Ported Speaker Assembly Tolerance Absorption

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Solution Overview

Problem

The manufacture of speaker assemblies, particularly those with large low-frequency drivers and tuned-frequency resonator chambers, faces challenges in part tolerancing and assembly complexity, leading to larger enclosures and increased difficulty in mating subassemblies.

Innovation Solution

A ported speaker assembly design featuring an outer enclosure with a front opening and an inner frame that forms a resonator chamber, where a perimeter port allows sound wave communication and a plurality of fastener joints absorb assembly tolerance, ensuring the overall dimensions are determined by the outer enclosure alone, allowing for easier assembly and reduced size constraints.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional speaker assembly designs are used with multiple subassemblies, then the speaker can achieve required audio performance, but the assembly complexity and difficulty in mating subassemblies increases

Engineering Contradiction:
Improveaudio performanceVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the inner frame and outer enclosure into a single integrated assembly where the inner frame is positioned within the outer enclosure to form a unified structure. This integration eliminates the complexity of mating multiple subassemblies while maintaining the required audio performance through the combined resonator chamber and ported enclosure design.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If tuned-frequency resonator chamber is incorporated, then audio performance is improved, but the overall enclosure size increases

Engineering Contradiction:
Improveaudio performanceVSAvoidenclosure size
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent implements nesting by positioning the inner frame within the outer enclosure, where the inner frame forms the resonator chamber and the outer enclosure provides the external housing. This nested configuration allows the resonator chamber to be integrated within the existing enclosure volume rather than requiring a separate larger chamber, thus maintaining audio performance while minimizing overall enclosure size.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If precise tolerancing is required across multiple fastening locations, then assembly precision is improved, but manufacturing cost and complexity increases

Engineering Contradiction:
Improveassembly precisionVSAvoidmanufacturing cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by modifying the tolerance requirements from strict precise tolerancing to relaxed tolerances that can be absorbed by the fastener joints. The fastener joints are designed with sufficient clearance and adjustment capability to accommodate dimensional variations, allowing manufacturing within standard tolerance ranges while still achieving proper assembly and audio performance.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If more fastener joints are distributed around multiple sides, then assembly tolerance is absorbed better, but the number of parts and assembly steps increases

Engineering Contradiction:
Improvetolerance absorptionVSAvoidnumber of fastener joints
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the fastening system into multiple distributed fastener joints positioned around different sides of the inner frame. This segmentation allows each fastener joint to independently absorb local assembly tolerances and misalignments, providing cumulative tolerance compensation across multiple locations while maintaining a relatively simple fastening mechanism at each individual joint.

Inventive Principle:
Principle #1Segmentation

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 simplifies the assembly process and reduces size requirements by absorbing assembly tolerances through fastener joints, maintaining performance regardless of inner frame placement, thus minimizing the need for precise tolerances and optimizing space efficiency.

Implementation Method 1

A perimeter port is formed between the outer perimeter portion of the inner frame and the front opening of the outer enclosure to establish sound wave communication between the resonator chamber and a surrounding external atmosphere for tuned-frequency resonance output

Methodology Applied
Scientific EffectSound wave communication: Sound

Implementation Method 2

to establish sound wave communication between the resonator chamber and a surrounding external atmosphere for tuned-frequency resonance output

Methodology Applied
Scientific EffectTuned-frequency resonance: Resonance

Implementation Method 3

The plurality of fastener joints are configured to absorb all assembly tolerance between the outer enclosure and the inner frame such that the tolerances on the overall dimensions of the speaker assembly are determined by the outer enclosure alone

Methodology Applied
Scientific EffectTolerance absorption: Mechanical Fastener

Data Source

PatentEP4027655B1Ported speaker assembly
Publication Date: 2024.11.27 ROBERT BOSCH GMBH
  • EP4027655B1 patent drawingFigure 1~2
  • EP4027655B1 patent drawingFigure 3
  • EP4027655B1 patent drawingFigure 4~5

AI summary

A ported speaker assembly includes an outer enclosure having a front opening. An inner frame of the speaker assembly is positioned at least partially within the outer enclosure and has an outer perimeter edge proximate the front opening of the outer enclosure. A resonator chamber is defined between an interior of the outer enclosure and an exterior of the inner frame. At least one speaker driver is mounted to the inner frame and configured to emit sound from a front end of the ported speaker assembly. A perimeter port is formed between the outer perimeter portion of the inner frame and the front opening of the outer enclosure. The perimeter port extends uninterrupted to encircle the outer perimeter portion. A plurality of fastener joints secure the inner frame to the outer enclosure, and at least some are distributed around multiple sides of the inner frame and positioned closer to the front opening of the outer enclosure than a rear end of the inner frame.