Orthogonal Gas Generator Actuator for Compact Vehicle Hood Lifting

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Solution Overview

Problem

Conventional actuators for vehicle safety systems, such as hood lifting devices, are typically long due to the sequential arrangement of gas generators and piston rods, which limits their compactness and mounting flexibility.

Innovation Solution

The actuator design incorporates a gas generator that overlaps with the piston section orthogonally, allowing for a shorter length while maintaining a large pressure-receiving area, and includes a sealing mechanism to ensure gas sealing property and steady output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the gas generator and piston rod are arranged in series along the axial center, then the actuator structure is simple and easy to manufacture, but the length of the actuator becomes long

Engineering Contradiction:
Improvestructural simplicityVSAvoidactuator length
Core Design Contradiction:
Ease of manufactureVSLength of moving object

Solution Approach 1:

The patent transitions from a one-dimensional axial arrangement to a two-dimensional overlapping arrangement. The gas generator is positioned to overlap with the piston rod in a direction orthogonal to the axial center, effectively utilizing radial space to reduce the overall length of the actuator while maintaining the series functional arrangement for manufacturing simplicity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Length of moving object

If the gas generator overlaps with the piston section orthogonally, then the actuator length is shortened, but the sealing complexity increases

Engineering Contradiction:
Improveactuator lengthVSAvoidsealing mechanism complexity
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The sealing mechanism is nested within the overlapping region of the gas generator and piston rod. The sealing member is integrated into the structural interface where the two components overlap, allowing the sealing function to be incorporated without adding external sealing components or increasing overall device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Adaptability or versatility

If the actuator is made compact for limited mounting space, then the mounting flexibility is improved, but the working stroke may be reduced

Engineering Contradiction:
Improvemounting flexibilityVSAvoidworking stroke
Core Design Contradiction:
Adaptability or versatilityVSDuration of action of moving object

Solution Approach 1:

The overlapping arrangement in the radial direction enables the actuator to achieve a compact axial length suitable for limited mounting spaces while preserving the full working stroke along the axial direction. The dimensional reconfiguration allows the piston rod to travel its required distance without increasing the overall footprint of the actuator.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 results in a compact, efficient actuator that can achieve a long working stroke with high output force, suitable for limited spaces around vehicle hood hinges, ensuring effective pedestrian protection in impact scenarios.

Implementation Method 1

a gas generator (70) that generates an actuating gas (G) when actuated

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2891583B1Actuator
Publication Date: 2018.02.14 TOYODA GOSEI CO LTD
  • EP2891583B1 patent drawingFigure 1
  • EP2891583B1 patent drawingFigure 2
  • EP2891583B1 patent drawingFigure 3

AI summary

An actuator (21) includes a gas generator (70) that generates an actuating gas when actuated, a housing section (22) that houses and holds the gas generator and a pressing section (52) that is deployable with an actuating gas in such a fashion as to move forward relative to the housing section and be separated from the housing section. The pressing section and the housing section are slidable against each other. Either one out of sliding portions (22a; 52a) of the pressing section and housing section serves as an inner section (22a) that is located closer to a moving central axis (C) of the pressing section than the other whereas the other out of the sliding portions of the pressing section and housing section serves as an outer section (52a) that surrounds the inner section (22a). The gas generator (70) is located closer to the moving central axis (C) than the sliding portion (52a) of the pressing section and partially overlaps with a part (52b) of the pressing section (52) in an inactive state.