Acceleration Device Projection for Foreign Object Discharge
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Solution Overview
Problem
Existing acceleration devices face issues with foreign objects entering the housing, leading to accumulation and potential negative influences on the shaft's rotation, as previous designs with projections on both the boss portion and housing inner wall fail to effectively discharge these objects, causing them to accumulate and hinder the device's performance.
Innovation Solution
The acceleration device incorporates a projection formed at only one of the boss portion's outer wall or the communication passage's inner wall, which disturbs the air flow and reduces the entry of foreign objects, allowing them to be easily discharged along the opposite wall, thereby reducing accumulation and maintaining the device's efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If projections are formed at both the boss portion outer wall and the communication passage inner wall to prevent foreign objects from entering, then foreign object entry is reduced, but foreign objects that have entered cannot be easily discharged and accumulate inside the housing
Solution Approach 1:
The communication passage is divided into two functional zones: an upstream section with projections that prevent foreign object entry, and a downstream section without projections that enables foreign object discharge. This segmentation allows each zone to perform its specific function optimally without interfering with the other.
Solution Approach 2:
Projections are selectively formed only in specific locations (at both the radially outer wall of the boss portion and the inner wall of the housing forming the communication passage) rather than uniformly throughout. This local quality approach prevents foreign objects at the entry point while maintaining discharge capability in other areas.
2Speed
If the gap between the boss portion outer wall and the housing inner wall is maintained to allow air flow, then air circulation is ensured, but foreign objects contained in the air can enter the housing
Solution Approach 1:
Projections act as intermediary elements positioned within the gap between the boss portion and housing. These projections disturb the air flow in a controlled manner, creating turbulence that causes foreign objects to separate from the air stream and be discharged outward, while still allowing air circulation to continue.
Solution Approach 2:
The projections create mechanical disturbance in the air flow passing through the gap. This disturbance generates turbulent flow patterns that effectively separate foreign objects from the air stream, causing them to be deposited or discharged rather than entering the housing interior.
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 effectively reduces the number of foreign objects entering the support portion by disturbing air flow and facilitates their easy discharge, minimizing accumulation and ensuring smooth operation of the acceleration device.
Implementation Method 1
the flow of the air is likely to be disturbed
Data Source
AI summary
An acceleration device includes: a support portion that has a communication passage, which communicates between a receiving space and an outside; a shaft that is rotatably supported by the support portion; a pedal boss portion that is located on a radially outer side of the shaft and is rotatable integrally with the shaft in the communication passage; a rotational angle sensor that is operable to sense a rotational angle of the shaft relative to the support portion; a pedal spring that urges rotation of the shaft in an accelerator closing direction; and a projection that is formed in a communication passage inner wall, which is an inner wall of the communication passage and is opposed to a boss portion outer wall of the pedal boss portion. The projection projects from the communication passage inner wall in a radially inward direction.