Dual Actuated Vehicle Hood Latch Mechanism
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Solution Overview
Problem
Current dual pull hood latches require higher static latching effort and closing energy due to travel and force requirements, making them less efficient compared to traditional latches, and often necessitate manual intervention to engage or disengage the secondary latching member.
Innovation Solution
A dual actuated hood latch mechanism with a housing, latch member, and cancel lever system that reduces static latching effort and closing energy, allowing for remote operation and improved engagement/disengagement of the secondary latching member without manual intervention, utilizing a cam surface and biasing members to pivot the latch member and fork bolt between latched and actuated positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dual pull latches are used to provide redundant safety latching, then safety is improved, but static latching effort and closing energy increase
Solution Approach 1:
The latch mechanism is divided into two independent latching members (primary and secondary) that operate separately. Each latching member has its own catch portion and can engage the striker independently, allowing the system to provide redundant safety while reducing the force required from each individual latching member compared to a single-latch design.
Solution Approach 2:
The latch mechanism uses spring-loaded biasing members that automatically engage and disengage the latching members based on the position and movement of the hood panel. This dynamic operation eliminates the need for manual intervention to engage the secondary latch and reduces the static force required to maintain the latched position.
2Reliability
If dual pull latches are used to provide redundant safety latching, then safety is improved, but closing energy increases
Solution Approach 1:
The biasing members are pre-loaded to automatically engage the latching members as the hood panel approaches the closed position. This preliminary action ensures that both primary and secondary latches engage without requiring additional closing force from the user, thereby reducing overall closing energy while maintaining redundant safety.
Solution Approach 2:
The latch mechanism is designed to automatically engage and disengage the secondary latching member without requiring manual intervention. The spring-loaded biasing members provide the necessary force to engage the latches during closing and disengage them during opening, making the system self-sufficient and reducing the energy input required from the user.
3Use of energy by moving object
If traditional hood latches are used, then closing energy is reduced, but manual intervention is required to engage the secondary latching member
Solution Approach 1:
The latch mechanism automatically engages the secondary latching member through spring-loaded biasing members that activate when the hood panel is closed. This self-service operation eliminates the need for the motorist to manually reach into the restricted space at the front edge of the hood, improving ease of operation while maintaining redundant safety.
Solution Approach 2:
The latch mechanism uses dynamic spring-loaded components that automatically respond to the movement of the hood panel. As the hood closes, the biasing members are compressed and automatically engage the latching members, providing hands-free operation and eliminating the need for manual intervention to engage the secondary latch.
4Reliability
If dual pull latches are used, then redundant safety latching is achieved, but device complexity increases
Solution Approach 1:
The primary and secondary latching members are integrated into a single housing structure, sharing common components such as the striker channel, biasing members, and pivot points. This merging of functions into a unified structure provides redundant safety latching while minimizing the increase in overall device complexity compared to having completely separate latch systems.
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
The mechanism reduces the static latching effort and closing energy required, enabling easier operation of the hood latch while maintaining safety through redundant latching, allowing the hood to be opened or closed with less force and without manual insertion into a restricted space.
Implementation Method 1
The latch cam surface is configured such that a force applied along the A-axis onto the latch cam surface, when the latch member is in the second position, causes the latch member to pivot to the first position
Implementation Method 2
a first biasing member operating bi-directionally and applying a force to selectively preload the latch member to selectively rotate in opposing directions
Implementation Method 3
the exterior cam surface is configured such that a force applied along the A-axis onto the exterior cam surface, when the latch member is in the second position, induces a moment M onto the second lever arm causing the latch member to rotate into the first position
Data Source
AI summary
A vehicle hood latching mechanism, having a latch member pivotally connected to a housing defining a striker channel. The latch member includes a primary catch portion between the intersection of a first lever arm and a second lever arm, a secondary catch portion on the first lever arm facing the primary catch portion, and a latch cam surface on the second lever arm proximal to the primary catch portion. The latch cam surface is configured such that a force applied onto the latch cam surface causes the latch member to pivot to a first position. A cancel lever is pivotally mounted to an end of the second lever arm of the latch member and includes an exterior cam surface configured such that a force applied onto the exterior cam surface induces a moment M onto the second lever arm causing the latch member to rotate into the first position.