CS251438B1 - Device for controlling the thickness of the melt blank - Google Patents

Abstract

The device for regulating the wall thickness of the melt blank is used in machines for extrusion blow molding of hollow plastic objects. It consists of a three-member mechanism, which is formed by side arms, rotatably mounted on the sides of the extrusion head, upper arms and a linear motor. A mandrel carrier crossbar is then rotatably mounted between the upper arms. One or more mandrel carriers are firmly connected to it, depending on the number of paths of the extrusion head.

Description

BACKGROUND OF THE INVENTION The present invention relates to a device for controlling the wall thickness of semi-melt goods used in extrusion blow molding machines for plastics hollow articles.

Previously known embodiments of the device for controlling the wall thickness of the melt semifinished products utilize a direct displacement of the cross-member of the mandrel carriers, which is guided by the mandrel carriers, the guide pin or the torsion bar with pinion and toothed racks. Other systems used with a single-reversible or double-lever lever transmission from a linear motor to a mandrel support require axial release of the mandrel support pin.

The principle of the thickness control device of the melt blank according to the invention consists in that the side arms rotatably mounted on the sides of the extrusion head, the upper arms and the linear motor form together a three-member mechanism. A cross-member of the mandrel support is pivotally mounted between the upper arms and the mandrel support itself is rigidly connected thereto. The cross-member of the mandrel carrier may be adapted to the desired number of mandrel carriers according to the number of extruding heads oest.

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The main advantages of the device for controlling the wall thickness of the melt blank according to the invention are the possibility of using a linear actuator to achieve multipoint control of the wall thickness, torsional stiffness in the multipass die design, eliminating the reaction effects extrusion heads, releasing the head face for the heater. *

In the drawing, FIG. 1 shows an embodiment of a device for controlling the wall thickness of a melt blank according to the invention in front view and in plan view.

Side arms pivotally attached to the side of the extrusion head 2 »are coupled to the arm top pin 2 with the rear ends of the arms opposite the top 2 are connected by a rotatably supported upper crosshead of the engine 2 ^{and the} opposite end side of the arms 3 are pivotally mounted the lower crosshead of the engine 6. Between these A rectangular motor 2 is then positioned by the crossbars

251438 upper rail of the engine 5 and the lower crosspiece 6.a engine by changing the deflection of the upper arm 2 ^from the side arm 1 is achieved by vertical movement of the traverse support mandrel 8 is rotatably mounted between the upper arm 2 ^»9 and by a crosspiece rigidly connected to the mandrel 2 ·

Claims (1)

Device for controlling the thickness of the melt blank, characterized in that the side arms (1) pivotally mounted on the sides of the extrusion head (2) together with the upper arms (3) and the rectilinear motor (7) form a three-member mechanism. 8) is pivotally mounted between the upper arms.