JP2000205042A - Multicylinder engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the vibration of overhangs provided on one side of cylinder heads to define convergent exhaust ports. SOLUTION: A cylinder head 12 has on its exhaust side an overhang 49 projecting out from the associated cylinder block side. In the overhang 49 is defined a convergent exhaust port 18 having an exhaust collecting portion 47 where exhaust ports 46 extending from a plurality of combustion chambers meet integrally. Out of four bolts 512, 513, 516 and 517 disposed about the combustion chamber nearest to the exhaust collecting portion 47 to connect the cylinder head 12 to the cylinder block, two exhaust-side bolts 512 and 513 stand away from a cylinder bank line L2 by a distance D2 that is longer than a distance D1 by which the other two intake-side bolts 516 and 517 stand away from the cylinder bank line L2. The overhang 49 can be coupled tight to the cylinder block so as to become rigid and refrain from vibration accordingly.

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 in which a collective exhaust port is formed inside a projecting portion provided on the exhaust side of 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. This cylinder head is
In order to ensure the durability even if a material having poor heat resistance is used, the entire circumference of a collective exhaust port that is integrally formed inside the cylinder head is surrounded by a water jacket to enhance cooling efficiency.

[0004]

When an overhang is formed on the side surface of the cylinder head to form the collective exhaust port, the rigidity of the overhang not directly connected to the cylinder block is insufficient. Vibration may occur during operation of the vehicle.

[0005] The present invention has been made in view of the above circumstances, and has as its object to suppress vibration of a projecting portion provided on a side surface of a cylinder head for forming a collective exhaust port.

[0006]

To achieve the above object, according to the first aspect of the present invention, the side of the cylinder head on the exhaust side is smaller than the side of the cylinder block to which the cylinder head is connected. An overhanging portion is provided on the overhanging portion, and an exhaust port extending from a plurality of combustion chambers arranged along the cylinder line is integrally collected at an exhaust gathering portion. In the cylinder engine, of the plurality of bolts arranged on the outer periphery of the combustion chamber closest to the exhaust collecting portion and connecting the cylinder head to the cylinder block, the distance from the cylinder line of the bolt located on the exhaust side is determined by the intake air. A multi-cylinder engine is proposed, characterized in that the bolt located on the side is set to be longer than the distance from the cylinder line.

According to the above construction, when the cylinder head is connected to the cylinder block with bolts, a plurality of cylinders arranged on the outer periphery of the combustion chamber closest to the exhaust collecting portion of the collective exhaust port formed in the projecting portion of the cylinder head. Since the bolts are arranged asymmetrically on the exhaust side and the intake side, the distance of the bolt located on the exhaust side from the cylinder line is set larger than the distance of the bolt located on the intake side from the cylinder line. ,
A projecting portion that projects laterally from the exhaust side of the cylinder head is firmly connected to the cylinder block to increase rigidity and suppress generation of vibration. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

According to the invention described in claim 2,
A protruding portion is provided on the exhaust side of the cylinder head so as to extend beyond the side of the cylinder block to which the cylinder head is coupled, and exhaust ports extending from a plurality of combustion chambers arranged along the cylinder line are exhausted. In a multi-cylinder engine in which a collective exhaust port formed as a single unit at the collecting portion is formed in the overhang portion, of the plurality of bolts that couple the cylinder head to the cylinder block, the number of bolts located on the exhaust side is A multi-cylinder engine is proposed in which the number of bolts located on the intake side is increased.

According to the above construction, when the cylinder head having the overhanging portion formed with the exhaust collecting port is connected to the cylinder block with bolts, the number of bolts located on the exhaust side is reduced by the number of bolts located on the intake side. Since the number is larger than the number of the cylinder heads, the projecting portion projecting laterally from the exhaust side of the cylinder head is firmly connected to the cylinder block to increase rigidity and suppress generation of vibration. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

According to the third aspect of the present invention,
A protruding portion is provided on the exhaust side of the cylinder head so as to extend beyond the side of the cylinder block to which the cylinder head is coupled, and exhaust ports extending from a plurality of combustion chambers arranged along the cylinder line are exhausted. A multi-cylinder engine in which a collective exhaust port formed by integrally collecting at a collecting portion is formed in the overhang portion, wherein the exhaust collecting portion is connected to a cylinder block by an exhaust collecting portion fastening bolt. Is proposed.

According to the above construction, the exhaust gathering portion formed on the projecting portion projecting sideways from the exhaust side of the cylinder head is connected to the cylinder block by the exhaust gathering portion fastening bolt, so that the projecting portion is connected to the cylinder block. To increase the rigidity and suppress the occurrence of vibration. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

[0012]

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.

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

As shown in FIG. 1, an 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 the upper surface of the cylinder head 12. A piston 15 is provided inside three cylinders 14 formed in the cylinder block 11.
Are slidably fitted, and a combustion chamber 16 is formed on the lower surface of the cylinder head 12 facing the upper surface of the piston 15. The intake ports 17 connected to the combustion chambers 16 are opened on the intake side of the cylinder head 12, and
A collective exhaust port 18 connected to the combustion chamber 16 is opened on the exhaust side of the cylinder head 12, and an exhaust pipe 19 is connected to this opening. An ignition plug insertion cylinder 21 for attaching and detaching the ignition plugs 20 is integrally formed with the cylinder head 12. Spark plug insertion tube 21 ... are inclined to the upper end collecting exhaust port 18 side with respect to the cylinder axis L _1, the thigh and the spark plug 20 is mounted to face the combustion chamber 16 at its lower end, to the upper end The ignition coil 22 is mounted.

A valve operating 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 into the intake valve holes 30, 30.
Is provided.

As shown in FIGS. 2 and 3, the three intake ports 17 extending from the three combustion chambers 16 are formed in a Y-shape, respectively.
Are cylinder heads 1 independently without assembling with each other
2 is opened on the side surface on the intake side. On the other hand, the collective exhaust port 18 is composed of a total of six exhaust ports 46 extending from the three combustion chambers 16 and an arched exhaust collecting part 47 in which the six exhaust ports 46 collectively. An exhaust outlet 48 to which the exhaust pipe 19 is coupled is formed at the center of the exhaust collecting part 47.

The cylinder head 12 facing the exhaust collecting part 47
The side wall 12 ₁ of the exhaust side and projecting outward curved in an arch shape, the side wall 11 ₁ of the cylinder block 11
And a projecting portion 49 protruding by a distance d. Therefore, the collective exhaust port 1 formed inside the overhang portion 49
8 is provided with an overhanging portion 49 which is curved in an arch shape.
It faces directly without going through the water jacket on the side wall 12 _1.

As described above, the exhaust collecting portion 47 of the collective exhaust port 18 formed inside the overhang portion 49 is
Since the side wall 12 ₁ of the faces directly without going through the water jacket, it is possible to compact cylinder head 12 as compared with the water jacket is interposed between the exhaust collecting section 47 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 can do.

As is apparent from FIGS. 2 and 4, four bolt holes 50 are formed in the cylinder head 12 on the intake side and the exhaust side, respectively. eight cylinder head fastening bolts 51 ₁ to 51 ₈ inserted from the cylinder block 1
The cylinder head 12 is fastened to the cylinder block 11 by screwing into the bolt holes 52 formed in the cylinder block 11.

Four cylinder heads arranged on the intake side
Fastening bolt 51_Five~ 51₈Are three cylinders 14 ...
Cylinder axis L₁Cylinder line L intersects_TwoDistance from
Release D ₁Are arranged on a straight line. On the other hand, placed on the exhaust side
Four bolts 51 for fastening cylinder heads_Five~ 51
₈Are two cylinder head fastening bolts 5 at both ends.
1 ₁, 51_FourCylinder line L_TwoDistance from D₁
But the two inner cylinder head fastening bolts 5
1_Two, 51_ThreeCylinder line L_TwoDistance from D₁
D greater than_TwoIt has become. That is, the collective exhaust port
Of the central cylinder 14 closest to the
Four cylinder head fastening bolts 5 arranged on the outer periphery
1_Two, 51_Three, 51₆, 51₇Of the two on the intake side
Cylinder head fastening bolt 51₆, 51₇And cylinder
Column line L_TwoIs D₁Whereas the exhaust side 2
Bolts for fastening cylinder heads 51_Two, 51_ThreeAnd Siri
Column line L_TwoAnd the distance is D₁D greater than_TwoSet in
Is defined.

The central exhaust port 18 has a central shell.
Partitions between the cylinder 14 and the cylinders 14 on both sides
The two wall portions 53 and 54 extend as shown in FIG.
Bolts 53, 54 for fastening two cylinder heads
51_Two, 51_ThreeRespectively penetrate. Two walls 53,
54, that is, two cylinder head fastening bolts.
To 51_Two, 51_ThreeCylinder line L_TwoEach side
Oil return passage 55₁, 55_TwoIs penetrating. Two
The walls 53 and 54 are provided with exhaust gas flowing through the collective exhaust port 18.
Exhaust outlet along the direction of the
48, so that the two
Linda head fastening bolt 51_Two, 51 _ThreeNext to it
Two oil return passages 55 in contact₁, 55_TwoExhausted
It is biased to the air outlet 48 side.

The projecting portion 49 formed so as to project laterally from the cylinder head 12 has insufficient rigidity, and the engine E
The vibration during the operation is likely to occur, it was placed in biasing the two cylinder head fastening bolts 51 ₂ and 51 ₃ close to the largest exhaust collecting portion 47 bulging amount in the exhaust collecting portion 47 side As a result, the overhang portion 49 is
1 to increase rigidity and effectively suppress generation of vibration. Further, since the vibration of the overhang portion 49 is suppressed, it is possible to ensure the sealing performance of the coupling surface between the cylinder head 12 and the cylinder block 11.

With the above 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 inside the collective exhaust port 18 is prevented while the cylinder head 12 is not enlarged. Can flow smoothly, and exhaust resistance can be reduced. Moreover, the cylinder head fastening bolt 51 disposed on the wall 53
As possible ₂ and the oil return passage 55 ₁ is brought close to avoid the increase in size of the cylinder head 12, as shown in FIG. 4, the seat of the cylinder head fastening bolts 51 ₂ and the oil return passage 55 ₁ in the top opening the difference is provided in the height, and the seat of the cylinder head fastening bolts 51 ₂ is flared so as to overlap the upper end opening of the oil return passage 55 _1. Incidentally, the cylinder head fastening bolt 51 of the wall portion 54 ₃ and the oil return passage 55
₂ also has the same arrangement to avoid the cylinder head 12 from being enlarged.

[0026] The exhaust outlet 48 of the cylinder head 12, three boss portions 58 ₁ screwing the three bolts 57 _{1-57 3} for coupling the mounting flange 56 of the exhaust pipe 19, 5
8 ₂ , 58 ₃ are formed, but two cylinder head fastening bolts 51 ₂ , 51 ₃ are attached to the two bosses 58 ₁ , 58 ₂ separated in the direction of the cylinder line L _2. It is offset by a distance α respectively to the column line L ₂ direction. Thereby, the wall portion 53 and the boss portion 58 ₁ are made closer to each other, and the wall portion 54 and the boss portion 58 ₂ are made closer to each other to increase the rigidity in the vicinity of the exhaust outlet 48 of the cylinder head 12. An increase in exhaust resistance can be prevented by preventing the flow path cross-sectional area of the collecting part 47 from becoming small.

Since the number of exhaust pipes 19 is one,
The two lower bosses 58 as viewed from above₁, 58_TwoIs exhaust
The two bosses 5 are not hidden under the pipe 19.
8₁, 58_TwoBolt 57 against₁, 57_TwoFastening work
Can be easily performed. Also on the upper side of the exhaust pipe 19
One boss 58_ThreeThe bolt 57 ₁
~ 57_ThreeThree exhaust pipes 19 while securing the workability of fastening
It can be fixed in place to increase the mounting rigidity.

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. the third oil return passage 55 ₃ is formed in the vicinity of the fastening bolt 51 _4. These three oil return passages 55 ₁ , 55 ₂ , 5
5 _3, the valve chamber 23 provided in the cylinder head 12, an oil return passage 60 formed in the cylinder block 11 ... through to communicate with the oil pan (not shown).

As described above, the two oil return passages 5
Since 5 ₁ and 55 ₂ are arranged in a region surrounded by the exhaust ports 46 of the adjacent cylinders 14 and the exhaust collecting portion 47, the oil is returned to the exhaust side of the cylinder head 12 without interfering with the collective exhaust port 18. Passages 55 ₁ , 5
5 ₂ it is possible to form the cylinder head 12
The oil in the valve operating chamber 23 can be reliably returned to the oil pan. Moreover, at low temperatures, the oil return passages 55 ₁ , 55
_Since the oil passing through ₂ can be heated by the exhaust gas passing through the collective exhaust port 18, it is possible to raise the temperature of the oil without providing a special oil heater and reduce the frictional resistance of each lubricating portion.

As is apparent from FIGS. 5 and 6, the three spark plug insertion cylinders 21... Arranged obliquely on the exhaust side of the cylinder head 12 and the upper surface of the overhang portion 49 are reinforced with a triangular cross section. Each is connected by walls 61. The rigidity of the overhang portion 49 is increased by the reinforcing walls 61, and the vibration of the overhang portion 49 during operation of the engine E can be effectively suppressed.

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. Collective exhaust port 18
Cylinder head 1 heated to high temperature by exhaust gas passing through
The two overhangs 49 are provided with water jackets J ₂ and J ₃ that cover the upper and lower surfaces of the collective exhaust port 18 respectively. A portion that does not interfere with the exhaust ports 46, that is,
The three upper and lower water jackets J ₂ and J ₃ communicate with each other through three water jackets J ₄ near the three spark plug insertion cylinders 21.

As described above, the area around the collective exhaust port 18 is
Water jacket J₁, J_Two, J _Three, J_FourCover with ...
As a result, the exhaust side of the cylinder head 12 that is likely to become hot
Can be cooled efficiently. In particular, auxiliary equipment that is sensitive to heat
As the ignition coil 22 and collective exhaust port
Water jacket J between 18_TwoIntervenes,
Effectively suppresses heat transfer to the ignition coil 22 ...
(See FIG. 6).

[0033] As is apparent from FIGS. 3 and 6, the outer portion of the collecting exhaust port 18, since the directly opposite side walls 12 ₁ of the protrusion 49 without passing through the water jacket, the casting of the cylinder head 12 Sometimes, the structure of the core for forming the water jackets J ₂ , J ₃ , J ₄ ... And the collective exhaust port 18 can be simplified.

First, a core for forming the water jackets J ₂ , J ₃ , J _4, ... Is inserted into the mold in the direction of arrow A, and then a core for forming the collective exhaust port 18 is inserted. In the same manner, the core is inserted in the mold in the direction of arrow A. At this time, an opening 62 exists between the upper and lower water jackets J ₂ and J _3. Can be inserted. Although the upper and lower water jacket J _2, J ₃ are connected to each other in three of the water jacket J ₄ ..., cores corresponding to the three water jacket J ₄ ... is the collecting exhaust port 18 Since the portions corresponding to the six exhaust ports 46 of the core to be formed are engaged with each other alternately, interference between both cores is avoided (see FIG. 2).

As described above, the water jackets J ₂ and J
_Since the core for molding ₃ , J ₄ ... Or the core for molding the collective exhaust port 18 can be assembled to the mold without dividing, the cost can be reduced when the cylinder head 12 is cast. Can be.

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

In the second embodiment, the cylinder head 12 is discharged.
Four cylinder head fastening bolts 5 arranged on the air side
1₁~ 51_Four, Disposed on the intake side of the cylinder head 12.
Four bolts 51 for fastening cylinder heads_Five~ 51₈
Are all the cylinder line L_TwoDistance D from₁Placed at
Have been. And the cylinder 14 in the center and the syringes on both sides
To the two walls 53, 54 that partition between the
Is an oil return passage 55 formed therein.₁, 55_Twoof
Outside (cylinder line L_TwoSide far from)
Furthermore, two exhaust assembly fastening bolts 51₉, 51_TenIs arranged
Is placed. In the present embodiment, the 2 on the exhaust collecting section 47 side added
Bolts 51 for fastening the exhaust assembly₉, 51 _TenThe combustion chamber
Two cylinder head fastening bolts 51 on the 16 side_Two, 5
1_ThreeBecause the diameter is smaller than
Can be avoided and exhaust resistance can be reduced.
You.

As described above, the two exhaust collecting portion fastening bolts 51 ₉ and 51 ₁₀ are added to the exhaust side of the cylinder head 12 to couple the exhaust collecting portion 47 to the cylinder block 11, so that the projecting portion 49 is formed. Not only can the rigidity be increased to effectively suppress the generation of vibration, but also the sealing performance of the coupling surface between the cylinder head 12 and the cylinder block 11 can be ensured. Moreover, two oil return passages 5
5 _1, 55 ₂ are each two bolts 51 _2, 51 _9; 51
_3, 51 since sandwiched by _10, the oil return passage 55
_1, also improved 55 ₂ sealability.

The two walls 53 and 54 are provided at the collective exhaust port 1
8 The central exhaust outlet follows the direction of the exhaust gas flowing through
It is curved toward the mouth 48 and the walls 53 and 54
Cylinder axis L_TwoOr the central cylinder axis L₁Close to
From the opposite side to the far side.
Lut 51_Two, 51_ThreeTwo oil passages 55₁, 55 _Two
And two exhaust assembly fastening bolts 51₉, 51_TenBut
Since they are arranged, it is possible to avoid an increase in the size of the cylinder head 12.
While the exhaust gas smoothly flows through the collective exhaust port 18
Exhaust resistance can be reduced by allowing the gas to flow.

Further, the cylinder head on the combustion chamber 16 side is fastened.
Bolt 51_Two, 51_ThreeAnd the exhaust gathering on the exhaust gathering part 47 side
Part fastening bolt 51₉, 51_TenOil return passage between
55 ₁, 55_TwoAnd the two bolts 5
1_Two, 51_Three; 51₉, 51_TenSeat in its axial direction
See oil return passage 55₁, 55_TwoTop opening and o
Burr wrap prevents large cylinder head 12
And oil return passage 55 ₁, 55_TwoTo improve sealing performance
Can contribute.

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

Also in the third embodiment, four cylinder head fastening bolts 5 arranged on the exhaust side of the cylinder head 12 are used.
1 ₁ to 51 _4, the four cylinder head fastening bolt disposed on the intake side of the cylinder head 12 51 _{5-51 8}
Bets are arranged all the cylinder row line L ₂ at a distance D _1. And on both sides of the exhaust outlet 48 of the overhang portion 49 of the cylinder head 12, the overhung portion 49 and the cylinder and the protruding portion 63 protruding from the side wall 11 ₁ of the block 11 are two small-diameter exhaust collector fastening bolt 51 ₉ , 51 ₁₀
Are combined. Since thus bound by the outermost 2 position in the protruding portion 63 of the cylinder block 11 of the present of the exhaust merging portion fastening bolt 51 _9, 51 ₁₀ of the overhang portion 49 of the cylinder head 12, Zhang cylinder head 12 The rigidity of the protrusion 49 can be effectively increased to reliably prevent the occurrence of vibration. Moreover, since exhaust collector 47 side of the two exhaust collecting section fastening bolts 51 _9, 51 ₁₀ is a smaller diameter than the combustion chamber for two cylinder head fastening the 16-side bolt 51 _2, 51 _3, a cylinder head 12 can be prevented from being enlarged.

The upper part of the exhaust pipe 19 is connected to the cylinder head 1.
Boss 58 into which bolt 57 ₃ to be connected to 2 is inserted
₃ , reinforcing ribs 65 ₁ , near the upper ends of the bolt holes 64 ₁ , 64 ₂ into which the two exhaust assembly fastening bolts 51 ₉ , 51 ₁₀ are inserted, and the central spark plug insertion tube 21, respectively.
65 _2, 66 are connected by, and a bolt 57 ₁ for coupling the lower portion of the exhaust pipe 19 to the cylinder head 12, 57 ₂
Bosses 58 ₁ , 58 ₂ into which the bolt holes 6 are inserted.
4 _1, so 64 is coupled with the _second lower end, to increase the rigidity of the exhaust outlet 48 near the cylinder head 12 the respective bolts 51 _9, 51 _10; to ensure the fastening force of 57 _{1-57 3} it can. Moreover, the exhaust assembly fastening bolt 5
The fastening work is facilitated because the ₁₉ , 51 ₁₀ can be inserted from above.

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

In the third embodiment (see FIG. 10), two small-diameter exhaust collecting portion fastening bolts 5 for connecting the projecting portion 49 of the cylinder head 12 to the projecting portion 63 of the cylinder block 11 are provided.
₁₉ and 51 ₁₀ are inserted from above, whereas in the fourth embodiment, the two exhaust collecting portion fastening bolts 51 ₉ and 51 10 are used.
₁₀ is inserted from below. Exhaust assembly fastening bolt 51
_9, by inserting a 51 ₁₀ from below, and because the head does not interfere with the side surface of the projecting portion 49, to approximate exhaust collector fastening bolt 51 _9, 51 ₁₀ in the cylinder row line L ₂ cylinder The head 12 can be reduced in size. Moreover, since the two exhaust collecting section fastening of exhaust collector 47 side bolt 51 _9, 51 ₁₀ is a smaller diameter than the combustion chamber for two cylinder head fastening the 16-side bolt 51 _2, 51 _3,
Enlargement of the cylinder head 12 can be prevented.
Furthermore, weight reduction is achieved by shortening the length of the exhaust assembly fastening bolts 51 ₉ and 51 ₁₀ .

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 three-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.

[0048]

As described above, according to the first aspect of the present invention, when the cylinder head is connected to the cylinder block with the bolt, the exhaust collecting portion of the collective exhaust port formed in the projecting portion of the cylinder head. A plurality of bolts arranged on the outer periphery of the combustion chamber nearest to the exhaust side and the intake side are arranged asymmetrically on the exhaust side and the intake side, and the distance of the bolt located on the exhaust side from the cylinder line is set to Since the distance is set to be larger than the distance from the cylinder line, the projecting portion projecting sideways from the exhaust side of the cylinder head is firmly connected to the cylinder block to increase rigidity and suppress generation of vibration. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

According to the second aspect of the present invention,
When connecting the cylinder head having the overhang with the exhaust collecting port to the cylinder block with bolts, the number of bolts located on the exhaust side was larger than the number of bolts located on the intake side. A projecting portion that projects laterally from the exhaust side of the head is firmly connected to the cylinder block to increase rigidity and suppress generation of vibration. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

According to the invention described in claim 3,
The exhaust gathering part formed on the overhang that protrudes laterally from the exhaust side of the cylinder head is connected to the cylinder block with the exhaust gathering part fastening bolt, so the overhang is firmly connected to the cylinder block to increase rigidity. In addition, generation of vibration can be suppressed. In addition, since the vibration of the overhang is suppressed, the sealing performance between the cylinder head and the cylinder block is also improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an 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 of FIG. 2;

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

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a view corresponding to FIG. 2 according to a second embodiment of the present invention;

8 is a sectional view taken along line 8-8 of FIG. 7;

FIG. 9 corresponds to FIG. 2 according to a third embodiment of the present invention.

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;

FIG. 12 is a view corresponding to FIG. 10 according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 Cylinder block 12 Cylinder head 16 Combustion chamber 18 Collective exhaust port 46 Exhaust port 47 Exhaust collecting part 49 Overhang part 51 _{1 to} 51 ₈ Cylinder head fastening bolt (bolt) 51 ₉ , 51 ₁₀ Exhaust collecting part fastening bolt (bolt) ) D ₁ distance D ₂ distance L ₂ cylinder line

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G004 BA04 DA02 DA12 3G024 AA11 DA01 DA06 DA18 DA19 FA02 FA08 FA13 FA14 GA04 GA27 GA28

Claims (3)

[Claims] 1. A side surface on an exhaust side of a cylinder head (12).
Cylinder head to which the cylinder head (12) is connected
Overhang (4) that protrudes outward from the side of the
9), and the cylinder line (L_Two)
An exhaust port (46) extending from the plurality of combustion chambers (16);
A collective exhaust port integrally collected at the exhaust collecting section (47).
A multi-cylinder air outlet (49) formed on the overhang (49).
In the engine, outside the combustion chamber (16) closest to the exhaust collecting section (47).
Around the cylinder head (12)
Bolts (51) connected to the _Two, 51
_Three, 51₆, 51₇), Bolts located on the exhaust side
(51_Two, 51 _Three) Cylinder line (L_TwoDistance from
(D_Two) With bolts (51₆, 5
1₇) Cylinder line (L_Two) (D)₁)Than
A multi-cylinder engine characterized by a large setting. 2. A side surface on the exhaust side of the cylinder head (12).
Cylinder head to which the cylinder head (12) is connected
Overhang (4) that protrudes outward from the side of the
9), and the cylinder line (L_Two)
An exhaust port (46) extending from the plurality of combustion chambers (16);
A collective exhaust port integrally collected at the exhaust collecting section (47).
A multi-cylinder air outlet (49) formed on the overhang (49).
In the engine, the cylinder head (12) is connected to the cylinder block (11).
A plurality of bolts (51₁~ 51_Ten) Out of
Bolt (51)₁~ 51_Four, 51 ₉, 51
_Ten) Of the bolt (51) located on the intake side._Five~ 51
₈Multi-cylinder engine characterized by having more than
gin. 3. An overhanging portion (4) projecting outward from a side surface of a cylinder block (11) to which the cylinder head (12) is coupled on an exhaust side surface of the cylinder head (12).
9), an exhaust port (46) extending from a plurality of combustion chambers (16) arranged along the cylinder line (L ₂ ), and being integrally collected at an exhaust collecting section (47). 18) in the overhang portion (49), wherein the exhaust collecting portion (47) is connected to the exhaust collecting portion fastening bolt (5).
1 _9, 51 ₁₀₎ in a multi-cylinder engine, characterized in that attached to the cylinder block (11).