Method For Manufacturing A Home Appliance Component In A Combined Injection-Molding Process Involving Thin-Wall Injection-Molding And Cascade Molding And Home Appliance Component

Abstract

A method for manufacturing a component for a home appliance includes making the home appliance component from plastic in an injection molding process. During at least some phases of the injection molding process a combination of the thin-wall injection molding technique and the cascade molding technique is used. The invention also relates to a home appliance component manufactured according to the method.

Claims

1-17. (canceled)

18. A method for manufacturing a home appliance component for a home appliance, the method comprising the following steps: producing the home appliance component from plastic; manufacturing the home appliance component by an injection-molding process; and using a combination of thin-wall injection-molding and cascade molding during at least some phases of the injection-molding process.

19. The method according to claim 18, which further comprises carrying out the thin-wall injection-molding at a wall thickness-flow path ratio of more than 1:200.

20. The method according to claim 19, which further comprises carrying out the thin-wall injection-molding at a wall thickness-flow path ratio of between more than 1:200 and 1:300.

21. The method according to claim 18, which further comprises carrying out the cascade molding by: centrally predetermining, in a direction of a longitudinal axis of the home appliance component to be manufactured, at least one injection point of a plurality of injection points through which an injection of a melt of a plastics material into an injection mold is initiated at least partially before an injection of the melt in at least one further injection point being predetermined eccentrically in the direction of the longitudinal axis.

22. The method according to claim 21, which further comprises: predetermining a time for a start of an injection in an eccentrically predetermined injection point according to at least one of: a type of melt to be injected, or a type of melt injected in the at least one central injection point, or a spacing measured along the longitudinal axis between the at least one central injection point and the eccentric injection point, or a diameter of the at least one central injection point, or a diameter of the eccentric injection point, or a number of eccentric injection points at an identical longitudinal position along the longitudinal axis relative to the eccentric injection point, or an injection pressure of the melt in at least one first central injection point, or an injection pressure provided in the eccentric injection point, or a quantity of the melt injected in the at least one central injection point, or a quantity of the melt provided to be injected in the eccentric injection point, or a time period of an injection of a melt through the central injection point, or predetermining a time for an end of an injection in an eccentrically predetermined injection point according to: the type of melt to be injected, or the type of melt injected in the at least one central injection point, or the spacing measured along the longitudinal axis between the at least one central injection point and the eccentric injection point, or the diameter of the at least one central injection point, or the diameter of the eccentric injection point, or the number of eccentric injection points at the same longitudinal position along the longitudinal axis relative to the eccentric injection point, or the injection pressure of the melt in the at least one first central injection point, or the injection pressure provided in the eccentric injection point, or the quantity of the melt injected into the at least one central injection point, or the quantity of the melt provided to be injected in the eccentric injection point, or the time period of an injection of a melt through the central injection point.

23. The method according to claim 21, which further comprises: predetermining at least one first eccentric injection point in at least the one central injection point in a first direction along the longitudinal axis; and starting from the at least one central injection point, predetermining at least one second eccentric injection point in a second direction opposing the first direction along the longitudinal axis; and with the injection of the melt in the at least one central injection point, partially or entirely simultaneously carrying out the injection of a melt in the at least one first and the at least one second eccentric injection points.

24. The method according to claim 18, which further comprises carrying out the cascade molding by predetermining at least two injection points on an identical longitudinal position and on opposing sides of a longitudinal axis of the home appliance component to be manufactured from a plurality of injection points through which a melt of plastics material is injected simultaneously into an injection mold.

25. The method according to claim 18, which further comprises using the combination of the thin-wall injection-molding and the cascade molding to manufacture the home appliance component with a wall thickness of less than 1.5 mm.

26. The method according to claim 18, which further comprises using the combination of the thin-wall injection-molding and the cascade molding to manufacture the home appliance component with a wall thickness of between 0.6 mm and 1 mm.

27. The method according to claim 18, which further comprises predetermining at least four injection points for the cascade molding.

28. The method according to claim 18, which further comprises manufacturing the home appliance component with a trough-shape.

29. The method according to claim 28, which further comprises manufacturing the trough-shaped home appliance component with a trough base having a quadrangular surface area with at least one of a first side length or width of at least 30 cm or a second side length or height of at least 25 cm.

30. The method according to claim 28, which further comprises predetermining at least one of a number or position of injection points for the cascade molding according to a size of the trough-shaped home appliance component or a size of a surface area of a trough base of the home appliance component.

31. The method according to claim 30, which further comprises predetermining at least one of a number of injection points along a longitudinal axis of the home appliance component to be manufactured or a position of the injection points along the longitudinal axis of the home appliance component to be manufactured according to the size of the trough-shaped home appliance component or the size of the surface area of the trough base of the home appliance component.

32. The method according to claim 30, which further comprises predetermining the number of injection points in pairs and on opposing sides of a longitudinal axis of the trough-shaped home appliance component, and predetermining the number of injection point pairs according to the size of the trough-shaped home appliance component or the size of the surface area of the trough base of the home appliance component.

33. The method according to claim 18, which further comprises limiting a locking force for locking an injection mold when injection-molding the home appliance component to a value of less than or equal to a weight of 1700 tons.

34. The method according to claim 18, which further comprises manufacturing an internal cladding of a door for a home refrigeration appliance as the home appliance component.

35. In a home appliance, the improvement comprising: an injection-molded plastic home appliance component having characteristics of having been formed by a combination of thin-wall injection-molding and cascade molding during at least some phases of injection-molding.

Description

[0051] Exemplary embodiments of the invention are described in more detail hereinafter with reference to schematic drawings, in which:

[0052] FIG. 1 shows a perspective view of an exemplary embodiment of a home appliance according to the invention with an embodiment of a home appliance component according to the invention;

[0053] FIG. 2 shows a perspective view of a first exemplary embodiment of a home appliance component with symbolically shown injection points;

[0054] FIG. 3 shows a perspective view of a further exemplary embodiment of a home appliance component having a size different from FIG. 2 and a number of injection points different from FIG. 2;

[0055] FIG. 4 shows an exemplary view of an embodiment for producing a home appliance component in which by the method according to the invention melt is introduced at different times via a plurality of injection points in series along a longitudinal axis of a home appliance component to be produced, wherein in FIG. 4 the respective flow fronts of this melt are also shown;

[0056] FIG. 5 shows a view according to FIG. 4, wherein in contrast to FIG. 4 the introduction of the melt in the injection points does not take place in one direction but in two opposing directions;

[0057] FIG. 6 shows a view according to FIG. 4 in which in contrast to FIG. 4, however, two parallel rows of injection points are configured;

[0058] FIG. 7 shows a view according to FIG. 5 in which in contrast to FIG. 5 two parallel rows of injection points are also predetermined;

[0059] FIG. 8 shows a perspective view of a partial region of a home appliance component produced with an integrated additional element in the form of a cam; and

[0060] FIG. 9 shows a view according to FIG. 8 with a correspondingly alternatively produced cam.

[0061] In the figures, elements which are the same or functionally the same are provided with the same reference numerals.

[0062] In FIG. 1 a home appliance 1 is shown in a perspective simplified view, said home appliance being a home refrigeration appliance and, for example, a refrigerator or a freezer or a combi fridge-freezer. The home appliance 1 is configured to receive food and has a housing 2 in which a corresponding receiving space 3 is configured. The receiving space 3 is defined by walls of an internal container 2a. At the front, the receiving space 3 is closable by a door 4 which is pivotably arranged on the housing 2. The door 4 is constructed in multiple parts and has an external door 5 and an internal door which represents an internal cladding 6. The internal cladding 6 is a component on the visible side of the door 4 and thus is an external component. In the closed state of the door 4 this internal cladding 6 faces the receiving space 3. This internal cladding 6 is integrally configured from plastics and represents a trough-like home appliance component. Between the external door 5 and the internal cladding 6 a thermally insulating material, in particular an insulating foam, is at least partially incorporated, said foam not being present on the visible side but being concealed by the external door 5 and the internal cladding 6.

[0063] Moreover, further components, for example at least one door rack which is not shown, may also be arranged on the internal cladding 6.

[0064] The home appliance component in the form of the trough-like internal cladding 6 is manufactured by injection-molding, wherein during this injection-molding a combination of thin-wall injection-molding and cascade molding is carried out at least partially during the manufacturing process. The thin-wall injection-molding in this case is carried out at a wall thickness-flow path ratio of more than 1:200, in particular of between more than 1:200 and 1:300.

[0065] As may be already identified from the schematic view in FIG. 1 and in the exemplary embodiment in FIG. 2, in which this internal cladding 6 is shown horizontally, a substantially larger region of this extent of the home appliance component is a planar or substantially planar surface area which in this case is formed by a trough base 7.

[0066] As indicated in FIG. 2, during this manufacture by injection-molding and by combining the thin-wall injection-molding technique and the cascade molding, a plurality of injection points is predetermined. In the exemplary embodiment shown here, six injection points 8, 9, 10, 11, 12 and 13 are predetermined. Thus it is provided here that, viewed along a longitudinal axis A of the home appliance component to be manufactured, three injection points 8, 10, 12 in a row, which extends parallel to the axis A, are predetermined. Moreover, three further injection points 9, 11 and 13 in a row parallel thereto, which is also parallel to the longitudinal axis A, are predetermined. Moreover, it is provided that in each case two injection points are respectively arranged opposing the longitudinal axis A and symmetrically thereto in pairs and in this connection in each case are predetermined at the same longitudinal position and/or on the same portion along the longitudinal axis A. Thus a first injection point pair is predetermined by the injection points 8 and 9, a second injection point pair is predetermined by the injection points 10 and 11 and a third injection point pair is predetermined by the injection points 12 and 13.

[0067] In particular, it is provided that the injection points 10 and 11 with regard to the length of the home appliance component and thus the internal cladding 6 are centrally arranged, viewed along the longitudinal axis A. Thus they represent central injection points 10 and 11. Moreover, the injection points 8 and 9 are first eccentric injection points and the injection points 12 and 13 are second eccentric injection points. The spacing, viewed in the direction of the longitudinal axis A, is the same between the central injection point 10 and the eccentric injection points 8 and 12. The same applies to the spacing of the eccentric injection points 9 and 13 relative to the central injection point 11. As may be identified according to the view in FIG. 2, the local positions of the injection points 8 to 13 are selected such that they are still present within the surface area of the trough base 7.

[0068] The manufacture of this internal cladding 6 according to FIG. 2 is carried out, in particular, in that initially the melt is injected simultaneously via the central injection points 10 and 11. During this time phase the injection is not yet carried out via the eccentric injection points 8, 9 and 12, 13.

[0069] According to the extent of the flow front of the melt, which is introduced via the injection points 10 and 11, subsequently the injection is carried out via the eccentric injection points 8 and 9 and 12 and 13.

[0070] In particular, a time for the start of an injection in an eccentrically predetermined injection point 8, 9, 12, 13 is predetermined according to the type of melt to be injected and/or according to the type of melt injected into the at least one central injection point and/or a spacing measured along the longitudinal axis between the at least one central injection point and the eccentric injection point and/or the diameter of the at least one central injection point and/or the diameter of the eccentric injection point and/or the number of eccentric injection points at the same longitudinal position along the longitudinal axis relative to this eccentric injection point and/or the injection pressure of the melt in the at least one first central injection point and/or the injection pressure provided in the eccentric injection point and/or the quantity of the melt injected in the at least one central injection point, and/or the quantity of the melt provided to be injected in the eccentric injection point and/or a time duration of an injection of a melt via the central injection point.

[0071] Additionally or alternatively, a time for the end of an injection in an eccentrically predetermined injection point 8, 9, 12, 13 is predetermined according to the type of melt to be injected and/or according to the type of melt injected in the at least one central injection point and/or a spacing measured along the longitudinal axis between the at least one central injection point and the eccentric injection point and/or the diameter of the at least one central injection point and/or the diameter of the eccentric injection point and/or the number of eccentric injection points at the same longitudinal position along the longitudinal axis relative to this eccentric injection point and/or the injection pressure of the melt in the at least one first central injection point and/or the injection pressure provided in the eccentric injection point and/or the quantity of the melt injected in the at least one central injection point and/or the quantity of the melt provided to be injected in the eccentric injection point and/or a time duration of an injection of a melt via the central injection point.

[0072] In FIG. 3 an exemplary embodiment of a trough-shaped home appliance component which is configured as an internal cladding 6 is shown, said component being larger in contrast to the embodiment according to FIG. 2, in particular in the length along the longitudinal axis A and optionally also in width and thus in a direction perpendicular to the longitudinal axis A. The height is measured in this case according to the view in FIG. 1 in the y-direction, wherein the width with the door 4 closed is measured in the x-direction.

[0073] In the embodiment in FIG. 3, due to the size, in particular, of the planar or substantially planar surface area, the trough base 7 is correspondingly different. In this case, considerably more injection points are present than in the embodiment in FIG. 2. In the exemplary embodiment 27 injection points are provided here. Here, three central injection points 14, 15 and 16 are provided, said central injection points being arranged adjacent to one another viewed at the same axial position in the direction of the longitudinal axis A. Thus a central middle injection point 15 is located on the longitudinal axis A and is thus centrally predetermined in the width direction of the home appliance component and thus of the internal cladding 6 to be manufactured. The two further central injection points 14 and 16 are accordingly predetermined in the width direction at the same spacing from the central injection point 15 in the middle. The further 24 eccentric injection points are predetermined in their rows parallel to the longitudinal axis A and arranged relative to one another and at the same spacing from one another. Moreover, in the eccentric injection points in each case three such injection points are arranged in the same longitudinal position and thus the same axial position on the longitudinal axis A relative to one another. All eccentric injection points on the left-hand side, and thus those injection points which are predetermined to the left of the longitudinal axis A, are also predetermined in turn in a row which extends parallel to the longitudinal axis A. The same is predetermined in the case of the eccentric injection points on the right-hand side, wherein these eccentric right-hand injection points are also in the row with the central injection point 16. Correspondingly, the central injection point 16 is predetermined in a row with the eccentric injection points on the left-hand side.

[0074] Also in this case, the manufacture is carried out such that initially the injection of the melt is initiated via the central injection points 14 to 16. Also, in particular according to the influencing factors already mentioned above, an injection is initially started at a time in an eccentrically predetermined injection point and/or the injection is completed at a time in an eccentrically predetermined injection point. In particular, the temperature and/or the internal pressure in the injection mold is also taken into consideration.

[0075] In FIG. 4 an embodiment is shown in a simplified view, in which along a longitudinal axis A a plurality of injection points 17, 18, 19, 20 and 21 are predetermined in only one row. The injection of the melt in this case takes place in only one direction R1 as indicated by the arrow. The injection is initially started with the injection point 17, wherein no melt is injected in the further injection points 18 to 21. Depending on the extent of a flow front 22 of the melt in the injection mold, the injection of the melt in the injection point 18 starts in a chronologically delayed manner relative to the injection in the injection point 17. The same then continues with the further respective flow fronts, as shown in FIG. 4 but not provided with reference numerals. Thus it is also possible that the melt which has been introduced via the first injection point 17 has already cooled sufficiently, although for example a primary introduction of melt has not yet been carried out in at least the last injection point 21 in the injection row. Then it may also be provided that even before completing the primary introduction of the melt at all injection points, the secondary filling has already started at, in particular, the first injection point 17 and/or this is carried out at the same time.

[0076] The same may also be carried out additionally or alternatively at other injection points, for example at the injection point 18.

[0077] In the view in FIG. 5, in contrast to the embodiment according to FIG. 4, it is provided that after the start of the injection of the melt via a central injection point 17, at the same time respectively in two different directions R1 and R2, the injection also takes place in subsequent eccentric injection points. Thus it is provided that after the injection in the central injection point 17, or at least chronologically delayed relative to the injection, then the injection of the melt starts at the same time in the following eccentric injection points 18 and 19 and in turn is subsequently delayed chronologically, in particular according to the speed of the flow fronts, the simultaneous injection in the row then being carried out further in the outward direction at the following eccentric injection points 20 and 21.

[0078] In a further exemplary embodiment according to FIG. 6 once again an injection scenario is shown in only one direction R1. In contrast to the view according to FIG. 4, embodiments according to FIG. 2 are shown here, in which injection point pairs are provided which are predetermined on opposing sides of the longitudinal axis A, and arranged and/or predetermined symmetrically relative to the longitudinal axis A. Here it is provided that via the injection points 17 and 17, in particular, the injection is started simultaneously and then according to the extent of the flow fronts, subsequently and chronologically delayed, the in particular simultaneous injection takes place in the injection points 18 and 18. Once again chronologically delayed, the further injection takes place in the further injection points 19 and 19 which follow in the series, and then chronologically delayed in the injection points 20 and 20 and then chronologically delayed in the further injection points 21 and 21. With regard to the preferable fixing of times for the start and the end of the injection in the eccentric injection points, reference should be made to the aforementioned dependence on influencing factors. Here, once again in particular the temperature of the injection mold at specific points and/or an internal pressure in the injection mold may be considered. In this context, once again conclusions may be respectively drawn about the locally specific position of a flow front and the resulting requirement of a primary injection of melt in a further subsequent injection point and/or the secondary filling of melt in an already present injection point, via which the primary injection of the melt has already taken place and cooling is already sufficiently present in the region of the melt.

[0079] In FIG. 7 a further example is shown in which, in contrast to FIG. 5, here once again not only one row of injection points is provided parallel to the longitudinal axis A, but injection point pairs are present, corresponding to the embodiment in FIG. 6 in each case. The injection takes place here proceeding from the start of the injection via the central injection points 17 and 17, in both directions R1 and R2, at subsequent eccentric injection points, in particular simultaneously.

[0080] In FIG. 8, a detail of the internal cladding 6 is shown. Here a raised, outwardly protruding cam 6b is integrated on a projection 6a, said cam being merely configured as a border and/or edge and/or contour projection. Such an embodiment has a corresponding degree of structural freedom which results from the invention and/or an advantageous embodiment when produced by this specific combination of injection-molding sequences.

[0081] In contrast thereto, in FIG. 9 an embodiment of an internal cladding part is shown, in which such a cam 6b is only produced as a raised bump and not as a delicate structure as formed in FIG. 8. In principle, therefore, it is also possible that the cam 6b according to FIG. 9 naturally may also be produced with a corresponding shape by means of the invention or an advantageous embodiment thereof. By means of the variants, as are shown in FIG. 8 and FIG. 9 in examples of shapes, a further advantage of the invention is also further reinforced.

LIST OF REFERENCE NUMERALS

[0082] 1 Home appliance [0083] 2 Housing [0084] 2a Internal container [0085] 3 Receiving space [0086] 4 Door [0087] 5 External door [0088] 6 Internal cladding [0089] 6a Projection [0090] 6b Cam [0091] 7 Trough base [0092] 8 Injection point [0093] 9 Injection point [0094] 10 Injection point [0095] 11 Injection point [0096] 12 Injection point [0097] 13 Injection point [0098] 14 Central injection point [0099] 15 Central injection point [0100] 16 Central injection point [0101] 17, 17, 17 Injection point [0102] 18, 18, 18 Injection point [0103] 19, 19, 19 Injection point [0104] 20, 20, 20 Injection point [0105] 21, 21, 21 Injection point [0106] 22 Flow front [0107] A Longitudinal axis [0108] R1 Direction [0109] R2 Direction