Damper Throttle Channel Design for Consistent Damping

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Solution Overview

Problem

Existing dampers for vehicles, such as twin-tube dampers, face issues with inconsistent damping behavior due to manufacturing tolerances and potential valve malfunctions, leading to unexpected high damping effects or blocking, and require complex designs with multiple components.

Innovation Solution

A damper design incorporating a throttle channel that connects the working and compensation chambers, allowing fluid to flow through in both push-in and pull-out directions, with the throttle channel's length influencing the damping effect, reducing reliance on manufacturing accuracy and eliminating the need for an annular gap between the piston rod and guide.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an annular gap between the piston rod and guide is used as a flow passage, then the damper can be produced with standard manufacturing tolerances, but the damping effect varies significantly with even small dimensional variations

Engineering Contradiction:
Improvemanufacturing toleranceVSAvoiddamping behavior consistency
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the critical parameter from annular gap dimensions (sensitive to manufacturing tolerances) to throttle channel dimensions (less sensitive). The throttle channel's cross-sectional area and length are designed to provide the desired damping effect while being less critical to precise manufacturing, thus resolving the contradiction between ease of manufacture and reliability.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If a valve is arranged in the piston rod guide to control oil flow, then directional damping control is achieved, but valve malfunction can cause blocking or unexpected high damping effects

Engineering Contradiction:
Improvedirectional damping controlVSAvoiddamper functionality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The invention extracts the valve component from the system and replaces it with a passive throttle channel. The throttle channel provides directional damping control through its geometry alone, eliminating the reliability issues associated with active valve components that can malfunction or block.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The throttle channel is designed as a simple, robust geometric feature that is less prone to failure than complex valve mechanisms. While the valve may fail, the throttle channel provides fail-safe operation, accepting some performance degradation rather than complete failure.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Force

If the piston rod guide is hermetically sealed by the valve during pull-out, then high damping effect is achieved, but any valve malfunction prevents oil flow and blocks the damper

Engineering Contradiction:
Improvedamping effectVSAvoidflow passage reliability
Core Design Contradiction:
ForceVSReliability

Solution Approach 1:

The throttle channel provides a reliable, fail-safe flow passage that cannot completely block the damper. Even if partially restricted, it maintains some flow capability, ensuring the damper never becomes completely non-functional while still providing adequate damping force.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Adaptability or versatility

If the damping effect is adjusted by changing annular gap size, then damping behavior can be modified, but this requires precise control of manufacturing tolerances increasing production cost

Engineering Contradiction:
Improvedamping effect adjustmentVSAvoidproduction cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The invention changes the adjustable parameter from annular gap size (requiring tight tolerances) to throttle channel cross-sectional area and length (tolerance-insensitive). This allows damping effect adjustment through standard manufacturing processes without requiring expensive precision machining.

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 damper achieves consistent damping behavior with directional control, avoiding blocking and manufacturing tolerance issues, while being compact, robust, and cost-effective, with the damping effect primarily determined by the throttle channel's length, allowing for easy adjustment and reduced component count.

Implementation Method 1

The throttle channel has a cross-sectional area oriented perpendicularly to a fluid flow direction with a clear width and a length and enables a throttled fluid connection between the working chamber and the compensation chamber. A throttling effect or a damping effect of the damper can take place in particular by varying the length of the throttle channel.

Methodology Applied
Scientific EffectThrottling effect: Pressure Drop

Implementation Method 2

When pulling out, the piston rod guide is hermetically sealed by the valve.

Methodology Applied
Scientific EffectHydraulic sealing:

Implementation Method 3

A valve arranged in the piston rod guide is known from public prior use, which valve opens when the piston rod is pushed in and allows the oil flow through the piston rod guide without resistance.

Methodology Applied
Scientific EffectValve opening: Valve

Implementation Method 4

It is also known from public prior use to use an annular gap present between the piston rod and the piston rod guide as a flow passage for the pressure fluid.

Methodology Applied
Scientific EffectAnnular gap flow:

Data Source

PatentEP2559911B1Amortisseur
Publication Date: 2019.03.13 SUSPA
  • EP2559911B1 patent drawingFigure 1~2
  • EP2559911B1 patent drawingFigure 3~4
  • EP2559911B1 patent drawingFigure 5~6

AI summary

The damper has an outer housing (3) provided on a guiding and sealing element (5) that closes a housing-end (19). A piston (13) is fastened at a piston rod (6) and guided in an inner housing (2) along a central-longitudinal axis (12), and a flow-through channel connects partial-operating chambers (15, 16) together. A compensating chamber (26) is arranged between the housings, and a throttle channel is arranged between an operating chamber and the compensating chamber. The throttle channel is integrated in the element, and includes a cross section surface with length and a clearance.