Tool closing system for plastic blow molding machines

Abstract

A tool closing system for plastic blow molding machines comprises a drive base plate, a front mold clamping plate and a rear mold clamping plate positioned between the front clamping plate and the base plate. The base plate, front clamping plate, and rear clamping plate are shiftably arranged on guides which are mounted on a carriage. A drive device is fastened to the base plate and comprises an extensible and retractable drive rod which is articulated to the rear clamping plate for force transmission without bending moment. Two substantially C-shaped or U-shaped frame elements are arranged side by side in parallel with the guides. Each have a substantially horizontally extending central web and two substantially vertically extending webs. A respective one of the two vertical webs is articulated to the base plate and the other vertical web is articulated to the front clamping plate.

Description

FIELD OF THE INVENTION[0001]The present invention refers to a tool closing machine for plastic blow molding machines.BACKGROUND OF THE INVENTION[0002]Various designs of tool closing systems for blow molding machines are known. A design used by various machine manufacturers accomplishes a symmetrical force introduction via a drive arranged underneath the mold and a symmetrical lever mechanism. In practice, however, this bottom type drive is objectionable in various production variants. Moreover, due to the lever mechanism used, the mechanical structure is relatively complicated and an increase in the opening stroke is only possible with great difficulty.[0003]A further common design is the so-called 3-plate system. The drive is arranged in this system behind the third plate (so-called crosshead). The synchronous movement of the two mold halves towards a joint mold parting plane is normally ensured via rack or lever synchronization. Advantages of this system are the relatively easy co...

AI Technical Summary

Benefits of technology

This patent describes a new closing system for blow molds that eliminates bending moments, reduces complexity, and allows for greater accessibility under the molds. The design permits different mold thicknesses and opening strokes while maintaining ease of access from below for bottom type blow stations and calibration. The attachment of the rear mold clamping plate and the force transmission points are located along a common horizontal line that coincides with the drive rod's height. The system is calibrated to cause minimal wear.

Problems solved by technology

In practice, however, this bottom type drive is objectionable in various production variants.

Moreover, due to the lever mechanism used, the mechanical structure is relatively complicated and an increase in the opening stroke is only possible with great difficulty.

Of disadvantage are the deformations in the area of the guides of the closing plate, the deformations being particularly caused by the bending moment produced due to the system on the front closing plate.

Especially in the case of large mold projections, problems arise with respect to the force distribution, which problems cannot easily be solved by the structural design of the whole force system.

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