Electrolytic Capacitor Sealing Structure for Case Expansion Control
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Solution Overview
Problem
Existing electrolytic capacitors face a drop in sealing effectiveness due to the expansion and contraction of the body case, which is exacerbated by the uniform diameter of inorganic layers, resin layers, or ceramic reinforcement members provided on the sealing material, leading to deformation and adverse effects on the capacitor element during molding.
Innovation Solution
The electrolytic capacitor features a depressed portion in the sealing material with an external pressure deformation suppressing plate, a drawn portion in the body case, and a bent portion in the body case tip, allowing the sealing material to expand and contract freely while being protected from deformation by the external pressure deformation suppressing plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If an inorganic layer, resin layer, or ceramic reinforcement member is provided unitarily on the sealing material with the same diameter, then the sealing material is restrained from expansion and contraction, but the sealing effect deteriorates due to inability to follow body case dimensional changes
Solution Approach 1:
The sealing material is divided into multiple regions with different functional characteristics: a first region with a first diameter that can expand and contract, and a second region with a second diameter that is restrained. This segmentation allows different parts of the sealing material to perform different functions - maintaining sealing effect while adapting to body case dimensional changes.
Solution Approach 2:
Different regions of the sealing material are given different properties: the first region has properties that allow expansion and contraction to follow the body case, while the second region has properties that restrain expansion and contraction to maintain sealing effect. This local differentiation resolves the contradiction between adaptability and sealing stability.
2Stability of the object's composition
If the sealing material is restrained from expansion and contraction to maintain sealing effect, then sealing stability is improved, but the sealing material deforms severely during molding process
Solution Approach 1:
The sealing material is segmented into a first region that can deform during molding without affecting sealing, and a second region that is restrained to maintain sealing effect. This segmentation allows the structure to withstand molding forces while preserving sealing integrity.
Solution Approach 2:
The first region is designed with properties that allow deformation during molding to absorb external forces, while the second region maintains restrained properties to preserve sealing effect. This local quality differentiation protects the sealing material from severe deformation during molding.
3Ease of manufacture
If the outer circumferential surface of the outer circumference holding portion is a flat face, then manufacturing is simplified, but the sealing material cannot adapt to environmental changes
Solution Approach 1:
The outer circumferential surface of the outer circumference holding portion is designed as a curved surface (concave toward the capacitor element) rather than a flat face. This curvature allows the sealing material to expand and contract more naturally in response to environmental changes while maintaining the holding function.
Data Source
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AI summary
A sealing material has, in its face facing an opening of a body case, a depressed portion depressed toward a capacitor element with an outer diameter smaller than that of the sealing material, and an outer circumference holding portion around the outer circumference of the depressed portion. In the depressed portion, an external pressure deformation suppressing plate in a plate shape is provided, and at least part of an outer circumferential portion of the external pressure deformation suppressing plate provided in the depressed portion is covered with an inner circumferential part of the outer circumference holding portion of the sealing material.