Numerical Controller DNC Buffering for Tool Mark Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Numerical controllers face challenges in controlling the timing of readout and buffering of machining programs when the transfer rate is low, leading to potential tool marks or vibrations due to buffer emptiness, and existing solutions lack practicality and effectiveness in setting reduction rates or enabling tool retreat functions.
Innovation Solution
A numerical controller with a DNC operation unit that buffers machining programs from external storage, includes buffering points for diagnosis and execution, and allows for tool retreat settings, ensuring continuous operation by inserting buffering points strategically to prevent buffer overflow and tool marks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If DNC operation is used to read machining programs from external storage or host, then internal memory capacity requirements are reduced, but readout time increases and machining time increases
Solution Approach 1:
The machining program is divided into multiple blocks, with a predetermined number of blocks buffered in the operation buffer at once. This segmentation allows the system to process multiple blocks in batches rather than one at a time, improving efficiency while managing limited memory resources effectively.
Solution Approach 2:
A predetermined number of machining program blocks are read and buffered in advance into the operation buffer before execution begins. This preliminary action ensures that the buffer is pre-filled with sufficient data to maintain continuous operation, reducing waiting time and preventing interruptions during machining.
2Productivity
If block-by-block processing is used to prevent increase in machining time, then machining continuity is maintained, but the operation buffer may become empty causing cutter marks or vibration
Solution Approach 1:
The system dynamically adjusts the number of blocks to be buffered based on the transfer rate. When the transfer rate is low, more blocks are buffered in advance to prevent buffer emptiness. This dynamic adaptation ensures continuous machining operation while maintaining surface quality by preventing cutter marks and vibration caused by buffer underflow.
Solution Approach 2:
The system monitors the transfer rate and uses this feedback to determine the appropriate number of blocks to buffer. This feedback mechanism allows the system to self-adjust buffering parameters in real-time, ensuring that the operation buffer remains sufficiently filled to maintain machining continuity and surface quality without unnecessary waiting time.
3Reliability
If cutting feed rate is reduced when operation buffer falls below predetermined block number, then buffer emptiness is prevented, but machining efficiency decreases
Solution Approach 1:
Instead of reactively reducing feed rate when the buffer is low, the system proactively buffers a predetermined number of blocks in advance based on the transfer rate. This preliminary action ensures the buffer remains sufficiently filled throughout operation, eliminating the need to reduce feed rate and maintaining machining efficiency while ensuring buffer continuity.
4Productivity
If tool retreat function is used when operation buffer becomes empty, then machining interruptions are prevented, but surface quality deteriorates due to tool movement
Solution Approach 1:
The system buffers a predetermined number of blocks in advance based on transfer rate monitoring, ensuring the operation buffer remains sufficiently filled before machining begins and throughout operation. This preliminary buffering action prevents buffer emptiness from occurring, eliminating the need for tool retreat functions and maintaining both machining continuity and surface quality without tool movement interruptions.
Data Source
AI summary
In a numerical controller including a DNC operation unit, an automatic operation execution unit includes a buffering completion checking result holding unit for checking whether a portion of a machining program to be buffered includes a buffering point, an execution checking result holding unit for checking whether a portion of the machining program to be executed includes a buffering point, a comparison unit for comparing the buffering completion checking result holding unit with the execution checking result holding unit, and an execution unit for performing any one of continuation, suspension, and resumption of the automatic operation based on a result of the comparison.