JPH10311220A - Exhaust gas pipe structure for series type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the assembly work of the exhaust pipe of a series type engine for an automobile, and provide structure having compatibility. SOLUTION: A flange 12 is arranged at the exhaust port of an exhaust manifold 10 made of a plate and a flange 15 is arranged at the inlet opening part 4a of an exhaust pipe 4 juxtaposed with a manifold converter on the inlet side. The bolt holes 12a for fastening of the flange 12 in a matched state between the flanges 12 and 15 are formed in uniformly divided three spots containing a spot seen from above between the ports 14. The thermal efficiency of a product material is high, weight is reduced, and size is decreased. The seal area of a joint between the two flanges 12 and 15 is reduced, and even when fastening is effected in three spots, sufficient sealing ability is ensured. Further, since a nut 9 is fastened from above equipment, a burden on a worker is relieved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION Exhaust systems of automobiles are equipped with catalysts such as maniverters due to exhaust gas regulations. The present invention relates to an exhaust pipe structure of an in-line engine having a structure in which a catalyst is mounted in close proximity to an exhaust manifold.

[0002]

2. Description of the Related Art In a conventional in-line type engine, for example, a four-cylinder engine, branches are gathered at a gathering portion of an exhaust manifold, and exhaust gas is discharged from an exhaust pipe connected to the gathering portion. At this time, the exhaust gas is purified by a maniverter provided along with the exhaust pipe. The manifold attached to the exhaust pipe is preferably arranged close to the exhaust manifold. As shown in FIG. 4, the manifold 2 is integrally connected to the exhaust manifold 1, and the connecting portion 3 is adjusted to the size of the diameter. Is changing. Then, the maniverter 2 is generally connected to the exhaust pipe 4 to form an exhaust system path. This means that the manifold 2 is disposed immediately downstream of the exhaust manifold 1.

A flange 5 is welded to the maniverter 2 so as to be aligned with the flange 6 provided on the exhaust pipe 4, and a gasket 7 is interposed between the maniverter 2 and a stud bolt 8. The stud bolt 8 is inserted into the bolt hole 6a of the flange 6 and tightened and fixed with a nut 9 from below. In this structure, since the separate flange 5 is directly welded to the maniverter 2, it is complicated to reduce the size of the flange 5. Are required.

[0004] In addition, there is an exhaust system having a structure in which a catalyst catalyst is tightened at five points by an exhaust manifold and a connecting flange (Japanese Patent Application Laid-Open No. Hei 6-73674).
Reference). In a V-type engine, a catalyst is provided at a position where the front exhaust manifold and the rear exhaust manifold are joined (Japanese Patent Laid-Open No. 8-14 / 1996).
There is a catalyst in which catalysts are separately provided before and after (see JP-A-7-63050).

[0005]

By the way, when the aforementioned maniverter 2 is attached to the exhaust pipe 4,
The flange 6 of the exhaust pipe 4 is aligned with the flange 5 of the maniverter 2, the stud bolt 8 is inserted, and the nut 9 is tightened at the lower position. For this reason, when assembling on the engine line, the worker lowers his / her hips and performs the assembling work in a low posture in order to assemble the place where the nut 9 is difficult to see directly. Since the operation is performed in an overhead atmosphere, the burden on the operator may be increased. In addition,
In the above-mentioned publication, there is no description for performing the same operation, but only for simply connecting the catalyst device to the exhaust manifold. Further, in the case of diversion to another vehicle in the conventional connection structure, a space of a shape formed by the exhaust manifold and the catalyst is not always secured in the other vehicle due to the layout, and the compatibility is lacking.

SUMMARY OF THE INVENTION An object of the present invention is to provide an interchangeable in-line engine exhaust pipe structure which facilitates an assembling operation.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a flange is provided at an outlet of a sheet metal exhaust manifold having a plurality of ports, and an inlet of an exhaust pipe is provided. A flange is provided in the opening, and a maniverter is also provided on the inlet side of the exhaust pipe. In the aligned state of the two flanges, three bolt holes for tightening the flanges of the exhaust manifold are equally distributed on the flange. And at a position visible from above the port.

[0008] According to a second aspect of the present invention, in the above structure, the collection portion of the exhaust manifold is located at the rear end side of the engine and is inclined with respect to the engine.

In the above configuration, by manufacturing the exhaust manifold having a plurality of ports (branches) from stainless steel, heat conduction is improved, the overall size can be reduced, and the flange of the exhaust manifold can be reduced. Further, since the flange is small, three fastening portions are provided, and stud bolts are fixed to the fastening bolt holes of the flange on the maniverter side. Also, the manifold is connected to the exhaust pipe side, and the exhaust manifold is made into a single unit.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The left exhaust manifold 10 shown in FIG. 1 is of a 2000 cc type, and the right exhaust manifold 11 is of a 1600 cc type. As will be described later, since the size and shape of the flange 12 are the same, the description will be made by taking the left exhaust manifold 10 as an example.

The plate 13 mounted on the engine body of the exhaust manifold 10 and the plurality of branches (ports) 14 and the flanges 12 connected to the plate 13 are formed by sheet metal processing using different stainless steels. The housing 2a and the flange 15 of the maniverter 2 attached to the exhaust pipe 4 are also formed by sheet metal processing using separate stainless steel.

The housing 2a is attached to an intermediate portion of the exhaust pipe 4, a flange 15 is welded to an inlet opening 4a of the exhaust pipe 4, a flange 12 is welded to an outlet 10a of the exhaust manifold 10, and a flange 15 is provided.
And size and shape are matched. The flange 15 of the exhaust pipe 4 is provided with three stud bolts 8. Also, the exhaust manifold 10
The flange 12 has three bolt holes 12a.

Further, as shown in FIG. 2, the bolt holes 12a provided in the flange 12 are laid out at locations where they can be seen from above, avoiding the port position, and the stud bolts 8 are located below this. In addition, both flanges 12, 15
The diameter of the gasket 7 is also reduced because the diameter of the joint becomes smaller.

In the above construction, the exhaust manifold 10 and the exhaust pipe 4 are made of stainless steel, which has higher heat retention than cast metal, so that the weight and size of the exhaust manifold 10 and the exhaust pipe 4 can be reduced. And sufficient sealing performance can be ensured even when tightened at three places. Further, since the nut 9 can be applied to the stat bolt 8 from above, the work is tightened from above the equipment, so that the work of dropping the hips or the work of overhead is not required, and the burden on the operator is reduced.

Furthermore, the conventional four-point tightening flanges interfere with other parts, but the three-point tightening flanges 12 and 15 utilize a space to make the bolt holes 12a visible and operable from above. In addition, since the direction of the collecting portion 16 is inclined to match the positions of the maniverter 2 and the exhaust pipe 4, there is an advantage that the space in the engine room is widened and the degree of freedom in layout is increased.

Also in the 1600 cc type exhaust manifold 11 shown in FIG. 1, a flange 12 of a similar size is welded to the discharge port 11a, and the position of the bolt hole 12a is also the same as shown in FIG. As a result, the engine installation space is secured, so for example, 1600cc, 20
Even if the engine is different, such as 00 cc, the exhaust pipe 4 can be shared and the compatibility is excellent. In other words, the three-point tightening flange structure enables compatibility between different bodies and different engines.

[0017]

According to the present invention, the exhaust system can be reduced in size and weight, and the flange at the junction between the exhaust manifold and the exhaust pipe (maniverter) can be reduced. ,And,
Since three bolt holes are assembled, the degree of freedom in layout is increased. Further, by reducing the size of the flange, the size of the gasket can be reduced, and the sealing performance can be ensured. As a result, the number of fastening points can be reduced and the cost can be reduced. Further, the miniaturization makes it possible to arrange the bolt holes at positions where the work can be performed from above, thereby reducing the burden on the operator during assembly. In addition, even if the engine is different, the space in the engine room is secured, so that the same model of exhaust pipe and flange can be used for common models.

[Brief description of the drawings]

FIG. 1 is a development view of an exhaust pipe structure of an in-line engine according to the present invention.

FIG. 2 is a top view showing an a-side flange portion of the exhaust pipe structure shown in FIG. 1;

FIG. 3 is a top view showing a b-side flange portion of the exhaust pipe structure shown in FIG. 1;

FIG. 4 is a development view of an exhaust pipe structure of a conventional in-line engine.

[Explanation of symbols]

 2 Maniverter 4 Exhaust pipe 4a Inlet opening 10, 11 Exhaust manifold 10a, 11a Outlet 12 Flange 12a Bolt hole 14 Port 15 Flange 16 Assembly

Claims (2)

[Claims] 1. A flange is provided at a discharge port of a sheet metal exhaust manifold having a plurality of ports, a flange is provided at an inlet opening of an exhaust pipe, and
A maniverter is provided on the inlet side of the exhaust pipe, and in the aligned state of the two flanges, the bolt holes for tightening the flanges of the exhaust manifold are provided at three equal parts of the flange, and from above the port. The exhaust pipe structure of a series engine, which is arranged in a visible position. 2. The exhaust pipe structure for an in-line engine according to claim 1, wherein the collecting portion of the exhaust manifold is located at the rear end of the engine and is inclined with respect to the engine.