Arc-Falling Weight Natural Frequency Measuring Device
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Solution Overview
Problem
Existing methods for measuring the natural frequency of a system, such as high-speed tensile testing machines, face issues with measurement accuracy due to variations in striking force and collision points when using hammers or falling balls, leading to resonance and vibration errors.
Innovation Solution
A natural frequency measuring device where a weight falls in an arc shape to strike the system parallel to the load direction, allowing for simple and accurate measurement by adjusting the striking position and using a magnetic or electromechanical mechanism to ensure consistent striking force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a hammer or falling ball method is used to measure natural frequency, then the measurement can be performed, but measurement accuracy deteriorates due to variations in striking force and collision points
Solution Approach 1:
The patent replaces the manual hammer striking method with an automated dropping weight mechanism guided by a guide groove. This mechanical substitution ensures consistent striking position and force by constraining the weight to follow a predetermined path, thereby improving measurement reliability and accuracy.
Solution Approach 2:
The guide groove acts as an intermediary element between the dropping weight and the system being tested. It mediates the striking action by ensuring the weight follows a precise trajectory and strikes at a consistent location, eliminating the variability inherent in manual hammer striking.
2Ease of operation
If manual hammer striking is used, then the measurement process can be performed, but device complexity increases due to the need for consistent operator technique
Solution Approach 1:
The dropping weight mechanism is self-regulating through the guide groove structure. The geometry of the guide groove automatically ensures consistent striking position and force without requiring operator skill or adjustment, making the system self-service and easy to operate while maintaining simplicity.
3Measurement precision
If the natural frequency of the force detector is lower than the test frequency, then the system can operate, but resonance and vibration occur causing large errors
Solution Approach 1:
The patent performs natural frequency measurement as a preliminary action before conducting material tests. By measuring the natural frequency of the force detector system in advance using the accurate dropping weight method, operators can identify potential resonance issues and adjust test parameters to avoid operating frequencies that would cause harmful vibrations during actual testing.
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 provides a straightforward and precise method for measuring the natural frequency of the system, minimizing errors and simplifying the measurement process by ensuring consistent striking force and position, thus improving the accuracy of the results.
Implementation Method 1
a weight falls in an arc shape to strike the system including the force detector toward a direction parallel to a load direction of a test force during a material test
Data Source
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AI summary
Provided are a striking device and a natural frequency measuring device capable of simply and accurately measuring a natural frequency of a system including force detector. The striking device includes an arm (62) capable of swinging around a spindle (63), and a steel ball (61) arranged in an end part of the arm on a side opposite to the spindle. The spindle is supported by a supporting part (64) capable of lifting up and down relative to a post (71) erected on a magnet stand (70). A supporting part (68) for supporting a supporting plate (67) is arranged at a position in the post and above the supporting part. A permanent magnet (66) is placed above the supporting plate. The steel ball falls down in an arc shape from a standby height position when the permanent magnet is removed.