JP2006207517A - Fuel injection nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection nozzle atomizing injected fuel without enlarging a size of a needle and suppressing drop in penetration accompanying atomization. <P>SOLUTION: The fuel injection nozzle 4 is provided with a first valve seat part 30 on an inner wall surface thereof, a second valve seat part 31 positioned on fuel downstream side of the first valve seat part 30, a nozzle body 5 having a plurality of injection hole groups composed of a plurality of injection holes 11, 12 penetrating from an inner wall surface toward outer wall surface formed thereon, and a needle 60 including a first and a second abutment part 61, 62 reciprocatingly and slidably supported by the nozzle body 5 and seated on and separated from the first and the second valve seat part 30, 31 respectively. Inlet parts 13, 14 of the plurality of injection holes are formed closely in series along an axial direction of the nozzle body 5 between the first and the second valve seat part 30, 31. Opening shape thereof is a circle or a polygon aspect ratio of which is greater than 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection nozzle, for example, a fuel injection nozzle of a fuel injection valve for an internal combustion engine (hereinafter referred to as an engine).

  Conventionally, as shown in FIG. 7, a first needle 600 formed in a hollow cylindrical shape, a second needle 700 accommodated in a hollow portion of the first needle 600, and a counter injection hole side of the first needle 600 There is known a variable injection hole type fuel injection nozzle (referred to as a conventional fuel injection nozzle) having a pressure control chamber formed on the end face of the same (Patent Document 1).

  In this fuel injection nozzle, the pressure in the pressure control chamber is adjusted by opening and closing the control valve, and is controlled by the pressure of the fuel applied to the end face on the side opposite to the injection hole and the end face on the injection hole of the first and second needles 600 and 700. The balance of the generated force is adjusted, and the first and second needles 600 and 700 are seated away from the first and second needle valve seats 300, 310, and 320 formed in the nozzle body 500, and the first and second needles are seated. The fuel injection from the two nozzle holes 100 and 200 is controlled.

  In particular, the first needle 600 has two contact portions 610 and 620 that are seated on the first needle valve seat portions 300 and 310 formed in the nozzle body 500 so as to sandwich the first injection hole 100. Yes. In this fuel injection nozzle, when the first needle 600 is seated on the first needle valve seat 300, 310, the fuel that is about to flow into the first injection hole 100 from both the fuel upstream side and the fuel downstream side is injected. I try to block it.

On the other hand, by making two or more small-diameter injection holes formed in the nozzle body adjacent to each other, so-called group injection holes, the atomization of fuel injected from the injection holes and the penetration associated with the atomization of fuel ( There is known a fuel injection nozzle that suppresses a decrease in penetration force (Patent Document 2).
International Publication No. 03/040543 Pamphlet International Publication No. 98/16736 Pamphlet

  The inventor, for example, applies the technique of the group injection hole described in Patent Document 2 to the fuel injection nozzle described in Patent Document 1 to atomize the injected fuel and the penetration associated with the atomization. We thought that it would be a variable injection hole type fuel injection nozzle capable of suppressing the decrease.

  However, if the technique of the group injection hole described in Patent Document 2 is applied as it is to the fuel injection nozzle described in Patent Document 1, the following problems are considered to occur.

  In order to form a group nozzle hole without changing the opening area of the nozzle hole of the fuel injection nozzle described in Patent Document 1, as shown in FIG. 8 or FIG. Two minute diameter injection holes 110 and 120 having an area that is approximately half the area and having a substantially circular opening shape are adjacent in series along a direction orthogonal to the axial direction of the nozzle body 500. It is conceivable that they are formed (formed in the horizontal direction) or formed adjacent to each other in series along the axial direction of the nozzle body 500 (formed in the vertical direction).

  As shown in FIG. 8, in the case where the small-diameter injection holes 110 and 120 are formed in the lateral direction, the distance Le between the injection hole 110 and the injection hole 130 is the injection hole and injection hole of the conventional fuel injection nozzle indicated by the broken line. Therefore, there is a possibility that the strength of the nozzle body 500 at this portion is lowered.

  On the other hand, as shown in FIG. 9, when the small diameter injection holes 110 and 120 are formed in the vertical direction, the distance between the first needle valve seats 300 and 310 is the first needle valve seat in the conventional fuel injection nozzle. Since the distance is longer than the distance between the two parts, the distance between the two first needle contact parts 610 and 620 of the first needle 600 as shown by the solid line is the two contact parts in the conventional fuel injection nozzle shown by the broken line. It must be longer than the distance between. If the distance between the contact portions 610 and 620 is increased without increasing the size of the needle (the outer diameter of the needle), as shown in FIG. 9, the pressure receiving area on the nozzle hole side of the conventional fuel injection nozzle is larger than that shown in FIG. The pressure receiving area of the injection hole side of the needle in the fuel injection nozzle is smaller.

  When this pressure receiving area is reduced, the force that pushes up the first needle 600 toward the counter-bore hole is weakened. Therefore, even if the control valve is opened at the same timing as in the prior art to reduce the pressure in the pressure control chamber, the first needle 600 does not operate at the conventional timing, but operates with a delay. Therefore, in order to operate the first needle 600 at the conventional timing, it is necessary to open the control valve at a timing earlier than the conventional timing to reduce the pressure in the pressure control chamber.

  However, when the fuel injection nozzle performs fuel injection multiple times during one combustion stroke, depending on the time interval between adjacent injections, before closing the control valve to end the previous injection, In order to perform the next injection, the control valve must be opened. In this case, the valve opening periods of the control valves are overlapped, which may cause a problem that the injection cannot be performed a plurality of times.

  The present invention has been made in view of the above problems, and its purpose is to atomize the fuel to be injected without increasing the size of the needle and to suppress the decrease in penetration due to atomization. A fuel injection nozzle is provided.

  In order to achieve the above object, a fuel injection nozzle according to claim 1 is a fuel injection nozzle for injecting fuel supplied from a fuel supply pump into a combustion chamber of an internal combustion engine, and (a) a fuel injection nozzle is disposed on an inner wall surface of the fuel injection nozzle. There are a plurality of nozzle hole groups consisting of one valve seat portion, a second valve seat portion located on the fuel downstream side of the first valve seat portion, and a plurality of nozzle holes penetrating from the inner wall surface toward the outer wall surface. The formed nozzle body, (b), and a first contact part and a second contact part, which are supported by the nozzle body so as to be slidable in a reciprocating manner, and which are separated from and seated on the first valve seat part and the second valve seat part, respectively. And a needle that shuts off and distributes the fuel when the first contact portion and the second contact portion are separated from and seated with the first valve seat portion and the second valve seat portion, respectively (c) The inlet portions of the plurality of nozzle holes of the nozzle hole group are disposed between the first valve seat portion and the second valve seat portion along the axial direction of the nozzle body. URN is formed adjacent to the series, is characterized in that (d) Further, the shape of the opening of the inlet portion, the aspect ratio of the opening shape is greater than one circular or polygonal.

  The nozzle body is formed with a plurality of nozzle holes having a circular or polygonal aspect ratio larger than 1 adjacent to each other in series along the axial direction of the nozzle body (formed in the vertical direction). A plurality of nozzle holes can be formed in the nozzle body without increasing the distance between the first and second contact portions formed in the first nozzle. Thereby, it is possible to atomize the injected fuel without increasing the size of the needle and to suppress the deterioration of the penetration due to the atomization.

  Specifically, according to the second aspect, the aspect ratio of the opening shape of the inlet portion of the nozzle hole is based on the distance between the first valve seat portion and the second valve seat portion and the material strength of the nozzle body. It is characterized by being determined. Thereby, the aspect ratio of the opening shape of the inlet portion of the injection hole can be determined in accordance with the size of the fuel injection nozzle.

  According to a third aspect of the present invention, the distance between adjacent nozzle holes is determined based on the workability of the nozzle holes in the nozzle body or the specifications of the internal combustion engine. Usually, when forming a nozzle hole in the nozzle body, a curved surface having a predetermined radius is formed around the nozzle hole by, for example, fluid polishing. However, there is a limit to the radius that can be formed. Therefore, there is a limit to the distance when adjoining the nozzle holes. Separately, since the injection characteristics change by changing the distance at which the nozzle holes are adjacent, it is necessary to change the distance at which the nozzle holes are adjacent according to the specifications of the internal combustion engine.

  On the other hand, in claim 3, since the distance between adjacent nozzle holes is determined based on the processability of the nozzle holes to the nozzle body or the specifications of the internal combustion engine, the processability of the nozzle holes, An injection hole suitable for the specifications of the internal combustion engine can be formed.

  Specifically, according to the fourth aspect, the opening shape of the outlet portion of the nozzle hole is substantially the same as the opening shape of the inlet portion, and is substantially equal to the opening area of the inlet portion. According to the fifth aspect of the present invention, the opening shape of the outlet portion of the nozzle hole is substantially the same as the opening shape of the inlet portion, and is larger than the opening area of the inlet portion. Further, according to a sixth aspect of the present invention, the opening shape of the outlet portion of the nozzle hole is substantially a perfect circle.

  According to a seventh aspect of the present invention, the central axis of the injection hole is substantially parallel to the stop axis of the injection hole adjacent to the injection hole. Furthermore, as described in claim 8, the central axis of the nozzle hole is characterized by forming a predetermined angle with the central axis of the nozzle hole adjacent to the nozzle hole.

  According to the description of the fourth to eighth aspects, it is possible to change the injection characteristics by changing the opening shape and opening area of the outlet portion of the nozzle hole or the angle formed by the central axes of the nozzle holes. .

(First embodiment)
One embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a partial sectional view of a nozzle portion of a fuel injection valve according to a first embodiment of the present invention. FIG. 1 shows when fuel injection is stopped. FIG. 2 is an enlarged partial cross-sectional view of a range I in FIG. FIG. 3 is a partial cross-sectional view of the nozzle hole portion of the nozzle body.

  First, the fuel injection valve 1, particularly the fuel injection nozzle, will be described with reference to FIGS. 1 and 2. A fuel injection valve 1 shown in FIG. 1 is a fuel injection valve that injects fuel stepwise or a plurality of times into a combustion chamber of a diesel engine (not shown), and the engine speed, load, or fuel, intake air, cooling water. It is driven by high-pressure fuel from a high-pressure pump that is calculated and controlled by a control device according to the input of temperature, pressure, and the like.

  The fuel injection valve 1 includes a nozzle holder portion 2, a plate portion 3, and a fuel injection nozzle 4. As shown in FIG. 1, the nozzle holder portion 2, the plate portion 3, and the fuel injection nozzle 4 are fixed to each other by a bottomed cylindrical retaining nut or the like (not shown). The fuel injection nozzle 4 includes a nozzle body 5, a first needle 60, a second needle 70, a first spring 80, and a second spring 81. In the present embodiment, the first needle 60 corresponds to the needle described in the claims.

  The nozzle body 5 is formed in a bottomed cylindrical shape, and an accommodation hole 40 is formed therein. A first nozzle hole 10 and a second nozzle hole 20 that penetrate the accommodation hole 40 and the outer wall surface of the nozzle body 5 are formed in the lower end portion 6 of the nozzle body 5. And the 1st needle 60 and the 2nd needle 70 are accommodated in the accommodation hole 40 so that reciprocation is possible.

  The first needle 60 is formed in a hollow cylindrical shape, and a first spring 80 is provided on the outer periphery thereof. The first needle 60 is always urged toward the lower end portion 6, in other words, in the direction in which the first injection hole 10 is present. Has been. Hereinafter, the direction in which the nozzle holes are present is referred to as the nozzle hole direction, and the opposite direction is referred to as the counter nozzle hole direction. A hollow portion of the first needle 60 accommodates a second needle 70 that is formed in a columnar shape. A second spring 81 is provided on the side opposite to the injection hole of the second needle 70, and the second needle 70 is always urged by the second spring 81 in the injection hole direction.

  A nozzle chamber 42 is formed in the nozzle body 5 between the first needle 60 and the accommodation hole 40. The nozzle chamber 42 communicates with a fuel passage 50 formed in the plate portion 3 so that high-pressure fuel from a common rail is supplied. When the first and second needles 60 and 70 are separated from the lower end 6, the high-pressure fuel supplied to the nozzle chamber 42 is injected from the first and second injection holes 10 and 20, and is seated on the lower end 6. 1. The injection from the second nozzle holes 10 and 20 is stopped.

  As shown in FIG. 2, the first nozzle hole 10 is composed of two first minute diameter nozzle holes 11 and 12 having a minute diameter. The second injection hole 20 is also composed of two second minute diameter injection holes 21 and 22 as in the first injection hole 10. The first and second nozzle holes 10 and 20 form the nozzle hole group described in the claims by a plurality of nozzle holes having a minute diameter. The first small-diameter nozzle holes 11 and 12 have first inlet portions 13 and 14 as inlet portions according to claims, and the first inlet portions 13 and 14 are inner wall surfaces of the lower end portion 6. In addition, the nozzle body 5 is formed adjacently in series along the axial direction of the nozzle body 5. Similarly to the first inlet portions 13 and 14, the second inlet portions 23 and 24 of the second minute diameter nozzle holes 21 and 22 are also adjacent to the inner wall surface of the lower end portion 6 substantially in series along the axial direction of the nozzle body 5. Is formed.

  As shown in FIG. 2, the first valve seat portion and the second valve according to the claims are provided on the fuel upstream side and the downstream side of the first minute diameter injection holes 11 and 12 on the inner wall surface of the lower end portion 6. First needle valve seat portions 30 and 31 as seat portions are formed, and a second needle valve seat portion 32 is formed on the fuel upstream side of the second minute diameter injection hole 21. Details of the first minute diameter injection holes 11 and 12 and the first needle valve seat portions 30 and 31 will be described later.

  As shown in FIG. 2, on the nozzle hole side of the first needle 60, the first needle contact portions 61 and 62 that contact the first needle valve seat portions 30 and 31, respectively, and the common rail in the nozzle chamber 42 are provided. A first pressure receiving surface 65 for receiving high pressure fuel is formed. A recess 63 is formed between the first needle contact portions 61 and 62, and when the first needle contact portions 61 and 62 are seated on the first needle valve seat portions 30 and 31, A sack chamber 64 is formed between the wall surface and the recess 63. On the nozzle hole side of the second needle 70, first needle contact portions 61, 62 and a second needle contact portion 71 are respectively provided to the first needle valve seat portions 30, 31, and the second needle valve seat portion 32. A second pressure receiving surface 72 for receiving high pressure fuel from the common rail in the nozzle chamber 42 is formed when the seat is separated from.

  When the fuel pressure is applied to the first and second pressure receiving surfaces 65 and 72, the first and second needles 60 and 70 generate a force that pushes up the first and second needles 60 and 70 in the direction of the anti-injection holes.

  As shown in FIG. 1, a pressure control chamber 41 that is surrounded by a wall surface in the plate portion 3 is formed on the side opposite to the injection holes of the first and second needles 60 and 70. The high pressure fuel from the common rail is also supplied to the pressure control chamber 41 through a fuel passage (not shown).

  The fuel pressure in the pressure control chamber 41 generated in each of the first and second needles 60, 70, the force in the nozzle hole direction due to the urging force of the first and second springs 80, 81, The seating with the lower end portion 6 of the first and second needles 60 and 70 is determined by the balance with the force in the anti-injection hole direction due to the fuel pressure.

  When the force in the nozzle hole direction is greater than the force in the counter nozzle hole direction, the first and second needle contact portions 61, 62, 71 of the first and second needles 60, 70 are the first and second needles. The fuel is not injected from the first and second nozzle holes 10 and 20 while seated on the valve seat portions 30, 31 and 32. On the other hand, when the force in the direction opposite to the injection hole is greater than the force in the direction of the injection hole, the first and second needle contact portions 61, 62, 71 of the first and second needles 60, 70 are The second needle valve seats 30, 31 and 32 are separated from each other, and fuel is injected from the first and second injection holes 10 and 20. By adjusting the balance of these forces, the fuel injection can be controlled.

  Adjustment of the balance of these forces can be achieved by adjusting the fuel pressure in the pressure control chamber 41. The adjustment of the fuel pressure in the pressure control chamber 41 is performed by a control valve (not shown) provided in the middle of the fuel passage formed in the nozzle holder portion 2 connecting the pressure control chamber 41 and a fuel tank (not shown). The operation of the control valve is controlled by a command from the control device. By opening the valve, the fuel in the pressure control chamber 41 is returned to the fuel tank, the pressure is lowered, and the control valve is closed. The high pressure fuel in the common rail is accumulated in the pressure control chamber 41.

  When fuel is injected from the first and second injection holes 10 and 20, the control device opens the control valve and gradually reduces the pressure in the pressure control chamber 41. When the pressure decreases, the anti-nozzle direction force generated in the first needle 60 wins, and the first needle contact portions 61 and 62 are separated from the first needle valve seat portions 30 and 31, and the first injection hole 10. Fuel is injected from. At the same time, the high-pressure fuel in the nozzle chamber 42 is supplied to the second pressure receiving surface 72.

  Further, when the pressure in the pressure control chamber 41 is reduced, the force in the anti-injection direction generated in the second needle 70 is won, the second needle contact portion 71 is separated from the second needle valve seat portion 32, and the second needle contact portion 71 is separated. Fuel is also injected from the two nozzle holes 20.

  When the fuel injection from the first and second injection holes 10 and 20 is stopped, the control device closes the control valve and gradually increases the pressure in the pressure control chamber 41 to the pressure in the common rail. When the pressure rises, the force in the direction of the nozzle hole generated in the first and second needles 60 and 70 wins, and the first and second needle contact portions 61, 62, and 71 become the first and second needle valve seat portions. The fuel injection from the first and second nozzle holes 10 and 20 is stopped after sitting on 30, 31, and 32.

  Next, the shapes of the first and second nozzle holes 10 and 20 will be described in detail with reference to FIG. FIG. 3A is a partial cross-sectional view of the first and second nozzle hole portions of the nozzle body 5. FIG. 3B is an enlarged partial cross-sectional view of the inlet portion of the first nozzle hole 10.

  As shown in FIG. 3 (a), the first minute diameter nozzle holes 11, 12 are first inlet portions 13, 14 formed on the inner wall surface of the lower end portion 6, and the first inlet ports 13, 14 formed on the outer wall surface of the lower end portion 6. 1 outlet part 17, 18, and first injection hole passages 15, 16 connecting the first inlet part 13, 14 and the first outlet part 17, 18. The first inlet portions 13 and 14 have an elliptical opening shape, and are formed adjacent to each other in series in the axial direction of the nozzle body 5 toward the inner wall surface. The first outlet portions 17 and 18 are also formed adjacent to each other in series in the axial direction of the nozzle body 5 toward the outer wall surface, similarly to the first inlet portions 13 and 14, and the opening shape thereof is elliptical. ing. The opening areas of the first inlet portions 13 and 14 and the first outlet portions 17 and 18 are substantially the same, and the central axes of the two first nozzle hole passages 15 and 16 are parallel to each other. First needle valve seats 30 and 31 are formed at locations on the inner wall where the first needle contact portions 61 and 62 contact.

  As shown in FIG. 3A, the second minute diameter nozzle holes 21 and 22 are also formed on the inner wall surface of the lower end portion 6 in the same manner as the first minute diameter nozzle holes 11 and 12. The second outlet portions 27 and 28 formed on the outer wall surface of the lower end portion 6, and the second injection hole passages 25 and 26 connecting the second inlet portions 23 and 24 and the second outlet portions 27 and 28. . Since the second minute diameter nozzle holes 21 and 22 have substantially the same structure as the first minute diameter nozzle holes 11 and 12, detailed description thereof is omitted here.

  Next, the opening shape, opening area, and arrangement relationship of the first inlet portions 13 and 14 of the first minute diameter nozzle holes 11 and 12 will be described in detail with reference to FIG.

  As shown in FIG. 3B, the opening shape of the first inlet portions 13 and 14 is an ellipse having a predetermined aspect ratio (La: Lb) larger than 1, for example. La is the diameter of the ellipse on the short axis side, and Lb is the diameter of the ellipse on the long axis side. The opening area S of each of the first inlet portions 13 and 14 is about half of the area of the inlet portion of the injection hole required by the engine specifications (engine type, shape of combustion chamber, swirl, etc.) and the like. Yes. The first inlet portions 13 and 14 are formed with an interval of a distance Lc. A curved surface having a predetermined radius R is formed around the first inlet portions 13 and 14.

  In addition, the opening area S of each of the first inlet portions 13 and 14 may be a sum of the two opening areas S as the area of the inlet portion of the injection hole required by the specifications of the engine.

  The above-mentioned various dimensions are within the distance Ld between the first needle valve seats 30 and 31, and the specifications of the engine or the portion where the first inlet portions 13 and 14 of the nozzle body 5 are formed. It is determined according to the material strength.

  Thereby, as shown in FIG. 3B, the first inlet portions 13 and 14 are not substantially circular, but are elliptical having a predetermined aspect ratio larger than 1, and the axis of the nozzle body 5. The axial distance is shortened as compared with the case where the regular circular inlet portion is formed substantially adjacent in series along the axial direction. Can do. The first minute diameter injection holes 11 and 12 having a plurality of minute diameters can be formed in the nozzle body 5 without increasing the distance between the first needle contact portions 61 and 62.

  As a result, in order to compensate for the decrease in the area of the first pressure receiving surface 65 due to the increase in the distance between the first needle contact portions 61 and 62, the injected fuel is not increased without increasing the size of the first needle 60. It becomes possible to suppress atomization and a decrease in penetration due to atomization.

  In the present embodiment, since the opening shape of the first inlet portions 13 and 14 is formed so that the diameter Lb is longer than the diameter La, the injected fuel is in the axial direction of the nozzle body 5. Diffuses in a nearly vertical direction. Thereby, it becomes a preferable injection characteristic for an engine.

  When determining the diameter La and the diameter Lb, for example, if Lb / La (> 1) is increased to form the first inlet portions 13 and 14, the diameter La tends to be small and the diameter Lb tends to be large. The first inlet portions 13 and 14 can be formed in Ld. However, since the diameter Lb is increased, the distance between the first inlet portions 13 and 14 and the first inlet portion of the adjacent nozzle hole group is shortened. For this reason, the material strength of the nozzle body 5 is reduced. Will end up.

  On the other hand, when Lb / La (> 1) is reduced and the first inlet portions 13 and 14 are formed, the diameter La tends to be larger and the diameter Lb tends to be smaller than the above condition. 14, the diameter La, the distance Lc, and the radius R of the curved surface may be larger than the distance Ld, and the first inlet portions 13, 14 are formed between the first needle valve seat portions 30, 31. There is a risk that it will not be possible.

  As described above, the diameter La and the diameter Lb satisfy the above-mentioned conflicting matters (the material strength of the nozzle body 5 and the distance Ld) of the fuel injection nozzle 4 that is to form the first minute diameter injection holes 11 and 12. It is preferable to determine so as to. Thereby, the aspect ratio of the opening shape of the first inlet portions 13 and 14 of the first minute diameter injection holes 11 and 12 can be determined in accordance with the size of the fuel injection nozzle 4.

  It is known that the required injection characteristic of the fuel injected from the fuel injection nozzle 4 is determined by the specifications of the engine, and the injection characteristic of the fuel injection nozzle 4 is the distance Lc between the first inlet portions 13 and 14. It is also known to change depending on. In the present embodiment, the curved surface formed around the first inlet portions 13 and 14 is formed by fluid polishing. The radius R of the curved surface has a limit on the radius R that can be formed due to the workability of fluid polishing, and also has a limit on the distance at which the first inlet portions 13 and 14 are brought close to each other.

  Therefore, since the distance Lc is determined by any of the above conditions, it is more preferable to determine the diameter La and the diameter Lb in consideration of this condition. Thereby, the 1st minute diameter injection hole 11 and 12 suitable for workability of an injection hole and the item of an engine can be formed.

  In the present embodiment, the opening shape of the first inlet portions 13 and 14 has been described as an ellipse. However, the opening shape may be a shape having an aspect ratio larger than 1, and may be a polygon. For example, a hexagonal, octagonal, or dodecagonal polygon can be adopted as the opening shape of the first inlet portions 13, 14.

  In the present embodiment, the present invention is applied to a so-called variable injection nozzle having two needles. However, the present invention may be applied to a fuel injection nozzle having only one needle. Moreover, in this embodiment, although this invention was applied to the fuel-injection nozzle for diesel engines, you may apply this invention for gasoline engines.

  Next, modified examples of the first and second outlet portions 17, 18, 27, and 28 of the first and second minute diameter nozzle holes 11, 12, 21, and 22 will be described with reference to FIGS. To do. In addition, the same function thing as 1st Embodiment attaches | subjects the same code | symbol. Here, only the feature points different from the first embodiment will be described.

(Modification 1)
As shown in FIG. 4, the opening shapes of the first and second outlet portions 17, 18, 27, and 28 of the first and second minute diameter nozzle holes 11, 12, 21, and 22 are the first and second inlet portions. Although it is substantially the same as the opening shape of 13, 14, 23, 24, the opening area is formed larger than the first and second inlet portions 13, 14, 23, 24.

(Modification 2)
As shown in FIG. 5, the opening shapes of the first and second outlet portions 17, 18, 27, and 28 of the first and second minute diameter nozzle holes 11, 12, 21, and 22 are the first and second inlet portions. Unlike the shapes of 13, 14, 23, and 24, they are formed to be substantially circular.

(Modification 3)
As shown in FIG. 6, the first and second nozzle hole passages 15, 16, 25, and 26 have an angle formed between the central axes of the nozzle hole passages 15, 16, 25, and 26, or a predetermined angle θa The angle θb is formed. The first and second nozzle hole passages 15, 16, 25, and 26 may be formed so as to be separated as the central axes go to the outer wall surface of the lower end portion 6 as shown in FIG. On the contrary, you may form so that it may approach.

  As described above, as shown in Modification 1 to Modification 3, the opening shape and the opening area of the first and second outlet portions 17, 18, 27, and 28, or the first and second nozzle hole passages 15, 16, and 25 are described. The injection characteristics can be changed by changing the angle formed by the central axes of.

  In addition, the opening shape and the opening area of the first and second outlet portions 17, 18, 27, and 28 described in the first embodiment and the first to third modifications, or the first and second nozzle passages The first and second outlet portions 17, 18, 27, 28, the first and second nozzle hole passages 15, 16, 25, 26 are formed by appropriately combining the angles formed by the central axes of the 15, 16, 25, 26. May be.

It is a fragmentary sectional view of the nozzle part of the fuel injection valve by a 1st embodiment of the present invention. It is the fragmentary sectional view which expanded the part of the range I in FIG. (A) is a fragmentary sectional view of the nozzle hole part of a nozzle body, (b) is the fragmentary sectional view which expanded the part of the range II in Fig.3 (a). It is a fragmentary sectional view of the nozzle hole part of the nozzle body by the modification 1 of 1st Embodiment. It is a fragmentary sectional view of the nozzle hole part of the nozzle body by the modification 2 of 1st Embodiment. It is a fragmentary sectional view of the nozzle hole part of the nozzle body by the modification 3 of 1st Embodiment. It is a fragmentary sectional view of the nozzle part of the fuel injection valve by a prior art. It is a top view of a nozzle body when a minute diameter injection hole is formed in a lateral direction in a nozzle portion of a fuel injection valve according to the prior art. It is a fragmentary sectional view of the nozzle hole part of a nozzle body at the time of forming a micro diameter nozzle hole in the nozzle part of the fuel injection valve by a prior art vertically.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 4 Fuel injection nozzle 5 Nozzle body 6 Lower end part 10 1st injection hole 11 1st micro diameter injection hole 12 1st micro diameter injection hole 13 1st inlet part 14 1st inlet part 15 1st injection hole channel | path 16 The first nozzle hole passage 17 The first outlet part 18 The first outlet part 20 The second nozzle hole 21 The second minute diameter nozzle hole 22 The second minute diameter nozzle hole 23 The second inlet part 24 The second inlet part 25 The second nozzle hole path 26 Second nozzle hole passage 27 Second outlet portion 28 Second outlet portion 30 First needle valve seat portion 31 First needle valve seat portion 32 Second needle valve seat portion 60 First needle 61 First needle contact portion 62 First 1 needle contact portion 65 first pressure receiving surface 70 second needle 71 second needle contact portion 72 second pressure receiving surface

Claims (8)

A fuel injection nozzle for injecting fuel supplied from a fuel supply pump into a combustion chamber of an internal combustion engine,
(A) A first valve seat portion on the inner wall surface, a second valve seat portion located on the fuel downstream side of the first valve seat portion, and a plurality of jets penetrating from the inner wall surface toward the outer wall surface A nozzle body in which a plurality of nozzle hole groups including holes are formed;
(B) and a first abutting portion and a second abutting portion that are supported by the nozzle body so as to be slidable in a reciprocating manner and are respectively attached to and detached from the first valve seat portion and the second valve seat portion. The first abutting portion and the second abutting portion are provided with a needle that shuts off and distributes fuel by separating and seating from the first valve seat portion and the second valve seat portion,
(C) The inlet portions of the plurality of nozzle holes of the nozzle hole group are adjacent to each other substantially in series along the axial direction of the nozzle body between the first valve seat portion and the second valve seat portion. Formed,
(D) Furthermore, the opening shape of the inlet portion is a circular or polygonal shape in which the aspect ratio of the opening shape is larger than 1, or a fuel injection nozzle.   The aspect ratio of the opening shape of the inlet portion is determined based on a distance between the first valve seat portion and the second valve seat portion and a material strength of the nozzle body. The fuel injection nozzle described.   3. The fuel injection according to claim 1, wherein a distance between the adjacent nozzle holes is determined based on workability of the nozzle holes to the nozzle body or specifications of the internal combustion engine. nozzle.   The opening shape of the outlet part of the nozzle hole is substantially the same as the opening shape of the inlet part, and is substantially equal to the opening area of the inlet part. The fuel injection nozzle according to Item.   The opening shape of the outlet portion of the nozzle hole is substantially the same as the opening shape of the inlet portion, and is larger than the opening area of the inlet portion. The fuel injection nozzle according to Item.   The fuel injection nozzle according to any one of claims 1 to 3, wherein an opening shape of an outlet portion of the injection hole is substantially a perfect circle.   The fuel injection nozzle according to any one of claims 1 to 6, wherein a central axis of the injection hole is substantially parallel to a stop axis of the injection hole adjacent to the injection hole.   The fuel injection according to any one of claims 1 to 6, wherein a central axis of the nozzle hole forms a predetermined angle with a central axis of the nozzle hole adjacent to the nozzle hole. nozzle.

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