Fuel Injection Valve Sub Orifice Design for Rapid Pressure Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel injection valves experience a response delay between control-chamber pressure changes and valve body operations, limiting the ability to shorten the injection interval between fuel injections.
Innovation Solution
The fuel injection valve incorporates a movable plate and control valve with sub and in-orifices to allow for simultaneous fuel discharge and supply, enabling the control-chamber pressure to be decreased before the movable plate contacts the fixed plate, thus allowing for earlier initiation of the next fuel injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the diameter of the orifice in the high pressure passage is made larger, then the fuel pressure in the pressure control chamber is not rapidly decreased when the control valve is opened, but the response for starting fuel injection is getting worse
Solution Approach 1:
The patent divides the single orifice into two separate orifices: a first orifice in the high pressure passage and a second orifice in the low pressure passage. This segmentation allows independent optimization of each orifice's function - the first orifice controls high pressure fuel supply while the second orifice controls low pressure fuel discharge, resolving the contradiction between response speed and injection efficiency.
Solution Approach 2:
The movable plate acts as an intermediary element that selectively blocks or opens the first orifice based on operational requirements. By introducing this intermediate component, the system can dynamically control the flow path and pressure distribution, enabling rapid response while maintaining overall injection efficiency.
2Speed
If the diameter of the orifice in the high pressure passage is made smaller, then the fuel pressure in the pressure control chamber is rapidly increased when the control valve is closed, but the response for terminating fuel injection is getting worse
Solution Approach 1:
By separating the orifices into two distinct locations with different functions, the system can optimize each for its specific purpose. The first orifice (in high pressure passage) is optimized for rapid pressure buildup during termination, while the second orifice (in low pressure passage) maintains efficient fuel discharge capability.
Solution Approach 2:
The movable plate is positioned to block the first orifice in advance during normal operation, creating a sealed environment for rapid pressure increase. This preliminary positioning enables fast response for terminating fuel injection without compromising the overall injection efficiency.
3Speed
If the movable plate is provided to block the high pressure passage, then the response for starting fuel injection is improved, but the injection interval between multiple fuel injections cannot be shortened
Solution Approach 1:
The movable plate transitions from a static blocking element to a dynamic component that can rapidly move between blocked and unblocked positions. This dynamic capability allows the system to maintain fast response for single injections while enabling shorter intervals between multiple injections by quickly switching the plate position to allow premature opening of the control valve.
Solution Approach 2:
The system changes the positional parameter of the movable plate to alter the flow characteristics. By adjusting the plate position dynamically, the system can optimize the injection interval timing while maintaining rapid response capability, effectively resolving the time loss issue.
4Device complexity
If the control valve is opened after the movable plate contacts the fixed plate, then the system operation is simplified, but the injection interval cannot be shortened due to waiting time
Solution Approach 1:
The movable plate is positioned in advance to block the first orifice before the control valve opening is required. This preliminary positioning enables the control valve to be opened earlier without causing instability, thereby shortening the injection interval while maintaining relatively simple control logic.
Solution Approach 2:
The patent replaces purely mechanical interlocking (where valve opening is physically prevented until plate contacts fixed plate) with a pressure-controlled mechanism. The control valve can open based on pressure conditions rather than mechanical position, enabling earlier operation and shorter injection intervals.
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 a reduction in the injection interval by decreasing the control-chamber pressure to a value close to the valve-body opening pressure, enabling smoother and more rapid fuel injection without being influenced by response delays or waiting times.
Implementation Method 1
a high pressure passage for supplying high pressure fuel to the pressure control chamber
Implementation Method 2
the movable plate is moved in the direction to the fixed plate so as to be in contact with the fixed plate and to close the high pressure passage
Implementation Method 3
a low pressure passage for discharging the fuel from the pressure control chamber
Data Source
AI summary
A sub out-orifice and an in-orifice are respectively formed in a low pressure passage and a high pressure passage of a fixed plate. A control valve is provided at an outlet port of the low pressure passage. In a normal control, the control valve starts its control-valve opening operation when a movable plate is in contact with the fixed plate. In an interval-shortening control, the control valve starts the control-valve opening operation at an earlier timing than that in the normal control, namely during a course in which a valve body is still in its valve-body closing operation.