Load Cell Placement for Roll Load Control in Substrate Cleaning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate cleaning apparatuses face challenges in accurately measuring and controlling the roll load applied to substrates due to mechanical friction, backlash, and other structural issues, leading to fluctuations and reduced cleaning performance.
Innovation Solution
A substrate cleaning apparatus with a load cell positioned between the vertically movable unit and the roll holder, eliminating intermediate structures that cause friction and ensuring accurate transmission and measurement of the roll load, coupled with a controller for feedback control using an electropneumatic regulator to maintain a preset roll load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If intermediate structures (bearings, link rods, beams) are used between the pressure sensor and roll holder, then mechanical support and movement guidance are provided, but mechanical friction and backlash increase, reducing measurement precision
Solution Approach 1:
The patent extracts and eliminates the intermediate structures (bearings, link rods, beams) from the measurement system. The load cell is directly coupled to the roll holder, removing the problematic intermediate components that caused friction and backlash, thereby improving measurement precision without excessive complexity
Solution Approach 2:
The load cell serves multiple functions: it provides mechanical support for the roll holder, guides vertical movement, and simultaneously measures the roll load. This multi-functionality eliminates the need for separate intermediate support structures, reducing both complexity and measurement error
2Extent of automation
If feedback control is implemented using supply pressure measurement, then roll load control is attempted, but measurement accuracy is insufficient because supply pressure does not precisely indicate actual roll load
Solution Approach 1:
The patent replaces the pneumatic pressure measurement system with a direct mechanical measurement system using a load cell. This substitution provides accurate mechanical force measurement, enabling precise feedback control of the roll load while maintaining automation
Solution Approach 2:
The load cell provides real-time measurement of the actual roll load, which is fed back to the control system. This feedback enables continuous adjustment of the air cylinder output to maintain the desired roll load, achieving both automation and measurement precision
3Device complexity
If roll load is adjusted only at startup or maintenance, then device complexity is reduced, but the actual roll load during operation cannot be accurately controlled due to property variation and time-dependent changes
Solution Approach 1:
The patent implements a feedback control system where the load cell continuously measures the actual roll load and the control system adjusts the air supply to the cylinder. This closed-loop control maintains consistent roll load despite property variations or time-dependent changes in the cleaning member
Solution Approach 2:
The system performs self-adjustment of the roll load through automatic feedback control. The load cell and control system work together to automatically compensate for changes in the cleaning member properties without requiring manual intervention, ensuring reliable and consistent operation
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 configuration allows for precise measurement and control of the roll load, enhancing cleaning performance by ensuring uniform contact and reducing initial disturbances, thus improving the accuracy and reliability of the cleaning process.
Implementation Method 1
a load cell provided between the vertically movable unit of the vertical movement mechanism and the roll holder and configured to measure the roll load
Implementation Method 2
a controller configured to perform feedback control of the roll load through the regulating device of the actuator based on a measured value of the load cell
Data Source
AI summary
A substrate cleaning apparatus for performing scrub cleaning of a surface of a substrate by rotating both of the substrate and a roll cleaning member while keeping the roll cleaning member in contact with the surface. The apparatus includes a roll holder configured to support and rotate a roll cleaning member, a vertical movement mechanism, having a vertically movable unit vertically movable by actuating an actuator having a regulating device, configured to vertically move the roll holder coupled to the vertically movable unit so the roll cleaning member applies a roll load to the substrate W while cleaning the substrate. A load cell provided between the vertically movable unit of the vertical movement mechanism and the roll holder is configured to measure the roll load. A controller is configured to perform feedback control of the roll load through the regulating device based on a measured value of the load cell.