JP5109968B2 - Engine exhaust pipe cooling structure - Google Patents

Description

  The present invention relates to a cooling structure for an exhaust pipe of an engine, and more particularly to a cooling structure for an exhaust pipe of an engine provided with a flow path of cooling water along the arrangement direction of the exhaust pipe.

  Conventionally, as a technique for cooling a plurality of exhaust pipes provided corresponding to engine cylinders, a technique in which a cooling water flow path is provided along the arrangement direction of a plurality of exhaust pipes arranged in series is known. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 08-260958

  By the way, when cooling the exhaust pipe, specifically, for example, an engine exhaust pipe cooling structure (hereinafter also simply referred to as a cooling structure) as shown below has been conventionally used. FIG. 7 schematically shows a conventional cooling structure 1X, and FIG. 8 schematically shows a conventional cooling structure 1Y. Specifically, in FIGS. 7 and 8, (a) shows these in a perspective view, and (b) shows them in the cross section shown in (a).

In the cooling structure 1X, a member 15X that forms a cooling water flow path WJ between each of the plurality of exhaust pipes 11 is provided so as to individually surround each of the plurality of exhaust pipes 11 of the general exhaust manifold 10. ing. That is, the cooling structure 1X has a structure in which the plurality of exhaust pipes 11 of the exhaust manifold 10 are entirely doubled. However, the cooling structure 1X has a problem that it is difficult to make the flow of the cooling water W uniform for each exhaust pipe 11.
In the cooling structure 1Y, a member 15Y that forms a flow path WJ between the plurality of exhaust pipes 11 is provided so as to surround the plurality of exhaust pipes 11 of the exhaust manifold 10. That is, the cooling structure 1 </ b> Y has a structure that wraps the entire plurality of exhaust pipes 11. However, the cooling structure 1Y has a problem that the flow of the cooling water W becomes more non-uniform and the pressure loss becomes higher than that of the cooling structure 1X because of the structure that entirely encloses the plurality of exhaust pipes 11.

  On the other hand, a cooling structure can also be comprised as follows, for example. FIG. 9 is a perspective view schematically showing a conventional cooling structure 1Z in cross section. In the cooling structure 1 </ b> Z, the outer wall portion 41, together with the first partition plate 44 </ b> Z and the second partition plate 45, surrounds the plurality of exhaust pipes 5 arranged in series so as to be between the plurality of exhaust pipes 5. A flow path WJ having a U-shaped cross section is formed. Further, in the cooling structure 1Z, portions of the outer wall portion 41 disposed on the upper side and the lower side of the plurality of exhaust pipes 5 are formed in a bellows-like shape smoothly curved along the plurality of exhaust pipes 5 as a whole. ing.

According to the cooling structure 1Z, the flow of the cooling water W can be made more uniform as compared with the cooling structures 1X and 1Y by providing the flow path WJ having a U-shaped cross section. Moreover, according to the cooling structure 1Z, the above-described bellows-like shape can reduce the area of the channel as a whole, thereby reducing the pressure loss and improving the fluidity of the cooling water.
However, cooling water W containing air may flow into the cooling structure 1Z, for example, when water is injected or when the engine is cold started. For this reason, in the cooling structure 1Z, the air that has flowed in accumulates in the flow path, hinders the contact between the cooling water W and the exhaust pipe 5, or hinders the flow of the cooling water, which may reduce the cooling effect. There was a problem at one point.

  Therefore, the present invention has been made in view of the above problems, and when a cooling water flow path is provided along the arrangement direction of the exhaust pipes, the air venting performance is improved while cooling the exhaust pipes uniformly, thereby It is an object of the present invention to provide a cooling structure for an exhaust pipe of an engine that can ensure a desired cooling effect.

An engine exhaust pipe cooling structure of the present invention for solving the above-described problems is provided so as to surround a plurality of exhaust pipes arranged in series corresponding to the cylinders of the engine, A cooling water flow means for forming a cooling water flow path between the plurality of exhaust pipes, a plurality of first partition plates provided with air vent holes between the plurality of exhaust pipes, and an arrangement direction of the plurality of exhaust pipes A second partition plate disposed on one end side of the first and second cooling plates, and the cooling water circulation means is formed in a bellows-like shape curved along the plurality of exhaust pipes as a whole below the plurality of exhaust pipes. provided with a first portion which is, above the plurality of exhaust pipes, a second portion having an upper surface formed in the generally substantially planar shape, said second portion, said plurality of exhaust The one end side in the arrangement direction of the pipes and the cooling water It has a discharge port for discharging the cooling water on the downstream end side in the flow direction, and the first part and the second part are the one end side in the arrangement direction of the plurality of exhaust pipes. It is partitioned off by a second partition plate and communicates at the other end side in the arrangement direction of the plurality of exhaust pipes .

In the present invention, the cooling water circulation means may be formed in a U-shaped cross section.

  According to the present invention, when the cooling water flow path is provided along the arrangement direction of the exhaust pipes, it is possible to improve the air bleeding performance while cooling the exhaust pipes uniformly, thereby ensuring a desired cooling effect. it can.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing a cooling structure 1A for an exhaust pipe of an engine according to this embodiment. The cooling structure 1 </ b> A is a single structure including a head side flange 2, an exhaust manifold side flange 3, and a cooling unit 4. The head side flange 2 is attached to a cylinder head of an inline 4-cylinder engine (not shown). An exhaust manifold flange (not shown) is attached to the exhaust manifold side flange 3.
The cooling unit 4 includes an outer wall 41 around the exhaust pipe 5. A plurality (four in this case) of exhaust pipes 5 are provided corresponding to the cylinders of the engine, and are arranged in series. In this embodiment, the exhaust pipe 5 is fixed to each of the flanges 2 and 3, and opens on the flange surfaces of the flanges 2 and 3. The outer wall 41 is fixed to each of the flanges 2 and 3, and a cooling water inlet 42 and a cooling water outlet 43 are provided on one end side of the outer wall 41 in the exhaust pipe arrangement direction. For example, SUS can be applied to the material of the cooling structure 1.

  FIG. 2 is a perspective view schematically showing the cooling structure 1 </ b> A in a cross-section at the connection position between the exhaust manifold side flange 3 and the cooling unit 4. The outer wall portion 41 is provided so as to surround the plurality of exhaust pipes 5. Of the outer wall portion 41, a portion (corresponding to the first portion) 41 a disposed below the plurality of exhaust pipes 5 is formed in a bellows-like shape smoothly curved along the plurality of exhaust pipes 5 as a whole. ing. On the other hand, a portion (corresponding to the second portion) 41b disposed above the plurality of exhaust pipes 5 in the outer wall portion 41 is substantially flat, and the portion 41b is along the exhaust pipe arrangement direction. Stretched. The outer wall 41 forms a flow path WJ with the exhaust pipe 5. The cooling water inlet 42 is positioned at the lower end of the flow path WJ having a U-shaped cross section, and the cooling water outlet 43 is positioned at the upper side of the flow path WJ having a U-shaped cross section. The channel ends communicate with each other. In the present embodiment, a cooling water circulation means is realized by the outer wall portion 41 (more precisely, together with the head side flange 2 and the exhaust manifold side flange 3).

  The cooling unit 4 further includes a first partition plate (separator) 44 </ b> A between the plurality of exhaust pipes 5. The first partition plate 44A is provided between the plurality of exhaust pipes 5 and substantially at the center. Each first partition plate 44A is provided with a partially cylindrical air vent hole 44aA. In the present embodiment, the air vent hole 44aA is provided in the first partition plate 44A in the vicinity of the head-side flange 2 and the exhaust manifold-side flange 3, substantially at the center. In addition, the cooling structure 1A includes an exhaust pipe 5 provided on one end side where the cooling water introduction port 42 and the cooling water discharge port 43 are located in the exhaust pipe arrangement direction. A second partition plate 45 is provided on the side. In the cooling structure 1A, the flow path WJ is formed in a U-shaped cross section by including the first partition plate 44A and the second partition plate 45.

  Next, the function and effect of the cooling structure 1A will be described. In the cooling structure 1, the cooling water W is introduced from the cooling water inlet 42. The introduced cooling water W flows through a flow path WJ having a U-shaped cross section, and is discharged from the cooling water discharge port 43. At this time, the flow F of the cooling water is a uniform flow because the flow path WJ is formed in a U-shaped cross section by the first and second partition plates 44 and 45, and the cooling water W flows through the flow path WJ. Heat is received from the plurality of exhaust pipes 5 while being uniformly distributed. Thereby, the several exhaust pipe 5 can be cooled equally.

On the other hand, when the cooling water W includes air Ar, the air Ar included in the cooling water W tends to accumulate below the first partition plate 44A when the flow path WJ is distributed. However, an air vent hole 44aA is provided in the first partition plate 44A. For this reason, the air Ar moves to the upper part of the flow path WJ through the air vent hole 44aA. Furthermore, in the cooling structure 1A, since the portion 41b has a flat shape, the air Ar moved to the upper portion of the flow path WJ is smoothly discharged from the cooling water discharge port 43 along the flow of the cooling water W. As a result, it is possible to improve the air venting performance while cooling the plurality of exhaust pipes 5 uniformly, thereby ensuring a desired cooling effect.
In the cooling structure 1A, the rigidity of the cooling structure 1A can be increased by providing the first partition plate 44A between the plurality of exhaust pipes 5.
As described above, the cooling structure 1A improves the air venting performance while cooling the exhaust pipe 5 evenly when the flow path WJ is provided along the arrangement direction of the exhaust pipe 5, thereby ensuring a desired cooling effect. be able to.

FIG. 3 is a perspective view schematically showing the cooling structure 1B according to the present embodiment in the same cross section as FIG. The cooling structure 1B is substantially the same as the cooling structure 1A except that it includes a first partition plate 44B instead of the first partition plate 44A.
The first partition plate 44B is provided in an upper portion between the plurality of exhaust pipes 5, and has an outer peripheral surface of two adjacent exhaust pipes 5 that are curved smoothly so as to protrude downward. And connected smoothly. The degree of curvature is set to such a degree that the first partition plate 44B can smoothly guide the flow F of the cooling water. In the first partition plate 44 </ b> B, partial cylindrical air vent holes 44 a </ i> B are provided in the vicinity of the connection portion between the two adjacent exhaust pipes 5 and in the vicinity of the head side flange 2 and the exhaust manifold side flange 3.

Next, the effect of the cooling structure 1B will be described. In the cooling structure 1B, since the first partition plate 44B is provided, the cooling water W can smoothly flow through the upper portion of the flow path WJ, thereby reducing the pressure loss.
Further, in the cooling structure 1B, by providing the air vent hole 44aB as described above, the air that is to be stored below the first partition plate 44B is moved to the upper part of the flow path WJ, and the cooling water discharge port 43 is provided. Can be discharged smoothly.
Thus, the cooling structure 1B can further reduce the pressure loss as compared with the cooling structure 1A.

FIG. 4 is a view schematically showing the cooling structure 1C according to the present embodiment in the same cross section as FIG. The cooling structure 1C is substantially the same as the cooling structure 1A, except that the first partition plate 44C is provided instead of the first partition plate 44A.
The first partition plate 44C includes an upper partition plate 441C and a lower partition plate 442C. The upper partition plate 441C is provided in an upper portion between the plurality of exhaust pipes 5 and smoothly connected to the outer peripheral surfaces of two adjacent exhaust pipes 5 in a smoothly curved shape so as to protrude downward. Has been. The lower partition plate 442C is provided in a lower portion between the plurality of exhaust pipes 5, and smoothly smoothes with the outer peripheral surfaces of two adjacent exhaust pipes 5 in a shape that is smoothly curved so as to be convex upward. It is connected. These partition plates 441C and 442C are connected to each other between the plurality of exhaust pipes 5 at substantially the center. In the first partition plate 44C, a partial cylindrical air vent hole 44aC is located between the plurality of exhaust pipes 5, approximately at the center (that is, the connecting portion of the partition plates 441C and 442C), the head side flange 2, and the exhaust manifold side flange 3. It is provided in each of the nearby parts.

Next, the effect of the cooling structure 1C will be described. In the cooling structure 1C, since the first partition plate 44C is provided, the cooling water W smoothly flows through the upper and lower portions of the flow path WJ. For this reason, the pressure loss can be further reduced as compared with the cooling structure 1B.
Further, in the cooling structure 1C, by connecting the partition plates 441C and 442C, the rigidity can be further increased as compared with the cooling structure 1B.
Thus, the cooling structure 1C can further reduce pressure loss and increase rigidity as compared with the cooling structure 1B.

FIG. 5 is a perspective view schematically showing the cooling structure 1D according to the present embodiment in the same cross section as FIG. The cooling structure 1D is substantially the same as the cooling structure 1C except that the cooling structure 1D is further provided.
A plurality (three in this case) of flow control plates 46 are provided in the upper part of the flow path WJ and in the upper part of the first partition plate 44C. Each of the flow adjusting plates 46 has a V-shape that is smoothly curved along the shape of the upper partition plate 441C. Each upper end portion of the flow adjusting plate 46 is connected to the portion 41b. An air vent hole 46a is provided in each of the upper end portion of the flow adjusting plate 46 and in the vicinity of the head side flange 2 and the exhaust manifold side flange 3.

Next, the effect of the cooling structure 1D will be described. In the cooling structure 1D, since the flow adjusting plate 46 is provided, the cooling water W can be more evenly distributed to the plurality of exhaust pipes 5, thereby enhancing the cooling effect.
Further, in the cooling structure 1D, the air can be smoothly discharged from the cooling water discharge port 43 by providing the air vent hole 46a at the upper end of the flow adjusting plate 46 (see FIG. 6).
In this way, the cooling structure 1D can further enhance the cooling effect while ensuring air bleedability as compared with the cooling structure 1C.

The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
For example, in the cooling structure of the present invention, the position, number, and shape of the air vent holes are not limited to the above-described embodiments.
In the third and fourth embodiments described above, the special cooling water is not circulated in the space S surrounded by the partition plates 441C and 442C and the exhaust pipe 5 among the head side flange 2 and the exhaust manifold side flange 3. For example, in the head side flange 2 and the exhaust manifold side flange 3, a set of second cooling water inlets and second cooling water discharge ports are further provided in a set corresponding to the space S, and the space S has cooling water. May be distributed. Thereby, the cooling effect can be further enhanced.
In this case, cooling water supply / stop means (for example, a valve such as an electromagnetic valve) may be further provided in the cooling water supply path to the second cooling water introduction port. Thereby, cooling water can also be appropriately circulated through the space S according to, for example, the engine operating state.
In the above-described embodiment, the case where the engine is an in-line four-cylinder engine has been described. However, the engine is not necessarily limited thereto, and may be an appropriate engine. In this regard, for example, when the engine is a V-type 6-cylinder engine, the cooling structure of the present invention can be realized for each bank.

It is a perspective view showing typically cooling structure 1A. It is a perspective view which shows typically 1 A of cooling structures in a cross section. It is a perspective view which shows typically the cooling structure 1B in a cross section. It is a perspective view which shows 1 C of cooling structures typically in a cross section. It is a perspective view which shows cooling structure 1D typically in a cross section. It is sectional drawing which shows typically a mode that air distribute | circulates in cooling structure 1D. It is a figure which shows the conventional cooling structure 1X typically. It is a figure which shows the conventional cooling structure 1Y typically. It is a perspective view which shows the conventional cooling structure 1Z typically in a cross section.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cooling structure 2 Head side flange 3 Exhaust manifold side flange 4 Cooling part 41 Outer wall part 42 Cooling water introduction port 43 Cooling water discharge port 44 1st partition plate 44a Air vent hole 441 Upper partition plate 442 Lower partition plate 45 2nd partition plate Partition plate 46 Flow adjustment plate 46a Air vent hole 5 Exhaust pipe

Claims (2)

Cooling water circulation means provided so as to surround a plurality of exhaust pipes arranged in series corresponding to the cylinders of the engine, and forming a flow path of cooling water between the plurality of exhaust pipes ;
A plurality of first partition plates provided with air vent holes between the plurality of exhaust pipes;
A second partition plate disposed on one end side in the arrangement direction of the plurality of exhaust pipes ,
The cooling water circulation means includes a first portion formed in a bellows-like shape curved along the plurality of exhaust pipes as a whole below the plurality of exhaust pipes, and
Above the plurality of exhaust pipes, a second portion having an upper surface formed in a substantially flat shape as a whole ,
The second portion has a discharge port for discharging the cooling water on the one end side in the arrangement direction of the plurality of exhaust pipes and on the downstream end side in the flow direction of the cooling water,
The first part and the second part are partitioned by the second partition plate on the one end side in the arrangement direction of the plurality of exhaust pipes, and the other end in the arrangement direction of the plurality of exhaust pipes Engine exhaust pipe cooling structure that communicates on the side . The engine exhaust pipe cooling structure according to claim 1,
An engine exhaust pipe cooling structure in which the cooling water circulation means is formed in a U-shaped cross section .

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