Intake Manifold Inlet Indentations for NVH Reduction
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Solution Overview
Problem
Existing intake manifold designs face challenges in reducing noise, vibration, and harshness (NVH) while minimizing weight, cost, and complexity, as measures to enhance stiffness can exacerbate noise generated by flow past the throttle.
Innovation Solution
The intake manifold incorporates radially inward indentations at specific inflection points in the inlet passage and a plurality of ribs on the exterior surface, maintaining wall thickness without increasing weight or complexity, and synergistically works with throttle flow noise reduction methods like vanes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If braces are integrally formed with the intake manifold cover to enhance structure and reduce NVH, then NVH is reduced, but weight, cost, and complexity increase
Solution Approach 1:
The patent applies local quality by creating indentations only at specific inflection points in the inlet passage where NVH is generated, rather than uniformly strengthening the entire manifold. This localized approach reduces NVH at critical locations while avoiding unnecessary material addition elsewhere, thus not increasing overall weight or complexity.
Solution Approach 2:
Instead of adding structural elements (braces) to reduce NVH, the patent inverts the approach by removing material through indentations at inflection points. This inversion achieves NVH reduction through a different mechanism - modifying the flow path geometry rather than adding structural reinforcement - thereby avoiding the weight and complexity penalties of integral braces.
2Strength
If wall thickness is increased to maintain pressure and sealing, then pressure resistance and sealing are improved, but weight and complexity increase
Solution Approach 1:
The patent maintains wall thickness at critical locations (inflection points) where pressure and sealing are most important, while allowing the indentation to reduce material elsewhere. This localized quality approach ensures pressure resistance and sealing are maintained where needed without uniformly increasing weight throughout the entire manifold.
3Object-affected harmful factors
If stiffness is increased to reduce NVH, then NVH is reduced, but noise from flow past the throttle increases
Solution Approach 1:
The patent applies local quality by targeting the specific inflection points in the inlet passage where NVH is generated, rather than uniformly increasing stiffness throughout the manifold. This localized modification reduces NVH at critical locations while avoiding the global stiffness increase that would exacerbate throttle flow noise.
Data Source
AI summary
Various systems for reducing noise, vibration, and harshness in an intake manifold are provided. In one example, an intake manifold includes one or more runners, a plenum fluidically coupled to the one or more runners, an inlet having a wall thickness, and a first and a second indentation, where the first indentation protrudes radially inward at a first inflection point in a first direction, the second indentation protrudes radially inward at a second inflection point in a second direction substantially anti-parallel to the first direction, and the wall thickness is maintained at the first and second inflection points. In this way, noise, vibration, and harshness associated with the intake manifold and its inlet may be reduced without additional weight, cost, or complexity.