JPS62150071A - Fuel injection device for engine - Google Patents

Abstract

PURPOSE:To save fuel by constituting such that a fuel injection timing command valve arranged in a fuel injector can be opened or closed by means of a pressure receiving actuator and by making this pressure receiving part face a combustion chamber of an engine. CONSTITUTION:By pushing up a nozzle cylinder 10 resisting a push-back spring 22 installed in a cooling water chamber 21, which pressure fuel in a fuel chamber 13 is made to flow into a needle accommodation chamber 23 located in the nozzle chamber 10 to make a needle valve 24 open resisting an opening setting valve 24 only for a period of time during which fuel passages 19 and 20 are communicating with each other. Thus, since an injection timing is set with a pressure within the combustion chamber, a fuel injection timing command valve is not actuated when the combustion chamber pressure is reduced at the time of starting or stopping an engine saving fuel consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a fuel injection device for a fuel injection type engine.

(Prior Art) Conventionally, in a fuel injection engine, a fuel injection pump is operated by a cam that is linked to rotation of a crankshaft, and fuel pressurized by the fuel injection pump is supplied to a fuel injection nozzle.

Furthermore, in order to prevent a pressure drop on the way from the fuel injection pump to the fuel injection nozzle, some fuel injectors use a unit injector in which the fuel injection pump is integrally assembled with the fuel injection nozzle. In this case as well, the fuel injection pump was configured to be driven directly or indirectly by a cam that was linked to the rotation of the crankshaft.

(Problem to be solved) In conventional fuel injection systems, the fuel injection pump is linked to the rotation of the crankshaft.The rotation of the crankshaft must be transmitted to the drive mechanism of the fuel injection pump with accurate timing. However, there is a problem in that the transmission system must be formed with high precision.

Also, fuel is injected as the crankshaft rotates. Even if the combustion chamber is depressurized when starting or stopping the engine, fuel is injected in conjunction with the rotation of the crankshaft. Therefore, there is also the disadvantage that there is a lot of wasteful consumption of fuel.

(Means for Solving the Problems) The present invention injects fuel using the pressure inside the combustion chamber, and its specific structure includes an engine that includes cylinder heads, pistons, etc. that constitute the combustion chamber. A fuel injector is fixed to the structure, a fuel injection timing command valve is located within the fuel injector, the fuel injection timing command valve is configured to be able to be opened and closed by a pressure receiving actuator, and the pressure receiving input section of the pressure receiving actuator is connected to the combustion chamber. It is unique in that it faces the room.

(Function) In the present invention, since the pressure receiving input part of the pressure receiving actuator that operates the fuel injection timing command valve is provided so as to face the combustion chamber, when the internal pressure of the combustion chamber rises to a predetermined pressure or higher, the fuel injection timing control valve is activated. The timing control valve operates to inject high-pressure fuel from the fuel injector into the combustion chamber, and if the internal pressure of the combustion chamber is not sufficiently increased, fuel injection is cut.

(Example) FIG. 1 is a vertical cross-sectional view of the main part, and FIG. 2 is a vertical cross-sectional view of a fuel injector.

In the figure, (1) is the piston, (2) is the cylinder block, (3) is the cylinder head, and the piston (1) is the cylinder head.
The upper surface (4) and the inner peripheral surface (5) of the shilling block (2)
and the lower surface (6) of the cylinder head (3) and the combustion chamber (7).
) is formed.

The fuel injector (8) is fixed to the cylinder head (3) with its tip facing the combustion chamber (7).The fuel injector (8) has an open tip as shown in Figure 2. A nozzle tube (10) is arranged concentrically within a cylindrical casing (9) formed in a shape, and a flange plate (11) that can slide up and down the inner circumferential surface of the casing is provided from the tip of the nozzle tube (10). A toric body (12) consisting of a rotating body having a U-shaped longitudinal section is arranged above the collar plate (11), and this toric body (12) is integrally extended.
2) to the casing (9), and the fixed torus (12)
The nozzle tube (10) is fitted into the center hole of the tube so that it can be slid up and down. The internal space (13) of the annular fixed body (12) is communicated with the fuel injection pump (14) via the high-pressure fuel reservoir (15), thereby forming the space (13) into a fuel chamber. The upper tsuba (16) of the annular fixed body (12)
) and the lower flange (17) and the peripheral wall of the nozzle tube (10), fuel communication holes (19) and (20) are transparently provided with different phases in the vertical direction. .

Annular fixed body (12) Lf) lower flange (17) and nozzle tube (1
This space (21) is formed into a cooling water chamber by flowing cooling water into the space (21) between the flange plate (11) extending from the cooling water chamber (21). A return spring (22) for the nozzle tube (10) is arranged inside.

Then, the pressure in the combustion chamber (7) acting on the flange (11) integrated with the nozzle body (10) returns the nozzle # (10) and pushes it up against the spring (22). (19) The high-pressure fuel in the fuel chamber (13) is allowed to flow into the needle accommodation chamber (23) in the nozzle tube (10) only when the needle valve (20) is opened, and the needle valve (24) is opened by the opening setting spring. The valve is opened against (25).

That is, in this example, the vertical wall (18) of the annular fixed body (12)
The nozzle tube (10) and the return spring (22) constitute a fuel injection timing command valve (V), and the collar plate (11) extending from the nozzle tube (10) is connected to the pressure receiving input part (1) and the nozzle tube. (10
) is the pressure actuator (M).

In this fuel injection 11tl (8), the engine piston (
1) until the combustion chamber pressure becomes lower than the spring pressure of the return spring (22), that is, the nozzle pipe (1)
0), a rotation guide (26) is formed between the annular fixed body (12) and the nozzle tube (10), as shown in Fig. 3. ing. This daily movement ID (26) consists of a guide V groove (27) carved on the outer circumferential surface of the nozzle tube (10) and a pin (28) protruding from the inner circumferential surface of the vertical wall (18) of the annular fixing body (12). ).

FIG. 4 shows a modification of the invention, which has a fuel injector (8
) The casing (9) is formed of a cylindrical body with an open end, and the nozzle cylinder (10) is positioned at the axial center of the casing (9) facing the fir tree. Three partition plates (29) (
30) (31,) are placed vertically at appropriate intervals. The upper partition plate (29) is fixed to the casing (9) and the nozzle tube (10), and the middle partition plate (230 is fixed to the casing (9). The lower partition plate (31)
is formed by an L-shaped rotating body, and this lower partition plate (3
The rising wall (32) of 1) is fitted into the nozzle tube (10) so as to be slidable up and down. The rising wall of the lower partition plate (31) (
32), the upper part of which is inserted above the intermediate partition plate (30), and the fuel communication passage (19) is inserted into this inserted part.
) are transparent. By bringing the inner end of the intermediate partition plate (30) into airtight contact with the rising wall (32) of the lower partition plate (31), the second partition plate (29) and the intermediate partition plate (30) are An opening is formed in the fuel chamber (13). In addition, the middle partition plate (30) and the lower partition plate (31)
A cooling water chamber (21) is formed at the opening, and a return spring (22) for biasing the lower partition plate (32) downward is arranged in the cooling water chamber (21).

A fuel communication passage (20) is transparently provided at a position of the nozzle tube (10) corresponding to the fuel chamber (13).

In this example, the pressure inside the combustion chamber (7) is lower than the lower partition plate (
31), the lower partition plate (31) releases the return spring (
22), the casing (9) and the nozzle tube (10
), and the fuel communication passage (19) and nozzle tube (1) formed in the rising wall (32) of the lower partition plate (31)
When the high-pressure fuel in the fuel chamber (13) is aligned with the fuel communication passage (20) formed in the needle storage chamber (
23).

In the case of this example, the lower partition plate (31) is connected to the pressure receiving input section (1).
), and the rising wall (32) portion of the lower partition plate (31) becomes the pressure receiving actuator (M).

FIG. 5 shows a modification of the invention, which has a fuel injector (
An annular fixed body (12) consisting of a rotating body having a U-shaped longitudinal section is fitted into the inner peripheral surface of the casing (9) of 8) so as to be able to move up and down in an airtight manner, and the outer peripheral surface of the nozzle tube (10) and the casing ( An annular fixed body (12) between the inner circumferential surface of 9)
A pressure fluid chamber (33) is formed on the upper side of the upper flange (16), and a pressure receiving cylinder chamber (34) is formed with a bottom opening on the bottom surface (6) of the cylinder head (3).
3) and the pressure receiving cylinder chamber (34) are communicated through a communication passage (35), and the pressure within the combustion chamber (7) is detected by a plunger (35) located within the pressure receiving cylinder chamber (34). By pushing down the annular fixed body (12) against the return spring (22) using the pressure in the pressure fluid chamber (33) that varies depending on the internal pressure of the combustion chamber (7), the fuel communication passage (19) ( 20) to communicate fuel to the needle storage chamber (
23).

In this case, the annular fixed book (12) becomes the pressure-receiving actuator (M), and the plunger (35) of the pressure-receiving cylinder chamber (34) becomes the pressure-receiving input part (I).

In each of the above embodiments, the fuel injector (8) is fixed to the cylinder head (3), but the fuel injector (8) is fixed to the cylinder head (3).
8) may be fixed to the piston (1) so that its tip portion faces the combustion chamber (7) from the upper surface of the piston (1).

(Effects) Since the fuel injection device of the present invention sets the fuel injection timing based on the internal pressure of the combustion chamber, when the combustion chamber is depressurized during engine starting or engine stopping operations, , the fuel injection timing command valve does not operate and fuel is not injected. This prevents fuel from being wasted.

In addition, the internal pressure of the combustion chamber also operates the fuel injection timing command valve.
Since the high-pressure fuel is caused to flow into the needle storage chamber, the fuel pressure becomes high from the beginning of the flow into the needle storage chamber, unlike a system in which the injection timing is set by increasing the fuel pressure by a pump stroke. Therefore, high-pressure fuel can be jetted out at once, and its atomization performance can be improved.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of the main part, Fig. 2 is a longitudinal sectional view of the fuel injector, Fig. 3 is an extracted perspective view of the main part, Fig. 4 is a longitudinal sectional view of the main part of another embodiment, and Fig. 5 is a longitudinal sectional view of the main part of the fuel injector. The figure is a longitudinal sectional view of a main part of a modified example. DESCRIPTION OF SYMBOLS 1...Piston, 3...Cylinder head, 4...Top surface of (1), 6...Bottom surface of (3), 7. Combustion chamber, 8...Fuel injector, ■... Fuel injection timing command valve, M...Pressure receiving actuator, ■...Pressure receiving input section. 3rd layer＼” Figure 1 Figure 4 5th Leap

Claims (4)

[Claims] 1. A fuel injector (8) is fixed to the engine structure constituting the combustion chamber (7), and a fuel injection timing command valve (V) is provided within the fuel injector (8). A fuel injection device for an engine, characterized in that the pressure receiving input part (I) of the pressure receiving actuator (M) faces a combustion chamber (7) of the engine. 2. A fuel injection device for an engine according to claim 1, wherein the pressure receiving input portion (I) of the pressure receiving actuator (M) is formed on the front end surface of the fuel injector (8). 3. Claim 1: The fuel injector (8) is fixed to the cylinder head (3), and the pressure receiving input portion (I) of the pressure receiving actuator (M) is formed on the lower surface (6) of the cylinder head (3). Fuel injection system for the engine described in section 4. According to claim 1, the fuel injector (8) is fixed to the piston (1), and the pressure receiving input part (I) of the pressure receiving actuator (M) is formed on the upper surface (4) of the piston (1). Fuel injection system for the engine described