JP6457797B2 - Fuel injection nozzle - Google Patents

Description

  The present invention relates to a fuel injection nozzle that directly injects fuel into a combustion chamber of an internal combustion engine.

[Conventional technology]
Conventionally, a fuel injection nozzle that directly injects fuel into a combustion chamber formed in a cylinder of a direct injection internal combustion engine (direct injection engine) is well known as a fuel injection nozzle.
The fuel injection nozzle includes a needle and a nozzle body, and has a plurality of injection holes for injecting fuel on the distal end side in the central axis direction of the nozzle body.
Each injection hole of the fuel injection nozzle is a straight injection hole having a constant injection hole diameter or a tapered injection hole having a hole diameter at the injection hole inlet larger than that at the injection hole outlet. The tapered nozzle hole has an effect of improving the flow coefficient of the nozzle hole because the pressure drop associated with the separation of the fuel flow at the nozzle hole inlet can be reduced as compared with the straight nozzle hole.

The flow coefficient (Cd) is defined by the following equation (1).
[Equation 1]
Q = A ・ V
V = Cd · √ (2ΔP / ρ)
Q = Cd · A · √ (2ΔP / ρ)
Q is the amount of fuel injected from a single injection hole into the combustion chamber. A is the opening cross-sectional area of the nozzle hole outlet. V is the flow rate of fuel. ΔP is a differential pressure before and after the nozzle hole. Ρ is the density of the fuel.
That is, the nozzle hole with a large flow coefficient has a high fuel flow velocity (V), a large fuel injection amount (flow rate), and a nozzle hole having a shape in which the fuel easily flows.

Here, the plurality of nozzle holes are arranged at equal intervals on the same circumference of the nozzle body. In order to further increase the flow coefficient of the nozzle hole, it is conceivable to make the hole diameter of the nozzle hole extremely larger than the hole diameter of the nozzle hole outlet.
In this case, since the distance between the nozzle hole inlets adjacent to the circumferential direction of the inner wall of the nozzle body becomes extremely short, there is a possibility that the strength of the inner wall on the nozzle seat side where the valve portion of the needle seats cannot be maintained. There is.
Therefore, a fuel injection nozzle (see, for example, Patent Document 1) with an improved nozzle hole shape is known for the purpose of maintaining the strength of the nozzle body by increasing the flow coefficient while increasing the distance between adjacent nozzle hole inlets. It is.
Each injection hole of the fuel injection nozzle is a circle that opens from the injection hole inlet having an opening cross section of a long hole shape (for example, an oval shape) to the tip end side of the nozzle body, on the outer wall opposite to the injection hole inlet. A nozzle hole channel extending in the nozzle hole axial direction is provided up to the nozzle hole outlet having a shaped opening cross section.

[Problems of conventional technology]
However, in the fuel injection nozzle described in Patent Document 1, as shown in FIG. 14, the major axis direction of the nozzle hole inlet and the nozzle central axis direction coincide with each other. During the injection period of the fuel spray injected into the combustion chamber 101, the amount of fuel flow separation at the nozzle hole inlet changes so that the fuel injection direction from the nozzle hole outlet into the combustion chamber 101 changes the wall surface of the cylinder head 102. In addition, there is a concern that the vertical cross section of the combustion chamber such as the top of the piston 103 may change greatly. In particular, there is a concern that the fuel injection direction may fluctuate greatly in the vertical direction where there is little space in the combustion chamber 101 of the direct injection engine.

Therefore, when the common central axis direction of the cylinder central axis and the nozzle central axis (CL) is the vertical direction, the injection hole of the fuel injection nozzle 100 is formed on the lower wall surface of the cylinder head 102 or the upper wall surface of the top of the piston 103. There is a problem that the fuel droplets injected from the outlet are likely to adhere, the amount of harmful substances such as exhaust black smoke (smoke) and hydrocarbon (HC) generated increases, and the exhaust emission decreases.
Here, the term “injection period” refers to a period during which the needle is lifted from the nozzle seat, that is, a valve opening period of the needle.

JP-T-2004-521266

  The object of the present invention is to reduce the amount of fuel adhering to the combustion chamber wall of the internal combustion engine by reducing the fluctuation range of the injection direction of the fuel injected from the nozzle hole outlet of the nozzle body into the combustion chamber. An object of the present invention is to provide a fuel injection nozzle capable of reducing material.

The invention according to claim 1 is a fuel injection nozzle that directly injects fuel from a nozzle hole outlet into a combustion chamber of a direct injection type internal combustion engine.
The injection hole of the fuel injection nozzle has an injection hole channel that communicates the inside and the outside of the nozzle body. The nozzle hole channel extends in the nozzle axis direction from the nozzle hole opening opened at the inner wall of the nozzle body to the nozzle hole outlet opened at the outer wall of the nozzle body.
The nozzle hole inlet has a long hole-shaped opening cross section in which the short axis and the long axis are orthogonal to each other. The major axis direction of the nozzle hole inlet (long hole major axis direction) is inclined by a predetermined angle in the same (rotating) direction as the swirl flow with respect to the nozzle central axis direction.
The nozzle hole outlet has a circular opening cross section.
Further, the nozzle hole channel is formed such that the channel cross-sectional area gradually decreases from the nozzle hole inlet toward the nozzle hole outlet.

According to the first aspect of the present invention having the above characteristics, the major axis direction of the nozzle hole inlet of the nozzle body is inclined by a predetermined angle in the same direction as the swirl flow with respect to the nozzle central axis direction. The fuel injected from the nozzle hole outlet into the combustion chamber is injected obliquely with respect to the central axis of the nozzle body.
At the time of needle low lift corresponding to the initial stage of fuel injection, separation occurs in the upstream portion of the nozzle hole inlet, and the fuel flow path downstream of the nozzle seat in the fuel flow direction passes through the nozzle hole inlet to enter the nozzle hole flow path. The fuel that flows into the combustion chamber is injected into the combustion chamber from the outlet of the nozzle hole along the wall surface of the nozzle hole in the downstream portion of the nozzle hole channel.
On the other hand, at the time of high needle lift, the flow velocity of the fuel flowing into the nozzle hole channel from the fuel channel downstream of the nozzle seat in the fuel flow direction through the nozzle hole inlet becomes smaller, and the upstream side of the nozzle hole Since the separation at the portion is reduced, the fuel flow along the nozzle hole wall surface in the upstream portion of the nozzle hole channel and the nozzle wall surface in the downstream portion of the nozzle hole channel are located before the nozzle hole outlet. Fuel is injected from the nozzle hole outlet into the combustion chamber at an angle that combines with the fuel flow.
For this reason, the injection direction of the fuel injected from the nozzle hole outlet into the combustion chamber changes during the fuel injection period in accordance with the behavior of the needle (needle lift amount), but the fluctuation range of the injection direction of the fuel spray is small. Thus, the collision of fuel with the combustion chamber wall surface of the internal combustion engine is reduced. Therefore, since the amount of fuel adhering to the combustion chamber wall surface of the internal combustion engine can be reduced, harmful substances such as smoke can be reduced.

In addition, by inclining the major axis direction of the nozzle hole inlet by a predetermined angle in the same direction as the swirl flow with respect to the nozzle central axis direction, the fuel injected from the nozzle hole outlet into the combustion chamber at the time of low needle lift The swirl is generated in the combustion chamber.
After that, when the needle is further lifted when the needle is further lifted, the fuel spray at the time of the needle low lift is arranged in the space between the fuel sprays injected from the nozzle hole outlet into the combustion chamber. It is difficult to spatially overlap the fuel spray at the time of high needle lift. Therefore, the ignition delay from the ignition of the fuel spray at the low needle lift to the ignition of the fuel spray at the high needle lift becomes longer, and the fuel spray at the high needle lift is far from the nozzle body and the fuel droplets evaporate. Since it proceeds and ignites from the place where the mixing with air proceeds, harmful substances such as smoke and HC can be reduced.
Therefore, it is possible to suppress the deterioration of exhaust emission discharged from the combustion chamber of the internal combustion engine.

FIG. 3 is a cross-sectional view schematically showing fuel spray injected from a fuel injection nozzle into a combustion chamber (Example 1). It is sectional drawing which showed the fuel-injection nozzle (Example 1). It is sectional drawing which showed the nozzle nozzle part at the time of a needle low lift (Example 1). FIG. 4 is a sectional view taken along line IV-IV in FIG. 3 (Example 1). It is sectional drawing which showed the nozzle nozzle part at the time of needle high lift (Example 1). (A) is the top view which showed the inclination angle of the major axis direction of the nozzle hole inlet with respect to a nozzle central axis, (b) is the schematic diagram which showed the rotation direction of the nozzle hole flow path and the swirl flow (Example 1) ). (A) is the schematic diagram which showed the mode of the fuel flow in the nozzle hole channel at the time of needle low lift, (b) is the schematic diagram which showed the mode of the fuel flow in the nozzle hole channel at the time of needle high lift (Example 1). It is explanatory drawing which showed the state which the fuel spray of a needle high lift and a needle low lift does not overlap (Example 1). (Example 2) which was sectional drawing which showed the nozzle nozzle part at the time of a needle low lift. It is sectional drawing which showed the nozzle nozzle part at the time of needle high lift (Example 2). (A), (b) is the top view which showed the inclination angle of the major axis direction of the nozzle hole inlet with respect to a nozzle central axis (Example 3). (A), (b) is the top view which showed the inclination-angle of the major axis direction of the nozzle hole inlet with respect to a nozzle central axis (Example 4). (A)-(f) is the top view which showed the long hole shape of the nozzle hole inlet, (g) is explanatory drawing which showed the inclination angle of the nozzle axis at the major axis direction with respect to the nozzle center axis (Example) 5). It is sectional drawing which showed typically the fuel spray injected into the combustion chamber from the fuel injection nozzle (conventional example 1). It is explanatory drawing which showed the state with which the fuel spray of a needle high lift and a needle low lift overlaps (conventional example 1).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Configuration of Example 1]
1 to 8 show an injector (Embodiment 1) having a fuel injection nozzle to which the present invention is applied.

The direct injection internal combustion engine of the present embodiment is a diesel engine (hereinafter referred to as a direct injection engine) for driving a vehicle such as an automobile, and a fuel injection valve (hereinafter referred to as an injector) is provided for each cylinder of the direct injection engine. It is installed.
The injector includes a fuel injection nozzle 1 on the tip end side (the lower end side in the figure) in the nozzle central axis direction. The injector is configured by integrating a fuel injection nozzle 1 and a solenoid valve (solenoid valve: not shown) that opens and closes a needle valve (hereinafter referred to as a needle) 2 of the fuel injection nozzle 1 by screw fastening. Yes.
Details of the solenoid valve will be described later.

The fuel injection nozzle 1 includes a needle 2 that can reciprocate in the nozzle central axis (CL) direction, and a mini-sack type nozzle body 3 that fits and supports the needle 2 in the reciprocating direction.
The nozzle body 3 has a bottomed cylindrical shape in which a base end side (upper end side in the drawing) in the nozzle central axis (CL) direction is opened and a distal end side (lower end side in the drawing) opposite to the nozzle body 3 is closed. The nozzle injection hole portion 4 for directly injecting the fuel spray is provided in the combustion chamber R formed in each of the cylinders. The nozzle injection hole 4 is provided with a plurality of injection holes 5 communicating with the inside and outside of the nozzle body 3.
The nozzle center axis (CL) is a nozzle axis line extending straight in the direction of the center line of the fuel injection nozzle 1, at least the nozzle body 3.

The plurality of nozzle holes 5 are each provided with a nozzle hole channel 6 that communicates the inside and outside of the nozzle nozzle part 4. Each nozzle hole channel 6 extends in the nozzle axis (HL) direction from the nozzle hole inlet 7 opened at the inner wall of the nozzle nozzle hole 4 to the nozzle hole outlet 8 opened at the outer wall of the nozzle nozzle hole 4. Yes.
The injector is attached to each cylinder such that at least the nozzle injection hole 4 protrudes into the combustion chamber R in an injector attachment hole H formed through the cylinder central axis of the cylinder head 9.
Details of the injector will be described later.

The direct injection engine includes a cylinder head 9 that closes an opening of each cylinder, each cylinder barrel 10 of a cylinder block that is coupled to the lower portion of the cylinder head 9, and each cylinder wall (inner wall) of the plurality of cylinder barrels 10. And a plurality of pistons 11 that are in sliding contact with each other.
Each piston 11 is connected to a crankshaft (an output shaft of a direct injection engine) via a corresponding connecting rod. Thereby, each piston 11 reciprocates within each cylinder bore of the plurality of cylinder barrels 10.
A reentrant cavity 12 is formed at the top of each piston 11. Between the bottom surface of the cavity 12 and the wall surface of the cylinder head 9, a combustion chamber R is formed in which an air-fuel mixture of fuel and intake air (intake air) burns. Further, the central portion of the bottom of the cavity 12 is raised toward the opening end side of the cavity 12.

The cylinder head 9 is provided with a plurality of intake ports 13 that communicate the intake passages in the intake pipe and the combustion chambers R, and a plurality of exhaust ports that communicate the exhaust passages in the exhaust pipe and the combustion chambers R. .
Each intake port 13 is connected to an intake pipe via an intake manifold. An intake valve (intake valve) 14 that opens and closes each port opening is provided at the end of each intake port 13 on the combustion chamber side. Each intake port 13 is a helical port that generates a swirl flow in each combustion chamber R.

Each exhaust port is connected to an exhaust pipe via an exhaust manifold. Exhaust valves (exhaust valves) that open and close the respective port openings are installed at the end portions of these exhaust ports on the combustion chamber side.
Here, FIG. 3, FIG. 5, FIG. 6 and FIG. 7 show the rotation direction of the tumble flow of the intake air that swirls around the nozzle center axis (CL) that substantially coincides with each cylinder center axis of the direct injection engine. .
A swirl control valve (SCV) that generates a swirl flow in each combustion chamber R may be installed in each intake port 13 or in an intake passage communicating with the intake port 13. In a direct injection engine in which two first and second intake ports communicate with one combustion chamber R, a swirl control valve (SCV) may be installed in one first intake port.

Next, details of the injector of this embodiment will be described with reference to FIGS.
The fuel injection nozzle 1 includes a bottomed cylindrical nozzle body 3 that accommodates a needle 2 so as to be capable of reciprocating movement, a cylindrical injector body that accommodates a command piston and a return spring, and a nozzle body 3 and an injector body. And an annular chip packing sandwiched therebetween. The fuel injection nozzle 1 is configured by integrating a coupling surface of a nozzle body 3 and a coupling surface of an injector body through a tip packing by screw fastening by a screw fastening axial force of a cylindrical retaining nut. .

The injector body is formed with a fuel passage communicating with a fuel passage (a fuel hole 41 described later) of the nozzle body 3 and a piston accommodation hole communicating with the needle accommodation hole 15 of the nozzle body 3 via the communication hole of the tip packing. Has been.
A command piston and a return spring are accommodated in the piston accommodation hole. The piston accommodation hole is provided with a piston guide hole that slidably supports the sliding portion on the base end side of the command piston. A control chamber having a high pressure port and a low pressure port is provided on the base end side opposite to the tip end side of the piston accommodation hole.

The command piston reciprocates in conjunction with the needle 2, and the end face on the tip side is in contact with the needle 2.
The return spring generates a biasing force that biases the command piston in the valve closing direction of the needle 2.
The control chamber is a space surrounded by the proximal end surface of the sliding portion of the command piston, the hole wall surface of the piston accommodation hole, and the ceiling surface of the control chamber. A fuel (supply) passage connected to a high pressure generating section such as a supply pump or a common rail provided on the high pressure side of the fuel system communicates with the high pressure port of the control chamber. A fuel (discharge) passage connected to a fuel tank or the like provided on the low pressure side of the fuel system communicates with the low pressure port of the control chamber. Further, the fuel pressure introduced into the control chamber acts as an oil pressure that urges the needle 2 in the valve closing direction of the needle 2.

The solenoid valve is an electromagnetic valve that adjusts (increases / decreases) the hydraulic pressure in the control chamber provided immediately above the command piston and controls the opening / closing operation of the needle 2. The solenoid valve includes a spool valve that opens and closes a low-pressure port that allows fuel to flow out from the control chamber to the low-pressure side of the fuel system, and a valve body that accommodates the spool valve in a reciprocable manner.
The solenoid valve includes an electromagnetic actuator (solenide) that drives the spool valve in the valve closing direction.

The solenoid includes an external connection connector and is configured to be energized and controlled by an injector drive current applied from an engine control unit (electronic control unit: ECU). The solenoid includes a coil wound around the outer periphery of the coil bobbin, a stator core disposed on the inner and outer periphery of the coil, an armature that reciprocates within the stator core, and the like.
When supplied with power (applied to voltage or energized), the coil generates a magnetic force that attracts the armature to the magnetic pole surface of the stator core. That is, when the coil is energized, the spool valve opens the low pressure port, and when the coil is deenergized, the spool valve closes the low pressure port.

Thus, when the low pressure port of the control chamber is opened, the fuel in the control chamber flows out of the injector (low pressure side of the fuel system) via the low pressure port. As a result, the fuel pressure in the control chamber quickly decreases below the valve opening pressure of the needle, so that the needle 2 separates (lifts) from the nozzle seat 16 of the nozzle body 3 and fuel is supplied to the combustion chamber R of each cylinder of the direct injection engine. Is injected directly.
When the low pressure port is closed, the fuel system stops flowing out to the low pressure side, and high pressure fuel is introduced into the control chamber from the outside of the injector (fuel injection pump or common rail) via the high pressure port. As a result, the fuel pressure in the control chamber rises more quickly than the valve closing pressure of the needle, so that the needle 2 is seated (seat) on the nozzle seat 16 of the nozzle body 3, and therefore the combustion chamber R of each cylinder of the direct injection engine. This completes the fuel injection.

  The needle 2 extends straight in the direction of the nozzle central axis (CL) from the proximal end side toward the distal end side. The needle 2 has a columnar head 21 provided on the base end side, and a columnar head 21 having an outer diameter larger than that of the head 21 and supported so as to be reciprocally movable in the needle guide hole of the needle accommodation hole 15. A large-diameter shaft portion (sliding portion) 22 is provided. The sliding portion 22 of the needle 2 is provided at the end portion (base end portion) on the side opposite to the injection hole in the central axis direction of the needle 2. In addition, the outer peripheral surface of the sliding portion 22 can reciprocate with respect to the hole wall surface of the needle guide hole of the nozzle body 3.

The needle 2 has a small-diameter shaft portion 23 having an outer diameter smaller than that of the sliding portion 22 and a medium-diameter shaft portion 24 having an outer diameter smaller than that of the sliding portion 22 and larger than that of the small-diameter shaft portion 23. Is provided. The needle 2 is provided with a conical pressure receiving surface 25 between the sliding portion 22 and the small diameter shaft portion 23. The pressure receiving surface 25 is a fuel pressure receiving portion that receives the fuel pressure in the fuel reservoir chamber 17 of the needle accommodation hole 15 when the needle 2 starts to lift.
Further, a valve portion 26 having an outer diameter smaller than that of the medium diameter shaft portion 24 is provided on the tip side of the medium diameter shaft portion 24.

The valve portion 26 of the needle 2 is provided at the nozzle hole side end portion (tip portion) of the needle 2 in the central axis direction. The valve portion 26 is a reduced diameter portion in which the outer diameter gradually decreases from the edge line of the medium diameter shaft portion 24 toward the distal end side in the needle central axis direction.
The valve portion 26 includes first and second seal surfaces 31 and 32 and a conical surface 33 whose outer diameter gradually decreases toward the distal end side.

The first seal surface 31 has a conical shape. The second seal surface 32 has a conical surface shape with a steeper (taper) angle than the first seal surface 31. The conical surface 33 has a conical surface shape with a steeper (taper) angle than the second seal surface 32.
An annular intersection ridge line (first sheet line) formed between the first seal surface 31 and the second seal surface 32 is an annular nozzle seal (needle seal portion) that is in close contact with the nozzle sheet 16 of the nozzle body 3. ) 34 as a function.
In addition, instead of the nozzle seal 34, an annular cross ridge line (second sheet line) formed between the second seal surface 32 and the conical surface 33 is used as a nozzle sheet surface including the nozzle sheet 16 of the nozzle body 3. You may use as the annular nozzle seal (needle seal part) 35 which closely_contact | adheres to 43. FIG.

  The nozzle body 3 is provided with a needle accommodation hole 15 that opens in the coupling surface on the proximal end side and extends in the nozzle central axis (CL) direction from the opening side to the nozzle nozzle hole portion 4 on the back side. A needle guide hole for supporting the needle 2 so as to be slidable back and forth is provided on the proximal end side of the needle accommodation hole 15. A fuel reservoir chamber 17 having a hole diameter larger than that of the needle guide hole is provided at the center of the needle accommodation hole 15.

High-pressure fuel is introduced into the fuel reservoir chamber 17 through a fuel hole 41 connected to a high-pressure generator such as a supply pump or a common rail. The fuel pressure introduced into the fuel reservoir chamber 17 acts as an oil pressure that urges the needle 2 in the valve opening direction of the needle 2.
The fuel hole 41 is a fuel passage that extends obliquely from the coupling surface of the nozzle body 3 to the fuel reservoir chamber 17. Further, the nozzle body 3 is formed with a fuel passage (cylindrical clearance) 42 extending straight from the fuel reservoir chamber 17 to the nozzle injection hole portion 4 between the outer periphery of the medium diameter shaft portion 24 of the needle 2. . The clearance 42 is a fuel flow path upstream of the nozzle seat 16 in the fuel flow direction.

A nozzle seat surface 43 including the nozzle seat 16 on which the valve portion 26 of the needle 2 can be seated is provided in the nozzle injection hole portion 4 of the nozzle body 3. The nozzle sheet surface 43 is formed as an inclined surface having a conical surface shape in which the flow path cross-sectional area decreases toward the tip side.
An annular clearance 44 is formed between the valve portion 26 of the needle 2 and the nozzle seat surface 43 of the nozzle body 3 when the needle 2 is lifted.
The clearance 44 is a fuel flow path downstream of the nozzle seat 16 in the fuel flow direction. The clearance 44 is an annular fuel flow path formed between the valve portion 26 of the needle 2 and the nozzle seat surface 43 when the needle 2 is lifted.

  In the nozzle injection hole portion 4, a sac chamber 45 that is a sac volume is provided downstream of the nozzle seat surface 43 in the fuel flow direction. The sac chamber 45 is formed in a bottomed cylindrical sack portion (circular top portion) 46 provided at the tip of the nozzle body 3 in the central axis direction. The inner peripheral wall surface of the sack, which is the inner wall of the sack portion 46, is formed of a spherical concave curved surface. Further, the outer peripheral wall surface of the sack, which is the outer wall of the sack portion 46, is formed with a spherical convex curved surface.

The sac chamber 45 is a distribution chamber that communicates the clearance 44 and the plurality of nozzle holes 5, collects fuel flowing in an annular shape at the clearance 44, temporarily stores the fuel, and then distributes and supplies the fuel to the plurality of nozzle holes 5. is there.
Here, when the nozzle seal 34 of the valve portion 26 contacts the nozzle seat 16, the communication state between the fuel reservoir chamber 17 and the clearance 42 and the clearance 44 and the suck chamber 45 is blocked.
Further, when the nozzle seal 34 of the needle 2 is detached (lifted) from the nozzle sheet 16, the fuel reservoir chamber 17 and the clearance 42 are in communication with the clearance 44 and the sack chamber 45, and the nozzle holes 5 are formed through the clearances 42 and 44. Fuel is introduced into the sac chamber 45 that is always in communication with the sack chamber 45.

The plurality of nozzle holes 5 are provided so as to extend radially outward from the center axis of the nozzle (CL) in the radial direction. These injection holes 5 are formed along the circumferential direction of the sac portion 46 so that the fuel spray is efficiently distributed in each combustion chamber R of the direct injection engine. The plurality of nozzle holes 5 are formed at a predetermined interval (equal interval) in the circumferential direction of the sack portion 46 (6 to 12 in this example: 8).
The plurality of nozzle holes 5 include nozzle hole channels (inner and outer communication holes) 6 that penetrate the nozzle nozzle part 4 and communicate the sack inner peripheral wall surface of the sac part 46 and the sack outer peripheral wall surface of the sack part 46. .

  The nozzle hole flow path 6 includes a nozzle hole inlet 7 opened at the inner peripheral wall surface of the sack 46 and a nozzle hole outlet 8 opened at the outer wall surface of the sack 46. The nozzle hole channel 6 is formed such that the channel cross-sectional area gradually decreases from the nozzle hole inlet 7 toward the nozzle hole outlet 8. The nozzle hole channel 6 extends in the nozzle hole axis (HL) direction from the nozzle hole inlet 7 to the nozzle hole outlet 8. The nozzle hole axis (HL) direction is inclined downward in the figure with respect to a plane perpendicular to the nozzle center axis CL. The nozzle hole axis (HL) is the nozzle axis extending straight in the direction of the center line of the nozzle hole channel 6.

The plurality of nozzle holes 5 increases the flow coefficient of the nozzle hole 5 by making the hole diameter of the nozzle hole inlet 7 larger than the hole diameter of the nozzle hole outlet 8. In addition, rounded chamfering is performed on the periphery of each nozzle hole inlet 7 in order to increase the flow coefficient. The nozzle hole 5 having a shape in which the fuel easily flows has a high flow coefficient. As a result, the fuel easily flows from the sac chamber 45 into the nozzle hole passage 6 through the nozzle hole inlet 7.
In each of the plurality of nozzle holes 5, each nozzle hole inlet 7 is opened on the inner wall on the downstream side in the fuel flow direction from the nozzle sheet 16, in the present embodiment, on the inner peripheral wall surface of the sac portion 46. The plurality of nozzle holes 5 have respective nozzle hole outlets 8 opened on the outer wall on the opposite side to each nozzle hole inlet 7, in the present embodiment, on the outer peripheral wall surface of the sack portion 46.

The injection hole inlets 7 of the plurality of injection holes 5 are arranged at predetermined intervals (equal intervals) on the same circumference around the nozzle central axis (CL) on the inner peripheral wall surface of the sac of the sack portion 46. .
Each nozzle hole inlet 7 has a long hole-shaped opening cross section having a short axis and a long axis perpendicular to each other. Specifically, the opening shape of each nozzle hole inlet 7 is an oval shape.
If the length (LL) of the long axis of each nozzle hole inlet 7 is slightly longer than the length (SL) of the short axis of each nozzle hole inlet 7, it is included in the “long hole shape” in the claims. . Note that LL is the length of a straight line (long axis) connecting A ′ on the outline of each nozzle hole inlet 7 and B ′ on the outline of each nozzle hole inlet 7. SL is the length of a straight line (short axis) connecting C ′ on the outline of each nozzle hole inlet 7 and D ′ on the outline of each nozzle hole inlet 7.

  The major axis direction of each nozzle hole inlet 7 is inclined by a predetermined angle (θ) in the same direction as the rotation direction of the swirl flow of the intake air with respect to the nozzle central axis (CL) direction. For example, when the major axis (A-B) of each nozzle hole inlet 7 is vertically projected onto a projection plane including the nozzle center axis (CL) located on the radially inner side, the major axis (A ′) of each nozzle hole inlet 7 is projected. The −B ′) direction is inclined with respect to the nozzle central axis (CL) direction by a predetermined angle (θ) in the same direction as the rotational direction of the swirl flow of the intake air. At this time, the short axis (C′-D ′) of each nozzle hole inlet 7 is orthogonal to the long axis (A′-B ′) of each nozzle hole inlet 7.

  Here, the predetermined angle is greater than 0 degrees and less than 90 degrees, with the inclination in the same direction as the rotation direction of the swirl flow being positive. In this embodiment, the major axis of each nozzle hole inlet 7 is inclined about 45 degrees in the same direction as the rotation direction of the swirl flow of the intake air with respect to the nozzle center axis (CL) direction. The intersection of the nozzle central axis (CL) and the major axis (A′-B ′) of each nozzle hole inlet 7 is the intersection A of the major axis of each nozzle hole inlet 7 and the outline of each nozzle hole inlet 7. It can be anywhere between -B.

The nozzle hole outlets 8 of the plurality of nozzle holes 5 are arranged at predetermined intervals (equal intervals) on the same circumference around the nozzle central axis (CL) on the sack outer peripheral wall surface of the sack portion 46.
Each nozzle hole outlet 8 has a diameter of a predetermined length, and has a circular opening cross section smaller than the opening cross sectional area of each nozzle hole inlet 7.
Each nozzle hole inlet 7 of the plurality of nozzle holes 5 has an upper peripheral edge 51 located on one end side (upper part of the nozzle hole) in the nozzle center axis (CL) direction and the other end side (injection hole) in the nozzle center axis (CL) direction. It has a lower peripheral edge 52 located at the lower part.

The upper peripheral edge 51 of each nozzle hole inlet 7 is a part located at the upstream side (most upstream part) in the fuel flow direction flowing into the sac chamber 45 from the clearance 44 at each nozzle hole inlet 7. Further, the lower peripheral edge 52 of each nozzle hole inlet 7 is a portion located at the downstream side (most downstream part) in the fuel flow direction flowing into the sack chamber 45 from the clearance 44 at each nozzle hole inlet 7.
Each nozzle hole outlet 8 of the plurality of nozzle holes 5 has an upper peripheral edge 53 located on one end side (upper hole upper part) in the nozzle center axis (CL) direction and the other end side (nozzle hole) in the nozzle center axis (CL) direction. It has a lower peripheral edge 54 located at the lower part.

Each nozzle hole channel 6 of the plurality of nozzle holes 5 has linear first and second nozzle wall surfaces 61 and 62, and these first and second nozzle wall surfaces 61 and 62 are inlets of the nozzle holes. 7 and the opening periphery of each nozzle hole outlet 8 are connected.
The first nozzle hole wall surface 61 is an inclined surface inclined by a first inclination angle with respect to a vertical plane perpendicular to the nozzle center axis (CL). The first nozzle hole wall surface 61 connects the outer line of each nozzle hole 8 with a straight line from the intersection of the outer line of each nozzle hole 7 and the long axis.
The second nozzle hole wall surface 62 is an inclined surface inclined by a second inclination angle that is gentler than the first inclination angle with respect to a vertical plane perpendicular to the nozzle center axis (CL). The second nozzle hole wall surface 62 connects the outline of each nozzle hole outlet 8 with a straight line from the intersection of the outline of each nozzle hole inlet 7 and the long axis.
The first tilt angle is steeper than the second tilt angle.

Each nozzle hole inlet 7 of the plurality of nozzle holes 5 has a first semicircular portion on the upstream side in the fuel flow direction flowing into the sac chamber 45 from the clearance 44, and a downstream side in the fuel flow direction flowing into the sack chamber 45 from the clearance 44. Two semicircular parts and a rectangular part connecting the first semicircular part and the second semicircular part.
The plurality of nozzle holes 5 includes a first imaginary line CL1 that connects the center point HCC1 of the first semicircular portion of each nozzle hole inlet 7 and the center point CC of the circle portion of each nozzle hole outlet 8 in a straight line, and each nozzle hole. There is a second imaginary line CL2 that connects the center point HCC2 of the second semicircular portion of the inlet 7 and the center point CC of the circular portion of each nozzle hole outlet 8 with a straight line.

[Operation of Example 1]
Next, the operation of the injector provided with the fuel injection nozzle 1 of this embodiment will be briefly described with reference to FIGS.

Here, when the energization to the coil of the electromagnetic valve is stopped, the valve portion 26 of the needle 2 is seated on the nozzle sheet 16 on the nozzle sheet surface 43, so that the fuel flow direction is higher than that of the nozzle sheet 16. Communication between the upstream fuel reservoir chamber 17 and clearance 42 and the clearance 44 and sac chamber 45 downstream of the nozzle seat 16 in the fuel flow direction is blocked.
Therefore, the fuel injection nozzle 1 is in a closed (full closed) state in which the needle 2 is closed, and enters the combustion chamber R formed in each cylinder of the direct injection engine from each injection hole outlet 8 of the plurality of injection holes 5. The fuel injection is not made.

  On the other hand, when the coil of the solenoid valve is energized by a control command from the ECU, a magnetic force is generated in the coil, and the armature is attracted to the magnetic pole surface of the stator core. As a result, the spool valve of the solenoid valve opens the low pressure port, so that fuel in the control chamber flows out of the injector (low pressure side of the fuel system) through the low pressure port. As a result, the fuel pressure in the control chamber quickly drops below the needle opening pressure determined by the urging force of the return spring or the like, so that the needle 2 separates (lifts) from the nozzle seat 16 of the nozzle body 3.

Here, when the amount of lift of the needle 2 at the initial stage of fuel injection is small, that is, when the needle is lifted low, the flow of the clearance 44 formed between the valve portion 26 of the needle 2 and the nozzle seat surface 43 of the nozzle body 3. The road cross-sectional area is relatively small, and the flow rate of fuel flowing from the clearance 42 through the clearance 44 into the sac chamber 45 is high.
As a result, separation of the fuel flow occurs at the upper peripheral edge 51 of each nozzle hole inlet 7, and the fuel that flows into each nozzle hole channel 6 from the sac chamber 45 flows into each nozzle hole channel 6 as shown in FIG. It flows along the lower side surface (second nozzle hole wall surface 62) of the nozzle hole channel 6. The direct injection engine has a vertical surface (left-right direction in the figure) perpendicular to the nozzle center axis (CL) from each nozzle hole outlet 8 or a fuel hole direction slightly downward with respect to the nozzle hole axis (HL) direction. It is injected into the combustion chamber R.

Thereafter, when the fuel pressure in the control chamber further decreases, the lift amount of the needle 2 becomes larger. When the lift amount of the needle 2 is large, that is, when the needle is highly lifted, as shown in FIG. 7B, the flow direction of the fuel from the sac chamber 45 into each nozzle hole channel 6 changes, Fuel flow separation at the upper peripheral edge 51 of the hole inlet 7 is reduced. Therefore, at each nozzle hole outlet 8, the fuel flow that reaches the upper part of the nozzle hole, that is, the downstream part of each nozzle hole channel 6 (immediately before the nozzle hole outlet) along the first nozzle hole wall surface 61, That is, the injection direction changes (becomes upward) at an angle that combines with the fuel flow that reaches the downstream portion (immediately before the nozzle hole outlet) of each nozzle hole channel 6 along the second nozzle hole wall surface 62.
As described above, in the fuel injection nozzle 1 of this embodiment, as shown in FIGS. 1 and 7, the fuel injection direction is changed during the fuel injection period in accordance with the behavior (lift amount) of the needle 2. Change.

  Here, as shown in FIG. 8, the initial stage of fuel injection, that is, the low lift spray (fuel spray at the time of needle low lift) is caused to flow into the swirl flow of the intake air, and the nozzle injection hole portion 4 of the fuel injection nozzle 1. Are arranged in a space between high lift sprays (fuel sprays during needle high lift) adjacent to each other in the circumferential direction. For this reason, the fuel spray at the time of low needle lift and the fuel spray at the time of high needle lift do not overlap spatially. Thereby, the ignition delay from the ignition of the fuel spray at the time of low needle lift to the ignition of the fuel spray at the time of high needle lift becomes longer.

[Effect of Example 1]
As described above, in the fuel injection nozzle 1 of the present embodiment, the needle 2 that can reciprocate, the nozzle body 3 that has the nozzle seat 16 on which the valve portion 26 of the needle 2 can be seated, and the nozzle body 3 And a plurality of nozzle holes 5 communicating with the inside and outside of the nozzle nozzle part 4.
The plurality of nozzle holes 5 are tapered such that the cross-sectional area of the flow path gradually decreases from each nozzle hole inlet 7 opened at the inner wall of the nozzle nozzle hole part 4 toward each nozzle hole outlet 8 opened at the outer wall of the nozzle nozzle hole part 4. Each nozzle hole channel 6 having a cross-sectional shape is provided. Further, by providing an R-shaped chamfered portion at the periphery of each nozzle hole inlet 7, while increasing the flow coefficient of the nozzle hole 5, between the nozzle hole inlets 7 adjacent in the circumferential direction on the inner wall of the nozzle nozzle hole 4. Since the distance can be separated by a predetermined distance, the strength of the inner wall of the nozzle body on the nozzle seat side where the valve portion 26 of the needle 2 seats can be maintained.

Further, the major axis direction of each nozzle hole inlet 7 of the plurality of nozzle holes 5 communicating with the inside and outside of the nozzle hole part 4 of the nozzle body 3 of the fuel injection nozzle 1 extends straight at least in the direction of the center line of the nozzle body 3. The nozzle is tilted by a predetermined angle (θ) in the same direction as the swirl flow with respect to the nozzle central axis (CL) direction. That is, the fuel injected into the combustion chamber R from each nozzle hole outlet 8 by angling the major axis direction of each nozzle hole inlet 7 in the same direction as the swirl flow with respect to the nozzle central axis (CL) direction. Are injected obliquely with respect to the nozzle central axis (CL) direction, which is the common central axis of the needle 2 and the nozzle body 3.
At the time of needle low lift corresponding to the initial stage of fuel injection, separation of the fuel flow occurs at the upper peripheral edge 51 of each nozzle hole inlet 7, and each nozzle hole inlet 7 enters the fuel flow path downstream of the nozzle sheet 16 in the fuel flow direction. The fuel that has flowed into the nozzle hole channel 6 through the nozzles is injected into the combustion chamber R from the nozzle hole outlets 8 along the second nozzle hole wall surface 62 of the nozzle hole channel 6.

  On the other hand, at the time of high needle lift, the flow velocity of the fuel flowing into the nozzle hole channel 6 from the fuel channel downstream of the nozzle seat 16 in the fuel flow direction via the nozzle hole inlets 7 becomes smaller. Since the fuel flow separation at the upper peripheral edge 51 of the hole inlet 7 is reduced, the fuel flow along the first nozzle hole wall surface 61 of the nozzle hole flow path 6 and the nozzle hole flow are located in front of each nozzle hole outlet 8. Fuel is injected into the combustion chamber R from each nozzle hole outlet 8 at an angle that combines with the fuel flow along the second nozzle hole wall surface 62 of the passage 6.

Therefore, in accordance with the behavior of the needle 2 (needle lift amount), the injection direction of the fuel injected from the injection hole outlets 8 into the combustion chamber R changes during the fuel injection period. The fluctuation range of the fuel is reduced, and the collision of fuel with the cylinder head wall surface and the piston wall surface is reduced.
Therefore, since the amount of fuel adhering to the combustion chamber wall surface of the direct injection engine can be reduced, harmful substances such as smoke and HC can be reduced.

  Here, in the conventional fuel injection nozzle 100, as shown in FIG. 15, the major axis direction of each nozzle hole inlet of the plurality of nozzle holes and the nozzle central axis (CL) direction coincide with each other. The fuel spray (LF) at the time of low needle lift and the fuel spray (HF) at the time of high needle lift are easily spatially overlapped. The fuel spray (HF) at the time is also ignited at the same time, so the ignition delay is shortened, and the fuel spray (HF) at the time of needle high lift is close to the fuel injection nozzle 100 and there is a region where the evaporation of droplets is not completed. Since it burns, there is a problem that harmful substances such as smoke increase.

In the fuel injection nozzle 1 of the present embodiment, the major axis direction of each nozzle hole inlet 7 is tilted by a predetermined angle (θ) in the same direction as the swirl flow with respect to the nozzle center axis (CL) direction. During the needle low lift, the fuel injected from each nozzle hole outlet 8 into the combustion chamber R flows into the swirl flow generated in the combustion chamber R.
Thereafter, when the needle 2 is further lifted, the fuel spray at the time of low needle lift is arranged in the space between the fuel sprays (HF) injected from the respective nozzle hole outlets 8 into the combustion chamber R at the time of high needle lift. The fuel spray (LF) at the time of low needle lift and the fuel spray (HF) at the time of high needle lift are difficult to overlap spatially.

Therefore, the ignition delay from the ignition of the fuel spray (LF) at the time of low needle lift to the ignition of the fuel spray (HF) at the time of high needle lift becomes long, and the fuel spray (HF) at the time of high needle lift is the nozzle body. Since the fuel droplets evaporate further from the nozzle nozzle hole portion 3 and ignited from the location where the mixing with the air proceeds, harmful substances such as smoke and HC can be reduced.
Accordingly, it is possible to prevent deterioration of exhaust emission discharged from the combustion chamber R of each cylinder of the direct injection engine.

[Configuration of Example 2]
9 and 10 show a fuel injection nozzle 1 (Embodiment 2) to which the present invention is applied.
Here, the same reference numerals as those in the first embodiment indicate the same configuration or function, and the description thereof is omitted.

The injector of the present embodiment is a valve-covered orifice (VCO) type fuel in which each injection hole inlet 7 of the plurality of injection holes 5 is covered with a second seal surface 32 downstream of the nozzle seal 34 in the fuel flow direction. An injection nozzle 1 is provided.
Similarly to the first embodiment, the plurality of nozzle holes 5 are each nozzle hole inlet 7 opened at the upstream end in the nozzle hole axial direction of each nozzle hole channel 6 and the nozzle hole axial direction of each nozzle hole channel 6. Each nozzle hole outlet 8 opened at the downstream end is provided.
The fuel injection nozzle 1 has a circumferential direction around a clearance (annular flow path) 44 in which each of the injection hole inlets 7 of the plurality of injection holes 5 communicates with a clearance 42 upstream of the nozzle seat 16 in the fuel flow direction. Are open in the same plane as the nozzle sheet surface 43 having a conical surface shape. Each nozzle hole inlet 7 opens at the nozzle sheet surface 43 on the downstream side in the fuel flow direction from the nozzle sheet 16.
As described above, the fuel injection nozzle 1 of this embodiment has the same effects as those of the first embodiment.

[Configuration of Example 3]
FIG. 11 shows a fuel injection nozzle 1 (Embodiment 3) to which the present invention is applied.
Here, the same reference numerals as those in the first and second embodiments indicate the same configuration or function, and the description thereof will be omitted.

Each injection hole inlet 7 of the present embodiment has a rectangular (long hole shape) opening cross section having a short axis and a long axis perpendicular to each other, as shown in FIG.
Further, each nozzle hole inlet 7 of the present embodiment has a rectangular shape (long hole) having a short axis and a long axis perpendicular to each other, and having a round shape portion at a corner as shown in FIG. Shape) opening cross section.
The major axis (A′-B ′) direction of each nozzle hole inlet 7 is inclined by a predetermined angle (θ) in the same direction as the rotation direction of the swirl flow of the intake air with respect to the nozzle central axis (CL) direction. ing. In addition, the short axis (C′-D ′) of each nozzle hole inlet 7 is orthogonal to the long axis (A′-B ′) of each nozzle hole inlet 7.
As described above, the fuel injection nozzle 1 of this embodiment has the same effects as those of the first and second embodiments.

[Configuration of Example 4]
FIG. 12 shows a fuel injection nozzle 1 (Embodiment 4) to which the present invention is applied.
Here, the same reference numerals as in the first to third embodiments indicate the same configuration or function, and the description thereof is omitted.

Each injection hole inlet 7 of the present embodiment has a semicircular (long hole shape) opening cross section having a short axis and a long axis perpendicular to each other, as shown in FIG.
Further, each nozzle hole 7 of the present embodiment has an elliptical shape (long hole) having a short axis and a long axis perpendicular to each other and a round shape portion at a corner as shown in FIG. Shape) opening cross section.
The major axis (A′-B ′) direction of each nozzle hole inlet 7 is inclined by a predetermined angle (θ) in the same direction as the rotation direction of the swirl flow of the intake air with respect to the nozzle central axis (CL) direction. ing. In addition, the short axis (C′-D ′) of each nozzle hole inlet 7 is orthogonal to the long axis (A′-B ′) of each nozzle hole inlet 7.
As described above, the fuel injection nozzle 1 of this embodiment has the same effects as those of the first to third embodiments.

[Configuration of Example 5]
FIG. 13 shows a fuel injection nozzle 1 (Embodiment 5) to which the present invention is applied.
Here, the same reference numerals as in the first to fourth embodiments indicate the same configuration or function, and the description thereof is omitted.

The plurality of nozzle holes 5 may employ the following if the opening shape of each nozzle hole inlet 7 is a long hole shape having a short axis and a long axis orthogonal to each other.
You may employ | adopt the trapezoidal injection hole inlet 7 as shown to Fig.13 (a).
Moreover, you may employ | adopt the long hole-shaped injection hole inlet 7 which combined the rectangle as shown in FIG.13 (b), and two sets of squares.
Moreover, you may employ | adopt the long hole-shaped injection hole inlet 7 which combined the rectangle as shown in FIG.13 (c), and three sets of squares.
Moreover, you may employ | adopt the long hole-shaped injection hole inlet 7 which combined the rectangle as shown in FIG.13 (d), and two sets of circles.

Moreover, you may employ | adopt the long hole-shaped injection hole inlet 7 which combined 2 sets of rectangles as shown in FIG.13 (e).
Moreover, you may employ | adopt the nozzle hole 7 of a triangular (long hole) shape as shown in FIG.13 (f). These long hole-shaped injection hole inlets 7 are such that the long axis (X) direction of the injection hole inlet 7 is inhaled with respect to the nozzle central axis (CL) direction as shown in FIG. It is inclined by a predetermined angle (θ) in the same direction as the rotation direction of the swirl flow. Further, the minor axis (Y) of the nozzle hole inlet 7 is orthogonal to the major axis (X) of each nozzle hole inlet 7.
As described above, the fuel injection nozzle 1 of this embodiment has the same effects as those of the first to fourth embodiments.

[Modification]
In this embodiment, the fuel injection nozzle of the present invention is applied to the fuel injection nozzle 1 that directly injects high-pressure fuel introduced from a supply pump or a common rail into the combustion chamber of the direct injection engine. The fuel injection nozzle is directly pumped into the fuel reservoir chamber from a fuel injection pump such as a row type fuel injection pump or a distribution type fuel injection pump, and the fuel pressure (nozzle opening force) in the fuel reservoir chamber is spring ( Fuel that directly injects fuel into the combustion chamber of a direct-injection internal combustion engine (direct-injection engine) when the force exceeds the urging force of the spring) (axial force in the valve closing direction: nozzle closing force) You may apply to an injection nozzle.

In this embodiment, a solenoid valve that adjusts (increases / decreases) the fuel pressure in the control chamber provided immediately above the command piston linked to the needle 2 and controls the opening / closing operation of the needle 2 is adopted as an actuator for opening and closing the needle. However, a piezo actuator that adjusts (increases / decreases) the fuel pressure in the control chamber provided immediately above the command piston linked to the needle 2 and controls the opening / closing operation of the needle 2 may be employed.
Further, the needle 2 of the fuel injection nozzle 1 may be directly driven by a driving force of a solenoid actuator or a piezoelectric actuator.
Further, a needle lift amount variable mechanism that can change the lift amount of the needle 2 between a first state in which the needle lift amount is relatively small and a second state in which the needle lift amount is relatively large may be employed.

In this embodiment, a direct injection engine such as a diesel engine is employed as an internal combustion engine that directly injects fuel from the nozzle hole outlet of the fuel injection nozzle 1 into the combustion chamber, but a direct injection such as a gasoline engine is employed as the internal combustion engine. An engine may be adopted.
Further, the nozzle central axis (CL) may be offset from the central axis of the cylinder of the internal combustion engine. Further, the nozzle central axis (CL) direction may be inclined with respect to the cylinder central axis direction.

R Combustion chamber 1 Fuel injection nozzle 2 Needle 3 Nozzle body 5 Injection hole 6 Injection hole flow path 7 Injection hole inlet 8 Injection hole outlet 16 Nozzle seat 26 Needle valve

Claims (5)

A fuel injection nozzle (1) applied to a direct injection internal combustion engine (9 to 11) capable of generating a swirl flow in a combustion chamber (R),
(A) a needle (2) having a valve portion (26) on the tip side in the direction of the nozzle central axis (CL);
(B) An annular nozzle seat (16) on which the valve portion (26) of the needle (2) can be seated, and an injection hole inlet (7) on the inner wall on the downstream side in the fuel flow direction from the nozzle seat (16). Has an open nozzle hole (5),
A bottomed cylindrical nozzle body (3) that supports the needle (2) in a reciprocating manner in the nozzle central axis (CL) direction;
When the needle (2) is lifted from the nozzle seat (16), in the fuel injection nozzle (1) for directly injecting fuel into the combustion chamber (R) from the nozzle hole (5),
The nozzle hole (5) communicates the inside and the outside of the nozzle body (3), and the nozzle hole outlet (8) opened from the nozzle hole inlet (7) on the outer wall opposite to the nozzle hole inlet (7). ) Has a nozzle hole channel (6) extending in the nozzle hole axis (HL) direction,
The nozzle hole inlet (7) has a long hole-shaped opening cross section having a minor axis and a major axis orthogonal to each other, and the major axis direction of the nozzle hole inlet (7) is the nozzle central axis (CL) direction. Is inclined by a predetermined angle (θ) in the same direction as the swirl flow ,
The nozzle hole outlet (8) has a circular opening cross section,
The fuel injection nozzle, wherein the nozzle hole channel (6) is formed such that a channel cross-sectional area gradually decreases from the nozzle hole inlet (7) toward the nozzle hole outlet (8) . The fuel injection nozzle (1) according to claim 1,
The fuel injection nozzle according to claim 1, wherein the elongated hole-shaped opening section includes at least one of a rectangular-shaped opening section, a semicircular-shaped opening section, and an elliptical-shaped opening section . The fuel injection nozzle (1) according to claim 1 or claim 2,
The fuel injection nozzle, wherein the injection holes (5) are a plurality of injection holes (5) provided at predetermined intervals in the circumferential direction of the nozzle body (3) . A fuel injection nozzle (1) according to any one of claims 1 to 3,
The nozzle hole inlet (7) has a spherical sac circumference that surrounds the circumference of the sac chamber (45) communicating with the fuel flow path (42) upstream of the nozzle seat (16) in the fuel flow direction. a fuel injection nozzle which is characterized that you have opened in the wall. A fuel injection nozzle (1) according to any one of claims 1 to 3 ,
The nozzle hole inlet (7) has a conical surface shape surrounding the periphery of an annular flow path (44) communicating with the fuel flow path (42) upstream of the nozzle seat (16) in the fuel flow direction . A fuel injection nozzle opening at the seat surface (43) .

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