Vehicle Body Lower Structure Mud Guard Shielding Backflow Air
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Solution Overview
Problem
The existing vehicle body lower structures fail to effectively prevent backflow air from the rear end of a vehicle from flowing outside at the shortest distance through the rear wheel arch, leading to airflow discrepancies.
Innovation Solution
A vehicle body lower structure featuring a mud guard with a plate-shaped shielding portion extending from the inner side of the rear wheel housing towards the front, positioned below and above the tail pipe's height, to divert backflow air and prevent it from exiting at the shortest distance, combined with a recess in the rear bumper face to house the tail pipe outlet and a plate-shaped underneath flow straightening portion for improved airflow management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional mud guard structure is used, then the structure is simple, but backflow air flows outside the vehicle at the shortest distance through the rear wheel arch
Solution Approach 1:
The mud guard is divided into multiple functional portions: a main body portion covering the rear wheel housing, a plate-shaped shielding portion extending toward the front to block backflow air, and an underneath flow straightening portion. Each portion performs a specific airflow control function, allowing the complex airflow management task to be achieved through segmented, specialized components rather than a single complex structure.
Solution Approach 2:
The shielding portion extends in the vehicle front-rear direction (longitudinal dimension) rather than only covering the wheel area laterally. This additional dimensional extension creates a three-dimensional airflow barrier that blocks backflow air from taking the shortest path through the rear wheel arch, effectively adding a new spatial dimension to the airflow control strategy.
2Reliability
If the shielding portion extends above the tail pipe, then backflow air is effectively blocked, but the mud guard structure becomes more complex
Solution Approach 1:
The shielding portion is configured with specific local characteristics: it extends only in certain areas (toward the front from the rear edge), has specific height requirements (extending above the tail pipe portion), and is positioned at specific locations (inner side of rear edge toward front). This localized, differentiated configuration provides effective backflow blocking only where needed, rather than using a uniformly complex structure throughout.
3Manufacturing precision
If a simple mud guard is used, then manufacturing is easy, but airflow does not conform to analysis due to backflow components
Solution Approach 1:
The mud guard is segmented into distinct portions (main body, shielding portion, flow straightening portion) that can be manufactured separately and then assembled. This segmentation allows each portion to be optimized for its specific function while maintaining manufacturing feasibility, achieving complex airflow control without requiring a single monolithic complex component.
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 configuration effectively prevents backflow air from exiting the vehicle at the shortest distance, enhancing airflow conformity within the rear wheel housing and improving the structural rigidity of the mud guard.
Implementation Method 1
the shielding portion makes it possible to prevent a situation where a backflow component of air from the rear end of the vehicle body flows outside the vehicle from the rear wheel housing at the shortest distance
Implementation Method 2
air flow flowing from the inside of the rear wheel arch toward a lateral surface of a vehicle body) due to a vehicle body lateral flow flowing along the vehicle body lateral surface at a relatively high flow rate
Data Source
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AI summary
It is intended to provide a vehicle body lower structure capable of preventing a backflow component from flowing outside the vehicle from a rear wheel housing at the shortest distance. The vehicle body lower structure of a vehicle comprising a rear wheel housing 12, and a mud guard 71 integrally attached to an inner surface of a rear portion of the rear wheel housing 12, wherein the mud guard 71 has a plate-shaped shielding portion 71b extending from a vehicle width directional inner side of a rear edge of the rear wheel housing 12 toward a front side of the vehicle, and wherein the shielding portion 71b has an up-down directional length extending from a bottom portion of the mud guard 71 to a position above at least a tail pipe 33 whose outlet portion 33a is oriented toward a rear surface of a vehicle body adjacent thereto.