JPH039016A - Exhaust mechanism of multiple cylinder engine - Google Patents

Abstract

PURPOSE:To avoid mutual interference among multiple exhaust passages and make the exhaust system compact by arranging a downstream part of the multiple exhaust passage in a group of cylinders on an upstream side vertically just below the multiple exhaust passage in a group of cylinders on a downstream side. CONSTITUTION:A serial six cylinder engine A has independent exhaust pipes 1 to 6, respectively extending from exhaust ports 7 to 12 of each cylinder, of which exhaust pipes the first to third independent exhaust pipes 1 to 3 having exhaust orders not in sequence are connected to one multiple exhaust pipe 13, while fourth to sixth independent exhaust pipes 4 to 6 also having exhaust orders not in sequence to the other multiple exhaust pipe 14. The multiple exhaust pipe 13 on the upstream side of the exhaust direction is bent in the direction toward the base of the engine A along the engine frame thereof at the downstream of joint flow part of the independent pipe 3, that is, to the vertical direction, and extended parallelly thereto and rearward direction of a vehicle body just below the multiple exhaust pipe 14 in order to avoid the interference of the multiple exhaust pipe 14 on the downstream side.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an exhaust structure for a multi-cylinder engine.

(Prior Art) Engines are known in which exhaust passages are extended in one direction in the cylinder row direction due to constraints on engine arrangement.

In multi-cylinder engines, in order to prevent exhaust interference, for example, as disclosed in Japanese Utility Model Application No. 61-190419, an independent exhaust passage for each cylinder is provided for each cylinder group consisting of cylinders whose exhaust order is not consecutive. An exhaust structure that communicates with a common collective exhaust passage is generally employed. Further, among these, an exhaust structure is known in which cylinders whose exhaust order is not consecutive due to the ignition order form two cylinder groups adjacent to each other in the cylinder row direction.

(Problem to be Solved by the Invention) In a multi-cylinder engine, in view of the requirement to prevent exhaust interference and the relationship between the ignition order, two adjacent cylinder groups in the cylinder row direction consisting of cylinders whose exhaust order is not consecutive are provided, and each cylinder is It may be necessary to connect the independent exhaust passages to a common collective exhaust passage for each cylinder group, and to extend the collective exhaust passage in one direction in the cylinder row direction due to constraints on engine arrangement. In this case, if it is attempted to avoid mutual interference between the two collective exhaust passages extending in the same direction, it becomes difficult to configure the exhaust system compactly.

An object of the present invention is to provide two groups of cylinders adjacent in the direction of the cylinder row consisting of cylinders whose exhaust order is not consecutive, to communicate the independent exhaust passages of each cylinder to a common collective exhaust passage for each cylinder group, and to To provide an exhaust structure for a multi-cylinder engine in which a collective exhaust passage is extended in one direction in the cylinder row direction, in which the exhaust system can be configured compactly while avoiding mutual interference of a plurality of collective exhaust passages.

(Means for Solving the Problems) In order to solve the above problems, in the exhaust structure of the present invention, two groups of cylinders adjacent in the direction of the cylinder row are provided, which are composed of cylinders whose exhaust order is not consecutive, and each cylinder is independent. In a multi-cylinder engine exhaust structure in which exhaust passages are connected to a common collective exhaust passage for each cylinder group and the collective exhaust passage is extended in one direction in the cylinder row direction of the engine, the exhaust passage is located on the upstream side in the direction of exhaust flow. The downstream part of the collective exhaust passage of the cylinder group is arranged so that it passes vertically below the collective exhaust passage of the cylinder group located downstream in the direction of exhaust flow, or below the collective exhaust passage of the engine frame rather than vertically below. .

(Function) In the present invention, the downstream part of the collective exhaust pipe located on the upstream side in the exhaust direction is a downstream collective exhaust pipe sandwiched between a vertical plane including the downstream collective exhaust pipe and the frame of the engine. Since it passes through the dead space below the exhaust system, the exhaust system can be configured compactly.

(Example) Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 is a front view of an in-line six-cylinder engine equipped with an exhaust structure according to an embodiment of the present invention, FIG. 2 is a view taken along arrow II in FIG. 1, and FIG. 3 is a ■It is an arrow view.

In Figures 1 to 3, A is a vertically mounted vehicle in which the ignition order is set in the following order: 1st cylinder, 5th cylinder, 3rd cylinder, 6th cylinder, 2nd cylinder, and 4th cylinder. It is an in-line six-cylinder engine with cylinders arranged in the direction of the engine. 1 to 6 are exhaust ports 7 to 12 of the first to sixth cylinders of engine A, respectively.
In order to prevent exhaust interference of each cylinder, the independent exhaust pipes 1 to 3 of the first to third cylinders whose exhaust order is not consecutive are connected to the collective exhaust pipe 13, and in order to prevent exhaust interference of each cylinder, Independent exhaust pipes 4 for the 4th to 6th cylinders that are not continuous
6 is connected to a collective exhaust pipe 14.

The collective exhaust pipes 13 and 14 extend parallel to the frame of the engine A toward the rear of the vehicle body, that is, in the direction from the first cylinder to the sixth cylinder. In order to avoid interference with the collective exhaust pipe 14 located on the side, the independent exhaust pipe 3 is bent in the direction toward the base of the engine A, that is, vertically downward, along the engine A frame downstream of the merging position of the independent exhaust pipe 3. It extends directly below the pipe 14 and parallel to the collective exhaust pipe 14 toward the rear of the vehicle body. The collective exhaust pipes 13 and 14 are connected to the exhaust pipe 15 on the rear side of the vehicle body with respect to the independent exhaust pipe 12.

As can be seen from the above, the multi-cylinder engine A according to this embodiment
In the exhaust structure, the downstream portion of the collective exhaust pipe 13 located on the upstream side in the exhaust direction is located on the downstream side sandwiched between the vertical plane containing the collective exhaust pipe 14 located on the downstream side and the frame of engine A. Since it passes through the dead space below the collective exhaust pipe 14, the exhaust system is compact.

In addition, as shown by the two-dot chain line in FIG. 1, the collective exhaust pipe 13
Downstream of the merging position of the independent exhaust pipes 3, fold it in the direction toward the engine A frame and toward the base of the engine A, that is, diagonally downward toward the engine A. Diagonally downward is the collective intake pipe 1
It may be extended parallel to 4 towards the rear of the vehicle. With this arrangement, the downstream portion of the upstream collective exhaust pipe 13 is in closer contact with the frame of the engine A, making the exhaust system even more compact.

FIG. 4 shows a front view of a multi-cylinder engine equipped with an exhaust structure according to another embodiment of the present invention.

Engine B according to this embodiment is an in-line six-cylinder engine similar to engine A in FIG. 1 except that the bank is inclined. In this engine B, the downstream portion of the upstream collective exhaust pipe 13' is bent vertically downward just before the downstream collective exhaust pipe in order to avoid interference with the downstream collective exhaust pipe (not shown). It extends directly below the downstream side exhaust pipe and parallel to the downstream side exhaust pipe toward the rear of the vehicle body. According to this arrangement, as in the embodiment shown in FIG. tube 13'
Since the downstream part of the exhaust system passes through the exhaust system, the exhaust system becomes more compact. As in the embodiment shown in FIG. 1, the downstream portion of the upstream collective exhaust pipe 13' is shown by the chain double-dashed line in FIG.
Immediately before the downstream collective exhaust pipe, from the vertically downward direction, engine B
By bending it downward toward the frame of engine B, that is, diagonally downward toward the frame of engine B, the exhaust system can be made even more compact.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made within the scope of the invention described in the claims. do not have.

(Effects of the Invention) As described above, in the present invention, the downstream portion of the collective exhaust passage of the cylinder group located on the upstream side with respect to the exhaust direction is moved vertically below the collective exhaust passage of the cylinder group located on the downstream side. Alternatively, by configuring the exhaust pipe to pass below the engine frame rather than vertically downward, the downstream part of the collective exhaust pipe located on the upstream side with respect to the exhaust direction is connected to the vertical plane including the collective exhaust pipe located on the downstream side. Since it passes through the dead space below the downstream collective exhaust pipe sandwiched between the exhaust pipe and the engine frame, the exhaust system can be configured compactly while avoiding interference between the collective exhaust passages.

[Brief explanation of the drawing]

FIG. 1 is a front view of an in-line six-cylinder engine equipped with an exhaust structure according to an embodiment of the present invention, FIG. 2 is a view taken along arrow II in FIG. 1, and FIG. 3 is a ■It is an arrow view. FIG. 4 is a front view of an in-line six-cylinder engine equipped with an exhaust structure according to another embodiment of the present invention. A... In-line 6-cylinder engine, 1-6... Independent exhaust pipe, 7-12... Exhaust port, 13... Upstream side collective exhaust pipe, 14... Downstream side collective exhaust pipe, 15. ...Exhaust pipe, B...Inline 6-cylinder engine, 13'...Upstream collective exhaust pipe. ro-ku song size

Claims (1)

[Claims] There are two groups of cylinders that are adjacent in the cylinder row direction, each consisting of cylinders whose exhaust order is not consecutive, and the independent exhaust passages of each cylinder are connected to a common collective exhaust passage for each cylinder group. In the exhaust structure of a multi-cylinder engine, the downstream part of the collective exhaust passage of the cylinder group located on the upstream side with respect to the direction of exhaust flow is the downstream part of the collective exhaust passage of the cylinder group located on the downstream side with respect to the direction of exhaust flow. An exhaust structure characterized by passing vertically below a collective exhaust passage, or passing below the engine frame closer to the engine frame than vertically below.