JP6775219B2 - Electromagnetic fuel injection valve - Google Patents

Description

The present invention relates to a fuel injection valve mainly used in a fuel supply system of an internal combustion engine, and in particular, a valve seat member having a valve hole penetrating the valve seat and a central portion thereof, and a valve hole in cooperation with the valve seat. A fuel passage that includes a valve body that opens and closes and an injector plate that has a fuel injection hole and is coupled to the outer end surface of the valve seat member, and communicates between the valve seat member and the injector plate and between the valve hole and the fuel injection hole. It relates to an electromagnetic fuel injection valve which is provided with.

In the above-mentioned electromagnetic fuel injection valve, the injector plate is composed of a press-molded metal plate in order to eliminate the cutting process of the fuel passage to the end face of the valve seat member and to reduce the thickness of the injector plate and ensure the formability. It is known that, at the same time as the press molding, a recess for defining the fuel passage is formed on one surface of the injector plate (that is, the surface facing the valve seat member) (see, for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 2005-201081

By the way, when a fuel passage having a complicated shape (for example, a guide passage extending in the radial direction from the communication portion with the valve hole and a swivel chamber connected to the guide passage) is recessed on one surface of the injector plate by press molding, during press molding. The deeper the drawing depth of the metal material, that is, the larger the pressing amount, the larger the load for forming the fuel passage, which increases the risk of cracking or breaking around the fuel passage of the molded product.

The present invention has been proposed in view of the above, and when the fuel passage is recessed on one surface of the injector plate by press molding, the load of forming the fuel passage can be reduced even if the drawing depth is increased. An object of the present invention is to provide an electromagnetic fuel injection valve capable of effectively preventing cracks and breakage in a peripheral portion of a fuel passage.

In order to achieve the above object, the present invention comprises a valve seat, a valve seat member having a valve hole penetrating the central portion of the valve seat, and a valve body that opens and closes the valve hole in cooperation with the valve seat. And an injector plate having a fuel injection hole and coupled to the outer end surface of the valve seat member, the injector plate is the injector in an electromagnetic fuel injection valve composed of a press-molded metal plate. A fuel passage for guiding fuel from the valve hole toward the fuel injection hole is recessed on the surface of the plate facing the valve seat member, and the fuel passage is opened on the valve seat member side. The surface is closed with the valve seat member, and a raised portion corresponding to the fuel passage is formed on the outer surface of the injector plate on the side opposite to the valve seat member by the press molding. The outer peripheral surface of the raised portion is provided with a tapered surface that is inclined toward the center of the raised portion from the root portion of the raised portion toward the top surface when viewed in a cross section in a direction crossing each portion of the raised portion. The peripheral surface of the fuel passage has an upright surface portion that rises straight from the bottom surface of the fuel passage, and a curved surface portion that extends from the upper end of the upright surface portion to the facing surface and is deeper than the upright surface portion. When viewed in a cross section orthogonal to the upright surface portion, the position along the plate surface of the injector plate is substantially the same as the outer peripheral end serving as the starting point of the tapered surface on the top surface of the raised portion, or more than the outer peripheral end. It is arranged at a position on the inner side, and the curved surface portion is convexly curved toward the fuel passage side when viewed in a cross section orthogonal to the upright surface portion, and as it approaches the facing surface, the upright surface portion is described as described. The first feature is that the fuel is formed so as to gradually separate outward in the direction along the plate surface.

Further, in the present invention, in addition to the first feature, the width of the curved surface portion in the direction along the plate surface is set to a length equal to or larger than the minimum wall thickness of the injector plate when viewed in the cross section. The second feature is that.

Further, in the present invention, in addition to the first feature, the width of the curved surface portion in the direction along the plate surface is equal to or larger than the minimum wall thickness of the injector plate when viewed in a cross section orthogonal to the upright surface portion . The second feature is that the length is set.

Further, in the present invention, in addition to the first or second feature, the outer peripheral edge of the curved surface portion is outside the raised portion in the direction along the plate surface when viewed in a cross section orthogonal to the upright surface portion. The third feature is that it is located on the side.

According to the first feature of the present invention, the peripheral surface of the fuel passage has an upright surface portion that rises straight from the bottom surface of the passage and an upright surface portion that is connected to the upper end of the upright surface portion and extends to the surface of the injector plate facing the valve seat member. It has a deeper curved surface portion, and the upright surface portion is located at substantially the same position as the outer peripheral edge of the top surface of the raised portion in the direction along the plate surface of the injector plate when viewed in a cross section orthogonal to the upright surface portion, or the outer periphery thereof. It is arranged at a position inward from the end, and the curved surface portion is convexly curved toward the fuel passage side when viewed in the cross section, and the direction from the upright surface portion to the plate surface as it approaches the facing surface. Since it is formed so as to gradually separate from the outer side, the top of the raised portion is relatively outward with respect to the upright surface portion, and a relatively deep and wide curved surface portion (sagging portion) is formed in connection with the upright surface portion. In the molding mode, the fuel passage can be press-molded, and therefore, the upright surface portion and the curved surface portion can be accurately formed with a relatively small press load while suppressing the flow amount of the metal material as much as possible during press molding. As a result, even when the drawing depth during press molding is deep, the load of forming the fuel passage can be effectively reduced, which is effective in preventing cracks and breakage in the vicinity of the fuel passage of the injector plate. It is possible to reduce the frequency of defective products. Further, depending on the molding mode, the depth of the fuel passage can be made deeper than, for example, the thickness of the injector plate, which increases the degree of freedom in design. Further, since the upright portion of the peripheral surface of the fuel passage near the bottom surface rises straight from the bottom surface, the flow of fuel toward the fuel injection hole in the fuel passage can be stabilized.

Further, in particular, according to the second feature, since the width of the curved surface portion in the direction orthogonal to the upright surface portion is set to a length equal to or larger than the minimum wall thickness of the injector plate, the curved surface portion is sufficiently widened and the fuel passage is provided. It can contribute to further reduction of the forming load of.

Further, in particular, according to the third feature, since the outer peripheral edge of the curved surface portion is located on the outer side of the raised portion, the curved surface portion is used as the fuel passage while suppressing the partial decrease in the wall thickness of the injector plate as much as possible. The width can be sufficiently widened to the outer side, which can contribute to further reduction of the load for forming the fuel passage.

Further, according to the fourth feature, the fuel passage has a guide passage extending in a predetermined direction from the communication portion with the valve hole and a swivel chamber connected to the downstream end of the guide passage to swivel the fuel. It is possible to add swirl to the passing fuel and contribute to the promotion of atomization of the injected fuel. Further, even if the fuel passage has a complicated passage form by having the guide passage and the swivel chamber in this way, it can be easily and accurately formed on the injector plate by press molding, and at the time of the press molding. It is possible to effectively avoid cracks and breaks in the peripheral parts of the guide passage and the swivel chamber by specially installing a relatively deep and wide curved surface part (sagging part).

Longitudinal sectional view of an electromagnetic fuel injection valve for an internal combustion engine according to an embodiment of the present invention. Enlarged view of the 2 arrow view in FIG. 1 (cross-sectional view taken along line 2-2 in FIG. 3) and a partially enlarged view thereof. 3-3 arrow view of FIG. 2 and its partially enlarged view It is a process explanatory view explaining an example of the press molding process of an injector plate paying attention to 4-4 line cross section part of FIG. 3, (A) shows the state just before molding which set a work in a mold, and (B) ) Indicates the state immediately after press molding and before mold release.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, in FIGS. 1 and 2, the casing 1 of the electromagnetic fuel injection valve I for an internal combustion engine is liquid-tightly coupled to the cylindrical valve housing 2 (magnetic material) and the front end portion of the valve housing 2. It is composed of a bottom cylindrical valve seat member 3 and a cylindrical fixed core 5 that is liquid-tightly coupled with an annular spacer 4 sandwiched at the rear end of the valve housing 2.

The annular spacer 4 is made of a non-magnetic metal such as stainless steel, and the valve housing 2 and the fixed core 5 are abutted against both end surfaces thereof and are liquid-tightly welded all around, and a laser beam is used for the welding. ..

A first fitting cylinder portion 3a and a second fitting cylinder portion 2a are formed at the opposite ends of the valve seat member 3 and the valve housing 2, respectively. Then, the first fitting cylinder portion 3a is press-fitted into the second fitting cylinder portion 2a together with the stopper plate 6, and the stopper plate 6 is sandwiched between the valve housing 2 and the valve seat member 3. After that, the valve housing 2 and the valve seat member 3 are subjected to laser welding or beam welding over the entire circumference of the corner sandwiched between the outer peripheral surface of the first fitting cylinder portion 3a and the end surface of the second fitting cylinder portion 2a. Are tightly coupled to each other.

The valve seat member 3 has a conical valve seat 8 that opens a downstream end to its flat front end surface, that is, an outer end surface, and an opening to the outer end surface of the valve seat member 3 that penetrates the central portion of the valve seat 8. A valve hole 10 to be provided and a cylindrical guide hole 9 connected to the upstream end of the valve seat 8, that is, a large diameter portion are provided, and the guide hole 9 is coaxial with the second fitting cylinder portion 2a. It is formed.

A movable core 12 facing the front end surface of the fixed core 5 is slidably housed in the valve housing 2 and the annular spacer 4, and is slidably housed in the guide hole 9 in the movable core 12. The valve body 16 is integrally connected. The valve body 16 comes into contact with a spherical valve portion 16a that can be seated on the valve seat 8, a pair of front and rear journal portions 16b and 16b that are slidably supported in the guide hole 9, and a valve that comes into contact with the stopper plate 6. A flange 16c that defines a valve opening limit of the body 16 is integrally provided, and each journal portion 16b is provided with a plurality of flat surfaces 17, 17 ... That enable the flow of fuel.

The fixed core 5 has a hollow portion 21 communicating with the inside of the valve housing 2, and the movable core 12 is urged into the hollow portion 21 in the closing direction of the valve body 16, that is, in the seating direction to the valve seat 8. A coil-shaped valve spring 22 and a pipe-shaped retainer 23 that supports the rear end of the valve spring 22 are housed. The retainer 23 is fixed by caulking in the hollow portion 21.

At the rear end of the fixed core 5, an inlet cylinder 25 having a fuel inlet 25a communicating with the hollow portion 21 of the fixed core 5 via a pipe-shaped retainer 23 is integrally provided, and a fuel filter 27 is connected to the fuel inlet 25a. Is installed.

A coil assembly 28 is fitted on the outer periphery of the annular spacer 4 and the fixed core 5. The coil assembly 28 includes a bobbin 29 that is fitted to an annular spacer 4 and a fixed core 5 on an outer peripheral surface, and a coil 30 that is wound around the bobbin 29. A coil housing 31 that surrounds the coil assembly 28. One end of the valve housing 2 is welded to the outer peripheral surface of the valve housing 2.

The coil housing 31, the coil assembly 28, and the fixed core 5 are embedded in a coating body 32 made of synthetic resin, and a coupler provided in the middle portion of the coating body 32 is provided with a connection terminal 33 connected to the coil 30. 34 are integrally installed.

As is clearly shown in FIG. 2, a disk-shaped injector plate 36 is liquid-tightly welded all around the front end surface of the valve seat member 3, and a laser beam is used for the welding. The injector plate 36 is composed of a press-molded product obtained by press-molding a metal plate (for example, a stainless steel plate or another steel plate) into a predetermined shape. The injector plate 36 is provided with a plurality of fuel injection holes 43 arranged at equal intervals on the same circumference around the axis of the valve hole 10. The injector plate 36 has a thin plate shape having a thickness of, for example, about 0.1 mm. In the drawings, the thickness of the injector plate 36 is slightly exaggerated in order to make the invention easier to understand.

On the upper surface of the injector plate 36, that is, the surface 36i facing the outer end surface of the valve seat member 3, a shallow recess serving as a fuel passage FP for guiding the flow of fuel from the valve hole 10 toward the fuel injection hole 43 is formed by the above press molding. It is formed. The fuel passage FP has a complicated planar shape (petal shape in the present embodiment) as described below in order to impart swirl to the passing fuel and contribute to the promotion of atomization of the fuel injected from the fuel injection hole 43. The peripheral surfaces FPs of the fuel passage FP are formed.

That is, the fuel passage FP has a central oil chamber 37 as a communication portion that directly communicates with the valve hole 10, and a predetermined direction from the central oil chamber 37 along the plate surface of the injector plate 36 (in the present embodiment, the center of the valve hole 10). A plurality of guide passages 38 extending linearly in the radial direction with respect to the guide passage 38, and a swivel chamber 39 in which the downstream end of each guide passage 38 opens in the tangential direction are provided. The swivel chamber 39 is offset from the center line L of the guide passage 38 on one side in the width direction of the guide passage 38 (in other words, on one side in the circumferential direction of the injector plate 36).

The upstream end of the fuel injection hole 43 is opened on the bottom surface of the swivel chamber 39. The fuel injection hole 43 is formed by, for example, drilling the injector plate 36 after press molding.

The open surface on the valve seat member 3 side of most of the fuel passage FP (more specifically, the outer peripheral portion of the central oil chamber 37, each guide passage 39 and each swivel chamber 39) is closed by the valve seat member 3. .. Further, the region of the upper surface 36i of the injector plate 36 surrounding the fuel passage FP is placed in close contact with the outer end surface of the valve seat member 3. Then, the fuel flowing through the fuel passage FP reaches the fuel injection hole 43 from the valve hole 10 through the central oil chamber 37, the guide passage 38, and the swivel chamber 39 in order without leaking to the outside.

Further, the peripheral surface of the swivel chamber 39 is a curved peripheral surface 39f that is convexly curved outward in the radial direction, and the fuel that has flowed into the swivel chamber 39 through the guide passage 38 due to the swivel guidance action of the curved peripheral surface 39f. Turns smoothly. As a result, swirl can be applied to the fuel immediately before flowing into the fuel injection hole 43.

On the other hand, both inner side surfaces of the guide passage 38 facing each other, that is, the first and second inner side surfaces 38i and 38o extend linearly in the longitudinal direction of the guide passage 38 (that is, the radial direction with respect to the center of the valve hole 10).

Of the first and second inner side surfaces 38i and 38o described above, the swivel chamber 39 is located closer to the center of the swivel chamber 39 in the width direction of the guide passage 38 (that is, the side where the swivel chamber 39 is offset with respect to the passage center line L). The downstream end of the first inner surface 38i and the downstream end of the curved peripheral surface 39f of the swivel chamber 39 are smoothly connected by a curved surface r. The downstream end of the first inner side surface 38i and the downstream end of the curved peripheral surface 39f may be directly connected to each other without, for example, a curved surface r.

Further, the downstream end of the second inner side surface 38o of the guide passage 38 and the upstream start end of the curved peripheral surface 39f of the swivel chamber 39 are smoothly connected without a step. As a result, the high-pressure fuel can smoothly flow into the swivel chamber 39 from the guide passage 38.

By the way, on the lower surface of the injector plate 36 (that is, the outer surface opposite to the valve seat member 3) 36o, the injector plate 36 is press-molded as described later to form a raised shape corresponding to the fuel passage FP (this implementation). A petal-shaped ridge 41 is formed in the form. The outer peripheral surface of the raised portion 41 is inclined toward the center of the raised portion 41 (that is, tapered) from the root portion of the raised portion 41 toward the top surface 41f when viewed in a cross section in a direction crossing each portion of the raised portion 41. It is formed on the tapered surface 41t .

Further, the peripheral surfaces FPs of the fuel passage FP are connected to the upright surface portion 101 that rises straight and substantially vertically from the flat bottom surface FPb of the fuel passage FP, and extends curvedly to the upper surface 36i of the injector plate 36. The curved surface portion 102 is provided over the entire circumference of the peripheral surface FPs. Thus, the depth d of the fuel passage FP is the sum of the depth d1 of the upright surface portion 101 and the depth d2 of the curved surface portion 102. In the present embodiment, a slight radius is provided between the bottom surface FPb of the fuel passage FP and the upright surface portion 101, but this radius is omitted so that the upright surface portion 101 stands up steeply (at right angles) from the bottom surface FPb. You may.

In the present embodiment, the upright surface portion 101 is viewed in a cross section orthogonal to the upright surface portion 101 (see, for example, FIGS. 2 and 4 (B)), and the direction along the plate surface of the injector plate 36 (for example, left and right in FIG. 4). In the direction), at a position offset to the inward side (for example, toward the center of the fuel passage FP in FIG. 4B) from the outer peripheral end 41fe which is the starting point of the tapered surface 41t on the flat top surface 41f of the raised portion 41. Be placed. Although not shown, as a modification of the present embodiment, the upright surface portion 101 is arranged at substantially the same position as the outer peripheral end 41fe of the top surface 41f of the raised portion 41 in the direction along the plate surface when viewed in the cross section. You may. In this case, the "substantially the same position" includes not only the same position in the strict sense but also a position slightly deviated from the same position.

The curved surface portion 102 is a curved surface that is convex toward the fuel passage FP side when viewed in the cross section, and is outward from the upright surface portion 101 in the direction along the plate surface as it approaches the upper surface 36i of the injector plate 36. For example, in FIG. 4B, the fuel passage FP is formed so as to gradually move away from the center of the fuel passage FP). Moreover, the outer peripheral end 102e of the curved surface portion 102 (that is, the opening end of the curved surface portion 102 to the upper surface 36i of the injector plate 36) is on the outer side of the raised portion 41 in the direction along the plate surface when viewed in the cross section. positioned.

Further, the curved surface portion 102 is set to a depth d2 equal to or greater than the depth d1 of the upright surface portion 101. Moreover, the width w of the curved surface portion 102 in the direction along the plate surface when viewed in the cross section is set to a length equal to or greater than the minimum wall thickness t _MIN of the injector plate 36. In the present embodiment, as illustrated in FIG. 2, the wall thickness of the plate portion sandwiched between the root portion of the outer surface of the raised portion 41 of the injector plate 36 and the outer peripheral edge portion of the bottom surface FPb of the fuel passage FP is the injector. The minimum wall thickness of the plate 36 is t _MIN .

Next, the operation of the embodiment will be described. In the degaussed state of the coil 30, the movable core 12 and the valve body 16 are pressed forward by the urging force of the valve spring 22, and are seated on the valve seat 8. Therefore, the high-pressure fuel supplied into the valve housing 2 through the fuel filter 27 and the inlet cylinder 25 is made to stand by in the valve housing 2.

When the coil 30 is excited by energization, the magnetic flux generated by the energization runs through the fixed core 5, the coil housing 31, the valve housing 2, and the movable core 12 in that order, and the movable core 12 is attracted to the fixed core 5 together with the valve body 16 by the magnetic force. Since the valve body 16 is separated from the valve seat 8, the high-pressure fuel in the valve housing 2 sequentially passes through the flat surfaces 17, 17 ... Of the valve body 16, the valve seat 8 and the valve hole 10, and moves to the fuel passage FP. , The central oil chamber 37 of the fuel passage FP branches into a plurality of guide passages 38, and reaches the plurality of swivel chambers 39 while diffusing radially.

At this time, since the high-pressure fuel flows from each guide passage 38 into the corresponding turning chamber 39 in the tangential direction at high speed, the inflow fuel is given a swirl by turning the turning chamber 39 at high speed, and also passes through the guide passage 38. Since there is no sudden bending in the fuel flow until it reaches the swivel chamber 39 and the flow becomes smooth, the speed loss of the fuel is small. As a result, promotion of atomization of the injected fuel injected from the fuel injection hole 43 of each swivel chamber 39 toward the injected portion (for example, the intake port) of the engine is achieved, a good spray foam is obtained, and the fuel The responsiveness of injection is good. As a result, the combustibility of the fuel in the combustion chamber is enhanced, and the combustion control is performed with high accuracy.

The fuel passage FP has a plurality of guide passages 38 and swivel chambers 39 as described above, so that the fuel passage FP has a complicated passage form, which can be easily and accurately formed on the injector plate 36 by press molding. Is.

Next, an example of the press forming process of the injector plate 36 is shown with reference to FIG.

As shown in FIG. 4A, the work 036 made of a metal plate pre-processed into a disk shape having the same shape as the final product of the injector plate 36 is first placed on the die 50 and then by the punch guide 52. The outer circumference can be suppressed. The work 036 is then pressurized between the die 50 and the punch 51 descending along the punch guide 52, as shown in FIG. 4B. By the pressurization, a recess serving as a fuel passage FP (that is, a central oil chamber 37, a guide passage 38, and a swivel chamber 39) is press-formed on the upper surface 36i of the work 036.

In this case, the guide holes 52a of the punch 51 and the punch guide 52 are both formed in the same cross-sectional shape as the peripheral surface FPs of the fuel passage FP, particularly the upright surface portion 101, and the punch 51 is vertically slid into the guide hole 52a. It is movably fitted and supported, and is interlocked with an elevating drive means (not shown). The punch 51 has an upright surface / bottom surface forming portion for forming the upright surface portion 101 and the bottom surface FPb of the fuel passage FP at the front portion 51a, and the tip surface 51ae of the front end portion 51a is the fuel passage FP. It is formed on a flat surface corresponding to the bottom surface FPb.

Further, the die 50 is formed with a molding recess 50a facing the tip portion 51a of the punch 51 and slightly larger than the upright surface portion 101 of the fuel passage FP. The bottom surface of the molding recess 50a is formed on a flat surface, and the inner peripheral surface is formed on a tapered surface 50at. In the direction across the molding recess 50a (horizontal direction in FIG. 4), the peripheral surface of the tip portion 51a of the punch 51 is at substantially the same position as the small diameter end (lower end in FIG. 4) of the tapered surface 50at of the molding recess 50a, or the above. It is arranged at a position offset to the inward side (that is, the central portion side of the molding recess 50a) from the small diameter end.

Therefore, according to the above-mentioned press forming step, the corresponding portion of the work 036 is shear-formed by the tip portion 51a of the punch 51, and as a result, the fuel passage FP is formed on the upper surface 36i of the work 036 after the press forming. The dent, particularly the bottom surface FPb and the upright surface portion 101 that rises substantially perpendicularly from the bottom surface FPb are formed so as to follow the shape of the tip portion 51a of the punch 51, and the curved surface portion 102 (sag portion) that is connected to the upper end of the upright surface portion 101. Is formed around the tip portion 51a of the punch 51, while the raised portion 41 corresponding to the fuel passage FP is formed on the lower surface 36o of the work 036 so as to follow the molding recess 50a of the die 50. At the same time, the outer peripheral surface of the raised portion 41 is formed in a tapered surface 41t following the tapered surface 50at of the forming recess 50a.

As described above, in the present embodiment, the peripheral surface FPs of the fuel passage FP are connected to the upright surface portion 101 that rises straight and substantially vertically from the flat bottom surface FPb, is connected to the upper end of the upright surface portion 101, and extends to the upper surface 36i of the injector plate 36. It has a curved surface portion 102 deeper than the upright surface portion 101, and the upright surface portion 101 has a raised portion 41 in a direction along the plate surface of the injector plate 36 when viewed in a cross section (for example, FIG. 4) orthogonal to the curved surface portion 101. The top surface 41f is arranged at substantially the same position as the outer peripheral end 41fe which is the starting point of the tapered surface 41t, or at a position inward from the outer peripheral end 41fe, while the curved surface portion 102 is an injector when viewed in the cross section. It is formed so as to gradually move outward from the upright surface portion 101 as it approaches the upper surface 36i of the plate 36.

That is, in the present embodiment, the top of the raised portion 41 is relatively outward with respect to the upright surface portion 101 of the fuel passage FP, and a relatively deep curved surface portion 102 (sagging portion) is formed in connection with the upright surface portion 101. In the embodiment, since the fuel passage FP is press-molded, it is possible to accurately form the peripheral surface FPs of the fuel passage FP with a relatively small press load while suppressing the flow amount of the metal material as much as possible at the time of press molding. As a result, even when the drawing depth d during press molding is deep, the load of forming the fuel passage FP can be reduced, so that cracks and breaks in the vicinity of the fuel passage FP of the injector plate 36 can be effectively prevented. This can reduce the frequency of defective molding products.

In order to perform press molding in the above molding mode while ensuring the required wall thickness and strength of the injector plate 36, at least the peripheral surface of the tip portion 51a of the punch 51 is formed in a direction crossing the molding recess 50a. It is necessary to arrange the recess 50a at substantially the same position as the small diameter end (lower end in FIG. 4) of the tapered surface 50at, or at a position offset to the inward side (that is, the central portion side of the molding recess 50a) from the small diameter end. In addition, it is necessary to consider the pushing stroke of the punch 51 (that is, the drawing depth d of the fuel passage FP), the pushing load, and the like in consideration of the thickness and material of the injector plate 36.

Thus, the fuel passage FP can improve the molding accuracy even if the passage form is complicated, which is advantageous in ensuring a smooth flow of fuel in the fuel passage FP and promoting atomization of the injected fuel. Further, depending on the molding mode, the depth d of the fuel passage FP can be made deeper than, for example, the plate thickness t of the injector plate 36, so that the degree of freedom in design is increased accordingly. Further, since the upright surface portion 101 of the peripheral surface FPs of the fuel passage FP near the bottom surface FPb rises substantially vertically and straight from the flat bottom surface FPb, the fuel flows in the fuel passage FP and flows toward the fuel injection hole 43. It can be stabilized.

Further, in the present embodiment, a molding mode is selected such that the width w of the curved surface portion 102 in the direction orthogonal to the upright surface portion 101 is set to a length equal to or greater than the minimum wall thickness t _MIN of the injector plate 36. As a result, the curved surface portion 102 is sufficiently widened, and the load for forming the fuel passage FP can be further reduced.

Moreover, in the present embodiment, the outer peripheral end 102e of the curved surface portion 102 is in a direction orthogonal to the upright surface portion 101 with respect to the raised portion 41 bulging formed on the outer surface 36o of the injector plate 36 corresponding to the fuel passage FP. The molding mode is selected so that it is located on the outer side. As a result, the curved surface portion 102 can be sufficiently widened to the outer side of the fuel passage FP while suppressing a partial decrease in the wall thickness of the injector plate 36 as much as possible, and the load for forming the fuel passage FP can be further reduced.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. Is.

For example, the number and arrangement of the guide passages 38 and the swivel chambers 39 in the fuel passage FP can be appropriately selected according to the required number and shape of the fuel spray foams. For example, in the above-described embodiment, the guide passage 38 is radially and linearly extended from the central oil chamber 37 (communication portion with the valve hole 10) of the fuel passage FP, but in the present invention, the guide passage 38 is provided. It may be applied to the one which is slightly inclined in the circumferential direction from the radial direction and extends outward in the radial direction, or the guide passage 38 which is slightly curved and extended in a curved shape. The number of sets of the guide passage 38 and the swivel chamber 39 is 6 in the embodiment, but any other number, for example, 4 sets may be used.

Further, in the above embodiment, in order to particularly promote atomization of the injected fuel, the fuel passage FP is provided with a plurality of guide passages 38 and a plurality of swivel chambers 39 in which the downstream ends of the guide passages 38 are opened in the tangential direction. Although the passage configuration is combined, the passage configuration of the fuel passage of the present invention is not limited to the above embodiment, and any passage configuration that can smoothly guide the fuel from the valve hole 10 to the fuel injection hole 43 may be used. .. For example, as shown in Patent Document 1, the present invention can be applied to a fuel passage in which a swivel chamber is omitted and a fuel injection hole is opened on the bottom surface of a plurality of guide passages at the downstream end.

Further, in the above embodiment, as a means for connecting the injector plate 36 and the valve seat member 3, all-around welding w by a laser beam is exemplified, but the means for connecting the injector plate 36 and the valve seat member 3 is not limited to the welding means. That is, various coupling means can be adopted as long as it is a coupling means capable of liquid-tightly coupling between the injector plate 36 and the valve seat member 3 over the entire circumference.

Further, in the above-described embodiment, the injector plate 36 has an example of a thin-walled plate having a plate thickness of, for example, about 0.1 mm, but the present invention is thicker or thinner than the embodiment (provided that the press is pressed). It can also be applied to an injector plate (thick enough to accurately mold the fuel passage FP (guide passage 38 and swivel chamber 39)) by molding.

d1 ・ ・ ・ ・ ・ Depth of upright surface d2 ・ ・ ・ ・ ・ Depth of curved surface FP ・ ・ ・ ・ ・ Fuel passage FPb ・ ・ ・ ・ ・ ・ Bottom surface FPs of fuel passage ・ ・ ・ ・ Circumferential surface I of fuel passage・ ・ ・ ・ ・ ・ Fuel injection valve t _MIN・ ・ ・ ・ Minimum thickness of injector plate w ・ ・ ・ ・ ・ ・ Width of curved surface 3 ・ ・ ・ ・ ・ ・ Valve seat member 8 ・ ・ ・ ・ ・ ・ Valve Seat 10 ... Valve hole 16 ... Valve body 36 ... Injector plate 36i ... Top surface (opposing surface to valve seat member)
36o ... Lower surface (outer surface on the opposite side of the valve seat member)
37 ... Central oil chamber (communication section)
38 ・ ・ ・ ・ ・ Guide passage 39 ・ ・ ・ ・ ・ Swivel chamber 41 ・ ・ ・ ・ ・ Raised part 41f ・ ・ ・ ・ Top surface 41fe ・ ・ ・ Outer peripheral end 41t of the top surface ・ ・ ・ ・Tapered surface ( outer peripheral surface) )
43 ... Fuel injection hole 101 ... Standing surface portion 102 ... Curved surface portion 102e ... Outer peripheral edge of curved surface portion

Claims (4)

A valve seat member (3) having a valve seat (8) and a valve hole (10) penetrating the central portion of the valve seat (8), and the valve hole (10) in cooperation with the valve seat (8). ), An injector plate (36) having a fuel injection hole (43) and being coupled to the outer end surface of the valve seat member (3), and the injector plate (36). However, in an electromagnetic fuel injection valve composed of a press-molded metal plate,
A fuel passage (FP) that guides fuel from the valve hole (10) toward the fuel injection hole (43) on the surface (36i) of the injector plate (36) facing the valve seat member (3). ) Is recessed, and the open surface of the fuel passage (FP) on the valve seat member (3) side is closed by the valve seat member (3).
On the outer surface (36o) of the injector plate (36) opposite to the valve seat member (3), a raised portion (41) corresponding to the fuel passage (FP) is formed by the press molding. Ori,
The outer peripheral surface (41t) of the raised portion (41) is viewed from the root portion of the raised portion (41) toward the top surface (41f) when viewed in a cross section in a direction crossing each portion of the raised portion (41). A tapered surface (41t) inclined toward the center of the raised portion (41) is provided.
The peripheral surfaces (FPs) of the fuel passages (FP) are connected to an upright surface portion (101) that rises straight from the bottom surface (FPb) of the fuel passage (FP) and the upper end of the upright surface portion (101), and the facing surfaces (FPs). It has a curved surface portion (102) deeper than the upright surface portion (101) extending to 36i).
The upright surface portion (101) is seen on a cross section orthogonal to the upright surface portion (101), and is the above-mentioned on the top surface (41f) of the uplift portion (41) in a direction along the plate surface of the injector plate (36). It is arranged at substantially the same position as the outer peripheral end (41fe) which is the starting point of the tapered surface (41t), or at a position on the inner side of the outer peripheral end (41fe).
The curved surface portion (102) is curved convexly toward the fuel passage (FP) side when viewed in a cross section orthogonal to the upright surface portion (101), and the upright surface portion (36i) approaches the facing surface portion (36i). An electromagnetic fuel injection valve characterized in that it is formed so as to gradually move outward from 101) in a direction along the plate surface. The width (w) of the curved surface portion (102) in the direction along the plate surface when viewed in a cross section orthogonal to the upright surface portion (101) is the minimum wall thickness (t _MIN ) of the injector plate (36). The electromagnetic fuel injection valve according to claim 1, wherein the length is set to the above. The outer peripheral end (102e) of the curved surface portion (102) is located on the outer side of the raised portion (41) in the direction along the plate surface when viewed in a cross section orthogonal to the upright surface portion (101). The electromagnetic fuel injection valve according to claim 1 or 2, wherein the fuel injection valve is characterized by the above. The fuel passage (FP) is connected to a guide passage (38) extending in a predetermined direction from a communication portion (37) with the valve hole (10) and a downstream end of the guide passage (38). It is characterized by having at least a swivel chamber (39) in which the fuel flowing in from the guide passage (38) is swirled and the upstream end of the fuel injection hole (43) is opened at the bottom. The electromagnetic fuel injection valve according to any one of claims 1 to 3.

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