1. Background

The Chinese automobile industry has exceeded 20 million vehicles, becoming an important support for China's die-casting industry. In recent years, the prosperous development of China's die-casting industry is closely related to the transfer of a large number of foreign automotive die-casting parts to domestic manufacturing. At the same time, foreign automotive die-casting molds also have stricter requirements for die-casting technology. For example, testing the porosity of die castings. Previously, the detection of pores in domestic die castings was carried out using industrial X-ray inspection equipment, but now it is required to use industrial CT for detection. The stricter and more quantitative quality requirements for die-casting parts require us to meet the technical requirements of die-casting equipment, mold design, and intelligent control of mold temperature.

In die-casting production, the control of surface temperature of automotive die-casting molds directly affects product porosity and local porosity defects. A scientifically designed high-pressure water cooling control system with significantly controllable cooling effects is crucial.

2. Current status of mold water cooling control

At present, the surface temperature control of automotive die-casting molds is mainly achieved by introducing heat exchange media such as oil or water into the cooling channel of the mold; The traditional method used by domestic die casting plants is to continuously pass cooling water with a pressure of 0.2-0.3MPa into the mold cooling channel, and the opening, closing, and flow of the cooling water are controlled through manual valves. Its disadvantage is that the control of the surface temperature of automotive die-casting molds relies on the experience of operators and repeated adjustments, making the operation difficult; The surface temperature of local areas is difficult to control, resulting in severe shrinkage and porosity defects in die castings, low qualification rate of die castings, and low production efficiency.

3. High pressure water cooling control technology for molds

3.1 Overview of high-pressure water cooling control technology

The brief description of high-pressure water cooling control technology is to achieve intelligent control of mold Thermal equilibrium through digital management of automotive die casting mold cooling water. Its core is high-pressure cooling water control technology and mold temperature zoning control. Through practical application, this technology can effectively control the surface temperature of automotive die-casting molds, thereby reducing the porosity and local porosity defects of die-casting products and improving the product qualification rate.

3.2 Working principle of high-pressure water cooling control

Boost the cooling water for the automotive die-casting mold to 0.6-1.2MPa, and quickly introduce the mold cooling water channel while filling the mold with alloy material to cool the mold. When the cooling time is up, stop the water flow and blow compressed air into the cooling channel to remove residual cooling water.

3.3 Mold temperature zoning control

The high-pressure point cooler provides 6 sets of independent controllable water supply and air blowing circuits (including 16 sets of high-pressure mold coolers); The temperature control of automobile die casting mold can be divided into different areas. Each area can independently control the opening time and water supply time of cooling water and cleaning gas to control the temperature of different areas of the mold and achieve Thermal equilibrium of the overall mold temperature.

3.4 Parameter quantification, mold temperature control parameter storage, and intelligent control.

The application of programmable controllers (PLCs) and touch screens allows for easy adjustment and storage of mold temperature control parameters, making it more conducive to intelligent management of die-casting processes.

4. Mold high-pressure water cooling control equipment

4.1 The high-pressure water cooling control equipment for molds is divided into two major series: high-pressure point coolers and high-pressure mold coolers;

4.2 High pressure point cooling machine is mainly used for high-pressure point cooling of automotive die-casting mold core pins (insert pins). It is generally used for point cooling pipes with a diameter of 0.85-2.5mm, and the pressure of cooling water is about 1MPa; Through high-pressure and high-speed cooling water heat exchange, the temperature of local points in the mold can be quickly controlled, eliminating casting shrinkage or thermal cracking defects caused by local overheating of the mold.

4.3 Combination of high-pressure point chiller and distribution box for single point controllable and return water monitoring super point cooling; It can also be used separately for single channel control;

4.4 Main functions of high-pressure point cooler:

1) Automatic control of water storage level, low water outlet level and high temperature alarm;

2) Pipeline overpressure safety control and alarm;

3) 2-6-way host water supply and reverse blowing selection control;

4) Backwater monitoring and alarm;

For more demand for automotive die-casting molds, please contact Fenda Mold.