JPH11270437A - Fuel injection type engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily mount and demount a head cover by projecting a cylinder shaft in the direction of the extension of a shaft center of a fuel injector, on an overflown fuel outlet portion of the fuel, injector, and mounting a seal material between a cylinder shaft insertion through hole formed on the head cover opposite to the cylinder shaft and a connector bolt head. SOLUTION: A fuel injector 13 in each cylinder is mounted in a head cover 5 of a cylinder head 3, and comprises a high pressure fuel receiving port 14 on its side face and an overflown fuel outlet 14 on its upper end. On this occasion, at the overflown fuel outlet 15, a cylinder shaft 24 is led out in the direction of the extension of a shaft center of the fuel injector 13 from an upper face of the head part of a bolt 23 which fastens an I-connector 22 to an upper edge of the fuel injector 13. A cylinder shaft insertion hole 26 is formed on a part opposite to the cylinder shaft 24 of the head cover 5, and a seal material 27 which is internally mounted on the cylinder shaft insertion hole 26 for keeping the air-tightness in the head cover 5, is kept into contact with the head upper face of the bolt 23 when the head cover 5 is mounted on the cylinder head 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel injection type engine in which fuel is injected by a fuel injector.

[0002]

2. Description of the Related Art Conventionally, a configuration shown in FIG. 5 is known as a fuel supply device for the above-mentioned fuel injection type engine. The fuel injection type engine shown in FIG. 5 is a vertical diesel engine. The bottom of a fuel tank (50) communicates with a fuel injection pump (52) and a fuel injector (53) through a fuel supply path (51). A fuel filter (55), a feed pump (56) and an auxiliary filter (57) are provided in order in a fuel supply path (54) from the fuel injection pump (52) to the fuel injection pump (52), and the fuel in the fuel tank (50) is filtered by both filters.
(55) ・ (57) filter to remove dust, feed pump (56) to pump fuel to fuel injection pump (52), and pressurize high pressure fuel pressurized by fuel injection pump (52). Fuel pipe (5
In 8), fuel is fed to the fuel injector (53) so that fuel is injected from the fuel injector (53) into each combustion chamber.

The overflow fuel from the fuel injection pump (52) and the overflow fuel from each fuel injector (53) are supplied to the fuel tank (50) by the overflow fuel return pipe (54).
Back to Here, in the engine in which the fuel injector (53) is housed in the engine head cover (59), in order to return the overflow fuel from the fuel injector (53), the fuel injector (53) is provided on the side wall of the head cover (59). At least one insertion hole for the overflow fuel return pipe (54) will be provided.

[0004]

However, in the above-mentioned conventional fuel injection engine, the connection between the fuel injector (53) and the overflow fuel return pipe (54) is located in the head cover (59), and the overflow The fuel return pipe (54) will pass through the head cover (59). In addition, since the inside of the head cover (59) is in an air atmosphere containing oil mist due to valve operating mechanism lubrication and blow-by gas, the opening provided in the head cover (59) is to be kept confidential with a sealing material or the like. Become. Therefore, when attaching and detaching the head cover (59), the head cover (59) must be moved along the pipe direction of the overflow fuel return pipe (54), and the insertion hole portion of the overflow fuel return pipe (54) must be moved. Therefore, there is a problem that the opening / closing operation of the head cover (59) is poor.

In order to improve the operability, the head cover (59) may be divided at the insertion hole of the overflow fuel return pipe (54). However, the head cover (59) is divided. As a result, the manufacturing cost rises, and it is still necessary to provide a sealing material disposed so as not to leak the blow-by gas or the like even between the divided type and the high-pressure fuel receiving port. However, there is a problem that the configuration becomes complicated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection engine in which a head cover can be easily attached and detached without requiring any special operation. It should be noted that the problems of the invention other than those described above and the means for solving the problems will be described in detail in the following specification.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention forms an overflow fuel outlet at a protruding tip of a fuel injector located in a head cover, and forms an overflow fuel outlet in one fuel injector. The outlet is formed by projecting a cylinder shaft from the joint bolt in the direction of extending the axis of the fuel injector, and a cylinder shaft insertion hole is provided through a head cover facing the overflow fuel outlet forming the cylinder shaft. It is characterized in that a sealing material is arranged between the cylindrical shaft insertion hole and the head of the joint bolt.

[0008]

According to the present invention, the overflow fuel outlet portion of the fuel injector projects from the joint bolt in the direction in which the axis of the fuel injector extends so as to extend the axis of the fuel injector. Since the shaft insertion hole is penetrated and the sealing material is arranged between this cylinder shaft insertion hole and the head of the joint bolt, the tip of the cylinder shaft, which is the over fuel outlet of the fuel injector, is outside the head cover. Will be located. For this reason, the head cover can be attached to and detached from the cylinder head simply by attaching and detaching the head cover in a state in which the overflow return pipe is not connected to the tip end of the cylinder shaft, and the attaching and detaching operation of the head cover can be easily performed. Can be done. Further, since the head cover can be formed integrally, the configuration does not become complicated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram for explaining a fuel injection engine according to the present invention, and FIG. 2 is a longitudinal sectional view of a main part of a cylinder head. In this fuel injection type engine (1), as shown in FIGS. 1 and 2, a cylinder head (3) is assembled to a cylinder block (2), and a valve operating chamber (4) is provided above the cylinder head (3). It is formed. A head cover (5) is attached to the peripheral wall of the valve operating chamber (4).

A fuel supply system for the fuel injection type engine (1) communicates fuel in a fuel tank (6) to a fuel injection pump (8) through a fuel supply passage (7), and supplies fuel from the fuel tank (6). Fuel filter in fuel supply path (7) to injection pump (8)
(9), a feed pump (10) and an auxiliary filter (11) are provided in this order. The fuel in the fuel tank (6) is filtered by both filters (9) and (11) to remove dust and the feed pump (10). )
To pump fuel to the fuel injection pump (8),
The high-pressure fuel pressurized in (8) is injected into the fuel injector by the high-pressure fuel pipe (12).
(13) so that fuel can be injected into the combustion chamber of each cylinder from the fuel injector (13).

FIG. 1 exemplifies a three-cylinder engine, and each cylinder is provided with one fuel injector (13). The tip of each fuel injector (13) is a cylinder head (3)
From the upper wall of each cylinder.

Each fuel injector (13) is arranged in a head cover (5), and each fuel injector (13) has a high-pressure fuel inlet (14) formed on a side surface thereof and an overflow port on an upper end portion. A fuel outlet (15) is formed. As shown in FIG. 1, an overflow fuel passage (16) for communicating overflow fuel from the fuel injection pump (8) to a first fuel injector (13a) on the fuel injection pump side, and a first fuel injector ( 13
a), the nozzle-to-nozzle overflow fuel passage (17) which communicates the second fuel injector (13b) and the third fuel injector (13c), respectively.
And an overflow fuel return path (18) for guiding the fuel from the last third fuel injector (13c) out of the head cover (5).
Are provided. With this configuration, the surplus fuel of the fuel injection pump (8) is supplied to the first to third fuel injectors (13).
a) ・ (13b) ・ (13c) Fuel tank with surplus fuel
(6) can be returned.

As shown in FIG. 3, a through hole (19) is provided in a portion of the head cover (5) facing the high pressure fuel receiving port (14), and is attached to the tip of the high pressure fuel pipe (12). Connected fittings (20)
Into the through hole (19), and connect the connector (20) to the fuel injector.
The high pressure fuel inlet (14) of (13) is fastened and fixed.

Then, a sealing material (21) is attached between the inner peripheral surface of the through hole (19) penetrating through the head cover (5) and the outer peripheral surface at the insertion part of the connecting tool (20). The blow-by gas mixed with an oil mistake in (5) is prevented from leaking out of the head cover (5) from the through hole (19). The inner edge portion of the seal member (21) is configured not to overlap with the distal end surface of the high-pressure fuel inlet (14).

Further, in the present embodiment, each fuel injector (13a)
An overflow fuel outlet (15) is formed at each upper end of (13b) and (13c). This overflow fuel outlet (1
5) is configured by fitting an eye fitting (22) to the upper end of the fuel injector (13). The overflow fuel outlet (15) of the last third fuel injector (13c) is connected to the eye joint (22) of the third fuel injector (13c) as shown in FIGS. From the upper surface of the head of the bolt (23) fixed to the upper end, the cylinder shaft (24) is led out in the direction (upward) in which the axis of the fuel injector (13c) is extended, and the leg (not shown) of the bolt (23) ) And the cylindrical shaft
It is constituted by forming an overflow fuel passage (25) inside (24).

The cylinder shaft (2) in the head cover (5)
The cylinder shaft insertion hole (26) is penetrated at a position opposite to (4), and when the head cover (5) is attached to the cylinder head (3), the tip of the cylinder shaft (24) has the cylinder shaft insertion hole (26). 26) and is exposed outside the head cover (5).
The overflow fuel return path (18) is connected to the tip of (4). As a result, not only the overflow fuel from the fuel injector (13) but also the overflow fuel from the fuel injection pump (8) flows into the overflow fuel return path (1).
From 8), the fuel is returned to the fuel tank (6).

In order to maintain the airtightness in the head cover (5), a sealing material fitted inside the cylindrical shaft insertion hole (26).
(27) is brought into contact with the upper surface of the head of the bolt (23).

The fuel injection type engine configured as described above
In (1), a through-hole (19) is provided in the head cover (5) at a location facing the high-pressure fuel inlet (14) of the fuel injector (13),
The fitting (2) attached to the tip of the high-pressure fuel pipe (12) in the through hole (19)
0), and the inner end of the sealing material (21) attached between the inner peripheral surface of the through hole (19) and the outer peripheral surface of the connector (20) is the fuel injector.
The seal member (21) does not need to be moved when the head cover (5) is attached or detached because the high pressure fuel inlet (14) of (13) is arranged so as not to overlap with the high pressure fuel inlet (14).
Can be easily attached and detached.

Further, a cylinder shaft insertion hole (26) is provided through the head cover (5) at a position facing the overflow fuel outlet (15) of the fuel injector (13), and overflows into the cylinder shaft insertion hole (26). The cylinder shaft (24) constituting the fuel outlet (15) is inserted, and the inner peripheral surface of the cylinder shaft insertion hole (26) and the upper surface of the bolt (23) constituting the overflow fuel outlet (15) are formed. Since the seal member (27) is provided between the head cover (5) and the head cover (5), the hermetic seal can be performed by attaching and detaching the head cover (5).

In the above embodiment, a three-cylinder vertical fuel injection engine has been described as an example. However, the present invention is applicable to a single-cylinder fuel injection engine, a two-cylinder fuel injection engine, and a four-cylinder fuel injection engine.
The present invention can also be applied to a multi-cylinder fuel injection engine having more than one cylinder. In the case of a multi-cylinder engine having two or more cylinders, only the fuel injector (13) arranged in the cylinder farthest from the position where the fuel injection pump is provided is connected to the cylinder shaft (24) through the overflow fuel outlet (15). ) Can be extended.

In the above embodiment, the fuel tank (6)
The overflow fuel return path (18) is connected to the cylinder shaft (24) serving as the overflow fuel outlet (15) of the fuel injector (13), but the overflow fuel return path is formed in the engine head block. If you have a fuel injection pump
The pump overflow fuel passage (16) from (8) may be connected.

[0022]

According to the present invention, the overflow fuel outlet portion of the fuel injector is provided by projecting the cylinder shaft from the joint bolt in the direction in which the axis of the fuel injector is extended, and the head cover facing the cylinder shaft is provided with a cylinder. Since the shaft insertion hole is penetrated and the sealing material is arranged between this cylinder shaft insertion hole and the head of the joint bolt, the tip of the cylinder shaft, which is the over fuel outlet of the fuel injector, is outside the head cover. Will be located. For this reason, the head cover can be attached to and detached from the cylinder head simply by attaching and detaching the head cover in a state where the overflow return pipe is not connected to the tip end of the cylinder shaft, and the attaching and detaching operation of the head cover can be easily performed. Can be done. Further, since the head cover can be formed integrally, the configuration does not become complicated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a fuel system of a fuel injection engine.

FIG. 2 is a longitudinal sectional view of a cylinder head portion.

FIG. 3 is an enlarged view of a part III in FIG. 2;

FIG. 4 is an enlarged view of a part IV in FIG. 2;

FIG. 5 is a schematic configuration diagram showing a conventional fuel system.

[Explanation of symbols]

3 ... cylinder head, 5 ... head cover, 8 ... fuel injection pump, 12 ... high-pressure fuel pipe, 13 ... fuel injector, 15 ... overflow fuel outlet, 23 ... joint bolt, 24 ... cylinder shaft, 26 ... cylinder shaft insertion hole, 27… Seal member.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Aoshima 64 Ishizukitamachi, Sakai-shi, Osaka Inside Kubota Sakai Works

Claims (1)

[Claims] A fuel injector (13) disposed on a cylinder head (3) is surrounded by a head cover (5), and a head cover (5) is provided.
In a fuel injection type engine having a through hole for an overflow fuel passage from at least one of a fuel injector (13) and a fuel injection pump (8), a fuel injector (5) located in a head cover (5) is provided. An overflow fuel outlet (15) is formed at the protruding tip of (13), and the overflow fuel outlet (15) in one fuel injector (13) is connected to the cylinder shaft (24) from the joint bolt (23) by the fuel injector (15). 13) is formed so as to protrude in the direction in which the axis of the shaft extends, and a cylinder shaft insertion hole (26) is provided through the head cover (5) facing the overflow fuel outlet (15) in which the cylinder shaft (24) is formed. A fuel injection engine in which a seal member (27) is arranged between the cylindrical shaft insertion hole (26) and the head of the joint bolt (23).