Rotatable Permanent Magnet Clamping for Adjustable Holding Force

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Solution Overview

Problem

Existing magnetic clamping devices face issues such as mechanical deformation of workpieces, high weight and complexity in logistics, unreliable holding force reproducibility, and high energy consumption due to the use of electromagnets, as well as space inefficiency and cost-effectiveness concerns with multiple permanent magnet arrangements.

Innovation Solution

A magnetic holding device featuring at least one first permanent magnet and one second permanent magnet, where the second magnet is rotatably mounted relative to the first, allowing continuous adjustment of the holding force by changing the angle between their pole directions, eliminating the need for electromagnets and enabling reproducible and adjustable magnetic forces without mechanical deformation or thermal load.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a movable permanent magnet is used to clamp sheet metal, then the holding force can be adjusted by changing distance, but the magnet adheres to the sheet metal and causes local deformation during release

Engineering Contradiction:

Improveholding forceVSAvoidmechanical deformation

Core Design Contradiction:

ForceVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical piston-cylinder actuation system with a magnetic field-based actuation system. Instead of mechanically moving the magnet away from the workpiece (which causes deformation), the invention uses a second electromagnet to generate a magnetic field that pulls the permanent magnet away from the workpiece. This substitution of mechanical release with magnetic release eliminates the harmful mechanical deformation of the sheet metal during the release process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If electromagnets are used for clamping, then holding force can be controlled, but the devices are heavy and require cooling due to thermal losses

Engineering Contradiction:

Improvecontrollability of holding forceVSAvoidweight of clamping device

Core Design Contradiction:

Ease of operationVSWeight of moving object

Solution Approach 1:

The patent merges the advantages of permanent magnets (light weight, no thermal losses) with the controllability of electromagnets. The permanent magnet provides the base holding force, while a second electromagnet serves as an actuator to control the magnetic circuit. This combination allows electronic control of the holding force without the weight and thermal problems of using a full electromagnet for clamping.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The invention introduces a second electromagnet as an intermediary actuator that controls the magnetic circuit rather than directly clamping the workpiece. This intermediary electromagnet enables controllability of the holding force while the permanent magnet does the actual clamping, thus avoiding the weight and thermal issues of using the permanent magnet as an active electromagnet.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Force

If multiple permanent magnets are arranged to provide adjustable holding force, then holding force can be varied, but the device requires large space and has high wear due to continuous movement

Engineering Contradiction:

Improveadjustable holding forceVSAvoidspace requirement and wear

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical displacement system with an electromagnetic actuation system. Instead of physically moving multiple permanent magnets to adjust holding force (which requires large space and causes wear), the invention uses a second electromagnet to control the magnetic circuit. This substitution eliminates the need for large displacement spaces and reduces wear by replacing continuous mechanical movement with electromagnetic control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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, space-saving, cost-effective, and low-wear magnetic holding device with continuously adjustable holding forces, enhancing reproducibility and reducing mechanical and thermal impacts on workpieces, suitable for machining applications.

Implementation Method 1

at least one first permanent magnet (11) and at least one second permanent magnet (12)... the magnetic holding force can be adjusted

Methodology Applied

Scientific EffectMagnetic force: Magnetism

Implementation Method 2

the pole direction of the second permanent magnet (12) is rotatable relative to the pole direction of the first permanent magnet (11)... causing the magnetic holding force to change

Methodology Applied

Scientific EffectMagnetic field orientation: Magnetism

Data Source

PatentUS11915864B2Magnetic retaining device

Publication Date: 2024.02.27 BERNDORF BAND GMBH

AI summary

The invention relates to a magnetic holding device (10), in particular a clamping device, comprising a holding surface (9) and at least one first permanent magnet (11), characterized in that the holding device (10) comprises at least one second permanent magnet (12) which is rotatably mounted relative to the at least one first permanent magnet (11) about a rotational axis (3), whereby the pole direction (2) of the second permanent magnet (12) is rotatable relative to the pole direction (1) of the first permanent magnet (11).