Grinding Machine Light Barrier for In-Process Clamping Length Measurement

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Solution Overview

Problem

Grinding machines face challenges in achieving high throughput due to the time-consuming process of determining the unclamping length of workpieces, which is essential for maintaining machining accuracy and efficiency.

Innovation Solution

The implementation of a light barrier with a transmitter and receiver for contactless measurement of the workpiece clamping length, allowing for simultaneous determination of the unclamping length during the movement of the workpiece spindle from the changing position to the machining position, eliminating the need for additional measurement time and enhancing throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a mechanical probe is used to scan the clamped workpiece to determine the clamping length, then the clamping length can be accurately measured, but additional time is required after the workpiece spindle returns to the machining position, reducing throughput

Engineering Contradiction:
Improveclamping length measurement accuracyVSAvoidworkpiece throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The light barrier is positioned to detect the workpiece clamping length during the movement of the workpiece spindle from the automation cabin to the machining position, before the spindle actually arrives at the machining position. This preliminary measurement eliminates the need for separate measurement time after positioning, as the measurement occurs concurrently with the positioning movement itself

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The mechanical probe measurement system is replaced with an optical measurement system using a light barrier. This substitution eliminates mechanical contact with the workpiece and enables measurement during the spindle's movement, rather than requiring the spindle to be stationary at the machining position for measurement

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

2Manufacturing precision

If the workpiece spindle moves to the machining position before determining the unclamping length, then accurate measurement can be performed, but the additional time required reduces the achievable throughput

Engineering Contradiction:
Improvemachining accuracyVSAvoidtime for unclamping length determination
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The unclamping length is determined in advance during the spindle's movement from the automation cabin to the machining position, using a light barrier positioned along the movement path. This preliminary determination ensures measurement is completed before the spindle reaches the machining position, eliminating any additional time loss

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If a robot is arranged outside the workspace in an automation cabin, then the robot does not intervene in the workspace during workpiece change, but the workpiece spindle must move towards or into the automation cabin, requiring additional space and time

Engineering Contradiction:
Improveworkpiece change operationVSAvoidworkpiece change speed
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

A light barrier is introduced as an intermediary measurement device positioned along the movement path between the automation cabin and the machining position. This allows the measurement function to be performed during the necessary movement, rather than requiring the movement to be slower or to wait for measurement after arrival

Inventive Principle:
Principle #24Intermediary (Mediator)

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 significantly increases the throughput of the grinding machine by eliminating the time required for separate unclamping length determination, enabling faster workpiece processing and maintaining high machining accuracy through contactless optical measurement.

Implementation Method 1

a light barrier with a transmitter and at least one receiver is provided for determining the unclamping length of the workpiece in the workpiece spindle when the workpiece spindle retracts from the automation cabin

Methodology Applied
Scientific EffectLight: Light

Data Source

PatentEP4467285A1Grinding machine and method for operating a grinding machine
Publication Date: 2024.11.27 ADELBERT HAAS GMBH
  • EP4467285A1 patent drawingFigure 1
  • EP4467285A1 patent drawingFigure 2
  • EP4467285A1 patent drawingFigure 3

AI summary

The invention relates to a grinding machine (1) with a machine bed (10) on which a workpiece spindle (20) with a workpiece holder (21) and a tool spindle (40) with a tool holder (41) are arranged such that a workpiece (100) held in the workpiece spindle (20) can be moved or rotated along several axes relative to a tool (45) held in the tool holder (40), wherein a cabin (30) is arranged on the machine bed (10) which defines a working area (31) in which, in particular, the tool spindle (40) and the workpiece spindle (20) are arranged for machining workpieces (100), wherein the grinding machine (1) has a robot (60) for workpiece change, which is arranged outside the working area (31) in an automation cabin (61).wherein the workpiece spindle (20) can be moved on the X-axis towards or into the automation cabin (61) for a workpiece change, so that the robot (60) does not interfere with the work area (31) during the workpiece change, characterized in that the grinding machine (1) has a light barrier (90) encompassing the X-axis with a transmitter (91) and at least one receiver (92) for determining the clamping length of the workpiece (100) in the workpiece spindle (20) when the workpiece spindle (20) is moved back from the automation cabin (61) after the workpiece change, and a method for operating such a grinding machine (1).