Linear Motor Hammer Control for Smooth Reversal

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Solution Overview

Problem

Existing hammer operating technologies fail to effectively control and regulate linear motors during the impact and rebound phases, leading to potential damage and inefficient energy use, particularly in preventing abrupt reversals and managing sticky or strong rebounds.

Innovation Solution

A method where the linear motor's power is controlled by a control unit based on time, speed, and position, with the field inversion occurring before impact to manage hysteresis cycles, and additional devices for braking and acceleration are used to optimize the hammer's operation, allowing for early intervention and reduced energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the linear motor is switched off before the hammer reaches the lower reversal point, then energy consumption is reduced, but the hammer may experience abrupt reversal causing damage to the linear motor components

Engineering Contradiction:
Improveenergy consumptionVSAvoiddamage to linear motor components
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The control unit inverts the polarity of the linear motor's magnetic field in advance, before the hammer reaches the lower reversal point. This preliminary field inversion ensures that when the motor is switched off, the hammer experiences a smooth deceleration and reversal rather than an abrupt stop, preventing mechanical damage while still allowing the motor to be de-energized early for energy savings

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts the linear motor's operational state based on real-time position and velocity feedback. The motor transitions from powered operation to field-inverted coasting to complete stop, with the control unit continuously monitoring hammer position and adjusting the field inversion timing to optimize both energy consumption and mechanical protection

Inventive Principle:
Principle #15Dynamics

2Reliability

If the field of the linear motor is inverted early to provide a time window for hysteresis cycle, then the reversal of movement is controlled cleanly, but the time window for control intervention is extended

Engineering Contradiction:
Improveclean reversal of movementVSAvoidtime window for control intervention
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The magnetic field inversion is performed in advance of the actual reversal point, creating a controlled transition period. During this pre-inversion phase, the hammer continues moving downward while the reversed field begins to decelerate it, providing a smooth and controlled reversal that prevents mechanical shock while the control system has adequate time to manage the transition

Inventive Principle:
Principle #10Preliminary action

3Reliability

If additional braking and acceleration devices are controlled based on linear motor performance, then operational reliability is increased, but device complexity increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidbraking and acceleration devices
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit serves as an intelligent intermediary that coordinates between the linear motor and the auxiliary braking/acceleration devices. It monitors the linear motor's performance in real-time and activates the auxiliary devices only when necessary, such as providing additional braking force during strong rebounds or supplementary acceleration when needed, thereby increasing reliability without requiring constant operation of complex auxiliary systems

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically adjusts operational parameters based on real-time conditions. The control unit monitors hammer position, velocity, and acceleration, and only activates the braking or acceleration devices when specific threshold conditions are met, such as when rebound strength exceeds a predetermined level or when the linear motor cannot provide sufficient control alone

Inventive Principle:
Principle #35Parameter changes

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 method enables clean and controlled movement of the hammer, preventing damage to the linear motor components, optimizing hammer blows, and enhancing operational reliability while minimizing energy use and preventing sticky impacts.

Implementation Method 1

at least one linear motor (9, 10) accelerates the bear (3) before it hits a workpiece (16), with the control unit (13) switching off the linear motor(s) (9, 10) before it reaches a lower reversal point (U)

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

the polarity of the field of the linear motor(s) (9, 10) is reversed, with the linear motor(s) (9, 10) then being activated again to take the bear (3) with it in its upward movement

Methodology Applied
Scientific EffectField inversion: Electromagnetic Induction

Data Source

PatentEP2373446B1Method for operating a hammer
Publication Date: 2015.09.23 SCHULER PRESSEN GMBH & CO KG
  • EP2373446B1 patent drawingFigure 1
  • EP2373446B1 patent drawingFigure 2
  • EP2373446B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a hammer (1, 2), comprising at least one ram (3) that can be driven by at least one linear motor (9, 10) and a regulating unit (13).