JPS5918259A - Start assisting apparatus utilizing air vent disposed in fuel passage - Google Patents

Abstract

PURPOSE:To improve the starting performance of a diesel engine, by connecting an air outlet of an air vent valve disposed in a fuel passage of the engine to an intake port, and thereby adding fuel to intake air positively by the use of the negative pressure developed in the intake port. CONSTITUTION:A fuel pump 1 is driven reciprocally by a cam 4 to supply pressurized fuel to a fuel injection nozzle via an injection pipe 5. The body 7 of an air vent valve 6 is attached to an upper portion of the body of the fuel pump 1, and its fuel inlet port 8 is connected to a fuel tank via a fuel pipe 9. Further, an air vent passage 11 extending to an air vent tap 10 is formed in the body 7 of the valve 6, and a valve element 14 is disposed at a valve seat 12 of the passage 11. Here, the mouth piece 10 is connected to a mouth piece 19 opened in an intake port 21 via a pipe 17. With such an arrangement, fuel discharged from the mouth piece 10 is utilized as start assisting fuel by adding it to the intake air positively by use of the negative pressure developed in the intake port 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting assist device that uses a fuel system air bleed valve for Diesel/L' engines, which minimizes the addition of parts and automatically starts the engine when air is bleed. The purpose is to provide supplementary fuel supply.

Conventionally, priming devices and oil cup systems have been common as starting aid devices for diesel engines. The priming device requires repeated lever operations when air is trapped in the fuel system line, which is not a time-consuming process, and requires a separate lever for priming, which increases the number of parts. , becomes a cost amplifier. In the oil cup system, an oil cup for injecting fuel is installed on the upper wall of the intake pipe near the combustion chamber, but since it is a method of supplying fuel from another source, the operation is time-consuming. There is also the risk of using gasoline or the like as a starting auxiliary fuel, and there is also the risk of dust entering from the cup, which shortens the life of the engine.

Conventionally, a system has been proposed in which a starting fuel supply passage is provided from the fuel tank to the intake pipe, and a manual reciprocating pump and a cock are arranged in the middle. However, in this case, it is necessary to first open the cock, press the pump knob several times, and then close the cock after the predetermined amount of fuel has been injected, which is complicated and time-consuming.

Also, if you forget to close the cock, excessive fuel will be sucked in, causing sudden rotation. Also, since fuel is directly introduced without going through a tank drainer, there is a risk that dirt and water at the bottom of the tank may be sucked in. Air removal is a separate KJ [! j9, which not only makes operation cumbersome, but also requires a large number of parts, resulting in high costs.

Furthermore, a push-button type air bleed valve is installed on the top of the fuel pump body, and there is also a one-touch air bleed valve that opens and closes the passage connecting the air bleed pipe and the upper end of the air retention space 1 and 1 in the fuel pump. Proposed. However, in this case, fuel is also released into the atmosphere from the air vent fitting when the air is vented, which is uneconomical.

The present invention uses the negative pressure in the intake port to actively add fuel released from the air vent fitting of the one-touch air vent valve to the intake air so that it can be used as starting auxiliary fuel. Let me explain.

The fuel pump 1 in Fig. 1 has 7 lunges 2 connected to the crank booth 3.
The cam 4 receives a reciprocating driving force as shown by the arrow A, and internally pressurized fuel is injected from the high pressure pipe 5 into the fuel injection nozzle Iv (not shown). ). The body 7 of the one-touch air bleed valve 6 is attached to the upper part of the body of the fuel pump 1.
The fuel population 8 communicates with the upper space in the fuel pump 1 where air accumulates, and also passes through the fuel pipe 9 to the upper fuel tank (
(not shown) K-connected. There is an air vent passage 1 in the body 7 which communicates with the inlet 8 and which leads to the metal 10.
1 is installed in the middle of passage 11 (D bottom opening kite-A
A valve body 1 is attached to the lower end of a push button 13 on a shaped valve seat 12.
4 is normally pressed against the elasticity of the compression coil spring 15 to close the passage 11.

An O-ring 14a is attached to the valve body 14.

The lower end of a pipe 17 is connected to the air vent 10, and the pipe 17 extends upward, and the upper end is connected to a mouthpiece 19 provided on a cylinder head 18 as shown in FIG. The mouthpiece 19 passes through the punch hole 20 of the cylinder head 18 and opens into a portion of the intake port 21 near the intake valve seat 22. 23 is an intake valve, and 24 is an air arena directly attached to the cylinder head 18.

At the time of starting, the push button 13 in FIG. 1 is temporarily pushed down in the direction of arrow B. Then, the air vent passage 11 will open,
The air retention space inside the fuel pump 1 is a passage 11. Base 10
, through the pipe 17, the mouthpiece 19 (Fig. 2), and the perforation hole 2o to the intake port 21. The air in the fuel pump 1 is replaced with fuel supplied from the pipe 9 by the action of gravity. It rises in the passage 11 and is discharged into the intake port 21. The interior of the simultaneous button passage 11 is partially or entirely filled with fuel. With the push button 13 pressed, or after the push button 13 is pressed to the extent that an appropriate amount of starting auxiliary fuel flows out into the intake port 21 through the pipe 17, the push button 1 is pressed.
With 3 open, give starting rotation to the engine such as the crank and recoil starter. Then the intake bow)2
The fuel in the vibrator 1 is actively sucked out by the fast intake air passing through the engine 1, and the fuel that had been released into the intake port 21 is sucked into the combustion chamber along with the intake air, promoting startup. Ru.

FIG. 3 shows the mounting structure of the mouthpiece 19 when the intake pipe 26 is attached to the cylinder head 18. A partition plate 2 for forming a venturi is placed inside the intake pipe 26 facing the opening of the mouthpiece 19.
7 is provided to increase the flow velocity at the nozzle 19 portion and promote suction of the starting auxiliary fuel.

As explained above, in the present invention, the air outlet of the one-touch air bleed valve is connected to the intake port 21 to apply negative pressure, so the pipe 17 is added to the conventional one-touch air bleed valve and the cylinder head 18 is By adding a small amount of machining, such as machining the perforation hole 20 and attaching the cap 19, the fuel that overflows during air bleeding can be effectively used as starting auxiliary fuel, improving the engine's starting performance. Due to busy schedules, addition of parts must be kept to a minimum.
It has the advantage of being low cost. Furthermore, since the auxiliary supply of starting fuel is automatically performed when air is removed, the effect is particularly great for recoil starters that are required to be able to start with one compression cycle. Air bubbles are generated in the fuel system during engine operation, and air tends to get trapped in the twisting pump after being stored for a long period of time, making it necessary to bleed the air. In addition, in applications such as combine harvesters where the engine's rotating shaft easily becomes hot, fuel vapor is likely to be generated in the fuel system, and from this point of view, air bleeding is also necessary.

Therefore, it is effective to bleed the air each time the engine is started to ensure reliable fuel injection, but according to the present invention, the overflowing fuel can be added to the intake air each time the air bleed operation is performed. This ensures reliable starting even in combine harvesters, which are prone to paper lock due to the generation of fuel vapor, and reduces fuel costs because no fuel is released into the atmosphere. Since it uses a wonton chair release valve, it eliminates operational errors such as forgetting to tighten it, improving operability.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a vertical engine to which the present invention is applied;
FIGS. 2 and 3 are longitudinal sectional views of the intake boat portion. 6
...Push button type air bleed valve, 10...1 air vent (air outlet), 11...Passage (fuel system path), 21
...Intake port 397-

Claims (1)

[Claims] A starting aid device that utilizes air bleed from a fuel system, characterized in that the air outlet of an air bleed valve provided in the fuel system is connected to an intake port.