JP2010112317A - Fuel injection valve of internal combustion engine - Google Patents

Abstract

A fuel passage 2 extending in a main body axis C direction is formed in a main body 1a, and a valve body 3 movable in the main body axis direction is disposed in the fuel passage. The tip surface 1d constituting the tip 2a has at least one first injection hole 4a on the first radius around the main body axis and at least one second jet on the second radius around the main body axis smaller than the first radius. In the fuel injection valve in which the hole 4b is formed, the difference in the degree of atomization between the fuel injected from the first injection hole and the fuel injected from the second injection hole is reduced.
A first inclined angle TC1 with respect to a body axis at a part of a tip surface that comes into contact with a fuel portion immediately before flowing into a first nozzle hole is defined as a tip surface that comes into contact with the fuel portion immediately before flowing into a second nozzle hole. Is set to be larger than the second inclination angle TC2 with respect to the main body axis.
[Selection] Figure 1

Description

  The present invention relates to a fuel injection valve for an internal combustion engine.

  A fuel injection valve for supplying fuel to an internal combustion engine has, for example, a fuel passage extending in the body axial direction in the body, and a valve body movable in the body axial direction is disposed in the fuel passage. A plurality of nozzle holes are formed on the tip surface constituting the tip of the fuel passage that can be closed by the valve body. In such a fuel injection valve, at the time of fuel injection, by opening the valve body, high pressure fuel flows from the periphery of the valve body to the tip of the fuel passage, and fuel is injected from each injection hole.

  In such fuel injection, the fuel advances from the periphery of the valve body along the front end surface of the fuel passage in the main body axial direction and flows into each nozzle hole. Thus, the fuel that has flowed into each nozzle hole passes through the inner wall of the nozzle hole. Is peeled off from the periphery of the valve body and injected along the main body axis side of the inner wall of the nozzle hole.

  Here, as the fuel flowing into the nozzle hole is largely separated from the valve body peripheral side of the nozzle hole inner wall, that is, the fuel peeling angle formed by the extending direction of the valve hole inner wall on the valve element peripheral side and the fuel inflow direction becomes larger. The larger the fuel is, the thinner the fuel is injected along the main body axis side of the inner wall of the injection hole, so that the injected fuel is more easily atomized.

  When many injection holes formed in the front end surface of the fuel passage are located on substantially the same radius around the main body axis (for example, refer to Patent Document 1), the inflow angle of the fuel flowing into each injection hole with respect to the main body axis Are substantially equal, and the fuel separation angle is substantially equal in each nozzle hole in which the extension angle of the inner wall on the inner wall side with respect to the main body axis is equal, so that fuel atomized to the same degree is injected from each nozzle hole. Is done.

JP2008-121517A JP 2006-249989 A JP2005-106006

  However, in order to form a larger number of nozzle holes, the first group of nozzle holes on the first radius around the main body axis and the second group of nozzles on the second radius smaller than the first radius are formed on the end surface of the fuel passage. If the hole is formed, the fuel inflow angle with respect to the main body axis in the first group of nozzle holes close to the valve body periphery side is less damped by the velocity component in the main body axis direction when passing around the valve body. The second group close to the main body axis side into which the fuel that has traveled relatively long on the front end surface of the fuel passage and attenuated the velocity component in the main body axis direction before flowing into the nozzle hole due to the inflow of fuel that has not flowed in In the first nozzle hole and the second nozzle hole, the extending angle of the inner wall of the nozzle hole around the valve body is equal to the main axis. And the first group of nozzle holes and the second group of nozzle holes Of different fuel peeling angle that affect atomization approximately between fuel injected from the fuel and the second group of injection holes injected from the first group of injection holes is largely different.

  Accordingly, an object of the present invention is to form a fuel passage extending in the main body axial direction in the main body, and disposing a valve body movable in the main body axial direction in the fuel passage, and closing the fuel passage by the valve body. The front end surface constituting the front end portion of the at least one first injection hole on the first radius around the main body axis, and at least one second injection hole on the second radius around the main body axis smaller than the first radius, In the fuel injection valve in which is formed, the difference in the degree of atomization between the fuel injected from the first injection hole and the fuel injected from the second injection hole is reduced.

  According to a first aspect of the present invention, there is provided a fuel injection valve for an internal combustion engine, wherein a fuel passage extending in a direction of a main body axis is formed in a main body, and the valve is movable in the direction of the main body axis in the fuel passage. A front end surface constituting a front end portion of the fuel passage which can be closed by the valve body and has at least one first injection hole on a first radius around the main body axis and the smaller than the first radius In the fuel injection valve in which at least one second injection hole on a second radius around the main body axis is formed, the main body axis in a portion of the tip surface that comes into contact with the fuel portion immediately before flowing into the first injection hole The first tilt angle on the tip end side with respect to the first tip side is set to be larger than the second tilt angle on the tip end side with respect to the main body axis in a part of the tip face that comes into contact with the fuel portion immediately before flowing into the second nozzle hole. , The first inclination angle Compared to the case where the second inclination angle is equal to the second inclination angle, the fuel inflow angle on the tip side with respect to the main body axis in the first nozzle hole and the fuel on the tip side with respect to the main body axis in the second nozzle hole It is characterized in that the inflow angle is made closer.

  A fuel injection valve for an internal combustion engine according to claim 2 according to the present invention is the fuel injection valve for internal combustion engine according to claim 1, wherein the first inclination angle and the second inclination angle are acute angles. To do.

  A fuel injection valve for an internal combustion engine according to claim 3 according to the present invention is the fuel injection valve for internal combustion engine according to claim 1, wherein the first inclination angle and the second inclination angle are 90 degrees or more. It is characterized by that.

  According to a fourth aspect of the present invention, there is provided a fuel injection valve for an internal combustion engine according to a fourth aspect of the present invention, wherein the fuel injection valve for the internal combustion engine according to the third aspect is provided with a flap that makes at least the first inclination angle variable. And

  According to a fifth aspect of the present invention, there is provided a fuel injection valve for an internal combustion engine, wherein a fuel passage extending in a main body axial direction is formed in a main body, and a valve body movable in the main body axial direction is disposed in the fuel passage. And at least one first injection hole on the first radius around the main body axis and a first axis around the main body axis smaller than the first radius on the front end surface constituting the front end portion of the fuel passage which can be closed by the valve body. In the fuel injection valve in which at least one second injection hole on two radii is formed, a first recess is formed in a part of the end face of the valve body that comes into contact with the fuel part immediately before flowing into the first injection hole The second concave portion shallower than the first concave portion is formed in a part of the end face of the valve body that is in contact with the fuel portion immediately before flowing into the second injection hole, or the concave portion is not formed. The first recess and the second recess are on the end surface of the valve body. Compared with the case where it is not formed, the fuel inflow angle on the tip end side with respect to the main body axis in the first injection hole is made closer to the fuel inflow angle on the tip end side with respect to the main body axis in the second injection hole. Features.

  According to a sixth aspect of the present invention, there is provided a fuel injection valve for an internal combustion engine, wherein a fuel passage extending in a main body axial direction is formed in a main body, and a valve body movable in the main body axial direction is disposed in the fuel passage. And at least one first injection hole on the first radius around the main body axis and a first axis around the main body axis smaller than the first radius on the front end surface constituting the front end portion of the fuel passage which can be closed by the valve body. In the fuel injection valve in which at least one second injection hole on two radii is formed, the valve body is formed with a chamfer for forming a sealing corner portion that contacts the seat portion of the fuel passage, The first obtuse angle on the tip end side with respect to the main body axis in a portion of the chamfer where the fuel portion flowing into the first nozzle hole comes into contact is the chamfered portion where the fuel portion flowing into the second nozzle hole contacts. Said part relative to said body axis in part Compared to the case where the first obtuse angle and the second obtuse angle of the chamfer are equal to each other and smaller than the second obtuse angle on the end side, the tip part with respect to the main body axis in the first nozzle hole The fuel inflow angle on the side and the fuel inflow angle on the tip end side with respect to the main body axis in the second injection hole are made closer to each other.

  According to the fuel injection valve of the internal combustion engine of the first aspect of the present invention, in the part of the front end surface of the fuel passage where the fuel part comes into contact immediately before flowing into the first injection hole on the first radius around the main body axis. The first inclination angle on the tip end side of the fuel passage with respect to the main body axis is set to be equal to the front end face of the fuel passage where the fuel portion comes into contact immediately before flowing into the second injection hole on the second radius around the main body axis smaller than the first radius. The fuel inflow angle on the front end side of the fuel passage with respect to the main body axis in the first injection hole and the fuel passage with respect to the main body axis in the second injection hole are larger than the second inclination angle on the front end side of the fuel passage with respect to the main body axis in part The fuel inflow angle on the front end side of the fuel cell is made closer to the fuel inlet angle. Therefore, if the first inclination angle and the second inclination angle are equal, the velocity component in the main body axial direction when passing around the valve body is attenuated too much in the first nozzle hole near the valve body periphery. The fuel inflow angle with respect to the main body axis becomes smaller because no fuel flows in, and the second injection hole close to the main body axis moves relatively long on the front end surface of the fuel passage before flowing into the injection hole. The fuel inflow angle with respect to the main body axis increases because the fuel with the velocity component in the direction attenuated, and the fuel separation angle that affects atomization of the injected fuel differs between the first injection hole and the second injection hole. In the fuel injection valve for an internal combustion engine according to claim 1, the degree of atomization differs greatly between the fuel injected from the first injection hole and the fuel injected from the second injection hole. Of fuel flowing into one injection hole The degree of attenuation of the degree component and the degree of attenuation of the velocity component of the fuel flowing into the second nozzle hole are close to each other, so that the fuel inlet angle at the first nozzle hole and the fuel inlet angle at the second nozzle hole are The difference in the degree of atomization between the fuel injected from the first injection hole and the fuel injected from the second injection hole can be reduced.

  According to the fuel injection valve of the internal combustion engine of the second aspect of the present invention, in the fuel injection valve of the internal combustion engine of the first aspect, the first inclination angle and the second inclination angle are acute angles.

  According to a fuel injection valve for an internal combustion engine according to claim 3 of the present invention, in the fuel injection valve for internal combustion engine according to claim 1, the first inclination angle and the second inclination angle are 90 degrees or more. Thereby, compared with the case where the first inclination angle and the second inclination angle are acute angles, the fuel inflow angle in the first injection hole and the second injection hole can be increased, and the first injection hole and the second injection hole The fuel peeling angle at the two nozzle holes is increased, and the fuel injected from the first nozzle holes and the second nozzle holes can be sufficiently atomized.

  According to the fuel injection valve of the internal combustion engine according to claim 4 of the present invention, since the fuel injection valve of the internal combustion engine according to claim 3 is provided with the flap that makes at least the first inclination angle variable. Even when the lift amount of the valve body is variable, the fuel inflow angle in the first nozzle hole and the fuel inflow angle in the second nozzle hole can be made closer by changing the first inclination angle by the flap. The difference in the degree of atomization between the fuel injected from the first nozzle hole and the fuel injected from the second nozzle hole can be kept small.

  According to the fuel injection valve for an internal combustion engine according to claim 5 of the present invention, a part of the end face of the valve body that comes into contact with the fuel portion immediately before flowing into the first injection hole on the first radius around the main body axis is formed on the fuel injection valve. A second recess shallower than the first recess is formed in a part of the end face of the valve body where the first recess is formed and the fuel portion contacts immediately before flowing into the second injection hole on the second radius around the main body axis smaller than the first radius. The tip of the fuel passage with respect to the main body axis in the first nozzle hole is utilized by making use of the fact that the recess is formed or not formed, and the fuel vortex formed in the recess has a greater pressure reducing action as the recess is deeper. The fuel inflow angle on the part side and the fuel inflow angle on the tip side of the fuel passage with respect to the main body axis in the second nozzle hole are made closer to each other. Therefore, if the concave portion is not formed on the end face of the valve body, the fuel in which the velocity component in the main body axial direction when passing through the periphery of the valve body is not significantly attenuated in the first injection hole near the valve body periphery. The fuel inflow angle with respect to the main body axis becomes smaller due to the inflow, and the second injection hole close to the main body axis side travels relatively long on the front end surface of the fuel passage before flowing into the injection hole, and the velocity in the main body axis direction Since the fuel with the attenuated component flows in, the fuel inflow angle with respect to the main body axis increases, and the fuel separation angle that affects atomization of the injected fuel differs between the first injection hole and the second injection hole. Although the degree of atomization differs greatly between the fuel injected from the hole and the fuel injected from the second nozzle hole, in the fuel injection valve for an internal combustion engine according to claim 5 according to the present invention, Fuel inflow angle and fuel flow in the second nozzle hole Angle and are close, it is possible to reduce the difference of about atomization at the fuel injected from the fuel and the second injection hole is injected from the first injection hole.

  According to the fuel injection valve for an internal combustion engine according to claim 6 of the present invention, the valve body is formed with a chamfer for forming a seal corner portion that contacts the seat portion of the fuel passage, The first obtuse angle on the tip end side with respect to the main body axis in the part of the chamfer where the fuel portion flowing into the first nozzle hole on one radius contacts is the second on the second radius around the main body axis smaller than the first radius. Decrease the velocity component in the main body axial direction of the fuel flowing into the first nozzle hole by making it smaller than the second obtuse angle on the tip end side with respect to the main body axis in the part of the chamfer where the fuel portion flowing into the nozzle hole contacts. The fuel inflow angle at the front end side of the fuel passage with respect to the main body axis in the first injection hole is made closer to the fuel inflow angle at the front end side of the fuel passage with respect to the main body axis in the second injection hole. Accordingly, if the first obtuse angle and the second obtuse angle of the chamfering of the valve body are equal, the first nozzle hole near the valve body peripheral side has a speed in the body axis direction when passing around the valve body. Since the fuel whose component is not attenuated flows in, the fuel inflow angle with respect to the main body axis is reduced, and the second injection hole close to the main body axis is relatively on the front end surface of the fuel passage before flowing into the injection hole. The fuel inflow angle with respect to the main body axis increases because the fuel that has traveled long and whose velocity component in the main body axis direction has attenuated flows in, and the first injection hole and the second injection hole affect the atomization of the injected fuel. The degree of atomization differs greatly between the fuel injected from the first injection hole and the fuel injected from the second injection hole because the separation angle is different, but the internal combustion engine according to claim 6 according to the present invention. In the fuel injection valve, the fuel inflow angle in the first nozzle hole and Fuel inflow angle and is close in second injection hole, it is possible to reduce the difference of about atomization at the fuel injected from the fuel and the second injection hole is injected from the first injection hole.

  FIG. 1 is a cross-sectional side view of a tip half of a fuel injection valve for an internal combustion engine according to the present invention from a main body central axis. This fuel injection valve is used for injecting fuel directly into a cylinder like a diesel engine, for example. In FIG. 1, 1a is a main body of the fuel injection valve, 1b is a main body tip formed separately from the main body 1a, and is attached to the main body 1a by welding or the like after the injection holes and the like are processed. By forming the main body tip 1b in which the nozzle hole is processed in this manner as a separate body from the main body 1a, the processing of the nozzle hole is facilitated. It can be independent of yield. A fuel passage 2 is formed in the main body 1 and extends in the direction of the main body axis C. A valve element 3 that can move in the direction of the main body axis C is disposed in the fuel passage 2. As an actuator for the valve body 3, a piezo actuator, an electromagnetic actuator, an oil pressure, or the like can be used. In FIG. 1, the valve body 3 is opened by moving upward, and the valve body 3 is moved by moving downward. Closes.

  By closing the valve body 3, the seal corner 3 b of the valve body 3 formed by the chamfer 3 a on the tip side comes into contact with the seat portion 1 c of the frustoconical wall of the fuel passage 2, and the fuel passage 2 The front end portion 2a is closed. On the other hand, as shown in FIG. 1, when the valve body 3 is opened, the seal corner 3 b of the valve body 3 and the seat portion 1 c of the fuel passage 2 are separated from each other, and the upstream end portion 2 a of the fuel passage 2 is upstream. Side high pressure fuel is supplied through the periphery of the valve body 3 of the fuel passage 2, and fuel is injected from the injection holes 4 a and 4 b formed in the front end surface 1 d of the fuel passage 2 constituting the front end portion 2 a of the fuel passage 2. The For example, pressurized fuel is supplied to the upstream side of the fuel passage 2 in a pressure accumulating chamber common to the fuel injection valves of the respective cylinders.

  A front end surface 1d constituting the front end 2a of the fuel passage 2 that can be closed by the valve body 2 is an inner surface of the main body front end 1b in the present embodiment, and is a plan view of the main body front end 1b as shown in FIG. Thus, for example, there are four first nozzle holes 4a on the first radius R1 around the main body axis C and four second nozzle holes 4b on the second radius R2 around the main body axis C smaller than the first radius R1. Is formed. The first nozzle hole 4a and the second nozzle hole 4b are round nozzle holes, and are inclined obliquely outward at the same angle with respect to the main body axis C.

  The number of the first nozzle holes 4a and the second nozzle holes 4b can be increased or decreased as required. Each fuel hole that flows into the nozzle hole 4a and 4b from the periphery of the valve body 3 to the tip portion 2a of the fuel passage 2 and travels in the direction of the main body axis C along the tip surface 1d of the fuel passage 2 flows into the nozzle holes 4a and 4b. Therefore, as shown in FIG. 2, the first injection hole 4a and the second injection hole 4b must not be positioned on the same radiation of the main body axis C. If the first injection hole 4a and the second injection hole 4b are located on the same radiation L as indicated by the phantom line in FIG. 2, the second injection hole 4b (on the imaginary line) on the main body axis C side is provided. The portion of the fuel that should flow into (shown) flows into the first injection hole 4a located on the same radiation L, and fuel is not sufficiently injected from the second injection hole 4b.

  10 and 11 show a conventional fuel injection valve in which a first injection hole 4a ′ and a second injection hole 4b ′ similar to the fuel injection valve of the present embodiment are formed on the front end surface 1d ′ of the fuel passage 2. FIG. FIG. 10 is a sectional view of the first nozzle hole 4a ′, and FIG. 11 is a sectional view of the second nozzle hole 4b ′. At the time of fuel injection, the fuel flows from the periphery of the valve body 3 to the front end portion 2a of the fuel passage, and then proceeds in the direction of the main body axis C along the front end surface 1d 'of the fuel passage 3 and flows into each nozzle hole. To do. The fuel thus flowing into each nozzle hole is peeled off from the valve body 3 peripheral side w1 of the inner wall of the nozzle holes 4a 'and 4b' and is injected along the main body axis C side w2 of the inner wall of the nozzle hole.

  Here, the greater the amount of fuel flowing into the nozzle hole from the valve body peripheral side w1 of the inner wall of the nozzle hole, that is, the fuel separation that the extending direction of the valve body peripheral side w1 of the inner wall of the nozzle hole and the fuel inflow direction form. The larger the angle, the thinner the fuel is injected along the main body axis side w2 of the inner wall of the injection hole. Therefore, the injected fuel is more easily atomized.

  In the nozzle holes located on the same radius around the main body axis C, the fuel inflow angles flowing into the respective nozzle holes with respect to the main body axis C are substantially equal, and the extension angles of the valve body peripheral side w1 of the inner wall with respect to the main body axis are formed equal. Since the fuel separation angles are equal in each of the nozzle holes, the fuel atomized to the same degree is injected from each nozzle hole.

  However, even if it is formed to be inclined obliquely outward at the same angle with respect to the main body axis C, that is, even if the extension angle of the valve body peripheral side w1 of the inner wall with respect to the main body axis C is formed equal, the first injection hole 4a. Since the first radius R1 around the body axis C where 'is located and the second radius R2 around the body axis C where the second injection hole 4b' is located are different, as shown in FIG. In the first injection hole 4a ′ close to, the fuel inflow angle TB1 on the tip end 2a side of the fuel passage 2 with respect to the main body axis C is much attenuated in the velocity component in the main body axis C direction when passing around the valve body 3. Since the uninjected fuel flows in, the angle becomes relatively small, and the fuel peeling angle TA1 becomes relatively small. On the other hand, as shown in FIG. 11, in the second injection hole 4b ′ close to the main body axis C, the fuel inflow angle TB2 on the tip 2a side of the fuel passage 2 with respect to the main body axis C is the fuel inflow before flowing into the injection hole. The fuel travels relatively long on the front end face 1d ′ of the passage 2 and the fuel whose velocity component in the direction of the main body axis C is attenuated flows. Therefore, the fuel peeling angle TA2 becomes relatively large.

  Thus, the degree of atomization differs greatly between the fuel injected from the first nozzle hole 4a ′ and the fuel injected from the second nozzle hole 4b ′, and the degree of atomization of the fuel injected from the first nozzle hole 4a ′. Becomes lower than the degree of atomization of the fuel injected from the second injection hole 4b ′.

  The degree of atomization of the injected fuel can be improved, for example, by increasing the fuel injection pressure, so that fuel of a desired degree of atomization is injected from each of the nozzle holes 4a ′ and 4b ′. It is necessary to reduce the difference in the degree of atomization of the fuel injected from the first injection hole 4a ′ and the second injection hole 4b ′.

  In the first embodiment shown in FIGS. 1 and 2, the fuel passage with respect to the main body axis C in the portion P1 of the front end face 1d of the fuel passage 2 that comes into contact with the fuel portion immediately before flowing into the first injection hole 4a on the valve body peripheral side. The fuel passage with respect to the main body axis C at the portion P2 of the front end surface 1d of the fuel passage 2 where the fuel portion comes into contact immediately before the first inclination angle TC1 on the front end portion 2a side flows into the second injection hole 4b on the main body axis C side. Is larger than the second inclination angle TC2 on the tip end side of the cylinder, and the attenuation of the velocity component of the fuel flowing into the first injection hole 4a in the direction of the main body axis C is further promoted, and the main axis C in the first injection hole 4a The fuel inflow angle on the front end 2a side of the fuel passage 2 and the fuel inflow angle on the front end 2a side of the fuel passage 2 with respect to the main body axis C in the second injection hole 4b are preferably brought closer, as shown in FIG. Two fuel flows So that the angle becomes equal to TB. In the present embodiment, as shown in FIGS. 1 and 2, the portions P1 and P2 of the tip surface 1d described above are truncated cone surfaces, respectively, and the fuel portion immediately before flowing into the second injection hole 4b. The first nozzle hole 4a is formed in the truncated conical surface P2 that contacts with.

  Thereby, in the first injection hole 4a and the second injection hole 4b, the fuel peeling angle formed by the extending direction of the inner wall of the injection hole on the valve body peripheral side and the fuel inflow direction can be made closer and preferably equalized. A difference in the degree of atomization of the fuel injected from the hole 4a and the second injection hole 4b can be reduced and preferably eliminated.

  In the present embodiment, the first inclination angle TC1 and the second inclination angle TC2 are both obtuse, thereby greatly attenuating the velocity component in the main body axis direction in the fuel flowing into the nozzle holes 4a and 4b. The fuel inflow angle TB in the first nozzle hole 4a and the second nozzle hole 4b can be increased, the fuel peeling angle in the first nozzle hole and the second nozzle hole is increased, and the first nozzle hole and The fuel injected from the second injection hole can be sufficiently atomized. Here, the first inclination angle TC1 may be an obtuse angle, and the second inclination angle TC2 may be 90 degrees.

  Further, the direction of the inclination may be reversed, and the first inclination angle TC1 and the second inclination angle TC2 may both be acute angles. In this case, in the fuel flowing into the nozzle holes 4a and 4b, the velocity in the main body axial direction The component cannot be attenuated so much, but by making the first inclination angle TC1 larger than the second inclination angle TC2, the fuel inflow angles in the first injection hole 4a and the second injection hole 4b are made closer, preferably equal. Thereby, the difference in the degree of atomization of the fuel injected from the first nozzle hole and the second nozzle hole can be reduced, and preferably eliminated.

  3 to 5 show a second embodiment of the fuel injection valve of the internal combustion engine according to the present invention. In the present embodiment, as shown in FIG. 3, a part of the front end surface of the fuel passage 2 with which the fuel portion comes into contact immediately before flowing into the first nozzle hole 4a ′ is the first flap 5a, which is shown in FIG. Thus, a part of the front end surface of the fuel passage 2 with which the fuel portion comes into contact immediately before flowing into the second nozzle hole 4b ′ is the second flap 5b. As shown in FIG. 5, the first flap 5 a or the second flap 5 b is present on each radiation from the main body axis C for all the first nozzle holes 4 a ′ and all the second nozzle holes 4 b ′. Has been placed.

  The first flap 5a forms an obtuse first tilt angle TC1 with respect to the body axis C similar to the first embodiment, and the second flap 5b forms an obtuse angle with respect to the body axis C similar to the first embodiment. By forming the two inclined angles TC2, as in the first embodiment, the fuel inflow angle on the tip 2a side of the fuel passage 2 with respect to the main body axis C in the first injection hole 4a ′ and the main body in the second injection hole 4b ′. From the first injection hole 4a ′ and the second injection hole 4b ′, preferably the two fuel inflow angles are made equal so that the fuel inflow angle on the tip end 2a side of the fuel passage 2 with respect to the axis C is made closer. The difference in the degree of atomization of the injected fuel can be reduced and preferably eliminated. By setting the first inclination angle TC1 to an obtuse angle appropriately selected, the second inclination angle TC2 may be set to 90 degrees and the second flap 5b may be omitted.

  In FIG. 5, an actuator (not shown) is attached to each rotation shaft S of the first flap 5a and the second flap 5b, and the first inclination angle TC1 and the second inclination angle TC2 are variable. Thus, for example, when the fuel injection rate is changed with the lift amount of the valve body 3 being variable, if the lift amount of the valve body 3 is increased in order to increase the fuel injection rate, the fuel passage 2 is surrounded from the periphery of the valve body 3. Since the velocity component in the direction of the main body axis C of the fuel flowing into the tip portion 2a increases, if the first inclination angle TC1 of the first flap 5a is left as it is, the fuel inflow angle (main body axis line to the first injection hole 4a ′) (With respect to C) becomes smaller, the fuel peeling angle becomes smaller, and the degree of atomization of the injected fuel worsens.

  Since the second nozzle hole 4b 'is similar to the first nozzle hole 4a', although the degree is smaller than that of the first nozzle hole 4a ', in this case, the first flap angle 5c is reduced by the first flap 5a, and the second flap hole 4b' is shown. It is preferable to reduce the second inclination angle TC2 by 5b (less than the decrease of the first inclination angle). As described above, even if the lift amount of the valve body 3 changes, fuel having a desired atomization degree can be injected from the first injection hole 4a 'and the second injection hole 4b'.

  FIG. 6 shows a third embodiment of the fuel injection valve of the internal combustion engine according to the present invention. In the present embodiment, the main body 1a and the main body tip 1b ′ have the same structure as the conventional one shown in FIGS. 10 and 11, but the fuel portion comes into contact immediately before flowing into the first injection hole 4a ′. A first recess 6a is formed in a part of the end face 3c 'of the valve body 3', and a part of the end face 3c 'of the valve body 3' that the fuel part contacts just before flowing into the second injection hole 4b ' A second recess 6b shallower than the one recess 6a is formed. The second recess can be omitted by appropriately selecting the depth of the first recess 6a.

  When the recess 3 is formed in the end surface 3c ′ of the valve body 3 ′ as described above, a part of the fuel that flows from the periphery of the valve body 3 ′ to the tip end portion 2a of the fuel passage 2 and proceeds in the direction of the main body axis C However, as shown by the arrow, it flows into the recess and forms a vortex, and the central pressure of the vortex decreases. The deeper the recess, the stronger the vortex and the greater the pressure drop at the center. As a result, the strong vortex formed by the first recess 6a greatly pulls up the portion of the fuel that is about to flow into the first nozzle hole 4a ′, and if left as it is, the relatively small fuel inflow direction TB1 ′ is made larger as TB ′. . In addition, the weak vortex formed by the second recess 6b also pulls up the portion of the fuel that is about to flow into the second nozzle hole 4b ', and slightly increases the fuel inflow direction TB2' as TB '.

  In this way, the fuel inflow angle on the front end side of the fuel passage with respect to the main body axis C in the first injection hole 4a ′ is made closer to the fuel inflow angle on the front end side of the fuel passage with respect to the main body axis in the second injection hole. When the fuel inflow angle is the same TB ′, the difference in the degree of atomization between the fuel injected from the first injection hole 4a ′ and the fuel injected from the second injection hole 4b ′ can be reduced and preferably eliminated.

  7 to 9 show a fourth embodiment of the fuel injection valve of the internal combustion engine according to the present invention. In the present embodiment, the main body 1a and the main body tip 1b ′ have the same structure as the conventional one shown in FIGS. 10 and 11, but for forming the seal corner 3b ″ of the valve body 3 ″. In the chamfering, as shown in FIG. 8, the angle on the front end side with respect to the main body axis in the chamfered part 3d ″ where the fuel part flowing into the first nozzle hole 4a ′ on the valve body peripheral side comes into contact is set to the first obtuse angle As shown in FIG. 9, the angle on the tip end side with respect to the main body axis in the chamfered portion 3a ″ where the fuel portion flowing into the second injection hole 4b ′ on the main body axis side comes into contact is defined as a second obtuse angle TD2. The first obtuse angle TD1 is smaller than the second obtuse angle TD2. Thus, as shown in FIG. 7 which is a plan view of the end face 3c ″ of the valve body 3 ″, the chamfer formed around the end face 3c ″ is divided into the first obtuse angle part 3d ″ and the second obtuse angle part. 3a ″ are alternately formed.

  As a result, in order to come into contact with the chamfered portion 3d ″ having a small first obtuse angle, the attenuation of the velocity component in the main body axial direction of the fuel flowing into the first nozzle hole 4a ′ is greatly promoted, and the second nozzle hole 4b. Since the fuel flowing into 'comes into contact with the chamfered portion 3 a ″ having a large second obtuse angle, at this time, the attenuation of the velocity component in the main body axial direction is not promoted so much. 'When traveling relatively long, the velocity component in the main body axis direction is sufficiently attenuated, the fuel inflow angle on the tip side of the fuel passage with respect to the main body axis line in the first nozzle hole, and the fuel with respect to the main body axis in the second nozzle hole The fuel inflow angle on the tip end side of the passage is made close to each other, and preferably the two fuel inflow angles are set equal to TB ″. In this way, the fuel injected from the first injection hole 4a ′ and the injection from the second injection hole 4b ′. With fuel The difference of about granulation smaller, preferably be eliminated.

  Finally, one direction with respect to the main body axis C can be expressed by two angles, that is, the tip end 2a side and the counter tip end side of the fuel passage 2. It is expressed by the angle on the two sides.

1 is a schematic cross-sectional view of a fuel injection valve tip side half of a main body central axis showing a first embodiment of a fuel injection valve of an internal combustion engine according to the present invention. It is a top view of the main-body front-end | tip part of the fuel injection valve of FIG. It is an expanded sectional view of the vicinity of the 1st injection hole of the front-end | tip part of a main body which shows 2nd embodiment of the fuel injection valve of the internal combustion engine by this invention. It is an expanded sectional view of the 2nd injection hole vicinity of the main part tip part showing a 2nd embodiment of a fuel injection valve of an internal-combustion engine by the present invention. It is a top view of the vicinity of the arbitrary injection hole of the main-body front-end | tip part which shows 2nd embodiment of the fuel injection valve of the internal combustion engine by this invention. It is a schematic sectional drawing of the fuel injection valve front end side half of the main body central axis showing the third embodiment of the fuel injection valve of the internal combustion engine according to the present invention. It is a top view of the end surface half of the valve body which shows 4th embodiment of the fuel injection valve of the internal combustion engine by this invention. It is a schematic sectional drawing of the fuel injection valve front end side in the 1st injection hole of a half from the main body central axis which shows 4th embodiment of the fuel injection valve of the internal combustion engine by this invention. It is a schematic sectional drawing of the fuel injection valve front end side in the 2nd injection hole of the half from the main body central axis which shows 4th embodiment of the fuel injection valve of the internal combustion engine by this invention. It is a schematic sectional drawing of the fuel injection valve front end side in the 1st injection hole which is a half from the main body central axis which shows the fuel injection valve of the conventional internal combustion engine. It is a schematic sectional drawing of the fuel injection valve front end side in the 2nd injection hole which is a half from the main body central axis which shows the fuel injection valve of the conventional internal combustion engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Main body 1b, 1b 'Main body front-end | tip part 1c Seat part 1d, 1d' Front end surface of fuel path 2 Fuel path 2a Front end part of fuel path 3, 3 ', 3 "Valve body 3a, 3a' Chamfer 3b, 3b ', 3b ″ seal corner 3a ″, 3d ″ part of chamfer 4a, 4a ′ first injection hole 4b, 4b ′ second injection hole 5a first flap 5b second flap 6a first recess 6b second recess TC1 first inclination Angle TC2 Second tilt angle TB, TB 'Fuel inflow angle TA1, TA2 Fuel separation angle

Claims (6)

  A fuel passage extending in the direction of the main body axis is formed in the main body, a valve body movable in the direction of the main body axis is disposed in the fuel passage, and a tip of the fuel passage that can be closed by the valve body The distal end surface constituting the portion includes at least one first injection hole on a first radius around the main body axis and at least one second injection hole on a second radius around the main body axis smaller than the first radius. In the fuel injection valve in which the first injection hole is formed, the first inclination angle on the tip end side with respect to the main body axis in the part of the tip surface that is in contact with the fuel portion immediately before flowing into the first injection hole is defined as the second injection hole. When the first inclination angle and the second inclination angle are equal to each other, the first inclination angle and the second inclination angle are larger than the second inclination angle on the tip end side with respect to the main body axis in the portion of the tip surface that is in contact with the fuel portion immediately before flowing into Compared to the above The fuel injection valve of an internal combustion engine, characterized in that close to the fuel inflow angle of the distal end portion side with respect to the body axis of the fuel inflow angle and the second injection hole of the distal end portion side with respect to the body axis in the injection hole.   The fuel injection valve for an internal combustion engine according to claim 1, wherein the first inclination angle and the second inclination angle are acute angles.   The fuel injection valve for an internal combustion engine according to claim 1, wherein the first inclination angle and the second inclination angle are 90 degrees or more.   The fuel injection valve for an internal combustion engine according to claim 3, further comprising a flap that makes at least the first inclination angle variable.   A fuel passage extending in the main body axial direction is formed in the main body, and a valve body movable in the main body axial direction is disposed in the fuel passage, and constitutes a tip portion of the fuel passage that can be closed by the valve body The front end surface has at least one first injection hole on the first radius around the main body axis and at least one second injection hole on the second radius around the main body axis smaller than the first radius. In the injection valve, a first recess is formed in a part of the end face of the valve body that comes into contact with the fuel portion immediately before flowing into the first injection hole, and the fuel portion comes into contact immediately before flowing into the second injection hole. The first recess and the second recess are not formed on the end surface of the valve body so that a second recess shallower than the first recess is formed on a part of the end surface of the valve body or no recess is formed. Compared to the case, the first nozzle hole The fuel injection valve of an internal combustion engine, characterized in that close to the fuel inflow angle of the distal end portion side with respect to the body axis and the fuel inflow angle of the distal end portion side with respect to the body axis of the second injection hole.   A fuel passage extending in the main body axial direction is formed in the main body, and a valve body movable in the main body axial direction is disposed in the fuel passage, and constitutes a tip portion of the fuel passage that can be closed by the valve body The front end surface has at least one first injection hole on the first radius around the main body axis and at least one second injection hole on the second radius around the main body axis smaller than the first radius. In the injection valve, the valve body is formed with a chamfer for forming a sealing corner portion that abuts against a seat portion of the fuel passage, and a part of the chamfer in contact with a fuel portion flowing into the first injection hole. The first obtuse angle on the front end side with respect to the main body axis is smaller than the second obtuse angle on the front end side with respect to the main body axis in a part of the chamfer where the fuel portion flowing into the second nozzle hole contacts. The first of the chamfer Compared to the case where the obtuse angle and the second obtuse angle are equal, the fuel inflow angle on the tip side with respect to the main body axis in the first nozzle hole and the tip side on the main body axis in the second nozzle hole A fuel injection valve for an internal combustion engine characterized in that the fuel inflow angle of the internal combustion engine is made closer.

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