JP7264785B2 - engine exhaust system - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine exhaust system, and more particularly to an engine exhaust system in which the tightening force of fasteners is less likely to decrease.

2. Description of the Related Art Conventionally, as an engine exhaust system, there is an exhaust passage component that is provided with an iron-based metal exhaust passage component and that is coated with a heat-resistant rust-preventive resin film (see, for example, Patent Document 1).

Japanese Patent Publication No. 6-39582

<Problem> The tightening force of the fastener may be greatly reduced.
In the exhaust system of this type of engine, it is possible to prevent red rust from occurring in exhaust passage components due to exhaust heat with a rust-preventing resin film. If the pressure-receiving surface that receives the tightening force is coated with an antirust resin film, plastic deformation of the antirust resin film may significantly reduce the tightening force of the fastener.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exhaust system for an engine in which the tightening force of fasteners is less likely to decrease.

The main configuration of the present invention is as follows.
As illustrated in FIG. 4(B), the exhaust outlet flange (3d) of the exhaust manifold (3) is positioned closer to the rear end than the front end of the collector portion (3h), and the collector portion (3h) is located at the exhaust outlet flange. A mounting seat (3f) is provided on the rear side of (3d), and as illustrated in FIG. The exhaust inlet flange (4b) on the side is fastened, and the exhaust inlet flange (5a) on the front side of the exhaust relay pipe (5) is fastened to the exhaust outlet portion (4e) on the rear side of the exhaust turbine housing (4a). The lower mounting flange (5c) of the pipe (5) is fastened to the upper mounting seat (3f) of the collector portion (3h),
As exemplified in FIG. 1(C), a threaded fastener (2) is provided to fasten the exhaust inlet flange (4b) of the exhaust turbine housing (4a) to the exhaust outlet flange (3d) of the exhaust manifold (3). , The upper surface of the exhaust outlet flange (3d) of the exhaust manifold (3) is provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). An exhaust system for an engine, characterized in that a film (1b) is formed thereon.

According to the invention of the engine exhaust system of the present application, the following effects can be obtained.
Compared with the antirust resin film, the oxide film (1b) of triiron tetroxide is less likely to be plastically deformed, and the tightening force of the fastener (2) is less likely to decrease. In addition, due to the antirust action of the triiron tetraoxide oxide film (1b), the pressure receiving surface (1a) of the exhaust passage component (1) is prevented from being red rusted due to exhaust heat.

1(A) is a side view of the main part of the engine, FIG. 1(B) is an enlarged sectional view taken along line BB of FIG. 1(A), and FIG. FIG. 1(C) is an enlarged cross-sectional view taken along line CC of FIG. 1(A), FIG. 1(D) is an enlarged cross-sectional view taken along line DD of FIG. 1(A), and FIG. ), and FIG. 1(F) is an enlarged cross-sectional view taken along the line FF of FIG. 1(A). 2 is a side view of the engine of FIG. 1; FIG. 2 is a front view of the engine of FIG. 1; FIG. 4(A) is a side view, FIG. 4(B) is a view in the direction of arrow B in FIG. 4(A), and FIG. 4(D) is a view in the direction of arrow D in FIG. 4(A), and FIG. 4(E) is a view in the direction of arrow E in FIG. 4(C). 5(A) is a side view, FIG. 5(B) is a view in the direction of arrow B in FIG. 5(A), and FIG. 5(A) is a view in the direction of arrow C, FIG. 5(D) is a view in the direction of arrow D in FIG. 5(A), and FIG. 5(E) is a view in the direction of arrow E in FIG. 5(D) .

1 to 5 are diagrams illustrating an engine equipped with an exhaust system according to an embodiment of the invention.
In this embodiment, a vertical water-cooled series multi-cylinder diesel engine will be described.

As shown in FIGS. 2 and 3, this engine comprises a cylinder block (7), a cylinder head (6) assembled on the upper part of the cylinder block (7), and a cylinder assembled on the upper part of the cylinder head (6). A head cover (8) and a front cover (10) assembled to the front part of a cylinder block (7) with the installation direction of a crankshaft (9) as the longitudinal direction, and an engine arranged in front of the cylinder head (6). It has a cooling fan (11), a flywheel (12) arranged behind the cylinder block (7), and an oil pan (13) assembled under the cylinder block (7).
A crankshaft (9) is cranked by a starter motor (22). The engine cooling fan (11) is driven from the crankshaft (9) through a belt transmission (19). An oil filter (21) is attached to the front cover (10) via an oil cooler (20).
This engine has an intake system, a fuel supply system and an exhaust system.

As shown in FIGS. 2 and 3, the intake system includes an intake pipe (14), an air compressor housing (4i) of the supercharger (4), a supercharging pipe (15), and an intake manifold (16). , supply intake air to the cylinders (not shown) in the cylinder block (7). A compressor wheel (not shown) is accommodated in the air compressor housing (4i). As shown in FIG. 3, the intake manifold (16) is arranged on one lateral side of the cylinder head (6), with the width direction of the engine perpendicular to the longitudinal direction being the lateral direction.

As shown in FIG. 3, the fuel supply system is arranged on one lateral side of the engine where the intake manifold (16) is arranged. (not shown) to supply fuel to the cylinders.
As shown in FIG. 2, the exhaust system includes an exhaust manifold (3), an exhaust turbine housing (4a) of a supercharger (4), and an exhaust relay pipe (5) to discharge exhaust from the cylinder. A turbine wheel (not shown) is accommodated in the exhaust turbine housing (4a). As shown in FIG. 3, the exhaust manifold (3) is mounted on the other lateral side of the cylinder head (6) opposite to the lateral side on which the intake manifold (16) is arranged.

An exhaust muffler or an exhaust duct is connected to the exhaust downstream side of the exhaust relay pipe (5) shown in FIG. 2, but an exhaust aftertreatment device (not shown) may be connected. The exhaust aftertreatment device accommodates the DOC on the upstream side of the exhaust in the aftertreatment case, and the DPF on the downstream side of the exhaust. DOC is an abbreviation for Diesel Oxidation Catalyst, and DPF is an abbreviation for Diesel Particulate Filter.

As shown in FIGS. 1(B) to (F), FIGS. 4(A) to (E), and FIGS. , a fastener (2) for fastening the exhaust passage component (1) to another part, and the exhaust passage component (1) has a pressure receiving surface (1a) that receives the tightening force of the fastener (2). ing.
A specific example of the exhaust passage component (1) will be described later.

As shown in FIGS. 1(B) to 1(F), an oxide film (1b) of triiron tetroxide is formed on the pressure receiving surface (1a) of the exhaust passage component (1).
Therefore, the following effects can be obtained with this exhaust device.
That is, compared with the antirust resin film, the oxide film (1b) of triiron tetroxide is less likely to be plastically deformed, and the tightening force of the fastener (2) is less likely to decrease.
In addition, due to the antirust action of the triiron tetraoxide oxide film (1b), the pressure receiving surface (1a) of the exhaust passage component (1) is prevented from being red rusted due to exhaust heat.

As shown in FIGS. 1(B) to (F), FIGS. 4(A) and 5(A), tetraoxide is also present on the outer surface (1c) of the exhaust passage component (1) other than the pressure receiving surface (1a). An oxide film (1b) of triiron is formed.
Therefore, the following effects can be obtained with this exhaust device.
That is, the oxide film (1b) of triiron tetroxide is superior in heat resistance to the antirust resin film, and cracks and discoloration are less likely to occur on the outer surface (1c) of the exhaust passage component (1).
In addition, the triiron tetraoxide oxide film (1b) prevents red rust due to exhaust heat on the outer surface (1c) of the exhaust passage component (1) excluding the pressure-receiving surface (1a).

As shown in FIGS. 4(A), 4(B), 5(B) to 5(D), an oxide film (1b) of triiron tetroxide is also formed on the inner surface (1d) of the exhaust passage component (1). ) is formed.
Therefore, the following effects can be obtained with this exhaust device.
That is, the oxide film (1b) of triiron tetraoxide prevents the generation of red rust due to exhaust heat on the inner surface (1d) of the exhaust passage component (1).

In this embodiment, as shown in FIGS. 1(A), 2 and 4(A)-(E), the first specific example of the exhaust passage component (1) is the exhaust manifold (3). .
Therefore, the following effects can be obtained with this exhaust device.
That is, since the tightening force of the fastener (2) received by the pressure receiving surface (1a) of the exhaust manifold (3) shown in FIGS. High adhesion is maintained between the exhaust manifold (3) and other parts (the cylinder head (6), the exhaust turbine housing (4a) of the supercharger (4), and the exhaust relay pipe (5)). .

As shown in FIG. 1(B), the pressure receiving surface (1a) of the exhaust manifold (3) is formed on the front and rear surfaces of the exhaust inlet flange (3a). The exhaust inlet flange (3a) is fastened with fasteners (2) to the lateral wall (6a) of the cylinder head (6).
This fastener (2) is a bolt (2a) with a head, and has a bolt head (2b) and a male threaded portion (2c). It penetrates and is screwed into a female screw hole (6b) of a lateral wall (6a) of the cylinder head (6), and a washer (2d) or a first gasket ( The exhaust inlet flange (3a) is sandwiched together with 3c), and the tightening force of the headed bolt (2a) is applied to pressure receiving surfaces (1a) formed on the front and rear surfaces of the exhaust inlet flange (3a).
An oxide film (1b) of triiron tetraoxide is formed on the pressure receiving surface (1a).

As shown in FIG. 1(C), the pressure receiving surface (1a) of the exhaust manifold (3) is also formed on the upper surface of the exhaust outlet flange (3d). An exhaust inlet flange (4b) of an exhaust turbine housing (4a) of a turbocharger (4) is fastened to the exhaust outlet flange (3d) with a fastener (2).
The fastener (2) is a stud nut (2e) comprising a stud (2f) and a nut (2g), the stud (2f) being attached to the exhaust outlet flange (3d) of the exhaust manifold (3). The stud bolt (2f) is screwed into the female threaded hole (3e) and passes through the bolt insertion hole (4c) of the exhaust inlet flange (4b) of the exhaust turbine housing (4a) of the supercharger (4), A nut (2g) is screwed onto the stud bolt (2f), and a washer (2d) and a second gasket (4d) are provided between the exhaust outlet flange (3d) of the exhaust manifold (3) and the nut (2g). The exhaust inlet flange (4b) of the exhaust turbine housing (4a) is sandwiched therewith, and a stud bolt nut (2e) is inserted into the pressure receiving surface (1a) formed on the upper surface of the exhaust outlet flange (3d) of the exhaust manifold (3). of tightening force is applied.
An oxide film (1b) of triiron tetraoxide is also formed on the pressure receiving surface (1a).

In this embodiment, as shown in FIGS. 1(A) and 2, the second specific example of the exhaust passage component (1) is the exhaust turbine housing (4a) of the supercharger (4).
Therefore, the following effects can be obtained with this exhaust device.
That is, since the tightening force of the fastener (2) received by the pressure receiving surface (1a) of the exhaust turbine housing (4a) shown in FIGS. High sealing performance is maintained between the exhaust turbine housing (4a) of the supercharger (4) and other parts (exhaust manifold (3) and exhaust relay pipe (5)).

As shown in FIG. 1(C), the pressure receiving surface (1a) of the exhaust turbine housing (4a) is formed on the upper and lower front and back surfaces of the exhaust inlet flange (4b). As mentioned above, the exhaust inlet flange (4b) is fastened to the exhaust outlet flange (3d) of the exhaust manifold (3) with a stud bolt nut (2e).
Therefore, the tightening force of the stud bolt and nut (2e) is applied to the pressure receiving surfaces (1a) formed on the upper, lower, front and back surfaces of the exhaust inlet flange (4b) of the exhaust turbine housing (4a).
An oxide film (1b) of triiron tetraoxide is formed on the pressure receiving surface (1a).

As shown in FIG. 1(D), the pressure receiving surface (1a) of the exhaust turbine housing (4a) is also formed on the rear surface of the exhaust outlet portion (4e). An exhaust inlet flange (5a) of the exhaust relay pipe (5) is fastened with a fastener (2) to an exhaust outlet portion (4e) of the exhaust turbine housing (4a).
This fastener (2) is a headed bolt (2a), and has a bolt head (2b) and a male threaded portion (2c). It penetrates through the bolt insertion hole (5b) and is screwed into the female screw hole (4f) of the exhaust outlet part (4e) of the exhaust turbine housing (4a) to connect the bolt head (2b) and the exhaust turbine housing (4a). The exhaust inlet flange (5a) of the exhaust relay pipe (5) is sandwiched with the washer (2d) and the third gasket (4g) between the exhaust outlet portion (4e) and the exhaust outlet portion of the exhaust turbine housing (4a). The tightening force of the headed bolt (2a) is applied to the pressure receiving surface (1a) formed on the rear surface of (4e).
An oxide film (1b) of triiron tetraoxide is also formed on the pressure receiving surface (1a).

In this embodiment, as shown in FIGS. 1(A) and 2, the third specific example of the exhaust passage component (1) is the exhaust relay pipe (5).
Therefore, the following effects can be obtained with this exhaust device.
That is, since the tightening force of the fastener (2) received by the pressure receiving surface (1a) of the exhaust relay pipe (5) shown in FIGS. A high degree of sealing is maintained between the connected exhaust relay pipe (5) and other parts (exhaust turbine housing (4a), exhaust manifold (3), exhaust muffler, exhaust duct, or exhaust aftertreatment case).

As shown in FIG. 1(D), the pressure receiving surface (1a) of the exhaust relay pipe (5) is formed on the front and back surfaces of the exhaust inlet flange (5a). As described above, the exhaust inlet flange (5a) of the exhaust relay pipe (5) is fastened to the exhaust outlet (4e) of the exhaust turbine housing (4a) with the headed bolt (2a).
Therefore, the tightening force of the headed bolt (2a) is applied to the pressure receiving surfaces (1a) formed on the front and back surfaces of the exhaust inlet flange (5a) of the exhaust relay pipe (5).
An oxide film (1b) of triiron tetraoxide is also formed on the pressure receiving surface (1a).

As shown in FIG. 1(E), the pressure-receiving surfaces (1a) of the exhaust relay pipe (5) are also formed on the upper, lower, front and back surfaces of the mounting flange (5c).
A mounting flange (5c) of the exhaust relay pipe (5) is fastened with a fastener (2) to the upper surface of a mounting seat (3f) arranged above the exhaust manifold (3).
This fastener (2) is a headed bolt (2a), which comprises a bolt head (2b) and a male threaded portion (2c). It penetrates the insertion hole (5d) and is screwed into the female screw hole (3g) of the mounting seat (3f) of the exhaust manifold (3), and the bolt head (2b) and the mounting seat (3f) of the exhaust manifold (3) are screwed. ) and the mounting flange (5c) of the exhaust relay pipe (5) are sandwiched between the washer (2d) and the upper and lower surfaces of the mounting seat (3f) of the exhaust manifold (3) and the mounting flange (5c) ( The tightening force of the headed bolt (2a) is applied to the pressure receiving surfaces (1a ) formed on the upper, lower, front and back surfaces .
An oxide film (1b) of triiron tetraoxide is also formed on the pressure receiving surface (1a).

As shown in FIG. 1(F), pressure-receiving surfaces (1a) of the exhaust relay pipe (5) are also formed on the front and rear surfaces of the exhaust outlet flange (5e). The exhaust inlet flange of the exhaust aftertreatment case is fastened to the exhaust outlet flange (5e) with fasteners (bolts and nuts, not shown) passing through the bolt insertion holes (5f) of the exhaust outlet flange (5e). be.
For this reason, the tightening force of the fastener is applied to the pressure receiving surfaces (1a) formed on the front and rear front and back surfaces of the exhaust outlet flange (5e) of the exhaust relay pipe (5).
An oxide film (1b) of triiron tetraoxide is also formed on the pressure receiving surface (1a).

As shown in FIGS. 4(A) to (E), the exhaust manifold (3) includes a collector portion (3h) elongated in the front-rear direction and a plurality of exhaust inlet flanges arranged laterally of the collector portion (3h). (3a), a single exhaust outlet flange (3d) located above the collector portion (3h), and a mounting seat (3f) located above the rear portion of the collector portion (3h). An oxide film (1b) of triiron tetroxide is also formed on the outer surface (1c) other than the pressure receiving surface (1a).
The exhaust passage inside the collector portion (3h), the bolt insertion hole (3b) of the exhaust inlet flange (3a) shown in FIG. 4(A), and the exhaust outlet of the exhaust outlet flange (3d) shown in FIG. 4(B). An oxide film (1b) of triiron tetraoxide is also formed on each inner surface (1d) of (3j).

As shown in FIG. 1(A), the exhaust turbine housing (4a) of the supercharger (4) includes a housing body (4h) and an exhaust inlet flange (4b) arranged in front of the housing body (4h). , and an exhaust outlet portion (4e) arranged on the lower side of the housing body (4h), and an oxide film (1b) of triiron tetroxide is formed on the outer surface (1c) of each portion other than the pressure receiving surface (1a). formed.
Triiron tetroxide is also applied to the inner surfaces of the exhaust passage of the housing body (4h), the exhaust inlet (not shown) of the exhaust inlet flange (4b), and the exhaust outlet (not shown) of the exhaust outlet portion (4e). of oxide film is formed.

As shown in FIGS. 5(A) to (E), the exhaust relay pipe (5) includes a pipe portion (5g), an exhaust inlet flange (5a) arranged in front of the pipe portion (5g), a pipe portion Equipped with an exhaust outlet flange (5e) arranged behind (5g) and a mounting flange (5c) arranged below the exhaust outlet flange (5e), the outer surfaces of these parts other than the pressure receiving surface (1a) An oxide film (1b) of triiron tetroxide is also formed on (1c).
The exhaust passage inside the pipe portion (5g), the bolt insertion hole (5d) of the mounting flange (5c) shown in FIG. 5(B), and the exhaust inlet ( 5h) and bolt insertion holes (5b), and the inner surfaces (1d ) of the exhaust outlet (5i) and bolt insertion holes (5f) of the exhaust outlet flange (5e) shown in FIG. of oxide film (1b) is formed.

The film thickness of the triiron tetraoxide oxide film (1b) is preferably 5 μm to 11 μm.
In this case, the following effects are obtained.
If the thickness of the oxide film (1b) is less than 5 μm, the antirust function of the oxide film (1b) against red rust is insufficient, and if it exceeds 11 μm, the processing time for forming the oxide film (1b) is long or While the treatment temperature is high, when the thickness is 5 μm to 11 μm, the antirust effect of the oxide film (1b) against red rust is sufficient, and the treatment time is short or the treatment temperature is low.
In order to form an oxide film (1b) of triiron tetroxide on the surface of the iron-based metal exhaust passage component (1), the iron-based metal exhaust passage component (1) is subjected to steam coating treatment in a steam atmosphere. do.

The film thickness of the triiron tetraoxide oxide film (1b) may be more than 11 μm and 20 μm or less.
The reason is as follows.
As in an industrial engine where high-load operation continues for a long time, the operating conditions of the engine are severe, and if the thermal deterioration rate of the oxide film (1b) due to combustion heat is high, the oxide film (1b) due to vibration ) has a high wear rate, if the film thickness is 11 μm or less, the service life of the oxide film (1b) may be insufficient. On the other hand, if the film thickness exceeds 20 μm, the treatment time for the oxide film (1b) may exceed the allowable range for production efficiency, or the treatment temperature may exceed the allowable range for protection of production equipment.
On the other hand, when the film thickness of the oxide film (1b) of triiron tetroxide exceeds 11 μm and is 20 μm or less, a sufficient service life can be obtained even when the operating conditions of the engine are severe. The time tends to fall within the permissible range for manufacturing efficiency, and the processing temperature also tends to fall within the permissible range for protecting manufacturing equipment.
For the same reason as above, the lower limit of the film thickness may be set to 10 μm, and the range of the film thickness may be set to 10 μm to 20 μm.

In the above embodiment, the oxide film (1b) of triiron tetroxide is formed on the surface of the exhaust passage component (1) that is not surface-treated. It may be formed on the surface of 1).
For example, an oxide film (1b) of triiron tetroxide may be formed on the surface of the nitrogen compound layer of the exhaust passage component (1) obtained by nitriding surface treatment.
In this case, the following effects are obtained.
The nitrogen compound layer can increase the hardness of the pressure-receiving surface, and the oxide film (1b) suppresses softening due to denitrification of the nitrogen compound layer, so that the tightening force of the fastener (2) is less likely to decrease.

In the above embodiment, cast iron is used as the ferrous metal that is the material of the exhaust passage component (1), but steel may also be used.
Steel is used as the material for the fastener (2), washer (2d), and gaskets (3c), (4d), and (4g).
As is clear from the above description and drawings, this embodiment has the following configuration.
As shown in FIG. 1(A), the exhaust passage components (1) include an exhaust manifold (3), a supercharger (4), an exhaust turbine housing (4a), and an exhaust relay pipe (5). As shown in 4(A), (B), (E), the exhaust manifold (3) has a collector section (3h) with multiple exhaust inlet flanges (3a) and a single exhaust outlet flange (3d). As shown in FIGS. 1(A) and 4(B), a plurality of exhaust inlet flanges (3a) are arranged with the direction of the crankshaft of the engine as the front-rear direction and the width direction of the engine perpendicular to the front-rear direction as the lateral direction. are arranged longitudinally along the lateral sides of the collector portion (3h), and a single exhaust outlet flange (3d) is arranged above the collector portion (3h), as shown in FIG. , the supercharger (4) includes an exhaust turbine housing (4a) and an air compressor housing (4i), and is located above the collector (3h) of the exhaust manifold (3) with one of the longitudinal directions as the front. An air compressor housing (4i), an exhaust turbine housing (4a), and an exhaust relay pipe (5) are arranged side by side in this order.
As shown in FIG. 4(B), the exhaust outlet flange (3d) of the exhaust manifold (3) is positioned closer to the rear end than the front end of the collector portion (3h), and the collector portion (3h) is located at the exhaust outlet flange ( A mounting seat (3f) is provided on the rear side of 3d), and as shown in FIG. An exhaust inlet flange (4b) is fastened, and an exhaust inlet flange (5a) on the front side of the exhaust relay pipe (5) is fastened to an exhaust outlet portion (4e) on the rear side of the exhaust turbine housing (4a). 5), the lower mounting flange (5c) is fastened to the upper mounting seat (3f) of the collector portion (3h).
As shown in FIG. 1(C), a threaded fastener (2) for fastening an exhaust inlet flange (4b) of an exhaust turbine housing (4a) to an exhaust outlet flange (3d) of an exhaust manifold (3), The upper surface of the exhaust outlet flange (3d) of the exhaust manifold (3) is provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). (1b) is formed.
As shown in FIG. 1(C), the upper and lower surfaces of the exhaust inlet flange (4b) of the exhaust turbine housing (4a) are provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). An oxide film (1b) of triiron tetroxide is formed on the surface (1a).
As shown in FIG. 1(B), the exhaust inlet flange (3a) of the exhaust manifold (3) is fastened to the lateral wall (6a) of the cylinder head (6), and the exhaust manifold (6a) is fastened to the lateral wall (6a) of the cylinder head (6). A threaded fastener (2) for fastening the exhaust inlet flange (3a) of (3) is provided, and both lateral surfaces of the exhaust inlet flange (3a) of the exhaust manifold (3) are threaded fasteners (2). It has a pressure receiving surface (1a) that receives a fastening force, and an oxide film (1b) of triiron tetraoxide is formed on this pressure receiving surface (1a).
As shown in FIG. 1(D), a screw type fastener (2) for fastening an exhaust inlet flange (5a) of an exhaust relay pipe (5) to an exhaust outlet (4e) of an exhaust turbine housing (4a) is provided. , The rear surface of the exhaust outlet portion (4e) of the exhaust turbine housing (4a) is provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). An oxide film (1b) is formed.
As shown in FIG. 1(D), a screw type fastener (2) for fastening an exhaust inlet flange (5a) of an exhaust relay pipe (5) to an exhaust outlet (4e) of an exhaust turbine housing (4a) is provided. , The front and rear surfaces of the exhaust inlet flange (5a) of the exhaust relay pipe (5) are provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). of oxide film (1b) is formed.
As shown in FIG. 1(E), a screw type fastener (2) for fastening the mounting flange (5c) of the exhaust relay pipe (5) to the mounting seat (3f) of the collector section (3h) is provided. The upper surface of the mounting seat (3f) of (3h) is provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2), and the pressure receiving surface (1a) is coated with an oxide film (1b) of triiron tetroxide. is formed.
As shown in FIG. 1(E), the mounting seat (3f) of the collector portion (3h) is provided with a screw fastener (2) for fastening the mounting flange (5c) of the exhaust relay pipe (5). The upper and lower surfaces of (5c) are provided with pressure-receiving surfaces (1a) that receive the fastening force of the screw-type fastener (2), and an oxide film (1b) of triiron tetraoxide is formed on this pressure-receiving surface (1a). .

(1) Exhaust passage component, (1a) Pressure receiving surface, (1b) Oxide film, (1c) Outer surface, (1d) Inner surface, (2) Fastener, (3) Exhaust manifold, ( 4) ... supercharger, (5) ... exhaust relay pipe.

Claims (13)

Exhaust passage components (1) include an exhaust manifold (3), an exhaust turbine housing (4a) of a supercharger (4), and an exhaust relay pipe (5). A collector portion (3h) having an inlet flange (3a) and a single exhaust outlet flange (3d) is provided, and the longitudinal direction is the direction of the crankshaft of the engine, and the lateral direction is the width direction of the engine perpendicular to the longitudinal direction. The exhaust inlet flanges (3a) are arranged side by side in the longitudinal direction along the lateral sides of the collector section (3h), and the single exhaust outlet flange (3d) is arranged above the collector section (3h), and the supercharger (4) is provided with an exhaust turbine housing (4a) and an air compressor housing (4i), above the collector portion (3h) of the exhaust manifold (3), with one of the front and back directions as the front, air A compressor housing (4i), an exhaust turbine housing (4a) and an exhaust relay pipe (5) are arranged side by side,
The exhaust outlet flange (3d) of the exhaust manifold (3) is positioned closer to the rear end than the front end of the collector section (3h), and the collector section (3h) is located behind the exhaust outlet flange (3d). 3f), the exhaust inlet flange (4b) on the lower side of the exhaust turbine housing (4a) is fastened to the exhaust outlet flange (3d) on the upper side of the exhaust manifold (3), and the exhaust inlet flange (4b) on the lower side of the exhaust turbine housing (4a) is fastened. An exhaust inlet flange (5a) on the front side of the exhaust relay pipe (5) is fastened to the exhaust outlet portion (4e), and a mounting flange (5c) on the lower side of the exhaust relay pipe (5) is on the upper side of the collector portion (3h). fastened to the mounting seat (3f),
The exhaust outlet flange (3d) of the exhaust manifold (3) is provided with a threaded fastener (2) for fastening the exhaust inlet flange (4b) of the exhaust turbine housing (4a) to the exhaust outlet flange (3d) of the exhaust manifold (3). 3d) has a pressure-receiving surface (1a) that receives the fastening force of the screw-type fastener (2), and an oxide film (1b) of triiron tetroxide is formed on this pressure-receiving surface (1a). An engine exhaust system characterized by: In the engine exhaust system according to claim 1,
The upper and lower surfaces of the exhaust inlet flange (4b) of the exhaust turbine housing (4a) are provided with pressure receiving surfaces (1a) that receive the fastening force of the screw fasteners (2). An exhaust system for an engine, characterized in that an oxide film (1b) is formed. In the engine exhaust system according to claim 1 or claim 2,
The exhaust inlet flange (3a) of the exhaust manifold (3) is fastened to the lateral wall (6a) of the cylinder head (6), and the exhaust inlet flange (3a) of the exhaust manifold (3) is fastened to the lateral wall (6a) of the cylinder head (6). and both lateral surfaces of the exhaust inlet flange (3a) of the exhaust manifold (3) form a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2). and an oxide film (1b) of triiron tetraoxide formed on the pressure receiving surface (1a). In the engine exhaust system according to any one of claims 1 to 3,
A threaded fastener (2) for fastening an exhaust inlet flange (5a) of an exhaust relay pipe (5) to an exhaust outlet (4e) of the exhaust turbine housing (4a) is provided, and the exhaust outlet of the exhaust turbine housing (4a) is provided. The rear surface of the portion (4e) is provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2), and an oxide film (1b) of triiron tetraoxide is formed on the pressure receiving surface (1a). , an exhaust system for an engine. In the engine exhaust system according to any one of claims 1 to 4,
A screw type fastener (2) for fastening an exhaust inlet flange (5a) of an exhaust relay pipe (5) to an exhaust outlet (4e) of an exhaust turbine housing (4a) is provided, and an exhaust inlet of the exhaust relay pipe (5) is provided. The front and rear surfaces of the flange (5a) are provided with a pressure receiving surface (1a) that receives the fastening force of the screw type fastener (2), and the pressure receiving surface (1a) is formed with an oxide film (1b) of triiron tetroxide. An engine exhaust system characterized by: In the engine exhaust system according to any one of claims 1 to 5,
A mounting seat (3f) of the collector part (3h) is provided with a screw type fastener (2) for fastening the mounting flange (5c) of the exhaust relay pipe (5), and the mounting seat (3f) of the collector part (3h) The upper surface is provided with a pressure-receiving surface (1a) that receives the fastening force of a screw-type fastener (2), and the pressure-receiving surface (1a) is formed with an oxide film (1b) of triiron tetroxide. engine exhaust system. In the engine exhaust system according to any one of claims 1 to 6,
The mounting seat (3f) of the collector part (3h) is provided with a screw type fastener (2) for fastening the mounting flange (5c) of the exhaust relay pipe (5), and the upper and lower surfaces of the mounting flange (5c) are provided with screw type fasteners (2). An engine exhaust system comprising a pressure receiving surface (1a) for receiving the fastening force of a fastener (2), and an oxide film (1b) of triiron tetroxide formed on the pressure receiving surface (1a). . In the engine exhaust system according to any one of claims 1 to 7 ,
An exhaust system for an engine characterized in that an oxide film (1b) of triiron tetraoxide is also formed on an outer surface (1c) of an exhaust passage component (1) other than a pressure receiving surface (1a). In the engine exhaust system according to any one of claims 1 to 8 ,
An exhaust system for an engine, characterized in that an oxide film (1b) of triiron tetroxide is also formed on an inner surface (1d) of an exhaust passage component (1). In the engine exhaust system according to any one of claims 1 to 9 ,
An exhaust system for an engine, characterized in that the film thickness of the oxide film (1b) of triiron tetraoxide is 5 μm to 11 μm. In the engine exhaust system according to any one of claims 1 to 10 ,
An exhaust system for an engine, characterized in that an oxide film (1b) of triiron tetroxide is formed on the surface of the nitrogen compound layer. In the engine exhaust system according to any one of claims 1 to 9 ,
1. An exhaust system for an engine, characterized in that the film thickness of an oxide film (1b) of triiron tetraoxide is more than 11 μm and is 20 μm or less. In the engine exhaust system according to claim 12 ,
An exhaust system for an engine, characterized in that an oxide film (1b) of triiron tetroxide is formed on the surface of the nitrogen compound layer.

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