JP3682985B2 - Model engine fuel supply system - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a fuel supply device for a model engine.
[0002]
[Prior art]
In general, in a model engine, a fuel pump is operated by driving the engine so that fuel in a fuel tank is sent to a carburetor. In the carburetor, the fuel and air are mixed, and the mixture is sucked into the combustion chamber of the engine.
[0003]
When the engine for a model is switched from an idling state to a high-speed rotation state, the air passage of the carburetor is switched from a state close to a fully closed state to a fully opened state to increase the supply amount of the air-fuel mixture. At this time, the passage switching speed of the carburetor is slightly faster than the rising speed of the engine, and the air passage of the carburetor is fully opened until the engine reaches high speed rotation.
[0004]
[Problems to be solved by the invention]
By the way, the fuel pump incorporated in the fuel supply device of the model engine decreases the operating rate when the engine speed decreases, but the fuel pump is of a constant discharge type such as a diaphragm pump or a gear pump. Fuel control is difficult.
[0005]
For this reason, when the engine is switched from the idling state to the high-speed rotation state, the amount of fuel supplied with respect to the amount of air increases until the engine reaches the high-speed rotation, so that there is a problem that the startup performance of the engine is poor.
[0006]
In view of this, the present invention solves the above-described problems, and enables an air-fuel mixture in an amount corresponding to the rotational speed of the engine to be supplied to the engine combustion chamber when the engine is switched from the idling state to the high speed rotation. The technical challenge is to improve the engine start-up performance.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, in the present invention, a pressure chamber is provided on the discharge side of a fuel pump that sends fuel in a fuel tank to a carburetor, and the opening of the fuel passage is controlled by pressure fluctuation in the pressure chamber. A regulator to be adjusted was incorporated, and a configuration was adopted in which the pressure chamber of the regulator and the muffler muffler chamber connected to the exhaust port of the engine communicated with each other through a passage.
[0008]
[Action]
With the above configuration, when the engine is driven, the pressure of the exhaust flowing from the engine into the muffler is applied to the pressurizing chamber, and the exhaust pressure and the engine speed are in a proportional relationship. As the rotational speed increases, the pressure in the pressurizing chamber of the regulator also increases. As the pressure in the pressurizing chamber rises, the opening of the fuel passage also increases, and an amount of fuel corresponding to the rotational speed of the engine can be supplied to the carburetor.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0010]
As shown in FIGS. 1 and 2, a muffler 3 is connected to the exhaust port 2 of the model engine 1. A carburetor 4 is connected to the engine 1, a fuel pump 7 is incorporated in a fuel passage 6 communicating with the carburetor 4 and the fuel tank 5, and a regulator 8 is incorporated on the discharge side of the fuel pump 7.
[0011]
Here, the fuel pump 7 may be a diaphragm pump that operates by pressure fluctuation in the crank chamber of the engine 1 or may be a gear pump that operates by rotation of the crankshaft of the engine 1.
[0012]
4 and 5 show an example of the carburetor 4. The carburetor 4 is provided with an air passage 10 and a rotor storage hole 11 intersecting the air passage 10 in the carburetor body 9, and an opening degree of the air passage 10 is inserted into a rotor 12 rotatably incorporated in the rotor storage hole 11. A through-hole 13 in the radial direction for adjusting the angle is formed. The rotor 12 is formed with an axial insertion hole 14 communicating with the through hole 13, while the carburetor body 9 is provided with a screw hole 15 coaxially with the insertion hole 14 and is screwed into the screw hole 15. The tip of the fuel injection pipe 16 is positioned in the through hole 13 from the insertion hole 14.
[0013]
The carburetor 4 sprays the fuel supplied from the fuel passage 6 to the fuel injection pipe 16 into the through hole 13 and mixes it with the air flowing from the inlet 10a of the air passage 10 to form an air-fuel mixture. The air-fuel mixture is sent from the outlet 10 b of the air passage 10 to the combustion chamber of the engine 1.
[0014]
FIG. 3 shows the regulator 8. This regulator 8 has a diaphragm 18 attached to the regulator body 17 to form a pressurizing chamber 19 and a fuel adjustment chamber 20 inside the body, and an inlet side passage 21 and an outlet side passage 22 are connected to the fuel adjustment chamber 20. Yes.
[0015]
Further, a thin plate spring 23 having elasticity is provided in the fuel adjustment chamber 20, a bent piece 24 at one end of the plate spring 23 is fixed to the bottom surface of the fuel adjustment chamber 20, and the plate spring 23 is attached to the lower surface of the diaphragm 18. The bent piece 25 at the other end is brought into contact with one end portion of the strip-like valve support plate 26. A central portion 27 in the length direction of the valve support plate 26 is swingably supported. One end of the valve support plate 26 is pressed upward by a spring 33, and a valve body 28 for adjusting the opening degree of the inlet side passage 21 is provided at the other end. Is provided.
[0016]
Two nipples 29 and 30 are screwed into the peripheral wall of the pressurizing chamber 19, and one nipple 29 and the sound deadening chamber of the muffler 3 are connected by a passage 31. The other nipple 30 and the fuel tank 5 are connected by a passage 32.
[0017]
Now, when the engine 1 is driven, the fuel pump 7 is operated, and the fuel in the fuel tank 5 is supplied to the fuel injection pipe 16 of the carburetor 4 through the fuel adjustment chamber 20 of the regulator body 17. The fuel is sprayed into the through hole 13 from the tip of the fuel injection pipe 16 and mixed with the air flowing into the air passage 10 from the inlet 10a.
[0018]
The air-fuel mixture is sent into the combustion chamber of the engine 1 and burned, and the combustion exhaust gas is discharged from the exhaust port 2 into the muffler 3.
[0019]
Here, since the muffler 3 and the pressurizing chamber 19 of the regulator 8 communicate with each other via the passage 31, the exhaust flows into the pressurizing chamber 19, and the diaphragm 18 is moved downward by the pressure of the exhaust. To sing.
[0020]
Due to the bending of the diaphragm 18, the leaf spring 23 is deformed downward and presses one end of the valve support plate 26. For this reason, the valve support plate 26 swings and the valve element 28 adjusts the opening degree of the inlet side passage 21.
[0021]
Here, since the pressure of the exhaust gas flowing into the pressurizing chamber 19 is proportional to the rotational speed of the engine 1, when the engine 1 is in the idling state, the exhaust pressure is low and the deformation amount of the diaphragm 18 is small.
[0022]
For this reason, the valve body 28 is only slightly separated from the inlet side passage 21 of the regulator 8, the opening degree of the inlet side passage 21 is small, and a small amount of fuel is sent to the carburetor 4. At this time, the air passage 10 of the carburetor 4 is in a state of being narrowed down by the rotor 12.
[0023]
When the engine 1 is switched from the idling state to the high speed rotation, the air passage 10 of the carburetor 4 is immediately fully opened by the rotation of the remotely operated rotor 12, but the rotational speed of the engine 1 does not increase rapidly, and the carburetor The rise speed of the engine 1 is different from the switching speed of the four air passages 10.
[0024]
At this time, the pressure of the exhaust gas gradually increases according to the speed change of the engine 1, and the deformation amount of the diaphragm 18 of the regulator 8 gradually increases due to the pressure increase of the exhaust gas, and the valve body 28 gradually separates from the inlet side passage 21. The opening degree of the inlet-side passage 21 increases with a change in the rotational speed of the engine 1.
[0025]
For this reason, an amount of fuel corresponding to the rotational speed of the engine 1 is fed into the carburetor 4.
[0026]
As in the embodiment, by connecting the regulator 8 and the fuel tank 5 through the passage 32, the exhaust gas flowing into the pressurizing chamber 19 of the regulator 8 flows into the fuel tank 5, so that the oil content in the exhaust gas is removed from the fuel tank. 5 can be returned.
[0027]
FIG. 6 shows another example of the regulator 8. In the regulator 8, an upper hollow end plate 17a, an annular plate 17b, and a lower end plate 17c joined together by tightening screws form an internal hollow regulator body 17, and the lower end plate 17c includes an inlet-side passage 21 and The outlet side passage 22 is provided, and the outlet of the inlet side passage 21 is opened at the upper end surface of the protrusion 40 formed at the center of the upper surface of the lower end plate 17c.
[0028]
Further, the outer peripheral portion of the diaphragm 18 provided inside the regulator body 17 is sandwiched between the upper end plate 17a and the annular plate 17b, and the valve plate 41 for adjusting the opening degree of the outlet of the inlet side passage 21 on the lower surface of the diaphragm 18. The pressure regulating chamber 42, the pressurizing chamber 19 and the fuel adjusting chamber 20 are formed from the upper part inside the regulator body 17 by sandwiching the outer periphery of the valve plate 41 between the annular plate 17b and the lower end plate 17c. doing.
[0029]
Further, the outlet side passage 22 and the pressure regulating chamber 42 are communicated with each other through the passage 43. The passage 43 may be provided at the center of the diaphragm 18 and the valve plate 41 so as to allow the fuel adjustment chamber 20 and the pressure adjustment chamber 42 to communicate with each other, as indicated by a two-dot chain line in FIG.
[0030]
A spring that presses the diaphragm 18 toward the outlet of the inlet-side passage 21 may be incorporated in the pressure regulating chamber 42.
[0031]
The regulator 8 having the above-described configuration connects the muffler 3 silencer chamber and the pressurizing chamber 19 through a passage 31, and connects the pressurizing chamber 19 and the fuel tank 5 through a passage 32.
[0032]
Further, the discharge port of the fuel pump 7 and the inlet side passage 21 are communicated, and the outlet side passage 22 and the carburetor 4 are communicated by the fuel passage 6.
[0033]
With the above configuration, when the engine 1 is switched from the idling state to the high speed rotation, the exhaust pressure proportional to the rotational speed of the engine 1 flows into the pressurizing chamber 19. At this time, the diaphragm 18 is deformed toward the pressure regulating chamber 42 due to the difference in pressure receiving area between the diaphragm 18 and the valve plate 41, the valve plate 41 is separated from the outlet of the inlet side passage 21, and the opening degree of the outlet is that of the engine 1. It increases gradually according to the rotation speed.
[0034]
For this reason, the fuel according to the rotational speed of the engine 1 flows from the outlet side passage 22 to the carburetor 4, and the startup performance of the engine 1 can be improved.
[0035]
【The invention's effect】
As described above, in the fuel supply device according to the present invention, the exhaust having a proportional relationship between the rotational speed and the pressure of the engine is led to the pressurizing chamber of the regulator to adjust the opening of the fuel passage. The amount of fuel corresponding to the rotational speed of the engine can be fed into the carburetor, and the engine startup performance can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view schematically showing a fuel supply apparatus according to the present invention. FIG. 2 is a front view of the same. FIG. 3 is a sectional view of a regulator of the same. 5 is a cross-sectional view taken along line VV in FIG. 4. FIG. 6 is a cross-sectional view showing another example of the regulator same as above.
1 Engine 2 Exhaust port 3 Muffler 4 Carbator 5 Fuel tank 6 Fuel passage 7 Fuel pump 8 Regulator 19 Pressure chamber

Claims (1)

Embedded fuel pump to the fuel passage communicating the fuel tank and the carburetor, the fuel in the fuel tank to form a mixture by feeding the carburetor by the actuation of the fuel pump, is flowed the mixture into combustion chamber of an engine In the model engine fuel supply apparatus as described above, a pressure chamber is provided on the discharge side of the pump, and a regulator for adjusting the opening of the fuel passage according to the pressure fluctuation in the pressure chamber is incorporated. A fuel supply device for an engine for a model, characterized in that a chamber and a muffler muffler chamber connected to an exhaust port of the engine are communicated by a passage.

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