METHOD FOR PRODUCING A SUBASSEMBLY FOR A DOMESTIC APPLIANCE, AND SUBASSEMBLY

Abstract

In a method for producing a subassembly for a household appliance, at least one of a first rail and a separate second rail is cleaned by a mechanical and/or chemical cleaning operation. Subsequently the first and second rails are connected to one another so as to be able to slide relative to one another and thereby form a rail withdrawal device of the subassembly.

Claims

1. A method for producing a subassembly for a household appliance, said method comprising: cleaning at least one of a first rail and a separate second rail by a mechanical and/or chemical cleaning operation; and subsequently connecting the first and second rails to one another so as to be able to slide relative to one another and thereby form a rail withdrawal device of the subassembly.

2. The method of claim 1, wherein the at least one of the first and second rails is the first rail, and further comprising coating the first rail with a layer comprising silicon oxide and/or silicon dioxide after the first rail has undergone the mechanical and/or chemical cleaning operation and before being connected with the second rail.

3. The method of claim 1, wherein the at least one of the first and second rails is the second rail, and further comprising coating the second rail with a layer comprising silicon oxide and/or silicon dioxide after the second rail has undergone the mechanical and/or chemical cleaning operation and before being connected with the first rail.

4. The method of claim 1, wherein the at least one of the first and second rails is the second rail, and further comprising, prior to undergoing the mechanical and/or chemical cleaning operation, mounting the second rail to a further component of the subassembly embodied as a retaining device; and cleaning the second rail together with the retaining device by the mechanical and/or chemical cleaning operation.

5. The method of claim 4, further comprising coating the second rail together with the retaining device with a layer comprising silicon oxide and/or silicon dioxide.

6. The method of claim 3, further comprising: prefabricating a rolling element device with a rolling element cage and rolling elements arranged thereon; and attaching the rolling element device at least in subcomponents to the second rail after the second rail has been coated and before the first rail is connected to the second rail.

7. The method of claim 6, further comprising, after the rolling element device has been attached on the second rail, push-fitting the first rail onto the second rail such that the rolling element device is arranged in an intermediate space between the first and second rails to thereby allow displacement of the first and second rails relative to one another via the rolling element device.

8. The method of claim 1, wherein the mechanical cleaning operation includes a blasting process.

9. The method of claim 8, wherein the blasting process is at least one process selected from the group consisting of an ice blasting process with blasting medium additive, a carbon dioxide pellet blasting process, a carbon dioxide snow blasting process, an ultrasound method, a plasma method and a laser cleaning process.

10. The method of claim 1, wherein the chemical cleaning operation is a process using liquid carbon dioxide, alkaline solutions, calcium carbonate and/or chemical stripping.

11. The method of claim 1, further comprising using a plasma process for coating the at least one of the first and second rail with a layer comprising silicon oxide and/or silicon dioxide after the at least one of the first and second rails has undergone the mechanical and/or chemical cleaning operation and before the first and second rails are connected to one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Exemplary embodiments of the invention are explained in more detail below with reference to schematic drawings, in which:

[0025] FIG. 1 shows a schematic view of an exemplary embodiment of a household appliance according to the invention;

[0026] FIG. 2 shows a perspective view of components of a subassembly of the household appliance in a specific stage of a production method;

[0027] FIG. 3 shows a perspective view of the subassembly according to FIG. 2 with further components that are mounted; and

[0028] FIG. 4 shows a perspective view of a further exemplary embodiment of a subassembly of the household appliance.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE PRESENT INVENTION

[0029] In the figures, like or functionally like elements are labeled with like reference signs.

[0030] FIG. 1 is a simplified perspective view showing a household appliance 1 which is embodied for the preparation of foodstuffs and is a cooking appliance, for example. The household appliance 1 comprises a housing 2 in which there is formed a cooking chamber 3 which is delimited by walls of a muffle 4. In addition, the household appliance 1 comprises a door 5 which is embodied for closing the cooking chamber 3 and is arranged in a pivotable manner on the housing 2. A user control and/or display device 6, to be understood simply by way of example in terms of its embodiment and location, is present.

[0031] A plurality of rail withdrawal devices 7, one of which is explained in more detail below, are arranged on opposite vertical side walls 4a and 4b of the muffle 4.

[0032] The rail withdrawal devices 7 are arranged in pairs opposite one another at the same levels, considered along a height direction (y-direction), such that insertion levels are also defined hereby. A cooked food carrier, such as a grill rack, a drip pan or a baking tray, for example, can be placed on said rail withdrawal devices 7 assigned in pairs and thus be slid into the cooking chamber 3 or withdrawn from the cooking chamber 3 in the depth direction (z-direction).

[0033] FIG. 1 shows an exemplary embodiment of a rail withdrawal device 7 in a perspective view. In the embodiment shown, the rail withdrawal device 7 comprises a first rail 8 and a rail 9 separate therefrom. The rail withdrawal device 7 has a longitudinal axis L, which is also the longitudinal axis of the two rails 8 and 9. The two rails 8 and 9 are displaceable relative to one another in the direction of said longitudinal axis, by means of which a displacement direction is also defined. The two rails 8 and 9 are substantially equal in length or one of the two rails is formed with a length that is between 80 percent and 100 percent of the length of the other rail. The first rail 8 represents an outer rail which forms the runner rail. The second rail 9 is an inner rail and represents a fixed rail, which means that it is fastened to the inner face of the side wall 4a.

[0034] The first rail 8 surrounds the second rail 9 or the second rail 9 is installed or guided in the first rail 8. The two rails 8 and 9 are embodied as hollow, in particular in the manner of a channel.

[0035] FIG. 2 shows components of a subassembly 10. The subassembly 10 comprises a retaining device 11, which in the exemplary embodiment is a rack support grid. In addition, the subassembly 10 also comprises the rail withdrawal device 7, as has already been explained with reference to FIG. 1.

[0036] As can be seen in FIG. 1, in the finished assembled state the subassembly 10 is arranged on a vertical side wall, a subassembly 10 of said type being arranged with a retaining device 11 and at least one rail withdrawal device 7 both on the left-hand vertical side wall 4a and on the right-hand vertical side wall 4b. In this arrangement, the rail withdrawal device 7 is fastened to the retaining device 11 and consequently arranged indirectly on a vertical side wall 4a or 4b.

[0037] In order to produce the subassembly 10, it is provided here in the first instance that the rack support grid or retaining device 11 is provided in one method step. In addition, the second rail 9 is provided as a separate part by the rail withdrawal device 7. In this manufacturing state, the rail withdrawal device 7 is therefore still fully disassembled. In FIG. 2 it is shown, in a manner to be understood simply by way of example, that a plurality of rail withdrawal devices can then be arranged on the retaining device 11, so that a plurality of second rails 9 are also shown here. Said rails 9, of which henceforth reference will always merely be made to one of the rails, are then mounted on the retaining device 11. For example, a screwing or snap-fitting or hooking-in operation may be provided in this case.

[0038] As the following method step, said intermediate module is cleaned together with the retaining device 11 and the rails 9 fastened thereto, a mechanical and/or chemical cleaning method being carried out for this purpose.

[0039] Following said cleaning operation or before said cleaning operation or concurrently with said cleaning operation, a corresponding cleaning of the first rail 8 can also be carried out by means of a chemical and/or mechanical cleaning method of the first rail 8, the first rail then likewise still being provided here as a separate component.

[0040] After the cleaning of the intermediate assembly module, as is shown in FIG. 2, a coating process is performed, at least one layer comprising silicon oxide and/or silicon dioxide being applied in this case. Preferably a multilayer coating is applied, which may then also comprise another layer, for example silicon carbide. Preferably an outer layer is a silicon oxide layer or a silicon dioxide layer.

[0041] The coating is preferably performed by means of a plasma deposition method and said coating is performed in particular using a high-rate PECVD deposition method, said silicon oxide layer or silicon dioxide layer being produced as an outer layer at a deposition rate of greater than 0.5 μm/min.

[0042] Once said coating of said intermediate assembly module comprising the retaining device 11 and a second rail 9 of a rail withdrawal device 7 has been completed, the further assembly of the rail withdrawal device 7 is performed. To that end, as is shown in FIG. 3, onto a second rail 9, a likewise produced intermediate module in the form of a rolling element device 12 is then firstly push-fitted onto said second rail 9 according to arrow P1. Said rolling element device 12 comprises a rolling element cage 13 and rolling elements 14 mounted thereon. In the exemplary embodiment it is provided that the rolling element cage 13 is a carrier component, C-shaped in cross-section, on the top wall of which a plurality of rolling elements 14, in particular three, are arranged and on an oppositely disposed base wall of which a plurality of further rolling elements 15, in particular three, are arranged. The rolling elements 14 and 15 may be rollers or balls and they are in each case mounted on the rolling element cage 13 so as to be rotatable via an axis mounting arrangement.

[0043] In the assembled state, the second rail 9 therefore extends through the hollow, in particular C-shaped, rolling element carrier or rolling element cage 13.

[0044] Following said assembly of the rolling element device 12 on the second rail 9, the first rail 8, which has then likewise been cleaned and optionally also coated subsequent to the cleaning operation, is push-fitted, as is indicated by the arrow P2. The assembly or push-fitting of the rolling element device 12 onto the second rail 9 is represented by the arrow P1. In the assembled state, said rolling element device 12 is then arranged in an intermediate space between the first rail 8 and the second rail 9. In FIG. 3, the lower two rail withdrawal devices 7 are shown already in the assembled final state, and moreover in the inserted state.

[0045] FIG. 4 shows a view of a further exemplary embodiment of a subassembly 10. In contrast to the embodiment according to FIG. 3, it is provided in this case that the embodiments of the rolling element devices 12 are different. In the implementation according to FIG. 3, only one rolling element device 12 is provided per rail withdrawal device 7, which rolling element device 12 is arranged in that case as displaceable relative to both rails 8 and 9 in the intermediate space between the rails 8 and 9. The rolling element device 12 can therefore be displaced relatively along the longitudinal axis L of the rail withdrawal device 7, which axis also represents the displacement direction of the two rails 8 and 9 relative to one another.

[0046] In FIG. 4 it is provided that the rolling element device 12 has two separate rolling element units 16 and 17 which are arranged at different ends and are separate units. It is provided in particular that the rear rolling element unit 16 has a rolling element carrier 18 on which a plurality of rolling elements are rotatably mounted. Said rolling element unit 16 is preferably arranged in a fixed position on the first rail 8, in particular clipped or snap-fitted into place, and then fastened in particular to a rear end 8a of said first rail 8. The rolling elements of said first rolling element unit 16 then run on raceways of the second rail 9. The further rolling element unit 17 likewise comprises a rolling element carrier 19, on which two rolling elements 20 and 21 are rotatably mounted in the exemplary embodiment. Said further rolling element unit 17 is arranged in a fixed position on the second rail 9, in particular at a front end 9a. The rolling elements 20 and 21 then contact raceways on the first rail 8. In this implementation too, the production method corresponds to the implementation shown in FIG. 2 and FIG. 3. Instead of the rolling element device 12 being push-fitted, in this case, in the corresponding method step, the rolling element unit 17 is then mounted on the second rail 9 before the first rail 8 is push-fitted. In addition, the rolling element unit 16 is push-fitted onto the second rail 9 and then connected, in particular snap-fitted, to the second rail 8 when the second rail 8 is slid over the rolling element unit 17 fastened to the second rail 9.