JP2018178748A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device for, when a needle valve is greatly moved upward inside an injection device body, enabling sufficient atomization of fuel injected from an injection hole and the securement of a sufficient flow amount.SOLUTION: A fuel injection device 13 for injecting fuel F into a cylinder 11 of an internal combustion engine 2 includes an injection device body 14 having a suck chamber 193 capable of storing the fuel F and an injection hole 23 communicating the suck chamber 193 with the internal of the cylinder 11, and a needle valve 16 provided movably inside the injection device body 14 for opening/closing the suck chamber 193. In either the front end of the needle valve 16 or the inside face of the injection device body 14, a fuel guide groove 32 is formed to guide the fuel F to an inlet 231 of the injection hole 23 so as to flow inside the injection hole 23 spirally around its axis line J.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fuel injection device for injecting fuel into a cylinder of an internal combustion engine.

  An internal combustion engine that obtains power by burning fuel in a cylinder includes a fuel injection device for injecting fuel into the cylinder. This fuel injection device is provided inside a hollow injection device main body in which a suck chamber capable of storing fuel is formed at the tip end portion, and the injection device main body, and moves up and down so as to close or open the suck chamber. And a needle valve. Then, when the needle valve ascends to open the suck chamber, the high-pressure fuel introduced into the injection device main body flows into the suck chamber, and the fuel flows into the cylinder through the injection hole formed at the tip of the injection device main body. It is injected to.

  By the way, when the needle valve opens the suck chamber, the flow of fuel flowing into the injection hole through the gap between the needle valve and the injector main body is roughly divided into two flows. One flow is a flow of fuel that flows along the inner surface of the injector main body and flows directly into the injection hole after passing through the gap between the needle valve and the injector main body. It is a stable flow. The other flow is the flow of fuel that flows into the sack chamber after passing through the gap between the needle valve and the injector main body, forms a vortex in the sack chamber, and then flows into the injection hole. Is a big flow.

  Here, when a wide gap is generated between the needle valve and the injector main body by raising the needle valve inside the injector main body, the flow rate of the fuel passing through the gap is relatively low. Therefore, most of the fuel that has passed through the gap flows along the inner surface of the injector main body and directly flows into the injection hole, and only once little flows into the injection hole after flowing into the suck chamber. As a result, since the fuel injected from the injection hole is in a small and stable state as described above, there is a problem that the fuel is not sufficiently atomized at the time of injection.

  Therefore, for the purpose of solving such a problem, there is conventionally known a fuel injection device that controls the flow of fuel by forming a swirl groove at the tip of a needle valve (see, for example, Patent Document 1) ). In this fuel injection device, all the fuel that has passed through the gap between the needle valve and the fuel injection device main body is guided to the suck chamber by the swirl groove, and after swirling is formed inside the suck chamber, the fuel is injected from the injection hole Be done. Therefore, as described above, the highly turbulent fuel is injected from the injection hole in a sufficiently atomized state.

Unexamined-Japanese-Patent No. 2006-118493

  However, in the conventional fuel injection device, there is a problem that a sufficient flow rate can not be secured for the fuel injected from the injection hole. That is, in the conventional fuel injection device, all of the fuel that has passed through the gap between the needle valve and the fuel injection device is guided by the swirl groove to the suck chamber to form a swirl. Therefore, although the fuel jetted from the injection hole can ensure sufficient turbulence, the initial velocity of the fuel injected from the injection hole is compared with the case where the fuel passing through the gap directly flows into the injection hole without passing through the suck chamber. Decreases, so the fuel flow rate decreases.

  Accordingly, the present invention has been made in view of such circumstances, and the object thereof is to sufficiently atomize the fuel injected from the injection hole when the needle valve has moved largely upward inside the injection device main body. It is an object of the present invention to provide a fuel injection device that enables the flow rate to be secured together.

According to one aspect of the invention,
A fuel injection device for injecting fuel into a cylinder of an internal combustion engine, comprising:
An injection device body having a suck chamber capable of storing fuel, and an injection hole communicating the suck chamber and the interior of the cylinder;
A needle valve movably provided inside the injector body so as to close or open the suck chamber;
A fuel guide for guiding fuel to the inlet of the injection hole so as to flow helically inside the injection hole on at least one of the tip of the needle valve and the inner surface of the injection device main body There is provided a fuel injection device characterized in that a groove is formed.

The fuel injection device according to one aspect of the present invention is
The fuel may be guided such that the fuel guide groove flows in a direction inclined with respect to the axis of the injection hole in plan view.

Further, a fuel injection device according to one aspect of the present invention is
The fuel guide groove may be formed at the tip of the needle valve downstream of a region in contact with the inner surface of the injector main body.

Further, a fuel injection device according to one aspect of the present invention is
At the upstream end and the downstream end of the fuel guide groove, R portions may be formed in which the groove depth gradually decreases toward the end in the longitudinal sectional view.

  According to the fuel injection device according to one aspect of the present invention, sufficient sufficient atomization of the fuel injected from the injection hole is achieved while the needle valve is moved upward largely inside the injection device main body. Flow rate can also be secured.

FIG. 1 is a schematic view showing an internal combustion engine system 1 provided with a fuel injection device 13 according to a first embodiment of the present invention. It is a schematic longitudinal cross-sectional view which shows the structure of the fuel-injection apparatus 13 which concerns on 1st embodiment. FIG. 6 is a partially enlarged cross-sectional view in which the periphery of the injection hole 23 at the tip of the fuel injection device 13 is enlarged. It is an AA line arrow directional view in FIG. FIG. 5 is a partially enlarged cross-sectional view of a tip end portion of the fuel injection device 13; It is a BB arrow line view in FIG. It is a schematic longitudinal cross-sectional view which shows the structure of the fuel-injection apparatus 40 which concerns on 2nd embodiment. FIG. 6 is a partially enlarged cross-sectional view in which the periphery of the injection hole 23 at the tip of the fuel injection device 40 is enlarged. It is a figure which shows the planar view shape of the fuel guide groove 50,60,70 which concerns on a modification. It is a figure which shows the fuel guide groove 80,90,100 which concerns on another modification, Comprising: The cross section which followed the extension direction is shown.

First Embodiment
First, the configuration of the fuel injection device according to the first embodiment of the present invention will be described.

(Configuration of internal combustion engine system)
FIG. 1 is a schematic view showing an internal combustion engine system 1 provided with a fuel injection device 13 according to a first embodiment of the present invention. The internal combustion engine system 1 includes an internal combustion engine 2, an intake passage 3 for supplying intake air drawn from the outside to the internal combustion engine 2, an exhaust passage 4 for discharging the exhaust gas discharged from the internal combustion engine 2 to the outside, The operation of each part is controlled based on the detection results obtained from various sensors and the like, the EGR device 5 for recirculating a part of the exhaust gas into the intake passage 3, the exhaust gas purification device 6 for purifying the exhaust gas flowing through the exhaust passage 4 And a control device 7 for

  The internal combustion engine 2 is a four-cylinder compression ignition internal combustion engine mounted on a vehicle, that is, a diesel engine. As shown in FIG. 1, the internal combustion engine 2 has an internal combustion engine body 8, a fuel injection unit 9, and a rotational speed sensor 10. Although the illustrated example shows the in-line four-cylinder internal combustion engine 2, the cylinder arrangement type of the internal combustion engine 2, the number of cylinders, and the like are arbitrary.

  The internal combustion engine body 8 includes structural parts such as a cylinder head, a cylinder block, and a crankcase, and movable parts such as a piston, a crankshaft, and a valve accommodated therein, though not shown in detail in the figure. As shown in FIG. 1, four cylinders 11 are formed in the internal combustion engine body 8.

  The fuel injection unit 9 is a so-called common rail fuel injection unit, and plays a role of injecting fuel into the cylinder 11. As shown in FIG. 1, the fuel injection unit 9 includes a common rail 12 for storing fuel in a high pressure state, and four fuel injection devices 13 connected to the common rail 12 for injecting fuel into the four cylinders 11 respectively. And.

  FIG. 2 is a schematic vertical sectional view showing the configuration of the fuel injection device 13 according to the first embodiment. The fuel injection device 13 includes a hollow injection device main body 14, a solenoid 15 accommodated on the proximal end side inside the injection device main body 14, and a needle valve 16 similarly accommodated on the tip end side inside the injection device main body 14. And a needle spring 17 interposed between the injector main body 14 and the needle valve 16. In FIG. 2, the needle valve 16 is shown in a partially broken state.

  The injector main body 14 serves to internally store the fuel to be injected into the cylinder. As shown in FIG. 2, the injection device main body 14 is a substantially cylindrical member having a conical outer end. The injection device body 14 has a proximal end cavity 18 formed on the proximal side, a distal cavity 19 formed on the distal end, and an introduction passage 20 communicating the distal cavity 19 with the outside. A discharge passage 21 communicating the proximal cavity 18 with the distal cavity 19, a recovery passage 22 communicating the proximal cavity 18 with the outside, and two injection holes formed at the distal end. And 23). Then, as shown in FIG. 2, the tip end side hollow portion 19 constitutes a pressure control chamber 191 having a substantially rectangular cross section which constitutes the uppermost portion, a fuel chamber 192 having a substantially pentagonal sectional shape which constitutes a central portion, and a lowermost portion. And a suck chamber 193 having a substantially semicircular cross section.

  The solenoid 15 serves to close or open the discharge passage 21 of the injector body 14. As shown in FIG. 2, the solenoid 15 is fixed to a fixing core 24 fixedly provided inside the proximal end cavity 18 and a solenoid coil 25 provided inside the fixing core 24. An armature 26 made of a conductive material is provided below the core 24 and spaced apart, and a return spring 27 provided between the fixing core 24 and the armature 26.

  According to the solenoid 15 configured as described above, when no current is applied to the solenoid coil 25, the armature 26 receiving the biasing force from the return spring 27 stops at the position at which the discharge path 21 is closed. On the other hand, when a current is applied to the solenoid coil 25, the fixing core 24 to which the electromagnetic force is applied from the solenoid coil 25 attracts the armature 26, whereby the armature 26 resists the biasing force of the return spring 27. Move to Thus, the discharge passage 21 is opened.

  The needle valve 16 serves to close or open the suck chamber 193 of the injector body 14. The needle valve 16 is a substantially cylindrical member as shown in FIG. 2 and has a servo piston portion 28 provided with a proximal end portion projecting in the radial direction, and an axial intermediate portion projecting in the radial direction. A nozzle piston portion 29 provided to be provided, a cone portion 30 having a tip portion formed in a substantially truncated cone shape, a seating surface 31 provided at a base end portion of the cone portion 30, and a cone portion 30 And a plurality of fuel guide grooves 32 formed by cutting out the outer peripheral surface on the front end side of the fuel cell.

  The needle spring 17 plays a role of urging the needle valve 16 toward the tip end side of the injector main body 14. The needle spring 17 is a so-called compression spring, and as shown in FIG. 2, a spring receiving portion 33 provided radially on the inner side surface of the injection device main body 14 and a nozzle piston portion 29 of the needle valve 16. And in a compressed state.

  FIG. 3 is a partially enlarged cross-sectional view in which the periphery of the injection hole 23 at the tip of the fuel injection device 13 is enlarged. The fuel guide groove 32 serves to guide the fuel F flowing out of the fuel chamber 192 to the inlet portion 231 of the injection hole 23. The fuel guide groove 32 extends from a position on the distal end side of the seating surface 31 in the outer peripheral surface of the cone portion 30 to a predetermined position on the proximal end side from the tip of the cone portion 30. It is a direction which intersects with the generatrix BS1 of a predetermined angle. The fuel guide groove 32 has a substantially rectangular shape when viewed in the direction orthogonal to the outer peripheral surface of the cone portion 30, and the groove width is set to be approximately the same as or slightly smaller than the radius of the injection hole 23. It is done. Moreover, FIG. 4 is an AA line arrow line view in FIG. The fuel guide groove 32 has a substantially rectangular cross-sectional shape in the direction orthogonal to the extending direction, and has a constant groove depth D over the entire length in the extending direction.

(Action effect)
Next, the operation and effect of the fuel injection device 13 according to the first embodiment of the present invention will be described. In the fuel injection device 13, when the armature 26 shown in FIG. 2 closes the discharge passage 21, high-pressure fuel stored in the common rail 12 (see FIG. 1) flows through the introduction passage 20 into the fuel chamber 192 and the pressure control chamber. It is introduced inside 191. Then, the sum of the force of the fuel F inside the pressure control chamber 191 pressing the servo piston portion 28 to the tip side and the force of the needle spring 17 biasing the nozzle piston portion 29 to the tip side The internal fuel is greater than the force pressing the nozzle piston 29 proximally. As a result, the needle valve 16 is lowered, that is, moved to the tip side inside the distal cavity 19.

  Here, FIG. 5 is a partially enlarged cross-sectional view in which the front end portion of the fuel injection device 13 is enlarged. When the needle valve 16 is lowered, the seating surface 31 of the needle valve 16 is in close contact with the seat surface 34 which constitutes a part of the inner side surface of the injector main body 14. As a result, the suck chamber 193 provided on the front end side of the seat surface 34 is closed.

  Then, with the suck chamber 193 closed, as shown by the broken line in FIG. 2, when the discharge passage 21 is opened by the armature 26 being sucked by the fixing core 24, the fuel F introduced into the pressure control chamber 191 Is discharged to the proximal cavity 18 through the discharge passage 21, so that the internal pressure of the pressure control chamber 191 is reduced. Then, the force by which the fuel F inside the fuel chamber 192 presses the nozzle piston portion 29 to the base end side and the force by which the fuel F inside the pressure control chamber 191 presses the servo piston portion 28 to the tip side 17 is greater than the sum of the force with which the nozzle piston 29 is urged toward the tip end. As a result, the needle valve 16 moves upward, i.e., proximally, inside the distal cavity 19. The fuel F discharged to the proximal end cavity 18 is recovered to a fuel tank (not shown) via the recovery path 22.

  When the needle valve 16 ascends inside the distal end side cavity 19, as shown in FIG. 3, the seating surface 31 of the needle valve 16 is separated from the seat surface 34 of the injection device main body 14, whereby the suck chamber 193 is opened. Ru. As a result, the fuel F inside the fuel chamber 192 flows out to the front end side through the gap C created between the seating surface 31 of the needle valve 16 and the seat surface 34 of the injector main body 14.

  Here, when the rising distance of the needle valve 16 is large and a wide gap C is generated between the needle valve 16 and the injector main body 14, the flow velocity of the fuel F flowing out from the fuel chamber 192 to the tip end is relatively high. slow. Accordingly, as shown by the solid arrows in FIG. 3, the fuel F is guided to the fuel guide groove 32 for the most part, whereby the flow direction is changed. Here, FIG. 6 is a view taken along the line B-B in FIG. The mainstream MF which is the flow of the fuel F guided by the fuel guide groove 32 flows from the inlet portion 231 into the injection hole 23 while flowing in a direction inclined at an angle α to the axis J of the injection hole 23 in plan view. Do. The main flow MF collides with the inner wall surface of the injection hole 23 and thereby flows spirally around the axis J inside the injection hole 23. In the specification of the present application, "plan view" means viewing from a direction perpendicular to the axis J of the injection hole 23 in the vertical cross section shown in FIG. There is.

  On the other hand, as shown by the two-dot chain line arrow in FIG. 3, a part of the fuel F which has flowed out of the fuel chamber 192 goes straight without changing the flow direction by the fuel guide groove 32 and flows into the suck chamber 193. . The countercurrent SF, which is the flow of the fuel F flowing into the suck chamber 193, forms a swirl in the suck chamber 193. Then, the bypass flow SF flows into the injection hole 23 from the suck chamber 193 as shown by a double-dotted arrow in FIG. 6 so as to be caught in the mainstream MF flowing in a spiral shape in the injection hole 23. Thereafter, the main flow MF and the backflow SF flow downstream in the injection hole 23, and are injected from the outlet 232 to the inside of the cylinder 11 (shown in FIG. 1).

  Here, the main flow MF flowing directly into the injection hole 23 without passing through the suck chamber 193 by being guided by the fuel guide groove 32 has a flow velocity compared with the flow SF flowing into the injection hole 23 through the suck chamber 193. Hold fast. Most of the fuel F injected from the outlet portion 232 of the injection hole 23 is the main flow MF. Therefore, the fuel F injected from the injection hole 23 is injected at a relatively high initial velocity, and a sufficient flow rate is secured.

  Further, the countercurrent SF which has formed a swirl in the suck chamber 193 also flows into the injection hole 23 as being caught in the main flow MF as described above. Since the side flow SF forms a swirl in the suck chamber 193, the turbulence is maintained in a large state as compared with the main flow MF flowing directly into the injection hole 23 without passing through the suck chamber 193. Therefore, the fuel F injected from the injection hole 23 has an initial disturbance at the time of injection as compared with the case where only the main flow MF flows into the injection hole 23 and is injected by the side flow SF being partially contained therein. It is in a large state. As a result, sufficient atomization of the fuel F injected from the outlet portion 232 of the injection hole 23 is ensured.

  As described above, in the case where the needle valve 16 largely moves upward inside the injection device main body 14, it is possible to achieve sufficient atomization and securement of a sufficient flow rate for the fuel F injected from the injection hole 23.

Second Embodiment
Next, the configuration of a fuel injection device according to a second embodiment of the present invention will be described. In the internal combustion engine system 1 shown in FIG. 1, the configuration other than the fuel injection device 13 is the same as that of the first embodiment, so the detailed description will be omitted here.

  FIG. 7 is a schematic vertical sectional view showing the configuration of the fuel injection device 40 according to the second embodiment. The fuel injection device 40 includes a hollow injection device main body 41, a solenoid 15 housed on the base end side inside the injection device main body 41, and a needle valve 42 similarly housed on the tip end side inside the injection device main body 41. And a needle spring 17 interposed between the injector main body 41 and the needle valve 42. In addition, since the solenoid 15 and the needle spring 17 are the same structures as 1st embodiment, they use the same code | symbol as FIG. 2, and abbreviate | omit description here.

  The injection device main body 41 is different from the injection device main body 41 of the first embodiment in that a plurality of fuel guide grooves 43 are formed on the inner side surface at the tip (in FIG. 7, one injection Only one fuel guide groove 43 is shown per hole 23). The other configuration of the injection device main body 41 is the same as that of the injection device main body 14 of the first embodiment, so the same reference numerals as in FIG. 2 are used, and the description thereof is omitted here.

  FIG. 8 is a partially enlarged cross-sectional view in which the periphery of the injection hole 23 at the tip of the fuel injection device 40 is enlarged. The fuel guide groove 43 extends from a position on the tip side of the seat surface 34 on the inner side surface of the injector main body 41 to a position slightly on the proximal side of the injection hole 23. It is a direction that intersects with the generatrix BS2 at the tip of the sensor at a predetermined angle. The fuel guide groove 43 has a shape as viewed in a direction orthogonal to the inner surface of the injection device main body 41, a groove width, a cross-sectional shape in a direction orthogonal to the extending direction, and a groove depth The fuel guide groove 32 is the same as the fuel guide groove 32 of the first embodiment, and thus the description thereof is omitted here.

  The needle valve 42 is different from the needle valve 16 of the first embodiment in that the fuel guide groove 32 is not formed on the outer peripheral surface of the cone portion 30. The other configuration of the needle valve 42 is the same as that of the needle valve 16 of the first embodiment, and therefore, the same reference numerals as in FIG. 2 are used, and the description thereof is omitted here.

(Action effect)
Next, the operation and effect of the fuel injection device 40 according to the second embodiment of the present invention will be described. The present embodiment differs from the first embodiment only in that the fuel F is guided by the fuel guide groove 43 of the injector main body 41 instead of the fuel guide groove 32 of the first embodiment. The flow of the fuel F guided by the fuel guide groove 43 and the function and effect thereof are the same as in the first embodiment, and thus the description thereof is omitted here.

(Modification)
As mentioned above, although 1st embodiment and 2nd embodiment of this invention were described, the modification as shown below is also considered as embodiment of this invention.

  (1) In the first embodiment, the two injection holes 23 are provided at the tip of the injection device main body 14, and the fuel F is guided by the two fuel guide grooves 32 toward the inlets 231 of the injection holes 23. For this purpose, a total of four fuel guide grooves 32 are provided at the tip of the needle valve 16. In the second embodiment, two injection holes 23 are provided at the tip of the injection device main body 41, and the fuel F is guided by the two fuel guide grooves 43 toward the inlets 231 of the injection holes 23. In addition, a total of four fuel guide grooves 43 are provided at the tip of the needle valve 16. However, according to the formation position and the number of the injection holes 23 in the injection device main body 14 and 41, the design position and the number of the fuel guide groove 32 and the fuel guide groove 43 can be arbitrarily changed.

  (2) The extending direction of the fuel guide grooves 32, 43, the length in the extending direction, the shape of the cross section orthogonal to the extending direction, the shape in plan view, the groove width, the groove depth, etc. The present invention is not limited, and design changes can be made as appropriate without interfering with the adjacent fuel guide grooves 32 and 43.

  (3) FIG. 9 is a view showing a plan view shape of fuel guide grooves 50, 60, 70 according to a modification. In the first embodiment and the second embodiment, the fuel guide grooves 32 and 43 are formed in an elongated rectangular shape in plan view, but instead, for example, they have a tapered shape in plan view as shown in FIG. It is also possible to form a crown shape in a plan view as shown in (b) and an inverse crown shape in a plan view as shown in FIG. 9 (c). When formed in a tapered shape or an inverted crown shape in a plan view, there is an advantage that the fuel F easily flows into the inside of the fuel guide groove 43 from the base end side where the groove width is wide.

  (4) FIG. 10 is a view showing a fuel guide groove 80, 90, 100 according to another modification, showing a cross section along the extending direction thereof. In the fuel guide groove 80 shown in FIG. 10A, the inflow guide R portion 81 is provided at the proximal end side in the extending direction, and the outflow guide R portion 82 is provided at the front end side portion. . The inflow guide R portion 81 is formed such that the groove depth D gradually increases from the proximal end side toward the distal end side. On the other hand, the outflow guide R portion 82 is formed such that the groove depth D gradually decreases from the proximal end side toward the distal end side.

  Further, in the fuel guide groove 90 shown in FIG. 10B, an inflow guide inclined surface 91 in which the groove depth D gradually becomes deeper from the base end side toward the tip end side at the proximal end side in the extension direction. Is provided, and at the distal end thereof, there is provided an outflow guiding inclined surface 92 in which the groove depth D is gradually reduced from the proximal end toward the distal end.

  Further, in the fuel guide groove 100 shown in FIG. 10C, at the proximal end side in the extension direction, the inflow guide step portion 101 in which the groove depth D gradually increases from the proximal end toward the distal end. And an outflow guiding step portion 102 in which the groove depth D gradually decreases from the proximal end toward the distal end.

  Thus, by providing the inflow guide R portion 81, the inflow guide inclined surface 91, and the inflow guide stair portion 101 at the proximal end, the fuel F flows in from the proximal end side of the fuel guide grooves 80, 90, 100. It has the advantage of being easy. Further, by providing the outflow guide R portion 82, the outflow guide inclined surface 92, and the outflow guide stair portion 102 at the front end side end, there is an advantage that the fuel F easily flows out from the front end side of the fuel guide grooves 80, 90, 100. is there.

  In addition, it is also possible to provide the inflow guide R portion 81, the inflow guide inclined surface 91, and the inflow guide stair portion 101 in an appropriate combination at the proximal end portion. Similarly, it is also possible to provide the outflow guide R portion 82, the outflow guide inclined surface 92, and the outflow guide step portion 102 in an appropriate combination at the tip end side.

  (5) The positions at which the fuel guide grooves 32 and 43 are formed are the outer peripheral surface of the needle valve 16 in the first embodiment and the inner surface of the injection device main body 41 in the second embodiment. However, the fuel guide grooves 32, 43 may be formed on at least one of the outer peripheral surface of the needle valve 16, 42 and the inner side surface of the injector main body 14, 41. The outer peripheral surface of the needle valve 16, 42 and the injector main body It is also possible to form fuel guide grooves 32, 43 on both of the inner side surfaces of 14, 14.

2 internal combustion engine 11 cylinder 13, 40 fuel injection device 14, 41 injection device main body 16, 42 needle valve 23 injection hole 32, 43 fuel guide groove 81 inflow guide R portion 82 outflow guide R portion 193 suck chamber 231 inlet portion D groove depth F fuel J axis

Claims (4)

A fuel injection device for injecting fuel into a cylinder of an internal combustion engine, comprising:
An injection device body having a suck chamber capable of storing fuel, and an injection hole communicating the suck chamber and the interior of the cylinder;
A needle valve movably provided inside the injector body so as to close or open the suck chamber;
A fuel guide for guiding fuel to the inlet of the injection hole so as to flow helically inside the injection hole on at least one of the tip of the needle valve and the inner surface of the injection device main body A fuel injection device characterized in that a groove is formed. The fuel injection device according to claim 1, wherein the fuel guide groove guides the fuel to flow in a direction inclined with respect to the axis of the injection hole in a plan view. The fuel injection device according to claim 1 or 2, wherein the fuel guide groove is formed at a tip end portion of the needle valve downstream of a region in contact with the inner side surface of the injection device main body. . The upstream end portion and the downstream end portion of the fuel guide groove are respectively formed with an R portion in which the groove depth gradually becomes shallow toward the end portion side in a longitudinal sectional view. 3. A fuel injection device according to any one of 3. to 3.

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