JPS61275566A - Auxiliary fuel feeder for starting of engine - Google Patents

Abstract

PURPOSE:To enable predetermined quantity of auxiliary fuel supply through single touch operation by providing a return fuel sump while communicating with fuel return path and placing a piston for feeding the fuel in the sump to the cylinder side through sliding operation in said sump. CONSTITUTION:Upon depression of pushing button 30 when starting an engine, a piston 23 will move to the left. Consequently, an inlet hole 25 is choked by the outercircumferential face of piston 23 to separate the piston rear face section 33 from the tapered section 34 of case 21 thus to form a space section 40 at the rear face side of piston 23 and to provide positive pressure at the sump section of return fuel sump 22. Consequently, the fuel in the fuel sump 22 will push in a ball valve 38 which will pass through a valve insertion hole 36 and a communication hole 37 into the space section 40. Upon release of push button 30, the piston 23 will move to the right through a return spring 32 while the ball valve 38 will choke the path in the valve insertionhole 36 to push out the fuel in the space section 40 through pumping function and feed through an outlet hole 27 to an intake tube 13.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to an auxiliary fuel supply device for supplying auxiliary fuel at the time of starting a diesel engine to improve startability.

BACKGROUND ART Conventionally, in order to improve the starting performance of a diesel engine, an auxiliary fuel supply path for starting was provided in the return path from the fuel injection nozzle to the fuel tank, branching from the return path, and this auxiliary fuel supply path was provided at the time of starting. It is known to supply auxiliary fuel from a supply channel.

In this case, if the auxiliary fuel supply path always leads to the fuel tank, for example, if the starting aid is operated when the fuel tank is full or the engine is tilted, the fuel in the fuel tank will drain. It flows backwards and is supplied to the cylinder side.
This may cause inconveniences such as reverse rotation or sudden rotation (for example,
8-52349).

To solve this problem, a measuring container and an on-off valve are installed in the middle of the auxiliary fuel supply path, and at startup, the on-off valve is opened and a fixed amount of auxiliary fuel is supplied while being measured with the measuring container. (Jikko 51-21)
No. 245 Publication) or the same (A pump capable of delivering only a certain amount of fuel to an auxiliary fuel supply path, etc., and a valve that opens and closes the auxiliary fuel supply path are provided, and at the time of startup, the pump is operated by opening and closing this valve. (1166 Utility Model 1977
(Refer to Publication No. 34).

Problems to be Solved by the Invention However, in the invention disclosed in Japanese Utility Model Publication No. 51-21245, the operation is troublesome as the on-off valve must be operated while always looking at the metering container at the time of starting. Showa 52
The invention disclosed in Japanese Patent No. 116634 has the disadvantage that both the on-off valve and the pump must be operated, and in this case as well, the operation is troublesome. Further, in both cases, other parts such as a pump or a measuring container are required in addition to the on-off valve, and there is a disadvantage that the entire apparatus cannot be made compact.

That is, the present invention eliminates such conventional drawbacks and can always supply only a fixed amount of auxiliary fuel without the fuel in the fuel tank flowing back to the cylinder side.
It is an object of the present invention to provide an auxiliary fuel supply device that can supply such a fixed amount of auxiliary fuel with a single touch by simply sliding a piston.

Means for Solving the Problems In order to achieve the above object, the present invention provides a return fuel reservoir that communicates with a fuel return path (10) for returning excess fuel from the fuel injection nozzle (7) to the fuel tank (1). (22) is provided,
This return fuel reservoir (22) includes a return fuel reservoir (22).
) and the engine cylinder side are always maintained in a closed state, but when the piston ( 23) is featured internally.

When the working piston is slid, the fuel in the return fuel reservoir is
An amount corresponding to the stroke of the piston is supplied to the cylinder side of the engine, and when the piston is not slid, the communication between the return fuel reservoir and the cylinder side is closed, and even at times other than starting. Preventing fuel from being supplied.

Embodiment Hereinafter, the structure of the present invention will be explained based on the illustrated embodiment. In FIG. 3, (1) is a fuel tank, and the fuel in this fuel tank (1) is passed through a fuel strainer (2). The fuel is supplied from the fuel pump (4) to the fuel injection nozzle (6) mounted on the cylinder head (6).
7) via the fuel supply pipe (5). Excess fuel overflowing from the fuel injection nozzle (7) returns to the fuel tank (1) from a pipe joint (8) at the rear end of the fuel injection nozzle (7) via a return pipe (9). . That is,
In this embodiment, a fuel return path (10) is formed by a pipe joint (8) and a return pipe (9)'. In the middle of this fuel return path (10), a supply pipe (11) that branches from the pipe joint (8) and constitutes an auxiliary fuel supply path for starting is connected, and the end of this supply pipe (11) Starting aid device (12)
is connected. The outlet side of this starting aid device (12) is screwed into the middle of the intake pipe (13), so that when the starting aid device (12) is operated, a portion of the excess fuel is released from the intake pipe (13). It is designed to be supplied to the cylinder side.

In Figure 1, which shows the structure of the starting aid device (12), (21) is a case;
A return fuel reservoir (22) is formed in 21), and a piston (23) is installed inside this return fuel reservoir (22). (24) is this return fuel reservoir (
22) is a cover plate for closing. Similarly, the return fuel reservoir (
22) has an inlet hole (25) opened at the sliding surface with the piston (23), and this inlet hole (25)
is a joint part (26) formed protruding from the outside of the case (21).
) to the outside, and the aforementioned supply pipe (11) is connected to this joint (26). In this FIG. 1, the inlet hole (25) is located at the front end surface (23a) of the piston (23).
It is located on the left side of the fuel reservoir (22) and is always in communication with the fuel reservoir (22). An outlet hole (27) is opened on the back side of the piston opposite to the inlet hole (25).
7) is a threaded part (
28) to the outside. This threaded portion (28) is threaded onto the intake pipe (13), so that the interior of the intake pipe (13) and the outlet hole (27) are always in communication.

Similarly, in FIG. 1, a loft (29) is integrally formed on the back side of the piston (23), and this loft (29) protrudes from the case (21), and an operation button is provided at the tip of the protrusion. (30) is attached.

In addition, a return spring (32) is provided between this operation button (30) and the spring support plate (31) on the end face of the case (21).
is interposed. Furthermore, the piston (23) has a back surface (3) connecting the outer periphery of the piston (23) and the loft (29).
3) is tapered, and the surface of the return fuel reservoir (22) facing the back surface (33) is also tapered (34) so that the return spring (32) causes the piston (23) to As shown in Figure 1 (in the state of being pushed back to the right), the back surface portion (33) and the tapered portion (34) match each other.
This is a sealing O-ring attached to the outer periphery of the piston back surface (33).

The piston (23) has a valve insertion hole (36) extending from the end surface on the inlet hole (25) side in the sliding direction of the piston (23).
) is formed, and a plurality of communication holes (37) are formed from the inner end of the valve insertion hole (36) toward the outer peripheral surface of the piston (23).
) (37) is installed through it. This communication hole (37)
The outlet portion of the piston is opened at a position closer to the inlet hole (25) than the O-ring (35) in the piston back surface (33). Therefore, in FIG. 1, this communication hole (37) is in a state where communication with the outlet hole (27) side is cut off. A ball valve (38) is housed inside the valve insertion large (36), and a cylindrical valve seat body (3) is inserted from the outside of the ball valve (38).
9) is inserted and the ball valve (38) comes into contact with the inner end surface of the valve seat body (39), the return fuel reservoir (22) and the communication hole (3
7) is now closed.

In the state shown in Fig. 1 above, the piston (
23) is held in the right position in the figure by the action of the return spring (32), and in this state, the return fuel reservoir (22) is connected to the fuel return path (10) via the inlet hole (25) and the fuel supply pipe (11). ) side, and a portion of the return fuel in the fuel return path (10) is stored in this return fuel reservoir (22). On the other hand, since the piston (23) is held at the right position in the figure as described above, the tapered back surface (33), especially the O-ring (35), is in contact with the tapered portion (34) of the case (21). contact, hence the return fuel pool (
22) is not supplied to the outlet hole (27) side.

In such a state, when starting, the push button (30)
When pushed in, the piston (23) slides to the left in the figure. At this time, the inlet hole (25) is as shown in FIG.
While being blocked by the outer peripheral surface of the piston (23),
The piston back surface (33) and the tapered portion (34) of the case (21) are separated, and a space (40) is formed on the back surface of the piston (23), and a return fuel reservoir (22) is formed therein. As a result, the fuel in the fuel reservoir (22) pushes the ball valve (38), passes through the valve insertion hole (36) through the communication hole (37), and enters the space (40).
) move inside. The push button pressed in this way (30)
When released, the force of the return spring (32) causes the piston (2
3) moves to the right, and as the piston (23) moves, the ball valve (38) comes into contact with the inner end surface of the valve seat body (39) and closes the passage in the valve insertion hole (36). Therefore, the fuel in the space (40) is pushed out by the pumping action of the piston (23) and flows from the outlet hole (27) to the intake pipe (
13) and is supplied to the cylinder side. In this case, the amount of fuel supplied to the cylinder side is not strictly the same as the volume of the return fuel reservoir (22), but a constant amount is always supplied that corresponds to the stroke of the piston (23). . Then, the piston (23) returns to the position shown in FIG. 1, and at the same time, fuel accumulates in the return fuel reservoir (22). - If the fuel supply is insufficient, just press the push button (30) again to supply the fuel.
If this is repeated several times as necessary, a fixed amount of auxiliary fuel for starting will be supplied each time.

Effects of the Invention According to the present invention, there is no need for troublesome operations such as operating an on-off valve while looking at a measuring cup, or opening an on-off valve and operating a pump, as in the past, and the piston can be simply pushed in. This has the effect of supplying auxiliary fuel for starting with a one-touch operation. Moreover, since only a fixed amount is supplied according to the stroke of the piston, there is no risk of the fuel in the fuel tank flowing backwards and being supplied in large quantities, and there is also communication between the return fuel reservoir side and the engine cylinder side. is kept closed at all times by this piston, so there is no need to provide a special opening/closing valve, and it can be made compact.

[Brief explanation of the drawing]

FIGS. 1 and 2 are longitudinal sectional views of a starting assist device according to an embodiment of the present invention, and FIG. 3 is an overall configuration diagram showing the fuel supply system from the fuel tank to the fuel injection nozzle and the starting assist device. (1) Fuel tank, (7) Fuel injection nozzle, (10) Fuel return path, (22) Return fuel reservoir, (23) Piston.

Claims (1)

[Claims] A return fuel reservoir is provided in communication with a fuel return path that returns excess fuel from the fuel injection nozzle to the fuel tank, and communication between the return fuel reservoir and the engine cylinder side is maintained in a normally closed state in the return fuel reservoir. An auxiliary fuel supply device for starting an engine, characterized in that a piston is installed therein to supply fuel in the return fuel reservoir to the cylinder side by an amount corresponding to the stroke of the sliding operation.