JP5109957B2 - Exhaust manifold for internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust manifold of an internal combustion engine. More specifically, the present invention relates to an outer pipe formed integrally with a flange connected to the internal combustion engine and a connection flange connected to the exhaust system. The present invention relates to an exhaust manifold of an internal combustion engine having a double-pipe structure in which inner pipes are internally provided at intervals.

  Generally, an exhaust manifold of an internal combustion engine collects exhaust gas discharged from each exhaust port of the internal combustion engine into one by a collecting pipe and then discharges it to a catalyst or the like attached downstream of the collecting pipe. It is.

  For example, the exhaust manifold includes an engine-side flange attached to an internal combustion engine, a collecting pipe in which a plurality of branch pipes connected to the exhaust hole of the flange are gathered together on the downstream side, and an end of the collecting pipe And a connecting flange connected to the portion.

  By the way, in the internal combustion engine provided with the turbocharger, the turbocharger is mounted on the connecting flange.

  Since the turbocharger is made of metal and has a corresponding weight, in order to reliably support the turbocharger, the turbocharger is mounted on the exhaust manifold on which the turbocharger is mounted. A certain degree of support rigidity (strength) is required.

  If the support rigidity is low, vibration from the turbocharger cannot be reduced sufficiently, which causes noise and the like, which is not preferable.

  For this reason, a conventional exhaust manifold of an internal combustion engine generally has these flanges, collecting pipes, and connecting flanges integrally formed of rigid cast iron.

  However, such an exhaust manifold made of cast iron is preferable in that it has the above-mentioned support rigidity and can reduce vibration of the turbocharger, but on the other hand, there is a problem that it is heavy because of its thick wall thickness. It was.

  Further, when the wall thickness is increased, the heat capacity is increased, the temperature of exhaust gas supplied to the catalyst is lowered, the heat loss of the exhaust system is caused, and there is a problem that it is difficult to comply with exhaust gas regulations.

  Therefore, recently, a so-called double-pipe structure exhaust manifold made of a material having high heat resistance and corrosion resistance such as stainless steel has been proposed (for example, see Patent Document 1).

  Specifically, this exhaust manifold has a double pipe structure in which an inner pipe is internally provided with a space from the outer pipe inside the outer pipe, and the inner pipe and the outer pipe have heat resistance and corrosion resistance. It is formed in the cylindrical shape with the stainless steel plate which has.

  Further, a slide member such as a wire mesh ring formed by pressing wire-shaped stainless steel into a ring shape by press molding is interposed between the outer tube and the inner tube on the exhaust system side.

  Therefore, the inner tube and the outer tube are arranged at a predetermined interval, and the inner tube has a floating structure that can move relative to the outer tube in the axial direction.

  According to such an exhaust manifold of an internal combustion engine having a double-pipe structure, heat resistance and corrosion resistance are higher than those of the cast iron exhaust manifold. Can be achieved.

  Further, since the outer tube and the inner tube are held at a predetermined interval, an air layer is formed between the outer tube and the inner tube, and heat radiation from the inner tube to the outer tube is generated. Reduced.

Therefore, the heat capacity in the exhaust manifold can be reduced, the exhaust gas temperature supplied to the catalyst can be prevented from decreasing, and the recent exhaust gas regulations can be met.
JP-A-7-224649

  However, this double-pipe structure exhaust manifold has the above-mentioned advantage, but the outer pipe and the inner pipe are made thinner, so that the support rigidity of the exhaust manifold is higher than that of the cast iron. There was a problem that it would fall.

  In particular, in the exhaust manifold to which the turbocharger is attached, the support rigidity may be insufficient.

  Therefore, in fact, in the conventional exhaust manifold having a double pipe structure, in order to secure the support rigidity, auxiliary members such as a plurality of metal stays are attached to the turbocharger, and the turbocharger By supporting this, the necessary support rigidity is secured.

  An object of the present invention is to provide a manifold for an internal combustion engine that can reduce the weight while securing a necessary supporting strength and that does not require an auxiliary member such as a metal stay. is there.

To solve the above problem,
The manifold of the internal combustion engine according to the present invention includes an inner pipe that is integrally formed with a flange that is connected to the internal combustion engine side and a connection flange that is connected to the exhaust system side. The tube is internally provided, and the wall of the outer tube is provided with an opening through which the inner tube can be inserted, and a lid that can seal the opening . An internal combustion engine side insertion portion that is inserted into an exhaust hole opened on the internal combustion engine side in the outer pipe and welded to an edge of the exhaust hole in a state where the opening of the outer pipe is sealed And an exhaust system side insertion portion that is inserted into a supply port provided on the exhaust system side of the outer pipe and welded to an edge of the supply port. Further, a part of the branch pipe that is on the internal combustion engine side of the inner pipe is welded to the peripheral edge of the exhaust hole of the outer pipe, and in the gap between the collecting part on the exhaust system side of the inner pipe and the outer pipe, A slide member is interposed, whereby the inner tube and the outer tube are arranged at a predetermined interval, and the inner tube has a floating structure that can move relative to the outer tube in the axial direction. The internal combustion engine side insertion portion of the lid portion inserted into the exhaust hole of the outer pipe is a part of the inner surface of the exhaust hole and the outer surface of the branch pipe of the inner pipe, and the exhaust hole of the outer pipe While it is welded to the edge of the exhaust hole in a state of being sandwiched between a portion that is not welded to the peripheral edge, the end edge of the collecting portion of the inner pipe is retreated from the supply port of the outer pipe At the same time, the exhaust system side insertion portion of the lid portion inserted into the supply port extends to the supply port side from the edge of the collecting portion of the inner pipe and is welded to the edge portion of the supply port. ing. Further, the slide member is formed as a wire mesh ring obtained by pressing and solidifying wire-like stainless steel in a ring shape .

  That is, in the present invention, the outer tube provided with the flange, the connecting flange, and the opening is integrally formed. Specifically, the outer tube is integrally formed with a hard material such as cast iron having rigidity. Become.

Therefore, it is possible to ensure the same support rigidity as that of a conventional cast iron exhaust manifold, and in particular, an internal combustion engine having a turbocharger attached to the connecting flange does not use an auxiliary member such as a metal stay. However, the turbocharger can be reliably supported.

  In the present invention, since an opening is formed in the outer tube, the inner tube can be easily inserted through the opening, and assembly and manufacture can be facilitated.

  The opening is appropriately opened according to the shape, size, and the like of the inner tube, but it is sufficient that the opening is at least open to the extent that the inner tube can be inserted.

  However, the size of the opening is preferably as small as possible from the viewpoint of securing the support rigidity of the outer tube, but on the other hand, as large as possible from the viewpoint of reducing the weight, it seems preferable. The size is appropriately determined according to the weight of the turbocharger mounted on the connecting flange.

  Further, according to the present invention, since the opening is formed in the outer tube, the entire outer tube can be reduced in weight by the area of the opening.

  However, since the inner tube is finally built in the outer tube and the lid is fixed to the opening, the overall weight of the present invention is the outer tube, the inner tube, and the lid. The total weight of the part.

  Therefore, in the present invention, the inner tube and the lid are formed of a metal thin plate having high oxidation resistance and heat resistance, for example, a stainless steel plate or a steel plate by sheet metal or welding.

  If the inner tube and the lid are formed by such a thin metal plate, the inner tube and the lid portion are thin, so that they can be formed very lightly, and the overall weight can be reduced compared to the conventional cast iron exhaust manifold. Can be planned.

  Further, since the inner tube and the lid formed of the metal thin plate can be formed thin, the heat capacity in the exhaust manifold can be reduced, and the exhaust gas supplied to the catalyst can be prevented from lowering in temperature. It can also handle regulations.

Further, since the outer tube and the inner tube are held at a predetermined interval, an air layer is formed between the outer tube and the inner tube, and heat radiation from the inner tube to the outer tube is performed. Reduced.

  Therefore, the heat capacity in the exhaust manifold can be reduced, the exhaust gas temperature supplied to the catalyst can be prevented from decreasing, and exhaust gas regulations in recent years can be fully met.

  According to the manifold of the internal combustion engine of the present invention, it is possible to reduce the weight while securing the necessary support strength, and an auxiliary member such as a metal stay can be dispensed with.

  Hereinafter, the manifold of the internal combustion engine of the present invention will be described with reference to the drawings.

  FIG. 1 is an overall front view showing an embodiment of the present invention.

  FIG. 2 is a side view showing a partially broken state of FIG. 1, and FIG. 3 is an enlarged side view of a state taken along line BB of FIG.

The exhaust manifold A of the internal combustion engine of the present embodiment is an outer pipe in which a flange 1 connected to the internal combustion engine (not shown) side and a connection flange 2 connected to the exhaust system (not shown) side are integrally formed. 3, an inner tube 4 is internally provided at a distance from the outer tube 3.
Hereinafter, each member will be described in detail.

  The flange 1 is formed with a plurality of attachment holes 11 on the periphery, and is attached to a cylinder head (not shown) of the internal combustion engine by bolting or the like through the attachment holes 11.

  The flange 1 is provided with a plurality of exhaust holes 12 for introducing exhaust.

  These exhaust holes 12 are opened at positions corresponding to the outlets of the exhaust ports (not shown) of the cylinder head, and each exhaust port of the cylinder head is connected to the end of the inner pipe 4 through the exhaust holes 12. It communicates with the department.

  The connection flange 2 is formed with a plurality of attachment holes 21 at the periphery, and is attached to the exhaust system such as a turbocharger or a catalyst by bolting or the like through the attachment holes 21.

  In the present embodiment, in order to mount the turbocharger on the connecting flange 2, the connecting flange 2 is integrally formed with the flange 1 so as to be substantially orthogonal, and when the flange 1 is attached to the internal combustion engine, the connecting flange 2 Are arranged in a substantially horizontal state.

  The connection flange 2 is provided with a supply port 22 for supplying the exhaust gas flowing through the inner pipe 4 to the turbocharger.

  The outer tube 3 is made of cast iron having rigidity, and is integrally formed with the flange 1 and the connecting flange 2.

  And the opening 31 of the magnitude | size and shape which can insert the inner pipe | tube 4 in the wall body of the surface side of this outer pipe | tube 3 is opened.

  The size of the opening 31 is preferably as small as possible from the viewpoint of securing the support rigidity of the outer tube 3, while it is preferably as large as possible from the viewpoint of reducing the overall weight. The size is appropriately determined according to the weight of the turbocharger mounted on the connecting flange 2.

  The inner tube 4 is formed by forming a thin metal plate having high heat resistance and corrosion resistance, for example, a stainless steel plate or a steel plate into a cylindrical shape by sheet metal or welding, as in the conventional case.

  Specifically, the inner pipe 4 is assembled into a plurality of cylindrical branch pipes 41 that are fixed to the periphery of each exhaust hole 12 of the flange 1 and these branch pipes 41 merge on the downstream side. And a cylindrical collecting pipe 42.

  The lid portion 5 is made of the same material as the inner tube 4, that is, a thin metal plate having high heat resistance and corrosion resistance, for example, a stainless steel plate or a steel plate, formed by sheet metal or the like in a shape that seals the opening 31 of the outer tube 3. Become.

  In the present embodiment, the slide member 6 is interposed in the gap between the outer tube 3 and the inner tube 4 on the exhaust system side.

  The slide member 6 is formed, for example, as a wire mesh ring obtained by pressing wire-shaped stainless steel into a ring shape by press molding.

  The exhaust manifold A of the internal combustion engine of the present embodiment thus formed is manufactured, for example, in the following manner.

  4 (a), 4 (b), 5 (c), and 5 (d) are assembly operation diagrams schematically illustrating a manufacturing example of the present embodiment.

  In addition, the same code | symbol is attached | subjected to the site | part which is common in FIGS. 1-3, and the overlapping description is abbreviate | omitted.

  That is, in the manifold A of the internal combustion engine of the present embodiment, first, the inner tube 4 is inserted from the outside toward the opening 31 of the outer tube 3 integrally formed of a hard material such as cast iron [FIG. See (a) and (b). ].

  At this time, the slide member 6 is fitted on the end portion of the collecting pipe 42 on the exhaust system side of the inner pipe 4 and then the inner pipe 4 is inserted.

  Next, the end of the branch pipe 41 on the internal combustion engine side of the inner pipe 4 is positioned and welded to the periphery of the exhaust hole 12 of the flange 1 to fix these branch pipes 41 (see FIG. 5C). . ].

  In this way, the inner tube 4 and the outer tube 3 are arranged at a predetermined interval by the slide member 6, and the inner tube 4 is a floating structure that can move relative to the outer tube 3 in the axial direction. It becomes.

  And after attaching the inserted inner tube | pipe 4, the opening part 31 of the outer tube | pipe 3 of the open state covers the cover part 5 from the outer side, and the said opening part 31 is sealed [FIG.5 (c) ), See (d). ].

  In addition, it is preferable to form a positioning step or the like for fitting the lid portion 5 around the periphery of the opening portion 31 because the lid portion 5 can be easily covered with the opening portion 31.

  Finally, the outer periphery of the lid portion 5 that seals the opening portion 31 is welded to the connecting portion between the opening portion 31 and the opening portion 31 of the outer tube 3 so that the exhaust gas does not leak from the connecting portion. The lid 5 is sealed (see FIG. 5D). ].

  According to the manifold A of the internal combustion engine of the present embodiment formed as described above, the outer tube 3 is integrally formed of a hard material such as cast iron having rigidity. Support rigidity comparable to that of the exhaust manifold can be secured.

  Therefore, particularly in an internal combustion engine equipped with a turbocharger, it is possible to secure sufficient support rigidity without using an auxiliary member such as a metal stay and to support the turbocharger by mounting it. The vibration of the turbocharger can be sufficiently reduced, and noise and other factors can be prevented.

  In addition, since the inner tube 4 and the outer tube 3 have a double tube structure arranged at a predetermined interval by the slide member 6, an air layer is formed between the inner tube 4 and the outer tube 3. Thus, heat radiation from the inner tube 4 to the outer tube 3 is reduced.

  Therefore, the heat capacity in the exhaust manifold can be reduced, the exhaust gas temperature supplied to the catalyst can be prevented from decreasing, and the recent exhaust gas regulations can be met.

  In addition, since the opening 31 is formed in the outer pipe 3, the weight corresponding to the area of the opening 31 is lighter than that of the conventional exhaust manifold made of cast iron.

  However, since the inner tube 4 is finally built in the outer tube 3 and the lid portion 5 is fixed to the opening 31, the overall weight of the present embodiment is This is the total weight of the tube 4 and the lid 5.

  Therefore, if the opening portion 31, the inner tube 4 and the lid portion 5 of the outer pipe 3 are formed so that the total weight is lighter than that of a conventional cast iron exhaust manifold, the conventional cast iron exhaust manifold is formed. The weight can be further reduced.

  Furthermore, since the inner tube 4 can be easily inserted through the opening 31 provided in the outer tube 3, manufacturing can be facilitated.

  Thus, according to the exhaust manifold A of the present embodiment, it is possible to reduce the weight while ensuring the necessary support strength, and it is possible to eliminate the need for auxiliary members such as metal stays.

It is a whole front view showing one embodiment of the present invention. FIG. 2 is a side view showing a partially broken state of FIG. 1. FIG. 3 is an enlarged side view of the state taken along line BB in FIG. 1. (A), (b) is an assembly operation | movement figure which outlined the manufacture example of this embodiment. (C), (d) is the assembly operation | movement figure which outlined the manufacture example of this embodiment.

Explanation of symbols

A. Exhaust Manifold of Internal Combustion Engine 1 Flange 2 Connecting Flange 3 Outer Pipe 31 Opening 4 Inner Pipe 5 Lid 6 Slide Member

Claims (3)

A double-pipe structure in which an inner pipe is built in an outer pipe formed by integrally forming a flange connected to the internal combustion engine side and a connecting flange connected to the exhaust system side with a space from the outer pipe. An exhaust manifold of the internal combustion engine of
The wall of the outer tube is provided with an opening that allows the inner tube to be inserted therein, and is provided with a lid that can seal the opening.
An internal combustion engine side insertion portion that is inserted into an exhaust hole opened on the internal combustion engine side in the outer pipe and welded to an edge of the exhaust hole in a state where the opening of the outer pipe is sealed And an exhaust system side insertion portion that is inserted into a supply port opened on the exhaust system side in the outer pipe and welded to an edge portion of the supply port,
A part of the branch pipe that is on the internal combustion engine side of the inner pipe is welded to the peripheral edge of the exhaust hole of the outer pipe, and a slide member is provided in the gap between the collecting part on the exhaust system side of the inner pipe and the outer pipe There is interposed, thereby, and the inner tube and the outer tube, while being arranged at predetermined intervals, the inner tube, which is axially movable relative floating structure with respect to the outer tube,
The internal combustion engine side insertion portion of the lid portion that is inserted into the exhaust hole of the outer pipe is a part of the inner surface of the exhaust hole and the outer surface of the branch pipe of the inner pipe, and on the periphery of the exhaust hole of the outer pipe. While being welded to the edge of the exhaust hole in a state of being sandwiched between unwelded parts, the end edge of the collecting portion of the inner pipe is retreated from the supply port of the outer pipe, The exhaust system side insertion portion of the lid portion inserted into the supply port is extended to the supply port side from the edge of the collecting portion of the inner pipe, and is welded to the edge portion of the supply port. ,
An exhaust manifold for an internal combustion engine, wherein the slide member is formed into a wire mesh ring in which wire-like stainless steel is pressed and consolidated into a ring shape. The exhaust manifold of the internal combustion engine according to claim 1,
An exhaust manifold for an internal combustion engine, wherein the outer tube is integrally formed of cast iron, and the inner tube and the lid are each formed of a stainless steel plate or a steel plate. In the exhaust manifold of the internal combustion engine according to claim 1 or 2,
An exhaust manifold of an internal combustion engine, wherein a turbocharger is attached to the connection flange.

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