Adapter Bushing for Sensor with Resilient Tongues and Fixed Points

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Solution Overview

Problem

Current clamping bushes for rod sensors in ABS brake systems face challenges in maintaining precise and uniform holding forces, leading to increased thermal and mechanical loads due to frictional heat, especially in commercial vehicles with disc brakes, which affects the accuracy and reliability of sensor operations.

Innovation Solution

The clamping bush design incorporates fixed points and lifting/guiding elements with a chamfer and insertion contour, allowing for precise force distribution and easier assembly, reducing the need for high clamping forces and minimizing frictional heat, thereby enhancing the uniformity and accuracy of holding forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high clamping forces are used to hold the sensor securely, then the holding force is sufficient to prevent sensor movement during operation, but the frictional heat increases the thermal load on the sensor

Engineering Contradiction:
Improveholding forceVSAvoidthermal load
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The clamping bushing features localized contact zones (protrusions and recesses) that concentrate the clamping force at specific points rather than distributing it uniformly. This allows sufficient holding force to be achieved with lower overall clamping pressure, thereby reducing frictional heat generation while maintaining sensor stability during operation.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If precise and uniform holding forces are maintained, then sensor operation accuracy is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveforce uniformityVSAvoidbushing structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The clamping bushing is segmented into multiple identical protrusion-recess pairs distributed around its circumference. Each pair generates a identical clamping force component, and the superposition of these symmetrically arranged forces results in uniform total holding force on the sensor, achieving precise force distribution through modular repetition rather than complex continuous structures.

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If simple assembly is enabled through frictional connection, then installation ease is improved, but the holding force may be insufficient to prevent sensor movement

Engineering Contradiction:
Improveassembly simplicityVSAvoidsensor stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The clamping bushing design enables self-adjustment during operation: the sensor automatically adjusts its position relative to the protrusions and recesses, and the resilient tongues deform to distribute clamping forces evenly. This self-service mechanism ensures both simple initial assembly and reliable ongoing stability without requiring external adjustment mechanisms.

Inventive Principle:
Principle #25Self-service

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 design reduces the overall thermal and mechanical loads on the sensor, allowing for precise and consistent force measurement, lower production costs, and improved assembly efficiency, while maintaining the required clamping force with minimal tolerance, thus enhancing the quality and process capability from production to customer delivery.

Implementation Method 1

The clamping bush, as in the above Printed illustrated, provided with resilient tongues. The tips of these tabs touch the inside wall of the rod sensor holder bore. The middle parts of the tongues, which are bent inwards, touch the rod sensor and press it onto opposite fixed points of the clamping bush

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

From the publication 'WABCO Anti-Blocking System', September 81 edition, it is known to mount the rod sensor by means of a clamping bush in a bore of a rod sensor holder with a defined frictional connection

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

During this automatic air gap adjustment while driving and while doing temporary contact of the magnet wheel with the sensor, z. B. when wheel bearing play occurs and elastic deformations in the axle, additional heat input into the sensor occurs due to frictional heat

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2257770B1Adapter bushing for a sensor
Publication Date: 2011.09.07 ZF CV SYST HANNOVER GMBH
  • EP2257770B1 patent drawingFigure 1~2
  • EP2257770B1 patent drawingFigure 3~4b
  • EP2257770B1 patent drawingFigure 4c~5

AI summary

The invention relates to an adapter bushing (6) for a sensor (1) for fixing and adjusting the sensor (1) in a non-positive manner in a bore of a retaining piece, wherein the adapter bushing (6) is provided with at least one resilient tongue (2) and at least one fixed point (10), wherein the at least one resilient tongue (2) is connected on one side to the adapter bushing (6) and is freely movable on the tip thereof, wherein at least one lift/guide element (15, 15') is disposed before at least one fixed point (10) and/or at least one resilient tongue (2).