Tool Gripper Arrangement With Free Rotation For Collet Alignment

Solution Overview

Problem

Robot arms used for loading tools into grinding or milling machines face accuracy issues due to environmental changes like temperature and humidity fluctuations, leading to misalignment and incorrect loading, especially in low clearance situations, resulting in wasted time and materials.

Innovation Solution

A tool gripping arrangement with a tool clamp gripper that provides compliance through rotational movement, allowing horizontal adjustment to align tools with the collet, mounted on a robot arm for free rotation to accommodate misalignment caused by thermal expansion, with mechanical stops to limit excessive rotation and ensure accurate alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If a robot arm is used to load tools into a collet, then automation and safety are improved, but positioning accuracy deteriorates due to environmental changes

Engineering Contradiction:

Improverobot loadingVSAvoidtool positioning accuracy

Core Design Contradiction:

Extent of automationVSManufacturing precision

Solution Approach 1:

The tool clamp gripper is mounted for free rotation relative to the mounting arrangement, allowing the gripper to dynamically adjust its angular position to compensate for thermal expansion and contraction of the robot arm, maintaining accurate tool alignment with the collet despite environmental changes

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system allows the angular parameter of the tool clamp gripper to change freely within a limited range (0.5 to 2 degrees), enabling automatic compensation for dimensional changes in the robot arm caused by temperature and humidity variations

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the robot arm is made rigid to maintain positioning accuracy, then manufacturing precision is improved, but adaptability to environmental changes deteriorates

Engineering Contradiction:

Improvetool alignment accuracyVSAvoidcompensation for thermal expansion

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The tool clamp gripper is mounted for free rotation relative to the mounting arrangement, allowing the gripper to dynamically adjust its angular position to compensate for thermal expansion and contraction of the robot arm, maintaining accurate tool alignment with the collet despite environmental changes

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system allows the angular parameter of the tool clamp gripper to change freely within a limited range (0.5 to 2 degrees), enabling automatic compensation for dimensional changes in the robot arm caused by temperature and humidity variations

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If frequent recalibration is performed to maintain accuracy, then manufacturing precision is improved, but productivity deteriorates due to downtime

Engineering Contradiction:

Improveloading accuracyVSAvoidmachine downtime

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The tool clamp gripper automatically compensates for robot arm dimensional changes through free rotation, eliminating the need for frequent manual recalibration and maintaining accurate tool loading without production downtime

Inventive Principle:

Principle #25Self-service

4Manufacturing precision

If the clearance between tool and collet is reduced to improve precision, then manufacturing precision is improved, but reliability deteriorates due to sensitivity to misalignment

Engineering Contradiction:

Improveclearance toleranceVSAvoidloading success rate

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The tool clamp gripper is mounted for free rotation relative to the mounting arrangement, allowing the gripper to dynamically adjust its angular position to compensate for thermal expansion and contraction of the robot arm, maintaining accurate tool alignment with the collet despite environmental changes

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system allows the angular parameter of the tool clamp gripper to change freely within a limited range (0.5 to 2 degrees), enabling automatic compensation for dimensional changes in the robot arm caused by temperature and humidity variations

Inventive Principle:

Principle #35Parameter changes

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 ensures accurate loading and machining by accommodating misalignment up to 300 microns, reducing downtime and material waste by allowing quick and precise alignment without the need for frequent recalibration, maintaining tool integrity and machine efficiency.

Implementation Method 1

the robot arm expands or contracts due to changes in temperature or humidity

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS9919396B2Tool gripper arrangement

Publication Date: 2018.03.20 ANCA PTY LTD

AI summary

A tool gripping arrangement for loading an elongate tool having a lengthwise axis into a collet. The tool gripping arrangement includes a tool clamp comprising a pair of tool clamp grippers for clamping the tool along a clamping axis. The tool gripping arrangement further includes a mounting arrangement for mounting the gripping arrangement to a robot arm, the tool clamp being mounted for free rotation relative to the mounting arrangement.