Forging Press Ram Control via Flywheel Segmentation

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Solution Overview

Problem

Existing forging press systems require extremely powerful and energy-consuming direct drive motors to achieve a freely configurable ram movement, leading to high power requirements and economic burdens.

Innovation Solution

The method involves using a rotary drive with a flywheel to provide forming energy and a direct drive to adjust the ram's fall acceleration, allowing for a counterforce to reduce acceleration in the upper stroke range and coupling to the rotary drive in the lower range, enabling precise control of the ram movement with a smaller, more energy-efficient servo motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an electric direct drive is used to achieve a freely configurable ram movement curve, then the ram stroke time profile can be precisely controlled, but extremely high power requirements and expensive direct drive motors are required

Engineering Contradiction:
Improvestroke time profile control precisionVSAvoiddirect drive motor power requirement
Core Design Contradiction:
Measurement precisionVSPower

Solution Approach 1:

The drive system is segmented into two independent parts: a rotary direct drive (flywheel) that provides forming energy during the downward stroke, and a separate direct drive motor that only needs to provide auxiliary functions (positioning, dwell time control, reversing). This segmentation allows the main power requirement to be met by the flywheel while the electric motor handles only control functions, dramatically reducing power requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system uses periodic energy storage and release through the flywheel, which accumulates energy during the upward stroke and releases it during the downward forming stroke. This periodic action allows the electric motor to operate intermittently with much lower power requirements rather than continuously at full power.

Inventive Principle:
Principle #19Periodic action

2Productivity

If a powerful direct drive motor is used to manipulate the heavy ram at 30-60 strokes per minute, then the forming energy can be delivered, but the power requirement and connection value become extremely high

Engineering Contradiction:
Improvestrokes per minuteVSAvoidpower requirement
Core Design Contradiction:
ProductivityVSPower

Solution Approach 1:

The flywheel performs preliminary energy accumulation during the upward stroke phase, storing potential energy that will be used during the downward forming stroke. This preliminary action allows the motor to avoid delivering full power continuously, instead only needing to manage the flywheel and provide auxiliary control, thereby reducing overall power requirements while maintaining productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system recovers energy that would otherwise be wasted during the upward stroke by allowing the heavy ram to drive the flywheel backward, converting gravitational potential energy into kinetic energy stored in the flywheel. This energy recovery mechanism reduces the net power requirement from the electric motor while maintaining the required stroke rate.

Inventive Principle:
Principle #34Discarding and recovering

3Device complexity

If the ram is driven with a classic sinus rhythm via eccentric-driven crank press, then the mechanism is simple, but the dwell time in the upper stroke area is limited and workpiece manipulation is constrained

Engineering Contradiction:
Improvedrive mechanism complexityVSAvoiddwell time in upper stroke area
Core Design Contradiction:
Device complexityVSDuration of action of moving object

Solution Approach 1:

The system dynamically adjusts the ram movement profile by controlling when the clutch engages and disengages between the electric motor and the flywheel-crank mechanism. This allows the dwell time in the upper stroke area to be extended or reduced as needed for workpiece manipulation, while the forming stroke maintains the required speed and force, achieving flexibility without excessive complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The clutch acts as an intermediary between the electric motor and the flywheel-crank mechanism, allowing selective engagement and disengagement of the two drive systems. This intermediary component enables the system to switch between precise motor control (for dwell time and positioning) and the mechanical advantage of the flywheel-crank system (for forming power), achieving flexible control without major structural complexity.

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 approach reduces the need for powerful direct drive motors, allows for flexible ram movement control, minimizes wear, and increases the dwell time in the upper stroke range for workpiece manipulation and cooling, resulting in improved cycle efficiency and reduced pressure contact time.

Implementation Method 1

a rotary direct drive, which provides the required forming energy on the ram and which is preferably designed as a flywheel drive

Methodology Applied
Scientific EffectFlywheel: Flywheel

Implementation Method 2

The gravitational acceleration, which results from the well-known laws of gravitation, pulls every body downwards with its weight

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP2367676B1Method for controlling a forging press
Publication Date: 2016.06.01 SCHULER PRESSEN GMBH & CO KG
  • EP2367676B1 patent drawingFigure 1
  • EP2367676B1 patent drawingFigure 2
  • EP2367676B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating a forming machine or a forming line, wherein – the ram performs an accelerated falling motion in an upper stroke range, - the falling motion is affected, preferably braked, by a force generated by the ram counterweight, - the rotary drive is coupled to the shaft at a point in time of a defined falling speed synchronized with the speed of the rotary drive, wherein – the coupling process preferably takes place in the lower stroke range, especially shortly before forming, and wherein – shortly after forming in the lower stroke range, the rotary drive is decoupled again at a synchronized ram speed, and wherein – the dwell time of the ram in the lower stroke range is reduced relative to the dwell time in the upper stroke range by a factor of at least 1:2.