Vehicle Speaker Cooling via Bobbin Air Course

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Solution Overview

Problem

Existing vehicle-mounted acoustic apparatuses face issues with weather resistance, deterioration in acoustic characteristics controllability, and heat dissipation due to closed spaces and temperature changes, which affect the stability and performance of the speaker.

Innovation Solution

The acoustic apparatus features an air chamber between the diaphragm and the rear cover member, allowing air exchange with the outside space through a route passing through the bobbin, which stabilizes pressure changes and facilitates heat dissipation by positioning the voice coil outside the air chamber, ensuring efficient cooling and improved weather resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a closed space is provided between the rear face of the speaker and the rear cover member, then the speaker is protected from rainwater and dust, but the neutral position of the voice coil becomes unstable due to temperature-induced volume changes

Engineering Contradiction:
Improveprotection from rainwater and dustVSAvoidstability of voice coil neutral position
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent segments the air chamber into two functional zones: a sealed portion containing the speaker to protect it from elements, and a communication portion that allows air exchange with the interior space. This segmentation enables the air chamber to simultaneously provide environmental protection and pressure equalization, resolving the contradiction between protection and stability.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If a closed space is provided between the rear face of the speaker and the rear cover member, then the speaker is protected from rainwater and dust, but heat generated by the voice coil accumulates and cannot be discharged

Engineering Contradiction:
Improveprotection from rainwater and dustVSAvoidheat discharge capability
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The air chamber is segmented into a sealed portion for protection and a communication portion for heat dissipation. The communication portion creates an air flow path that allows heat generated by the voice coil to be discharged to the interior space while maintaining environmental protection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes pneumatic principles by creating an air communication path between the air chamber and interior space. This allows air flow to occur naturally due to pressure differences, enabling heat dissipation through convection without requiring active cooling mechanisms.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Object-affected harmful factors

If the air chamber is a closed space, then the speaker is protected from environmental factors, but pressure changes hinder the vibration of the diaphragm

Engineering Contradiction:
Improveprotection from environmental factorsVSAvoiddiaphragm vibration
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The air chamber is divided into a sealed portion that provides environmental protection and a communication portion that equalizes pressure. This segmentation allows the diaphragm to vibrate freely while the speaker remains protected from environmental factors.

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 configuration enhances weather resistance, maintains stable acoustic characteristics, and effectively discharges heat generated by the voice coil, preventing damage and ensuring consistent performance.

Implementation Method 1

an air course between the air chamber and the in-cabin space follows a route passing through a space on an inner side of the bobbin

Methodology Applied
Scientific EffectAir flow: Convection

Implementation Method 2

when an electric current is supplied to the voice coil so as to cause the bobbin to undergo a reciprocal motion for vibrating the diaphragm, the vibration of the diaphragm generates a sound pressure in the closed space

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3340651B1Vehicle-mounted acoustic apparatus with cooling arrangement
Publication Date: 2020.10.14 ALPINE ELECTRONICS INC
  • EP3340651B1 patent drawingFigure 1
  • EP3340651B1 patent drawingFigure 2
  • EP3340651B1 patent drawingFigure 3A~3B

AI summary

A vehicle-mounted acoustic apparatus includes a frame including an annular portion and a supporting portion and attachable to an opening of a partition plate between an in-cabin space and an off-cabin space, a diaphragm vibratorily supported by the annular portion, a magnetic circuit supported by the supporting portion and having a magnetic gap, a cylindrical bobbin provided on the diaphragm with one end thereof projecting from one side of the diaphragm, a voice coil wound around the bobbin and positioned in the magnetic gap, and a rear cover member defining an air chamber provided between the rear cover member and the diaphragm. The rear cover member is vibratorily supported and allows back pressure to be conducted to the off-cabin space. An air course between the air chamber and the in-cabin space follows a route passing through a space on an inner side of the bobbin.