JPH06173830A - Fuel injection type internal combustion engine - Google Patents

Abstract

PURPOSE:To spread and supply fuel and lubrication oil stably even in a throttle valve opening area where intake air flow is limited. CONSTITUTION:Regarding a fuel injection type internal combustion engine having a fuel injection nozzle 29 and an oil discharge opening 28 as well as a throttle valve 25 arranged in an intake air pipe 24, this fuel injection type internal combustion engine has the fuel injection nozzle 29 and the oil discharge opening arranged near a valve end 25A where the flow velocity of an intake air A passing through the throttle valve 25 becomes fast.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection type internal combustion engine, and more particularly to a fuel injection type internal combustion engine of a separate oil supply lubrication system in which lubricating oil is mixed into intake air.

[0002]

2. Description of the Related Art The invention described in Japanese Patent Application Laid-Open No. 2-40079 (first
A conventional example) and the invention described in Japanese Patent Application Laid-Open No. 1-170758 (second conventional example) disclose a fuel injection type two-cycle engine in which an injector is installed in an intake pipe. In these conventional examples, fuel is designed to be injected from the injector toward the reed valve.

Further, in the invention described in Japanese Patent Application Laid-Open No. 2-218862 (third conventional example) and the invention described in Japanese Patent Application Laid-Open No. 1-207114 (fourth conventional example), injection is performed in a fuel injection type two-cycle engine. It is disclosed that an injector is installed so that the fuel is directed to the oil discharge port of the lubricating oil and the scattering property of the lubricating oil is improved.

[0004]

Generally, the fuel injection type 2
In a cycle engine, atomized fuel injected by an injector travels from an intake pipe through a reed valve to a crank chamber, and is guided from this crank chamber through a scavenging passage into a cylinder. If the diameter is large, it is easily liquefied. This phenomenon is particularly noticeable when the throttle valve opening is small and the intake flow rate is small.
There is a risk that the concentration of the air-fuel mixture flowing into the cylinder will be non-uniform.

In the above-mentioned first and second conventional examples, no measures are taken regarding atomization of the fuel injected from the injector. Therefore, as described above, particularly when the valve opening of the throttle valve is small, the intake air flow rate is small, and there is a possibility that atomization of the atomized fuel cannot be promoted.

Also in the third and fourth conventional examples, in the region where the valve opening of the throttle valve is small and the air flow rate is small, the scattering of oil from the oil discharge port becomes insufficient.
However, in order to improve fuel efficiency and reduce exhaust gas, if the injection of fuel from the injector is cut and any cylinder is deactivated, it is not possible to expect an improvement in the dispersion of discharged oil due to the injected fuel. May be insufficiently lubricated.

The present invention has been made in consideration of the above circumstances, and is a fuel injection type internal combustion engine capable of stably diffusing and supplying fuel and oil even in the throttle valve opening region where the intake flow rate is small. The purpose is to provide an institution.

[0008]

According to the present invention, there is provided a fuel injection type internal combustion engine in which a throttle valve is installed in an intake pipe and a fuel injection port and an oil discharge port are also installed in the intake pipe. And the oil discharge port is installed near the valve end where the flow velocity of intake air passing through the throttle valve becomes faster.

[0009]

According to the fuel injection type internal combustion engine of the present invention,
Since the fuel injection port and the oil discharge port were installed near the valve end of the throttle valve where the flow velocity of the intake air is faster, the injected fuel and the discharged lubricating oil are discharged even in the region where the throttle valve opening is small. The intake air having a high flow velocity is more preferably atomized and scattered. Therefore, the diffusion of fuel and oil is stabilized, and the concentrations of the air-fuel mixture and lubricating oil introduced into the internal combustion engine can be made uniform.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an essential part of FIG. 2, and FIG. 2 is a sectional view of a two-cycle engine showing an embodiment of a fuel injection type internal combustion engine according to the present invention.

As shown in FIG. 2, a two-cycle engine 1
Reference numeral 0 denotes a crankcase 12 in which a crankshaft 11 is rotatably supported, a cylinder block 15 installed in the crankcase 12 and accommodating a piston 14 in a cylinder 13 so that the piston 14 can reciprocate, and a cylinder block 15 in the cylinder block 15. And a cylinder head 17 which is installed and constitutes a combustion chamber 16 between the cylinder 13 and the piston 14.

The piston 14 and the crankshaft 11 are connected by a connecting rod 18, and the reciprocating motion of the piston 14 is converted into the rotary motion of the crankshaft 11. Further, a spark plug 19 is installed on the cylinder head 17 to ignite and burn an air-fuel mixture (described later) in the combustion chamber 16.

The crankcase 12 includes a crank chamber 20.
Are formed for each cylinder (cylinder 13), and the crank chamber 20 is communicated with each cylinder 13 via a scavenging passage 21. Further, the cylinder block 15 is formed with an exhaust passage 22 for discharging exhaust gas burned in the combustion chamber 16.

An intake passage 30 is formed in the crankcase 12, a reed valve 23 is installed in the intake passage 30, and an intake pipe 24 is connected to the intake passage 30. This intake pipe 2
Reference numeral 4 is connected to an air cleaner (not shown) and guides intake air into the crank chamber 20 via the reed valve 23. The intake pipe 24 has a throttle valve 25 and a valve shaft 26.
Is rotatably supported by. The valve opening is determined by the rotation angle of the throttle valve 25, and the intake flow rate is determined according to the valve opening.

As shown in FIGS. 1 and 3, an injector 27 and an oil discharge port 28 are installed in the intake pipe 24. Fuel is injected from the injector 27 into the intake pipe 24, and the atomized fuel is mixed with the intake air to form a mixture, which passes through the reed valve 23 shown in FIG.
0 is pre-pressurized and is transferred from the scavenging passage 21 to the cylinder 13
It flows in and is burned in the combustion chamber 16. Oil outlet 2
Lubricating oil is discharged into the intake pipe 24 from 8, and the discharged oil is scattered in the air-fuel mixture and the crank chamber 20
Lubricate the inside, the cylinder 13, the piston 14, and the like.

As shown in FIGS. 1 and 3, the fuel injection port 29 and the oil discharge port 28 of the injector 27 are for intake air passing through the throttle valve 25 (indicated by arrow A in FIG. 1). It is installed near the valve end 25A where the flow velocity becomes faster. That is, the throttle valve 25 rotates about the valve shaft 26 in the range of the angle θ, but when the throttle valve 25 is rotated to increase the valve opening,
The valve end 25B moves in a direction opposite to the intake flow A, and the valve end 25A moves in a direction along the intake flow A. Therefore, particularly when the rotation angle θ of the throttle valve 25 is small and the valve opening is small, most of the intake air flows toward the valve end 25A side, and the intake flow rate flowing through the valve end 25A side increases.
The fuel injection port 29 and the oil discharge port 28 are installed in the intake pipe 24 near the valve end 25A of the throttle valve 25.

As described above, the fuel injection port 29 and the oil discharge port 28 have the throttle valve 25 with a higher intake flow velocity.
Since it was installed near the valve end 25A of the
The fuel injected from the fuel injection port 29 is atomized more preferably by the intake air having the high flow velocity, and the lubricating oil discharged from the oil discharge port 28 is also the intake air having the high flow velocity even in a region where the valve opening degree is small. Is more preferably scattered by. In this way, atomization of the atomized fuel is promoted and the scattering property of the lubricating oil is improved, so the diffusion of the fuel and lubricating oil is stabilized, and the concentrations of the air-fuel mixture and lubricating oil introduced to the internal combustion engine are made uniform. be able to.

[0019]

As described above, according to the fuel injection type internal combustion engine of the present invention, the fuel and the lubricating oil can be stably diffused and supplied even in the throttle valve opening region where the intake flow rate is small.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of FIG.

FIG. 2 is a sectional view of a two-cycle engine showing an embodiment of a fuel injection type internal combustion engine according to the present invention.

FIG. 3 is a view taken along the line III-III in FIG.

[Explanation of symbols]

 10 2 Cycle Engine 24 Intake Pipe 25 Throttle Valve 25A Throttle Valve End 27 Injector 28 Oil Discharge Port 29 Fuel Injection Port A Intake Flow Direction

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area F02M 69/04 P 7825-3G

Claims (1)

[Claims] 1. A fuel injection internal combustion engine in which a throttle valve is installed in an intake pipe and a fuel injection port and an oil discharge port are also installed in the intake pipe, wherein the fuel injection port and the oil discharge port are A fuel injection type internal combustion engine, which is installed near a valve end where the flow velocity of intake air passing through a throttle valve becomes faster.