INJECTION-MOULDED COMPONENT, JOINT, INJECTION-MOULDING DEVICE, AND METHOD FOR PRODUCING AN INJECTION-MOULDED COMPONENT

Abstract

An injection-molded component having a casing body of plastics material and a core which is made of a core material, in particular of a metal, which is at least partially received within the casing body and is at least partially insert-molded. The injection-molded component may in particular serve as a joint part of a joint. As a result of the preferably metallic core, the injection-molded component, despite comparatively small dimensioning, is capable of being comparatively highly stressed. By virtue of the casing body of plastics material, a minor actuation noise may be implemented for the joint, even without complex lubrication.

Claims

1. An injection-molded component, characterized by a casing body (13) of plastics material and a core (11) of a core material, which is at least partially received within the casing body (13) and is at least partially insert-molded.

2. The injection-molded component as claimed in claim 1, characterized in that the casing body (13) has an external contour which in terms of shape deviates from the external contour of the core (11).

3. The injection-molded component as claimed in claim 1, characterized in that the core (11) has a cylindrical external contour.

4. The injection-molded component as claimed in claim 1, characterized in that the core (11) at two mutually opposite ends has in each case one retaining depression (14) or a retaining protrusion.

5. The injection-molded component as claimed claim 4, characterized in that the retaining depression (14) or the retaining protrusion is configured so as to taper off.

6. The injection-molded component as claimed in claim 1, characterized in that an external face of the casing body (13) is configured as an anti-friction face.

7. A joint having an injection-molded component as claimed in claim 6, and a joint component which is mounted so as to be movable on the anti-friction face of the injection-molded component.

8. A method for producing an injection-molded component as claimed in claim 1, characterized by automated infeeding and positioning of the core (11) in a cavity (4) of an injection-molding tool; and subsequent insert-molding of the core (11) with the plastics material for configuring the casing body (13).

9. The method as claimed in claim 8, characterized in that the core (11) is infed to the cavity (4) and positioned therein by means of at least two positioning elements which are displaceable in a parallel or coaxial manner and engage at mutually opposite ends of the core (11).

10. An injection-molding device having an injection-molding tool which comprises at least two tool parts which are displaceable between a closed position, in which they configure a closed cavity (4), and an opened position, and an injection device for injecting a plastics material in free-flowing form into the cavity (4), characterized by means for infeeding and positioning a core (11) of a core material in the cavity (4) of the injection-molding tool.

11. The injection-molding device as claimed in claim 10, characterized in that the means for infeeding and positioning the core (11) comprise at least two positioning elements which are displaceable in a parallel or coaxial manner and are provided so as to engage on mutually opposite ends of the core (11).

12. The injection-molding device as claimed in 11, characterized in that the positioning elements, on the contact faces which are provided for engaging on the core (11), configure a retaining protrusion or a retaining depression.

13. The injection-molding device as claimed in claim 12, characterized in that the retaining protrusion or the retaining depression is configured so as to taper off.

14. The injection-molding device as claimed in claim 13, characterized by means for infeeding the core (11) in the radial direction into a guide duct (9) which extends along the motion axis (5) of at least one of the positioning elements.

15. The injection-molding device as claimed in claim 14, characterized in that the means for infeeding the core (11) are configured for storing a plurality of cores (11).

16. An injection-molded component, comprising a casing body (13) of plastics material and a core (11) of a core material, which is at least partially received within the casing body (13) and is at least partially insert-molded; wherein the casing body (13) has an external contour which in terms of shape deviates from the external contour of the core (11), wherein the core (11) has a cylindrical external contour, wherein the core (11) at two mutually opposite ends has in each case one retaining depression (14) or a retaining protrusion, wherein the retaining depression (14) or the retaining protrusion is configured so as to taper off, wherein an external face of the casing body (13) is configured as an anti-friction face.

17. A joint having an injection-molded component as claimed in claim 16, and a joint component which is mounted so as to be movable on the anti-friction face of the injection-molded component.

Description

[0023] The invention will be explained in more detail hereunder by means of an exemplary embodiment which is illustrated in the drawings in which:

[0024] FIGS. 1 to 5 schematically show various steps of a method according to the invention for producing an injection-molded component according to the invention; and

[0025] FIG. 6 shows a longitudinal section of an injection-molded component according to the invention, in an alternative design embodiment.

[0026] FIGS. 1 to 5 in a simplified illustration show various steps of a method according to the invention for producing an injection-molded component according to the invention. The injection-molding device according to the invention used for carrying out this method comprises an injection-molding tool having two main tool parts 1, 2, and two further tool parts which as so-called slides 3 are displaceable in a transverse manner and, specifically, in the present case perpendicularly in relation to a (relative) motion axis of the main tool parts 1, 2. The main tool parts by means of means (not illustrated) are (mutually) displaceable between a closed position which configures a closed cavity 4 (cf. FIGS. 1 to 3), and an opened position (cf. FIGS. 4 and 5) which enables demolding of an injection-molded component which has been cured in the cavity 4 of the injection-molding tool. In the present exemplary embodiment, only one (2) of the main tool parts 1, 2 is displaceable along the motion axis 5, while the other main tool part 1 is configured so as to be stationary. However, it is likewise possible for both main tool parts 1, 2 to be configured so as to be displaceable. The slides 3 in the exemplary embodiment shown are coupled to the displaceable main tool part 2, and are thus entrained conjointly with the latter along the motion axis 5 of the main tool parts 1, 2.

[0027] FIG. 1 shows a first step in the production of an injection-molded component according to the invention, in the context of a method according to the invention. Said first step is characterized by closing the injection-molding tool and by displacing two positioning elements of the injection-molding device to a collection position. The positioning elements in a coaxial alignment are disposed at mutually opposite ends of the cavity 4, each comprising, for example, a hydraulically (or alternatively pneumatically or electro-motively, for example) displaceable piston 6 which is guided in a cylinder tube 7 and which at the free end thereof is connected (optionally in an integral manner) to a cylindrical positioning bar 8 which is guided in a guide duct 9 which is configured by the respective main tool part 1, 2. The coaxial arrangement of the positioning elements herein relates at least to the two positioning bars 8. In the exemplary embodiment shown, the associated hydraulic cylinders (composed of the piston 6 and of the cylinder tube 7) are also aligned so as to be mutually coaxial.

[0028] In the collection position, the piston 6 of the positioning element which is disposed within the stationary main tool part 1 is completely retracted into the associated cylinder tube 7. The associated positioning bar 8 herein terminates just ahead of the one end, which in relation to the cavity 4 is the distal end, of a transfer portion 10 of the guide duct 9 of the stationary main tool part 1. A core 11 which, in order to configure an injection-molded component according to the invention, is intended to be introduced into the cavity 4 and may be composed of steel, for example, may be infed to this transfer portion 10. This may be performed purely by gravity, for example, by the core 11 dropping from a storage receptacle 12 which is disposed above the transfer portion 10 and which is configured in the stationary main tool part 1 and is dimensioned in such a manner that said storage receptacle may receive a plurality of respective cores 11 simultaneously. Herein, dropping and thus transferring a core 11 into the (empty) transfer portion 10 is always performed when (in the collection position) the positioning bar 8 of the positioning element of the stationary main tool part 1 is not disposed within the transfer portion 10.

[0029] By contrast, the positioning bar 8 of the positioning element of the displaceable main tool part 2 is never located within the transfer portion 10 which is configured by the guide duct 9 of the stationary main tool part 1. Rather, said positioning bar terminates just ahead of the other end, which in relation to the cavity 4 is the proximal end, of the transfer portion 10 when (in the collection position of the positioning elements) the associated piston 6 is located in the completely deployed position within the associated cylinder tube 7. In the collection position, the positioning bar 8 of the positioning element of the displaceable main tool part 2 thus penetrates through the cavity 4.

[0030] The cores 11 have a cylindrical shell surface without steps or any other diameter variations, simplifying infeeding to the cavity 4 by means of the positioning elements. The diameter of the shell surfaces of the cores 11 corresponds substantially to the diameter of the positioning bars 8 which are likewise configured so as to be cylindrical and without diameter variations, on account of which both the cores 11 and the positioning bars 8 are guided with a comparatively minor clearance within the correspondingly dimensioned guide ducts 9.

[0031] Proceeding from the collection position illustrated in FIG. 1, a core 11 which is located in the transfer portion of the guide duct 9 of the stationary main tool part 1, by collectively displacing the pistons 6 and thus the positioning bars 8 of the two positioning elements, are infed to the respective other terminal position within the associated cylinder tubes 7 of the cavity 4 and are positioned (retained) therein (injection position; cf. FIG. 2). As is shown for the exemplary embodiment, the core 11 in this injection position may be disposed exclusively in the cavity 4 and thus completely outside the guide ducts 9. In order for a sufficiently positive positioning of the core 11 to be nevertheless guaranteed within the cavity 4, despite the significant forces which during the injection of plastics material for configuring a casing body 13 for the injection-molded component to be produced act on the latter, the two end-side end faces of each core 11 each have a central retaining depression 14 (cf. in a corresponding manner to this end the alternative injection-molded component according to FIG. 6), in each of which a corresponding retaining protrusion which is configured on the end side on the free end of each positioning bar 8 may engage. By way of a conical shape of the retaining depressions 14 as well as of the retaining protrusions, the resulting combinations act in a self-centering manner such that a coaxial alignment of the positioning bars 8 and of the core 11 held by the latter, and thus also of this core 11 within the casing body 13 of plastics material, the external contour of the latter potentially being configured so as to be entirely or at least partially rotationally symmetrical (about the longitudinal axis 15 of the core 11), may be achieved.

[0032] FIG. 3 elucidates the configuration of the casing body 13 of the injection-molded component to be produced, by insert-molding the core 11 with a plastics material in a free-flowing state, the latter having been introduced into the cavity 4 by way of one or a plurality of injection openings (not illustrated). Herein, the core 11 in the exemplary embodiment shown is disposed across the entire length within the casing body 13. At the same time, the core 11 in the region of the entire shell surface thereof is insert-molded with the plastics material.

[0033] Upon (sufficient) curing of the plastics material configuring the casing body 13, the optionally already finished injection-molded component (the latter may optionally be post-processed) may then be demolded, to which end the injection mold is displaced to the opened position. To this end, the displaceable main tool part 2, together with the slides 3, is displaced away from the stationary main tool part 1. Additionally, the slides 3 are displaced radially outward (in relation to the longitudinal axis 15 of the core 11, or of the injection-molded component, respectively) (cf. FIG. 4). Subsequently, the injection-molded component may be ejected from that portion of the cavity 4 that is configured by the movable main tool part 2 in that the positioning element of this main tool part 2 is again deployed (cf. FIG. 5). Herein, the positioning element of the stationary main tool part 1 may simultaneously be retracted again. This may be provided in particular when the two positioning elements are integrated in the same hydraulic control circuit such that retracting the one positioning element leads to simultaneous deployment of the other positioning element along a substantially identical path (and vice-versa). Such integration of the positioning elements in the same hydraulic control circuit may lead to a design embodiment of the injection-molding device which is comparatively simple in terms of both construction and control technology.

[0034] The injection-molded component which is produced according to FIGS. 1 to 5 comprises a fastening part 16 which may be provided for fastening to an arbitrary support structure (not illustrated), and a partially spherical joint part 17 which extends from one side of the fastening part 16 and of which the external face serves as an anti-friction face on which a likewise partially spherical and internal anti-friction face of a (further) joint component (not illustrated) may be mounted in a sliding manner. On account thereof, the injection-molded component produced, in the function thereof as a joint component, and the further joint component configure a (rotary) joint according to the invention. It can be clearly seen that in the case of this injection-molded component the casing body 13 has an external contour which in terms of shape deviates from the (cylindrical) external contour of the core 11.

[0035] This also applies to the alternative injection-molded component which is illustrated in FIG. 6 and which represents an axle-shaped joint component, a further joint component (not shown) being potentially mounted in a sliding manner (in at least one portion) on the shell surface of said axle-shaped joint component. A rotary joint as well as a sliding joint as well as a combined rotary-cum-sliding joint may be configured herein. The external contour of the casing body 13 of this injection-molded component is cylindrical in a first portion 18 (with machined ends), transitioning in a conically widening manner into a second portion 19 which is also substantially cylindrical but in one region configures an encircling bulge 20. By contrast, the core 11 (at least in terms of shape) corresponds to that core which is used in the production of an injection-molded component according to FIGS. 1 to 5 and which thus across the entire length has a cylindrical external contour without diameter variation.

[0036] Production of the injection-molded component according to FIG. 6 may be performed in an injection-molding device which, except for the shape of the cavity 4, corresponds to the injection-molding device according to FIGS. 1 to 5. The integration of slides 3 in the injection-molding tool may optionally be dispensed with such that the latter may only be configured from two main tool parts 1, 2, since the injection-molded component according to FIG. 6 does not configure any undercut in relation to directions defined by the longitudinal axis 15 of said injection-molded component.

LIST OF REFERENCE SIGNS

[0037] 1 Stationary main tool part [0038] 2 Displaceable main tool part [0039] 3 Slide [0040] 4 Cavity [0041] 5 Motion axis of the main tool parts [0042] 6 Piston of a positioning element [0043] 7 Cylinder tube of a positioning element [0044] 8 Positioning bar of a positioning element [0045] 9 Guide duct [0046] 10 Transfer portion [0047] 11 Core [0048] 12 Storage receptacle [0049] 13 Casing body [0050] 14 Retaining depression [0051] 15 Longitudinal axis of the core/of the injection-molded component [0052] 16 Fastening part of the injection-molded component [0053] 17 Joint part of the injection-molded component [0054] 18 First portion of the shell surface of the casing body of the injection-molded component according to FIG. 6 [0055] 19 Second portion of the shell surface of the casing body of the injection-molded component according to FIG. 6 [0056] 20 Encircling bulge of the shell surface of the casing body of the injection-molded component according to FIG. 6