Adjustable Toggle Lever Drive Apparatus for Variable Force-Displacement Curves

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Solution Overview

Problem

Conventional drive devices for forming processes are technically complex and inflexible, with high energy consumption and limited variability in force-displacement curves, making them unsuitable for diverse machining operations.

Innovation Solution

A drive device with an adjustable toggle lever mechanism that allows for variable force-displacement curves by changing the angle of the toggle lever, enabling different machining processes with low energy consumption and cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If hydraulic drives are used for pulling processes, then an approximately constant force curve for longer stroke distances is achieved, but compressibility of hydraulic oil causes high heat development and low rigidity

Engineering Contradiction:
Improveforce curveVSAvoidheat development
Core Design Contradiction:
ForceVSLoss of energy

Solution Approach 1:

The patent replaces the hydraulic drive system with a mechanical drive system consisting of an electric motor, gearbox, and crank mechanism. This substitution eliminates the compressibility issues and heat generation associated with hydraulic oil while maintaining the ability to generate constant force over long stroke distances through pure mechanical transmission.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If mechanical drive systems with continuous electric motors are used, then low energy requirement and higher rigidity are achieved, but only a limited number of variations in process sequence are allowed

Engineering Contradiction:
Improveenergy requirementVSAvoidprocess variations
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent introduces a programmable control system that can dynamically adjust the operation sequence, stroke length, and force characteristics of the mechanical drive system. This allows the same mechanical hardware to adapt to different processing requirements (deep drawing, embossing, cutting) through software control, achieving versatility without sacrificing energy efficiency or rigidity.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If servo drives with roller spindles are used, then control over a wide range is achieved, but lifting speed is limited to the maximum possible speed of the spindle

Engineering Contradiction:
Improvecontrol rangeVSAvoidlifting speed
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The patent employs a crank mechanism that converts continuous rotary motion from the electric motor into periodic reciprocating motion of the output member. This periodic action enables high-speed lifting during the upward stroke while maintaining precise control over the downward working stroke, achieving both speed and control versatility that roller spindles cannot provide.

Inventive Principle:
Principle #19Periodic action

4Power

If extremely high torque servo motor is connected directly to drive shaft, then torque is transmitted directly, but extreme peaks in torque curve require expensive energy storage

Engineering Contradiction:
Improvetorque transmissionVSAvoidtechnical complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent introduces a gearbox as an intermediary between the electric motor and the crank mechanism. The gearbox acts as a torque multiplier that enables the motor to operate at lower, more efficient torque levels while still delivering the high forces required at the output. This eliminates the need for expensive energy storage systems to handle torque peaks, reducing both cost and 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

The drive device provides flexibility in force-displacement curves, allowing for various machining processes with constant drive force, reducing energy consumption and technical complexity, and enabling precise control over forming operations.

Implementation Method 1

a transmission element (18) which is rotatably mounted about a pivot point (26), the transmission element (18) being connected to the drive unit (14) in such a way that a torque can be transmitted to the transmission element (18), and the transmission element (18) having an output articulation point (28), a connecting element (34) being articulated at the output articulation point (28) and forming a toggle lever (42) with the transmission element (18)

Methodology Applied
Scientific EffectToggle lever mechanism: Lever

Data Source

PatentEP2911871B1Drive apparatus
Publication Date: 2017.03.29 MODUS ONE
  • EP2911871B1 patent drawingFigure 1
  • EP2911871B1 patent drawingFigure 2a~2b
  • EP2911871B1 patent drawingFigure 2c~2d

AI summary

The present invention relates to a drive apparatus (10), particularly for driving a forming device (12), with a drive unit (14) which provides a drive force (30) or a drive torque, a take-off unit (16) which has an input element (20) and a translationally movable output element (22), wherein the take-off unit (16) has a progressive force-travel characteristic between the input element (20) and the output element (22), and a transmission element (18) which is rotatably mounted on a point of rotation (26), wherein: the transmission element (18) is connected to the drive unit (14) in such a manner that a torque (38) can be transferred to the transmission element (18); the transmission element (18) has an output pivot point (28) to which a connecting element (34) is hinged, which connecting element forms together with the transmission element (18) an elbow lever (42); the connecting element (34) is connected to the input element (20) of the drive unit (16) in such a manner that a force can be transmitted onto the take-off unit (16); an angle (44) of the elbow lever (42) can be changed for a starting position of the output element (22) in order to adjust the force-travel characteristic of the output element (22).