DE212009000120U1 - Plastic pipe - Google Patents

Abstract

Plastic pipe (26; 26 ') for attachment to an opening (22) defined by an edge (24), which plastic pipe (26; 26') is made of a thermoplastic material that is hard at operating temperature and at one end region (80) with an im The circumferential sealing element (30; 30 ') made of an elastomeric soft component is provided, which is made of an elastomeric soft component and is fixed in a groove (34) provided on the outside of the end region (80) of the plastic pipe (26; 26') by the 2K method and at the interface to the plastic pipe (26; 26 ') is connected to this by melting, which sealing element (30) is arranged on the end region (80) of the plastic pipe (26; 26') and on its outside in the end region (80) of the Plastic pipe (26; 26 ') has a circumferential annular groove (36) which is designed to receive the edge (24) of such an opening (22) during assembly with at least temporary deformation of the soft component (30).

Description

The invention relates to a plastic pipe, as it finds particularly for the transport of cooling air use. Pipe pieces from such plastic pipes are often used for the production of pipe systems that can be quite complex and z. B. serve to transport air from a central fan to various devices that need to be cooled. Because of the strange shape of such pipe systems (air duct systems) one occasionally speaks of a "deer antler".

Such air duct systems must be designed very carefully, so that a uniform and low back pressure is guaranteed. This means that such pipe sections must not have abrupt cross-sectional changes, bottlenecks, dead spaces and paragraphs. Such aerodynamic optimization lowers the operating noise, increases the amount of cooling air, and facilitates subsequent retrofitting of additional components with cooling air demand.

To connect such pipe pieces with corresponding counterparts, z. B. with a so-called air box, using so-called fixing tabs on which screws are provided, and during assembly, these screws are screwed to the air box or the like, which requires depending on the mounting point correspondingly long assembly times and increases the cost.

It is therefore an object of the invention to provide a new plastic tube.

According to the invention this object is achieved by the subject of the protection claim. 1

Further details and advantageous developments of the invention will become apparent from the hereinafter described and illustrated in the drawings, in no way as a limitation of the invention to be understood embodiments, and from the dependent claims. It shows:

1 a plastic pipe provided on its right side with a peripheral element made of a soft component, before it engages in the opening of a wall formed in 1 shown on the right,

2 a section, seen along the line II-II of 1 .

3 an intermediate step just before the catch,

4 the plastic tube of the 1 to 3 in the locked state,

5 the arrangement after 4 in which a radial fan, which is driven by a brushless DC motor, is connected to the free end of the plastic tube,

6 the arrangement after 5 in longitudinal section,

7 an enlarged view of detail VII of 6 .

8th a rotatable mold for making the in 1 on the left side shown plastic pipe in the so-called direct 2K process,

9 a variant too 8th for producing a peripheral sealing element made of a soft component in the so-called indirect 2K method,

10 a representation analog 9 , for a better explanation,

11 a perspective view of one with the shape 9 and 10 produced blown pipe,

12 an enlarged view of detail XII the 11 , and

13 a longitudinal section through the in 11 front end of the pipe section shown there.

In the following description, like or equivalent parts will be denoted by the same reference numerals and described only once. Terms such as left, right, up, down refer to the respective figure.

1 symbolically shows a part of an air box on the right 20 , This one has an opening 22 with a border 24 , The opening 22 serves to fix the right end 28 a plastic pipe 26 , which is made of a thermoplastic material, for. B. off PE - polyethylene HDPE - High density polyethylene PA - polyamide PP - polypropylene, or another suitable thermoplastic material. This is dimensionally stable at the temperatures occurring during operation.

The right end of the pipe 26 is with a print 30 made of a suitable elastomer. Suitable for this are: TPE - thermoplastic elastomer Santoprene ^® - Elastomer silicone These material specifications apply to all embodiments.

2 shows an enlarged section - along the line II-II of 1 - by the edition 30 , The latter is in a groove 34 of the plastic pipe 26 and even at its outer periphery has a groove 36 , which corresponds to the thickness of the edge 24 is adapted, cf. 7 , On its right side has the edition 30 a frusto-conical section 38 that is inserting into the opening 22 relieved, and on her left side she has a section 40 whose right edge 41 the groove 36 limited.

3 shows an intermediate step in the attachment of the pipe section 26 in the opening 22 ,

4 shows the pipe section 26 after its attachment in the opening 22 , The edge 24 is in the groove 36 ( 2 ) engaged. So you get a connection that can be made very easily by the pipe section 26 with its elastomeric pad 30 in the opening 22 is pressed in, so that the pad 30 in the opening 22 locks. Such a compound is largely dense, so has little air loss, and it can be made easily and inexpensively, because an additional screw is not needed in most cases. Also causes the elastomer pad 30 a noise damping and decoupling.

5 shows as a radial fan 46 with its outlet 48 on a connecting link 50 at the left end of the plastic pipe 26 is attached. This is the outlet pipe 48 of the fan 46 in the connecting link 54 plugged in and locked there. To drive the radial fan 46 is preferably a brushless DC motor 52 , as this causes a particularly quiet running of the fan 46 and high efficiency. The latter is particularly important in cooling applications, as in this case the fan 46 sucked air is hardly heated by this.

6 also shows the fan 46 and its locking connection with the connecting member 50 of the pipe 26 , This connection is very beneficial. It is the subject of DE 20 2007 018 175.2 from 16.12.2007.

7 shows an enlarged view of the detail VII of 6 , The pipe section 26 has at its left end the circumferential groove 34 , and in this is the edition 30 injected in 2K injection molding, as the following 8th is explained, so that the material of the edition 30 with the groove 34 merges and thus forms a very strong and lasting connection. In the edition 30 is the circumferential ring groove 36 into which the edge 24 is engaged. In addition has the condition 30 the oblique flank in the form of the frustoconical portion 38 What the insertion of the pipe 26 in the opening 22 ( 1 ) facilitates which opening through the edge 24 is defined. This way you get one largely airtight connection that can be easily mounted. In most cases, you do not need any tools to assemble, but you need a force that can be applied by hand.

8th shows a mold plate 56 , This has a rotatable mold insert 58 , the left with a cavity 60 is provided for the hard component, so in the example of the production of the plastic pipe 26 , Right has the mold insert 58 a cavity 62 for the production of the soft component 30 ,

So first is in the cavity 60 the hard component of the pipe 26 produced by injection molding, and then the mold insert 58 rotated and it is the soft component on the right in the 2K process 30 made as they are in 1 and 2 is shown.

The mold plate 56 has two inflow channels: left one channel 64 for the material of the hard component, ie the pipe 26 , Right has the mold insert 58 a cavity 62 for the soft component 30 ,

First, in the cavity 60 the pipe 26 made from the hard component. Then the mold insert 58 turned, and right becomes the soft component 30 made as in the 1 and 2 is shown.

It is a so-called direct 2K injection molding process, which provides an excellent bond between the pipe 26 and the elastomeric pad 30 receives.

For reasons of better manufacturing accuracy, it is generally preferred to use tubes which are produced as injection-molded parts. For example, show the 1 to 8th a pipe 26 , which can be produced by injection molding. However, this manufacturing method is possible only with relatively simple parts.

9 shows a plastic tube as a counterexample 26 ' , which can not be manufactured by injection molding because of its shape. Therefore, it is made as a blow molding tube made of a thermoplastic material.

In such Formblasrohren can be used with advantage for the production of a mold, as in the 9 to 13 is shown and described.

For long pipes you would according to the method according to 8th need very large and therefore expensive forms. Especially in these cases you can use a form with advantage, as in the 9 to 13 is shown and described.

Here you use a form 70 with a cavity 72 into which the blow-molding tube 26 ' is inserted after its manufacture and that is why it is designed so that it enters the cavity 72 fits. The pipe 26 ' is at 9 in the direction of an arrow 78 into the cavity 72 inserted.

At the end 80 of the pipe 26 ' Here, in the so-called indirect 2K process, a soft component is to be injected. That's why the cavity has 72 a corresponding annular groove 82 from the in 9 only the lower half is visible.

The right end 80 of the pipe 26 ' (made of hard plastic) fits exactly in the cavity 72 but has, as in 9 shown, no radial protrusions in the annular groove 82 but forms a radially inner boundary for the annular groove 82 ,

A supply line 84 for that for the soft component 30 ' used elastomeric material leads to the annular groove 82 , so that through this feed line the right end 80 of the blow molding 26 ' in the 2K process with the soft component 30 ' can be splashed, cf. 10 , This melts the hot soft component 30 ' the material in the end 80 the blow molding tube 26 ' so that a close, intimate connection between the blowpipe 26 ' and the soft component 30 ' arises.

The 11 to 13 show the end result of the process just described. At the end of the pipe 80 is now the ring of the soft component 30 ' who, as well as in 2 , with a ring channel 36 is provided.

12 shows an enlarged view of the detail XII of 11 , The ring channel 36 is right by a shoulder 86 limited. The shoulder 86 is formed by a ring 88 which, as shown, may have an approximately rectangular cross-section.

On his in 11 and 12 left side has the channel 36 one shoulder 90 , and from this he goes into a frustoconical section 92 above. This in turn goes over into the outside of the pipe section 80 like that too 13 is shown.

By the method used, one also obtains a cohesive connection between the tube 26 ' made of hard plastic and the material of the soft component 30 ' , The production is simple and very safe. This also allows the soft component, as shown, at the end of the tube 26 or 26 ' to install, cf. z. B. 4 ,

Naturally, in the context of the invention multiple modifications and modifications are possible, for. B. by modification of the shape and material of the soft component 30 ' according to the respective requirements, especially with regard to noise insulation.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 202007018175 [0027]

Claims (11)

Plastic pipe ( 26 ; 26 ' ) for attachment to a by an edge ( 24 ) defined opening ( 22 ), which plastic pipe ( 26 ; 26 ' ) is formed from a thermoplastics material that is hard at operating temperature and at an end region ( 80 ) with a circulating sealing element (2K process) ( 30 ; 30 ' ) is made of an elastomeric soft component which is in a on the outside of the end portion ( 80 ) of the plastic pipe ( 26 ; 26 ' ) groove ( 34 ) by the 2K process and at the interface with the plastic pipe ( 26 ; 26 ' ) is connected thereto by melting, which sealing element ( 30 ) at the end region ( 80 ) of the plastic pipe ( 26 ; 26 ' ) and on its outside in the end region ( 80 ) of the plastic pipe ( 26 ; 26 ' ) a circumferential annular groove ( 36 ), which is adapted, during assembly under at least temporary deformation of the soft component ( 30 ) the edge ( 24 ) of such an opening ( 22 ). Plastic pipe according to claim 1, wherein the circumferential sealing element ( 30 ) is produced in the direct 2K process. Plastic pipe according to claim 1, wherein the circumferential sealing element ( 30 ' ) is produced in the indirect 2K process. Plastic pipe according to claim 2, which as an injection molded part ( 26 ) is trained. Plastic pipe according to claim 3, which is used as blow molding ( 26 ' ) is trained. Plastic pipe according to claim 5, wherein the blow molded part ( 26 ' ) on its outside with the soft component of the peripheral sealing element ( 30 ' ) is encapsulated in the 2K process, so that the sealing element ( 30 ' ) is connected by melting with this outside. Plastic pipe according to claim 6, which during injection molding an insert of the injection mold ( 70 ) forms, so that the sealing element ( 30 ' ) by injecting the soft component into one between the injection mold ( 70 ) and the outside of the blow molding tube ( 26 ' ) formed cavity ( 82 ) is producible. Plastic pipe according to one of the preceding claims, in which the sealing element ( 30 ; 30 ' ) in the region of a pipe end ( 80 ) is provided. Plastic pipe according to one of the preceding claims, wherein a pipe end with a blower ( 46 ) connected is. Plastic pipe according to claim 9, in which the blower ( 46 ) by a locking connection designed as a plug connection with the plastic pipe ( 26 ; 26 ' ) connected is. Plastic pipe according to claim 9 or 10, wherein the blower ( 46 ) is designed as a radial fan.

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