Tool Setting Device Backup Trigger Signal for CNC Blind Window
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Solution Overview
Problem
Existing tool setting devices may fail to recognize complex signals from rotating tools, leading to potential accidental damage due to incorrect tool positioning, and some CNC machine tools have a 'blind window' period where they do not react to valid trigger signals, causing crashes.
Innovation Solution
A secondary trigger signal generating circuit and an oscillating trigger signal are introduced to ensure fail-safe operation by providing a backup trigger signal if the main analysis circuit fails, and repeated trigger signals are generated after the blind window to ensure the controller reacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a main analysis circuit is used to detect complex signals from rotating tools, then measurement precision and repeatability are improved, but reliability deteriorates due to potential failure to recognize signals in rare circumstances
Solution Approach 1:
A secondary backup trigger signal generating circuit is provided in parallel with the main analysis circuit. This backup circuit uses a simpler detection method that generates a trigger signal if the receiver signal remains in a given state for longer than a predetermined time period, providing a safety net against main circuit failures.
Solution Approach 2:
The patent changes the detection parameter from complex signal pattern recognition (main circuit) to simple state duration detection (secondary circuit). The secondary circuit monitors whether the receiver signal remains in a given state for a predetermined time period, using a different detection approach to ensure reliability.
2Device complexity
If a single trigger signal is sent to the CNC controller, then device complexity is reduced, but reliability deteriorates due to the blind window period where the controller fails to react
Solution Approach 1:
An oscillator or oscillation generator is connected to provide an oscillating trigger signal, associated with the secondary circuit. This causes repeated trigger outputs after the end of the delay period, ensuring that if a tool breaks the beam within the blind window, the repeated signals will continue until after the end of the blind window and ensure the controller reacts.
Solution Approach 2:
The system prepares for the blind window problem by implementing a secondary circuit with delay and oscillation capabilities that can generate trigger signals that persist through the controller's non-responsive period, ensuring eventual detection and response.
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 reliable tool detection and positioning, preventing accidental damage by providing a fail-safe mechanism that guarantees the machine tool stops moving during the blind window, thus enhancing safety and accuracy.
Implementation Method 1
a light source for producing a light beam
Implementation Method 2
a light receiver for receiving the light beam and producing therefrom a signal indicative of the amount of light received
Data Source
AI summary
A tool setting or tool analysis device for a machine tool includes a light source for producing a light beam. A light receiver receives the light beam and produces a signal indicative of the amount of light received. This is analyzed by a main analysis circuit to generate a trigger signal to a machine controller when the beam is at least partially occluded. To provide fail-safe operation should the main circuit not recognize the tool, a back-up trigger signal is produced after a delay by a delay circuit. In one preferred form, the back-up trigger signal may oscillate, providing repeated edges which can ensure fail-safe operation even if the machine controller suffers from a blind window and therefore misses the initial trigger signal.