How to deal with mold processing malfunctions

　　When a malfunction occurs during the mold processing, it is necessary to quickly locate the root cause of the problem and adopt a systematic solution to avoid chain reactions. The following is the phased processing flow and key technical points:

　　1、 Emergency response phase

　　1. Shutdown protection

　　Immediately cut off the power/gas supply of the equipment and maintain the status of the fault site (such as unfinished workpiece position, tool damage fragments).

　　Attention: The quasi dense machine tool needs to perform a safe zeroing operation first to avoid servo motor step loss.

　　2. Preliminary diagnosis

　　Sensory judgment: Observe the location of abnormal noise (such as spindle bearings), odor (burnt cables), and abnormal vibration frequency.

　　Equipment alarm code: Record CNC system alarm information (such as FANUC's "PS 410" indicating servo overload).

　　2、 Fault classification and handling plan

　　(1) Machine tool equipment malfunction

　　Key technical points of fault type handling steps

　　Spindle lock 1 Check the coolant flow rate

　　2. Detect the temperature curve of the bearing and use an infrared thermal imager to locate high temperature points (abnormal above 80 ℃)

　　Rail crawling 1 Re lubricate (ISO VG68 rail oil)

　　2. Check the straightness of the preloading slider gauge (if the error is greater than 0.02mm/m, it needs to be adjusted)

　　Random knives in the knife storage 1 Reset the origin of the tool magazine

　　2. Check the Hall sensor signal and manually verify the tool position on the teaching pendant (within an error of ± 0.5 °)

　　(2) Processing technology malfunction

　　Problem phenomenon solution, process parameter optimization

　　The workpiece size exceeds the tolerance by 1 Compensate for tool wear

　　2. Verify the G54 coordinate system and leave a 0.02mm margin for fine adjustment during precision machining

　　Surface vibration pattern 1 Reduce feed rate by 30%

　　2. Use a variable pitch milling cutter to avoid the resonance frequency band of the machine tool (such as around 12000rpm)

　　Abnormal electrical loss 1 Check the electrical spark performance settings

　　2. Adjust the pulse interval. When processing steel parts with copper, the pulse width should be ≤ 50 μ s

　　(3) Mold design defects

　　Welding repair: For cracked areas (such as the R angle of the mold core), laser cladding is used followed by re grinding (hardness error ≤ HRC2).

　　Structural optimization: Adjust the gate position through Moldflow analysis (such as changing the edge gate to a fan-shaped gate to improve filling).

　　3、 Deep analysis and prevention

　　Root Cause Analysis (RCA)

　　Example of 5Why analysis method:

　　→ Problem: Pin breakage

　　Why 1: The material of the top pin is not qualified (measured HRC52 is lower than the required HRC58)

　　Why 2: The supplier did not follow the SOP for heat treatment (tracing the purchase batch)

　　→ Why 3: Failure to perform full hardness inspection on incoming goods (only 10% sampling inspection)

　　2. Error prevention measures

　　Hardware error prevention: Install an electrical automatic detection device on EDM machine tools.

　　Software error prevention: Set the tool diameter tolerance lock during CAM programming (such as prohibiting operation outside ± 0.01mm).

　　3. Data based monitoring

　　Deploying IoT sensor monitoring:

　　Spindle vibration acceleration (normal value<2.5m/s ²)

　　Cutting force fluctuation (triggering warning if exceeding the mean by 20%)

　　4、 Typical fault handling cases

　　Case 1: Deep cavity mold sticking

　　Phenomenon: Tearing of ABS products during demolding

　　Handling:

　　Polish the mold cavity to Ra0.05 μ m (original Ra0.4 μ m)

　　Increase the demolding slope to 2 ° (originally 0.5 °)

　　Raise the mold temperature from 60 ℃ to 85 ℃ to reduce shrinkage stress

　　Effect: Waste rate reduced from 15% to 0.3%

　　Case 2: Distortion of tooth profile in quasi dense gear mold

　　Phenomenon: involute profile error 0.03mm (requirement 0.01mm)

　　Handling:

　　Verify the angle of the grinding wheel dresser (error compensation 0.1 °)

　　Using CBN grinding wheel instead of ordinary grinding wheel

　　Temperature controlled workshop processing (20 ± 1 ℃)

　　Effect: Achieve DIN 3962 level 4 accuracy

　　5、 Construction of standardized fault library

　　Establish a fault code manual

　　Description of fault code symptoms, average processing time for solutions

　　MC-004 slow wire breakage inspection deionized water resistivity (>50k Ω/cm) 2.5 hours

　　Develop an expert diagnostic system

　　Input symptoms (such as "over cutting at the bottom of the cavity") → output possible causes (coordinate system offset/tool length compensation error, etc.) and processing priority.

　　6、 Personnel capability enhancement

　　Practical training:

　　Conduct monthly 'fault simulation drills' (such as intentionally setting spindle encoder faults for technicians to troubleshoot).

　　Skill certification:

　　Establish the qualification certification of "Mold Emergency Physician" (required to independently handle over 20 types of malfunction cases).

　　Key principles

　　Safety first: When dealing with high-voltage electricity/heavy components, two people must work together.

　　Data driven: After troubleshooting, the PDCA cycle table (plan execute check improve) needs to be updated.

　　Cost balance: Repairs exceeding 50000 yuan require an assessment of the remaining life of the mold (refer to the injection molding frequency records).

　　Through systematic fault management, unplanned downtime of molds can be controlled within<2% per year, reaching Toyota TPS level.