Magnetic Position Detection Device for Machine Tools
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Solution Overview
Problem
Conventional position detection devices for movable bodies in machine tools have a short lifespan due to mechanical contact deterioration and poor continuity, leading to reduced detection accuracy.
Innovation Solution
A position detection device using a magnet or light source with different poles/discrepancies moving along a path, paired with identical magnetic or light sensors spaced equally from a reference line, allowing for position detection without mechanical contact by coinciding sensor outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical contact is used for position detection, then position detection can be performed, but the contacts deteriorate due to repeated mechanical turning on/off resulting in short life span
Solution Approach 1:
The patent replaces the mechanical contact-based position detection system with a magnetic field-based detection system. Magnetic sensors detect the position of a magnet attached to the movable body through magnetic field interactions without any physical contact, thereby eliminating wear and extending the system's operational life span.
Solution Approach 2:
The patent introduces a magnetic field as an intermediary between the movable body and the detection system. The magnet attached to the movable body generates a magnetic field that is detected by magnetic sensors, allowing position detection without direct mechanical contact between the sensor and the movable body.
2Measurement precision
If mechanical contact is used for position detection, then position detection can be performed, but poor continuity between contacts occurs due to inclusion of foreign matter or formation of oxide film
Solution Approach 1:
The patent replaces mechanical contact with magnetic field interaction for position detection. The magnetic sensors detect changes in magnetic field strength or direction caused by the magnet's position, providing continuous and reliable detection without the contact continuity issues that plague mechanical systems.
Solution Approach 2:
The magnetic field serves as an intermediary that transmits position information without requiring direct contact. This intermediary approach eliminates the problems of foreign matter inclusion and oxide film formation that disrupt contact continuity in mechanical systems.
3Measurement precision
If mechanical contact is used for position detection, then position detection can be performed, but detection accuracy is lowered due to wear or denting of the contact caused by repeated contact
Solution Approach 1:
The patent substitutes mechanical contact with magnetic field-based detection. The magnetic sensors measure position by detecting the magnet's position through magnetic field interactions, completely avoiding the wear and denting that occur in mechanical contact systems and thereby maintaining detection accuracy throughout the system's operational life.
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 solution provides stable and accurate position detection with a long lifespan, eliminating contact-related issues and maintaining accuracy across temperature changes and external influences.
Implementation Method 1
a magnetic sensor that detects a position of the magnet based on a magnetic field
Implementation Method 2
a light sensor that detects a position of the light source
Data Source
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AI summary
Provided is a position detection device that can stably detect a position with high detection precision over a long lifespan. A position detection device 2 is provided with a magnet 40 configured so as to move, together with a movable body 2, on a movement path M extending along the X-direction. The magnet 40 has different magnetic poles 41, 42 in the Z-direction. The position detection device 2 is provided with a pair of magnetic sensors 21, 22 that are separated by equal distances, in the Z-direction, from the movement path M, and that are disposed at equal distances from a reference line S extending in the Z-direction. The magnetic sensors 21, 22 have the same sensor characteristics. The position detection device 2 is provided with a detection unit 30 that is configured so as to detect that the magnet 40 is positioned on the reference line S when the outputs of the magnetic sensors 21, 22 match.