JP2020016243A - Fuel injection valve - Google Patents

Abstract

To provide a fuel injection valve having a swirl chamber and a lateral passage which can adjust a flow rate of a fuel injected from a fuel injection hole, while suppressing change in atomization performance.SOLUTION: A fuel injection valve includes: a fuel injection hole 220 provided on the downstream side of a valve seat where a valve body comes into contact/is separated from; a swirl chamber 212 in which an inlet 220i of the fuel injection hole 220 opens to a bottom surface 212b, the surroundings of the bottom surface 212b is surrounded by an inner peripheral wall 212c, and a swirl flow passage of a fuel is formed; and a lateral passage 211 which opens to the inner peripheral wall 212c by one side wall 211o being connected to the upstream side in a flow direction of a swirl fuel of the inner peripheral wall 212c and the other side wall 211i being connected to the downstream side of the inner peripheral wall 212c, and which supplies the fuel to the swirl chamber 212. An extension line 211il extending along the other side wall 211i so as to come into contact with the other side wall 211i of the lateral passage 211 passes the center O of the fuel injection hole 220.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fuel injection valve that generates swirl fuel upstream of a fuel injection hole and injects the swirl fuel from the fuel injection hole.

  As a background art in the present technical field, a fuel injection valve described in JP-A-2003-336562 (Patent Document 1) is known. The fuel injection valve has a lateral passage communicating with a downstream end of a valve seat between a valve seat member and an injector plate joined to a front end surface of the valve seat member, and a downstream end of the lateral passage. A swirl chamber that opens in the tangential direction, and a fuel injection hole for injecting the swirled fuel in the swirl chamber is formed in the injector plate. It is arranged at a predetermined distance offset on the upstream end side of the directional passage (see abstract). In this fuel injection valve, the above configuration promotes atomization of fuel after injection and improves fuel injection response.

  Further, in the fuel injection valve of Patent Document 1, the direction of the lateral passage is offset from the center of the swirl chamber, and the downstream end of the lateral passage is opened in the tangential direction of the swirl chamber. Further, the inlet opening of the fuel injection hole does not intersect with an extended line extended to the swirl chamber side along the side face located on the swirl chamber center side among the two side faces forming the lateral passage, The swirl chamber is formed so as to fit into the swirl chamber bottom surface closer to the swirl chamber center side than the extension line. That is, the fuel injection hole is opened from the upstream end side of the lateral passage to the bottom portion of the swirl chamber that cannot be seen through the lateral passage (see FIGS. 6 and 12).

JP 2003-336562 A

  As in the fuel injection valve of Patent Document 1, a fuel injection valve having a lateral passage communicating with a downstream end of a valve seat, and a swirl chamber (swirl chamber) in which the downstream end of the lateral passage opens tangentially. The cross-sectional area of the lateral passage and the cross-sectional area (diameter) of the fuel injection hole affect the flow rate of fuel injected from the fuel injection hole. Therefore, it is necessary to adjust the cross-sectional area of the lateral passage and the cross-sectional area of the fuel injection hole so that the flow rate of the fuel injected from the fuel injection hole satisfies the specified value.

However, if the cross-sectional area of the lateral passage and the cross-sectional area of the fuel injection hole are changed to adjust the flow rate,
The shape (spray angle and particle size) of the fuel spray injected from the fuel injection hole greatly changes, and the atomization performance greatly changes. Therefore, it is not easy to design the cross-sectional area of the lateral passage and the cross-sectional area of the fuel injection hole such that the atomization performance and the fuel flow rate satisfy the specifications. Alternatively, it has not been easy to change the cross-sectional area of the lateral passage and the cross-sectional area of the fuel injection hole to adjust the fuel flow rate in a fuel injection valve designed to obtain desired atomization performance.

  An object of the present invention is to adjust a flow rate of fuel injected from a fuel injection hole while suppressing a change in atomization performance in a fuel injection valve having a swirl chamber and a lateral passage connected to the swirl chamber. Another object of the present invention is to provide a structure that has a high quality.

In order to achieve the above object, the fuel injection valve of the present invention
A fuel injection hole provided on a downstream side of a valve seat with which the valve body comes and goes, an inlet of the fuel injection hole is opened at a bottom surface, a periphery of the bottom surface is surrounded by an inner peripheral wall, and a swirling flow of fuel flows around the entrance. A swirl chamber in which a path is formed, and one side wall is connected to an upstream side of the inner peripheral wall in a flow direction of the swirling fuel, and the other side wall is connected to a downstream side of the inner peripheral wall to open to the inner peripheral wall, and the swirl is formed. A lateral passage for supplying fuel to the chamber;
An extension extending along the other side wall so as to contact the other side wall of the lateral passage passes through the center of the fuel injection hole.

  ADVANTAGE OF THE INVENTION According to this invention, the flow rate of the fuel injected from a fuel injection hole can be adjusted, suppressing the change of atomization performance. This facilitates the design or design change of the fuel injection valve.

FIG. 2 is a longitudinal sectional view showing a section along a valve axis (center axis) of the fuel injection valve according to the present invention. FIG. 2 is an enlarged vertical cross-sectional view (a vertical cross-sectional view corresponding to a cross section taken along the line II-II in FIG. 3) of the vicinity of a valve portion and a fuel injection portion (a nozzle portion) of the fuel injection valve in FIG. 1. FIG. 3 is a plan view of the nozzle plate viewed from the direction of arrows III-III in FIG. 1. FIG. 4 is an enlarged plan view showing a swirl chamber and a fuel injection hole (an enlarged plan view of a portion IV shown in FIG. 3). FIG. 5 is a diagram illustrating an analysis result of a fuel flow in a cross section taken along a line VV in FIG. 4. FIG. 5 is a plan view showing a configuration of a lateral passage, a swirl chamber, and a fuel injection hole in a comparative example with the present embodiment. FIG. 7 is a diagram showing an analysis result of a fuel flow in a section taken along line VII-VII of FIG. 6. 1 is a cross-sectional view of an internal combustion engine equipped with a fuel injection valve.

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

  The overall configuration of the fuel injection valve 1 will be described with reference to FIG. FIG. 1 is a vertical cross-sectional view showing a cross section along a central axis 1a of a fuel injection valve 1 according to the present embodiment. The central axis 1a coincides with the axis (valve axis) of the mover 27 on which the valve element 17 described later is integrally provided, and coincides with the central axis of the cylindrical body 5 described later. The central axis 1a also coincides with a central line of a valve seat 15b described later.

  The fuel injection valve 1 is provided with a metallic tubular body 5 extending from the upper end to the lower end. The fuel flow path 3 is formed inside the cylindrical body 5 so as to substantially extend along the central axis 1a. In FIG. 1, the upper end (upper end) is referred to as a base end (base end), and the lower end (lower end) is referred to as a distal end (front end). The designations of the proximal end (proximal side) and the distal end (distal end side) are based on the fuel flow direction. That is, in the fuel flow direction, the base end is on the upstream side, and the tip is on the downstream side. In addition, the vertical relationship described in this specification is based on FIG. 1 and has no relationship with the vertical direction when the fuel injection valve 1 is mounted on the internal combustion engine.

  A fuel supply port 2 is provided at a base end of the tubular body 5. A fuel filter 13 is attached to the fuel supply port 2. The fuel filter 13 is a member for removing foreign matter mixed in the fuel.

  An O-ring 11 is provided at the base end of the tubular body 5. The O-ring 11 functions as a sealing material when the fuel injection valve 1 is connected to a fuel pipe.

  A valve portion 7 including a valve body 17 and a valve seat member 15 is formed at the tip of the tubular body 5. The valve seat member 15 has a stepped valve body accommodation hole 15a for accommodating the valve body 17. A conical surface is formed in the middle of the valve body housing hole 15a, and the valve seat 15b is formed on the conical surface. A guide surface 15c that guides the movement of the valve body 17 in a direction along the central axis 1a is formed in a portion of the valve body housing hole 15a on the upstream side (base end side) of the valve seat 15b. The valve seat 15b and the valve element 17 cooperate to open and close the fuel passage. When the valve element 17 contacts the valve seat 15b, the fuel passage is closed. Further, the fuel passage is opened by separating the valve element 17 from the valve seat 15b.

  The valve seat member 15 is inserted inside the distal end side of the tubular body 5 and is fixed to the tubular body 5 by laser welding. The laser welding 19 is performed over the entire circumference from the outer peripheral side of the tubular body 5. The valve body receiving hole 15a penetrates the valve seat member 15 in a direction along the central axis 1a. A nozzle plate 21n is attached to a lower end surface (a front end surface) of the valve seat member 15. The nozzle plate 21n covers the opening of the valve seat member 15 formed by the valve body housing hole 15a.

  In this embodiment, the fuel injection unit 21 that injects swirl fuel is constituted by the valve seat member 15 and the nozzle plate 21n. The nozzle plate 21n is fixed to the valve seat member 15 by laser welding. The laser welding portion 23 surrounds the injection hole forming region in which the fuel injection holes 220-1, 220-2, 220-3, and 220-4 (see FIG. 3) are formed, and surrounds the injection hole forming region. Is going around. The valve seat member 15 may be pressed into the inside of the distal end side of the tubular body 5 and then fixed to the tubular body 5 by laser welding.

  In the present embodiment, the valve body 17 uses a spherical ball valve. For this reason, a plurality of notched surfaces 17a are provided in the portion of the valve body 17 facing the guide surface 15c at intervals in the circumferential direction. The notched surface 17 a forms a gap between the notch surface 17 a and the inner peripheral surface of the plate seat member 15. This gap forms a fuel passage. In addition, the valve element 17 can be configured by a member other than the ball valve. For example, a needle valve may be used.

  In the present embodiment, the valve portion 7 including the valve seat member 15 and the valve element 17 and the nozzle plate 21n constitute a nozzle portion for injecting fuel. A nozzle plate 21n in which a fuel injection hole 220 and a swirling passage 210 (lateral passage 211 and swirl chamber 212) to be described later are formed is joined to a tip end surface of the nozzle unit main body side where the valve unit 7 is formed. is there.

  A drive unit 9 for driving the valve body 17 is arranged at an intermediate portion of the tubular body 5. The drive unit 9 is configured by an electromagnetic actuator. Specifically, the drive unit 9 includes a fixed iron core 25, a mover (movable member) 27, an electromagnetic coil 29, and a yoke 33.

  The fixed iron core 25 is made of a magnetic metal material, and is press-fitted and fixed inside the longitudinally intermediate portion of the tubular body 5. The fixed iron core 25 is formed in a cylindrical shape, and has a through-hole 25a that penetrates the center in the direction along the central axis 1a. The fixed iron core 25 may be fixed to the cylindrical body 5 by welding, or may be fixed to the cylindrical body 5 by using both welding and press fitting.

  The mover 27 is disposed inside the tubular body 5 at a position closer to the distal end than the fixed iron core 25. A movable iron core 27 a is provided on the base end side of the mover 27. The movable iron core 27a is opposed to the fixed iron core 25 via a small gap δ. A small diameter portion 27b is formed on the distal end side of the mover 27, and the valve element 17 is fixed to the distal end of the small diameter portion 27b by welding. In the present embodiment, the movable iron core 27a and the connecting portion 27b are formed integrally (one member made of the same material), but may be formed by joining two members. The mover 27 includes the valve element 17 and displaces the valve element 17 in the opening / closing valve direction. The mover 27 is configured such that the valve element 17 contacts the valve seat member 15 and the outer peripheral surface of the movable iron core 27a contacts the inner peripheral surface of the cylindrical body 5, so that the movable element 27 is in the direction along the central axis 1 a (opening / closing valve direction). The movement is guided at two points in the valve axis direction.

  A concave portion 27c is formed in the movable iron core 27a on the end face facing the fixed iron core 25. A spring seat 27e of a spring (coil spring) 39 is formed on the bottom surface of the concave portion 27c. A through hole 27f is formed on the inner peripheral side of the spring seat 27e along the central axis 1a to the distal 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 peripheral surface of the small-diameter portion 27b, so that the fuel passage 3 communicating the fuel passage 3 formed in the fixed iron core 25 and the valve portion 7 is formed. Is configured.

  The electromagnetic coil 29 is externally inserted on the outer peripheral side of the tubular body 5 at a position where the fixed iron core 25 and the movable iron core 27a oppose each other via the minute gap δ. The electromagnetic coil 29 is wound around a tubular bobbin 31 made of a resin material, and is externally inserted on the outer peripheral side of the tubular body 5. The electromagnetic coil 29 is electrically connected to a connector pin 43 provided on the 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.

  The yoke 33 is made of a magnetic metal material. The yoke 33 is disposed on the outer peripheral side of the electromagnetic coil 29 so as to cover the electromagnetic coil 29, and also serves as a housing of the fuel injection valve 1. The lower end of the yoke 33 is opposed to the outer peripheral surface of the movable iron core 27a via the cylindrical body 5, and the magnetic flux generated by energizing the electromagnetic coil 29 together with the movable iron core 27a and the fixed iron core 25 is generated by the yoke 33. A flowing closed magnetic circuit is formed.

  A coil spring 39 is disposed in a compressed state across the through hole 25a of the fixed iron core 25 and the recess 27c of the movable iron core 27a. The coil spring 39 functions as an urging member that urges the mover 27 in a direction in which the valve element 17 contacts the valve seat 15b (valve closing direction). An adjuster (adjuster) 35 is provided inside the through hole 25 a of the fixed iron core 25, and a proximal end of the coil spring 39 is in contact with a distal end surface of the adjuster 35. By adjusting the position of the adjuster 35 in the through hole 25a in the direction along the center axis 1a, the urging force of the movable element 27 (that is, the valve element 17) by the coil spring 39 is adjusted.

  The adjuster 35 has the fuel flow path 3 penetrating the center part in the direction along the central axis 1a. After flowing through the fuel flow path 3 of the adjuster 35, the fuel flows into the fuel flow path 3 at the tip end portion of the through hole 25 a of the fixed iron core 25, and flows through the fuel flow path 3 formed in the mover 27.

  An O-ring 46 is externally inserted at the tip of the tubular body 5. When the fuel injection valve 1 is mounted on the internal combustion engine, the O-ring 46 is liquid-tight between the inner peripheral surface of the insertion port 109 a (see FIG. 5) formed on the internal combustion engine side and the outer peripheral surface of the yoke 33. Functions as a seal to ensure airtightness.

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

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

  When the electromagnetic coil 29 is not energized (that is, when no drive current is flowing), the movable element 27 is urged in the valve closing direction by the coil spring 39, and the valve element 17 is in contact with (seated) the valve seat 15b. It is in. In this case, a gap δ exists between the distal end surface of the fixed core 25 and the proximal end surface of the movable core 27a. In this embodiment, the gap δ is equal to the stroke of the mover 27 (that is, the valve element 17).

  When the electromagnetic coil 29 is energized and a drive current flows, a magnetic flux is generated in a closed magnetic path formed by the movable iron core 27a, the fixed iron core 25, and the yoke 33. Due to this magnetic flux, a magnetic attractive force is generated between the fixed iron core 25 and the movable iron core 27a opposed to each other with the gap δ interposed therebetween. When the magnetic attraction overcomes the urging force of the coil spring 39 and the resultant force such as the fuel pressure acting on the mover 27 in the valve closing direction, the mover starts to move in the valve opening direction. When the valve body 17 separates 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 starts. In the present embodiment, when the mover 27 moves in the valve opening direction by a distance δ equal to the gap δ, and the movable core 27a abuts on the fixed core 25, the movable core 27a stops moving in the valve opening direction, The valve opens and reaches a stationary state.

  When the energization of the electromagnetic coil 29 is discontinued, the magnetic attraction decreases and eventually disappears. When the magnetic attractive force becomes smaller than the urging force of the coil spring 39 at the stage where the magnetic attractive force decreases, the mover 27 starts moving in the valve closing direction. When the valve element 17 comes into contact with the valve seat 15b, the valve element 17 closes the valve portion 7 and comes to a stationary state.

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

  Note that the plan view of FIG. 3 is a plan view of the nozzle plate 21n viewed from the inlet side of the fuel injection hole, and is a plan view of the upper end face 21nu of the nozzle plate 21n. The upper end surface 21nu is a surface facing the distal end surface 15t of the valve seat member 15. An end face opposite to the upper end face 21nu is referred to as a lower end face 21nb.

  In the present embodiment, as shown in FIG. 2, the nozzle plate 21n is formed of a plate-like member having both end surfaces formed as flat surfaces, and the upper end surface 21nu and the lower end surface 21nb are parallel. That is, the nozzle plate 21n is formed of a flat plate having a uniform plate thickness. In the present embodiment, the fuel injection valve 1 is configured such that the central axis 1a intersects the nozzle plate 21n at the center 21no.

  The front end surface (lower end surface) 15t of the valve seat member 15 is formed as a flat surface (flat surface) perpendicular to the central axis 1a. The nozzle plate 21n is joined to the distal end surface 15t of the valve seat member 15, and the distal end surface 15t is in contact with the upper end surface 21nu of the nozzle plate 21n.

  As shown in FIG. 3, the nozzle plate 21n has lateral passages 211-1, 211-2, 211-3, 211-4, swirl chambers (swirl chambers) 212-1, 212-2, 212-3, 212-4 and fuel injection holes 220-1, 220-2, 220-3, 220-4 are formed. The four sets of swirling passages 210-1, 210-2, 210-3, 210-4 and the fuel injection holes 220-1, 220-2, 220-3, 220-4 have the same configuration. These will be described as the lateral passage 211, the swirl chamber 212, and the fuel injection hole 220 without distinction. When the configuration is changed in each group, description will be given as appropriate. The lateral passage 211 and the swirl chamber 212 constitute a swirl passage 210 for applying a swirl force to the fuel and injecting the swirl fuel from the fuel injection holes 220.

  As shown in FIG. 2, a conical valve seat surface 15 b is formed on the valve seat member 15 so as to decrease in diameter toward the downstream side. The downstream end of the valve seat surface 15b is connected to the fuel introduction hole 300. The downstream end of the fuel introduction hole 300 opens at the tip end surface 15t of the valve seat member 15. The fuel introduction hole 300 forms a fuel passage for introducing fuel into the swirl passage 210.

  The swirling passage 210 is provided such that the upstream end of the lateral passage 211 faces the opening surface of the fuel introduction hole 300 in order to receive supply of fuel from the fuel introduction hole 300. In the present embodiment, as shown in FIG. 3, four sets of lateral passages 211-1, 211-2, 211-3 and 211-4 are configured such that their upstream ends communicate with each other. -1, 211-2, 211-3, and 211-4 may be configured independently.

  In FIG. 2, the horizontal passage 211, the swirl chamber 212, and the fuel injection holes 220 are all formed in a nozzle plate 21n formed of a single plate-shaped member. The nozzle plate 21n can be composed of a plurality of plates, for example, by dividing in the thickness direction. For example, the lateral passage 211 and the swirl chamber 212 are formed on one plate, and the fuel injection holes 220 are formed on another plate. Then, these two plates may be stacked to form the nozzle plate 21n.

  Further, in the present embodiment, as shown in FIG. 2, the fuel injection holes 220 are formed parallel to the central axis 1a, but may be inclined at an angle larger than 0 ° with respect to the central axis 1a. The fuel may be injected in a plurality of directions by making the directions of inclination different.

  In the present embodiment, as shown in FIG. 3, the swirl passage 210-1 and the fuel injection hole 220-1 form one fuel passage, and the swirl passage 210-2 and the fuel injection hole 220-2 are connected to each other. One fuel passage is formed, 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 are one fuel passage. Is formed. The swirling passage 210-1 includes a lateral passage 211-1 and a swirling chamber 212-1. The swirling passage 210-2 includes a lateral passage 211-2 and a swirling chamber 212-2. The passage 210-3 includes a lateral passage 211-3 and a swirl chamber 212-3, and the swirl passage 210-4 includes a lateral passage 211-4 and a swirl chamber 212-4.

  In the present embodiment, a fuel passage including a total of four sets of swirling passages 210 and fuel injection holes 220 is formed in the nozzle plate 21n. Each of the four sets of fuel passages is 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 of the nozzle plate 21n to the outer peripheral side, and extends in the radial direction of the nozzle plate 21n. Further, each fuel passage is formed at an angular interval of 90 ° in the circumferential direction.

  The number of the swirling passages 210 and the fuel injection holes 220 is not limited to four, but may be two or three, or five or more. Alternatively, only one set of the swirling passage 210 and the fuel injection hole 220 may be provided.

  Here, the relationship between the swirl chamber 212 and the fuel injection holes 220 will be described in detail with reference to FIG. FIG. 4 is an enlarged plan view showing the swirl chamber 212 and the fuel injection holes 220 (an enlarged plan view of a portion IV shown in FIG. 3).

  The lateral passage 211 is connected to the swirl chamber 212 so as to be offset with respect to the center O of the inlet opening 220i of the fuel injection hole 220. The center O is also the center of the swirl chamber 212. For this reason, the lateral passage 211 is connected to the swirl chamber 212 so as to be offset also from the center of the swirl chamber 212. The downstream end of the lateral passage 211 is connected to an inner peripheral wall (side wall) 212c of the swirl chamber 212, and forms an opening in the inner peripheral wall 212c.

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

  The lateral passage 211 has a rectangular cross section perpendicular to the extending direction or the fuel flow direction, and the side walls (side surfaces) 211o and 211i and the bottom surface 211b are constituted by a nozzle plate 21n. The upper surface (ceiling surface) 211u (see FIG. 2) of the lateral passage 211 is constituted by the lower end surface 15t of the valve seat member 15.

  The side wall 211o of the lateral passage 211 is connected to the start end 212cs of the inner peripheral wall 212c of the swirl chamber 212 at the downstream end. Further, the side wall 211i of the lateral passage 211 is connected to the terminal end portion 212ce of the inner peripheral wall 212c of the swirling chamber 212 on the downstream end side.

  The start end 212cs is an end located on the side (upstream side) where fuel flows in the swirl chamber 212. That is, the starting end 212cs is an end located on the upstream side in the flow direction of the swirling fuel. On the other hand, the terminal end portion 212ce is an end portion located on a side (downstream side) on which fuel flowing into the swirl chamber 212 flows down while swirling the swirl chamber 212 along the inner peripheral wall 212c.

  Further, the side wall 211o is a side wall located on the outer diameter side in the radial direction of the swirl chamber 212. On the other hand, the side wall 211i is a side wall located on the inner diameter side (inner than the outer diameter) in the radial direction of the swirling chamber 212.

  In the present embodiment, one side wall 211o is connected to the upstream side in the flow direction of the swirling fuel of the inner peripheral wall 212c, the other side wall 211i is connected to the downstream side of the inner peripheral wall 212c, and the downstream end of the traveling direction passage 211 is It is open to the inner peripheral wall 212c.

  In the present embodiment, the swirling chamber 212 is formed such that the inner peripheral wall 212c between the start end 212cs and the end 212ce has a constant radius R from the center O. That is, the inner peripheral wall 212c is constituted by a part of the circumference that forms a perfect circle or a perfect circle. As a result, a bottom surface 212b forming a fuel passage is formed between the inlet opening edge 220i of the fuel injection hole 220 and the inner peripheral wall 212c of the swirl chamber 212.

  The inner peripheral wall 212c may be formed so as to draw a spiral curve or an involute curve so as to approach the inlet opening i of the fuel injection hole 220 or its center O while turning the fuel. In this case, the cross-sectional area of the swirl flow path gradually decreases toward the downstream side. When the inner peripheral wall 212c forms a spiral curve, the center O of the swirl chamber is the center of the spiral curve. When the inner peripheral wall 212c forms an involute curve, the center O of the swirl chamber is the center of the base circle.

  The inlet opening edge 220i of the fuel injection hole 220 extends beyond an extension 211il (particularly, an extension extending toward the swirl chamber 212) extending from the side wall 211i connected to the terminal end portion 212ce, and extends along the side wall of the lateral passage 211. It is arranged on the side of the extension line 211ol of the side wall 211o or the side wall 211o. The extension line 211il is an imaginary line that is in contact with the side wall 211i and extends along the side wall 211i. The extension line 211ol is a virtual line that is in contact with the side wall 211o and extends along the side wall 211o.

  Hereinafter, in order to make the description easy to understand, the fuel injection hole 220, the swirl chamber 212, the lateral passage 211, the extension line 211ol (the first extension line) are provided on a plane (projection plane) perpendicular to the central axis 1a of the fuel injection valve 1. ) And an extension line 211il (second extension line). This figure is the same as the plan view of FIG. That is, each projected view of the fuel injection hole 220, the swirl chamber 212, the lateral passage 211, the first extension line 211ol, and the second extension line 211il is shown in FIG. The passage 211 coincides with the first extension line 211ol and the second extension line 211il.

  Therefore, a description will be given below with reference to FIG. Since the projected points, lines and figures (projected figures) overlap the original points, lines and figures to be projected, the projected figures are also given the same symbols as the original points, lines and figures to be projected. Will be explained.

  In this embodiment, a point (projection diagram) O where the center O of the fuel injection hole 220 is projected is located on a line segment (projection diagram) 211il where the extension line 211il of the side wall 211i is projected. For this reason, the projected view 220i that projects the inlet opening 220i of the fuel injection hole 220 projects the side wall 211o beyond the line segment (projected view) 211il that projects the extended line 211il by the radius r of the fuel injection hole 220. The projected line protrudes to the side of the projected line (projection diagram) 211o or the extended line 211ol.

  The configuration required in this embodiment is that the projected view 220i of the inlet opening edge 220i of the fuel injection hole 220 exceeds the projected view 211il of the extended line 211il of the side wall 211i, The configuration is such that it protrudes to the projection view 211ol side. The amount of protrusion is not limited to the size of the radius of the fuel injection hole 220 as described in FIG. Further, the center of the fuel injection hole 220 and the center of the swirl chamber 212 do not need to coincide with the center O, and they may be shifted.

  The projected view 220i of the inlet opening edge 220i of the fuel injection hole 220 intersects the projected view 211il of the extension line 211il at two points 2201a and 220ib. In this embodiment, since the bottom surface 212b of the swirling chamber 212 is formed perpendicular to the central axis 1a, the extension line 211il and the entrance opening edge 220i are projected on the bottom surface 212b instead of a plane perpendicular to the central axis 1a. Is also good.

  In the present embodiment, with the above-described configuration, the first extension line 211ol that is in contact with the one side wall 211o of the lateral passage 211 and extends along the one side wall 211o and the other side wall 211i of the lateral passage 211 A second extension line 211il that is in contact with and extends along the other side wall 211i is imagined as a fuel injection hole 220, a swirl chamber 212, a lateral passage 211, a first extension line 211ol, and a second extension line 211il. Is projected onto a plane perpendicular to the central axis 1a of the fuel injection valve 1, the projected view 220i of the inlet opening 220i of the fuel injection hole 220 exceeds the line segment (projected view) 211il on which the second extension line 211il is projected. One side wall 211o is projected on the line segment (projection diagram) 211o side or the first extension line 211ol is projected on the line segment (projection diagram) 211ol side. The fuel injection valve 1.

  In the fuel injection valve 1 of the present embodiment, the projected view 211il of the extension line 211il and the projected view 220i of the inlet opening 220i of the fuel injection hole 220 intersect at two points.

  In the case of realizing the configuration of the present embodiment, the projection surface is set so that the inlet opening edge 220i of the fuel injection hole 220 easily protrudes beyond the extension line 211il of the side wall 211i and toward the side wall 211o or the extension line 211ol. Above, the entire projection 220i of the inlet opening 220i of the fuel injection hole 220 is disposed on the center O side of the swirl chamber 212 with respect to the line segment 212cel without intersecting with the line segment 212cel (see FIG. 4). Good. The line segment 212cel passes through a point (projection diagram) 212ce where the downstream end 212ce of the inner peripheral wall 212c is projected on the projection plane, and a line segment (first line segment) 211il where the second extension line 211il is projected. Is virtualized as a second line segment 212cel perpendicular to.

  The downstream end 212ce of the inner peripheral wall 212c is a connection between the inner peripheral wall 212c and the side wall 211i of the lateral passage 211. A chamfered portion such as an inclined portion or a round portion is formed in the downstream end portion 212ce by performing the processing. In such a case, the intersection of the virtual lines extending from the inner peripheral wall 212c and the side wall 211i may be defined as the downstream end 212ce.

  Next, the fuel flow in the swirling passage 210 and the fuel injection holes 220 will be described.

  The fuel flow flowing into the swirl chamber 212 from the lateral passage 211 flows along the inner peripheral wall 212 c of the swirl chamber 212, and swirls around the inlet opening 220 i of the fuel injection hole 220. At this stage, a turning force is applied to the fuel. The fuel flow provided with the swirling force flows into the fuel injection hole 220 while swirling. The fuel injected from the fuel injection holes 220 forms a liquid film while maintaining the swirling force, and is further divided into droplets while swirling. Thereby, atomized fuel spray is formed.

  In the present embodiment, since the inlet opening 220i of the fuel injection hole 220 is configured to protrude toward the side wall 211o beyond the extension line 211il of the side wall 211i, the fuel flowing from the lateral passage 211 into the swirl chamber 212 is formed. Flows into the fuel injection hole 220 almost without swirling the swirl chamber 212. That is, the fuel easily flows into the fuel injection holes 220. By changing the amount of protrusion to the side wall 211o side, it is possible to adjust the ease of inflow of the fuel flow into the fuel injection hole 220, and to adjust the flow rate of the fuel flowing into the fuel injection hole 220, that is, the injection amount. be able to. Normally, as the amount of protrusion toward the side wall 211o increases, the flow rate (injection amount) of the fuel flowing into the fuel injection hole 220 increases.

  The flow of the fuel flowing from the swirl chamber 212 into the fuel injection hole 220 will be described with reference to FIGS. FIG. 5 is a diagram showing an analysis result of a fuel flow in a cross section taken along line VV of FIG. 4. FIG. 6 is a plan view showing a configuration of a lateral passage 211 ', a swirl chamber 212', and a fuel injection hole 220 'in a comparative example with the present embodiment. FIG. 7 is a diagram showing an analysis result of a fuel flow in a cross section taken along line VII-VII of FIG.

  In this embodiment, the spray form is as shown in FIG. On the side 501 where the fuel flows into the fuel injection hole 220 without sufficiently swirling through the swirl chamber 212, the fuel spray having a large flow velocity (axial speed) in the axial direction of the fuel injection hole 220 and a strong penetration force is formed. It is formed. On the 501 side, the spray angle is small and the penetration is long. On the other hand, on the 502 side, the fuel flow swirled in the swirl chamber 212 flows into the fuel injection hole 220. For this reason, the fuel spray is formed on the 502 side at a lower velocity in the axial direction of the fuel than on the 501 side, and has a low penetration force. Further, on the 502 side, since the turning force is stronger than on the 501 side, the spray angle is large and the penetration is short.

  On the other hand, in the configuration of the comparative example in FIG. 6, the entire inlet opening 220i 'of the fuel injection hole 220' is located closer to the center O 'of the swirl chamber 212 than the extension 211il of the side wall 211i. In this case, the fuel flow provided with the swirling force flows over the entire circumference of the inlet opening 220i 'of the fuel injection hole 220'. Therefore, in the comparative example, as shown in FIG. 7, a fuel spray in which the spray angle and the fuel flow rate on the 701 side are equal to the spray angle and the fuel flow rate on the 702 side is formed.

  In this embodiment, since the swirling force of the fuel flow is weak on the 501 side, the effect of atomization using the swirling force is reduced. However, by increasing the axial speed, it is possible to suppress or maintain / improve the deterioration of the atomization performance by utilizing frictional heat with air. Therefore, in the present embodiment, it is possible to easily adjust the fuel injection amount while suppressing the reduction in the atomization performance. Further, as described above, although the spray form (angle and particle size) of the fuel is changed, the spray form of the spray form is different from the case where the cross-sectional area of the lateral passage 211 and the fuel injection hole 220 is changed for flow rate adjustment. The amount of change can be reduced.

  When the fuel injection hole 220 is configured to protrude toward the side wall 211o beyond the extension line 211il of the side wall 211i, for example, in the comparative example of FIG. 6, the fuel injection hole 220 is shifted downward in the drawing. Become. That is, the fuel injection hole 220 'is shifted in a direction away from the inner peripheral wall 220c' located on the upper side in the drawing. If the fuel injection hole 220 ′ is simply shifted, the fuel flow into the fuel injection hole 220 ′ is inhibited as much as the fuel injection hole 220 ′ is separated from the inner peripheral wall 220 c ′. For this reason, it is preferable that the inner peripheral wall 220c 'located on the upper side in the drawing is closer to the fuel injection hole 220' by the amount by which the fuel injection hole 220 'is shifted downward in the drawing. When the inner peripheral wall 220c 'located on the upper side in the drawing is brought closer to the fuel injection hole 220', the volume of the swirl chamber 212 can be reduced accordingly, and the dead volume formed downstream of the valve seat 15b is reduced. be able to.

  An internal combustion engine equipped with the fuel injection valve according to the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view of the internal combustion engine on which the fuel injection valve 1 is mounted.

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

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

  A mounting portion 109 for the fuel injection valve 1 is formed in the intake pipe 108, and an insertion port 109 a for inserting the fuel injection valve 1 is formed in the mounting portion 109. The insertion port 109a penetrates to the inner wall surface (intake channel) 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 channel. In the case of two-way spraying, each fuel spray is directed toward each intake port 103 (intake valve 105) for an internal combustion engine in which two intake ports 103 are provided in the engine block 101.

  Note that the present invention is not limited to the above-described embodiments, and some components may be deleted or other components not described may be added. Further, between the embodiments, the configuration described in each embodiment can be replaced or added.

  DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve, 1a ... Valve axis (center axis), 2 ... Fuel supply port, 3 ... Fuel flow path, 5 ... Cylindrical body, 7 ... Valve part, 9 ... Drive part, 11 ... O-ring, 13 ... fuel filter, 15 ... valve seat member, 15a ... valve body accommodation hole, 15b ... valve seat, 15c ... guide surface, 15t ... front end side end surface, 17 ... valve body, 17a ... notch surface, 19 ... laser welding, 21 ... fuel injection part, 21n ... nozzle plate, 21nu ... upper end face, 21nb ... lower end face, 23 ... laser welded part, 25 ... fixed iron core, 25a ... through hole, 27 ... movable element, 27a ... movable iron core, 27b ... small diameter part , 27c recess, 27d opening, 27e annular surface, 27f through hole, 29 electromagnetic coil, 31 bobbin, 33 yoke, 35 adjuster, 39 spring (coil spring), 41 ... Connector, 43 ... Connector pin, 45 ... Wire member, 46 O-ring, 47 resin cover, 49 protector, 100 internal combustion engine, 101 engine block, 102 cylinder, 103 intake port, 104 exhaust port, 105 intake valve, 106 exhaust valve , 107: intake passage, 107a: inlet end, 108: intake pipe, 109: mounting part of fuel injection valve 1, 109a: insertion port, 110: fuel pipe, 210, 210-1, 210-2, 210 -3, 210-4, 210 ': turning path, 211, 211-1, 211-2, 211-3, 211-4, 211': lateral path, 211b: bottom surface, 211i, 211o: side wall (side surface) ), 211il, 211ol ... extension line of side wall, 211u ... top surface (ceiling surface), 212, 212-1, 212-2, 212-3, 212-4, 212 '... swirl chamber (swirl chamber) , 212b: bottom surface, 212c, 212c ': inner peripheral wall (side surface), 212ce: inner peripheral wall end portion, 212cs: inner peripheral wall starting end, 220, 220-1, 120-2, 220-3, 220-4, 220'. ... fuel injection holes, Oa, Oa '... centers of fuel injection holes and swirl chambers, 220i, 220i' ... inlet openings (edges of inlet openings), 220ia, 220ib ... intersections between extension lines 211il and inlet openings of fuel injection holes, 300: fuel introduction hole.

Claims (3)

A fuel injection hole provided on a downstream side of a valve seat with which the valve body comes and goes, an inlet of the fuel injection hole is opened at a bottom surface, a periphery of the bottom surface is surrounded by an inner peripheral wall, and a swirling flow of fuel flows around the entrance. A swirl chamber in which a path is formed, and one side wall is connected to an upstream side of the inner peripheral wall in a flow direction of the swirling fuel, and the other side wall is connected to a downstream side of the inner peripheral wall to open to the inner peripheral wall, and the swirl is formed. A lateral passage for supplying fuel to the chamber;
A fuel injection valve, wherein an extension line extending along the other side wall of the lateral passage so as to contact the other side wall passes through the center of the fuel injection hole. The fuel injection valve according to claim 1,
A nozzle plate in which the fuel injection holes, the swirl chamber and the lateral passage are formed,
The fuel injection is provided between an extension extending along the other side wall of the lateral passage so as to be in contact with the other side wall and a line passing through the center of the nozzle plate and being parallel to the lateral passage. A fuel injection valve, wherein a part of a hole is arranged. The fuel injection valve according to claim 1,
A nozzle plate having a plurality of the fuel injection holes, the swirl chamber and the lateral passage,
A first extension line extending along the one side wall so as to contact the one side wall of the lateral passage, and extending along the other side wall so as to contact the other side wall of the lateral passage A second extension line, imagining the center of the nozzle plate, the entrance openings of the plurality of fuel injection holes, the swirl chamber, the lateral passage, the first extension line and the second extension line as a fuel injection valve When projected on a plane perpendicular to the central axis of
The projected view of the entrance opening of the first fuel injection hole out of the plurality of fuel injection holes is located on the side of the projected view of the one side wall or the projected view of the first extension line beyond the second extension line,
On a line connecting a projection of the center of the nozzle plate and a projection of the center of the inlet opening of the first fuel injection hole, and the projection of the center of the nozzle plate with respect to the projection of the first fuel injection hole. A fuel injection valve having a second fuel injection hole having a projected view of the center of the inlet opening opposite to a projected view of the center of the inlet opening.

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