EP1788137B1 - Plastic tub for a laundry treatment machine and laundry treatment machine - Google Patents

Abstract

The container (2) has a cylindrical container (31) surrounding a drum (32). A metallic carrier (1) with a sleeve like hub (3) for a drive shaft of the drum is fitted into the plastic body of a side wall. The carrier is formed from a ring (8) with the hub connected in the center by radial spokes. The side flanks of the ring are parallel. The flanks and inner circumference of the ring are arranged in the plastic body. The outer circumference of the ring is in a region without the plastic body. Independent claims also cover a washing machine or drier with such a container.

Description

The invention relates to a plastic tub for a laundry treatment machine such as washing machine or washer-dryer, comprising a cylinder-shaped container surrounding a drum, wherein in one of the end walls of a metallic support contour with a sleeve-like hub for receiving a drive shaft for the drum is at least partially integrated in the plastic mass.

Are known plastic containers for washing machines in which a rotatably mounted drum is arranged. The tub includes a cylindrical container, wherein the rear side of the machine of the cylindrical container in the front wall a metallic support contour, for example in the form of a bearing cross with a sleeve-like hub for receiving a drive shaft for the drum and is incorporated here in the plastic mass.

Such a tub with an integrated support contour is off EP 1 528 136 A2 known. The plastic tub is molded in an injection mold, wherein the metallic bearing cross or the supporting contour is molded in the mold. The gating takes place via a so-called umbrella gate, which is made centrally over the hub for complete filling of the injection mold. During injection molding care must be taken that the bearing cross is surrounded on all sides with plastic melt. In the complete encapsulation of a cast-iron bearing cross, it comes through the much larger thermal expansion coefficient of the plastic compared to gray cast iron to a strong shrinking of the tub on the bearing cross or the support structure. This results in very large self-extensions, which strain the plastic heavily. Therefore, reserves for the additional thermal and mechanical loads in the wash or spin operation hardly remain reserves to absorb the loads and it comes z. B. early failure.

The invention thus poses the problem of providing a plastic tub which is improved in terms of thermal and mechanical loads.

According to the invention this problem is solved with a tub with the features of claim 1 and with a washing machine according to claim 8. Advantageous embodiments and modifications of the invention will become apparent from the dependent claims 2 to 7.

The advantages achievable with the invention are that the metallic support contour allows a relative movement with respect to the wall of the plastic tub as a result of their optimized geometric design under thermal load. This advantageously makes it possible for the tub to have hardly any expansions after the production process. The end wall of the tub and the jacket can freely pull together, so that a small gap is formed between the tub and the inner annular surface of the metallic support contour. On the outer surfaces of the lateral flanks of the bearing cross ring then finds a sliding movement to the wall, here to the end wall of the tub instead. To make this possible, it is necessary that the outer peripheral surface of the bearing contour formed as a bearing ring ring remains free of plastic. This area must therefore be sealed at the sealing points in the injection mold. For this, the sealing surfaces on the bearing cross ring have to be machined before. It is further required that the lateral flanks be substantially parallel to each other, since the sliding movement takes place along the outer surfaces of the flanks.

In an expedient embodiment, the lateral flanks of the bearing cross ring have a flat and smooth surface. This facilitates a possible sliding movement along the outer surfaces of the flanks.

To produce such a tub with enclosed metallic support contour, which allows a relative movement in the plastic material, the injection-molded tool consists of several tool jaws, which are moved apart after the injection molding process, so that the tub can be molded with the over-molded bearing ring. In this case, the supporting contour is formed from a ring in the center of which the sleeve-like hub is integrated by means of radially arranged struts. The ring has in this case in an advantageous manner in cross section a U-shape, on the bottom side of the struts are arranged, which are connected radially to the outer surface of the hub. Thus results for the support contour occupied by a spokes wheel, in the center of which the hub is arranged. The ring resembles a kind of rim, wherein the bottom inside of the ring has a slightly curved shape and wherein the ends of the curvature line merges into the inner edge of the legs of the U-shape.

The blunt-ended leg ends of the U-shape are thereby covered by the injection molding tool that no plastic material can penetrate into the open U. In particular on this area covered by the injection molding tool, a final tension clearance is created for the supporting contour, so that in this area, in particular, the relative movements of the supporting contour with respect to the plastic mass can take place.

In a further development of the invention, the struts have a T-shape, the horizontal leg is arranged facing the front wall side of the container. The struts are in this case equipped for better power transmission with a T-shaped profile, wherein the thicker side is placed on the side facing the tub and the thin rib of the T thereon located on the side facing away from the tub. The connection points of the struts to the hub or the outer ring are generously rounded in order to avoid voltage spikes. The struts of the bearing cross ring have over the remaining length of a constant cross-section, so that any expansion or shrinkage processes of the tub along the arms towards the center are not hindered.

In an advantageous embodiment, the end wall on the directed to the interior of the tub side with a substantially smooth and flat surface. This prevents dirt or mold deposits on the end wall on the inside of the container. You stability of the end wall is provided by the formation of the metallic support contour.

The outer ring of the bearing cross has a circumferential recess between the sealing surfaces, which remains free of plastic after the injection process. This surface is ideal for the molding or for the subsequent mounting of other functional elements such. B. spring suspensions or engine mounts. This possibility represents a significant advantage of Tragkonturgeometrie, because the upper and lower surface of the bearing ring ring from a functional point of view is also important for a good power transmission to the bearing ring in the tub in the washing and spinning operation.

In order to achieve, in particular, the regions of the supporting contour which are recessed from plastic mass, it is proposed that the injection mold consist of a plurality of tool jaws, each of which covers the leg ends with one region. Here, a tool jaw is arranged with an axial Entformungsrichtung in the tool, the other jaws are provided with a radial Entformungsrichtung.

The invention also relates to a laundry treatment machine, such as washing machine or washer-dryer with a plastic container according to the described features.

Figur 1

eine perspektivische Darstellung der erfindungsgemäßen metallischen Tragkontur für einen Kunststofflaugenbehälter;

Figur 2

eine geschnittene Ansicht gemäß der Schnittlinie A/A in Figur 1;

Figur 3

eine weitere geschnittene Ansicht gemäß der Schnittlinie B/B in Figur 1;

Figur 4a, b, c

einen Teilbereich der metallischen Tragkontur, und hier insbesondere den Ringbereich in geschnittener Darstellung mit eingefasster Kunststoffmasse in Darstellungen der Relativbewegung und

Figur 5

eine schematische Darstellung einer Waschmaschine.

An embodiment of the invention is shown purely schematically in the drawings and will be described in more detail below. Show it:

FIG. 1

a perspective view of the metallic support contour according to the invention for a plastic container;

FIG. 2

a sectional view along the section line A / A in FIG. 1 ;

FIG. 3

another sectional view along the section line B / B in FIG. 1 ;

FIG. 4a, b, c

a portion of the metallic support contour, and in particular the ring area in a sectional representation with enclosed plastic mass in representations of the relative movement and

FIG. 5

a schematic representation of a washing machine.

In Fig. 5 is a washing machine 14 with a tub 2 sketched in a side view as a sectional view. The tub 2 consists at least of a cylindrical container 31 surrounding a drum 32. The cylindrical container 31 is closed by at least one end wall 21. In the end wall 21, a metallic support structure 1 is integrated with a bearing cross ring 8 and a hub 3, which receives the drive shaft 33 for the drum 32.

The FIG. 1 shows in perspective a metallic support structure 1 for a plastic tub, as shown for example in the FIG. 2, 3 and 5 represented by the reference numeral 2 for a washing machine.

As in FIGS. 2 and 3 illustrated, the metallic support structure 1 in an injection molding tool 5, which is formed in particular from the tool jaws 5.1 and 5.2, for the production of the liquor container 2 according to the invention, so involved that the plastic mass 4, as it is in particular in the FIG. 4a represents, only partially or partially the support structure 1 einbindet. Thus becomes recognizable, also from the Zusammenschau of the individual representations in the FIGS. 4a to c in that the regions 6 recessed by the plastic mass 4 allow relative movements in the case of thermal loads in boundary regions of the different materials (plastic / metal), so that, as in FIG Fig. 4b represented, in the shrinkage of the plastic mass 4 forms a gap 7, which closes again upon expansion of the plastic mass 4, as in the Figure 4c shown.

As the metallic support structure 1 builds up, is in particular from the FIGS. 1 . 2 and 3 to recognize more clearly. Thus, the supporting contour 1 is formed from a ring 8, in the center of which the sleeve-like hub 3 is integrated by means of radially arranged struts 9. The ring 8 in this case has a U-shape in cross-section, which more clearly from the FIG. 2 , but also from the FIG. 4a can be seen. Thus, the struts 9 are arranged on the inner circumference 11 of the ring 8, which are connected radially to the outer circumferential surface 12 of the hub 3. The ring 8 has a U-shape in section, forming a bottom inside 13, which has a slightly curved shape, which merges into the inner edges of the vertical blunt-ended legs 18 and 19 of the U-shape.

Like from the FIG. 1 becomes clear, the struts 9 have a T-shape, wherein the horizontal leg 20 is arranged facing the front wall side 21 of the container. The struts 9 as such are rounded in their attachment points 22 of the lateral surface 12 and bottom bottom side 23 rounded. In an advantageous manner, in particular between the connection points 22 and 23 over the lateral surface 12 of the hub 3 radially distributed additional ribs 24 are arranged so that a toothed connection between the plastic material 4 and supporting contour 1 and here in particular the hub 3 is given. The directed to the interior of the tub 2 side of the end wall 21 is substantially smooth and flat. This is especially true for the areas that are not covered by the metallic support contour 1 on the outside.

The FIGS. 2 and 3 As already mentioned above, the invention partially and partially integration of the supporting contour 1 in the plastic mass 4 is achieved in that the injection molding tool 5 consists of several tool jaws, in this detailed view only two tool jaws 5.1 and 5.2 are shown. In this case, the tools 5.1 and 5.2 cover the outer circumferential surface 6 of the ring 8 so that the leg ends 18 and 19 are sealingly covered by the tool 5.1 and 5.2 tools, so that this area remains free of plastic compound 4, when the injection mold 5 is closed. It is clear that the tool 5.1 has an axially directed Entformungsrichtung 25, wherein, however, the tool 5.2 has a radial Entformungsrichtung 26 with respect to the tub 2. In Fig. 3 the region of the struts 9 is shown, which extend from the hub 3, starting in one piece to the outer peripheral surface 6.

The injection molding tool 5 thus consists in the sketched portion of the bearing ring 8 of at least two tool jaws 5.1 and 5.2, which are moved apart after the injection molding process, so that the tub 2 can be removed from the mold with the support ring formed as bearing ring 1. In the FIGS. 2 and 3 the tool jaws 5.1 and 5.2 are visualized with the respective shaping directions. With this principle, it is advisable to place the plane of the tool separation in the area between the two sealing points of the bearing cross ring 8. However, deviating from this principle tool components are conceivable.

The outer ring 8 offers in addition to the properties already described initially the possibility to subsequently attach further functional elements. For this purpose, the circumferential recess 13 is provided, which has an inwardly curved between the leg ends 18 and 19 inwardly curved shape, which is free of plastic even after the injection molding process. As functional elements are projections in the recess 13 for spring suspension or engine mounting conceivable. This possibility represents a further significant advantage of the new bearing cross ring 8.

In Fig. 4a is shown enlarged in a sectional view of the outer ring 8. The lateral flanks 29 and 30 of the bearing cross ring 8 are from a functional point of view important for a good power transmission from the support structure 1 in the tub 2 in the washing and spinning operation. The flanks 29, 30 are parallel, at least substantially parallel to each other. As a result, a sliding movement of the ring 8 is allowed or allowed within the cured plastic compound 4. In order to facilitate the possible sliding movement or to make it more reliable, the lateral flanks 29, 30 have a flat and smooth surface.

Due to the thus formed or shaped bearing cross ring 8, it is now possible that between the outer ring 8 of the support structure 1 and the plastic tub 2 at thermal load z. B. cooling and thus shrinkage or heating and thus expansion relative movement is possible, as in the FIG. 4b and FIG. 4c in the individual presentations becomes clear. In Fig. 4b is illustrated by the illustrated arrow 27, as the plastic mass 4 relative to the ring 8 can shrink to form a gap 7. In Fig. 4c is illustrated how the expansion of the plastic mass 4 in the direction of arrow 28 takes place under closure of the gap 7. As a result, the plastic liquid container 2 hardly has any self-expansion after the production process. The tub bottom and the jacket can pull together almost unhindered, so that between the tub 2 and the inner annular surface of the supporting contour 1, a small gap 7 is formed. On the upper edge 29 and the lower edge 30 of the bearing cross ring 8 then takes place a sliding movement of the plastic tub 2. In order to make this possible, the outer circumferential surface 6 of the bearing cross ring 8 is free of plastic compound 4. This region is sealed at the sealing points 18, 19 in the injection mold 5 ( FIGS. 2 and 3 ).

Claims (9)

1. Plastics material washing liquid tub (2) for a laundry treatment machine such as a washing machine or a washer-drier, said plastics materials washing tub comprising a cylindrically formed receptacle (31) that surrounds a drum (32), wherein in one of the end walls (21) a metal support contour (1) with a sleeve-like hub (3) for the accommodation of a drive shaft (33) for the drum (32) is embedded in the plastics material compound (4) at least in a regional manner, characterised in that the support contour (1) is formed by a ring (8), in the centre of which the sleeve-like hub (3) is connected by means of radially disposed struts (9), in that the lateral flanks (29, 30) of the ring (8) are substantially parallel one to another, wherein the inside circumferential face and the lateral flanks (29, 30) are embedded in the plastics material compound and in that the outside circumferential face (6) of the ring (8) is disposed in a region cut out of the plastics material compound (4).
2. Plastics material washing liquid tub according to claim 1, characterised in that the lateral flanks (29, 30) of the ring (8) have a flat, smooth surface.
3. Plastics material washing liquid tub according to claim 1 or 2, characterised in that the ring (8) is U-shaped in cross-section, on the bottom underside (11) of which the struts (9) are disposed, the said struts being connected to the outside surface (12) of the hub (3) in a radial manner.
4. Plastics material washing liquid tub according to claim 3, characterised in that the U-shape of the cross-section has a bottom inner side (13) of the ring (8) with a profiling that is slightly curved inwards, wherein the ends of the line of the curve merge into the inside edges of the portion (18/19) of the U-shape, the said portion ending obtusely in a perpendicular manner.
5. Plastics material washing liquid tub according to claim 4, characterised in that the struts (9) are T-shaped, the horizontal portion (20) of which is disposed pointing towards the end wall side (21) of the receptacle.
6. Plastics material washing liquid tub according to claim 5, characterised in that the struts (9) are developed in a rounded manner the connection point (22/23) to the outside surface (12) and/or to the bottom underside (11).
7. Plastics material washing liquid tub according to claim 6, characterised in that ribs (24) are disposed over the outside surface (12) of the hub (3) distributed in a radial manner.
8. Plastics material washing liquid tub according to claim 1, characterised in that the end wall (21) on the side directed towards the interior of the washing liquid tub (2) has a substantially smooth, flat surface.
9. Laundry treatment machine, such as a washing machine or washer-drier with a plastics material washing liquid tub (2) in accordance with one of claims 1 to 8.

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