Bottom Valve Intermediate Chamber for Quieter Telescopic Dampers

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Solution Overview

Problem

Existing telescopic dampers in motor vehicle chassis generate noise during the compression stage due to fluid flow between the working and compensation chambers.

Innovation Solution

A bottom valve with a valve body and a separating element that separates the working and compensation chambers, featuring throttle bores allowing fluid flow only in one direction, creating an intermediate space for gradual pressure reduction and noise reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If fluid flows directly from the working chamber to the compensation chamber through the bottom valve, then the structure is simple, but noise is generated during the compression stage

Engineering Contradiction:
ImprovenoiseVSAvoidvalve structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The bottom valve is segmented into multiple functional components: a valve body with throttle bores, a separating element, and an intermediate chamber. This segmentation allows the fluid flow path to be divided into stages (working chamber → intermediate chamber → compensation chamber), enabling noise reduction through gradual pressure reduction while maintaining a manageable structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediate chamber is introduced as a mediator between the working chamber and the compensation chamber. This intermediate space allows fluid to be gradually decelerated and pressurized reduced in stages, thereby minimizing noise generation during the compression process without requiring direct high-velocity flow between the main chambers

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If throttle bores are designed to allow fluid flow from working chamber to compensation chamber, then pressure control is improved, but flow resistance increases

Engineering Contradiction:
Improvepressure controlVSAvoidflow resistance
Core Design Contradiction:
Stress or pressureVSLoss of energy

Solution Approach 1:

Different regions of the bottom valve are assigned different local qualities: the throttle bores in the valve body provide localized flow resistance for pressure control, while the intermediate chamber provides a larger volume space for gradual pressure equalization. This local differentiation allows effective pressure control without excessive overall flow resistance

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The valve system dynamically adapts to different operating conditions. During compression, the throttle bores provide controlled resistance to build pressure in the intermediate chamber. During rebound, the separating element moves to allow faster fluid exchange. This dynamic behavior optimizes both pressure control and energy efficiency across different damper cycles

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If a separating element is added to create an intermediate space, then noise reduction is achieved, but device complexity increases

Engineering Contradiction:
ImprovenoiseVSAvoidvalve components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The separating element is merged with the valve body to form an integrated bottom valve assembly. The separating element serves multiple functions: it creates the intermediate chamber volume, it acts as a flow control boundary, and it integrates with the valve body structure. This merging reduces the number of separate components while achieving noise reduction through the intermediate space

Inventive Principle:
Principle #5Merging (Combining)

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 design achieves a stepped pressure reduction, reducing noise in the compression stage by throttling fluid flow from the working chamber to the compensation chamber, thereby minimizing noise.

Implementation Method 1

at least one throttle bore is formed in the valve body, via which only one fluid flow in the direction of the second side can be achieved, whereas an opposite fluid flow via the at least one throttle bore in the direction of the first side is prevented

Methodology Applied
Scientific EffectThrottling: Pressure Drop

Implementation Method 2

a separating element is provided which, together with the valve body, delimits an intermediate space

Methodology Applied
Scientific EffectFluid accumulation: Hydraulic Accumulator

Data Source

PatentEP4589167A1Bottom valve for a telescopic damper and telescopic damper
Publication Date: 2025.07.23 ZF FRIEDRICHSHAFEN AG
  • EP4589167A1 patent drawingFigure 1
  • EP4589167A1 patent drawingFigure 2
  • EP4589167A1 patent drawingFigure 3

AI summary

The invention relates to a base valve (2) comprising a valve body (7) having a first side (8) and a second side (9), wherein the valve body (7) is designed, when the base valve (2) is installed in a telescopic damper (1), to separate a working chamber (6) of the telescopic damper (1), located on the first side (8), from a part (5) of a compensation chamber (4) of the telescopic damper (1), located on the second side (9). At least one throttle bore (11) is formed in the valve body (7), via which only one fluid flow can be achieved from the first side (8) of the valve body (7) in the direction of the second side (9), whereas an opposite fluid flow via the at least one throttle bore (11) is prevented.In addition, a separating element (19) is provided which, together with the valve body (7), delimits at least one intermediate space (20), wherein the at least one intermediate space (20) is delimited at least at one opening of the at least one throttle bore (11) facing the second side (9) of the valve body (7) and is delimited by a compensation region (21) in which, when the base valve (2) is installed in the telescopic damper (1), the part (5) of the compensation chamber (4) is provided. Fluid can be exchanged between the at least one intermediate space (20) and the compensation region (21) via at least one transition.