JPH06173733A - Fuel injection device for engine - Google Patents

Abstract

PURPOSE:To gasify and stomize fuel in good condition so as to supply fuel with good responsiveness by providing a fuel injection amount control means for making the rate of a fuel amount injected from a downstream side fuel injector larger as the number of rotation comes in a higher range. CONSTITUTION:Fuel injectors 9, 17 are provided respectively on upstream and downstream sides of an intake passage communicated with the combustion chamber 2 of a single cylinder. The upstream side fuel injector 9 is arranged toward the fuel collision member 20 of an upstream side air funnel part, while the downstream side fuel injector 17 is arranged in an intake valve direction. In an engine high rotation range, the injection rate of a downstream side fuel injector is enlarged relatively larger than that of the downstream side fuel injector 17. At the time of normal operation, fuel is injected around the upstream side fuel injector 9, and supplied to an engine combustion chamber after gasifying fuel sufficiently by utilizing a large intake passage length.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine fuel injection device.

[0002]

2. Description of the Related Art As disclosed in, for example, Japanese Examined Patent Publication No. 2-14974, there are two fuel injectors, a first cylinder and a second fuel injector, on the upstream side and the downstream side of an intake passage of a single cylinder in an engine. There is one provided.

When there are separate fuel injectors in the upstream and downstream portions of the intake passage, which fuel injector is used depends on the operating region of the engine, and the required fuel injection amount of the engine is determined. Accordingly, the fuel injection ratio from both fuel injectors can be variably controlled, the fuel supply efficiency is improved, and the output responsiveness is improved.

[0004]

However, in the conventional structure, the two fuel injectors do not have particularly different injection characteristics, and the control methods of the two fuel injectors are substantially the same. ing. Therefore, in the case of such a fuel injection device, in an engine in which the engine temperature and operating conditions change frequently, such as an engine having a wide engine rotation range and a large load change, it is possible to meet the request at each time point. There is a problem that fuel injection with good response cannot be realized.

[0005]

The inventions described in each of claims 1 to 5 of the present application have been made for the purpose of solving the above problems, and are configured as follows. .

(1) Structure of the Invention According to Claim 1 In the fuel injection device for an engine according to the invention described in claim 1, the fuel injectors are respectively provided on the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In an engine in which fuel is injected from both fuel injectors in accordance with the operating state, a fuel injection amount control means for increasing the ratio of the fuel injection amount from the downstream side fuel injector in a higher rotation range is provided. To do.

(2) Configuration of the Invention According to Claim 2 In the fuel injection device for an engine according to the invention described in claim 2, the fuel injectors are respectively provided on the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In an engine in which fuel is injected from both fuel injectors in accordance with the operating state, a fuel injection amount control means for increasing the ratio of the fuel injection amount from the downstream fuel injector in a higher load range is provided. To do.

(3) Structure of the Invention According to Claim 3 In the fuel injection device for an engine according to the invention described in claim 3, the fuel injectors are respectively provided on the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In an engine in which fuel is injected from both fuel injectors according to operating conditions, a fuel injection amount control means is provided for increasing the ratio of the fuel injection amount from the downstream side fuel injector to the higher rotation speed and higher load range. It is characterized by.

(4) Structure of the Invention According to Claim 4 The fuel injection device for an engine according to the invention of claim 4 is based on the structure of the invention according to claim 1, 2 or 3 above,
In the same configuration, the engine is a multi-cylinder engine,
It is characterized in that a fuel injection amount correction means for increasing the ratio of the fuel injection amount from the downstream side fuel injector to a cylinder having a larger heat load is provided.

(5) Structure of the invention according to claim 5 The fuel injection device for an engine according to claim 5 is based on the structure of the invention according to claim 1, 2, 3 or 4, and has the same structure. In the second aspect, a means for supplying two kinds of fuels having different vaporizability is provided, and the fuel having a higher vaporizability is supplied to the downstream side fuel injector.

[0011]

The invention according to each of claims 1 to 5 of the present application operates as follows corresponding to the above configuration.

(1) Operation of the invention according to claim 1 In the engine fuel injection device according to claim 1, as described above, the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In each engine equipped with fuel injectors and injecting fuel from both fuel injectors according to the operating state, a fuel injection amount control means for increasing the ratio of the fuel injection amount from the downstream side fuel injector in a higher rotation range is provided. It is configured.

Therefore, according to this structure, during steady operation, the fuel can be injected around the upstream fuel injector, sufficiently vaporized by utilizing the long intake passage length, and then supplied to the engine combustion chamber. It is possible to obtain good and stable combustion performance.

On the other hand, when the operating state of the engine shifts to a high speed region and a prompt supply of fuel is required, the fuel injection ratio from the downstream fuel injector near the engine combustion chamber is increased, Fuel is quickly supplied to the engine combustion chamber, and fuel responsiveness is improved.

(2) Operation of the invention described in claim 2 In the engine fuel injection device of the invention described in claim 2, as described above, the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In each engine equipped with fuel injectors and injecting fuel from both fuel injectors in accordance with the operating state, a fuel injection amount control means for increasing the proportion of the fuel injection amount from the downstream side fuel injector in a higher load range is provided. It is configured.

Therefore, according to this configuration, during steady operation, fuel can be injected centering on the upstream fuel injector, and can be sufficiently vaporized by utilizing the long intake passage length before being supplied to the engine combustion chamber. It is possible to obtain good and stable combustion performance.

On the other hand, when the operating state of the engine shifts to a high load region where the intake air amount is large and a prompt supply of fuel is required, the fuel injection ratio from the downstream fuel injector near the engine combustion chamber is demanded. Has been increased,
Fuel is quickly supplied to the engine combustion chamber, and fuel responsiveness is improved.

(3) Operation of the invention according to claim 3 In the fuel injection device for an engine according to claim 3, as described above, the upstream side and the downstream side of the intake passage communicating with the combustion chamber of a single cylinder. In an engine that is equipped with each fuel injector, and injects fuel from both fuel injectors according to the operating state, the fuel that increases the proportion of the fuel injection amount from the downstream fuel injector as the rotation speed increases and the load increases. The injection amount control means is provided.

Therefore, according to this structure, during steady operation, the fuel can be injected around the upstream fuel injector, sufficiently vaporized by utilizing the long intake passage length, and then supplied to the engine combustion chamber. It is possible to obtain good and stable combustion performance.

On the other hand, the operating condition of the engine is high rotation,
In addition, when the engine shifts to the high load region and prompt supply of fuel is required, the fuel injection ratio from the downstream fuel injector near the engine combustion chamber is increased, and fuel is supplied to the engine combustion chamber in a quick manner. And
Fuel responsiveness is improved.

(4) Operation of the invention according to claim 4 In the fuel injection device for an engine according to the invention described in claim 4, the configuration of the invention according to claim 1, 2 or 3 is the basic configuration as described above, and the same configuration The engine is a multi-cylinder engine, and the fuel injection amount correction means is provided to increase the ratio of the fuel injection amount from the downstream side fuel injector to the cylinder having a larger heat load in each cylinder group.

Therefore, the intake port of the cylinder having a large heat load is cooled by the fuel from the downstream fuel injector, the heat load is reduced, and the combustibility is improved.

(5) Operation of the invention according to claim 5 The fuel injection device for an engine according to claim 5 is premised on the configuration of the invention according to claim 1, 2, 3 or 4 above.
In the configuration, two types of fuel supply means having mutually different vaporizability are provided so that the fuel having a higher vaporizability is supplied to the downstream fuel injector.

Therefore, it is possible to improve the fuel responsiveness at the time of high rotation, high load, high speed / high load operation, and also improve the vaporization property, and the output responsiveness is improved as much as possible.

[0025]

As a result of the above, according to the present invention, it is possible to improve the fuel vaporization in the steady operation region as much as possible, and improve the fuel responsiveness at the time of high rotation such as acceleration and high load. As a result, the combustion efficiency of the engine can be improved as much as possible.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of an engine fuel injection system according to an embodiment of the present invention.

In the figure, reference numeral 1 is an engine body of this embodiment, and the engine body 1 is constructed by integrating an upper cylinder head 1A and a lower cylinder block 1B.

Between them, the engine combustion chamber 2
Are formed. An intake port 3 is formed on the wall surface of the cylinder head with respect to the engine combustion chamber 2, and an intake manifold 6 is connected to and integrated with an intake manifold mounting portion 5 of the intake port 3.

The upstream opening of the intake manifold 6 is connected to a downstream opening end of an air funnel 7 for introducing intake air more efficiently than a wide-diameter intake introducing portion 8 provided downstream of the air cleaner, for example. It is integrated.

An upstream first fuel injector 9 is provided at the upstream opening of the air funnel 7 via a fuel injector mounting portion 12 having a nozzle hole fitting port 12a. The first fuel injector 9 is arranged and fixed such that its injection hole portion 9a is directed toward the center of the fuel collision surface 20a of the upstream side fuel collision member 20 provided in the air funnel 7. On the other hand, as shown in the drawing, the fuel collision member 20 is formed in a shape in which the upstream surface side projects in a streamlined shape so as to reduce intake resistance as much as possible, while the downstream surface side thereof is formed by the first fuel injector 9 described above. The fuel injected from the fuel cell collides and is atomized efficiently, and the reflected fuel is introduced into the intake passage formed by the air horn 7 and the intake manifold 6 in the direction of the central axis of the intake hood. Is formed on a substantially flat surface that is inclined and faces the fuel injector 9 direction.

On the other hand, the throttle body portion of the intake manifold 6 is provided with a throttle valve 15 in a freely rotatable state from a solid line position to an imaginary line position via a throttle shaft 16 as shown in the figure.

Further, reference numeral 17 is a second fuel injector for injecting fuel to the heating wall surface 3a in the intake port 3 in front of the intake valve 4, and the second fuel injector 17 is of the intake port 3. It is attached to the intake manifold attachment portion via a fuel injector attachment portion 21 in which a fitting port 21a of the injection port portion 17a is formed.

Therefore, in this configuration, the throttle valve 15 is in the state shown by the solid line in the figure (fully closed) or the state shown by the phantom line in the figure.
In any state of (fully open) or in the middle thereof, first, the fuel injected from the first fuel injector 9 hits the fuel collision surface 20a, which is the downstream side surface of the fuel collision member 20, surely and rapidly. Is atomized into air from the air funnel 7 to the intake manifold 6 and the intake port 3
After that, it is introduced into the engine combustion chamber 2 and vaporization becomes good. As a result, as in the conventional case, the liquid droplets are supplied to the combustion chamber as they are and the combustibility of the air-fuel mixture is deteriorated. Also, the transportation delay occurs due to the adhesion of the wall surface, and the heating wall surface of the intake port is cooled. Will disappear. Also,
There is no possibility that fuel will be scattered on the upstream side of intake air as in the case of wall injection.

Next, the fuel injected from the second fuel injector 17 hits the wall surface of the high temperature intake port near the intake valve 4 to be rapidly heated and vaporized, and in a quick manner in synchronization with the opening of the intake valve 4. It is supplied into the engine combustion chamber 2.

As a result, the combustion performance and the combustion efficiency are improved as much as possible over the entire operating range of the engine, and the output response at the time of acceleration is also improved.

On the other hand, the fuel supply system for the first and second fuel injectors 9 and 17 is, for example, as shown in FIG.
The special gasoline (A in Fig. 5) and the regular regular gasoline, which are especially highly volatile, are configured as shown in
The fuel supply control according to the operating state of the engine is performed by using two kinds of gasoline having different vaporizability from (FIG. 5B).

In FIG. 2, reference numerals VL and VR respectively indicate the left and right bank portions of, for example, a V-type 10 cylinder engine in which the intake system and the fuel injection device are configured as shown in FIG. No. 1 to No. 5 and No. of parts VR and VL
The first and second fuel injectors 9 and 17 described above are similarly provided on the upstream side and the downstream side of the intake passages of the cylinders No. 6 to No. 10, respectively, as shown in the drawing.

The first delivery pipes 9DPL, 9DPR of the first fuel injector group 9, 9 ... Of each bank VR, VL are connected to the first fuel supply pipe FP ₁ by the first fuel pump FP ₁ . Regular gasoline B is supplied from the regular gasoline tank RGT via SP ₁ , while each bank V
Second fuel injector group for L, VR 17,17
The second delivery pipe 17DPL of ..., the 17DPR, special gas tank SPG than the second fuel supply pipe SP ₂ via the second fuel pump FP ₂
Special gasoline A is supplied from T.

The fuel injection states of the first and second fuel injectors 9, 9 ..., 17, 17 ... are determined by the engine control unit (ECU).
30 is controlled by, for example, the first fuel injector 9, 9 ... Injects regular gasoline toward the fuel collision member 20 upstream of the air funnel 7 in the low and medium load operating region of the engine. Then, the particles are thoroughly atomized, and are vaporized as much as possible by utilizing the long intake passage length before being supplied to the engine combustion chamber 2. In addition, the second fuel injector 17,17.
.. is a special gasoline A that has a higher vaporization property than regular gasoline (B) toward the high temperature intake port wall near the intake valve 4 in the medium and high load operation region, as shown in FIG.
Is injected to reduce the heat load through port cooling using latent heat of vaporization, and the fuel vaporized efficiently by heating is quickly supplied to the engine combustion chamber to improve the output responsiveness during acceleration. Further, the ratio of the fuel injection amounts among the first and second fuel injectors 9, 9, ..., 17, 17 ... is as shown in FIGS. 3 and 4 when the total fuel is the same. As shown in the figure, the higher the rotation speed and the higher the load, the more the second fuel injector 17,1
In addition to increasing the injection rate from 7 ... to improve output performance, a high temperature cylinder (cylinder with a high liner wall temperature) that has a larger heat load than a normal temperature cylinder (a cylinder with a normal liner wall temperature) Second fuel injector 17,17
・ The ratio of injection from ・ is increased to protect the liner by cooling the port and achieve combustion stability.

[Brief description of drawings]

FIG. 1 is a partially cutaway cross-sectional view of a fuel injection device for an engine according to an embodiment of the present invention.

FIG. 2 is a piping diagram showing a fuel supply system to a fuel injector section of the same apparatus.

FIG. 3 is a graph showing the influence of engine speed on the fuel injection amount per cylinder in the same device.

FIG. 4 is a graph showing the influence of engine load on the fuel injection amount per cylinder in the same device.

FIG. 5 is a graph showing the distillation properties of special gasoline and regular gasoline used in Examples of the present invention in comparison.

[Explanation of symbols]

1 is an engine body, 2 is an engine combustion chamber, 3 is an intake port, 6 is an intake manifold, 9 is a first fuel injector, 15 is a throttle valve, 16 is a throttle shaft,
Reference numeral 17 is a second fuel injector, and 20 is a fuel collision member.

Claims (5)

[Claims] 1. An engine in which fuel injectors are provided on the upstream side and the downstream side of an intake passage communicating with a combustion chamber of a single cylinder, and fuel is injected from both fuel injectors in accordance with an operating state, A fuel injection device for an engine, comprising fuel injection amount control means for increasing a ratio of a fuel injection amount from the downstream side fuel injector. 2. An engine in which fuel injectors are provided on the upstream side and the downstream side of an intake passage communicating with a combustion chamber of a single cylinder, and fuel is injected from both fuel injectors depending on operating conditions, the higher the load range is, A fuel injection device for an engine, comprising fuel injection amount control means for increasing a ratio of a fuel injection amount from the downstream side fuel injector. 3. An engine in which fuel injectors are provided on the upstream side and the downstream side of an intake passage communicating with a combustion chamber of a single cylinder, and fuel is injected from both fuel injectors according to operating conditions A fuel injection device for an engine, comprising fuel injection amount control means for increasing a ratio of a fuel injection amount from the downstream fuel injector in a load region. 4. The engine is a multi-cylinder engine, and a fuel injection amount correction means for increasing the ratio of the fuel injection amount from the downstream side fuel injector to a cylinder having a larger heat load is provided. The fuel injection device for an engine according to 1, 2, or 3. 5. A fuel supply device for supplying two kinds of fuels having different vaporizability to each other, and the fuel having a higher vaporizability is supplied to the downstream fuel injector. 2. A fuel injection device for an engine according to 2, 3 or 4.