Fault Causes, Repair Method, and Prevention Measures of Camshaft Fracture of B-Type Fuel Injection Pump
Abstract
The camshaft of the B-type fuel injection pump is an important part in the fuel supply system of diesel engines. When the camshaft of the B-type fuel injection pump is broken, the diesel engine will not run. According to the cause analysis and summary of B-type fuel injection pump camshaft fracture occurrences in the past, the main causes of camshaft fracture are sea water corrosion, poor lubrication, poor assembly fit, and metallurgical defects. In order to avoid similar failures in the future, it is necessary to take measures such as periodic maintenance and inspection, strengthening technology management, and improving the assembly process.
Key Words: B-Type Fuel Injection Pump; Camshaft; Fracture; Fault Cause; Repair Method; Prevention Measure
1. Introduction
The camshaft, which is an important part of the fuel supply system of the diesel engine, is commonly used on medium and large-scale diesel engines. It is connected to the crankshaft link by the timing gear, and the reciprocating movement of the crankshaft drives the camshaft and valve to realize the opening and closing of the fuel injection valve and the hitting of the plunger to lift the valve for fuel injection.
According to statistics, the camshaft of the B-type fuel injection pump has been repeatedly broken over the years due to improper use and maintenance, resulting in a decrease in diesel engine fuel supply performance and an increase in maintenance costs and the difficulty of maintenance. Therefore, the cause of camshaft fracture of B-type fuel injection pump needs to be analyzed in detail and preventive measures need to be taken.
2. Fault Cause
2.1 Sea Water Corrosion
Sea water corrosion is a common cause of camshaft fracture. Sea water or condensed water has a corrosive effect on the lubricating oil, which eventually causes the camshaft to break.
2.2 Poor Lubrication
Poor lubrication is also one of the main causes of camshaft fracture. Poor lubrication will increase the wear of the camshaft and eventually cause it to break.
2.3 Poor Assembly Fit
Poor assembly fit can also lead to camshaft fracture. The camshaft and flywheel of the fuel injection pump should be matched to ensure that the camshaft can rotate freely. When the size of the camshaft and flywheel does not match, the camshaft will be at an angular position while spinning, which will cause the camshaft to break.
2.4 Metallurgical Defects
Metallurgical defects can also cause the camshaft to break. Each camshaft should be quenched in order to increase its hardness. If the quenching is not carried out in time or the quenching process fails, the camshaft will not have sufficient hardness and the camshaft will be easily fractured.
3.Repair Method
3.1 Cleaning
The first step in repairing a broken camshaft is to clean the parts. It is necessary to remove the dirt and debris from the parts to ensure that the parts are restored to their original state.
3.2 Replacement
The broken camshaft needs to be replaced with a new one. Before installation, it is necessary to check whether the size of the camshaft and flywheel is matched.
3.3 Adjust The Timing
When the camshaft is replaced, the timing chain should be adjusted accordingly. After adjusting the timing chain, the camshaft and flywheel timing should be further adjusted.
3.4 Reinforce
After replacing the camshaft, it is necessary to reinforce the camshaft to prevent it from breaking again in the future. The reinforcement method is to weld a steel plate onto the camshaft and then quench it.
4. Prevention Measure
4.1 Periodic Maintenance And Inspection
Periodic engine maintenance and inspection can help detect potential problems before they become serious. Regular inspections of the fuel injection pump can help to detect any deformities or cracks on the camshaft in time and replace it before the camshaft fractures.
4.2 Regular Oil Change
It is important to replace the oil in the fuel injection pump on a regular basis. If the oil is not changed or replaced on time, it can cause the oil to be contaminated, which can lead to camshaft fracture.
4.3 Strengthen Technology Management
It is necessary to strengthen the management of technology, especially the technology of assembly, welding and quenching. All processes need to be strictly monitored to ensure that the parts are assembled properly and all processes are carried out in a professional manner.
4.4 Improve The Assembly Process
The assembly process can be improved by proper selection of the camshaft, flywheel, and timing chain. When selecting, it is necessary to determine the size of the camshaft and flywheel to ensure that they match each other.
5.Conclusion
The camshaft fracture of B-type fuel injection pump will cause the diesel engine to stop running, so it is necessary to analyze the fault and take preventive measures to prevent similar failures in the future. The causes of camshaft fracture are mainly sea water corrosion, poor lubrication, poor assembly fit, and metallurgical defects. The repair method is to first clean the parts, then replace the camshaft, adjust the timing, and finally reinforce the camshaft. The preventive measures are to carry out periodic maintenance and inspection, replace the oil in the pump on a regular basis, strengthen technology management, and improve the assembly process.
6. Reference
[1] China Diesel Engine Guide Book, Chemical Industry Press, 2019
[2] W. Kim et al., “Investigation of Mechanical and Metallurgical Properties of Injection Pumps for Durability and Reliability,” The International Conference on Quality and Durability of Automotive Components and Parts, vol. 1, no. 2, pp. 25-30, 2015.
