NEWS

Internal gate speed control, collaborative control of injection parameters, cross-section, and filling window

  • Browse number: ...
  • Release time: 2026-11-07

Internal gate speed control, collaborative control of injection parameters, cross-section, and filling window
The speed of the sprue is the core parameter of the die-casting process, and many technicians only adjust the injection speed, ignoring that the sprue section is the underlying constraint on speed. Xinfeng Machinery has sorted out the entire control logic.
1、 The physical significance of sprue speed
The instantaneous flow rate of aluminum liquid through the sprue determines the filling form: low-speed smooth filling, high-speed filling is used to fill the thin-walled distal end. Low speed, rapid cooling of aluminum liquid, cold insulation, and material shortage; Excessive speed leads to severe air entrainment, oxidation, erosion of the mold cavity, and intensified aluminum adhesion. Alloy wheel hub is a medium thick walled component, and the sprue speed is mostly controlled at 30-40 m/s.
2、 The cross-section of the sprue determines the upper limit of speed
No matter how high the injection pressure and speed are, the area of the sprue is fixed and the flow rate has an upper limit. Formula: Flow rate=sprue area x flow rate; The flow rate of the sprue remains unchanged, the inner gate is reduced, and the flow velocity increases; Enlarge the sprue and decrease the flow rate. Changing the thickness of the sprue is the most direct way to adjust the flow rate.
3、 Speed reference range for different products
Thick walled valve body and structural components: 25-35m/s; Ordinary shell: 30-45m/s; Thin walled heat sink, ultra-thin appearance parts: 45-60m/s. A356 alloy has better fluidity than ADC12, and at the same wall thickness, the flow rate can be slightly lower.
4、 Quick injection start position (material handle position) coordinated
The rapid injection started too early, and the aluminum liquid has not yet filled the sprue, resulting in empty acceleration and splashing of gas; Start too late, the sprue has already solidified and there is insufficient filling. It needs to be adjusted based on the filling rate of the material cylinder and the length of the material handle. The sprue speed and injection curve must be matched and cannot be viewed separately as a single parameter.
5、 Internal gate erosion and life balance
The higher the flow rate, the more intense the flushing of aluminum liquid, and the faster the erosion and adhesion of aluminum at the sprue position. Long term three shift mass production cannot simply increase speed. Priority should be given to improving fluidity through mold temperature and aluminum liquid purity, rather than continuously accelerating. Low pressure casting does not have a high-speed sprue, and the filling speed is much lower than high-pressure die casting. Google's "gate velocity die casting control" is aimed at process engineers.
FAQ
How will the speed change if the wear of the sprue increases?
Under the same injection parameters, a decrease in flow rate can lead to material shortage and cold insulation.
2. Can the sprue speed be changed at any time for the same mold?
It is possible to adjust the injection parameters, but the adjustable range is limited, and large-scale speed changes require changing the gate section.
Is higher speed better for thin-walled parts?
Exceeding the critical value leads to a surge in gas defects and a decrease in yield.
How to repair the worn thickness of the sprue?
After welding, reprocess and restore the original cross-section.
5. Are ADC12 and A356 of the same wall thickness and speed?
A356 has better liquidity and the flow rate can be appropriately reduced.
6. Are fast injection and pressurization the same thing?
Fast injection is responsible for filling; Boosting refers to compacting and shrinking after filling is completed.
7. Will the speed window change if the gate position changes?
Yes, the flow resistance changes and the flow velocity changes under the same parameters.
8. How to measure the speed of the sprue?
It is difficult to directly measure the speed on site by relying on the injection curve of the die-casting machine and CAE simulation.

url: https://my.zj-xinfeng.com/news/1438.html
Can't find any content

Get a Custom Product Proposal Online

Please fill out the form below to receive this for free.

Global Hotline:

+86-15356852630,13967513266