JP2000265905A - Multicylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration by strongly fastening a plurality of exhaust passage members provided with exhaust emission control catalusts to an exhaust outlet of a collective exhaust port, in an engine a plurality of collective exhaust ports in a cylinder head. SOLUTION: Attaching flanges 56 of exhaust pipes 19 respectively provided with exhaust emission control catalysts 41 are fastened to exhaust outlets 48 of two collective exhaust ports 18a, 18b formed inside a cylinder head 12 of a serial six cylinder engine by means of bolts 57. The exhaust emission control catalysts 41 are connected to each other, while two exhaust pipes 19 are integrated with each other by means of the common attaching flange 56. The exhaust pipes 19 including the exhaust emission control catalysts 41 are improved in support rigidity in respect to the cylinder head 12, for reducing vibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder engine provided with a collective exhaust port in which exhaust ports extending from a plurality of combustion chambers are integrally collected by an exhaust collecting section formed inside a cylinder head.

[0002]

2. Description of the Related Art In general, an exhaust port formed in a cylinder head of a multi-cylinder engine performs only collection of exhaust gas discharged from a plurality of exhaust valve holes of the same cylinder inside a cylinder head, and is discharged from each cylinder. The collection of exhaust gases takes place in a separate exhaust manifold coupled to the cylinder head.

On the other hand, Japanese Patent No. 27098 discloses a system in which exhaust gas discharged from each cylinder is collected inside a cylinder head without using a separate exhaust manifold.
No. 15 publicly known. In the in-line six-cylinder engine disclosed in the above publication, a combined exhaust port in which the exhaust ports of the three cylinders at one end of the cylinder line are integrated together with an exhaust port of the three cylinders at the other end of the cylinder line. And a collective exhaust port collectively.

[0004]

In an engine provided with such a collective exhaust port, when an exhaust pipe integrally provided with an exhaust gas purifying catalyst is fastened to the exhaust outlet of the collective exhaust port, each exhaust gas purifying catalyst becomes 3 Despite the need for the capacity corresponding to the cylinder and the increase in weight, the exhaust outlet of the collective exhaust port to which the mounting flange of the exhaust pipe is connected is not particularly large, so the exhaust pipe is connected to the exhaust outlet. However, there is a problem that the rigidity to be fastened is insufficient and vibration is likely to occur.

The present invention has been made in view of the above circumstances, and in an engine having a plurality of collective exhaust ports in a cylinder head, an exhaust passage member having an exhaust gas purifying catalyst is provided at an exhaust outlet of the collective exhaust port. The purpose is to increase the supporting rigidity to support.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, a cylinder head is disposed along a cylinder line in a projection formed on a side wall of a cylinder head. In a multi-cylinder engine in which at least two collective exhaust ports are formed by integrally collecting exhaust ports extending from a plurality of combustion chambers at an exhaust collecting part, at least two exhaust passage members are provided at an exhaust outlet of the collective exhaust port. A multi-cylinder engine is proposed in which one end portions are respectively fastened, an exhaust gas purifying catalyst is provided at the other end portion of each of the exhaust passage members, and the exhaust passage members are integrally connected.

According to the above construction, since the exhaust gas purifying catalyst is provided directly on the exhaust passage member fastened to the exhaust outlet of the collective exhaust port, the distance from the combustion chamber to the exhaust gas purifying catalyst is shortened. The purification catalyst can be activated early. Also, despite the provision of a heavy exhaust gas purifying catalyst in the exhaust passage member, each exhaust passage member is integrally connected, and each exhaust passage member is fastened to the exhaust outlet of an adjacent collective exhaust port. Therefore, it is possible to increase the support rigidity of the exhaust passage member including the exhaust gas purifying catalyst and reduce the vibration. Moreover, since a reinforcing member such as a stay for supporting the exhaust passage member can be eliminated to reduce vibration, the number of parts can be reduced and the engine can be made more compact.

In order to connect the respective exhaust passage members integrally, in addition to directly connecting the exhaust passage members, for example, an exhaust gas purifying catalyst provided on the exhaust passage member or a mounting flange of the exhaust passage member may be used. Indirect connection through such a connection member is also included.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 7 show a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a multi-cylinder engine, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 4 is a sectional view taken along line 4-3 of FIG. 2, FIG. 5 is a sectional view taken along line 5-5 of FIG.
6 is a view in the direction of arrows in FIG. 2, and FIG. 7 is a sectional view taken along line 7-7 in FIG.

As shown in FIGS. 1 and 3, an in-line six-cylinder engine E includes a cylinder head 12 coupled to an upper surface of a cylinder block 11.
The head cover 13 is joined to the upper surface of the head. Pistons 15 are slidably fitted inside the six cylinders 14 formed in the cylinder block 11.
The combustion chambers 16 are formed on the lower surface of the cylinder head 12 facing the upper surface of. The intake ports 17 connected to the combustion chambers 16 open on the intake side of the cylinder head 12 and the first collective exhaust port 1 connected to the combustion chambers 16.
8a and a second collective exhaust port 18b are opened on the exhaust side of the cylinder head 12, and exhaust gas purifying catalysts 41, 41 are provided at lower ends of exhaust pipes 19, 19 having upper ends fastened to the two openings. Can be An ignition plug insertion tube 2 for attaching and detaching ignition plugs 20 to / from the cylinder head 12.
Are integrally formed. Spark plug insertion tube 21 ... upper end is first with respect to the cylinder axis L _1, the second collecting exhaust port 18a, is inclined 18b side, the ignition plug 20 is mounted to face the combustion chamber 16 at its lower end Originally, the ignition coil 22 is attached to the upper end.

A valve chamber 23 formed above the cylinder head 12 and covered by the head cover 13 has a camshaft 2 having an intake cam 24 and an exhaust cam 25.
6 and a rocker arm shaft 29 for swingably supporting the intake rocker arms 27 and the exhaust rocker arms 28.

The valve stems 32, 32 of the intake valves 31, 31, which open and close the two intake valve holes 30, 30 facing each combustion chamber 16, project into the valve operating chamber 23 and are mounted on the projecting portions. The intake valves 31, 31 are urged by the valve springs 33, 33 in the valve closing direction. A roller 34 is provided at one end of each intake rocker arm 27 to contact the intake cam 24, and the other end contacts the upper ends of the valve stems 32, 32 of the intake valves 31, 31. Further, the valve stems 37, 37 of the exhaust valves 36, 36 for opening and closing the two exhaust valve holes 35, 35 facing the respective combustion chambers 16 project into the valve operating chamber 23, and the valves mounted on the projecting portions thereof. The exhaust valves 36, 36 are urged in the valve closing direction by the springs 38, 38. Each exhaust rocker arm 28
Is provided at one end thereof with a roller 39 which is in contact with the exhaust cam 25, and the other end is provided with a valve stem 37 of the exhaust valves 36, 36.
37 contacts the upper end.

Each of the intake ports 17 has an injector 40 for injecting fuel in a direction toward the intake valve holes 30, 30.
Is provided.

Referring to FIG. 2 together, it is apparent that
Six intake ports 17 extending from six combustion chambers 16.
Are formed in a Y-shape, and the six intake ports 17... Open independently on the intake side surface of the cylinder head 12 without being assembled with each other. On the other hand, the first and second collective exhaust ports 18a and 18b
6 exhaust ports 46 extending from the combustion chambers 16.
, And arch-shaped first and second exhaust collecting portions 47a, 47b in which the six exhaust ports 46 are integrally collected, and the first and second exhaust collecting portions 47a, 47b.
Exhaust pipe 1 constituting the exhaust passage member of the present invention at the center of
Exhaust outlets 48, 48 to which the 9, 9 are coupled are formed.

The six cylinders 14 are sequentially numbered # 1, # 2, # 3, # 4, # 5 and # 6 from the cam drive chain chamber 59 side.
, The first collective exhaust port 18a is # 1, # 2,
Exhaust gas from the combustion chambers 16 of the # 3 cylinder is collected, and the second collective exhaust ports 18b are # 4, # 5, # 6
Exhaust gas from the combustion chambers 16 of the cylinders is collected, and the first collective exhaust port 18a and the second collective exhaust port 18b have substantially the same structure. By dividing the collective exhaust port into a first collective exhaust port 18a and a second collective exhaust port 18b and having the same structure, the core that forms the collective exhaust port when casting the cylinder head 12 is formed. Not only the size can be reduced, but also the type of the core can be reduced to one type to contribute to cost reduction.

The ignition sequence of cylinders # 1, # 2, # 3, # 4, # 5, and # 6 is # 1 → # 5 → # 3 → # 6 → # 2 → # 4
And three #s corresponding to the first collective exhaust port 18a.
The # 1, # 2, and # 3 cylinders do not have a continuous ignition order, and the three # 4, # 5, and # 5 cylinders corresponding to the second collective exhaust port 18b
The ignition order of the # 6 cylinder is not continuous. Therefore, three # 1, # 2, and # 3 corresponding to the first collective exhaust port 18a
No exhaust interference occurs between the cylinders, and no exhaust interference occurs between the three # 4, # 5, and # 6 cylinders corresponding to the second collective exhaust port 18b.

[0018] The first, second exhaust collector 47a, 2 or locations of the exhaust side wall 12 ₁ of the cylinder head 12 47b faces has projecting outward curved in an arch shape, respectively the cylinder block 11 first, second projecting portion 49a projecting from the side wall 11 _1, it constitutes a 49b. Therefore, the first and second exhaust collecting portions 47a and 47b of the first and second collecting exhaust ports 18a and 18b formed inside the first and second overhang portions 49a and 49b are curved in an arch shape. 1, the second projecting portion 49a, and faces directly without going through the water jacket on the side wall 12 ₁ of 49b.

As described above, the first and second overhang portions 49a, 4
First and second collective exhaust ports 18 formed inside 9b
a, first 18b, the second exhaust collector 47a, 47b are first, second projecting portion 49a, so that faces directly without going through the water jacket on the side wall 12 ₁ of the 49b, the first, second it can be made compact cylinder head 12 as compared with the water jacket is interposed between the exhaust collector 47a, and 47b and the side wall 12 _1. Moreover, since the side wall 12 ₁ is formed in an arch shape, not only allows more compact width of longitudinal end portions of the cylinder head 12 is reduced, contributing to the improved rigidity of the cylinder head 12 In addition, the flow of the exhaust gas can be made smooth and the molding of the cylinder head 12 can be facilitated. Moreover, the first and second overhangs 49
Since the concave portion 71 (see FIG. 2) is formed between a and 49b, the size of the engine E can be reduced by effectively utilizing the space of the concave portion 71.

As is apparent from FIGS. 2 and 4, seven bolt holes 50 are formed in the cylinder head 12 on the intake side and the exhaust side, respectively. The cylinder head 12 is fastened to the cylinder block 11 by screwing the ₁₄ cylinder head fastening bolts 51 _{1 to} 51 ₁₄ inserted from the cylinder block 11 into the bolt holes 52 formed in the cylinder block 11.

Inside the first collective exhaust port 18a, three cylinders 1 corresponding to the first collective exhaust port 18a are provided.
4 ... and between extending the two wall portions 53 and 54 to partition, these two wall portions 53 and 54 of the two cylinder head fastening bolts 51 _2, 51 ₃ penetrates respectively.
The distal end side of the two wall portions 53 and 54, i.e., two cylinder heads fastening bolts 51 _2, 51 ₃ the first exhaust merging section 47a side from the oil return passage 55 _1, 55 as each oil passage ₂ penetrates. Similarly, inside the second collective exhaust port 18b, the second collective exhaust port 18b
To partition between three cylinders 14.
The two wall portions 53 and 54 extend, and these two wall portions 5
3 and 54 are connected to two cylinder head fastening bolts 51 ₅ ,
51 ₆ penetrates respectively. The tip side of the two wall portions 53 and 54, that is, two cylinder head fastening bolts 5
1 _5, 51 and second exhaust collecting section 47b side than _6, respectively the oil return passage 55 ₃ as an oil passage, 55 ₄ passes.

In the first collective exhaust port 18a, the two walls 53 and 54 are directed along the direction of the exhaust gas flowing in the first collective exhaust port 18a, that is, the exhaust outlet 48 located at the center. So that it is curved
Two oil return passages 55 _1, 55 ₂ are offset to the exhaust outlet 48 side with respect to the two cylinder head fastening bolts 51 _2, 51 ₃ adjacent thereto. Oil return passages 55 ₁ and 55 ₂ and cylinder head fastening bolts 51
_2, the 51 ₃ above arrangement, while avoiding an increase in size of the cylinder head 12, it is possible to exhaust gas in the first collecting exhaust port 18a to reduce the exhaust resistance so as to flow smoothly. The second collective exhaust port 18b has the same structure.

Referring to FIG. 6 together, it is apparent that
At the first collective exhaust port 18a, the cylinder head 1
2 is provided with a mounting flange 56 of the exhaust pipe 19.
The three bosses 58 ₁ , 58 ₂ , 58 ₃ into which the three bolts 57 are screwed are formed. Three bolts 5
Since the number of exhaust pipes 19 fastened at 7 is one,
The two boss portions 58 ₁ and 58 ₂ on the lower side as viewed from above are not hidden below the exhaust pipe 19 and the two boss portions 5 1
8 _1, 58 ₂ fastening operation of the bolt 57 relative to can be performed easily. Further, by providing one boss portion 58 ₃ also on the upper side of the exhaust pipe 19, the exhaust pipe 19 can be fixed at three places and the mounting rigidity can be increased while securing the fastening workability of the bolts 57. The second collective exhaust port 18b has the same structure.

A cam drive chain chamber 59 for accommodating a cam drive chain (not shown) is formed at one longitudinal end of the cylinder head 12, and the cylinder head located on the opposite side of the cam drive chain chamber 59 is formed. fifth oil return passage 55 ₅ is formed in the vicinity of the fastening bolt 51 _5. These five oil return passages 55 _{1 to} 55 ₅
The valve chamber 23 provided in the cylinder head 12 is communicated with an oil pan (not shown) through oil return passages 60 provided in the cylinder block 11. On the side of the exhaust side of the cylinder head 12 connected to one end of the first overhang portion 49a,
Tensioner mounting seat 63 facing cam drive chain chamber 59
(See FIG. 2), and a predetermined tension is applied to a cam drive chain (not shown) by a chain tensioner 65 (see FIG. 2) fixed to the tensioner mounting seat 63 with three bolts 64.

As described above, the first and second overhang portions 49a, 4
9b, two oil return passages 55₁,
55_Two; 55_Three, 55_FourOf adjacent cylinders 14 ...
And the first and second exhaust collecting portions 47a, 4
7b, the first and second regions are arranged.
It is possible to perform serial communication without interfering with the collective exhaust ports 18a and 18b.
Oil return passage 55₁, 55
_Two; 55_Three, 55_FourCan be formed.
Oil in the valve operating chamber 23 of the
Can be reliably returned. Moreover, the oil is returned when the temperature is low
Road 55₁, 55 _Two; 55_Three, 55_FourOil passing through
Exhaust passing through the first and second collective exhaust ports 18a, 18b
Because it can be heated with gas,
The temperature of the oil is raised without any
Resistance can be reduced.

[0026] Incidentally, the oil return passage 55 _to 554 ₄ even when used as an oil passage, such as blow-by gas passage and the oil supply passage, it is possible to obtain the same effect.

As is apparent from FIGS. 6 and 7, the six spark plug insertion cylinders 21 arranged at an angle to the exhaust side of the cylinder head 12 and the first and second overhang portions 49a, 49 are provided.
b are connected to each other by reinforcing walls 61 having a triangular cross section. The first and second overhangs 49 are formed by these reinforcing walls 61.
a, 49b, especially the mounting flange 56 of the exhaust pipe 19;
The rigidity of the upper two boss portions 58 ₃ , 58 ₃ for connecting the first and second overhang portions 4 during the operation of the engine E is increased.
The vibrations of 9a, 49b can be effectively suppressed, and the exhaust pipes 19, 19 can be firmly supported.

As shown in FIGS. 1 to 4, the interior of the cylinder head 12 water jacket J ₁ along the cylinder row line L ₂ is formed. Also, the first and second overhangs 49a, 4 of the cylinder head 12 that become hot due to the exhaust gas passing through the first and second collective exhaust ports 18a, 18b.
9b is provided with water jackets J ₂ and J ₃ that cover the upper and lower surfaces of the first and second collective exhaust ports 18a and 18b, respectively. The upper and lower water jackets J ₂ , J ₃ communicate with each other through six water jackets J _{4 in} the vicinity of a portion that does not interfere with the exhaust ports 46, that is, in the vicinity of the six ignition plug insertion cylinders 21.

As described above, the first and second collective exhaust ports 1
Water jackets J ₁ , J ₂ , 8a, 18b
By covering with J ₃ , J ₄ ..., The exhaust side of the cylinder head 12, which tends to become high in temperature, can be efficiently cooled. In particular, weak ignition coil 22 ... and the first thermal, second collecting exhaust port 18a, for intervening water jacket J ₂ is between 18b, can be effectively suppressed heat transfer to the ignition coil 22 ... (See FIG. 7).

As is clear from FIGS. 2, 5 and 6, the first and second overhang portions 49a, 49 formed in an arch shape.
9b, the first and second collective exhaust ports 18a, 18b
A concave portion 71 is formed along the shape of the concave portion 7.
A pair of upper and lower connecting walls 7 arranged on the upper side and the lower side of 1
The first and second overhangs 49a and 49b are connected by 2 and 73. Thus, the first and second overhangs 49a, 49
Since b is connected by the connecting walls 72 and 73, not only the first and second overhanging portions 49a and 49b can reinforce each other to increase rigidity and suppress the generation of vibration, but also reduce the generation of high-temperature exhaust gas. First and second collective exhaust ports 18a, 18b flowing
It is possible to minimize the thermal distortion of the first and second overhangs 49a and 49b in which is formed.

As is clear from FIGS. 1, 2 and 6, the first and second overhangs 49a, 49b are connected to the exhaust outlets 48, 48 of the first and second collective exhaust ports 18a, 18b. The upstream portions of the two exhaust pipes 19 are integrally connected by a common mounting flange 56. That is, the mounting flange 56 has the boss 5
8 ₁ , 58 ₂ , 58 ₃ , _two opposing upper boss portions 58 ₃ , 58 ₃ are connected by a rod-shaped connecting portion 74, and two opposing lower boss portions are provided. 58 ₁ , 58
₂ are connected by a rod-shaped connecting portion 75. Therefore, the mounting flanges 56 of the two exhaust pipes 19 are connected to the cylinder head 12 by a total of six bolts 57.

In particular, the mounting flange 5 of the exhaust pipes 19, 19
6, the two opposing boss portions 58 ₃ , 58 ₃ are connected to the spark plug insertion tubes 21, 21 and the first and second overhang portions 49 a, 49.
b, bolts 57 on reinforcing walls 61 connecting the upper surface of
Since it is fastened at 57, it is possible to greatly increase the support rigidity of the exhaust pipes 19, 19 and reduce vibration.

The two exhaust gas purifying catalysts 41, 41 provided at the lower part of the two exhaust pipes 19, 19, respectively,
The exhaust gas purifying catalyst 41 and the exhaust gas purifying catalyst 41,
41 are integrally coupled by a coupling flange 76 provided at the lower end.

By providing the exhaust gas purifying catalysts 41, 41 directly at the lower ends of the exhaust pipes 19, 19 whose upper ends are fastened to the cylinder head 12, the exhaust gas purifying catalysts 41, 41 from the combustion chambers 16 to the exhaust gas purifying catalysts 41, 41 are provided. The distance can be shortened to prevent the temperature of the exhaust gas from lowering, and the exhaust gas purifying catalysts 41 can be quickly activated by the heat of the exhaust gas to enhance the exhaust gas purifying performance.

Further, since the heavy exhaust gas purifying catalysts 41, 41 are provided in the exhaust pipes 19, 19, the two exhaust pipes 19, 19 easily vibrate together with the exhaust gas purifying catalysts 41, 41. The lower portions of the exhaust pipes 19, 1 are integrally connected by the exhaust gas purifying catalysts 41, 41 and the upper portions thereof are integrally connected by the mounting flange 56.
9. Exhaust gas purification catalysts 41, 41 and mounting flange 5
6 mutually reinforce each other to reduce vibration.
Moreover, since the both end portions mounting flange 56 has a sufficiently long span cylinder row line L ₂ direction are fastened to the first, second collecting exhaust ports 18a, 18b of the exhaust outlet 48, exhaust pipe 19, The support rigidity of 19 increases, and the vibration reduction effect is further enhanced. As a result, reinforcing members such as stays for supporting the exhaust pipes 19 and the exhaust gas purifying catalysts 41 and 41 for reducing the vibration become unnecessary, which contributes to a reduction in the number of parts and a compact engine E. .

8 to 11 show a second embodiment of the present invention. FIG. 8 is a longitudinal sectional view of a multi-cylinder engine, and FIG.
9 is a sectional view taken along the line 9-9, FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9, and FIG.

The second embodiment is an assembly in which the downstream parts of two exhaust pipes 19, 19 connected to the exhaust outlets 48, 48 of the first and second collective exhaust ports 18a, 18b are gathered in a Y-shape. An exhaust pipe 77 is provided, and one exhaust gas purification catalyst 41 is provided at a downstream end of the collective exhaust pipe 77. A common mounting flange 56 provided upstream of the two exhaust pipes 19, 19 is provided with two upper bosses 58 ₃ , 58 opposed to each other.
₃ are connected by a rod-shaped connecting portion 74, and two opposing lower boss portions 58 ₁ and 58 ₂ are connected by a rod-shaped connecting portion 75.

Also in this embodiment, the exhaust gas purifying catalyst 41 is provided directly in the collective exhaust pipe 77, so that the exhaust gas purifying catalyst 41 can be quickly activated and the exhaust gas purifying performance can be improved. Also, the downstream part of the two exhaust pipes 19, 19 is assembled to form a collective exhaust pipe 77, and the upstream part of the collective exhaust pipe 77 is integrally connected by the mounting flange 56, so that the collective exhaust pipe 77 itself is Rigidity, first and second
The support rigidity of the collective exhaust ports 18a, 18b to the exhaust outlets 48, 48 can be increased to effectively reduce vibration.

The first and second collective exhaust ports 18a, 1
A heat shield plate 78 also serving as a gasket is sandwiched and fixed between the exhaust outlets 48 of 8b and the mounting flange 56. The heat shield plate 78 is interposed between the side wall 11 ₁ of half a cylinder block 11 on the collecting exhaust pipe 77 and the exhaust gas purification catalyst 41, the heat of their collecting exhaust pipe 77 and the exhaust gas purifying catalyst 41 by hardly transmitted to the cylinder block 11, the cooling effect by water jacket J _B formed in the cylinder block 11 is prevented. By reducing the number of the exhaust gas purifying catalysts 41 to one using the collective exhaust pipe 77, not only the exhaust gas purifying catalyst 41 can be compactly arranged, but also the size of the heat shield plate 78 can be minimized. It becomes possible to suppress to.

An oxygen concentration sensor 79 for detecting the oxygen concentration in the exhaust gas is attached to the forked portion of the exhaust pipe 77. By arranging the oxygen concentration sensor 79 using the space between the two exhaust pipes 19, 19, the engine E can be prevented from being enlarged.

Although the embodiments of the present invention have been described in detail, various design changes can be made in the present invention without departing from the gist thereof.

For example, in the embodiment, the in-line six-cylinder engine E
However, the present invention can be applied to each bank of other in-line engines and V-type engines having different numbers of cylinders.

The engine E of the embodiment has an overhang 49a,
49b, two exhaust collecting parts 47a, 47b, and two collecting exhaust ports 18a, 18b, respectively, but the number thereof may be three or more, and the entire side wall on the exhaust side of the cylinder head 12 projects. A plurality of collective exhaust ports may be provided inside the overhang.

[0044]

As described above, according to the first aspect of the present invention, the exhaust gas purifying catalyst is provided directly on the exhaust passage member fastened to the exhaust outlet of the collective exhaust port. By shortening the distance to the purification catalyst, the exhaust gas purification catalyst can be activated early. Also, despite the provision of a heavy exhaust gas purifying catalyst in the exhaust passage member, each exhaust passage member is integrally connected, and each exhaust passage member is fastened to the exhaust outlet of an adjacent collective exhaust port. Therefore, it is possible to increase the support rigidity of the exhaust passage member including the exhaust gas purifying catalyst and reduce the vibration. Moreover, since a reinforcing member such as a stay for supporting the exhaust passage member can be eliminated to reduce vibration, the number of parts can be reduced and the engine can be made more compact.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a multi-cylinder engine.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 2;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2;

FIG. 6 is a view in the direction of arrows in FIG. 2;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a longitudinal sectional view of a multi-cylinder engine according to a second embodiment of the present invention.

9 is a sectional view taken along line 9-9 in FIG.

FIG. 10 is a sectional view taken along line 10-10 of FIG. 9;

FIG. 11 is a view taken in the direction of arrow 11 in FIG. 9;

[Explanation of symbols]

12 Cylinder head 12 ₁ Side wall 16 Combustion chamber 18a First collective exhaust port (collective exhaust port) 18b Second collective exhaust port (collective exhaust port) 19 Exhaust pipe (exhaust passage member) 41 Exhaust gas purification catalyst 46 Exhaust port 47a First exhaust collector (exhaust collecting portion) 47b second exhaust collector (exhaust collector) first extended portion 48 exhaust outlet 49a (projecting portion) 49b first overhanging portion (protruding portion) L ₂ cylinder row line

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masakatsu Honda 1-4-1, Chuo, Wako, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Inventor Shinji Yamada 1-4-1, Chuo, Wako, Saitama F-term in Honda R & D Co., Ltd. (reference) 3G024 AA11 BA23 DA01 DA06 DA09 DA18 DA19 FA02 FA14 GA04 3G091 AA23 AA28 AA29 AB01 BA00 EA00 HA01 HA25 HB02

Claims (1)

[Claims] 1. A side wall (1) of a cylinder head (12).
Inside the 2 ₁₎ to form the extended portion (49a, 49b),
Exhaust ports (46) extending from a plurality of combustion chambers (16) arranged along the cylinder line (L ₂ ) are collectively assembled at an exhaust collecting portion (47a, 47b) at least two collective exhaust ports ( 18a, 18b), the exhaust outlet (48) of the collective exhaust port (18a, 18b).
And one end of at least two exhaust passage members (19) are fastened to each other, an exhaust gas purifying catalyst (41) is provided at the other end of each exhaust passage member (19), and each of the exhaust passage members is A multi-cylinder engine wherein (19) is integrally connected.