1. Layout points
Triangle principle: Triangle distribution at four corners and center of mold core (spacing ≤200mm)
Priority area: Support columns must be added at the bottom of slider, directly below lifter, and around glue inlet
Avoidance restricted area: Distance from ejector pin/waterway ≥5mm, distance from screw hole ≥3mm
2. Quick size check
Diameter range: φ12-30mm (φ12-16mm for small molds, φ20-30mm for automotive molds)
Height reserve: 0.03-0.05mm lower than mold frame (to prevent mold clamping injuries)
Chamfer specification: R1.5mm at the top, R3mm at the bottom (to prevent stress concentration)
3. Material selection
Conventional mold: SKD61 (hardness HRC48-52)
High-precision mold: carbide (tungsten steel)
Taboo: Pre-hardened steel such as P20 is prohibited (easy to deform)

1. Structural design
Step design: Bottom is 2-5mm wider than top (anti-eccentric load)
Guide reinforcement: 10mm wide guide strips are added on both sides (clearance 0.02-0.03mm)
Oil tank standard: "田"-shaped oil tank is opened on working surface (depth 0.5mm, width 2mm)
2. Matching accuracy
Gap with mold frame: 0.01-0.03mm in front/back direction, 0.03-0.05mm in left and right direction
Surface treatment: 0.1-0.15mm nitride layer (reduce friction coefficient)
Wear warning: Cumulative ejection > 100,000 times requires flatness inspection (tolerance > 0.05mm scrapped)
3. Pit avoidance guide
Avoid right-angle connection: Corners must be rounded R3 or more (to prevent cracking)
Avoid unilateral fixation: Fixing screws ≥4 and symmetrically distributed
Avoid no anti-rotation: At least 2 φ6 positioning pins are set

1. Size matching
Hole depth = spring free length + 5mm (preload space)
Aperture = spring outer diameter + 0.5mm (nitrogen spring requires + 1.0mm)
A φ3 exhaust hole must be set at the bottom (to prevent vacuum adsorption)
2. Installation iron rule
Spring compression ≤ 30% of free length (yellow spring ≤ 25%)
Height difference of springs in same group ≤ 0.05mm
Weekly inspection: Replace immediately if > 3 spiral cracks appear on the surface of spring
3. Life management
Ordinary spring: forced replacement after 100,000 times
Nitrogen spring: forced replacement after 300,000 times
Death mark: Spring verticality > 1° or surface oxidation and peeling

1. Must-do air-avoidance area
Ejector plate periphery: 0.5-1.0mm air-avoidance on one side
Slide rail: 0.3mm air-avoidance on one side of non-working surface
Hot runner wiring slot: depth is 2mm larger than wire diameter
2. Air-avoidance dimension specification
Screw hole: hole diameter = screw diameter + 0.5mm
Guide post hole: diameter = guide post diameter + 0.02mm (only 10mm section at the entrance)
Slanted ejector seat: 0.1mm air-avoidance on all four sides (to prevent jamming)
3. Taboos in air avoidance design
Avoid full-section air avoidance: Only 15mm section of guide sleeve hole is air avoided
Avoid sharp-angle air avoidance: Bottom of all air avoidance grooves must be R0.5mm or more
Avoid no marking: Air avoidance position during EDM processing must be marked with a "△" mark

Case 1: Support column fracture
Phenomenon: After 3000 molds of automobile door panel mold were produced, all 4 support columns were broken
Reason: φ16mm support column uses 45# steel (insufficient hardness)
Solution: Replace with φ20mm SKD61 support column, life extended to 100,000 molds
Case 2: Ejector block stuck
Phenomenon: Ejector delay of 0.5 seconds for every 500 molds produced
Reason: Ejector block oil groove blocked + guide clearance 0.08mm (3 times standard)
Solution: Re-match clearance + oil groove changed to spiral pattern, failure rate reduced to 0
Case 3: Spring burst
Phenomenon: Sparks from spring hole after 8 hours of continuous production
Reason: φ30 spring hole not vented + compression volume reached 35%
Solution: Drill φ3 vent hole at the bottom + replace 10mm long spring, no more bursts

 

Does support column avoid the ejector pin/waterway?
Is ejector block guide clearance ≤0.03mm?
Is there any vent at the bottom of spring hole?
Are all avoidance positions free of sharp corners?
Are there any electronic components within 10mm around nitrogen spring?
Key points:
Support column should be "hard" (material)
Ejector block should be "smooth" (surface)
Spring should be "loose" (preload)
Avoidance should be "accurate" (position)
Mastering these four elements can avoid 90% of mold support system failures. When encountering problems, check assembly accuracy first instead of blindly modifying design!