Hood Lock Additional Spring for Sensor Position Accuracy

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Solution Overview

Problem

Motor vehicle hood locks face challenges in reliably determining the closed position due to the hood's weight interfering with sensors, leading to incorrect position detection when the adjusting spring malfunctions.

Innovation Solution

An additional torsion spring is introduced to take over the function of the adjusting spring, ensuring the hood is raised if it fails, preventing the sensor from incorrectly indicating a closed position, and thus ensuring accurate position detection by the sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the hood's weight acts on the sensor, then the sensor can detect the closed position, but the position detection becomes incorrect when the adjusting spring malfunctions

Engineering Contradiction:
Improveposition detection accuracyVSAvoidsensor reading reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces a counterweight mechanism that compensates for the hood's weight effect on the sensor. When the adjusting spring fails, the counterweight system automatically adjusts to balance the hood's weight, preventing the sensor from receiving incorrect position signals. This ensures the sensor accurately reflects the actual hood position regardless of spring malfunction.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent employs an intermediary mechanism between the hood and the sensor that isolates the sensor from direct weight influence. This intermediary system includes additional springs and mechanical linkages that mediate the force transmission, ensuring the sensor only detects actual position changes rather than weight-induced position variations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If only a single adjusting spring is used, then the device complexity is reduced, but the reliability of hood position control decreases when the spring fails

Engineering Contradiction:
Improvespring system complexityVSAvoidhood position control reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a redundant spring system where additional springs are pre-installed to take over if the primary adjusting spring fails. This beforehand cushioning approach ensures that when the main spring malfunctions, the backup springs immediately compensate, maintaining reliable hood position control without requiring complex real-time monitoring systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent modifies the spring system parameters by adding auxiliary springs with specific force characteristics that complement the main adjusting spring. These additional springs are calibrated to engage only when the primary spring fails, changing the overall force-parameter profile of the system to maintain reliability while minimizing complexity.

Inventive Principle:
Principle #35Parameter changes

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

This solution reliably distinguishes between the open and closed states of the hood, preventing accidents by ensuring the driver is informed of an improperly closed hood and preventing false signals to the control unit.

Implementation Method 1

an additional spring is provided in addition to the adjusting spring, which raises the hood if the adjusting spring fails

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3580414B1Motor vehicle door lock, more particularly hood lock
Publication Date: 2023.04.05 KIEKERT AG
  • EP3580414B1 patent drawingFigure 1
  • EP3580414B1 patent drawingFigure 2

AI summary

The subject matter of the present invention is a motor vehicle door lock, more particularly a hood lock. The basic structure of the hood lock is composed of a raising mechanism (3, 4, 5), for a locking bolt (2) or another stop part, on a hood (1). An actuating spring (9) acting on the raising mechanism (3, 4, 5) is also provided, in addition to a sensor (6) for sensing the position of the hood (1). According to the invention, an additional spring (10) is provided which raises the hood (1) if the actuating spring (9) breaks down and/or malfunctions.