JP3876139B2 - engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is an engine in which an exhaust port is led out from an exhaust valve port along the head width direction of a cylinder head, as in the present invention.
In this type of engine, an EGR gas outlet passage is led out from a collecting pipe of an exhaust manifold.
[0003]
[Problems to be solved by the invention]
The above prior art has the following problems.
<Problem> In some cases, a sufficient exhaust gas recirculation amount cannot be secured.
Since the EGR gas outlet passage is led out from the exhaust manifold collecting pipe, the exhaust gas recirculation is performed only by the differential pressure between the intake and exhaust pressures, and a sufficient exhaust gas recirculation amount may not be ensured.
[0004]
The subject of this invention is providing the engine which can solve the said problem.
[0005]
[Means for Solving the Problems]
(Invention of Claim 1)
As shown in FIG. 2, in an engine in which an exhaust port (11) is led out from exhaust valve ports (32a) and (32b) along the head width direction of the cylinder head (1),
The longitudinal direction of the cylinder head (1) is the front-rear direction, and one of them is the front. Of the exhaust port (11), from the lead-out start end portion (39) along the head width direction of the cylinder head (1) to the intermediate portion (38 ) In the forward direction, and the EGR gas outlet passage (42) is led out from the location where the exhaust gas is guided by the intermediate portion (38) .
As shown in FIG. 2, when using a swirl intake port as an intake port ( 5 ) ,
The intake port wall portion ( 6 ) near the intake valve ports ( 10 a ) ( 10 b ) is formed as shown in FIG. 1, with the width direction of the cylinder head ( 1 ) being the horizontal direction and the intake port ( 5 ) being formed horizontally long. along the inner wall surface (8), as viewed from the side, it is inclined so as to approach the cylinder center axis (7) toward the cylinder (21), the inner wall surface (8) to the inclination of the glow plug (3) of Align the opposing wall surface (8a) of the inner wall (8), as viewed from the side, up along the direction parallel to the cylinder center axis (7), wedge between these walls (8) (8a) Port portion ( 5a ) is formed, and when viewed from the side , the wedge-shaped port portion ( 5a ) has a cross-sectional shape having two sides of the wall surface ( 8 ) ( 8a ) and is wide toward the cylinder ( 21 ). To be
As shown in FIG. 1, the tip of the glow plug ( 3 ) is inserted into the cylinder center ( 4 ) , and the glow plug ( 3 ) is tilted back and forth with the longitudinal direction of the cylinder head ( 1 ) as the longitudinal direction . As shown in FIG. 6, the terminal ( 3a ) of the glow plug ( 3 ) is positioned at the center in the width direction of the cylinder head ( 1 ) when viewed in a direction parallel to the cylinder center axis ( 7 ). Engine.
[0006]
【The invention's effect】
(Invention of Claim 1)
The invention of claim 1 has the following effects.
<< Effect 1 >> A sufficient exhaust gas reduction amount can be secured.
As shown in FIG. 2, since the EGR gas lead-out passage (42) is led out from the blow-off point of the exhaust guided by the middle part (38) of the curved exhaust port (11), in addition to the pressure difference between the supply and exhaust, Exhaust reduction can be performed using the pushing force of the exhaust, and a sufficient exhaust reduction amount can be ensured.
<< Effect 1-2 >> The swirl in the cylinder can be strengthened.
The intake air passing through the intake port ( 5 ) is strongly pushed into the intake valve ports ( 10a ) and ( 10b ) while being pressed against the opposing wall ( 5a ) by the wedge-shaped port portion ( 5a ) . Therefore, high-speed intake air flows into the inner peripheral surface side of the cylinder (21), swirl in the cylinder (21) is enhanced.
( Invention of Claim 2 )
In addition to the effect of the invention of claim 1, the invention of claim 2 has the following effect.
<Effect> A large volume of the breather chamber can be secured.
As shown in FIG. 5 ( A ) , the glow plug ( 3 ) is shifted in the direction opposite to the biasing direction of the breather chamber ( 20 ) . For this reason, the breather chamber ( 15 ) can be expanded in the direction opposite to the biased direction without being obstructed by the glow plug ( 3 ) penetrating the head cover ( 15 ), and the volume of the breather chamber ( 15 ) is increased. Can be secured.
[0007]
(Invention of Claim 4 )
The invention of claim 4 has the following effects in addition to the effects of any one of claims 1 to 3 .
<Effect 2> A dedicated EGR gas radiator is not required.
As shown in FIG. 2, since the EGR gas outlet passage (42) passes through the head jacket (43), a dedicated EGR gas radiator is not necessary.
[0008]
<< Effect 3 >> Parts placement of the cylinder head is facilitated.
Since there is no need to attach a dedicated EGR gas radiator to the cylinder head (1), the arrangement of the parts of the cylinder head (1) is facilitated.
[0009]
(Invention of Claim 5 )
The invention of claim 5 has the following effects in addition to the effects of any one of claims 1 to 4 .
<Effect 4> Parts arrangement of the cylinder head is facilitated.
As shown in FIG. 2, since the EGR gas supply passage (44) following the EGR gas outlet passage (42) is formed in the wall of the intake air distribution means (13), the EGR gas supply passage ( 44) does not overhang, and the part arrangement of the cylinder head (1) is facilitated.
[0010]
(Invention of Claim 6 )
The invention of claim 6 has the following effects in addition to the effects of any one of claims 1 to 5 .
<Effect 5> Thermal degradation of the valve actuator is suppressed.
As shown in FIG. 2, since the flange portion (45) is led out from the intake air distribution means (13) and the valve actuator (35) is attached to the flange portion (45), the valve actuator (35) is attached to the cylinder head ( Compared with the case where it is directly attached to 1), thermal degradation of the valve actuator (35) is suppressed.
[0011]
(Invention of Claim 7 )
The invention of claim 7 has the following effects in addition to the effects of any one of claims 1 to 6 .
<Effect 6> The valve seat can be easily maintained.
As shown in FIG. 2, the valve seat (47) of the EGR valve (46) driven by the valve actuator (35) is formed on the side surface (23) of the cylinder head (1). It can be done easily.
[0012]
(Invention of Claim 8 )
The invention of claim 8 has the following effects in addition to the effects of any one of claims 1 to 7 .
<< Effect 7 >> Exhaust efficiency is high.
As shown in FIG. 2, since the bypass passage (41) for exhaust from the first exhaust valve port (32a) is formed behind the second exhaust valve port (32b), the first exhaust valve port (32a) The exhaust gas does not hinder the outflow of exhaust gas from the second exhaust valve port (32b), and the exhaust efficiency is high.
[0013]
<< Effect 8 >> Overheating of the peripheral portion of the second exhaust valve port is suppressed.
As shown in FIG. 2, since the exhaust from the first exhaust valve port (32a) passes through the bypass passage (41) at the rear of the second exhaust valve port (32b), the exhaust of the second exhaust valve port (32b) Overheating of the peripheral portion is suppressed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 to 6 are diagrams for explaining an embodiment of the present invention. In this embodiment, a vertical overhead valve type multi-cylinder diesel engine will be described.
[0015]
The configuration of this engine is as follows.
As shown in FIG. 1, the cylinder head (1) is assembled to the upper part of the cylinder block (49), and the head cover (15) is assembled to the upper part thereof. A fuel injection nozzle (2) and a glow plug (3) are attached to the cylinder head (1).
[0016]
The mounting structure of the fuel injection nozzle (2) and the glow plug (3) is as follows.
As shown in FIG. 1, the tip of the fuel injection nozzle (2) faces the cylinder center (4), and the intake port wall (6) between the fuel injection nozzle (2) and the intake port (5) The glow plug (3) is penetrated, and the glow plug (3) is inclined by a predetermined angle (Θ1) with respect to the fuel injection nozzle (2), and the tip thereof is inserted into the cylinder central portion (4). As shown in FIG. 1 , the glow plug ( 3 ) is tilted in the front-rear direction with the longitudinal direction of the cylinder head ( 1 ) as the front-rear direction, and in a direction parallel to the cylinder center axis ( 7 ) as shown in FIG. As seen, the terminal ( 3a ) of the glow plug ( 3 ) is positioned at the center in the width direction of the cylinder head ( 1 ) .
[0017]
The advantages of the above configuration are as follows.
Since the glow plug (3) is passed through the intake port wall portion (6) between the fuel injection nozzle (2) and the intake port (5), the heat of the exhaust gas passing through the exhaust port (11) is increased by the glow plug (3 ) Is difficult to communicate. For this reason, overheating of the glow plug (3) can be suppressed. Further, since the tip of the glow plug (3) is inserted into the cylinder center (4), the entire combustion chamber can be heated evenly. Further, since the glow plug (3) is tilted with respect to the fuel injection nozzle (2), the tip of the glow plug (3) is connected to the cylinder central portion (4) without interfering with the fuel injection nozzle (2). Can be included. For this reason, the glow plug (3) can be easily inserted.
[0018]
The configuration of the intake port (5) is as follows.
As shown in FIG. 1, a swirl intake port is used as the intake port (5). The inner wall surface (8) of the intake port wall portion (6) near the intake valve ports (10a, 10b) is inclined so as to approach the cylinder center axis (7) as it approaches the cylinder (21). The wall surface (8) is made to follow the inclination of the glow plug (3), the opposing wall surface (8a) of the inner peripheral wall (8) is raised along the direction parallel to the cylinder center axis (7), and these wall surfaces (8) A wedge-shaped port portion (5a) that is wider toward the intake valve ports (10a) and (10b) is formed between (8a). Therefore, the intake air passing through the intake port (5) is strongly pushed into the intake valve ports (10a) and (10b) while being pushed against the opposing wall (5a) by the wedge-shaped port portion (5a). For this reason, high-speed intake air flows near the inner peripheral surface of the cylinder (21), and the swirl in the cylinder (21) is strengthened.
The configuration will be described more specifically as follows.
That is, as shown in FIG. 2, the width direction of the cylinder head ( 1 ) is set to the horizontal direction, the intake port ( 5 ) is formed in a horizontally long shape, and as shown in FIG. 1, the intake valve ports ( 10a ) ( 10b ) are closer to each other. The inner wall surface ( 8 ) of the intake port wall portion ( 6 ) is inclined so as to approach the cylinder center axis ( 7 ) as it approaches the cylinder ( 21 ) when viewed from the side , and the inner wall surface ( 8 ) is inclined. along a slope of the glow plug (3), the opposing wall surface (8a) of the inner wall (8), as viewed from the side, up along the direction parallel to the cylinder center axis (7), these walls (8 ) ( 8a ) , a wedge-shaped port portion ( 5a ) is formed, and the wedge-shaped port portion ( 5a ) has a cross-sectional shape having two sides of the wall surface ( 8 ) ( 8a ) when viewed from the side. It is designed to become wider toward the cylinder ( 21 ) .
[0019]
The mounting structure of the fuel injection nozzle (2) is as follows.
As shown in FIG. 2, the fuel injection nozzle (2) is inserted through the nozzle boss (6a) bulged from the intake port wall (6). For this reason, the heat of the exhaust gas passing through the exhaust port (11) is hardly transmitted to the fuel injection nozzle (2), and overheating of the fuel injection nozzle (2) can be suppressed.
[0020]
The relationship between the glow plug (3) and the head jacket (43) is as follows.
As shown in FIG. 2 , an interport crossing water channel (12) is formed between the intake port (5) and the exhaust port (11), and the glow plug (3) is passed through the interport crossing water channel (12). The intake port wall (6) is facing. For this reason, overheating of the glow plug (3) is suppressed. Further, the cooling water passing through the inter-port transverse water channel (12) is directed from the intake air distribution means (13) side to the exhaust gas merging means (14) side. For this reason, exhaust heat is not easily transmitted to the intake air distribution means side, an increase in intake air temperature can be suppressed, and intake air charging efficiency is high.
[0021]
The relationship between the glow plug (3) and the head cover (15) is as follows.
As shown in FIG. 1, the end of the glow plug (3) is passed through the outer wall (16) of the head cover (15) attached to the cylinder head (1), and the terminal of the glow plug (3) is connected to the outside of the head cover (15). Protruding. For this reason, there is no possibility that dew condensation water, oil mist, etc. in the head cover (15) will adhere to this terminal, and leakage of the glow plug (3) can be suppressed. Further, as shown in FIG. 1, a portion of the outer wall ( 16 ) of the head cover ( 15 ) penetrating the end of the glow plug ( 3 ) is retreated toward the cylinder head ( 1 ) , and the outer wall ( 16 ) are arranged pin (3a) of the glow plug (3) in the head cover (15) formed in the recess space (15a) with the retraction of.
[0022]
The relationship between the glow plug (3) and the breather chamber (20) is as follows.
As shown in FIG. 5, when viewed in a direction parallel to the cylinder center axis (7), the breather chamber (20) provided on the ceiling of the head cover (15) is biased toward one side of the crankshaft center axis (17). As shown in FIG. 6, two intake valve ports (10a) (10b) are provided for each intake port (5), and the intake port wall portion (6) between the intake valve ports (10a) (10b) is provided. The penetration of the glow plug (3) is as follows. As shown in FIG. 6, when viewed in a direction parallel to the cylinder center axis (7), the virtual connection line (18) connecting the center points of the two intake valve ports (10a) (10b) is connected to the crankshaft. From a posture orthogonal to the center axis (17), the glow plug (3) is rotated in a direction opposite to the biasing direction of the breather chamber (20) by rotating the cylinder center axis (7) by a predetermined angle (Θ2). It is shifted. For this reason, the breather chamber ( 20 ) can be expanded in the direction opposite to the biasing direction without being obstructed by the glow plug (3) penetrating the head cover (15), and the volume of the breather chamber ( 20 ) is increased. Can be secured.
[0023]
The configuration of the intake device is as follows.
As shown in FIGS . 2 and 3 , the intake air distribution means (13) is disposed on the side surface (23) of the cylinder head (1), and the intake air distribution means (13) is disposed on the side surface (23) of the cylinder head (1). A longitudinal case structure is formed, the side surface of the intake air distribution means (13) facing the side surface (23) of the cylinder head (1) is fully opened, and the opening edge (24) is formed on the side surface of the cylinder head (1) ( 23). Further, a mounting edge (25) is provided on the side surface (23) of the cylinder head (1), and an opening edge (24) of the intake air distribution means (13) is mounted on the mounting edge (25), so that the side surface of the cylinder head (1) Of (23), the portion surrounded by the mounting edge (25) is retracted to the inside of the head from the mounting edge (25). For this reason, even if the width dimension of the intake distribution means (13) is shortened, a sufficient intake passage cross-sectional area can be secured, and the intake distribution means (13) from the side surface (23) of the cylinder head (1) can be secured. The overhang dimension can be shortened.
[0024]
Further, as shown in FIG. 2, the outwardly facing surface (27) located between the intake port inlets (26), (26) of adjacent cylinders, and the inner peripheral surface of each intake port inlet (26) (26) ( 26a) (26a) are rounded at the boundary portions (26b) and (26b). Therefore, there is no possibility of turbulent flow at the boundary portions (26b) and (26b) when the intake air is introduced from the intake air distribution means (13) to the intake ports (5) and (5), and the intake ports (5) and (5) Intake into the air smoothly. Further, when the mounting edge (25) is polished, a part of the round is cut off, and the defect that the edge is formed does not occur, and the smooth round can be surely formed. Further, since the radius can be provided in advance before the mounting edge (25) is polished, this radius can be formed by the casting mold of the cylinder head (1), and the radius can be easily formed.
[0025]
The parts mounting structure to the cylinder head (1) is as follows.
As shown in FIG. 2, the cylinder head (1) is provided with an intake distribution means (13), an exhaust merging means (14), and a thermostat case (31) for circulating cooling water, and intake valve ports (10a) (10b) The intake port (5) and the exhaust port (11) are led out from the exhaust valve ports (32a) and (32b) in the head width direction of the cylinder head (1) in opposite directions, and the intake distribution means (13) is provided. The cylinder head (1) is attached to one side surface (23), and the exhaust merging means (14) is attached to the other side surface (34).
[0026]
As shown in FIG. 2, the thermostat case (31) is arranged on the side surface (34) of the cylinder head (1) to which the exhaust merging means (14) is attached at one end in the longitudinal direction of the cylinder head (1). The head longitudinal direction is the front-rear direction, and one end of the cylinder head (1) where the thermostat case (31) is disposed is viewed as the front, and the exhaust valve ports (32a) and (32b) of each cylinder are taken into the intake of the cylinder. Disposed behind the valve ports (10a) and (10b), the exhaust merging means (14) is disposed behind the intake air distributing means (13), and in front of the exhaust merging means (14), the cylinder head A thermostat case (31) is attached to the side surface (34) of (1).
[0027]
The advantages of the above configuration are as follows.
Since the large thermostat case (31) can be disposed on the side surface (34) of the cylinder head (1), the overall length of the engine can be shortened. In addition, since the exhaust merging means (14) can be disposed rearward, the large thermostat case (31) can be attached to the large attachment surface formed on the side surface (34) of the cylinder head (1) in front of it. The side surface (34) of the cylinder head (1) can be used without waste as a component mounting surface.
[0028]
Further, as shown in FIG. 2, the valve actuator (35) of the EGR device (30) is arranged on the side surface (23) of the cylinder head (1) in front of the intake air distribution means (13). In this way, a large thermostat case (31) is disposed in a wide space in front of the exhaust merging means (14), and a small valve actuator (35) is disposed in a narrow space in front of the intake air distributing means (13). Therefore, the components can be stored in the cylinder head (1), and the cylinder head (1) can be compactly assembled.
[0029]
The relationship between the exhaust port (11) and the push rod (36) is as follows.
As shown in FIG. 2, when the push rods (36) (36) of the valve operating device are arranged on the outlet side of the exhaust port (11), the cylinder central axis is viewed in a direction parallel to the cylinder central axis (7). (7) An imaginary transverse line (37) perpendicular to the crankshaft central axis (17) is assumed on the upper side, and the intake valve ports (10a) and (10b) of the cylinder are placed in front of the imaginary transverse line (37) The exhaust valve ports (32a) and (32b) of the cylinder are respectively disposed in the cylinder, and the intermediate portion (38) of the exhaust port (11) is deflected forward from the lead-out start end portion (39) along the head width direction. The leading end portion (40) along the head width direction is biased forward to a position where it overlaps the virtual transverse line (37), and a pair of push rods (36) (36) (36) of the cylinder are provided before and after the leading end portion (40). 36) are arranged in a distributed manner.
[0030]
The advantages of the above configuration are as follows.
As shown in FIG. 6, the rocker arms (48) and (48) can be set in a posture parallel to the virtual transverse line (37) or in a posture close to parallel, and the rocker arms (48) and (48) can be shortened. . For this reason, the weight inertia of the rocker arms (48) and (48) is reduced, and the follow-up performance of the rocker arms (48) and (48) with respect to the push rod (36) is increased, so that the valve operating can be performed accurately. Further, the lead-out terminal portion (40) of the exhaust port (11) and the pair of push rods (36) (36) can be arranged without difficulty, and the exhaust port ( It is not necessary to narrow the leading end portion (40) of 11), and the passage resistance of the exhaust port (11) can be reduced.
[0031]
The configuration of the exhaust port (11) is as follows.
As shown in FIG. 2, a pair of exhaust valve ports (32a) (32b) are arranged in the exhaust port (11) along the head width direction, and the first exhaust valve port (32a) is connected to the exhaust port (11). When opening the second exhaust valve port (32b) at the middle portion (38) of the exhaust port (11), the lead-out portion along the head width direction of the exhaust port (11) is opened. The intermediate portion (38) is bent forwardly from the starting end portion (39), and the second exhaust valve port (32b) is opened at the center position of the curved arc of the intermediate portion (38). An exhaust bypass passage (41) from the first exhaust valve port (32a) is formed behind the exhaust valve port (32b). For this reason, the exhaust from the first exhaust valve port (32a) does not hinder the outflow of the exhaust from the second exhaust valve port (32b), and the exhaust efficiency is high. Further, since the exhaust from the first exhaust valve port (32a) passes through the detour passage (41) at the rear of the second exhaust valve port (32b), overheating of the peripheral portion of the second exhaust valve port (32b) is caused. It is suppressed.
[0032]
The relationship between the exhaust device and the EGR device (30) is as follows.
As shown in FIG. 2, the EGR gas lead-out passage (42) is led out from the location where the exhaust gas is guided by the curved intermediate portion (38) of the exhaust port (11). Exhaust gas reduction can be performed using the pushing force of exhaust gas in addition to the supply / exhaust pressure difference, and a sufficient exhaust gas reduction amount can be ensured. The EGR gas outlet passage (42) passes through the head jacket (43). This eliminates the need for a dedicated EGR gas radiator and facilitates the arrangement of the parts of the cylinder head (1). An EGR gas supply passage (44) following the EGR gas outlet passage (42) is formed in the wall of the intake air distribution means (13). For this reason, the EGR gas supply passage (44) does not protrude greatly from the cylinder head (1), and the arrangement of the parts of the cylinder head (1) becomes easy.
[0033]
The mounting structure of the valve actuator (35) of the EGR device (30) is as follows.
As shown in FIG. 2, a flange portion (45) is led forward from the intake air distribution means (13), and a valve actuator (35) of the EGR device (30) is attached to the flange portion (45). Compared with the case where the valve actuator (35) is directly attached to the cylinder head (1), thermal degradation of the valve actuator (35) is suppressed. The valve seat (47) of the EGR valve (46) driven by the valve actuator (35) is formed on the side surface (23) of the cylinder head (1) to which the intake air distribution means (13) is attached. For this reason, the maintenance of the valve seat (47) can be easily performed.
[Brief description of the drawings]
FIG. 1 is a vertical side view of a periphery of a front end portion of a cylinder head of an engine according to an embodiment of the present invention.
2 is a cross-sectional plan view of a front end portion of a cylinder head of the engine of FIG. 1. FIG.
3A is a cross-sectional view taken along the line III-III of FIG. 2, and FIG. 3B is a side view of the cylinder head of the engine of FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIGS. 5A and 5B are views for explaining a head cover of the engine of FIG. 1, in which FIG. 5A is a plan view and FIG. 5B is a side view.
6 is a plan view with the head cover of the engine of FIG. 1 removed. FIG.
[Explanation of symbols]
(11) ... Exhaust port, (32a) (32b) ... Exhaust valve port, (35) ... Valve actuator, (36) ... Push rod, (37) ... Virtual transverse line, (38) ... Intermediate part, (39) Derivation start end portion, (41) ... Detour passage, (42) ... EGR gas lead-out passage, (43) ... Head jacket, (45) ... Flange, (46) ... EGR valve, (47) ... Valve seat

Claims (8)

In the engine in which the exhaust port (11) is led out from the exhaust valve ports (32a) and (32b) along the head width direction of the cylinder head (1),
The longitudinal direction of the cylinder head (1) is the front-rear direction, and one of them is the front. Of the exhaust port (11), from the lead-out start end portion (39) along the head width direction of the cylinder head (1) to the intermediate portion (38 ) In the forward direction, and the EGR gas outlet passage (42) is led out from the location where the exhaust gas is guided by the intermediate portion (38) .
In using the swirl intake port as the intake port ( 5 ) ,
With the width direction of the cylinder head ( 1 ) as the horizontal direction, the intake port ( 5 ) is formed horizontally long, and the inner wall surface ( 8 ) of the intake port wall portion ( 6 ) near the intake valve ports ( 10 a ) ( 10 b ) , when viewed from the side, is inclined so as to approach the cylinder center axis (7) toward the cylinder (21), and along the inner wall surface (8) to the inclination of the glow plug (3), the inner circumferential wall (8 opposing wall surface (8a) of) as viewed from the side, up along the direction parallel to the cylinder center axis (7), forming a wedge-shaped port portion (5a) between the wall surfaces (8) (8a) The wedge-shaped port portion ( 5a ) has a cross-sectional shape having two sides of the wall surface ( 8 ) ( 8a ) when viewed from the side, and becomes wider toward the cylinder ( 21 ) ,
Insert the tip of the glow plug (3) to the cylinder center part (4), as the front-rear direction in the longitudinal direction of the cylinder head (1), with tilting the glow plug (3) in the longitudinal direction, the cylinder center axis (7) An engine characterized in that the terminal ( 3a ) of the glow plug ( 3 ) is positioned at the center in the width direction of the cylinder head ( 1 ) when viewed in parallel . The engine according to claim 1,
cylinder head ( 1 ) Head cover attached to ( 15 ) Outside wall ( 16 ) To glow plug ( 3 ) Glow plug through the end of ( 3 ) The terminals of the head cover ( 15 ) Cylinder center axis ( 7 ) Head cover in a direction parallel to ( 15 ) Breather room on the ceiling ( 20 ) The crankshaft center axis ( 17 ) Each intake port is biased toward one side ( 5 ) Two intake valve ports each ( 10a ) ( 10b ) This intake valve port ( 10a ) ( 10b ) Inlet port wall part between ( 6 ) To glow plug ( 3 ) When penetrating
Cylinder center axis ( 7 ) The two intake valve ports ( 10a ) ( 10b ) Virtual connection line connecting the center points of ( 18 ) The crankshaft center axis ( 17 ) Cylinder center axis from ( 7 ) Around the angle ( Θ2 ) Only by rotating the glow plug ( 3 ) Breather room ( 20 ) The engine is characterized by being shifted in a direction opposite to the bias direction. The engine according to claim 2,
Head cover ( 15 ) Outside wall ( 16 ) Out of glow plug ( 3 ) The part that penetrates the end of the cylinder head ( 1 ) Retreat towards this outer wall ( 16 ) Head cover with retreat ( 15 ) Recessed space formed in ( 15a ) Glow plug inside ( 3 ) Terminal ( 3a ) An engine characterized by the arrangement. The engine according to any one of claims 1 to 3 ,
An engine characterized in that the EGR gas outlet passage (42) passes through the head jacket (43). The engine according to any one of claims 1 to 4 ,
An engine characterized in that an EGR gas supply passage (44) following the EGR gas outlet passage (42) is formed in the wall of the intake air distribution means (13). The engine according to any one of claims 1 to 5 ,
An engine characterized in that a flange portion (45) is led forward from the intake air distribution means (13), and a valve actuator (35) of an EGR device (30) is attached to the flange portion (45). The engine according to any one of claims 1 to 6 ,
An engine characterized in that a valve seat (47) of an EGR valve (46) driven by the valve actuator (35) is formed on a side surface (23) of a cylinder head (1) to which an intake air distribution means (13) is attached. . The engine according to any one of claims 1 to 7 ,
A pair of exhaust valve ports (32a) and (32b) are arranged in the exhaust port (11) along the head width direction, and the first exhaust valve port (32a) is formed at the leading end portion (39) of the exhaust port (11). When opening the second exhaust valve port (32b) at the middle portion (38) of the exhaust port (11),
Of the exhaust port (11), the intermediate portion (38) is bent from the leading start end portion (39) along the head width direction while being led forward, and the intermediate portion (38) is bent at the center position of the curved arc. Two exhaust valve ports (32b) are opened, and a bypass passage (41) for exhaust gas from the first exhaust valve port (32a) is formed behind the second exhaust valve port (32b). To engine.

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