High Pressure Fuel Pump Leak Detection via Low Pressure Reduction
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Solution Overview
Problem
Current methods for controlling high pressure pumps in fuel injection systems are inadequate for early detection of impaired performance due to leaks, particularly between the inlet valve and pump chamber, and between the piston and pump chamber wall, leading to inefficient operation and potential damage.
Innovation Solution
A method that reduces fuel pressure in the low pressure part of the system to a minimum level, allowing for comparison with a reference value to assess the high pressure pump's functionality, identifying leaks by measuring the pressure difference and determining the pump's functionality through controlled pressure reduction and comparison with a limit pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fuel pressure is reduced to minimum level for leak detection, then detection sensitivity is improved, but system operating pressure stability deteriorates
Solution Approach 1:
The system performs preliminary pressure reduction to a minimum level specifically for leak detection purposes before returning to normal operating pressure. This temporary preliminary action allows sensitive leak detection while maintaining stable normal operation, resolving the contradiction between detection sensitivity and operational stability.
Solution Approach 2:
The pressure reduction and leak detection is performed periodically rather than continuously. The system alternates between normal operating pressure and minimum detection pressure, enabling periodic leak checks without compromising overall system pressure stability. This periodic cycling resolves the contradiction by separating detection needs from operational requirements.
2Reliability
If continuous monitoring is implemented for early leak detection, then reliability is improved, but energy consumption increases
Solution Approach 1:
Instead of continuous monitoring, the system implements periodic monitoring at stationary operating conditions. The feeding pump operates intermittently to reduce pressure for detection, then remains idle. This periodic approach maintains reliability through regular checks while dramatically reducing energy consumption compared to continuous operation.
Solution Approach 2:
The system uses its own existing pressure reduction capability to perform self-diagnosis. The feeding pump's normal pressure reduction function is repurposed for leak detection, eliminating the need for separate continuous monitoring systems and reducing overall energy requirements while maintaining reliability.
3Measurement precision
If pressure is reduced to detect leaks between piston and pump chamber wall, then detection capability is improved, but pumping efficiency deteriorates
Solution Approach 1:
The system performs preliminary pressure reduction specifically for detection purposes before the pumping cycle begins. This preliminary detection phase is separate from the actual pumping operation, allowing leak detection without compromising pumping efficiency during normal operation. The detection is a preliminary check that does not interfere with subsequent productive pumping cycles.
Solution Approach 2:
The system separates detection and pumping into periodic cycles. During detection phases, pressure is reduced to detect leaks; during pumping phases, normal pressure and efficiency are restored. This periodic separation ensures that leak detection capability is maintained while pumping efficiency deterioration is limited to brief detection intervals rather than continuous operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables reliable and efficient detection of leaks and assessment of high pressure pump functionality, requiring only brief stationary engine operation, facilitating timely maintenance and reducing the risk of pump failure.
Implementation Method 1
the feeding pump (2) is controlled to reduce the fuel pressure (Pin) at said position (P1)
Implementation Method 2
the pressure (Ps) in the accumulator tank (6) is measured and compared to a requested reference value (PB) for this
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method for function control of a high pressure pump (5) in a system for fuel injection in a combustion engine is carried out during stationary operating conditions in the combustion engine, with a constantly requested reference value for the fuel pressure in an accumulator tan k (6). Thus, a feeding pump (2) in a low pressure part (3) of the system is controlled so that the fuel pressure in the low pressure part at the inlet to the high pressure pump falls, and at the same time th is fuel pressure is measured, as well as the fuel pressure in the accumulator tan k. The development of the measured fuel pressure in the accumulator tank is compared to said reference value during the pressure reduction in the low pressure part, for the generation of information about the high pressure pump's functionality.