Electromagnetic Pushing Object Detector Resolving Gap and Power Trade-offs

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Solution Overview

Problem

Existing object-position sensors face challenges such as high power consumption, material adhesion, mechanical vulnerability, and reliability issues under harsh conditions like high temperature and pressure, making them unsuitable for detecting objects in extreme environments.

Innovation Solution

An electromagnetic pushing and knocking-type object sensor using a magnetic swinging rod and an electromagnet with dual functions for driving and signal collection, which reduces power consumption, simplifies installation, and enhances resistance to adhesion and harsh conditions by employing a permanent magnet pendulum and high-temperature-resistant components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the gap between the pendulum and electromagnet is increased to tolerate larger gaps, then the maximum tolerated gap is improved, but the electromagnet cannot attract and hold the pendulum

Engineering Contradiction:
Improvegap toleranceVSAvoidattraction capability
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent changes the fundamental interaction mechanism from electromagnetic attraction to electromagnetic repulsion. By using two electromagnets with opposite polarity that both face the same direction, the system generates a pushing force that propels the pendulum away from the electromagnets. This parameter change allows the pendulum to be reliably actuated even at larger gaps (up to 20mm) without suffering from the inverse-square law limitations of attraction-based systems.

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If the ampere-turns and cross-section area of the electromagnet are increased to increase the maximum tolerated gap, then the gap tolerance is improved, but the product becomes bulkier and heavier

Engineering Contradiction:
Improvegap toleranceVSAvoidelectromagnet weight
Core Design Contradiction:
Length of stationary objectVSWeight of stationary object

Solution Approach 1:

The patent inverts the traditional electromagnetic interaction by using repulsion instead of attraction. Instead of one electromagnet attracting the pendulum, two electromagnets push the pendulum away. This inversion allows the use of smaller, lighter electromagnets while achieving the same or better gap tolerance, directly resolving the contradiction between gap capability and device weight.

Inventive Principle:
Principle #13The other way round (Inversion)

3Length of stationary object

If the ampere-turns and cross-section area of the electromagnet are increased to increase the maximum tolerated gap, then the gap tolerance is improved, but the power consumption increases

Engineering Contradiction:
Improvegap toleranceVSAvoidelectromagnet power consumption
Core Design Contradiction:
Length of stationary objectVSUse of energy by stationary object

Solution Approach 1:

By inverting the electromagnetic interaction from attraction to repulsion, the patent enables the use of smaller electromagnets with lower ampere-turns requirements. This dramatically reduces the power consumption while maintaining or improving gap tolerance capability.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent employs periodic pulsing of the two electromagnets in sequence rather than continuous operation. The first electromagnet pushes the pendulum away, then the second electromagnet pushes it back, creating a continuous oscillating motion through periodic action. This reduces average power consumption compared to continuous high-power attraction systems.

Inventive Principle:
Principle #19Periodic action

4Force

If the electromagnetic attractive force direction is aligned with adhesive force direction, then the attraction is improved, but the resistance to material adhesion decreases

Engineering Contradiction:
Improveelectromagnetic attraction forceVSAvoidmaterial adhesion
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the direction of electromagnetic force from attraction to repulsion. By using opposite polarity electromagnets that push the pendulum away rather than pull it in, the electromagnetic force acts in the opposite direction to adhesive forces. This creates a natural counteracting effect that prevents material adhesion to the pendulum surface.

Inventive Principle:
Principle #13The other way round (Inversion)

5Device complexity

If a single swing signal collection component is used, then the structure is simplified, but the detection reliability under harsh conditions decreases

Engineering Contradiction:
Improvesignal collection structureVSAvoiddetection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent makes the electromagnets multi-functional by having them serve both as actuation devices (pushing the pendulum) and as signal collection sensors (detecting pendulum position through magnetic field changes). This eliminates the need for separate signal collection components while maintaining high detection reliability, as the electromagnets are inherently robust against harsh environmental conditions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 a reliable, maintenance-free, and highly sensitive object detection system capable of operating under various harsh conditions, with reduced material and production costs, and extended service life, while allowing for detection of solids and liquids with good or poor flow properties.

Implementation Method 1

uses an electromagnet to periodically attract an iron pendulum, causing it to move continually in the air as a single pendulum

Methodology Applied
Scientific EffectElectromagnetic pushing force: Electromagnetic Propulsion

Implementation Method 2

detects the movement status of the pendulum using an object-position signal-collecting component

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP2685225B1Electromagnetic pushing and knocking type object detector
Publication Date: 2020.09.30 CHEN YIHUA
  • EP2685225B1 patent drawingFigure 1
  • EP2685225B1 patent drawingFigure 2
  • EP2685225B1 patent drawingFigure 3~4

AI summary

A level sensor, particularly an electromagnetic pushing and knocking-type object detector, comprising: a magnetic swinging rod, an electromagnet that is disposed on one side of the magnetic swinging rod, and an electronic module that controls the electromagnet in driving the magnetic swinging rod to swing, and amplifies, processes, and time-delay outputs the swinging signals of the magnetic swinging rod, which swinging signals are collected by the electromagnet, said magnetic swinging rod is suspended with a suspension device on one side of a main housing, and the electromagnet, which is composed of an electromagnet iron core and an electromagnet coil, is disposed inside the main housing. The electric module comprises a power supply circuit, a pulse generation circuit, a pulse driving circuit, a signal amplification circuit, a signal processing circuit, and a signal time delay output circuit, and the aforementioned circuits are all disposed in the main housing or are isolated from the main housing and enclosed separately. The present invention has the advantages of high sensitivity, accuracy, and reliability; has a wide range of applications; is maintenance-free; and features a long service life.