| 摘要 |
Process and device for tempering molding tools for processing plastics. In convention tempering processes, it is not possible to adapt the temperature conditions to the instantaneous process parameters, and both quantities of interference in the injection molding process and the unfavorable position of cooling surfaces relative to the tool contour of complicated tools cannot be compensated. As a solution, it is proposed that the tempering process is divided in two phases, a start-up phase and a stationary operating phase, each having different tempering conditions, whereby the start-up phase is completed after the preset nominal tool temperature has been reached or exceeded for the first time, and the meantool temperature is continuously measured during the entire cycle duration at a precisely defined site, and whereby at time Z2, the latter being fixed by a signal of the machine sequence control, a cooling medium impulse, the latter taking into account the tempering in the preceding cycles; is induced close in time to the injection process in order to effect the required heat dissipation within the time range of the greatest temperature difference between the injected melt and the cooling duct, and further cooling medium impulses are induced as the result of a should be-actual comparison occurring at time Z2 if the preset nominal temperature is exceeded, whereby the time Z2 is fixed by a signal of the machine sequence control, such signal being triggered at a defined time close in time to the end of the cycle. The invention is preferably applied in the tempering of injection molding tools and leads to cycle time reductions of about 5 to 15%, a reduction of the reject quota by up to 35%, and to a reduction of the specific energy consumption by about 10 to 20%.
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