Speaker Diaphragm with Local Circularity for Reliable Bobbin Joining
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Solution Overview
Problem
Speakers with diaphragms longer in the major axis than in the minor axis face issues of unbalanced stress and deformation at the hole and outer peripheral end during manufacturing, making it difficult to reliably join the diaphragm and bobbin together.
Innovation Solution
A speaker design with a diaphragm featuring a perfectly circular cross-sectional area near the hole and an arc-shaped outer surface with varying radii, reinforced by an intermediate area and a reinforcing sheet, ensuring balanced stress distribution and preventing deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the diaphragm is made with an oval or elliptical outer peripheral end to improve low-frequency reproduction characteristics, then the area of the diaphragm increases, but the stress becomes unbalanced between the major axis direction and the minor axis direction, causing deformation at the hole and outer peripheral end
Solution Approach 1:
The diaphragm is designed with different cross-sectional shapes at different locations: a perfectly circular cross-section in the predetermined height range from the intermediate portion to the base (where the hole is located), and an oval or elliptical cross-section in other portions. This local differentiation allows the hole to maintain its circular shape for precise bobbin joining while the outer peripheral end retains the oval/elliptical shape for improved low-frequency reproduction characteristics.
2Area of stationary object
If the diaphragm is made with an oval or elliptical outer peripheral end, then the diaphragm area increases, but the outer peripheral end becomes liable to warp, making it impossible to join the outer peripheral end and the edge member together
Solution Approach 1:
The diaphragm is designed with different cross-sectional shapes at different locations: a perfectly circular cross-section in the predetermined height range from the intermediate portion to the base (where the hole is located), and an oval or elliptical cross-section in other portions. This local differentiation allows the hole to maintain its circular shape for precise bobbin joining while the outer peripheral end retains the oval/elliptical shape for improved low-frequency reproduction characteristics.
3Area of stationary object
If the diaphragm is made with an oval or elliptical cross section to improve low-frequency reproduction, then the diaphragm area increases, but it becomes difficult to reliably join the diaphragm and bobbin together due to hole deformation
Solution Approach 1:
The diaphragm is designed with different cross-sectional shapes at different locations: a perfectly circular cross-section in the predetermined height range from the intermediate portion to the base (where the hole is located), and an oval or elliptical cross-section in other portions. This local differentiation allows the hole to maintain its circular shape for precise bobbin joining while the outer peripheral end retains the oval/elliptical shape for improved low-frequency reproduction characteristics.
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 allows for reliable joining of the diaphragm and bobbin, reduces deformation, and enhances sound quality and output by maintaining a stable structure during operation.
Implementation Method 1
a voice coil wound around the bobbin, and a magnetic circuit configured to provide magnetic flux to the voice coil
Data Source
AI summary
A speaker includes a diaphragm having a perfectly circular hole in which a bobbin is attached and an oval or elliptical outer peripheral end. The diaphragm includes a perfectly circular cross-sectional area in the range of a predetermined height above a base having the perfectly circular hole. The diaphragm further includes an intermediate area whose outer surface has a small curvature radius above the perfectly circular cross-sectional area and an expanded area that is oval in cross section above the intermediate area.