Thermoplastic Coating for Vehicle Door Lock Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor vehicle door locks with elastomeric coatings between the rotary latch and locking bolt experience rapid wear and provide temporary noise reduction, failing to maintain effective noise insulation over long periods and during relative movements.
Innovation Solution
A thermoplastic coating, specifically polyacetals like polyoxymethylene, is used between the rotary latch and locking bolt, combined with a thermoplastic polyester elastomer casing, to enhance noise insulation and durability, suppressing rattling noises through precise injection molding and design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If elastomeric coating is used between locking bolt and rotary latch, then noise reduction is achieved, but the coating wears out quickly and noise insulation deteriorates over time
Solution Approach 1:
The patent changes the material parameters by transitioning from elastomeric plastic to thermoplastic material for the coating. This parameter change fundamentally alters the wear characteristics while maintaining noise reduction capabilities, resolving the contradiction between initial noise performance and long-term durability.
Solution Approach 2:
The patent employs a composite structure combining thermoplastic coating material with the metallic rotary latch and locking bolt components. This composite approach integrates the noise-dampening properties of thermoplastics with the structural integrity of metal parts, achieving both noise reduction and enhanced wear resistance.
2Object-affected harmful factors
If elastomeric plastic coating is applied to locking bolt, then noise insulation is provided temporarily, but relative movements cause deterioration of noise behavior
Solution Approach 1:
The patent changes the material parameters by using thermoplastic instead of elastomeric plastic, which fundamentally alters the friction and wear characteristics. This parameter change ensures stable noise insulation performance throughout the service life, preventing deterioration caused by relative movements between components.
3Reliability
If thermoplastic coating is used instead of elastomeric coating, then wear resistance and noise insulation stability are improved, but processing complexity may increase
Solution Approach 1:
The patent replaces the traditional mechanical assembly approach with injection molding technology for applying the thermoplastic coating. This substitution eliminates complex mechanical fastening systems and enables automated, high-precision coating application, actually simplifying the manufacturing process while improving wear resistance.
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 thermoplastic coating and casing combination provides permanent noise insulation and wear protection, ensuring optimized noise behavior and preventing mechanical impacts in the door lock mechanism, with improved aging resistance and strength compared to elastomeric materials.
Implementation Method 1
the forces occurring at this point are not absorbed by the metallic areas of the rotary latch, but by the known elastomeric coating
Implementation Method 2
thermoplastics are characterized by the fact that they soften when heat is applied and can be shaped in almost any way
Implementation Method 3
the thermoplastics in question, in particular polyacetals, are characterized by favorable sliding and wear behavior
Implementation Method 4
With the help of the coating made of thermoplastic material, a relative movement between the rotary latch and the locking bolt or lock holder as a whole is practically suppressed
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a door lock for a motor vehicle, said lock comprising a locking mechanism (1, 2) essentially consisting of a rotary catch (1) and a stop pawl (4). The insertion opening (4) of the rotary catch (1) has a noise-attenuating coating (9) at least in the region of a surface (8) brought into contact with a locking bolt (3) of a lock holder.