Fuel Injector Pressure Booster Piston Conical Spring Support
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Solution Overview
Problem
The existing fuel injector designs for internal combustion engines face challenges in pre-assembly of the pressure booster piston and spring element, leading to installation space disadvantages and increased wear due to the spring element's larger outside diameter requirement.
Innovation Solution
A fuel injector design where the spring element is supported on a conically tapered surface of the pressure booster piston, allowing for pre-assembly with a spring plate and ring element, preventing wear and enabling easier assembly by using a snap ring and chamfer for secure mounting, and a 3/2-way control valve for hydraulic connection to the compression chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the spring element is supported on a cylindrical surface of the pressure booster piston, then the spring element can be easily assembled, but the spring element rubs against the piston causing wear
Solution Approach 1:
The support surface for the spring element is changed from a cylindrical surface to a conically tapered surface. This local geometric modification creates a self-aligning feature that prevents rubbing while maintaining assembly simplicity. The conical taper provides a unique contact point that eliminates lateral movement and rubbing against the piston.
2Stability of the object's composition
If the outside diameter of the spring element is made larger to provide sufficient support area, then the spring element is more stable, but the installation space requirement increases
Solution Approach 1:
The support geometry transitions from a cylindrical surface (one-dimensional contact) to a conically tapered surface (two-dimensional contact area). This dimensional change allows the spring element to achieve stable support with a smaller outside diameter, as the conical taper provides both radial and axial positioning, reducing the installation space requirement while maintaining stability.
3Device complexity
If the pressure booster piston and spring element are assembled separately during final assembly, then the assembly process is more complex, but pre-assembly is not possible
Solution Approach 1:
The conically tapered support surface enables pre-assembly of the spring element with the pressure booster piston. The taper geometry allows the spring element to be installed on the piston before final assembly into the fuel injector, simplifying the overall assembly process and improving productivity through modular pre-assembly.
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 allows for stable seating of the spring element, reducing wear and installation space issues while enabling efficient fuel injection by utilizing a 3/2-way control valve for precise pressure control, enhancing the overall performance and assembly efficiency of the fuel injector.
Implementation Method 1
The conical taper on the side on which the spring element is supported against the pressure booster piston prevents the spring element from rubbing against the upper section of the pressure booster piston, which it encloses, and thus contributing to the wear of the pressure booster piston or the spring element.
Implementation Method 2
The spring element is preferably a spiral spring designed as a compression spring.
Implementation Method 3
a spring element which is supported on one side on the injector housing and on the other side on the pressure booster piston
Implementation Method 4
a pressure booster, with which fuel under system pressure is compressed to injection pressure
Implementation Method 5
The pressure booster piston delimits a compression space, a differential pressure space and a control space
Data Source
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AI summary
The invention relates to a fuel injector for injecting fuel into a combustion chamber (35) of an internal combustion engine, which fuel injector comprises an injection valve element (33), for opening and closing at least one injection opening (34) and a pressure intensifier (7), by way of which fuel which is at system pressure is compressed to injection pressure. The pressure intensifier (7) is actuated via a first control valve (17) and the injection valve element (33) is actuated via a second control valve (31). The pressure intensifier (7) comprises a pressure intensifier piston (9) which is assigned a spring element (13) which is supported by way of one side on the injector housing (10) and by way of the other side on the pressure intensifier piston (9). The pressure intensifier piston (9) delimits a compression space (23), a differential pressure space (19) and a control space (6), wherein the control space (6) is arranged at that end of the pressure intensifier piston (9) which lies opposite the compression space (23), the spring element (13) is received in the control space (6) and the spring element (13) is supported on one side on the injector housing (10) and on the other side on the pressure intensifier piston (9).