Vehicle Drive Cable Denticulation Noise Reduction
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Solution Overview
Problem
Existing drive cables for actuating vehicle members, such as retractable roof lids, face issues with noise behavior due to denticulation sliding and lack of flexibility in the transverse direction, leading to rattling and high wear, especially when using gradient cables with flock coatings.
Innovation Solution
A drive cable with a polymer cable body featuring a denticulation design where the tips of teeth are set back within a guide tube, and continuous armouring reinforcement beneath the teeth roots, reducing contact and friction, and utilizing armouring harnesses for enhanced flexibility and stiffness to maintain correct orientation with the driving toothed wheel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the denticulation is made to engage with the guide face, then the drive cable achieves sufficient tensile strength and stability, but the denticulation slides at the guide face causing rattling and noise
Solution Approach 1:
The patent extracts the harmful sliding contact function from the denticulation by setting the tooth tips back from the peripheral face, so that only the root region engages with the guide face. This separates the load-bearing function from the guiding function, eliminating the sliding rattling while maintaining tensile strength through the root engagement.
Solution Approach 2:
The patent applies local quality by creating different engagement characteristics at different parts of the denticulation: the root region (between tooth tips) engages with the guide face for stability and strength, while the tooth tips are set back to avoid sliding contact and noise. This localized differentiation resolves the contradiction between strength and noise.
2Object-generated harmful factors
If the denticulation is set back from the peripheral face to reduce noise, then contact with guide members is minimized, but the flexibility in the transverse direction may be compromised
Solution Approach 1:
The patent uses a flexible plastic cable body that can deform in the transverse direction. The set-back denticulation design allows the cable body to flex and adapt to guide tube contours while the root engagement maintains positional accuracy. The flexible plastic material enables the cable to conform to curved paths without compromising the engaged root region's ability to define position.
3Reliability
If gradient cables with flock coating are used, then the periphery is provided with coating, but the non-homogeneous periphery prevents proper guiding in guide tubes without generating noise
Solution Approach 1:
The patent removes the flock coating from the cable periphery and instead provides a homogeneous plastic surface. The denticulation is set back so that the root region engages with the guide face, eliminating the need for flock coating to prevent skipping. This creates a uniform guiding surface that eliminates noise while maintaining reliable engagement through the root contact.
Data Source
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AI summary
The invention relates to a drive cable for actuating a vehicle member being movable as against a vehicle structure, comprising a cable body (26) which is made of plastics, and which includes an denticulation (28) extending in the axial direction for engaging with a driving toothed wheel (24) and through which an armouring extending in the axial direction reaches. The denticulation (28) is formed by pocket-like recesses (34) which are spaced apart in the axial direction at regular intervals, and which are limited, in the longitudinal direction of the cable, by flanks of resulting tips of teeth (36) formed by the cable body (26) and in the transverse direction of the cable, on each of their two sides, by a pocket flank (38) and which are in each instance limited by a root of a tooth (40) on the bottom side, the armouring reaching through said cable body (26) beneath said recesses (34) and said tips of teeth (36), the armouring defining an armouring plane (A) which extends in the transverse direction of the cable and in the longitudinal direction of the cable, and in which at least two continuous armouring harnesses (30A, 30B, 30C) extending in the axial direction are arranged side by side and/or in which at least one armouring harness (30) having a flat cross-section is arranged.