JPS59200060A - Fuel injecting device - Google Patents

Abstract

PURPOSE:To reduce production of NOX, by a method wherein a large main feed hole and a small auxiliary feed hole are formed in a plunger barrel, and auxiliary reed with a small injection rate made prior to main injection and a main reed with a given rate of main injection are located, facing the respective holes. CONSTITUTION:A large main feed hole 2 and a small auxiliary feed hole 3 are formed in a plunger barrel 1 such that the two holes are positioned facing each other with the upper surfaces thereof located at the same level. Meanwhile, a main reed 6 and an auxiliary reed 5, facing the two holes 2 and 3 respectively, are attached to a plunger 4, in a lift position relation of h2 and h1, respectively, from the top of a plug 4. Thus, raising of the plunger 4 results in control to a small mount fuel injection rate by means of the auxiliary reed 5 with the narrow lift h1, and thereafter to a given fuel amount injection rate by means of the main reed 6 with the wide lift h2. This performs 2-stage injection through a simple construction and enables reduction of production of NOX and creation of combustion noise.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a fuel injection device C for an internal combustion engine.

<Prior art> As a means of reducing exhaust gas (Nox) and combustion noise in internal combustion engines, pilot injection, which injects a small amount of fuel prior to main injection and uses this as a spark for combustion of the main injected fuel, has traditionally been effective. However, in this case, two systems of equipment are required. There is also two-stage injection, but in this case, a two-stage valve opening pressure nozzle holder using two types of springs, strong and weak, is used. In any of these cases, there is a drawback that the injection device is complicated.

<Objective of the Invention> The present invention is a simplified two-stage injection device for reducing exhaust gas and combustion noise of an internal combustion engine.

<Structure of the Invention> The present invention provides a plunger barrel of a fuel injection pot with a large-diameter main feed hole, a small-diameter sub-feed hole, and a metal plate, and the plunger is paired with the sub-feed hole, and a small amount of feed is provided in the plunger prior to main injection. The present invention provides a fuel injection device provided with a sub-lead for controlling the fuel injection rate and a main lead for controlling the required main injection rate 1/((1/()) by pairing with the main feedhole.

<Examples> Examples of the present invention will be described below with reference to the drawings. , In FIG. 1, ■ is the plunger barrel of the fuel injection pump. This plunger barrel IK is provided with a large-diameter main feed hole 2 and a small-diameter sub-feed hole 3. The main feed hole 2 and the sub feed hole 3 are formed facing each other with their upper wall surfaces on the same line.

Reference numeral 4 denotes a plunger that is slidably fitted into the plunger barrel 1, and the plunger 4 has a sub-lead 5 that matches the sub-feed hole 3, and a main lead 6 that matches the main feed hole 2. and is provided. The side door 5 has a lift h1 from the top surface of the plunger 4.
is small, and the lift h2 of the main lead 6 from the top surface of the plunger 4 is large.

Therefore, as shown in FIGS. 2 and 3, the plunger 4
As a result of the increase in the fuel injection rate, the fuel injection rate is first controlled to a small amount A by the sub-lead 5 of the small lift h1, and then controlled to the required main fuel injection rate B by the main lead 61C of the large lift h2.

In the graph of FIG. 2, there is an interval of injection time between the injection rate A by the sub-lead 5 and the main injection rate B by the main lead 6, and in the graph of FIG. Next comes the main injection rate B, which means that the injection rate waveform depending on the load can be controlled depending on the combination of the main IJ-drol and the auxiliary lead 5, so in any case two-stage injection is controlled. It is something.

<Effects> According to the present invention, the plunger has a simple structure in which the main lead and the upper lead are provided, and has the advantage that pilot and two-stage injection can be performed using a single injection system.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part of the device of the present invention, and FIGS. 2 and 3 are graphs showing injection rate control by the device of the present invention. 1-e Plunger barrel hole, 3 Sub feed hole, 4 Self franchisor, 5 Sub lead, 6 Main lead. Figure 1 Figure 2 Figure 3 Time Clear skies

Claims (1)

[Claims] A large-diameter main feed hole and a small-diameter sub-feed hole are provided in the plunger barrel of a fuel injection pump for an internal combustion engine,
The plunger is provided with a sub-lead that mates with the auxiliary feedhole and controls the fuel injection rate to a small amount prior to main injection, and a main lead that mates with the main feedhole and controls the main injection rate to a desired level. A fuel injection device characterized by: