JP2020012377A - Fuel injection valve - Google Patents

Abstract

To enhance the stability of fuel spray by reducing the separation in an injection hole.SOLUTION: The fuel injection valve includes twisted injection holes (32, 33, 35, 36) constructed with injection hole axes (32c, 33c, 35c, 36c) twisted in directions different from straight lines between a valve element center axis 305 and each of the centers of injection hole inlets (32a, 33a, 35a, 36a). Pitch angles (A23, A34, A45, A56) between the twisted injection holes (32, 33, 35, 36) and twisting direction side injection holes (33, 34, 34, 35) adjacent to one another in twisting directions (32e, 33e, 35e, 36e) are smaller than pitch angles (A12, A23, A56, A61) between the twisted injection holes (32, 33, 35, 36) and counter twisting direction side injection holes (31, 32, 36, 31) adjacent to one another in opposite directions to the twisting directions (32e, 33e, 35e, 36e).SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fuel injection valve used for an internal combustion engine such as a gasoline engine.

  In recent years, there has been an increasing demand for gasoline engines in automobiles to improve fuel efficiency.As an engine with excellent fuel efficiency, fuel is directly injected into a combustion chamber, and a mixture of injected fuel and intake air is ignited by a spark plug. Explosive in-cylinder injection engines have become widespread. In a fuel injection valve used in an in-cylinder injection type engine, if fuel droplets scattered during fuel injection adhere to the tip, incomplete combustion may cause a particulate matter (Particulate Matter: PM) to be generated. It has become.

  On the other hand, Patent Literature 1 discloses a technique in which the fuel is suppressed from adhering and the generation of PM is suppressed by forming the spray and the wall surface of the fuel injection hole opening away from each other.

Patent No. 5696901

  Patent Literature 1 describes a technique relating to a wall shape that suppresses fuel adhesion to the tip of a fuel injection valve. On the other hand, no consideration has been given to a method of forming an optimal spray for reducing the amount of fuel adhering to the tip of the fuel injection valve.

  In view of the above, an object of the present invention is to provide a fuel injection valve that reduces separation in an injection hole and enhances spray stability.

  In order to solve the above-mentioned problem, the present invention relates to a fuel injection valve for directly injecting fuel into a combustion chamber of an internal combustion engine, wherein an injection hole axis connecting a center of an injection hole inlet and a center of an injection hole outlet has a valve body center. A straight line connecting an axis and the center of the injection hole inlet is provided with a twisted injection hole twisted in a different direction, and a pitch angle between the twisted injection hole and the twist direction side injection hole adjacent in the torsion direction is increased. The pitch angle between the twist injection hole and the counter twist direction injection hole adjacent in the direction opposite to the twist direction is configured to be smaller.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel injection valve which reduces the peeling in an injection hole and improves the stability of spraying can be provided.

FIG. 1 is a diagram showing an internal combustion engine according to the present invention. FIG. 2 is a diagram showing a cross section of a fuel injection valve according to the present invention. FIG. 2 is an enlarged sectional view of a lower end portion of the fuel injection valve according to the first embodiment of the present invention. FIG. 3 is a diagram showing a viewpoint from an upstream side of an injection hole inlet arrangement of a lower end portion of the fuel injection valve according to the first embodiment of the present invention. FIG. 2 is a view showing a viewpoint from an upstream side of an injection hole inlet arrangement of a lower end portion of the fuel injection valve and a cross section of the injection hole according to the first embodiment of the present invention. FIG. 2 is a view showing a viewpoint from an upstream side of an injection hole inlet arrangement of a lower end portion of the fuel injection valve and a cross section of the injection hole according to the first embodiment of the present invention. FIG. 3 is a diagram illustrating a relationship between a spray direction and an injection hole of the internal combustion engine according to the first embodiment of the present invention. FIG. 2 is a view showing a viewpoint from an upstream side of an injection hole inlet arrangement of a lower end portion of the fuel injection valve and a cross section of the injection hole according to the first embodiment of the present invention. It is the figure which showed the viewpoint from the upstream of the injection hole inlet arrangement | positioning of the lower end part of the fuel injection valve which concerns on the 2nd Example of this invention. It is a figure showing a viewpoint from the upper stream side of an injection hole entrance arrangement of a fuel injection valve lower end concerning a 3rd example of the present invention.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

  An internal combustion engine and a fuel injection valve according to a first embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a diagram showing an outline of a configuration of a direct injection engine. The basic operation of the direct injection engine will be described with reference to FIG. In FIG. 1, a combustion chamber 104 is formed by a cylinder head 101, a cylinder block 102, and a piston 103 inserted into the cylinder block 102, and an intake pipe 105 and an exhaust pipe 106 are branched into two toward the fuel chamber 104. It is connected. An intake valve 107 is provided at an opening of the intake pipe 105, and an exhaust valve 108 is provided at an opening of the exhaust pipe 106. The intake valve 107 operates to open and close by a cam operation method.

  The piston 103 is connected to a crankshaft 115 via a connecting rod 114, and the engine speed can be detected by a crank angle sensor 116. The value of the rotation speed is sent to an ECU (engine control unit) 118. A cell motor (not shown) is connected to the crankshaft 115. When the engine is started, the crankshaft 115 can be rotated by the cell motor to start the engine. The cylinder block 102 is provided with a water temperature sensor 117, which can detect the temperature of engine cooling water (not shown). The temperature of the engine cooling water is sent to the ECU 118.

  Although FIG. 1 describes only one cylinder, a collector (not shown) is provided upstream of the intake pipe 105 to distribute air to each cylinder. An air flow sensor and a throttle valve (not shown) are provided upstream of the collector, and the amount of air taken into the fuel chamber 104 can be adjusted by the opening of the throttle valve.

  Fuel is stored in a fuel tank 109 and sent to a high-pressure fuel pump 111 by a feed pump 110. The feed pump 110 raises the pressure of the fuel to about 0.3 MPa and sends it to the high-pressure fuel pump 111. The fuel pressurized by the high-pressure fuel pump 111 is sent to the common rail 112. The high-pressure fuel pump 111 raises the pressure of the fuel to about 30 MPa and sends it to the common rail 112. The common rail 112 is provided with a fuel pressure sensor 113 for detecting a fuel pressure (fuel pressure). The value of the fuel pressure is sent to the ECU 118.

  FIG. 2 is a diagram illustrating an example of an electromagnetic fuel injection valve as an example of the fuel injection valve according to the first embodiment of the present invention. The fuel injection valve 119 of this embodiment injects fuel directly into the combustion chamber 104 of the internal combustion engine. The basic operation of the injection device will be described with reference to FIG. In FIG. 2, fuel is supplied from a fuel supply port 212 and supplied to the inside of a fuel injection valve. The electromagnetic fuel injection valve 119 shown in FIG. 2 is a normally-closed electromagnetic drive type. When the coil 208 is not energized, the valve body 201 is urged by a spring 210 and is welded to the nozzle body 204 by welding or the like. The fuel is pressed against the joined sheet member 202 to seal the fuel. At this time, in the in-cylinder fuel injection valve, the supplied fuel pressure is in a range of approximately 10 MPa to 50 MPa.

  When the coil 208 is not energized, a gap having a predetermined size is formed between the core 207 and the anchor 206 in the axial direction of the valve body. The anchor 206 has a concave portion 206a that is recessed from the upper surface toward the downstream side, and the bottom surface of the concave portion 206a of the anchor 206 and the lower surface of the large diameter portion 201a of the valve body 201 are engaged. The anchor 206 is urged from the downstream side to the upstream side by the anchor urging spring 213 to determine the stop position in the valve closed state.

  When the coil 208 is energized through the connector 211, a magnetic flux density is generated in the core (fixed core) 207, the yoke 209, and the anchor 206 that constitute the magnetic circuit of the solenoid valve, and a magnetic attraction force is generated between the core 207 and the anchor 206. Is generated. When the magnetic attraction force becomes larger than the urging force of the spring 210 and the above-described force due to the fuel pressure, the anchor 206 is attracted toward the core 207, whereby the anchor 206 becomes larger in the above-described gap in the valve element axial direction. Move so that the value becomes zero. At this time, the bottom surface of the concave portion 206a of the anchor 206 engages with the lower surface of the large diameter portion 201a of the valve body 201 and pushes it up. As a result, the rod portion 201b of the valve body 201 is driven in the upstream direction (valve opening direction) while being guided by the downstream guide member 203 and the upstream valve body guide 205, and the valve is opened. When the valve is opened, a gap is created between the seat portion 304a of the seat member 202 and the valve body-side seat portion 201c of the valve body 201, and fuel injection is started. When the fuel injection is started, the energy given as the fuel pressure is converted into kinetic energy, and the fuel is injected into a fuel injection hole opened at the lower end of the fuel injection valve.

  Next, FIG. 3 is an enlarged cross-sectional view of the lower end portion of the fuel injection valve, and is composed of a seat member 202 and a valve body 201 (rod portion 201b). The seat member 202 has a substantially planar shape and is formed so as to be inclined from the valve body central axis 305 over the entire circumference, and has an inlet on the same plane as the valve seat surface 304 on the downstream side of the seat portion 304a. It has a plurality of fuel injection holes (injection holes) in which a portion is formed. FIG. 3 illustrates the first injection hole 31 as an example. The valve seat surface 304 and the valve element 201 extend axially symmetrically about the valve element central axis 305. When the valve body 201 is not lifted, the valve body side seat portion 201c of the valve body 201 comes into line contact with the seat portion 304a of the valve seat surface 304 of the seat member 202, and the flow of fuel is shut off.

  When the valve body 201 is lifted by a certain lift amount, the fuel passes through a gap between the seat portion 304a of the seat member 202 and the valve body-side seat portion 201c of the valve body 201, passes through a path indicated by an arrow 311 and passes through the injection hole 31. Injected from. A recess (suck chamber 302) that is recessed in the downstream direction is formed in the sheet member 202 at a distal end portion downstream of the plurality of injection holes 31. Part of the fuel flows into the sack chamber 302 and flows into the injection hole 31 from the path indicated by the arrow 312.

  FIG. 4 is a view of the arrangement of the inlets of the plurality of injection holes in the present embodiment as viewed from the upstream side. In this embodiment, as shown in FIG. 4, the seat member 202 has the first injection hole 31, the second injection hole 32, and the third injection hole 33 on the pitch circle 401 centered on the valve body central axis 305 in a counterclockwise direction. , A fourth injection hole 34, a fifth injection hole 35, a sixth injection hole 36, and six injection holes. However, the present invention is not limited to six injection holes, and can be applied to three or more injection holes. The inlets of the respective injection holes are referred to as a first injection hole inlet 31a, a second injection hole inlet 32a, a third injection hole inlet 33a, a fourth injection hole inlet 34a, a fifth injection hole inlet 35a, and a sixth injection hole inlet 36a. .

  Each injection hole inlet (31a-36a) is perforated toward the injection hole outlet (31b-36b), and the fuel flows in from the injection hole inlet (31a-36a) and from the injection hole outlet (31b-36b). leak. In FIG. 4, the fuel flows radially toward the center in a flow direction 402, and flows into the respective injection hole inlets (31a to 36a).

  In FIG. 4, a second injection hole shaft 32c connecting the center of the second injection hole inlet 32a and the center of the second injection hole outlet 32b is a straight line 32d connecting the valve body central axis 305 and the center of the second injection hole inlet 32a. It is twisted and set differently. In this embodiment, at least one injection hole 32 having the injection shaft 32c in the twisted direction is thus set. The angle formed between the straight line 32d and the second injection hole axis 32c is referred to as a torsion angle 32e, and the direction in which the second injection hole axis 32c is formed with respect to the straight line 32d is referred to as a torsion direction 32f. In this embodiment, in addition to the second injection hole 32, the injection hole axes (33 c, 35 c, 36 c) of the third injection hole 33, the fifth injection hole 35, and the sixth injection hole 36 correspond to the valve body central axis 305. It is set to be twisted so as to be different from the straight line (33d, 35d, 36d) connecting the center of the injection hole inlet (33a, 35a, 36a). In a fuel injection valve, it is necessary to appropriately set an injection direction in order to obtain an optimum air-fuel mixture, and an injection hole having a twist angle is required to inject fuel in a target direction.

  FIG. 5A is a view showing the flow into the second injection hole inlet 32a from the same viewpoint as FIG. FIG. 5B is a diagram showing a tangent line 403 of the pitch circle 401 having the center of the second injection hole inlet 32a as a contact point and a cross section passing through the second injection hole axis 32c. The effect of this embodiment will be described with reference to FIG. In FIG. 5B, the second injection hole shaft 32c is inclined with respect to the valve body shaft 305. Therefore, at the inlet of the injection hole, an edge portion 404 having a steep inflow inclination angle and an edge portion 405 having a gentle inflow inclination angle are formed. The path of the flow that flows into the injection hole takes a path 407 that largely wraps around and flows around the edge portion 404 having a steep inflow inclination angle. On the other hand, around the edge portion 405 having a gentle inflow inclination angle, a path 406 inflowing at an angle close to the second injection hole axis 32c is taken.

  In other words, in FIG. 5B, the edge 404 of the second injection hole shaft 32 c in the inclination direction (rightward direction in FIG. 5B) with respect to the valve body shaft 305 is the valve seat surface near the second injection hole 32. The inflow inclination angle formed by 304 and the inclination-direction-side inner diameter portion 32g is formed to be an acute angle. In FIG. 5B, the edge 405 on the side opposite to the direction in which the second injection hole shaft 32 c is inclined with respect to the valve body shaft 305 (the left direction in FIG. 5B) is close to the second injection hole 32. The inflow inclination angle formed by the valve seat surface 304 and the anti-inclination side inner diameter portion 32h is formed to be an obtuse angle.

  In FIG. 5A, paths 407 and 406 flowing horizontally into the tangent line 403 are the corresponding flow paths. Here, in FIG. 5B, flow separation 408 is likely to be formed due to the flow path 407. In order to increase the stability of the spray and to suppress the adhesion of the fuel droplets to the fuel injection valve, it is necessary to reduce the separation. Here, in the present embodiment, a straight line 32d connecting the valve body center axis 305 and the center of the second injection hole inlet 32a, and a straight line 33d connecting the valve body center axis 305 and the center of the third injection hole inlet 33a. The angle formed is referred to as a pitch angle between the second injection hole 32 and the third injection hole 33. In this embodiment, the pitch angle A23 between the second injection hole 32 having a twist angle and the third injection hole 33 adjacent to the second injection hole 32 on the side of the torsion direction 32f corresponds to the second injection hole. The pitch angle A12 between the first injection hole 31 and the second injection hole 31 adjacent to the side opposite to the twist direction 32f of 32 is increased.

  Accordingly, the flow of the inflow path 406 having a gentle inflow inclination angle can be strengthened with respect to the inflow path 407 having a steep inflow inclination angle. This is because the strength relationship between the flows passing through the flow path 407 and the flow path 406 is as follows: path 407 <path 406. Due to the magnitude relationship of the pitch angle, the magnitude of the cross-sectional area of the path upstream of the injection hole is established, and the strength of the inflow can be generated. According to this embodiment, the flow of the inflow path 406 having a gentle inflow inclination angle can be strengthened with respect to the inflow path 407 having a steep inflow inclination angle, and separation 408 can be suppressed. That is, by configuring the pitch angle A12 to be larger than the pitch angle A23, it is possible to reduce the separation in the injection holes, increase the stability of the spray, and suppress the adhesion of the fuel droplets to the fuel injection valve. Can be.

  The twist direction 32f does not necessarily need to be downward in FIG. 5A, that is, on the third injection hole 33 side, but may be upward, that is, on the first injection hole 31 side. In this case, a desired effect can be obtained by reversing the magnitude relationship between the pitch angle A12 and the pitch angle A23 and setting the pitch angle A12 <the pitch angle A23. Further, the centers of the first injection hole inlet 31a, the second injection hole inlet 32a, and the third injection hole inlet 33a do not all need to be on the same pitch circle 401, and the centers of any of the injection hole inlets are different. It may be set on the pitch circle. In this case, the strength relationship between the flows passing through the flow path 407 and the flow path 406 needs to match the present embodiment. That is, the effect of the present embodiment can be obtained in a range where the flow path cross-sectional area of the path 406 is larger than the flow path cross-sectional area of the path 407 on the upstream side of the injection hole.

  FIG. 6A is a diagram showing the flow into the third injection hole inlet 33a adjacent to the second injection hole inlet 32a from the same viewpoint as FIG. 5A. FIG. 6B is a diagram showing a tangent line 420 of the pitch circle 401 having the center of the third injection hole inlet 33a as a contact point and a cross section passing through the third injection hole axis 33c. The flow of the fuel injection valve according to the present embodiment into the injection hole different from the injection hole shown in FIG. 5 will be described with reference to FIG. In FIG. 6A, similarly to the second injection hole inlet 32a of FIG. 5A, the third injection hole shaft 33c connecting the center of the third injection hole entrance 33a and the center of the third injection hole outlet 33b is formed. The straight line 33d connecting the valve body center axis 305 and the center of the third injection hole inlet 33a is twisted differently. The torsion angle between the third injection hole shaft 33c and the straight line 33d is 33e, which is formed so as to have a downward torsion direction 33f in FIG. 6A.

  At this time, in the cross section shown in FIG. 6B, similarly to FIG. 5B, an edge portion 424 having a steep inflow inclination angle and an edge portion 425 having a gentle inflow inclination angle are formed. The flow path of the flow flowing into the injection hole takes a path 426 that largely wraps around the edge 424 with a steep inflow inclination angle, and takes a path 426 around the edge 425 with a gentle incline inclination angle. A path 427 that flows in at an angle close to the three injection hole axis 33c is taken. In FIG. 6A, a path 424 and a path 425 that flow horizontally into the tangent line 420 are the corresponding flow paths.

  Here, in FIG. 6B, a flow separation 428 is formed by the flow path 426. In order to increase the stability of the spray and to suppress the adhesion of the fuel droplets to the fuel injection valve, it is necessary to reduce the separation. Therefore, in the present embodiment, injection having a twist angle is performed with respect to the pitch angle A34 between the third injection hole 33 having the twist angle and the fourth injection hole 34 adjacent to the third injection hole 33 on the twist direction 33f side. The pitch angle A23 between the hole 33 and the injection hole 32 adjacent on the side opposite to the twist direction 33f is increased. Accordingly, the flow of the inflow path 425 having a gentle inflow inclination angle can be strengthened with respect to the inflow path 424 having a steep inflow inclination angle, and separation 428 can be suppressed. That is, by configuring the pitch angle A23 to be larger than the pitch angle A34, it is possible to enhance the stability of spraying and suppress the adhesion of the fuel droplets to the fuel injection valve.

  The second injection hole 32 in FIG. 5A corresponds to the third injection hole 33 in FIG. 6A, and the third injection hole 33 in FIG. 5A corresponds to the fourth injection hole in FIG. It corresponds to the hole 34. The pitch angle A23 in FIG. 5A corresponds to the pitch angle A34 in FIG.

  That is, as described above, in the present embodiment, the pitch angle A12 is configured to be larger than the pitch angle A23. The pitch angle A23 between the third injection hole 33 having a torsion angle and the second injection hole 32 adjacent to the third injection hole 33 on the side opposite to the twist direction 33f is equal to the third injection hole 33 and the third injection hole 33. It is configured to be larger than the pitch angle A34 between the injection hole 33 and the second injection hole 32 adjacent to the twist direction 33f side.

  As described above, the fuel injection valve of the present embodiment has an injection hole axis (32c) connecting the center of the injection hole inlet (32a, 33a, 35a, 36a) and the center of the injection hole outlet (32b, 33b, 35b, 36b). , 33c, 35c, 36c) are twisted in a direction different from a straight line connecting the valve body center axis 305 and the center of the injection hole inlet (32a, 33a, 35a, 36a). , 35, 36). The pitch angle between the torsional injection holes (32, 33, 35, 36) and the torsional direction injection holes (33, 34, 34, 35) adjacent in the torsional direction (32e, 33e, 35e, 36e) ( A23, A34, A45, A56) are adjacent to the torsional injection holes (32, 33, 35, 36) in the opposite direction to the torsional direction (32e, 33e, 35e, 36e). 32, 36, 31) is smaller than the pitch angle (A12, A23, A56, A61).

  Thereby, in each of the second injection hole 32 and the third injection hole 33, it is possible to increase the flow from the direction (406, 427) where the inflow inclination angle is gentle, and it is possible to suppress the separation in the injection hole. . Thereby, the stability of the spray can be enhanced, and the adhesion of the fuel droplets to the fuel injection valve can be suppressed.

  FIG. 7A shows an overview of a center cross section of the internal combustion engine according to the present embodiment and a side view of a spray injected from a fuel injection valve. The fuel injection device 119 is installed on the side of the internal combustion engine, and is injected from a plurality of injection holes of the fuel injection valve. The injected fuel forms a spray in the direction of the central axis of the injection hole. The fuel injection valve according to the present embodiment forms a spray S1 directed toward the spark plug 120 and a spray S2, a spray S3, and a spray S4 directed toward the wall surface of the internal combustion engine.

  FIG. 7B is a diagram showing the relationship between the injection hole and the spray from the same viewpoint as in FIG. 5A. The first injection hole 31 of FIG. 7B forms the spray S1 of FIG. 7A. The second injection hole 32 adjacent to the first injection hole 31 and the sixth injection hole 36 adjacent to the first injection hole 31 on the opposite side to the second injection hole 32 form the spray S2. Further, a third injection hole 33 adjacent to the second injection hole 32 on the opposite side to the first injection hole 31 and a fifth injection hole 35 adjacent to the sixth injection hole 36 on the opposite side to the first injection hole 31 are formed. A spray S3 is formed. Further, the fourth injection hole 34 arranged between the third injection hole 33 and the fifth injection hole 35 forms the spray S4. In this embodiment, the first injection hole entrance 31a and the fourth injection hole entrance 34a are arranged such that the centers of the first injection hole entrance 31a and the fourth injection hole entrance 34a are on the straight line 500. The second injection hole inlet 32a and the sixth injection hole inlet 36a, and the third injection hole inlet 33a and the fifth injection hole inlet 35a are respectively arranged symmetrically about the straight line 500. FIG. 7A is a view from the side of the spray, and the sprays S2 from the second injection hole inlet 32a and the sixth injection hole inlet 36a are shown overlapping. Similarly, the spray S3 from the third injection hole inlet 33a and the fifth injection hole inlet 35a are also shown overlapping.

  In this embodiment, in FIG. 7, the first injection holes 32 forming the spray S1 directed to the ignition plug are referred to as first-stage injection holes. The second injection hole 32 and the sixth injection hole 36 that are adjacent to the first-stage injection hole and form the spray S2 are referred to as second-stage injection holes. The third injection hole 33 and the fifth injection hole 35 that are adjacent to the second-stage injection hole and form the spray S3 are referred to as third-stage injection holes. The fourth injection hole 35 adjacent to the third-stage injection hole and forming the spray S4 is referred to as a fourth-stage injection hole.

  Since the installation position of the fuel injection device 119 and the installation position of the spark plug 120 are on the same cross section in FIG. 7A, the first-stage injection hole has no torsion angle. The second-stage injection hole and the third-stage injection hole are configured to have a twist angle so as to be directed toward the piston 103 (that is, the lower side in the piston axial direction) in order to widely disperse the fuel in the combustion chamber. . That is, the injection direction of the second-stage injection hole and the third-stage injection hole requires a twist direction in the direction of the fourth-stage injection hole. The fourth-stage injection holes are arranged on the straight line 500 and do not have a twist angle because it is necessary to form a spray uniformly in the combustion chamber.

  In this embodiment, as described above, the pitch angle between the first-stage injection hole and the second-stage injection hole is set to be larger than the pitch angle A23 between the second-stage injection hole and the third-stage injection hole. To be configured. That is, as described above, the pitch angle A12> the pitch angle A23, and at the same time, between the sixth injection hole 36 having the twist angle and the fifth injection hole 35 adjacent to the sixth injection hole 36 in the twist direction 36f. With respect to the pitch angle A56, the pitch angle A61 between the sixth injection hole 36 and the first injection hole 31 adjacent to the twist direction 36f on the opposite side is increased.

  Further, it is necessary to make the pitch angle larger than the pitch angle between the third-stage injection hole and the fourth-stage injection hole. That is, as described above, the pitch angle A23> the pitch angle A34, and between the fifth injection hole 35 having the twist angle and the fourth injection hole 34 adjacent to the fifth injection hole 35 in the twist direction 35f. With respect to the pitch angle A45, the pitch angle A56 between the fifth injection hole 35 and the sixth injection hole 36 adjacent to the twist direction 35f on the opposite side is increased.

Thereby, the separation in the injection hole can be reduced, the stability of the spray can be increased, and the attachment of the fuel droplet to the fuel injection valve can be suppressed. Note that the fuel injection valve of the present embodiment is not limited to a fuel injection valve having six injection holes, and a desired effect can be obtained by similarly setting the pitch angle of the injection holes having three or more injection holes. Can be
Further, the effect of the present embodiment can be more suitably obtained in a configuration in which the injection hole in the fuel flow path has a minimum sectional area. More specifically, when the valve body 201 is lifted until the anchor 206 collides with the core 207, the seat cross-sectional area between the seat portion 304a of the seat member 202 and the valve body-side seat portion 201c of the valve body 201 is: Desirably, the total area of the injection hole inlets (31a to 36a) is reduced.

  With this configuration, the flow velocity decreases upstream of the injection hole inlet, and the effect of reducing separation by optimizing the pitch angle can be more appropriately obtained. However, the present embodiment is not limited to the configuration in which the injection hole has the final cross-sectional area of the flow path, and may be configured so that, for example, the sheet portion 304 has the minimum cross-sectional area of the flow path. Further, R may be provided at the inlet of the injection hole. By setting in this manner, the separation in the injection hole can be more suitably reduced, the stability of the spray can be increased, and the adhesion of the fuel droplet to the fuel injection valve can be suppressed. Further, the sectional area of the outlet of the injection hole may be smaller than the sectional area of the inlet of the injection hole. By setting in this manner, the separation in the injection hole can be more suitably reduced, the stability of the spray can be increased, and the adhesion of the fuel droplet to the fuel injection valve can be suppressed.

  Next, in FIG. 8, the pitch angle including the first-stage injection hole (first injection hole 31) and the fourth-stage injection hole (fourth injection hole 34) of the fuel injection valve according to this embodiment and the flow into the injection hole are shown. Is described. FIG. 8A is a diagram showing the flow into the injection hole having no twist angle in the same cross section as FIG. 5A. In this embodiment, the first-stage injection holes (first injection holes 31) and the fourth-stage injection holes (first injection holes 34) are injection holes having no twist, and both are arranged on the straight line 500. I have. The second-stage injection holes (the second injection holes 32 and the sixth injection holes 36) adjacent to the first injection holes 31 are arranged on the left and right of the drawing, and form a pitch angle A12 and a pitch angle A61, respectively.

  In this embodiment, the pitch angle A12 and the pitch angle A61 are configured to be equal. Similarly, third-stage injection holes (third injection holes 33 and fifth injection holes 35) adjacent to the fourth-stage injection holes (fourth injection holes 34) are arranged on the left and right in the figure, and have a pitch angle A34 respectively. And a pitch angle A45. In this embodiment, the pitch angle A34 and the pitch angle A45 are configured to be equal. For the injection holes having no twist angle, it is desirable to make the flow into the left and right equal and to reduce the bias of the flow.

  FIG. 8B is an enlarged view near the injection hole in a cross section on the straight line 500. The left half of the figure is a sectional view of the fourth injection hole 34, and the right half of the figure is a sectional view of the first injection hole 31. The central axis 34c of the fourth injection hole 34 is inclined by an angle 505 from the valve body central axis 305, and the first central axis 31c of the first injection hole 31 is inclined by an angle 506 from the valve body central axis. In the present embodiment, the inclination angle 505 of the fourth central axis 34c of the fourth injection hole 34 is set to be larger than the inclination angle 506 of the first central axis 31c of the first injection hole 31. At this time, the first injection hole 31 forms a gentle slope 507 on the upstream side and a sharp slope 508 on the suck chamber 302 side. On the other hand, in the fourth injection hole 34, the edge 509 has a steep slope, and the edge 510 has a gentle slope.

  At this time, in the first injection hole 31, the sack side edge portion 508 having a steep inclination is easily separated. Therefore, it is desirable that the flow 511 from the upstream side is strong and the separation on the suck chamber side is reduced. On the other hand, in the fourth injection hole 34, since the upstream edge 509 has a steep inclination, the separation can easily occur on the upstream side. Therefore, the flow 512 from the upstream side is weak, and it is desirable to reduce the separation on the upstream side.

  Therefore, with respect to the fourth injection hole 34 having a large inclination 505 of the fourth injection hole axis 34c from the valve body central axis 305, the pitch angle A34 between the adjacent third injection hole 34 and the fifth injection hole 35 and the pitch Reduce the angle A45. Thereby, the inflow 512 from the upstream side is weakened, and the separation formed on the upstream side can be suppressed. On the other hand, for the first injection hole 31 having a small inclination 506 of the first injection hole axis 31c from the valve body central axis, the pitch angle A12 and the pitch angle between the adjacent second injection hole 31 and sixth injection hole 36 are set. A61 is configured to be widened. Thereby, the inflow 511 from the upstream side is strengthened, and the separation formed on the suck chamber side can be suppressed.

  That is, in the fuel injection valve 119 of this embodiment, the injection hole axes (31c, 34c) connecting the centers of the injection hole inlets (31a, 34a) and the injection hole outlets (31b, 34b) are aligned with the valve body central axis. A plurality of injection holes (31, 34) are provided in the same direction as a straight line (31d, 34d) connecting the center of the injection hole entrances (31a, 34a) with 305. Of the plurality of injection holes (31, 34), the small-inclination injection hole (first injection hole 31) and the small-inclination angle 506 formed by the valve body central axis 305 and the injection hole axis (first injection hole axis 31c) are small. The pitch angles (A12, A61) between the injection holes (the second injection holes 32, the sixth injection holes 36) adjacent to the injection holes (the first injection holes 31) correspond to the valve body central axis 305 and the injection hole axis ( The large-inclined injection hole (fourth injection hole 34) and the injection hole (third injection hole 33, the fifth injection hole) adjacent to the large-inclined injection hole (fourth injection hole 34) are formed with a large angle between the fourth injection hole shaft 34c). It is configured to be larger than the pitch angle (A34, A45) with the hole 35). Thereby, the separation in the injection hole can be reduced, the stability of the spray can be increased, and the attachment of the fuel droplet to the fuel injection valve can be suppressed.

  Further, in the present embodiment, the fourth injection hole 34 in which the inclination of the fourth injection hole axis 34c from the valve element central axis 305 is large is directed toward the piston 103, and the first injection hole 34c from the valve element central axis 305 The first injection hole 31 having a small inclination of the injection hole shaft 31c is directed toward the tip of the spark plug 120. That is, the pitch angle between the injection hole pointing to the spark plug and the injection hole adjacent to the injection hole is larger than the pitch angle between the injection hole pointing to the piston side and the injection hole adjacent to the injection hole. The configuration is as follows.

  In other words, the fuel injection valve 119 of this embodiment has a plug-directed injection hole (first injection hole 31) pointing toward the tip of the ignition plug 120 and an injection hole (first injection hole) adjacent to the plug-directed injection hole (first injection hole 31). The pitch angle (A12, A61) between the second injection hole 32 and the sixth injection hole 36) is directed toward the center of the upper surface of the piston 103. It is configured to be larger than the pitch angle (A34, A45) with the injection hole (the third injection hole 33, the fifth injection hole 35) adjacent to the fourth injection hole 34).

  As described above, the fuel injection valve of the present embodiment is a horizontal cross-sectional view of a plurality of injection holes viewed from the upstream side (FIGS. 4, 5 (a), 6 (a), 7 (b), 8 (a)). , The first injection hole 31 pointing to the tip of the ignition plug 120, the second injection hole 32 adjacent to the first injection hole 31, and the first injection hole 31 are separate from the first injection hole 31. On the opposite side, a third injection hole 33 adjacent to the second injection hole 32, a fourth injection hole 34 pointing toward the center of the upper surface of the piston 103, and a center passing through the first injection hole 31 and the valve element central axis 305. A fifth injection hole 35 formed on the side opposite to the third injection hole 33 with respect to the line, and a sixth injection hole 36 formed on the side opposite to the second injection hole 32 with respect to the center line 305. . The pitch angle A12 between the first injection hole 31 and the second injection hole 32 is configured to be larger than the pitch angle A23 between the second injection hole 32 and the third injection hole 33.

  The pitch angle A23 between the second injection hole 32 and the third injection hole 33 is configured to be larger than the pitch angle A34 between the third injection hole 33 and the fourth injection hole 34. Is desirable. The pitch angle A61 between the first injection hole 31 and the sixth injection hole 36 is configured to be larger than the pitch angle A56 between the fifth injection hole 35 and the sixth injection hole 36. Is desirable. Further, the pitch angle A56 between the fifth injection hole 35 and the sixth injection hole 36 may be configured to be larger than the pitch angle A45 between the fourth injection hole 34 and the fifth injection hole 35. desirable. With the above configuration, it is possible to reduce the separation in the injection hole, increase the stability of the spray, and suppress the adhesion of the fuel droplet to the fuel injection valve.

  FIG. 9 shows the arrangement of the injection holes of the fuel injection valve according to the second embodiment from the same viewpoint as FIG. In the fuel injection valve 119 according to the second embodiment, the center of each of the second injection hole inlet 32a, the third injection hole inlet 33a, the fifth injection hole inlet 35a, and the sixth injection hole inlet 36a around the valve body central axis 305. And a pitch circle 600 passing through the center of each of the first injection hole inlet 31a and the fourth injection hole inlet 34a. The radius of the pitch circle 600 is configured to be smaller than the radius of the pitch circle 401. The rest of the configuration is the same as in the first embodiment. In this embodiment, the first injection holes 31 and the fourth injection holes 34 having no twist angle are arranged on a pitch circle 600, and the remaining injection holes are arranged on a pitch circle 401.

  At this time, in the first injection hole 31, the sack side edge portion 508 shown in FIG. Therefore, it is desirable that the flow 511 from the upstream side is strong and the separation on the suck chamber side is reduced. In this embodiment, the pitch angle A12 between the first injection hole 31 and the second injection hole 32 and the pitch angle A61 between the first injection hole 31 and the sixth injection hole 36 are set to be large. . Therefore, when the upstream flow velocity is large, the flow 601 into the sack chamber tends to be large. Therefore, in the present embodiment, the center of the first injection hole inlet 31a and the center of the fourth injection hole inlet 34a are arranged on the pitch circle 600 having a small pitch circle radius, so that the sheet portion 304a having the high flow velocity can be moved from the first injection hole 31 to the first injection hole 31. And the flow 601 to the suck chamber 302 can be suppressed. Thereby, the separation in the first injection hole 31 can be reduced, the stability of the spray can be increased, and the attachment of the fuel droplets to the fuel injection valve can be suppressed.

  On the other hand, in the fourth injection hole 34, the upstream edge 509 is steeply inclined as shown in FIG. Therefore, the flow 512 from the upstream side is weak, and it is desirable to reduce the separation on the upstream side. Further, in the present embodiment, since the pitch angles (A34, A45) between the third injection hole 33 and the fifth injection hole 35 and the fourth injection hole 34 are set to be small, the flow 602 into the suck chamber is made. Is less. Therefore, in the present embodiment, the fourth injection hole inlet 34a is arranged on the pitch circle 600 having a small pitch circle radius. That is, when a circle passing through the injection hole inlet with the valve body center axis 305 as the center is defined as a pitch circle, the radius of the pitch circle 401 where the injection holes (32, 33, 35, 36) having a twist angle are located is determined by the twist angle. It is configured to be larger than the radius of the pitch circle 600 where the injection holes (31, 34) not having are located. Thereby, the flow 512 from the upstream side is weakened, and the separation inside the fourth injection hole 34 can be reduced. Thereby, the stability of the spray can be enhanced, and the adhesion of the fuel droplets to the fuel injection valve can be suppressed.

  FIG. 10 shows an injection hole arrangement of the fuel injection valve according to the third embodiment from the same viewpoint as FIG. The fuel injection valve according to the third embodiment includes a first injection hole H1 pointing in the direction of the tip of the spark plug 120, and a second-stage injection hole (second injection hole H2, fifth injection hole H2) adjacent to the first injection hole H1. The five injection holes H5) and the third injection hole (third injection hole H3, fourth injection hole H4) adjacent to the second injection hole (second injection hole H2, fifth injection hole H5). Consists of holes. Other configurations are the same as those of the fuel injection valve according to the first embodiment.

  In the second-stage injection hole (second injection hole H2, fifth injection hole H5), the injection hole axis (second injection hole axis H2c, fifth injection hole axis H5c) is inclined in the twist direction (H2f, H5f). . Therefore, the second-stage injection hole (second injection hole H2, fifth injection hole H5) and the third-stage injection hole (third injection hole H3, fourth injection hole H4) adjacent to the twist direction (H2f, H5f). The pitch angle (AH23, AH45) between the first and second injection holes H2 (the second and fifth injection holes H2, H5) and the first-stage adjacent to the twist direction (H2f, H5f) are opposite to each other. The pitch between the injection holes (first injection holes H1) is smaller than the pitch angle (AH12, AH51). Thereby, the inclination of the first injection hole inlet 2a and the fifth injection hole inlet 5a is strengthened with a gentle flow, and the separation inside the first injection hole 2 and the fifth injection hole 5 can be reduced. Thereby, the stability of the spray can be enhanced, and the adhesion of the fuel droplets to the fuel injection valve can be suppressed.

  That is, the fuel injection valve according to the present embodiment includes the injection holes (the second injection holes H2 and the fifth injection holes H5) having the helix angles (H2e and H5e) and the injection holes (H2f and H5f) adjacent to the torsion directions (H2f and H5f). The pitch angle (AH23, AH45) between the third injection hole H3 and the fourth injection hole H4) is defined by the above-mentioned injection hole (the second injection hole H2, the fifth injection hole H5) and the twist direction (H2f, H5f). Are configured to be smaller than the pitch angle (AH12, AH51) between the injection holes (first injection holes H1) adjacent in the opposite direction. Thereby, the separation in the injection hole can be reduced, the stability of the spray can be increased, and the attachment of the fuel droplet to the fuel injection valve can be suppressed.

  In the third injection hole H3 of the third injection hole, the third injection hole axis H3c is inclined by the twist angle H3e in the twist direction H3f. Therefore, in this embodiment, the pitch angle AH34 formed between the third injection hole H3 and the fourth injection hole H4 of another third-stage injection hole adjacent to the side in the torsional direction H3f is the third injection hole. The pitch angle AH23 between the hole H3 and the second injection hole H2 adjacent on the opposite side to the twisting direction H3f is configured to be smaller. Thereby, the flow of the injection hole entrance having a gentle inclination can be strengthened, and the separation inside the third injection hole H3 can be reduced. Thereby, the stability of the spray can be enhanced, and the adhesion of the fuel droplets to the fuel injection valve can be suppressed.

  When the fourth injection hole axis H4c is inclined by the twist angle H4e in the torsion direction H4f, the fourth injection hole H4 and the third injection hole H3 adjacent to the torsion direction H4f for the same reason as described above. May be configured to be smaller than the pitch angle AH45 between the fourth injection hole H4 and the fifth injection hole H5 adjacent on the opposite side to the torsional direction H4f. desirable. That is, the pitch angle between the injection holes having a torsion angle and the injection holes adjacent in the torsion direction is smaller than the pitch angle between the injection holes and the injection holes adjacent in the direction opposite to the torsion direction. To be configured. Thereby, the separation in the injection hole can be reduced, the stability of the spray can be increased, and the attachment of the fuel droplet to the fuel injection valve can be suppressed.

101 cylinder head 102 cylinder block 103 piston 104 combustion chamber 105 intake pipe 106 exhaust pipe 107 intake valve 108 exhaust valve 109 fuel tank 110 feed pump 111 high-pressure fuel pump 112 common rail 113 fuel pressure Sensor 114 Connecting rod 115 Crank shaft 116 Crank angle sensor 117 Water temperature sensor 118 ECU
119 fuel injection valve 120 spark plug 201 valve body 201a valve body position 201b in a low lift state valve body position 202 in a high lift state 202 seat member 203 guide member 204 nozzle body 205 valve body guide 206 ... Anchor 207 ... Core 208 ... Coil 209 ... Yoke 210 ... Spring 211 ... Connector 212 ... Fuel supply port 31, 32, 33, 34, 35, 36 ... Injection hole 302 ... Sack chamber 304 ... Valve seat surface 305 ... Valve element Central axis 311: Inflow from seat side 312: Inflow from sack chamber side

Claims (8)

In a fuel injection valve that injects fuel directly into a combustion chamber of an internal combustion engine,
An injection hole axis connecting the center of the injection hole inlet and the center of the injection hole outlet is provided with a twisted injection hole configured to be twisted in a direction different from a straight line connecting the valve element central axis and the center of the injection hole inlet,
The pitch angle between the torsional injection hole and the torsional direction injection hole adjacent in the torsional direction is the pitch angle between the torsional injection hole and the anti-twist direction side injection holes adjacent in the opposite direction to the torsional direction. A fuel injection valve configured to be smaller than. The fuel injection valve according to claim 1,
An injection hole axis connecting the center of the injection hole inlet and the center of the injection hole outlet includes a plurality of injection holes configured in the same direction as a straight line connecting the valve element central axis and the center of the injection hole inlet,
Among the plurality of injection holes, a pitch angle between a small inclined injection hole having a small angle formed by the valve body center axis and the injection hole axis and an injection hole adjacent to the small inclined injection hole is the valve body central axis. A fuel injection valve configured to be larger than a pitch angle between a large inclined injection hole having a large angle between the injection hole axis and an injection hole adjacent to the large inclined injection hole. The fuel injection valve according to claim 1,
The pitch angle between the plug-facing injection hole pointing toward the tip of the spark plug and the injection hole adjacent to the plug-facing injection hole is adjacent to the piston-facing injection hole facing the center of the piston upper surface and the piston-facing injection hole. A fuel injection valve configured to be larger than a pitch angle with an injection hole to be formed. In a fuel injection valve that injects fuel directly into a combustion chamber of an internal combustion engine,
In a horizontal cross-sectional view of the plurality of injection holes viewed from the upstream side, a first injection hole pointing toward the tip of the spark plug, a second injection hole adjacent to the first injection hole, and the first injection hole Is a separate injection hole adjacent to the second injection hole on the opposite side to the first injection hole, a fourth injection hole pointing toward the center of the upper surface of the piston, the first injection hole, and a valve. A fifth injection hole formed on the opposite side to the third injection hole with respect to a center line passing through the body center axis, and a sixth injection formed on the opposite side of the second injection hole with respect to the center line. And a hole,
A fuel injection valve configured such that a pitch angle between the first injection hole and the second injection hole is larger than a pitch angle between the second injection hole and the third injection hole. The fuel injection valve according to claim 4,
A fuel injection valve configured such that a pitch angle between the second injection hole and the third injection hole is larger than a pitch angle between the third injection hole and the fourth injection hole. The fuel injection valve according to claim 4,
A fuel injection valve configured such that a pitch angle between the first injection hole and the sixth injection hole is larger than a pitch angle between the fifth injection hole and the sixth injection hole. The fuel injection valve according to claim 4,
A fuel injection valve configured such that a pitch angle between the fifth injection hole and the sixth injection hole is larger than a pitch angle between the fourth injection hole and the fifth injection hole. The fuel injection valve according to claim 1, wherein
When the circle passing through the inlet of the injection hole with the center axis of the valve body as the pitch circle, the radius of the pitch circle where the injection hole with the twist angle is located is the radius of the pitch circle where the injection hole without the twist angle is located. A fuel injection valve configured to be larger than.

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