Multi-component injection-molding machine having a rotatable center part

Abstract

In a three-plate injection-molding machine comprising a nozzle plate, a movable second mold clamping plate, a movable end plate, a closing unit that acts between the end plate and the second mold clamping plate, and a turning unit arranged between the nozzle plate and the second mold clamping plate, rails extend between the nozzle plate and the end plate. The mold-half carrier of the turning unit is supported on a support structure so that it can be rotated about an axis transverse to the machine axis, which support structure forms the abutment for the mold-half carrier rotary drive. The weight of the support structure and mold-half carrier of the turning unit is transferred into the machine bed by means of linear guides, and a substantial part of the reaction torque applied to the support structure is transferred to one of the rails by means of one supporting guide.

Claims

1. An injection-molding machine in three-plate design with a machine bed (1), a first mold-clamping plate (2), which is provided with a nozzle penetration and with which a first injection unit (SE 1) is associated, an end plate (E), a second mold-clamping plate (3), which can be moved parallel to a machine axis (M), is braced via a closing assembly (S) against the end plate (E) and with which a second injection unit (SE2) is associated, a plurality of bars (H) extending between the first mold-clamping plate (2) and the end plate (E), and a turning unit (6), which comprises a mold-half carrier (9) and is disposed between the first mold-clamping plate (2) and the second mold-clamping plate (3), wherein the end plate (E) is braced on the machine bed (1) such that it can be displaced along the machine axis (M) and the mold-half carrier (9) is mounted on a support structure (7) to rotate around an axis of rotation (D) oriented transversely relative to the machine axis (M), the said support structure forming an abutment for a mold-half-carrier rotary drive, wherein the weight of the support structure (7) and of the mold-half carrier (9) of the turning unit (6) is transferred via linear guides (11) directly from the support structure (7) into the machine bed (1) and at least a substantial part of a reaction torque exerted on the support structure (7) during rotational acceleration of the mold-half carrier (9) is transferred via at least one bracing guide (16) into at least one of the bars (H), wherein the linear guides comprise guide rails associated with the machine bed and guide elements associated with the support structure, and wherein the guide elements embrace the guide rails interlockingly.

2. The injection molding machine of claim 1, wherein the bars (H) are fixed on the first mold clamping plate (2) and at the end plate are positionally secured in adjustable manner by means of a mold-height positioning device.

3. The injection molding machine of claim 1, wherein the second mold-clamping plate (3) is braced by means of guide elements (14) associated therewith on guide rails (12) identical to those guides elements associated with the support structure (7) of the turning unit (6).

4. The injection molding machine of claim 1, wherein the second mold-clamping plate (3) is braced by means of guide elements (14) associated therewith on separate guide rails (15), which are not identical to those guide rails (12) on which the support structure (7) of the turning unit (6) is braced.

5. The injection molding machine of claim 1, wherein the turning unit (6) comprises an upper crossbeam structure (8), on which the mold-half carrier (9) is mounted to rotate around the axis of rotation (D).

6. The injection molding machine of claim 5, wherein the support structure (7) and the crossbeam structure (8) are part of a closed frame structure.

7. The injection molding machine of claim 5, wherein the crossbeam structure (8) is braced via bracing guides (10) on the bars (H).

8. The injection molding machine of claim 5, wherein longitudinal positioning drives (18, 19) act on each of the support structure (7) and on the crossbeam structure (8) by way of associated stop plates.

9. The injection molding machine of claim 1, wherein longitudinal positioning drives act exclusively on the support structure (7) by way of a stop plate.

10. The injection molding machine of claim 1, wherein the closing assembly is constructed as a toggle-lever closing assembly.

11. The injection molding machine of claim 1, wherein the closing assembly is of hydraulic construction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be explained in more detail hereinafter on the basis of a preferred exemplary embodiment illustrated in the drawing, wherein:

(2) FIG. 1 shows a schematic side view of an injection-molding machine constructed according to the present invention,

(3) FIG. 1a shows a side view in enlarged detail of the part of the injection-molding machine according to FIG. 1 that is most important here,

(4) FIG. 2 shows a cross section through the injection-molding machine shown in FIG. 1A along line A-A,

(5) FIG. 3 shows an overhead view of detail X of FIG. 2, and

(6) FIG. 4 shows a modification of the injection-molding machine according to FIGS. 1a to 3 with illustration of a correspondingly modified cross section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) The injection-molding machine shown in the drawing (only partly in FIG. 1a) is constructed in three-plate design. It comprises a machine bed 1, a (fixed) first mold-clamping plate 2 provided with a nozzle penetration (not illustrated), a second mold-clamping plate 3, which can be moved (arrow B) parallel to machine axis M and an end plate Ewhich in FIG. 1a is disposed at the left, in front of second mold-clamping plate 3. Four bars H fixed on the nozzle plate, namely two lower bars 4 and two upper bars 5, extend between first mold-clamping plate 2 (nozzle plate) and end plate E. Between second mold-clamping plate 3 and the end plate, a closing assembly S, which (as illustrated schematically in FIG. 1) may be constructed in particular as a toggle-level closing assembly, acts in a manner known in itself.

(8) End plate E is braced directly on machine bed 1 such that it can be displaced along the machine axis. A mold-height-positioning device F is associated therewith. By means of this, the position of end plate E is adjustable and in the respective end-plate position bars H are positionally secured on end plate E in such a way that the reaction force that corresponds to the closing and holding force exerted on second mold-clamping plate 3 can be transferred from end plate E into bars H.

(9) In such a known manner, (at least) one first injection unit SE1 is associated with nozzle plate 2 and (at least) one second injection unit SE2 is associated with mold-clamping plate 3. To simplify the diagram, the injection units are not also shown in FIG. 1a, since their construction and arrangement are not decisive in the present case.

(10) A turning unit 6, which can be displaced (arrow C) parallel to machine axis M, is disposed between nozzle plate 2 and second mold-clamping plate 3. This comprises a lower support structure 7, an upper crossbeam structure 8 and a mold-half carrier 9 mounted on lower carrier structure 7 and upper crossbeam structure 8 to rotate around axis of rotation D perpendicular to machine axis M. A mold-half-carrier rotary drive is provided for the said rotation of mold-half carrier 9. For this, lower support structure 7 forms the abutment, in the sense that the reaction torques occurring during rotational acceleration (positive and negative rotational accelerations, i.e. including braking) of mold-half carrier 9 are first absorbed by lower support structure 7 andas described hereinafterare transferred from this at least partly into at least one lower bar 4. Incidentally, lower support structure 7 supports the weight of mold-half carrier 9 plus the mold halves respectively attached thereto. Meanwhile, the weight of upper crossbeam structure 8 is absorbed by upper bars 5, for which purpose upper crossbeam structure 8 is braced via bracing guides 10 at its ends on upper bars 5.

(11) The weight of lower support structure 7, of mold-half carrier 9 and of the mold halves attached thereto is transferred via linear guides 11 directly from support structure 7 into machine bed 1. For this purpose, linear guides 11 comprise guide rails 12 associated with machine bed 1 and guide elements 13 associated with support structure 7. The latter embrace guide rails 12 interlockingly. In the injection-molding machine according to FIGS. 1 to 3, movable mold-clamping plate 3 is braced by means of guide elements 14 associated therewith on guide rails 12 identical to those of support structure 7 of turning unit 6. In contrast, in the modification according to FIG. 4, support structure 7 is braced by means of guide elements 13 associated therewith on the one hand and movable mold-clamping plate 3 is braced by means of guide elements 14 associated therewith on the other hand on different guide rails 12 and 15 respectively, wherein guide rails 12 serving as bracing for turning unit 6 are disposed between guide rails 15, on which movable mold-clamping plate 3 is braced. As regards the modification according to FIG. 4, it must also be further pointed out that a special assembly 22, which comprises a plate 23 with guide rails 12 mounted thereon, is provided for the bracing of turning unit 6. Assembly 22 rests on shoulders 24 of machine bed 1. Assembly 22 is omitted in injection-molding machines of otherwise identical design without turning unit 6.

(12) For bracing of lower support structure 7 of turning unit 6 on one of the lower bars 5, in order to transfer at least a substantial part of the reaction torque exerted during rotational acceleration of mold-half carrier 9 on support structure 7 into the lower bar 5 in question, a bracing guide 16 is used. This comprises a two-piece guide member 17, which is attached vertically on lower support structure 7, i.e. it can be displaced parallel to axis of rotation D (arrow V), and is equipped with half-shell sliding bearings. Thus the transfer of the weight forces of lower support structure 7, of mold-half carrier 9 and of the mold halves attached thereto into machine bed 1 as described in the foregoing is assured without hereby loading lower bars 5, while at the same time at least a substantial part of the reaction torques occurring during rotational acceleration of mold-half carrier 9 are transferred into at least one lower bar 5. A modification of the illustrated injection-molding machine to the effect that support structure 7 is coupled with both lower bars 5 via the illustrated bracing guides 16 is possible with the advantages described hereinabove.

(13) Shifting (arrow C) of turning unit 6 along machine axis M is provided by two longitudinal positioning drives 18, 19. In this connection, a lower longitudinal positioning drive 18 acts via an associated stop plate 20 on support structure 7 and an upper longitudinal positioning drive 19 acts via an associated stop plate 21 on crossbeam structure 8.