Rotary Latch Safety Device for Motor Vehicle Hood
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Solution Overview
Problem
Existing pedestrian protection devices for motor vehicles face challenges in quickly raising the front hood to a protective position during collisions, leading to potential safety hazards due to time delays and after-vibrations, which can endanger individuals.
Innovation Solution
A safety device featuring a lock holder, pawl, and rotary latch with a blocking element and spring mechanisms that allow for immediate engagement and deceleration of the front hood, eliminating the need for an actuator and reducing the time delay to zero seconds, thereby enhancing safety by providing a protective layer upon impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the hood is raised quickly to a protective position using an actuator, then the protective function is improved, but time delay and after-vibrations occur which compromise safety
Solution Approach 1:
The locking mechanism serves itself by automatically engaging the blocking element when the rotary latch is quickly rotated closing-directionward. The spring-loaded blocking element is pre-positioned and automatically activates without external control, allowing the mechanism to protect itself during rapid movement
Solution Approach 2:
The blocking element is pre-positioned in a spring-loaded state ready to engage the rotary latch. This preliminary positioning ensures that when the rotary latch is quickly rotated, the blocking element is already in place to immediately engage and prevent after-vibrations, eliminating the need for sequential control steps
2Reliability
If a blocking element is added to prevent after-vibrations, then safety is improved, but device complexity increases
Solution Approach 1:
The blocking element is merged with the existing locking mechanism components. The blocking element, rotary latch, and pawl work together as an integrated system where the blocking element is spring-loaded and automatically engages with the rotary latch, combining multiple functions into a unified mechanism rather than adding separate independent components
Solution Approach 2:
The spring-loaded blocking element is self-activating and requires no external control system. When the rotary latch is quickly rotated closing-directionward, the blocking element automatically engages, making the system self-regulating and eliminating the need for additional control mechanisms or sensors
3Ease of operation
If the pawl is deflected opening-directionward to release the rotary latch, then the opening function is improved, but the blocking element may engage prematurely
Solution Approach 1:
The system dynamically adapts based on the direction and speed of rotary latch movement. When opened slowly by deflecting the pawl, the blocking element remains disengaged. When the rotary latch is quickly rotated closing-directionward, the blocking element automatically engages. This dynamic behavior ensures both easy opening and reliable protection
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 safety device ensures rapid engagement and deceleration of the front hood, reducing the risk of injury by eliminating time delays and preventing swinging back, thus enhancing the safety of individuals in the event of a collision.
Implementation Method 1
A safety device featuring a lock holder, pawl, and rotary latch with a blocking element and spring mechanisms that allow for immediate engagement and deceleration of the front hood
Implementation Method 2
one embodiment incorporates an elastic element in an elongated hole, which is compressed by a pin and is intended to dissipate energy
Data Source
Figure 1a~1f
Figure 2a~2f
Figure 3~4
AI summary
The invention relates to a safety device (1; 101; 201) for a motor vehicle, which has a striker (2; 102; 202), a pawl (3; 103; 203), a rotary latch (4; 104; 204) having an opening direction of rotation (7; 107; 207), a closing direction of rotation (8; 108; 208), and a main locking position, and preferably a front hood (66), wherein the safety device (1; 101; 201) has a blocking element (61; 161; 261), which has a blockage position and a release position, and the rotary latch (4; 104; 204) is blocked in the closing direction of rotation (8; 108; 208) in the blockage position of the blocking element (61; 161; 261), wherein the rotary latch (4; 104; 204) is released in the closing direction of rotation (8; 108; 208) by the blocking element (61; 161; 261) in the release position of the blocking element (61; 161; 261) and lowering of the striker (2; 102; 202) is enabled in the main locking position of the rotary latch (4; 104; 204) and movement of the blocking element (61; 161; 261) from the release position to the blockage position is controlled by means of the pawl (3; 103; 203).