Injection molding machine for multi-component injection molding

Abstract

In an injection molding machine for multi-component injection molding with a clamping unit (1) and an injection unit (2), a frame (3) is provided with two plasticizing units (4a, 4b) arranged side by side on it, each unit having a cylinder and an axially displaceable screw therein. Each of the plasticizing units (4a, 4b) is arranged on a carrier element and is movable relative to it in the longitudinal direction of the carrier element, with each of the carrier elements being movable independently of the other on the frame orthogonal to the longitudinal axis of the injection unit (2). A linear drive is provided for each of the plasticizing units (4a, 4b) by means of which the respective plasticizing unit is movable on its carrier element in the longitudinal direction of the injection unit (2), with each of the two linear drives being articulated on one side to the plasticizing unit (4a, 4b) of the respective carrier element and on the other side articulated to the clamping unit (1).

Description

[0001] The invention relates to an injection molding machine for multi-component injection molding, wherein the injection unit comprises two plasticizing units arranged side by side.

[0002] It is known from the prior art to provide an injection unit with several plasticizing units for multi-component injection molding to prepare the required melt component and inject it into a mold. Various arrangements of these multiple plasticizing units are possible, both among themselves and in relation to the mold (Dr.-Ing. Friedrich Johannaber, Kunststoff-Maschinenführer, 4th edition, 2004, page 236, Figure 164). One of these known arrangements involves two adjacent plasticizing units.

[0003] In such an arrangement, it is usual that the two plasticizing units can be moved both in the longitudinal direction of the injection unit and orthogonally to it, whereby the distance between the longitudinal axes of the plasticizing units remains constant.

[0004] Based on this, the invention is based on the object of specifying an injection molding machine for multi-component injection molding, which is characterized by a high degree of flexibility in the positioning of the plasticizing units in relation to the clamping unit and wherein the injection unit requires a comparatively small amount of space.

[0005] This object is achieved by an injection molding machine having the features of claim 1. Advantageous embodiments and further developments can be found in the dependent claims.

[0006] According to a first core concept of the present invention, each of the plasticizing units is arranged on its own support element and is movable relative to it in the longitudinal direction of the support element. Each of the support elements is movable independently of one another on a frame orthogonal to the longitudinal axis of the injection unit. This allows the distance between the injection nozzles of the two plasticizing units, hereinafter also referred to as the nozzle spacing, to be variably adjusted and thus adapted to different requirements or differently designed clamping units without great effort.

[0007] According to a further core concept of the present invention, a linear drive is provided for each of the plasticizing units, with which the respective plasticizing unit can be moved on its support element in the longitudinal direction of the injection unit, wherein each of the two linear drives is connected in an articulated manner to the plasticizing unit of the respective support element on the one hand and to the clamping unit on the other. The articulated connection on the clamping unit is preferably provided on the stationary mold clamping platen. In principle, however, it could also be arranged on the machine bed of the injection molding machine, preferably in the area of ​​the machine bed on which the stationary mold clamping platen is located. A rotary joint with a vertical axis of rotation can be provided as the articulated connection, wherein preferably each of the articulated connections is designed as a rotary joint.The joint fork and joint pin can be arranged such that the joint pins are located on the linear drive and the joint forks on the clamping unit, or vice versa. The aforementioned arrangement can be used in the same way for the articulated connection on the plasticizing unit side.

[0008] Thanks to the articulated connection of the linear drives on both sides, the two support elements with the plasticizing units mounted on them can be moved orthogonally to the machine's longitudinal axis without having to change the mounting of the linear drives. Depending on the position of the support elements, the longitudinal axes of the linear drives are not parallel to the machine's longitudinal axis, but form an acute angle with this longitudinal axis.

[0009] On the frame of the injection unit, several guide rails can be provided, arranged orthogonally to the longitudinal axis of the injection unit and parallel to one another, on which the support elements can be moved orthogonally to the longitudinal axis of the machine. The support elements can be equipped with guide jaws that engage with the guide rails. Preferably, a separate drive is provided for each support element, with which the support elements can be moved independently of one another on the guide rails. Separate guide rails can be provided for each support element. However, guide rails can also be provided on which both support elements can be moved.

[0010] According to one embodiment of the invention, each of the two linear drives can be designed as a hydraulic drive, which is connected at one end in an articulated manner to the plasticizing unit and at the other end in an articulated manner to the clamping unit. Preferably, the cylinder is articulated to the plasticizing unit, and the piston rod is articulated to the clamping unit. However, other linear drives can also be provided, for example, an electric drive, in particular a spindle drive with an electric motor.

[0011] For each of the plasticizing units, at least one holder can be provided, in which the plasticizing unit is preferably detachably fastened and which is mounted on the respective support element for longitudinal displacement in the longitudinal direction. In this case, each of the linear drives can be articulated to one of the holders of a plasticizing unit. For each of the plasticizing units, a holder in the manner of a U-shaped shell can be provided. However, several essentially fork-shaped holders can also be provided one behind the other. Each of the support elements preferably has guide rails which lie parallel to the longitudinal axis of the machine and on which the holders are mounted for displacement. The movement of a plasticizing unit in the longitudinal direction of the machine thus preferably takes place by means of the linear drive hinged to one of the holders.

[0012] Each of the support elements can be designed like a support frame, which has a height on its long sides running parallel to the longitudinal axis of the injection units that is greater than the vertical extent of a linear drive, and which is at least partially open or interrupted on the side facing the clamping unit. In this way, each of the linear drives is surrounded by a support frame, viewed in the vertical direction, at least in the region of the long sides of the support frame. On the side of the support frame facing the clamping unit, the linear drive can protrude from the support frame through the open area of ​​the support frame or over the interrupted area of ​​the support frame, viewed in the longitudinal direction of the support frame, and be hinged to the clamping unit. One can also say that each linear drive is embedded inside a support frame. The plasticizing units are located above the linear drives.If the articulated connections of the linear drives are taken into account, their longitudinal alignment or the position of their longitudinal axis in relation to the longitudinal axis of the injection unit inside the respective carrier element changes depending on its displacement and position.

[0013] According to an advantageous embodiment, each of the support frames can comprise U-shaped beams on its longitudinal sides, which are arranged in such a way that the open sides of the U face each other in each support frame. The distance between the top and bottom of the horizontal U-shaped beam is greater than the vertical extension of a linear drive, for example, greater than the cross-section of the cylinder of a hydraulic drive. The entire linear drive is thus embedded between the top and bottom of the horizontally arranged U-shaped beams.

[0014] The invention will be explained in more detail below using an exemplary embodiment and with reference to the figures. They show: Fig. 1 schematic representation of an injection molding machine in plan view with injection unit according to the invention; Fig. 2 Top view of an injection moulding machine without the plasticising units, with the clamping unit only partially shown; Fig. 3 perspective view of Fig. 2; Fig. 4 perspective view of the plasticizing unit from Fig. 2; Fig. 5 perspective view of a support element.

[0015] According to the Fig. 1, an injection molding machine according to the invention comprises a clamping unit 1 of a known design and an injection unit 2 according to the present invention. The injection unit 2 comprises a frame 3, on which two plasticizing units 4a and 4b are arranged side by side. The plasticizing units 4a, 4b are movable independently of one another in the direction of the machine's longitudinal axis and orthogonally thereto relative to the frame 3, which is made possible by the Fig. 1 is intended to illustrate the double arrows drawn.

[0016] The Fig. 2 shows parts of the injection unit 2 designed according to the invention and the stationary mold mounting plate 5 of a clamping unit 1. Support elements 6a and 6b are mounted on guide rails 7 and can be moved orthogonally to the machine's longitudinal axis by means of electric drives 8a and 8b. Hand cranks can also be provided instead of the electric drives 8a, 8b. The guide rails 7 are fastened to the frame 3, not shown here. Separate guide rails can be provided for each of the support elements 6a, 6b. However, the guide rails 7 can also be designed and arranged such that one or more of the guide rails 7 can be used for both support elements 6a and 6b. A hydraulic drive 9a, 9b is provided in each of the support elements, each comprising a cylinder 10a, 10b and a piston rod 11a, 11b.The piston rods 11a, 11b are fastened by means of hinge pins 12a, 12b in hinge plates 13a, 13b, which are located on the fixed mold clamping plate 5. The cylinders 10a, 10b are similarly connected in an articulated manner to holders 14a, 14b, which are mounted on guide rails 15 on the support elements 6a, 6b for displacement in the longitudinal direction of the plasticizing unit 2, and which are designed to receive and secure the plasticizing units 4a, 4b.

[0017] The Fig. 3 and Fig. 4 show perspective views of the top view of Fig. 2, where in the Fig. 4 the fixed mold clamping plate has been omitted. The support elements 6a and 6b are shown in a moved-apart state, so that the longitudinal axes of the hydraulic drives 9a and 9b each form an acute angle with the machine's longitudinal axis. In this state, the maximum value of the nozzle distance is reached. Each of the support elements 6a, 6b has two longitudinal supports 16 running parallel to one another, which are connected to one another by means of several cross supports 17. At the end of the longitudinal supports 16 facing away from the clamping unit 1, additional vertical end pieces 18 can be provided. The longitudinal supports 16 have a U-shaped cross-section and are arranged on the frame 3 (not shown here) in such a way that the open sides of the U of the longitudinal supports 16 face one another in each of the support elements 6a, 6b.For each of the support elements, the unit comprising longitudinal beam 16, cross beam 17, and end piece 18 can be viewed together as a support frame 19, which is open on the side facing the closing unit 1. The height of the longitudinal beams 16 and thus also the height of the support frame 19 is greater than the vertical extension of a hydraulic drive 9a, 9b. This results in the . Fig. 2, the following recognizable situation is that each of the hydraulic drives 9a, 9b is embedded inside a support frame 19. The piston rods 11a, 11b can be moved orthogonally to the machine's longitudinal axis when moving the support elements 6a, 6b and thus orthogonally to the machine's longitudinal axis when moving the plasticizing units 4a, 4b according to the desired nozzle spacing within the open side of the support frames 19 and thus between the associated longitudinal supports 16.

[0018] Based on the Fig. 5, the holders 14a, 14b for holding the plasticizing units 4a, 4b will be described in more detail, whereby for the sake of simplicity, only the support element 6b with its holder 14b is shown. The holder 14b comprises two elongated holding elements 19a and 19b, which are slidably supported on the guide rails 15. A U-shaped holding element 20 and a support element 21 are also provided for supporting the plasticizing unit 4b (not shown here). Fig. 5, the hydraulic drive is centered in the middle of the support frame 18, ie the longitudinal axes of piston rod 11b and cylinder 10b are parallel to the two longitudinal beams 16. List of reference symbols 1 locking unit 2 injection units 3 frame 4a, 4b plasticizing units 5 Fixed mold clamping plate 6a, 6b support elements 7 guide rails of the first type - orthogonal to the machine's longitudinal axis 8a, 8b Electric drives 9a, 9b Hydraulic drives 10a, 10b cylinders 11a, 11b piston rods 12a, 12b hinge pins 13a, 13b Joint plates 14 Bracket 15 guide rails of the second type - parallel to the machine's longitudinal axis 16 longitudinal members 17 cross members 18 supporting frames 19a, 19b Holding elements 20 U-shaped retaining element 21 Support element 22 guide jaws QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited non-patent literature

[0000] Dr.-Ing. Friedrich Johannaber, Plastics Machine Operator, 4th Edition, 2004, page 236, Figure 164

[0002]

Claims

[1] Injection molding machine for multi-component injection molding with a clamping unit (1) and an injection unit (2), wherein the injection unit (2) comprises a frame (3) with two plasticizing units (4a, 4b) arranged thereon and lying next to one another, each with a plasticizing cylinder and a screw axially displaceable therein, wherein each of the plasticizing units (4a, 4b) is arranged on a carrier element (6a, 6b) and is movable relative thereto in the longitudinal direction of the carrier element (6a, 6b), wherein each of the carrier elements (6a, 6b) is movable independently of one another on the frame (3) orthogonal to the longitudinal axis of the injection unit (2), wherein a linear drive (9a, 9b) is provided for each of the plasticizing units (4a, 4b), with which the respective plasticizing unit (4a, 4b) on its carrier element (6a, 6b) is movable in the longitudinal direction of the injection unit (2) is movable, wherein each of the two linear drives (9a, 9b) is on the one hand articulated with the plasticizing unit (4a,4b) of the respective support element (6a, 6b) and on the other hand is connected in an articulated manner to the closing unit (1). [2] Injection molding machine according to claim 1, characterized by that on the frame (3) there are provided a plurality of guide rails (7) which are orthogonal to the longitudinal axis of the injection unit (2) and parallel to one another (= guide rails of the first type), that the carrier elements (6a, 6b) are equipped with guide jaws (22) which are in engagement with the guide rails (7), and that for each carrier element (6a, 7b) a drive (8a, 8b) is provided with which the carrier elements (6a, 6b) can be moved independently of one another on the guide rails (7). [3] Injection moulding machine according to claim 1 or 2, characterized bythat each of the two linear drives is designed as a hydraulic drive (9a, 9b) which is connected at one end in an articulated manner to the plasticizing unit (4a, 4b) and at its other end in an articulated manner to the closing unit (1), wherein preferably the cylinder (10a, 10b) is connected in an articulated manner to the plasticizing unit (4a, 4b) and the piston rod (11a, 11b) is connected in an articulated manner to the closing unit (1), or that each of the two linear drives is designed as an electric motor, in particular as a spindle drive with an electric motor. [4] Injection molding machine according to one of the preceding claims characterized by that for each of the plasticizing units (4a, 4b) at least one holder (14a, 14b) is provided, which is mounted on the respective support element (6a, 6b) so as to be displaceable in the longitudinal direction, and that each of the linear drives (8a, 8b) is articulated to the respective holder (14a, 14b) of a plasticizing unit (4a, 4b). [5] Injection molding machine according to one of the preceding claims, characterized by that each of the support elements (6a, 6b) is designed in the manner of a support frame (18) which has a height on its longitudinal sides (16) running parallel to the longitudinal axis of the injection unit (2) which is greater than the vertical extent of a linear drive (8a, 8b), and which is at least partially open or interrupted on the side facing the closing unit (1). [6] Injection moulding machine according to claim 5, characterized by that each of the support frames (6a, 6b) comprises U-profile supports as longitudinal supports (16) on its long sides, which are arranged relative to one another in such a way that in each of the support frames (18) the open sides of the U of the longitudinal supports (16) face one another.

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