Automotive Bonnet Hinge Rigidity via Segmented Protrusions

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Solution Overview

Problem

Conventional bonnet structures for automotive vehicles lack sufficient hinge support rigidity, leading to improper deflection or vibration during traveling and inadequate absorption of impact energy in collisions, particularly at the rear portion of the bonnet.

Innovation Solution

The bonnet structure incorporates a central protrusion portion and a rear protrusion portion arranged side by side, with a deep-drawn groove between them extending in the vehicle width direction, and a hinge reinforcement extending from beside the rear protrusion portion to the central protrusion portion, passing through the deep-drawn groove, enhancing vertical-bending rigidity and preventing mouth-opening deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a conventional bonnet structure with a single central protrusion portion is used, then the structure is simple, but the hinge support rigidity is insufficient causing deflection and vibration

Engineering Contradiction:

Improvehinge support rigidityVSAvoidbonnet structure complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The single central protrusion portion is segmented into two separate protrusion portions (first and second) positioned at different locations on the bonnet inner panel. This segmentation allows each protrusion to independently support hinge loads, thereby increasing overall hinge support rigidity while maintaining a relatively simple structural approach

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The protrusion portions are arranged in the vehicle width direction (lateral dimension) rather than only in the longitudinal direction. This dimensional change creates a wider distribution of support points, enhancing rigidity in the vehicle width direction and preventing lateral deflection and vibration of the bonnet

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Stability of the object's composition

If hinge reinforcement is added to increase rigidity, then hinge support rigidity improves, but the structure becomes more complex and heavier

Engineering Contradiction:

Improvehinge support rigidityVSAvoidbonnet weight

Core Design Contradiction:

Stability of the object's compositionVSWeight of moving object

Solution Approach 1:

Instead of adding universal reinforcement across the entire bonnet structure, the invention provides localized reinforcement through protrusion portions positioned specifically at areas requiring hinge support. This localized approach increases rigidity where needed without adding unnecessary weight to other areas of the bonnet

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The hinge support function is merged with the existing bonnet inner panel structure by forming protrusion portions from the panel itself, rather than adding separate reinforcement components. This integration achieves rigidity enhancement while minimizing additional material and weight

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If the bonnet structure lacks sufficient rigidity, then manufacturing is easier, but deflection and vibration occur during traveling

Engineering Contradiction:

Improvebonnet flexibilityVSAvoiddeflection and vibration

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The protrusion portions are pre-formed during the bonnet manufacturing process as integral features of the inner panel, rather than being added as separate components. This preliminary formation ensures the rigidity-enhancing structure is built-in from the start, preventing deflection and vibration before they can occur during vehicle operation

Inventive Principle:

Principle #10Preliminary action

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 significantly increases the hinge support rigidity of the bonnet's rear portion, effectively preventing deflection and vibration caused by traveling vibrations and air pressure, while also improving impact energy absorption during collisions, ensuring the bonnet remains securely attached to the vehicle body.

Implementation Method 1

the above-described deep-drawn groove can be formed in a recess shape having a deep depth through plural-time pressing (press processing)

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS9868472B2Bonnet structure of automotive vehicle

Publication Date: 2018.01.16 MAZDA MOTOR CORP

AI summary

A bonnet inner panel includes a central protrusion portion protruding upward in a vehicle elevational view and a rear protrusion portion located in back of the central protrusion portion, which are arranged side by side in a vehicle longitudinal direction, a deep-drawn groove is provided between the both protrusion portions to extend in a vehicle width direction, and a hinge reinforcement is provided to extend from a position beside the rear protrusion portion to a position at a rear end of the central protrusion portion, passing through beside the deep-drawn groove. Thereby, the hinge support rigidity of the rear portion of the bonnet having the central protrusion portion can be increased, so that occurrence of any improper deflection or vibration caused to the bonnet by the traveling vibration, the traveling-air pressure or the like can be prevented.