Fuel Injection Device Grooved Control Member Fluid Resistance
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Solution Overview
Problem
Conventional fuel injection devices with large contact surface areas between control members and other components experience increased fluid resistance, leading to fluctuating injection characteristics due to varying fuel viscosity with temperature.
Innovation Solution
The fuel injection device incorporates multiple grooves on the control member and/or cylinder surfaces to divide the contact surface into island portions, reducing fluid resistance by creating flow paths and minimizing the contact area, thereby stabilizing fuel injection characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the contact surface area between the control member and housing member is large, then the sealing performance is improved, but the fluid resistance increases and response deteriorates
Solution Approach 1:
The contact surface between the control member and housing member is divided into multiple island portions by grooves, creating a segmented structure. This segmentation reduces the total contact area to minimize fluid resistance while maintaining sufficient sealing at the discrete contact points, thus resolving the contradiction between sealing performance and response speed.
2Reliability
If the contact surface area between the control member and housing member is large, then the sealing performance is improved, but the fuel injection characteristics become unstable due to increased fluid resistance
Solution Approach 1:
The contact surface is segmented into multiple island portions by grooves, reducing the total contact area. This segmentation decreases fluid resistance and its fluctuation, thereby stabilizing fuel injection characteristics while maintaining adequate sealing performance at the discrete contact regions.
3Stability of the object's composition
If the contact surface area is large, then the structural stability is improved, but the fluid resistance increases causing response degradation
Solution Approach 1:
The contact surface is divided into multiple island portions through grooves, creating a segmented structure that maintains structural stability while reducing total contact area. This segmentation minimizes fluid resistance and improves response speed without compromising structural integrity.
4Force
If the contact surface area is large, then the load bearing capacity is improved, but the fluid resistance increases leading to injection characteristic fluctuations
Solution Approach 1:
The contact surface is segmented into multiple island portions by grooves, reducing the total contact area. This segmentation decreases fluid resistance and its temperature-dependent fluctuation, stabilizing injection characteristics while the distributed island portions collectively maintain adequate load bearing capacity.
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
The grooved design enhances the response of the fuel injection device by reducing fluid resistance, ensuring stable fuel injection characteristics even with temperature variations.
Implementation Method 1
the control member receives with fluid resistance at its surface of contact with any other member
Data Source
AI summary
A fuel injection device includes a cylinder that defines a pressure chamber at an end portion of a nozzle needle. A floating plate as a control member is placed in the cylinder. A cutout portion and multiple grooves are formed in the floating plate. The cutout portion and the grooves causes a gap between a large-diameter inner circumferential surface and an outer circumferential surface to communicate with the pressure chamber. The cutout portion and the grooves reduce a contact surface portion between the cylinder and the floating plate and divide the contact surface portion into multiple island portions. As a result, it is possible to reduce the contact surface portion.