High-Pressure Pump Fuel Discharge Control via Communication Hole
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-pressure pumps face challenges in accurately controlling fuel discharge quantity due to premature bouncing of the movable core and needle valve, leading to inconsistent fuel discharge timing and increased fuel flow, which complicates precise control over the fuel supply system.
Innovation Solution
The design incorporates a needle guide with a communication hole of controlled opening sectional area, adjusting fuel flow to the movable core chamber, thereby restricting the bouncing of the movable core and needle valve, ensuring a proper relationship between coil energization time and fuel discharge amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the opening sectional area of the communication hole is made larger, then the flow resistance of fuel becomes smaller and the operation speed increases, but the movable core and needle valve bounce toward the fixed core after collision, causing premature valve closing and inaccurate fuel discharge control
Solution Approach 1:
The patent optimizes the opening sectional area of the communication hole to a specific range (0.3mm² to 1.2mm²) to balance flow resistance and bounce control. This parameter optimization allows the movable core to operate quickly while preventing excessive bouncing that would cause premature valve closing, thereby maintaining accurate fuel discharge control.
Solution Approach 2:
The patent introduces a damper chamber that dynamically absorbs the bouncing motion of the movable core after collision with the stopper. The damper chamber provides a controlled fluid path that dissipates kinetic energy, preventing the movable core from rebounding toward the fixed core and ensuring precise timing of the needle valve closing action.
2Productivity
If the opening sectional area of the communication hole is made larger, then the fuel flow rate increases, but the relationship between coil energization time and fuel discharge amount becomes inconsistent
Solution Approach 1:
The patent specifies an optimal range for the communication hole area (0.3mm² to 1.2mm²) that maintains a linear relationship between coil energization duration and fuel discharge quantity. Within this range, the hole provides sufficient fuel flow while preventing bounce-induced timing errors that would disrupt the proportional relationship between energization time and discharge amount.
Solution Approach 2:
The damper chamber acts as a feedback mechanism that stabilizes the movable core's motion. By absorbing excess kinetic energy from bounce, it ensures that the needle valve closes at the intended time based solely on coil de-energization, maintaining consistent feedback between control input (energization time) and output (fuel discharge amount).
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
This solution allows for precise control of the fuel discharge quantity, maintaining the intended relationship between energization start time and fuel discharge, reducing noise vibration, and minimizing erosion on the core surfaces, thus enhancing the operational efficiency and accuracy of the high-pressure pump.
Implementation Method 1
An opening sectional area of the communication hole is defined so that a fuel discharged amount decreases as an energization start time of the coil is delayed
Implementation Method 2
after the needle biases the suction valve toward stopper by means of a biasing force of a biasing portion
Implementation Method 3
when the movable core and the needle valve are magnetically attracted to the fixed core in a metering stroke
Data Source
AI summary
Between a movable core chamber and a fuel supply passage, a needle guide slidably supports a needle fixed to a movable core. The needle guide has a communication hole which fluidly connects the movable core chamber and the fuel supply passage. An opening sectional area of the communication hole is defined in such a manner that a fuel discharged amount decreases as an energization start time of a coil is delayed. In a suction stroke, it is restricted that the movable core and the needle bounce toward the fixed core after the needle biases a suction valve toward a stopper by means of a biasing force of a second spring. A relationship between the energization start time of the coil and the fuel discharged amount is properly maintained, so that the fuel discharged amount of the high-pressure pump can be controlled correctly.