JP3298310B2 - Fuel injection valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fuel injection valve suitable for injecting and supplying fuel to a cylinder of an internal combustion engine.

[0002]

2. Description of the Related Art There are various types of fuel injection valves used in an internal combustion engine, and there are various types of fuel injection valves. They can be broadly divided into those of the opening type.

Therefore, as an example of the first prior art fuel injection valve, an inward-opening fuel injection valve disclosed in Japanese Utility Model Laid-Open Publication No. Sho 57-114163 will be described as an example with reference to FIGS. I do.

FIG. 9 is a sectional view of a fuel injection valve. A stepped cylindrical injection nozzle 102 is provided at one end of a casing 101 forming a valve housing. A shaft hole 103 that defines a fuel flow path is formed in the injection nozzle 102 in the axial direction. An injection hole 104 that opens into a combustion chamber (not shown) is integrally formed at one end of the shaft hole 103. Is formed. On one side of the shaft hole 103, a substantially conical valve seat 105 is formed near the injection hole 104.

[0005] The needle valve 106 is provided in the shaft hole 103 so as to be movable in the axial direction. This needle valve 106
Is substantially constituted by a valve shaft 107 inserted into the shaft hole 103, and a substantially conical seat portion 108 formed at one end of the valve shaft 107 and detachably seated on the valve seat 105.
7 is provided with a pair of chamfers 109 formed, for example, in a pentagonal shape as a whole and spaced apart in the axial direction. Each of the chamfers 109 provides a spiral flow to the fuel flowing in the shaft hole 103 toward the injection hole 104 by forming the fuel flow path into a maze.

The other end of the valve shaft 107 is fitted and fixed to an anchor 110 made of a magnetic material.
The needle valve 106 opens and closes when 0 is sucked into the core 111. A yoke 11 is provided on the outer peripheral side of a core 111 formed in a stepped cylindrical shape from a magnetic material.
2, an electromagnetic coil 113 wound around the core 11 is provided.
A valve spring 114 that constantly urges the needle valve 106 in the valve closing direction via the anchor 110 is disposed between one end of the anchor 1 and the other end of the anchor 110.

Reference numeral 115 denotes a connector connected to a control unit (neither is shown) via a harness. A fuel injection signal from the control unit is applied to the electromagnetic coil 113 via the connector 115. You. Reference numeral 116 denotes a fuel inlet, and the fuel inlet 116 is connected to a fuel pump (both not shown) that sucks up fuel in the fuel tank via a fuel supply pipe, a pressure regulator, and the like. 117 is the injection hole 10
4 and a spiral groove 11 is formed on the peripheral surface of the fitting member 117 as shown in an enlarged view of FIG.
8 are formed.

The fuel injection valve according to the first prior art is constructed as described above, and is mounted, for example, facing the combustion chamber and used as a direct injection type fuel injection valve (in-cylinder direct injection type fuel injection valve). Can be Then, in a normal state where the fuel injection signal is not output from the control unit, the needle valve 106 is closed by the spring force of the valve spring 114. On the other hand, when a fuel injection signal from the control unit is applied to the electromagnetic coil 113 via the connector 115, an electromagnetic force is generated, and the anchor 110 is moved to the valve spring 114.
Is attracted to the core 111 against the spring force of As a result, when the needle valve 106 is displaced upward and opens, the fuel supplied into the shaft hole 103 is ejected from the injection hole 104 into the combustion chamber with a predetermined fuel pressure (fuel injection pressure). Here, since the fuel is ejected along the groove 118 of the fitting member 117 fitted to the injection hole 104, the fuel injected from the injection hole 104 has a swirling flow.

FIG. 11 shows a second prior art. In this technique, the fuels collide with each other to atomize the fuel.

That is, the injection nozzle 201 attached to one end of a casing (not shown) has
A shaft hole 202, an injection hole 203, and a valve seat 204 are provided, and a needle valve 205 that detaches and seats on the valve seat 204 to open and close the injection hole 203 is provided so as to be movable in the axial direction.

A nozzle plate 206 is integrally formed at one end of the injection nozzle 201, and a pair of injection holes 207 and 208 are formed in the nozzle plate 206 at an angle. These injection holes 207 and 208 are formed such that their axes AA and BB intersect outside the injection nozzle 201.

The second prior art is generally configured as described above. When the needle valve 205 is opened, the shaft hole 202 is opened.
The fuel supplied to the inside flows out from the injection holes 203 toward the nozzle plate 206 and is jetted to the outside through the injection holes 207 and 208 formed in the nozzle plate 206.
Here, the fuel injected from each of the injection holes 207 and 208 collides with each other at an intersection P outside the injection nozzle 201 and is atomized.

[0013]

In the first prior art (Japanese Utility Model Laid-Open No. 57-114163), fuel is swirled by a spiral groove 118 formed in a fitting member 117. However, since the fuel is simply swirled and the fuels do not directly collide with each other, the atomization of the fuel cannot be effectively performed.

In the second prior art, a pair of injection holes 207, 208 inclined toward one end in the axial direction are provided, and the fuel injected from each of the injection holes 207, 208 collides with each other to atomize the fuel. Is being planned. However, this technology
It merely stops the fuels from colliding with each other and does not sufficiently exhibit the atomization performance. In addition, since the injection holes 207 and 208 are formed in the nozzle plate 206, when used as a direct injection type fuel injection valve, combustion products gradually adhere to the injection holes 207 and 208, and a "clogging" phenomenon may eventually occur. There is.

The present invention has been made in view of such problems of the prior art, and a main object thereof is to improve the atomization performance of fuel. Further, another object of the present invention is to prevent a "clogging" phenomenon due to a combustion product or the like and improve reliability even when used as a direct injection type.

[0016]

Accordingly, a fuel injection valve according to the present invention is provided with a casing, an injection nozzle provided on one end side of the casing and having a valve seat and an injection hole, and axially moving into the injection nozzle. And a needle valve that is provided so as to be able to open and close the injection hole by detaching from and seating on the valve seat, wherein the needle valve has one end side of a valve shaft having the same inclination angle as the valve seat. A first tapered portion that is detachably seated on the valve seat, and an inclination angle that is provided on one end side of the first tapered portion facing the injection hole and is smaller than the first tapered portion. From a second tapered portion formed with the second tapered portion, and an inclined surface portion which is located opposite to the second tapered portion and is provided so as to be inclined so that the respective inclined axes intersect outside the injection nozzle. It is characterized by having comprised.

A fuel injection valve according to a second aspect is provided with a casing, an injection nozzle provided on one end side of the casing, having a valve seat and an injection hole, and provided movably in an axial direction in the injection nozzle. A needle valve that opens and closes the injection hole by detaching and seating on the valve seat, wherein the needle valve is formed at one end of a valve shaft at the same inclination angle as the valve seat; The first to take off and sit on the valve seat
A second tapered portion provided on one end side of the first tapered portion facing the injection hole and formed at a smaller inclination angle than the first tapered portion; And a slanted surface portion which is located opposite to the second tapered portion and is provided so as to be slanted so that their respective slant axes intersect outside the injection nozzle. It is characterized in that each groove is formed.

According to a third aspect of the present invention, there is provided a fuel injection valve provided at one end of the casing, an injection nozzle having a valve seat and an injection hole, and provided in the injection nozzle so as to be movable in the axial direction. A needle valve which opens and closes the injection hole by being separated from and seated on a seat, wherein the needle valve is formed at one end of a valve shaft at the same inclination angle as the valve seat; A first tapered portion which is attached to and detached from the first tapered portion, and a second tapered portion provided at one end side of the first tapered portion facing the injection hole and formed with a smaller inclination angle than the first tapered portion. A tapered portion, and an inclined surface portion having an arc-shaped cross section which is located opposite to the second tapered portion, and is provided so as to be inclined so that the respective inclined axes intersect outside the injection nozzle. It is characterized by.

When the needle valve is opened,
The ratio of the flow area of the fuel injected from the one inclined surface to the flow area of the fuel injected from the other inclined surface is set to be in a range of 1.56 to 12.3. Is preferred.

[0020]

When the needle valve is displaced to the other end and opened, the fuel supplied into the injection nozzle is ejected along the peripheral surface of the second tapered portion and each inclined surface. Here, since the flow passage is relatively small between the peripheral surface of the second tapered portion and the inner surface of the injection hole, most of the fuel is ejected along each inclined surface having a large flow passage area. Then, the fuel ejected along each inclined surface portion collides with each other outside the injection nozzle and is atomized.

According to the second aspect of the present invention, a groove having an arc-shaped cross section is formed in each inclined surface, so that fuel injection
Most of the fuel can be guided obliquely to one end side through each of the grooves, so that the fuel can collide outside the injection nozzle to perform atomization.

Further, if each inclined surface portion is formed to have an arc-shaped cross section, the fuel can be made to collide outside the injection nozzle and be atomized in substantially the same manner as described in the first aspect.

The ratio of the flow area of the fuel injected from the one inclined surface to the flow area of the fuel injected from the other inclined surface is in the range of 1.56-12.3. With such a setting, when fuel injected from each inclined surface side collides outside the injection nozzle, a strong resonance phenomenon occurs, so that atomization is further promoted.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to FIGS.

First, FIGS. 1 to 4 relate to a first embodiment of the present invention, and FIG. 1 is an enlarged sectional view showing a main part of a fuel injection valve, and one end of a casing 1 forming a valve housing. On the side, a stepped cylindrical injection nozzle 2 is provided, and on the other end side of the casing 1, as described above with reference to FIG. 9, an electromagnetic coil, a core, a valve spring, a fuel inlet (all not shown), and the like. Is provided. A shaft hole 3 defining a fuel flow path is formed in the injection nozzle 2 in the axial direction, and an injection hole 4 opening into a combustion chamber (not shown) is formed at one end of the shaft hole 3. I have. On one side of the shaft hole 3, a substantially conical valve seat 5 is formed near the other side of the injection hole 4.

As shown in FIG. 2, the needle valve 6 is provided in the shaft hole 3 so as to be vertically movable (movable in the direction of the axis C) and rotatable in the circumferential direction. Valve stem 7
And the same inclination angle θ _{1 as the} valve seat 5 at one end of the valve shaft 7.
And a sheet portion 8 as a first tapered portion formed in a substantially frustoconical shape, and integrally provided so as to face the inside of the injection hole 4 from one end side of the sheet portion 8 and have an inclination angle of the sheet portion 8. The _second formed with the inclination angle θ ₂ smaller than θ ₁
A curved portion 9 as a tapered portion, a first inclined surface portion 10 and a second inclined surface portion 11 provided opposite to the curved portion 9, and a central portion of each of the inclined surface portions 10, 11. The first groove 12 and the second groove 13 having a semi-cylindrical shape are roughly constituted.

Here, the curved portion 9 and each inclined surface portion 10, 11
Will be described in detail. First, before processing, a conical portion having a predetermined inclination angle theta ₂ to the one end side of the seat portion 8 is formed. The needle valve 6
Is vertically formed with respect to the axis C, thereby forming a distal end surface 9A located substantially on the same plane as the outlet of the injection hole 4 at the time of assembly. Then, by cutting diagonally at a predetermined angle theta ₃ from the front end surface 9A to one end face of the seat portion 8 to form a first inclined surface portion 10. Furthermore, this first
A predetermined angle θ ₄ is obliquely cut from the front end surface 9A to one end surface of the sheet portion 8 so as to face the inclined surface portion 10 of
The second inclined surface portion 11 is formed. The curved portion 9 and the inclined surface portions 10 and 11 are formed, for example, in this manner, but the above description is for understanding the shape, and the forming method is not particularly limited. For example, the present invention is not limited to this, and the curved portion 9 and the like may be simultaneously formed by a mold.

Here, the respective inclined surfaces 10 and 11 have their respective inclination angles θ ₃ and θ ₄ such that their inclination axes X ₁ and X ₂ intersect at an intersection P on an axis C outside the injection nozzle 2. (In the present embodiment, the respective inclination angles θ ₃ and θ ₄ are equal). In addition, the reason why the respective tilt axis lines X ₁ and X ₂ intersect here is to cause fuels to collide with each other as described later. Therefore, it is not necessary that the inclined axes X ₁ , X ₂ intersect at the intersection P strictly geometrically, and even if there is some distance between the axes, the inclined axes X ₁ and X ₂ are substantially aligned so that the injected fuels collide with each other. It is enough if they cross each other.

The first groove portion 12 and the second groove portion 13 provided on each of the inclined surface portions 10 and 11 are formed as semi-cylindrical grooves having a semi-circular cross-section. The axis is the inclined axis X ₁ of each inclined surface portion 10, 11,
X ₂ is consistent with. Here, each of these inclined surface portions 10,
The inclination angles θ ₃ , θ _{4 of} 11 and the diameters R ₁ , R ₂ of the grooves 12, 13 are, as described later, the flow area of the fuel ejected from the first inclined surface 10 and the first groove 12. In order to make the ratio of the flow area of the fuel ejected from the second inclined surface portion 11 and the second groove portion 13 to the range of 1.56 to 12.3,
Each is set. In this embodiment, since the inclination angles θ ₃ and θ ₄ of the inclined surface portions 10 and 11 are set to the same value, the predetermined area ratio is exclusively determined by the respective groove portions 12 and 1.
3 are realized by the radial dimensions R ₁ and R ₂ . However, the present invention is not limited thereto, by increasing one of the inclination angle theta ₃ than the other inclined angle theta _4, may be configured to obtain a desired area ratio, tilt angle theta _3, theta ₄ and diameter A predetermined area ratio may be obtained by adjusting both R ₁ and R ₂ .

In FIG. 1, reference numeral 14 designates, for example, a pentagonal chamfer formed integrally with the valve shaft 7 vertically apart from each other. A spiral flow is given to the fuel flowing toward the injection hole 4 by forming the fuel flow path in the injection nozzle 2 into a maze.

Reference numeral 15 denotes an anchor made of a magnetic material attached to the other end of the valve shaft 7.
5 is constantly urged toward one end by a valve spring disposed between the core and the core.

Next, the operation of the present embodiment will be described.

First, the fuel injection area will be described with reference to FIG. FIG. 3 is a plan view of the needle valve 6 at the time of fuel injection viewed from one end side in a state in which the injection nozzle 2 is omitted. When the seat portion 8 is separated from the valve seat 5, the needle valve 6 is supplied into the shaft hole 3. As shown by the dotted pattern in FIG.
A gap between the first inclined surface portion 10 and the first groove portion 12 and the injection hole 4 (hereinafter, this is referred to as a “first flow path F ₁ ”)
The second inclined surface 11 and the second groove 13 and the injection hole 4
(Hereinafter, referred to as a “second flow path F ₂ ”), and is ejected from the ejection nozzle 2 to the outside of the ejection nozzle 2, as shown by hatching in FIG. Injection is performed through gaps between the injection holes 4 (hereinafter, referred to as “third flow path F ₃ ”).

More precisely, the projected flow channel areas S _F1 , S _F2 , S _F3 when the respective flow channels F ₁ , F ₂ , F ₃ are projected on a plane perpendicular to the axis C of the needle valve 6. Are shown in FIG. 3 as a dot pattern and a hatched pattern, respectively.

Here, each third flow path F ₃ has a projection area S
Although it looks wide as _F3 , the gap between both side surfaces of the curved portion 9 and the injection hole 4 is small and the flow resistance is large, so that most of the fuel (about 88%) in the shaft hole 3 has the flow resistance. Injection is performed through relatively small first flow path F ₁ and second flow path F ₂ . Then, each inclined surface portion 10, 11 and each groove portion 12, 1
3 is inclined by predetermined inclination angles θ ₃ , θ ₄ , and the inclination axes X ₁ , X ₂ intersect at a point P outside the injection nozzle 2, so that injection is performed from each of the flow paths F ₁ , F _2. The fuels collide with each other at the intersection P.

Next, the relationship between the resonance phenomenon at the time of fuel collision and the flow path area ratio, which was uniquely found in the present invention, will be described with reference to FIG. That is, FIG. 4 shows the first flow path F
The ratio S _α (S of the _first flow area S _F1 and the second flow area S _F2)
F1 / S _F2 ) and the resonance phenomenon, and is a characteristic diagram. When this area ratio S _α is changed in a range of 1 to 25, for example,
It has been found that a non-linear change occurs in the intensity of resonance generated when fuels having different particle sizes collide with each other.

Specifically, when the area ratio S _α is increased to “1.56”, the intensity of resonance increases to a level equal to or higher than that of the prior art, and the area ratio S _α becomes “around 2.25”. , The intensity of the resonance reaches the maximum level M ₁ . Then, further the area ratio S _alpha raise and gradually decreases the intensity of the resonance, the area ratio S _alpha is the level M ₂ of the strength comparable to prior art and again resonance becomes "12.3".

Accordingly, the area ratio S _{α is set} to “1.56-12.
It can be understood that setting "3" makes it possible to obtain a stronger resonance than in the prior art, and it is possible to achieve atomization of the fuel by utilizing this strong resonance phenomenon. Therefore, in this embodiment, it is limited to the range of "1.56 to 12.3" as the value of the area ratio S _alpha.

When the control unit outputs a fuel injection signal to the electromagnetic coil, the electromagnetic force generated by the electromagnetic coil causes the anchor 15 to be attracted to the core against the spring force of the valve spring, and the needle valve 6 to move to another position. Displaced toward the end. As a result, the seat portion 8 separates from the valve seat 5 and opens, and the fuel in the shaft hole 3 enters the combustion chamber, which is the outside of the injection nozzle 2, through each of the flow paths F ₁ , F ₂ , and F _3. It is injected.

Here, as described above, the third flow path F ₃ formed between both side surfaces of the curved portion 9 and the injection hole 4 is narrow and has a large flow resistance. On the other hand, the first flow path F ₁ and the second flow path F ₂
Is an inclined surface portion 1 inclined toward the axis C of the needle valve 6.
Since it is formed widely by 0, 11, etc., the flow resistance is small. Therefore, most of the fuel in the shaft hole 3 (about 88% in the present embodiment) is supplied to each flow passage F having a relatively small flow resistance.
_1, is injected via the F _2. Then, the fuel injected from each of the flow paths F ₁ and F ₂ collides with each other at the intersection P outside the injection nozzle 2 and is sufficiently atomized by the above-described resonance phenomenon.

Here, the fuel atomization performance according to the present embodiment is compared with the prior art for each fuel pressure as shown in Table 1 below.

[0042]

[Table 1] According to Table 1 above, even when the area ratio S _α is “1”, compared to the conventional technology in which atomization by fuel collision is not performed,
It can be seen that the atomization effect occurs. Further, in the case of setting the area ratio S _alpha to "2.25" as the maximum resonance effect is obtained, atomization is further promoted, thereby improving about half of the fuel particle size obtained by the prior art .

As described above, according to the present embodiment, the following effects can be obtained.

First, the curved portions 9 located in the injection hole 4 are provided with inclined surfaces 10 and 11 facing each other, and the inclined axes X ₁ and X ₂ of these inclined surfaces 10 and 11 are set outside the injection nozzle 2. , The flow paths F ₁ , F ₂ having a smaller flow resistance than the flow path F ₃ between both side surfaces of the curved portion 9 and the injection hole 4. Can be formed to guide most of the fuel, and each of these flow paths F ₁ , F ₂
Can be made to collide with each other at the intersection P to atomize the fuel. As a result, it is possible to stabilize the combustion state, reduce emission, fuel consumption, and the like, and improve output.

Secondly, since the inclined surfaces 10 and 11 are provided with the grooves 12 and 13 having a semicircular cross section, the directivity of fuel injection can be sharpened and the flow paths F ₁ and F ₂ can be formed.
Flow area S _F1 , S _F2 to increase flow resistance
Most of the fuel injected each time can be guided to the collision flow paths F ₁ and F ₂ . As a result, the atomization effect due to fuel collision can be further increased in combination with the effect of providing the inclined surface portions 10 and 11.

Third, based on the facts that were independently found,
Since the ratio S _alpha of the first flow path F ₁ of the flow path area S _F1 and the flow passage area S _F2 of the second channel F _2, it was set to be in the range of 1.56 to 12.3, By generating a resonance phenomenon at the time of fuel collision, atomization can be promoted.

Fourth, since the needle valve 6 is rotated by the fluid force of the fuel flowing through the shaft hole 3 at the time of fuel injection, combustion products and the like adhere to each of the flow paths F ₁ , F ₂ , and F _3. The phenomenon can be prevented from occurring. As a result, reliability and durability can be improved even when used for in-cylinder direct injection.

Fifthly, atomization of fuel can be greatly promoted while having a relatively simple structure in which only the inclined surfaces 10 and 11 and the grooves 12 and 13 are provided at one end of the needle valve 6. It is easy to manufacture, and the cost required for increasing the atomization performance can be reduced.

Sixth, since the inclined axes X ₁ , X ₂ of the inclined surfaces 10, 11 intersect on the axis C of the needle valve 6, the needle valve 6 rotates and the inclined surfaces 10, 1 are rotated.
Even if the position 1 changes in the circumferential direction, the position of the intersection P where the fuel collides does not shift. As a result,
The fuel can be atomized at the same position (intersection P), and the combustion state and the like can be stably improved.

Next, a second embodiment of the present invention will be described with reference to FIGS. In each embodiment described below, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The feature of this embodiment lies in that only each inclined surface portion is formed in the curved portion.

That is, the bending portion 21 according to the present embodiment is formed at one end of the sheet portion 8 with a small inclination angle θ ₂ , similarly to the bending portion 9 described in the first embodiment, and has a front end surface 21A. Is perpendicular to the axis C, and is provided with a pair of inclined surface portions 22 and 23 facing each other. Also,
As shown in the plan view of FIG.
The ratio S _α of the flow path area S _F1 of the flow path F ₁ formed between the injection hole 4 and the flow path area S _F2 of the flow path F ₂ formed between the second inclined surface portion 23 and the injection hole 4. Is set in the range of “1.56 to 12.3”.

However, in this embodiment, since only the curved portions 21 and 23 are provided in the curved portion 21 and the grooves 12 and 13 described in the first embodiment are not formed, each of the inclined portions 22 and 23 is not formed.
The flow path area ratio is set in a desired range by the inclination angles θ ₃ and θ _{4 formed} by the 23 inclination axes X ₁ and X ₂ with the axis C of the needle valve 6. That is, in the present embodiment, the flow path area S _F1 of the _first flow path F ₁ is set to “1.5” of the flow path area S _F2 of the second flow path F _2.
The second inclined surface portion 2 is set to about 6 to 12.3 "times.
The third inclination angle θ ₄ is larger than the inclination angle θ ₃ of the first inclined surface portion 22 (θ ₄ > θ ₃ ).

Thus, also in the present embodiment having the above-described configuration, substantially the same operation and effect as those of the first embodiment can be obtained. However, in this embodiment, each of the grooves 12,
Since the flow path areas S _F1 and S _F2 are reduced by an amount not provided with 13, the ratio of fuel ejected from each of the inclined surfaces 22 and 23 and colliding is about 70%. However, in the present embodiment, since the grooves 12 and 13 are not formed, the processing is further facilitated, and the manufacturing cost is greatly reduced.

Next, a third embodiment of the present invention will be described with reference to FIGS. The feature of the present embodiment is that an inclined surface having a semicircular cross section is formed.

The bending portion 31 according to the present embodiment is formed at one end of the sheet portion 8 with a small inclination angle θ ₂ similarly to the bending portion 9 described in the first embodiment, and has an axis C at one end. Is formed perpendicularly to the end surface 31A. However, the curved portion 31 according to the present embodiment is different from the flat inclined surfaces 10 and 11 (22, 23) described in the above embodiments in that the first inclined surface 32 and the second inclined arc 32 have a semi-circular cross section. In that an inclined surface portion 33 is provided.

As shown as R ₁₁ , R ₁₂ , R ₂₁ , R ₂₂ in FIG. 7, each of the inclined surfaces 32, 33 has one end from the other end where the cross section is continuous with the sheet portion 8 toward the front end surface 31 A. (R ₁₁ > R ₁₂ , R ₂₁ > R ₂₂ ). As shown in FIG. 8, the flow area S _F1 of the flow path F ₁ between the first inclined surface portion 32 and the injection hole 4 is equal to the second inclined surface portion 33 and the injection hole 4.
"1.56 to 12 of the flow path F ₂ of the flow passage area S _F2 between.
The diameters R ₁₁ , R ₁₂ , R ₂₁ , R ₂₂ and the inclination angles θ ₃ , θ _{4 of the} inclined surfaces 32, 33 are set so as to be “3” times.

Thus, also in the present embodiment having the above-described configuration, basically the same operations and effects as those of the above-described first embodiment can be obtained. However, in this embodiment, since the flow passage areas S _F1 and S _F2 of the flow passages F ₁ and F ₂ cannot be made as large as those in the first embodiment, the fuel injected from the inclined surfaces 32 and 33 and colliding with each other is 1 The proportion of the total injected fuel per cycle is about 80%. However, as described in the second embodiment, in this embodiment, the overall structure is simple, so that the manufacturing cost can be reduced as compared with the first embodiment.

In the present embodiment, the case where direct injection in a cylinder is used has been described as an example. However, the present invention is not limited to this and can be applied to port injection.

[0059]

As described above in detail, according to the fuel injection valve of the present invention, the fuel injected along each inclined surface can collide with each other outside the injection nozzle to atomize it, and the combustion state And emission and fuel efficiency can be reduced.

Further, since the grooves having an arc-shaped cross section are formed in each inclined surface, most of the fuel can be guided obliquely toward one end through each of the grooves at the time of fuel injection. As a result, it is possible to increase the amount of atomized fuel while increasing the directivity of the injected fuel.

Further, since the configuration in which each inclined surface portion is formed in an arc shape in cross section is adopted, the manufacturing cost can be reduced in addition to the basic effects substantially similar to those of the first aspect.

The ratio of the flow area of the fuel injected from the one inclined surface to the flow area of the fuel injected from the other inclined surface is in the range of 1.56-12.3. With this setting, when fuel injected from each inclined surface side collides outside the injection nozzle, a strong resonance phenomenon can be generated, and atomization can be further promoted.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of a fuel injection valve according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing a needle valve in FIG. 1;

FIG. 3 is a plan view showing the needle valve when the valve is opened, excluding an injection nozzle.

FIG. 4 is a characteristic diagram showing a relationship between a resonance intensity at the time of a fuel collision and a flow path area ratio.

FIG. 5 is an enlarged perspective view showing a needle valve of a fuel injection valve according to a second embodiment of the present invention.

FIG. 6 is a plan view showing the needle valve when the valve is opened, excluding an injection nozzle.

FIG. 7 is an enlarged perspective view showing a needle valve of a fuel injection valve according to a third embodiment of the present invention.

FIG. 8 is a plan view similar to FIG. 6, showing the needle valve when the valve is opened.

FIG. 9 is a sectional view of a fuel injection valve according to a first prior art.

FIG. 10 is an enlarged sectional view showing a needle valve tip and the like in FIG. 9;

FIG. 11 is a sectional view showing a main part of a fuel injection valve according to a second prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Injection nozzle 4 ... Injection hole 5 ... Valve seat 6 ... Needle valve 7 ... Valve shaft 8 ... Seat part (1st taper part) 9, 21, 31 ... Curved part (2nd taper part) 10, 22, 32 ... first inclined surface portion 11, 23, 33 ... second inclined surface portion 12 ... first groove portion 13 ... second groove portion

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F02M 63/00 F02M 63/00 N (56) References JP-A-3-160150 (JP, A) JP-A-7-127549 (JP, A JP-A-57-110770 (JP, A) JP-A-50-42608 (JP, A) JP-A-7-305669 (JP, A) Fully open 58-146081 (JP, U) Fully open 171662 (JP, U) JP-A-57-114163 (JP, U) JP-A-5-83365 (JP, U) Patent 78517 (JP, C2) (58) Fields investigated (Int. Cl. ⁷ , DB name) ) F02M 51/06 F02M 61/18 320 F02M 61/18 330 F02M 61/18 350 F02M 61/18 360 F02M 63/00

Claims (4)

(57) [Claims] 1. A casing, an injection nozzle provided on one end side of the casing, having a valve seat and an injection hole, and provided in the injection nozzle so as to be movable in an axial direction, and being detachably seated on the valve seat. A needle valve that opens and closes an injection hole, wherein the needle valve is formed at one end of a valve shaft at the same inclination angle as the valve seat, and a first taper that detaches and seats on the valve seat. A second tapered portion provided on one end side of the first tapered portion facing the injection hole, and formed with a smaller inclination angle than the first tapered portion; A fuel injection valve, comprising: a slanting surface portion which is located opposite to the tapered portion, and which is provided so as to be slanted such that their respective slant axes intersect outside the injection nozzle. 2. A casing, an injection nozzle provided on one end side of the casing and having a valve seat and an injection hole, and provided in the injection nozzle so as to be movable in the axial direction. A needle valve that opens and closes an injection hole, wherein the needle valve is formed at one end of a valve shaft at the same inclination angle as the valve seat, and a first taper that detaches and seats on the valve seat. A second tapered portion provided on one end side of the first tapered portion facing the injection hole, and formed with a smaller inclination angle than the first tapered portion; An inclined surface portion which is located opposite to the tapered portion and is provided so as to be inclined so that their respective inclined axes intersect outside the injection nozzle.The inclined surface portions each have an arc-shaped groove portion. Fuel injection characterized by each formed . 3. A casing, an injection nozzle provided on one end side of the casing, having a valve seat and an injection hole, and provided in the injection nozzle so as to be movable in the axial direction. A needle valve that opens and closes an injection hole, wherein the needle valve is formed at one end of a valve shaft at the same inclination angle as the valve seat, and a first taper that detaches and seats on the valve seat. A second tapered portion provided on one end side of the first tapered portion facing the injection hole, and formed with a smaller inclination angle than the first tapered portion; A fuel injection valve, comprising: a slanted surface section having an arc-shaped cross section, which is positioned to face the tapered portion and is provided so as to be slanted such that their respective tilt axes intersect outside the injection nozzle. 4. When the needle valve is opened, the ratio of the flow area of the fuel injected from the one inclined surface to the flow area of the fuel injected from the other inclined surface is determined. The fuel injection valve according to any one of claims 1 to 3, wherein the fuel injection valve is set to fall within a range of 1.56 to 12.3.