JP4185045B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve used in an internal combustion engine, and more particularly to a fuel injection valve having a plurality of fuel injection holes to improve atomization performance of injected fuel.

As a conventional technique for promoting atomization of fuel by a fuel injection valve having a plurality of injection holes, a plurality of fuel passages configured as separate members installed on the downstream side of the valve seat and a spiral at the end of the fuel passage A technology has been proposed that promotes atomization by providing a swirling chamber in the shape of the chamber and generating a swirling flow in the fuel flowing out from an injection hole installed on the downstream side (for example, Patent Document 1 and Patent Document 2). reference).
JP 2002-98028 A JP 2003-336561 A

  As disclosed in the prior art, atomization of fuel using a plurality of injection holes requires that the fuel flow rate during injection be maintained high in the injection holes. Further, in the atomization of fuel by the fuel injection valve having the swirl chamber, it is necessary to design so that the energy given as the fuel pressure is efficiently replaced with the swirl speed energy at the injection hole outlet. That is, the prior art uses the turning speed energy to reduce the thickness of the injected fuel and promote atomization.

  In the prior art, as a means for improving the atomization performance, a fuel swirl chamber is provided downstream of the valve body and the valve seat with a long and narrow introduction passage. It cannot be said that the configuration is suitable for extracting the flow velocity energy, and the maximum atomization performance is not always obtained.

  An object of the present invention is to provide a fuel injection valve that can improve the atomization performance of fuel injected by the fuel injection valve, realize the atomization performance with a simple configuration, and reduce the manufacturing cost.

In order to solve the above problems, the present invention mainly adopts the following configuration.
A valve body that can be opened and closed to inject and stop injection of fuel, a nozzle plate having a valve seat that is in contact with the valve body to inject and stop injection of fuel, and a plurality of fixed and fixed to the nozzle plate A fuel injection valve comprising an orifice plate having fuel injection holes,
The nozzle plate includes a fuel introduction hole having a diameter reduced from the valve seat, a plurality of concave fuel passages extending in a valve diameter direction downstream of the fuel introduction hole and connected to the fuel injection hole, and the concave fuel. A convex portion having a curved surface separating the passage ; and a groove formed further outward of the convex portion; and the fuel introduction hole, the concave fuel passage, the convex portion, and the groove. Formed by the same member, the fuel introduction hole and the concave fuel passage in the nozzle plate are formed by the same stroke processing which is a subsequent processing in a state where the nozzle plate member is positioned without moving,
The orifice plate forms a concave bottom surface portion having a plurality of fuel injection holes arranged concentrically in the valve diameter direction, and forms an outer peripheral convex surface portion thicker than the concave bottom surface portion on the outer peripheral portion. ,
The concave bottom surface portion has a curved surface shape equivalent to the curved surface of the convex shape portion of the nozzle plate,
A fuel injection valve in which the outer peripheral convex surface portion of the orifice plate is inserted into the groove of the nozzle plate and the orifice plate is fixed to the nozzle plate.

Further, an openable / closable valve body for performing fuel injection and injection stop, a nozzle plate having a valve seat for separating and contacting the valve body to perform fuel injection and injection stop, and fixed to the nozzle plate A fuel injection valve comprising an orifice plate having a plurality of fuel injection holes,
The nozzle plate includes a fuel introduction hole having a diameter reduced from the valve seat, a plurality of concave fuel passages extending in a valve diameter direction downstream of the fuel introduction hole and connected to the fuel injection hole, and the concave fuel. A convex portion having a curved surface separating the passage ; and a groove formed further outward of the convex portion; and the fuel introduction hole, the concave fuel passage, the convex portion, and the groove. Formed by the same member, the fuel introduction hole and the concave fuel passage in the nozzle plate are formed by the same stroke processing which is a subsequent processing in a state where the nozzle plate member is positioned without moving,
The orifice plate forms a concave bottom surface portion in which a plurality of fuel injection holes are arranged concentrically in the valve diameter direction, and an outer peripheral convex surface portion thicker than the concave bottom surface portion on the outer peripheral portion. ,
The concave bottom surface portion has a curved surface shape equivalent to the curved surface of the convex shape portion of the nozzle plate,
The orifice plate is fixed to the nozzle plate by inserting the outer peripheral convex portion of the orifice plate into the groove of the nozzle plate,
The fuel injection valve in which the plurality of fuel injection holes are divided into two groups, and the spray injected from the plurality of fuel injection holes forms a two-way spray for each group.

  According to the present invention, the fuel flows in the plurality of fuel passages are radially divided and distributed, and the cross sections of the respective passages are narrowed. Flow velocity energy is obtained and atomization can be promoted.

  In addition, since the flow rate check is performed using the nozzle plate and orifice plate as a subassembly, it is possible to provide an inexpensive fuel injection valve with excellent cost performance without causing defective products as a fuel injection valve assembly. it can.

  The fuel injection valves according to the first and second embodiments of the present invention will be described below with reference to FIGS.

“First Embodiment”
The fuel injection valve according to the first embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a cross-sectional view of the overall configuration of a fuel injection valve according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the lower end portion of the nozzle in the fuel injection valve according to the first embodiment. FIG. 3 is a view for explaining the operation of the nozzle plate and the orifice plate constituting the lower end portion of the nozzle in the fuel injection valve according to the first embodiment. FIG. 4 is a view showing a hole arrangement of the nozzle plate and the orifice plate constituting the nozzle lower end portion in the fuel injection valve according to the first embodiment. FIG. 5 is a diagram showing a process for processing the orifice plate in the fuel injection valve according to the first embodiment. FIG. 6 is a diagram showing a nozzle plate processing step in the fuel injection valve according to the first embodiment.

  In the drawings, 1 is a nozzle plate, 2 is a valve seat, 3 is a fuel introduction hole, 4 is a convex portion, 5 is a groove, 6 is a valve body, 13 is a nozzle, 14 is a member for a fuel passage, and 25 is a vertical orifice plate. , 26 indicates a concave fuel passage, 27 indicates a convex portion of the orifice plate, 28 indicates a bottom surface of the concave portion of the orifice plate, 29 indicates a fuel injection hole, 30 indicates an outlet surface portion, and 41 indicates an outer peripheral wall of the fuel injection hole.

  In FIG. 1, the lower end portion of the nozzle 13 is provided with a valve body 6, a fuel passage member 14 that guides the valve body 6 with its inner peripheral surface 22, and a nozzle plate 1. The outer periphery is fixed by a method such as welding 23 (see FIG. 2).

  The valve body 6 is slidably guided by a hole provided in the central portion of the guide plate 15 and the inner peripheral surface 22 of the fuel passage member 14. The valve body 6 is formed by joining a movable iron core 7, a cylindrical member 8, and a rod 9 by a method such as welding. The damper plate 10 provided inside the movable iron core 7 is formed such that the outer peripheral portion thereof is supported in the vertical direction by the upper end surface of the cylindrical member 8. The motion member 12 is supported so as to be slidable in the axial direction inside the inner fixed iron core 11. The distal end portion of the movement member 12 is positioned so as to contact the inside of the damper plate 10. The damper plate 10 functions as a leaf spring by supporting the outer peripheral portion and bending the inner peripheral portion in the axial direction.

  The nozzle 13 is fixed inside the nozzle housing 16. A ring 17 for adjusting the stroke of the valve body 6 is provided at the upper end portion. A spring pin 20 is fixed inside the inner fixed iron core 11, and a spring 21 is provided in a compressed state with the lower end of the spring pin 20 as a fixed end. The spring force is transmitted to the valve body 6 via the moving member 12 and the damper plate 10, and the valve body 6 is pressed against the valve seat 2 of the nozzle plate 1 along with this. In this state, since the fuel passage is closed, the fuel stays inside the fuel injection valve 100 and fuel injection from the plurality of fuel injection holes 29 is not performed.

  The nozzle housing 16, the movable iron core 7, the inner fixed iron core 11, and the outer fixed iron core 18 constitute a magnetic circuit that goes around the coil 19. When the injection pulse is turned on, a current flows through the coil 19, the movable iron core 7 is attracted to the inner fixed iron core 11 by electromagnetic force, and the valve body 6 has a top end surface in contact with a lower end surface of the inner fixed iron core 11. Move up. In this open state, a gap is formed between the valve body 6 and the valve seat 2, so that the fuel passage is opened and fuel is injected from the plurality of fuel injection holes 29. When the injection pulse is turned off, no current flows through the coil 19 and the electromagnetic force disappears. Therefore, the valve body 6 returns to the closed state by the spring force, and the fuel injection ends.

  As described above, the operation of the fuel injection valve 100 is to switch the position of the valve body 6 between the valve open state and the valve closed state according to the injection pulse, and to control the fuel supply amount. Further, by spraying from a plurality of fuel injection holes 29, a fuel spray having a small fuel particle size, that is, good atomization is formed.

  FIG. 2 shows the nozzle plate 1 and the orifice plate 25 which are the main parts of this embodiment. 3 is an enlarged cross-sectional view of the vicinity of a lower end portion of a nozzle 13. FIG. FIG. 2 shows a so-called valve open state in a state where the valve body 6 is lifted upward. A cylindrical fuel passage member 14 and a nozzle plate 1 (an orifice plate 25 is welded to the nozzle plate 1 in advance) are inserted into the lower end of the nozzle 13, and the outer peripheral edge of the nozzle plate 1 is It is fixed by welding 23 or the like.

  In the nozzle plate 1, a valve seat 2, a fuel introduction hole 3 in which the diameter of the valve seat 2 is narrowed, and a plurality of concave fuel passages 26 are formed in the convex portion 4 that continues downstream thereof. Further, a groove 5 is formed further outward from the convex portion 4, and an orifice plate 25 is inserted into this portion, and its outer peripheral edge is fixed by welding 24 or the like.

  FIG. 3 shows a partially assembled state in which the nozzle plate 1 and the orifice plate 25 are coupled. The orifice plate 25 has a saddle shape (an upper concave shape with an appropriate curvature), and an outer peripheral convex surface portion 27 is inserted into the groove 5 of the nozzle plate 1. A plurality of fuel injection holes 29 are opened in the concave bottom portion 28. This ridge shape is formed with increased mechanical strength, and prevents thermal deformation around the injection hole 29 during welding. In such a shape, the illustrated height H of the orifice plate 25 is preferably 0.4 mm or more (welding is performed at the lower portion of the orifice plate, but thermal deformation during the welding affects the fuel injection hole 29. In other words, the influence of welding distortion on the fuel injection hole 29 can be suppressed.

  The thin portion h is preferably in the range of 0.1 mm to 0.3 mm, and has various benefits such as cost reduction due to the ease of hole machining and reduction in hole size variation due to die machining. Further, it is preferable that the gap between the curved surface portion of the convex portion 4 and the inner surface of the concave bottom portion 28 is a minimum gap that does not hinder the assembly and does not exist as much as possible. This gap is a space that is not necessary for the fuel flow (the fuel flow is performed in the concave fuel passage 26), and adversely affects the fuel injection, for example, acting in the direction of decreasing the fuel flow velocity. Here, in consideration of the workability and mechanical strength as described above, it is preferable to use ferritic stainless steel for the material of the orifice plate 25.

  As shown in FIG. 4, the fuel injection holes 29 are arranged concentrically. With such an arrangement, uniform fuel can be supplied to the respective injection holes, so that variations in flow rate are suppressed and accurate injection is obtained. As for the setting of the number of the fuel injection holes 29, 4 to 6 are selected as the optimum values as a result of various examinations from the viewpoint of processing surface and spray performance.

  For example, if the number of holes is reduced, the hole diameter is increased in order to secure the flow rate, so the atomization performance deteriorates. Conversely, when the number of holes is increased, the hole diameter is reduced in order to make the flow rate the same, but the arrangement is dense due to geometrical dimensional constraints around the hole arrangement. This causes unnecessary mutual interference and recombination of the atomized spray, resulting in an undesirable spray in both atomization and shape control. Examples of geometric dimensional constraints include dimensions necessary for ensuring pressure resistance and dimensions for minimizing the space volume that is not necessary for injection control.

  Further, as shown in FIG. 6C, the fuel injection hole 29 is formed in the outlet surface portion 30 so as to form a desired angle θ with respect to the axis of the fuel injection valve.

  The processing method and assembly method of the nozzle plate 1 and the orifice plate 25 will be described with reference to FIGS.

  FIG. 5 shows a processing flow of the nozzle plate 1. In FIG. 5, processing proceeds in the order of (a) to (d). (A) is the shape of a blank state, and the shape which has the convex part 4 in an internal center part is made by forge molding etc. FIG. (B) is a state in which the cross-shaped concave fuel passage 26 extending in the radial direction is processed, and the convex portion 4 is formed by plastic processing or the like. (C) is a state in which the fuel introduction hole 3 is processed, and the introduction hole does not penetrate but is called half-piercing processing in which the processing is finished in the middle of the material. This processing is based on the same process as the processing of the concave fuel passage 26, so that the coaxiality of both is maintained. (D) is a state in which the seat surface (valve seat) 2 is cut, and after quenching, the seat surface finish is performed again while ensuring the coaxiality with the fuel introduction hole 3.

  FIG. 6 shows a processing flow of the orifice plate 25. In FIG. 6, processing proceeds in the order of (a) to (c). (A) is the shape of a blank state, and the concave shape which has the outer peripheral convex-surface part 27 for ensuring the mechanical strength at the time of welding is made by forging molding etc. FIG. (B) is a state in which a plurality of straight holes 29 are processed, and is produced by punching. Since it is a straight hole, processing is easy, which is advantageous in terms of cost. In addition to punching, the same effect can be obtained by drilling or electric discharge machining. (C) is a state of R molding processing (press processing by a pressing die having a curvature R), which is an operation process for determining the spray direction. The curvature of the R surface is made to be substantially the same as the R surface of the convex portion 4 of the nozzle plate 1, and in the partially assembled state as shown in FIG. Is maintained. In this partially assembled state, a flow rate check is performed, and the fuel is separated according to the rank of the flow rate and assembled to the fuel injection valve body.

  Next, the injection form in the nozzle configuration as described above will be described. In general, the fuel passes from the outer peripheral passage of the fuel passage member 14 to the fuel introduction hole 3 of the nozzle plate 1 through the lower passage (groove 14a in FIG. 2), and further to the plurality of fuel injection holes opened downstream thereof. 29, injection control is performed in a desired direction.

  More specifically, the fuel flows in from the fuel introduction hole 3 having a reduced diameter, collides with the concave bottom surface 28 of the orifice plate 25, and then flows radially. At this time, it flows so as to rise the curvature surface (R surface) of the bottom surface 28. Since this fuel flow is a fuel flow in which the passage cross-section is narrowed (see FIG. 3), the fuel passage 26 has a flat upper portion in the lateral direction, while the concave bottom surface 28 of the orifice plate 25 is an injection valve. Since the curvature surface is formed radially upward from the shaft core, the vertical interval is narrowed in the cross-sectional view of FIG. 3 from the shaft core to the injection hole), thereby preventing the fuel flow rate from decelerating. .

  In addition, the fuel introduction hole 3 and the concave fuel passage 26 are processed in the same process (when the passage 26 and the hole 3 are processed, the processing tools of the passage 26 and the hole 3 are replaced, but the work piece is held. That is, since the hole 3 is processed following the processing of the passage 26 without moving the workpiece, positioning in both processes is established), and the fuel is equally divided with high accuracy. Flows radially. Thereafter, the fuel reaches a plurality of fuel injection holes 29 concentrically arranged on the bowl-shaped orifice plate 25 and is uniformly injected to the outside.

  In the fuel injection hole 29, fuel is supplied while maintaining high-speed flow velocity energy. Further, the fuel that has flowed radially into the fuel injection hole 29 is the outer peripheral wall 41 of the fuel injection hole 29 (the wall portion of the hole 29 on the side away from the valve shaft core of the injection valve, see FIG. 6C). Therefore, it has a C-shaped jet shape. Here, since the shape of the fuel jet ejected from the injection hole 29 having a circular cross section is ejected following the flow along the outer peripheral wall 41 of the injection hole 29, a C-shape is formed. The C shape means a shape or a horseshoe shape that is biased in the circumferential direction on the outer wall side of the injection hole 29 having a circular cross section. This C-shaped jet is more active in energy exchange with the surrounding air than the normal contracted flow type, so that the splitting is promoted and the atomization is good. Here, in order to more reliably generate a C-shaped jet shape having a large contact area with the surrounding air, referring to FIG. 3, the distance d between the diameter d of the fuel introduction hole 3 and the center of the fuel injection hole. The ratio do / d to do is preferably 2 or more according to experimental results.

  In addition, the sub-assembly of the nozzle plate 1 and the orifice plate 25 is subjected to a flow rate check in the state of this assembly to classify the flow rate. As a result, an inexpensive fuel injection valve having excellent cost performance can be obtained without generating a defective fuel injection valve assembly.

“Second Embodiment”
A fuel injection valve according to a second embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 7 is a view showing the arrangement of injection holes in the orifice plate of the fuel injection valve according to the second embodiment of the present invention and the fuel flow around the injection holes. FIG. 8 is a view for explaining two-way injection when the fuel injection valve according to the second embodiment is employed. FIG. 9 is a diagram showing a configuration example in which the fuel injection valves according to the first and second embodiments of the present invention are mounted on a port injection type internal combustion engine. FIG. 10 is a cross-sectional view of FIG. 9 as viewed from the direction C, showing the relationship between the intake valve and the spray.

  In the drawings, 31 and 32 are fuel injection holes, 36 is a concave fuel passage, 37, 38 and 39 are sprays, 100 is a fuel injection valve, 101 is a multi-cylinder internal combustion engine, 102 is a combustion chamber, 103 is a piston, 104 is The piston cavity, 105 is a cylinder, 106 is a cylinder head, 107 is an intake valve, 108 is an intake port, 108a is a central partition, 108b is a side wall, 109 is an exhaust valve, 110 is a spark plug, and 111 is an intake passage.

  FIG. 7 shows a second embodiment of the present invention in which a swirling flow is generated in the injection holes 31 and 32 to promote fuel atomization. The upper part of FIG. 7 shows the hole arrangement of the plurality of fuel injection holes 31 and 32 arranged in the orifice plate 35. The plurality of injection holes 31 and 32 are provided so as to be shifted from the center of the concave fuel passage 36 in any wall direction. And it arrange | positions so that each injection hole may mutually adjoin. The two groups of the injection hole 31 and the group of the injection hole 32 are divided.

  Further, the injection holes 31 and 32 having a circular cross section are arranged concentrically on the inlet side, and are inclined in a desired direction at the injection hole outlet (the circular cross section and the concentric arrangement are not essential requirements). One case). Specifically, the pairs of injection holes 31 are inclined in opposite directions, and the jets ejected from the pairs are such that the jets of the pairs interfere with each other on the B surface shown in FIG. Tilt. This situation is shown in the middle of FIG. A similar inclined shape is also formed for the pair of injection holes 32. Further, the lower part of FIG. 7 schematically shows the fuel flow to the injection hole 31 from the result of numerical analysis. A swirl flow is generated in the fuel flow 34 into the injection hole 31.

  As shown in the upper part of FIG. 8, the spray becomes a two-way spray 39 by a pair of injection holes 31 and a pair of injection holes 32 (spray 37 is the injection hole 31, and spray 38 is the injection hole 32). FIG. 8 schematically shows a spray photograph obtained by optical photographing of the spray using strobe light or laser light. The sprays 37 and 38 are formed so that their spreads are substantially the same, so that the energy replacement to the ambient air is also substantially the same, and therefore the reach distance is the same.

On the other hand, as shown in the BB sectional view of FIG. 8, in this cross section, the spray 37 is formed by the sprays 37 a and 37 b and the spray 37 c in which both interfere. Further, the spray 38 is formed by the sprays 38a and 38b and the spray 38c with which both interfere. The density of the sprays 37c and 38c in the interfering portion is higher than that of the surrounding area. In other words, each of the sprays forming the two-way sprays 37 and 38 is a fuel spray injected from two or more fuel injection holes (in FIG. 7, two injection holes are paired, but three or more may be used. ) By making two or more sprays close to each other in the front, the density of the central portion is high and the spray becomes gradually dilute toward the outside. The two-way spray as shown in FIG. And a multi-cylinder internal combustion engine as shown in FIG. FIG. 9 is a view showing a state where the multi-cylinder internal combustion engine is mounted on the intake pipe. FIG. 10 is a view as seen from the direction C, showing the positional relationship between the intake port 108, the fuel injection valve 100, and the spray 39 from the injection valve.

  In FIG. 9, reference numeral 101 denotes one of the cylinders of the multi-cylinder internal combustion engine, which is an intake two-valve type in which the fuel injection valve 100 is disposed toward the intake port 108. Reference numeral 102 denotes a combustion chamber, 103 denotes a piston having a cavity 104, 105 denotes a cylinder, and 106 denotes a cylinder head. Reference numeral 107 denotes an intake valve, 111 denotes an intake passage having a central partition wall 108a for separating the intake port 108 and communicates on the upstream side, 109 denotes an exhaust valve, and 110 denotes an ignition plug. The fuel injection valves 100 are arranged one by one on the upstream side of the intake valve 107, and have a fuel injection method that is a multipoint injection (MPI) system.

  In order to improve the quality and formation state of the air-fuel mixture in the cylinder, the atomization degree of the spray 39 is increased. Further, in order to reduce fuel adhesion to the inner wall surface of the cylinder head 106 and the intake passage 111. In addition, the directionality and shape of the spray are optimized. That is, the spray shape of the fuel injection valve 100 of the present embodiment has a small spread on the inner wall surface of the intake passage 111. Further, as shown in FIG. 10, the spray is laid out so as to avoid adhesion to the central partition wall 108 a and to be directed to the stem center of the intake valve 107. In particular, the sprays 37 and 38 have a dense portion directed toward the center of the stem, and remarkably prevent the intake passage from adhering to the central partition wall 108a and the inner wall 108b. In other words, as shown in FIG. 10, each of the two-way sprays from the plurality of fuel injection valves toward the center of the intake port 107 forms a substantially oval shape that fits within the umbrella portion of the intake valve 107, The dense part in the center is directed toward the stem center of the intake valve.

  When the combustion test of the internal combustion engine was carried out, the exhaust gas performance and the fuel consumption were improved. The spray of the fuel injection valve 100 suppressed the fuel adhesion to the inner wall surface of the intake pipe, and the quality of the air-fuel mixture and It was confirmed that the formation state was improved.

  As described above, the fuel injection valve according to the embodiment of the present invention is characterized in that it has the following configuration, function and action. That is, a fuel passage extending from the valve seat of the fuel injection valve to the plurality of injection holes, a fuel introduction hole having a diameter smaller than the valve seat diameter, and a concave fuel passage branched and communicated in a plurality of directions from the fuel introduction hole; A plurality of fuel injection holes located concentrically outside the fuel passage are provided. The fuel introduction hole and the concave fuel passage are formed integrally with the nozzle plate having the valve seat, and the coaxial processing of the valve seat and the fuel introduction hole, and the same between the fuel introduction hole and the concave fuel passage. There is a process. The vertical orifice plate having a plurality of fuel injection holes covers the curved surface of the convex portion (covers the concave fuel passage), thereby communicating the plurality of fuel passages with the plurality of fuel injection holes. Form. At this time, the gap between the convex portion of the nozzle plate and the concave curved surface portion of the orifice plate is designed to be minimized.

  After the fuel flow in the plurality of fuel passages collides with the center of the concave bottom portion from the fuel introduction hole, it is equally divided radially and reaches each injection hole. At this time, the concave fuel passage is formed so that the cross section of the passage narrows toward the outside, and the fuel flow energy does not significantly attenuate. Therefore, an efficient fuel flow rate is obtained and atomization is promoted. Moreover, since each injection hole is concentrically arranged, the fuel flow velocity is made uniform, and good atomization is performed at each injection hole. In addition, the orifice plate has a concave shape that can increase the mechanical strength, so that deformation around the injection hole is suppressed during welding, and there is no variation in the efficient flow velocity energy in each injection hole. Is obtained and atomization is promoted.

  In addition, the nozzle plate and orifice plate subassembly (see FIG. 3) employs a flow rate adjustment method in which the flow rate is checked and the flow rate is ranked in such a state, resulting in a defective fuel injection valve assembly. Thus, an inexpensive fuel injection valve with excellent cost performance can be obtained.

It is sectional drawing of the whole structure of the fuel injection valve which concerns on the 1st Embodiment of this invention. It is sectional drawing to which the lower end part of the nozzle in the fuel injection valve which concerns on 1st Embodiment was expanded. It is a figure explaining the effect | action of the nozzle plate and orifice plate which comprise the nozzle lower end part in the fuel injection valve which concerns on 1st Embodiment. It is a figure which shows the hole arrangement | positioning of the nozzle plate and orifice plate which comprise the nozzle lower end part in the fuel injection valve which concerns on 1st Embodiment. It is a figure which shows the manufacturing process of the orifice plate in the fuel injection valve which concerns on 1st Embodiment. It is a figure which shows the manufacturing process of the nozzle plate in the fuel injection valve which concerns on 1st Embodiment. It is a figure which shows the injection hole arrangement | positioning in the orifice plate of the fuel injection valve which concerns on the 2nd Embodiment of this invention, and the fuel flow around an injection hole. It is a figure explaining the two-way injection in the case of employ | adopting the fuel injection valve which concerns on 2nd Embodiment. It is a figure which shows the structural example which mounts the fuel injection valve which concerns on the 1st and 2nd embodiment of this invention in the port injection type internal combustion engine. FIG. 10 is a cross-sectional view of FIG. 9 as viewed from the direction C, showing the relationship between the intake valve and the spray.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Valve seat 3 Fuel introduction hole 4 Convex part 5 Groove 6 Valve body 13 Nozzle 14 Fuel passage member 25 Vertical orifice plate 26 Concave fuel passage 27 Convex part of orifice plate 28 Concave bottom face of orifice plate 29, 31 , 32 Fuel injection hole 30 Outlet surface portion 36 Concave fuel passage 37, 38, 39 Spray 41 Outer peripheral wall of fuel injection hole 100 Fuel injection valve 101 Multi-cylinder internal combustion engine 102 Combustion chamber 103 Piston 104 Piston cavity 105 Cylinder 106 Cylinder head 107 Intake Valve 108 Intake port 108a Central partition wall 108b Side wall 109 Exhaust valve 110 Spark plug 111 Intake passage

Claims (5)

A valve body that can be opened and closed to inject and stop injection of fuel, a nozzle plate having a valve seat that is in contact with the valve body to inject and stop injection of fuel, and a plurality of fixed and fixed to the nozzle plate A fuel injection valve comprising an orifice plate having fuel injection holes,
The nozzle plate includes a fuel introduction hole having a diameter reduced from the valve seat, a plurality of concave fuel passages extending in a valve diameter direction downstream of the fuel introduction hole and connected to the fuel injection hole, and the concave fuel. A convex portion having a curved surface separating the passage ; and a groove formed further outward of the convex portion; and the fuel introduction hole, the concave fuel passage, the convex portion, and the groove. Formed by the same member, the fuel introduction hole and the concave fuel passage in the nozzle plate are formed by the same stroke processing which is a subsequent processing in a state where the nozzle plate member is positioned without moving,
The orifice plate forms a concave bottom surface portion having a plurality of fuel injection holes arranged concentrically in the valve diameter direction, and forms an outer peripheral convex surface portion thicker than the concave bottom surface portion on the outer peripheral portion. ,
The concave bottom surface portion has a curved surface shape equivalent to the curved surface of the convex shape portion of the nozzle plate,
The fuel injection valve , wherein the outer peripheral convex portion of the orifice plate is inserted into the groove of the nozzle plate, and the orifice plate is fixed to the nozzle plate . The fuel injection valve according to claim 1, wherein
The orifice plate in which the concave bottom surface portion is formed is a material obtained by concentrically processing a plurality of fuel injection holes in a flat surface portion, and is formed by press molding using a pressing die having a curvature. Fuel injection valve. The fuel injection valve according to claim 1 or 2,
The curved surface portion of the convex portion of the nozzle plate and the curved surface portion of the concave bottom surface portion of the orifice plate have a minimum gap that does not hinder assembly when the orifice plate is assembled and fixed to the nozzle plate. A fuel injection valve characterized by forming. A valve body that can be opened and closed to inject and stop injection of fuel, a nozzle plate having a valve seat that is in contact with the valve body to inject and stop injection of fuel, and a plurality of fixed and fixed to the nozzle plate A fuel injection valve comprising an orifice plate having fuel injection holes,
The nozzle plate includes a fuel introduction hole having a diameter reduced from the valve seat, a plurality of concave fuel passages extending in a valve diameter direction downstream of the fuel introduction hole and connected to the fuel injection hole, and the concave fuel. A convex portion having a curved surface separating the passage ; and a groove formed further outward of the convex portion; and the fuel introduction hole, the concave fuel passage, the convex portion, and the groove. Formed by the same member, the fuel introduction hole and the concave fuel passage in the nozzle plate are formed by the same stroke processing which is a subsequent processing in a state where the nozzle plate member is positioned without moving,
The orifice plate forms a concave bottom surface portion having a plurality of fuel injection holes arranged concentrically in the valve diameter direction, and forms an outer peripheral convex surface portion thicker than the concave bottom surface portion on the outer peripheral portion. ,
The concave bottom surface portion has a curved surface shape equivalent to the curved surface of the convex shape portion of the nozzle plate,
The orifice plate is fixed to the nozzle plate by inserting the outer peripheral convex portion of the orifice plate into the groove of the nozzle plate,
The plurality of fuel injection holes are divided into two groups, and the spray injected from the plurality of fuel injection holes forms a two-way spray for each group. The fuel injection valve according to claim 4, wherein
Each spray forming the two-way spray is a fuel spray injected from two or more fuel injection holes,
The fuel injection valve according to claim 1, wherein the two or more sprays are brought close to each other in the forward direction so that the density of the central portion is high and the fuel gradually becomes lean toward the outside.

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