WO2006053594A1

WO2006053594A1 - Method for producing a copy of a sample object and device for investigating sealing mechanisms

Info

Publication number: WO2006053594A1
Application number: PCT/EP2005/009105
Authority: WO
Inventors: Ralf Salameh
Original assignee: Federal-Mogul Sealing Systems Bretten Gmbh
Priority date: 2004-11-18
Filing date: 2005-08-23
Publication date: 2006-05-26
Also published as: DE102004055660A1; DE102004055660B4

Abstract

The invention relates to a method for producing a transparent copy of a sample object with a front face and a rear face, said transparent copy permitting an investigation of the sealing effects that cannot be carried out on the sample object. Said method comprises the provision of the sample object (S 100), the application of an impression compound to the sample object to obtain a negative impression of the sample object from the impression compound (S 102) and the pouring of a pouring mass into the negative impression to subsequently obtain the transparent copy of the sample object (S 104).

Description

Method for producing a copy of an object sample and device for researching sealing mechanisms

The present invention relates to a method of making a copy of an object sample, the copy of the object sample and a device for exploring sealing mechanisms.

In the design of sealing systems, such as e.g. in the automotive industry, it should be noted that the gasket and the surface of the flanges to be sealed are substantially completely intermeshed. In this case, an almost perfect connection between two flanges, for example an engine block, is created, so that no oil or water can escape during operation. In general, the flanges and the gasket are pressed against each other so that the sealing material is spread on the functional surface of the flanges, so that the holes, which are due to the surface structure of the flanges, are clogged and closed. Functional surface is hereinafter also referred to as the surface which is brought into contact with the sealing material of the seal.

In the design of sealing systems are many different characteristics, such as tolerances of the components used, deformations caused by the contact pressure, influences due to aging or relaxation effects, etc. Another important aspect is the surface texture or surface structure of the flanges or components to be sealed , The basic task of a sealing system is to ensure a certain contact pressure on the flanges, thus forming a closed contact surface together with the sealing material. The surface structure has a great influence on the sealing behavior of the system, since the sealing material is introduced into the "mountains and valleys" or holes of the surface structure distributed with the help of the contact pressure in order to close them as completely as possible In general, the "rougher" the functional surface structure is, the more difficult it is for the elastomeric gasket or sealing material to close said surface accurately.

The surfaces to be sealed are generally technical surfaces that have been created by the production and processing of various materials. For example, the milled surface of an aluminum component has a different surface structure than the structure of a magnesium engine block. Other surfaces in the range of sealing systems are, for example, casting surfaces of oil pans or cylinder head covers.

In the study of sealing mechanisms or sealing systems and in the determination of surface factors or surface effects, it is necessary to press a seal on a functional surface, such as a Sandgußoberfläche, and to investigate the adaptability of the sealing material to the surface structure depending on the contact pressure.

Since this study can not always be carried out directly on the original functional surface, it is advantageous to obtain an accurate image of the functional surface structure in order to examine the adaptability of the seal on the basis of this image. It would also be advantageous if this image or copy of the surface structure would be transparent or transparent. As a result, the adaptability of the gasket can not only be studied from a lateral perspective, but the interaction of the gasket with the functional surface can also be viewed directly through the transparent copy.

It is therefore advantageous to be able to obtain an image of different Sandgußoberflächen or Gußoberflächen with different Rauheitsgraden to the above to be able to carry out the aforementioned investigations.

Trials, e.g. To produce glass components with a surface with different roughness have failed. The glass manufacturers claim that the production of such surface structures e.g. by etching, etc. is not possible. Another attempt was to e.g. to mold a casting surface with heated glass. Here, the problem arises that even if the method had been successful, the resulting surface corresponds to an impression of the surface, and does not have a virtually identical structure of the functional surface structure.

Other technical surfaces, such as milled surfaces, can be easily produced by milling a Plexiglas plate. However, it is questionable whether the resulting surface structure is identical to the original functional surface structure. In addition, the Plexiglasabbildung must be subsequently polished, which affects the optical properties of the resulting image, and thus indirectly complicates the investigation of the above-mentioned sealing behavior.

The object of the present invention is to provide a method which makes it possible to produce a copy of an object, this copy having a virtually identical surface structure as the original object. The resulting copy can essentially be used to study sealing mechanisms.

According to a first aspect of the present invention, there is provided a method of making a transparent copy of an object sample. The object sample is taken from an original object and has a front surface and a back surface. After the removal and the provision of the object sample, an impression compound is applied to the object sample. Subsequently, a negative mold is obtained from the impression mass. In order to obtain the final transparent copy of the specimen, the negative mold is poured with preferably transparent Ausgießmasse. Finally, the negative mold can be removed and the transparent copy is obtained. It is preferred that the surface of the copy have a virtually identical surface structure as the object sample. This gives the copy an accurate image of the surface structure of the original object, which is further advantageous in exploration.

It is preferred that the method comprises grinding and then polishing the back surface of the object sample. This has a significant influence on the transparency of the copy of the object sample. The smooth polished back surface can significantly improve the optical properties of the copy of the specimen.

It is preferred that an additional layer is applied to the back surface of the object sample. As a result, the thickness of the specimen can be adjusted to the desired dimensions. Furthermore, the additional layer can be polished very smoothly, so that the optical properties of the copy are improved in an advantageous manner.

It is preferred that material be removed from the back surface of the object sample. If the thickness of the specimen does not meet the desired requirements, an appropriate adjustment can be made by removing material from the back surface.

It is preferred that the back surface of the clear copy be provided with an antireflection coating. This improves the optical properties of the copy of the object sample.

It is preferred that the back surface of the clear copy be provided with a scratch-resistant coating. This allows a more comfortable handling of the copy and ensures the preservation of the optical properties.

It is preferred that the application of the impression material be carried out by means of a vacuum casting process. The vacuum casting process allows the removal of all air bubbles that may form in the impression mass. It is preferable that the pouring of the pouring mass is performed by the vacuum casting method. This allows a bubble-free pouring of the pouring mass.

It is preferred that the recovery of the negative mold is achieved by curing the impression compound, wherein the object sample is removed by splitting the negative mold. The negative mold can be handled easily after curing and is split in an advantageous manner. The object sample is removed and the negative mold is available for further processing.

It is preferred that the recovery of the copy be achieved by curing the pouring mass, and achieved by a subsequent removal of the negative mold. The curing of the pouring mass results in a sufficiently firm and transparent copy obtained after removal of the hardened mass.

It is preferred that the impression compound allows a very high imaging accuracy of surface structures and preferably has silicone composition. As a result, a very accurate image of the surface structure can be realized. Silicone material is very well suited as an impression mass, as it has a very high adaptability.

It is preferred that the pouring compound be made of liquid plastic which is solid and transparent after curing. This results in a clear copy that is simple and robust to use.

According to a second aspect of the present invention, a transparent copy of an object sample for exploring sealing mechanisms is provided. The surface structure of the copy is virtually identical to the surface structure of the object sample and thus of the original object.

It is preferred that the copy has a front surface and a back surface. This corresponds to an identical embodiment as the object sample.

It is preferable that the front surface of the functional surface corresponds to the object sample. As a result, further investigations of the functional surface can be carried out on the basis of the copy of the object sample.

It is preferable that the surface texture of the copy may have different roughness values due to a manufacturing process. This allows the production of different copies in order to carry out more detailed investigations.

It is preferred that the back surface has an antireflection coating. This improves the optical properties of the object sample.

It is preferred that the back surface has a scratch resistant coating. This improves the handling of the copy of the object sample and the robustness of the back surface is increased.

According to a third aspect of the present invention, there is provided an apparatus for exploring a sealing mechanism. The apparatus comprises means for securing a copy of an object sample and means for pressing the sealing material onto the front surface of the copy. The contact pressure can be variably adjusted to examine the adaptability of the sealing material as a function of the contact pressure. The means for securing the sealing material ensures safe operation of the device. With the help of the visual viewer, the back surface of the copy of the object sample can be viewed. Thus, the adaptability of the sealing material can be practically examined by the copy.

It is preferred that the visual viewing device comprises a microscope. This allows a structural close and accurate examination of the adaptability of the sealing material to the functional surface structure. This is done on the basis of the transparent copy of the object sample. It is preferred that the microscope can be connected to a video camera or camera to assess the adaptability of the sealing material. By connecting a video camera, the dynamic behavior of the sealing material can be examined depending on the contact pressure. Using the camera, so-called snapshots of the examined sealing material can be made.

It is preferred that the apparatus further comprises means for performing sustained load tests and means for performing relaxation and aging tests. This allows the acquisition of practice-relevant data on the wear behavior.

Further advantages and features of the present invention will become apparent from the following description of embodiments of the invention, in which reference is made to the attached drawing, in which:

Fig. 1 is a schematic representation of a functional surface together with a taken object sample;

Fig. 2 is a flow chart of a method of making a copy of an object sample;

FIG. 2a is a more detailed flow diagram of a method according to the invention for producing a copy of an object sample; FIG. and

Fig. 3 illustrates a part of a device for exploring a sealing mechanism.

FIG. 1 shows a schematic representation of a functional surface and additionally shows the removal or cutting out of an object sample. It is an example

Part 1 of an engine block with a corresponding opening 8 shown by means of a Seal to be sealed. The opening 8 may correspond to a combustion chamber opening and it is necessary to reliably close this opening with the aid of a sealing material. Thus, the functional surface 10 of the engine block is shown. This surface has a specific surface structure 5 in the region to be sealed. The sealing material must fill all these unevenness or holes, so that the highest possible density and reliability is achieved.

From the functional surface 10, an object sample 3 is removed or cut out, which is to be further used. The object sample 3 has a front surface 4 and a rear surface 6. Thus, the front surface 4 has the same surface structure 5 as the functional surface of the engine block 1. The thickness of the extracted object sample 3 is made clear by the mark d. After removal of the specimen 3, the thickness d can be adjusted according to the desired dimensions. For example, material can be removed from the back surface. Also, an additional layer can be applied to the back surface 6, if the thickness d is too low. The front surface 4 of the object sample 3 should not be falsified by further processing, since it corresponds to the functional surface structure 5 of the surface to be sealed.

2 shows the individual steps of a method according to the invention for producing a transparent copy of an object sample. The method is to be understood as a non-limiting example, and is explained in more detail below.

In the first step S 100, an object sample is first provided. The object sample has two surfaces, namely a front surface and a back surface. The front surface has the functional surface structure of the part to be examined. Subsequently, step S 102 is carried out, with the impression material being applied to the object sample. The impression compound is applied, for example, by means of a vacuum casting method and can consist of or comprise silicone compound. After the impression material has cured, the negative sample of the object sample is obtained. The splitting of the negative mold allows the removal of the original object sample. Finally, in step S 104, the negative mold is poured with a pouring mass, thus obtaining the transparent copy of the object sample. The pouring compound has been produced in such a way that it adapts very precisely to the surface structure of the negative mold and thus will ultimately have the same surface structure as the object sample. After curing of the pouring mass, the transparent copy of the object sample can be removed. The pouring of the negative mold can also be carried out by means of the vacuum casting process. Step S 106 symbolizes the end of the procedure after the copy of the object sample is ready for further use.

FIG. 2a describes a method for making a copy of an object sample, with the individual steps being broken down in more detail. In step S 200, an object sample with desired dimensions is removed or cut out of a component or object to be examined.

If the dimensions of the component to be examined do not correspond to the desired requirements, then an adaptation of the object sample can be carried out. This means that material can be removed from the back surface or an additional layer can be applied as an additional structure. These steps may only be performed on the back surface so as not to falsify the surface structure to be examined.

In the next step S 202, the back surface is ground and polished. This step is essentially responsible for the desired transparency of the copy of the object sample. The impression mass, which is also used in the production of the negative mold, thus does not adhere to the back surface. As a result, errors in the transparency of the copy and optical properties can be avoided.

With the aid of the vacuum casting method, silicone is poured out in step S 204, the object sample created after step S 202. The silicone material used allows a very high adaptability and can practically the entire surface of the

Fill in the object sample and simulate it. In the subsequent step S 206 cures the Silicone material and the resulting form is split. The thus exposed object sample can now be removed and a so-called negative form has emerged. The negative mold has two sides. The first side bears the negative of the functional surface structure and the second side forms the negative of the back surface of the object sample. As already mentioned, this area should be almost completely smooth.

In the next step S 208, the negative mold is again filled with a special plastic by means of the vacuum casting process. The plastic is sufficiently strong and transparent after curing. Subsequent to step S 210, the plastic used may cure and the clear copy of the original object sample may be provided in the last step. The resulting copy is a nearly identical image of the object sample and has the same surface structure on the front surface as the functional surface of the original object.

Fig. 3 shows a part of a device for investigating sealing mechanisms in which the transparent copy of the object sample has been clamped. The copy 30 is inserted in a fastening device 13 and pressed together with the sealing material 15. The fastening device 13 is part of a more complex device, which is not shown here. The contact force F presses the sealing material 15 of a seal onto the functional surface structure of the copy 30. The reference symbol V symbolizes the direction in which a microscope or other viewing device can be installed in order to assess the adaptability of the sealing material as a function of the contact force F. Thus, the functionality of the sealing material as a function of the contact force F can be examined by the copy 30 of the object sample. The seal should completely conform to the surface structure of the part to be sealed.

The area 16 of the device is shown, which is also transparent and allows observation of the back of the copy according to the direction of observation V.

Influences due to relaxation and aging effects on the Judging sealing effect of elastomeric seals. The copy can also be integrated as an opposing surface in existing leak test facilities, where, for example, with medium or with internal pressures tested. It is not only possible to set the limit values as with the use of the known surfaces, but in parallel it is possible to observe and explore the effects of the plate. The transparent copies are also a good help in presenting the seals in the customer area.

Claims

claims

A method of making a transparent copy of an object sample having a front surface and a back surface, the transparent copy permitting a study of sealing effects that can not be performed on the object sample, comprising:

- providing the object sample (S 100);

- Applying an impression mass on the object sample and obtaining a negative mold of the object sample from the impression mass (S 102);

- Pouring the negative mold with a pouring mass and then obtaining the transparent copy of the object sample (S 104).

2. The method of claim 1, wherein the entire surface of the copy has a virtually identical surface structure as the object sample.

The method of claim 1, further comprising grinding and then polishing the back surface (S 202) of the object sample.

4. The method according to any one of the preceding claims, further comprising

Apply an additional layer on the back surface of the object sample.

The method of any one of the preceding claims, further comprising removing material from the back surface of the object sample.

A method according to any one of the preceding claims, wherein the back surface of the transparent copy is provided with an antireflection coating.

A method according to any one of the preceding claims, wherein the back surface of the clear copy is provided with a scratch-resistant coating.

8. The method of claim 1, wherein the application of the impression material by means of a Vakuumgießverfahrens (S 204) is performed.

The method of claim 1, wherein the pouring of the pouring mass is performed by the vacuum casting method (S 208).

10. The method of claim 1, wherein obtaining the negative mold is achieved by curing (S 206) the impression mass, and wherein the specimen is removed by splitting the negative mold.

11. A method according to claim 1, wherein the recovery of the copy is achieved by curing (S 210) the pouring mass, and is achieved by a subsequent removal of the negative mold.

12. The method of claim 1, wherein the impression mass is a very high

Allows imaging accuracy of surface structures and preferably has a silicone composition.

13. The method of claim 1, wherein the pouring compound is made of liquid plastic, which is solid and transparent after curing.

14. A transparent copy (30) of an object sample for exploring sealing mechanisms, wherein the entire surface of the transparent copy (30) has a virtually identical surface structure (5) as the object sample (3).

The clear copy of claim 14, wherein the copy (30) has a front surface and a back surface.

The clear copy according to claim 15, wherein the front surface of the functional surface corresponds to the object sample (3).

The clear copy according to claim 14, wherein the surface texture of the copy (30) can exhibit different roughness values due to a manufacturing process.

18. A clear copy according to claim 14, wherein the back surface is a

Having antireflection coating.

The clear copy of claim 14, wherein the back surface has a scratch resistant coating.

20. A device for studying a sealing mechanism, comprising:

- means for securing a copy (30) of an object sample having a front surface and a back surface and being substantially transparent, the front surface corresponding to a surface structure according to a functional surface of the object sample;

- Means for pressing a sealing material (15) on the front surface of the copy (30), wherein the contact pressure can be variably adjusted;

a means for attaching the sealing material;

- A visual viewer, which is directed to the back surface of the copy (30).

21. The apparatus of claim 20, wherein the visual viewing device comprises a microscope.

22. The apparatus of claim 20, wherein the microscope to a video camera or

Photocamera can be connected to assess the adaptability of the sealing material.

23. The apparatus of claim 20, further comprising means for carrying out continuous load tests and means for performing relaxation and aging tests.