Machine Tool Clamping That Releases Side-Wall Stress During Machining

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Solution Overview

Problem

Modern internal combustion engines require precise machining of lightweight, filigree components, which poses challenges for traditional clamping devices in maintaining the necessary precision during machining processes, especially for components like connecting rods.

Innovation Solution

A machine tool design where the side wall delimiting the receptacle is movable and/or deformable transversely to the machining axis, allowing it to be entirely or substantially free of stress and unsupported by positioning surfaces during processing, enabling precise machining without lateral interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional clamping devices with fixed side wall positioning surfaces are used, then workpiece positioning is stable, but machining precision deteriorates for thin-walled or resilient components due to stress and lateral interference

Engineering Contradiction:
Improvemachining precisionVSAvoidworkpiece stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The side wall positioning surfaces are designed to be movable rather than fixed, allowing them to adapt their position during machining. This dynamic capability enables the positioning surfaces to move away from the workpiece when needed, eliminating stress and lateral interference on thin-walled components while maintaining positioning stability when required.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The positioning system changes the physical state of the side wall positioning surfaces from fixed to movable, altering the mechanical constraints applied to the workpiece. This parameter change allows the system to transition between providing stable positioning and eliminating stress, depending on the machining requirements.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If side wall positioning surfaces are used to laterally support the workpiece, then workpiece positioning is maintained, but machining precision deteriorates due to stress on the side wall during machining

Engineering Contradiction:
Improvemachining precisionVSAvoidside wall stress
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The side wall positioning surfaces are extracted from the fixed structure and made independently movable. This allows them to be positioned away from the workpiece during machining operations, completely removing the stress and lateral interference that would otherwise be applied to the side wall of thin-walled or resilient components.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The positioning surfaces transition from a static, stress-applying configuration to a dynamic, stress-free configuration during machining. The ability to move the positioning surfaces eliminates continuous lateral support and stress on the workpiece side wall, enabling high-precision machining of delicate components.

Inventive Principle:
Principle #15Dynamics

3Stability of the object's composition

If the side wall is fixed and supported during machining, then structural stability is maintained, but machining precision deteriorates for lightweight and filigree engine components

Engineering Contradiction:
Improvestructural stabilityVSAvoidmachining precision
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The clamping device incorporates movable side wall positioning surfaces that can dynamically adjust their engagement with the workpiece. During machining of lightweight and filigree components, these surfaces can be positioned to provide minimal or no lateral support, eliminating stress on the delicate structure while maintaining overall structural stability through the clamping arrangement.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3509787B1Machine tool comprising a clamping device and method
Publication Date: 2023.05.10 ALFING KESSLER SONDERMASCHINEN GMBH
  • EP3509787B1 patent drawingFigure 1
  • EP3509787B1 patent drawingFigure 2
  • EP3509787B1 patent drawingFigure 3

AI summary

The invention relates to a machine tool (10) comprising a clamping device (11) for a workpiece (80) and a machining tool for mechanically machining the workpiece (80), where the machining tool (60) penetrates, along a machining axis (63), into a receiving area of the workpiece, which extends from a front side of the workpiece (80) to a rear side of the workpiece, and is defined by a side wall (86) of the workpiece, the clamping device (11) comprising at least one side-wall-positioning surface (27, 28) for applying to the side wall of the workpiece with a force direction perpendicular to the machining axis (63), where the clamping device (11) has a positioning drive arrangement (20) for the relative positioning of the workpiece and the at least one side-wall-positioning surface (27, 28) perpendicularly to the machining axis (63), the clamping device (11) comprising at least one rear side clamping surface (143, 144) and at least one front side clamping surface (43, 44) for applying to the rear side or the front side of the workpiece and a clamping drive arrangement (40) for a relative adjustment of the front side clamping surface (43, 44) and the rear side clamping surface into a clamping position in which the workpiece is clamped between the rear side clamping surface and the front side clamping surface (43, 44) for machining by the machining tool. A control system controls the positioning drive arrangement (20) before the machining by the machining tool in order to remove the at least one side-wall-positioning surface (27, 28) from the workpiece, out of a positioning position (P) supporting the workpiece into a release position releasing the workpiece, such that the side wall defining the receiving area (85) is unloaded perpendicularly to the machining axis by the at least one side-wall-positioning surface (27, 28) when the machining tool penetrates into the receiving area.