Auto Door Pneumatic Exhaust Control After Emergency Stop
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Solution Overview
Problem
Existing pneumatic control systems for auto doors in machine tools experience sudden acceleration after an emergency stop, compromising controllability during restarts.
Innovation Solution
A pneumatic control device with a first directional control valve, door detection sensors, and second directional control valves that exhaust compressed air at reduced speed upon an emergency stop signal, allowing the controller to manage the door's open/close state and adjust exhaust speed to prevent sudden acceleration during restarts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the compressed air is supplied to the door cylinder at normal speed, then the door operation efficiency is maintained, but sudden acceleration occurs after emergency stop which deteriorates controllability
Solution Approach 1:
The patent applies dynamics by making the exhaust speed of compressed air variable rather than fixed. The control valve adjusts the exhaust speed of compressed air from the door cylinder based on operational conditions, particularly after emergency stop. This dynamic adjustment prevents sudden acceleration by controlling the rate at which compressed air is exhausted, thereby maintaining controllability while allowing normal operation speed efficiency.
2Speed
If the compressed air is exhausted quickly from the door cylinder, then the door stops rapidly during emergency stop, but the door may collide with obstacles due to high deceleration
Solution Approach 1:
The patent applies beforehand cushioning by introducing a controlled exhaust mechanism that gradually reduces the speed of compressed air exiting the door cylinder. The control valve is configured to limit the exhaust speed of compressed air, creating a cushioning effect that prevents sudden deceleration. This ensures the door stops at a controlled rate after emergency stop, reducing the risk of collision damage while still achieving rapid stopping.
3Reliability
If the second directional control valves are added to control exhaust speed, then sudden acceleration is prevented, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing the control valve to perform multiple functions: it controls the exhaust speed of compressed air under normal operation, manages emergency stop deceleration, and prevents sudden acceleration after emergency stop. By making the control valve multi-functional, the patent avoids adding separate dedicated components for each function, thereby limiting the increase in device complexity while achieving reliable controllability in various operational scenarios.
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
Prevents sudden acceleration of the door during system restarts after an emergency stop by gradually exhausting compressed air, ensuring controlled and safe operation.
Implementation Method 1
second directional control valves installed in first and second exhaust lines respectively connected to first and second outlet ports of the first directional control valve, and capable of changing positions to reduce an exhaust speed of the compressed air
Data Source
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AI summary
A pneumatic control device of auto door includes a first directional control valve configured to control a direction of a compressed air supplied to a door cylinder for opening and closing a door, a door detection sensor configured to detect an open/close state of the door, first and second exhaust lines respectively connected to first and second outlet ports of the first directional control valve, and second directional control valves installed in the first and second exhaust lines respectively to operably exhaust the compressed air exhausted from the first and second outlet ports according to an emergency stop signal, and capable of changing positions to reduce an exhaust speed of the compressed air in case that the door is not completely open or closed when an operation signal is generated after the emergency stop signal.