Chassis Shock Absorber Guide Element Leaf Spring Mounting

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Solution Overview

Problem

Existing guide elements for tension buffer springs in chassis dampers cause undesirable noise due to play on the piston rod, which increases friction when reduced, and previous solutions like elastomer rings enhance friction further.

Innovation Solution

A leaf spring element is used to press the guide element against the piston rod without play, providing a low-friction, backlash-free mounting that prevents noise by compressing radially to absorb impacts in all directions, allowing for a compact and space-efficient design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If play is provided on the piston rod, then friction is reduced, but noise is generated due to hitting the piston rod

Engineering Contradiction:
ImprovefrictionVSAvoidnoise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by introducing a damping element that proactively absorbs impacts between the guide element and piston rod before they occur during operation. This prevents the harmful hitting noise while maintaining the play gap, resolving the contradiction between reducing friction and preventing noise.

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

Solution Approach 2:

The damping element serves as an intermediary between the guide element and piston rod, mediating the interaction by absorbing impact energy. This intermediary component allows the play gap to exist for low friction while preventing direct contact that causes noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-generated harmful factors

If play is reduced on the piston rod, then noise is reduced, but friction increases

Engineering Contradiction:
ImprovenoiseVSAvoidfriction
Core Design Contradiction:
Object-generated harmful factorsVSForce

Solution Approach 1:

The patent segments the interaction system into three distinct components: the guide element, the damping element, and the piston rod. This segmentation allows the play gap to be maintained between the guide element and piston rod for low friction, while the damping element independently handles the noise prevention function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

By introducing the damping element as an intermediary, the system maintains the play gap necessary for low friction operation while the damping element actively prevents noise through energy absorption, thus resolving the contradiction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If an elastomer ring is used to reduce hitting noise, then noise is reduced, but friction significantly increases

Engineering Contradiction:
ImprovenoiseVSAvoidfriction
Core Design Contradiction:
Object-generated harmful factorsVSForce

Solution Approach 1:

The patent applies local quality by positioning the damping element specifically in the impact zone where noise occurs, rather than using a circumferential elastomer ring that contacts the piston rod over a large area. This localized approach prevents noise while minimizing friction impact.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The damping element changes the interaction parameters by introducing controlled energy dissipation through damping, rather than relying on high-friction elastomeric contact. This allows noise reduction through energy absorption rather than through friction-based contact.

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

The solution significantly reduces noise generation during lateral acceleration by ensuring the guide element does not hit the piston rod, maintaining low friction and allowing for easy assembly without preloading the spring elements.

Implementation Method 1

a spring element, which is basically known for this purpose, is a leaf spring. Such a leaf spring element presses the guide element against the piston rod

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the guide element is prevented from hitting the piston rod or is at least dampened or cushioned by the spring element

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the guide element is prevented from hitting the piston rod or is at least dampened or cushioned by the spring element, so that the generation of noise is significantly reduced

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP3155290B1Guide element for a buffer spring in a chassis shock absorber and chassis shock absorber
Publication Date: 2018.08.29 BAYERISCHE MOTOREN WERKE AG
  • EP3155290B1 patent drawingFigure 1~2
  • EP3155290B1 patent drawingFigure 3~5

AI summary

In a guide element (28) for a buffer spring (20) in a chassis shock absorber (20) which is slidably mounted on a piston rod (14) of the chassis shock absorber (10), with a guide (32) that has a cylindrical receiving space (36) for the piston rod (14) and a receptacle (34) for an end (26) of the buffer spring (20), there is provided on the guide (32) at least one spring element (42) which extends into the receiving space (36) and can be resiliently seated against the piston rod (14).