JPH0216352A - Starting fuel feed device of carburettor - Google Patents

Abstract

PURPOSE:To miniaturize a carburettor body and make the installation to an internal combustion engine body easy by piping and connecting an electric primer pump separated from a carburettor body in which an accumulator and an electromagnetic switching valve are disposed to said carburettor body through a plurality of check valves. CONSTITUTION:When a pump switch not shown is turned on before starting an internal combustion engine, a primer pump 45 is driven by an electric motor 43, and its piston 90 is reciprocated. Then, the fuel in a metering chamber 38 in the fuel feed mechanism B of a carburettor 1 is sucked into a cylinder 81 through a check valve 56 and a pipe line 91, and also the fuel in the cylinder 81 is exhausted to the cumulating chamber 64 of the accumulator C in the carburettor 1 through the pipe line 91 and a check valve 57. When the electromagnetic switching valve D of the carburettor 1 is opened and a starting electric motor not shown is driven, then, the fuel in the accumulating chamber 64 is force fed to the lower space 19 of a throttle valve 18 through each passage 30, 20, and sucked into an inlet passage 11 by the sucking negative pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a starting fuel supply device for a Rochry throttle valve type carburetor.

[Prior art 1] The diaphragm carburetor of an internal combustion engine installed in a portable IJ machine such as a brush cutter is capable of operating the engine in all positions.
The engine is equipped with a fuel supply mechanism that supplies the appropriate amount of fuel depending on the operating conditions of the engine, but in cold weather the range of mixture concentration that can be started is limited.
A starting fuel supply device as disclosed in Japanese Patent No. 6 is separately provided. In this starting fuel supply system, the fuel in the metering chamber of the fuel supply mechanism is measured and stored in the starting fuel reservoir chamber using a manual primer pump, and the starting fuel is supplied by opening the manual on-off valve when starting the engine. of fuel is supplied to the lower cavity of the rotary throttle valve by natural head.

In this starting fuel supply system for a carburetor, the starting operation is troublesome because it is necessary to open the on-off valve with one hand and at the same time operate the engine speed coil with the other hand.

By the way, in recent years, even portable working machines have come to be equipped with engines equipped with a starter generator driven by battery power, so the inventor of the present invention has developed a system that automatically switches the primer pump and opening/closing valve during a cold start. The starting fuel supply system for the carburetor, which is driven by battery power, was fired at 17f1. According to this starting fuel supply system for a carburetor, the primer pump and on-off valve are physically attached back to the carburetor body, but the overall size is somewhat large, so it takes up a lot of space to install it in the engine. arise.

That is, as shown in Fig. 4.5, in an internal combustion engine 101 with a starting electric motor, an air cleaner 102 and a carburetor 1.7 flask 104 are connected to the engine body, and a fuel tank 32 is connected to the lower part of the fitting. be done. As shown in FIG. 5, the power source battery 73 is disposed on the side of the fuel tank 32. Therefore, in general, the starting power source 78 is connected to the carburetor 1 and the fuel tank 3.
2, and is configured to rotate the crankshaft 105 via a reduction gear system @103. In this case, the space around the carburetor 1 tends to become narrower, and the increased size of the carburetor 1 makes installation of the main body of the carburetor a national problem.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, the purpose of the present invention is to avoid increasing the size of the carburetor by arranging the electric primer pump separately from the carburetor, and to An object of the present invention is to provide a starting fuel supply device for a carburetor that can be easily started.

[Means for Solving the Problem] In order to achieve the above object, the present light is configured to include a pressure accumulator that can communicate with the metering chamber via a passageway that includes two check valves that allow the flow of fuel into the pressure accumulator chamber. and the N[41
An on-off valve and a relief valve disposed in the passage connecting the pressure accumulation chamber and the fuel tank are disposed in the carburetor body, and the space between the two check valves is separated by a single pipe. It is connected to an electric primer pump.

Check valves 56 and 57 that allow flow from the metering chamber 38 to the pressure accumulation chamber 64 are disposed in the middle of the passage 50.65 connecting the metering chamber 38 and the pressure accumulation chamber 64 of the pressure accumulator C. be done. A hollow space 95 between the check valves 56 and 57 is connected by a pipe 91 (vinyl hose or the like) to an electric primer pump 45 disposed at a location remote from the engine mounting portion of the working machine, for example.

When the primer pump 45 is reciprocated by the electric power 1+11143, the fuel in the metering chamber 38 is sucked into the cylinder 81'\ of the primer pump 45 through the passage 50, the check valve 56, and the pipe 91, and then from the cylinder 81 into the pipe. 91, the passage 65, and the check valve 57 to the pressure storage chamber 64, and excess fuel is returned to the fuel tank 32 through the passage 30, the relief valve 26, and the passage 27. At ωj, the metering room 38/
\New fuel is refilled from the fuel tank 32.

゛ih While the magnetic valve is closed, the starting electric motor 1f178 is activated at the same time! IJ 7+' 6 t, a[[64] Fuel supply 't
830, the valve is closed during f26f1, and the fuel is fed under pressure to the lower cavity of the rotary throttle valve 8 through the passage 20, and as the engine cranks, the fuel in the lower cavity 19 is sucked into the intake passage 11 and becomes an intake air. Since the mixture is mixed with the mixture and drawn into the engine as a high-a degree air-fuel mixture, cold starting of the engine can be easily achieved.

The Bry7 bomb 45 is provided separately from the carburetor main body, and the pipe 91
By connecting the carburetor 1 to the carburetor 1, it is possible to avoid an increase in the size of the carburetor 1 due to the electrical evolution of the engine.

[Embodiment J of the Invention As shown in FIG. 1, the starting fuel supply device for a carburetor according to the present invention includes a fuel supply pump A, a separate fuel supply tank 8, and a pressure accumulator C in the carburetor main body 18. , 71 and the magnetic closed valve O, while a separate electric primer pump 45 is connected to the pipe 9.
1 is connected to the carburetor main body 18.

The vaporizer 1 is constructed as follows. A cylindrical portion 2 extending in the vertical direction is formed in the center of a main body 18 having an intake passage 11 extending in the lateral direction, and the upper end portion of the cylindrical portion 2 is closed by a lid 12 . Rotary throttle valve 8 having a throttle hole 8a in the cylindrical portion 2
(hereinafter simply referred to as a throttle valve) is fitted so as to be rotatable and circumferentially movable in the axial direction. A shaft portion 14 extending upward from the throttle valve 8 is supported by the lid 12, and a lever 1 coupled to the upper end of the shaft portion 14 is supported by the lid 12.
5 supports a follower 16. Due to the force of a spring 13 that is located between M12 and the valve 8 and surrounds the shaft portion 14, the follower 16 is biased into engagement with the cam 17 provided on the M12, and when the lever 15 is rotated, the throttle valve is closed. 8 moves in the axial direction. At this time, the adjustment bolt 14a screwed into the screw hole of the shaft portion 14 and the rod valve 3 of the body also move in the axial direction. A spring 5 surrounding the rod valve 3 inside the threaded hole has a shaft portion 14.
This facilitates adjustment of the position of the rod valve 3 relative to the rod valve 3.

A fuel supply pipe 7 whose opening degree of the nozzle hole 6 is adjusted by the rod valve 3 is fixedly supported on the bottom wall of the main body 18 . The fuel supply pipe 7 is connected through a fuel jet 46 and a check valve 47 to a metering port 38 that holds the fuel at a constant pressure.

The fuel supply pump A has a daicephram 53 on the bottom surface of the main body 18.
and the main body 70 to form a pulsating pressure introducing seedling 54 having a pulsating pressure introducing port 59 on the upper side and a pump 55 on the lower side. The pulsating pressure introduction chamber 54 is connected, for example, to the entire crank of a two-stroke engine, and causes the diaphragm 53 to reciprocate up and down.

The pump seedling 55 includes a passage 51, a check valve 10, a filter 37,
It can communicate with a fuel connector 32 via a connecting pipe 31. Further, the pump seedling 55 can communicate with the metering 38 via the check valve 4, the passage 52, and the fuel inflow valve 9.

The fuel supply mechanism B is configured as follows. A diaphragm 34 and a cover 28 are coupled to the lower surface of the main body 70, and the diaphragm 34 defines an atmospheric chamber 36 having a metering 38 on the upper side and an atmosphere 058 on the lower side.

Lever 41 with support @ 40 inside metering 38
is supported.

The left end of the lever 41 is opposed to the tire flam 34 by a spring, while the right end supports the tapered fuel inlet valve 9.

Pressure accumulator C is constructed as follows. The main body 33 is connected to the lower side of the cover 28 with a diaphragm 61 interposed therebetween, and a pressure accumulator 64 is formed above the tire flamm 61, and an atmospheric chamber 62 having an atmospheric air port 49 is formed below. The diaphragm 61 is pushed up by the spring 63 of the atmospheric chamber 62 via the backing plate, and the fuel in the pressure accumulator 64 is pressurized. Pressure accumulator 64
is communicated with the valve chamber 25 through the passage 30. All valves 25 are connected to the fuel tank 32 via a relief valve 26, a passage 27, and a discharge pipe 29.
It is possible to communicate with Further, the valve chamber 25 includes an electromagnetic on-off valve D,
It communicates with the lower cavity 19 of the throttle valve 8 via the passage 2o.

The pressure accumulator 64 can communicate with the metering 38 via the check valve 57, the passage 65, the cavity 95, the check valve 56, and the passage 50.

The electric primer pump 45 communicates the cylinder 81 with the above-mentioned cavity 95 through a pipe 91. A shaft 85 of a gear 86 is supported inside a housing 83 that is integrated with the cylinder 81.
This gear 86 is meshed with a worm 87 connected to the shaft 44 of the electric motor 43.

One end of the crank 88 is connected to the gear 86 by an eccentric pin 84 of the gear 86, while the other end is connected by the pin 82 to a piston 90 having a seal member 89 fitted in the cylinder 81.

The electromagnetic on-off valve consists of a valve seat 68 provided at the end of the passage 20 that opens into the valve chamber 25, and a valve body 69 that is pressed against the valve seat 68 by the force of the spring 24. A plunger 69a, which is supported so as to be movable and is integral with the stem, is projected into the inside of the mm coil 67.

Figure 2 shows the electric motor 11143 that drives the electric primer pump 45 in the above-mentioned starting fuel supply system, the electromagnetic coil 67 of the electromagnetic on-off valve, and the starting type that starts the engine! JI is an electrical circuit diagram with 78.

Pump switch 74 and electric motor 11 for power supply battery 73
43 are connected in series. A switch 75, an electromagnetic coil 67 of an electromagnetic on-off valve, and a temperature switch 76 (eg, a bimetallic switch) that closes when the ambient temperature of the engine is below a predetermined value (eg, 5° C.) are connected in series to the power source battery 73. Further, the power supply battery 73 is connected to the switch 75.
A starting switch 77 for IJ and a starting motor 78 are connected in series.

Next, the operation of the carburetor starting fuel supply system according to the present invention will be described. Pump switch 7 before starting the engine
4, the electric motor 43 is driven and the electric primer pump 45 is rotated.

As the gear 86 rotates, the piston 90 is moved forward via the crank 88. When the piston 90 moves to the right, the fuel in the metering chamber 38 flows through the passage 50, the check valve 56, the cavity 95, and the pipe 91. The fuel in the cylinder 81 is sucked into the cylinder 81, and when the screw 1-90 subsequently moves to the left, the fuel in the cylinder 81 is supplied to the pressure accumulator 64 via the pipe 91, the cavity 95, the passage 65, and the check valve 57. Redy A7 noram 61 is spring 63
It is pushed down against the force of. f! in the pressure accumulation chamber 64. ! ! $
When 11 is filled, the fuel +4 passes through the passage 30 (valve chamber 25
1＼Full, surplus fuel goes to relief valve 26, passage 27, lJ
[It is returned to the fuel tank 32 via the outlet pipe 29.

On the other hand, when the fuel in the metering chamber 38 becomes low and the pressure becomes lower than atmospheric pressure, the diaphragm 34 is pushed up and the lever 41 is pulled down to pull down the fuel inlet valve ↑9, so that the passage 52 is connected to the metering chamber 38. Communication - 4ru. Fuel in the fuel tank 32 is replenished into the metering chamber 38 through the connecting pipe 31, filter 37, check valve 10, passage 51, check valve 4, passage b2, and fuel inlet valve 9. Then, the fuel outlet 3 (inflow valve 9 closes).

Then, when the electric bushie rma bomb 45 is stopped with the pump 1st r2 f-74 and the start switch 77 and the switch 75 are closed, the electric motor 78 is rotated and the motor 78 is rotated.
Uranking in between begins. At the same time, the electromagnetic coil 67, which previously had a closed electromagnetic valve when the ambient temperature was higher than a predetermined ship temperature, is energized.
The six pieces are pushed against the force of the spring 24 by the plunging cello 9a. Once, I! pressure was accumulated in the pressure accumulation chamber 64! ! The paddy passes through the passage 30, the valve chamber 25, and the passage 20, and then enters the throttle 1.
1] It is ejected into the lower cavity 19 of 8. This fuel product is determined by the needle pressure Tl 64. The fuel in the lower cavity 19 is drawn into the intake passage 11 by the intake negative pressure, mixed with intake air, and supplied to the engine. Also, the throttle 7L8 of the comparison valve 8
In the intake air passing through a, the furnace material in the metering chamber 38 is sucked into the nozzle hole 6 through the check valve 47, the fuel jet 4G, and the fuel supply pipe 7.

When the starting switch 77 and switch 75 are opened just after the engine has been started, the starting voltage 8 and 78 are stopped by PF, and the voltage closing valve closes. In this way, when driving at Tsutomu J, Rimo High School 81
When the degree of U aiki is generated, the engine is started smoothly.

Actual hI shown in Figure 3! ! In the example, a diaphragm 93 with the above-mentioned cavity 95 as the pump end 95a and a cover 94 with the working chamber 92 (6) connected to the carburetor main body constitute the gasphram pump 45△, and this working chamber 02 is connected to the cylinder 81 of the electric primer pump 45 through a single tube 91. In this case, the primer bomb 145
acts as a fluid (generally air) pump and costs ¥9 per operation.
When the fuel from the metering ring 38 is sucked into the cylinder 81 of the brine pump 115, the diaphragm 93 is displaced downward, and the fuel from the metering ring 38 is sucked into the pump 9ba, while the air from the cylinder 81 is sucked into the working chamber 92. When it is pumped, the Gui T Tsunoram 93 moves upward to the A, fi position, and the pump 'i! 9
5a is fed under pressure to the pressure storage "1W6t+.The other configurations are the same as the embodiment shown in FIG. .

[Effects of the Invention] As described above, the present invention prevents combustion from flowing into the pressure accumulator.
A pressure accumulator that can communicate with the metering chamber is connected to a passage containing two check valves. In addition, a relief well installed in the passage connecting the pressure accumulation! and the combustion tank is installed in the carburetor body, and the space between the two check valves is connected to a separate electric motor with a single pipe. Since it is connected to a type primer pump, a predetermined amount of starting fuel is stored in the pressure accumulator by operating a switch before starting, and excess fuel is returned to the fuel tank using the relief valve. Fuel is replenished. Simultaneously with the activation of the starting motor by the subsequent switch operation, the initial VJ fuel in the pressure accumulator is sent under pressure to the lower space of the throttle valve, and is sucked into the intake passage by negative intake pressure, resulting in a high-a mixture. In this way, just by operating a switch, starting fuel is automatically supplied to the intake passage when cold, and a high-a degree air-fuel mixture is generated. However, the engine can be started easily.

According to the present invention, since the primer pump is connected to the pressure accumulator of the carburetor body through a single pipe, it is possible to avoid increasing the size of the carburetor due to the addition of a starting fuel supply device, and the carburetor can be easily attached to the machine body. It is attached.

In addition, since the primer pump and the electrical equipment that drives it are separate from the carburetor, they are placed in a well-balanced location for work I, away from the fuel tank and carburetor, where there is no risk of fuel leakage. Easy to set up.

[Brief explanation of the drawing]

Figure 1 is a side cross-sectional view of the carburetor which has been removed from this starting fuel supply system (this explanation is provided below); Figure 2 is an electric circuit diagram of the same equipment;
The figure is a side sectional view of a starting fuel supply device for a carburetor according to a second embodiment of the present invention, FIG. It is a front view of the same. △°Fuel supply pump B: Fuel supply n structure C: Pressure accumulator
D: Telephone…listening valve 8. Rotary throttle valve 11: Intake passage 19゛ lower space 32: Fuel tank 38: Metering chamber 43: Electric motor 45 Near h dynamic primer pump 65: M pressure air 74: Pump switch 75° switch 77: Start switch - 178: Start 8 electric 0

Claims (1)

[Claims] A pressure accumulator that can communicate with the metering chamber via a passage containing two check valves that allow fuel to flow into the pressure accumulation chamber, and a passage that connects the pressure accumulation chamber of the pressure accumulator and the lower cavity of the rotary throttle valve. A solenoid on-off valve installed in the carburetor and a relief valve installed in the passage connecting the pressure accumulation chamber and the fuel tank are installed in the carburetor body, and the empty space between the two check valves is connected with a single pipe. A starting fuel supply device for a carburetor, characterized in that it is connected to a separate electric primer pump.