Lower Bending Tool Preload Mechanism for Friction Reduction

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Solution Overview

Problem

Existing tool changing systems for bending machines are costly and prone to damage during tool replacement due to high frictional forces between the lower tool and the tool holder, leading to potential damage and increased maintenance intervals.

Innovation Solution

A friction reduction device is integrated into the lower tool, featuring a preload force mechanism that reduces the apparent weight of the tool on the holder, allowing for easier and safer tool changes by minimizing frictional forces through adjustable spring elements and optimized friction coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lower tool is moved along the tool holder during tool changing, then the tool can be replaced, but the high frictional force causes damage to the lower tool surface and/or tool holder surface

Engineering Contradiction:
Improvetool changing easeVSAvoidsurface damage
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A friction reduction device is introduced as an intermediary element between the lower tool and the tool holder. This device includes a friction reduction element with a low-friction coating applied to its surface, which contacts the tool holder during tool changing operations. The low-friction coating acts as a mediator that reduces the frictional force between the tool components, enabling easier tool changing while preventing surface damage to both the lower tool and tool holder.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the frictional force is reduced by using a separate sliding carriage with rigid rollers and pneumatic system, then the tool can be moved more easily, but the technical effort and production costs increase significantly

Engineering Contradiction:
Improvetool movement easeVSAvoidsystem complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the complex pneumatic system and sliding carriage mechanism from the tool changing system. Instead, it integrates a compact friction reduction device directly into the lower tool structure, containing only the essential friction reduction element with low-friction coating. This extraction of unnecessary complexity achieves the same friction reduction effect while dramatically simplifying the overall system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The friction reduction device is merged with the lower tool structure, combining the tool body and friction reduction components into a single integrated unit. The friction reduction element is positioned within the lower tool and works in conjunction with the tool shank and tool shoulders, eliminating the need for separate sliding carriages and external pneumatic systems while achieving the desired tool movement capability.

Inventive Principle:
Principle #5Merging (Combining)

3Force

If the lower tool weight is reduced by applying preload force through the friction reduction device, then the frictional force is reduced, but the apparent weight reduction is achieved through force application rather than mass reduction

Engineering Contradiction:
Improvefrictional forceVSAvoidapparent weight
Core Design Contradiction:
ForceVSWeight of moving object

Solution Approach 1:

The friction reduction device applies a preload force that creates a counterbalancing effect, reducing the apparent weight of the lower tool during movement. The low-friction coating on the friction reduction element enables this preload force to effectively counteract portions of the tool's weight force, reducing the normal force between the tool and holder, and thereby reducing frictional force without requiring actual mass reduction.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

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 reduces the risk of damage to the tool and holder, extends tool life, and enables faster setup times while preventing jamming, thus enhancing safety and reducing maintenance needs.

Implementation Method 1

adjustable spring elements

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

reduce a frictional force between the underside and the tool holder

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3790680B1Lower tool with friction reduction device
Publication Date: 2022.06.29 TRUMPF MASCHEN AUSTRIA
  • EP3790680B1 patent drawingFigure 1
  • EP3790680B1 patent drawingFigure 2~3
  • EP3790680B1 patent drawingFigure 4

AI summary

The invention relates to a lower tool (3) for a bending machine (1), in particular a die bending machine, comprising a longitudinally extending main body (5) which, on its underside (6), has a tool shaft (8) for receiving in a guide groove (9) of a tool holder (10) and optionally in the transverse direction (13), tool shoulders (7), and at least one friction reduction device (11) is arranged on the underside (6) of the main body (5) in order to reduce a friction force (15) between the underside (6) and the tool holder (10) during a displacement of the lower tool (3) in the longitudinal direction (12), characterized in that the at least one friction reduction device (11) is designed in such a way that a weight force (17) of the lower tool (3) on the tool holder (10), under the application of a pretensioning force (16) in the direction of the weight force (17), causes a resultant normal force (18) of the lower tool (3) on the tool receptacle (10) which is lower relative to the weight force (17).