DE102012215312B4 - Method for producing an inner container for a household refrigerator, container for a household refrigerator and a corresponding household refrigerator - Google Patents

Abstract

Method for producing a container (3) of a household refrigeration appliance (1), in which a base part (6) made of plastic is provided and this is deformed by thermoforming to form the container (3), characterized in that at least one material thin point (8 ) of the plastic is specifically filled with an adhesive (9).

Description

The invention relates to a method for producing a container of a household refrigerator, in which a base part made of plastic is provided and this is deformed to the container by thermoforming. The invention also relates to a container for a household refrigeration device and a corresponding household refrigeration device.

From the DE 10 2009 045 658 A1 a household refrigerator with an inner container is known, the inner container being produced by thermoforming.

In addition, from the DE 10 2010 029 583 A1 a household refrigerator and a manufacturing method for such a refrigerator are known. There, an inner container is produced by thermoforming and an evaporator is attached to the inner container by means of an adhesive fastening. The adhesive attachment can be produced during the thermoforming process, using appropriate adhesives for this purpose.

In the manufacture of inner containers for a household refrigerator made of plastic by means of thermoforming, points are created due to the process and geometry that fall below a minimum wall thickness required by the application. If these material thin spots are recognized after the thermoforming process, the inner container or the inner door generated is currently ground in and fed back into the process chain as regranulate.

However, if these thin spots are not recognized, these manufactured parts with quality defects are passed on to the further production process chain. Such thin spots can lead to damage to the parts occurring during the subsequent processing steps, in which case they cannot be used and have to be disposed of. In addition, depending on the type, it is necessary that, due to the complex shaping of such inner containers, blanks or

Base parts with a high material thickness must be used in order to maintain the required minimum wall thickness in critical areas of the thermoformed parts. As a result, the minimum required wall thickness can be achieved in most areas, but at the same time there is an unnecessarily high wall thickness in other areas of the thermoformed part. On the one hand, plastic material is wasted as a result, and on the other hand, the wall thickness may be made undesirably high at specific points.

It is known that in the case of thin spots that are currently occurring, these should be eliminated in a laborious manner by masking with an adhesive tape on the foam side of the inner container. In addition to a high workload, reinforcement of three-dimensional structures is only possible to a limited extent. In addition, there is an increase in the material thickness of the output board to compensate for the thin spots. This has the consequence that higher material costs arise and, in addition, higher cycle times occur with regard to production. In addition, with such an increase in material thickness, subsequent assembly on other parts is no longer possible or only possible with greater difficulty.

Out FR 2 652 032 A1 a method is known in which weak points of a thermoformed part are eliminated by attaching a preformed reinforcement part.

It is the object of the present invention to provide a method and a container and a household refrigeration appliance with such a container, with which or in which the container design is improved with regard to thin areas of material that occur.

This object is achieved by a method, a container and a household refrigerator according to the independent claims.

In a method according to the invention for producing a container of a household refrigerator, a base part made of plastic is first provided. This is then deformed or reshaped by thermoforming, so that the container to be produced is formed at the end of the manufacturing process. An essential aspect of the invention can be seen in the fact that at least one thin point of the plastic material produced during thermoforming is specifically filled with an adhesive. By doing so, the above problems can be solved. In particular, there is no longer any waste of material to the effect that, in principle, thicker base parts than necessary have to be provided. By specifically filling up the thin areas of the material, the material thickness can be generated evenly and adapted and the thin area can also be filled very specifically and precisely. In addition, this procedure can be integrated very easily into the manufacturing process in terms of manufacturing technology, so that the related manufacturing and labor costs can be kept very low.

With regard to its deformability, adhesive is extremely suitable for completely filling up the thin point of the material. On the other hand, this material also achieves a configuration in which the filling material is very hard afterwards and withstands corresponding mechanical loads. In addition, an adhesive also achieves a reliable mechanical connection to the material of the base part or the intermediate molded part that has already been formed. In particular, the surface design of the filled thin point area is then also possible very precisely, so that in particular a stepless surface design and a corresponding transition to the surfaces that adjoin the original material thin point is achieved.

In addition, the filling with an adhesive is particularly easy to integrate into the production process and a corresponding production line is easy to convert or upgrade in this regard.

It is preferably provided that the adhesive is sprayed on. By using a spray head in particular, the locally very focused and quantitatively very precisely metered application of the adhesive can be achieved. On the one hand, this has significant advantages with regard to the fastest possible filling of such thin material areas, so that the production process can also be minimized in terms of time. In addition, the material distribution on or in the thin point is possible very precisely through such a spraying. The applied amount of adhesive can therefore also be tailored to requirements, so that no waste occurs here either, and no extensive further post-processing of the adhesive is required and, if necessary, partial removal is avoided again.

It can also be provided that the adhesive is painted on. For example, an adhesive bead can also be applied here. A combination of spraying on with brushing on can also take place. In the case of brushing on, both the bead-like application and the areal application are included.

It is preferably provided that the adhesive is poured into the thin point of the material after the end of the thermoforming. Such a procedure is particularly advantageous in that a further undesired deformation of the intermediate mold part no longer occurs and the material thin point is already relatively exact with regard to its dimensions and can be filled.

It is preferably provided that the thin area of material is filled up after the intermediate molded part produced by the thermoforming has been trimmed. This also avoids situations in which undesirable deformations or mechanical forces occur during trimming, so that the adhesive might be removed from the thin area or might deform itself in such a way that again no desired material thickness would be present.

It is preferably provided that the filling of the thin point of material is carried out before or after the intermediate molded part produced by the thermoforming is punched into the container.

In particular, it is provided that a material thin point is detected and recognized locally and / or with regard to the thin point depth by means of a thickness measurement. This can be done, for example, by appropriate measurements during and / or after thermoforming. Such a precise localization of material thin spots can also be used to fill up very quickly and precisely. In this way, adhesive is actually only applied in a targeted manner at those points where material reinforcement and thus material thickening is to take place. This is also optimized with regard to the amount of adhesive. Depending on the situation, only enough adhesive is poured into the corresponding thin point of the material until a surface design, in particular flush with the adjacent surface areas, is achieved.

The thickness measurement and / or localization of a thin point in the material can be carried out using a wide variety of measurement methods. For example, a measurement using laser, ultrasound, etc. can be carried out here. For example, in ongoing series production, the containers are measured regularly, around every fiftieth part, using ultrasonic sensors at previously defined points. If the measurement results deviate from the target value, the production machine is readjusted.

In this context, it can be provided that the occurrence of a thin point in the material is checked continuously in terms of location and / or time, and in particular is carried out at least temporarily during the thermoforming.

It is preferably provided that the material thin point is filled with adhesive to such an extent that a flush transition to the surface area of the plastic adjoining the material thin point is produced.

This filling of the thin material points produced on the thermoformed part results in the required properties, for example with regard to the stiffness of the component and / or diffusion tightness.

It is particularly advantageous that as a result, three-dimensional structures are also formed Thin areas of material can be filled and the surfaces can be designed accordingly. Ribs or local undercuts can thus also be filled in accordingly.

In particular, filling is an automated process that is carried out during the manufacturing process of the container. This is preferably done by means of a robot and an adhesive application unit. In addition, a suction unit can also be provided, which can perform adhesive suction.

The adhesive application unit preferably comprises one or more application heads or application units. The components required to convey the adhesive are also provided. In addition, a control unit is provided which controls the adhesive application unit as a function of recognized thin material points that are detected by corresponding detectors.

The thickness of the applied adhesive layer depends on the dwell time and / or the speed of movement as well as the flow rate of the application head used.

For example, a two-component reactive adhesive can be applied, in particular sprayed on.

With regard to a fully automatic introduction of the adhesive into a material thin point, the number and position of the points to be reinforced or the material thin points as well as the application quantity of the adhesive per thin point must be defined for each container to be produced. If, for example, with a procedure and a specific shape of a container it is known in advance where such material thin spots occur, then in the automatic production process it can already be specified when and in what quantities adhesive is applied locally to the then known material thin spots.

This procedure enables a production process for each individual shape of a container, in which the robot is controlled in a defined manner with positions and movement speeds and this takes place automatically.

It can also be provided that the wall thickness can be increased step-by-step by repeated application to the same thin areas of material on the component. The proposed method also makes it possible for the provided base parts to be made available in a thinner form, since the thin areas of material that then occur can be specifically filled. As a result, plastic material can also be saved. By also reducing the cycle time or the heating time during thermoforming, it is also possible to save energy in the manufacturing process.

• 1 eine perspektivische Darstellung eines Ausführungsbeispiels eines erfindungsgemäßen Haushaltskältegeräts;
• 2 verschiedene Fertigungszustände beim Herstellen eines Ausführungsbeispiels eines erfindungsgemäßen Behälters;
• 3 eine schematische Darstellung einer Fertigungsanlage für einen derartigen Behälter; und
• 4 ein vereinfachtes Ablaufdiagramm mit Teilschritten bei der Herstellung eines entsprechenden Behälters.

Embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

• 1 a perspective view of an embodiment of a household refrigerator according to the invention;
• 2 different manufacturing states in the manufacture of an embodiment of a container according to the invention;
• 3 a schematic representation of a production plant for such a container; and
• 4th a simplified flow chart with partial steps in the production of a corresponding container.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

In 1 is a perspective view of a household refrigerator 1 shown, which, for example, a refrigerator or a freezer or a combination device, which is provided for cooling and freezing of refrigerated goods, in particular food, can be. The household refrigerator 1 includes an outer housing 2 , which represents an outer container. It also includes an inner container 3 whose walls are a recording room 4th for the refrigerated goods. A front loading opening of the inner container 3 is through a door 5 lockable.

The inner container 3 is a one-piece component which is formed by specific manufacture.

For this purpose, according to the representation in 2 , the exemplary intermediate manufacturing states of the inner container 3 shows the manufacture carried out. In a manufacturing process, a circuit board or a base part is initially used for this purpose 6th made of plastic. This is then reshaped by thermoforming, so that an intermediate molded part 7th from the base part 6th is formed. The intermediate molded part produced in this way 7th shows thin areas of material at specific points 8th on. According to the further illustration in 2 become these material thin spots 8th after finishing thermoforming, filled with an adhesive. For this purpose, an application unit is installed on the production line according to the exemplary embodiment shown 10 mounted, which is a spray head in the embodiment shown. By means of this application unit 10 the adhesive is dosed very precisely locally and extremely precisely in terms of quantity 9 sprayed on, so that the material thin point 8th is completely filled. In the rightmost illustration in 2 is then the intermediate molded part 7th shown in which the material thin point 8th completely with the glue 9 is filled. It can also be seen that a surface 9a of the applied adhesive 9 flush with an adjacent surface 7a of the intermediate molded part 7th is.

The filling of the thin point of the material 8th with the glue 9 is after the end of the thermoforming and also after a trimming of the intermediate molded part produced by the thermoforming 7th carried out. In addition, it can optionally before or after punching the intermediate molded part produced by the thermoforming 7th to the container 3 be performed.

In 3 is a schematic representation of a manufacturing plant 11 shown with partial components. On a turntable 12th the plant 11 are the intermediate molded parts 7th promoted after they are also starting from the respective basic parts 6th were thermoformed accordingly. A turntable with a conveyor belt is provided. In addition, the facility includes 11 an industrial robot 13th with which the local positioning of the application unit 10 can be done quickly and precisely. In addition, there is a control unit 14th provided, by means of which the control of the system 11 and in particular the subcomponents.

It can be provided that the system 11 also has one or more detectors, by means of which the material thin point 8th of the individual intermediate molded parts 7th can be detected. However, it can also be provided that, depending on the shapes already desired in advance, the container 3 that are to be generated, those points are known at which material thin points occur. In the case of such configurations, it is possible to specify and program in advance, like the robot 13th and the at least one application unit 10 have to be controlled and positioned in order to be able to precisely fill the already known thin areas of the material with the adhesive.

In 4th a simplified flow chart with sub-steps of production is shown. It is there according to a step S1, the intermediate molded part 7th transported on the conveyor belt. In a further step S2, the application unit 10 by the robot 13th brought to the specific position at which the intermediate molded part to be processed subsequently 7th a thin point in the material 8th having. According to a step S3, the material thin point is then 8th with the glue 9 filled and thus coated accordingly. It is then checked in a step S4 whether further thin areas of the material 8th on the intermediate molded part currently to be processed 7th available. If this is not the case, according to step S5, this intermediate molded part that has just been processed is made 7th transported further and then processed accordingly if necessary. If, however, it is determined in step S4 that at least one further material thin point 8th is present, a jump is made back to step S2, so that a partial wall thickness increase by means of the adhesive 9 is carried out.

List of reference symbols

1

Household refrigerator

2

Outer casing

3

Inner container, container

4th

Recording room

5

door

6th

Base part

7th

Surface, area

7th

Intermediate molded part

8th

Thin point of material

9

Filler material, glue

9a

surface

10

Order unit

11

Manufacturing plant, plant

12th

Turntable

13th

robot

14th

Control unit

Claims (11)

Method for producing a container (3) of a household refrigeration appliance (1), in which a base part (6) made of plastic is provided and this is deformed by thermoforming to form the container (3), characterized in that at least one material thin point (8 ) of the plastic is specifically filled with an adhesive (9). Procedure according to Claim 1 , characterized in that the adhesive (9) is sprayed or painted on. Method according to one of the preceding claims, characterized in that the adhesive (9) is filled into the thin material point (8) after the end of the thermoforming. Method according to one of the preceding claims, characterized in that the filling of the thin material point (8) with the adhesive (9) is carried out after trimming an intermediate molded part (7) produced from the base part (6) by thermoforming. Method according to one of the preceding claims, characterized in that the thin material (8) is filled with the adhesive (9) before or after an intermediate molded part (7) produced by thermoforming from the base part (6) for the container (3) is punched becomes. Method according to one of the preceding claims, characterized in that a thin point of material (8) is detected and recognized locally and / or in terms of depth by a thickness measurement. Procedure according to Claim 6 , characterized in that the occurrence of a material thin point (8) is checked locally and / or temporally continuously during the thermoforming. Method according to one of the preceding claims, characterized in that the thin material point (8) is filled with adhesive (9) to such an extent that a flush transition to the surface area (7a) of the plastic adjoining the thin material point (8) is produced. Method according to one of the preceding claims, characterized in that a localized material thin point (8) is filled with adhesive (9) in a quantitative and / or locally defined manner to match the material thin point (8). Container, in particular inner container (3), which is produced according to a method of the preceding claims. Household refrigeration device (1), which has a container, in particular an inner container (3), according to Claim 10 having.

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