KR100325032B1 - Cylinder head structure in multi-cylinder engine - Google Patents

Abstract

The collective exhaust port 18 provided in the cylinder head 12 is constituted by an exhaust port 46 extending from the exhaust valve hole 35 of each cylinder 14, and an exhaust assembly part 47 which aggregates these exhaust ports 46 and the like. It is. The cylinder head 12 has a protrusion 49 projecting in an arch shape outward from the side wall 11 ₁ of the cylinder block 11, and the exhaust collecting portion 47 of the collective exhaust mechanism 18 is a protrusion ( It directly faces the inner surface of the side wall 12 ₁ of 49). Water jackets J ₂ and J ₃ for cooling the protrusions 49 are provided on the upper and lower surfaces of the protrusion 49 on which the collective exhaust pipe 18 is formed, and the side walls 12 ₁ of the protrusion 49 are provided. And the exhaust collection section 47 are not provided. As a result, the compact cylinder head 12 having the collective exhaust pipe 18 integrally formed can be molded while avoiding the complexity of the core structure.

Description

CYLINDER HEAD STRUCTURE IN MULTI-CYLINDER ENGINE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder head structure of a multi-cylinder engine having an aggregate exhaust mechanism formed by collectively gathering exhaust ports extending from several combustion chambers arranged in a cylinder matrix in an exhaust collection section formed inside a cylinder head.

In general, the exhaust port formed in the cylinder head of the multi-cylinder engine only collects the exhaust gas discharged from several exhaust valve holes of the same cylinder in the cylinder head, and the exhaust gas discharged from each cylinder is coupled to the cylinder head. This is done in a separate exhaust manifold.

On the other hand, Japanese Patent Laid-Open No. 2709815 discloses that the collection of exhaust gas discharged from each cylinder is performed inside the cylinder head without using a separate exhaust manifold. In order to ensure durability even when using a material having insufficient heat resistance, the cylinder head is surrounded by a water jacket to improve cooling efficiency by surrounding the entire circumference of the collectively provided exhaust pipe integrated in the cylinder head. have.

However, in the above-mentioned patent publication No. 2709815, since the whole side part of the cylinder head provided with an exhaust collection part protrudes largely to the side at the compound surface with the cylinder block, there existed a problem that a cylinder head became large. Since the entire circumference of the collective exhaust pipe which is integrated integrally inside the cylinder head is surrounded by a water jacket, the cylinder head becomes large and the compactness of the whole engine is prevented and the vibration increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and an object thereof is to make the cylinder head which is provided with an integrated exhaust pipe as compact as possible.

In order to achieve the above object, according to a feature of the present invention, an exhaust port extending from several combustion chambers arranged in a column of a cylinder matrix is provided in a collectively provided exhaust gas collection unit which is integrated in an exhaust collection unit formed inside the cylinder head. As a cylinder head structure of a cylinder engine, a side of the cylinder head has a protrusion extending outward from a side of the cylinder block to which the cylinder head is coupled, and this protrusion is a cylinder of a multi cylinder engine that protrudes outward from the exhaust assembly portion. A head structure is proposed.

According to the above configuration, since the protrusion extending outward from the side of the cylinder head extends outwardly from the exhaust assembly portion, the water jacket is provided on the outside of the exhaust assembly portion. It can contribute to compactness, and the weight of the protrusion is reduced thereon, so that the vibration reduction of the cylinder head functions.

These and other objects, features and advantages of the present invention will become apparent from the following description of the most suitable embodiment which will be described later in detail with reference to the accompanying drawings.

1 is a longitudinal sectional view of a head portion of an engine;

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

3 is a cross-sectional view taken along line 3-3 of FIG.

4 is a cross-sectional view taken along the line 4-4 of FIG. 2.

Figure 5 is a five-way arrow of Figure 2;

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

7 is a view corresponding to FIG. 2;

8 is a sectional view taken along line 8-8 of FIG.

9 is a sectional view of a mold for forming a sand core;

Fig. 10 is a view corresponding to Fig. 2 according to the third embodiment of the present invention.

FIG. 11 is a view corresponding to FIG. 2 according to the fourth embodiment of the present invention; FIG.

FIG. 12 is a view corresponding to FIG. 2 according to a fifth embodiment of the present invention; FIG.

13 is a view corresponding to FIG. 2;

FIG. 14 is a four-way arrow in FIG. 13; FIG.

FIG. 15 is a view corresponding to FIG. 2 according to the seventh embodiment of the present invention; FIG.

16 is a longitudinal sectional view of the engine.

FIG. 17 is a 17-way arrow diagram of FIG. 16; FIG.

18 is a sectional view taken along line 18-18 of FIG. 17;

19 is a view corresponding to FIG. 2;

20 is an arrow diagram of 20 direction in FIG. 19.

21 is a sectional view taken along the line 21-21 in FIG. 20;

22 is a view corresponding to FIG. 2;

FIG. 23 is a 23-way arrow of FIG. 22;

Hereinafter, a first embodiment of the present invention will be described with reference to Figs.

As shown in FIG. 1, the in-line three-cylinder engine E has a cylinder head 12 coupled to an upper surface of a cylinder block 11, and a head cover 13 is coupled to an upper surface of the cylinder head 12. It is. The piston 15... Is fitted to the inside of the three cylinders 14... Formed in the cylinder block 11 so as to slide freely, and the lower surface of the cylinder head 12 facing the upper surface of the piston 15. The combustion chamber 16... Is formed. While the inlet port 17..., Leading to the combustion chamber 16 .., opens on the side face of the intake side of the cylinder head 12, the collective exhaust mechanism 18 leading to the combustion chamber 16 is located on the exhaust side of the cylinder head 12. It is open in the side surface, and the exhaust pipe 19 is couple | bonded with this opening. The cylinder head 12 is integrally formed with the spark plug insertion cylinder 21... For attaching and detaching the spark plug 20. The spark plug insertion cylinder 21... Has an upper end inclined with respect to the cylinder axis L ₁ on the side of the collective exhaust pipe 18, and an ignition plug 20 facing the combustion chamber 16 is mounted at the bottom thereof. An ignition coil 22 is mounted on the top.

The valve chamber 23 formed on the cylinder head 12 and covered by the head cover 13 has a cam shaft 26 and an intake rocker arm having an intake cam 24... And an exhaust cam 25. A rocker arm shaft 29 and the like that support the rocker arm 27... and the exhaust rocker arm 28.

The valve stems 32 and 32 of the intake valves 31 and 31 which open and close the two intake valve holes 30 and 30 facing each combustion chamber 16 protrude in the valve chamber 23. The intake valves 31 and 31 are pressurized in the injection closing direction by the valve springs 33 and 33 attached to the protrusions. One end of each of the intake cam arms 27 is provided with a roller 34 which abuts on the intake cam 24, and the other end abuts on the upper ends of the valve stems 32 and 32 of the intake valves 31 and 31. Moreover, the valve seats 37 and 37 of the exhaust valves 36 and 36 which open and close the two exhaust valve holes 35 and 35 facing each combustion chamber 16 protrude in the valve chamber 23, and The exhaust valves 36 and 36 are pressurized in the injection closing direction by the valve springs 38 and 38 mounted to the protrusions. One end of each exhaust rocker arm 28 is provided with a roller 39 which abuts on the exhaust cam 25, and the other end abuts on the upper ends of the valve seats 37 and 37 of the exhaust valves 36 and 36.

Each inlet 17 is provided with an injector 40 for injecting fuel toward the intake valve holes 30 and 30.

As shown in Fig. 2 and Fig. 3, the three intake openings 17, which extend from the three combustion chambers 16, are formed in the Y-shape, respectively, and these three intake openings 17 ... are assembled together. Independently, it opens to the side of the intake side of the cylinder head 12. On the other hand, the collective exhaust mechanism 18 includes a total of six exhaust ports 46..., Extending from three combustion chambers 16..., And an arch-shaped exhaust collection section 47 where the six exhaust ports 46. And an exhaust outlet 48 to which an exhaust pipe 19 is coupled to a central portion of the exhaust collection portion 47.

The exhaust side wall 12 ₁ on the exhaust side of the cylinder head 12 facing the exhaust assembly portion 47 is curved in an arch shape and protrudes outward, and is separated from the side wall 11 ₁ of the cylinder block 11. The protruding portion 49 protrudes by (d). Accordingly, the exhaust collecting portion 47 of the collecting exhaust mechanism 18 formed inside the protrusion 49 directly faces the side wall 12 ₁ of the protrusion 49 curved in an arch shape without interposing a water jacket. have. Above the exhaust collection part 47, a water jacket extending outward from the side wall for partitioning the movable valve chamber is provided.

In this way, since the exhaust collection portion 47 of the collective exhaust port 18 formed inside the projection 49 faces directly without interposing the water jacket on the side wall 12 ₁ of the projection 49, the exhaust collection portion ( The cylinder head 12 can be made compact compared to the case where the water jacket is interposed between the 47 and the side wall 12 ₁ . Since the side wall 12 ₁ is formed in an arch shape, the width of both end portions of the cylinder head 12 in the longitudinal direction is reduced, thereby enabling further compactness and contributing to the increase in rigidity of the cylinder head 12. Can be.

As apparent from Figs. 2 and 4, the four cylinder holes 50 are formed on the intake side and the exhaust side of the cylinder head 12, respectively, and these eight holes are inserted from the top. As the eight cylinder head fastening bolts 51 ₁ to 51 ₈ are screwed into the bolt holes 52... Formed in the cylinder block 11, the cylinder head 12 is fastened to the cylinder block 11. It is.

Inside the collective exhaust mechanism 18, two wall portions 53 and 54 extend to divide between the central cylinder 14 and the cylinders 14 and 14 on both sides, and these two wall portions 53 and 54 are extended. Two cylinder head fastening bolts 51 ₂ and 51 ₃ pass through each. The oil return passages 55 ₁ and 55 ₂ respectively penetrate the distal end side of the two wall portions 53 and 54, that is, the exhaust collection portion 47 side than the two cylinder head fastening bolts 51 ₂ and 51 ₃ . .

The two wall parts 53 and 54 are curved so as to follow in the direction of exhaust gas flowing in the collective exhaust pipe 18, that is, to direct the exhaust outlet 48 located at the center, and thus the two oil return passages 55 _1. And 55 ₂ are arranged on the exhaust outlet 48 side with respect to the two cylinder head fastening bolts 51 ₂ and 51 ₃ adjacent thereto. According to the arrangement of the oil return passages 55 ₁ and 55 ₂ and the cylinder head fastening bolts 51 ₂ and 51 ₃ , exhaust gas is introduced into the collective exhaust pipe 18 while avoiding the enlargement of the cylinder head 12. The exhaust resistance can be reduced by flowing smoothly.

Further, three bosses 58 ₁ , 58 ₂ , 58 ₃ , which twist three bolts 57... Which engage the attachment flange 56 of the exhaust pipe 19 to the exhaust outlet 48 of the cylinder head 12. ), But for the two boss portions 58 ₁ , 58 ₂ spaced apart in the cylinder line L ₂ direction, the two oil return passages 55 ₁ , 55 ₂ are directed in the cylinder line L ₂ direction. Each is shorted by the distance α. Accordingly, the wall portion 53 and the boss portion (58 ₁₎ the sikimyeo to each other, and the wall 54 and the boss portion (58 ₂₎ by approaching to each other the stiffness of the vicinity of the exhaust outlet 48 of the cylinder head 12 It is possible to prevent the increase in the exhaust resistance by avoiding the decrease in the flow path cross-sectional area of the exhaust assembly section 47 while increasing the.

Since the number of the exhaust pipes 19 is one thereon, the two bosses 58 ₁ and 58 _{2 on the} lower side as seen from above are not obscured from below the exhaust pipe 19, and the two boss parts are not visible. The fastening operation of the bolts 57 and 57 to (58 ₁ , 58 ₂ ) can be facilitated. Further, bolts (57 ...), the exhaust pipe 19 can be enhanced attachment rigidity is fixed at three points while ensuring the tightening of the as installing one boss portion (58 ₃₎ to the upper side of the exhaust pipe (19) .

In addition, at one end in the longitudinal direction of the cylinder head 12, a chamber 59, which is a cam driving body for storing a cam driving chain (not illustrated), is formed. the third of the oil return passageway (55 ₃₎ in the vicinity of the bolt (51 ₄₎ for fastening is formed. These three oil return passages 55 ₁ , 55 ₂ , 55 ₃ are provided via the oil return passages 60... Where the valve chambers 23 provided on the cylinder head 12 are provided on the cylinder block 11. Communicate with an oilpan (not shown).

In this way, the two oil return passages 55 ₁ , 55 ₂ are arranged in the area surrounded by the exhaust port 46... And the exhaust collection section 47 of the adjacent cylinder 14. The oil return passages 55 ₁ and 55 ₂ can be formed on the exhaust side of the cylinder head 12 without interference, so that the oil in the valve chamber 23 of the cylinder head 12 is reliably returned to the oil pan. can do. At low temperatures, the oil passing through the oil return passages 55 ₁ and 55 ₂ can be heated by the exhaust gas passing through the collective exhaust duct 18. Thus, the oil is heated by lubricating each oil without installing a special oil heater. Negative frictional resistance can be reduced.

As is apparent from FIGS. 5 and 6, the three spark plug insertion cylinders 21..., The upper surfaces of the projections 49, etc., which are disposed inclined on the exhaust side of the cylinder head 12, have a triangular cross-section, and the reinforcement wall 61. ... are each connected. The rigidity of the protrusion 49 increases in these reinforcing walls 61... And the vibration of the protrusion 49 during the operation of the engine E can be effectively suppressed.

As shown in FIGS. 1 to 4, the water jacket J ₁ is formed inside the cylinder head 12 so as to follow the cylinder line L ₂ . In addition, water jackets J ₂ and J ₃ respectively covering the upper and lower surfaces of the collective exhaust port 18 are provided on the protrusion 49 of the cylinder head 12 that becomes hot due to the exhaust gas passing through the collective exhaust port 18. do. The upper and lower jackets J ₂ and J ₃ communicate with each other by three water jackets J ₄ ..., In the vicinity of the parts that do not interfere with the exhaust port 46... do.

In this way, by covering the periphery of the collective exhaust pipe 18 with the water jackets J ₁ , J ₂ , J ₃ , J ₄ ..., The exhaust side of the cylinder head 12 that tends to become high temperature can be efficiently cooled. have. In particular, the water jacket J ₂ is interposed between the ignition coil 22... As an auxiliary machine that is weak to heat, and the collective exhaust mechanism 18 can effectively suppress heat transfer to the ignition coil 22. .

As apparent from Figs. 3 and 6, the outer portion of the collecting exhaust 18 faces directly to the side wall 12 ₁ of the protrusion 49 without interposing the water jacket, so that the casting of the cylinder head 12 is performed. The structure of the core for forming the water jackets J ₂ , J ₃ , J ₄ ... And the collective exhaust mechanism 18 can be simplified.

This is because, first, the core for molding the water jackets J ₂ , J ₃ , J ₄ ... Is inserted into the mold in the direction of arrow A as well, and then the core for forming the collective exhaust port 18 is similarly arrowed in the mold ( The opening 62 is inserted between the upper and lower water jackets (J ₂ , J ₃ ) in this case, but the core for forming the collective exhaust mechanism 18 is inserted through the opening 62. The upper and lower water jackets J ₂ and J ₃ are connected to each other by three water jackets J ₃ , while the cores corresponding to the three water jackets J ₄ . By alternately engaging portions corresponding to the six exhaust ports 46... Of the core for forming 18), interference of the cores on both sides is avoided (see FIG. 2).

In this way, since the core for molding the water jackets J ₂ , J ₃ , J ₄ ..., Or the core for forming the collective exhaust pipe 18 can be assembled into the mold without dividing, the cylinder head 12 is cast. We can reduce cost in ship.

Next, a second embodiment of the present invention will be described with reference to Figs.

As is apparent from Figure 7, bolts for fastening the cylinder head 4 disposed on the intake side (51 _{5-51 8)} is a cylinder line intersecting the cylinder axis (L ₁₎ of the three cylinders (14 ...) (L ₂₎ from and is disposed on a straight line in the distance (D _1). On the other hand, bolt for fastening the cylinder head 4 disposed on the exhaust side (51 _{5-51 8)} is the distance from the cylinder line (L ₂₎ of the bolt (51 ₁ ~51 ₄₎ for fastening the two ends of the cylinder head D ₁ However, the distance from the cylinder line L ₂ of the two inner cylinder head fastening bolts 51 ₂ and 51 ₃ is D ₂ larger than the above D ₁ . That is, among the four cylinder head fastening bolts 51 ₂ , 51 ₃ , 51 ₆ , 51 ₇ arranged on the outer periphery of the central cylinder 14 closest to the exhaust collection part 47 of the collective exhaust pipe 18, Two cylinder head fastening bolts 51 ₂ , 51 ₃ on the exhaust side, while the distance between the two cylinder head fastening bolts 51 ₆ , 51 ₇ on the intake side and the cylinder line L ₂ is D _1. ) and has a distance greater than that set in the D ₂ D ₁ and the cylinder line (L _2).

Inside the collective exhaust mechanism 18, two wall portions 53 and 54 extend so as to divide between the center cylinder 14 and the cylinders 14 and 14 on both sides, and these two wall portions 53 and 54 are formed. Two cylinder head fastening bolts 51 ₂ and 51 ₃ pass through each. The oil return passages 55 ₁ and 55 ₂ respectively penetrate the base end side of the two wall portions 53 and 54, that is, the cylinder line L ₂ side than the two cylinder head fastening bolts 51 ₂ and 51 ₃ . have. The two wall sections 53 and 54 are curved to follow in the direction of the exhaust gas flowing in the collective exhaust pipe 18, that is, to direct the exhaust outlet 48 located in the center, and thus, the two cylinder head fastening bolts. (51 ₂ , 51 ₃ ) arranges the two oil return passages (55 ₁ , 55 ₂ ) adjacent to the exhaust outlet (48) side.

The protrusion 49 formed to protrude laterally from the cylinder head 12 has a lack of rigidity, which makes vibration easy to occur during operation of the engine E. However, the two cylinder heads close to the exhaust assembly 47 having the largest protrusion amount are fastened. As the bolts 51 ₂ and 51 ₃ are arranged by the side of the exhaust assembly portion 47, the protrusions 49 are firmly fastened to the cylinder block 11 to increase rigidity and effectively suppress the generation of vibration. can do. Moreover, since the vibration of the protrusion 49 is suppressed, the sealing property of the engagement surface of the cylinder head 12 and the cylinder block 11 can be ensured.

By the arrangement of the oil return passages 55 ₁ and 55 ₂ and the cylinder head fastening bolts 51 ₂ and 51 ₃ , the exhaust gas flows into the collective exhaust pipe 18 while avoiding the enlargement of the cylinder head 12. Can be smoothly flowed to reduce the exhaust resistance.

As shown in FIGS. 7 and 8, the water jacket J ₁ formed at the center of the cylinder head 12 has a heat dissipation wall 12 ₃ extending in a straight line following the cylinder line L ₂ therein. Equipped. This water jacket J ₁ is formed by the sand core C shown in FIG. 9 at the time of casting of the cylinder head 12, and the sand core C is formed in the T mold D _L and the upper mold. It is formed by the molding die provided with (D _U ). In addition, the heat dissipation wall 12 ₃ is also formed by the sand core C, so that the heat dissipation wall 12 ₃ is easy to separate the molds D _L and D _U after formation of the sand core C is completed. It is formed so that flesh thickness may become small as it goes to upper direction.

Thus, the heat dissipation wall 12 ₃ which is provided in the cylinder head 12 and extends upward from the lower surface of the water jacket J ₁ extending in the arrangement direction of each combustion chamber 16... Above the combustion chamber 16. By installing the cylinder head 12 continuously in the array direction of 16..., The heat transfer area to the cooling water around the combustion chamber 16... Is increased by the heat dissipation wall 12 ₃ . While the heat dissipation to the cooling water can be sufficiently improved in the surroundings, and the heat dissipation wall 12 ₃ is continuous in the arrangement direction of the combustion chamber 16..., The overall rigidity of the cylinder head 12 can be improved. .

In addition, since the water jacket J ₁ is formed by the sand core C at the time of casting the cylinder head 12, the heat dissipation wall 12 ₃ is formed so that the flesh thickness becomes small as it goes upward. Since the mold of the sand core C is easily formed, and the heat dissipation wall 12 ₃ is cast integrally with the cylinder head 12, the effect of improving the rigidity of the cylinder head 12 by the heat dissipation wall 12 ₃ is also achieved. More remarkable.

On top of that, in the second embodiment, the export outlet 12 ₄ of the water jacket J ₁ is arranged on the intake side with respect to the heat dissipation wall 12 ₃ , but the export outlet 12 ₄ is radiated. extended as much as possible the water outlet (12 ₄₎ and equalizing the distribution to the cooling water outlet radiating wall (12, _3), the side (12 ₄₎ from both sides of the wall (12, _3), the heat-radiating wall (12, ₃₎ arranged on the extension of can do. Therefore, the rigidity of the cylinder head 12 can be further improved, and the heat dissipation can be improved by equalizing the circulation of cooling water on both sides of the heat dissipation wall 12 ₃ .

Next, a third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, four cylinder head fastening bolts 51 ₁ to 51 ₄ disposed on the exhaust side of the cylinder head 12 and four cylinder head fastening bolts arranged on the intake side of the cylinder head 12 (51 ₅ to _{5 8} ) and the like are all arranged at the position of the distance D ₁ in the cylinder line L ₂ . In addition, the two wall portions 53 and 54 which divide between the central cylinder 14 and the cylinders 14 and 14 on both sides are disposed outside the oil return passages 55 ₁ and 55 ₂ formed therein (cylinder lines). are arranged ₍₂ L) newly set two exhaust portion for fastening bolts (51 _9, 51 ₁₀ positioned at the distal)). Two bolt fastening portions of the exhaust set in the exhaust collection portion 47 side more in this embodiment (51 _9, 51 _10), the two cylinder head fastening bolts (51 ₂ for the combustion chamber 16 side, 51 ₃ Since the diameter is smaller than), it can contribute to the avoidance of enlargement of the cylinder head 12 and reduction of exhaust resistance.

In this way, two exhaust assembly fastening bolts 51 ₉ and 51 ₁₀ are added to the exhaust side of the cylinder head 12, and the exhaust assembly 47 is coupled to the cylinder block 11. By increasing the stiffness of 49, it is possible not only to effectively suppress the occurrence of vibration, but also to ensure the sealing property of the coupling surface of the cylinder head 12 and the cylinder block 11. The two oil return passages 55 ₁ , 55 ₂ are sandwiched by two bolts 51 ₂ , 51 ₉ , 51 ₃ , 51 _10, respectively, so that the oil return passages 55 ₁ , 55 ₂ It also improves sealability.

The two wall parts 53 and 54 are curved toward the central exhaust outlet 48 so as to follow in the direction of the exhaust gas flowing in the collective exhaust port 18, and the cylinder line L _{2 is} connected to the wall parts 53 and 54. As shown in FIG. ) Or two cylinder head fastening bolts (51 ₂ , 51 ₃ ), two oil return passages (55 ₁ , 55 ₂ ) and two exhaust assembly parts from the near to the central cylinder axis (L ₁ ) Since the bolts 51 ₉ and 51 ₁₀ are disposed, it is possible to reduce the exhaust resistance by allowing the exhaust gas to flow smoothly in the collective exhaust mechanism 18 while avoiding the enlargement of the cylinder head 12.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

In the fourth embodiment, four cylinder head fastening bolts 51 ₁ to 51 ₄ disposed on the exhaust side of the cylinder head 12 and four cylinder head fastening bolts arranged on the intake side of the cylinder head 12 (51 ₁ to _{5 4 4} ) and the four cylinder head fastening bolts _{5 1} to _{5 8} arranged on the intake side of the cylinder head 12 all have a distance D ₁ from the cylinder line L ₂ . It is arranged at the position of. On both sides of the exhaust outlet 48 of the projection 49 of the cylinder head 12, the projection 49 and the projections protruded from the side wall 11 ₁ of the cylinder block 11 have two small diameter exhausts. It is coupled to the collective fastening bolts 51 ₉ and 51 ₁₀ . In this way, the outermost position of the protrusion 49 of the cylinder head 12 is coupled to the protrusion of the cylinder block 11 by two exhaust assembly fastening bolts 51 ₉ and 51 ₁₀ . The rigidity of the protrusion 49 of 12) can be effectively raised to prevent the occurrence of vibration. The two exhaust assembly fastening bolts 51 ₉ and 51 ₁₀ on the exhaust assembly 47 side are smaller in diameter than the two cylinder head fastening bolts 51 ₂ and 51 ₃ on the combustion chamber 16 side. The enlargement of the cylinder head 12 can be prevented.

Next, a fifth embodiment of the present invention will be described with reference to FIG.

As is apparent from FIG. 12, the exhaust pipe 19 coupled to the exhaust outlet 48 of the collective exhaust port 18 formed in the protrusion 49 of the cylinder head 12 is bent downward by 90 °, and there is a substantially cylindrical shape. The exhaust gas purification catalyst 41 of the phase is provided. A part of the exhaust gas purification catalyst 41 arranged in the up-down direction as coming to the side of the cylinder block 11 enters below the protrusion 49 of the cylinder head 12. In other words, when viewed in the cylinder axis L ₁ direction, a part of the exhaust gas purifying catalyst 41 overlaps the lower portion of the protrusion 49 of the cylinder head 12.

In this way, at least a part of the exhaust gas purifying catalyst 41 is formed by the lower surface of the protrusion 49 of the cylinder head 12, the side surface of the cylinder block 11, and the upper surface of the crankcase bulge 11 ₂ . Since it is accommodated in the recessed part 43 used, the whole engine E containing the exhaust gas purification catalyst 41 can be compactized. Since the exhaust gas purification catalyst 41 is disposed at a position very close to the exhaust outlet 48 of the collective exhaust port 18, a high temperature exhaust gas is supplied to the exhaust gas purification catalyst 41 to quickly warm up and activate its activation. I can promote it.

Subsequently, a sixth embodiment of the present invention will be described with reference to Figs. 13 and 14.

In the sixth embodiment, the first exhaust secondary air passage 66 and the second exhaust secondary air passage 67 are formed in the cylinder head 12. In the arch-shaped side wall 12 ₁ of the protrusion 49 of the cylinder head 12, two ribs 68 and 69 are formed to extend in the longitudinal direction of the cylinder head 12 with the exhaust outlet 48 therebetween. The first exhaust secondary air passage 66 is formed inside the rib 69 on the other hand. Since the first exhaust secondary air passage 66 is formed next to the side wall 12 ₁ of the arch-shaped protrusion 49, the enlargement of the cylinder head 12 and the increase in vibration can be suppressed.

The outlet 66 ₁ (air inlet for introducing exhaust secondary air into the exhaust system) of the first exhaust secondary air passage 66 was opened near the exhaust outlet 48 of the exhaust assembly 47. In addition, the other end is opened in the end surface of the cylinder head 12 and is closed by the lid 70. The second exhaust secondary air passage 67, which is formed in the cross section of the cylinder head 12, has one end opened near the other end of the first exhaust secondary air passage 66, and the other end is the cylinder head 12. It opens in the side wall 12 ₂ of the intake side of the. The exhaust secondary air built in the air purifier 72 by the air pump 71 passes through the control valve 73 to the second exhaust secondary reservoir opening to the side wall 12 ₂ of the intake side of the cylinder head 12. It is supplied to the furnace 67. The air pump 71 and the control valve 73 are connected to and controlled by the electronic control unit U. Thus, the operation of the air pump 71 and the control valve 73 is controlled by the command from the electronic controller U at the time of inactivation of the exhaust gas purifying catalyst immediately after the engine E is started, so that the second exhaust 2 The exhaust secondary air supplied to the primary air passage 67 is supplied to the exhaust collection section 47 of the collective exhaust port 18 via the first exhaust secondary air passage 66. In addition, harmful components such as HC and CO in the exhaust gas can be reburned to be harmless, and an exhaust gas purification catalyst can be activated early to obtain a sufficient exhaust gas purification effect thereon.

Thus, in order to gather several exhaust ports 46, the outlet 66 ₁ of the 1st exhaust secondary air path 66 was opened to the exhaust collection part 47 which is hard to be influenced by the inertia and pulsation of exhaust gas. Therefore, it is possible to stably supply the exhaust secondary air without removing the influence of the inertia and pulsation of the exhaust gas without complicating the structure of the passage for supplying the exhaust secondary air. In addition, since the first and second exhaust secondary air passages 66 and 67 are integrally formed in the cylinder head 12, a space is compared with the case where an exhaust secondary air passage is provided as a separate member outside the cylinder head 12. And part scores can be reduced. In addition, since the two ribs 68 and 69 are squeezed out from the side wall 12 ₁ of the protrusion 49, the ribs 68 and 69 can increase the rigidity of the protrusion 49 to reduce vibration. In particular, since the two ribs 68 and 69 connect the bosses 58 ₁ and 58 ₂ for attaching the exhaust pipe 19 to the ends of the cylinder head 12, the rigidity of the exhaust pipe 19 is increased. Also contributes to the improvement. In particular, the other rib 69 is connected to the tensioner attachment sheet 63 supporting the chain tensioner 65, thereby providing both the attachment rigidity of the exhaust pipe 19 and the attachment rigidity of the chain tensioner 65. It is raising effectively.

In addition, in the sixth embodiment, the EGR passage is formed by using the protrusion 49 of the cylinder head 12. The EGR gas supply system includes a first EGR gas passage 66 ′ and a second EGR gas passage 67 ′, and the first EGR gas passage 66 ′ is provided at the protrusion 49 of the cylinder head 12. It is formed inside the rib 68 on the other side. The inlet 66 ₁ ′ of _one end of the first EGR gas passage 66 ′ is opened near the exhaust outlet 48 of the exhaust assembly 47, and the other end is opened to the end face of the cylinder head 12. It is closed with a cover 70 '. One end of the second EGR gas passage 67 ', which is formed along the cross section of the cylinder head 12, is opened near the other end of the first EGR gas passage 66', and the other end is intake of the cylinder head 12. It opens in the side wall 12 ₁ of the side. The second EGR gas passage 67 ', which is opened on the side wall 12 ₂ of the intake side of the cylinder head 12, is connected to three intake ports 17 through the EGR valve 74 which controls the flow rate of the EGR gas. Each is connected.

Thus, the exhaust gas discharged from the collective exhaust port 18 is refluxed to the intake machine via the first and second EGR gas passages 66 'and 67' and the EGR valve 74, thereby causing combustion. The generation of NOx can be suppressed to reduce the NOx in the exhaust gas.

In this way, the inlet 66 ₁ ′ of the first EGR gas passage 66 ′ is opened in the exhaust collection section 47 where the inertia and pulsation of the exhaust gas are difficult to be affected because a plurality of exhaust ports 46 are collected. Therefore, it is possible to stably supply the EGR gas by removing the influence of the inertia and pulsation of the exhaust gas. In addition, since the first and second EGR gas passages 66 'and 67' are integrally formed in the cylinder head 12, the space and parts thereof are compared to the case where the EGR gas passage is installed as a separate member outside the cylinder head 12. You can reduce your score.

Next, a seventh embodiment of the present invention will be described with reference to FIG.

In the seventh embodiment, an oxygen concentration sensor 82 for detecting the oxygen concentration in the exhaust gas is attached near the exhaust outlet 48 formed at the outer end of the protrusion 49 of the cylinder head 12. Detecting the oxygen concentration sensor 82 is installed at a front end of the body portion (82 ₁₎ and a body portion (82 ₁₎ fixed to the vicinity of the exhaust outlet 48 of the protrusion 49, treat the exhaust collection portion 47 (82 ₂₎ and that extends from the rear end of the body portion (82 ₁₎ and offers the Agnes (harness) (82 ₃₎ or the like, the main body portion (82 ₁₎ is opposite to the side wall (12 ₁₎ of the projection (49) It is arranged in parallel with the cylinder line (L ₂ ) so as to.

In this way, the detection unit 82 ₂ of the oxygen concentration sensor 82 is removed from the exhaust collection unit 47 where the exhaust gases from the three combustion chambers 16... (E) The oxygen concentration in the entire exhaust gas can be detected, and the number of oxygen concentration sensors 82 can be suppressed to a minimum. As the oxygen concentration sensor 82 is installed on the exhaust assembly portion 47 of the cylinder head 12 thereon, the oxygen concentration sensor 82 is used by using the heat of the high-temperature exhaust gas immediately after exiting the combustion chamber 16. ) Can be activated by raising the temperature early.

In addition, since the protrusion 49 is formed in an arch shape, an invalid space is formed at both ends of the protrusion 49 in the cylinder line L ₂ direction, but the oxygen concentration sensor 82 is formed in the arch-shaped protrusion 49. And the main body portion 82 ₁ is opposed to the side wall 12 ₁ of the protrusion 49 so as to effectively use the one of the void spaces, and the oxygen concentration sensor 82 It is possible to arrange the compactly. On top of the body portion (82 ₁₎ of the oxygen concentration sensor 82 from the projections 49 of the lower Agnes (82 ₃₎ extending from the side wall (12 ₁₎ becomes gradually going from the body portion (82 ₁₎ of the projection (49) of sufficiently securing the distance, the lower the Agnes (82 ₃₎ it is possible to reduce the heat affected subject.

In addition, since the oxygen concentration sensor 82 is disposed on the opposite side to the cam drive chain chamber 59 in which other members such as the chain tensioner 65 are installed, the chain tensioner 65 is attached and detached when the oxygen concentration sensor 82 is attached or detached. The workability is improved by preventing interference with other members such as), and the oxygen concentration sensor 82 and the other members can be divided into two sides in the cylinder line L ₂ direction and arranged in a compact manner.

Next, an eighth embodiment of the present invention will be described with reference to FIGS. 16 to 18. FIG.

In the eighth embodiment, two vibration absorbing means (D, D) are provided on the side wall (11 ₁ ) on the exhaust side of the cylinder block (11). The through holes _{1 1 3} formed in the side wall _{1 1} of the cylinder block 11 to attach the respective vibration absorbing means D are opened in a water jacket J ₅ whose inner end is formed in the cylinder block 11. At the same time, the outer end is opened to the outer surface of the side wall 11 ₁ of the cylinder block 11. A housing 92 having a male thread formed on the outer circumferential surface thereof is screwed into the female thread formed on the inner circumferential surface of the through hole 11 ₃ from the outer surface side of the side wall _{1 1} , thereby sealing the sealing member 93 between the cylinder block 11. Insert and fix. The elastic membrane 94 is spread out at the front end opening of the housing 92 having a cavity inside, and a space 95 sealed between the elastic membrane 94 and the housing 92 is formed. The elastic film 94 in the state of being mounted in a through hole (11 ₃₎ of the housing (92) is facing the water jacket (J _5).

The elastic membrane 94 is composed of rubber or synthetic resin reinforced with fabric, synthetic fibers or glass fibers, and is fixed by, for example, being attached to an opening of the housing 92. With the vibration absorbing means (D) attached to the through hole (11 ₃ ) of the side wall (11 ₁ ) of the cylinder block (11), the elastic membrane (94) does not protrude into the water jacket (J ₅ ). It is disposed approximately on one side of the wall of the water jacket J ₅ .

By the way, when the piston 15... Moving up and down during the operation of the engine E collides with the inner wall of the cylinder 14 .., the vibration is transmitted from the cylinder 14... To the cooling water in the water jacket J ₅ . , A large pressure change occurs in the coolant, which is an incompressible fluid, and the side wall 11 ₁ of the cylinder block 11 vibrates, so that the piston slap sound that causes noise is radiated to the outside from the cylinder block 11. However, in the engine E of the present embodiment in which the vibration absorbing means (D, D) are provided, the elastic membrane (94) of the vibration absorbing means (D, D) is elastic in accordance with the pressure change of the cooling water in the water jacket (J ₅ ). As deformed, the pressure change of the cooling water is absorbed. As a result, since the excitation force transmitted from the coolant to the side wall _{1 1} of the cylinder block 11 becomes small, the vibration of the side wall _{1 1} is weakened, so that the piston slap sound radiated outwardly from the cylinder block 11. This decreases. Since the outer surface of the elastic membrane 94 facing the space 95 is covered by the housing 92, the noise caused by the vibration of the elastic membrane 94 is not directly radiated to the outside.

As clearly shown in FIG. 17, when the side wall 11 ₁ of the exhaust side of the cylinder block 11 is viewed from the front, the two vibration absorbing means D and D are deviated to the left and right of the exhaust pipe 19. It is located at the position. That is, when the exhaust pipe 19 is projected on the side wall 11 ₁ of the exhaust side of the cylinder block 11, two vibration absorbing means D and D are disposed outside the projection range. By this arrangement, the heat of the exhaust pipe 19, which is at a high temperature, is less likely to be transmitted to the vibration absorbing means D and D, and the durability of the elastic membrane 94, which is weak to heat, can be prevented. By arranging the heat shield plate 96 between the exhaust pipe 19 and the cylinder block 11 thereon, the heat transmitted to the vibration absorbing means (D, D) can be further reduced.

In addition, in order to enhance the noise prevention effect, it is preferable to arrange the vibration absorbing means (D, D) at a position close to the top dead center of the piston (15), that is, at a position close to the cylinder head (12). If the D, D) approaches the cylinder head 12, it is easy to interfere with the exhaust pipe 19. However, according to this embodiment, since the vibration absorbing means (D, D) are arranged outside the projection range of the exhaust pipe (19), the vibration absorbing means (D, D) even when the exhaust pipe (19) approaches the cylinder block (11). ), The engine E can be made compact by making the exhaust pipe 19 sufficiently close to the cylinder block 11.

Next, a ninth embodiment of the present invention will be described with reference to Figs. The engine E of the ninth embodiment is a six-cylinder in-line engine, and the six intake openings 17..., Extending from the six combustion chambers 16. It does not aggregate with each other and opens to the side of the intake side of the cylinder head 12 independently. On the other hand, the first and second integrated exhaust mechanisms 18a and 18b each have an arch type in which six exhaust ports 46..., Which extend from three combustion chambers 16. Exhaust outlets 48 and 48 composed of first and second exhaust collection portions 47a and 47b on the top, and exhaust pipes 19 and 19 coupled to a central portion of the first and second exhaust collection portions 47a and 47b. ) Is formed.

When the six cylinders 14... Are # 1, # 2, # 3, # 4, # 5, and # 6 in order from the cam drive chain chamber 59 side, the first collective exhaust mechanism 18a is a cylinder line ( The exhaust gas from the combustion chambers 16... Of the three # 1, # 2, and # 3 cylinders on one end of L ₂ ) are collected in the first exhaust collection section 47a, and the second collective exhaust mechanism 18b By collecting the exhaust gas from the combustion chambers 16... Of the three # 4, # 5, and # 6 cylinders on the other end side of the cylinder line L ₂ in the second exhaust collection section 47b, the first collective exhaust pipe ( 18a) and the second collective exhaust mechanism 18b have substantially the same structure. By dividing the collective exhaust duct into two parts, the first collective exhaust duct 18a and the second collective exhaust duct 18b, and having the same structure, the core forming the collective exhaust duct can be miniaturized when the cylinder head 12 is constructed. Not only will it be possible. By making one kind of said core, it can contribute to cost reduction.

The ignition sequence of # 1, # 2, # 3, # 4, # 5, # 6 cylinders is # 1 → # 5 → # 3 → # 6 → # 2 → # 4 and corresponds to the first integrated exhaust mechanism 18a. The three # 1, # 2, # 3 cylinders do not have a continuous ignition sequence, and the three # 4, # 5, # 6 cylinders corresponding to the second collective exhaust mechanism 18b do not have a continuous ignition sequence. Therefore, no interruption occurs between the three # 1, # 2, # 3 cylinders corresponding to the first collective exhaust mechanism 18a, and three # 4, # corresponding to the second collective exhaust mechanism 18b. There is no interference between the 5 and # 6 cylinders.

Two parts of the side wall 12 ₁ on the exhaust side of the cylinder head 12 to which the first and second exhaust collection portions 47a and 47b face each other are curved in an arch shape and protrude outwards, respectively. The 1st, 2nd protrusion part 49a, 49b which protruded out from the side wall 11 ₁ of 11 is comprised. Accordingly, the first and second exhaust collection portions 47a and 47b of the first and second collective exhaust pipes 18a and 18b formed inside the first and second protrusions 49a and 49b are curved in an arc shape. First, the side walls 12 ₁ of the second protrusions 49a and 49b are directly faced without interposing a water jacket.

In this manner, the first and second exhaust collection portions 47a and 47b of the first and second collection and discharge mechanisms 18a and 18b formed inside the first and second protrusions 49a and 49b are the first and the second. Since the water jacket directly faces the side walls 12 ₁ of the protrusions 49a and 49b without interposing the water jacket, the water jacket is disposed between the first and second exhaust collection portions 47a and 47b and the side walls 12 ₁ . Compared to the interposition, the cylinder head 12 can be made compact, and molding is easy thereon. Since the side wall 12 ₁ is formed in an arch shape, the width of both end portions of the cylinder head 12 in the longitudinal direction is reduced, thereby enabling further compactness, and also improving the rigidity of the cylinder head 12. Can contribute, and also smooth the flow of exhaust gas. Since the recessed portion 101 (see FIG. 19) is formed between the first and second protrusions 49a and 49b, the engine E can be miniaturized by effectively using the space of the recessed portion 101. Can be.

The cylinder head 12 is provided with seven bolt holes 50... On the intake side and the exhaust side, respectively, and the fourteen cylinder head fastening bolts 51 inserted from above in total of these 14 bolt holes 50. _The cylinder head 12 is fastened to the cylinder block 11 by twisting ₁ to 51 ₁₄ into the bolt holes 52... Formed in the cylinder block 11.

Inside the first collective exhaust mechanism 18a, two wall portions 53 and 54 extend so as to divide between the three cylinders 14... Corresponding to the first collective exhaust mechanism 18a. These two wall portions are extended. Two cylinder head fastening bolts 51 ₂ and 51 ₃ pass through 53 and 54, respectively. The oil return passageway 55 ₁ as the oil passage is provided at the distal end side of the two wall portions 53 and 54, that is, the first exhaust collection portion 47a side than the two cylinder head fastening bolts 51 ₂ and 51 ₃ . 55 ₂ ) penetrates. Similarly, two wall portions 53 and 54 extend in the second collective exhaust mechanism 18b so as to divide between the three cylinders 14... Corresponding to the second collective exhaust mechanism 18b. The two wall heads 53 and 54 penetrate two cylinder head fastening bolts 51 ₅ and 51 ₆ , respectively. The oil return passageway 55 ₃ as the oil passage is provided at the distal end side of the two wall portions 53 and 54, that is, the second exhaust collection portion 47b side than the two cylinder head fastening bolts 51 ₅ and 51 ₆ . 55 ₄ ) penetrates.

In the first collective exhaust mechanism 18a, the two wall portions 53 and 54 follow the direction of the exhaust gas flowing in the first collective exhaust mechanism 18a, that is, to direct the exhaust outlet 48 located at the center. As a result, the two oil return passages 55 ₁ and 55 ₂ are arranged on the exhaust outlet 48 side with respect to the two cylinder head fastening bolts 51 ₂ and 51 ₃ adjacent thereto. By the arrangement of the oil return passages 55 ₁ , 55 ₂ and the cylinder head fastening bolts 51 ₂ , 51 ₃ , the inside of the first collective exhaust mechanism 18a is exhausted while avoiding the enlargement of the cylinder head 12. The exhaust resistance can be reduced by allowing the gas to flow smoothly. On top of that, the second collective exhaust mechanism 18b also has the same structure.

Between the first and second protrusions 49a and 49b formed in the shape of an arch, recesses 101 are formed to follow the first and second collective exhaust mechanisms 18a and 18b. The first and second protrusions 49a and 49b are connected by a pair of upper and lower connecting walls 102 and 103 disposed on the upper side and the lower side. It is supported to the cylinder head 12 on the upper surface of the 15th of the head portion connected to the lower wall of the cylinder head fastening bolt (51 ₅₎ (103) for fastening the cylinder block 11. According to the above configuration, the fastening portions of the cylinder head 12 and the cylinder block 11 by the _15th cylinder head fastening bolt 51 ₁₅ can be made compact, and later on the upper side of the connecting wall 102. The flow path cross-sectional area of the communicating passage 107 to be described can be increased.

In addition, a sixth oil return passage (55 ₆ ) as an oil passage is formed between two cylinder head fastening bolts (51 ₄ , 51 ₁₅ ), and the oil return passage (55 ₆ ) is a cylinder block (11). It communicates with an oil pan via the oil return passage 109 formed in the upper portion. In this way, since the oil return passage 55 ₆ is formed at the position sandwiched between the first and second protrusions 49a and 49b, not only the cylinder head 12 can be enlarged, but also the oil return passage 55 ₆ The formation part functions as a connecting wall of the first and second protrusions 49a and 49b, and the rigidity of the cylinder head 12 can be increased to reduce vibrations of the first and second protrusions 49a and 49b. In addition, by using heat from the first and second collective exhaust pipes 18a and 18b of the first and second protrusions 49a and 49b without installing a special oil heater, the vicinity of the oil return passage 55 ₆ is removed. It is possible to reduce the friction of the oil by heating and lowering the viscosity of the oil.

In this way, since the first and second protrusions 49a and 49b are connected to the connection walls 102 and 103, the first and second protrusions 49a and 49b are reinforced with each other to increase rigidity and to suppress the generation of vibration. In addition, thermal deformation of the first and second protrusions 49a and 49b in which the first and second collective exhaust pipes 18a and 18b through which hot exhaust gas flows can be minimized. Since the cylinder head 12 is fastened to the cylinder block 11 by the cylinder head fastening bolt 51 ₁₅ between the first and second protrusions 49a and 49b, the first and second protrusions 49a are provided. , By increasing the rigidity of 49b), it is possible not only to effectively prevent the occurrence of vibration, but also to improve the sealing property between the cylinder head 12 and the cylinder block 11.

Flow passages 107 and 108 through which cooling water flows are formed in the upper and lower connecting walls 102 and 103, respectively, and the first and second protrusions 49a are formed in the communication path 107 of the upper connecting wall 102. , The water jackets J ₂ and J _{2 on} the upper side of 49b communicate with each other, and the water jackets on the lower side of the first and second protrusions 49a and 49b on the communication path 108 of the lower connection wall 103. (J ₃ , J ₃ ) communicate with each other. In this way, the upper water jackets J ₂ and J ₂ adjacent to the first and second protrusions 49a and 49b are connected to each other in the communication path 107 of the upper connecting wall 102 so as to be adjacent to each other. Since the water jackets J ₃ and J ₃ are connected to each other in the communication path 108 of the lower connecting wall 103, the water jackets J ₂ and J _{2 of} the first and second protrusions 49a and 49b are connected to each other. The cooling effect can be enhanced by smoothing the flow of cooling water in J ₃ and J ₃ ) and preventing the occurrence of sinking parts.

Next, a tenth embodiment of the present invention will be described with reference to FIG. 22 and FIG. The basic structure of the engine E of the tenth embodiment is a series six-cylinder engine as in the ninth embodiment. Upstream portions of the two exhaust pipes 19 and 19 coupled to the exhaust outlets 48 and 48 of the first and second collective exhaust pipes 18a and 18b of the first and second protrusions 49a and 49b have a common attachment flange. It is connected integrally by 56. That is, the attachment flange 56 has boss portions 56, 56 ₂ and 56 ₃ at both ends thereof, and the two boss portions 56 ₃ and 56 _{3 on} the upper sides facing each other are rod-shaped connecting portions. The two bosses 56 ₁ , 56 ₂ which are connected by 114 and which face each other are connected by a rod-shaped connecting part 115. Thus, the attachment flanges 56 of the two exhaust pipes 19 and 19 are coupled to the cylinder head 12 by a total of six bolts 57...

In particular, two bosses 56 ₃ and 56 ₃ of the attachment flanges 56 of the exhaust pipes 19 and 19 face each other with the spark plug insertion cylinders 21 and 21 and the first and second protrusions 49a and 49b. Since the bolts 57 and 57 are fastened to the reinforcing walls 61 and 61 connecting the upper surface of the crankshaft, the support rigidity of the exhaust pipes 19 and 19 can be greatly increased to reduce vibration.

In addition, the two exhaust gas purification catalysts 41 and 41 respectively provided below the two exhaust pipes 19 and 19 are coupled to the exhaust part so as to couple the downstream exhaust pipe (not illustrated) to be integrally coupled to each other. It is integrally coupled by a coupling flange 116 provided on the lower ends of the purification catalysts (41, 41).

Thus, the exhaust gas purification catalysts 41 and 41 are directly installed at the lower ends of the exhaust pipes 19 and 19 in which the upper end is fastened to the cylinder head 12. Thus, the exhaust gas purification catalysts 41 and 41 in the combustion chamber 16. By shortening the distance to), the temperature of the exhaust gas is prevented, and the exhaust gas purification catalysts 41 and 41 can be quickly activated by the heat of the exhaust gas to increase the exhaust gas purification performance.

In addition, since the heavy exhaust gas purification catalysts 41 and 41 are provided in the exhaust pipes 19 and 19, the two exhaust pipes 19 and 19 are liable to vibrate together with the exhaust gas purification catalysts 41 and 41. Since the lower parts of the exhaust pipes 19 and 19 are integrally connected to the exhaust gas purification catalysts 41 and 41, and the upper parts are integrally connected to the attachment flange 56, those exhaust pipes 19 and 19, the exhaust gas purification The catalysts 41 and 41 and the attachment flange 56 reinforce each other and fit together to reduce vibration. The attachment flange 56 has a span long enough in the direction of the cylinder line L ₂ , and both ends thereof are fastened to the exhaust outlets 48 and 48 of the first and second collective exhaust pipes 18a and 18b. 19, 19) the support rigidity is increased, the vibration reduction effect is further increased. As a result, the vibration reduction reduces the need for reinforcing members such as the stay lines supporting the exhaust pipes 19 and 19 and the exhaust gas purifying catalysts 41 and 41, thereby reducing the number of parts and making the engine E compact. Can contribute to

As mentioned above, although the Example of this invention was described in detail, this invention can make a various design change in the range which does not deviate from the summary.

For example, in the embodiment, a series three-cylinder engine E and a series six-cylinder engine E are illustrated, but the present invention can be applied to each bank of a series engine or a V-type engine having a different number of cylinders.

In embodiments, although an example an oil return path (55 _{1-55 6)} as an oil passage, in addition to the oil passage, the said oil return passage (55 _{1-55 6)} of the present invention, a cylinder in the cylinder block 11 An oil supply passage for supplying oil to the valve chamber 23 in the head 12 or a blowby gas for communicating blow valve by communicating the valve chamber 23 and the crankcase in the cylinder head 12 with each other. A bi gas passage is included.

In embodiment, the exhaust gas purifying catalyst 41 is however provided with a cross-section of a circle, the cross section must be circular one need not, the cylinder axis (L _1), oval or cylinder axis having a constriction in the direction toward the (L _{When the} noncircular cross-section is expanded in the direction toward ₁ ), the void space below the protruding portion 49 can be used more effectively.

In addition, the structures of the vibration absorbing means D and D are not limited to those of the embodiment, and those having various other structures can be adopted.

In addition, in the case where the protrusions, the exhaust collection unit and the collective exhaust mechanism are each provided, the number thereof is not limited to two, but may be three or more. In this case, the connecting walls 102 and 103 are not necessarily limited to two, but may be one or three or more, and the water jacket J is provided on the upper and lower surfaces of the first and second exhaust collection portions 47a and 47b. Instead of forming ₂ , J ₃ ), only one of them may be formed.

Claims (27)

A cylinder head structure of a multi-cylinder engine having a collective exhaust mechanism in which exhaust vents extending from a plurality of combustion chambers arranged in a cylinder matrix are collectively assembled in an exhaust assembly section formed inside the cylinder head. And a protrusion extending outward from a side of the cylinder block to which the cylinder head is coupled, the protrusion projecting outward from the exhaust assembly portion. The multi-cylinder engine according to claim 1, wherein the cylinder head is provided with a spark plug insertion cylinder, and a water jacket is interposed between the ignition coil attached to the upper opening of the spark plug insertion cylinder and the collective exhaust pipe. Cylinder head structure. The cylinder head is provided with an ignition plug insertion cylinder inclined to the exhaust assembly side with respect to the cylinder axis, and the ignition plug insertion cylinder and the upper surface of the protrusion are connected by a reinforcing wall. The cylinder head structure of the multi-cylinder engine. The cylinder head structure of a multi-cylinder engine according to claim 1 or 2, wherein an oil passage is formed in a region surrounded by a pair of exhaust ports and an exhaust collection section extending from adjacent combustion chambers. 3. The cylinder head fastening bolt according to claim 1 or 2, wherein a cylinder head fastening bolt for coupling the cylinder head to the cylinder block is disposed in an area surrounded by an exhaust port and an exhaust assembly extending from an adjacent combustion chamber. In addition, the cylinder head structure of the multi-cylinder engine, characterized in that an oil passage is formed at a position closer to the exhaust assembly portion. 6. The cylinder head structure of a multi-cylinder engine as set forth in claim 5, wherein the oil-head-mounted bolt for fastening the cylinder head is deflected in an assembly direction of an exhaust port directed to the exhaust assembly section. The multi-cylinder according to claim 1 or 2, wherein an EGR gas passage for returning the exhaust gas to the intake system is formed inside the cylinder head, and the inlet of the EGR gas passage is opened to the exhaust collection section. The cylinder head structure of the engine. 3. An exhaust gas collecting portion is formed inside the protrusion protruding sideways from the cylinder head, and an EGR gas passage is formed in the outside provided next to the side wall of the protrusion. Cylinder head structure of multi-cylinder engine. The exhaust secondary air passage for introducing air into the exhaust system is formed inside the cylinder head, and an outlet of the exhaust secondary air passage is opened to the exhaust assembly. The cylinder head structure of the multi-cylinder engine. The distance from the cylinder axis of the bolt located on the exhaust side of the plurality of bolts arranged on the outer periphery of the combustion chamber closest to the exhaust collection section and fastening the cylinder head to the cylinder block. The cylinder head structure of the multicylinder engine characterized by setting larger than the distance from the cylinder axis of the bolt located in the side. The multi-cylinder according to claim 1 or 2, wherein the number of bolts located on the exhaust side is larger than the number of bolts located on the intake side, among a plurality of bolts coupling the cylinder head to the cylinder block. The cylinder head structure of the engine. 3. The cylinder head structure of a multi-cylinder engine according to claim 1 or 2, wherein the exhaust assembly portion is coupled to the cylinder block with a bolt for fastening the exhaust assembly portion. The exhaust gas purifying catalyst according to claim 1 or 2, which is disposed next to the side of the cylinder block at the same time as the exhaust gas purifying catalyst which is connected to the collective exhaust pipe, overlaps at least a part of the exhaust gas purifying catalyst in the projection in the axial direction of the cylinder. The cylinder head structure of the multi-cylinder engine characterized by the above-mentioned. The multi-cylinder engine according to claim 1 or 2, wherein the detection section of the oxygen concentration sensor for detecting the oxygen concentration in the exhaust gas is faced to an exhaust collection section formed inside the cylinder head. Cylinder head structure. The exhaust assembly of claim 1 or 2, wherein an exhaust assembly is formed in the protrusion which protrudes outward from the side of the cylinder head in an arch shape, and the oxygen concentration sensor detects the oxygen concentration in the exhaust gas. A cylinder head structure of a multi-cylinder engine, wherein the main body portion of the oxygen concentration sensor is opposed to the side wall of the protruding portion. The method according to claim 1 or 2, further comprising at least two protrusions each having a collective exhaust mechanism therein, wherein neighboring protrusions are connected to each other at a connecting wall, and the connecting wall is fastened to the cylinder block. The cylinder head structure of the multi cylinder engine characterized by the above-mentioned. 3. The apparatus according to claim 1 or 2, further comprising at least two protrusions each having a collective exhaust mechanism therein, wherein adjacent neighboring protrusions are connected to each other by a connection wall, and at least the top and bottom surfaces of the exhaust assembly portion. On the other hand, a cylinder jacket structure of a multi-cylinder engine, wherein a water jacket is formed, and adjacent water jackets are connected to each other in a communication path formed on a connecting wall. The multi-cylinder engine according to claim 1 or 2, wherein at least two protrusions each having a collective exhaust mechanism are formed therein, and recesses formed in the shape of the exhaust assembly portion are formed between adjacent protrusions. Cylinder head structure. 3. The multi-cylinder engine according to claim 1 or 2, wherein at least two protrusions each having a collective exhaust mechanism are formed therein, and an oil passage is formed at a position sandwiched between adjacent protrusions of the cylinder head. Cylinder head structure. The two protrusions according to claim 1 or 2, each of which has at least two protrusions each having a collective exhaust mechanism formed therein, wherein the two protrusions protrude in an arch form from the side wall of the cylinder head. Cylinder head structure of a multi-cylinder engine, characterized in that each formed inside. The method according to claim 1 or 2, wherein at least two collective exhaust vents are formed inside the protruding portion, and one end of each exhaust passage member is respectively fastened to the exhaust outlet of each collective exhaust vent, and the other end of each exhaust passage member is provided. A cylinder head structure of a multi-cylinder engine, wherein an exhaust gas purification catalyst is provided and each exhaust passage member is integrally connected. An exhaust passage member according to claim 1 or 2, further comprising an exhaust passage member coupled to the cylinder head so as to be connected to the collective exhaust pipe, a cylinder block having a water jacket formed to surround the outer circumference of the cylinder, and vibration absorbing means provided on the side wall of the cylinder block. And a vibration absorbing means having an elastic membrane having one side facing the water jacket and a housing defining a space portion at the other side of the elastic membrane outside the projection range of the exhaust passage member to the side wall of the cylinder block. Cylinder head structure of multi-cylinder engine. 3. A cylinder according to claim 1 or 2, wherein a protrusion protruding in an arc shape outward from the side of the cylinder block to which the cylinder head is coupled is formed on the side of the cylinder head, and at the side of the protrusion and the exhaust assembly portion, A cylinder head structure of a multi-cylinder engine, wherein the exhaust assembly part is formed so that a water jacket is not interposed between the two. 24. The cylinder head structure of a multi-cylinder engine according to claim 23, wherein a water jacket is formed on an upper surface or a lower surface of the exhaust collection portion. 2. The cylinder head structure of a multi-cylinder engine as set forth in claim 1, wherein the exhaust assembly portion extends outward from a side wall for partitioning the movable valve chamber. 26. The cylinder head structure of a multi-cylinder engine according to claim 25, wherein a water jacket extending outward from a side wall for partitioning the movable valve chamber is provided above the exhaust collection section. 27. The cylinder head structure of a multi-cylinder engine according to claim 26, wherein the water jacket is provided on at least one of the upper and lower surfaces of the exhaust collection portion in a flat shape.