Movable Guide Bushing for Dual-Spindle Lathe Precision

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Solution Overview

Problem

Existing machine tools with front and back spindles having the same axial line face challenges in precision machining due to the need for multiple guide bushings, which increases tool complexity and limits the ability to machine workpieces between spindles without vibration and deflection suppression.

Innovation Solution

A method employing a movable guide bushing with aligned axial lines between the front and back spindles, allowing the workpiece to be inserted and machined from either end, with the guide bushing supporting the workpiece to suppress vibrations and deflections, and enabling the tool post to move synchronously with the guide bushing in the axial direction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If guide bushings are provided respectively to front and back spindles to suppress vibrations and deflections, then machining precision is improved, but the machine tool becomes relatively enlarged and more complex

Engineering Contradiction:
Improvemachining precisionVSAvoidmachine tool complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the guide bushing function into a single integrated component positioned between the front and back spindles, rather than providing separate guide bushings for each spindle. This single guide bushing serves both spindles by guiding the workpiece from either end, thereby reducing the number of components and simplifying the machine tool structure while maintaining vibration and deflection suppression capabilities

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide bushing is designed with multi-functionality to serve both the front spindle and the back spindle. By positioning it between the two spindles and enabling workpiece insertion from either end, the single guide bushing performs the guidance function for both spindles, eliminating the need for separate guide bushings and reducing overall device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If a single guide bushing is used between front and back spindles to simplify the machine tool, then device complexity is reduced, but the ability to machine workpieces from both spindles is limited

Engineering Contradiction:
Improvemachine tool complexityVSAvoidmachining versatility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The guide bushing is designed to be movable in the axial direction, allowing it to dynamically adjust its position to accommodate workpieces being machined from either the front spindle or the back spindle. This dynamic positioning capability enables the single guide bushing to adapt to different machining configurations, maintaining versatility while simplifying the overall machine tool structure

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The guide bushing is divided into two functional ends, with each end capable of guiding the workpiece when inserted from the corresponding spindle side. This segmentation of the guide function across two ends of a single component allows the machine tool to maintain the ability to machine from both spindles while using only one guide bushing

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If the guide bushing is made movable in axial direction to enable workpiece insertion from either end, then adaptability is improved, but control complexity increases

Engineering Contradiction:
Improveworkpiece insertion adaptabilityVSAvoidcontrol complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The guide bushing is designed to move automatically in the axial direction in response to workpiece insertion from either the front or back spindle, without requiring complex external control mechanisms. The movement is driven by the workpiece insertion itself, allowing the guide bushing to self-adjust its position to maintain proper alignment and guidance, thereby reducing control complexity while maintaining adaptability

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2548679B1Method for machining using a machine tool
Publication Date: 2019.04.24 CITIZEN MASCH CO LTD
  • EP2548679B1 patent drawingFigure 1
  • EP2548679B1 patent drawingFigure 2
  • EP2548679B1 patent drawingFigure 3

AI summary

There is provided a machine tool capable of working a workpiece regardless whether it is gripped by a front spindle or a back spindle while guiding a free end side thereof by one guide bushing (160), is simplify and compacted and suppresses an increase of a number of axes to be controlled. The machine tool comprises the front and back spindles (112) and (122) having one and same axial line and disposed so as to face to each other and a guide bushing (160) having an axial line identical with the axial line. The guide bushing (160) is disposed between the front and back spindles (112) and (122), is configured so that the guide bushing (160) can guide the workpiece on both ends of the workpiece (W), so that the workpiece gripped either by the front spindle (112) or the back spindle (122) can be inserted, and so that the guide bushing (160) is movable in an axial direction.