Sensor Attachment Structure for Vehicle Bumper Vibration Resistance

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Solution Overview

Problem

Sensors attached to resin components in vehicles are prone to detachment due to vibration, as the resin is fragile and cannot withstand the fastening torque applied by screws.

Innovation Solution

A sensor attachment structure that locks the sensor case to the panel body without using screws, incorporating a fall-preventing mechanism to secure the sensor case in place, even if the locking region fails or is damaged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If screws are used to fix the sensor case to the resin panel body, then the sensor case can be firmly attached, but the resin is prone to loosening and detachment due to vibration because the loosening torque is smaller than the fastening torque

Engineering Contradiction:

Improveattachment strengthVSAvoidresistance to vibration

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The attachment structure is divided into multiple independent locking regions (first locking region with first protrusion and first recess, second locking region with second protrusion and second recess) distributed at different positions on the sensor case and panel body. This segmentation distributes the attachment force across multiple points, preventing any single point from failing under vibration stress.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The locking protrusions and recesses are pre-formed integral structures on the sensor case and panel body respectively, created during the molding process. This preliminary formation ensures precise positioning and eliminates the need for separate fastening operations, creating a robust attachment that resists vibration from the outset.

Inventive Principle:

Principle #10Preliminary action

2Strength

If screws are used for fixation, then the sensor case can be securely attached, but the resin component is fragile and cannot withstand the fastening torque

Engineering Contradiction:

Improveattachment strengthVSAvoidfastening torque

Core Design Contradiction:

StrengthVSForce

Solution Approach 1:

The invention extracts and eliminates the screws and fastening mechanisms from the attachment system. Instead, it uses integral locking protrusions and recesses that are molded directly into the sensor case and panel body, completely removing the need for separate fastening components and the associated high fastening torque that would damage the resin.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The locking structures (protrusions and recesses) are merged with the sensor case and panel body as integral parts, formed simultaneously during the molding process. This merging creates a unified structure where the attachment function is inherent to the components themselves, eliminating the need for separate fastening elements.

Inventive Principle:

Principle #5Merging (Combining)

3Device complexity

If a simple locking mechanism is used, then the device complexity is reduced, but the attachment may fail if the locking region breaks or malfunctions

Engineering Contradiction:

Improveattachment structure complexityVSAvoidattachment reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

Different regions of the sensor case are assigned different attachment functions: the first locking region (with first protrusion and first recess) provides primary attachment, while the second locking region (with second protrusion and second recess) provides secondary attachment. This local differentiation ensures that if one region fails, the other maintains attachment reliability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The dual locking region design acts as a backup system where the second locking region serves as a reserve attachment point. If the first locking region breaks or malfunctions, the second locking region prevents complete detachment, providing beforehand cushioning against attachment failure.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Data Source

PatentUS11180101B2Sensor attachment structure and energy absorption structure

Publication Date: 2021.11.23 HONDA MOTOR CO LTD

AI summary

A sensor attachment structure includes an energy absorption member, a sensor attachment portion provided to the energy absorption member and configured to attach a sensor case that houses a pressure sensor, and a cover that defines a space to house the sensor case between the cover and the sensor attachment portion. The sensor case is attached to the sensor attachment portion by locking. At least one of the sensor case, the sensor attachment portion, and the cover includes a fall preventing structure that prevents the sensor case from falling off an opening formed by the sensor attachment portion and the cover.