JP2000230467A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure that fuel is injected in a required direction by providing a fuel introduction port for each of a plurality of fuel passageways, while providing a common fuel injection port and allowing each of the fuel introduction ports to be shut off independently of each other. SOLUTION: A pair of fuel injection passageways 62 comprise main passageways 63 that extend in predetermined directions and sub-passageways 64 that extend in directions different from the main passageways 63. Each of the main passageways 63 is provided with a fuel introduction port 63a and each of the sub-passageways 64 is provided with a fuel introduction port 64a. Each of the main passageways 63 and each of the sub-passageways 64 share a common fuel injection port 65. When a valve body 61 is moved to release only the fuel introduction ports 63a of the main passageways 63 in this configuration, fuel is injected in a direction in which the main passageways 63 extend. Even though fuel leaks to flow into the sub-passageways 64 at this time, it flows with the fuel that flows through the main passageways 63, being injected through the common fuel injection ports 65. This helps minimize the influence of a fuel leak on a normal fuel injection flow, thus allowing fuel to be injected correctly in a required direction only.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fuel injection valve.

[0002]

2. Description of the Related Art In particular, in a direct injection type internal combustion engine, it is required to change the injection direction of fuel injected from a fuel injection valve in order to form a required combustion state in a cylinder according to an engine operating state. Therefore, for example, Japanese Patent Application Laid-Open No. 9-23606
Japanese Patent Application Publication No. 7-107803 provides a fuel injection valve having a pair of fuel injection passages, each fuel injection passage having a separate fuel inlet and a separate fuel injection outlet. The fuel injection passage is formed so that the fuel injected from the opening merges with the fuel injected from the fuel injection opening of the other fuel injection passage, and the fuel introduction openings of the fuel injection passage can be independently shut off or closed. I have. Here, when only the fuel inlet of one fuel injection passage is open, the direction of injection of the fuel injected from the fuel injection valve as a whole is the fuel injection when the fuel inlets of both fuel injection passages are open. Different from direction. That is, by controlling the shutoff operation of the fuel inlet of the fuel injection passage, it is possible to change the injection direction of the fuel injected from the fuel injection valve as a whole.

[0003]

Generally, in a fuel injection valve, there is a considerable gap between each part of the fuel injection valve due to a manufacturing error and a reduction in frictional resistance between sliding parts. This means that even if the fuel inlet of the fuel injection passage is closed, fuel flows into the closed fuel injection passage. For this reason, fuel is originally injected from a fuel injection port where fuel should not be injected, and when this fuel injection flow merges with another regular fuel injection flow, the direction of fuel injection from the fuel injection valve is the intended direction. Is completely different. Even when the fuel injection flow does not merge with another normal fuel injection flow, an unnecessary fuel injection flow is formed separately from the normal fuel injection flow, and as a result, the fuel injected from the fuel injection valve as a whole is consequently formed. The injection direction is different from the normal direction. In these cases, the combustion state required according to the engine operating state cannot be formed in the cylinder.

It is an object of the present invention to reliably inject fuel in a normal direction in a fuel injection valve capable of changing the fuel injection direction.

[0005]

According to a first aspect of the present invention, there is provided a fuel injection valve for injecting fuel, wherein a plurality of fuels for injecting fuel from inside the fuel injection valve to the outside are provided. The fuel passages each have a separate fuel inlet and a common fuel injection port, and each fuel inlet is independently shut off. According to this, the fuel is injected from the common fuel injection port when the fuel is injected through any of the fuel passages.

According to a second aspect, in the first aspect, the amount of fuel flowing into each fuel inlet can be controlled independently.

[0007]

FIG. 1 shows a case where the present invention is applied to a four-stroke compression ignition type internal combustion engine. Referring to FIG. 1, 1 is an engine body, 2 is a cylinder block, 3 is a cylinder head, 4 is a piston, 5 is a combustion chamber, 6 is an electrically controlled fuel injection valve, 7 is an intake valve, 8 is an intake port, 9 Denotes an exhaust valve, and 10 denotes an exhaust port. The intake port 8 is connected to a surge tank 12 via a corresponding intake branch pipe 11, and the surge tank 12 is connected to a supercharger, for example, an outlet of a compressor 16 of an exhaust turbocharger 15 via an intake duct 13 and an intercooler 14. Be linked. An inlet of the compressor 16 is connected to an air cleaner 18 via an air suction pipe 17, and a throttle valve 20 driven by a step motor 19 is arranged in the air suction pipe 17. The air suction pipe 17 upstream of the throttle valve 20
A mass flow detector 21 for detecting a mass flow rate of the intake air is disposed therein.

On the other hand, the exhaust port 10 is connected to the exhaust manifold 2.
The exhaust turbine 2 of the exhaust turbocharger 15 via the
3 and an outlet of the exhaust turbine 23 is connected via an exhaust pipe 24 to a catalytic converter 26 having a built-in catalyst 25 having an oxidizing function. Exhaust manifold 22
Inside, an air-fuel ratio sensor 27 is arranged. Exhaust pipe 28 connected to the outlet of catalytic converter 26 and throttle valve 2
The exhaust gas recirculation (hereinafter referred to as E)
(Referred to as GR) through a passage 29, and
E driven by a step motor 30 is provided in the passage 29.
A GR control valve 31 is provided. In the EGR passage 29, an intercooler 32 for cooling the EGR gas flowing in the EGR passage 29 is arranged. In the embodiment shown in FIG. 1, the engine cooling water is guided into the intercooler 32, and the engine cooling water cools the EGR gas.

On the other hand, the fuel injection valve 6 is connected to a fuel reservoir, a so-called common rail 34, via a fuel supply pipe 33. Fuel is supplied into the common rail 34 from an electric control type variable discharge fuel pump 35, and the fuel supplied into the common rail 34 is supplied to the fuel injection valve 6 through each fuel supply pipe 33. A fuel pressure sensor 36 for detecting the fuel pressure in the common rail 34 is attached to the common rail 34, and the fuel pump 35 is controlled so that the fuel pressure in the common rail 34 becomes the target fuel pressure based on the output signal of the fuel pressure sensor 36. Is controlled.

The electronic control unit 40 is composed of a digital computer, and is connected to a ROM (Read Only Memory) 42, a RAM (Random Access Memory) 43, a CPU (Microprocessor) 44, an input port 45, An output port 46 is provided. The output signal of the mass flow detector 21 is input to the input port 45 via the corresponding AD converter 47, and the output signals of the air-fuel ratio sensor 27 and the fuel pressure sensor 36 are also input to the input port via the corresponding AD converter 47, respectively. 45 is input. A load sensor 51 that generates an output voltage proportional to the amount of depression L of the accelerator pedal 50 is connected to the accelerator pedal 50, and the output voltage of the load sensor 51 is input to the input port 45 via the corresponding AD converter 47. . Also,
The input port 45 has a crank angle sensor 52 that generates an output pulse every time the crankshaft rotates, for example, by 30 °.
Is connected. On the other hand, the output port 46 is connected to the fuel injection valve 6, the throttle valve control step motor 19, the EGR control valve control step motor 3 via the corresponding drive circuit 48.
0 and the fuel pump 35.

Next, the fuel injection valve of the first embodiment will be described in detail. The fuel injection valve 6 of the first embodiment includes a housing 60,
Valve body 61 slidably housed in housing 60
And The housing 60 is substantially cylindrical. A pair of fuel injection passages 62 (only two are shown in FIG. 2) are provided at the substantially frustoconical tip of the housing 60.
These fuel injection passage pairs 62 are provided at equal intervals in the circumferential direction of the housing 60.

The fuel injection passage pair 62 has a main passage 63 extending in a predetermined direction and a sub passage 64 extending in a direction different from the main passage 63. The main passage 63 has a fuel introduction port 63a for introducing fuel into the main passage 63. On the other hand, the sub-passage 64 has a fuel inlet 64 a for allowing fuel to flow into the sub-passage 64. Further, in this embodiment, the main passage 63 and the sub passage 64 are connected to the common fuel injection port 65.
Having. That is, the main passage 63 and the sub passage 64 have a fuel inlet opening at a different position and a fuel injection opening opening at the same position. The valve body 61 is substantially cylindrical.
The valve element 61 has a substantially cylindrical distal end 66 that fits into a substantially cylindrical space at the distal end of the housing 60. Valve element 61
A space 69 for storing fuel (hereinafter referred to as a fuel storage space) is provided between an outer wall surface 67 of the housing 60 and an inner wall surface 68 of the housing 60.
Is formed. The distal end portion 66 of the valve body 61 has a fuel flow passage 70 for communicating the fuel storage space 69 with the fuel injection passage pair 62. The valve body 61 is provided in the housing 60.
Inside the housing 60 along the central axis C of the housing 60.

As shown in FIG. 2, when the valve body 61 is moved until only the fuel inlet 63a of the main passage 63 is opened, the fuel flows in the extending direction of the main passage 63, that is, as indicated by an arrow A in FIG. Injected in the direction. At this time, even if the fuel slightly leaks and flows into the sub-passage 64 through the space between the front end portion 66 of the valve body 61 and the inner wall surface at the front end of the housing 60, this fuel is deposited on the fuel flowing through the main passage 63. The fuel is injected from a common fuel injection port 65. Therefore, the influence of the leakage of the fuel on the normal fuel injection flow from the fuel injection valve 6 is extremely small, and the fuel injection flow is not formed separately from the normal fuel injection flow. Therefore, according to the present embodiment, the fuel is injected only in the correct direction.

When the valve body 61 is moved until the fuel inlet 63a of the main passage 63 and the fuel inlet 64a of the sub passage 64 are opened as shown in FIG. Injected in the direction. The direction of the arrow B is a direction between the extending direction of the main passage 63 and the extending direction of the sub passage 64, and the flow rate of the fuel flowing in the main passage 63 is smaller than the flow rate of the fuel flowing in the sub passage 64. Main passage 6
3 is closer to the extension direction, and the smaller the number is, the closer to the extension direction of the sub-passage 64 is. Therefore, the variable range of the direction of the fuel flow injected from the fuel injection valve 6 is determined by adjusting the passage diameter and the extending direction of the main passage 63 and the sub passage 64.

In the first embodiment, only the fuel inlet of the main passage may be closed and only the fuel inlet of the sub passage may be opened. In the first embodiment, the amount of fuel flowing into the fuel inlet of the sub passage may be controlled by controlling the degree of movement of the valve element. In this case, the direction of the fuel injection flow from the fuel injection valve can be controlled more finely.

Next, a fuel injection valve according to a second embodiment will be described.
Similarly to the first embodiment, the fuel injection valve 6 of the second embodiment also includes a housing 60 and a valve body 62 slidably housed in the housing 60. The front end of the housing 60 is provided with a pair of fuel injection passages 62 (only two are shown in FIGS. 4 and 5) similar to the first embodiment. The valve body 72 includes a valve body portion 73 and a float cap 74. The valve body portion 73 has a substantially cylindrical shape, and its tip is substantially conical. Further, the valve body portion 73 has a fuel pressure passage 75 for allowing pressurized fuel to pass therethrough. The fuel pressure passage 75 extends in the axial direction of the valve body portion 73,
Open at the conical outer wall surface. The float cap 74 has a substantially conical shape, and has a substantially conical space therein. The substantially conical inner wall surface of the float cap 74 that defines this space is in close contact with the conical outer wall surface of the valve body portion 73. That is, the conical tip of the valve body portion 73 is accommodated in the space inside the float cap 74. The substantially conical outer wall surface of the float cap 74 is in close contact with the substantially conical inner wall surface at the tip of the housing 60. Further, the float cap 74 has a plurality of through holes 76. These through holes 76 are provided at equal intervals in the circumferential direction of the float cap 74.

When high-pressure fuel is acting on the conical inner wall surface of the float cap 74 via the fuel pressure passage 75, the fuel pressure acting on the inner wall surface of the float cap 74 is higher than the fuel pressure acting on the outer wall surface of the float cap. high. Therefore, the distal end of the valve body portion 73 is
When it is moved away from the tip of the float cap 74, it moves away from the float cap 74. Accordingly, the float cap 74 has its conical outer wall surface kept in close contact with the conical inner wall surface of the housing 60. For this reason, the main passage 63 communicates with the fuel storage space 69 via the through hole 76 of the float cap 74. However, the auxiliary passage 64 does not communicate with the fuel storage space 69 because the fuel inlet 63 a is closed by the float cap 74. Accordingly, at this time, fuel is injected from the fuel injection valve 6 mainly through the main passage 63 in the direction of arrow D as shown in FIG. For this reason, according to the second embodiment, even if the fuel leaks into the sub-passage 64 as in the first embodiment, the influence on the normal fuel injection flow from the fuel injection valve 6 is extremely small. No fuel injection flow is formed separately from the regular fuel injection flow. Therefore, according to the present embodiment, the fuel is injected only in the correct direction.

On the other hand, when high pressure fuel is not acting on the inner wall surface of the float cap 74 via the fuel passage 75, the fuel pressure acting on the outer wall surface of the float cap 74 is higher than the fuel pressure acting on the inner wall surface of the float cap 74. . Therefore, the distal end of the valve body portion 73 is
Move with the float cap 74 when it is moved away from the tip. In this case, both the main passage 63 and the sub passage 64 communicate with the fuel storage space 69. Accordingly, at this time, fuel is injected from the fuel injection valve 6 through the main passage 63 and the sub passage 64 in the direction of arrow E as shown in FIG. The direction of the arrow E can be changed by adjusting the passage diameter and the extending direction of the main passage 63 and the sub passage 64 as in the first embodiment.

In this embodiment, unlike the first embodiment,
There is no sliding part between the valve body part 73 and the float cap 74 and between the float cap 74 and the tip of the housing 60. For this reason, no clearance is required for the sliding portion, so that the sealing between the valve body portion 73 and the float cap 74 and the sealing between the float cap 74 and the tip of the housing 60 are high. That is, the overall sealing performance between the elements of the fuel injection valve 6 is higher in the second embodiment than in the first embodiment.

Next, a fuel injection valve according to a third embodiment will be described.
Similarly to the second embodiment, the fuel injection valve 6 of the third embodiment also includes a housing 60 and a valve body 62 slidably accommodated in the housing 60. A pair of fuel injection passages 62 (only two are shown in FIGS. 6 and 7) are provided at the distal end of the housing 60 as in the second embodiment. The valve body 72 includes a valve body portion 73 ′, a float cap 74 ′, and a sliding ring 77. The valve body portion 73 'has a substantially cylindrical shape, and its tip is substantially conical. The valve body portion 73 'has a fuel pressure passage 75' through which pressurized fuel is passed. The fuel pressure passage 75 'is provided in the valve body 7
It extends in the axial direction of 3 'and opens at the cylindrical outer wall surface of the valve body portion 73'. The float cap 74 'has a substantially conical shape, and has a substantially conical space therein. The substantially conical inner wall surface of the float cap 74 ′ that defines this space is in contact with the conical outer wall surface of the valve body portion 73. That is, the conical tip of the valve body portion 73 'is accommodated in the space inside the float cap 74'. The substantially conical outer wall surface of the float cap 74 ′ is in contact with the substantially conical inner wall surface at the tip of the housing 60. Further, the float cap 74 'has a plurality of through holes 76'. These through holes 76 'are provided at equal intervals in the circumferential direction of the float cap 74'.

The sliding ring 77 is slidably mounted on the cylindrical body 73 'of the valve body 73'. The sliding ring 77 covers the opening of the fuel pressure passage 75 'on the cylindrical outer wall surface of the valve body portion 73'. Therefore, high-pressure fuel can act on the inner wall surface of the sliding ring 77 via the fuel pressure passage 75 '. When high-pressure fuel is acting on the inner wall surface of the sliding ring 77 via the fuel pressure passage 75 ', the sliding ring 77 slides toward the float cap 74', and comes into contact with and adheres to the float cap 74 '. Therefore, the fuel in the fuel storage space 69 cannot flow between the valve body portion 73 'and the float cap 74'.
It can only flow between the float cap 74 'and the housing 60. Thus, the valve element portion 73 'moves with the float cap 74' when its distal end is moved away from the distal end of the housing 60. In this case, both the main passage 63 and the sub passage 64 communicate with the fuel storage space 69. Accordingly, at this time, as shown in FIG. 6, fuel is injected from the fuel injection valve 6 through the main passage 63 and the sub passage 64 in the direction indicated by the arrow. The direction of the arrow F can be changed by adjusting the passage diameter and the extending direction of the main passage 63 and the sub passage 64 as in the second embodiment.

On the other hand, when high pressure fuel is not acting on the inner wall surface of the sliding ring 77 via the fuel pressure passage 75 ', the sliding ring 77 is separated from the float cap 74' by the pressure of the fuel in the fuel storage space 69. To slide. Even if the sliding ring 77 does not slide, the adhesion between the sliding ring 77 and the float cap 74 'is very small. Therefore, the fuel in the fuel storage space 69 is supplied to the valve portion 73 '.
And the float cap 74 '. For this reason, the valve body portion 73 '
When it is moved away from the zero point, it moves away from the float cap 74 '. Accordingly, the float cap 74 ′ remains with its conical outer wall surface in close contact with the conical inner wall surface of the housing 60. Therefore, the main passage 63 communicates with the fuel storage space 69 through the through hole 76 ′ of the float cap 74. However, the sub-passage 64 has a fuel inlet 63a whose float cap 74
And is not in communication with the fuel storage space 69. Accordingly, at this time, fuel is injected from the fuel injection valve 6 mainly through the main passage 63 in the direction of arrow G as shown in FIG. For this reason, according to the third embodiment, even if the fuel leaks into the sub passage 64 as in the second embodiment, the influence on the normal fuel injection flow from the fuel injection valve 6 is extremely small. No fuel injection flow is formed separately from the normal fuel injection flow. Therefore, according to the present embodiment, the fuel is injected only in the correct direction.

In the above-described embodiment, the fuel injection ports of the main passage and the sub passage of the fuel injection passage pair are used as a common outlet.
The main passage and the sub passage merge in the housing wall,
The same effect as in the above embodiment can be obtained by connecting to a common passage. Further, in the above embodiment, the fuel injection passage pair has two passages (main passage and sub passage), but may have two or more passages.

[0024]

According to the first and second aspects of the present invention, fuel is injected from a common fuel injection port regardless of whether fuel is injected through any of the fuel passages. That is, the fuel inlet of any one of the fuel passages was shut off, but fuel leakage occurred,
Even if fuel flows into the fuel passage that should have been closed, the fuel is injected from the fuel injection valve on the fuel flowing through the open fuel passage. At this time, since the influence of the leaked fuel on the normal fuel injection flow is extremely small, the fuel injection flow does not deviate from the normal direction. Of course, the fuel injection flow is not formed separately from the regular fuel injection flow. Thus, the fuel is injected exactly in the correct direction.

[Brief description of the drawings]

FIG. 1 is a view showing an internal combustion engine provided with a fuel injection valve of a first embodiment.

FIG. 2 is a sectional view of the fuel injection valve of the first embodiment.

FIG. 3 is a sectional view of the fuel injection valve of the first embodiment.

FIG. 4 is a sectional view of a fuel injection valve according to a second embodiment.

FIG. 5 is a sectional view of a fuel injection valve according to a second embodiment.

FIG. 6 is a sectional view of a fuel injection valve according to a third embodiment.

FIG. 7 is a sectional view of a fuel injection valve according to a fourth embodiment.

[Explanation of symbols]

 6 fuel injection valve 60 housing 61 valve body 62 fuel injection passage pair

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AA07 AA11 AA13 AB02 AD12 CC12 CC14 CC18 CC23 CC28 CC30 CC37 CC48 CC66 DC01 DC04 DC05 DC11 DC24

Claims (2)

[Claims] A fuel injection valve for injecting fuel has a plurality of fuel passages for injecting fuel from inside to outside of the fuel injection valve, each of which has a separate fuel inlet. A fuel injection valve having a common fuel injection port so that each fuel inlet can be shut off independently. 2. The fuel injection valve according to claim 1, wherein the amount of fuel flowing into each fuel inlet can be controlled independently.