JP7194663B2 - electromagnetic fuel injection valve - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electromagnetic fuel injection valve used in a fuel supply system of an internal combustion engine. It has a coil arranged around a fixed core, a valve body that cooperates with the valve seat to open and close the valve hole, and a movable core that is magnetically attracted to the fixed core based on the magnetic force generated by the coil and opens the valve body. The valve member includes a valve member, and a resin covering portion having a covering portion main body covering at least the coil from the radially outer side and molded with an insulating synthetic resin. The present invention relates to improvement of an electromagnetic fuel injection valve installed.

In this type of electromagnetic fuel injection valve, it is conventionally known to provide a plurality of functional surfaces (for example, a fitting surface for a seal ring or a cushion ring) on the outer peripheral portion of the main body of the resin coating ( See, for example, Patent Literature 1).

Japanese Patent Application Laid-Open No. 2006-77728

In the conventional fuel injection valve, after the resin coating is molded, when the resin coating is removed from the mold, a release jig (for example, a knockout pin) is pressed against the outer circumference of the main body of the resin coating. The pressing may cause burrs and dents on the surface of the product. If the burrs or dents are applied to the functional surface, the original function of the functional surface will be hindered. There are problems such as loss of sealing performance.

In order to accurately position the fuel injection valve in the valve support hole of the internal combustion engine, for example, it is conceivable to provide a positioning surface (for example, a flat portion for positioning) on the outer peripheral surface of the main body of the resin coating. In this case, if burrs or dents are formed on the positioning surface due to the pressing of the mold release jig, the positioning function with respect to the fuel injection valve is impaired. There is also a problem that it becomes a factor for lowering the

The present invention has been made in view of such circumstances. An object of the present invention is to provide an electromagnetic fuel injection valve that can solve the problem.

In order to achieve the above object, the present invention provides a valve casing having a valve seat and a valve hole at one end, a fixed core provided at the other end of the valve casing, and a coil arranged around the fixed core. , a valve member having a valve body that opens and closes the valve hole in cooperation with the valve seat, and a movable core that is magnetically attracted to the fixed core based on the magnetic force generated by the coil to open the valve body; The solenoid is fitted into a valve support hole provided in an internal combustion engine, and includes a resin coating portion that has a coating portion main body that covers the coil from the radially outer side and is molded with an insulating synthetic resin. In the fuel injection valve, the resin coating portion has a jig receiving surface against which a mold release jig is pressed during the molding process of the resin coating portion, and a center of the fuel injection valve, the resin coating portion being positioned in the valve support hole. A first functional surface for positioning at a predetermined position around the axis and at least one second functional surface for fitting an elastic ring functioning as at least a seal ring or a cushion ring are formed on the outer peripheral portion of the covering body. It has a coupler main body portion which is located at a different position from each other, holds a coupler terminal connected to the coil, and protrudes to one side from the outer peripheral portion of the covering main body, wherein the first functional surface is It has at least one flat positioning surface portion and is arranged closer to the coupler main body than the jig receiving surface, while the one second functional surface is arranged closer to the valve seat than the jig receiving surface. the radial distance of the jig receiving surface from the central axis is shorter than the radial distance of the first functional surface from the central axis, and the one second functional surface has a radial distance from the central axis The stepped surface, which is set longer than the radial distance and is formed between the jig receiving surface and the one second functional surface, is the elastic portion held by the inner peripheral stepped portion of the valve support hole. A ring engaging surface that can be engaged with a ring is formed, and the main body of the covering portion is a taper that continues to the edge of the one second functional surface on the side of the valve seat and that decreases in diameter as it approaches the valve seat. A first feature is that it has a surface .

In addition to the first feature, the present invention has a second feature that the flat positioning surface is arranged at a different position from the coupler main body in the circumferential direction of the cover main body.

In the present invention, the term "internal combustion engine" includes not only the main body of the internal combustion engine, but also accessories of the internal combustion engine (for example, a throttle body and an intake pipe).

Further, in the present invention, the term "elastic ring" includes an elastic ring that exhibits only one function of a seal ring or a cushion ring, and an elastic ring that exhibits both the functions of a seal ring and a cushion ring. is also included.

According to the first feature of the present invention, the resin coating portion to be molded in the electromagnetic fuel injection valve includes a jig receiving surface against which a release jig is pressed during the molding process, and a valve support hole. A first functional surface for positioning a fitted fuel injection valve at a predetermined position around its central axis, and at least one second functional surface for fitting an elastic ring functioning as at least a seal ring or a cushion ring. are located at different positions on the outer peripheral portion of the covering portion main body. As a result, even if the mold release jig is pressed against the outer peripheral portion of the main body of the covering portion when the resin covering portion is removed from the mold after the resin covering portion is molded, the pressing portion does not correspond to the first and second functional surfaces. Since the first and second functional surfaces do not have burrs or dents due to the pressing of the jig, each functional surface can be formed with high accuracy, and each original It becomes possible to effectively exhibit the function, and it is possible to contribute to the quality improvement of the resin-coated portion. As a result, for example, the fuel injection valve can be accurately positioned with respect to the internal combustion engine by the first functional surface, and the performance of the engine can be improved. As a result, the workability of assembling the elastic ring can be improved.

Further, the first functional surface has at least one flat positioning surface portion and is arranged closer to the coupler main body portion than the jig receiving surface, while the one second functional surface is positioned closer to the valve body than the jig receiving surface. Located on the seat side, the radial distance from the center axis of the jig receiving surface is shorter than the radial distance from the center axis of the first functional surface and more than the radial distance from the center axis of the second functional surface Therefore, when fitting the fuel injection valve into the valve support hole, the first and second functional surfaces are placed on corresponding portions of the inner circumference of the valve support hole without interfering with the valve support hole. It can be inserted without difficulty. In addition, since the stepped surface formed between the jig receiving surface and the one second functional surface serves as a ring engaging surface that can be engaged with the elastic ring, a simple structure using the stepped surface is provided. provides a ring-engaging surface. In addition, since there is no possibility that burrs or dents are formed on the ring engaging surface due to pressing of the release jig, the elastic ring can be accurately engaged and brought into contact therewith. Furthermore, since the covering portion main body has a tapered surface continuous with the edge of the second functional surface on the side of the valve seat and decreasing in diameter as it approaches the valve seat, the tapered surface guides the elastic ring. It can be smoothly fitted to the second functional surface, and the assembling workability of the elastic ring can be further improved.

According to the second feature, the flat positioning surface portion is arranged at a different position from the coupler main body portion in the circumferential direction of the covering portion main body, so that the flat positioning surface portion is located at a different position from the coupler main body portion, which tends to have a complicated shape. - A flat positioning surface portion is formed, so that the positioning surface portion can be easily molded without affecting the molding of the coupler main body.

FIG. 3 is a vertical cross-sectional view showing an example of a mounting state of an electromagnetic fuel injection valve according to one embodiment of the present invention to an internal combustion engine (cross-sectional view along line 1-1 in FIG. 3); A side view of the electromagnetic fuel injection valve viewed from the same side as in FIG. 3-3 line sectional view of FIG. 4-4 line sectional view of FIG. FIG. 2 is an exploded perspective view showing only the coil housing of the electromagnetic fuel injection valve;

One embodiment of the present invention will be described below based on preferred examples of the present invention shown in the accompanying drawings. In the present invention and this specification, "axial direction", "radial direction", and "circumferential direction" are based on the central axis X of the electromagnetic fuel injection valve I. The direction is the axial direction, the radial direction about the central axis X is the radial direction, and the circumferential direction about the central axis X is the circumferential direction. Further, in this specification, in the electromagnetic fuel injection valve I, the fuel injection side is referred to as the front, and the fuel inlet side as the rear.

1 to 4, a valve housing Ih of an electromagnetic fuel injection valve I for an internal combustion engine includes a cylindrical valve seat member 3 and a rear end portion of the valve seat member 3 which is fitted and liquid-tightly welded. a non - magnetic cylindrical body 6 that abuts against the rear end of the magnetic cylindrical body 4 and is liquid-tightly welded to the magnetic cylindrical body 4; A cylindrical stationary core 5 which is liquid-tightly welded to the fixed core 5 and a fuel inlet tube 26 integrally connected to the rear end of the stationary core 5 and made of the same material are successively connected from the front end to the rear end. be.

The valve seat member 3, the magnetic cylinder 4, and the non-magnetic cylinder 6 constitute a valve casing 2 that accommodates a valve assembly V, which will be described later. The valve housing Ih consisting of the valve casing 2, the fixed core 5 and the fuel inlet tube 26 has the same outer peripheral surface diameter except for the small diameter portion 26a at the rear end of the fuel inlet tube 26. As shown in FIG.

The valve seat member 3 includes a valve hole 7 opening at the front end face, a conical valve seat 8 continuing to the inner end of the valve hole 7, and a cylindrical guide hole 9 continuing to the large diameter portion of the valve seat 8. and A steel plate injector plate 10 having a plurality of fuel injection holes 11 communicating with the valve holes 7 is liquid-tightly welded to the front end face of the valve seat member 3 .

A portion not fitted to the fixed core 5 is left at the front end of the non-magnetic cylindrical body 6, and a valve assembly V as a valve member is housed in the valve casing 2 extending from that portion to the valve seat member 3. .

The valve assembly V comprises a spherical valve body 14 which can slide in the guide hole 9 so as to cooperate with the valve seat 8 to open and close the valve hole 7, and a rod portion 13 joined to the valve body 14 by welding. The movable core 12 is slidably fitted and supported by the inner peripheral surface of the magnetic cylindrical body 4 and opposed to the fixed core 5 . A plurality of flat surfaces are formed around the spherical valve body 14 to allow fuel to pass therethrough.

The valve assembly V is provided with a vertical hole 19 starting from the rear end surface of the movable core 12 and ending at an intermediate portion of the rod portion 13 , and a horizontal hole 20 opening the vertical hole 19 to the outer peripheral surface of the rod portion 13 . An annular spring seat 24 facing the fixed core 5 side is formed in the middle of the vertical hole 19 .

The fixed core 5 has a vertical hole 21 that communicates the hollow portion of the fuel inlet tube 26 with the front end face side of the fixed core 5 . The vertical hole 21 has a smaller diameter than the hollow portion of the fuel inlet tube 26 and communicates with the vertical hole 19 of the movable core 12 .

A slotted pipe-shaped retainer 23 is press-fitted into the vertical hole 21 of the fixed core 5, and between the retainer 23 and the spring seat 24, the movable core 12 is biased toward the valve closing side of the valve element 14. The valve spring 22 is compressed. At this time, the set load of the valve spring 22 is adjusted by the fitting depth of the retainer 23 into the vertical hole 21 .

A ring-shaped stopper member 37 made of a nonmagnetic material is embedded in the movable core 12 , and the stopper member 37 projects slightly from the rear end surface of the movable core 12 facing the fixed core 5 . The stopper member 37 contacts the front end surface of the fixed core 5 when the fixed and movable cores 5 and 12 are attracted to each other, thereby forming a predetermined gap between the opposed end surfaces of the fixed core 5 and the movable core 12 . It is something that remains.

A cylindrical coil assembly 28 is fitted around the outer periphery of the valve housing Ih so as to correspond to the fixed core 5 and the movable core 12 . The coil assembly 28 includes a bobbin 29 fitted to the outer peripheral surface of the magnetic cylindrical body 4 from the rear end of the magnetic cylinder 4 to the stationary core 5, and a coil 30 wound thereon. The bobbin 29 and the coil 30 are cylindrical, and their central axes coincide with the central axis X of the fuel injection valve I. As shown in FIG. A base end portion 33 a of a coupler terminal 33 projecting to one side of the bobbin 29 is held at the rear end portion of the bobbin 29 , and the end of the coil 30 is connected to the coupler terminal 33 .

This coil assembly 28 is surrounded by a coil housing H made of a magnetic material. Both front and rear ends of the coil housing H contact and are fixed to the outer peripheral surfaces of the valve casing 2 and the fixed core 5 . As will be described later, the coil housing H forms a magnetic circuit between the valve casing 2 and the fixed core 5 when the coil 30 is energized so that the movable core 12 (and thus the valve assembly V) is magnetically attracted to the fixed core 5. This allows the valve element 14 to open. A specific structure of the coil housing H will be described in detail later.

The outer shell of the fuel injection valve I is composed of a resin covering portion 32 molded with an insulating synthetic resin. The resin covering portion 32 includes a covering portion main body 32m having a substantially stepped cylindrical shape concentric with the valve housing Ih, and a coupler main body portion 32c projecting to one side from the outer peripheral portion of the covering portion main body 32m.

The covering main body 32m includes a portion of the valve casing 2 (that is, the rear half of the magnetic cylinder 4 and the non-magnetic cylinder 6), the fixed core 5, and most of the fuel inlet tube 26 (excluding the rear end). , and the coil assembly 28 and the coil housing H are molded together with the coupler body portion 32c.

More specifically, the covering portion main body 32m includes an intermediate large-diameter portion 32ma surrounding the front half of the fixed core 5 and the coil housing H, and the magnetic cylindrical body 4 connected to the front side of the intermediate large-diameter portion 32ma. and a rear small-diameter portion 32mc connected to the rear side of the intermediate large-diameter portion 32ma and surrounding the rear half of the stationary core 5 and the fuel inlet tube 26. .

In particular, the intermediate large-diameter portion 32ma has a reduced-diameter portion 60 having a smaller diameter than the other portions on its front outer periphery, and an annular portion is formed between the front end of the reduced-diameter portion 60 and the front small-diameter portion 32mb. A step surface 61 is formed. The outer peripheral surface of the reduced diameter portion 60 functions as a jig receiving surface f0 against which a release knockout pin 90 is pressed during the molding process of the resin coating portion 32 .

The outer peripheral surface of the intermediate large-diameter portion 32ma on the rear side of the reduced-diameter portion 60 rotates around the central axis X within the valve support hole 70 in which the resin coating portion 32 (and thus the fuel injection valve I) is fitted. A first functional surface f1 is configured for positioning at a predetermined position. The first functional surface f1 has at least one (in this embodiment, a pair of) flat positioning surface portions 50 and is located closer to the coupler body portion 32c than the jig receiving surface f0. Each positioning surface portion 50 is formed by flatly notching a portion of the outer peripheral surface of the intermediate outer diameter portion 32ma, that is, by chamfering.

Moreover, the pair of positioning surface portions 50 are arranged at positions different from the coupler main body portion 32c in the circumferential direction of the covering portion main body 32m (more specifically, at positions with a phase difference of approximately 90 degrees when viewed from the central axis X). , and both positioning surfaces 50 are parallel to each other.

The coupler main body 32c accommodates and holds the coupler terminal 33, and is joined to the cover main body 32m so as to straddle the intermediate large diameter portion 32ma and the rear small diameter portion 32mc. be. A coupler 34 is composed of the coupler body portion 32 c and the coupler terminal 33 . The coupler 34 is detachably fitted and connected to an external coupler (not shown) connected to the external wiring.

Further, the coupler main body 32c has left and right side surfaces 81, 82 of a root portion 80 projecting outward from the outer periphery of the covering main body 32m and formed into flat surfaces parallel to the central axis X of the fuel injection valve I. The distance between the left and right side surfaces 81, 82 is approximately equal to the outer diameter of the rear small diameter portion 32mc.

The root portion 80 is slimmed down by having its lower portion 80 less outwardly projecting than its upper portion. A projecting portion 83a is integrally provided. The reinforcing projecting portion 83a can integrally connect the lower surface of the side projecting portion of the coupler main body portion 32c and the intermediate large diameter portion 32ma to increase the support rigidity of the coupler main body portion 32c. This effectively reinforces the coupler 34 .

On the other hand, a stepped valve support hole 70 for fitting and supporting the fuel injection valve I is provided in the internal combustion engine E (specifically, the engine body) to which the fuel injection valve I is to be mounted. The valve support hole 70 includes a small-diameter hole portion 71 into which the front small-diameter portion 32mb is fitted, and a large-diameter hole portion 71 that continues to the open end of the small-diameter hole portion 71 via an annular stepped portion 72 and into which the intermediate large-diameter portion 32ma is fitted. and a diameter hole portion 73 .

The large-diameter hole portion 73 is formed with a flat portion 73a for positioning that brings the pair of positioning surface portions 50 into surface contact with each other. Therefore, due to the surface contact, the fuel injection valve I is reliably positioned at a predetermined position around the central axis X with respect to the valve support hole 70 (therefore, the internal combustion engine E).

The annular stepped portion 72 serves as a bearing surface of a seal ring 51 that is fitted around the outer periphery of the front small diameter portion 32mb and that seals between the front small diameter portion 32mb and the large diameter hole portion 73 in a liquid-tight manner. Therefore, the seal ring 51 is axially sandwiched between the annular stepped portion 72 and the stepped surface 61 of the covering portion main body 32m. Seal ring 51 is an example of an elastic ring.

Thus, the stepped surface 61 constitutes a ring engaging surface that can be axially engaged with the seal ring 51 held on the annular stepped portion 72 . Further, the outer peripheral surface of the front small diameter portion 32mb is arranged closer to the valve seat 8 than the jig receiving surface f0, and constitutes one second functional surface f2 on which the seal ring 51 is fitted.

When the fuel injection valve I is set in the valve support hole 70 so that the seal ring 51 of this embodiment is axially pressed between the stepped surface 61 and the annular stepped portion 72, Also works as a cushion ring.

Further, the covering portion main body 32m has a tapered surface ft that tapers to the front end of the front small diameter portion 32mb. Since this tapered surface ft serves as a guide surface when fitting the seal ring 51 to the front small diameter portion 32mb, the seal ring 51 can be smoothly mounted.

Further, on the outer periphery of the rear small diameter portion 32mc, a ring mounting portion 62 for fitting the cushion ring 52 and an annular protrusion 63 serving as a seating surface for the cushion ring 52 are provided on the rear side of the root portion 80 of the coupler body portion 32c. is provided. The outer peripheral surface of the ring mounting portion 62 constitutes another second functional surface f2' to which the cushion ring 52 is fitted. The cushion ring 52 is another example of an elastic ring.

On the other hand, an annular seal groove 26ag facing the rear end surface of the rear small diameter portion 32mc of the resin coating portion 32 is formed in the outer peripheral surface of the rear small diameter portion 26a of the fuel inlet cylinder 26. A seal ring 53 is formed in the seal groove 26ag. is fitted.

As is clear from the above description, the resin coating portion 32 includes a jig receiving surface f0 against which the releasing knockout pin 90 is pressed during the molding process, and a resin coating portion fitted in the valve support hole 70. A first functional surface f1 for positioning 32 (and thus fuel injection valve I) at a predetermined position around center axis X, one second functional surface f2 for fitting seal ring 51, and cushion ring 52 are fitted. and another second functional surface f2' that allows the outer peripheral portion of the covering portion main body 32m to be positioned at different positions.

Moreover, the radial distance of the jig receiving surface f0 from the central axis X is shorter than the radial distance of the first functional surface f1 from the central axis X, and the second functional surface f2 is distant from the central axis X. It is set longer than the radial distance.

Further, a cylindrical main body 43m of the fuel filter 43 is fixed (for example, press-fitted) to the inlet of the fuel inlet tube 26, that is, the rear end opening. A mounting flange 43f that engages with the rear end surface of the fuel inlet tube 26 is continuously provided at the outer end of the tubular body 43m.

By the way, when the fuel injection valve I is set in the internal combustion engine E, first, the front portion of the fuel injection valve I is inserted into the valve support hole 70 via the seal ring 51 . Next, a fuel distribution pipe 55 connected to a fuel pump (not shown) is fitted into the fuel inlet cylinder 26 via a seal ring 53, and a cushion ring 52 is pressed between the fuel distribution pipe 55 and the annular protrusion 63. , and thereafter, the fuel distribution pipe 55 is fixed (for example, bolted) in place on the internal combustion engine E. As a result, the fuel distribution pipe 55 and the fuel inlet cylinder 26 are connected in an oil-tight manner, and the fuel distribution pipe 55 presses and holds the front portion of the fuel injection valve I against the valve support hole 70 . Thus, the fuel injection valve I is set in the internal combustion engine E in the manner of installation illustrated in FIG.

In this embodiment, the valve support hole 70 is provided in the engine body of the internal combustion engine E, but the valve support hole 70 is provided in an accessory of the internal combustion engine E (for example, throttle body, intake pipe, etc.). may

Next, the coil housing H will be described with reference to FIG. 5 as well.

The coil housing H is divided into first and second coil housing halves H1 and H2 which are each formed in a substantially semi-cylindrical shape (in other words, a minor arc shape in cross section) and which are arranged to face each other so as to sandwich the coil assembly 28 therebetween. Configured. Circumferentially adjacent side edges e1, e2; e1', e2' of the first and second coil housing halves H1, H2 face each other while being spaced apart from each other. Accordingly, first and second gaps Sw and Ss extending in a slit shape along the central axis X of the fuel injection valve I are provided between the mutually opposing side edges e1 and e2; e1' and e2', respectively. be done.

The first and second gaps Sw and Ss are arranged on one diameter line passing through the central axis X, and particularly the first gap Sw is wider than the second gap Ss. Moreover, the coupler 34 is arranged on the extension line of the one diameter line on the side facing the wide first gap Sw. During the molding process of the resin coating portion 32, the inside of the coil housing H (more specifically, the gap 27 between the first and second coil housing halves H1 and H2 and the coil assembly 28) and the coupler This is for allowing the mold resin to smoothly flow through the relatively wide first gap Sw between the inside of the mold cavity corresponding to the main body portion 32m.

Thus, the resin filled in the gap 27 during the molding process of the resin coating portion 32 insulates and seals between the coil housing halves H1, H2 and the coil assembly 28 (and thus the coil 30).

The first and second coil housing halves H1 and H2 are composed of a body portion 44 that covers the outer peripheral portion of the coil assembly 28 and both front and rear end surfaces of the bobbin 29 that are bent radially inward from both ends of the body portion 44 in the axial direction. a front connection wall portion 45 and a rear connection wall portion 46 abutting on the front and rear connection wall portions 45 and 46; 48 each.

The front and rear connecting tubular portions 47 and 48 are narrowed radially inward from the body portion 44 , and have a smaller radius of curvature from the central axis X of the coil 30 than the body portion 44 . The front and rear connecting tubular portions 47 and 48 are closely fixed (welded in this embodiment) to the outer peripheral surfaces of the valve casing 2 (more specifically, the magnetic cylindrical body 4) and the fixed core 5, respectively.

In the present embodiment, the front and rear connecting tubular portions 47 and 48 are formed so that the portions to be welded, which are welded to the valve housing Ih and the fixed core 5 respectively, are thinner than other portions. By reducing the thickness of the welded portion in this way, the energy for welding can be saved.

The first and second coil housing halves H1 and H2 are manufactured by press-molding a magnetic plate. It can be easily molded without

Next, the operation of the embodiment will be described.

In assembling the electromagnetic fuel injection valve I, for example, the main parts of the coil assembly 28 and the valve housing Ih, excluding the valve seat member 3, are manufactured separately. Next, the coil assembly 28 is fitted in a predetermined intermediate portion of the outer periphery of the valve housing Ih, and the first and second coil housing halves H1 and H2 are inserted from the left and right so as to enclose the coil assembly 28 from the left and right. close to each other. Then, with the coil assembly 28 housed in the body portion 44 of both coil housing halves H1 and H2, the front connecting tubular portion 47 is positioned on the outer peripheral surface of the magnetic cylinder 4, and the rear connecting tubular portion 48 is positioned on the outer peripheral surface of the fixed core 5. The thin portions of the front and rear connecting cylindrical portions 47 and 48 are laser-welded at a plurality of locations. Thus, the coil housing H is attached to the valve housing Ih.

After that, the resin coating portion 32 is molded, and the coil assembly 28, the coil assembly 28, the coil housing H, and the base portion of the coupler terminal 33 are embedded by injection molding of an insulating synthetic resin. Then, the resin coating portion 32 is formed around the valve housing Ih. At this time, the first and second gaps Sw and Ss are provided between the first and second coil housing halves H1 and H2 on the side sandwiching the base end portion 33a of the coupler terminal 33 and on the opposite side. , and gaps Sw and Ss, the injection resin easily enters and fills the gap 27 between the coil housing halves H1 and H2 and the coil assembly . As a result, the coil assembly 28 can be reliably embedded and fixed, and its insulation and waterproof properties can be ensured.

After molding the resin coating portion 32, the valve assembly V is housed in the magnetic cylinder 4, and the valve seat member 3 is fitted to the front end portion of the magnetic cylinder 4 and welded. Then, the valve spring 22 and the retainer 23 are mounted in the valve housing Ih from the side of the fuel inlet cylinder 26, and then the fuel filter 43, the seal rings 51, 53 and the cushion ring 52 are mounted to assemble the electromagnetic fuel injection valve I. is completed.

The fuel injection valve I assembled in this way is set in the internal combustion engine E in the manner of installation as shown in FIG. In this set state, the fuel pressure-fed from the fuel pump to the fuel inlet tube 26 through the fuel distribution pipe 55 is filtered by the fuel filter 43 and then fills the insides of the fixed core 5 and the valve casing 2 . When the coil 30 is demagnetized, the valve assembly V is pushed forward by the biasing force of the valve spring 22, causing the valve body 14 to be seated on the valve seat 8 and the valve hole 7 to be closed. When the coil 30 is excited by energization, the magnetic flux generated thereby runs through the coil housing H, the magnetic cylinder 4, the movable core 12, and the fixed core 5 in sequence, and the magnetic attraction generated between the cores 5 and 12 causes the movable core 12 to move. Since the fixed core 5 is attracted against the set load of the valve spring 22 and the valve element 14 is separated from the valve seat 8, the valve hole 7 is opened. As a result, the high-pressure fuel in the valve seat member 3 exits the valve hole 7 and is injected from the fuel injection hole 11 of the injector plate 10 in the form of mist.

The resin coating portion 32 of the fuel injection valve I of the present embodiment includes a jig receiving surface f0 against which a mold release knockout pin 90 is pressed during the molding process, and a fuel injection valve fitted in the valve support hole . A first functional surface f1 for positioning the valve I at a predetermined position around the central axis X, at least one (two in the embodiment) second functional surfaces f2 for fitting the seal ring 51 or the cushion ring 52, f2' are located at different positions on the outer peripheral portion of the covering portion main body 32m.

As a result, even if the mold release knockout pin 90 is pressed against the outer peripheral portion of the coating portion main body 32m when the resin coating portion 32 is removed from the mold after the resin coating portion 32 is molded, the jig receiving surface to be pressed against the mold release knockout pin 90 remains unchanged. Since f0 is located at a different location from the first and second functional surfaces f1, f2, f2', burrs and dents caused by the pressing of the knockout pin 90 may occur on the first and second functional surfaces f1, f2, f2. '. Therefore, each functional surface f1, f2, f2' can be formed with high accuracy without being affected by the knockout pin 90, so that each intrinsic function can be effectively exhibited, and the quality of the resin coated portion can be improved. be done.

As a result, for example, the fuel injection valve I can be accurately positioned in the direction around the central axis X with respect to the internal combustion engine E based on the positioning function of the first functional surface f1, thereby improving engine performance. Further, since the seal ring 51 or the cushion ring 53 as an elastic ring can be properly fitted and brought into contact with the second functional surfaces f2 and f2', the assembling workability, the sealing performance and the cushioning performance can be improved.

The first functional surface f1 has at least one flat positioning surface portion 50 and is arranged closer to the coupler body portion 32c than the jig receiving surface f0, while the one second functional surface f2 is the jig receiving surface. The jig receiving surface f0 is disposed closer to the valve seat 8 than f0, and the radial distance from the central axis X of the jig receiving surface f0 is shorter than the radial distance from the central axis X of the first functional surface f1, and the second It is set longer than the radial distance from the center axis X of the functional surface f2. As a result, when the fuel injection valve I is fitted into the valve support hole 70, the first and second functional surfaces f1 and f2 are positioned within the valve support hole 70 without the jig receiving surface f0 interfering with each part of the valve support hole 70. can be inserted into the corresponding portions of the inner peripheral surface of (that is, the large-diameter hole portion 73 and the small-diameter hole portion 71) without difficulty.

In addition, the stepped surface 61 formed between the jig receiving surface f0 and the one second functional surface f2 serves as a ring engaging surface that engages with the seal ring 51 in the axial direction. A ring engaging surface can be obtained with a simple structure using 61 . Further, since there is no risk of burrs or dents being formed on the stepped surface 61 (ring engaging surface) due to pressing of the release knock-out pin 90, the seal ring 51 can be properly engaged therewith. can.

Furthermore, since the tapered surface ft whose diameter decreases as it approaches the valve seat 8 continues to the edge of the one second functional surface f2 on the side of the valve seat 8, the tapered surface ft guides the seal ring 51. can be smoothly fitted to the second functional surface f2, and the assembling workability of the seal ring 51 can be further improved.

In addition, the flat positioning surface portion 50 of the first functional surface f1 is disposed at a position different from the coupler main body portion 32c in the circumferential direction of the covering portion main body 32m. , flat positioning surface portions 50 are formed in different parts and directions. As a result, the positioning surface portion 50 can be easily molded without affecting or being affected by the molding of the coupler main body portion 32c.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and various design changes are possible without departing from the scope of the invention.

For example, in the above-described embodiment, the jig receiving surface f0 against which the release knockout pin 90 (jig) is pressed when the resin coating portion 32 is removed from the mold after molding is formed on a specific surface of the coating portion main body 32m. Although only one surface (more specifically, the outer peripheral surface of the reduced diameter portion 60 of the intermediate large diameter portion 32ma) is shown, in addition to this specific surface, the other surface of the covering portion main body 32m Alternatively, the resin-coated portion 32 may be removed from the mold by pressing the release knockout pin 90 against it. However, even in this case, the other surface (that is, the second jig receiving surface) is set on a portion of the resin coating portion 32 different from the first and second functional surfaces f1, f2, f2'.

Further, in the above-described embodiment, the first functional surface f1 of the covering main body 32m has a pair of flat and parallel positioning surfaces 50, but the positioning surfaces 50 may not be parallel to each other. It does not necessarily have to be flat as long as it has a shape that can restrict the rotation of the fuel injection valve I with respect to the valve support hole 70 . Alternatively, there may be one positioning surface 50, or three or more.

In the above-described embodiment, the intermediate large diameter portion 32ma fitted in the valve support hole 70 has the first functional surface f1 for positioning the fuel injection valve I at a predetermined position around the central axis X with respect to the valve support hole 70. Although the configuration of the outer peripheral surface is shown, the first functional surface f1 of the present invention may be a portion other than the intermediate large diameter portion 32ma of the covering portion main body 32m as long as it is different from the jig receiving surface f0, or It may be provided at a site away from the valve support hole 70 . For example, the outer peripheral surface of the rear small diameter portion 32mc may function as the first functional surface f1 without functioning as the second functional surface f2' (that is, the fitting surface of the cushion ring 52). By providing, for example, at least one flat positioning surface on the outer peripheral surface of the portion 32mc and engaging this positioning surface with a corresponding flat positioning surface provided on the fuel distribution pipe 55, the fuel injection valve I It can be positioned at a predetermined position around the central axis X with respect to the valve support hole 70 .

Further, in the above embodiment, the coil housing H is divided into the first and second coil housing halves H1 and H2. However, the coil housing H may be integrated. A coil housing having a single axially extending slit-shaped gap formed on one side of the coil housing body may be used.

I...Electromagnetic fuel injection valve V...Valve assembly as a valve member X...Center axis f0 of fuel injection valve...Jig receiving surface f1 ... First functional surface f2, f2' Second functional surface ft Tapered surface 2 Valve casing 5 Fixed core 7 Valve hole 8 Valve seat 12 Movable core 14 Valve body 30 Coil 32 Resin coated portion 32m Coating portion main body 32c Coupler main body portion 33 Coupler terminal 50 Flat positioning surface portion 51 Seal ring 52 as an elastic ring Elastic ring cushion ring 70 as ... valve support hole 90 ... knockout pin as mold release jig

Claims (2)

A valve casing (2) having a valve seat (8) and a valve hole (7) at one end, a fixed core (5) provided at the other end of the valve casing (2), and the periphery of the fixed core (5) a coil (30) arranged in a body, a valve body (14) that cooperates with the valve seat (8) to open and close the valve hole (7), and the fixed core based on the magnetic force generated by the coil (30) A valve member (V) having a movable core (12) that is magnetically attracted to (5) to open the valve body (14); 32 m) and a resin coating part (32) molded with an insulating synthetic resin,
In an electromagnetic fuel injection valve fitted in a valve support hole (70) provided in an internal combustion engine (E),
The resin coating portion (32) includes a jig receiving surface (f0) against which a release jig (90) is pressed during the molding process of the resin coating portion (32), and the valve support hole (70). A first functional surface (f1) for positioning the fuel injection valve (I) at a predetermined position around the central axis (X) of the fuel injection valve (I), and an elastic ring ( 51, 52), and at least one second functional surface (f2, f2') at different positions on the outer peripheral portion of the covering body (32m), and at the coil (30) It has a coupler main body (32c) that holds the connected coupler terminal (33) and protrudes to one side from the outer peripheral portion of the covering main body (32m),
The first functional surface (f1) has at least one flat positioning surface (50) and is arranged closer to the coupler body (32) than the jig receiving surface (f0). two second functional surfaces (f2) are arranged closer to the valve seat (8) than the jig receiving surface (f0),
The radial distance of the jig receiving surface (f0) from the central axis (X) is shorter than the radial distance of the first functional surface (f1) from the central axis (X), and is set longer than the radial distance from the central axis (X) of the second functional surface (f2),
A stepped surface (61) formed between the jig receiving surface (f0) and the one second functional surface (f2) is held by an inner peripheral stepped portion (72) of the valve support hole (70). forming a ring engaging surface that can be engaged with the elastic ring (51) that is
The covering part body (32m) is a tapered surface ( ft) . 2. The electromagnetic coupling according to claim 1, wherein the flat positioning surface portion (50) is arranged at a position different from the coupler body portion (32c) in the circumferential direction of the covering portion body (32m). formula fuel injection valve.

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