JPH1030511A - Fuel supplier of intra-cylinder fuel injection engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an intra-cylinder fuel injection injector to be simply connected to a fuel distributing common rail provided in a high pressure fuel line. SOLUTION: A relay tube 7a provided in a common rail 7 of a high pressure fuel line and the fuel flowing-in connection terminal part 4a of a intra-cylinder injecting injector 4 faced to the combustion chamber 1c of each cylinder are connected to each other via an anti-pressure fuel piping 8. In this case, at first, the flowing-inlet and ejecting outlet of the anti-pressure fuel piping 8 are faced to the relay tube 7a and the fuel flowing-in connection terminal part 4a respectively and both of these are simultaneously connected together via joints 18b, 18a composed of a one-touch coupler, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply device for a direct injection engine which improves the attachment / detachment of a pressure-resistant fuel pipe which communicates a direct injection injector with a common rail provided in a high pressure fuel line.

[0002]

2. Description of the Related Art In general, this type of in-cylinder injection engine for directly injecting fuel into a combustion chamber is disclosed in, for example,
As disclosed in JP-A-83922, high-pressure fuel pressurized by a high-pressure fuel pump is supplied to a common rail, and is distributed from the common rail to in-cylinder injectors facing the combustion chamber of each cylinder.

In a direct injection engine, the fuel pressure is extremely high, for example, 70 kg / cm ² or more, in order to inject fuel against the pressure in the combustion chamber (so-called in-cylinder pressure). Between, for example, as disclosed in JP-A-57-195857,
When the injector is connected with a rubber hose used in a so-called manifold injection engine that is arranged upstream of the intake port, a large fuel pressure is applied to this rubber hose, so that the appropriate fuel pressure is not transmitted to the injector, and the variation in the injection amount is large. Become.

[0004] Therefore, the common rail and the in-cylinder injector are often communicated with each other by using a pressure-resistant hose or a fuel pipe having a pressure resistance such as a steel pipe.

[0005]

However, a pressure hose,
Alternatively, a fuel pipe such as a steel pipe has a high rigidity, and it takes time and effort to connect the common rail and the in-cylinder injector, resulting in poor workability. Also, in many cylinder engines, the common rail and each in-cylinder injector are often individually connected via a fuel pipe, and the fuel pipe must be connected for each in-cylinder injector, resulting in a work efficiency. Is bad.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a fuel supply device for a cylinder injection engine, which is capable of assembling a common rail and an in-cylinder injector via a fuel pipe in a very short time and has good workability. The purpose is to do.

[0007]

In order to achieve the above object, the present invention provides an in-cylinder injector for directly injecting fuel into a combustion chamber in a cylinder head, the in-cylinder injector and a high-pressure fuel pump. In a direct injection engine that communicates with a fuel distribution common rail provided downstream through a pressure-resistant fuel pipe, a storage portion for immersing the pressure-resistant fuel pipe is formed on the surface of a rocker cover that is crowned on the cylinder head. The fuel supply section of the common rail and the fuel inlet of the in-cylinder injector are directed in the same direction, and the pressure-resistant fuel is directed in the direction of the fuel supply section of the common rail and the fuel inlet of the in-cylinder injector. An upstream port and a downstream port of the pipe are opposed to each other, and the upstream port and the downstream port of the pressure-resistant fuel pipe are connected to the fuel supply section of the common rail and the cylinder. To the fuel inlet of the injector, characterized in that connected via a detachable joint at the same time.

That is, the upstream port and the downstream port of the pressure-resistant fuel pipe are provided to the fuel inlet of the in-cylinder injector directed in the same direction and the fuel supply section of the fuel distribution common rail provided downstream of the high pressure fuel pump of the fuel line. The mouth is opposed, and both are connected simultaneously via a joint. Then, the pressure-resistant fuel pipe is immersed in a storage portion formed in the rocker cover, and the in-cylinder injector is connected to the common rail via the pressure-resistant fuel pipe.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 in the drawing denotes an engine, which in the present embodiment indicates a horizontally opposed four-cylinder engine. A cover 3 is crowned. Incidentally, reference numeral 1a in FIG.
Reference numeral denotes a crank pulley which is mounted on a crankshaft 1b (see FIG. 3) of the engine 1.

The cylinder head 2 has a mounting hole 2b for fixing an in-cylinder injector 4 provided for each cylinder.
The injection nozzle of the in-cylinder injector 4 fixed to the mounting hole 2b is connected to the combustion chamber 1 of each cylinder.
c. Note that reference numeral 5 is a spark plug.

The rocker chamber 2a and the rocker chamber 2a
The rocker cover 3 covers the mounting hole 2b of the in-cylinder injector 4 and is formed with a storage portion 3a into which a pressure-resistant fuel pipe 8 described later is immersed.
A fuel inflow connecting portion 4a as a fuel inflow port protruding from the rear end of the in-cylinder injector 4 mounted in the mounting hole 2b is exposed.

Reference numeral 6 denotes a fuel line for supplying a fuel of a predetermined pressure to the in-cylinder injector 4. As shown in FIG. 3, a feed pump 10 is provided on the fuel tank 9 side. A high-pressure fuel pump 12 is interposed downstream of the high-pressure fuel pump 12 via a fuel filter 11, and the discharge side of the high-pressure fuel pump 12 is connected via a check valve 14 that allows only the fuel discharge from the high-pressure fuel pump 12. And is communicated with the common rail 7. The fuel return side of the common rail 7 is the high pressure pressure regulator 1
5, is connected to the fuel tank 9 via a low-pressure pressure regulator 16; The high-pressure fuel pump 1
Reference numeral 2 denotes a so-called engine-driven pump connected to the crank pulley 1a via a belt 13.

The fuel line 6 has a low-pressure delivery line 6 extending from the fuel tank 9 to the upstream of the high-pressure fuel pump 12.
a, from the downstream of the high-pressure fuel pump 12 to the high-pressure pressure regulator 15 through the common rail 7
b, a portion from the downstream of the high pressure regulator 15 to the fuel tank 9 constitutes a low pressure return line 6c.

The common rail 7 is disposed substantially at the center of the upper portion of the engine body, and a relay pipe 7a as a fuel supply section made of a flexible pressure-resistant hose or a steel pipe extends from the common rail 7 toward the left and right banks 1L and 1R. Have been. The relay pipe 7a and the fuel inflow connection end 4a of the in-cylinder injector 4 are horizontally oriented in the same direction, that is, in the present embodiment, in the extending direction of the left and right banks 1L and 1R. The relay pipe 7a communicates with the fuel inflow connection end 4a of the in-cylinder injector 4 via the pressure-resistant fuel pipe 8.

The pressure-resistant fuel pipe 8 has a bank rail 8a communicating between the fuel inflow connection ends 4a of the in-cylinder fuel injection injectors 4 provided before and after each bank, and a substantially central portion of the bank rail 8a. And a fuel pipe 8b connected to the rocker cover 3. The bank rail 8a is immersed in the opening 3b of the storage section 3a formed in the rocker cover 3, and the fuel pipe 8b is formed in the guide formed in the storage section 3a. Groove 3
b, and is extended upward. The guide groove 3b is provided with a camshaft 17 provided in the rocker chamber 2a and a cam 17a provided in the camshaft 17.
A guide portion 3b formed at a position for avoiding interference with interior parts such as a camshaft 17 is provided at a position where the connecting portion between the bank rail 8a and the fuel pipe 8b of the pressure-resistant fuel pipe 8 is immersed. It is formed at a position crossing between 17a.

The bank rails 8a are formed so as to be inclined upward from both ends to a central portion where the fuel pipes 8b are connected, and the two ends of the bank rails 8a are connected to the fuel injectors 4 for in-cylinder fuel injection. A joint 18a that is connected to the fuel inflow connection end 4a is screwed into a portion facing the end 4a. Another end of the fuel pipe 8b facing the relay pipe 7a is also provided with another joint 18 connected to the relay pipe 7a.
b is attached. These joints 18a, 18b
Is a so-called one-touch coupler which incorporates a click mechanism and the like (not shown), and is positioned in advance so that the fuel inflow connection end 4a and the relay pipe 7a can be simultaneously attached and detached from the same direction.

A flange 8c projecting downward in FIG. 1 is fixed to the bank rail 8a, and the flange 8c is bolted to a boss 3d fixed to the opening 3b of the storage section 3a. Fixed by 19. Further, a cover 20 which is substantially flush with the surface of the rocker cover 3 is attached to the opening 3b.

Next, the operation of the embodiment having the above configuration will be described. A relay pipe 7a provided on a common rail 7 interposed in the high pressure line 6b of the fuel line 6, and a fuel inflow connection end 4a of an in-cylinder injector 4 mounted in a mounting hole 2b formed in the cylinder head 2. Is connected via a pressure-resistant fuel pipe 8 that is integrally assembled in advance, first, a joint 18b attached to an upstream port of a fuel pipe 8b provided on the inflow side of the pressure-resistant fuel pipe 8 is connected.
And a joint 18a attached to the downstream ports at both ends of the bank rail 8a are attached to the relay pipe 7a and the fuel inflow connection end 4a at the same time.

Then, the pressure-resistant fuel pipe 8 is immersed in the storage section 2a formed on the surface of the rocker cover 2, and
The relay pipe 7a and the fuel inflow connection end 4a are simultaneously connected to each other via the joints 18b and 18a, and the assembly is completed in a short time.

Thereafter, a flange 8c protruding from the bank rail 8a is fixed to a boss 3d fixed in the storage portion 3a by a bolt 19, and the pressure-resistant fuel pipe 8
Is fixed. Then, the opening 3b of the storage section 3a for storing the bank rail 8a is closed with a cover 20, and
Complete the assembly work.

At the time of maintenance and inspection, the pressure-resistant fuel pipe 8 can be easily removed by performing a procedure reverse to the procedure described above.

As described above, the relay pipe 7a communicating with the common rail 7 interposed in the high-pressure line 6b communicates with the fuel inflow connection end 4a of the in-cylinder injector 4 through the pressure-resistant fuel pipe 8. At this time, joints 18b and 18a provided at the inlet and the outlet of the pressure-resistant fuel pipe 8 provide
Since the pressure-resistant fuel pipe 8 can be mounted with one touch, the assembling operation can be completed in a short time.

Since only one fuel pipe 8b of the pressure-resistant fuel pipe 8 is connected to the common rail 7, the structure is simplified and the number of parts can be reduced.

Further, at least the opening 3b for accommodating the bank rail 8a of the accommodating portion 3a is closed by the cover 20, so that the interior of the opening 3b is easily heated at the time of low-temperature start, and the bank rail is accordingly correspondingly heated. The temperature of the fuel flowing through 8a can be raised at an early stage, the atomization of fuel can be promoted, the warm-up operation can be shortened, and the fuel efficiency can be improved.

Further, since the pressure-resistant fuel pipe 8 is housed in the housing portion 3a formed on the surface of the rocker cover 3, the surface of the rocker cover 3 becomes flat, and the assembling work of accessories around the rocker cover 3 and Wiring work becomes easy.

[0026]

As described above, according to the present invention,
The fuel supply section of the common rail interposed in the high pressure line of the fuel line and the fuel inlet of the in-cylinder injector are directed in the same direction, and the fuel supply section of the common rail and the fuel inlet of the in-cylinder injector are arranged in the same direction. The upstream port and the downstream port of the pressure-resistant fuel pipe are opposed to each other in the direction in which the fuel supply section of the common rail and the fuel inlet of the in-cylinder injector are connected to the upstream port and the downstream port. Since it can be attached and detached simultaneously through joints, assembly can be completed in a short time, efficiency of assembly work can be improved, and the pressure-resistant fuel pipe can be easily removed at the time of maintenance and inspection etc. Workability is good.

Further, since the pressure-resistant fuel pipe is immersed in a storage portion formed on the surface of the rocker cover enclosing the cylinder head, the surface of the rocker cover becomes flat, and auxiliary equipment and the like disposed around the rocker cover. Assembly work and wiring work become easy.

[Brief description of the drawings]

FIG. 1 is a side view of an engine viewed from a rocker cover side.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a circuit diagram of a fuel line.

FIG. 4 is a perspective view of an engine.

[Explanation of symbols]

 1c Combustion chamber 2 Cylinder head 3 Rocker cover 3a Storage section 4 In-cylinder injector 4a Fuel inlet 7 Common rail 7a Fuel supply section 12 High-pressure fuel pump 18a, 18b Coupling

Claims (1)

[Claims] An in-cylinder injector for directly injecting fuel into a combustion chamber is provided in a cylinder head, and a pressure-resistant fuel pipe is connected between the in-cylinder injector and a fuel distribution common rail provided downstream of a high-pressure fuel pump. In the in-cylinder injection engine which communicates through the cylinder head, a storage portion for immersing the pressure-resistant fuel pipe is formed on the surface of the rocker cover provided on the cylinder head, and the fuel supply portion of the common rail and the in-cylinder direct injection injector are provided. The fuel inlet is directed in the same direction, and the upstream port and the downstream port of the pressure-resistant fuel pipe are opposed to each other in the direction in which the fuel supply section of the common rail and the fuel inlet of the in-cylinder injector are directed. The upstream port and the downstream port of the pressure-resistant fuel pipe are connected to the fuel supply section of the common rail and the fuel inlet of the in-cylinder injector. The fuel supply apparatus for a direct injection engine, characterized in that connected via a detachable joint.