I. Structural Durability: Is there irreversible deformation or fatigue damage?
Structural components are the "skeleton" of the equipment. Plastic deformation or cracks will directly affect welding safety and accuracy.
Key warning signs:
Permanent bending or cracks in the frame or guide rails (especially in the weld area), even slight ones require immediate shutdown and inspection.
Significant platform shaking or abnormal noises during full-load operation indicate loose connecting bolts or decreased structural rigidity.
Deflection measurement exceeding L/800 (e.g., deformation > 5mm for a 4-meter span).
✅ Recommendation: Regularly screen high-stress areas using magnetic particle testing or ultrasonic testing. Initiate a major overhaul assessment immediately upon detection of microcracks.
II. Hydraulic System Stability: Is there pressure runaway or frequent leakage?
The hydraulic system is a high-risk area for failure. Its performance degradation is often gradual, but exceeding a certain threshold will lead to complete machine failure.
Key Judgment Signals:
Decreased Pressure Holding Capacity: Pressure drop >5% after holding pressure for 10 minutes at rated pressure.
Slow or Creeping Movement: Unstable cylinder extension/retraction, accompanied by shaking or stagnation.
Persistently High Oil Temperature: Oil temperature >65℃ after 1 hour of continuous operation, with no improvement from the cooling system.
Frequent Seal Leaks: Especially at the piston rod root, oil stains need to be wiped off weekly, and the problem persists even after replacement.
✅ Recommendation: If the main pump, proportional valve, or cylinder has failed more than twice consecutively, the entire hydraulic station should be overhauled or replaced.
III. Welding Actuator Accuracy: Does it affect weld consistency?
The accuracy of the fixture and electrode directly determines the weld quality; inaccurate accuracy can lead to batch defects.
Key Judgment Signals:
Repeat Positioning Accuracy > ±0.3mm: Multiple clamping deviation measurements using a dial indicator; exceeding this range indicates wear on the guide mechanism.
Clamping Force Fluctuation > 10%: Excessive range in three measurements may indicate internal leakage in the hydraulic cylinder or mechanical jamming.
Significantly Increased Electrode Grinding Frequency: Grinding has increased from once every 1000 cycles to once every 300 cycles.
Weld Point Quality Fluctuation: The proportion of defects such as undercut and incomplete fusion has increased, after ruling out material and process factors.
✅ Recommendation: Establish an electrode life monitoring table and analyze the welding current waveform to determine if the entire actuator unit needs replacement.
IV. Maintenance Costs: Have we entered the "replacement is worse than repair" stage?
Economics is the ultimate benchmark for overhaul decisions. When maintenance costs approach the price of a new machine, replacement is more cost-effective.
Key warning signs:
Annual maintenance costs exceed 40% of the new machine price.
Cost of a single major overhaul (e.g., replacing the main hydraulic cylinder and valve assembly) exceeds 60% of the new machine price.
Average monthly downtime > 48 hours, severely impacting production and delivery.
Energy consumption is more than 50% higher than new models, rendering energy-saving modifications ineffective.
