JPH02125961A - Fuel supply device for two-cycle internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the lubricating performance of each portion within a crank case at what is equipped with an injector conducting the supply of fuel to a crank case side, by providing an oil supplying means that discharges and supplies oil to the spraying range of fuel injected by the injector. CONSTITUTION:A crank case 10 at a 2 cycle engine 1 is connected with an intake pipe 16, and a lead valve 14 is fitted at the vicinity of where the intake pipe 16 is connected to the crank case 10. Also, an injector 20 is provided on the upper stream side where the lead 14 of the intake pipe 16 is located, and this injector 20 is controlled by means of an electronic control unit 26 in accordance with an opening condition. In this case, it is so constituted that an oil discharge opening 40 is opened between the lead valve 14 and the injector 20, and oil is supplied from a plunger pump 22 through a passage 21. The plunger pump 22 is driven by means of a cam linking with the engine, and makes the supply amount of oil changeable according to the revolution number of the engine.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a two-stroke internal combustion engine (hereinafter also referred to as an engine).
The fuel supply system uses an injector and uses a separate lubrication method (an oil pump and oil tank are installed to forcibly supply oil to the necessary locations to lubricate the side of the crankcase). Regarding.

(Prior art) Conventionally, as a lubrication method for bearings such as the crankshaft and connecting rods in the crankcase of a two cycle engine, a method of lubricating the bearings such as the crankshaft and connecting rods in the crankcase is a method in which oil is mixed in a fixed proportion with fuel, the so-called mixed lubrication method (U.S. Patent 4,290,
394, etc.), a method in which an oil pump and an oil tank are installed, and oil is supplied to the necessary oil tank for lubrication.
The so-called minute 11 lubricating system (Japanese Patent Application Laid-Open No. 60-156971
(see Japanese Utility Model Application Publication No. 61-200447, etc.) are known.

In the above-mentioned mixed refueling system, the mixing ratio of fuel and oil is generally set in accordance with the case in which oil is consumed the most.

Therefore, even when the amount of oil is at least sufficient in a low-speed rotation operating state of -L franc, for example, excess oil is supplied, which may result in wasted oil consumption. In addition, if fuel mixed with oil is used in an injector, the oil may dry at the injection port of the injector.
This causes the problem of clogging, which makes it impossible to close the valve of the injector, which is likely to cause so-called blow-out. 1. On the other hand, in the conventional separate oil supply system, the oil consumption can be reduced when the engine is running at low speed by controlling the Δ oil supply 13 in conjunction with the engine speed, etc., and the mixed oil supply method The drawbacks of this method can be avoided.

Therefore, in the separate oil supply system using a carburetor, a method is adopted in which oil is sucked into the crankcase together with the air-fuel mixture. However, this method has the problem that the oil is not sufficiently atomized, and therefore the oil does not sufficiently lubricate each part of the crankcase.

(Problems to be Solved by the Invention) Therefore, in order to solve the problems of the prior art described above, the present invention provides a fuel supply device that can realize effective lubrication in a two-stroke internal combustion engine using an injector. The problem to be solved is to

(Means for solving the problem) The above problem is solved by the means described below. 1 In other words, in a two-stroke internal combustion engine that has an injector that supplies fuel to the crankcase side, U)-(,!'II ii
I of the fuel injected by the L injector! i A to 8m range
This can be solved by providing an oil supply means for discharging and supplying oil.

Further, by providing an air supply means for supplying high-pressure air to the spray range of the fuel injected by the injector, a layer effect can be achieved. 1 (Function) Next, the effects of the present invention having the above configuration will be explained.

Since the oil is discharged and supplied to the spray range of the fuel injected by the injector, the oil is strongly atomized by the fuel injected by the injector and is forcefully sucked into the crankcase side. Therefore, each part within the crankcase is effectively lubricated. In particular, if high-pressure air is also supplied, the above action will be very active.

(Example) <First Example> A first example according to the present invention will be described with reference to FIGS. 1 to 3.

Figure 1 is a schematic configuration diagram of the first embodiment. In Figure 11, 1 is 2.
This is a cycle engine, and the cylinder 2 has a scavenging hole (not shown) and a υF air hole (1) in the wall surface of the cylinder 2. Both of the holes are opened and closed by the linear backward movement of the piston 4 within the cylinder 2, thereby exchanging gas. In the figure, numeral 10 is a crankcase, in which a connecting rod 6 and a crank 8 convert the movement of the piston 4 into rotational movement.

The crankcase 10 communicates with an intake pipe 16, and a reed valve 14 is installed near where the intake pipe 16 is connected to the crankcase 10. In the figure, 20 is an injector, which is installed on the first flow side of the intake pipe 16 where the reed valve 14 is located. The injector 20 is connected to a fuel pump 28 via a connecting pipe 27, and the fuel pump 28 is connected to a fuel tank 30 via a connecting pipe 29.
is connected to. Furthermore, the injector 20 is connected to an electronic control unit (hereinafter referred to as ECU) 2 via a connection line 25.
6. In addition, the injector 20
The fuel pressure inside the engine is controlled by a pressure regulator (not shown) so that the differential pressure between the fuel pressure and the intake pipe pressure becomes a predetermined pressure. The ECU 26 is also electrically connected to various sensors (not shown), and controls the injection of the injector 20. Note that an injection port 20a is provided at the tip of the injector 20.

An oil discharge port 40 is opened between the reed valve 14 and the injector 20, and oil is supplied from the plunger pump 22 through a passage 21. The plunger pump 22 is connected to an oil tank 24 via a connecting pipe 23. The plunger pump 22 is mechanically connected to a cam (not shown) driven by the engine 1, and the amount of oil supplied can be changed depending on the engine speed.

A throttle valve 18 is attached to the first stream of the intake pipe 16 where the injector 20 is located, and the amount of intake air to each engine 1 is adjusted according to its opening degree.

FIG. 2 is a schematic vertical sectional view of a portion where the oil discharge port 40 is located. As shown in the figure, the reed valve 14 is installed between the intake passage 16a and the intake passage 16b of the intake pipe 16.
4b etc. That is, air, fuel mixture, and oil are allowed to flow into the crankcase 10, and their outflow from the crankcase 10 is prohibited.

FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. The oil discharge port 40 is the injection port 2 of the injector 20.
It opens into the intake pipe 16 near 0a. Aile discharge 1”
Reference numeral 40 denotes an opening of an oil supply groove 42 formed in the intake pipe 16, which opens into the intake pipe 16. 1 Furthermore, the oil supply groove 42 is connected to an oil introduction section 34 that introduces oil from the plunger pump 22.

Next, the operation of the first embodiment will be described.

When the engine 1 is operating and the piston 4 is in an upward stroke (intake/compression stroke), the inside of the crankcase 10 becomes negative pressure. The air regulated by the throttle valve 18 mixes with the fuel injected from the injector 20 and flows into the crankcase 10 through the open reed valve 14. At this time, the plunger pump 22 supplies oil to the oil outlet 40, the amount of which is adjusted according to the engine speed, etc.
It is discharged from. The discharged oil is vigorously mixed with the injected fuel injected from the injector 20, atomized, and vigorously flows into the crankcase 10 together with the injected fuel. Therefore, each part in the crankcase 10 is effectively lubricated 1, and since the amount of oil supplied is determined according to the engine speed etc., oil consumption is efficient at least when the engine 1 rotates at low speed.

Note that an electric oil pump electrically connected to the ECU 26 may be used instead of the plunger pump 22 as a pump for supplying oil.

As a result, precise control of the -layer oil supply is realized.

<Second Embodiment> Next, a second embodiment according to the present invention will be described with reference mainly to FIGS. 4 and 5. Note that FIGS. 4 and 5 correspond to FIGS. 2 and 3 of the first embodiment, respectively.

The same reference numerals are given to the same members as in the first embodiment, and the explanation thereof will be omitted.

In the first embodiment, as shown in FIG.
In the second embodiment, the oil discharge port 50 is opened in the wall surface on the opposite side where the injector 20 is located. In addition, 52 in the figure is formed in the intake pipe 16, and 1 [
This is the oil supply groove. The configuration of the second embodiment is the same as that of the first embodiment, so a description thereof will be omitted.

According to the second embodiment, even if the air-fuel mixture blows back from the crankcase 10, it is possible to sufficiently prevent oil from adhering to the injection port 20a of the injector 20. Clogging is less likely to occur, the valve (not shown) of the injector 20 is prevented from being in a constantly open state, and so-called blow-out of the injector 20 is less likely to occur. Other functions and effects are substantially the same as those in the first embodiment, so explanations thereof will be omitted.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. 6 and 7. Note that the same reference numerals are used for the same members as in the second embodiment, and the description thereof will be omitted.

The third embodiment is the same as the second embodiment, with the addition of a device for supplying high-pressure air, and a schematic configuration diagram thereof is shown in FIG. That is, a high-pressure air jet port 60 is opened in the wall surface of the intake pipe 16 between the injector 20 and the oil discharge port 50.

Furthermore, the air sent from the air pump 64 is
The passage 6 is opened by the opening operation of the high pressure air control valve 62 through the
1 and a high-pressure air outlet 60. Note that the high-pressure air control valve 62 is electrically connected to the ECU 26 via the connection line 31, and controls the injection timing and injection amount of high-pressure air.

FIG. 7 is a schematic vertical sectional view of a portion where the high pressure air control valve 62 is located. The high pressure air control valve 62 includes a ball valve 71, an armature integrated with the ball valve 71, an armature 78, a stopper 72,
It is composed of a solenoid coil 74, a spring 76, and the like. The ball valve 71 is connected to the passage 6 by a spring 76.
5 and the passage 61 are always urged to seal the sealing surface 68 in an open state. Note that 66 in the figure is a high-pressure air supply port, which is connected to the air pump 64.

The other configurations are the same as those of the second embodiment, so their explanation will be omitted.

1EcU26 causes the high pressure air control valve 62 to open. When controlled as follows, that is, when the solenoid coil 74 is energized and the armature 1778 is sucked, the ball valve 71 opens the passage 65 and the passage 61. Let it be.

The high pressure air sent from the air pump 64 passes through the passage 65 and the passage 61 and is ejected from the high pressure air outlet. Therefore, the oil is further atomized by the injected fuel from the injector 20 and the high pressure air from the high pressure air control valve 62, and the various parts within the crankcase 10 are effectively lubricated. Note that the positions of the high-pressure air outlet 60 and the oil outlet 50 are not limited to the embodiment shown in FIG. 7.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference mainly to FIG. 8. Note that the same reference numerals are given to the same members in the third embodiment, and the explanation thereof will be omitted.

The fourth embodiment is the same as the third embodiment shown in FIG. 6, but is provided with a common discharge lower 0 in which the oil discharge port 50 and the high pressure air jet port 60 are shared. In FIG. 8, the common discharge lower 0 is located on the upper wall surface of the intake pipe 16, downstream of the injector 20, and near the injection port 20a of the injector 20. In addition, in the third embodiment [
An electric oil pump 32 is used instead of the plunger pump 22, and is electrically connected to the ECU 26 via a connecting line 33 to control the amount of oil discharged.

In the fourth embodiment, since the oil discharge port 50 and the high-pressure air injection port 60 are common, the atomization of the oil is further promoted. Since it is located nearby, IIJ
The injected fuel and oil that are vigorously injected from the port 20a are actively atomized and are sucked into the crankcase 10 through the reed valve 14, thereby providing effective lubrication.

Note that the mode of the common discharge lower 0 is not limited to the mode shown in FIG.
Any mode is acceptable as long as the oil can be discharged and supplied to the I+# injected fuel so that the oil is atomized into the injected fuel from the injector 20.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIGS. 9 to 11. Incidentally, parts having the same features as those in the fourth embodiment are designated by the same reference numerals, and explanation thereof will be omitted.

In the fifth embodiment, an adapter 80 is installed in the injector 20 of the fourth embodiment shown in FIG.
A passage 19 communicating with the oil pump 32 and a passage 59 communicating with the high pressure air control valve 62 are communicated with each other.

FIG. 10 shows a partial longitudinal sectional view of the adapter 80 of the injector 20. FIG. 11 shows a CC sectional view in FIG. 10. As shown in the figure, the adapter 80 is provided with an oil discharge port 90 and a high-pressure air jet port 100 on the downstream side of the jet port 20a so as to surround the jet port 20a. In the figure, one oil discharge port 90 and two high-pressure air jet ports 100 are provided, but the number and shape of these openings are not limited to those shown in FIGS. 10 and 11.

In the fifth embodiment as well, atomization of the oil is promoted by high-pressure air and injected fuel within the adapter 80, and substantially the same effect as in the fourth embodiment can be obtained.

(Effects of the Invention) The present invention can promote atomization of oil by discharging and supplying oil to the spray range of fuel injected by an injector, thereby effectively lubricating various parts within the crankcase. Furthermore, by supplying high-pressure air to the fuel spray range, atomization of the oil can be further promoted, and the lubrication of various parts within the crankcase becomes more effective.

[Brief explanation of drawings]

1 to 3 are diagrams showing a first embodiment according to the present invention, in which FIG. 1 is a schematic configuration diagram, FIG. 2 is a partial schematic longitudinal sectional view,
FIG. 3 is a Δ-Aliifi diagram of FIG. 2. 4 and 5 are diagrams showing a second embodiment of the present invention, in which FIG. 4 is a partially schematic vertical sectional view, and FIG. 5 is a 1° B-B sectional view. FIG. 7 is a diagram showing a third embodiment according to the present invention, FIG. 6 is a schematic configuration diagram, and FIG. 7 is a partial schematic longitudinal sectional view. FIG. 8 is a schematic configuration diagram of a fourth embodiment according to the present invention. 9 to 11 are diagrams showing a fifth embodiment according to the present invention, FIG. 9 is a schematic configuration diagram of the fifth embodiment, FIG. 10 is a longitudinal sectional view of the adapter portion of the injector, and FIG. The figure is the first
It is a CC sectional view in figure 0. 1... Engine 10... Crank case 14... Reed valve 16... Intake pipe 18... Throttle valve 20... Injector 22... Plunger pump 26... ECU 32... Oil pump 405090...Oil discharge port 60100...High pressure air outlet 62...High pressure air control valve 70...Common discharge port 80...Adapter Figure Figure Figure

Claims (2)

[Claims] (1) A two-stroke internal combustion engine having an injector for supplying fuel to the crankcase side, the fuel supply device comprising an oil supply means for discharging and supplying oil to a spray range of fuel injected by the injector. (2) The fuel supply device according to claim 1, further comprising air supply means for supplying high-pressure air to a spray range of the fuel injected by the injector.