JP2719962B2 - Fuel injection device for two-stroke internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fuel injection device for a two-stroke internal combustion engine that supplies fuel from a scavenging passage.

2. Description of the Related Art There is known a two-cycle internal combustion engine provided with an injector for injecting fuel into a scavenging passage and an air valve for injecting high-pressure air.

According to this, air can be supplied from the crank chamber to the combustion chamber through the scavenging passage, the combusted exhaust gas can be discharged from the exhaust passage, and then the fuel can be supplied to the scavenging passage. Can be reduced.

[Problems to be Solved by the Invention] By the way, this fuel injection device can prevent fuel from flowing through the exhaust passage by injecting the fuel at a fixed timing, but the high-pressure air is supplied in a short time when the scavenging passage is open. It is difficult to supply fuel by injection. Therefore,
Since the injection amount of the high-pressure air is small, the atomization of the fuel cannot be effectively performed, and the ignitability is poor, there is room for further improvement in fuel efficiency.

The present invention has been made in view of these circumstances,
It is an object of the present invention to provide a fuel injection device for a two-stroke internal combustion engine that can effectively atomize fuel, has good ignitability, and improves fuel efficiency.

[Means for Solving the Problems] In order to solve the above problems, a fuel injection device for a two-stroke internal combustion engine of the present invention includes a fuel passage for supplying fuel,
In a two-stroke internal combustion engine opened to a scavenging passage, a hydrogen passage for supplying hydrogen is provided, a hydrogen outlet of the hydrogen passage is opened to the fuel passage, and a hydrogen supply timing from the hydrogen passage is set after the scavenging passage is opened. The hydrogen injection is started, and the hydrogen injection is terminated before the scavenging passage is closed.

[Operation] In the present invention, hydrogen is injected from the hydrogen passage in a short time when the scavenging passage is open, and the fuel in the fuel passage is supplied by hydrogen injection. As described above, since the fuel in the fuel passage is supplied by high-speed hydrogen injection, the scavenging passage is opened in a short time,
A predetermined amount of fuel can be supplied effectively, and the ignitability is good, and the fuel efficiency is improved.

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

FIG. 1 is an overall configuration diagram of a fuel injection device for a two-cycle internal combustion engine according to the present invention, and FIG. 2 is a diagram showing injection timings of fuel and hydrogen.

In the drawings, reference numeral 1 denotes a water-cooled two-cycle internal combustion engine, in which a cylinder block 3 is mounted on a crankcase 2, and a cylinder head 4 is mounted on the cylinder block 3.
Is installed. A combustion chamber 6 is defined by the cylinder block 3, the cylinder head 4 and the piston 5, and the cylinder head 4 is provided with a spark plug 7. The spark plug 7 is sparked at a predetermined timing by the control device 8, and ignites the air-fuel mixture compressed in the combustion chamber 6.

The piston 5 is connected to a crankshaft 10 via a connecting rod 9 and rotates the crankshaft 10 by reciprocating the piston 5.

An intake passage 12 for sucking air into the crankcase 11 is formed in the crankcase 2, and a reed valve 13 is provided in the intake passage 12 for sucking air into the crankcase 11. An exhaust passage 14 for discharging exhaust gas from the combustion chamber 6 is formed in the cylinder block 3, and a scavenging passage 15 for sending air in the crank chamber 11 into the combustion chamber 6 is formed.

The two-stroke internal combustion engine is provided with a fuel injection device 16. The fuel injection device 16 has a fuel supply means 17 for injecting gasoline as a fuel and a hydrogen supply means 18 for injecting hydrogen, and these are attached to the cylinder block 3 via a support 19. Fuel is supplied from a fuel tank 21 to a fuel injector 20 constituting the fuel supply means 17 through a pump 22, and the pressure of the supplied fuel is adjusted to be constant by a pressure regulator 23.

The hydrogen injector 24 of the hydrogen supply means 18 has a hydrogen cylinder.
From 25, the pressure of hydrogen is adjusted by the regulator 26, and the surge tank 27 supplies the hydrogen by absorbing the pressure fluctuation.

A bleed pipe 28 is fitted from the fuel injector side to the support on which the fuel injector 20 and the hydrogen injector 24 are mounted, and an injection nozzle 29 is provided at the tip end in a scavenging passage.
It is fitted to face 15. This bleed pipe 28
A fuel passage 30 for supplying fuel is formed by the injection nozzle 29 and the fuel passage 30 is open to the scavenging passage 15. The volume of the fuel passage 30 is set to a volume that can store the fuel injected by the fuel injector 20 when the scavenging passage 15 is closed.

A part of the outer periphery of the bleed pipe 28 is formed to have a small diameter, a plurality of through holes 31 are formed around the small diameter part 28a, and a hydrogen passage 32 is further provided between the small diameter part 28a and the support 19.
Are formed. This hydrogen passage 32 is a hydrogen injector
The bleed pipe 28 communicates with the hydrogen passage 33 that supplies hydrogen from the bleed pipe 28 through the through hole 31, and the injection nozzle 29.
The hydrogen outlets of the hydrogen passages 32 and 33 are open to the fuel passage 30.

The fuel injector 20 and the hydrogen injector 24 are each operated by a drive signal from the control device 8, and inject fuel and hydrogen at predetermined timing.

FIG. 2 shows the injection timing of fuel and hydrogen,
The scavenging passage 15 opens before the bottom dead center of the operation of the piston 5,
It closes after the bottom dead center, during which fresh air is supplied to the combustion chamber 6. By supplying the fresh air to the combustion chamber 6, the burned exhaust gas is pushed and pushed out of the exhaust passage 14.

The fuel injector 20 is operated before the top dead center, before the scavenging passage 15 is closed, and before hydrogen is supplied from the hydrogen injector 24, so that the fuel passage 30 is filled with fuel in advance.

The operating period of the fuel injector 20 may be extended to a period during which hydrogen is injected, as shown by a broken line in FIG. 2, or the period may be shortened when the engine load is small, as necessary. Can be changed. In this case, it is preferable to shorten the injection period by keeping the fuel injection end timing constant and delaying the injection start timing.

The hydrogen injection timing of the hydrogen injector 24 is before the bottom dead center, and after the fuel is injected, the scavenging passage 15 is operated and opened after the scavenging passage 15 is opened, and the hydrogen injection is terminated before the scavenging passage 15 is closed, Thus, the fuel previously stored in the fuel passage 30 is supplied to the combustion chamber 6 from the scavenging passage 15 by injecting hydrogen.

As described above, since the hydrogen outlet of the hydrogen passage is opened in the fuel passage 30, a predetermined amount of fuel is stored in the fuel passage 30 in advance, and hydrogen can be injected and supplied at a predetermined timing. Therefore, even when the scavenging passage 15 is open for a short time, a predetermined amount of fuel can be reliably supplied by hydrogen. Moreover, even if the atomization of the fuel is poor, lean combustion is possible due to the good ignitability of hydrogen, and the fuel efficiency is improved.

In addition, hydrogen is lighter than air, and the sound speed is about 3.
Since it is eight times as large, a predetermined amount of fuel can be extruded at a high speed, and this fuel collides with air, thereby promoting atomization of fuel.

Moreover, a predetermined amount of fuel is stored in the fuel passage 30 in advance,
Since this fuel is supplied by hydrogen injection, the whole fuel can be extruded at a high speed, and atomization is further promoted.

Further, after the scavenging passage 15 is opened, the injection of hydrogen is started, and before the scavenging passage 15 is closed, the injection of hydrogen is terminated.Therefore, there is no leakage of hydrogen to the crank chamber 11 or the like, and the flashback Occurrence can be suppressed.

It is also possible to make the supply amount of hydrogen constant regardless of the engine load. This is because the ignitability of the fuel itself is improved under a high load as compared with a low load, so that it is not necessary to increase the supply amount of hydrogen. This makes it possible to minimize the amount of hydrogen stored in the vehicle and to control the supply amount easily because the supply amount of hydrogen is kept constant.

FIG. 3 is a sectional view of a fuel injection device according to another embodiment.
In this embodiment, the same components as those shown in FIGS. 1 and 2 have the same configuration and the same function, and therefore, the description is omitted.

Injection nozzle 29 fitted to support 19 of fuel injection device 16
Is provided with a check valve 40 in the opening 29a at the end thereof, and is urged by a spring 41 to close the opening 29a. The spring 41 is supported by a ring 42 having an opening, and the ring 42 is locked to an end portion 29 b of the injection nozzle 29.

The spring 41 of the check valve 40 does not open at the pressure when the fuel is supplied, and when the fuel is filled with the fuel in the fuel passage 30, the check valve 40 opposes the spring 41 when injecting hydrogen. It moves and opens the opening 29a to supply fuel.

As described above, since the opening 29a of the injection nozzle 29 is closed except when hydrogen is injected, the injection nozzle 29 can supply a predetermined amount of fuel. Further, the supply of hydrogen is completed in a short time when the scavenging passage 15 is open, and thereafter the fuel passage 30 is closed by the check valve 40.
It is possible to prevent flashback in the direction of 29.

[Effect of the Invention] As described above, the fuel injection device for a two-stroke internal combustion engine according to the present invention has a hydrogen outlet in the hydrogen passage opened to the fuel passage, and the hydrogen supply timing from the hydrogen passage is set after the scavenging passage is opened. Since the injection is started and the hydrogen injection is terminated before the scavenging passage is closed, the excellent ignitability of hydrogen enables significant lean combustion even if the atomization of the fuel is poor.

Further, the whole fuel can be pushed out at high speed by the injection of hydrogen, and by colliding with air, atomization of the fuel is promoted and the size of the apparatus can be reduced.

Further, since the supply of hydrogen is completed in a short time when the scavenging passage is open, flashback in the direction of the crankcase can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a fuel injection device for a two-cycle internal combustion engine according to the present invention, FIG. 2 is a diagram showing fuel and hydrogen injection timings, and FIG. It is sectional drawing of another Example. In the drawings, reference numeral 1 is a two-cycle internal combustion engine, 5 is a piston, 15 is a scavenging passage, 16 is a fuel injection device, 17 is a fuel supply means, 18 is a hydrogen supply means, 28 is a bleed pipe, 29 is an injection nozzle, and 30 is an injection nozzle. A fuel passage, 32 and 33 are hydrogen passages, and 40 is a check valve.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication F02M 67/14 F02M 67/14 69/10 69/10

Claims (1)

(57) [Claims] 1. A two-stroke internal combustion engine in which a fuel passage for supplying fuel is opened to a scavenging passage, a hydrogen passage for supplying hydrogen is provided, and a hydrogen outlet of the hydrogen passage is opened to the fuel passage. Wherein the hydrogen injection is started after the scavenging passage is opened, and the hydrogen injection is terminated before the scavenging passage is closed.