Quartz Vibration Element Weight Layout for Noise Vibration Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tuning fork type quartz crystal vibrator elements suffer from noise vibrations due to the shift in the center of gravity of the weight and metal film, causing unwanted vibration components in the thickness direction to leak outside, leading to noise issues.
Innovation Solution
A vibration element design where the weight's center of gravity is positioned closer to one principal surface, and the weight film's center of gravity is closer to the opposite principal surface, minimizing vibrations in the thickness direction, and the weight film is disposed on one surface to simplify manufacturing and reduce noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the metal film is provided on the weight to adjust frequency, then the frequency adjustment capability is improved, but the center of gravity shifts in the thickness direction causing noise vibration leakage
Solution Approach 1:
The patent applies asymmetry by positioning the weight's center of gravity and the weight film's center of gravity at opposite sides of the center plane in the thickness direction. This asymmetric arrangement allows the two centers of gravity to balance each other, bringing the combined center of gravity close to the center plane, thereby reducing out-of-plane vibrations and noise leakage while maintaining frequency adjustment capability.
Solution Approach 2:
The patent uses the weight film's center of gravity as a counterbalance to the weight's center of gravity. By positioning them on opposite sides of the center plane, the gravitational effects cancel each other out, preventing the combined center of gravity from shifting away from the center plane and thus reducing unwanted vibrations in the thickness direction.
2Object-generated harmful factors
If the weight structure is designed with thickness variation to position center of gravity, then the vibration control is improved, but the manufacturing complexity increases
Solution Approach 1:
The patent addresses the center of gravity positioning problem by utilizing the thickness dimension (z-direction) rather than only the planar dimensions. By adjusting the thickness distribution of the weight and positioning components along the thickness direction, the patent achieves precise center of gravity control without requiring complex lateral structural modifications, thus reducing overall device complexity.
Data Source
AI summary
A vibration element includes a base and a vibrating arm extending from the base. The vibrating arm includes an arm positioned between the base and a weight. A weight film is disposed on the weight. The weight has a first principal surface and a second principal surface in a front and back relationship with respect to a center plane of the arm. A center of gravity of the weight is located between the first principal surface and the center plane of the arm. A center of gravity of the weight film is located between the second principal surface and the center plane of the arm.