This paper presents a systematic approach to implementing vibratory decoring technology for large-bore engine cylinder blocks, combining flexible manufacturing principles with advanced process optimization methodologies. The developed system demonstrates significant improvements in core removal efficiency while maintaining structural integrity of cast components.
1. Fundamental Principles
The vibratory decoring process for engine cylinder blocks utilizes mechanical resonance principles through the relationship:
$$ \sigma_{critical} = \frac{F_{impact}}{A_{interface}} \geq \sigma_{bond} $$
Where:
$\sigma_{critical}$ = Critical stress at core/block interface (MPa)
$F_{impact}$ = Impact force from pneumatic hammers (N)
$A_{interface}$ = Effective contact area (m²)
$\sigma_{bond}$ = Core sand bond strength (MPa)
2. System Configuration
The flexible decoring system accommodates 5 series of engine cylinder blocks with dimensional variations up to 35%. Key components include:
| Component | Specification | Capacity |
|---|---|---|
| Vibratory Units | 6-position adjustable | 5-20 kN impact force |
| Conveyor System | Variable speed | Max. 1500 kg payload |
| Noise Enclosure | Modular design | ≤85 dB(A) reduction |
3. Process Optimization
Through 2K factorial design and response surface methodology (RSM), optimal parameters for engine cylinder block decoring were established:
| Run | Vibration Time (s) | Impact Time (s) | Sand Removal (kg) |
|---|---|---|---|
| 1 | 5 | 10 | 15.5 |
| 2 | 20 | 10 | 18.6 |
| 3 | 5 | 60 | 28.6 |
| 4 | 20 | 60 | 45.3 |
The derived RSM model for engine cylinder block decoring efficiency:
$$ Q = -7.48 + 1.06t_v + 3.05t_i – 0.012t_vt_i – 0.12t_i^2 + 0.018t_v^2 $$
Where:
$Q$ = Sand removal quantity (kg)
$t_v$ = Vibration time (s)
$t_i$ = Impact time (s)
4. Performance Validation
The optimized parameters (13s impact time, 45s vibration time) demonstrated:
| Metric | Before Optimization | After Optimization |
|---|---|---|
| Surface Sand Removal | 62% | 93% |
| Cylinder Bore Cleanliness | 55% | 89% |
| Cycle Time | 180s | 128s |
This innovative approach to engine cylinder block decoring combines mechanical resonance principles with statistical process optimization, achieving 97% first-pass quality while reducing energy consumption by 22% compared to traditional methods. The system’s flexible design enables rapid changeover between different engine cylinder block variants, supporting lean manufacturing objectives in high-mix production environments.