installed fuel injection pump. The plunger sleeves that adjust the height of the roller drive components can have different plunger diameters. If the plunger diameter is incorrectly installed, it is impossible to achieve normal oil supply. The plunger of the same diameter is installed on the left or right side of the diesel engine according to the fuel injection pump, and is divided into two types: "left machine" and "right machine". The chute of the plunger head is also divided into "left-handed" and "right-handed", and the corresponding ones are used for "left machine" and "right machine". If it is installed incorrectly, it will cause the joystick to move in the direction of increasing oil supply, and the plunger will move in the direction of reducing oil supply. Such a fuel injection pump cannot work. When replacing the new plunger and plunger sleeve, it can be used. The original old pieces are compared with each other to avoid errors.

2. When loading the oil discharge valve and valve seat, pay attention to the cleaning of the upper end surface of the plunger sleeve and the lower end surface of the oil outlet valve seat so that the joint surface is tight. If mechanical impurities are trapped, the plunger will work, and high pressure oil will leak, so that the uniformity of the oil supply of each cylinder cannot be adjusted. There should be a slight clearance between the inner diameter of the oil discharge valve gasket and the outer diameter of the oil discharge valve body. If it is too tight, after the oil outlet seat is pressed, the oil outlet seat will be deformed, and there is a danger of getting stuck in the oil outlet valve. The outer diameter of the gasket should not be too small, otherwise the sealing will not be strict, and low pressure oil will leak from the gap of the screw hole of the oil outlet valve of the pump body. When screwing into the pressure valve seat, it reaches 49~68. SN.m torque is suitable. Too tight will deform the plunger sleeve and the plunger will become stuck in the plunger sleeve. If there is no torque wrench or lack of experience, tighten the oil valve pressure seat, and insert the plunger into the plunger sleeve for testing. If the plunger moves freely. If the twist occurs, indicating that the torque is too large, slowly loosen the oil valve press seat until it is suitable.

3. When loading the plunger, it should be careful and accurate, and should not be touched. After loading, it should be able to move up, down, left and right freely. In the fuel injection pump of the rack-type control mechanism, the two directions of the lower end of the plunger can be inserted into the straight slot of the control sleeve. Generally, the manufacturer marks the tongue on the lower end of the plunger. The mark should be oriented upwards.

4. When the hole on the pump body is deformed or has burrs, when the plunger set is not inserted, the reamer reaming is applied to make the plunger sleeve loosely fit.

5. When installing the camshaft, the direction of rotation of the fuel injection pump and the order of fuel injection should be clarified before loading the pump body. The oil seal at both ends should seal the lubricant inside the pump body and must not be installed incorrectly. After the bearing housings on both sides are installed, the camshaft rotation should be flexible, and the axial clearance should meet the requirements of the specification. If it is not suitable, the gasket can be adjusted.

6. After the roller drive parts that have been repaired and installed, after the L-J dust 乇 L camshaft is turned into the pump body, it should be flexible and free to move up and down, and it is not allowed to be stuck. The adjusting screw on the screw should be adjusted in advance, and it should not be too high. Otherwise, the plunger and other parts will be crushed during the subsequent assembly and fastening process.

7. When installing the plunger spring, the upper and lower plunger spring seats should not be reversed, otherwise the fuel injection pump will be partially issued. When loading the spring seat, check the adjustment ring gear for axial clearance. If the adjusting ring gear is dead, the spring seat hole is worn. The corresponding spring seat should be re-fitted or a circular ring pad should be added on the upper seat of the spring to ensure flexible rotation of the adjusting ring gear. The wire retaining ring of the lower spring seat should be securely inserted into the groove, and no skewing is allowed.

8. Before adjusting the ring gear, first install the adjusting rack into the pump body and determine the installation position. When there is a scribed mark on the adjustment toothed rod, the scribe line should face the end face of the pump casing. When there is an eye-catching mark on the adjusting toothed rod, the eye-catching and the adjusting rack bushing on the pump body should be aligned. Then keep the position of the adjustment rack unchanged and insert the adjustment ring gear to engage the adjustment rod. The side of the ring gear should be adjusted outwards. At this time, the adjustment position of the adjusting ring gear and the control sleeve can be temporarily ignored. After the pump body is installed, the locking screw on the adjusting ring gear is loosened, and the alignment mark is aligned. (When the fuel injection pump is shipped from the factory, adjust the fit of the ring gear and the control sleeve, use the hard note of the chisel, or mark with paint) and tighten. For the fuel injection pump without the gear rod assembly mark, or the adjustment of the ring gear opening is not upward, the assembly should be strictly in accordance with the mark made when disassembling, otherwise it will bring great difficulties to the debugging, and even cause all rework. In the case that the fuel injection pump has been assembled, if it is found that the adjustment ring gear and the adjustment toothed rod are not in the correct position and need not be disassembled, the adjustment ring gear can be smashed down with the screwdriver together with the control sleeve to make them and the adjustment teeth. The levers are disengaged, then the ring gear is moved or the rack is moved, and the screwdriver is loosened to get the correct engagement position.