JP2000328938A - Exhaust structure of engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a heat-insulating cover and reduce its weight by configuring the heat-insulating cover with at least two cover bodies and providing a catalyst housing with one boss and the other boss for mounting the cover adjacently so that the covers are abutted to form a corner portion. SOLUTION: In this engine exhaust structure, an exhaust manifold and a catalystic device are provided. A catalystic body is held to a catalyst cover 30 in the catalystic device, and the catalyst housing 30 has a heat-insulating cover for insulating heat to peripheral parts. In this case, the heat-insulting cover consists of first and second cover bodies of the same shape whose sectional shape is an arc that is smaller tan a semi circle. Bosses 68-1a to 68-1c and 68-2a to 68-2c for mounting the cover are provided on an outer peripheral surface of a housing main body 34 of the catalyst housing 30 so as to abut the first and second cover bodies and forming a corner portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust structure of an engine, and more particularly to an exhaust structure of an engine provided with a catalyst device provided with a heat shield cover.

[0002]

2. Description of the Related Art In a vehicle, a catalyst device for purifying exhaust gas is provided in an exhaust system of an engine. In this catalyst device, a catalyst body is held in a catalyst case, and the catalyst case is provided with a heat shield cover that shields heat from peripheral components.

That is, as shown in FIGS. 15 to 18, a catalyst case 102 has a cylindrical case body 104 and a plurality (4) of which is attached to a turbo outlet pipe (not shown) at one end of the case body 104. And the case body 1 having the flange holes 106 formed therein.
And a pipe connecting portion 110 to which an exhaust pipe (not shown) is attached at the other end side of the pipe. This catalyst case 10
2, a heat shield cover 112 is attached. The heat shield cover 112 is, as shown in FIG.
, And includes two first and second cover bodies 114-1 and 114-2 having a semicircular cross section and the same shape. The first and second cover bodies 114-1 and 114-
Reference numeral 2 is provided on the front side and the rear side of the vehicle, respectively. The first and second cover bodies 114-1 and 114-2
The case body 1 of the catalyst case 102
The two first and second cover mounting bosses 1 are provided on the outer peripheral surface of
16-1a and 116-2a are provided so as to protrude outward from the outer peripheral surface, and two first and second cover mounting bosses 116-1b are provided at positions opposed to each other in the left-right direction on the pipe connection portion 110 side. , 116-2b are provided to protrude outward from the outer peripheral surface. The first and second cover mounting bosses 116-1a and 116-2a and the first and second cover mounting bosses 116-1b and 116-2b are provided with first and second boss bolt holes 118-1a, 118-2a and first and second boss bolt holes 118-1b and 118-2b are formed.

[0004] Such an exhaust structure of an engine is disclosed, for example, in Japanese Patent Application Laid-Open No. 8-340321. This publication discloses an upper heat shield cover that covers an upper part of a catalytic converter, a guide groove formed by bending a lower side edge of the upper heat shield cover into a gutter shape, and a guide groove formed along the guide groove. And an opening end for dropping the liquid flowing down to a position where it does not touch the catalytic converter.

[0005]

However, in the conventional exhaust structure of an engine, as shown in FIG. 18, the entire case body of the catalyst case is covered with a heat shield cover including a portion that does not need heat shield. As a result, the heat shield cover becomes larger, the weight increases, the shape becomes complicated, and the workability decreases.In addition, in order to attach the large heat shield cover, the cover of the case body is required. The mounting boss must be formed large, which requires a large amount of boss meat and increases the weight. In addition, the first and second cover mounting bosses are formed on the outer peripheral surface in the same radial direction from the case body. , The maximum width X (see FIG. 12) of the catalyst case becomes large, and there is a disadvantage that the layout becomes difficult.

[0006]

SUMMARY OF THE INVENTION Therefore, in order to eliminate the above-mentioned disadvantages, the present invention provides a catalyst case for holding a catalyst body in an exhaust system of an engine mounted on a vehicle and a heat shield for peripheral parts. In an exhaust structure of an engine provided with a catalyst device provided with a heat shield cover, the heat shield cover is constituted by at least two cover bodies, and the two cover bodies are faced to form a corner. One cover mounting boss for mounting one cover body and the other cover mounting boss for mounting the other cover body are provided close to each other on the catalyst case.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a cover mounting boss for mounting one cover so as to form a corner by two face-to-face mating, and another cover mounting for mounting the other cover. The boss is located close to the catalyst case, so only the parts of the catalyst case that require heat shielding are covered with a heat shield cover, making the heat shield cover smaller, reducing the weight of the heat shield cover, and increasing its shape. In order to improve the workability by simplifying the size and to attach a small heat shield cover, the cover mounting boss can be made smaller, thereby reducing the boss thickness and reducing the weight, and ,
The cover mounting boss is prevented from protruding in the same radial direction from the outer peripheral surface of the catalyst case, and the maximum width of the catalyst case can be reduced to facilitate the layout.

[0008]

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 10 show the first embodiment of the present invention.
It shows an embodiment. 8 to 10, reference numeral 2 denotes an engine mounted horizontally on a vehicle (not shown), 4 denotes a cylinder block, 6 denotes a cylinder head, 8 denotes an oil pan, 10 denotes a cylinder head cover, 12 denotes an air cleaner, and 14 denotes an intercooler. , 16 is the throttle body, 1
8, an intake manifold; 20, a supercharger; 22-1, a first intake pipe between the air cleaner 12 and the supercharger 20; 22-2, a second intake pipe between the intercooler 14 and the supercharger 20; It is a bypass pipe.

An exhaust manifold 26 and a catalyst device 28 are provided on the front side of the engine 2 so as to form an exhaust structure. In the catalyst device 28, a catalyst body (not shown) is held in a catalyst case 30, and the catalyst case 30 is provided with a heat shield cover 32 that shields heat from peripheral components.

The catalyst case 30 has a cylindrical case body 34.
And a mounting flange 38 having a plurality (four) of flange holes 36 formed at one end of the case main body 34 and a pipe connection portion 40 at the other end of the case main body 34. The mounting flange 38 is mounted on the turbo outlet pipe 42. This turbo outlet pipe 42 is shown in FIG.
7, a pipe main body 44 and a turbo mounting flange 46 connected to the pipe main body 44 are provided, and the pipe main body 44 has flange bolt holes 4 corresponding to the flange holes 36.
8 are formed. The turbocharger 20 is mounted on the turbo mounting flange 46 by a turbo mounting tool 50 made of bolts or the like. The catalyst case 30 is attached to the pipe body 44 by a catalyst attachment 52 made of bolts or the like. An exhaust pipe (not shown) is connected to the pipe connection section 40.

As shown in FIGS. 1, 5, and 6, the heat shield cover 32 attached to the catalyst case 30 does not cover the entire outer periphery of the case main body 34, but only covers a portion requiring heat shield. Two first and second cover bodies 56-1 and 5-5 having the same shape with a cross-sectional arc shape smaller than the semi-arc shape
6-2. The first and second cover bodies 56-1, 5
6-2 are disposed on the front side and the side side of the vehicle, respectively, and are not located on the rear side on the engine 2 side when attached. The cover body 56 includes an arc-shaped cover portion 58 slightly larger than a quarter-arc shape with respect to the circular cross-section, and an axially linear one-side mounting portion provided on one side of the arc-shaped cover portion 58. 60, and an axially linear other-side mounting portion 62 continuously provided on the other side of the arc-shaped cover portion 58. The one-side mounting portion 60 has two one-side bolt holes 6 in the axial direction.
4-1a and 64-1b, and the other side mounting portion 62
Has a bolt hole 64-1c on the other side substantially at the center.

The first and second cover bodies 56-1 and 56-
The first cover mounting boss 68, which is one cover mounting boss, is provided on the outer peripheral surface of the case body 34 of the catalyst case 30 in order to attach the two so that the corners 66 are formed in a face-to-face manner. -1a, 68-1b, 68-1c are provided, and the second cover mounting bosses 68-2a, 68-2b, 68-2 which are the other cover mounting bosses on the side.
c is provided.

As shown in FIG. 2, the first cover mounting boss 6 is provided.
8-1a is provided on one side of the front side on the mounting flange 38 side so as not to protrude from the outer peripheral surface of the case main body 34. The first cover mounting boss 68-1b is located on the pipe connection portion 40 side on one side on the front side and is separated from the first cover mounting boss 68-1a by the distance A1 in the axial direction, and It is provided similarly to the first cover mounting boss 68-1a so as not to protrude from the outer peripheral surface. These first cover mounting bosses 68-1a, 68-1
b, one side bolt holes 64-1a, 64-1 from the front side.
b corresponding to the first bolt screw holes 70-1a, 70-1b
Are formed. First cover mounting boss 68-1c
Is located at a distance A2 from the first cover mounting boss 68-1a in the axial direction and a distance A3 from the first cover mounting boss 68-1b, and furthermore, in the radial direction, the first cover mounting boss 68-1a, It is provided on the side of the case body 34 (the right side in FIG. 1) at a distance B from 68-1b so as to protrude from the outer peripheral surface. This first cover mounting boss 68-
A first bolt screw hole 70-1c corresponding to the other bolt hole 64-1c from the front side is formed in 1c. First
Cover mounting boss 68-1a and first cover mounting boss 6
The first cover body 56-1 is attached to 8-1b and the first cover attaching boss 68-1c by the first attaching bolt 72-1.

As shown in FIG. 4, the second cover mounting boss 6 is provided.
8-2a is provided on one side, that is, close to the first cover mounting boss 68-1a and substantially perpendicular to the mounting flange 38 side so as not to protrude from the outer peripheral surface of the case body 28. ing. At this time, the second cover mounting boss 68-2a is arranged to be offset (offset) by a distance C from the first cover mounting boss 68-1a toward the mounting flange 38. The second cover mounting boss 68-2b is
As in the case of the cover mounting boss 68-2a, the case body is located on the side of the pipe connecting portion 40 on one side and at a distance A1 from the second cover mounting boss 68-2a in the axial direction. 34 so as not to protrude from the outer peripheral surface of
It is provided near and substantially orthogonal to the cover mounting boss 68-1b. This second cover mounting boss 68-2b
Are offset from the first cover mounting boss 68-2b toward the mounting flange 38 by a distance C (offset). These second cover mounting bosses 68-2a, 68-2.
b, one side bolt hole 64-1a, 64-1 from the side.
b-2 bolt screw holes 70-2a and 70-2b corresponding to b
Are formed so as not to overlap the first bolt screw holes 70-1a and 70-1b. Second cover mounting boss 68-
2c is a second cover mounting boss 68-2 in the axial direction.
a at distance A3 from the second boss a and the second cover mounting boss 68-2b
At a distance A2 from the second cover mounting bosses 68-2a, 68-2b in the radial direction and at a position B at the rear of the case body 34 from the outer peripheral surface. The second cover mounting boss 68-2c includes:
The second bolt screw hole 70-2c corresponding to the other bolt hole 64-1c from the side is formed so as not to overlap the first bolt screw hole 70-1c. A second mounting bolt 72 is provided between the second cover mounting boss 68-2a, the second cover mounting boss 68-2b, and the second cover mounting boss 68-2c.
-2 attaches the second cover body 56-2.

Accordingly, each first cover mounting boss 68-1 is provided.
Are equal to the respective intervals of the second cover mounting bosses 68-2, the front first cover mounting bosses 68-2 on the front side.
-1a, 68-1b, the first attached to 68-1c
If the cover body 56-1 is point symmetric and turned upside down,
The first cover body 56-1 can be used as the second cover body 56-2.

Next, the operation of the first embodiment will be described.

The heat shield cover 32 that covers the catalyst case 30 does not cover the entire outer periphery of the case body 34 but only the portion that requires heat shield, and has the same cross-sectional arc shape smaller than the semicircular arc shape. Since the first and second cover bodies 56-1 and 56-2 are formed in a shape, the heat shield cover 32 is reduced in size, the weight of the heat shield cover 32 is reduced, and the shape is simplified to improve workability. can do.

Further, in the catalyst case 30, the first cover mounting bosses 68-1a and 68-1b and the second cover mounting bosses 68-2a and 68-2b are close to each other so as not to protrude from the outer peripheral surface. Since it is provided, the weight of the boss is reduced to reduce the weight, and as shown in FIGS. 2 and 4, the first cover mounting boss 68-1c on the front side and the second cover mounting boss 68 on the lateral side. −2c in the radial direction, the maximum width W of the catalyst case 30 is changed to the conventional maximum width X.
And a compact design can be achieved.

Further, the two first and second cover bodies 56-
1, 56-2 is required, but since the cover body 56 can be used upside down and used on the front side and the side side,
Since a kind of cover body 56 may be formed, parts can be shared, the number of parts can be reduced, and processing can be facilitated.

FIG. 11 shows a special configuration of the present invention, which shows a second embodiment.

In the following embodiments, portions having the same functions as those in the above-described first embodiment will be described with the same reference numerals.

The features of the second embodiment are as follows. In other words, the case body 34 is provided with the common cover mounting boss 82 at a portion where the first cover body 56-1 and the second cover body 56-2 meet. A common bolt screw hole 84 is formed in the common cover mounting boss 82.

According to the structure of the second embodiment, the first and second cover members 56-1, 56-1,
56-2 can be mounted in common, so that it is only necessary to provide one common cover mounting boss 82 on the front side and the side at the corner portion 66 of the mating surface, further reducing the weight and size. And the number of processing steps can be reduced.

FIG. 12 shows a special configuration of the present invention, and shows a third embodiment.

The features of the third embodiment are as follows. That is, a heat insulating material 86 is provided between the cover mounting boss 68 and the cover body 56.

According to the structure of the third embodiment, the heat of the case body 34 is cut off by the heat insulating material 86 and the cover body 56 is cut off.
, And the heat shielding effect can be improved.

FIG. 13 shows a special configuration of the present invention, and shows a fourth embodiment.

The features of the fourth embodiment are as follows. That is, the cover body 56 is provided with the upper wind receiving member 92-1 at the upper portion and the side wind receiving member 92-2 at the one side portion.

According to the structure of the fourth embodiment, during traveling of the vehicle, the traveling wind is collected at the central portion of the cover body 56 by the upper wind receiving member 92-1 and the side wind receiving member 92-2. As a result, the cover body 56 is cooled, and radiant heat is less likely to be generated, so that the heat shielding effect can be improved.

FIG. 14 shows a special configuration of the present invention, and shows a fifth embodiment.

The features of the fifth embodiment are as follows. That is, the cover body 56 is provided with the upper wind receiving member 92-1 in the upper portion, the side wind receiving member 92-2 is provided in one side portion, and the upper portion is directed vertically in the central portion. An air guide member 94 is provided, and a punching hole 96 and a punching remaining portion 98 are formed so as to protrude from the surface by punching.

According to the configuration of the fifth embodiment, during traveling of the vehicle, the traveling wind is collected at the central portion of the cover body 56 by the upper wind receiving member 92-1 and the side wind receiving member 92-2. As a result, the cover body 56 is cooled to make it difficult for radiant heat to be generated, thereby improving the heat shielding effect.
4, the case body 34 itself can be cooled to reduce the temperature of the case body 34, and the remaining part 98 can be made to function as a cooling fin. Can be closed.

[0033]

As apparent from the above detailed description, according to the present invention, the heat shield cover is constituted by at least two cover members, and the two cover members are faced to form a corner. By providing one cover mounting boss for mounting one cover body and the other cover mounting boss for mounting the other cover body in close proximity to the catalyst case, only the portion of the catalyst case that needs heat shielding is shielded. The cover is covered with a heat cover to reduce the size of the heat shield cover to reduce weight and simplify the shape to improve workability. Also, since a small heat shield cover is attached, the cover mounting boss is made smaller. This makes it possible to reduce the weight of the boss by reducing the thickness of the boss, and to prevent the cover mounting boss from protruding in the same radial direction from the outer peripheral surface of the catalyst case. It may facilitate the layout by reducing significantly.

[Brief description of the drawings]

FIG. 1 is an assembly drawing of a catalyst device.

FIG. 2 is a front view of a catalyst case.

FIG. 3 is a plan view of a catalyst case.

FIG. 4 is a side view of a catalyst case.

FIG. 5 is a sectional view of the catalyst case taken along line 5-5 in FIG. 2;

FIG. 6 is a sectional view of the catalyst case taken along line 6-6 in FIG. 2;

FIG. 7 is a plan view of a turbo outlet pipe.

FIG. 8 is a front view of the engine.

FIG. 9 is a side view of the engine.

FIG. 10 is a plan view of the engine.

FIG. 11 is an enlarged sectional view of a cover mounting boss in the second embodiment.

FIG. 12 is an enlarged sectional view of a cover mounting boss in the third embodiment.

FIG. 13 is a perspective view of a cover according to a fourth embodiment.

FIG. 14 is a perspective view of a cover according to a fifth embodiment.

FIG. 15 is a front view of a conventional catalyst case.

FIG. 16 is a plan view of a conventional catalyst case.

FIG. 17 is a side view of a conventional catalyst case.

18 is a sectional view taken along line 18-18 in FIG.

[Explanation of symbols]

 2 Engine 26 Exhaust manifold 28 Catalyst device 30 Catalyst case 32 Heat shield cover 34 Case body 56 Cover body 66 Corner 68 Cover mounting boss

Claims (3)

[Claims] 1. An exhaust structure of an engine provided with a catalyst device provided with a catalyst case for holding a catalyst body in an exhaust system of an engine mounted on a vehicle and a heat shield cover for shielding heat from peripheral components. The heat shield cover is constituted by at least two cover bodies, and one of the cover mounting bosses and the other cover body are mounted by mounting one of the cover bodies so that the two cover bodies are faced to form a corner. An exhaust structure for an engine, wherein the catalyst case is provided adjacent to the other cover mounting boss. 2. The heat shielding cover according to claim 1, wherein the two cover bodies are formed in the same shape, and the cover body is formed in a cross-sectional arc shape smaller than a cross-sectional semi-arc shape. The exhaust structure of the described engine. 3. A bolt hole is formed at the same position in each of the two cover bodies, and one bolt screw hole formed in the one cover mounting boss in accordance with the bolt hole and the other cover mounting hole. The engine according to claim 1, wherein the one cover mounting boss and the other cover mounting boss are biased so as not to overlap with the other bolt screw hole formed in the boss. Exhaust structure.