Motor Vehicle Bonnet Lock Pre-Ratchet Mechanism
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Solution Overview
Problem
Current motor vehicle bonnet locks require multiple actions on the release element to open, posing safety risks as the bonnet can swing open uncontrollably, obstructing the driver's view and potentially causing accidents.
Innovation Solution
A motor vehicle door lock design that transitions to a pre-ratchet position after a single actuation of the release element, ensuring the bonnet is secured, allowing it to be opened by moving it in the longitudinal direction, thus preventing unintentional opening and enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the release element is actuated once to open the locking mechanism, then the locking bolt is released and the bonnet can be opened, but the bonnet may swing open uncontrollably and obstruct the driver's view
Solution Approach 1:
The locking mechanism is segmented into two distinct states: a first ratchet position (fully locked) and a second ratchet position (pre-ratchet/partially locked). The pawl can engage with different ratchets on the rotary latch, creating intermediate secure states. This segmentation allows the system to transition from a fully locked state to a pre-ratchet state without complete unlocking, preventing uncontrolled bonnet opening while maintaining safety.
Solution Approach 2:
The system performs a preliminary unlocking action that transitions the locking mechanism to a pre-ratchet position rather than fully opening it. The pawl is lifted from the first ratchet and engages with a second ratchet, creating an intermediate secured state. This preliminary action prepares the system for opening while maintaining safety, requiring a additional deliberate action (moving the bonnet in longitudinal direction) to fully open.
2Ease of operation
If the release element is actuated twice to open both latches, then the bonnet can be opened from inside the vehicle, but the operator can still drive off with the vehicle and the bonnet may swing open uncontrollably
Solution Approach 1:
The locking mechanism is segmented into two distinct states: a first ratchet position (fully locked) and a second ratchet position (pre-ratchet/partially locked). The pawl can engage with different ratchets on the rotary latch, creating intermediate secure states. This segmentation allows the system to transition from a fully locked state to a pre-ratchet state without complete unlocking, preventing uncontrolled bonnet opening while maintaining safety.
Solution Approach 2:
A sensor detects the position of the pawl and the engaged ratchet, providing feedback about the locking mechanism's state. When the pawl engages with the second ratchet in the pre-ratchet position, the sensor generates a signal that can be used to prevent vehicle driving or alert the driver, adding a safety feedback layer that complements the mechanical segmentation.
Data Source
AI summary
A motor vehicle bonnet lock includes a locking mechanism which substantially consists of a rotary latch and a pawl. The locking mechanism interacts with a striker element on a bonnet. The lock further has an unlocking/opening mechanism for the bonnet, which mechanism is equipped with a release element provided in the interior of a motor vehicle body. It is required to operate the release element preferably twice to open the bonnet. The locking mechanism is transferred to a pre-latched position after the release element has been operated at least once, with the striker element still being trapped. The bonnet is opened from said pre-latched position by a movement in its longitudinal direction.