JP6190917B1 - Fuel injection valve - Google Patents

Abstract

Provided is a fuel injection valve having a compact fuel passage for imparting a turning force to fuel, a small dead volume, atomization of fuel spray, and good pressure resistance. A nozzle hole 36, a swirl chamber 41, and a swirl passage 42 of a nozzle hole plate 35, which is a tip portion of a fuel injection valve 1, are arranged such that fuel spray injected from two adjacent nozzle holes 36 is a fuel liquid film. It is set so as to interfere on the upstream side from the position where it splits from the state 51 and becomes the fuel liquid yarn 52. The hollow conical fuel liquid film 51 has a non-uniform thickness in the circumferential direction and interferes with avoiding the thickest part 51a in the circumferential direction, so deterioration of atomization due to the interference between the fuel liquid films 51. Can be suppressed. Further, since the distance between the adjacent injection holes 36 can be reduced, the entire fuel passage can be made compact, the dead volume can be reduced, and the atomization of the fuel spray at the initial stage of injection can be improved. It is done. [Selection] Figure 3

Description

  The present invention relates to a fuel injection valve used for supplying fuel to an internal combustion engine of an automobile, and more particularly to a fuel injection valve that promotes atomization in spray characteristics.

  In recent years, as exhaust gas regulations for automobile internal combustion engines have been strengthened, atomization of fuel sprays injected from fuel injection valves has been demanded. As a prior art for achieving atomization of fuel spray, a technique for providing atomization by applying a swirling force to the fuel and forming a swirling flow is proposed.

  For example, Patent Document 1 proposes a fuel injection valve in which a swirl imparting chamber communicated with an opening on the downstream side of a valve seat through a communication passage is provided in an injection hole plate. The swirl imparting chamber imparts a swirling force by swirling fuel inside, and a plurality of nozzle holes are provided at the bottom of the swirl imparting chamber. In this example, the fuel spray injected from each nozzle hole is prevented from interfering with the liquid film portion, and atomization of the fuel spray is achieved.

  Further, in Patent Document 2, as swirl force applying means for applying a swirl force to fuel, two swirl chambers provided with a fuel injection hole in the center are connected to face each other in the tangential direction of the swirl chamber, and the upstream side A fuel passage arrangement having two offset passages for introducing fuel from a direction offset from the center of the swirl chamber with respect to the center of the swirl chamber is presented. In this example, the form of the two fuel sprays to be injected is a holocone-shaped spray form in which the outer (peripheral) portion is dark and the center is thin, and the flow distribution of each fuel spray on the downstream side is as follows: Distributed almost symmetrically with respect to the center of flow.

JP 2013-167161 A JP 2002-202031 A

  As described above, atomization of fuel spray can be achieved by applying a swirl force to the fuel to form a swirl flow, but on the other hand, the following problems occur. In Patent Document 1, it is necessary to increase the distance between adjacent nozzle holes so that the fuel spray injected from the nozzle holes does not interfere with the liquid film portion. For this reason, the communication path becomes longer, and the entire structure of the fuel path becomes larger, so that there is a problem that the layout is deteriorated.

  In addition, the dead volume is increased by the length of the communication path, and fuel with insufficient fuel rectification and acceleration is injected immediately after the start of injection, and atomization of fuel spray at the initial stage of injection deteriorates. Further, since it is necessary to increase the weld diameter between the nozzle hole plate provided with the fuel passage including the nozzle hole and the swirl imparting chamber and the valve seat, the stress applied to the plate by the fuel pressure increases and the durability deteriorates. There is.

  Furthermore, considering the deterioration of atomization due to the increase in dead volume as described above and the deterioration of durability due to the expansion of the plate weld diameter, it is difficult to make a multi-hole structure that increases the overall structure of the fuel passage, and the required flow rate However, there is a problem that it cannot be applied to an engine with a large displacement.

  Further, in Patent Document 2, since fuel from upstream is uniformly introduced into the swirl chamber from the two offset passages, a fuel liquid film formed along the inner wall when swirled fuel flows into the nozzle hole The fuel liquid film formed immediately after the injection from each nozzle hole has a uniform thickness in the circumferential direction. For this reason, if the distance between the nozzle holes is reduced to make the entire structure of the fuel passage compact, there is a problem that uniform and thick fuel liquid films interfere with each other and atomization deteriorates.

  The present invention has been made to solve the above-described problems. The overall structure of the fuel passage for imparting a turning force to the fuel is compact, the dead volume is small, the atomization of the fuel spray is achieved, and the pressure resistance is improved. An object of the present invention is to provide a fuel injection valve with good performance.

The fuel injection valve according to the present invention includes a valve seat having an opening on the downstream side, a valve body that controls opening and closing of the fuel passage by contact and separation with the valve seat, and a plate thickness that is fixed to the downstream side of the valve seat. A fuel injection valve having a nozzle hole plate having a plurality of nozzle holes penetrating in a direction, the upstream side end surface of the nozzle hole plate being opposed to the opening of the valve seat and having a diameter larger than that of the opening. A large recess is provided, and the plurality of injection holes are arranged on the outer peripheral side of the injection hole plate with respect to the opening inside the recess, and each of the injection holes is provided inside the recess as a part of the fuel passage. A plurality of swirl chambers for swirling inflowing fuel, and a swirl passage having an upstream end communicating with the opening of the valve seat and a downstream end communicating with the swirl chamber are provided . A center axis side turning passage that allows fuel to flow into the valve seat center axis side with respect to the center, and a nozzle hole plug with respect to the center of the turning chamber. An outer periphery side turning passage for allowing fuel to flow into the outer periphery side of the seat, and the center axis side turning passage and the outer periphery side turning passage are oriented in directions offset from each other with respect to the center of the turning chamber. The swirl chamber communicates with the nozzle hole, swirl chamber, and swirl passage through the swirl chamber from the central axis side swirl passage and the swirl chamber from the outer swirl passage. The fuel spray injected from each nozzle hole is different from the state of the fuel liquid film in which the thickness in the circumferential direction is not uniform. The fuel liquid film is split into fuel droplets through the state of the fuel liquid yarn, and the fuel liquid film injected from the nozzle holes adjacent to each other is upstream of the position where the fuel liquid yarn is in the circumferential direction. thickness is the Umo interference and if to avoid the thickest part.

  According to the fuel injection valve of the present invention, the hollow conical fuel liquid film having a non-uniform circumferential thickness injected from the adjacent nozzle holes is upstream of the position where the fuel liquid yarn is in a state. Therefore, since the interference is avoided by avoiding the thickest part in the circumferential direction, the deterioration of atomization due to the interference between the fuel liquid films can be suppressed and the distance between the adjacent nozzle holes can be reduced. can do. As a result, the overall structure of the fuel passage can be made compact, and the dead volume can be reduced, so that atomization of the fuel spray can be achieved. Moreover, since the diameter of the welding circle between the nozzle hole plate and the valve seat provided outside the fuel passage can be reduced, the stress applied to the nozzle hole plate by the fuel pressure is suppressed, and the durability is improved.

It is sectional drawing which shows the fuel injection valve which concerns on Embodiment 1 of this invention. It is a partial expanded sectional view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a top view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the structure of the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention, and the flow of a fuel. It is an image figure which shows the adjacent fuel spray injected from the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the fuel liquid film in the nozzle hole exit of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the fuel liquid film in the position of the distance L1 which the adjacent fuel spray interferes in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the structure of the front-end | tip part of the fuel injection valve which concerns on Embodiment 2 of this invention, and the flow of a fuel. It is a figure explaining the structure of the front-end | tip part of the fuel injection valve which concerns on Embodiment 2 of this invention, and the flow of a fuel. It is a figure explaining the structure of the front-end | tip part of the fuel injection valve which concerns on Embodiment 2 of this invention, and the flow of a fuel. It is a figure explaining the structure of the front-end | tip part of the fuel injection valve which concerns on Embodiment 3 of this invention, and the flow of a fuel. It is sectional drawing which shows the nozzle hole of the fuel injection valve which concerns on Embodiment 3 of this invention. It is a top view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 4 of this invention. It is a top view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
Hereinafter, a fuel injection valve according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a fuel injection valve according to the first embodiment, FIG. 2 is a partially enlarged cross-sectional view showing a tip portion of the fuel injection valve according to the first embodiment, and FIG. It is the top view which looked at the part shown by AA from the upstream. In the drawings, the same reference numerals are given to the same and corresponding parts in the drawings.

  The fuel injection valve 1 includes a solenoid device 2 that generates electromagnetic force, and a valve device 3 that operates by energizing the solenoid device 2. The solenoid device 2 includes a housing 21 that forms a yoke portion of a magnetic circuit, a core 22 that is a fixed iron core provided inside the housing 21, a coil 23 provided so as to surround the core 22, and an inner side of the coil 23. Is provided with an armature 24 that is a movable iron core that reciprocates.

  The valve device 3 has a cylindrical shape and is press-fitted and welded to the outer diameter portion of the tip of the core 22, and is provided in the middle of a passage through which fuel flows inside the valve body 31. A valve seat 32 having a portion 32 b, a valve body 33 provided inside the valve body 31, for controlling the opening and closing of the fuel passage by contact and separation with the valve seat 32, and a compression provided upstream of the valve body 33 A spring 34 is provided, and an injection hole plate 35 is connected to the downstream side of the valve seat 32 by welding, and the injection hole plate 35 is provided with a plurality of injection holes 36 penetrating in the plate thickness direction.

  The amateur 24 is welded after being pressed into the valve body 33. The valve body 33 has a ball 37 fixed by welding to the tip of a hollow rod press-fitted and welded to the inner surface of the armature 24. As shown in FIG. 2, the ball 37 has a chamfered portion 37 a parallel to the central axis of the fuel injection valve 1. The valve seat 32 has a valve seat portion 32 a that contacts the ball 37.

  Next, the operation will be described. When an operation signal is sent from the engine control device to the drive circuit of the fuel injection valve 1, a current is passed through the coil 23 of the fuel injection valve 1, and the armature 24, the core 22, the housing 21, and the valve body 31 are configured. Magnetic flux is generated in the magnetic circuit.

  As a result, the armature 24 is suctioned toward the core 22, and when the valve body 33 that is integral with the armature 24 is separated from the valve seat portion 32 a and a gap is formed, the fuel is welded to the tip of the valve body 33. From the chamfered portion 37 a of the ball 37, it passes through the gap between the valve seat portion 32 a and the ball 37 and is injected into the engine intake passage from the plurality of injection holes 36.

  Further, when an operation stop signal is sent from the engine control device to the drive circuit of the fuel injection valve 1, the energization of the coil 23 is stopped, the magnetic flux in the magnetic circuit is reduced, and the valve body 33 is pushed in the valve closing direction. The gap between the valve element 33 and the valve seat portion 32a is closed by the compression spring 34, and fuel injection is completed. The valve body 33 slides with the armature 24 at a guide portion 24 a with the valve body 31, and the upper surface 24 b of the armature 24 comes into contact with the lower surface of the core 22 in the valve open state.

  The structure of the front-end | tip part of the fuel injection valve 1 which concerns on this Embodiment 1 is demonstrated in detail using FIGS. The upstream end face 35a of the nozzle hole plate 35 is provided with a recess 35b that faces the valve seat opening 32b and has a diameter larger than that of the valve seat opening 32b. The plurality of injection holes 36 are arranged on the outer peripheral side of the injection hole plate 35 with respect to the valve seat opening 32b inside the recess 35b.

  In the recess 35b of the nozzle hole plate 35, a plurality of swirl chambers 41 for swirling the fuel flowing into the respective nozzle holes 36 as fuel passages for imparting swirl to the fuel, and upstream end portions are valve seat openings. The central shaft side turning passage 42 a and the outer periphery side turning passage 42 b (generically referred to as the turning passage 42) that are in communication with the portion 32 b and whose downstream end is in communication with the turning chamber 41 are provided.

  As shown in FIG. 3, the tip of the fuel injection valve 1 includes three nozzle holes 36 arranged at equal intervals on the same circumference, and three nozzles surrounding the peripheral part of each nozzle hole 36. The swirl chamber 41 has a central axis side swirl passage 42a and an outer peripheral swirl passage 42b through which fuel flows into each swirl chamber 41. A part of the turning passage 42 is constituted by a concave side wall 35c.

  A substantially arc-shaped center axis side turning passage 42a and an outer side turning passage 42b are connected to each of the swirl chambers 41 provided on the outer peripheral side of the valve seat opening 32b. Fuel is introduced from the common fuel introduction passage 43 into the central axis side turning passage 42 a corresponding to one turning chamber 41 and the outer side turning passage 42 b corresponding to the adjacent turning chamber 41.

  The structure of the swirl chamber 41 and the swirl passage 42 and the fuel flow in the first embodiment will be described in detail with reference to FIG. A nozzle hole center 36a, which is the center of the inlet side (upstream side) of the nozzle hole 36, coincides with the center of a substantially circular swirl chamber 41 indicated by a dotted line in the figure, and the nozzle hole 36 and the swirl chamber 41 are concentrically arranged. (X1 = X2). Further, the center axis side turning passage 42a and the outer periphery side turning passage 42b have the same passage width and passage sectional area (Y1 = Y2).

  The central axis side turning passage 42a and the outer periphery side turning passage 42b communicate with the turning chamber 41 so as to be oriented in directions offset from each other with respect to the center of the turning chamber 41 (here, the same as the nozzle hole center 36a). Yes. The central axis side turning passage 42 a allows fuel to be introduced from the fuel introduction portion 41 a into the swirl chamber 41, and allows fuel to flow into the valve seat central axis Z side with respect to the center of the swirl chamber 41. In the figure, an arrow 5a indicated by a dotted line indicates the main flow of the fuel flow that has flowed into the swirl chamber 41 from the central axis-side swirl passage 42a.

  Further, the outer circumferential side turning passage 42 b introduces fuel into the swirl chamber 41 from the fuel introduction portion 41 b and allows the fuel to flow into the outer circumferential side of the nozzle hole plate 35 with respect to the center of the swirl chamber 41. In the figure, an arrow 5b indicated by a dotted line indicates the main flow of the fuel flowing into the swirl chamber 41 from the outer periphery-side swirl passage 42b. The fuel introduction portions 41a and 41b are near the boundary between the swirl chamber 41 and the swirl passage 42, and do not indicate only one point.

  In this way, the fuel is introduced into the swirl chamber 41 from the two fuel introduction portions 41a and 41b by the two swirl passages 42 that are directed in directions that are offset from each other with respect to the center of the swirl chamber 41. The swirling directions of the respective fuel flows generated in the chamber 41 are the same, and the flow of each other is not significantly hindered. Therefore, a strong swirl flow (indicated by an arrow 5 in the figure) as shown in FIG. 3 can be generated. The turning passage 42 is provided so that the fuel turning directions in the plurality of turning chambers 41 are all the same.

  Next, fuel spray injected from the injection hole 36 of the fuel injection valve 1 will be described with reference to FIG. FIG. 5 is an image diagram showing adjacent fuel sprays injected from the fuel injection valve according to the first embodiment. As shown in FIG. 5, the fuel spray injected from the fuel injection valve 1 includes three states: a fuel liquid film 51, a fuel liquid yarn 52, and a fuel droplet 53. In the figure, L1, L2, and L3 indicate distances from the nozzle hole outlet 36b.

  When the fuel swirled in the swirl chamber 41 is introduced into the nozzle hole 36, the fuel is turned into a liquid film along the inner wall of the nozzle hole 36. For this reason, the fuel spray injected from the nozzle hole outlet 36b is in the state of the hollow conical fuel liquid film 51 immediately after the injection. The fuel liquid film 51 gradually splits as it spreads downstream, and is almost in the state of the fuel liquid yarn 52 at the position of the distance L2, and finally the fuel droplets 53 split into fine particles at the position of the distance L3. It becomes a state.

  The nozzle hole 36 of the nozzle hole plate 35, which is the tip of the fuel injection valve 1, the swirl chamber 41, and the swirl passage 42, the fuel spray injected from the two adjacent nozzle holes 36 from the state of the fuel liquid film 51. These specifications are set so that interference occurs at the position of the distance L1 upstream from the position of the distance L2 where the fuel liquid yarn 52 is split. In the figure, P indicates a location P where two adjacent fuel liquid films 51 begin to interfere with each other.

  Further, the tip of the fuel injection valve 1 is configured such that the circumferential thickness of the hollow conical fuel liquid film 51 injected from the injection hole 36 is not uniform. In the first embodiment, as specific means, the fuel that flows into the nozzle hole 36 from the one turning passage 42 through the turning chamber 41 and the swirling chamber 41 from the other turning passage 42. The ratio of the fuel flowing into the nozzle hole 36 is varied.

  Since the two swirling passages 42 have a substantially circular arc shape, as shown in FIG. 4, the main flow of the fuel flowing into the central shaft side swirling passage 42a from the valve seat opening 32b (shown by an arrow in the figure) 5a) and the main flow (in the figure, arrow 5b) of the fuel flowing into the outer periphery side turning passage 42b are biased toward the recess side wall 35c. That is, the direction of fuel flow can be controlled by the shape of the recess side wall 35c.

  In the example shown in FIG. 4, the center axis side turning passage 42a communicates with the turning chamber 41 closer to the nozzle hole center 36a than the outer periphery side turning passage 42b. For this reason, the flow of the fuel flowing into the swirl chamber 41 from the central axis side swirl passage 42a is closer to the nozzle hole center 36a than the flow of the fuel flowing into the swirl chamber 41 from the outer periphery swirl passage 42b.

  With this configuration, it is possible to increase the amount of fuel that flows from the central axis side turning passage 42a through the turning chamber 41 into the injection hole 36, and from the two turning passages 42 to the injection hole 36. It is possible to make a difference in the ratio of the fuel flowing into the fuel. As a result, the circumferential thickness of the hollow conical fuel liquid film 51 injected from the injection hole 36 can be made non-uniform.

The form of the fuel liquid film at the nozzle hole outlet 36b of the fuel injection valve 1 and the form of the fuel liquid film at the position of the distance L1 where the adjacent fuel spray interferes will be described with reference to FIGS. 6 shows a fuel liquid film at a position indicated by BB in FIG. 5, and FIG. 7 shows a fuel liquid film at a position indicated by CC in FIG.

  The three nozzle holes 36 are arranged on the same circumference with the valve seat central axis Z as the center, and the directions of the swirl flows generated in the swirl chambers 41 are the same as shown in FIG. . As shown in FIG. 6, the fuel liquid film 50 at the nozzle hole outlet 36 b is formed with an uneven thickness in the circumferential direction, and the thickest portion 50 a of the fuel liquid film 50 is disposed on the valve seat central axis Z side. Is set to

  Further, on the upstream side of the position of the distance L2 at which the injected fuel spray splits from the state of the fuel liquid film 51, the fuel liquid film 51 has an injection hole outlet 36b due to the influence of the swirling flow of fuel generated in the injection hole 36. In the direction of the tangent (indicated by arrow T). Each fuel liquid film 51 immediately after injection has a non-uniform thickness in the circumferential direction, and rotates in the same direction (90 ° in the example shown in FIG. 7) with respect to the fuel liquid film 50 at the nozzle hole outlet 36b. doing.

  As shown in FIG. 7, at the position of the distance L1 at which the two adjacent fuel liquid films 51 begin to interfere with each other, the thickest portions 51a of the fuel liquid film 51 are not opposed to each other. The thick portion 51a does not interfere. The portion P where the two adjacent fuel liquid films 51 start to interfere with each other is on a straight line connecting the nozzle hole centers 36a of the adjacent nozzle holes 36 when viewed from the valve seat central axis Z direction. 51 is the place where interference occurs most easily.

  With the above configuration, the distance between the adjacent injection holes 36 can be made smaller than in the case where the thickness in the circumferential direction of the fuel liquid film immediately after injection is uniform, and the entire structure of the fuel passage can be reduced. It is possible to make it compact. Moreover, since the two adjacent fuel liquid films 51 interfere with each other while avoiding the thickest part 51a in the circumferential direction, deterioration of atomization due to the interference between the fuel liquid films 51 can be suppressed.

  Further, since the fuel spray injected from the adjacent injection hole 36 is caused to interfere with the upstream side from the position where the hollow conical fuel liquid film 51 starts to split, the fuel liquid film 51 splits the adjacent fuel spray. The distance between the adjacent nozzle holes 36 can be made smaller than in the case of causing interference on the downstream side of the position where the operation starts. Furthermore, by providing the common fuel introduction passage 43 in which the upstream portions of the central axis side turning passage 42a and the outer periphery side turning passage 42b are integrated, the overall structure of the fuel passage can be made more compact.

  From the above, according to the first embodiment, the fuel spray is atomized by applying a swirling force to the fuel to form a swirling flow, and the fuel passage including the swirling chamber 41 and the swirling passage 42 is provided. The overall structure can be made compact, and the layout is improved. Further, the layout can be improved so that the fuel passage structure can be made into a plurality of injection holes, and can be applied to a large displacement engine having a large required flow rate.

  Further, as the entire fuel passage becomes more compact, the dead volume can be reduced, the atomization of the fuel spray at the initial stage of injection can be improved, and the nozzle hole plate 35 and the valve seat provided outside the fuel passage. Since the diameter of the welding circle of 32 can be reduced, the stress applied to the nozzle hole plate 35 by the fuel pressure is suppressed, and the effect of improving the durability is also obtained.

Embodiment 2. FIG.
In the second embodiment, a modification of the structure for causing a difference in the ratio of the fuel flowing into the nozzle hole 36 from the two turning passages 42 will be described with reference to FIGS. In addition, since the whole structure of the fuel injection valve which concerns on this Embodiment 2 is the same as that of the said Embodiment 1, FIG. 1 is diverted and description of each part is abbreviate | omitted.

  In the example shown in FIG. 8, the communication direction of the central axis side turning passage 42a to the turning chamber 41 is closer to the nozzle hole center 36a than the direction of communication of the outer periphery side turning passage 42b to the turning chamber 41. Thus, the flow of fuel flowing from the central axis side turning passage 42a into the swirl chamber 41 (arrow 5a in the figure) is the flow of fuel flowing from the outer periphery side turning passage 42b into the turning chamber 41 (in the figure, arrow 5a). It is closer to the nozzle hole center 36a than 5b).

  In the first embodiment, the center of the injection hole 36a coincides with the center of the swirl chamber 41. However, in the example shown in FIG. Is shifted to the valve seat central axis Z side rather than the center. Thereby, the nozzle hole center 36a is disposed closer to the downstream end of the center axis side turning passage 42a with respect to the center of the turning chamber 41 (X2> X1).

  In the first embodiment, the passage widths of the central axis side turning passage 42a and the outer periphery side turning passage 42b are set equal (Y1 = Y2) and the passage sectional areas are set equal to each other. In the example, the passage width Y1 of the center axis side turning passage 42a is made larger than the passage width Y2 of the outer side turning passage 42b (Y1> Y2), and the passage sectional area of the two turning passages 42 is increased. Set differently.

  With the configuration shown in FIGS. 8 to 10, the amount of fuel flowing into the nozzle hole 36 from the central axis side turning passage 42a through the turning chamber 41 can be increased. A difference can be made in the ratio of the fuel flowing into the nozzle hole 36 from the passage 42. Further, the difference can be further increased by combining the configurations of FIGS. For example, by combining the configurations of FIG. 9 and FIG. 10, one swirl passage 42 is communicated with the swirl chamber 41 closer to the nozzle hole center 36 a than the other swirl passage 42, and the two swirl passages 42 The passage cross-sectional areas may be different.

  In the example shown in FIGS. 8 to 10, the amount of fuel flowing from the central axis side turning passage 42a through the turning chamber 41 into the nozzle hole 36 is increased, but the outer side turning passage 42b. The amount of fuel that flows into the nozzle hole 36 through the swirl chamber 41 may be increased. For example, the nozzle hole center 36a may be disposed closer to the downstream end of the outer periphery side turning passage 42b with respect to the center of the turning chamber 41.

  According to the second embodiment, the thickness in the circumferential direction of the hollow conical fuel liquid film 51 injected from the injection hole outlet 36b can be made non-uniform, as in the first embodiment. By making adjacent fuel sprays interfere with each other while avoiding the thickest portion 51a of the fuel liquid film 51, the overall structure of the fuel passage can be made compact, and the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG.
FIG. 11 shows the structure of the tip of the fuel injection valve and the fuel flow according to the third embodiment of the present invention. In the fuel injection valve 1 according to the third embodiment, the thickness of the injection hole plate 35 is used as a means for making the circumferential thickness of the hollow conical fuel liquid film 51 injected from the injection hole outlet 36b uneven. The nozzle hole 36A is inclined with respect to the direction. In addition, since the whole structure of the fuel injection valve which concerns on this Embodiment 3 is the same as that of the said Embodiment 1, FIG. 1 is diverted and description of each part is abbreviate | omitted.

  12 is a cross-sectional view of the portion indicated by DD in FIG. 11 as viewed from the arrow side. As shown in FIG. 12, the injection hole 36A of the fuel injection valve according to the third embodiment is inclined toward the valve seat central axis Z from the upstream side toward the downstream side.

  By inclining the nozzle hole 36A, when the fuel swirled in the swirl chamber 41 flows into the nozzle hole 36A, the degree of fuel separation at the circumferential position of the nozzle hole inlet is different. The circumferential thickness of the fuel liquid film 50 formed along the inner wall of 36A can be made non-uniform, and as a result, the circumferential direction of the hollow conical fuel liquid film 51 injected from the nozzle hole outlet 36b. Can be made non-uniform in thickness.

  According to the third embodiment, as in the first embodiment, since the circumferential thickness of the hollow conical fuel liquid film 51 injected from the injection hole outlet 36b can be made non-uniform, By making adjacent fuel sprays interfere with each other while avoiding the thickest portion 51a of the fuel liquid film 51, the overall structure of the fuel passage can be made compact, and the same effect as in the first embodiment can be obtained.

Embodiment 4 FIG.
13 and 14 are plan views showing the tip of the fuel injection valve according to Embodiment 4 of the present invention. In the first to third embodiments, the case where the number of the swirling chamber 41 and the nozzle holes 36 and 36A is three has been described as an example. However, the number of the swirling chamber 41 and the nozzle holes 36 and 36A is It is not limited to.

  FIG. 13 shows an example provided with four swirl chambers 41 and nozzle holes 36, and FIG. 14 shows an example provided with two swirl chambers 41 and nozzle holes 36. In the examples shown in FIGS. 13 and 14, the plurality of nozzle holes 36 are arranged on the same circumference, but may not necessarily be on the same circumference. Thus, even if the number of swirl chambers 41 and nozzle holes 36 is changed, the same effect as in the first embodiment can be obtained.

  Further, in the first to fourth embodiments, the upstream portion of the central axis side turning passage 42a and the outer peripheral side turning passage 42b are integrated in order to reduce the overall structure of the fuel passage and reduce the dead volume. Although the common fuel introduction path 43 is provided, the upstream portion of the two swirling passages 42 is not necessarily used when the number of swirl chambers 41 is small and there is a sufficient space for installing fuel passages or when the dead volume is small. Need not be integrated.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted. For example, the injection hole 36A that is inclined with respect to the thickness direction of the injection hole plate 35 shown in the third embodiment can be applied to the modification shown in the second embodiment.

  The present invention can be used as a fuel injection valve used for supplying fuel to an internal combustion engine of an automobile.

1 fuel injection valve, 2 solenoid device, 3 valve device, 4 fuel passage,
21 housing, 22 core, 23 coil, 24 amateur, 31 valve body,
32 valve seat, 32a valve seat, 32b valve seat opening, 33 valve body,
34 compression spring, 35 nozzle hole plate, 35a upstream end face, 35b recess,
35c concave side wall, 36, 36A nozzle hole, 36a nozzle hole center, 36b nozzle hole outlet,
37 balls, 37a chamfered part, 41 swirl chamber, 41a, 41b fuel introducing part,
42 turning passage, 42a central axis turning passage, 42b outer turning turning passage,
43 Common fuel introduction path, 50, 51 Fuel liquid film, 52 Fuel liquid yarn, 53 Fuel droplet

Claims (9)

A valve seat having an opening on the downstream side, a valve body that controls opening and closing of the fuel passage by contact and separation with the valve seat, and a plurality of holes that are fixed to the downstream side of the valve seat and penetrate in the plate thickness direction A fuel injection valve comprising an injection hole plate having injection holes,
The upstream end surface of the nozzle hole plate is provided with a recess facing the opening of the valve seat and having a diameter larger than that of the opening, and the plurality of nozzle holes are the openings in the recess. Than the outer peripheral side of the nozzle hole plate,
Inside the recess, as a part of the fuel passage, a plurality of swirl chambers for swirling the fuel flowing into each nozzle hole, and an upstream end communicated with the opening of the valve seat on the downstream side A swirl passage having an end communicating with the swirl chamber is provided;
The swirl passage has a center shaft-side swirl passage that allows fuel to flow into the valve seat central axis with respect to the center of the swirl chamber, and allows fuel to flow into the outer peripheral side of the nozzle hole plate with respect to the center of the swirl chamber. An outer peripheral side turning passage, and the central axis side turning passage and the outer peripheral side turning passage communicate with the swirl chamber so as to be oriented in directions offset from each other with respect to the center of the swirl chamber. ,
The nozzle hole, the swirl chamber, and the swirl passage are formed of fuel that flows into the nozzle hole from the center axis swirl passage through the swirl chamber, and the swirl chamber from the outer periphery swirl passage. The fuel spray injected from each of the nozzle holes is arranged in a hollow conical shape with a nonuniform thickness in the circumferential direction. The fuel liquid film is split from the state, becomes a fuel droplet state through the state of the fuel liquid yarn, and the fuel liquid film injected from the nozzle holes adjacent to each other is upstream of the position where the state of the fuel liquid yarn becomes, fuel injection valve thickness of the circumferential direction and wherein the TURMERIC interference engagement to avoid the thickest portion. One of said swirling passage, the fuel injection valve according to claim 1, wherein the than the other of said swirling path in communication with said swirl chamber closer to the center of the inlet side of said injection hole. The central axis side swirling passage and the outer peripheral side swirling passage, claim 1 or claim 2 fuel injection valve according to characterized in that the cross-sectional area different. The fuel injection valve according to any one of claims 1 to 3 , wherein a part of the turning passage is configured by a side wall of the recess. The fuel injection according to any one of claims 1 to 4 , wherein the swirling passage is provided so that the swirling directions of fuel in the plurality of swirling chambers are all in the same direction. valve. The fuel injection valve according to any one of claims 1 to 5 , wherein the injection hole is provided such that a center on an inlet side coincides with a center of the swirl chamber. 6. The injection hole according to any one of claims 1 to 5 , wherein a center of the inlet side is provided closer to the downstream end of one of the turning passages with respect to the center of the turning chamber. A fuel injection valve according to claim 1. The fuel injection valve according to any one of claims 1 to 7 , wherein the injection hole is inclined with respect to a plate thickness direction of the injection hole plate. The fuel injection valve according to any one of claims 1 to 8 , wherein the plurality of nozzle holes are arranged at equal intervals on the same circumference.

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