Rotation Indexing Oil Level Sensing for Accurate Machine Tools

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Solution Overview

Problem

In machine tools with rotation indexing devices, managing the oil level in storage parts is burdensome due to dirt accumulation and coolant mixing, leading to inaccurate lubrication and reduced angular position accuracy.

Innovation Solution

A detection device is provided for each storage part to detect the oil level, with a display device showing the detected information, allowing for easy management and reducing the need for manual cleaning and visual checks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a direct-view type oil gauge is provided for visual checking of oil level, then the operator can check the oil amount, but the oil gauge becomes obscured by dirt accumulation in the machining area

Engineering Contradiction:
Improveoil level informationVSAvoiddirt accumulation on oil gauge
Core Design Contradiction:
Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/visual direct-view oil gauge with an optical detection system using a level sensor and display device. The level sensor detects the oil level electronically and transmits this information to a display device, eliminating the need for direct visual observation through a gauge that is susceptible to dirt accumulation. This substitution of the monitoring mechanism resolves the contradiction by maintaining information accessibility while removing the vulnerability to contamination.

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

2Reliability

If manual visual checking of oil level is required, then the oil amount can be monitored, but the operator burden increases due to cleaning operations and frequent checks

Engineering Contradiction:
Improveoil level monitoringVSAvoidoperator burden for oil management
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system implements self-service monitoring where the level sensor automatically detects and reports the oil level without requiring operator intervention for visual inspection. The display device continuously shows the oil level information, and the system can automatically alert when lubrication is needed, eliminating the manual cleaning and frequent visual checking that burdened the operator while maintaining reliable monitoring.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent establishes a feedback loop where the level sensor continuously monitors the oil level and provides real-time information to the display device. This automatic feedback mechanism replaces manual checking by providing continuous, up-to-date information about the lubrication state without requiring operator action, thereby reducing burden while maintaining reliability.

Inventive Principle:
Principle #23Feedback

3Reliability

If coolant liquid flows into the storage part, then the storage part can be sealed, but the lubricating oil becomes mixed with coolant and lubricating performance deteriorates

Engineering Contradiction:
Improvelubrication qualityVSAvoidcoolant liquid contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by implementing a level sensor that detects oil level changes before significant contamination can occur. When the oil level drops (indicating potential leakage or contamination), the system alerts the operator in advance, allowing corrective action to be taken before the lubricating oil becomes severely mixed with coolant and performance deteriorates. This preventive monitoring maintains lubrication quality by enabling early intervention.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4101582A1Machine tool including rotation indexing device
Publication Date: 2022.12.14 KOMATSU NTC LTD
  • EP4101582A1 patent drawingFigure 1
  • EP4101582A1 patent drawingFigure 2
  • EP4101582A1 patent drawingFigure 3

AI summary

A machine tool (1) includes a rotation indexing device (2). The rotation indexing device includes a frame (5, 6) accommodates a rotary shaft, a drive motor (21; 41) rotationally drives the rotary shaft (8; 17), a drive transmission mechanism (28; 43) accommodated in a space inside the frame, and a detection device (61, 62, 63, 64). The drive transmission mechanism (28; 43) includes a gear mechanism (26; 27; 44; 45), and the space includes one or more storage parts (31, 32, 33, 34) for storing lubricating oil. The detection device (61, 62, 63, 64) detects a height position of an oil level of the lubricating oil, and is provided on a oneto-one basis with respect to a detection target storage part, which is set as a detection target, of the one or more storage parts (31, 32, 33, 34).