Fuel Injection Valve Sleeve Force Balance via Segmented Seat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel injection valves face issues with hydraulic forces acting on the valve sleeve during operation, leading to potential leaks and increased wear, especially when surface adjustments occur, requiring stronger actuators and potentially resulting in unwanted openings.
Innovation Solution
The fuel injection valve design maintains a force-balanced state by ensuring no appreciable hydraulic forces act on the valve sleeve axially, with a closing spring force that does not need to account for hydraulic opening forces, reducing wear and allowing for increased surface adjustment without leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the seat diameter differs from the guide diameter to generate hydraulic closing forces, then the permissible surface adjustment increases and wear reduces, but a stronger actuator is required to overcome the hydraulic closing force
Solution Approach 1:
The valve seat is segmented into two functional zones: an annular guide portion with diameter dg that provides guiding and sealing, and a valve seat portion with diameter ds that generates hydraulic closing forces. This segmentation allows the guide and seat to have different diameters, enabling hydraulic closing forces to act on the valve sleeve while maintaining proper guidance and sealing
Solution Approach 2:
Different portions of the valve seat are assigned different diameters for different functions. The annular guide portion has diameter dg for guiding and initial sealing, while the valve seat portion has diameter ds for generating hydraulic closing forces. This local differentiation resolves the contradiction by providing both guidance and force generation without requiring a stronger actuator
2Stability of the object's composition
If the seat diameter equals the guide diameter to maintain force balance, then no hydraulic opening forces arise, but surface adjustment is limited and wear increases
Solution Approach 1:
The valve seat is divided into two portions with different diameters: the annular guide portion (dg) and the valve seat portion (ds). This segmentation allows the valve sleeve to be guided and sealed at the smaller dg diameter while experiencing hydraulic closing forces at the larger ds diameter, maintaining force balance while enabling surface adjustment
Solution Approach 2:
The problem is solved by transitioning from a single-diameter design to a two-diameter design, adding a dimensional parameter. The annular guide portion provides a different diameter than the valve seat portion, creating an additional degree of freedom that allows both force balance and surface adjustment to be achieved
3Reliability
If a stronger actuator is used to overcome hydraulic closing forces, then the valve can handle surface adjustment, but the device complexity and cost increase
Solution Approach 1:
The valve system uses itself to generate the necessary closing force through hydraulic pressure acting on the valve seat portion. The pressure differential across the valve seat creates hydraulic closing forces that automatically compensate for surface adjustments, eliminating the need for a stronger actuator and reducing device complexity
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 design reduces wear and eliminates the need for stronger actuators, maintaining a balanced state even with surface adjustments, preventing unwanted openings and leaks, thus enhancing the valve's operational reliability and efficiency.
Implementation Method 1
The valve sleeve is pressed against a valve seat by a closing spring
Implementation Method 2
the valve sleeve is lifted off the valve seat by the electromagnet
Implementation Method 3
The pressure in a control chamber exerts a closing force indirectly on the nozzle needle via a valve piston
Data Source
Figure 1
Figure 2a~2b
Figure 2c
AI summary
A fuel injection valve for internal combustion engines comprises a valve needle (4) that controls the opening of at least one injection opening (5) with the longitudinal movement thereof, a control chamber (17) connected to a high-pressure side (14), wherein the pressure thereof acts on the valve needle (4) at least indirectly, and a control valve (23) having a valve seat (26), which provided radially between a valve chamber (22) on the high-pressure side connected to the control chamber (17) and a valve chamber (24) on the low-pressure side, and having a valve sleeve (25) that can be guided in a displaceable manner and radially delimits the valve chamber (22) on the high-pressure side and interacts with the valve seat (26). According to the invention, the valve sleeve (25) comprises an annular projection (29) radially protruding into the valve chamber (22) on the high pressure side. The projection surface (29a) of said projection facing the valve seat (26) forms a sealing surface interacting with the valve seat (26).