Sensor Device Biasing Mechanism for Vibration Detection

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Solution Overview

Problem

Existing sensor devices with a spring biasing a vibration detecting unit often experience inaccurate vibration detection due to the biasing force being applied directly to the piezoelectric element through a rubber vibration isolator and weight, causing disturbances in voltage fluctuations.

Innovation Solution

A sensor device design where a spring biases a holder to project a detection probe, isolating the biasing force from the piezoelectric element, allowing accurate detection of vibrations by preventing the spring's biasing force from acting as a disturbance on the piezoelectric element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the spring is connected to the rubber vibration isolator to bias the vibration detecting unit, then the vibration detecting unit can be biased forward to cause the detection probe tip to project from the casing, but the biasing force of the spring is applied to the piezoelectric element through the rubber vibration isolator and weight, causing disturbance to the piezoelectric element and inaccurate vibration detection

Engineering Contradiction:
Improveprojection of detection probe tipVSAvoidvibration detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent divides the biasing mechanism into two independent parts: the spring biases the holder forward to project the detection probe tip, while the piezoelectric element is biased separately by a push member (weight) without connection to the spring. This segmentation prevents the spring's biasing force from disturbing the piezoelectric element, resolving the contradiction between probe projection and detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the piezoelectric element's biasing function from the spring mechanism. Instead of the spring directly biasing the piezoelectric element through the rubber vibration isolator and weight, the piezoelectric element is biased by a separate push member (weight) that is independently positioned. This extraction eliminates the harmful disturbance force from the spring while maintaining the necessary biasing function for accurate vibration detection.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If the spring biases the vibration detecting unit forward, then the detection probe tip can contact the measurement object for vibration detection, but the biasing force acts as a disturbance on the piezoelectric element, causing voltage fluctuations that include disturbance components

Engineering Contradiction:
Improvecontact of detection probe with measurement objectVSAvoidsignal accuracy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent segments the biasing functions: the spring handles the forward biasing to enable probe contact with the measurement object, while a separate push member (weight) handles the piezoelectric element biasing. This segmentation ensures that the spring's biasing force does not transmit as disturbance to the piezoelectric element, maintaining signal accuracy while enabling reliable vibration detection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a separate push member (weight) as an intermediary between the piezoelectric element and the spring mechanism. This intermediary ensures that the piezoelectric element receives appropriate biasing force while being isolated from the spring's biasing force that would otherwise act as disturbance. The push member serves as a mediator that maintains the necessary mechanical connection for vibration detection while blocking the harmful disturbance force.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design enables precise detection of vibrations by ensuring the biasing force does not interfere with the piezoelectric element, resulting in improved accuracy and reduced disturbances from external forces.

Implementation Method 1

vibrations of the measurement object are transmitted to the detection probe and acts on the piezoelectric element as pressure variations to thereby cause voltage fluctuations

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The spring is disposed rearward of the vibration detecting unit, is configured to contact the holder to bias the holder forward, and causes a tip of the detection probe to project from the casing

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 3

the biasing force of the spring is applied to the piezoelectric element by way of the rubber vibration isolator and the weight in this order

Methodology Applied
Scientific EffectVibration isolation: Damping

Data Source

PatentEP3196612B1Sensor device
Publication Date: 2023.03.15 TLV CO LTD
  • EP3196612B1 patent drawingFigure 1
  • EP3196612B1 patent drawingFigure 2
  • EP3196612B1 patent drawingFigure 3

AI summary

Provided is a sensor device that can accurately detect vibrations of a measurement object with a spring biasing a vibration detecting unit to cause a tip of a detection probe to project. A sensor device 1 includes: a cylindrical casing 10; a vibration detecting unit 20 including a detection probe 21, a bottomed cylindrical holder 22 having a bottom in which a rear end of the detection probe 21 is inserted and fixed, piezoelectric elements 25 and 26 disposed rearward of the detection probe 21 in the holder 22 and configured to contact the rear end of the detection probe 21, and a push member 32 held in the holder 22 and configured to push the piezoelectric elements 25 and 26 against the rear end of the detection probe 21, the vibration detecting unit 20 being disposed in the casing 10; and a coil spring 35 that is disposed rearward of the vibration detecting unit 20, is configured to contact the holder 22 to bias the holder 22 forward, and causes a tip 21d of the detection probe 21 to project from the casing 10, wherein the tip 21 d of the detection probe 21 is pushed against a measurement object to detect vibration of the measurement object.