DD301476A7

DD301476A7 - Centering device for inserts in injection molds

Info

Publication number: DD301476A7
Application number: DD32936089A
Authority: DD
Inventors: Juergen Herrmann; Norbert Dipl Ing Jastram
Original assignee: Norkun Gmbh
Priority date: 1989-06-08
Filing date: 1989-06-08
Publication date: 1993-02-11

Abstract

Die Erfindung bezieht sich auf das Umspritzen von stabförmigen Einlegeteilen, die wegen ihrer Länge quer zur Schließrichtung des Spritzgießwerkzeuges eingelegt werden. Sie eignet sich besonders für das Anbringen von Plastformteilen an deren Enden. Die Zentrierung erfolgt mit der Schließbewegung des Werkzeuges durch federnd gelagerte Zentrierstücke, die in der Werkzeugtrennebene außerhalb des Formnestes münden. Ihre vorderen Stirnseiten sind mit konischen Zentrierflanken versehen, die vorzugsweise V-förmig ausgebildet sind. Jedem Formnest ist ein Zentrierstück in einer Formplatte und parallel dazu ein Zentrierstückpaar in der gegenüberliegenden Formplatte zugeordnet. Fig. 2{Formnest; Formplatten; konische Zentrierflanken; Plastformteil; quer zur Schließrichtung; Spritzgießwerkzeug; stabförmiges Einlegeteil; Umspritzen; Werkzeugtrennebene; Zentrierstück; Zentriervorrichtung}The invention relates to the encapsulation of rod-shaped inserts, which are inserted because of their length transversely to the closing direction of the injection mold. It is particularly suitable for attaching plastic moldings at their ends. The centering takes place with the closing movement of the tool by spring-mounted centering, which open in the mold parting plane outside of the mold cavity. Their front end faces are provided with conical Zentrierflanken, which are preferably V-shaped. Each mold cavity is assigned a centering piece in a mold plate and parallel to it a pair of centering pieces in the opposite mold plate. Fig. 2 {mold nest; Mold plates; conical centering flanks; Plast molding; transverse to the closing direction; injection molding; rod-shaped insert; insert molding; Mold parting line; centering; centering}

Description

Die stempelseitige Formplatte 1 weist unmittelbar neben dem Formnest 3 für das Plastformteil einen Durchbruch 4 für die in Schließrichtung wirksame Führung des Zontrierstückes 5 auf. Er ist an seinem Ende ringförmig erweitert, um den Bund 7 des Zentrierstückes aufzunehmen und den Hub zu begrenzen. Das Zentrierstück 5 wurde in Achsrichtung mit einer zentralen Bohrung für die Druckfeder 6 versehen, die sich auf der anliegenden Werkzeugplatte abstützt. An der vorderen Stirnseite ist das Zentrierstück V-förmig mit im stumpfen Winkel angeordneten Zentrierflanken 8 ausgebildet. Deren Scheitel nimmt das automatisch zugeführte Einlegeteil 9 auf (Fig. 1). Parallel dazu sind auf der gesenkseitigen Formplatte 2 beiderseits des ersten Zentrierstückes je ein gleicher Durchbruch mit Druckfedern und Zentrierstücken angeordnet, die bei der Werkzeugschließbewegung dafür sorgen, daß der Umfang des Einlegeteiles 9 allseitig unter Überwindu,.3 der Federkraft beaufschlagt wird. Die Symmetrie der paarweisen Anordnung der Zentrierstücken 5 auf einer Formplatte 2 garantiert ein exaktes Zentrieren des Einlegeteiles in den Scheiteln der gegenüberliegenden Zentrierflanken 8 und damit im Formnest 3 (Fig. 2 und 3). Die Fig.4 macht den Verlauf der Dichtkontur deutlich. Nach der Formgebung und mit der Werkzeugöffnungsbewegung gelangen die Zentrierstücken 5 durch Federkraft wieder in die vordere Position, in der die Freigabe des komplettierten Einlegeteiles mit den entformten Plastformteibn sowie die Aufnahme des folgenden Einlegeteiles nach Fig. 1 erfolgen.The stamp-side mold plate 1 has immediately adjacent to the mold cavity 3 for the plastic molding a breakthrough 4 for the effective in the closing direction of the guide Zontrierstückes 5. It is annularly widened at its end to receive the collar 7 of the centering piece and to limit the stroke. The centering piece 5 was provided in the axial direction with a central bore for the compression spring 6, which is supported on the adjacent tool plate. At the front end face, the centering piece is V-shaped with centering flanks 8 arranged at an obtuse angle. Their vertex receives the automatically fed insert 9 (Fig. 1). In parallel, a respective breakthrough with compression springs and centering pieces are arranged on the die-side mold plate 2 on both sides of the first centering that ensure the tool closing movement that the scope of the insert 9 on all sides under Überwindu. 3 of the spring force is applied. The symmetry of the paired arrangement of the centering pieces 5 on a mold plate 2 guarantees an exact centering of the insert in the vertices of the opposite Zentrierflanken 8 and thus in the mold cavity 3 (Figures 2 and 3). 4 shows the course of the sealing contour. After the shaping and the tool opening movement, the centering pieces 5 return by spring force to the front position, in which the release of the completed insert with the demolded Plastformteibn and the inclusion of the following insert part of FIG. 1.

Documents considered:

Muk „Grundzüge der Spritzgießtechnik' Zechner & Hüthig Verlag GmbH, 1979 DE-PS 1045640Muk "principles of injection molding" Zechner & Hüthig Verlag GmbH, 1979 DE-PS 1045640

DE-OS 3822665DE-OS 3822665

Claims

1. centering device for rod-shaped inserts in injection molds, which is actuated by the closing movement of the tool, characterized in that in the mold plates (1,2) both mold halves in the mold parting plane outside of the mold cavity (3) centering (5) open, the back by a compression spring (6) are acted upon, have a stroke in the closing direction and are provided by front end faces with conical flanks (8) zurZentrierung of the insert (9) transversely to the closing direction.

2. centering device for rod-shaped inserts in injection molds according to claim 1, characterized in that immediately adjacent to the mold cavity in a mold plate (1) at least one centering piece (5) and opposite in the other mold plate (2) on both sides parallel to a Zentrierstückpaar out, said the Zentrierflanken (8) are V-shaped at an obtuse angle.

For this 1 page drawings

Field of application of the invention

The invention relates to the tool technical means for encapsulation of long, stabförmon parts. It is involved in the completion of such parts, e.g. at the ends, applicable with plastic moldings.

Characteristics of the known prior art

A precise centering of the insert is important for trouble-free production and for an effective mold space seal against mass leakage. According to an older proposal, a grooved pin is inserted as an insert from behind through a pressure and a holding plate of the tool in cone jaws. During the closing process, the conical seat of the mold plate interacts with the cone jaws in the holding plate and allows a dense mold cavity closure in the centered position of the insert (DD 97157). The solution is useful only for relatively short rods that do not exceed the tool opening travel. For very long rod-shaped parts, the insert must be arranged transversely to the closing direction. For this purpose, no suitable centering devices are known.

Object of the invention

The new device is to allow the centering of rod-shaped parts whose length exceeds the working range of the injection mold, with simple means. This also applies to an automatic driving style with simultaneously zuzuspritzenden parts in several areas of the rod length parts.

Essence of the invention

The object is to provide means centered by the closing movement of the tool transversely to the closing direction of the injection mold to be arranged rod-shaped inserts. According to the invention open in the mold plates of both mold halves in the mold parting plane outside of the mold cavity centering, which are acted upon by a compression spring back. They have a stroke in the closing direction and were provided on the front end faces with conical flanks for centering the insert. Preferably, immediately adjacent to each mold cavity in a mold plate at least one centering and opposite in the other mold plate parallel thereto a Zentrierstückpaar are arranged. Their front side flanks are V-shaped with a blunt angle. With the closing movement of the tool, the bar to be inserted centered in the apex of the flanks on the opposite centering overcoming the spring force.

exemplary

The drawings show sections of an injection molding tool for the simultaneous injection molding of eyelets at both ends of a cylindrical metal rod of 1000mm length and 4.5mm diameter. In this case, each tool has the centering device with three centering pieces shown. Show it

Fig. 1: the sectional view of the device in the centering in the feed position

Fig. 2: the rotated to Fig. 1 by 90 ° sectional view in the closed tool position

FIG.

3: a sectional view along the plane A-A

4 shows the sealing contours as a section B-B.