EP1573195B1 - Intake manifold and associated production method - Google Patents

Abstract

The invention relates to an intake manifold (1) for a primary air system of an internal combustion engine, especially in a motor vehicle. The inventive intake manifold (1) comprises a pipe section (2) that is composed of at least two pipe parts (3, 4) which are produced as injection-molded parts and are joined to each other by means of a connection (12). Said connection (12) is formed by a material that is sprayed on or injected in the area of a dividing line (5) between the pipe parts (3, 4).

Description

The present invention relates to a suction pipe for a fresh air tract of an internal combustion engine, in particular in a motor vehicle, with the features of the preamble of claim 1. The invention also relates to a method for producing such a suction pipe, having the features of the preamble of claim.

An internal combustion engine, especially in motor vehicles, is supplied with fresh air via a fresh air tract. A suction pipe of the type mentioned forms a part of the fresh air supply within such a fresh air tract. For example, the intake manifold leads the fresh air from an air filter to a fresh air collector, from which the fresh air is distributed to individual cylinders of the internal combustion engine.

From the US 6,021,753 For example, a suction pipe for a fresh air duct of an internal combustion engine is known, which has a pipe section which is assembled from at least two pipe parts which are produced as injection-molded parts and connected to one another by means of a connection. The connection is formed by a material arranged in the region of a parting line between the pipe parts. The connecting material, for example an adhesive, is applied to one of the pipe parts in the region of a parting line.

The present invention addresses the problem of providing an improved embodiment for a suction tube or for an associated production method, which leads in particular to low production costs.

This problem is solved according to the invention by the subject matters of the independent claims. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea to assemble a pipe section of the intake manifold from a plurality of, in particular made of plastic, injection-molded pipe parts which are fastened together in the region of their parting line with an on or injected material. In contrast to blow moldings injection molded parts can be readily prepared with uniform wall thicknesses. For the production of the suction pipe according to the invention thus a two-stage manufacturing process is required, in which the pipe parts are injected in a first stage and in which in a second stage, the composite pipe parts are attached by injection or injection of the compound formed by the material to each other. This process is particularly easy to automate. Furthermore, the invention makes use of the possibility of injecting at least one further component onto the pipe section during the second stage of the production process, namely a bellows section and / or a ring seal.

Plastics, elastomers, resins and rubber are particularly suitable as the material for producing the compound by injection or injection.

The injection molding of the bellows section or the annular seal is then expediently carried out in the same process stage or in the same operation as the connection or injection of the connection. An additional operation can thus be saved.

The inventively proposed multi-part design makes it possible to select a suitable material according to the requirements of the respective component of the suction tube. For example, this can make the bellows section considerably more flexible than the pipe section. In a corresponding manner, a material suitable for sealing in a special way can be used for the ring seal.

It is particularly advantageous to use the same material for the connection and for the bellows section or for the ring seal, whereby the second production step can be considerably simplified.

In an advantageous development, the composite tube parts can form at least one injection channel in the region of their parting line, into which the material of the connection is injected according to the method according to the invention. By this construction, the injection mold for the Forming the connection integrated into the pipe parts, so far as the shape of the injection molding tool is simplified.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

A preferred embodiment of the invention is illustrated in the drawings and will be explained in more detail in the following description, wherein like reference numerals refer to identical or functionally identical or similar components.

Fig. 1

eine perspektivische Ansicht auf ein erfindungsgemäßes Saugrohr,

Fig. 2

eine auseinandergezogene Darstellung eines Rohrabschnitts des Saugrohrs,

Fig. 3

eine Schnittansicht durch das Saugrohr entsprechend den Schnittlinien III in Fig. 1 und

Fig. 4

eine Schnittansicht durch das Saugrohr entsprechend den Schnittlinien IV in Fig. 1.

Show, in each case schematically,

Fig. 1

a perspective view of an inventive suction tube,

Fig. 2

an exploded view of a pipe section of the suction tube,

Fig. 3

a sectional view through the suction pipe according to the section lines III in Fig. 1 and

Fig. 4

a sectional view through the suction pipe according to the section lines IV in Fig. 1 ,

Corresponding Fig. 1 has an inventive suction tube 1 a pipe section 2, which is assembled from several, here two, pipe parts 3 and 4. The two pipe parts 3, 4 are each made as injection-molded parts and suitably made of plastic and border in the assembled state along a parting line 5 to each other. Furthermore, the suction tube 1 in the preferred embodiment shown here has a bellows section 6, which is also made as an injection molding and advantageously made of plastic. Preference is given to an integral construction, in which the bellows section 6 is injection-molded or vulcanized onto a first end 7 of the pipe section 2.

Referring to Fig. 2 the pipe section 2 is divided into its pipe parts 3 and 4 so that the first pipe part 3 and the second pipe part 4 are each formed as half-shells that complement each other in a complementary manner. It is of interest that both the first pipe end 7 and a second pipe end 8 remote therefrom are formed integrally or integrally on the second pipe part 4. This construction makes it possible to design the pipe ends 7, 8 in each case as one-piece flanges in which there are no disruptive parting lines.

In the region of the parting line 5, one of the pipe parts, in this case the first pipe part 3, has a U-profile 9 which is open toward the second pipe part 4 and which extends completely closed along an outer edge of the first pipe part 3 which is not specified. Complementary to this is am Second tube part 4, a collar 10 is formed, which also corresponding to the outer edge of the first tube part 3 also completely closed surrounds. If the two pipe parts 3, 4 are properly assembled, the collar 10 closes the open side of the U-profile 9 along the entire length of the U-profile 9, whereby a cavity is formed. This cavity forms an injection channel 11 into which a suitable material for forming a connection 12 (cf. Fig. 3, 4 ) is injectable. With the help of this compound 12, the two pipe parts 3, 4 are fastened together.

Corresponding Fig. 4 can be molded or vulcanized on the second pipe end 8, here inside, an axially acting ring seal 13, for example made of plastic.

According to the invention, the suction pipe 1 can be manufactured as follows:

First, in a first stage or in a first operation of the manufacturing process, the pipe parts 3, 4 are produced as separate injection molded parts. Subsequently, the pipe parts 3, 4 are assembled in a second step or operation and attached to each other by the injection or injection of the compound 12.

The injection-molding of the bellows section 6 and / or the sealing ring 13 can be carried out expediently also in the second operation or method step, so that the pipe parts 3, 4 in the same tool with the connection 12, the bellows section 6 and / or the ring seal 13 are equipped. The suction tube 1 can thus be made particularly inexpensive.

The selection of the material used for the respective component takes place in principle depending on the requirements that are placed on the respective component during operation of the intake manifold 1. For example, the bellows section 6 must be relatively flexible in order to optimally fulfill its function in the installed state of the intake manifold 1. Preferably, the intake manifold 1 is installed in a fresh air tract, not shown here, of an internal combustion engine, in particular of a motor vehicle. During operation of the internal combustion engine, due to oscillations and / or vibrations, relative movements may occur between two sections of the fresh air tract, which are connected to one another via the intake manifold 1. In order to compensate for these relative movements, the suction tube 1 is equipped with the bellows section 6.

In contrast, the material for the ring seal 13 is selected so that the desired sealing effect sets.

For the compound 12, the material is chosen so that a sufficiently strong and sufficiently gas-tight coupling between the two pipe parts 3, 4 can be produced.

For example, compound 12 may be based on adhesion. The material applied or injected to form the connection 12 is then chosen as a function of the material used for the pipe parts 3, 4 such that an adhesive bond with the wetted wall sections in the injection channel 11 forms until the sprayed-on material has hardened.

In order to improve the adhesion effect, it may be expedient, within the spray channel 11, to increase the surface wettable by the material of the compound 12 on the pipe parts 3, 4. For example, could be integrally formed on the collar 10, a protruding web, which projects into the U-profile 9 in the assembled state. Likewise, several webs on the collar 10 and in the U-profile 9 are possible.

However, the material of the connection 12 can also be chosen so that when connecting or injecting the connection 12, a fusion based coupling between the material of the connection 12 and the material of the tube parts 3, 4 is formed. In such a fusion connection, the material of the pipe parts 3, 4 is melted on the surface, whereby a diffusion zone is formed, in which the materials connect materially together. In this procedure results in a cohesive connection between the two pipe parts 3, 4 via the connection 12, which corresponds to a weld virtually.

In order to improve the fusion effect, it is possible to attach at least one Aüfschmelzsteg in the U-profile 9 and / or on the collar 10, which is shaped so that it is particularly easy on the molding of the compound 12 due to the prevailing temperatures on or melts. This supports the diffusion effect, ie the fusion of the materials.

Furthermore, it is possible with the aid of the connection 12 to produce a form-fitting coupling between the pipe parts 3, 4, in that the contours formed by the material of the connection 12 are correspondingly shaped in the region of the parting line 5. For example, undercuts are formed, which can also allow mutual engagement. In such a form-fitting based connection principle no adhesion or fusion between the materials of the connection 12 and the pipe parts 3, 4 must occur. However, it is clear that the aforementioned connection principles can also occur as a mixed form in order to achieve a particularly intensive connection between the pipe parts 3, 4.

The connecting principles described above for the connection 12 can in principle also be realized in the molded-on bellows section 6 and in the molded-on annular seal 13. That is, even between the pipe section 2 and the bellows section 6 on the one hand and / or between the pipe section 2 and the ring seal 13 on the other hand, the connection by adhesion and / or fusion and / or positive engagement.

As materials for the formation of the pipe parts 3, 4 of the bellows section 6, the ring seal 13 and the compound 12, plastics, adhesives, elastomers, resins and rubber can be used.

In order to simplify the manufacturing process, in particular the second production step or operation, it is expedient to inject the same material for the connection 12 and the bellows section 6 and / or for the ring seal 13. This material may differ from that used for the production of the pipe parts 3, 4.

Furthermore, it may be advantageous to make an injection mold, not shown here, which is used for molding the connection 12 and the bellows 6 and / or the ring seal 13, so that a cavity for forming the connection 12, so here the injection channel 11 with another cavity, which serves to form the bellows section 6, and / or with a further cavity, which serves to form the ring seal 13 communicates. For at least two of the total of three molded components (connection 12, bellows section 6, ring seal 13), the same injection openings and ventilation openings can thus be used, which simplifies and rationalizes the realization of the second operation. Provided the cavities for the formation of the connection 12 and the bellows section 6 communicate with each other form in the finished intake manifold 1, the connection 12 and the bellows section 6 an integral, one-piece unit. The same applies to the connection 12 and the ring seal 13 when the cavities communicate to form these components.

Claims (12)

1. An intake manifold for a fresh-air tract of an internal combustion engine, in particular in a motor vehicle, having a tubular section (2) which is composed of at least two tubular parts (3, 4) that are manufactured as an injection moulded part and are connected to one another by means of a connection (12) that is formed from a material arranged between the tubular parts (3, 4) in the region of a dividing line (5),
   characterised in that

   - the material for forming the connection (12) is moulded on or in the region of the dividing line (5),

   - an annular seal (13) and/or a bellows section (6) is/are injection moulded on the tubular section (2),

   - the connection (12) is integrally injection moulded with the annular seal (13) and/or with the bellows section (6).
2. The intake manifold as specified in claim 1,
   characterised in that
   the connection (12) and the bellows section (6) are manufactured from the same material.
3. The intake manifold as specified in claim 1 or claim 2,
   characterised in that
   the tubular parts (3, 4) in the region of their dividing line (5) form at least one injection canal (11) into which the connection (12) is injection moulded.
4. The intake manifold as specified in any one of claims 1 to 3,
   characterised in that
   the material of the connection (12) is matched with the material of the tubular parts (3, 4) in such a manner that the material of the connection (12) fastens the tubular parts (3, 4) to one another by adhesion and/or fusion.
5. The intake manifold as specified in any one of claims 1 to 4,
   characterised in that
   the tubular parts (3, 4) in the region of their dividing line (5) are configured in such a manner that the material of the connection (12) form-fittingly fastens the tubular parts (3, 4) to one another.
6. A method for the production of an intake manifold (1) for a fresh-air tract of an internal combustion engine, in particular in a motor vehicle,

   - in which at least two tubular parts (3, 4) are manufactured as injection moulded parts,

   - in which the tubular parts (3, 4) are assembled into a tubular section (2),

   - in which a connection (12) is arranged in the region of a dividing line (5) between the tubular parts (3, 4), said connection being made out of a material that fastens the tubular parts (3, 4) to one another,

   characterised in that

   - in the assembled state, the tubular parts (3, 4) form at least one injection canal (11) in the region of their dividing line (5), into which canal the material for the connection (12) is injected,

   - a bellows section (6) is injection moulded onto one end (7) of the tubular parts (3, 4),

   - the injection moulding of the connection (12) and the injection moulding of the bellows section (6) is conducted in one shared production step,

   - prior to the injection moulding of the connection (12) and prior to the injection moulding of the bellows section (6), a hollow space for receiving the material of the bellows section (6) communicates with one hollow space or with a plurality of hollow spaces for receiving the material of the connection (12).
7. The method as specified in claim 6,
   characterised in that
   the same material is used for the connection (12) as well as for the bellows section (6).
8. The method as specified in claim 6 or claim 7,
   characterised in that
   an annular seal (13) is injection moulded onto or vulcanised onto one end (8) of the tubular section (2).
9. The method as specified in claim 8,
   characterised in that
   the injection moulding of the annular seal (13) is effected in the same production step as the injection moulding of the bellows section onto (6) and/or the injection moulding of the connection (12).
10. The method as specified in any one of the claims 6 to 9,
    characterised in that
    the material of the connection (12) is matched with the material of the tubular parts (3, 4) in such a manner that the material of the connection (12) fastens the tubular parts (3, 4) to one another by adhesion and/or fusion.
11. The method as specified in any one of the claims 6 to 10,
    characterised in that
    the tubular parts (3, 4) in the region of their dividing line (5) are configured in such a manner that the material of the connection (12) form-fittingly fastens the tubular parts (3, 4) to one another.
12. The method as specified in any one of the claims 6 to 11,
    characterised in that
    the same material is used for at least two members of the group consisting of connection (12), bellows section (6), and annular seal (13).

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