CASE STUDIES
Throughout last couple of years, AS CASTING has implemented iTherm® shot block into their production and reached substantial productivity improvements, based on shorter cycle time and longer component lifespan.
With 5 casting machines ranging from 400 – 1000 t, they supply parts up to 13 kg to both domestic and international customers in the electrical and automotive industries. Their goal was to optimize the performance to the extent where the die or its components are not limiting the cycle time reduction.
Prior to implementing the iTherm®, conventionally drilled shot blocks were used at AS CASTING’s facility. Their cycle time at that point has been 59 seconds. Based on the proposed solution from HTS, they have replaced it with the iTherm® conformally cooled shot block. The outcome of close cooperation in areas of engineering and R&D are two versions of iTherm® shot block. Both were developed in order to meet the target cycle time, with each succeeding version being more efficient.
Conventional shot block (left), iTherm® V1 (middle) and iTherm® V2 (right)
The initial comparison of conventional and iTherm® shot blocks has shown, that conformally cooled iTherm® shot block should bring a good optimization of the cooling speed and a more even heat distribution across the working surface. As a logical consequence of better thermal management also a longer lifespan was expected.
Figure 3: Preliminary results of heat transfer analysis. Conventional (left), iTherm® V1 (right)
The highest temperature difference between conventional and iTherm® blocks was expected in the area that is in direct contact with molten aluminium.
Figure 4: Average temperature of working surface. Avg T left 398°C avg T right 336°C
After reducing the cycle time by 4,5%, to 52 seconds, it became clear that there was more potential for cycle time reduction. Based on that, the second version of the shot block has been developed. By upgrading conformal cooling arrangements (cross-section, shape) the flow rate was improved by 56%, without any adjustments to fluid velocity.
Figure 4: Preliminary results of heat transfer analysis. iTherm® V1 (left), iTherm® V2 (right)
Figure 5: Average temperature of working surface. Avg T left 336°C avg T right 288°C
Cycle time could further be decreased to 46 seconds, however, now the limiting factor is the die casting cell robot.
Both of the iTherm® shot blocks are still in operation and have surpassed the lifespan of conventional shot block by more than 2 times.
