Speaker Diaphragm Composite Structure for Vibration Space
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Solution Overview
Problem
Existing speaker diaphragms with composite structures of high modulus plastic substrates and silicone rubber face issues of poor sound quality due to low elastic modulus and increased weight, leading to reduced sensitivity and vibration space.
Innovation Solution
A speaker diaphragm comprising two surface layers and at least one intermediate layer, where one surface layer is a thermoplastic polyester elastomer film with a specific copolymer composition, providing a balance of stiffness, damping, and resilience, allowing for a thinner design with improved sensitivity and reduced weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If silicone rubber is used to improve waterproof and high sound quality requirements, then the diaphragm strength is improved, but the diaphragm weight increases and vibration space is reduced
Solution Approach 1:
The patent employs a composite structure consisting of a PEEK substrate layer and a TPU film layer. The PEEK substrate provides high strength and stiffness, while the TPU film layer contributes to waterproofing and sound quality. This composite material approach allows the diaphragm to achieve both strength and lightweight properties simultaneously, resolving the contradiction between diaphragm strength and vibration system weight.
2Strength
If the diaphragm is made thicker to ensure strength under same F0 requirements, then the diaphragm strength is improved, but the space allowance for vibration is reduced
Solution Approach 1:
The composite structure of PEEK substrate and TPU film enables the diaphragm to achieve high strength with reduced thickness. The PEEK substrate provides structural integrity while the thin TPU coating (few micrometers) adds functionality without significant thickness increase, thus maintaining vibration space allowance.
Solution Approach 2:
The TPU film layer is applied as a thin flexible coating on the PEEK substrate. This thin film structure provides the necessary strength and waterproofing properties without adding significant thickness, thereby preserving the vibration space allowance required for diaphragm movement.
3Strength
If the diaphragm is made thicker to ensure strength under same F0 requirements, then the diaphragm strength is improved, but the sensitivity is reduced
Solution Approach 1:
The PEEK-TPU composite structure achieves high strength with minimal thickness increase, keeping the vibration system mass low. Lower mass directly improves sensitivity as the lighter diaphragm can be accelerated more easily by the voice coil, resolving the contradiction between strength and sensitivity.
Solution Approach 2:
The thin TPU film layer provides sufficient strength and waterproofing without adding significant mass to the vibration system. The reduced mass enhances the diaphragm's responsiveness to electrical signals, thereby improving speaker sensitivity while maintaining structural integrity.
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 achieves excellent stiffness and damping performance, enabling a thinner diaphragm with enhanced vibration space and sensitivity, while maintaining high resilience and durability, thus improving sound quality and reducing the resonant frequency.
Implementation Method 1
an elastic recovery rate of the thermoplastic polyester elastomer film layer after 10% strain is greater than or equal to 80%
Implementation Method 2
an adhesive force between the adhesive layer and the thermoplastic polyester elastomer film layer is greater than 100 g/25 mm (180° peeling)
Implementation Method 3
a loss factor of the thermoplastic polyester elastomer is greater than or equal to 0.015
Data Source
AI summary
The present disclosure provides a speaker diaphragm and a speaker. The diaphragm includes two surface layers compounded together and at least one intermediate layer located between the two surface layers, wherein at least one of the surface layers is a thermoplastic polyester elastomer film layer, at least one of the intermediate layers is an adhesive layer, a thermoplastic polyester elastomer is a copolymer composed of a polyester hard segment A and a polyether or aliphatic polyester soft segment B, a thickness of the thermoplastic polyester elastomer film layer is 5-70 μm, and a thickness of the adhesive layer is 1-40 μm.