JPS6098163A - Fuel supply device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve firing property in start in a fuel supply device for an internal combustion engine using low quality fuel by forming compressed gas flow around a liquid fuel flowing port of a fuel flowing nozzle to promote the atomization of fuel. CONSTITUTION:A fuel injection nozzle 32 of an internal combustion engine 11 consists of a hosing 33, a compressed air supply pipe 34 and a liquid fuel supply pipe 35. Said pipe 35 is formed on the end with a liquid fuel flowing port 37. And between an opening end of the housing 33 and the end of said 35 is formed a compressed gas discharging port 38. Before starting the engine 11 is actuated a pump 47 to fill air in a compressed gas tank 43. Then, when a starter is operated, a switch valves 41, 45 are opened and compressed air is sent from a tank 43 to said pipe 34 of the nozzle 32 and discharged from said port 38 toward a scavenging path 27. Thus, the fuel flowing port 37 has negative presssure so that fuel is sucked from an auxiliary cabureter 29, mixed with air and atomized to explode in a combustion chamber 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to a fuel supply system optimal for an internal combustion engine that uses low-quality fuel such as alcohol, kerosene, or light oil.

[Background technology]

Low-quality fuels such as alcohol do not atomize well and cause problems with ignitability during startup. For this reason, in order to improve the ignition performance during starting, divine fuel supply devices have been proposed.

For example, the device proposed in Japanese Patent Application No. 57-227466 by the same applicant uses a glow plug to warm the fuel sent into the combustion chamber just before ignition to promote atomization and improve ignitability. .

As described above, conventional fuel supply devices are based on the idea of improving atomization by heating the fuel using a heating means such as a glow plug, and an energy source is required to heat the glow plug or the like. .

As an energy source, a silver source is usually used,
At least a heating element such as a glow plug, an electric wire, and a means for connecting these are required, resulting in a problem that the apparatus becomes complicated and large.

(Object of the Invention) The present invention was made in view of the above-mentioned conventional problems, and aims to improve ignition performance at the time of starting with a simple structure.
The purpose is to ensure and stabilize combustion conditions.

(Structure of the Invention) In order to achieve the above object, the present invention is provided with a compressed gas flow path disposed in a fuel path, and a liquid fuel outflow boat disposed within the flow path. A fuel supply device for an internal combustion engine, comprising a fuel outflow nozzle, a compressed gas supply means capable of supplying compressed gas to the fuel outflow nozzle, and a liquid fuel supply means capable of supplying liquid fuel to the fuel outflow nozzle. This is what we provide.

(Detailed description of the invention) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a two-stroke internal combustion engine for an outboard motor equipped with a fuel supply device as an embodiment of the present invention, FIG. 2 is a sectional view showing an example of a fuel outflow nozzle, and FIG. 3 is a sectional view showing an example of a fuel outflow nozzle. , is a sectional view showing another example of the fuel outflow nozzle.

The internal combustion engine 11 uses low-quality fuel such as alcohol or kerosene, and is of a horizontal type mounted on the top of an outboard motor body (not shown), with cylinders 13 arranged horizontally inside a cylinder block 12. .

A cylinder head 14 is integrated into the cylinder block 12, and a crankcase 15 is also integrated into the cylinder block 12. A crankshaft 16 is rotatably supported by the crankcase 15 , and a piston 18 is connected to the crankshaft 16 via a connecting rod 17 .

A main carburetor 22 is connected to a crank chamber 19 formed by the crank case 15 and the cylinder block 12 via a main intake passage 21 in which a main reed valve 20 is built-in.

A combustion chamber 23 can be formed in the cylinder 13.
1 ignition plug 24 is installed in the cylinder head 14 facing approximately the center of 3.
is located. The cylinder block 12 includes an exhaust passage 25 and a scavenging passage 27 that opens an outlet 26 to the cylinder 13 . An inlet of the scavenging passage 27 opens into the crank chamber 19 . There are two scavenging passages 27 at positions not shown, and the well-known Schneen scavenging system is employed.

A low-speed auxiliary intake passage 28 is formed in the cylinder block 12 facing the scavenging passage 27 in the figure.

The auxiliary carburetor 29 is connected to the open end, and a auxiliary reed valve 30 is provided in the auxiliary intake passage 2B.
is in communication with the scavenging passage 27 via this sub-board lift 30.

An opening 31 is provided in the cylinder block 12 adjacent to the outlet 26 of the scavenging passage 2T, and a grain outflow nozzle 32 is disposed in this opening 31 facing the scavenging passage 27.

The fuel outflow nozzle 32 has a no.
Crank 33. It also includes a compressed gas supply pipe 34 and a liquid fuel supply pipe 35.

The housing 33 has a cylindrical shape with both ends open, and one open end has a female thread. The other open end is narrower than the inner diameter and has a smaller diameter.

A flange 36 is formed on the liquid fuel supply pipe 35 , and a male thread is cut on the outer periphery of the flange 36 , and the flange 36 is screwed into the female thread of the crank 33 . The tip of the liquid fuel supply pipe 35 is
It opens slightly inward from the open end of the crank 33 and forms a liquid fuel outflow boat 37. Then,
A compressed gas jet boat 38 is formed between the open end of the nozzle 33 and the tip of the liquid fuel supply pipe 35 .

The liquid fuel supply pipe 34 is connected to a float chamber (not shown) of the auxiliary carburetor 29 through a fuel supply passage 39 .

The fuel supply passage 39 includes a check valve 40 that opens only in the direction of the fuel outflow nozzle 32, and a first opening/closing valve that opens by a link mechanism, solenoid, etc. at the same time as the electric starter or manual star coil starter is activated. 41 is provided 11
ing.

The base end of the compressed gas supply pipe 350 is connected to 1f: compressed gas supply passage 4
2, it is connected to a compressed gas tank 43. The compressed gas supply passage 42 includes a check valve 44 that opens only in the direction of the fuel outflow nozzle 32, and a second on-off valve that opens in conjunction with the operation of an electric starter or the like, like the first on-off valve 41. 45 are provided.

The compressed gas tank 43 is connected to a pump 47 via a compressed gas filling passage 46. The bo/zo 47 can be operated manually or electrically to pump air into the compressed gas tank 43. A check valve 48 that opens only in the direction of the compressed gas tank 43 is provided in the compressed gas filling passage 46 . Further, the compressed gas tank 43 is provided with a regulator 49 for adjusting the internal pressure, and when the internal pressure rises above a predetermined level, it opens to leak the internal gas (air) to the outside. Thus, the compressed gas tank 43 can store the compressed air sent by the pump 4T while maintaining it at a predetermined pressure.

Next, the operation of the above embodiment will be explained.

Before starting the internal combustion engine 11, the driver first starts the pump 4.
7 to fill the compressed gas tank 43 with air. At this time, the second on-off valve 45 is closed, and since there is a check valve 48, the air is unilaterally turned into compressed gas/gas 43.
going into. and.

When the air is compressed to a predetermined value [E], the regulator 49 is also released to the outside to release the excess air, and the inside of the tank 43 is maintained at the predetermined pressure. On the other hand, at this time, the first on-off valve 41
Since both are closed, the auxiliary carburetor 29 and the fuel outflow nozzle 32
It is not communicating with.

Next, when the electric starter or manual starter is activated, the first on-off valve 41 and the second on-off valve 4 are activated in conjunction with this.
5 opens. When the second on-off valve 45 opens, the check valve 4
4, compressed air is vigorously sent out from the compressed gas tank 43 to the compressed gas supply pipe 34 of the fuel outflow nozzle 32. The delivered compressed air is ejected from the compressed gas ejection boat 38 toward the scavenging passage 27 . Therefore, the fuel outflow boat 37 becomes a negative pressure, and a misting effect occurs, which opens the first on-off valve 41 and the check valve 40, which are open, and closes the auxiliary vaporizer 29.
Fuel is sucked from the float chamber.

The fuel mixes with air near the fuel spill boat 37 and becomes extremely fine mist. The atomized mixture is sent to the combustion chamber 23, and when a spark hits one spark plug 24, it is easily ignited and explodes. After that, the air pressure in the compressed gas tank 43 rapidly decreases, and the air is no longer jetted out from the compressed gas jet boat 38, or once an explosion occurs, the fuel outflow nozzle 32
Even if there is no air-fuel mixture supplied from the auxiliary carburetor 29, the internal combustion engine 11 can continue to operate with the fuel from the auxiliary carburetor 29. Therefore, the first on-off valve 41 and the second on-off valve 45 are closed at an appropriate time after startup, and further, when the warm-up operation is completed, the supply of fuel to the sub-carburizer 29 is also stopped and normal operation begins.

According to the above embodiment, since heating means such as glow plugs and power sources are not required, the ignition performance at the time of starting can be improved with an extremely simple structure, and the compressed air becomes part of the air-fuel mixture after being blown out. Therefore, there is no risk of any disturbance in the operation of the engine 11.

In the above embodiment, air was used as the compressed gas, but the present invention is not limited to this, and any gas that can convert the fuel may be used, for example.

As shown by the two-dot chain line 50 in FIG.
As shown at +52, the air-fuel mixture or the exhaust air in the combustion chamber 23 or even the exhaust air in the exhaust passage 25 can also be used. All of these can be sent to the compressed gas tank 43 by crank chamber pressure, combustion chamber pressure, and exhaust pressure.
There is an advantage that the pump 47 is not required. However, last time)
Since the gas must be stored during JJ rotation, it is necessary to ensure sufficient airtightness of the compressed gas tank 43 in case the compressed gas tank 43 is not operated for a long period of time.

Further, 1. In the above embodiment, a fuel outflow nozzle having a shape as shown in FIG. 2 was used, but the present invention is not limited to this. For example, the fuel outflow nozzle 5 shown in FIG.
5, a compressed gas supply pipe 57 is provided integrally with the housing 56, and a liquid fuel supply pipe 58 is provided so as to face the center of the interior from the side surface of the housing 56.

The tip end thereof serves as an outflow boat 59. In this case as well, the compressed gas ejected from the compressed gas supply pipe 51 creates a negative pressure in the housing 5G, and the fuel is also sucked out from the fuel supply pipe 58 due to the atomizing effect and is atomized and supplied, as shown in the second figure. It is the same as the example. In addition,
Although the fuel outflow boat 37 shown in the second figure opens slightly inward from the open end of the housing 33, it may open anywhere within the compressed gas flow path that produces a substantial atomizing effect. Of course.

Although the above embodiment is a two-stroke internal combustion engine, the same method can be applied to a four-stroke internal combustion engine, and in this case, the fuel outflow nozzle may be provided in the middle of the intake pipe.

Further, the above embodiment can be similarly implemented in a general two-cycle internal combustion engine that is provided with a low-speed auxiliary purifier in the scavenging passage or is not provided with it. In this case, the fuel supply passage may be connected to the main carburetor '1-'.

In the above embodiment, the first and second on-off valves were set to open at the same time as the starter was activated, but the operation was divided into two operations, and the first and second on-off valves were opened for the purpose of starting. It is also possible to set the starter so that it sends a completely different mixture and starts operating the starter from ''.

(Effects of the Invention) As described above, the internal combustion (2) related fuel supply device according to the present invention is disposed in the fuel supply path, includes a compressed gas flow path, and has liquid fuel in the flow path. A fuel outflow 7' nozzle configured by arranging an oIL exit boat, a compressed gas supply means capable of supplying compressed gas to the fuel outflow nozzle, and a compressed gas supply means capable of supplying /lf body fuel to the fuel outflow nozzle 7 It has compensatory fuel supply means. Therefore, when starting an engine, by forming a compressed gas flow around the liquid fuel outflow boat at the fuel outflow nozzle, the fuel, which has been atomized by the atomizing effect, flows out from the fuel outflow nozzle into the fuel supply path. This makes it possible to ensure and stabilize the combustion state of the engine.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a two-stroke internal combustion engine for an outboard motor equipped with a fuel supply device as an embodiment of the present invention, FIG. 2 is a cross-sectional view showing an example of a fuel outflow nozzle, and FIG. , is a sectional view showing another example of the fuel outflow nozzle. 32.55゛...Fuel outflow nozzle, 34.57...Compressed gas supply pipe, 35.58...Liquid fuel supply pipe, 3
7.59...Liquid fuel spill boat. Agent Patent Attorney Osamu Shiokawa

Claims (1)

[Claims] (1) A fuel outflow nozzle that is disposed in the fuel supply path and includes a compressed gas flow path and a liquid fuel outflow boat arranged in the flow path, and compressed gas can be supplied to the fuel outflow nozzle. A fuel supply device for an internal combustion engine, comprising compressed gas supply means capable of supplying liquid fuel to a fuel outflow nozzle.