Press Machine Load Detection for Negative Load Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Press machines face difficulties in detecting and managing negative loads during the breakthrough phase of the pressing process, leading to potential damage and defects due to excessive loads, which existing control systems fail to adequately address.
Innovation Solution
A control system for press machines that includes a load detector to measure both positive and negative loads, a determination unit to assess when to execute an emergency stop based on predetermined overload or lower limit values, and a drive control unit to promptly stop or move the slide to a standby position, thereby preventing abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If only the pressing force (positive load) of the slide is detected, then the detection system is simple, but the negative load at the time of breakthrough cannot be properly detected
Solution Approach 1:
The system continuously monitors the load on the slide and provides feedback to the control unit. The load detector measures both positive pressing forces and negative breakthrough forces, and this real-time feedback enables the control unit to detect abnormal loads and trigger emergency stops, thereby resolving the contradiction between detection capability and system complexity.
2Reliability
If the pressing force is increased to ensure proper pressing, then pressing effectiveness is improved, but damage to components or defects occur more easily due to excessive force
Solution Approach 1:
The load detector provides continuous feedback on the actual pressing force applied to the workpiece. The control unit compares this feedback against predetermined thresholds and triggers an emergency stop when abnormal loads are detected, ensuring reliable pressing quality while preventing damage from excessive force.
Solution Approach 2:
The system establishes predetermined first and second overload determination values as safety thresholds before operation begins. These pre-set limits act as a cushioning mechanism that prevents excessive loads from causing damage, allowing the system to operate at high pressing forces while maintaining component safety.
3Reliability
If the slide is stopped immediately when abnormal load is detected, then component damage is prevented, but productivity decreases due to production interruption
Solution Approach 1:
The system applies partial emergency stop action by first moving the slide to a standby position rather than an immediate complete stop. This partial action approach maintains component safety by stopping the pressing operation while minimizing production interruption, thereby resolving the contradiction between reliability and productivity.
4Productivity
If the slide is moved to standby position instead of immediate stop, then productivity is maintained, but component protection response time is delayed
Solution Approach 1:
The system implements partial emergency stop by moving the slide to a standby position that is not immediately adjacent to the workpiece. This allows the slide to be repositioned safely without requiring an abrupt stop, thereby maintaining production continuity while still providing adequate component protection through the controlled deceleration and positioning process.
Data Source
AI summary
A control system includes a load detector, a determination unit, and a drive control unit. The load detector detects a load of a slide. The load of the slide includes a positive load due to a pressing force of the slide during pressing and a negative load at the time of a breakthrough. The determination unit determines whether to execute emergency stopping of the slide based on the positive load and the negative load detected by the load detector. The drive control unit controls the driving of the slide based on the determination result of the determination unit.