Maintenance and assembly of fuel injection pump an

2022-08-16
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Guide for maintenance and assembly of fuel injection pump and governor components of truck crane

(L) the working environment must be highly clean, and the workbench, parts and tools used must be thoroughly cleaned

(2) after the parts to be installed pass the cleaning and inspection, they shall be neatly arranged on the workbench to ensure that they are orderly arranged and not messy

2. precautions for assembly of fuel injection pump

(L) open end wrenches, box wrenches, socket wrenches, screwdrivers, wood wool and various special tools must be used in the assembly process, and general tools such as adjustable wrenches and pipe wrenches are not allowed

(2) when assembling the camshaft, pay attention to its installation direction. After the fastening bolts of the camshaft intermediate bearing are tightened evenly, the camshaft should rotate flexibly. Its advanced automation system is not limited to one type, and the axial clearance should be 0 06mm。 Be careful not to install the oil seal in the opposite direction

(3) the assembly sequence of the plunger assembly is opposite to the disassembly procedure. When installing the plunger sleeve into the flange sleeve, pay attention to align the positioning groove on the plunger sleeve with the positioning pin hole; After pressing the pin, the plunger sleeve should be able to move up and down slightly. When installing the O-ring, apply a little lubricating oil to prevent damage and facilitate installation

pay attention to the difference between the top and bottom when installing the guide ring, and do not install it incorrectly. In addition, clamp the snap ring firmly with snap ring pliers during installation

when installing the oil outlet valve coupling, keep the upper end face of the plunger sleeve and the lower end face of the oil outlet valve seat highly clean, so as to make the joint surface tight, so as to prevent oil leakage during the operation of the plunger and affect the uniformity of oil supply of each cylinder. The tightening torque of the oil outlet valve pressing seat is 107.8 n m, and the tightening purpose is achieved in the sequence of tightening, loosening and tightening

(4) after installing the plunger control sleeve, pay attention to make the steel ball completely enter the ball groove of the oil supply control rod. After installation, manually check whether the left and right movement of the oil supply control rod is smooth

(5) when installing the plunger into the plunger sleeve, pay special attention to make the marked side on the plunger flange block face the direction of the locating pin, and do not install it in the wrong position, otherwise the fuel injection pump will not work after installation. After the plunger is installed into the plunger sleeve, pull the oil supply control rod left and right to check whether it is blocked

3. precautions for assembling the governor

(L) when installing the sliding sleeve and bushing, first confirm the five key improvement points, such as the impact of the quality of circulating materials, the melting of iron tools into the liquid aluminum, the melting of the shelling hammer into the liquid aluminum, the anodizing of the blanking port, and the melting of the rust skin of the phosphorus iron steel claw into the liquid aluminum, accurately press the ball bearing into the bushing, and then press the sliding sleeve; After fixing the sliding sleeve, pay attention to check whether the bushing rotates smoothly

(2) when installing the flying block, the round nut used for fixing it should be 58 Relevant staff must check the different structures and parts of the fatigue testing machine and tighten it with 5N m torque

(3) the gear rod stroke adjusting bolt can be temporarily installed for debugging

(4) when the governor is installed into the pump body, the joint surface should be coated with adhesive to prevent oil leakage that will cause the hardness to be unable to be displayed or the hardness value to be low

(5) because the governor is a dual-purpose governor, a control arm for controlling speed is added, and the adjusting bolts on it should not be loosened at will before commissioning

4. Fault Example

there is a truck crane. After the maintenance and commissioning of the fuel injection pump, the following faults occurred during the installation and commissioning: when the engine is at medium speed, loosen the throttle, not only the speed cannot be reduced, but it is getting faster and faster, which seems to show signs of flying. After disassembling the fuel injection pump, it was found that when the plunger was installed into the sleeve, the plunger was installed at the wrong position by 180, resulting in the opposite direction of oil supply and shutdown. When the throttle is retracted, the fuel supply control lever moves in the direction of reducing fuel supply, while the plunger moves in the direction of increasing fuel supply, causing the fuel injection pump to fail to work. Then turn the plunger 180 and try again after installation. Everything is normal

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