Outboard Motor Intake Manifold Sensor Mounting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional intake manifolds for outboard motors face challenges in securing mechanical strength and preventing assembling errors when assembling sensor units to the outer wall of the surge tank.
Innovation Solution
The intake manifold features a surge tank with a die-molded flange part and reinforcement rib, where the sensor unit is installed. The flange part is rotationally symmetric with a fitting hole and boss parts, and the reinforcement rib includes a limitation piece to prevent incorrect assembly of the sensor unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a boss part and flange part are die-molded together with a reinforcement rib to secure mechanical strength, then the mechanical strength is improved, but a sink mark may occur due to local shrinkage during cooling after molding
Solution Approach 1:
The flange part is separated into two distinct components: a boss part (protruding structure) and a flange part (flat mounting surface). This segmentation allows the boss part to provide structural strength while the flange part provides a stable mounting surface for the sensor unit, preventing sink marks and dimensional inaccuracies that would occur if all features were molded as a single integrated structure.
Solution Approach 2:
Different regions of the flange part are designed with different properties: the boss part has increased thickness and structural reinforcement for mechanical strength, while the flange part maintains a thinner, more uniform thickness for precise sensor mounting. This local differentiation of structural properties allows each region to optimize its function without compromising the other.
2Ease of manufacture
If the flange part is designed with rotational symmetry to simplify manufacturing, then the ease of manufacture is improved, but an assembling error may occur where the sensor unit is assembled at an incorrect position rotated by 180 degrees
Solution Approach 1:
While the overall flange part maintains rotational symmetry for manufacturing simplicity, asymmetric features are introduced: the limitation piece protrudes from only one side of the flange part, and the sensor unit has asymmetric mounting holes or features. This asymmetric design within a symmetric framework provides visual and physical guidance for correct assembly orientation, preventing 180-degree rotation errors while preserving manufacturing efficiency.
Solution Approach 2:
The limitation piece is designed to physically block or interfere with incorrect assembly orientations before the sensor unit can be fully installed. This preliminary anti-action prevents assembling errors from occurring in the first place, rather than requiring post-assembly detection or correction, thereby ensuring assembly accuracy without complicating the manufacturing process.
3Strength
If multiple fixing parts are provided on the outer edge parts of the surge tank to secure the sensor unit, then the mechanical strength is improved, but the device complexity increases
Solution Approach 1:
The flange part integrates multiple functions into a single component: it provides structural reinforcement, serves as a mounting surface for the sensor unit, and incorporates the limitation piece for orientation guidance. This merging of functions into one integrated flange part eliminates the need for separate fixing parts, brackets, or additional structural elements, thereby reducing device complexity while maintaining mechanical strength.
Solution Approach 2:
The flange part is designed as a multi-functional component that simultaneously provides structural support, sensor mounting, and assembly guidance features. This universal design approach allows a single part to fulfill multiple roles that would otherwise require separate components, simplifying the overall device structure while ensuring mechanical strength and assembly accuracy.
Data Source
AI summary
An intake manifold includes: a surge tank, die-molded to temporarily store intake air; and branch pipes, in communication with the surge tank. The surge tank includes, on an outer wall thereof, a flange part and a reinforcement rib, a sensor unit configured to detect an intake air state quantity being installed to the a part. The flange part includes: a fitting hole, having an axis as a center to be fit with a detection part of the sensor unit; and boss parts, provided on a periphery of the fitting hole, and the flange part is formed to be rotationally symmetric with the axis as a center. The reinforcement rib includes a limitation piece interfering with a portion of the sensor unit to limit assembling at a time when the sensor unit is assembled erroneously for being deviated from a normal orientation.