Optical Tool Measurement Shutter for Sensor Contamination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical tool measurement devices for machine tools face challenges in protecting sensors from contamination in harsh environments, particularly due to the ineffectiveness of existing shutter systems in preventing debris and coolant ingress, especially for camera-based systems with larger apertures.
Innovation Solution
The optical tool measurement device incorporates a shutter assembly with three configurations: closed for maximum protection, open for full vision mode, and constricted with a smaller aperture for reduced contamination resistance, allowing measurements even in contaminated environments, combined with a pneumatic system for debris clearance and gas flow to prevent contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a mechanical shutter is opened to allow light to reach the sensor for tool measurement, then tool inspection capability is enabled, but contaminants in the machine tool environment can ingress through the aperture and contaminate the sensor
Solution Approach 1:
The shutter assembly is designed to be dynamically adjustable between multiple configurations (fully open, partially open with constricted aperture, and fully closed) rather than simply binary open/closed. This allows the aperture size to be optimized based on environmental conditions - fully open when clean for maximum light transmission, partially open when contaminated to maintain protection while enabling measurements, and fully closed when severely contaminated
Solution Approach 2:
The system changes the aperture parameter (opening size) based on contamination levels detected in the environment. The controller receives contamination level information and adjusts the shutter position accordingly, transforming the fixed aperture design into a variable aperture system that adapts to environmental conditions to balance light transmission and contamination protection
2Illumination intensity
If a large aperture is used in the shutter assembly to allow sufficient light for camera-based measurement, then imaging capability is improved, but contamination resistance is reduced
Solution Approach 1:
The shutter assembly provides dynamic control over aperture size, allowing the system to switch between large aperture (for maximum light transmission during clean operations) and small aperture (for contamination protection during polluted operations). This resolves the contradiction by making the aperture size adaptive rather than fixed
Solution Approach 2:
The shutter assembly is segmented into multiple positional states (fully open, partially open with constricted aperture, fully closed), allowing selective activation of different aperture sizes based on measurement needs and environmental conditions. This segmentation enables the system to optimize between light transmission and contamination protection on demand
3Object-affected harmful factors
If the shutter remains closed to protect the sensor from contamination, then sensor protection is maximized, but tool measurement capability is lost
Solution Approach 1:
Instead of uniformly opening the entire shutter, the system selectively opens only the necessary portion (constricted aperture) to allow light transmission for measurement while maintaining protection for the rest of the sensor area. This local quality approach ensures that the minimum necessary opening is provided for functionality while maximizing protection elsewhere
4Object-affected harmful factors
If compressed air flow is used to clear debris from the aperture, then contamination is reduced, but the pneumatic system complexity increases
Solution Approach 1:
The compressed air system is activated in advance (or simultaneously) with shutter opening to clear debris from the aperture area before contaminants can ingress. This preliminary cleaning action prevents contamination rather than just responding to it, reducing the need for complex post-contamination cleaning systems
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 device provides enhanced contamination resistance and flexibility, enabling reliable measurements in both vision and break-beam modes, with the constricted configuration allowing tool analysis even in the presence of contaminants, and ensuring the sensor remains protected from external contaminants.
Implementation Method 1
a light source for directing light towards a tool-sensing region, a sensor for detecting light from the tool-sensing region
Implementation Method 2
A flow of compressed air out of the apertures is used to reduce the risk of contaminants etc entering the device or obscuring the optical pathway
Data Source
Figure 1~2c
Figure 3~4
Figure 5a~5c
AI summary
An optical tool measurement device (2) for a machine tool is described. The device comprises a light source (10) for directing light towards a tool-sensing region (13) and a sensor (14) for detecting light from the tool-sensing region (13). A shutter assembly (40) for selectively protecting the sensor (14) from contamination is also provided. The shutter assembly (40) is configured to provide a closed configuration in which the sensor (14) is covered by the shutter assembly (40) thereby preventing contamination of the sensor (14) and an open configuration in which light can pass to the sensor (14) through a first aperture (72;102) of the shutter assembly (40). Furthermore, the shutter assembly (40) is additionally configured to additionally provide a constricted configuration in which light can pass to the sensor through a second aperture (74;104) of the shutter assembly (40), the second aperture being smaller than the first aperture. In this manner, the device (2) has enhanced resistance to contaminants, such as swarf and coolant, present in the machine tool environment.