How to use the die-casting machine punch to achieve better results?

The die-casting machine punch is easy to wear during the production process of the die-casting machine. The easy wear of the punch will directly affect the appearance of the die-casting or the return of the material, which will also increase the cost of the factory invisibly. How do we use and choose to maximize the value of the punch and improve work efficiency.

There are currently several types of punches on the market: gray iron punches, ductile iron punches, 45 steel high frequency punches, H13 die steel alloy punches, beryllium bronze punches, nano-ceramic laser punches, ceramic punches, etc. .

First, let’s talk about the hardness of the punch heat treatment:

For the surface hardness of the punch, it is recommended that the heat treatment hardness be HRC45±2 degrees. If the hardness is too high, it is easy to wear the feeding barrel, leading to the early scrapping of the feeding barrel; if the hardness is too low, the punch is easy to wear, which will reduce the service life of the punch.

Second, the punch lubrication effect

The good lubrication of the punch is an important link to prolong the life of the punch of the die-casting machine. Therefore, how to select and use the punch lubricant is very important. Currently commonly used lubricants include mineral oil-based graphite and graphite-free punch lubricants, synthetic-based water-soluble lubricants, and waxy granular lubricants.

Use factor

In the production process, the reasonable use of punches and proper methods can also extend the service life appropriately. In fact, the service life of the punch must be comprehensively measured in the entire die-casting system to get the optimal configuration.

The most important thing is the ideal gap between the punch and the die-casting machine barrel

The punch and the feed barrel are interdependent systems, and the punch slides linearly in the feed barrel. Taking into account the manufacturing error, installation error and the thermal expansion coefficient during use, there should be a certain fit gap between the punch and the barrel. It is not good if it is too large or too small. Practical experience shows that the ideal gap: Ф40mm, Ф50mm is about 0.08mm; Ф60mm, Ф70mm is about 0.10mm; Ф80mm, Ф90mm is about 0.12mm, Ф100mm and above specifications are about 0.12mm∽0.15mm. During injection, when the gap is too large, the aluminum alloy liquid may enter the gap, which will cause the punch lubricating oil to produce fireworks and alloy liquid leakage, which directly leads to excessive wear of the punch and reduction of the life of the punch; if the gap is too small, There will be dangers that the punch and the feed barrel will be welded, and the punch will be stuck. To control the gap, firstly, the dimensional tolerance must be strictly controlled when manufacturing the punch and the feeding barrel. Secondly, a good cooling system must be adopted to control the temperature of the punch and reduce the impact of thermal expansion on the size. The larger the diameter of the punch, the greater the impact of temperature changes on the size of the punch.