Seat Rail Fastening Washer for Self-Locking Bolt Pre-Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fastening devices for rail elements in vehicle seats are typically pre-assembled and lack sufficient strength, leading to potential damage during assembly and inadequate connection security.
Innovation Solution
A fastening device with a retaining washer featuring lugs or internal threads that allow self-locking, enabling secure pre-fixation of bolts by frictional engagement, reducing the risk of damage to the bolt threads and enhancing connection strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional pre-assembled fastening device is used, then assembly is simplified, but connection strength is insufficient and damage occurs during assembly
Solution Approach 1:
The fastening device is divided into separate components (retaining washer, bolt, rail element) that are assembled in sequence. The retaining washer is first attached to the rail element, then the bolt is inserted and self-locked, finally the nut is tightened to achieve full connection strength.
Solution Approach 2:
The retaining washer with lugs is pre-assembled to the rail element before the bolt is inserted. This preliminary arrangement ensures proper positioning and enables self-locking, preventing damage during the subsequent bolting operation while maintaining ease of assembly.
2Ease of manufacture
If a conventional fastening device without self-locking is used, then manufacturing is simpler, but assembly security is inadequate and bolts may loosen
Solution Approach 1:
The bolt performs dual functions: it connects the rail element to the structural component and simultaneously self-locks into the retaining washer through friction engagement with the lugs. This self-locking action eliminates the need for additional locking mechanisms while ensuring assembly security.
Solution Approach 2:
The friction coefficient between the bolt and the lugs is optimized to achieve self-locking. The lugs are designed with specific dimensions and surface properties that create sufficient friction to prevent bolt loosening while allowing easy insertion and removal during assembly.
3Duration of action of stationary object
If the retaining washer has high strength, then durability is improved, but the bolt threads may be damaged during assembly
Solution Approach 1:
The retaining washer has non-uniform thickness with varying local properties: thicker sections provide overall strength and durability, while thinner sections near the lugs allow controlled deformation. This local quality variation enables the lugs to deform and smooth out during assembly, preventing bolt thread damage while maintaining washer durability.
Solution Approach 2:
The potential harm of the retaining washer's strength is converted into a benefit through controlled deformation. The lugs are designed to deform plastically during assembly, smoothing out irregularities and creating a friction fit that locks the bolt in place. This controlled deformation prevents damage to the bolt threads while ensuring secure connection.
4Reliability
If multiple lugs are added to the retaining washer, then self-locking capability is improved, but device complexity increases
Solution Approach 1:
The lugs are arranged asymmetrically around the central axis of the retaining washer, with different angular positions and orientations. This asymmetric arrangement optimizes the self-locking capability by creating favorable friction engagement angles while maintaining manufacturing simplicity through a single-piece construction.
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 provides a secure, variable, and strong connection between rail elements and vehicle structures, ensuring reliable assembly and improved stress distribution, thus enhancing the durability of the fastening system.
Implementation Method 1
the lugs engage with the external threads of the bolt and are pre-fixed and held by friction
Implementation Method 2
the excess of the lugs results in plastic deformation and a frictional connection between the locking washer and bolt when they are joined
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a fastening device (7) for a rail element (42) of a longitudinal adjustment device (4), comprising at least one securing washer (6, 60, 600, 6000, 60000) with a through-opening (61) and a bolt (8) with at least one external thread (81), wherein the bolt (8) is pre-fixed and held in the through-opening (61) by means of self-locking, and wherein the securing washer (6, 60, 600, 6000, 60000) has a first strength and the bolt (8) has a second strength.