JP3740741B2 - Direct cylinder injection spark ignition engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a direct in-cylinder spark ignition engine.
[0002]
[Prior art]
As a cylinder head of a conventional direct in-cylinder spark ignition engine, for example, an internal structure thereof is shown as shown in FIG. 6 (Japanese Patent Laid-Open No. 7-83134).
A concave chamber is formed on the crown surface of the piston, and at the time of engine low load operation, fuel is injected toward the concave chamber at the end of the compression stroke to form an air-fuel mixture only in a limited region around the spark plug.
At this time, the upright intake port forms a reverse tumble flow and is disposed opposite to the fuel spray direction of the injection valve, thereby realizing combustion at a significant lean air-fuel ratio.
[0003]
[Problems to be solved by the invention]
However, in such a conventional direct in-cylinder spark ignition engine, the intake port has an upright port shape, the spark plug is disposed in the center of the combustion chamber, and the fuel can be injected directly into the combustion chamber. Because the injection valve was built into the side of the head,
(1) The intake port is placed upright in the center of the head. If an intake manifold / rocker cover or the like is placed, the overall height of the engine is significantly increased.
(2) When the head is viewed from the front-rear direction, the intake port, the exhaust port, the injection valve, the spark plug, and the intake / exhaust valve stem portion are concentrated and the cooling water passage is narrowed.
(3) This will give a significant change to the structure currently used, resulting in an increase in cost.
There was a problem.
[0004]
The present invention has been made paying attention to such a conventional problem, and without changing the overall height of the engine as in the conventional example, and by changing the core to the currently used structure. Directly capable of stable combustion in a large lean air-fuel ratio region in a direct-injection spark ignition engine by forming a reverse tumble flow in the cylinder without any increase in cost because it can be handled An object is to provide an in-cylinder injection spark ignition engine.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has one or more intake valves and one or more exhaust valves in one cylinder, and a cylinder in which an intake camshaft and an exhaust camshaft for driving the intake and exhaust valves are arranged. The head, an ignition plug disposed at a substantially central position between the intake valve and the exhaust valve, and the tip of the in-cylinder direct injection fuel injection valve are disposed farthest from the ignition plug with the intake valve in the vicinity of the intake valve interposed therebetween, The fuel injection valve main body is disposed at a position facing the exhaust port, and the cylinder head includes an opening on the side of the cylinder head upstream of the intake port connected to each intake valve seat and an opening on the side of the cylinder head downstream of the exhaust port. configured such that the side surface and the same surface, between the cylinder head-side opening of the intake port and intake valve seat and L-shaped intake port shape, intake and exhaust manifold Nihold is located on the same side of the engine, the intake manifold is located above the exhaust manifold, and each of them is curved downward, and when the vehicle is mounted, the driving wind hits the intake manifold and hits the exhaust manifold. To prevent this, the intake manifold was configured to cover the exhaust manifold.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0007]
(First embodiment)
1 and 2 are diagrams showing a first embodiment of the present invention.
[0008]
Reference numeral 1 denotes a cylinder head. An intake valve seat 3 and an exhaust valve seat 4 are disposed in the combustion chamber 2, and an ignition plug 5 is disposed in the vicinity of the approximate center of the combustion chamber. Reference numeral 6 denotes an intake port, which has an independent shape from each intake valve seat 3 toward the intake manifold mounting opening 7.
[0009]
Reference numeral 8 denotes an exhaust port, which has a shape joined from the exhaust valve seat 4 toward the exhaust manifold mounting opening 9 in the middle.
[0010]
The intake manifold attaching opening 7 and the exhaust manifold attaching opening 9 are arranged so as to be located on the same side surface of the head 1.
[0011]
An L-shaped intake port shape is formed between the intake manifold mounting opening 7 and the intake valve seat 3.
[0012]
Next, the operation of the first embodiment will be described.
That is, according to the first embodiment of the present invention, in the configuration in which the fuel injection valve is directly attached to the cylinder head, one cylinder has one or more intake valves and one or more exhaust valves, and A cylinder head having an intake camshaft and an exhaust camshaft for driving the valve, an ignition plug 5 disposed at a substantially central position between the intake valve and the exhaust valve, and a tip of the in-cylinder direct injection fuel injection valve 10 are located near the intake valve. The fuel injection valve 10 is disposed at a position farthest from the spark plug 5 with the intake valve interposed therebetween, and the main body of the fuel injection valve 10 is disposed at a position facing the exhaust port 8, upstream of the intake port 6 connected to each intake valve seat 3. The opening on the side surface of the cylinder head and the opening on the side surface of the cylinder head downstream of the exhaust port 8 are configured to be flush with the side surface of the cylinder head. Since the intake port shape between the cylinder side opening and the intake valve seat 3 has an L-shaped intake port shape, the intake air introduced into the intake port from the intake manifold mounting opening 7 through the intake manifold is L-shaped. It passes through the intake port of the mold and is introduced into the cylinder from the intake valve seat 3. At this time, the intake air forms a reverse tumble flow in the cylinder and forms a flow opposite to the direction of the fuel spray of the fuel injection valve 10, thereby realizing stable combustion at a large lean air-fuel ratio. Become.
[0013]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG.
[0014]
Cylinder head 1 having one or more intake valves and one or more exhaust valves per cylinder, and an intake camshaft and exhaust camshaft for driving the intake / exhaust valves, and an abbreviation of intake valve and exhaust valve The tip of the ignition plug 5 and the direct fuel injection valve 10 for direct injection in the cylinder are arranged at a position farthest from the ignition plug 5 with the intake valve in the vicinity of the intake valve interposed therebetween. An opening on the side of the cylinder head on the upstream side of the intake port 6 connected to each intake valve seat 3 and an opening on the side of the cylinder head on the downstream side of the exhaust port 8 are arranged at positions facing the exhaust port 8. The L-shaped intake port shape is formed between the intake port 6 and the cylinder head side opening of the intake port 6 and the intake valve seat 3. Further, the exhaust manifold 13 and the intake manifold 12 are disposed on the same side of the engine, and the intake manifold 12 is positioned above the exhaust manifold 13 and is curved downward in the engine. When the vehicle is mounted on the vehicle, traveling air can be applied to the intake manifold 12 to reduce the intake air temperature to increase the charging efficiency and to prevent the exhaust air from hitting the exhaust manifold 13. Is prevented from hindering the activity of the catalyst located downstream.
[0015]
(Third and fourth embodiments)
Next, a third embodiment of the present invention will be described with reference to FIG. 4, and a fourth embodiment will be described with reference to FIG. In these embodiments, the fuel path 14 is arranged at a location secured by moving the intake port to the exhaust port side, thereby eliminating the need for the fuel common rail that has been required in the past and at the same time. It is possible to greatly improve the setting location of the internal direct fuel injection valve 10, the mounting angle, and the degree of freedom in setting the injection valve structure.
[0016]
Needless to say, the present invention can also be applied to an in-line 4-cylinder, in-line 6-cylinder, V-type 6-cylinder, V-type 8-cylinder, etc., as long as it is a direct in-cylinder spark ignition engine.
[0017]
【The invention's effect】
As described above, according to the present invention, in a configuration in which the fuel injection valve is directly attached to the cylinder head, each cylinder has one or more intake valves and one or more exhaust valves, and the intake / exhaust Cylinder head with intake camshaft and exhaust camshaft for driving the valve, ignition plug arranged at the approximate center between the intake valve and exhaust valve, and the intake valve near the intake valve for the direct injection fuel injection valve for in-cylinder direct injection The fuel injection valve main body is disposed at a position facing the exhaust port, and the opening on the side surface of the cylinder head on the upstream side of the intake port connected to each intake valve seat. The opening on the side of the cylinder head on the downstream side of the exhaust port is flush with the side of the cylinder head. By adopting an L-shaped intake port shape between the lube seat, it is possible to respond to the structure currently in use by changing the core, etc. without increasing the overall engine height as in the conventional example. Therefore, without increasing the cost, a reverse tumble flow is formed in the cylinder to enable stable combustion in a large lean air-fuel ratio region in a direct injection spark ignition engine.
[0018]
Furthermore, by configuring as shown in other embodiments, effects such as improvement in filling efficiency, maintenance of catalyst activity, and improvement in design freedom of the fuel system can be obtained.
[0019]
The present invention can also be applied to an in-line 4-cylinder, in-line 6-cylinder, V-type 6-cylinder, V-type 8-cylinder, etc., as long as it is a direct in-cylinder spark ignition engine.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of the present invention.
FIG. 2 is a diagram showing a first embodiment of the present invention.
FIG. 3 is a diagram showing a second embodiment of the present invention.
FIG. 4 is a diagram showing a third embodiment of the present invention.
FIG. 5 is a diagram showing a fourth embodiment of the present invention.
FIG. 6 is a view showing a conventional direct in-cylinder injection spark ignition engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Combustion chamber 3 Intake valve seat 4 Exhaust valve seat 5 Spark plug 6 Intake port 7 Inner manifold attachment opening 8 Exhaust port 9 Exhaust manifold attachment opening 10 Fuel injection valve 11 Piston 12 Intake manifold 13 Exhaust manifold 14 Fuel path

Claims (2)

Each cylinder has one or more intake valves and one or more exhaust valves,
The intake camshaft for driving the intake / exhaust valve and the cylinder head having the exhaust camshaft disposed therein, the ignition plug disposed at substantially the center position between the intake valve and the exhaust valve, and the tip of the fuel injection valve for in-cylinder direct injection Place it at the farthest position from the spark plug across the intake valve near the valve,
Arranging the fuel injection valve body at a position facing the exhaust port;
The opening on the cylinder head side surface upstream of the intake port connected to each intake valve seat and the opening on the cylinder head side surface downstream of the exhaust port are configured to be flush with the cylinder head side surface.
An L-shaped intake port shape is formed between the cylinder head side opening of the intake port and the intake valve seat . The exhaust manifold and the intake manifold are disposed on the same side of the engine, and the intake manifold is located above the exhaust manifold. Directly characterized in that it is configured so that the intake manifold covers the exhaust manifold so that the running wind hits the intake manifold and prevents it from hitting the exhaust manifold when mounted on the vehicle, while curving downward on each engine In-cylinder injection spark ignition engine.   2. The direct in-cylinder injection spark ignition engine according to claim 1, wherein a fuel path is installed in a cylinder head facing the exhaust port with the combustion chamber interposed therebetween.