JP2009036166A - Aggregate part structure of exhaust manifold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aggregate part structure of an exhaust manifold, which suppresses cracking and collapsing of separation plates provided in clearances of a plurality of exhaust gas single tubes. <P>SOLUTION: A first to fourth exhaust single tubes extending from four exhaust ports of a four-cylinder engine, and two separation plates 41, 42 arranged in clearances of the first to fourth exhaust single tubes mutually combined at the cut-out parts 41c, 42c cut out in an exhaust emission flow direction and provided in the clearances of the first to fourth exhaust single tubes, are connected together at downstream ends 41a, 42a. Cut-out of the cut-out part 41c formed at the exhaust flow upstream end 41b of the separation plate 41 is shorter than that of the cut-out part 42c formed at the exhaust flow downstream end 42a of the separation plate 42. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a collective structure of an exhaust manifold used for a multi-cylinder engine.

  An exhaust manifold used for a multi-cylinder engine integrally bundles a plurality of exhaust single pipes extending from a plurality of exhaust ports, and an exhaust pipe or a direct type exhaust gas purification device is connected to a collective portion thereof. . Moreover, a partition plate is provided between each exhaust single pipe, and each exhaust single pipe is integrated by welding via this. That is, for example, for an exhaust manifold for a four-cylinder engine, each downstream end cross section of four exhaust single pipes is processed into a fan-shaped cross section having a central angle of 90 °, and the downstream end is a circular cross section. The four exhaust single pipes are bundled so as to be integrated with each other by welding to a partition plate provided in the gap between the exhaust single pipes. As a conventional partition plate provided in the gap between the exhaust single pipes, for example, as shown in FIGS. 10 and 11, there is a partition plate in an exhaust manifold for a 4-cylinder engine disclosed in Patent Document 1.

The notches 141c and 142c of the two partition plates 141 and 142 shown in FIG. 11 are formed in the central portion of each partition plate 141 and 142 in the radial direction (lateral direction in FIG. 11) in the cross section of the single exhaust pipe. In addition, in the exhaust flow direction (vertical direction in FIG. 11) in the single exhaust pipe, each is cut out to the center portion. The partition plates 141 and 142 are joined in a cross shape by the notches 141c and 142c, and are provided in the gaps between the exhaust single pipes at the downstream end of each exhaust single pipe, and are joined by welding together with the downstream ends of the single exhaust pipes. Is done.
JP 2007-9836 A

  By the way, in a collective portion in which the downstream ends of a plurality of exhaust single pipes are bundled and a partition plate is provided in the gap between them, heat distortion occurs due to the heat of exhaust gas discharged during engine operation. In particular, stress concentrates in the notch part of the partition plate, and thermal distortion increases because the periphery is not fixed in the notch part located upstream of the exhaust gas that is not welded to the exhaust pipe in the partition plate, There is a risk of cracks and buckling.

  The present invention has been made in view of such circumstances, and an object of the present invention is to collect exhaust manifolds that can prevent cracks and buckling from occurring in a partition plate provided in a gap between a plurality of exhaust single pipes. It is to provide a partial structure.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, a plurality of exhaust single pipes extending from a plurality of exhaust ports of a multi-cylinder engine are combined with each other at a notch cut out in the exhaust flow direction, and provided in a gap between the plurality of exhaust single pipes. Exhaust gas flow of the partition plate in a collective structure of an exhaust manifold having a plurality of partition plates formed and a joint portion joining together the plurality of exhaust single pipes and the downstream ends of the partition plates in the exhaust flow direction The gist is that the notch formed in the upstream end is cut out shorter than the notch formed in the exhaust flow downstream end of the partition plate.

  According to the above configuration, the cutout portion formed at the exhaust flow upstream end of the partition plate is cut shorter than the cutout portion formed at the exhaust flow downstream end of the partition plate. The length of the cutout portion at the upstream end can be made shorter than the cutout portion at the downstream end where the periphery is joined to the single exhaust pipe. As a result, since the rigidity of the notch formed in the exhaust flow upstream end of the partition plate can be increased, it is possible to prevent the partition plate from being cracked or buckled. Further, since the periphery of the notch at the downstream end of the exhaust flow of the partition plate is joined to the exhaust single pipe, the rigidity can be ensured even if the notch is longer than the notch at the upstream end. The configuration in which the cutout portion formed at the upstream end is cut shorter than the cutout portion formed at the downstream end includes the configuration in which the cutout portion is formed only at the downstream end.

The gist of the invention according to claim 2 is that, in the invention according to claim 1, the notch is formed only at the exhaust flow downstream end of the partition plate.
According to the said structure, since the said notch is formed only in the exhaust flow downstream end of the said partition plate, rigidity can be made high by not forming a notch in an upstream end.

  Specifically, according to the invention of claim 3, the exhaust manifold is composed of four exhaust single pipes, and the plurality of partition plates are configured by combining two plates in a cross shape, As described in claim 4, it is possible to adopt a configuration in which the joint is formed by welding.

  Hereinafter, an embodiment in which the exhaust manifold assembly structure according to the present invention is embodied in an exhaust manifold for a four-cylinder engine will be described with reference to FIGS.

  As shown in FIG. 1, the exhaust manifold 10 is employed in an in-line four-cylinder engine, has a plate-like mounting flange 20 coupled to a cylinder head of an engine (not shown), and first to fourth exhausts. The upstream ends of the single tubes 31 to 34 are welded to the flange 20, respectively. The first to fourth exhaust single pipes 31 to 34 are formed of stainless steel in a cylindrical shape, and the length is set so that desired engine characteristics can be obtained. The first to fourth exhaust single pipes 31 to 34 are appropriately bent from the welded upstream end and bundled by fitting each downstream end to the exhaust collecting pipe 50. The exhaust collecting pipe 50 is formed in a substantially cylindrical shape, and has a large diameter part 50a fitted to the first to fourth exhaust single pipes 31 to 34 and a small diameter part 50b connected to the downstream side thereof. Further, a flange portion 50c is formed in the small diameter portion 50b. The exhaust collecting pipe 50 is also made of stainless steel in consideration of heat resistance.

  As shown in the assembly diagram of the exhaust manifold in FIG. 2, the downstream ends of the first to fourth exhaust single pipes 31 to 34 are assembled, and the large-diameter portion 50a of the exhaust collection pipe 50 is fitted to the downstream ends. . Further, the exhaust pipe 60 is fitted and welded to the small diameter portion 50 b of the exhaust collecting pipe 50.

  FIG. 3 shows a cross section cut along the line AA shown in FIG. 2 from the upstream side of the exhaust flow. As shown in FIG. 3, the cross sections at the downstream ends 31 a to 34 a of the first to fourth exhaust single pipes 31 to 34 are processed into a sector of a substantially ¼ arc having a central angle of 90 °. And the said 1st-4th exhaust single pipes 31-34 are bundled so that the external shape of a cross section may make circular shape combining this downstream end 31a-34a. Further, first and second partition plates 41 and 42 are provided in the gap between the first to fourth exhaust single pipes so as to form a cross shape, and the first and second partition plates 41 and 42 are interposed therebetween. The first to fourth exhaust single pipes 31 to 34 are welded together to form a joint portion. That is, the contact portions of the first to fourth exhaust single pipes 31 to 34 and the first and second partition plates 41 and 42 are welded from the downstream side of the exhaust (from the direction perpendicular to the paper surface). The first to fourth exhaust single pipes 31 to 34 are formed so as to gradually change from a circular cross section to a sector cross section as they approach the downstream end.

  As shown in the perspective view of FIG. 4, the first and second partition plates 41 and 42 are formed with notches 41c and 42c cut in the exhaust flow direction (vertical direction in FIG. 4). A cross shape is formed by combining the notches 41c and 42c. As described above, the exhaust flow downstream ends 41a, 42a of the first and second partition plates 41, 42 are welded to the downstream ends 31a-34a of the first to fourth exhaust single pipes 31-34. Further, the exhaust flow downstream ends 31a to 34a of the first to fourth exhaust single pipes 31 to 34 to be welded and the exhaust flow downstream ends 41a and 42a of the first and second partition plates 41 and 42 are flush with each other. Yes.

  FIG. 5 shows an assembly diagram of the first and second partition plates 41 and 42. Corresponding to the notch 41c formed in the exhaust flow upstream end 41b of the first partition plate 41, the notch 42c is formed in the exhaust flow downstream end 42a of the second partition plate 42. The first partition plate 41 and the second partition plate 42 are combined with each other by the notches 41c and 42c. Then, the exhaust flow downstream ends 41a, 42a of the first and second partition plates 41, 42 are welded to the exhaust flow downstream ends 31a-34a of the first to fourth exhaust single pipes 31-34. That is, a notch 41c is formed at the exhaust flow upstream end 41b that is not welded in the first partition plate 41, and a notch 42c is formed at the exhaust flow downstream end 42a that is welded in the second partition plate 42. ing.

  The front view of FIG. 6 shows a state in which the first and second partition plates 41 and 42 are disassembled and arranged. As shown in FIG. 6, notches 41c and 42c are formed at the center of the partition plates 41 and 42 in the length direction (lateral direction in FIG. 6), respectively. The cutout portion 41 c is cut out from the exhaust flow upstream end 41 b of the partition plate 41 in the exhaust flow direction, and the cutout portion 42 c is cut out from the exhaust flow downstream end 42 a of the partition plate 42 in the exhaust flow direction. The length of the notch 41c formed in the exhaust flow upstream end 41b of the partition plate 41 in the exhaust flow direction is the same as the length of the notch 42c formed in the exhaust flow downstream end 42a of the partition plate 42. It is set shorter than the length. Specifically, the length of the notch 41c in the exhaust flow direction is set to approximately half the length of the notch 42c in the exhaust flow direction. The widths of the notches 41c and 42c are set slightly wider than the thickness of the partition plates 41 and 42 so that the partition plates 41 and 42 can be combined with each other at the notches 41c and 42c. The first and second partition plates 41 and 42 are both formed in a rectangular plate shape from stainless steel, and are equal in length, width and thickness except for the notches 41c and 42c.

According to the embodiment described above, the following effects can be obtained.
(1) According to this embodiment, the notch 41c formed at the exhaust flow upstream end 41b of the partition plate 41 is cut shorter than the notch 42c formed at the exhaust flow downstream end 42a of the partition plate 42. It was decided to be missing. For this reason, the notch 41c formed in the exhaust flow upstream end 41b whose periphery is not welded is made shorter than the notch 42c formed in the exhaust flow downstream end 42a whose periphery is welded. Can do. As a result, since the rigidity of the notch 41c formed at the exhaust flow upstream end 41b of the partition plate 41 can be increased, it is possible to prevent the partition plate 41 from being cracked or buckled.

  (2) On the other hand, according to the present embodiment, the notch portion 42 c formed at the exhaust flow downstream end 42 a of the partition plate 42 is notched at the exhaust flow upstream end 41 b of the partition plate 41. It was decided to be cut longer than 41c. However, since the notch 42c formed at the exhaust flow downstream end 42a of the partition plate 42 is welded to the first to fourth exhaust single pipes 31 to 34, the notch length is set to be long. Even if it is, rigidity can be secured.

  (3) Since it can be implemented only by changing the notch length of the conventional partition plate, the design change of the partition plate can be minimized. Further, since it is not necessary to change the external dimensions of the partition plate, it can be directly applied to a conventional exhaust manifold.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
In the above embodiment, the notch is formed on both of the two partition plates, but the notch is formed only at the exhaust flow downstream end of the partition plate, and the notch is formed at the exhaust flow upstream end. It is good also as a structure which does not. That is, as shown in FIG. 7, a configuration in which the notch 42 c is formed only in the exhaust flow downstream end 42 a that is the side to be welded in the second partition plate 42 and the notch is not formed in the first partition plate 43 is also possible. It can be adopted. That is, the rigidity can be further increased by not forming the notch in the exhaust flow upstream end 43b whose periphery is not welded. However, in order to make the exhaust flow downstream ends 43a, 42a of the first and second partition plates 43, 42 of this example flush with each other, the exhaust flow direction of the first partition plate 43 (vertical direction in FIG. 7). It is desirable to equalize the width of the notch part 42c formed in the second partition plate 42 in the exhaust flow direction.

  -Although the said embodiment showed the assembly part structure of the exhaust manifold employ | adopted as the 4-cylinder engine, it can also be employ | adopted also as a 6-cylinder engine, for example, a partition plate as shown in FIG.8 and FIG.9. A structure can also be adopted. Both structures are composed of three partition plates, and are provided in the gap between the six exhaust single pipes. First, in FIG. 8, two partition plates 45 having a “V” shape are provided, and a notch 45 c is formed at the exhaust flow upstream end 45 b of the partition plates 45. Further, in this example, a third partition plate 44 is provided, and the width (lateral size in FIG. 8) of the notch portion 44c formed in the exhaust flow downstream end 44a is compared with the above embodiment. It is getting bigger. This is because the partition plate 44 in which the notch portion 44c is formed has a width corresponding to two partition plates 45 in order to be combined with the two partition plates 45 formed in a “V” shape. This is because the notch 44c is necessary. Then, the two partition plates 45 and the third partition plate 44 forming the letter “V” are combined with each other by the notches 45c and 44c. Further, in FIG. 9, the first and second partition plates 47 and 48 are combined by notches 47c and 48c formed at the exhaust flow upstream end 47b or the downstream end 48a, respectively, and further at the exhaust flow downstream end 46a. A third partition plate 46 having a notch 46c is combined. About the notch part 46c formed in this 3rd partition plate 46, the width | variety and length (length of the vertical direction in FIG. 9) are the 3rd partition plate 46, the 1st and 2nd partition plates 47 and 48, and Can be appropriately changed so as to fit properly. In addition, the partition plate 45 is further increased in FIG. 8, or a partition plate in which a notch is formed at the downstream end of the exhaust flow in FIG. 9 is further provided for an engine having 6 or more cylinders. Is possible.

  In the above-described embodiment, the cross section of the exhaust flow downstream end of the single exhaust pipe is processed into a substantially arc-shaped fan having a central angle of 90 °, and the four are bundled to form an outer shape of the cross section of the downstream end. Although the shape is circular, the outer shape of the cross section of the exhaust flow downstream end of each exhaust single pipe does not necessarily have to be circular. However, it is necessary to weld the single exhaust pipe and the partition plate provided in the gap at the downstream end of the exhaust flow so that the exhaust does not leak from the gap. Further, the shape of each partition plate excluding the notch and the length, width, and thickness thereof are not necessarily equal, and the setting can be appropriately changed according to the cross-sectional shape of each single exhaust pipe. Similarly, it is not always necessary to form the notch portion in the partition plate at the center of the partition plate in the radial direction of the single exhaust pipe, and the notch portion can be changed as necessary. Moreover, you may change the formation location of a notch part with the change of the above partition plates.

  In the above embodiment, the single exhaust pipe and the partition plate provided in the gap are joined by welding at the downstream end of each exhaust flow, but joining may be performed by a method other than welding. For example, joining may be performed using a fastener such as a bolt or a nut as long as the exhaust does not leak from the gap between the exhaust single pipe and the partition plate.

  -In the above embodiment, the length in the exhaust flow direction of the notched portion where the periphery is not welded is set to approximately half the length of the notched portion in which the periphery is welded in the exhaust flow direction. As long as these long and short relations are not reversed, it is not necessary to limit to these lengths.

In the above embodiment, the exhaust single pipe, the exhaust collecting pipe, and the partition plate are made of stainless steel, but other materials having heat resistance may be used in consideration of weldability and the like.

FIG. 2 is a perspective view showing a collective portion structure of an exhaust manifold according to one embodiment of the present invention. The assembly figure which shows the assembly state about the assembly part structure of the exhaust manifold concerning the embodiment. Sectional drawing cut | disconnected by the AA line in the assembly part structure of the exhaust manifold of FIG. The perspective view of the partition plate in the gathering part structure of the exhaust manifold of FIG. The assembly figure which shows the assembly state of the partition plate of FIG. The front view which shows the structure of the partition plate of FIG. The top view which shows the structure about the example of a change of the partition plate of this invention. The assembly figure which shows the assembly state about the other modified example of the partition plate of this invention. The assembly figure which shows the assembly state about the other modified example of the partition plate of this invention. The assembly figure which shows the assembly state about the gathering part structure of the conventional exhaust manifold. The front view which shows the structure of the partition plate of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Exhaust manifold, 20 ... Mounting flange, 31 ... 1st exhaust single pipe, 32 ... 2nd exhaust single pipe, 33 ... 3rd exhaust single pipe, 34 ... 4th exhaust single pipe, 31a, 32a, 33a, 34a, 41a, 42a, 43a, 44a, 45a, 46a, 47a, 48a ... downstream end, 41, 43, 47, 141 ... first partition plate, 41b, 42b, 43b, 44b, 45b, 46b, 47b, 48b ... upstream end , 41c, 42c, 44c, 45c, 46c, 47c, 48c, 141c, 142c ... notch, 42, 48, 142 ... second partition plate, 44, 46 ... third partition plate, 45 ... partition plate, 50 ... Exhaust pipe, 50a ... large diameter part, 50b ... small diameter part, 50c ... flange part, 60 ... exhaust pipe.

Claims (4)

A plurality of exhaust pipes extending from a plurality of exhaust ports of a multi-cylinder engine, a plurality of partition plates that are combined with each other at a notch cut out in the exhaust flow direction and provided in a gap between the plurality of exhaust pipes; In the collective part structure of the exhaust manifold having the joint parts joining together the downstream ends of the exhaust flow direction of the plurality of exhaust single pipes and the plurality of partition plates,
The exhaust manifold having an exhaust flow upstream end of the partition plate is cut out shorter than the notch formed at the exhaust flow downstream end of the partition plate. Aggregate structure. In the assembly structure of the exhaust manifold according to claim 1,
The exhaust manifold assembly structure, wherein the notch is formed only at an exhaust flow downstream end of the partition plate. In the assembly structure of the exhaust manifold according to claim 1 or 2,
The exhaust manifold is composed of four exhaust single pipes, and the plurality of partition plates are formed by combining two plates in a cross shape. In the collective part structure of the exhaust manifold according to any one of claims 1 to 3,
An assembly structure of an exhaust manifold, wherein the joint is formed by welding.

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