Automotive Hood Locking Device with Dynamic Auxiliary Safety Latch
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Solution Overview
Problem
Existing hood locking devices for automotive vehicles can damage delicate components or the lock itself when excessive force is applied during closure, and they fail to absorb the impact in pedestrian collision scenarios due to interference with the hood's downward movement.
Innovation Solution
A locking device with an auxiliary safety latch and catch, actuated by a spring, that absorbs the closing impulse by interrupting the latch's rotation and automatically disengages to allow free rotation in case of a collision, using interlocking means and a ramp or projection to manage the rotational movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If fixed stop elements are used to interrupt latch rotation during hood closing, then the closing impulse is absorbed and components are protected, but the latch rotation is prevented in both closing and opening directions, causing pedestrian protection to fail
Solution Approach 1:
The patent applies the dynamics principle by making the stop means movable rather than fixed. The stop means is configured to be movable between a first position where it interrupts latch rotation to absorb closing impulse, and a second position where it allows free latch rotation for pedestrian protection. This dynamic repositioning resolves the contradiction between protecting components during closing and enabling pedestrian safety during collisions.
Solution Approach 2:
The patent segments the stop means into distinct functional positions (first position for impulse absorption, second position for pedestrian protection) that can be selectively engaged. This segmentation allows the same stop means to serve different protective functions at different times, resolving the contradiction between component protection and pedestrian safety.
2Reliability
If the latch is firmly retained by the catch during closing, then the hood is securely locked, but the latch cannot rotate freely to absorb impact in pedestrian collision scenarios
Solution Approach 1:
The patent applies dynamics by enabling the stop means to dynamically reposition based on operational conditions. During normal closing, the stop means is in the first position to ensure firm locking (reliability). During pedestrian collision, the stop means moves to the second position to allow free rotation and absorb impact force, thus resolving the contradiction between locking reliability and impact absorption.
Solution Approach 2:
The patent changes the positional parameter of the stop means between two states: engaged (first position) for reliable locking during closing, and disengaged (second position) for impact absorption during pedestrian collision. This parameter change resolves the contradiction between maintaining firm retention and allowing impact absorption.
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
Effectively absorbs the closing impulse without damaging vehicle components and allows the hood to move downward in pedestrian collisions, preventing damage and ensuring safe operation.
Implementation Method 1
an auxiliary safety catch, stressed by an auxiliary actuating spring according to a first rotation direction
Implementation Method 2
the interlocking means are capable of cooperating mechanically with the stop means provided in the auxiliary safety latch to interrupt the rotation of the latch
Implementation Method 3
the means for transmitting a rotational movement to the auxiliary safety catch comprise a ramp, arranged in the auxiliary safety latch, suitable for shifting or impelling, in a boosting instant, a corresponding support surface provided for such purpose in the auxiliary safety catch
Data Source
AI summary
The invention relates to a locking device (1) for an automotive vehicle hood, comprising a rotating latch (2), actuatable by the locking anchor (3) of a hood during the closing operation thereof, an auxiliary safety latch (4) rotating together with the latch, and a corresponding auxiliary safety catch (5) provided with interlocking means (7) intended to cooperate mechanically with complementary stop means (8) provided in the auxiliary safety latch to interrupt the rotation of the latch; and subsequently automatically move the interlocking means (7) away from the path of the auxiliary safety latch (4), consequently allowing the free rotation of the latch if, after the closing of the hood, it is actuated again by the locking anchor, for example when the latter shifts in the closing direction as a consequence of a crash or of running over a pedestrian.