JP2006207439A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of satisfying both large flow rate characteristics and atomization/penetration capacity. <P>SOLUTION: This fuel injection valve I is provided with a valve element 18; a valve seat member 3 having an annular and conical valve seat 8 on which the valve element 18 is seated so as to be openably/closably; and a nozzle 10 continued to a front end part of the valve seat member 3 to be positioned in the downstream side of the valve seat 8 and having a plurality of fuel nozzle holes 11 arranged around a centerline Y of the valve seat 8. The valve seat member 3 and the nozzle 10 are integrally formed by the same material, and each of the inner end face 10a of the nozzle 10 and the tip face 16b of the valve element 18 opposing to the inner end face 10a is constituted by a conical face or a spherical face with a diameter reduced toward the front side of the the fuel injection valve I. Each of the fuel nozzle holes 11 is arranged such that an extension L of a bus line of the valve seat 8 cross the inner face of each of the fuel nozzle holes 11, and a recessed part 13 for receiving the nozzle 10 are provided on the front end face of the valve seat member 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection valve mainly used for a fuel supply system of an internal combustion engine, and in particular, a valve body, a valve seat member having an annular conical valve seat on which the valve body is seated so as to be openable and closable, and a valve The present invention relates to an improvement in a fuel injection valve provided with a nozzle having a plurality of fuel injection holes arranged around a center line of a valve seat so as to be positioned on the downstream side of the seat.

  Such electromagnetic fuel injection valves are already known as disclosed in Patent Documents 1 and 2 below.

By the way, in recent internal combustion engines, there are increasing demands for output improvement and low pollution of exhaust gas. Therefore, the fuel injection valve has a large flow rate characteristic that can inject a large amount of fuel with good responsiveness in order to improve the output, and in order to purify the exhaust gas, the injected fuel is atomized and the intake passage of the fuel is injected. Atomization and penetration properties that suppress adhesion to the inner wall are important.
JP 2000-97129 A Japanese Patent No. 3027919

  However, since the fuel flow path connecting between the valve seat part and the fuel injection hole is also bent in both of Patent Documents 1 and 2, the fuel that has passed through the valve seat part when the valve body is opened. Before the fuel reaches the fuel nozzle hole of the nozzle, the pressure loss of the fuel increases, and it is difficult to satisfy the above-mentioned large flow characteristics and atomization / penetration.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide the fuel injection valve capable of simultaneously satisfying the large flow rate characteristics and atomization / penetration properties as described above.

  In order to achieve the above object, the present invention provides a valve body, a valve seat member having an annular and conical valve seat on which the valve body is seated so as to be openable and closable, and a valve seat member positioned downstream of the valve seat. In a fuel injection valve including a nozzle having a plurality of fuel injection holes that are connected to a front end portion of a seat member and are arranged around a center line of the valve seat, the valve seat member and the nozzle are integrally formed of the same material. In addition, the inner end face of the nozzle and the front end face of the valve body facing the inner end face are each formed of a conical surface or a spherical surface whose diameter decreases toward the front of the fuel injection valve, and is an extension of the bus seat bus line. The first feature is that each fuel nozzle hole is arranged so as to intersect the inner surface of each fuel nozzle hole, and a recess for receiving the nozzle is provided on the front end surface of the valve seat member.

  In addition to the first feature, the second feature of the present invention is that the concave portion is formed in a conical shape whose inner peripheral surface expands toward the front end surface of the valve seat member.

  Furthermore, in addition to the second feature, the third feature of the present invention is that the diameter of the small diameter portion of the inner peripheral surface of the recess is set smaller than the effective diameter of the valve seat.

  Furthermore, the present invention is characterized in that, in addition to the second or third feature, the height from the front end surface of the valve seat member to the valve seat is set to 1 mm or more.

  Furthermore, according to the present invention, in addition to any one of the first to the fourth, an annular step portion for avoiding mutual contact between the valve body and the nozzle is formed between the inner end face of the nozzle and the valve seat. It is characterized by.

  According to the first feature of the present invention, when the valve body is opened, the main flow of the fuel that has passed through the valve seat directly collides with the inner surface of the fuel nozzle hole with almost no pressure loss. The injected fuel can be effectively atomized and a high-speed spray foam can be formed. Therefore, this spray foam has a very high flow rate and high penetration, so there is little that adheres to the inner wall of the intake port of the engine, and there is little fuel pressure loss, so a large flow rate of fuel can be secured, and engine output is improved. And contribute to lower pollution of exhaust gas.

  In addition, the front end surface of the valve body and the inner end surface of the nozzle are conical surfaces or spherical surfaces having a small diameter toward the front of the fuel injection valve, thereby reducing the bending of the fuel flow path from the valve seat to each fuel injection hole. Therefore, internal pressure loss can be reduced and high energy fuel can be guided to each fuel nozzle hole, which can contribute to further improvement of the large flow rate characteristics of the fuel.

  Furthermore, the integration of the valve seat member and the nozzle with the same material eliminates the process of welding the nozzle to the valve seat member (welding), and also frees you from concerns about thermal distortion of the valve seat and nozzle due to welding. As a result, it is possible to improve the valve tightness and to improve the accuracy of the position and orientation of the fuel injection hole in the nozzle, so that the spray foam formed by the fuel injected from the fuel injection hole Can bring about stabilization.

  Furthermore, by receiving the nozzle in the recess formed in the front end surface of the valve seat member, the valve seat member itself can protect the nozzle from contact with other objects, and a special protective cap becomes unnecessary. In addition, the recess can suppress dripping due to fuel blowback.

  Further, according to the second feature of the present invention, the concave portion exhibits the Coanda effect and can be accurately directed to a predetermined target without disturbing the conical foam formed by the fuel injected from the nozzle. , It can contribute to the improvement of penetration.

  Furthermore, according to the third feature of the present invention, the axial thickness of the valve seat member in the valve seat is set to be smaller by setting the diameter of the inner peripheral surface small diameter portion of the recess to be smaller than the effective diameter of the valve seat. It can be secured sufficiently without being disturbed by the recess, and a great rigidity can be given to the valve seat. Therefore, the valve seat can be easily processed with high accuracy and the valve tightness can be improved.

  Further, according to the fourth aspect of the present invention, the axial thickness of the valve seat member in the valve seat is sufficient to provide high rigidity of the valve seat.

  Furthermore, according to the fifth feature of the present invention, the annular step formed between the valve seat and the inner end surface of the nozzle can avoid mutual interference between the valve body and the nozzle and improve the valve tightness. In addition, it facilitates the direct introduction of the fuel that has passed through the valve seat into the fuel injection hole, greatly contributing to the improvement of the fuel's large flow characteristics and penetration.

  In addition, the space between the valve element and the nozzle due to the presence of the annular step portion is a dead space that does not need to have a fuel flow path function inside the fuel injection hole group. As much as possible, the dead space can be reduced and the fuel injection characteristics can be stabilized against temperature changes.

  Further, when the annular valve seat is processed, the annular step portion prevents interference between the cutting tool and the nozzle, and the valve seat can be processed easily and accurately.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a longitudinal sectional side view of an essential part of an engine equipped with an electromagnetic fuel injection valve according to a first embodiment of the present invention, FIG. 2 is an enlarged longitudinal side view of the fuel injection valve, and FIG. 3 is a nozzle of the fuel injection valve. 4 is an enlarged view of the peripheral portion, FIG. 4 is a view taken in the direction of the arrow 4 in FIG. 3, FIG. 5 is a view showing the opened state of the fuel injection valve, a corresponding view with FIG. It is a principal part longitudinal cross-sectional view of a fuel injection valve.

  First, a description will be given of the first embodiment of the present invention shown in FIGS.

  In FIG. 1, an intake manifold 51 is joined to a side surface of the cylinder head 50 of the engine E where the intake port 50 a is opened, and the electromagnetic fuel injection valve I of the present invention is attached to the intake manifold 51. The front end face of the fuel injection valve I is directed to the downstream end of the intake port 50a, and the spray form formed by the fuel injected from the fuel injection valve I when the intake valve 52 that opens and closes the downstream end of the intake port 50a is opened. F is supplied toward the downstream end of the intake port 50a.

  In FIG. 2, the valve housing 2 of the fuel injection valve I is connected to a cylindrical valve seat member 3 having a valve seat 8 at the front end and a rear end portion of the valve seat member 3 coaxially and fluid-tightly. The magnetic cylinder 4, the nonmagnetic cylinder 6 coaxially and liquid-tightly coupled to the rear end of the magnetic cylinder 4, and the coaxial and liquid-tightly coupled to the rear end of the nonmagnetic cylinder 6 The fixed core 5 and the fuel inlet cylinder 26 connected coaxially to the rear end of the fixed core 5 are configured.

  The valve seat member 3 has a cylindrical guide hole 9 and an annular valve seat 8 connected to the front end of the guide hole 9. The valve seat member 3 includes an inner peripheral side of the valve seat 8, That is, the nozzle 10 located on the downstream side is integrally formed. Specifically, the valve seat member 3 and the nozzle 10 are integrally formed by cutting the same material. Further, a recess 13 for receiving the nozzle 10 is formed on the front end surface of the valve seat member 3.

  A plurality of fuel injection holes 11, 11... Are formed in the nozzle 10 and are arranged in an annular shape around the valve seat 8 and the center line Y of the nozzle 10 (see FIGS. 3 and 4).

  A hollow cylindrical fixed core 5 is press-fitted into the inner peripheral surface of the nonmagnetic cylindrical body 6 from the rear end side thereof, whereby the nonmagnetic cylindrical body 6 and the fixed core 5 are coaxially coupled to each other. At this time, a portion that does not fit with the fixed core 5 remains at the front end portion of the nonmagnetic cylindrical body 6, and the valve assembly V is accommodated in the valve housing 2 extending from the portion to the valve seat member 3.

  The valve assembly V is connected to the valve rod portion 17 including a valve portion 16 that opens and closes with respect to the valve seat 8 and a valve rod portion 17 that supports the valve portion 16, and is connected to the valve rod portion 17. It consists of a movable core 12 that straddles the cylindrical body 6 and is inserted into them and placed on the fixed core 5 on the same axis. The valve rod portion 17 is formed to have a smaller diameter than the guide hole 9, and a journal portion 17 a that protrudes in the radial direction and is slidably supported on the inner peripheral surface of the guide hole 9 is integrally formed on the outer periphery thereof. Is formed. In addition, a journal portion 17b that is slidably supported on the inner peripheral surface of the magnetic cylindrical body 4 is formed on the outer periphery of the movable core 12.

  The valve assembly V includes a vertical hole 19 that ends from the rear end surface of the movable core 12 before the valve portion 16, and a plurality of first horizontal holes 20 a that communicate with the outer peripheral surface of the movable core 12. A plurality of second lateral holes 20b are provided to communicate the vertical hole 19 with the outer peripheral surface of the valve rod part 17 between the journal part 17a and the valve part 16. At that time, an annular spring seat 24 facing the fixed core 5 is formed in the middle of the vertical hole 19.

  The fixed core 5 is made of a ferrite-based high hardness magnetic material. On the other hand, in the movable core 12, a collar-like high-hardness stopper element 14 surrounding the valve spring 22 is embedded in a suction surface opposite to the suction surface of the fixed core 5. The stopper element 14 has its outer end slightly protruded from the suction surface of the movable core 12 and is normally opposed to the suction surface of the fixed core 5 with a gap corresponding to the valve opening stroke of the valve body 18. The

  The fixed core 5 has a vertical hole 21 that communicates with the vertical hole 19 of the movable core 12, and a fuel inlet cylinder 26 that communicates internally with the vertical hole 21 is integrally connected to the rear end of the fixed core 5. The fuel inlet cylinder 26 is composed of a reduced diameter portion 26a connected to the rear end of the fixed core 5 and a subsequent enlarged diameter portion 26b, and a slotted pipe shape press-fitted into the vertical hole 21 from the reduced diameter portion 26a. A valve spring 22 for biasing the movable core 12 toward the valve closing side of the valve body 18 is provided between the retainer 23 and the spring seat 24. At that time, the set load of the valve spring 22 is adjusted by the depth of fitting of the retainer 23 into the vertical hole 21. A fuel filter 27 is mounted in the enlarged diameter portion 26b.

  A coil assembly 28 is fitted to the outer periphery of the valve housing 2 so as to correspond to the fixed core 5 and the movable core 12. The coil assembly 28 includes a bobbin 29 fitted to the outer peripheral surface from the rear end portion of the magnetic cylindrical body 4 to the fixed core 5 and a coil 30 wound around the bobbin 29. The front end of the coil housing 31 that surrounds 28 is welded to the outer peripheral surface of the magnetic cylindrical body 4, and the rear end is welded to the outer peripheral surface of the yoke 5 a that protrudes in a flange shape from the outer periphery of the rear end portion of the fixed core 5. The coil housing 31 has a cylindrical shape, and a slit 31a extending in the axial direction is formed on one side.

  A part of the magnetic cylinder 4, the coil housing 31, the coil assembly 28, the fixed core 5, and the front half of the fuel inlet cylinder 26 are embedded in a synthetic resin cylindrical mold part 32 by injection molding. At that time, the mold portion 32 is filled into the coil housing 31 through the slit 31a. A coupler 34 protruding in one side is integrally formed in the middle portion of the mold portion 32, and the coupler 34 holds a current-carrying terminal 33 connected to the coil 30.

  As shown in FIG. 3, the annular valve seat 8 is constituted by a conical surface having a small diameter toward the front of the fuel injection valve I, and the annular sealing surface 16a of the valve portion 16 facing this is a convex spherical surface. The tip surface 16b of the valve portion 16 is formed in a conical surface having a tangent to the sealing surface 16a as a generating line.

  On the other hand, the inner end surface 10a and the outer end surface of the nozzle 10 are also configured as conical surfaces having a small diameter toward the front of the fuel injection valve I, and thus have a generally convex shape toward the front of the fuel injection valve I. . An annular step portion 15 is provided between the valve seat 8 and the inner end surface 10 a of the nozzle 10 to secure a conical space 25 between the inner end surface 10 a of the nozzle 10 and the valve portion 16. The space 25 avoids mutual contact between the valve portion 16 and the nozzle 10, ensures seating of the valve portion 16 on the valve seat 8, and contributes to ensuring valve tightness.

  The plurality of fuel injection holes 11, 11... Which are formed in the nozzle 10 and are annularly arranged around the center line Y are inclined forward and away from the center line Y, and each fuel injection hole. 11 is arranged so that the inner surface of 11 intersects the extended line L of the bus bar of the conical valve seat 8.

  Here, when the cone angle of the inner end surface 10a of the nozzle 10 is α, the cone angle of the valve seat 8 is β, and the cone angle of the tip surface of the valve portion 16 is γ, these are expressed by the following equations (1) to (3 ) Is established.

α> γ (1)
α> β (2)
10 ° ≦ θ ≦ 30 ° (3) where θ = α−β
Further, when the effective diameter of the valve seat 8 is D1, and the pitch circle diameter of the plurality of annular fuel injection holes 11, 11,... Is D2, the valve seat 8 and the fuel injection holes 11, 11 are established so that the following equation is established. ... are arranged close to each other.

D1 / D2 ≦ 1.5 (4)
The concave portion 13 that is formed at the front end of the valve seat member 3 and receives the nozzle 10 is formed in a conical shape whose inner peripheral surface expands toward the front end surface of the valve seat member 3. At this time, the diameter D3 of the inner peripheral surface small diameter portion of the recess 13 is set smaller than the effective diameter D1 of the valve seat 8. That is,
D3 <D1 (5)
The height H from the front end surface of the valve seat member 3 to the valve seat 8 is set to 1 mm or more.

  Next, the operation of the first embodiment will be described.

  When the coil 30 is demagnetized, the valve assembly V is pressed forward by the biasing force of the valve spring 22, and the valve body 18 is seated on the valve seat 8. In this state, the fuel pumped from the fuel pump (not shown) to the fuel inlet cylinder 26 passes through the pipe-like retainer 23, the vertical hole 19 of the valve assembly V, and the first and second horizontal holes 20a and 20b. 3 is put on standby and used for lubrication around the journal portions 17a and 17b of the valve assembly V.

  When the coil 30 is energized by energization, the magnetic flux generated by the coil 30 sequentially travels through the fixed core 5, the coil housing 31, the magnetic cylindrical body 4, and the movable core 12, and the movable core 12 of the valve assembly V is set to the valve spring 22 by the magnetic force. Since the valve portion 16 of the valve body 18 is separated from the valve seat 8 of the valve seat member 3 as shown in FIG. 5, the mainstream of the high-pressure fuel in the valve seat member 3 is sucked by the fixed core 5 against the load. S advances to the nozzle 10 side along the conical surface of the valve seat 8.

  By the way, the plurality of fuel injection holes 11, 11... In the annular arrangement of the nozzle 10 are arranged so that the inner surface of each fuel injection hole 11 intersects with the extension line L of the generatrix of the conical valve seat 8. The main flow S of the fuel directly going from the valve seat 8 to each fuel injection hole 11 collides with the inner surface of each fuel injection hole 11 without pressure loss, and other fuel is narrow between the valve part 16 and the nozzle 10. Since the conical space 25 quickly joins and heads toward the nearest fuel injection hole 11, a relatively large amount of fuel is squeezed at each fuel injection hole 11 to accelerate the flow and is injected in front of the nozzle 10. .

  As described above, the main flow S of the fuel that has passed through the valve seat 8 directly collides with the inner surface of the fuel injection holes 11, 11,... With little pressure loss, and the conical space 25 is narrow and fuel other than the main flow S quickly joins. .., And the pressure loss is very small at this time. As a result, the flow of fuel in the fuel nozzles 11, 11. It is possible to effectively atomize the fuel injected from the fuel injection holes 11, 11... And to form the high-speed spray foam F. Therefore, since this spray form F has a very high flow rate and high penetration, there is very little loss of fuel adhering to the inner wall of the intake port 50b of the engine E, and fuel consumption can be reduced. In addition, a small fuel pressure loss means that a large flow rate of fuel can be secured. Thus, the electromagnetic fuel injection valve I of the present invention can satisfy the large flow rate characteristics and atomization / penetration properties of the fuel at the same time, so that it can greatly contribute to the improvement of the output of the engine E and the low pollution of the exhaust gas. it can.

  In particular, the annular step portion 15 formed between the valve seat 8 and the inner end face 10a of the nozzle 10 not only avoids mutual interference between the valve portion 16 and the nozzle 10, but also the main flow of fuel that has passed through the valve seat 8. This facilitates the direct introduction of S into each fuel injection hole 11 and greatly contributes to the improvement of the large flow rate characteristics and penetration of the fuel.

  Further, due to the presence of the annular step portion 15, the space 25 formed between the valve portion 16 and the nozzle 10 is a dead space that does not need to have a fuel flow path function, inside the fuel injection holes 11, 11,. Therefore, this can be narrowed as much as possible within the range in which mutual interference between the valve portion 16 and the nozzle 10 is avoided, the dead space can be reduced, and the fuel injection characteristics against temperature change can be stabilized.

  In this case, as shown in the above equation (1), if the cone angle γ of the front end surface of the valve portion 16 is set smaller than the cone angle α of the inner end surface 10a of the nozzle 10, the gap between the valve portion 16 and the nozzle 10 is increased. It decreases as it approaches the center line Y of the nozzle 10, and the volume of dead space inside the fuel injection holes 11, 11... Formed between the valve portion 16 and the nozzle 10 can be effectively reduced. Therefore, it is possible to further stabilize the fuel injection characteristics against temperature changes.

  Further, the front end surface 16b of the valve portion 16, the valve seat 8 and the inner end surface 10a of the nozzle 10 are configured as conical surfaces having a small diameter toward the front of the fuel injection valve I, so that each fuel injection hole extends from the valve seat 8. Therefore, it is possible to reduce the internal pressure loss by reducing the bending of the fuel flow path leading to 11, and to guide the high energy fuel to each fuel injection hole 11, thereby improving the large flow rate characteristic of the fuel. In addition, since the nozzle 10 with the inner end surface 10a having a conical surface has extremely high rigidity, it is possible to easily perform thin-wall processing by cutting the nozzle 10.

  Further, as shown in the above equations (2) and (3), the conical angle α of the inner end surface 10a of the nozzle 10 is set to be 10 to 30 ° larger than the conical angle β of the valve seat 8, thereby allowing the main flow of fuel. When the collision incident angle of S on the inner surface of each fuel injection hole 11 approaches 90 °, a severe impact occurs, and good atomization of the injected fuel and high penetration can be effectively obtained.

  If the difference θ between the cone angle α of the inner end surface 10a of the nozzle 10 and the cone angle β of the valve seat 8 smaller than 30 ° is 30 ° or more, the collision incidence angle of the fuel on the inner surface of the fuel nozzle hole As a result of the decrease, the axial component of the main fuel injection hole 11 increases to reduce the collision energy, making it difficult to obtain good atomization of the fuel. If the difference θ is 10 ° or less, the valve seat 8 Effective collision of the main flow S of the fuel that has passed through the inner surface of each fuel injection hole 11 does not occur.

  Further, if the valve seat 8 and the fuel injection holes 11, 11... Are arranged close to each other according to the equation (4), the responsiveness from the opening of the valve body 18 to the fuel injection can be improved. It can contribute to the improvement of high rotation and high output performance. When D1 / D2 exceeds 1.5, the distance between the valve seat 8 and the fuel injection holes 11, 11,... Is too large, and not only the responsiveness decreases, but also the fuel main stream S to the inner surface of each fuel injection hole 11 An effective collision cannot be obtained.

  Furthermore, by integrally forming the valve seat member 3 and the nozzle 10 with the same material, the step of joining the nozzle to the valve seat member 3 (welding) is eliminated, and the assembly of the fuel injection valve I is improved. , Free from concerns about thermal distortion of the valve seat 8 due to welding. Therefore, it is possible to improve the accuracy of the valve seat 8, and thus the valve tightness, and to improve the accuracy of the position and orientation of the fuel injection holes 11, 11,. Stabilization of the spray foam F formed by the injected fuel from the holes 11, 11. When the annular valve seat 8 is processed, the annular step 15 between the valve seat 8 and the inner end surface 10a of the nozzle 10 prevents interference between the blade and the nozzle, and the valve seat 8 can be processed easily and accurately. Can be done.

  Since the front end face of the valve seat member 3 is formed with a recess 13 for receiving the nozzle 10 integral with the valve seat member 3, the valve seat member 3 itself can protect the nozzle 10 from contact with other objects. This eliminates the need for special protective caps. In addition, the recess 13 can also play a role of suppressing dripping due to fuel blowback.

  Further, the concave portion 13 is formed in a conical shape whose inner peripheral surface is enlarged in diameter toward the front end surface of the valve seat member 3, so that a conical effect is exerted and a conical formed by the injected fuel from the nozzle 10. Without disturbing the shaped foam F, it can be accurately directed to a predetermined target, that is, downstream of the intake port 50a of the engine E, which contributes to improved penetration.

  Further, the diameter D3 of the inner peripheral surface small diameter portion of the recess 13 is set to be smaller than the effective diameter D1 of the valve seat 8 as shown in the equation (5), so that the axial thickness of the valve seat member 3 in the valve seat 8 is increased. Thickness can be sufficiently secured without being obstructed by the concave portion 13, and great rigidity can be imparted to the valve seat 8. Therefore, the valve seat 8 can be easily processed with high accuracy, and the valve tightness can be enhanced. At that time, as described above, if the height from the front end surface of the valve seat member 3 to the valve seat 8 is set to 1 mm or more, the axial thickness of the valve seat member 3 in the valve seat 8 is equal to that of the valve seat 8. It is sufficient for imparting high rigidity.

  Next, a second embodiment of the present invention shown in FIG. 6 will be described.

  In the second embodiment, the front end surface 16b of the valve portion 16 is formed of a spherical surface having the same radius R1 as that of the valve seat 8, and the inner end surface 10a of the nozzle 10 opposed thereto is formed of a spherical surface having a radius R2 larger than the radius R1. Is done. Since the configuration is the same as that of the previous embodiment, the same reference numerals as those of the previous embodiment are given to portions corresponding to those of the previous embodiment in FIG. Also according to the second embodiment, the same operational effects as the previous embodiment can be exhibited.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal side view of a main part of an engine equipped with an electromagnetic fuel injection valve according to a first embodiment of the present invention. The expanded vertical side view of the said fuel injection valve. The enlarged view of the nozzle peripheral part of the fuel injection valve. FIG. 4 is a view taken in the direction of arrow 4 in FIG. 3. FIG. 4 is a view corresponding to FIG. The principal part longitudinal cross-sectional view of the fuel injection valve which concerns on 2nd Example of this invention.

Explanation of symbols

3 ... Valve seat member 8 ... Valve seat 10 ... Nozzle 10a ... Nozzle inner end face 11 ... Fuel injection hole 13 ... Recess 15 ... Annular step portion 16... Valve portion 16 a... Tip end surface I of the valve portion... Fuel injection valve F... Fuel spray foam L. An extension S of the bus of the surface S ... Mainstream D1 of the fuel ... Effective diameter D3 of the valve seat ... A small diameter diameter H of the conical recess ... Valve from the front end surface of the valve seat member Height to seat

Claims (5)

The valve body (18), a valve seat member (3) having an annular and conical valve seat (8) on which the valve body (18) is seated so as to be openable and closable, and located downstream of the valve seat (8) And a nozzle (10) having a plurality of fuel injection holes (11) arranged around the center line (Y) of the valve seat (8). In the fuel injection valve,
The valve seat member (3) and the nozzle (10) are integrally formed of the same material, and the inner end surface (10a) of the nozzle (10) and the tip of the valve body (18) facing the inner end surface (10a) The surface (16b) is constituted by a conical surface or a spherical surface that is reduced in diameter toward the front of the fuel injection valve (I), and an extension line (L) of the bus bar of the valve seat (8) corresponds to each fuel injection hole (11). The fuel injection holes (11) are arranged so as to intersect with the inner surface of the valve seat member (3), and the front end surface of the valve seat member (3) is provided with a recess (13) for receiving the nozzle (10). Fuel injection valve. The fuel injection valve according to claim 1, wherein
The fuel injection valve characterized in that the recess (13) is formed in a conical shape whose inner peripheral surface expands toward the front end surface of the valve seat member (3). The fuel injection valve according to claim 2,
A fuel injection valve characterized in that the diameter (D3) of the inner peripheral surface small diameter portion of the recess (13) is set smaller than the effective diameter (D1) of the valve seat (8). The fuel injection valve according to claim 2 or 3,
A fuel injection valve characterized in that the height (H) from the front end face of the valve seat member (3) to the valve seat (8) is set to 1 mm or more. The fuel injection valve according to any one of claims 1 to 4,
An annular step portion (15) that avoids mutual contact between the valve element (18) and the nozzle (10) is formed between the inner end face (10a) of the nozzle (10) and the valve seat (8). Fuel injection valve.

Images