Injector Communication Hole Axis Alignment for Stress Reduction
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Solution Overview
Problem
Existing injectors for internal combustion engines face challenges in maintaining compressive strength at high injection pressures due to stress concentration at the intersections of connector, axial flow, and communication holes, leading to potential flow restrictions and reduced compression strength.
Innovation Solution
The injector design includes a communication hole axis aligned with the translated location of the connector hole axis, reducing the projection amount at the bent inner side area, thereby dispersing stress and increasing compressive strength by avoiding direct communication between the connector and axial flow passages, and setting the communication hole radius to prevent flow restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the connector hole and axial flow passage are directly communicated, then the fuel flow path is simplified, but a flow restriction may form and compression strength is reduced
Solution Approach 1:
The fuel flow path is segmented into three separate holes: connector hole, communication hole, and axial flow passage. This segmentation avoids the formation of acute projecting portions with small wall thickness that would occur in direct communication, thereby maintaining compression strength while still enabling fuel flow from the connector to the axial passage.
Solution Approach 2:
The communication hole acts as an intermediary element between the connector hole and the axial flow passage. By introducing this intermediate structure, the patent avoids direct communication that would create flow restrictions and weak points, while still achieving the necessary fuel flow path.
2Power
If injection pressure is increased to over 100 MPa, then fuel injection performance is improved, but stress concentration occurs at hole intersections
Solution Approach 1:
The patent applies local quality by making each hole (connector hole, communication hole, axial flow passage) have its own specific orientation and positioning rather than having them intersect. This local structural optimization eliminates stress concentration at intersection points, allowing the structure to withstand high injection pressures of over 100 MPa.
3Adaptability or versatility
If the axial flow passage is positioned at the radially outer side, then space for other devices is optimized, but stress concentration occurs in a narrow range
Solution Approach 1:
The patent resolves the space arrangement issue by utilizing three-dimensional spatial positioning of the holes. The connector hole, communication hole, and axial flow passage are arranged in different spatial dimensions and orientations, allowing the axial flow passage to be positioned at the radially outer side for optimal space utilization while avoiding stress concentration through proper angular separation.
Data Source
AI summary
A hole axis of a communication hole is placed at a location, which coincides with a translated location of a hole axis of a connector hole that is translated toward an axial distal end portion of a main body in an axial direction of the main body. In this way, with respect to a high pressure flow passage, which is bent by 90 degrees and extends through the connector hole, the communication hole and an axial flow passage, the amount of projection of a projecting portion at an inner side area of this bent, which is located on the inner side of the bent, is reduced.