Vehicle Door Energy Dissipation Structure

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Solution Overview

Problem

Existing motor vehicle side impact protection systems are inadequate in dissipating lateral collision energy, leading to reduced occupant safety and increased risk of injury due to insufficient deformation paths and energy absorption capacity.

Innovation Solution

A connection structure comprising a rotatably articulated first part integrated within the motor vehicle door and a rod-shaped or tubular second part connected to the vehicle body, which can pivot and extend to form a stable, horizontally oriented connection for efficient energy dissipation during a side impact, utilizing Shape Memory Alloy (SMA) elements for rapid activation and reversible operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the motor vehicle door is stiffened by providing longitudinal members with high rigidity, then the energy absorption capacity in the transverse direction is improved, but the dead weight of the motor vehicle increases

Engineering Contradiction:
Improveenergy absorption capacityVSAvoiddead weight
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent employs composite material structures in the connection structure, combining different materials to achieve high strength-to-weight ratio. The longitudinal members and cross members utilize composite construction to provide necessary rigidity and energy absorption capacity while minimizing weight increase compared to traditional solid metal structures.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The connection structure is designed with movable, articulated joints that allow dynamic response to collision forces. The structure transitions from a compact state during normal operation to an extended, energy-absorbing configuration during side impacts, optimizing protection while maintaining weight efficiency.

Inventive Principle:
Principle #15Dynamics

2Strength

If the connection structure is extended to improve energy dissipation, then the energy absorption capacity is improved, but the installation space required increases

Engineering Contradiction:
Improveenergy dissipation capacityVSAvoidinstallation space
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The connection structure features nested, telescopic longitudinal members that can be stored compactly within the door assembly during normal operation. During a side impact, these members extend outward to engage with the vehicle body, providing extended energy dissipation paths without permanently occupying additional installation space.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The articulated connection structure dynamically extends its energy dissipation path during collisions. The movable joints and telescopic elements allow the structure to lengthen and reconfigure under load, maximizing energy absorption capacity only when needed, while maintaining a compact form factor during normal vehicle operation.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a stable connection between door and vehicle body is created, then the occupant protection is improved, but the complexity of the device increases

Engineering Contradiction:
Improveoccupant protectionVSAvoidconnection structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connection structure is divided into modular segments including longitudinal members, cross members, and articulated joints. Each segment performs a specific function and can be independently manufactured, assembled, and maintained. This segmentation provides reliable occupant protection through coordinated action of multiple simple components rather than a single complex mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection structure is pre-configured with articulated joints and telescopic elements positioned to automatically engage and form stable connections during side impacts. Sensors and actuators are pre-installed to trigger the deployment sequence, eliminating the need for complex real-time decision-making mechanisms during the collision event.

Inventive Principle:
Principle #10Preliminary action

4Volume of moving object

If the connection structure is made retractable to minimize space, then the installation space is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveinstallation spaceVSAvoidretraction mechanism precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The telescopic longitudinal members are designed with nested sections that slide into one another during retraction. This mechanical nesting provides self-aligning features and tolerance compensation, reducing the need for extremely tight manufacturing tolerances while achieving compact storage dimensions.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The connection structure utilizes controlled parameter changes in material properties and geometric configurations to facilitate smooth retraction and extension. Shape memory alloys or superelastic materials are employed in certain components to provide automatic return forces and tolerance absorption, reducing dependency on high-precision mechanical tolerances for the retraction function.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively diverts crash energy away from the door, reducing occupant compartment intrusion and B-pillar load, enhancing safety and reliability while minimizing space and weight, and allowing for cost-effective production.

Implementation Method 1

utilizing Shape Memory Alloy (SMA) elements for rapid activation and reversible operation

Methodology Applied
Scientific EffectShape Memory Alloy: Shape Memory Alloy

Data Source

PatentEP2064079B1Device for a motor vehicle for protecting vehicle occupants when there is an application of energy directed at a motor vehicle door due to a collision
Publication Date: 2011.09.07 FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
  • EP2064079B1 patent drawingFigure 1a~1b

AI summary

The invention relates to a device for a motor vehicle for protecting vehicle occupants when there is an application of energy directed laterally at a motor vehicle door due to a collision, having a connecting structure which has at least two parts. The invention is defined by the fact that the first part (1) is coupled in a rotatably fixed fashion to a pivot bearing within the motor vehicle door (2) and can be moved reversibly from a vertical position into a horizontal position through application of force, in that the second part (3) is embodied in the form of a rod or tube and has a first end which is permanently connected to the motor vehicle bodywork, in that the second part has a second end which lies opposite the first end and can be moved reversibly from a first position into a second position through horizontal linear movement and through application of force, and in that the first part in the horizontal position and the second part in the second position can be operatively connected by means of a common joint region, in that the application of energy which acts on the motor vehicle door can be conducted away from the pivot bearing via the first and second parts to the first end, which is permanently connected to the motor vehicle bodywork, of the second part, along a linearly and horizontally oriented force flux.