Key structural components of a TDI casting machine (as an example, analyzed in the context of TDI technical background) include the following types:
I.Power and Hydraulic System Components
Hydraulic Pump and Cylinder
Hydraulic pump is the power source, provides high pressure oil to drive the hydraulic cylinder, carries out the functions of opening, closing, clamping and producing.
Hydraulic cylinders is divided into clamping cylinders and ejection cylinders. The clamping cylinder must be able to withstand the clamping force (as in a 600t-3500t die-casting machines), while the ejection cylinder can push the casting out of the mold.
Technical relationship: TDI technology high-pressure water injection system and hydraulic system have similar high-pressure characteristics and require precise control to achieve efficient energy transfer.
Boost
Pressure accumulation during the supercharger phase must be controlled to within 10-30ms to ensure rapid filling of the mold cavity with molten metal and to reduce cold sealing defects.
Similar to turbocharging in TDI engines, this boost improves molding efficiency by increasing transient pressure.
II. Clamping and locking System Components
Fixing and moving molds
Fixed mold: fixed on the injection molding machine, connected with the casting system, forming part of the mold cavity.
Move mould: move with a central plate, close with a fixed mould and complete the mold cavity. It features a built-in core pull and ejection mechanisms.
Material Requirements: H13 steel is commonly used for fixing and moving molds, heat resistance and heat fatigue requirements.
Clamping Mechanism
Hydraulic push bar: the mainstream design adopts push bar mechanism to amplify the thrust of hydraulic cylinder, which achieves high clamping force and low energy consumption.
Fully Hydraulic: clamp directly through the hydraulic cylinder. The design is simple but consumes more energy, mainly for small die-casting machines.
Mold Thickness Adjustment Device: Adjust die of different thickness to ensure precise clamping.
III. Injection and Gating System Components
Injection Punch and punch ring: injection punch molten metal into a die cavity at high speed. Punch rings must be heat and wear resistant to prevent leakage. Parameter Requirements: Maximum air injection speed 6-10 m/s to ensure rapid filling of molten metal.
Sprue Bushing and Diverter Cone
Sprue bushing guides the molten metal into the mold cavity, while the shunt cone optimizes metal flow and reduces turbulence.
Design Optimization: increase the number of feed intakes, lengthen the runways, and provide a slag trap that can reduce slag inclusion defects (as in diesel engine crankshaft castings).
IV. INTRODUCTION Core pull-out and Ejector Mechanism Components
Core pulling mechanism
Angled Guide Pin Core Pulling: Slant guide pin drive slide core, suitable for lateral core.
Hydraulic Core Pulling: Hydraulic cylinder drives the core directly, providing highly controllable core extraction force.
Rack-and-Pin Core Pulling pull: for complex core pull, rack-and-pinion transmission can achieve multi-directional core pulling.
Ejector Mechanism
Ejector Pin and thimble: The ejector pin touches the casting directly, and the thimble holds the the ejector pin in place and conveys ejection force.
Reset Device: Reset the ejector assembly before closing the die to avoid interference. Design Principles: The ejector pin should be placed on the thick wall of the casting to ensure uniform force and prevent deformation.
V. Mold Temperature Control Components
Cooling System
Water Cooling: for thick-walled castings or high-melting point metals (such as copper alloys). The cooling system is fast, but the temperature gradient is large, which leads to cracks on the cavity surface.
Air Cooling: Used for low melting point alloys (such as aluminum alloys). The system has simple structure but low cooling efficiency.
Design Point: Cooling channels must not pass through connectors and channel margins must be ≥10mm to prevent leakage.
Heaters
Resistant wire heating: Embedded directly in the mold body, suitable for large metal molds, require insulation protection.
Gas heating: used in various medium and small metal molds. The method has uniform heating but low control precision.