Fuel injection valve

Abstract

This fuel injection valve 1 comprises: a valve seat 15b and a valve body 17; a plurality of fuel injection holes 220-1 to 220-4; a swirling chamber 212 that is provided between the valve seat 15b and the fuel injection hole 220; and a lateral passage 211 that is connected to the swirling chamber 212. At least some fuel injection holes 220-1, 220-3 of the plurality of fuel injection holes 220 inject sprays SPS1, SPS3 having a cross-sectional shape perpendicular to an injection direction and biased from a circular shape. A plurality of sprays SPS1 to SPS4 injected from the plurality of fuel injection holes 220-1 to 220-4 are arranged such that the shape of an envelope ENV1 in contact with the outer edges of the plurality of sprays SPS1 to SPS4 is deformed from a circular shape in a cross-section perpendicular to an injection direction of the entire spray SPH formed by the plurality of sprays SPS1 to SPS4. As a result, the fuel spray can be widely diffused over a spatial cross section in an air inlet pipe.

Description

Fuel injection valve

[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.

[0002] As a conventional fuel injection valve, the one described in Patent Document 1 below is known. In this fuel injection valve having a swirling chamber and a lateral passage, in order to make it possible 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 fuel injection hole, a swirling chamber into 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 peripheral wall of the swirling chamber and the other side wall is connected to the downstream end of the inner peripheral wall, when a first extension line extending along one side wall and a second extension line extending along the other side wall are assumed, 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 on the projection side of one side wall or the projection side of the first extension line beyond the projection of the second extension line.

[0003] Japanese Unexamined Patent Application Publication No. 2018 - 165512

[0004] The fuel injection valve as in Patent Document 1 includes four fuel injection holes. The cross-sectional shape of the fuel spray injected from each fuel injection hole configured as in Patent Document 1 is elliptical as shown in FIG. 14(b). In this specification, the cross-section of the fuel spray SPS and the overall spray SPH is a cross-section perpendicular to the injection direction of the overall spray SPH. Usually, the fuel sprays SPS1 to SPS4 injected from the four fuel injection holes are arranged as shown in FIG. 14(c), and the envelope line contacting the outer edges of the fuel sprays SPS1 to SPS4 forms a substantially circular shape. That is, as shown in FIG. 15(b), for the fuel sprays injected from the four fuel injection holes, the spray angle θ1 of the fuel spray viewed from the X direction is equal to the spray angle θ2 of the fuel spray viewed from the Y direction (θ1 = θ2), and the spray distribution is circular as shown in FIG. 15(c).

[0005] As shown in Figure 16, the fuel injector 1 attached to the intake manifold 108 injects fuel toward the intake valve 105 in the direction of the central axis 1a of the fuel injector 1. In this case, the fuel spray is injected within the range indicated by ENV2, which prevents the fuel spray from adhering to the intake manifold 108. When viewed from the fuel injector 1 side, the cross-section of the space into which the fuel spray can be injected has an elliptical shape with a major axis W1 and a minor axis W2.

[0006] When injecting fuel spray into such an elliptical spatial cross-section, if one attempts to inject fuel spray with a circular cross-section without it adhering to the intake manifold, it becomes impossible to diffuse the fuel spray throughout the entire elliptical spatial cross-section having a major axis W1 and a minor axis W2.

[0007] Furthermore, in order to accommodate various configurations of the cross-sectional shape of the space in which fuel is injected, it is desirable that the cross-sectional shape of the overall spray injected from multiple fuel injection holes be formed into any shape deformed from a circle, rather than being limited to an elliptical shape.

[0008] The object of the present invention is to provide a fuel injection valve that can form the cross-sectional shape of the overall spray injected from multiple fuel injection holes from a circular shape to a deformed shape.

[0009] To achieve the above objective, the fuel injection valve of the present invention comprises a valve seat and a valve body that cooperate to open and close a fuel passage, a plurality of fuel injection holes, a swirl chamber provided between the valve seat and the fuel injection holes, and a lateral passage connected to the swirl chamber, wherein at least some of the plurality of fuel injection holes inject a spray having a cross-sectional shape perpendicular to the injection direction that is deviated from a circular shape, and the plurality of sprays injected from the plurality of fuel injection holes are arranged such that, in a cross-section perpendicular to the injection direction of the overall spray formed by the plurality of sprays, the shape of the envelope tangent to the outer edge of the plurality of sprays is deformed from a circular shape. Furthermore, in order to achieve the above objective, the fuel injection valve of the present invention comprises a valve seat and a valve body that cooperate to open and close a fuel passage, a plurality of fuel injection holes, and a plurality of swirling passages having a swirling chamber and a lateral passage that allows swirling fuel to flow into each of the plurality of fuel injection holes, wherein the lateral passage has a first side wall connected to the upstream end of the inner circumferential wall of the swirling chamber and a second side wall connected to the downstream end of the inner circumferential wall of the swirling chamber, wherein the fuel injection holes and the swirling passages are formed such that the inlet opening of the fuel injection hole extends beyond the extension line of the second side wall of the lateral passage toward the first side wall or toward the extension line of the first side wall, and wherein the plurality of swirling passages are formed such that the lateral passage extends independently radially outward for each swirling passage, and the direction of swirling of fuel in the swirling chamber is opposite for each circumferentially adjacent swirling passage.Furthermore, in order to achieve the above objective, the fuel injector of the present invention comprises a valve seat and a valve body that cooperate to open and close a fuel passage, a plurality of fuel injection holes, and a plurality of swirl passages having a swirl chamber and a lateral passage that allows swirl fuel to flow into each of the plurality of fuel injection holes, wherein the lateral passage has a first side wall connected to the upstream end of the inner circumferential wall of the swirl chamber and a second side wall connected to the downstream end of the inner circumferential wall of the swirl chamber, wherein in at least some of the fuel injection holes and swirl passages, the inlet opening of the fuel injection hole is formed to protrude beyond the extension line of the second side wall of the lateral passage toward the first side wall or toward the extension line of the first side wall, wherein the lateral passage is independently extended radially outward for each swirl passage, and wherein some of the fuel injection holes or swirl passages are configured to have a different shape or arrangement from the other fuel injection holes or swirl passages. Furthermore, in order to achieve the above objective, the fuel injection valve of the present invention comprises a valve seat and a valve body that cooperate to open and close a fuel passage, a plurality of fuel injection holes, and a swirling passage provided in each of the plurality of fuel injection holes, having a swirling chamber and a lateral passage, and allowing swirling fuel to flow in, wherein the lateral passage has a first side wall connected in the tangential direction to the inner circumferential wall of the swirling chamber, a second side wall connected to the side on which the inner circumferential wall of the swirling chamber bulges, and a plate on which the inner circumferential wall of the swirling chamber, the first side wall and the second side wall are formed, and in at least some of the plurality of fuel injection holes and the plurality of swirling passages, the inlet opening of the fuel injection hole is formed to protrude beyond the extension line of the second side wall of the lateral passage toward the first side wall or toward the extension line of the first side wall, The shape of the plate is configured such that, hypothetically, when the plate is rotated around the center of the valve body by a value obtained by dividing 360° by the number of swivel chambers, and the rotated plate shape is superimposed with the plate shape before rotation, the swivel passages have different shapes or arrangements when the plate is rotated compared to when it was rotated.

[0010] According to the present invention, the cross-sectional shape of the overall spray injected from multiple fuel injection holes can be formed from a circular shape to a deformed shape.

[0011] This is a longitudinal cross-sectional view showing a cross-section along the valve axis (central axis) of the fuel injector according to the present invention. This is a longitudinal cross-sectional view showing an enlarged view of the valve portion and the vicinity of the fuel injection portion (nozzle portion) of the fuel injector in Figure 1 (a longitudinal cross-sectional view corresponding to the view taken by arrow II-II in Figure 3). This is a plan view of the nozzle plate as seen from the direction of arrow III-III in Figure 1. This is a plan view showing an enlarged view of the swivel chamber and fuel injection hole (an enlarged plan view of part IV shown in Figure 3). This figure shows the form of a nozzle plate according to one embodiment of the present invention (Example 1: (a), (b), (c)), a state in which the nozzle diameter is different when the nozzle plate is virtually rotated by 90° and the nozzle holes are projected on top of each other (d), and an image of the arrangement and spray distribution of the fuel spray (e). This figure shows the form of a nozzle plate according to one embodiment of the present invention (Example 2: (a), (b), (c)), a state in which the nozzle position is different when the nozzle plate is virtually rotated by 90° and the nozzle holes are projected on top of each other (d), and an image of the arrangement and spray distribution of the fuel spray (e). This figure shows the shape of a nozzle plate according to one embodiment of the present invention (Example 3: (a), (b), (c)), a state in which the nozzle position is different when the nozzle plate is virtually rotated 90° and projected on top of it (d), and an image of the arrangement and spray distribution of the fuel spray (e). This figure shows the shape of a nozzle plate according to one embodiment of the present invention (Example 4: (a), (b), (c)), a state in which the nozzle position and swirl chamber are different when the nozzle plate is virtually rotated 90° and projected on top of it (d), and an image of the arrangement and spray distribution of the fuel spray (e). This figure shows the shape of a nozzle plate according to one embodiment of the present invention (Example 5: (a), (b)), a state in which the nozzle plate is virtually rotated 90° and projected on top of it (c), a state in which the height of the nozzle is different when the Y-Y line in figure (c) is cross-sectioned (d), and an image of the arrangement and spray distribution of the fuel spray (e). This figure shows a configuration of a nozzle plate according to one embodiment of the present invention (Example 6: (a)), a state in which the positions of the lateral passage, swirl chamber, and injection hole are different when the nozzle plate is virtually rotated 90° and projected on top of each other (b), and an image of the arrangement and spray distribution of the fuel spray (c).This figure shows the shape of a nozzle plate according to one embodiment of the present invention (Example 7: (a)), the state in which the positions of the lateral passages and swirl chambers are different when the nozzle plate is virtually rotated 90° and projected on top of each other (b), and an image of the arrangement and spray distribution of the fuel spray (c). Furthermore, (d) shows a modified example of Embodiment 7, in which the opposing ends on the opposite side of each swirl chamber of each lateral passage are separated, and (e) shows yet another modified example of Embodiment 7, in which each lateral passage is arranged in a cross shape at 90° positions in the circumferential direction. This figure shows the shape of a nozzle plate according to one embodiment of the present invention (a), the spray angle of the entire fuel spray (b), and the spray distribution of the fuel spray (c). This is a cross-sectional view of an internal combustion engine equipped with a fuel injector. This figure shows the shape of a nozzle plate according to a comparative example with the present invention (a), the cross-sectional shape of individual fuel sprays (b), and an image of the arrangement and spray distribution of the fuel spray (c). This figure shows the shape of a nozzle plate according to a comparative example with the present invention (a), the spray angle of the entire fuel spray (b), and the spray distribution of the fuel spray (c). This diagram illustrates the challenges of an intake manifold equipped with a fuel injection valve. It is a conceptual diagram illustrating the cross-sectional shape of the overall spray pattern (SPH).

[0012] Embodiments of the present invention will be described with reference to Figures 1 to 12.

[0013] The overall configuration of the fuel injection valve 1 will be explained using Figure 1. Figure 1 is a longitudinal cross-sectional view showing a cross-section along the central axis 1a of the fuel injection valve 1 according to this embodiment. The central axis 1a coincides with the axis (valve axis) of the movable element 27 on which the valve body 17, described later, is integrally attached, and coincides with the central axis of the cylindrical body 5, described later. Furthermore, the central axis 1a also coincides with the centerlines of the valve seat 15b and nozzle plate 21n, described later. In the following explanation, the central axis, axis (valve axis), and centerline will not be distinguished and will be referred to simply as the central axis 1a.

[0014] The fuel injector 1 is provided with a cylindrical metal body 5 extending from its upper end to its lower end. Inside this cylindrical body 5, a fuel passage 3 is configured to be approximately aligned with the central axis 1a. In Figure 1, the upper end (upper side) is referred to as the base end (base side), and the lower end (lower side) is referred to as the tip (tip side). The designations of the base end (base side) and tip (tip side) are based on the direction of fuel flow or the mounting structure to the fuel piping (not shown). That is, in the direction of fuel flow, the base end is on the upstream side and the tip is on the downstream side. Furthermore, the vertical relationship described herein is defined based on Figure 1 and is not related to the vertical direction when the fuel injector 1 is mounted on an internal combustion engine.

[0015] 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 component for removing foreign matter mixed in with the fuel.

[0016] An O-ring 11 is provided 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 the fuel piping.

[0017] The tip of the cylindrical body 5 is configured with a valve section 7 consisting of a valve body 17 and a valve seat member 15. The valve seat member 15 has a stepped valve body housing hole 15a for housing the valve body 17. A conical surface is formed in the middle of the valve body housing hole 15a, and the valve seat (seal section) 15b is formed on this conical surface. On the upstream side (base end side) of the valve body housing hole 15a from the valve seat 15b, a guide surface 15c is formed to guide the movement of the valve body 17 in the direction along the central axis 1a. The valve seat 15b and the valve body 17 work together to open and close the fuel passage. When the valve body 17 comes into contact with the valve seat 15b, the fuel passage is closed. Conversely, when the valve body 17 moves away from the valve seat 15b, the fuel passage is opened.

[0018] The valve seat member 15 is inserted into the inner side of the tip of the cylindrical body 5 and fixed to the cylindrical body 5 by laser welding. The laser welding 19 is performed from the outer circumference of the cylindrical body 5 all the way around. The valve body housing hole 15a penetrates the valve seat member 15 in a 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 closes the opening of the valve seat member 15 formed by the valve body housing hole 15a.

[0019] In this embodiment, a fuel injection unit 21 that injects swirling fuel is formed by a valve seat member 15 and a nozzle plate 21n. The nozzle plate 21n is fixed to the valve seat member 15 by laser welding. The laser-welded portion 23 surrounds the injection hole forming region where fuel injection holes 220-1, 220-2, 220-3, and 220-4 (see Figure 3) are formed, and encircles this injection hole forming region. The valve seat member 15 may be press-fitted into the inner side of the tip of the cylindrical body 5 and then fixed to the cylindrical body 5 by laser welding.

[0020] In this embodiment, the valve body 17 is a ball valve with a spherical shape. Therefore, multiple notched surfaces 17a are provided at circumferential intervals on the portion of the valve body 17 facing the guide surface 15c. These notched surfaces 17a form a gap between them and the inner circumferential surface of the valve seat member 15. This gap constitutes the fuel passage. It is also possible to construct the valve body 17 using something other than a ball valve. For example, a needle valve may be used.

[0021] In this embodiment, the valve section 7, including the valve seat member 15 and the valve body 17, and the nozzle plate 21n constitute a nozzle section for injecting fuel. The nozzle plate 21n, which has fuel injection holes 220-1, 220-2, 220-3, 220-4 and swivel passages 210-1, 210-2, 210-3, 210-4 (lateral passages 211-1, 211-2, 211-3, 211-4 and swivel chambers 212-1, 212-2, 212-3, 212-4) formed thereon, is joined to the tip surface of the nozzle section body (valve seat member 15) on which the valve section 7 is formed.

[0022] A drive unit 9 for driving the valve body 17 is located in the middle of the cylindrical body 5. The drive unit 9 is composed of an electromagnetic actuator. Specifically, the drive unit 9 is composed of a fixed iron core 25, a movable element (movable member) 27, an electromagnetic coil 29, and a yoke 33.

[0023] The fixed core 25 is made of a magnetic metal material and is press-fitted and fixed to the inside of the longitudinal middle portion of the cylindrical body 5. The fixed core 25 is formed in a cylindrical shape and has a through hole 25a that penetrates through its center in a direction along the central axis 1a. The fixed core 25 may be fixed to the cylindrical body 5 by welding, or it may be fixed to the cylindrical body 5 by a combination of welding and press-fitting.

[0024] The movable element 27 is positioned inside the cylindrical body 5, towards the tip of the fixed core 25. A movable core 27a is provided at the base end of the movable element 27. The movable core 27a faces the fixed core 25 with a small gap δ between them. A small diameter portion (connecting portion) 27b is formed at the tip of the movable element 27, and the valve body 17 is fixed to the tip of this small diameter portion 27b by welding. In this embodiment, the movable core 27a and the small diameter portion 27b are formed as a single unit (one member made of the same material), but they may also be constructed by joining two members. The movable element 27 includes the valve body 17 and displaces the valve body 17 in the valve opening and closing direction. The movable element 27 is guided at two points in the valve axis direction in the direction along the central axis 1a (valve opening and closing direction) by the valve body 17 contacting the valve seat member 15 and the outer circumferential surface of the movable core 27a contacting the inner circumferential surface of the cylindrical body 5.

[0025] A recess 27c is formed in the end face of the movable core 27a facing the fixed core 25. A spring seat 27e for the spring (coil spring) 39 is formed in the bottom surface of the recess 27c. A through hole 27f is formed on the inner circumference side of the spring seat 27e, extending along the central axis 1a to the tip end of the small diameter portion (connecting portion) 27b. An opening 27d is also formed on the side surface of the small diameter portion 27b. The through hole 27f opens in the bottom surface of the recess 27c, and the opening 27d opens in the outer circumference surface of the small diameter portion 27b, thereby forming a fuel passage 3 that connects the fuel passage formed in the fixed core 25 with the valve portion 7.

[0026] The electromagnetic coil 29 is externally fitted to the outer circumference of the cylindrical body 5 at a position where the fixed core 25 and the movable core 27a face each other with a small gap δ between them. The electromagnetic coil 29 is wound around a bobbin 31 formed in a cylindrical shape from a resin material and externally fitted to the outer circumference 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 supplied to the electromagnetic coil 29 via the connector pin 43 and the wiring member 45.

[0027] The yoke 33 is made of a magnetic metal material. The yoke 33 is positioned on the outer circumference of the electromagnetic coil 29, covering the electromagnetic coil 29, and also serves as the housing for the fuel injection valve 1. The lower end of the yoke 33 faces the outer surface of the movable core 27a via a cylindrical body 5, and together with the movable core 27a and the fixed core 25, it forms a closed magnetic path through which the magnetic flux generated by energizing the electromagnetic coil 29 flows.

[0028] A coil spring 39 is positioned in a compressed state, straddling 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 the direction in which the valve body 17 contacts the valve seat 15b (valve closing direction). An adjuster 35 is positioned inside the through-hole 25a of the fixed core 25, and the base end of the coil spring 39 contacts the tip end face of the adjuster 35. By adjusting the position of the adjuster 35 within the through-hole 25a in the direction along the central axis 1a, the biasing force of the movable element 27 (i.e., the valve body 17) by the coil spring 39 is adjusted.

[0029] The adjuster 35 has a fuel passage 3 that penetrates its center in a direction along the central axis 1a. After the fuel flows through the fuel passage 3 of the adjuster 35, it flows into the fuel passage 3 at the tip of the through hole 25a of the fixed iron core 25, and then into the fuel passage 3 configured within the movable element 27.

[0030] An O-ring 46 is fitted to the tip of the cylindrical body 5. The O-ring 46 functions as a seal to ensure liquid-tightness and airtightness between the inner surface of the insertion port 109a (see Figure 12) formed on the internal combustion engine side and the outer surface of the yoke 33 when the fuel injection valve 1 is attached to the internal combustion engine.

[0031] A resin cover 47 is molded and covers the fuel injector 1 from the middle section to near the base end. The tip end of the resin cover 47 covers a portion of the base end of the yoke 33. The resin cover 47 also covers the wiring member 45, and the connector 41 is integrally formed by the resin cover 47.

[0032] Next, the operation of the fuel injection valve 1 will be explained.

[0033] When the electromagnetic coil 29 is not energized (i.e., no drive current is flowing), the movable element 27 is biased in the valve closing direction by the coil spring 39, and the valve body 17 is in contact with (seaten) 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 body 17).

[0034] When the electromagnetic coil 29 is energized and a drive current flows, a magnetic flux is generated in the closed magnetic path formed by the movable core 27a, the fixed core 25, and the yoke 33. This magnetic flux generates a magnetic attractive force between the fixed core 25 and the movable core 27a, which are facing each other across a gap δ. When this magnetic attractive force overcomes the resultant force of the biasing force from the coil spring 39 and the fuel pressure acting on the movable element 27 in the valve closing direction, the movable element begins to move in the valve opening direction. When the valve body 17 moves away from the valve seat 15b, a gap (fuel passage) is formed between the valve body 17 and the valve seat 15b, and fuel injection begins. In this embodiment, when the movable element 27 moves a distance equal to the gap δ in the valve opening direction and comes into contact with the fixed core 25, the movable core 27a is stopped from moving in the valve opening direction and reaches an open, stationary state.

[0035] When the current to the electromagnetic coil 29 is cut off, the magnetic attractive force decreases and eventually disappears. When the magnetic attractive force decreases to a level smaller than the biasing force of the coil spring 39, the movable element 27 begins to move in the valve closing direction. When the valve body 17 comes into contact with the valve seat 15b, the valve body 17 closes the valve section 7 and comes to a stationary state.

[0036] Next, the structure of the valve section 7 and the fuel injection section 21 will be described in detail using Figures 2 and 3. Figure 2 is a magnified longitudinal cross-sectional view (corresponding to the longitudinal cross-sectional view taken along arrow II-II in Figure 3) showing the vicinity (nozzle section) of the valve section 7 and the fuel injection section 21 of the fuel injection valve 1 shown in Figure 1. Figure 3 is a plan view of the nozzle plate 21n as seen from the direction of arrow III-III in Figure 1.

[0037] The plan view in Figure 3 is a plan view of the nozzle plate 21n as seen from the fuel injection hole inlet side, and is a plan view of the upper end surface 21nu side of the nozzle plate 21n. The upper end surface 21nu is the surface facing 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.

[0038] In this embodiment, as shown in Figure 2, the nozzle plate 21n is made of a plate-like member with both end faces being flat, and the upper end face 21nu and the lower end face 21nb are parallel. That is, the nozzle plate 21n is made of a flat plate with a uniform thickness. In this embodiment, as shown in Figure 3, the fuel injection valve 1 is configured such that the central axis 1a intersects the nozzle plate 21n at the center 21no.

[0039] The tip surface (lower end surface) 15t of the valve seat member 15 is a 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 is in contact with the upper end surface 21nu of the nozzle plate 21n.

[0040] As shown in Figure 3, the nozzle plate 21n has 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 swirl force to the fuel upstream of the fuel injection holes 220-1, 220-2, 220-3, 220-4. The four sets of swivel passages 210-1, 210-2, 210-3, and 210-4 and the fuel injection ports 220-1, 220-2, 220-3, and 220-4 are all similarly configured, and therefore will not be distinguished from each other. They will be described as the swivel passage 210, the lateral passage 211, the swivel chamber 212, and the fuel injection port 220. If the configuration differs in each set, it will be explained as appropriate.

[0041] As shown in Figure 2, the valve seat member 15 has a conical valve seat 15b that tapers in diameter toward the downstream side. The downstream end of the valve seat 15b is connected to the fuel inlet 300. The downstream end of the fuel inlet 300 opens onto the tip surface 15t of the valve seat member 15. The fuel inlet 300 constitutes a fuel passage that introduces fuel into the swivel passage 210.

[0042] The swivel passage 210 is provided with the upstream end of the lateral passage 211 facing the opening of the fuel inlet 300 in order to receive fuel from the fuel inlet 300. In this embodiment, as shown in Figure 3, the four sets of lateral passages 211-1, 211-2, 211-3, and 211-4 are configured to communicate at their upstream ends, but each of the lateral passages 211-1, 211-2, 211-3, and 211-4 may be configured independently.

[0043] In FIG. 2, a nozzle plate 21n formed of a single plate-like member forms all of the lateral passage 211, the swirling chamber 212, and the fuel injection holes 220. The nozzle plate 21n can be formed of a plurality of plates, for example, by dividing it in the thickness direction. For example, the lateral passage 211 and the swirling chamber 212 can be formed in one plate, and the fuel injection holes 220 can be formed in another plate. Then, these two plates can be laminated to form the nozzle plate 21n.

[0044] Further, in the present embodiment, as shown in FIG. 2, although the fuel injection holes 220 are formed parallel to the central axis 1a, they may be inclined at an angle greater than 0° with respect to the central axis 1a. By varying the inclination directions, fuel may be injected in a plurality of directions.

[0045] In the present embodiment, as shown in FIG. 3, the swirling passage 210-1 and the fuel injection hole 220-1 form one fuel passage, the swirling passage 210-2 and the fuel injection hole 220-2 form one fuel passage, the swirling passage 210-3 and the fuel injection hole 220-3 form one fuel passage, and the swirling passage 210-4 and the fuel injection hole 220-4 form one fuel passage. The swirling passage 210-1 is composed of the lateral passage 211-1 and the swirling chamber 212-1, the swirling passage 210-2 is composed of the lateral passage 211-2 and the swirling chamber 212-2, the swirling passage 210-3 is composed of the lateral passage 211-3 and the swirling chamber 212-3, and the swirling passage 210-4 is composed of the lateral passage 211-4 and the swirling chamber 212-4.

[0046] In the present embodiment, a total of four sets of fuel passages each composed of a swirling passage 210 and a fuel injection hole 220 are formed in the nozzle plate 21n. The four sets of fuel passages are each formed radially from the center 21no side of the nozzle plate 21n toward the outer periphery. That is, the lateral passage 211 is provided radially from the center 21no side to the outer periphery side of the nozzle plate 21n and extends in the radial direction of the nozzle plate 21n. Also, each of the fuel passages is formed at an angular interval of 90° in the circumferential direction.

[0047] The swirling passage 210 and the fuel injection holes 220 are not limited to four sets, and may be two sets or three sets, or five or more sets may be provided. Alternatively, the swirling passage 210 and the fuel injection holes 220 may be provided as only one set.

[0048] Here, referring to FIG. 4, the relationship between the swirling chamber 212 and the fuel injection holes 220 will be described in detail. FIG. 4 is a plan view showing an enlarged view of the swirling chamber 212 and the fuel injection holes 220 (an enlarged plan view of part IV shown in FIG. 3).

[0049] In FIG. 4, a y0 - x0 coordinate system having a y-axis y0 and an x-axis x0 that are orthogonal to each other and having the center O2 of the inlet opening 220i of the fuel injection hole 220 as the origin, and a y1 - x1 coordinate system having a y-axis y1 and an x-axis x1 that are orthogonal to each other and having the center O2 of the inlet opening 220i of the fuel injection hole 220 as the origin are defined. 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 swirling chamber 212, the origins of the y0 - x0 coordinate system and the y1 - x1 coordinate system coincide with the center O1 of the swirling chamber 212. Also, the x0 axis coincides with the second side wall 211i and its extension line, the second extension line 211il, and the x1 axis coincides with a straight line L4 passing through the center 21no of the nozzle plate 21n and the center O2 of the inlet opening 220i of the fuel injection hole 220.

[0050] The lateral passage 211 is connected to the swirling chamber 212 so as to be offset with respect to the center O1 of the swirling chamber 212. One first side wall 211o of the lateral passage 211 is connected to an inner peripheral wall portion (the starting end portion of the inner peripheral wall, the upstream end portion) 212cs located on the upstream side in the flow direction of the swirling fuel, and the other second side wall 211i is connected to an inner peripheral wall (the ending end portion of the inner peripheral wall, the downstream end portion) 212ce portion located on the downstream side. For this reason, an opening 212co is formed in the inner peripheral wall (side wall) 212c of the swirling chamber 212 at the connection portion of the lateral passage 211.

[0051] The inner peripheral wall 212c of the swirling chamber 212 is formed so as to form a circumference around the inlet opening 220i of the fuel injection hole 220 so as to swirl the fuel flowing into the swirling chamber 212 from the lateral passage 211. That is, a swirling flow path 212d of fuel is formed between the inner peripheral wall 212c of the swirling chamber 212 and the inlet opening 220i of the fuel injection hole 220.

[0052] The first and second side walls (sides) 211o, 211i and the bottom surface 211b of the lateral passage 211 are made of nozzle plates 21n. The top surface (ceiling surface) 211u (see Figure 2) of the lateral passage 211 is made of the tip surface 15t of the valve seat member 15. Here, the first side wall 211o is the side wall opposite to the direction in which the fuel injection hole 220 opens relative to the center O1 of the swivel chamber 212, and the second side wall 211i is the side wall in the direction in which the fuel injection hole 220 opens relative to the center O1 of the swivel chamber 212.

[0053] The first side wall 211o of the lateral passage 211 is connected to the slewing chamber 212 at an angle that is in contact with the inner circumferential wall 212c of the slewing chamber 212. The downstream end of the first side wall 211o is connected to the starting end 212cs of the inner circumferential wall 212c of the slewing chamber 212.

[0054] Furthermore, the second side wall 211i of the lateral passage 211 is connected to the slewing chamber 212 at an angle that intersects with the inner circumferential wall 212c of the slewing chamber 212. Here, "intersection" means that the second side wall 211i and its extension cross the inner circumferential wall 212c. The downstream end of the second side wall 211i is connected to the end portion 212ce of the inner circumferential wall 212c of the slewing chamber 212.

[0055] The starting end 212cs of the inner circumferential wall 212c of the swirl chamber 212 is the end located on the upstream side in the direction of fuel swirl. The ending end 212ce of the inner circumferential wall 212c is the end located on the downstream side in the direction of fuel swirl. The ending end 212ce may have a chamfered portion such as an inclined portion or a rounded portion. In such cases, the intersection point where imaginary lines extending from the inner circumferential wall 212c and the second side wall 211i intersect can be defined as the ending end (downstream end) 212ce.

[0056] In this embodiment, the inner circumferential wall 212c of the swirling chamber 212 from the starting end 212cs to the ending end 212ce is formed to have an arc shape with a constant radius R from the center O1. That is, the inner circumferential wall 212c is composed of a part of the circumference of a perfect circle or a circle. On the other hand, the inlet opening 220i of the fuel injection hole 220 is circular with a radius r smaller than the radius R of the inner circumferential wall 212c of the swirling chamber 212. As a result, the bottom surface 212b of the swirling passage 212d is formed between the inlet opening edge 220ic of the fuel injection hole 220 and the inner circumferential wall 212c of the swirling chamber 212. Note that if the central axis 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 will not be circular but will be elliptical. Regardless of whether it is inclined or not, the central axis of the fuel injection port 220 passes through the center O2 of the inlet opening 220i.

[0057] Figure 4 is a plan view, showing the fuel injection port 220, the swirling chamber 212, and the lateral passage 211 projected onto a plane (projection plane) perpendicular to the central axis 1a of the fuel injection valve 1. Figure 4 also shows the projection of the extension line of the first side wall 211o (first extension line) 211ol and the extension line of the second side wall 211i (second extension line) 211il of the lateral passage 211. The first extension line 211ol is a virtual line extended along the first side wall 211o. The second extension line 211il is a virtual line extended along the second side wall 211i.

[0058] The second extension line 211il divides the bottom surface of the swivel chamber 212 (the bottom surface 212b of the swivel flow path 212d) into two regions A1 and A2. Region A1 is the region located on the side of the first side wall 211o or its extension line 211ol 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 the region located on the opposite side of the second extension line 211il from the first side wall 211o or its extension line 211ol. Region A2 is composed of the swivel flow path portion on the end end 212ce side of the inner circumferential wall 212c. Note that regions A1 and A2 do not include the line of the second extension line 211il.

[0059] A portion of the inlet opening edge 220ic of the fuel injection hole 220 is positioned to extend beyond the second extension line 211il and protrude toward region A1. That is, a portion of the inlet opening 220i of the fuel injection hole 220 opens toward region A1, and a portion of the inlet opening 220i of the fuel injection hole 220 is located on the extension of the lateral passage 211. With this configuration, the cross-sectional shape of the spray injected from the fuel injection hole 220 becomes a deflected shape from a circular shape. In this embodiment, the deflected shape from a circular shape in the cross-sectional shape of the spray is an ellipse.

[0060] In the following explanation, the cross-section and cross-sectional shape of the spray refer to the cross-section and cross-sectional shape perpendicular to the direction of spraying, and in cases where it is particularly clear, they may also be referred to as the perpendicular cross-section and perpendicular cross-sectional shape.

[0061] 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, into region A1. As a result, the inlet opening edge 220ic of the fuel injection hole 220 intersects the second extension line 211il at two points 220ia and 220ib. That is, the inlet opening 220i of the fuel injection hole 220 is positioned such that the inlet opening edge 220ic intersects the second extension line 211il at two points 220ia and 220ib. Note that the amount of overhang of the inlet opening 220i into region A1 is not limited to the size of the radius r of the fuel injection hole 220. This overhang may be larger or smaller than the radius r. By changing the amount of overflow, the size of the spray cross-section (spray distribution) can be changed.

[0062] Furthermore, the center O2 of the inlet opening 220i of the fuel injection hole 220 may be positioned offset from the center O1 of the swirling 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 swirling chamber 212. By changing this amount of eccentricity, the size of the spray cross-section (spray distribution) can be changed.

[0063] In this embodiment, the first side wall 211o and the second side wall 211i of the lateral passage 211 are formed parallel to each other, and the width of the lateral passage 211 is constant. Therefore, shifting the center O2 of the inlet opening 220i of the fuel injection hole 220 in the direction along the second extension line 211il from the center O1 of the swirling chamber 212 means shifting it in the direction along the center line L3 of the lateral passage 211.

[0064] Furthermore, the center O2 of the inlet opening 220i of the fuel injection hole 220 may be shifted in a direction along a straight line L4 that passes through the center 21no of the nozzle plate 21n and the center O2 of the inlet opening 220i of the fuel injection hole 220. This also allows for a change in the size of the spray cross-section (spray distribution).

[0065] Furthermore, the inner circumferential wall 212c of the swivel chamber 212 is not limited to having a constant radius R, but may also have a spiral shape, for example, such that R decreases from the upstream side to the downstream side in the direction of fuel swivel. In this case, the inner circumferential wall 212c of the swivel chamber 212 will have the shape shown by the dashed line 212c', the first side wall 211o of the lateral passage 211 will have the shape shown by the dashed line 211o', and the inner circumferential wall 212c and the first side wall 211o will be connected at point 212c'.

[0066] Figure 5 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 1: (a), (b), (c)), a state in which the nozzle plate 21n is virtually rotated by 90° and the injection holes are projected to overlap (d), and an image of the arrangement and distribution of the fuel spray (e). In the following description, the fuel injection holes will be referred to as injection holes.

[0067] In this example, as is clear from Figure 5(d), the nozzle diameters of the first and third nozzles are different from those of the second and fourth nozzles, with the nozzle diameter φ1 of the first nozzle 220-1 and the third nozzle 220-3 being larger than the nozzle diameter φ2 of the second nozzle 220-2 and the fourth nozzle 220-4. That is, the relationship between the nozzle diameter φ1 of the first nozzle 220-1 and the third nozzle 220-3 and the nozzle diameter φ2 of the second nozzle 220-2 and the fourth nozzle 220-4 is such that the first and third nozzle diameters φ1 > the second and fourth nozzle diameters φ2.

[0068] In other words, in this example, some of the fuel injection holes 220-1, 220-3 or fuel injection holes 220-2, 220-4 are configured with a different shape (size) from the other fuel injection holes 220-2, 220-4 or fuel injection holes 220-1, 220-3.

[0069] As shown in Figure 4, the cross-section of the spray ejected through the individual swirling passages 210 and nozzles 220 is elliptical (SPS1 to SPS4). Since the nozzle diameters of each nozzle have the relationship described above, the cross-sectional shapes of the sprays SPS1 and SPS3 ejected from the first nozzle 220-1 and the third nozzle 220-3 are larger than the cross-sectional shapes of the sprays SPS2 and SPS4 ejected from the second nozzle 220-2 and the fourth nozzle 220-4. Therefore, the cross-sectional shape of the overall spray SPH formed by the sprays SPS1 to SPS4 ejected from each nozzle 220-1 to 220-4 is not circular, but approaches an ellipse with a major axis and a minor axis. In other words, the cross-sectional shape of the overall spray SPH is such that the spray is more widely distributed in one axis direction of two mutually perpendicular axes than in the axis direction of the other. In this case, the cross-sectional shape of the spray is perpendicular to the injection direction.

[0070] Here, the cross-sectional shape of the overall spray SPH is not actually an ellipse as shown in Figure 5(e), but rather a shape that traces the outer edge of the combined cross-sectional shape of spray SPS1 to SPS4. The ellipse of the overall spray SPH is drawn so that spray SPS1 to SPS4 are in contact with each other. The overall spray SPH in Figures 6 to 12, which will be explained below, is also drawn in the same way as in Figure 5.

[0071] Figure 6 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 2: (a), (b), (c)), the nozzle hole position (d) when the nozzle plate 21n is virtually rotated 90° and superimposed and projected, and an image of the arrangement and spray distribution of the fuel spray (e).

[0072] In this example, as shown in Figures 6(b) to 6(d), the position of the fuel injection holes 220 is shifted in the y1 axis direction. In the first injection hole 220-1 and the third injection hole 220-3, the center O1' of the inlet opening is shifted from the reference position O1 in the (+) direction of the y1 axis, while in the second injection hole 220-2 and the fourth injection hole 220-4, the center O1'' of the inlet opening is shifted from the reference position O1 in the (-) direction of the y1 axis. As a result, the first injection hole 220-1 and the third injection hole 220-3 and the second injection hole 220-2 and the fourth injection hole 220-4 are positioned at offset locations in the axial direction of the y1 axis.

[0073] Specifically, the first nozzle 220-1 and the third nozzle 220-3 are offset relative to the second nozzle 220-2 and the fourth nozzle 220-4 in the axial direction of the y1 axis, on the opposite side from the first side wall 211o or its extension 211ol. The second nozzle 220-2 and the fourth nozzle 220-4 are offset relative to the first nozzle 220-1 and the third nozzle 220-3 in the axial direction of the y1 axis, on the side of the first side wall 211o or its extension 211ol.

[0074] Because the nozzle positions of each nozzle have the relationship described above, the cross-sectional shape of the spray SPS1 and SPS3 ejected from the first nozzle 220-1 and the third nozzle 220-3 is larger than the cross-sectional shape of the spray SPS2 and SPS3 ejected from the second nozzle 220-2 and the fourth nozzle 220-4. For this reason, the cross-sectional shape of the overall spray SPH ejected from each nozzle 220-1 to 220-4 is not circular, but approaches an ellipse with a major axis and a minor axis.

[0075] In other words, in this example, some of the fuel injection holes 220-1, 220-3 or fuel injection holes 220-2, 220-4 are configured in a different arrangement from the other fuel injection holes 220-2, 220-4 or fuel injection holes 220-1, 220-3.

[0076] Figure 7 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 3: (a), (b), (c)), a state in which the nozzle hole position is different when the nozzle plate 21n is virtually rotated by 90° and projected on top of each other (d), and an image of the arrangement and distribution of the fuel spray (e).

[0077] In this example, as shown in Figures 7(b) to 7(d), the position of the fuel injection holes 220 is shifted in the x1 axis direction (linear L4 direction). In the first injection hole 220-1 and the third injection hole 220-3, the center O1' of the inlet opening is shifted from the reference position O1 in the (-) direction of the x1 axis, and in the second injection hole 220-2 and the fourth injection hole 220-4, the center O1'' of the inlet opening is shifted from the reference position O1 in the (+) direction of the y1 axis. As a result, the first injection hole 220-1 and the third injection hole 220-3 and the second injection hole 220-2 and the fourth injection hole 220-4 are positioned at offset locations in the axial direction of the x1 axis.

[0078] Specifically, the first nozzle 220-1 and the third nozzle 220-3 are offset from the center 21no of the nozzle plate 21n in the axial direction of the x1 axis relative to the second nozzle 220-2 and the fourth nozzle 220-4. The second nozzle 220-2 and the fourth nozzle 220-4 are offset from the center 21no of the nozzle plate 21n in the axial direction of the x1 axis relative to the first nozzle 220-1 and the third nozzle 220-3.

[0079] Because the nozzle positions of each nozzle have the relationship described above, the cross-sectional shape of the spray SPS1 and SPS3 ejected from the first nozzle 220-1 and the third nozzle 220-3 is larger than the cross-sectional shape of the spray SPS2 and SPS4 ejected from the second nozzle 220-2 and the fourth nozzle 220-4. For this reason, the cross-sectional shape of the overall spray SPH ejected from each nozzle 220-1 to 220-4 approaches an ellipse with a major axis and a minor axis, rather than a circle, as shown in Figure 7(e).

[0080] In other words, in this example, some of the fuel injection holes 220-1, 220-3 or fuel injection holes 220-2, 220-4 are configured in a different arrangement from the other fuel injection holes 220-2, 220-4 or fuel injection holes 220-1, 220-3.

[0081] Figure 8 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 4: (a), (b), (c)), a state in which the nozzle hole position and swirl chamber are different when the nozzle plate 21n is virtually rotated by 90° and projected on top of each other (d), and an image of the arrangement and spray distribution of the fuel spray (e).

[0082] In this example, as shown in Figures 8(b) to 8(d), the swirling force of the fuel injected from the nozzle 220 is varied by differentiating the nozzle positions and the swirling chambers. The swirling force of the fuel is weakened (weak swirling) at the first nozzle 220-1 and the third nozzle 220-3, and strengthened (strong swirling) at the second nozzle 220-2 and the fourth nozzle 220-4. As a result, the swirling force of the fuel injected from the first nozzle 220-1 and the third nozzle 220-3 is different from that of the second nozzle 220-2 and the fourth nozzle 220-4.

[0083] Specifically, the first nozzle 220-1 and the third nozzle 220-3 have a weaker swirling force of fuel injected compared to the second nozzle 220-2 and the fourth nozzle 220-4. The second nozzle 220-2 and the fourth nozzle 220-4 have a stronger swirling force of fuel injected compared to the first nozzle 220-1 and the third nozzle 220-3.

[0084] Because the swirling force of the fuel injected from each nozzle has the relationship described above, the cross-sections of the spray SPS2 and SPS4 injected from the second nozzle 220-2 and the fourth nozzle 220-4 approach a circular shape. For this reason, the cross-sectional shape of the overall spray SPH injected from each nozzle 220-1 to 220-4 approaches an ellipse with a major axis and a minor axis, rather than a circle, as shown in Figure 8(e).

[0085] In other words, in this example, some of the slewing chambers 212-1, 212-3 or 212-2, 212-4 of the slewing passage are configured with a different shape from the slewing chambers 212-2, 212-4 or 212-1, 212-3 of the other slewing passages.

[0086] Figure 9 shows the form of a nozzle plate 21n according to one embodiment of the present invention (Example 5: (a), (b)), the state when the nozzle plate is virtually rotated 90° and superimposed and projected (c), the state when the height of the injection holes is different when the Y-Y line in figure (c) is cross-sectioned (d), and an image of the arrangement and spray distribution of the fuel spray (e).

[0087] In this example, as shown in Figures 9(b) to (d), the height H of the swivel chambers 212 where the first and third nozzles are located is different from the height H of the swivel chambers 212 where the second and fourth nozzles are located. Specifically, the height H of the swivel chambers 212-1 and 212-3 is increased for the first nozzle 220-1 and the third nozzle 220-3, while the height H of the swivel chambers 212-2 and 212-4 is decreased for the second nozzle 220-2 and the fourth nozzle 220-4. As a result, the height H of the swivel chambers differs between the first nozzle 220-1 and the third nozzle 220-3 and the second nozzle 220-2 and the fourth nozzle 220-4. Note that the nozzle diameters of nozzles 220-1 to 220-4 are assumed to be the same for this explanation.

[0088] Specifically, the first nozzle 220-1 and the third nozzle 220-3 have a higher height H of the swirling chambers 212-1 and 212-3 and a shorter nozzle length L compared to the second nozzle 220-2 and the fourth nozzle 220-4. The second nozzle 220-2 and the fourth nozzle 220-4 have a lower height H of the swirling chambers 212-2 and 212-4 and a longer nozzle length L compared to the first nozzle 220-1 and the third nozzle 220-3. As a result, the spray angles of the sprays SPS1 and SPS3 ejected from the first nozzle 220-1 and the third nozzle 220-3 are larger, and their cross-sectional shapes are larger than those of the sprays SPS2 and SPS4 ejected from the second nozzle 220-2 and the fourth nozzle 220-4, as shown in Figure 9(e). Therefore, the cross-sectional shape of the overall spray SPH ejected from each nozzle 220-1 to 220-4 is not circular, but rather approaches an ellipse with a major axis and a minor axis.

[0089] In this example, at least some of the fuel injection holes 220-1 and 220-3 have their flow rates of spray SPS1 and SPS3 injected from them, as well as the spray angles θ1 and θ2 of the overall spray SPH, set by adjusting the height H of the swirling chamber 212.

[0090] In other words, in this example, some of the slewing chambers 212-1, 212-3 or 212-2, 212-4 of the slewing passage are configured with a different shape (slewing chamber height) from the slewing chambers 212-2, 212-4 or 212-1, 212-3 of the other slewing passages.

[0091] Alternatively, in this example, some of the fuel injection holes 220-1, 220-3 or fuel injection holes 220-2, 220-4 are configured with a different shape (injection hole length) from the other fuel injection holes 220-2, 220-4 or fuel injection holes 220-1, 220-3.

[0092] Figure 10 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 6: (a)), a state in which the positions of the lateral passage, swirl chamber, and injection hole are different when the nozzle plate is virtually rotated 90° and projected on top of each other (b), and an image of the arrangement and spray distribution of the fuel spray (d).

[0093] In this example, as shown in Figures 10(a) and 10(b), the spray angles θ1 and θ2 of the lateral passages are made different. Let θ1 be the angle formed by the lateral passage 211-1 of the first nozzle 220-1 and the lateral passage 211-2 of the second nozzle 220-2, and the angle formed by the lateral passage 211-3 of the third nozzle 220-3 and the lateral passage 211-4 of the fourth nozzle 220-4. Let θ2 be the angle formed by the lateral passage 211-2 of the second nozzle 220-2 and the lateral passage 211-3 of the third nozzle 220-3, and the angle formed by the lateral passage 211-4 of the fourth nozzle 220-4 and the lateral passage 211-1 of the first nozzle 220-1. The lateral passages 211-1 to 211-4 are arranged such that θ1 < θ2.

[0094] In other words, the lateral passage 211-2 of the second nozzle 220-2 and the lateral passage 211-4 of the fourth nozzle 220-4 are positioned at an inclination with respect to the y0 axis. In this case, the cross-sectional shape (size) of each spray SPS1 to SPS4 ejected from each nozzle 220-1 to 220-4 will be the same, but the major axes of each spray SPS2 and SPS4 ejected from the second nozzle 220-2 and the fourth nozzle 220-4 will be inclined. Therefore, as shown in Figure 10(c), the cross-sectional shape of the overall spray SPH ejected from each nozzle 220-1 to 220-4 will not be circular, but will approach an ellipse with a major axis and a minor axis.

[0095] In this example, at least some of the nozzles are provided in multiples 220-1 to 220-4, and the flow rate of the spray SPS1 to SPS4 ejected from the nozzles 220-1 to 220-4 and the spray angles θ1 and θ2 of the overall spray SPH are set by the extension direction of the lateral passages 211-1 to 211-4 (angle with adjacent lateral passages).

[0096] In other words, in this example, the arrangement of lateral passages 211-1 and 211-2 and lateral passages 211-3 and 211-4 in some of the rotating passages is configured with a different arrangement (angle) than the arrangement of lateral passages 211-2 and 211-3 and lateral passages 211-4 and 211-1 in other rotating passages.

[0097] Figure 11 shows the configuration of a nozzle plate 21n according to one embodiment of the present invention (Example 7: (a)), a state in which the positions of the lateral passage and the swivel chamber are different when the nozzle plate is virtually rotated 90° and projected on top of each other (b), and an image of the arrangement and spray distribution of the fuel spray (c).

[0098] In this example, as shown in Figures 11(a) and 11(b), the swirling direction of the fuel injected from the nozzles 220 is made different between adjacent nozzles in the circumferential direction. The swirling direction of the fuel is set to CCW for the first nozzle 220-1 and the third nozzle 220-3, and for the second nozzle 220-2 and the fourth nozzle 220-4. As a result, the arrangement of the spray SPS2 and SPS4 injected from the second nozzle 220-2 and the fourth nozzle 220-4 changes relative to the spray SPS1 and SPS3 injected from the first nozzle 220-1 and the third nozzle 220-3. In other words, the spray SPS2 and SPS4 ejected from the second nozzle 220-2 and the fourth nozzle 220-4 are arranged in relation to the spray SPS1 and SPS3 ejected from the first nozzle 220-1 and the third nozzle 220-3, so that the cross-sectional shape of the overall spray SPH approaches an ellipse shape from a circle, as shown in Figure 11(c).

[0099] Therefore, the cross-sectional shape of the overall spray SPH injected from each nozzle 220-1 to 220-4 is not circular, but approaches an ellipse with a major axis and a minor axis, as shown in Figure 11(c). Figure 11(d) shows a modified example of form 7, and (e) shows yet another modified example of form 7. In the form of Figure 11(d), the opposing ends of each lateral passage 211 on the opposite side of each swirling chamber 212 are separated, and the line connecting the tip edges of each opposing end is formed in an approximately elliptical shape, with this elliptical portion being the upper surface of the nozzle plate 21n. The fuel inlet hole 300 of the valve seat member 15 is located in this elliptical portion, and the fuel inlet hole 300 opens at each of the opposing ends. In the form of Figure 11(e), each lateral passage 211 is arranged in a cross shape at 90° positions in the circumferential direction. Therefore, the fact that the fuel inlet hole 300 opens at the joined opposing ends of each lateral passage 211 is the same as in the configuration shown in Figure 11(a).

[0100] The fuel injector in this example comprises a plurality of fuel injection holes 220-1 to 220-4, a plurality of swirl passages 210-1 to 210-4 having swirl chambers 212-1 to 212-4 and lateral passages 211-1 to 211-4 that allow swirl fuel to flow into each of the plurality of fuel injection holes 220-1 to 220-4, the lateral passage 211 having a first side wall 211o connected to the upstream end (start end) 212cs of the inner circumferential wall 212c of the swirl chamber 212, and a second side wall 211i connected to the downstream end (end end) 212ce of the inner circumferential wall 212c of the swirl chamber 212, The fuel injection holes 220 and the swirling passages 210 are formed such that the inlet opening 220i of the fuel injection holes 220 extends beyond the extension line 211il of the second side wall 211i of the lateral passage 211 to the first side wall 211o or the extension line 211ol of the first side wall 211o. The plurality of fuel injection holes 220 and the plurality of swirling passages 210 are arranged such that the cross-sectional shape of the overall spray injected from the plurality of fuel injection holes is such that the spray is more widely distributed in one axial direction of two mutually perpendicular axes than in the other axial direction.

[0101] In other words, by setting the swirling direction of the fuel in the swirling chamber 212 to different directions CCW and CW, the flow rates of the spray SPS1 to SPS4 injected from the nozzles 220-1 to 220-4 and the spray angles θ1 and θ2 of the overall spray SPH are set.

[0102] In other words, in this example, some of the swirl chambers 212-1, 212-3 or swirl chambers 212-2, 212-4 are configured with a different shape (direction of fuel swirl) from the other swirl chambers 212-2, 212-4 or swirl chambers 212-1, 212-3.

[0103] Figure 12 shows the shape of a nozzle plate according to one embodiment of the present invention (a), the spray angle of the entire fuel spray (b), and the spray distribution of the fuel spray (c).

[0104] In Figure 12, for the nozzle plate 21n of embodiment example 7, the spray angles θ1 and θ2 of the overall spray are shown in (b), and the spray distribution of the fuel spray is shown in (c). From Figure 12, it can be seen that the spray angle θ1 viewed from the X direction is smaller than the spray angle θ2 viewed from the Y direction, and the cross-sectional shape of the overall spray SPH deforms from a circle.

[0105] In other words, the multiple sprays SPS1 to SPS4 ejected from the multiple nozzles 220 are arranged such that, in a cross section perpendicular to the injection direction of the overall spray SPH formed by the multiple sprays SPS1 to SPS4, the shape of the envelope tangent to the outer edges of the multiple sprays SPS1 to SPS4 is deformed from a circular shape, thereby allowing the overall spray SPH to be widely diffused into the cross-sectional space within the intake pipe. In this embodiment, the shape of the envelope is deformed from a circular to an elliptical shape.

[0106] The fuel injector 1 of the above-described embodiment examples 1 to 7 is configured as follows: The fuel injector 1 comprises a valve seat 15b and a valve body 17 that cooperate to open and close the fuel passage, a plurality of fuel injection holes 220-1 to 220-4, a swirling chamber 212 provided between the valve seat 15b and the fuel injection holes 220, and a lateral passage 211 connected to the swirling chamber 212, wherein at least some of the plurality of fuel injection holes 220, 220-1, 220-3, inject spray SPS1, SPS3 having a cross-sectional shape perpendicular to the injection direction that is deviated from a circular shape, and the plurality of spray SPS1 to SPS4 injected from the plurality of fuel injection holes 220-1 to 220-4 are arranged such that, in a cross-section perpendicular to the injection direction of the overall spray SPH formed by the plurality of spray SPS1 to SPS4, the shape of the envelope ENV1 tangent to the outer edges of the plurality of spray SPS1 to SPS4 is deformed from a circular shape.

[0107] Furthermore, the fuel injector 1 of the embodiment examples 1 to 3 and 5 to 7 is provided with a plurality of fuel injection holes 220-1 to 220-4 that inject a deflected spray, and the fuel injection holes 220-1 to 220-4 that inject sprays SPS1 to SPS4 with different deflection directions are arranged adjacent to each other in the circumferential direction of the nozzle plate 21n.

[0108] Furthermore, the fuel injector 1 of the embodiment examples 1 to 3 is provided with a plurality of fuel injection holes 220-1 to 220-4 that inject deflected atomized spray SPS1 to SPS4, and at least one of the nozzle diameters φ1 and φ2 of the fuel injection holes 220-1 to 220-4 and the positions O1' and O1'' of the fuel injection holes 220-1 to 220-4 within the swirling chamber 212 is adjusted to set the flow rate of the atomized spray SPS1 to SPS4 injected from the fuel injection holes 220-1 to 220-4 and the spray angles θ1 and θ2 of the overall atomized spray SPH.

[0109] Referring to Figure 17, the overall spray shape SPH of the spray SPS1 to SPS4 injected from fuel injection holes 220-1 to 220-4 will now be described. Figure 17 is a conceptual diagram illustrating the overall spray shape SPH. The cross-sectional shape of spray SPS1 to SPS4 shown in Figure 17 is a cross-section (vertical cross-section) cut by a virtual plane perpendicular to the fuel injection direction. In this embodiment, the fuel injection direction coincides with the extension of the central axis 1a of the fuel injection valve.

[0110] Figure 17 shows (a) the spray shown in Figure 5, (b) the spray shown in Figure 8, (c) the spray shown in Figure 9, and (d) the spray shown in Figure 10.

[0111] In the sprays of (a) to (c), the cross-sectional shapes of the sprays SPS1 and SPS3 are deformed from a circle, having a major axis and a minor axis, and the length of the major axis of sprays SPS1 and SPS3 is greater than the length or diameter of the major axis of the other sprays SPS2 and SPS4. In such cases, we can imagine a circle C0 having the largest diameter among the circles tangent to the multiple sprays (in this embodiment, SPS1 and SPS3).

[0112] Furthermore, the ellipse C1 is drawn such that it touches multiple sprays (SPS1, SPS3 in this embodiment) that are tangent to the virtual circle C0, and also touches other sprays (SPS2, SPS4 in this embodiment), or includes other sprays inside it.

[0113] In the spray of (d), the cross-sectional shape of the sprays SPS1 to SPS4 is deformed from a circle, having a major axis and a minor axis, and all sprays SPS1 to SPS4 have the same cross-sectional shape and the same cross-sectional area. In this case, a circle C0 tangent to all sprays SPS1 to SPS4 is assumed. Furthermore, an ellipse C1 is drawn tangent to the multiple sprays (SPS1 to SPS4 in this embodiment) tangent to the assumed circle C0.

[0114] In Figures 5-11, this ellipse C1 is shown as the cross-sectional shape of the overall spray SPH. Ellipse C1 has a major axis Ax1 and a minor axis Ax2, and is deformed from a circle C2 inscribed within this ellipse C1. In other words, the cross-sectional shape of the overall spray formed by sprays SPS1-SPS4 is a spray shape in which the spray is deflected from a circular shape (deflected cross-sectional spray).

[0115] Ellipse C1 is the envelope of the main sprays (sprays SPS1 and SPS3 in sprays (a) to (c), and sprays SPS1 to SPS4 in spray (d)) that determine the cross-sectional shape of the overall spray SPH. The deflection direction in the cross-sectional shape of the overall spray SPH is along the major axis of ellipse C1.

[0116] In order to realize the spray patterns described in Figures 5 to 11, the fuel injector 1 of this embodiment is configured as follows: It comprises a valve seat 15b and a valve body 17 that cooperate to open and close the fuel passage, a plurality of fuel injection holes 220-1 to 220-4, and a plurality of swirling passages 210-1 to 210-4 that have swirling chambers 212-1 to 212-4 and lateral passages 211-1 to 211-4 and allow swirling fuel to flow into each of the plurality of fuel injection holes 220-1 to 220-4, and the lateral passage 211 has a first side wall 211o connected to the upstream end 212cs of the inner circumferential wall 212c of the swirling chamber 212, and a second side wall 211i connected to the downstream end 212ce of the inner circumferential wall 212c of the swirling chamber 212. The fuel injection holes 220 and the swirling passage 210 are formed such that the inlet opening 220i of the fuel injection holes 220 extends beyond the extension line 211il of the second side wall 211i of the lateral passage 211 to the first side wall 211o or the extension line 211ol of the first side wall 211o. The multiple fuel injection holes 220-1 to 220-4 and the multiple swirling passages 210-1 to 210-4 are arranged such that the cross-sectional shape of the overall spray SPH injected from the multiple fuel injection holes 220-1 to 220-4 is such that the spray is more widely distributed in the direction of one axis Ax1 of two axes Ax1 and Ax2 that intersect perpendicularly to each other, than in the direction of the other axis Ax2.

[0117] Referring to Figure 13, an internal combustion engine equipped with the fuel injection valve according to the present invention will be described. Figure 15 is a cross-sectional view of an internal combustion engine equipped with the fuel injection valve 1.

[0118] An engine block 101 of the internal combustion engine 100 has a cylinder 102 formed thereon, and an intake port 103 and an exhaust port 104 are provided at the top of the cylinder 102. An intake valve 105 that opens and closes the intake port 103 is provided in the intake port 103, and an exhaust valve 106 that opens and closes the exhaust port 104 is provided in the exhaust port 104. An intake pipe 108 is connected to the inlet end 107a of an intake passage 107 formed in the engine block 101 and communicating with the intake port 103.

[0119] A fuel pipe 110 is connected to the fuel supply port 2 (see Figure 1) of the fuel injection valve 1.

[0120] A mounting portion 109 for the fuel injector 1 is formed in the intake pipe 108, and an insertion port 109a for inserting the fuel injector 1 is formed in the mounting portion 109. The insertion port 109a penetrates to the inner wall surface (intake passage) of the intake pipe 108, and the fuel injected from the fuel injector 1 inserted into the insertion port 109a is injected into the intake passage. In the case of bidirectional spray, for an internal combustion engine in which two intake ports 103 are provided in the engine block 101, each fuel spray is directed towards each intake port 103 (intake valve 105) and injected.

[0121] It should be noted that the present invention is not limited to the embodiments or modifications described above, and it is possible to delete some components or add other components not described. It is also possible to combine the configurations of the nozzle plates 21n of Embodiments 1 to 7.

[0122] 1...Fuel injector, 15b...Valve seat, 17...Valve body, 21n...Nozzle plate, 211, 211-1 to 211-4...Lateral passage, 212, 212-1 to 212-4...Swirling chamber, 220, 220-1 to 220-4...Fuel injection hole, CCW, CW...Swirling direction of fuel in swirling chamber 212, ENV1...Envelope tangent to the outer edges of multiple sprays SPS1 to SPS4, H...Height of swirling chamber 212, SPH...Overall spray, SPS1 to SPS4...Spray injected from fuel injection holes 220-1 to 220-4, θ1, θ2...Spray angle of sprays SPS1 to SPS4, φ1, φ2...Injection hole diameter of fuel injection holes 220-1 to 220-4.

Claims

DEPCT651. A fuel injection valve comprises: a valve seat and valve body, whose shared structure opens and closes the fuel passage; several fuel injection holes; swirl chambers, each provided between the valve seat and the fuel injection holes; and side passages, each connected to the swirl chambers, where at least some of the several fuel injection holes inject atoms whose cross-sectional shape perpendicular to the injection direction deviates from a circular shape; at least some of the fuel injection holes are numerous; at least one of the diameters of the fuel injection holes or the position of the fuel injection holes in the swirl chamber is adjusted so that the flow rate of the atoms injected from the fuel injection holes and the atomization angle of the entire atomization mass are determined; the cross-sectional shape of the entire atomization mass formed by injection from all fuel injection holes becomes such that the atoms in the direction of one of two perpendicular or significantly perpendicular axes spread wider than the atoms in the direction of the other axis.And a certain amount of atomization spray injected from a number of fuel injection holes is arranged so that the shape of the frame which is in contact with the outer edge of a certain amount of atomization spray deviates from a circular shape of cross-section perpendicular to the injection direction.

2. The fuel injection valve consists of: a valve seat and a valve body which together define the structure to open and close the fuel passage; a number of fuel injection holes; swirling chambers, each of which is provided between the valve seat and the fuel injection holes; and side passages, each of which is connected to the swirling chambers, where each of at least some of the fuel injection holes injects atomization spray whose cross-sectional shape perpendicular to the injection direction deviates from a circular shape. The fuel injection valve also consists of a nozzle plate which forms a number of fuel injection holes. The height of the swirling chamber of at least some of the fuel injection holes is adjusted so that the flow rate of atomization sprayed from the fuel injection holes and the atomization angle of the entire atomization spray are determined.The cross-sectional shape of the entire atomized spray formed by injection from all fuel injection holes becomes a shape in which the spray in the direction of one of two perpendicular or significantly perpendicular axes spreads wider than the spray in the direction of the other axis, and a certain amount of spray injected from a certain amount of fuel injection holes is arranged so that the shape of the frame tangent to the outer edge of a certain amount of spray deviates from a circular shape of cross-section perpendicular to the injection direction.

3. The fuel injection valve, which comprises: the valve seat and valve body, which have a mutually exclusive structure to open and close the fuel passage; a number of fuel injection holes; swirling chambers, each provided between the valve seat and the fuel injection holes; and side passages, each connected to a swirling chamber, where each of at least some of the number of fuel injection holes injects atoms whose cross-sectional shape perpendicular to the injection direction deviates from a circular shape; at least some of the fuel injection holes are numerous.The flow rate of the atomizer injected from the fuel injection holes and the atomization angle of the entire atomizer are determined by the direction of channel expansion through each channel. The cross-sectional shape of the atomizer formed by injection from all fuel injection holes becomes a shape in which the atoms in the direction of one of two perpendicular or significantly perpendicular axes spread out wider than the atoms in the direction of the other axis.And a certain amount of atomizer sprayed from a number of fuel injection holes is arranged so that the shape of the frame which is in contact with the outer edge of a certain atomizer spray deviates from a circular shape of cross-section perpendicular to the injection direction.

4. The fuel injection valve consists of: a valve seat and a valve body which are structurally defined to open and close the fuel passage; a number of fuel injection holes; a swirling chamber, each of which is provided between the valve seat and the fuel injection holes; and side passages, each of which is connected to the swirling chamber, where each of the fuel injection holes, at least some of the number of fuel injection holes, sprays atomizers whose cross-sectional shape perpendicular to the injection direction deviates from a circular shape; at least some of the fuel injection holes are numerous; the direction of fuel swirling in the swirling chamber is set to be in different directions, so the flow rate of the atomizer sprayed from the fuel injection holes and the atomization angle of the entire atomizer are determined.The cross-sectional shape of the entire atomized spray mass formed by injection from all fuel injection holes becomes a shape in which the spray in the direction of one of two perpendicular or significantly perpendicular axes spreads wider than the spray in the direction of the other axis, and a certain amount of spray injected from a certain amount of fuel injection holes is arranged so that the shape of the frame tangent to the outer edge of a certain amount of spray changes from a circular shape of cross-section perpendicular to the injection direction.

5. The fuel injection valve, which comprises: the valve seat and valve body, which together define the structure to open and close the fuel passage; a number of fuel injection holes; and a number of swirling passages, each swirling passage having a swirling chamber and lateral passages to swirl the fuel flow into each fuel injection hole respectively, where the lateral passages have a first side wall connected to the upstream end of the inner wall of the swirling chamber and a second side wall connected to the downstream end of the inner wall of the swirling chamber.The fuel injection hole and the swirl passage are shaped so that the fuel injection hole inlet crosses the junction line of the second side wall of the swirl passage and extends toward the first side wall or the junction line of the first side wall.And a number of swirling channels are formed so that the lateral channels for each swirling channel are formed for each lateral channel to extend outward in the radial direction and so that the direction of fuel swirling in the swirling chamber is opposite between adjacent swirling channels in the circumferential direction.

6. The fuel injection valve, which consists of: a valve seat and a valve body, which together are structured to open and close the fuel passages; a number of fuel injection holes; and a number of swirling channels, each swirling channel having a swirling chamber and lateral channels, and swirling the fuel flow into each fuel injection hole respectively, where the lateral channels have a first side wall connected to the upstream end of the inner wall of the swirling chamber and a second side wall connected to the downstream end of the inner wall of the swirling chamber.At least some of the fuel injection holes and at least some of the swirl passages of a certain number of swirl passages are formed so that the fuel injection hole inlets intersect the second side wall of the side passage and extend toward the first side wall or the first side wall boundary; a certain number of swirl passages are formed so that the side passages for each swirl passage are formed for each side passage to extend outward in a radial direction;And some of the fuel injection holes of a number of fuel injection holes and some of the swirl passages of a number of swirl passages are formed into different shapes or arrangements from the shape of the arrangement of the remaining fuel injection holes and the remaining swirl passages.

7. The fuel injection valve which consists of: the valve seat and the valve body which together are structured to open and close the fuel passages; a number of fuel injection holes; and a number of swirl passages in which each swirl passage has a swirl chamber and a lateral passage and are provided at each fuel injection hole respectively and cause the fuel flow to swirl into each fuel injection hole respectively, where the lateral passage has a first side wall that is connected to the swirl chamber in the tangential direction of the inner wall of the swirl chamber,The second side wall connected to the inner wall of the swirl chamber on the side where the inner wall of the swirl chamber is bulging and the plate which has formed the inner wall of the swirl chamber, the first side wall and the second side wall, at least some fuel injection holes of a certain number of fuel injection holes and at least some swirl passages of a certain number of swirl passages have been formed so that the fuel injection inlet crosses the extension line of the second side wall of the side passage and extends toward the first side wall or the extension line of the first side wall and when the plate is imagined rotating with the center of the valve body as the axis by an angle value obtained by dividing 360 degrees by the number of swirl chambers and overlapping the shapes of the rotated and non-rotating plate, the swirl passages therefore have a difference in shape and arrangement between the rotated and non-rotating plate.

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