Fuel Injection Valve

Abstract

To change a form of a spray as a whole, and to change a fuel distribution rate in a cross section of the spray as a whole, in a fuel injection valve for injecting the spray as a whole by combining a plurality of deflection sprays.SOLUTION: In a fuel injection valve of the present invention, a plurality of turning passages comprise at least three turning passages having long axes Ax1 and short axes Ax2 at spray cross sections, and when compared with the case that lateral passages of the plurality of turning passages are constituted as simple and linear passages, a first deflective spray SPS1, a second deflective spray SPS2 and a third deflective spray SPS4 which are injected from the three turning passages are arranged so that an overlap at a center part a0 of a spray cross section SPH as a whole which includes the first deflective spray SPS1, the second deflective spray SPS2 and the third deflective spray SPS4 is reduced, and the distribution density of fuel at the center part a0 is reduced.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a fuel injection valve that generates swirling fuel upstream of a fuel injection hole and injects the swirling fuel from the fuel injection hole. [Background technology]

[0002] A fuel injection valve described in JP 2018-165512 A (Patent Document 1) is known as a background art of the technical field. In this fuel injection valve, in order to adjust the flow rate of fuel injected from the fuel injection hole while suppressing changes in atomization performance in a fuel injection valve having a swirl chamber and a lateral passage, a fuel injection hole, a swirl chamber in which the inlet of the fuel injection hole opens, and a lateral passage in which one side wall is connected to the upstream end of the inner circumferential wall of the swirl chamber and the other side wall is connected to the downstream end of the inner circumferential wall, when a first extension line extended along one side wall and a second extension line extended along the other side wall are imagined, on a projection plane perpendicular to the central axis of the fuel injection valve, the projection of the inlet opening of the fuel injection hole is located beyond the projection of the second extension line and on the projection side of the one side wall or the projection side of the first extension line (see abstract).

[0003] Patent Document 1 also describes that there is fuel that flows into the fuel injection hole without sufficiently swirling through the swirl chamber, and fuel that flows into the fuel injection hole after sufficiently swirling through the swirl chamber, and that the fuel that flows into the fuel injection hole without sufficiently swirling through the swirl chamber has a high fuel flow velocity (axial velocity) and forms a fuel spray with strong penetrating power, a small spray angle, and a long penetration, while the fuel that flows into the fuel injection hole after sufficiently swirling through the swirl chamber has a low axial velocity and forms a fuel spray with weak penetrating power, a large spray angle, and a short penetration (see paragraph 0071). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-165512 A Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have discovered that a fuel spray having a flat cross-sectional shape as shown in FIG. 11C (hereinafter, referred to as a flat spray) can be injected by using a fuel injection valve having a swirl chamber and a fuel injection hole as in Patent Document 1. Hereinafter, this flat spray will be described with reference to FIGS. 11A to 11D. FIG. 11A is a plan view showing a nozzle plate 21n having swirl chambers 212-1 to 212-4 and fuel injection holes 220-1 to 220-4 as a comparative example of the present invention. FIG. 11B is a diagram showing the cross-sectional shape of a fuel spray according to a comparative example of the present invention. FIG. 11C is a conceptual diagram showing the arrangement of fuel sprays SPS-1 to SPS4 injected from the swirl passages 210-1 to 210-4. FIG. 11D is a diagram showing the distribution rate of fuel for the fuel sprays (whole spray) injected from the swirl passages 210-1 to 210-4. In the following description, when describing the cross-sectional shape of a fuel spray, unless otherwise specified, the description will be given in terms of a cross section perpendicular to the injection direction of the fuel spray or the central axis of the fuel injection valve.

[0006] The four sets of swirl chambers 212-1 to 212-4 and fuel injection holes 220-1 to 220-4 shown in Fig. 11A are configured similarly to the fuel injection valve of Patent Document 1, and inject the fuel that flows into the fuel injection holes 220-1 to 220-4 without sufficiently swirling through the swirl chambers 212-1 to 212-4, and the fuel that flows into the fuel injection holes 220-1 to 220-4 after sufficiently swirling through the swirl chambers 212-1 to 212-4. As a result, the four fuel sprays SPS1 to SPS4 are arranged as shown in Fig. 11C, and the cross-sectional shape of the fuel spray (full spray) SPH is formed to be circular.

[0007] As shown in FIG. 11B, the cross-sectional shape of each of the fuel sprays SPS1 to SPS4 injected from each of the fuel injection holes 220-1 to 220-4 is a flat shape having a major axis Ax1 and a minor axis Ax2. In this example, the cross-sectional shape of each of the fuel sprays SPS1 to SPS4 is generally an ellipse having a major axis Ax1 and a minor axis Ax2. A fuel spray whose cross-sectional shape is deflected and deviated from a circle, including an ellipse, is called a deflected spray. In a deflected spray, the deflection direction is determined by the positional relationship between the lateral passages 211-1 to 211-4 and the swirl chambers 212-1 to 212-4 connected to the lateral passages 211-1 to 211-4, but there are cases where it is desired to change the cross-sectional shape of the entire spray formed by a plurality of fuel sprays or to change the fuel distribution rate in the cross section of the entire spray. In this case, it is necessary to change the deflection direction of each of the fuel sprays in the plurality of fuel sprays SPS1 to SPS4. The deflection direction corresponds to the arrangement (orientation) of the major axis Ax1 and minor axis Ax2 in an elliptical spray, and changing the deflection direction corresponds to changing the arrangement (orientation) of the major axis Ax1 and minor axis Ax2 of the elliptical spray.

[0008] An object of the present invention is to provide a fuel injection valve that combines a plurality of deflected sprays to inject a total spray, and to make it possible to change the shape of the total spray and the fuel distribution rate within the cross section of the total spray. [Means for solving the problem]

[0009] In order to achieve the above object, the fuel injection valve of the present invention comprises: A fuel injection valve comprising: a valve seat and a valve body which cooperate to open and close a fuel passage; and a plurality of swirl passages which apply a swirling force to fuel and inject it downstream of the valve seat and the valve body, wherein the swirl passages comprise a fuel injection hole, a swirl chamber which is provided upstream of the fuel injection hole and swirls the fuel, and a lateral passage which is connected to the swirl chamber, The swirl passage injects a deflected spray having a cross-sectional shape that deviates from a circular shape, The lateral passage is an inner periphery-side passage portion disposed on the inner periphery side and extending radially outward; an outer periphery-side passage portion extending in a direction inclined with respect to the inner periphery-side passage portion so that a connection portion with the swirl chamber is located radially inward compared to a case in which the inner periphery-side passage portion is simply extended radially outward; and an outer periphery-side passage portion provided between the inner periphery-side passage portion and the outer periphery-side passage portion. A curved passage where the fuel flow direction changes and, Have death, The swirl chamber is disposed so as to protrude radially outward from the outer periphery side passage portion. do. Effect of the Invention

[0011] According to the present invention, in a fuel injection valve that combines a plurality of deflected sprays to inject a total spray, it is possible to change the shape of the total spray and the fuel distribution rate within the cross section of the total spray. [Brief description of the drawings]

[0012] [Figure 1] 1 is a cross-sectional view showing a cross section along a valve axis (central axis) 1a of a fuel injection valve 1 according to the present invention. [Diagram 2] 2 is an enlarged cross-sectional view (corresponding to the cross section taken along line II-II in FIGS. 3A and 3B) showing the vicinity (nozzle portion) of a valve portion 7 and a fuel injection portion 21 of the fuel injection valve 1 in FIG. 1. [Figure 3A] 3 is a plan view of a nozzle plate 21n as seen from the direction of arrows III-III in FIG. [Figure 3B] 3 is a plan view showing a modified example of the nozzle plate 21n, as seen in the direction of the arrows III-III in FIG. [Figure 4] 4 is an enlarged plan view showing the swirl chamber 212 and the fuel injection hole 220 (an enlarged plan view of part IV shown in FIGS. 3A and 3B). FIG. [Diagram 5] 2 is a plan view of the swirl passage 210 when the upper end surface of the nozzle plate 21n in which the swirl passage 210 is formed is viewed from above. [Figure 6] 4 is a conceptual diagram showing the form of fuel spray injected from swirl passages 210-1 to 210-4. FIG. [Figure 7A] This is a conceptual diagram showing the change in shape of the fuel spray cross section for fuel sprays SPS1, SPS4 injected parallel to the central axis 1a of the fuel injection valve 1 according to the distance (injection distance) L from the fuel injection valve 1 in the fuel injection direction (in the axial direction of the central axis 1a in this embodiment). [Figure 7B] FIG. 7B is a conceptual diagram illustrating the spray cross sections of fuel sprays SPS1 to SPS4 in the case of L=2.0 in FIG. 7A. [Figure 7C]This is a conceptual diagram showing the change in shape of the fuel spray cross section for fuel sprays SPS1 and SPS4 that are injected in directions away from each other, depending on the distance (injection distance) L from the fuel injection valve 1 in the fuel injection direction (in this embodiment, the axial direction of the central axis 1a). [Figure 8] FIG. 11 is a diagram showing the distribution rate of fuel with respect to fuel sprays SPS1, SPS4 injected from swirl passages 210-1 to 210-4. [Figure 9] 3A and 3B, in which (a) is a plan view of the nozzle plate 21n, and (b) is a conceptual diagram showing the form of fuel spray injected from the swirl passages 210-1 to 210-3. [Figure 10] 1 is a cross-sectional view of an internal combustion engine equipped with a fuel injection valve 1. FIG. [Figure 11A] FIG. 2 is a plan view showing a nozzle plate 21n having a swirl chamber and fuel injection holes 220-1 to 220-4, which is a comparative example of the present invention. [Figure 11B] FIG. 4 is a diagram showing a cross-sectional shape of a fuel spray according to a comparative example of the present invention. [Figure 11C] FIG. 2 is a conceptual diagram showing an arrangement of fuel sprays SPS-1 to SPS4 injected from swirl passages 210-1 to 210-4. [Figure 11D] FIG. 11 is a diagram showing the distribution rate of fuel with respect to fuel sprays (full sprays) injected from swirl passages 210-1 to 210-4. [Figure 12] 10A and 10B are plan views showing a nozzle plate 21n equipped with swirl passages 210-1 to 210-3 which are comparative examples to the embodiment of FIG. 9, where (a) shows a plan view of the nozzle plate 21n, and (b) is a conceptual diagram showing the form of the fuel spray injected from the swirl passages 210-1 to 210-3 in this modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will be described with reference to FIGS.

[0014] The overall configuration of a fuel injection valve 1 will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing a cross section along a valve axis (central axis) 1a of a fuel injection valve 1 according to the present invention.

[0015] In this embodiment, the central axis 1a of the fuel injection valve 1 coincides with the axis (valve axis) of a mover 27 with which a valve body 17 (described later) is integrally provided, and coincides with the central axis of a cylindrical body 5 (described later). The central axis 1a also coincides with the center lines of a valve seat 15b and a nozzle plate 21n (described later). In the following description, the central axis, axis (valve axis), and center line will not be differentiated, and will be referred to as the central axis 1a.

[0016] The fuel injection valve 1 is provided with a cylindrical body 5 made of a metal material that extends from the upper end to the lower end. The fuel flow path 3 is configured inside the cylindrical body 5 so as to be substantially along the central axis 1a. In FIG. 1, the upper end (upper end side) is called the base end (base end side), and the lower end (lower end side) is called the tip end (tip side). The names of the base end (base end side) and the tip end (tip side) are based on the fuel flow direction or the mounting structure to the fuel pipe (not shown). That is, in the fuel flow direction, the base end is the upstream side, and the tip end is the downstream side. The vertical relationship described in this specification is defined based on FIG. 1 and has no relation to the vertical direction in the state in which the fuel injection valve 1 is installed in the internal combustion engine.

[0017] A fuel supply port 2 is provided at the base end of the cylindrical body 5. A fuel filter 13 is attached to this fuel supply port 2. The fuel filter 13 is a member for removing foreign matter that has become mixed in the fuel.

[0018] An O-ring 11 is disposed at the base end of the cylindrical body 5. The O-ring 11 functions as a sealant when the fuel injection valve 1 is connected to a fuel pipe.

[0019] The valve portion 7, which is composed of a valve body 17 and a valve seat member 15, is formed at the tip of the cylindrical body 5. A stepped valve body accommodating hole 15a is formed in the valve seat member 15 to accommodate the valve body 17. A conical surface is formed in the middle of the valve body accommodating hole 15a, and a valve seat (seal portion) 15b is formed on this conical surface. A guide surface 15c is formed in the portion of the valve body accommodating hole 15a upstream (base end side) of the valve seat 15b, which guides the movement of the valve body 17 in the direction along the central axis 1a. The valve seat 15b and the valve body 17 cooperate to open and close the fuel passage. The fuel passage is closed when the valve body 17 abuts against the valve seat 15b. The fuel passage is opened when the valve body 17 moves away from the valve seat 15b.

[0020] The valve seat member 15 is inserted into the inside of the tip side of the cylindrical body 5 and fixed to the cylindrical body 5 by laser welding. Laser welding 19 is performed from the outer periphery side of the cylindrical body 5 around the entire circumference. The valve body accommodating hole 15a penetrates the valve seat member 15 in the direction along the central axis 1a. A nozzle plate 21n is attached to the lower end surface (tip surface) of the valve seat member 15. The nozzle plate 21n is attached so as to close the opening of the valve seat member 15 formed by the valve body accommodating hole 15a.

[0021] In this embodiment, the valve seat member 15 and the nozzle plate 21n constitute the fuel injection unit 21 that injects swirling fuel. The nozzle plate 21n is fixed to the valve seat member 15 by laser welding. The laser welded portion 23 goes around the periphery of the injection hole formation region in which the fuel injection holes 220-1, 220-2, 220-3, and 220-4 (see FIG. 3A) are formed so as to surround the injection hole formation region. The valve seat member 15 may be press-fitted into the inside of the tip end side of the cylindrical body 5 and then fixed to the cylindrical body 5 by laser welding.

[0022] In this embodiment, the valve body 17 is a ball valve having a spherical shape. Therefore, a plurality of cutout surfaces 17a are provided at intervals in the circumferential direction at a portion of the valve body 17 facing the guide surface 15c. The cutout surfaces 17a form gaps between the inner peripheral surface of the plate seat member 15. This gap forms a fuel passage. It is possible to form the valve body 17 with a valve other than a ball valve. For example, a needle valve may be used.

[0023] In this embodiment, the valve portion 7 including the valve seat member 15 and the valve body 17 and the nozzle plate 21n constitute a nozzle portion for injecting fuel. The nozzle plate 21n, in which fuel injection holes 220-1, 220-2, 220-3, 220-4 and swirl passages 210-1, 210-2, 210-3, 210-4 are formed, is joined to the tip surface on the nozzle portion main body (valve seat member 15) side where the valve portion 7 is constituted. The swirl passages 210-1, 210-2, 210-3, 210-4 are constituted by lateral passages 211-1, 211-2, 211-3, 211-4 and swirl chambers 212-1, 212-2, 212-3, 212-4.

[0024] A driving unit 9 for driving the valve body 17 is disposed in the middle of the cylindrical body 5. The driving unit 9 is composed of an electromagnetic actuator. Specifically, the driving unit 9 is composed of a fixed core 25, a movable element (movable member) 27, an electromagnetic coil 29, and a yoke 33.

[0025] The fixed core 25 is made of a magnetic metal material, and is press-fitted and fixed inside the longitudinal middle part of the cylindrical body 5. The fixed core 25 is formed in a cylindrical shape, and has a through hole 25a that passes through the center in the direction along the central axis 1a. The fixed core 25 may be fixed to the cylindrical body 5 by welding, or may be fixed to the cylindrical body 5 by a combination of welding and press-fitting.

[0026] The movable element 27 is disposed inside the cylindrical body 5 on the tip side of the fixed core 25. The movable element 27 has a movable core 27a at the base end side. The movable core 27a faces the fixed core 25 with a minute gap δ therebetween. A small diameter portion 27b is formed at the tip side of the movable element 27, and the valve body 17 is fixed to the tip of the small diameter portion 27b by welding. In this embodiment, the movable core 27a and the connection portion 27b are integrally formed (as one member made of the same material), but they may be formed by joining two members. The movable element 27 has a valve body 17 at its tip and displaces the valve body 17 in the valve opening / closing direction. The valve body 17 contacts the guide surface 15c of the valve seat member 15, and the outer peripheral surface of the movable core 27a contacts the inner peripheral surface of the cylindrical body 5, so that the movement of the movable element 27 in the direction along the central axis 1a (valve opening / closing direction) is guided at two points in the valve axis direction.

[0027] A recess 27c is formed in the end surface of the movable core 27a facing the fixed core 25. A spring seat 27e for a spring (coil spring) 39 is formed in the bottom surface of the recess 27c. A through hole 27f is formed on the inner periphery of the spring seat 27e, penetrating along the central axis 1a to the tip end of the small diameter portion (connection portion) 27b. An opening 27d is formed on the side surface of the small diameter portion 27b. The through hole 27f opens on the bottom surface of the recess 27c, and the opening 27d opens on the outer periphery surface of the small diameter portion 27b, thereby forming a fuel flow path 3 that communicates between the fuel passage 3 formed in the fixed core 25 and the valve portion 7.

[0028] The electromagnetic coil 29 is fitted around the outer periphery of the cylindrical body 5 at a position where the fixed core 25 and the movable core 27a face each other with a minute gap δ between them. The electromagnetic coil 29 is wound around a bobbin 31 formed in a cylindrical shape from a resin material, and fitted around the outer periphery of the cylindrical body 5. The electromagnetic coil 29 is electrically connected to a connector pin 43 provided on a connector 41 via a wiring member 45. A drive circuit (not shown) is connected to the connector 41, and a drive current is applied to the electromagnetic coil 29 via the connector pin 43 and the wiring member 45.

[0029] The yoke 33 is made of a magnetic metal material. The yoke 33 is disposed on the outer periphery side of the electromagnetic coil 29 so as to cover the electromagnetic coil 29, and also serves as a housing for the fuel injection valve 1. The lower end of the yoke 33 faces the outer periphery of the movable iron core 27a via the cylindrical body 5, and together with the movable iron core 27a and the fixed iron core 25, forms a closed magnetic circuit through which magnetic flux generated by energizing the electromagnetic coil 29 flows.

[0030] A coil spring 39 is disposed in a compressed state across the through hole 25a of the fixed core 25 and the recess 27c of the movable core 27a. The coil spring 39 functions as a biasing member that biases the movable element 27 in a direction in which the valve body 17 abuts against the valve seat 15b (valve closing direction). An adjuster (adjuster) 35 is disposed inside the through hole 25a of the fixed core 25, and the base end of the coil spring 39 abuts against the tip end face of the adjuster 35. The biasing force of the coil spring 39 on the movable element 27 (i.e., the valve body 17) is adjusted by adjusting the position of the adjuster 35 within the through hole 25a in the direction along the central axis 1a.

[0031] Adjuster 35 has a fuel flow passage 3 penetrating the center in the direction along central axis 1a. After flowing through fuel flow passage 3 in adjuster 35, fuel flows to fuel flow passage 3 in the tip side portion of through hole 25a of fixed core 25, and then flows to fuel flow passage 3 formed in movable member 27.

[0032] An O-ring 46 is fitted onto the tip of the cylindrical body 5. The O-ring 46 functions as a seal to ensure liquid-tightness and air-tightness between the inner peripheral surface of an insertion port 109a (see FIG. 10) formed on the internal combustion engine side and the outer peripheral surface of the yoke 33 when the fuel injection valve 1 is attached to the internal combustion engine.

[0033] A resin cover 47 is molded to cover the fuel injection valve 1 from the middle portion to the vicinity of the base end portion. The tip end portion of the resin cover 47 covers a part of the base end portion of the yoke 33. The resin cover 47 also covers the wiring member 45, and the connector 41 is integrally formed with the resin cover 47.

[0034] Next, the operation of the fuel injection valve 1 will be described.

[0035] When the electromagnetic coil 29 is not energized (i.e., no driving current flows), the movable element 27 is biased in the valve closing direction by the coil spring 39, and the valve element 17 is in contact (seated) with the valve seat 15b. In this case, a gap δ exists between the tip end face of the fixed core 25 and the base end face of the movable core 27a. In this embodiment, this gap δ is equal to the stroke of the movable element 27 (i.e., the valve element 17).

[0036] When the electromagnetic coil 29 is energized and a driving current flows, a magnetic flux is generated in a closed magnetic circuit formed by the movable core 27a, the fixed core 25, and the yoke 33. This magnetic flux generates a magnetic attraction force between the fixed core 25 and the movable core 27a, which face each other across the gap δ. When this magnetic attraction force overcomes the resultant force of the coil spring 39 and the fuel pressure acting on the movable core 27 in the valve closing direction, the movable core starts to move in the valve opening direction. When the valve body 17 moves away from the valve seat 15b, a gap (fuel flow path) is formed between the valve body 17 and the valve seat 15b, and fuel injection begins. In this embodiment, when the movable core 27 moves a distance δ equal to the gap δ in the valve opening direction and the movable core 27a abuts against the fixed core 25, the movable core 27a stops moving in the valve opening direction and opens and reaches a stationary state.

[0037] When the power supply to the electromagnetic coil 29 is cut off, the magnetic attractive force decreases and eventually disappears. When the magnetic attractive force decreases and becomes smaller than the biasing force of the coil spring 39, the movable element 27 starts to move in the valve closing direction. When the valve element 17 abuts against the valve seat 15b, the valve element 17 closes the valve portion 7 and comes to a stationary state.

[0038] Next, the structures of the valve portion 7 and the fuel injection portion 21 will be described in detail with reference to Figures 2 and 3A. Figure 2 is an enlarged cross-sectional view (corresponding to the cross-section taken along the line II-II in Figures 3A and 3B) showing the vicinity (nozzle portion) of the valve portion 7 and the fuel injection portion 21 of the fuel injection valve 1 in Figure 1. Figure 3A is a plan view of the nozzle plate 21n as viewed from the direction of the arrows III-III in Figure 1.

[0039] 3A is a plan view of the nozzle plate 21n as viewed from the inlet side of the fuel injection holes, and is a plan view of the upper end surface 21nu side of the nozzle plate 21n. A y0-x0 coordinate system is defined on the upper end surface 21nu of the nozzle plate 21n, which has mutually orthogonal y0 and x0 axes and has the center 21no of the nozzle plate 21n as the origin. The upper end surface 21nu is a surface that faces the tip surface 15t of the valve seat member 15. The end surface opposite to the upper end surface 21nu is called the lower end surface 21nb.

[0040] In this embodiment, as shown in Fig. 2, the nozzle plate 21n is made of a plate-like member with both end faces formed as flat surfaces, and the upper end face 21nu and the lower end face 21nb are parallel to each other. That is, the nozzle plate 21n is made of a flat plate with a uniform thickness. In this embodiment, as shown in Fig. 3A, the fuel injection valve 1 is configured so that the central axis 1a intersects with the nozzle plate 21n at the center 21no.

[0041] The tip surface (lower end surface) 15t of the valve seat member 15 is configured as a flat surface (flat surface) perpendicular to the central axis 1a. The nozzle plate 21n is joined to the tip surface 15t of the valve seat member 15, and the tip surface 15t abuts against the upper end surface 21nu of the nozzle plate 21n.

[0042] As shown in Fig. 3A, the nozzle plate 21n is formed with lateral passages 211-1, 211-2, 211-3, 211-4, swirl chambers 212-1, 212-2, 212-3, 212-4, and fuel injection holes 220-1, 220-2, 220-3, 220-4. The lateral passages 211-1, 211-2, 211-3, 211-4 and the swirl chambers 212-1, 212-2, 212-3, 212-4 form swirl passages 210-1, 210-2, 210-3, 210-4 for imparting a swirling force to the fuel upstream of the fuel injection holes 220-1, 220-2, 220-3, 220-4. The four sets of swirl passages 210-1, 210-2, 210-3, 210-4 and fuel injection holes 220-1, 220-2, 220-3, 220-4 are configured similarly, and therefore may not be differentiated and may be described as the swirl passage 210, the lateral passage 211, the swirl chamber 212, and the fuel injection hole 220. When the configuration of each set is changed, the description will be given appropriately.

[0043] 2, the valve seat member 15 is formed with a conical valve seat surface 15b whose diameter decreases toward the downstream side. The downstream end of the valve seat surface 15b is connected to a fuel introduction hole 300. The downstream end of the fuel introduction hole 300 opens to a tip end surface 15t of the valve seat member 15. The fuel introduction hole 300 constitutes a fuel passage that introduces fuel into the swirl passage 210.

[0044] In order to receive fuel from the fuel inlet hole 300, the swirl passage 210 has upstream ends of the lateral passages 211 arranged to face the opening surface of the fuel inlet hole 300. In this embodiment, as shown in Fig. 3, the upstream ends of the four sets of lateral passages 211-1, 211-2, 211-3, 211-4 are connected to each other, but the lateral passages 211-1, 211-2, 211-3, 211-4 may be independent from each other.

[0045] 2, the lateral passages 211, the swirl chamber 212, and the fuel injection holes 220 are all formed in the nozzle plate 21n, which is made up of a single plate-like member. The nozzle plate 21n can be made up of multiple plates, for example, by dividing it in the thickness direction. For example, the lateral passages 211 and the swirl chamber 212 are formed in one plate, and the fuel injection holes 220 are formed in another plate. These two plates may then be stacked to form the nozzle plate 21n.

[0046] 2, the fuel injection holes 220 are formed parallel to the central axis 1a, but may be inclined at an angle greater than 0° with respect to the central axis 1a. By varying the inclination direction, fuel may be injected in a plurality of directions.

[0047] In this embodiment, the nozzle plate 21n is configured with a total of four fuel passages, each consisting of a swirl passage 210 and a fuel injection hole 220. Each of the four fuel passages is formed from the center 21no side of the nozzle plate 21n toward the outer periphery. That is, the lateral passage 211 is provided from the center 21no side of the nozzle plate 21n toward the outer periphery, and a bent passage portion is provided midway. Furthermore, each fuel passage is formed at an angular interval of 90° in the circumferential direction.

[0048] The number of pairs of the swirl passage 210 and the fuel injection holes 220 is not limited to four, but may be two, three, or five or more. Alternatively, the number of pairs of the swirl passage 210 and the fuel injection holes 220 may be only one.

[0049] FIG. 3B is a plan view showing a modified example of the nozzle plate 21n, as seen from the direction of the arrows III-III in FIG.

[0050] In Fig. 3A, the inner peripheral wall of the swirl chamber 212 is formed with the same radius all around. In contrast, Fig. 3B shows a modified example in which the radius of the inner peripheral wall of the swirl chamber 212 decreases from the upstream side to the downstream side. The inner peripheral wall of the swirl chamber 212 is not limited to the configuration in Fig. 3A, and may be configured as shown in Fig. 3B.

[0051] The features of the inner peripheral wall of the swirl chamber 212 in FIGS. 3A and 3B will be described in detail in FIG.

[0052] The configurations of the swirl chamber 212 and the fuel injection holes 220 will be described in detail with reference to Fig. 4. Fig. 4 is an enlarged plan view showing the swirl chamber 212 and the fuel injection holes 220 (an enlarged plan view of part IV shown in Figs. 3A and 3B).

[0053] First, the configuration shown in Fig. 3A will be described. In Fig. 4, a y1-x1 coordinate system is defined, which has a y1 axis and an x1 axis perpendicular to each other and has the center O2 of the inlet opening 220i of the fuel injection hole 220 as its origin. In this embodiment, since the center O2 of the inlet opening 220i of the fuel injection hole 220 coincides with the center O1 of the swirl chamber 212, the origin of the y1-x1 coordinate system coincides with the center O1 of the swirl chamber 212. The x1 axis coincides with the side wall 211i and its extension 211il.

[0054] The lateral passage 211 is connected to the swirl chamber 212 so as to be offset with respect to the center O1 of the swirl chamber 212. One side wall 211o of the lateral passage 211 is connected to an inner circumferential wall portion (start end portion of the inner circumferential wall, upstream end portion) 212cs located upstream in the flow direction of the swirling fuel, and the other side wall 211i is connected to an inner circumferential wall portion (terminal end portion of the inner circumferential wall, downstream end portion) 212ce located downstream. For this reason, an opening 212co is formed in the inner circumferential wall (side wall) 212c of the swirl chamber 212 at the connection portion of the lateral passage 211.

[0055] An inner circumferential wall 212c of the swirl chamber 212 is formed to form a circle around the inlet opening 220i of the fuel injection hole 220 so as to swirl the fuel that has flowed into the swirl chamber 212 from the lateral passage 211. That is, a swirl flow path (swirl passage) 212d for fuel is formed between the inner circumferential wall 212c of the swirl chamber 212 and the inlet opening 220i of the fuel injection hole 220.

[0056] The nozzle plate 21n defines side walls (side surfaces) 211o, 211i and a bottom surface 211b of the lateral passage 211. The upper surface (ceiling surface) 211u (see FIG. 2) of the lateral passage 211 defines a lower end surface 15t of the valve seat member 15.

[0057] A side wall 211o of the lateral passage 211 is connected to the swirl chamber 212 at an angle tangent to an inner circumferential wall 212c of the swirl chamber 212. A downstream end of the side wall 211o is connected to a start end 212cs of the inner circumferential wall 212c of the swirl chamber 212.

[0058] Further, the side wall 211i of the lateral passage 211 is connected to the swirl chamber 212 at an angle intersecting with the inner circumferential wall 212c of the swirl chamber 212 or its extension. Here, intersecting means that the side wall 211i and its extension cross the inner circumferential wall 212c or its extension. The downstream end of the side wall 211i is connected to a terminal end 212ce of the inner circumferential wall 212c of the swirl chamber 212. In this embodiment, the extension of the inner circumferential wall 212c coincides with a two-dot chain line representing the opening 212co of the swirl chamber 212.

[0059] A starting end 212cs of the inner circumferential wall 212c of the swirl chamber 212 is an end located on the upstream side in the swirl direction of the fuel. A terminal end 212ce of the inner circumferential wall 212c is an end located on the downstream side in the swirl direction of the fuel. The terminal end 212ce may be formed with a chamfered portion such as an inclined portion or a rounded portion. In such a case, the terminal end (downstream end) 212ce may be determined as the intersection point of two virtual lines (extension lines) extending from the inner circumferential wall 212c and the side wall 211i to the terminal end 212ce.

[0060] In this embodiment, the inner circumferential wall 212c between the start end 212cs and the end end 212ce of the swirl chamber 212 is formed to have a circular arc shape with a constant radius R centered at O1. That is, the inner circumferential wall 212c is formed of a part of a circumference of a perfect circle or a circle. On the other hand, the inlet opening 220i of the fuel injection hole 220 forms a circle with a radius r smaller than the radius R of the inner circumferential wall 212c of the swirl chamber 212. As a result, the bottom surface 212b of the swirl flow passage 212d is formed between the inlet opening edge 220ic of the fuel injection hole 220 and the inner circumferential wall 212c of the swirl chamber 212. Note that when the central axis 220a (see FIG. 2) of the fuel injection hole 220 is inclined with respect to the bottom surface 212b, even if the cross section of the fuel injection hole 220 is circular, the inlet opening 220i is not circular but elliptical. In this embodiment, regardless of whether or not the fuel injection hole 220 is inclined, the central axis 220a (see FIG. 2) of the fuel injection hole 220 passes through the center O2 of the inlet opening 220i.

[0061] Fig. 4 is a plan view, showing the fuel injection hole 220, the swirl chamber 212, and the lateral passage 211 projected onto a virtual plane (projection plane) perpendicular to the central axis 1a of the fuel injection valve 1. Fig. 4 also shows an extension line (first extension line) 211ol of a side wall 211o of the lateral passage 211 and an extension line (second extension line) 211il of a side wall 211i projected onto the virtual plane (projection plane). The first extension line 211ol is a virtual line extended along the side wall 211o. The second extension line 211il is a virtual line extended along the side wall 211i.

[0062] The second extension line 211il divides the bottom surface of the swirl chamber 212 (bottom surface 212b of the swirl flow path 212d) into two regions A1 and A2. Region A1 is a region located on the side wall 211o or its extension line 211ol side with respect to the second extension line 211il. The starting end 212cs of the inner circumferential wall 212c is in region A1. Region A2 is a region located on the opposite side of the second extension line 211il from the side wall 211o or its extension line 211ol side. Region A2 is formed by the swirl flow path portion on the terminal end 212ce side of the inner circumferential wall 212c. Note that regions A1 and A2 do not include the area on the second extension line 211il.

[0063] The fuel injection hole 220 is arranged such that a part of the inlet opening edge 220ic extends beyond the second extension line 211il and into the region A1. That is, a part of the inlet opening 220i of the fuel injection hole 220 opens to the region A1 side and is located on the extension of the lateral passage 211. If the area of ​​the bottom surface 212b of the swirl chamber 212 located between the second extension line 211il and the side wall 211o or its extension line 211ol is regarded as the bottom surface 211b of the lateral passage 211, a part of the inlet opening 220i of the fuel injection hole 220 is located on the bottom surface 211b of the lateral passage 211. With this configuration, the cross-sectional shape of the fuel spray injected from the fuel injection hole 220 becomes a shape that is deformed from a circle to a flat shape. In this embodiment, the cross-sectional shape of the fuel spray is an ellipse having a major axis and a minor axis.

[0064] In the following description, the cross section and cross-sectional shape of the fuel spray refer to the cross section and cross-sectional shape perpendicular to the injection direction, and may be referred to as the perpendicular cross section and the perpendicular cross-sectional shape when expressing particularly clearly. In this embodiment, the fuel spray (whole spray) injected from the multiple fuel injection holes 220 will be described as being injected in a direction along the central axis 1a of the fuel injection valve 1.

[0065] In this embodiment, the center O2 of the inlet opening 220i of the fuel injection hole 220 is located on the second extension line 211il. Therefore, the inlet opening 220i of the fuel injection hole 220 extends beyond the second extension line 211il by the radius r of the fuel injection hole 220 toward the region A1 side. Therefore, the inlet opening edge 220ic of the fuel injection hole 220 intersects with the second extension line 211il at two points 220ia and 220ib. That is, the inlet opening 220i of the fuel injection hole 220 is disposed so that the second extension line 211il intersects with the inlet opening edge 220ic at two points 220ia and 220ib. Note that the amount of extension of the inlet opening 220i toward the region A1 side is not limited to the size of the radius r of the fuel injection hole 220. This amount of extension may be larger or smaller than the radius r. By changing the amount of extension, the shape and size of the spray cross section (spray distribution) can be changed.

[0066] Furthermore, the center O2 of the inlet opening 220i of the fuel injection hole 220 may be disposed at a position shifted from the center O1 of the swirl chamber 212 in the direction along the second extension line 211il. In other words, the center O2 of the inlet opening 220i of the fuel injection hole 220 may be eccentric with respect to the center O1 of the swirl chamber 212. By changing the amount of eccentricity, the shape and size of the spray cross section (spray distribution) can be changed.

[0067] In this embodiment, the side walls 211o and 211i of the lateral passage 211 are formed in parallel, and the width of the lateral passage 211 is constant. Displacing the center O2 of the inlet opening 220i of the fuel injection hole 220 from the center O1 of the swirl chamber 212 in the direction along the second extension line 211il means displacing the center O2 in the direction along the center line L3 of the lateral passage 211.

[0068] In this embodiment, the inner circumferential wall 212c of the swirl chamber 212 is not limited to having a constant radius R. As shown in the modified example of FIG. 3B, the inner circumferential wall 212c of the swirl chamber 212 may have a shape in which R decreases from the upstream side to the downstream side in the swirl direction of the fuel. In the modified example of FIG. 3B, the inner circumferential wall 212c of the swirl chamber 212 has an upstream portion shaped as shown by the broken line 212c', and is configured as an arc with a larger radius than the downstream portion. As a result, the inner circumferential wall 212c of the swirl chamber 212 is configured with an arc portion with a radius R (a portion above the second extension line 211il) and an arc portion with a radius larger than R (a portion of the broken line 212c'), and is configured with a shape in which the radius decreases from the upstream side to the downstream side in the swirl direction of the fuel.

[0069] In this case, the side wall 211o of the lateral passage 211 is disposed as shown by the dashed line 211o', and is connected to the inner peripheral wall 212c' at a point 212cs'.

[0070] In the modification example of FIG. 3B, a shape in which the radius decreases in two stages from the upstream side to the downstream side in the fuel swirling direction has been described. However, the inner circumferential wall 212c may have, for example, a spiral shape in which the radius gradually decreases continuously from the upstream side to the downstream side.

[0071] The configuration of the lateral passages 211 of the swirl passage 210 will be described with reference to Fig. 5. Fig. 5 is a plan view of the swirl passage 210 when the upper end surface of the nozzle plate 21n in which the swirl passage 210 is formed is viewed from above. In this embodiment, the above-mentioned four sets of swirl passages 210-1 to 210-4 are formed in the same manner, and therefore, as described above, the four sets of swirl passages 210-1 to 210-4 will not be distinguished from each other and will be described as the swirl passage 210.

[0072] The lateral passage 211 is provided with a curved passage section 2113 midway as it extends from the center 21no side of the nozzle plate 21n to the outer periphery side. That is, the lateral passage 211 includes a straight section (inner circumference side straight section) 2111 formed on the center 21no side of the nozzle plate 21n, a straight section (outer circumference side straight section) 2112 formed on the outer periphery side, and a curved passage section 2113 formed between the inner circumference side straight section 2111 and the outer circumference side straight section 2112.

[0073] The inner circumference side passage portion 2111 is disposed on the inner circumference side of the nozzle plate 21n and extends radially outward. The outer circumference side passage portion 2112 extends in a direction inclined with respect to the inner circumference side passage portion 2111 so that a connection portion with the swirl chamber 212 is located radially inward, compared to a case in which the inner circumference side passage portion 2111 extends radially outward as it is. The curved passage portion 2113 is provided between the inner circumference side passage portion 2111 and the outer circumference side passage portion 2112.

[0074] That is, the lateral passage 211 includes an inner circumference-side passage portion 2111 that is disposed on the inner circumference side and extends radially outward, and an outer circumference-side passage portion 2112 that extends in a direction inclined relative to the inner circumference-side passage portion 2111 so that a connection portion with the swirl chamber 212 is located radially inward compared to a case in which the inner circumference-side passage portion 2111 extends radially outward as it is, The curved passage portion 2113 is provided between the inner circumference side passage portion 2111 and the outer circumference side passage portion 2112 .

[0075] In this case, the swirl chamber 212 is disposed so as to protrude radially outward relative to the outer periphery side passage portion 2112 .

[0076] The curved passage portion 2113 changes the extension direction of the outer periphery side straight portion 2112 to a direction inclined from the extension direction of the inner periphery side straight portion 2111. That is, the curved passage portion 2113 changes the extension direction of the outer periphery side straight portion 2112 (axial direction of the central axis 211Ax2) to a direction inclined by an angle θ211 with respect to the extension direction of the inner periphery side straight portion 2111 (axial direction of the central axis 211Ax1). The curved passage portion 2113 may be formed so as to bend the outer periphery side straight portion 2112 from the inner periphery side straight portion 2111, or may be formed so that the outer periphery side straight portion 2112 changes direction gently from the inner periphery side straight portion 2111. In other words, the curved center line 211Ax3 may be provided near the intersection 211x where the central axis 211Ax1 and the central axis 211Ax2 intersect.

[0077] 4, the swirl passage 210 portion from the outer periphery straight portion 2112 to the swirl chamber 212 and the fuel injection hole 220 side is depicted, and the central axis 211Ax2 in FIG. 5 corresponds to the center line L3 of the lateral passage 211 in FIG.

[0078] The form of the fuel spray injected from the swirl passage 210 in this embodiment will be described with reference to Fig. 6. Fig. 6 is a conceptual diagram showing the form of the fuel spray injected from the swirl passages 210-1 to 210-4. Fig. 6 shows a cross section of the fuel spray perpendicular to the injection direction of the whole spray SPH (in this embodiment, the axial direction of the central axis 1a of the fuel injection valve 1).

[0079] The fuel spray SPS1 is injected from the swirl passage 210-1, the fuel spray SPS2 is injected from the swirl passage 210-2, the fuel spray SPS3 is injected from the swirl passage 210-3, and the fuel spray SPS4 is injected from the swirl passage 210-4.

[0080] The cross-sectional shape of the fuel sprays SPS1 to SPS4 injected from each of the swirl passages 210-1 to 210-4 is a flat shape having a major axis Ax1 and a minor axis Ax2, and is generally an elliptical shape having a major axis Ax1 and a minor axis Ax2, as described in FIG. 11C. A fuel spray having a cross-sectional shape that is deviated from a circle, including an elliptical shape, is called a deflected spray. In this embodiment, the deflected spray may also include a shape other than an elliptical shape. In the following description, a fuel spray having an elliptical spray cross section will be described as a deflected spray.

[0081] The orientation of the major axis Ax1 and the minor axis Ax2 of the elliptical fuel spray is determined by the positional relationship between the lateral passages 211-1 to 211-4 and the swirl chambers 212-1 to 212-4 connected to the lateral passages 211-1 to 211-4. That is, in this embodiment, the positional relationship between the lateral passages 211-1 to 211-4 and the swirl chambers 212-1 to 212-4 connected to the lateral passages 211-1 to 211-4 determines the deflection direction of the deflected spray.

[0082] In the arrangement of the lateral passages 211-1 to 211-4 and the swirl chambers 212-1 to 212-4 shown in Fig. 11A, each of the fuel sprays SPS1 to SPS4 is arranged such that one end of the major axis Ax1 is located at the center of the entire spray SPH and the other end is located on the outer periphery side of the entire spray SPH. The cross-sectional shape of the entire spray SPH is substantially circular as shown in Fig. 11C. In this case, the lateral passages 211-1 to 211-4 extend linearly (radially) from the center 21no of the nozzle plate 21n toward the outer periphery as shown in Fig. 11A, and no curved passage portion 2113 is provided between the center 21no of the nozzle plate 21n and the swirl chambers 212-1 to 212-4.

[0083] In this case, the cross-sectional shape and distribution rate of the fuel spray for the entire spray SPH are as shown in Figure 11D. Figure 11D shows the distribution rate of the fuel spray on the spray cross section, and this spray cross section is expressed as a plane whose vertical and horizontal axes correspond to the direction (angle) in which the fuel spray droplets fly.

[0084] In the entire spray SPH, the major axis Ax1 and minor axis Ax2 of the four fuel sprays SPS1 to SPS4 are arranged as shown in Fig. 11C, and the four fuel sprays SPS1 to SPS4 overlap with each other, so that the cross-sectional shape of the entire spray SPH becomes substantially circular. In this case, the four fuel sprays SPS1 to SPS4 overlap with each other at the center of the spray cross section of the fuel spray SPH, so that the distribution rate of the fuel spray is particularly high at the center of the fuel spray cross section, and a fuel spray (entire spray) SPH with a high distribution rate (peak distribution rate) at this center is formed. As a result, the concentration of the fuel spray tends to be higher at the center of the fuel spray cross section.

[0085] On the other hand, in an internal combustion engine, it is sometimes required to inject fuel so that the fuel spray is distributed uniformly within a cross section of the fuel spray.

[0086] In this embodiment, as shown in Figures 3A, 3B, and 5, a curved passage section 2113 is provided in the lateral passage 211, making it possible to change the positional relationship (arrangement) between the lateral passage 211 and the swirl chamber 212 on the nozzle plate 21n.

[0087] That is, the fuel injection valve 1 of this embodiment is a fuel injection valve including a valve seat 15b and a valve body 17 which cooperate to open and close the fuel passage, and a plurality of swirl passages 210 which apply a swirling force to the fuel and inject it on the downstream side of the valve seat 15b and the valve body 17, the swirl passages 210 including a fuel injection hole 220, a swirl chamber 212 which is provided upstream of the fuel injection hole 220 and swirls the fuel, and a lateral passage 211 connected to the swirl chamber 212, The swirl passage 210 sprays deflected sprays SPS1 to SPS4 whose cross-sectional shapes are deviated from a circle, The lateral passage 211 has a curved passage portion 2113 between the upstream end and the downstream end, where the direction of the fuel flow changes.

[0088] This makes it possible to change the arrangement (direction) of the major axis Ax1 and minor axis Ax2 of the fuel spray cross section, and to change the cross-sectional shape of the fuel spray or the distribution rate of fuel on the cross section of the fuel spray.

[0089] In order to explain the positional relationship (arrangement) between the lateral passage 211 and the swirl chamber 212, the direction of the swirl passage 210 is assumed to be as indicated by the arrow AW in Fig. 5. That is, the arrow AW is assumed to be perpendicular to the central axis 211Ax2 and to point in a direction from the center of the fuel injection hole 220 toward the opposite side to the central axis 211Ax2.

[0090] The direction AW of each of the swirl passages 210-1 to 210-4 on the nozzle plate 21n in Figures 3A and 3B is different from the direction AW of each of the swirl passages 210-1 to 210-4 on the nozzle plate 21n in Figure 11A. That is, the inclination of the arrows AW of each of the swirl passages 210-1 to 210-4 with respect to the radial direction in Figures 3A and 3B is different from the inclination of the arrows AW of each of the swirl passages 210-1 to 210-4 with respect to the radial direction in Figure 11A.

[0091] In this embodiment, by providing the lateral passages 211-1 to 211-4 with bent passage portions 2113, the direction AW of each of the swirl passages 210-1 to 210-4 on the nozzle plate 21n, i.e., the positional relationship (arrangement) between the lateral passages 211 and the swirl chamber 212 with respect to the nozzle plate 21n, is changed, and the arrangement of the major axis Ax1 and minor axis Ax2 of the fuel sprays SPS1 to SPS4 with respect to the nozzle plate 21n is changed. This changes the arrangement of the major axis Ax1 and minor axis Ax2 of the fuel sprays SPS1 to SPS4 in the entire spray SPH.

[0092] In this embodiment, as shown in FIG. 6, the fuel sprays SPS1 to SPS4 are arranged so that their major axes Ax1 are aligned along the circumferential direction (outer edge direction) of the circular whole spray SPH, and their minor axes Ax2 are aligned along the radial direction of the circular whole spray SPH.

[0093] In particular, in this embodiment, the swirl passages 210-1 to 210-4, including the curved passage portion 2113, are formed in the same shape and arranged at equal intervals in the circumferential direction, so that the two fuel sprays SPS1 and SPS3 are arranged point-symmetrically with respect to the center a0 of the entire spray SPH, and the two fuel sprays SPS2 and SPS4 are arranged point-symmetrically with respect to the center a0. In addition, the two fuel sprays SPS1 and SPS3 and the two fuel sprays SPS4 and SPS3 are arranged line-symmetrically with respect to a line segment passing through the center a0, points a8 and a6. In addition, the two fuel sprays SPS1 and SPS4 and the two fuel sprays SPS2 and SPS3 are arranged line-symmetrically with respect to a line segment passing through the center a0, points a5 and a7. Here, the points a5 to a8 are intersections where the major axes Ax1 of the fuel sprays SPS1 to SPS4 intersect, as described later.

[0094] The features of the fuel sprays SPS1 to SPS4 of this embodiment shown in FIG. 6 will be described below.

[0095] (1) Each of the fuel sprays SPS1 to SPS4 intersects with the longitudinal axis Ax1 of an adjacent fuel spray at both ends of the longitudinal axis Ax1. Note that in the following description, the terms "one side" and "the other side" used to refer to both ends of the longitudinal axis Ax1 do not always refer to the ends on the same side, but will be interchangeable in each description.

[0096] That is, one end side of the long axis Ax1 of the fuel spray SPS1 intersects with one end side of the long axis Ax1 of the fuel spray SPS2, and the other end side of the long axis Ax1 of the fuel spray SPS1 intersects with one end side of the long axis Ax1 of the fuel spray SPS4. The long axis Ax1 of the fuel spray SPS1 and the long axis Ax1 of the fuel spray SPS2 intersect at intersection a5, and the long axis Ax1 of the fuel spray SPS1 and the long axis Ax1 of the fuel spray SPS4 intersect at intersection a8, and the intersection a5 and the intersection a8 are located on the outer edge side of the fuel spray SPS1, sandwiching the center a1 (intersection point of the long axis Ax1 and the short axis Ax2) of the fuel spray SPS1 in the axial direction of the long axis Ax1.

[0097] One end side of the major axis Ax1 of the fuel spray SPS2 intersects with one end side of the major axis Ax1 of the fuel spray SPS3, and the other end side of the major axis Ax1 of the fuel spray SPS2 intersects with one end side of the major axis Ax1 of the fuel spray SPS1. The major axis Ax1 of the fuel spray SPS2 and the major axis Ax1 of the fuel spray SPS3 intersect at intersection a6, and the major axis Ax1 of the fuel spray SPS2 and the major axis Ax1 of the fuel spray SPS1 intersect at intersection a5, and the intersection a6 and the intersection a5 are located on the outer edge side of the fuel spray SPS2, sandwiching the center a2 (intersection of the major axis Ax1 and minor axis Ax2) of the fuel spray SPS2 in the axial direction of the major axis Ax1.

[0098] One end side of the major axis Ax1 of the fuel spray SPS3 intersects with one end side of the major axis Ax1 of the fuel spray SPS4, and the other end side of the major axis Ax1 of the fuel spray SPS3 intersects with one end side of the major axis Ax1 of the fuel spray SPS2. The major axis Ax1 of the fuel spray SPS3 and the major axis Ax1 of the fuel spray SPS4 intersect at intersection a7, and the major axis Ax1 of the fuel spray SPS3 and the major axis Ax1 of the fuel spray SPS2 intersect at intersection a6, and the intersection a7 and the intersection a6 are located on the outer edge side of the fuel spray SPS3, sandwiching the center a3 (intersection of the major axis Ax1 and minor axis Ax2) of the fuel spray SPS3 in the axial direction of the major axis Ax1.

[0099] One end side of the long axis Ax1 of the fuel spray SPS4 intersects with one end side of the long axis Ax1 of the fuel spray SPS1, and the other end side of the long axis Ax1 of the fuel spray SPS4 intersects with one end side of the long axis Ax1 of the fuel spray SPS3. The long axis Ax1 of the fuel spray SPS4 and the long axis Ax1 of the fuel spray SPS1 intersect at intersection a8, and the long axis Ax1 of the fuel spray SPS4 and the long axis Ax1 of the fuel spray SPS3 intersect at intersection a7, and the intersection a8 and the intersection a7 are located on the outer edge side of the fuel spray SPS4, sandwiching the center a4 (intersection of the long axis Ax1 and short axis Ax2) of the fuel spray SPS4 in the axial direction of the long axis Ax1.

[0100] 6, the intersection a5 is located closer to the outer edge of the fuel spray SPS1 than the center a1 of the fuel spray SPS1 in the axial direction of the major axis Ax1, and the intersection a8 is located closer to the outer edge of the fuel spray SPS1 than the center a1 of the fuel spray SPS1 in the axial direction of the major axis Ax1. That is, the intersections a5 and a8 are located closer to the outer edge of the fuel spray SPS1 than the midpoints a9 and a10 between the center a1 of the fuel spray SPS1 and the outer edge of the fuel spray SPS1 in the axial direction of the major axis Ax1. The intersections a6 and a5 formed for the fuel spray SPS2, the intersections a7 and a6 formed for the fuel spray SPS3, and the intersections a8 and a7 formed for the fuel spray SPS4 are also located in the same positions as the intersections a5 and a8 formed for the fuel spray SPS1.

[0101] That is, the multiple swirl passages 210 include at least three swirl passages 210-1, 210-2, and 210-4 that spray deflected sprays SPS1, SPS2, and SPS4 having a major axis Ax1 and a minor axis Ax2 in the spray cross section, The three swirl passages 210-1 to 210-3 inject a first deflected spray SPS1 and a second deflected spray SPS2 and a third deflected spray SPS4 adjacent to the first deflected spray SPS1 at both axial ends of the major axis Ax1 of the first deflected spray SPS1, The first deflected spray SPS1, the second deflected spray SPS2 and the third deflected spray SPS4 are The major axis Ax1 of the first deflected spray SPS1 and the major axis Ax1 of the second deflected spray SPS2 intersect at a first intersection point a5, The major axis Ax1 of the first deflected spray SPS1 and the major axis Ax1 of the third deflected spray SPS4 intersect at a second intersection point a8, the first intersection point a5 is located on one end side of the long axis Ax1 of the first deflected spray SPS1, and is located closer to the outer edge of the first deflected spray SPS1 than the center a1 of the long axis Ax1 of the first deflected spray SPS1 in the axial direction of the long axis Ax1 of the first deflected spray SPS1, The second intersection point a8 is located on the other end side of the long axis Ax1 of the first deflected spray SPS1, and is sprayed so as to have a spray cross-section that is located closer to the outer edge of the first deflected spray SPS1 than the center a1 of the long axis Ax1 of the first deflected spray SPS1 in the axial direction of the long axis Ax1 of the first deflected spray SPS1.

[0102] (2) The distance D2 between the intersection a5 on the major axis Ax1 of the fuel spray SPS1 and the outer edge of the entire spray SPH, and the distance D3 between the intersection a8 on the major axis Ax1 of the fuel spray SPS1 and the outer edge of the entire spray SPH are shorter than the distance D1 between the center a1 of the fuel spray SPS1 and the outer edge of the entire spray SPH. The fuel sprays SPS2 to SPS4 have the same configuration as the fuel spray SPS1.

[0103] The outer edge of the entire spray SPH is an envelope that is tangent to the fuel sprays SPS1 to SPS4, and may differ from a contour that faithfully follows the outer edge of each of the fuel sprays SPS1 to SPS4.

[0104] (3) When the major axes Ax1 of two circumferentially adjacent fuel sprays SPS1 to SPS4 begin to intersect, their intersection points a5 to a8 are located on the outer edges of the fuel sprays SPS1 to SPS4. In Fig. 6, when the major axis Ax1 of the fuel spray SPS1 begins to intersect with the major axis Ax1 of the fuel spray SPS2, the intersection point between the outer edge of the fuel spray SPS1 and the major axis Ax1 of the fuel spray SPS1 intersects with the intersection point between the outer edge of the fuel spray SPS2 and the major axis Ax1 of the fuel spray SPS2. For this reason, when the major axes Ax1 of the two fuel sprays SPS1, SPS2 begin to intersect, the intersection point a5 is located on the outer edges of the fuel sprays SPS1, SPS2.

[0105] (4) In a state having at least one of the characteristics of (1) to (3), a space is formed in a region including the center a0 of the entire spray SPH where the fuel sprays SPS1 to SPS4 are not present or where the fuel sprays SPS1 to SPS4 are thin.

[0106] That is, the multiple swirl passages 210 include three swirl passages 210-1, 210-2, and 210-4, and are configured as four swirl passages 210-1 to 210-4 that spray deflected sprays having a major axis Ax1 and a minor axis Ax2 in the spray cross section, The first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 sprayed from the four swirl passages 210-1 to 210-4 have a region in the center a0 of the entire spray cross section SPH formed by the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 where the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 do not exist, or where the fuel spray due to the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 is lean.

[0107] FIG. 7A is a conceptual diagram showing the change in shape of the cross section of fuel sprays SPS1, SPS4 injected parallel to the central axis 1a of the fuel injection valve 1 according to the distance (injection distance) L from the fuel injection valve 1 in the fuel injection direction (in the axial direction of the central axis 1a in this embodiment).

[0108] 7A shows schematic cross-sectional shapes of the two fuel sprays SPS1, SPS4 when L=1.0, when the distance is half (L=0.5), and when the distance is twice as long (L=2.0) with the fuel sprays SPS1, SPS4 shown in Fig. 6 taken as the reference (L=1.0). The two fuel sprays SPS1, SPS4 are injected from fuel injection holes 220-1, 220-4 formed parallel to the central axis 1a of the fuel injection valve 1, and the injection directions of the two fuel sprays SPS1, SPS4 are the same and parallel.

[0109] 6, a state in which each of the fuel sprays SPS1 to SPS4 intersects with the major axis Ax1 of the adjacent fuel spray at both ends of the major axis Ax1 has been described. The state of the fuel sprays SPS1 to SPS4 shown in FIG. 6 is realized when L=1.0 in FIG. 7A. However, when L is a distance shorter than 1.0, there is also a state in which the major axes Ax1 of the two adjacent fuel sprays SPS1 and SPS4 do not intersect with each other. On the other hand, when L is a distance longer than 1.0, the intersection a8 between the major axes Ax1 of the two adjacent fuel sprays SPS1 and SPS4 is located closer to the center a1 of the fuel spray SPS1 than the outer edge of the fuel spray SPS1 in the axial direction of the major axis Ax1 of the fuel spray SPS1, and is located closer to the center a4 of the fuel spray SPS4 than the outer edge of the fuel spray SPS4 in the axial direction of the major axis Ax1 of the fuel spray SPS4.

[0110] FIG. 7B is a conceptual diagram illustrating the spray cross sections of the fuel sprays SPS1 to SPS4 in the case of L=2.0 in FIG. 7A.

[0111] As shown in Fig. 7B, when L becomes longer, the four fuel sprays SPS1 to SPS4 overlap at the center a0 of the entire spray SPH. However, even in this case, the fuel distribution rate becomes small within a wide spray cross section where the fuel spray is sufficiently diffused, and the fuel sprays SPS1 to SPS4 overlap with the fuel distribution rate being low, so it is possible to suppress the occurrence of a peak with a high fuel distribution rate as shown in Fig. 11D (see "Reduction of peak distribution rate" in Fig. 8).

[0112] Figure 7C is a conceptual diagram showing the change in shape of the fuel spray cross section for fuel sprays SPS1 and SPS4 injected in directions away from each other, depending on the distance (injection distance) L from the fuel injection valve 1 in the fuel injection direction (in the axial direction of the central axis 1a in this embodiment).

[0113] 7C shows schematic cross-sectional shapes of the two fuel sprays SPS1, SPS4 when L=1.0, when the distance is half (L=0.5), and when the distance is twice as long (L=2.0) with the fuel sprays SPS1, SPS4 shown in Fig. 6 taken as the reference (L=1.0). The two fuel sprays SPS1, SPS4 are assumed to be injected from fuel injection holes 220-1, 220-4 which are inclined with respect to the central axis 1a of the fuel injection valve 1 and which are formed so as to move farther apart as L increases, and the injection directions of the two fuel sprays SPS1, SPS4 are inclined so as to move farther apart downstream.

[0114] In this case, the centers a1 and a4 of the fuel sprays SPS1 and SPS4 become more separated as they move downstream from the fuel injector 1. For this reason, the intersection a8 between the axis Ax1 of the fuel spray SPS1 and the axis Ax1 of the fuel spray SPS4 moves less on the major axis Ax1 compared to the case of Fig. 7A, and becomes less likely to approach the center a1 of the fuel spray SPS1 and the center a4 of the fuel spray SPS4.

[0115] In addition, since the overlap between the fuel sprays SPS1 and SPS4 becomes smaller, a space not including the fuel sprays SPS1 to SPS4 is easily formed in the region including the center a0 of the entire spray SPH. That is, in the case of Fig. 7B, a space not including the fuel sprays SPS1 to SPS4 is formed over a longer distance L in the injection direction than in the case of Fig. 7A.

[0116] 7A, 7B, and 7C, the above-described features (1) to (4) of this embodiment may not be realized depending on the distance L. However, there exists a distance L at which the features (1) to (4) of this embodiment are realized.

[0117] FIG. 8 is a diagram showing the distribution rate of fuel with respect to the fuel sprays SPS1 and SPS4 injected from the swirl passages 210-1 to 210-4.

[0118] In this embodiment, it is possible to prevent the four fuel sprays SPS1 to SPS4 from overlapping at the center a0 of the entire spray SPH, or to allow the fuel sprays SPS1 to SPS4 to overlap with a low fuel distribution rate. Even if the fuel sprays SPS1 to SPS4 overlap, it is possible to prevent the high distribution rate portions from overlapping. This makes it possible to prevent the occurrence of a high fuel distribution rate peak as shown in FIG. 11D and to reduce the peak distribution rate as shown in FIG. 8. Furthermore, it is possible to make the fuel distribution rate in the cross section of the fuel spray more uniform than in the case of FIG. 11C.

[0119] A modification of this embodiment will be described with reference to FIGS.

[0120] 9 is a diagram showing a modified example of the nozzle plate 21n shown in FIG. 3A and FIG. 3B, (a) shows a plan view of the nozzle plate 21n, and (b) is a conceptual diagram showing the form of the fuel spray injected from the swirl passages 210-1 to 210-3. FIG. 12 is a plan view showing the nozzle plate 21n provided with the swirl passages 210-1 to 210-3 as a comparative example to the embodiment of FIG. 9, (a) shows a plan view of the nozzle plate 21n, and (b) is a conceptual diagram showing the form of the fuel spray injected from the swirl passages 210-1 to 210-3 in this modified example. FIG. 9(b) and FIG. 12(b) show a cross section of the fuel spray perpendicular to the injection direction of the whole spray SPH (in this embodiment, the axial direction of the central axis 1a of the fuel injection valve 1).

[0121] Although the configuration having four swirl passages 210-1 to 210-4 has been described so far, the number of swirl passages may be three or two, or five or more swirl passages may be provided. Fig. 9 shows a configuration having three swirl passages 210-1 to 210-3. Configurations similar to those in the above-mentioned embodiment are given the same reference numerals as those in the above-mentioned embodiment, and description thereof will be omitted.

[0122] In the above-described embodiment, the four swirl passages 210-1 to 210-4 are disposed at equal intervals in the circumferential direction, and the central angle between adjacent swirl passages is 90 degrees. In contrast, in this example, the three swirl passages 210-1 to 210-3 are disposed at equal intervals in the circumferential direction, and the central angle between adjacent swirl passages is 120 degrees.

[0123] In this example, since the swirl passage 210-4 does not exist, the long axis Ax1 of the fuel spray SPS1 sprayed from the swirl passage 210-3 intersects with the long axis Ax1 of the fuel spray SPS3 sprayed from the swirl passage 210-3, and the intersection point between the long axis Ax1 of the fuel spray SPS1 and the long axis Ax1 of the fuel spray SPS3 is designated a7.

[0124] The three swirl passages 210-1 to 210-3 in Fig. 9 are provided with bent passage sections 2113-1 to 2113-3 in the lateral passages 211-1 to 211-3, similar to the embodiment described above. In contrast, in the three swirl passages 210-1 to 210-3 in Fig. 12, the lateral passages 211-1 to 211-3 extend linearly (radially) from the center 21no of the nozzle plate 21n to the outer periphery, and bent passage sections 2113-1 to 2113-3 are not provided, similar to the comparative example in Fig. 11A.

[0125] The fuel sprays SPS1 to SPS3 of this example have the same characteristics as the fuel sprays SPS1 to SPS4 of the above-mentioned embodiment. However, since the number of fuel sprays is small, it becomes difficult to form a space without the fuel sprays SPS1 to SPS3 in the region including the center a0 of the entire spray SPH when the major axes Ax1 of two adjacent fuel sprays intersect. However, even in this case, the fuel sprays SPS1 to SPS3 can be made to overlap with each other in a state where the fuel distribution rate of the fuel sprays SPS1 to SPS3 is low because the fuel sprays SPS1 to SPS3 are diffused over a wide cross-sectional area compared to the comparative example shown in FIG. 12. Also, it is possible to prevent the parts with high distribution rates from overlapping.

[0126] This makes it possible to suppress the occurrence of a high peak in the fuel distribution rate as shown in Fig. 11D, thereby reducing the peak distribution rate, and to make the fuel distribution rate in the cross section of the fuel spray more uniform than in the case of Fig. 11C.

[0127] As described above, the fuel injection valve 1 of this embodiment is a fuel injection valve including the valve seat 15b and the valve body 17 which cooperate to open and close the fuel passage, and a plurality of swirl passages 210 which apply a swirling force to the fuel and inject it downstream of the valve seat 15b and the valve body 17, the swirl passages 210 including the fuel injection hole 220, the swirl chamber 212 which is provided upstream of the fuel injection hole 220 and swirls the fuel, and the lateral passage 211 which is connected to the swirl chamber 212, The plurality of swirl passages include at least three swirl passages 210-1, 210-2, and 210-4 that spray a deflected spray having a major axis Ax1 and a minor axis Ax2 in a spray cross section, Compared to a case where the lateral passages 211 of the multiple turning passages 210 are configured as simple linear passages, The first deflected spray SPS1, the second deflected spray SPS2 and the third deflected spray SPS4 injected from the three swirl passages 210-1, 210-2, 210-4 are arranged so as to reduce overlap at the center a0 of the entire spray cross section SPH consisting of the first deflected spray SPS1, the second deflected spray SPS2 and the third deflected spray SPS4, thereby reducing the distribution density of fuel at the center a0.

[0128] In addition, in the fuel injection valve 1 of this embodiment, The multiple swirl passages 210 include three swirl passages 210-1, 210-2, and 210-4, and are configured as four swirl passages 210-1, 210-2, 210-3, and 210-4 that spray deflected sprays having a major axis Ax1 and a minor axis Ax2 in a spray cross section, The first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 sprayed from the four swirl passages 210-1, 210-2, 210-3, 210-4 have a region in the center a0 of the entire spray cross section SPH formed by the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 where the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 do not exist, or where the fuel spray due to the first deflected spray SPS1, the second deflected spray SPS2, the third deflected spray SPS4, and the fourth deflected spray SPS3 is lean.

[0129] An internal combustion engine equipped with a fuel injection valve according to the present invention will be described with reference to Fig. 10. Fig. 10 is a cross-sectional view of an internal combustion engine equipped with a fuel injection valve 1.

[0130] An engine block 101 of an internal combustion engine 100 has a cylinder 102 formed therein, and an intake port 103 and an exhaust port 104 are provided at the top of the cylinder 102. An intake valve 105 for opening and closing the intake port 103 is provided at the intake port 103, and an exhaust valve 106 for opening and closing the exhaust port 104 is provided at the exhaust port 104. An intake pipe 108 is connected to an inlet end 107a of an intake flow passage 107 formed in the engine block 101 and communicating with the intake port 103.

[0131] A fuel pipe 110 is connected to a fuel supply port 2 of the fuel injection valve 1 (see FIG. 1).

[0132] An attachment portion 109 for the fuel injection valve 1 is formed in the intake pipe 108, and an insertion port 109a for inserting the fuel injection valve 1 is formed in the attachment portion 109. The insertion port 109a penetrates to the inner wall surface (intake flow path) of the intake pipe 108, and the fuel injected from the fuel injection valve 1 inserted into the insertion port 109a is injected into the intake flow path. In the case of two-way spray, the target is an internal combustion engine in which two intake ports 103 are provided in the engine block 101, and each fuel spray is injected toward each intake port 103 (intake valve 105).

[0133] The present invention is not limited to the above-mentioned embodiment or modified example, and some of the configurations may be omitted or other configurations not described may be added. It is also possible to combine the configurations of the nozzle plate 21n of the first to seventh embodiments. [Explanation of symbols]

[0134] 1...fuel injection valve, 15b...valve seat, 17...valve body, 210,210-1,210-2,210-3,210-4...swivel passage, 211...lateral passage, 2111... Inner circumference side passage part, 2112...Outer circumference side passage part, 2113...Bending passage part, 212...Swirling chamber, 220...Fuel injection hole, Ax1...Long axis of spray cross section, Ax2...Short axis of spray cross section Axis, a0...Center of the entire spray cross section, a1...Center of the long axis Ax1 of the first deflected spray SPS1, a5...First intersection, a8...Second intersection, SPS1~SPS4...Deflected spray ( fuel spray), SPS1...first deflection spray, SPS2...second deflection spray, SPS4...third deflection spray, SPS3...fourth deflection spray, SPH...entire spray (entire spray cross section).

Claims

1. A fuel injection valve comprising: a valve seat and a valve body which cooperate to open and close a fuel passage; and a plurality of swirl passages which apply a swirling force to fuel and inject it downstream of the valve seat and the valve body, wherein the swirl passages comprise a fuel injection hole, a swirl chamber which is provided upstream of the fuel injection hole and swirls the fuel, and a lateral passage which is connected to the swirl chamber, The swirl passage injects a deflected spray having a cross-sectional shape that deviates from a circular shape, the lateral passage includes an inner-periphery-side passage portion disposed on the inner periphery side and extending radially outward, an outer-periphery-side passage portion extending in a direction inclined with respect to the inner-periphery-side passage portion so that a connection portion with the swirl chamber is located radially inward as compared with a case in which the inner-periphery-side passage portion is extended radially outward as it is, and a curved passage portion provided between the inner-periphery-side passage portion and the outer-periphery-side passage portion and in which a fuel flow direction is changed, The swirl chamber is disposed in the fuel injection valve so as to protrude radially outward from the outer periphery side passage portion.

2. 2. The fuel injection valve according to claim 1, the plurality of swirl passages include at least three swirl passages that inject a deflected spray having a major axis and a minor axis in a spray cross section, The three swirl passages inject a first deflected spray, and a second deflected spray and a third deflected spray adjacent to the first deflected spray at both axial ends of a major axis of the first deflected spray, The first deflected spray, the second deflected spray, and the third deflected spray, The major axis of the first deflected spray and the major axis of the second deflected spray intersect at a first intersection point, The major axis of the first deflected spray and the major axis of the third deflected spray intersect at a second intersection point, the first intersection is located on one end side of the major axis of the first deflected spray, and is located closer to an outer edge of the first deflected spray than to a center of the major axis of the first deflected spray in an axial direction of the major axis of the first deflected spray, A fuel injection valve that injects fuel so as to have a spray cross-section in which the second intersection is located on the other end side of the major axis of the first deflected spray and is located closer to the outer edge of the first deflected spray than to the center of the major axis of the first deflected spray in the axial direction of the major axis of the first deflected spray.

3. 3. The fuel injection valve according to claim 2, the plurality of swirl passages are constituted by four swirl passages including the three swirl passages that spray a deflected spray having a major axis and a minor axis in a spray cross section, The first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray injected from the four swirl passages are such that the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray do not exist in the center of an entire spray cross section composed of the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray, or a lean region of fuel spray due to the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray is present.

4. The fuel injection valve according to claim 1, the plurality of swirl passages include at least three swirl passages that inject a deflected spray having a major axis and a minor axis in a spray cross section, Compared to a case where the lateral passages of the plurality of turning passages are configured as simple linear passages, The fuel injection valve is arranged so that the first deflected spray, the second deflected spray, and the third deflected spray injected from the three swirl passages reduce overlap at the center of an entire spray cross-section including the first deflected spray, the second deflected spray, and the third deflected spray, thereby reducing the distribution density of fuel in the center.

5. 5. The fuel injection valve according to claim 4, the plurality of swirl passages are constituted by four swirl passages including the three swirl passages that spray a deflected spray having a major axis and a minor axis in a spray cross section, The first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray injected from the four swirl passages are a fuel injection valve having a region in which the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray are not present in the center of an entire spray cross section composed of the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray, or where the fuel spray due to the first deflected spray, the second deflected spray, the third deflected spray, and the fourth deflected spray is lean.

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