Mechanically Lockable Force-Building Cylinder for Efficient Press Changeover

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Solution Overview

Problem

Hydraulic presses with coupled cylinders for force-building and rapid movements require excessive hydraulic fluid movement, leading to high power consumption and valve loads, especially when larger cylinders are used for force-building and smaller ones for rapid movements.

Innovation Solution

An electro-hydrostatic drive system with a hydro-machine of variable volume and/or rotational speed, driven by an electric motor, featuring a first larger cylinder for force-building and a second smaller cylinder for rapid movements, where the moveable carrier plate is connected to both cylinders, and a clamping apparatus is used to clamp/unclamp the first cylinder to/from the pillar, optimizing fluid flow and reducing unnecessary fluid movement during rapid movements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If all cylinders are coupled to move over the same distance, then the force-building movement can be achieved, but excessively high power consumption and valve loads occur during rapid movement

Engineering Contradiction:
Improveforce-building capabilityVSAvoidpower consumption
Core Design Contradiction:
ForceVSUse of energy by moving object

Solution Approach 1:

The system segments the cylinder functions by separating the force-building cylinder (first cylinder) from the rapid movement cylinder (second cylinder). The clamping apparatus mechanically decouples the first cylinder from the moveable carrier plate during rapid movement, allowing the second cylinder to operate independently with reduced hydraulic fluid displacement, thereby lowering power consumption while maintaining force-building capability when needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically changes the mechanical connection state between the first cylinder and the moveable carrier plate through the clamping apparatus. During rapid movement, the clamping is released to disconnect the first cylinder, reducing the volume of hydraulic fluid that must be moved. During force-building movement, the clamping engages to connect both cylinders, enabling high force generation. This dynamic reconfiguration optimizes energy consumption across different operational phases.

Inventive Principle:
Principle #15Dynamics

2Force

If larger diameter cylinders are used for force-building movement, then sufficient force is generated, but high loads are imposed on valves during rapid movement

Engineering Contradiction:
Improveforce-building capabilityVSAvoidvalve loads
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

The system segments the functional requirements by using two separate cylinders: the first larger cylinder dedicated to force-building movements and the second smaller cylinder dedicated to rapid movements. The clamping apparatus enables selective engagement of the first cylinder only when force-building is required, preventing it from being dragged along during rapid movements and thus reducing unnecessary valve loads while maintaining adequate force-generation capability.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If the first cylinder is mechanically locked during rapid movement, then unnecessary hydraulic fluid movement is minimized, but the device complexity increases

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The clamping apparatus serves as an intermediary mechanical device that selectively connects or disconnects the first cylinder from the moveable carrier plate. This intermediary mechanism enables the system to minimize unnecessary hydraulic fluid movement during rapid movements by locking the first cylinder in place, while adding only moderate complexity through a relatively simple clamping mechanism rather than a fully complex variable displacement system.

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 solution significantly reduces energy consumption and load on valves by minimizing hydraulic fluid movement during rapid movements, enhancing the overall efficiency of the hydraulic press system.

Implementation Method 1

a hydro-machine with variable volume and/or rotational speed, driven by an electric motor, for providing a volume-flow of a hydraulic fluid

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

a clamping apparatus is included, to clamp and/or unclamp the first cylinder to or from the pillar, respectively

Methodology Applied
Scientific EffectMechanical clamping force: Mechanical Force

Data Source

PatentEP3720695B1Apparatus and method for cylinder changeover with a mechanically lockable force-building cylinder
Publication Date: 2022.01.19 MOOG GMBH
  • EP3720695B1 patent drawingFigure 1
  • EP3720695B1 patent drawingFigure 2
  • EP3720695B1 patent drawingFigure 3

AI summary

The present invention relates to hydraulic presses that has an electro-hydrostatic drive (10) for realizing a rapid movement and a force-building movement, comprising a hydro-machine (50) with variable volume and/or rotational speed, driven by an electric motor (60), for furnishing / providing a volume-flow of a hydraulic fluid, a first cylinder (100) with a housing (105), a piston (110), a cylinder rod (122), and a first (120) and a second (130) cylinder chamber, a second cylinder (200) with a piston (210), a cylinder rod (222), and a first (220) and a second (230) cylinder chamber, a moveable carrier plate (430), a pillar (410), and a clamping apparatus (390) to clamp and/or unclamp the first cylinder (100) to the pillar (410), where the hydraulic drive (10) has a closed hydraulic circuit, which has, when run, a positive pressure above atmospheric pressure and which, by means of the hydro- machine (50), can pressurize either the first (120) or the second (130) cylinder chamber of the first cylinder (100) and/or the first (220) or the second (230) cylinder chamber of the second cylinder (200). The invention is characterized in that the moveable carrier plate (430) is connected both to the first cylinder (100) and to the second cylinder (200), for the force-building movement, the first cylinder (100) is clamped, by the clamping apparatus (390), to the pillar (410) and one cylinder chamber (120, 130) of the first cylinder (100) is pressurized with the hydraulic fluid, and for the rapid movement, the first cylinder (100) is undamped, by the clamping apparatus (390), from the pillar (410) and one cylinder chamber (220, 230) of the second cylinder (200) is pressurized with the hydraulic fluid.