Motor Vehicle Hood Latching Device Gap Minimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor vehicle hood latching systems leave a significant gap between the hood and the chassis, leading to air turbulence, increased air resistance, and potential injuries from sudden closure, which existing technologies have not adequately addressed.
Innovation Solution
A latching device with a locking mechanism comprising a catch and pawl, utilizing a retention lever and swing arm to minimize the hood gap by detecting movement and applying force-limited movement to reduce the gap to a safe level, protected by sensors and impact absorbers to prevent damage and injury.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hood is closed using a conventional latching device, then the hood can be secured in the closed position, but a significant gap remains between the hood and the chassis
Solution Approach 1:
The latching device incorporates a movable catch that can be actuated by a drive mechanism (electric motor, muscle motor, or elastic element) to dynamically adjust the hood gap after initial closure. The catch moves from a first position to a second position, actively minimizing the gap between hood and chassis rather than relying on fixed mechanical alignment.
Solution Approach 2:
The patent replaces purely mechanical gap adjustment with driven actuation systems. The drive mechanism (electric motor 19, muscle motor 21, or elastic element 23) substitutes for traditional mechanical linkages, enabling precise control of the catch position and hood gap minimization through powered movement rather than mechanical leverage alone.
2Loss of energy
If the hood closes quickly to minimize gap, then air resistance is reduced, but the risk of finger injury increases
Solution Approach 1:
The latching device performs preliminary actions in a specific sequence: first the hood is closed to a preliminary position where the catch engages the pawl, then the drive actuates the catch to minimize the gap. This staged approach allows the system to prepare the closure path before final engagement, reducing the risk of sudden pinching forces on fingers.
Solution Approach 2:
The patent incorporates cushioning elements (element 31) and controlled deceleration mechanisms that prepare for potential impacts before they occur. The drive system can be programmed to reduce speed near the closed position, and mechanical cushioning elements are positioned to absorb residual closure forces, protecting against finger injuries before the hood fully closes.
3Length of moving object
If a drive mechanism is added to minimize the hood gap, then the gap is reduced, but the device complexity increases
Solution Approach 1:
The catch serves multiple functions: it acts as both the latching element that secures the hood and the movable component that minimizes the gap when actuated by the drive. The pawl provides both the locking function and the stop for the catch's movement range. This multi-functionality reduces the need for separate dedicated components for each function.
Solution Approach 2:
The drive mechanism is integrated with the existing latching components rather than being a completely separate system. The electric motor 19, muscle motor 21, or elastic element 23 is coupled directly to the catch, merging the gap-minimization function with the latching mechanism. The control unit 28 also manages both the drive actuation and the latching sequence, consolidating control functions.
4Object-affected harmful factors
If the latching device is made more robust to prevent injury, then safety improves, but the ease of operation decreases
Solution Approach 1:
The latching device can be opened by simply lifting the hood, which automatically triggers the opening sequence through the catch and pawl mechanism. The drive system self-activates to move the catch out of engagement with the pawl, and the hood's own weight and movement provide the opening force, eliminating the need for separate manual activation mechanisms.
Solution Approach 2:
The control unit 28 receives feedback from sensors (such as microswitch 32 detecting catch position) to automatically control the drive mechanism. The system monitors the hood's position and the catch's engagement state, automatically initiating the opening or closing sequence based on detected conditions, making the operation intuitive and safe without requiring the user to understand the complex mechanisms.
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 solution effectively reduces the hood gap from 15 mm to less than 1 mm, minimizing air resistance, preventing finger injuries, and protecting the latching device from damage, while ensuring safe and reliable closure and opening mechanisms.
Implementation Method 1
The retention lever (11) forms an impact absorber in order to reduce impact forces
Implementation Method 2
the hood or the catch is moved together with the hood by a drive or using a drive, in such a way that a hood gap between the hood and the chassis of the motor vehicle is reduced
Data Source
AI summary
The problem addressed by the invention is to devise a method for closing a motor vehicle hood which makes it possible to minimize a gap between the hood and the vehicle body. This should in particular make it possible to keep the risk of injuries low. In order to solve said problem, the hood is closed as follows by means of a hood closing device comprising a locking bolt (35) and a locking mechanism consisting of a rotary latch (1) and a pawl (7): the open hood is moved in the direction of the closed position; this movement of the hood causes the locking bolt (35) to pivot the rotary latch (1) about its pin (4) in the direction of the latched position until the rotary latch (1) hits a breakthrough preventing contraption, in particular a catching lever (11), whereupon the hood or the rotary latch along with the hood is moved using a drive unit (19), in particular an electric drive unit, in such a way that the gap between the hood and the motor vehicle body is reduced; following this movement caused by the drive unit, the rotary latch (1) is locked by the pawl (7).