Multi-Spindle Lathe with Pivoting Carrier for Chip-to-Chip Time Reduction

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Solution Overview

Problem

Current lathes experience prolonged 'chip-to-chip time' due to inefficient workpiece changing processes, which negatively impacts production efficiency, especially when processing times are short.

Innovation Solution

The implementation of a lathe design featuring multiple independent workpiece spindles, each with a separate electric motor, allowing for simultaneous machining and workpiece loading/unloading, with a pivoting or translational movement mechanism that minimizes downtime by enabling workpiece change during ongoing machining operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single workpiece spindle is used, then the device complexity is low, but the productivity is reduced due to prolonged chip-to-chip time

Engineering Contradiction:
Improvechip-to-chip timeVSAvoidnumber of workpiece spindles
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The single workpiece spindle is segmented into multiple independent workpiece spindles (first and second workpiece spindles), each capable of independent operation. This allows one spindle to perform machining while another prepares or changes workpieces, thereby reducing chip-to-chip time and increasing productivity without requiring complex coordinated control systems.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second workpiece spindle is used to perform preliminary actions by preparing workpieces in advance while the first spindle is machining. This includes loading new workpieces onto the second spindle's workpiece holder, so that when the first spindle completes machining, the transition to the next workpiece is already prepared, minimizing downtime.

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If workpiece changing is performed manually, then the ease of operation is maintained, but the loss of time increases during workpiece changes

Engineering Contradiction:
Improveworkpiece change timeVSAvoidworkpiece change operation
Core Design Contradiction:
Loss of timeVSEase of operation

Solution Approach 1:

The system maintains continuity of useful action by ensuring that while one workpiece spindle is engaged in machining (useful action), the other spindle is engaged in workpiece preparation and changing (also useful action). This parallel execution eliminates idle time and ensures that useful work is being performed continuously across the system, reducing overall workpiece change time.

Inventive Principle:
Principle #20Continuity of useful action

3Reliability

If multiple workpiece spindles are provided with separate electric motors, then the reliability is improved, but the use of energy increases

Engineering Contradiction:
Improvespindle operation reliabilityVSAvoidenergy consumption of multiple motors
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies partial action by operating only the necessary number of workpiece spindles and motors at any given time. Since the spindles work in parallel with distinct functions (one machining, one preparing), the system avoids the excessive energy consumption that would result from coordinating multiple motors simultaneously, while still achieving the reliability benefits of having multiple independent spindles.

Inventive Principle:
Principle #16Partial or excessive action

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 design significantly reduces 'chip-to-chip time' by allowing continuous machining with minimal interruption, enhances energy efficiency through regenerative braking, and supports complex processing methods by providing a buffer of prepared workpieces.

Implementation Method 1

each having a separate electric motor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

enhances energy efficiency through regenerative braking

Methodology Applied
Scientific EffectRegenerative braking: Electromagnetic Induction

Data Source

PatentEP2272624B1Lathe with two workpiece spindles
Publication Date: 2011.06.01 LIESE GUNTHER
  • EP2272624B1 patent drawingFigure 1A
  • EP2272624B1 patent drawingFigure 1B
  • EP2272624B1 patent drawingFigure 1C

AI summary

The lathe (10) has a spindle, a clamping unit (22) for clamping a work piece (48), and a platen (18), particularly a turret, incorporating one or multiple work pieces (19). Multiple work piece spindles (20A,20B) are fixed to a spindle carrier (21). The spindle carrier has a traversing mechanism, which simultaneously moves out former work piece spindle from a machining chamber (15) serving the machining work pieces and moves in latter work piece spindle into the machining chamber.