JP2000328934A - Engine exhaust device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a catalyst housing from being shaken and prevent interference with other parts and damage of the catalyst housing and a connection piping portion, by providing a connection piping portion for connecting a supercharger and the catalyst housing and by configuring the connection piping portion with an expanded diameter portion and flange portion for mounting the supercharger. SOLUTION: In an engine provided with a supercharger, a catalyst housing 24 is provided near a cylinder block and a connection piping portion 26 is provided for connecting the supercharger and catalyst housing 24. In addition, the connection piping portion 26 comprises an expanded diameter portion 28 that expands gradually toward the catalyst housing 24 and a turbo flange portion 30 for mounting the supercharger. The turbo flange portion 30 is provided standing and extending in the axial direction of the expanded diameter portion 28 to be connected thereto. In other words, the connection piping portion 26 is used as replacement for an exhaust pipe for connecting the turbine side of the supercharger to the catalyst housing 24. Further, the expanded diameter portion 28 is formed in a conical shape and an opening of a turbo-mounting surface 30a on the turbo flange portion 30 is formed generally elliptic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system for an engine, and more particularly to an exhaust system for an engine in which a catalyst case can be mounted in a highly rigid state immediately downstream of a supercharger.

[0002]

2. Description of the Related Art Some engines are provided with a supercharger (also called "turbocharger" or simply "turbo"). The turbocharger rotates a turbine by exhaust gas discharged from the engine, pressurizes intake air by a compressor disposed coaxially with the turbine, and supplies the compressed air to the engine.

[0003] An exhaust system for the engine is disclosed in Japanese Patent Application Laid-Open No. 9-79043. The exhaust purification device for an internal combustion engine with a supercharger disclosed in this publication is:
An exhaust purification device for a supercharged internal combustion engine having a pair of turbochargers, wherein an exhaust inflow side of a square exhaust turbocharger is connected to a common exhaust inflow passage, and an exhaust outflow side of each exhaust turbocharger is separately provided. And the catalyst is arranged in one of the exhaust outlet passages,
The other exhaust outflow passage is provided with flow path resistance means having the same flow resistance as the catalyst, and makes each exhaust turbocharger function well without over-rotating.

[0004] Further, there is one disclosed in Japanese Patent Application Laid-Open No. 9-100715. The exhaust gas purifying apparatus for an internal combustion engine disclosed in this publication is an exhaust gas purifying apparatus for an internal combustion engine in which an electric heating catalyst for electrically heating a catalyst carrier is mounted in an exhaust passage. A generator is provided to generate electric power by an exhaust gas flow flowing through the inside, and when the electrically heated catalyst is energized, the generator is electrically operated so as to supply the electric power obtained by the generator to the electrically heated catalyst. If the electric heating type catalyst is connected to the heating type catalyst and energized to the electric heating type catalyst through the battery, poor starting of the internal combustion engine and deterioration of the battery occur, which is prevented.

[0005] Further, there is one disclosed in JP-A-9-209742. An exhaust control apparatus for a supercharged internal combustion engine disclosed in this publication includes an exhaust passage provided in a multi-cylinder internal combustion engine operable at a lean air-fuel ratio, a three-way catalyst provided in the exhaust passage, and a three-way catalyst. A NOx reduction catalyst that is provided in the exhaust passage downstream of the catalyst and reduces the NOx component by reacting the HC or CO component with the NOx component, and is provided in an exhaust passage between the three-way catalyst and the NOx reduction catalyst. The supercharger is provided in the bypass passage, which connects the upstream side of each of the three-way catalyst and the supercharger in the exhaust passage, bypasses the three-way catalyst, and passes a part of the exhaust gas, In an exhaust control apparatus for an internal combustion engine with a supercharger having a control valve capable of opening and closing the passage, when the internal combustion engine operates at a lean air-fuel ratio, HC or CO contained in the exhaust of the engine is used. Increase the component for a predetermined time And HC amount increasing means for, HC contained in the exhaust by HC increasing means,
Or a passage control means for opening the control valve and allowing the exhaust gas to pass through the bypass passage when the CO component has increased, so as to suppress the decrease in the supercharging efficiency of the supercharger while reducing the N
This prevents a reduction in the NOx purification action of the Ox reduction catalyst.

[0006]

In a conventional exhaust system for an engine, a supercharger and a catalyst case are connected by an exhaust pipe, and the supercharger and the catalyst case are arranged close to each other. The catalyst case was not provided immediately downstream of the turbocharger.

As a result, the rigidity of the catalyst case cannot be secured, and when the catalyst case swings, the catalyst case interferes with other parts and the catalyst case and the parts before and after the catalyst case are damaged. And there is a disadvantage that it is practically disadvantageous.

In addition, since the supercharger and the catalyst case are connected by the exhaust pipe, the compactness cannot be achieved, the arrangement state is disordered, and a large arrangement space is required. .

[0009]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an engine provided with a supercharger driven by exhaust gas to pressurize and supply intake air.
A catalyst case is provided close to the cylinder block, a connecting pipe portion for connecting the supercharger and the catalyst case is provided, and the connecting pipe portion is gradually expanded toward the catalyst case, And a turbocharger mounting flange portion erected so as to extend in the axial direction and to be continuous with the enlarged diameter portion.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION
When arranging the catalyst case, the connection pipe section attaches the catalyst case in a highly rigid state immediately downstream of the turbocharger, suppresses the oscillation of the catalyst case, interferes with other parts, and In addition, damage to the connecting pipe is reliably prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 7 show an embodiment of the present invention. In FIG. 7, reference numeral 2 denotes an engine.

The engine 2 includes a cylinder block 4
And a cylinder head 6 mounted on the upper surface of the cylinder block 4, a cylinder head cover 8 mounted on the upper surface of the cylinder head 6, and an oil pan 10 mounted on the lower surface of the cylinder block 6. .

The general intake system of the engine 2 includes an air cleaner 12, a first intake pipe 14 connected to the downstream side of the air cleaner 12, and an air passage disposed downstream of the first intake pipe 14. A compressor (not shown) of the charger 16 (also referred to as a “turbocharger” or simply “turbo”), a second intake pipe 18 communicating with the compressor side of the supercharger 16, and a downstream side of the second intake pipe 18 are arranged. An intercooler 20 provided, a third intake pipe (not shown) communicating with the downstream side of the intercooler 20, an intake manifold (not shown) arranged downstream of the third intake pipe, and a communication with the intake manifold. And an intake port (not shown) formed in the cylinder head 6 of the engine 2.

The supercharger 16 is driven by exhaust gas discharged from the engine 2, pressurizes intake air, and supplies the intake air to the engine 2.

The general exhaust system of the engine 2 includes an exhaust port (not shown) formed in the cylinder head 6 of the engine 2, an exhaust manifold 22 connected to a downstream side of the exhaust port, A first exhaust pipe (not shown) disposed downstream of the exhaust manifold 22, a turbine (not shown) of the supercharger 16 disposed downstream of the first exhaust pipe, and a turbine side of the supercharger 16. It has a second exhaust pipe (not shown) connected thereto, a catalyst case 24 disposed downstream of the second exhaust pipe, and an exhaust pipe not shown connected downstream of the catalyst case 24. .

At this time, a catalyst case 24 is provided close to the cylinder block 4 of the engine 2, and a connecting pipe portion 26 for connecting the supercharger 16 and the catalyst case 24 is provided. , Catalyst case 24
And a turbo-flange portion 30 as a turbocharger mounting flange portion which extends in the axial direction of the wide-diameter portion 28 and is erected so as to be continuous with the wide-diameter portion 28. And

More specifically, instead of the second exhaust pipe connecting the turbine side of the supercharger 16 and the catalyst case 24,
The connection piping section 26 is used.

As shown in FIGS. 1 and 2, the connecting pipe portion 26 is provided with an enlarged diameter portion 28 gradually expanding toward the catalyst case 24, and a catalyst case is provided at an end of the enlarged diameter portion 28. A catalyst case flange portion 32 as a mounting flange portion 24 is formed, and is integrally formed in a state where a turbo flange portion 30 is erected so as to extend in the axial direction of the enlarged diameter portion 28 and to be continuous with the enlarged diameter portion 28.

At this time, the enlarged diameter portion 2 of the connecting pipe portion 26
When the turbo flange portion 30 is erected on the space 8, a space portion that appears near the outer peripheral portion between the enlarged diameter portion 28 and the turbo flange portion 30 is connected by a surplus portion 34 having a predetermined width W, and a solid continuous Secure state.

That is, as shown in FIGS. 1 and 2, first and second extra portions 34-1 and 34- are provided on the left and right outer peripheral portions below the turbo mounting surface 30a of the turbo flange portion 30.
2 and the first and second excess portions 3
4-1 and 34-2 are formed so as to be in contact with the parting line L at the time of casting and to have a predetermined width W from the parting line L at the time of casting toward the turbo mounting surface 30a side of the turbo flange portion 30. I do.

The enlarged diameter portion 28 of the connecting pipe portion 26
1 and 2, the opening 36 of the turbo mounting surface 30a of the turbo flange 30 is formed in a substantially elliptical shape as shown in FIG.

The lower side 36-1 of the opening 36 of the turbo mounting surface 30a is used as a main passage opening on the downstream side of the turbocharger 16, and the upper side 36-2 of the opening 36 is used.
Is used as an opening for a bypass passage from a blow-off valve (not shown), and the internal passage 28 of the connection piping portion 26 is
As shown in FIGS. 1 and 2, the lower enlarged diameter portion 2 extends from the opening 36 of the turbo mounting surface 30 a through the turbo flange portion 30.
8 and is formed along the conical slope 28 f of the enlarged diameter portion 28.

Reference numeral 40 denotes two catalyst case covers mounted on the outer peripheral portion of the catalyst case 24, 42 denotes a catalyst case mounting bolt boss formed on the catalyst case flange 32 of the connection pipe 26, 44 Is a supercharger mounting bolt boss formed on the turbo flange portion 30 of the connection piping portion 26, and 46 is a sensor mounting boss.

Next, the operation will be described.

The turbo mounting surface 30a of the turbo flange portion 30 of the connecting pipe portion 26 is brought into contact with the downstream side of the supercharger 16 in the exhaust system of the engine 2 and is fixed using a catalyst case mounting bolt boss 44. .

The upstream side of the catalyst case 24 is brought into contact with the catalyst case flange portion 32 of the connection pipe portion 26, and is fixed using the catalyst case mounting bolt boss 42.

The lower side 36-1 of the opening 36 of the turbo mounting surface 30a functions as a main passage opening downstream of the turbocharger 16, and the upper side 36-2 of the opening 36 is a blow-off valve (not shown). From the internal passage 28 of the connecting pipe portion 26, that is, the opening 36 of the turbo mounting surface 30a, through the turbo flange portion 30, to the lower enlarged portion 28, and this enlarged portion 28
A portion formed along the conical slope 28f functions as a part of the exhaust system.

At this time, the connecting pipe portion 26 is in a continuous state between the enlarged diameter portion 28 and a turbo flange portion 30 which extends in the axial direction of the enlarged diameter portion 28 and is erected to be continuous with the enlarged diameter portion 28. Is secured by a surplus portion 34 having a predetermined width W.

As a result, the catalyst case 24 can be mounted in a highly rigid state immediately downstream of the supercharger 16 by the connecting pipe portion 26, thereby suppressing the swing of the catalyst case 24 and preventing interference with other components. Catalyst case 2
4 and the connecting pipe 26 can be avoided, which is practically advantageous.

Further, when the turbo flange portion 30 is erected on the enlarged diameter portion 28 of the connecting pipe portion 26, a space that appears near the outer peripheral portion between the enlarged diameter portion 28 and the turbo flange portion 30 is defined by a predetermined width W. Are connected by the excess thickness portion 34 having the diameter, the excess thickness portion 34 functions as a reinforcing rib, and the enlarged diameter portion 2
8 and the turbo flange portion 30 can be made solid, which can contribute to the high rigidity of the catalyst case 24 and reduce mold drop during casting of the connection pipe portion 26;
The occurrence of casting defects can be prevented.

Further, the opening 3 of the turbo mounting surface 30a
6 is used as an opening for a main passage on the downstream side of the turbocharger 16, and an upper side 36-2 of the opening 36 is used as an opening for a bypass passage from a blow-off valve (not shown). By forming the internal passage 28 of the portion 26 from the opening 36 of the turbo mounting surface 30a, through the turbo flange portion 30, to the lower enlarged portion 28, and along the conical slope 28f of the enlarged portion 28, It is possible to arrange the expanded parts close to each other and to make the whole compact, which is practically advantageous.

It should be noted that the present invention is not limited to the above-described embodiment, and various application modifications are possible.

For example, in the embodiment of the present invention, the enlarged diameter portion of the connecting pipe portion is formed in a conical shape, but may be formed in a pyramid shape or a spherical shape.

Further, in the embodiment of the present invention, when the turbo flange portion is erected on the enlarged diameter portion of the connecting pipe portion, a space portion which appears near the outer peripheral portion between the enlarged diameter portion and the turbo flange portion is formed. Although the connection is made by a surplus portion having a predetermined width, it is also possible to provide a surplus portion to a state where all the space parts appearing near the outer peripheral part between the enlarged diameter part and the turbo flange part are eliminated.

In this case, it is possible to increase the thickness of the wall of the connecting pipe portion, prevent the temperature from being reduced due to divergence, and reduce the distance between the enlarged portion and the turbo flange portion. In addition, the catalyst can be quickly brought into an operating state, heat management for the catalyst can be easily performed, which is practically advantageous, and can also reinforce the connecting pipe portion.

[0037]

As described above in detail, according to the present invention, in an engine provided with a supercharger driven by exhaust gas and pressurizing and supplying intake air, a catalyst case is provided in close proximity to a cylinder block. A connecting pipe section for connecting the feeder and the catalyst case is provided, and the connecting pipe section is
The connecting pipe is configured to have a diameter-expanding portion that gradually expands toward the catalyst case and a turbocharger mounting flange portion that extends in the axial direction of the diameter-expanding portion and is erected to be continuous with the diameter-expanding portion. The catalyst case can be mounted in a highly rigid state immediately downstream of the turbocharger by the part, suppressing the swing of the catalyst case, reliably preventing interference with other parts, and damaging the catalyst case and connecting piping This is practically advantageous because damage to the part can be avoided.

[Brief description of the drawings]

FIG. 1 is a left side view of a connecting pipe section showing an embodiment of the present invention.

FIG. 2 is a front view of a connecting pipe section.

FIG. 3 is a plan view of a connecting pipe section.

FIG. 4 is a front view of an opening formed in a turbo mounting surface of a turbo flange portion.

FIG. 5 is a schematic explanatory diagram of a second excess portion.

FIG. 6 is a perspective view showing a state in which a supercharger and a catalyst case are attached to a connecting pipe portion.

FIG. 7 is a front view of the engine.

[Explanation of symbols]

 2 Engine 4 Cylinder Block 6 Cylinder Head 8 Cylinder Head Cover 10 Oil Pan 12 Air Cleaner 14 First Intake Pipe 16 Supercharger 18 Second Intake Pipe 20 Intercooler 22 Exhaust Manifold 24 Catalyst Case 26 Connecting Pipe 28 Larger Diameter 30 Turbo Flange Reference Signs List 32 catalyst case flange portion 34 excess portion 34-1 first excess portion 34-2 second excess portion 36 opening 40 catalyst case cover

Claims (2)

[Claims] 1. An engine provided with a supercharger driven by exhaust gas and pressurizing and supplying intake air, a catalyst case is provided in close proximity to a cylinder block, and a connection pipe portion connects the supercharger and the catalyst case. And a connecting pipe portion, a diameter increasing portion that gradually expands toward the catalyst case, and a turbocharger mounting flange portion that extends in the axial direction of the diameter increasing portion and is erected so as to be continuous with the diameter increasing portion. An exhaust system for an engine, comprising: 2. The connecting pipe portion, wherein the enlarged diameter portion is formed in a conical shape, and a main passage on the downstream side of a supercharger and a bypass passage from a blow-off valve are formed along a conical slope of the enlarged diameter portion. The exhaust device for an engine according to claim 1.