JPS62139968A - Fuel injection device for engine - Google Patents

Abstract

PURPOSE:To prevent wasteful consumption of fuel without injecting fuel when starting or stopping an engine by providing the pressure input part of a received pressure operating device for operating a pressure fuel injector, faced to a combustion chamber. CONSTITUTION:In a fuel injector 8, a fuel pressurizing chamber 17 is connected to a needle housing chamber 19 through a pressure fuel introducing out passage 22, while also connected to a nozzle body housing chamber 14 through a fuel connecting port 23. Fuel from a fuel tank 25 is fed into the nozzle body housing chamber 14 via a quantity regulating device 26 and a feed pump 27, and from a fuel injection port 24. This fuel flows into the fuel pressurizing chamber 17 through the fuel connection port 23 and, after being pressurized by a plunger 20 which is moved together with a slider 11 driven by the inside pressure of a combustion chamber, flows into the needle housing chamber 19 through the pressure fuel introducing out passage 22, lifts up a needle 18 against an injection pressure setting spring 28, and is injected into the combustion chamber from a fuel injection port 29 formed on the tip end of a nozzle body 13.

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 injection engines 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 was linked to the rotation of the crankshaft, so the rotation of the crankshaft was transmitted to the drive mechanism of the fuel injection pump with accurate timing. Therefore, there was a problem in that the transmission system had to be formed with high precision.

In addition, since the fuel is injected by the rotation of the crankshaft, even if the combustion chamber is depressurized during engine starting or engine stopping operations, fuel is injected in conjunction with the rotation of the crankshaft. Therefore, there is a disadvantage that there is a lot of wasteful consumption of fuel.

(Means for Solving the Problems) Since the present invention injects fuel using the pressure inside the combustion chamber, the engine structure that constitutes the combustion chamber, such as the cylinder head and piston, has a similar structure. A fuel injector is fixed to the book, a pressurized fuel injector such as a plunger type pump or a fuel injection timing command valve is located within the fuel injector, and the pressurized fuel injector is configured to be operable by a pressure receiving actuator. It is characterized in that the pressure receiving input part of the pressure receiving actuator is provided facing the combustion chamber.

(A11 = For) In the present invention, since the pressure receiving input part of the pressure receiving actuator that operates the pressurized fuel injector is provided facing the combustion chamber, when the internal pressure of the combustion chamber increases to a predetermined pressure or higher, The pressurized fuel injector operates to inject high-pressure fuel 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 Figure 1, (1) is the piston, (2) is the cylinder block, (3) is the cylinder head, and the piston (
1) upper surface (4) and the inner circumferential surface of the cylinder block (2) (
5) and the lower surface (6) of the cylinder head (3) form a combustion chamber (7).

A fuel injector (8) is fixed to the cylinder head (3) with its tip facing the combustion chamber (7). Also, the combustion chamber (7) is located on the lower surface (6) of the cylinder head (3).
) is recessed, and a pressure receiving cylinder (9) that moves in and out in response to pressure within the combustion chamber (7) is disposed in this recess.

The fuel injector (8) is attached to the main body case (as shown in Figure 2).
10) is divided into upper and lower parts by a slider (11), the upper side of the slider (11) is formed into a pressure receiving chamber (12), and the lower side of the slider (11) is a nozzle body that accommodates a nozzle body (13). It is formed in the storage chamber (14).

The pressure receiving chamber (12) and the pressure receiving cylinder (9) arranged on the lower surface (6) of the cylinder head (3) are connected to the pressure communication passage (15).
The slider (
11).

The nozzle body (13) housed in the nozzle body housing chamber (14) vertically divides the inside of the valve #I (16) into a fuel pressurizing chamber (17) and a housing chamber (19) for the needle (18). A plunger type pump (21) is constructed by fitting a plunger (20) extending from the lower surface of the slider (11) into the fuel pressurizing chamber (17) so as to be retractable. There is.

The fuel pressurization chamber (17) and the needle storage chamber (19) are communicated through a pressurized fuel outlet path (22), and the fuel pressurization chamber (17), the nozzle body storage chamber (14), and the fuel communication hole (23
) for communication. A fuel injection hole (24) is provided in the side wall of the fuel injector (8) corresponding to the nozzle body housing chamber (14), and the fuel from the fuel tank (25) is passed through the metering device (26), It is designed to be sent into the nozzle body housing chamber (14) via the wide pump (27). The fuel sent into the nozzle body storage chamber (14) flows through the fuel communication hole (2).
3), the fuel flows into the pressurized chamber (17), and enters the combustion chamber (7).
) is pressurized by the plunger (20) that moves together with the slider (11) driven by the internal pressure of the pressurized fuel outlet path (
22) into the needle accommodation chamber (19), the needle (18) is raised against the injection pressure setting spring (28) that biases the needle (18) to close, and the nozzle body (13)
Fuel is injected into the combustion chamber (7) from a fuel injection hole (29) formed at the tip of the combustion chamber.

In this embodiment, a pressure receiving chamber (12), a slider (11), and a pressure receiving cylinder (9) constitute a pressure receiving actuator (M), the pressure receiving cylinder (9) is used as a pressure receiving input part (I), and the pressure receiving actuator ( Engine lubricating oil is used as the hydraulic oil for M). Further, a plunger type pump (21) constitutes a pressurized fluid injector (P). In the figure, reference numeral (30) is a lubricating oil pump, and (31) is a return spring for the plunger (20) disposed in the nozzle body storage chamber (14).

FIG. 2 shows a modification of the present invention, which has a fuel injector (
A nozzle body mounting hole (32) is formed inside the slider (11) that partitions the inside of the slider (11), and a housing chamber (14) for the nozzle body (13) formed on the lower side of the slider (11) is used as a plunger chamber. That is.

FIG. 4 shows another embodiment of the present invention, in which the fuel injector (8) is formed with an open end surface, and the flange plate (8) is inserted from the front end of the nozzle tube (16) of the nozzle body (13). 34) is integrally extended and this flange plate (34) is fitted into the inner peripheral surface of the fuel injector (8) so as to be movable in and out of the fuel injector (8), and this flange plate (34) is attached inside the fuel injector (8). A toric body (35) having a U-shaped longitudinal section is arranged on the opposite side, and this toric body (35) is fixed inside the fuel injector (8). The nozzle cylinder (16) of the nozzle body (13) is fitted into the central hole of the annular fixing book (35) so as to be slidable in and out. By communicating the internal space of the annular fixed body (35) with a fuel injection pump via a high-pressure fuel achievator, this space is connected to a fuel chamber (36).
The vertical wall of the annular fixing body (35) and the nozzle cylinder body (1
6) Change the upper and lower phases to the fuel communication holes (37) (38)
are transparent. By pushing up the nozzle cylinder body (16) with the pressure of the combustion chamber (7) acting on the flange plate (35), the fuel chamber (36) is pushed up only while both the fuel communication holes (37) and (38) are communicating. ) is made to flow into the needle storage chamber (19). In other words, in this example, the annular fixed body (35) and the nozzle cylinder body (
16) constitutes a fuel injection timing command valve (39). Lower wall (33) and collar plate (34) of the ring fixing body (35)
A cooling water chamber (40) is formed between the nozzle tube (16) and a return spring for the nozzle tube (16).

The fund in this example, the collar plate (34) becomes the pressure receiving input part (1),
The fuel injection timing command valve (39) serves as a pressurized fuel injector (P), and the nozzle body (16) serves as a pressure receiving actuator (M).

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), with its tip (9) facing the combustion chamber (7) from the top 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 an attempt to start or stop the engine, Pressurized fuel injector does not operate and does not inject fuel. This prevents fuel from being wasted.

In addition, since the timing of fuel injection is determined by the pressure in the combustion chamber, the structure of the transmission system is simpler compared to conventional Rano, which transmits the rotation of the crankshaft to the drive mechanism of the fuel injection pump at precise timing. can be converted into

[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. fjS3 is a longitudinal sectional view of the main part of a modification, and Fig. 4 is a longitudinal sectional view of the main part of another embodiment. . 1...Piston, 3...Cylinder head, 4...(
1) Upper surface, 6... Lower surface of (3), 7... Combustion chamber,
8...Fuel injector, 22...Plunger type pump,
39... Fuel injection timing command valve, P... Pressurized fuel injector, M... Pressure receiving actuator, ■... Pressure receiving input section. Patent applicant: Kubota Iron Works Co., Ltd.

Claims (1)

[Claims] 1. A fuel injector (8) is fixed to the engine structure constituting the combustion chamber (7), a pressurized fuel injector (P) is provided in the fuel injector (8), and a pressurized fuel injector (P) is provided inside the fuel injector (8). Connect the pressure fuel injector (P) to the pressure actuator (
A fuel injection device 2 for an engine, characterized in that the pressure receiving input part (I) of the pressure receiving actuator (M) faces the combustion chamber (7) of the engine, and the fuel injector ( 8) is fixed to the cylinder head (3), and the pressure receiving input part (I) of the pressure receiving actuator (M) is formed on the lower surface (6) of the cylinder head (3). A fuel injection device 4 for an engine according to claim 1, wherein the pressure receiving input part (I) of the pressure receiving actuator (M) is formed on the front end surface of the fuel injector (8); 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). The fuel injection device 5 of the described engine, the pressurized fuel injector (P) is a plunger type pump (21
) The fuel injection device 6 for an engine according to any one of claims 1 to 4, wherein the pressurized fuel injector (P) is a fuel injection timing command valve (39
) A fuel injection device for an engine according to any one of claims 1 to 4.