CN213450614U

CN213450614U - Internal combustion engine

Info

Publication number: CN213450614U
Application number: CN202022400008.0U
Authority: CN
Inventors: 原田丈也; 内田基
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2019-11-22
Filing date: 2020-10-26
Publication date: 2021-06-15
Anticipated expiration: 2030-10-26
Also published as: JP7112998B2; JP2021080908A

Abstract

The utility model provides an internal-combustion engine can restrain the disorder of air current and reduce the adhesion of spraying fuel in the suction opening. The internal combustion engine includes a cylinder head. The cylinder head includes: an air intake hole connected to the combustion chamber to guide air flowing into the combustion chamber; a fuel injection valve which extends from the valve body in an axial direction with a diameter smaller than that of the valve body and injects fuel from a nozzle hole at a front end toward a space in the intake hole; an annular body that receives the valve body in the axial direction and forms a through hole for the nozzle; and a recess recessed from an inner surface of the air intake hole, forming a space in an outer periphery of the nozzle in front of the annular body, and partially accommodating the nozzle. An internal combustion engine includes: and a bulging portion which is expanded from the inner surface of the suction hole upstream of the recess by the annular body.

Description

Internal combustion engine

Technical Field

The utility model relates to an internal-combustion engine, it includes the cylinder head. The cylinder head includes: an air intake hole connected to the combustion chamber to guide air flowing into the combustion chamber; a fuel injection valve which extends from the valve body in an axial direction with a diameter smaller than that of the valve body and injects fuel from a nozzle hole at a front end toward a space in the intake hole; an annular body that receives the valve body in the axial direction and forms a through hole for the nozzle; and a recess recessed from an inner surface of the air intake hole, forming a space in an outer periphery of the nozzle in front of the annular body, and partially accommodating the nozzle.

Background

An internal combustion engine having a fuel injection valve that injects fuel from a nozzle hole at a front end toward a space in an intake bore is widely known. In such an internal combustion engine, it is desirable to inject fuel from a position as close as possible to the center line of the intake passage. Nevertheless, the more the fuel injection valve enters the path of the air flow, the more turbulence the air flow is. Turbulence in the airflow promotes attachment of the spray fuel to the inner surfaces of the suction holes.

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2012 and 188937

SUMMERY OF THE UTILITY MODEL

[ problem to be solved by the utility model ]

Patent document 1 discloses a recess that is recessed from an inner surface of an intake hole, and that partially houses a nozzle of a fuel injection valve by forming a space in an outer periphery of the nozzle. If such a structure is combined with the curvature of the intake hole, the path of the fuel spray in a conical shape can be coaxially incorporated into the intake hole. However, the recess causes turbulence in the airflow. Further, the nozzle of the fuel injection valve, which greatly protrudes from the inner surface of the intake hole, also causes turbulence in the air flow.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an internal combustion engine capable of suppressing turbulence of an air flow in an intake port and reducing adhesion of spray fuel to an inner surface of the intake port.

[ means for solving problems ]

According to a first aspect of the present invention, an internal combustion engine is provided, comprising a cylinder head. The cylinder head includes: an air intake hole connected to the combustion chamber to guide air flowing into the combustion chamber; a fuel injection valve that extends from the valve body in an axial direction with a diameter smaller than a diameter of the valve body and injects fuel from a nozzle hole at a front end toward a space in the intake hole; an annular body that receives the valve body in the axial direction and forms a through hole for the nozzle; and a recess recessed from an inner surface of the air intake hole, forming a space in an outer periphery of the nozzle in front of the annular body, and partially accommodating the nozzle; wherein the internal combustion engine further includes a bulging portion that bulges from an inner surface of the intake hole upstream of the recessed portion based on the annular body.

According to a second aspect, in addition to the configuration of the first aspect, the fuel injection device further includes an escape surface formed on an inner surface of the intake hole so as to avoid a path of the spray fuel injected from the nozzle hole in a conical shape.

[ effects of the utility model ]

According to the first aspect, the annular body may be arranged such that the expanded portion is formed on the inner surface of the intake hole, and the fuel injection valve is arranged near the center of the intake hole. Further, it has been found that by securing a space in the recess on the outer periphery of the nozzle, turbulence of the air flow is suppressed when the air flow in the intake hole flows into the recess over the bulging portion. Therefore, the adhesion of the spray fuel to the inner surface can be suppressed in the intake hole. Good combustion can be achieved in the combustion chamber. The generation of Particulate Matter (PM) can be reduced.

According to the second aspect, the adhesion of the spray fuel to the inner surface can be suppressed in the intake hole by the action of the escape surface. Good combustion can be achieved in the combustion chamber. The generation of Particulate Matter (PM) can be reduced.

Drawings

Fig. 1 is a partial cross-sectional view of an internal combustion engine according to an embodiment of the present invention, schematically showing a configuration of a cross section including the axial centers of an intake valve and an exhaust valve.

Fig. 2 is a cross-sectional view taken along line 2-2 of fig. 1.

Fig. 3A and 3B are a side view and a plan view showing the shape of a core following an intake hole.

[ description of symbols ]

11: internal combustion engine

15: cylinder head

18: combustion chamber

24: air suction hole

35: nozzle orifice

36: fuel injection valve

36 a: valve body

36 b: nozzle with a nozzle body

38: through the hole

39: ring body

41: concave part

42: bulging part

43: (of the sprayed fuel) path

44: avoidance surface

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Fig. 1 is a conceptual diagram schematically showing an internal combustion engine according to an embodiment of the present invention. The internal combustion engine 11 includes: a cylinder block 13 having a cylinder bore (cylinder) 12 dividing a cylindrical space coaxial with a cylinder axis C; and a cylinder head 15 coupled to an upper end of the cylinder block 13 and supporting a valve train (valve train) 14. The cylinder head 15 is coupled to a head cover (not shown) that covers the valve mechanism 14.

A piston 16 is housed in the cylinder block 13, and the piston 16 is guided by the cylinder bore 12 so as to be reciprocatingly movable along the cylinder axis C. The piston 16 forms a combustion chamber 18 with the cylinder head 15 by a crown surface 17 facing the cylinder head 15. The opening of the cylinder bore 12 is surrounded by a bearing surface 19 which blocks the cylinder head 15. The bearing surface 19 extends in a plane SP orthogonal to the cylinder axis C. The cylinder block 13 is formed by casting a metal material such as an aluminum alloy.

A crankshaft 22 is connected to the piston 16, and the crankshaft 22 is supported by the crankcase so as to be rotatable about the rotation axis Rx. The connecting rod 23 connects the piston 16 with a crank pin of the crank shaft 22. The linear motion of the piston 16 is converted into rotational motion of the crankshaft 22 by the action of the connecting rod 23.

An intake port 24 and an exhaust port 25 are formed in the cylinder head 15, the intake port 24 is connected to the combustion chamber 18 to guide air flowing into the combustion chamber 18, and the exhaust port 25 is connected to the combustion chamber 18 to guide air flowing out of the combustion chamber 18. The suction hole 24 has: an introduction hole 24a extending toward the combustion chamber 18 in each cylinder bore 12; and individual holes 24b branched into two at the tip of the introduction hole 24a and opened in parallel on the top surface of the combustion chamber 18. The exhaust hole 25 has: two individual holes 25a opening in parallel on the top surface, and a collective hole 25b merging and extending from the individual holes 25 a. A valve seat 26 and a valve seat 27 are fixed to the opening of the intake port 24 and the opening of the exhaust port 25, respectively.

The valve mechanism 14 includes: an intake valve 28 supported by the cylinder head 15 so as to be axially displaceable and opening/closing an opening of the intake port 24 facing the combustion chamber 18; and an exhaust valve 29 supported by the cylinder head 15 so as to be axially displaceable, and opening and closing an opening of the exhaust port 25 to face the combustion chamber 18. A shaft guide 31 and a shaft guide 32 are fitted into the cylinder head 15, the shaft guide 31 is disposed coaxially with the valve seat 26 provided at the opening of the intake port 24 and guides the axial displacement of the intake valve 28, and the shaft guide 32 is disposed coaxially with the valve seat 27 provided at the opening of the exhaust port 25 and guides the axial displacement of the exhaust valve 29. An accommodation space 34 is formed in each hole 24b of the intake hole 24, and the accommodation space 34 extends from the shaft guide 31 toward the opening of the intake hole 24 and is connected to the reference flow path 33 of the intake hole 24. The shape of the housing space 34 is divided by a cylindrical surface coaxial with the shaft guide 31. Here, the reference flow path 33 is a virtual air flow path formed with a smooth curved surface without expansion or depression. The intake valve 28 and the exhaust valve 29 are seated on the valve seat 26 and the valve seat 27 when the intake port 24 and the exhaust port 25 are closed, respectively.

The valve mechanism 14 causes axial displacement of the intake valve 28 and the exhaust valve 29 by the action of a camshaft (not shown) supported by the cylinder head 15 so as to be rotatable about an axial center parallel to the rotation axis Rx of the crankshaft 22. When the intake valve 28 and the exhaust valve 29 are displaced in the axial direction, a rocker arm (not shown) may be interposed between the intake valve 28 and the exhaust valve 29 and the camshaft.

A fuel injection valve 36 is mounted on the cylinder head 15, and the fuel injection valve 36 faces the nozzle hole 35 at the front end to the space in the intake hole 24. The fuel injection valve 36 includes: a valve body 36 a; and a nozzle 36b extending forward from the valve body 36a in the axial direction and having a spout 35 at a tip end thereof. Here, two fuel injection valves 36 are attached to each introduction hole 24 a. Each fuel injection valve 36 is installed in the introduction hole 24a, pointing to each individual hole 24 b. The fuel injection valve 36 sprays fuel from the nozzle hole 35 toward the opening of the intake hole 24 in a conical shape coaxial with the nozzle 36 b.

The cylinder head 15 is formed with a mounting hole 37 that accommodates a cylindrical space of the valve body 36a of the fuel injection valve 36. An annular body 39 is disposed at the tip of the mounting hole 37, and the annular body 39 blocks the valve main body 36a in the axial direction to form a through hole 38 for the nozzle 36 b. The annular body 39 is integral with the metal body of the cylinder head 15. The annular body 39 has an outer diameter that ensures a wall thickness that maintains the rigidity of the fuel injection valve 36 around the mounting hole 37.

A recess 41 recessed from the inner surface of the air intake hole 24 is formed in front of the annular body 39. The recess 41 is located in front of the annular body 39, and partially accommodates the nozzle 36b by forming a space in the outer periphery of the nozzle 36 b. The shape of the recess 41 is divided by a cylindrical surface coaxial with the nozzle 36 b. The concave portion 41 forms a space expanded from the reference channel 33.

An expanded portion 42 is formed on the inner surface of the air intake hole 24, and the expanded portion 42 is expanded from the inner surface of the air intake hole 24 upstream of the concave portion 41 by the annular body 39. The bulging portion 42 forms a concave portion in the reference flow path 33 of the intake port 24. As shown in fig. 2, the shape of the expanded portion 42 reflects the shape of the annular body 39.

Between each recess 41 and the corresponding housing space 34, an escape surface 44 is formed on the inner surface of the intake hole 24, and the escape surface 44 avoids a path 43 of the spray fuel injected in a conical shape from the nozzle hole 35. The escape surface 44 is formed by a wall surface of the introduction hole 24a retreated from the reference channel 33. The shape of the escape surface 44 reflects, for example, the path of the sprayed fuel in a conical shape.

Fig. 3A and 3B show a core 46 used when casting the cylinder head 15. The core 46 includes: a main body 47 that follows the reference flow path 33 of the suction hole 24; two first projections 48, expanded from the body 47, each following the recess 41; and two second projections 49, which expand from the body 47 downstream of the first projections 48, follow the housing spaces 34, respectively. On the outer surface of the body 47, two recesses 51 recessed from the surface of the body 47 and following the bulging portion 42 are formed upstream of the first projection 48. An expansion portion 52 that protrudes from the body 47 and is connected to the second protrusion 49 is formed upstream of the second protrusion 49.

Next, the operation of the present embodiment will be described. When the piston 16 descends and the intake valve 28 opens the opening of the intake port 24, air flows into the combustion chamber 18 from each individual port 24 b. At this time, fuel is injected from the fuel injection valve 36 toward the air flowing into the combustion chamber 18. The fuel is sprayed from the nozzle 35 along a conical path coaxial with the nozzle 36 b. A mixed gas is generated in the suction hole 24.

In the present embodiment, the ring body 39 may be disposed so that the fuel injection valve 36 is close to the center of the intake hole 24 to the extent that the expanded portion 42 is formed on the inner surface of the intake hole 24. Further, it was found that by securing a space in the recess 41 on the outer periphery of the nozzle 36b, as shown in fig. 1, when the airflow in the intake hole 24 flows over the bulging portion 42 and into the recess 41, turbulence of the airflow is suppressed. Therefore, the adhesion of the spray fuel to the inner surface can be suppressed in the intake hole 24. Good combustion can be achieved within the combustion chamber 18. The generation of Particulate Matter (PM) can be reduced.

In the cylinder head 15 of the present embodiment, the escape surface 44 is formed on the inner surface of the intake hole 24 while avoiding the path of the spray fuel injected in a conical shape from the injection port 35. Adhesion of the spray fuel to the inner surface can be suppressed in the intake hole 24 by the avoiding surface 44. Good combustion can be achieved within the combustion chamber 18. The generation of Particulate Matter (PM) can be reduced.

Claims

1. An internal combustion engine, comprising:

a cylinder head (15) is provided,

the cylinder head (15) comprises:

an intake hole (24) connected to the combustion chamber (18) and guiding air flowing into the combustion chamber (18);

a fuel injection valve (36) which is extended from the valve body (36a) in the axial direction with a diameter smaller than that of the valve body (36a) and injects fuel from a nozzle hole (35) at the front end toward the space in the intake hole (24);

an annular body (39) that receives the valve body (36a) in the axial direction and forms a through hole (38) for the nozzle (36 b); and

a recess (41) recessed from the inner surface of the air intake hole (24), forming a space in the outer periphery of the nozzle (36b) in front of the annular body (39), and partially accommodating the nozzle (36 b);

wherein the internal combustion engine further comprises:

and a bulging section (42) that bulges out from the inner surface of the air intake hole (24) upstream of the recess (41) on the basis of the annular body (39).

2. The internal combustion engine of claim 1, further comprising:

and an escape surface (44) formed on the inner surface of the intake hole (24) so as to avoid a path (43) of the spray fuel injected in a conical shape from the nozzle hole (35).