JP4555955B2 - Fuel injection valve and internal combustion engine equipped with the same - Google Patents

Description

  The present invention relates to a fuel injection valve for supplying fuel to an internal combustion engine and an internal combustion engine equipped with the fuel injection valve.

  In recent years, exhaust gas regulations for automobiles have been strengthened, and it is required to reduce harmful hydrocarbon (HC) components in exhaust gas discharged from internal combustion engines. In order to reduce the HC component in the exhaust gas, it is effective to promote atomization of the fuel injected in a spray state from the fuel injection valve mounted on the internal combustion engine of the automobile. It is effective to prevent the fuel wall surface from adhering to the intake pipe or the like by accurately directing the fuel to the position (intake valve position).

  There is an injection hole type fuel injection valve as a fuel injection valve that promotes atomization of injected fuel and enhances the directivity of fuel injection. An injection hole type fuel injection valve includes a plate-shaped injection hole plate in which injection holes are formed, and a lateral flow that is a flow along the injection hole plate is generated in the fuel, and the fuel that has passed this lateral flow flows into the injection hole. Thus, the atomization of the injected fuel is promoted and high directivity of the fuel injection is obtained (for example, Patent Documents 1 to 3).

Japanese Patent Laid-Open No. 9-14090 JP-A-11-200998 JP-T-2006-513371

  In the fuel injection valve of the injection hole type as described above, there is an upper limit on the diameter of the injection hole due to the fuel atomization. Therefore, in order to obtain a predetermined fuel injection amount, a plurality of injection holes are generally provided in the injection hole plate. For example, in a fuel injection valve mounted on an internal combustion engine having intake valves in two directions, it is necessary to inject fuel sprays to the two-way intake valves, and a plurality of injection holes are provided for each fuel spray. Each fuel spray is formed as a combination of unit sprays injected from the fuel.

  As described above, a plurality of injection holes are provided in the injection hole plate. In the conventional fuel injection valve, a plurality of injection holes are arranged on the outer peripheral side of the disk-shaped injection hole plate. In such a configuration, there may be a case where it is not possible to provide a sufficient interval between the injection holes in relation to the effective size of the injection hole plate. And if there is not enough space between each injection hole, there will be interference between unit sprays from each injection hole, and there is a possibility that fuel fine particles will coalesce and become coarse particles due to the interference. Accompanied by.

  Such spray interference impairs the excellent atomization property in the injection hole method, and by making it possible to effectively suppress this, it becomes possible to further improve the atomization property in the fuel injection valve of the injection hole method. . Therefore, an object of the present invention is to effectively suppress the spray interference and increase atomization in the fuel injection valve of the injection hole type, and is equipped with such a fuel injection valve. An object of the present invention is to provide an internal combustion engine that can further reduce harmful components.

In the present invention, in order to solve the above problems, a valve seat surface formed in a conical shape, a valve body having a ball portion formed so as to be detachable from the valve seat surface, and a minimum diameter end of the valve seat surface A diameter-increasing tapered portion provided continuously to the nozzle portion, a nozzle hole plate provided continuously to the tapered portion, and a fuel injection valve provided with a plurality of injection holes for ejecting fuel provided in the nozzle hole plate In
The nozzle hole plate is divided into two areas by a plane passing through the central axis of the conical valve seat surface, and the plurality of injection holes in each area correspond to a circle with the smallest diameter of the valve seat surface. Formed by an outer peripheral injection hole formed outside the virtual circle to be set and at least one central injection hole formed inside the virtual circle;
The outer peripheral injection hole is formed to be inclined so as to eject the fuel toward the outside as viewed from a plane passing through the central axis, and the central injection hole is divided by a plane passing through the central axis. It is characterized in that it is formed so as to incline so as to eject the fuel in the same direction as the outer peripheral injection hole of the opposite area .

  As described above, by providing the central injection hole and the outer peripheral injection hole as the injection holes in the injection hole plate, only the injection hole corresponding to the outer peripheral injection hole is provided and the fuel injection amount is the same as that of the conventional structure. Thus, the number of outer peripheral injection holes can be reduced, and therefore the injection hole interval can be made sufficient for the outer peripheral injection holes. Further, the arrangement direction of the center side injection hole is different from that of the outer periphery side injection hole. For this reason, a sufficient interval can be secured for the center side injection holes. As a result, spray interference can be effectively suppressed and atomization can be further enhanced.

  Further, in the present invention, with respect to the fuel injection valve as described above, the injection hole plate has a central side flow that flows toward the center side and an outer peripheral side flow that flows toward the outer periphery side with respect to the lateral flow of the fuel along the injection hole plate. And the central injection hole is adapted to inject the central lateral flow fuel, and the outer peripheral injection hole is adapted to inject the outer lateral flow fuel. It is a feature. According to such a structure, the structure which divides | segments and provides an injection hole in a center side injection hole and an outer peripheral side injection hole can be utilized more effectively.

  One form of effectively utilizing the structure in which the injection hole is divided into the central injection hole and the outer peripheral injection hole is one spray that injects one spray using the central injection hole and the outer peripheral injection hole as a set. It is to form a group.

  About such a form, about the said one spray group, the form which makes the penetration force of the unit spray injected from the said center side injection hole higher than the penetration force of the unit spray injected from the said outer peripheral side injection hole is further more preferable. It will be a thing. By doing so, the directivity of the spray by the spray group can be enhanced by attracting the unit spray from the central side injection hole having a large penetrating force and high directivity, and the injection to the target position can be performed. It will be possible with high accuracy.

The fuel injection valve as described above, a raised portion which is adapted to protrude toward the upstream side relative to the flow of fuel is provided in the center of the injection hole plate, Ru provided with the central side jet holes in the raised portion It is preferable to do so. By doing in this way, the said center side lateral flow and an outer peripheral side lateral flow can be generated more effectively.

  Further, in the present invention, in order to solve the above-described problems, the fuel injection valve as described above is mounted on the internal combustion engine. In such an internal combustion engine, a highly dispersed spray with good atomization is formed for fuel injection, and the spray is injected as intended with a high directivity to a target portion of the internal combustion engine, thereby causing harmful components such as HC. It becomes possible to further reduce the discharge of water.

  According to the present invention as described above, it is possible to effectively suppress the spray interference, thereby making it possible to further increase atomization in the fuel injection valve of the injection hole system and to further reduce harmful components in the exhaust gas. An internal combustion engine that can be reduced is realized.

  Hereinafter, modes for carrying out the present invention will be described. FIG. 1 is a sectional view showing the overall configuration of the fuel injection valve according to the first embodiment. A fuel injection valve 1 in FIG. 1 is a multi-hole injector that is closed in a normal state, and is used for supplying fuel to an internal combustion engine used as an automobile engine, for example, and includes a casing 2. The casing 2 is formed into an elongated cylindrical shape as a whole by pressing, cutting, or the like. For example, a material obtained by adding a flexible material such as titanium to a ferritic stainless material is used as a magnetic material. have.

  The casing 2 is provided with a fuel supply unit 3 on the base end side, a fuel injection unit 4 on the distal end side, and is covered with a resin cover 5 between the fuel supply unit 3 and the fuel injection unit 4. .

  The fuel supply unit 3 is provided downstream of the fuel supply port 11 for removing foreign matters contained in the fuel, and a fuel supply port 11 provided at the base end of the casing 2 for flowing in fuel supplied from the outside. The filter 12 and an O-ring 13 attached around the fuel supply port 11 for sealing to flow into the fuel supply port 11 are included.

  The fuel injection unit 4 includes a drive mechanism 14, a valve body 15, a nozzle body 16, and an injection hole plate 17, and is protected by covering its periphery with a protector 18 formed in a cylindrical shape with a resin material or the like. Yes.

  The drive mechanism 14 electromagnetically drives the valve body 15 to move back and forth with respect to the nozzle body 16. The drive mechanism 14 includes an electromagnetic coil 21 attached to the outer periphery of the casing 2, a yoke 22 surrounding the electromagnetic coil 21, and an electromagnetic coil. The cylindrical core 23 and the valve body 15 provided in the casing 2 so as to correspond to the positions of the spring 21 and the spring 24 provided in the core 23 so as to press and urge the valve body 15 in the distal direction. A spring adjuster 25 that adjusts the pressing force on the fuel injection valve 15 and an O-ring 26 that functions as a seal at the attachment position when the fuel injection valve 1 is attached to the internal combustion engine.

  The valve body 15 has a ball valve structure and is formed in an elongated hollow rod shape as a whole, has an anchor portion 27 at a base end portion, a ball portion 28 at a tip end portion, and a fuel through hole at an intermediate portion. 29. In the valve body 15 in a state where the electromagnetic coil 21 is not energized, that is, in a valve closed state where the ball portion 28 is seated on the nozzle body 16 by being pressed by the urging force of the spring 24, the base end surface of the anchor portion 27 and the core 23 is incorporated in the casing 2 so that a certain gap is left between the front end surfaces of the casing 23.

  The anchor portion 27 is formed by processing a magnetic metal powder by a processing method such as a MIM (Metal Injection Molding) method. When an electric current as an injection pulse is applied to the electromagnetic coil 21, a magnetic circuit is formed together with the yoke 22 and the core 23. , Thereby receiving the suction force from the core 23 and functioning to retract the valve body 15 until the anchor portion 27 presses against the core 23.

  The ball portion 28 is a valve action portion that acts as a substantial valve, and is formed using a metal ball. As the metal ball, for example, a JIS standard ball bearing steel ball can be used. JIS standard ball bearing steel balls have high roundness and are mirror-finished, so they are suitable for improving the sheet properties for the nozzle body 16 and are mass-produced, so they can be manufactured at low cost. And is particularly suitable as a metal sphere for the ball portion 28. The diameter of the ball portion 28, that is, the diameter of the metal sphere is preferably about 3 to 4 mm in order to reduce the weight of the valve body 15.

  The fuel passage hole 29 functions to let the fuel that has flowed into the hollow interior of the valve body 15 through the hollow interior of the core 23 flow out into the space around the valve body 15 and flow down toward the nozzle body 16.

  The nozzle body 16 is made of a metal material that has been hardened and demagnetized by quenching. As shown in FIG. 2, a seat surface (valve seat surface) 31 and a nozzle hole 32 are provided, and a tapered portion is further provided. 33 is provided. 2 corresponds to a cross section taken along the line AA in FIG.

  The seat surface 31 functions to obtain a valve open state and a valve closed state by separating and contacting (seat and non-seat) the ball portion 28 of the valve body 15, has a predetermined inclination angle, and has a nozzle body 16. Is formed as a tapered conical surface on the tip side. The inclination angle is preferably in a range where the apex angle of the cone in the conical surface is 80 to 100 degrees, and particularly preferably about 90 degrees. This inclination angle is an optimum angle for polishing the vicinity of the seat position (valve seat position) 34 on the seat surface 31 or increasing the roundness of the seat position 34, that is, the grinding apparatus is in the best condition. The angle is suitable for use. Therefore, by setting such an inclination angle, the sheet property of the ball portion 28 can be greatly enhanced.

  The nozzle hole 32 is a fuel that flows in through a fuel passage formed between the ball portion 28 and the seat surface 31 when the ball portion 28 is in a non-seat state (the state shown in FIG. 2) with respect to the seat surface 31. Is made to flow down toward the nozzle hole plate 17, and the flowing fuel functions to form a lateral flow along the nozzle hole plate 17. The central axis A of the fuel injection valve 1 continues from the seat surface 31. It is formed in a circular hole shape having an inner wall surface 35 that is parallel to the inner wall surface. Here, in the lateral flow of the fuel along the nozzle hole plate 17, a portion where the extended surface of the seat surface 31 intersects with the nozzle hole plate 17 (indicated by a black dot P in FIG. 2 and a dotted circle Pc in FIG. 3). A central side flow that flows toward the center side and a peripheral side flow that flows toward the outer periphery side.

  The tapered portion 33 functions to form a fuel passage for the outer circumferential side flow between the nozzle body 16 and the nozzle hole plate 17 in order to give an appropriate flow distance to the outer circumferential side flow, and has a predetermined taper. A conical surface having a corner and tapering to the rear end side of the nozzle body 16 is formed on the front end surface 36 of the nozzle body 16 in a state of being continuous from the inner wall surface 35 of the nozzle hole 32. The taper angle, that is, the angle formed by the conical surface providing the taper portion 33 with respect to the tip edge of the nozzle hole 32 is preferably 10 to 30 degrees, and particularly about 20 degrees is for the outer side lateral flow. It is preferable in optimizing the fuel passage.

  As shown in FIG. 2, the nozzle hole plate 17 is formed in a disk shape corresponding to the circular tip surface 36 of the nozzle body 16, and is fixed to the tip surface 36 of the nozzle body 16 by welding or the like. Attached. The injection hole plate 17 is provided with a raised portion 41 and is provided with injection holes 42 to 45 in an arrangement as shown in FIG.

  The raised portion 41 protrudes in a dome shape toward the nozzle body 16 side, that is, the upstream side with respect to the fuel flow, and is provided at the center of the nozzle hole plate 17.

  The injection hole 42 and the injection hole 43 are center side injection holes provided closer to the center of the injection hole plate 17 (specifically, the center side than the above-mentioned intersection part P). Are provided one by one. Such center side injection holes 42 and 43 function to inject the fuel that has become the above-described center side lateral flow.

  On the other hand, the injection hole 44 and the injection hole 45 are outer peripheral side injection holes provided near the outer periphery of the injection hole plate 17 (specifically, on the outer peripheral side with respect to the above-described intersection part P). The outer peripheral side injection holes 44a to 44e and the outer peripheral side injection holes 45a to 45e are respectively provided at five positions apart from each other. The outer peripheral injection holes 44a to 44e and the outer peripheral injection holes 45a to 45e function to inject the fuel that has become the outer peripheral side flow described above.

  These injection holes form a single spray group (first spray group) by combining the central injection hole 42 and the outer peripheral injection holes 44a to 44e, while the central injection hole 43 and the outer peripheral injection hole. 45a to 45e are grouped to form another spray group (second spray group). Specifically, with respect to the first area 46 and the second area 47 set by dividing the nozzle hole plate 17 by a bisector S (FIG. 3) passing through the center of the nozzle hole plate 17, The outer peripheral side injection holes 44a to 44e of one spray group are arranged in the first area 46, the center side injection holes 42 of the first spray group are arranged in the second area 47, and the second spray group The outer peripheral injection holes 45 a to 45 e are arranged in the second area 47, and the central injection hole 43 of the second spray group is arranged in the first area 46.

  In such an arrangement, the outer peripheral injection holes 44a to 44e of the first spray group have their respective central axes at the central axis A of the injection hole plate 17 (which is also the central axis A of the fuel injection valve 1). By being provided in an inclined state so as to intersect at a predetermined angle, the unit spray is jetted in a direction inclined in the first area 46 toward the outer peripheral side of the nozzle hole plate 17. The center side injection hole 42 of the spray group is provided in the same inclined state as the outer peripheral side injection holes 44a to 44e, so that it is in the second area 47 and has the same direction as the outer peripheral side injection holes 44a to 44e (FIG. 2). Unit spray in the direction indicated by the arrow X in the middle), while the outer peripheral injection holes 45a to 45e of the second spray group have predetermined central axes with respect to the central axis A. Outer peripheral injection holes 44a-44e at an angle Is provided in an inclined state so as to intersect from the opposite direction, so that the unit spray is injected in a direction inclined to the outer peripheral side of the nozzle hole plate 17 in the second area 47, and the second spray. The central injection hole 43 of the group is provided in the same inclined state as the outer peripheral injection holes 45a to 45e, so that it is in the first area 46 and in the same direction as the outer peripheral injection holes 45a to 45e (in FIG. 2). In the direction indicated by the arrow Y).

  As described above, the central axis of each of the outer peripheral injection holes 44a to 44e and the central axis of each of the outer peripheral injection holes 45a to 45e intersect each other upstream of the injection hole plate 17, while In other words, the central axis and the central axis of the central injection hole 43 intersect each other on the downstream side of the injection hole plate 17. In the present embodiment, the outer peripheral side injection holes 44a to 44e and the outer peripheral side injection holes 45a to 45e, and the center side injection hole 42 and the center side injection hole 43 are symmetrically arranged with respect to the bisector S, and therefore, the respective central axes are arranged. Are supposed to be made on the central axis A. Here, the intersection of the central axis of the injection hole with respect to the central axis A and the intersection of the central axes of the injection valves mean an intersection that occurs when the central axis of the injection hole and the central axis A are projected on the same plane. Yes.

  It is important to appropriately set the diameter of the injection holes 42 to 45 as described above. As for the injection holes 42-45, the one where a hole diameter is small is good for promotion of atomization. However, if the hole diameter is reduced, the number of injection holes increases in order to ensure the necessary fuel injection amount, and the processing cost increases. In the case of this embodiment in which 12 injection holes are provided as described above under such conflicting requirements, it is appropriate to set the thickness to about 100 to 200 μm.

  The resin cover 5 is provided so as to cover a part of the casing 2 and the yoke 22 by, for example, a resin molding method. For this purpose, a connector 49 is provided.

  The above is the configuration of the fuel injection valve 1 in the first embodiment. Hereinafter, the operation of the fuel injection valve 1 will be described. When the electromagnetic coil 21 is not energized, the valve body 15 receives the bias of the spring 24 and causes the ball portion 28 to seat (closely contact) the ball portion 28 with the seat surface 31 of the nozzle body 16 at the seat position 34. Closed. In this valve closed state, the fuel passage is not formed between the valve body 15 and the ball portion 28 of the nozzle body 16, that is, the fuel passage is not opened, and the fuel flowing in from the fuel supply port 11 is not in the casing 2. Stays inside.

  When a current is applied as an injection pulse to the electromagnetic coil 21 in this state, the anchor portion 27 of the valve body 15 together with the yoke 22 and the core 23 forms a magnetic circuit, whereby the anchor portion 27 receives an attractive force from the core 23. Thus, the valve body 15 moves backward until the anchor portion 27 is pressed against the core 23, and the valve body 15 is in a non-seat state with respect to the nozzle body 16 and the valve is opened. When the valve is opened, a fuel passage is formed between the valve body 15 and the ball portion 28, that is, the fuel passage is opened. Then, the fuel flows down toward the nozzle hole plate 17 through the fuel passage. The fuel that has flowed down to the nozzle hole plate 17 becomes a lateral flow as described above along the nozzle hole plate 17 and is injected as a unit spray from each of the injection holes 42 to 45, and these unit sprays are the first and second nozzles described above. The two sprays 50 are obtained as a first spray 51 and a second spray 52 as shown in FIG. 4A shows the state of spraying from the side, and FIG. 4B shows a cross section taken along line BB in FIG.

  The first spray 51 is composed of a central spray 51a from the central spray hole 42 and an outer spray 51b in which unit sprays of the peripheral spray holes 44a to 44e are combined. Similarly, the second spray 52 includes a central spray 52a from the central spray hole 43 and an outer spray 52b in which unit sprays of the peripheral spray holes 45a to 45e are combined.

  In such first spray 51 and second spray 52, it is preferable that the penetrating force is different between the center side spray 51a or the center side spray 52a and the outer periphery side spray 51b or the outer periphery side spray 52b. As described above, the center side injection hole 42 and the outer peripheral side injection holes 44a to 44e are combined to form a first spray group, and the center side injection hole 43 and the outer peripheral side injection holes 45a to 45e are combined. In the configuration in which the second spray group is formed, that is, the configuration in which the central injection hole and the outer peripheral injection hole are combined, the penetrating forces of the unit sprays from the central injection port and the outer peripheral injection hole are different. In other words, it can be said that it is preferable.

  The penetrating force of the unit spray correlates with the flow distance (running distance) of the lateral flow, and the shorter the flow distance, the smaller the atomization property, but the larger the penetrating force. In this embodiment, as seen in FIG. 2 and FIG. 3, the intersection side P and Pc (this is also the part where the center side lateral flow and the outer side lateral flow are separated as described above) from the center side injection hole 42 and the center side. The distance to the injection hole 43 is shorter than the distance to the outer peripheral side injection holes 44a to 44e and the outer peripheral side injection holes 45a to 45e. Thereby, the penetration force of the unit spray from the center side injection hole 42 or the center side injection hole 43 is made larger than the penetration force of the unit spray from the outer periphery side injection holes 44a to 44e or the outer periphery side injection holes 45a to 45e. Yes. By doing so, the directivity of the first spray 51 and the second spray 52 is induced by attracting the unit spray from the center side injection hole 42 and the center side injection hole 43 having a large penetrating force and high directivity. Can be increased.

  The control of the injection amount in the fuel injection as described above is performed by adjusting the application timing of the injection pulse applied intermittently to the electromagnetic coil 21, that is, the switching timing between the valve opening and the valve closing.

  FIG. 5 shows a schematic flow of fuel in the vicinity of the outer peripheral injection hole 44 (outer peripheral injection hole 44c). In the vicinity of the outer peripheral injection hole 44, outer peripheral side flows 53a, 53b, 53c, etc. of the fuel are generated, and the fuel flows into the outer peripheral injection hole 44 as these outer peripheral side flows 53a, 53b, 53c. For this reason, the fuel that has flowed into the outer peripheral injection hole 44 is pressed along the inner wall surface of the outer peripheral injection hole 44 to form a liquid film 54a that spreads in the direction of the arrow Ma, while being unit sprayed from the outer peripheral injection hole 44. Injected as. At that time, the liquid film 54a is actively split by contacting with the suction air flow 55a due to the negative pressure generated by the inflow of fuel into the outer peripheral injection hole 44, thereby promoting atomization. This is the mechanism for promoting fuel atomization in the injection hole system.

  FIG. 6 shows a schematic flow of fuel in the vicinity of the central injection hole 43. In the vicinity of the center side injection hole 43, the center side lateral flows 56a, 56b, 56c and the like of the fuel are generated, and the fuel flows into the center side injection hole 43 as these center side lateral flows 56a, 56b, 56c. For this reason, the fuel that has flowed into the central injection hole 43 is pressed along the inner wall surface of the central injection hole 43 to form a liquid film 54b that spreads in the direction of the arrow Mb while unit spraying from the central injection hole 43. Injected as. Also in this case, as with the outer peripheral injection hole 44, atomization is promoted by the liquid film 54b coming into contact with the drawn-in air flow 55b.

  In the fuel injection valve 1 as described above, spray interference between unit sprays from each injection hole can be effectively suppressed. This is because the center side injection hole 42 and the center side injection hole 43 are provided. As described above, the spray interference is caused by the interval between a plurality of injection holes. That is, in the injection hole method, there is an upper limit on the size of the injection hole. For this reason, it is necessary to provide a certain number of injection holes to ensure the fuel injection amount. It means that spray interference is caused by being too narrow.

  In such a mechanism of occurrence of spray interference, by providing the center side injection hole 42 and the center side injection hole 43, the same fuel injection is performed as compared with the case where only the outer periphery side injection hole 44 and the outer periphery side injection hole 45 are provided. If it is an amount, the number of each of the outer peripheral side injection holes 44 and the outer peripheral side injection holes 45 can be reduced. In other words, the interval between the injection holes can be increased for the outer peripheral injection holes 44 and the outer peripheral injection holes 45. Further, the center side injection holes 42 and the center side injection holes 43 are small in number, and the arrangement direction is different from that of the outer periphery side injection holes 44 and the outer periphery side injection holes 45. For this reason, the center side injection hole 42 and the center side injection hole 43 can have a wide interval.

  According to experiments conducted by the inventors of the present invention, the radial spread generated in the spray before the spray injected from the injection hole reaches the fuel injection receiving portion of the internal combustion engine is about 4 with respect to the hole diameter of the injection hole. It will be about double. From this, it can be said that spray interference can be effectively suppressed if the interval between the injection holes is set to be four times or more the diameter of the injection holes. That is, spray interference can be effectively suppressed by setting L / D to be 4 or more, where L is the shortest center distance between adjacent injection holes and D is the hole diameter of the injection holes. In the case of the present embodiment in which the center side injection hole 42 and the center side injection hole 43 are provided, this condition can be sufficiently satisfied, and spray interference can be effectively suppressed.

  Here, the length of the injection holes 42 to 45 affects the formation of spray. For this reason, it is important to set the lengths of the injection holes 42 to 45 appropriately. The length of the injection holes 42 to 45 is determined by the thickness of the injection hole plate 17. Therefore, it is important to set the thickness of the nozzle hole plate 17 appropriately. If the thickness of the injection hole plate 17 is large, the injection holes 42 to 45 become longer and the guide property with respect to the fuel injection direction becomes high, and the directivity of the spray can be increased. The liquid film 54 (54a, 54b) in FIG. When the liquid film 54 becomes thin, the fuel injection speed becomes slow, and therefore the splitting force after injection becomes small. If the liquid film 54 is too thin, the fuel is injected inward from the inclination direction of the injection holes 42 to 45, which makes it difficult to inject the fuel to the intended position. Considering such factors relating to the thickness of the nozzle hole plate 17, it is desirable that the nozzle hole plate 17 has a thickness within a certain range. In the present embodiment, 70 to 120 μm is preferably adopted.

  7 and 8 show the configuration of the main part of the fuel injection valve according to the second embodiment. Note that FIG. 7 corresponds to a cross section taken along the line CC in FIG. The fuel injection valve of the present embodiment differs from the fuel injection valve 1 of the first embodiment in a part of the configuration of each of the nozzle body 61 and the nozzle hole plate 62. Therefore, in the following, the nozzle body 61 and the nozzle hole plate 62 will be described, and the above description will be used for the configuration and effects common to the fuel injection valve 1, and the common components in FIG. 2 and FIG. The same reference numerals are used.

  The nozzle body 61 has a tip surface 63 that is flattened to the edge of the nozzle hole 32. That is, the tapered portion 33 in the nozzle body 16 of the fuel injection valve 1 is omitted.

  The nozzle hole plate 62 is provided with a curved portion 64 so as to surround the periphery of the raised portion 41. The curved portion 64 is formed so as to bulge the periphery of the raised portion 41 toward the distal end side, and functions to form a fuel passage for the outer peripheral side flow between the nozzle body 61 and the nozzle hole plate 17b. . That is, the curved portion 64 has the function of the tapered portion 33 in the nozzle body 16 of the fuel injection valve 1. Even when such a curved portion 64 is provided, as shown in FIG. 8, the arrangement configuration of the center side injection hole 42, the center side injection hole 43, the outer peripheral side injection holes 44 a to 44 e, and the outer peripheral side injection holes 45 a to 45 e is as follows. This is the same as in the case of FIG.

  According to this embodiment, although the process which forms the curved part 64 by punching increases, the taper process which requires much labor compared with this process can be made unnecessary.

  9 and 10 show the configuration of an internal combustion engine equipped with the fuel injection valve 1 according to the first embodiment as an internal combustion engine according to one embodiment. The internal combustion engine 101 includes a combustion chamber 102 for burning fuel, a cylinder 103 for compressing the air-fuel mixture in the combustion chamber, an ignition plug 104 for igniting the compressed air-fuel mixture, an intake pipe 105 serving as a path for taking in air from the outside, fuel injection An intake port 106 to which the valve 1 is attached, an intake valve 107 through which the fuel injection valve 1 injects the spray 50, and an exhaust valve 108 serving as an on-off valve for discharging exhaust gas generated by fuel combustion are provided.

  FIG. 10 shows the arrangement relationship between the fuel injection valve 1 and the intake valve 107 as viewed in the direction D in FIG. 9, and as shown in this figure, the first spray with high directivity injected from the fuel injection valve 1 is shown. 51 and the second spray 52 are injected toward the center of the intake valve 107 of the internal combustion engine 101. The reason why the spray is collected near the center of the intake valve 107 is that when the intake valve 107 is opened, it is attracted to the inner air flow having a relatively high flow velocity, and the fuel is surely directed to the spark plug 104 and simultaneously to the port wall surface. This is to prevent the fuel from adhering and forming a rich air-fuel mixture during combustion. By doing so, the harmful exhaust gas HC from the internal combustion engine can be reduced, and at the same time, stable driving of the internal combustion engine can be realized.

  According to the internal combustion engine as described above, highly dispersed two-way spray with good atomization is formed for fuel injection, and each of the two-way sprays is injected toward the center of the intake valve with high directivity as intended. This makes it possible to further reduce the emission of harmful components such as HC from the internal combustion engine.

  As mentioned above, although some forms for implementing this invention were demonstrated, this is only a representative example and this invention can be implemented with various forms in the range which does not deviate from the meaning. it can. For example, in the above embodiment, the raised portion is provided on the nozzle hole plate. However, if the center side lateral flow and the outer side lateral flow can be effectively formed in the nozzle hole plate, the raised portion is not necessarily provided. In the above embodiment, twelve injection holes are used. However, the present invention is not limited to this, and the number of injection holes can be selected as appropriate. Further, in the above embodiment, the center side injection hole is made to function for the injection of the center side lateral flow, but is not limited thereto.

It is a figure showing the whole fuel injection valve composition by a 1st embodiment in a section. It is an enlarged view of the front-end | tip part of the fuel injection valve of FIG. It is a figure which shows the arrangement | positioning state of the injection hole in the injection hole plate of the fuel injection valve of FIG. It is a figure which shows typically the mode of the spray injected from the fuel injection valve of FIG. It is a figure which shows typically the flow of the fuel in the outer peripheral side injection hole vicinity. It is a figure which shows typically the flow of the fuel in the center side injection hole vicinity. It is an enlarged view of the front-end | tip part of the fuel injection valve by 2nd Embodiment. It is a figure which shows the arrangement | positioning state of the injection hole in the injection hole plate of the fuel injection valve of FIG. It is a figure showing the composition of the internal-combustion engine by one embodiment in section. It is a figure which shows the arrangement | positioning relationship of the fuel injection valve and intake valve seen in the D direction in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 15 Valve body 16 Nozzle body 17, 62 Injection hole plate 41 Raised part 42, 43 Center side injection hole 44, 45 Outer peripheral side injection hole 50 Two-way spray (spray)
51 First spray (spray)
52 Second spray (spray)
101 Internal combustion engine

Claims (5)

A valve seat surface formed in a conical shape, a valve body having a ball portion formed to be detachable from the valve seat surface, and an enlarged taper provided continuously to the minimum diameter end of the valve seat surface A fuel injection valve comprising a portion, an injection hole plate provided continuously to the taper portion, and a plurality of injection holes for injecting fuel provided in the injection hole plate ,
The nozzle hole plate is divided into two areas by a plane passing through the central axis of the conical valve seat surface, and the plurality of injection holes in each area correspond to a circle with the smallest diameter of the valve seat surface. Formed by an outer peripheral injection hole formed outside the virtual circle to be set and at least one central injection hole formed inside the virtual circle;
The outer peripheral injection hole is formed to be inclined so as to eject the fuel toward the outside as viewed from a plane passing through the central axis, and the central injection hole is divided by a plane passing through the central axis. A fuel injection valve, wherein the fuel injection valve is formed so as to incline so as to eject the fuel in the same direction as the outer peripheral injection hole in the opposite area . 2. The fuel injection valve according to claim 1, wherein the central injection hole and the outer peripheral injection hole are combined to form one spray group for injecting one spray. The penetrating force of the unit spray injected from the central side injection hole is higher than the penetrating force of the unit spray injected from the outer peripheral side injection hole for the one spray group. Item 3. The fuel injection valve according to Item 1 or 2 . The nozzle hole plate is provided with a raised portion at a central portion that protrudes toward the upstream side with respect to a fuel flow, and the central jet hole is provided at the raised portion. The fuel injection valve according to any one of claims 1 to 3 . An internal combustion engine on which the fuel injection valve according to any one of claims 1 to 4 is mounted.

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