EP0935687B1 - Cylinder washing machine - Google Patents

Description

The invention relates to a washing machine or a washer-dryer with an in a tub horizontal or inclined and rotatable drum with a jacket and two cover surfaces, the jacket or one of the cover surfaces with a removal opening is equipped, and wherein the jacket is wholly or partly made of sheet metal, which is provided with a domed structure facing the inside of the drum.

Drums of washing machines or washer dryers usually consist of sheet metal structures. Because of the high spin speeds of up to 1600 rpm, the drum construction great demands are placed on strength, shape retention and rigidity. It is known from DE 44 37 986 A1 and from DE-OS 25 57 215, the sheet metal which the drum is manufactured to provide with arched structures to increase its strength.

In washing machines, it is still common for the drum jacket and possibly also the top surfaces to be provided with holes so that an exchange of lye between the laundry and the tub is possible is guaranteed. These holes have diameters in today's washing machines in the order of 3.5 mm. Here, in the manufacturing process of the drum First punch holes with a diameter of approx. 2.5 mm in a sheet metal coil and then through a stamping process, the so-called penetration, deepened in a funnel shape and widened to 3.5 mm. When molding and welding a cut coil part The recess of the holes is directed outwards in a cylindrical jacket. this happens for the purpose that any burrs on the edge of the hole do not protrude into the inside of the drum and so the contact of the laundry to these ridges is avoided. The putting through and the associated structuring of the inside of the drum gives the effect that on the one hand the proportion of the flat surface on the entire lateral surface is reduced and on the other hand the light entering the drum is reflected diffusely. On the one hand, this creates the impression of solidity and shine, i.e. high-quality material conveyed, and scratches also fall or less contamination.

A washing machine is known from US Pat. No. 2,591,143, the drum of which has a curvature in Form of a corrugation extending over the entire length of the drum shell is trained. The drum perforation is in the outward-facing depressions arranged. This leads to residual water in the flat areas between the holes stops and drainage deteriorates. In addition, such a drum structure the laundry is rubbed very badly and thereby damaged.

With the aforementioned drums, it has proven disadvantageous that the relatively large Holes in textiles for pimples, laundry damage and the passage of threads and Lead foreign bodies. It has therefore already been proposed to increase the hole diameter reduce (DE-OS 14 10 985) and / or limit the perforation to parts of the jacket (DE 28 26 506 A1).

If you want to get through holes with a diameter of 2 mm, you can Punching tools have a maximum thickness of approximately 1.2 mm. This would be the case for Washing machine drums quickly used sheet thicknesses to break off the tools to lead. For this reason, it is not possible in an automated manufacturing process To produce washing machine drums with through holes of 2 mm in diameter.

Drums with a hole diameter of around 2 mm, which do not have to be put through, therefore have a relatively smooth surface, which has the optical properties described above absence. The same applies to drums with perforations in some areas, because here the unperforated jacket areas are completely smooth. It is also the case with such drums disadvantageous that residual water remains on the smooth surface and the drainage deteriorated.

The invention therefore presents the problem of designing the drum of a washing machine in such a way that that at the same time good optical properties and complete emptying of the Residual water can be reached.

According to the invention, this problem is solved by a drum washing machine with the features of independent claim 1 solved. Advantageous refinements and developments the invention result from the following dependent claims.

The advantages achievable with the invention exist in addition to the solution of the aforementioned Problem in increasing the stability of the drum. This can reduce the cost of Use of thick sheets or complex forming processes (e.g. expanding) are reduced become. Alternatively, the safety distance can be maintained while maintaining the sheet thickness between the drum and the tub, which touches the drum and Should prevent the tub from being reduced. This reduces the so-called Dead volume between drum and suds jacket, d. H. the free fleet is reduced (lower water and energy consumption) and the drum volume can be increased. Through the formation of the arch structure as polygons facing the inside of the drum and the Arrangement of the holes in the corner points of the edge contours results in a relatively simple pattern to be produced for the arch structure and also the holes are each on the lowest points, which leads to the drainage behavior of the wash liquor or the rinse water is greatly improved.

It is also advantageous if the edge contours a flat, in the circumferential direction of the Have drum jacket facing area and if the holes are arranged in this area are. In the manufacturing process described elsewhere (p.1, lines 14-21) into the perforated cylindrical shell by expanding shaping and stabilizing Contours embossed. Then it is by one of DE 44 37 986 A1 or DE-OS 25 57 215 known method provided with the arch structure. In such a procedure it is impossible to make the holes in the already rounded ones, provided with the arched structure To punch the drum jacket. It is relatively difficult to punch and punch the holes on the sheet metal coil to arrange the vaulted structure created by expanding the jacket so that one another the holes are exactly at the corner points of the structure. A change in the order of the Process steps in a process in which the structure is first introduced and subsequently punching is also disadvantageous in terms of production technology, since the arch structures can be damaged by punching the holes. By widening the edge contours the tolerance range in which the holes are to be arranged increases, which simplifies the punching in an automatic manufacturing process. This is particularly so the case when the width of the flat area is 1.5 times to 2.5 times the Has hole diameter.

It is also advantageous if the holes are compared to those of conventional drum washing machines are reduced to a diameter of approx. 2 mm. This is the step through reduced by fluff or threads, which is more gentle on the laundry.

Figur 1

den allgemeinen Aufbau einer Trommelwaschmaschine

Figur 2

den Längsschnitt durch eine Trommel (3)

Figur 3, 3a

schematisch die Gestaltung der Wölbstruktur und der Lochung in einem Bereich des Trommelmantels (3.1)

Figur 4

eine weitere Variante der Wölbstruktur und der Lochung in einem Bereich des Trommelmantels (3.1)

Exemplary embodiments of the invention are shown purely schematically in the drawings and are described in more detail below. It shows

Figure 1

the general structure of a drum washing machine

Figure 2

the longitudinal section through a drum (3)

Figure 3, 3a

schematic of the design of the arch structure and the perforation in an area of the drum casing (3.1)

Figure 4

another variant of the arch structure and the perforation in an area of the drum casing (3.1)

The drum washing machine (1) designed according to the invention has a tub (2) in which a drum (3) for receiving laundry (4) is rotatably mounted. The drive the drum (3) is driven by a motor (13) via a V-belt (13.1). The tub (2) is swingably suspended on the spring (5) in the housing (6) and becomes Damping of these vibrations in the lower area by shock absorbers (7) compared to Supported base (8).

The detergents / fabric softeners required to carry out a washing program are the tub (2) via a detergent dispenser (9) with a connected connecting hose (10) fed. For this, the desired substances can be selected by the user be filled into corresponding compartments (11) of a detergent drawer (12). About one in the drawings not shown water supply is the entire subject at the beginning of the respective program part washed into the tub (2).

A microprocessor control (MC) is used to control the different washing programs provided that via signal lines (14) with various transducers and the controls connected is. It issues time and status-dependent commands via control lines (15) to various actuators (motors, valves, display elements ...).

The drum (3) is in an automatic manufacturing process described in more detail elsewhere (not shown). This is done first for the drum jacket (3.1) cut a metal strip from a coil and punch it with the desired one Provide perforation (16). The sheet metal strip is then bent in a circle and welded the two mutually facing edges. The resulting cylinder is provided with shaping and stabilizing contours by known expansion processes. Then, by a method known from DE-OS 25 57 215 Vaulted structure on the coat. Then the floor (3.2) and the Cap (3.3).

Figure 3 shows a section of the drum shell (3.1) with the basic structure of the Arch structure and the arrangement of the holes (16) according to the invention:

The jacket (3.1) is complete or in sections with polygons curved inwards, preferably Hexagons (17). Figure 3a shows a section through the jacket (3.1) along the line A - A, from which the curvature of the hexagons (17) in the direction of the drum axis (3.4) becomes clear. Versions are also possible in which the cover surfaces (Cap (3.2) and bottom (3.3)) are provided with curved polygons. In a drum jacket (3.1) are holes (16) in a smaller number than in the usual drums (3) and if possible with a smaller diameter d (approx. 2 mm). These holes (16) are in the outward edge contours (17.1) of the curvature and here in particular in the Corner points of the hexagons arranged.

The arrangement of the holes (16) is determined by the requirement for rapid, residue-free Water drainage and good degree of textile drainage when spinning with pumps or only pumping, optimal laundry protection, low foreign body sensitivity and good looks.

Figure 4 shows a section of a drum shell (3.1) with an advantageous embodiment the vaulted structure in the form of hexagons (18) with curved edges, at the edge contours a flat, directed in the circumferential direction of the drum shell (3.1) Have area (19) from 1.5 times to 2.5 times the hole diameter (d) and the Holes (16) are arranged in this area (19). Are in the illustrated embodiment the areas (19) 4 mm wide and the hole diameter d is 2 mm. The wrench size s the structural pattern is about a fifth of the jacket width, here 38.48 mm. The advantages of one Such embodiments are described elsewhere.

The diameter of the drum (3) can be in all the embodiments described above appropriate material thickness and constant tub diameter by up to 10 mm, unless there is water jacket formation when spinning opposes. This allows the smallest distance between the drum casing (3.1) and The outer tub jacket is only approx. 5 mm.

Drum jackets (3.1) can be provided with the arch structure as cylinders and before or afterwards subjected to a further forming process (e.g. expansion). Just like that it is possible to produce finished circuit boards or coil material with curved structures (see DE 44 37 986 A1) to process or circuit boards or coil material in a continuous To provide the manufacturing process with the arch structures, to punch before or after and undergo further forming processes (e.g. roll forming, embossing, pressing, etc.), as well as to shape a cylinder.

The considerations can also be applied analogously to the bottom and the cap.

Claims (6)

1. Washing machine or washer-dryer, including a drum (3) which is mounted in a washing liquid container (2) horizontally or inclinedly and rotatably, said drum having a casing (3.1) and two covering surfaces (3.2, 3.3), the casing (3.1) or one of the covering surfaces (3.2, 3.3) being provided with an outlet aperture, and the casing being produced, at least partially, from a sheet metal plate which is provided, at least partially, with a curved structure orientated towards the interior of the drum, characterised in that the curved structure comprises polygons orientated towards the interior of the drum, and in that perforations (16) are provided in the casing (3.1) on the edge contours (17.1; 19) of the curvature, in the comer points thereof, which contours are orientated towards the exterior of the drum.
2. Drum-type washing machine (1) according to claim 1, characterised in that the edge contours have a flat region (19), which is orientated in the circumferential direction of the drum casing (3.1), and in that the perforations (16) are provided in these regions (19).
3. Drum-type washing machine (1) according to claim 2, characterised in that the width of the regions (19) is between 1.5-times and 2.5-times the perforation diameter (d).
4. Drum-type washing machine according to at least one of claims 1 to 3, characterised in that the perforations (16) are reduced to a diameter (d) of approx. 2 mm compared with those of conventional drum-type washing machines (1).
5. Drum-type washing machine (1) according to at least one of claims 1 to 4, characterised in that the spacing between drum casing (3.1) and washing liquid container casing is reduced by up to 5 mm compared with that of conventional drum-type washing machines (1).
6. Drum-type washing machine (1) according to claim 5, characterised in that the minimum spacing between drum casing (3.1) and washing liquid container casing is approx. 5 mm.

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