Machining Head Support Counterbalancing for Tolerance Stability

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Solution Overview

Problem

In large dimension machine tools, mechanical and thermal deformations in the support structure of the machining head due to the weight of the head itself significantly impact the achievable machine tolerances, necessitating a solution to counteract these deformations for improved performance.

Innovation Solution

A machine tool with a support structure featuring an action device comprising an actuator and action member, such as a hydraulic or mechanical pull-rod system, which generates pushing or pulling actions to counteract the weight-induced deformations, integrated with a control system using sensors and actuators to adjust the action based on deformation detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the support structure is made stiffer to reduce deformations, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improvemachine tolerancesVSAvoidsupport structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies counterbalancing weights that generate lifting forces to compensate for the weight-induced deformations of the machining head. These weights are positioned to create counteracting moments that balance the gravitational load on the support structure, thereby reducing deformations and improving manufacturing precision without requiring a completely stiffer support structure.

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

Solution Approach 2:

The patent modifies the gravitational parameter by introducing counterbalancing weights that change the net force distribution on the support structure. By adjusting the position and magnitude of these counterweights, the system optimizes the balance between the machining head weight and the counteracting forces, reducing support structure deformations while maintaining manageable structural complexity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the support structure is made lighter to improve speed, then productivity increases, but strength decreases leading to increased deformations

Engineering Contradiction:
Improvemachining speedVSAvoidsupport structure strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The counterbalancing weights compensate for the reduced strength of lighter support structures by generating counteracting forces that offset the machining head weight. This allows the use of lighter, more agile support structures that improve machining speed and productivity while the counterweights ensure sufficient strength and minimize deformations during operation.

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

3Manufacturing precision

If counterbalancing weights are added to compensate for head weight, then manufacturing precision improves, but device complexity increases

Engineering Contradiction:
Improvemachine tolerancesVSAvoidsystem complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces counterbalancing weights as a relatively simple mechanical addition to the existing machine tool structure. These weights are positioned to create counteracting moments that balance the gravitational load, providing a straightforward solution to reduce support structure deformations and improve manufacturing precision without requiring complex control systems or structural modifications.

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

Solution Approach 2:

The patent replaces potential complex active control systems with passive mechanical counterbalancing weights. By using gravitational forces from strategically positioned weights, the system achieves deformation compensation through pure mechanics, eliminating the need for complex sensors, actuators, and control algorithms that would otherwise be required to maintain precision.

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

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 solution effectively minimizes deformations in the support structure, enhancing machine tool performance by maintaining stability and reducing machine tolerances, thereby improving the precision of mechanical workpieces.

Implementation Method 1

the actuator means 24 are hydraulic (figure 4). In such embodiment, the actuator means 24 comprise a cylinder 26, with which the action member 22 is engaged so as to sealingly slide, and hydraulic pressure means for sending pressurised fluid into the cylinder 26 and operating the action member 22.

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

the machine tool comprises a control system 200 of the action device 20. Advantageously, the control system 200 comprises an electronic control device 202, for example a PLC or a micro processor, connected to the actuator means 24

Methodology Applied
Scientific EffectElectrical signal processing:

Data Source

PatentEP2953764B1Machine tool with a device for acting against the weight of a machining head
Publication Date: 2022.01.26 INNSE BERARDI SPA
  • EP2953764B1 patent drawingFigure 1a~1b
  • EP2953764B1 patent drawingFigure 1c
  • EP2953764B1 patent drawingFigure 2a~2b

AI summary

A machine tool (1, 100) comprises a support structure (4, 104) and a machining head (8) bearing a mandrel (12). The machine further comprises at least one action device (20) contained on the support structure (4,104) and applied to it, which generates pushing or pulling actions on said support structure (4, 104) acting against the action of the weight of the head (8) thereon.