Driven by the “dual-carbon” strategy, the new energy commercial vehicle industry is experiencing explosive growth. As a core component, the electronic control box needs to integrate high voltage power distribution, thermal management and other multi-functional modules in a limited space, and its design requirements show a significant trend of “thin-wall, integration, and lightweight”. A new generation of electronic control box products recently launched by a head of the automotive industry, not only requires the realization of the ultimate thin-wall design of 4-7mm, but also needs to be completed in a very short period of time from design verification to mass production and delivery of the whole process - this is the traditional casting process puts forward a nearly harsh challenge.
Technology Tackling: Facing Four Core Pain Points
The technical difficulty of the project is centered on three dimensions:
- 1. Structural limit challenges: the thinnest part of the shell is only 4mm, traditional sand casting is prone to cold segregation, underpouring and other defects.
- 2. Process complexity doubled: the need to simultaneously meet the multiple groups of shaped cooling channels, embedded mounting slots and other complex features of the one-time molding
- 3. Tight time window: the traditional process requires 3-5 design iterations, which can not be delivered within the specified time, and the project requires the first version of the mold to achieve > 90% pass rate
- 4. Cost control red line: the cost of a single prototype must not be higher than 150% of the mass production part.
The way to break the game: 3DP sand casting process technology matrix
We have innovatively constructed the solution of “Intelligent Design + 3D Printing Technology + Casting”:
1. Topology optimization and bionic design
- Adopt AI technology to reduce the weight of the shell by 23% on the premise of meeting the mechanical properties.
- Simulated honeycomb structure design reinforcement distribution, so that the stiffness of 7mm thin-walled area increased by 40%.
- Development of gradual wall thickness transition algorithm to eliminate more than 90% of stress concentration points
2. 3DP Sand Printing Technology Breakthroughs
- Use industrial-grade sand 3D printer to build complex sand molds with high precision.
- Innovative research and development of high-temperature resistant modified resin sand material, making the surface roughness of castings reach Ra12.5μm.
- Reduced mold filling time to 1/3 of the traditional process through multi-layer cooling channel design.
3. Digital verification of the whole process
- Multi-physical field coupling simulation, predict and correct 16 types of potential defects in advance.
- Establishment of process parameter knowledge base, optimization efficiency of key parameters such as pouring temperature and indenter height increased by 70%.
- Adopted real-time monitoring system to realize digital traceability of casting process.
Project result: redefine the industry benchmark
Through the application of 3DP sand casting process, the project achieved breakthrough progress:
40% compression of development cycle: from design freeze to qualified delivery of the first piece, the time was reduced by 40% compared with traditional casting
Comprehensive cost reduction of 41%: eliminating the cost of mold development, and controlling the cost of trial production at 128% of the mass production parts.
Performance indexes are fully surpassed:
✔ Wall thickness tolerance control at ±0.2mm
✔ 100% passing rate of airtightness test
✔ Heat dissipation efficiency increased by 35%.
Technology Outlook: The Future of Intelligent Casting
The successful implementation of this project marks that the 3DP sand casting process has entered a mature application stage in the field of manufacturing complex thin-walled parts. With the deep integration of metal 3D printing and sand printing, we will realize in the future:
- Fully automated closed-loop production of topology optimization - process simulation - intelligent printing
- 72-hour rapid delivery network in distributed cloud manufacturing mode
- The ultimate goal of zero-defect casting
In the wave of new energy revolution, we are using innovative casting technology to help car companies break through the engineering limit, and jointly promote China's smart manufacturing to high-end, intelligent.
