JP3572591B2 - Fluid injection nozzle and electromagnetic fuel injection valve using the same - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a fluid injection nozzle for improving atomization of fuel spray of an electromagnetic fuel injection valve and an electromagnetic fuel injection valve using the same.
[0002]
[Prior art]
Generally, a fuel injection valve used in an internal combustion engine has a valve member slidably housed in a guide hole formed in an axial direction of a valve body, and an injection hole opened at a tip end portion of the valve body is provided with a reciprocating straight line of the valve member. Open and close by exercise. For this reason, the lift amount of the valve member when the valve is opened is precisely controlled so as to secure an appropriate fuel injection amount.
[0003]
[Problems to be solved by the invention]
In order to cope with the exhaust gas regulation generated by the internal combustion engine, atomization of the spray is necessary, and in order to atomize the spray, the spray angle of the fuel is adjusted to the front side of the injection hole of the fuel injection valve. One with a sleeve nozzle is known. This is shown in FIGS. 7 and 8. In this conventional example, the separator 5 distributes the injector spray in two directions, and at the same time, promotes atomization as compared with a conventional round-hole-shaped sleeve.
[0004]
In this case, FIG. 7 (A), it is important to form a thin film to expand the angle theta ₁ and the diameter D of the tip of the pintle 1 shown in (B) and FIG. However, if the angle θ ₁ and the diameter D of the tip of the pintle are increased, the spray angle θ ₂ is increased, and the spray adheres to the inner wall surface of the sleeve nozzle 4, so that atomization is deteriorated and liquid dripping easily occurs. There's a problem.
[0005]
When the fuel injected from the injection hole 6 collides with the separator 5, a part of the atomized spray adheres to the sleeve inner wall side surface 7, and the attached fine particles are downstream due to the action of gravity with time. The fine particles gather at the lower end 37 of the sleeve nozzle 4 in the vertical direction and grow into droplets 38, and the volume of the droplets 38 gradually grows with time. There is a problem that a liquid dripping or the like is generated by the droplet.
[0006]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a fluid injection nozzle for preventing generation of droplets, liquid dripping, and the like of fuel injected from a fuel injection valve and an electromagnetic fuel injection valve using the same.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a fluid injection nozzle including a sleeve nozzle attachable to a tip end of an injection hole of a fuel injection valve, and a spray angle of a spray flow injected from the injection hole. has a separator for controlling the spray stream near the lowest point of the sleep nozzle is injected from the injection hole is, is disposed inclined with respect to the vertical direction when the engine is mounted, the lowest at this time A configuration is adopted in which a chamfered portion is formed toward a point .
[0008]
According to a second aspect of the present invention, in the fluid nozzle of the first aspect, the fuel attached to the inner wall surface of the sleeve nozzle is shaped to concentrate toward a lowermost point of the sleeve nozzle. And
According to a third aspect of the present invention, the lowermost point of the chamfered portion in the vertical direction when the engine is mounted is arranged to be substantially horizontal.
[0009]
5. The electromagnetic fuel injection valve according to claim 4 , wherein the valve comprises a reciprocally movable valve member, a guide hole capable of sliding the valve member in an axial direction, a valve seat capable of contacting the valve member, and an injection hole. A main body, an urging means for urging the valve member in a valve closing direction, and an electromagnetic actuator for generating an electromagnetic attraction force for separating the valve member from the valve seat against the urging force of the urging means, The fluid ejection nozzle according to any one of claims 1 to 3 is provided.
6. The electromagnetic fuel injection valve according to claim 5, wherein the valve member has a pintle at a tip end thereof, and the pintle penetrates the injection hole through a gap with an inner peripheral wall of the injection hole and protrudes from the injection hole. , Characterized in that the diameter increases from the proximal end side toward the distal end side.
[0010]
[Action and effect of the invention]
According to the fluid injection nozzle of the present invention, when the fuel injection valve is mounted on an internal-vehicle internal combustion engine (hereinafter, the engine is referred to as “engine”), the lowest point of the sleeve nozzle attached to the tip of the injection hole is Since the fuel flow is in the spray flow injected from the injection hole, the fuel flow attached to the inner wall of the sleeve nozzle is exposed to the spray flow injected from the injection hole. Therefore, the fuel droplets are prevented from growing into large particles, and are prevented from flowing into the combustion chamber from the intake port in the form of droplets. At the same time, atomization of the fuel spray injected from the fuel injection valve is not impaired. In order to prevent such fuel droplets and liquid dripping from occurring, it is possible to improve the operability of the engine and reduce the emission of exhaust gas.
[0011]
【Example】
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1 to 4 show an electromagnetic fuel injection valve according to a first embodiment of the present invention.
As shown in FIG. 4, the fuel injection valve 11 is mounted on an outer wall of the intake pipe 12 toward an intake passage 13 formed in the intake pipe 12 of the engine. In this case, the fuel injection valve 11 is provided for each branch pipe of the intake manifold that branches corresponding to a plurality of cylinders. FIG. 4 shows a partition wall 14 of the branch pipe. The fuel injection valve 11 shown in FIG. 4 injects the fuel from the injection hole 6 toward the intake passage 13 on the near side with respect to the paper surface of the partition wall 14.
[0012]
As shown in FIG. 3, the electromagnetically operated fuel injection valve 11 is attached to a delivery pipe for supplying fuel to each cylinder of the engine. As shown in FIG. 3, a housing 53 of the fuel injection valve 11 has a stepped cylindrical shape, and an electromagnetic coil 55 is wound around a spool 54 around a large diameter portion of the housing 53. A cylindrical iron core 56 is provided through the spool 54 from above, and an adjusting pipe 57 is inserted and fixed inside the iron core 56 in the axial direction.
[0013]
The nozzle body 16 is overlapped and fixed to the small-diameter portion of the housing 53 via a spacer 58, and the injection hole 6 is formed in an end face protruding downward of the nozzle body 16. Inside the guide hole 17 of the nozzle body 16, a needle valve 18 that can abut on a valve seat 19 is slidably provided, and a pintle 1 is formed at the tip of the needle valve 18. It penetrates through the gap with the inner peripheral wall of the injection hole 6 and protrudes from the injection hole 6. A stopper 60 is formed substantially at the center of the needle valve 18 so as to face the spacer 58. Further, a movable core 61 welded and fixed to the needle valve 18 is provided at the upper end of the needle valve 18 so as to face the iron core 56, and the movable core 61 is disposed between the iron core 56 and the adjusting pipe 57. It is urged downward by a coil spring 62. At the end of the nozzle body 16 where the injection hole 6 is formed, a sleeve nozzle 24 is provided so as to surround the end of the nozzle body 16.
[0014]
The sleeve nozzle 24 attached to the tip end of the nozzle body 16 of the fuel injection valve 11 is integrally formed of a material such as resin such as nylon 66, and its components are a cylindrical skirt portion 25, a cap portion 26, and a flange. It comprises a part 27 and a separator 29. Hereinafter, these components of the sleeve nozzle 24 will be sequentially described in detail with reference to FIGS.
[0015]
The skirt 25 has a hollow cylindrical shape, and has an internal space 30 through which the fuel spray passes.
The cap portion 26 is a portion attached to the distal end surface of the sleeve nozzle 24, and a small-diameter hole 28 having an inner diameter smaller than the internal space 30 is formed in the center of the cap portion 26. The small diameter hole 28 has a circular cross section, and the injection hole 6 is located at the center line position of the sleeve nozzle 24. A pintle 1 is provided at the center line of the small-diameter hole 28 so as to protrude from the tip of the needle valve 18. The inside diameter of the small-diameter hole 28 is formed so that the fuel flow of the fuel injected from the injection hole 6 along the outer wall of the pintle 1 does not directly hit the inner wall of the small-diameter hole 28.
[0016]
The flange portion 27 is connected to the cap portion 26 and is a portion that is press-fitted and fixed to the outer peripheral surface of the tip of the nozzle body 16.
The separator 29 has a slope 29a and a slope 29b on the opposite side formed at an outlet in a shape of an isosceles triangle in cross section from a position at a predetermined distance from the inlet of the skirt 25 toward the outlet. A rectangular bottom surface 29c including the diameter of the portion 25 is formed. A passage 34 is formed by the one slope 29a and the inner wall surface 25a of the skirt portion 25, and a passage 35 is formed by the other slope 29b and the inner wall surface 25a. The jet flow is injected in the directions of the two passages 34 and 35. The fuel flow which forms a liquid film along the outer peripheral wall of the pintle 1 through the injection hole 6 is atomized at a position away from the pintle 1 and becomes a spray flow. In the two directions and a role in controlling the spray angle of the separated spray flow. The spray angle is controlled by the angle between the inner wall surface 25a of the skirt 25 and the slopes 29a and 29b of the separator 29.
[0017]
Then, a chamfered portion 32 is formed to remove one side of the base of the separator 29 from the outlet of the skirt 25. The chamfered portion 32 is a flat surface cut into a flat shape. The flat surface is a surface that is inclined with respect to the axis of the sleeve nozzle 24, and has a shape in which the inclined surface 29 a and the inclined surface 29 b at the base of one side of the separator 29 are cut symmetrically. The lowermost point 33 in the vertical direction of the chamfered portion 32 when the engine is mounted is set to be substantially horizontal. The lowermost point 33 appears linearly, and the state when the engine is mounted is set so that the linear lowermost point 33 is located during spraying of the spray flow.
[0018]
The lowermost point 33 is set to the end point of the wall flow in which the flow of fuel adhering to the inner wall surface 25a of the skirt portion 25 flows due to gravity, and has a shape in which the wall flow is concentrated. Therefore, immediately before the fuel-wall-adhered flow flowing along the inner wall surface 25a of the sleeve nozzle 24 reaches the lowest point 33 of the chamfered portion 32, the wall-adhered flow is dropped toward the intake port by the fuel spray flow. For this reason, it is possible to prevent droplets and liquid dripping from occurring at the lowest point 33 of the sleeve nozzle 24.
[0019]
According to this embodiment, when the fuel injection valve 11 is attached to the engine mounted on the vehicle, the chamfered portion 32 is formed such that the lowermost point 33 of the sleeve nozzle 24 exists inside the spray flow. When a part of the spray particles of the fuel injected from the nozzle 6 scatter and adhere to the inner wall surface 25a, the wall-adhered flow is always removed by the spray flow, so that the wall-adhered flow is prevented from growing into droplets. As a result, it is possible to suppress the occurrence of liquid dripping, scattering of droplets, and the like. Therefore, according to this embodiment, it is possible to prevent the generation of fuel droplets, liquid dripping, and the like without impairing the atomization of the spray, so that the operability of the engine is improved and the exhaust gas emission reduction effect is great.
[0020]
(Second embodiment)
Next, a second embodiment of the present invention is shown in FIG. The second embodiment shown in FIG. 5 is an example in which a curved chamfered portion 42 is formed instead of the chamfered portion 32 shown in the first embodiment. In the chamfered portion 42 of the sleeve nozzle 24, a position where the lowest point 43 of the intersection of the sleeve outlet end and the chamfered portion 42 becomes the lowest point in the direction of gravity when the fuel injection valve 11 is mounted on the vehicle. It is in. The lowest point 43 is at a position where a part of the fuel spray flow injected from the injection hole 6 passes.
[0021]
In the second embodiment, as in the first embodiment, the flow adhering to the fuel wall that flows through the inner wall surface 24a of the sleeve nozzle 24 tends to concentrate at the lowest point 43. Since the liquid is dropped by the spray flow before being concentrated on the surface, it is possible to prevent liquid dripping before the flow adhering to the wall surface grows into droplets.
(Third embodiment)
FIG. 6 shows a third embodiment of the present invention.
[0022]
The third embodiment shown in FIG. 6 is an example in which a second chamfered portion 52 is further formed axially symmetrically in addition to the chamfered portion 32 of the first embodiment. The first chamfered portion 32 and the second chamfered portion 52 are formed axially symmetrically, and are formed axially symmetrically at the base portion on one side and the base portion on the other side of the separator 29.
The lowermost point 53 of the second chamfered portion 52 is set to be located in the fuel spray flow similarly to the lowermost point 33 of the first chamfered portion 32.
[0023]
According to the third embodiment, when the sleeve nozzle 24 is mounted on the outer peripheral portion of the distal end of the nozzle body 16, the mounting rotation angle of the sleeve nozzle 24 can be easily selected and set, so that the mounting workability is improved. is there.
Further, according to the electromagnetic fuel injection valve of the present embodiment, there is an effect that the angle θ of the spray flow can be easily adjusted.
[0024]
As described above, in each embodiment of the present invention, the fuel injection valve is mounted on the engine such that the lowest point of the sleeve nozzle is in the spray flow, and the wall is attached to the lowest point of the sleeve nozzle. Since the fuel is concentrated, the growth of the fuel droplets adhering to the wall surface of the sleeve nozzle is prevented, the generation of liquid dripping is prevented, and the atomization of the fuel spray is not impaired. Therefore, the operability of the engine can be improved by preventing the droplet growth of the fuel and the generation of the liquid dripping, and the effect of reducing the exhaust gas emission is large.
[Brief description of the drawings]
1A and 1B show a main part of a fuel injection valve according to a first embodiment of the present invention, in which FIG. 1A is a cross-sectional view, and FIG. 1B is an enlarged view in the direction of arrow B shown in FIG. is there.
2A is a cross-sectional view taken along line II-II shown in FIG. 1A, and FIG. 2B is an enlarged view taken in the direction of arrow B shown in FIG.
FIG. 3 is a sectional view of the fuel injection valve according to the first embodiment of the present invention.
FIG. 4 is a sectional view showing a state in which the fuel injection valve according to the first embodiment of the present invention is mounted on an engine.
FIG. 5 is a sectional view of a main part of a second embodiment of the present invention.
FIG. 6 is a sectional view of a main part of a third embodiment of the present invention.
7A and 7B show main parts of a conventional example, in which FIG. 7A is a cross-sectional view of the main parts, and FIG. 7B is an enlarged view of FIG.
FIG. 8 is a sectional view taken along line VIII-VIII shown in FIG.
[Explanation of symbols]
1 Pintle 6 Injection hole 11 Fuel injection valve 12 Intake pipe 13 Intake passage 16 Nozzle body (valve body)
17 Guide hole 18 Needle valve (valve member)
19 Valve seat 24 Sleeve nozzle (fluid injection nozzle)
25 Skirt 26 Cap 27 Flange 29 Separator 29a, 29b Slope 32 Chamfer 33 Lowest point 34, 35 Passage 42 Chamfer 52 Chamfer 55 Electromagnetic coil (electromagnetic actuator)
56 Iron core (electromagnetic actuator)
61 Movable core (electromagnetic actuator)
62 coil spring (biasing means)

Claims (5)

The fuel injection valve includes a sleeve nozzle that can be attached to a tip end of the injection hole, a separator that controls a spray angle of a spray flow injected from the injection hole, and a lowermost point of the sleeve nozzle from the injection hole. spray stream near injected is, is disposed inclined with respect to the vertical direction when the engine is mounted, the fluid injection nozzle, wherein a chamfered portion is formed toward the lowest point during the . The fluid injection nozzle according to claim 1, wherein the sleeve nozzle has a shape in which fuel attached to an inner wall surface of the sleeve nozzle is concentrated toward a lowermost point of the sleeve nozzle. 3. The fluid injection nozzle according to claim 1, wherein the lowermost point of the chamfered portion in the vertical direction when the engine is mounted is substantially horizontal. A reciprocable valve member;
A valve body having a guide hole slidable in the axial direction of the valve member, a valve seat capable of contacting the valve member, and an injection hole,
Urging means for urging the valve member in a valve closing direction,
An electromagnetic actuator that generates an electromagnetic attraction force that separates the valve member from the valve seat against the urging force of the urging means;
An electromagnetic fuel injection valve comprising: the fluid injection nozzle according to any one of claims 1 to 3 . The valve member has a pintle at the tip,
  The pintle penetrates the injection hole through a gap with an inner peripheral wall of the injection hole, protrudes from the injection hole, and has a diameter that increases from a base end side toward a distal end side. Item 6. An electromagnetic fuel injection valve according to Item 4.

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