Electromagnetic fuel injection valve

Abstract

The purpose of the present invention is to provide, at low cost, an electromagnetic fuel injection valve that suppresses the occurrence of an operation failure caused by contamination of a foreign object. An electromagnetic fuel injection valve 10 comprises: a rod 18; and a movable core 21 that is movable in the axial direction of the rod 18 and that has a through-hole 30 into which the rod 18 is inserted. The electromagnetic fuel injection valve is provided with a total of two annular guides 31 that form projections annularly provided in the circumferential direction of an inner circumferential surface 21A defined by the through-hole 30 of the movable core 21 and / or in the circumferential direction of an outer circumferential surface 18A of the rod 18 facing the inner circumferential surface 21A, that are arranged apart from each other in the axial direction of the rod 18, and that guide movement of the movable core 21 with respect to the rod 18.

Description

Electromagnetic fuel injection valve

[0001] The present invention relates to an electromagnetic fuel injection valve used in a fuel supply system.

[0002] For example, Patent Document 1 listed below describes an electromagnetic injection valve having a valve housing with a valve seat on one end side and a fixed core on the other end side, a rod arranged inside the valve housing, and a movable core that slides on the outer periphery of the rod.

[0003] In recent years, with the rise in fuel supply system pressure and the increasing precision of fuel injection performance due to multi-stage injection control, there is a need for measures to prevent malfunctions caused by foreign matter (contamination) getting caught in the sliding portion between the rod and moving core of the fuel injection valve.

[0004] Therefore, as a countermeasure against malfunctions caused by foreign matter getting caught in the sliding portion between the rod and the movable core, for example, NiP plating has been applied to the entire axial area of ​​the inner surface defined by the through hole of the movable core, and then Cr plating has been applied to both axial end portions of the inner surface in order to further improve durability.

[0005] Japanese Patent Application Laid-Open No. 2021-124075

[0006] However, conventional electromagnetic fuel injection valves have the problem of high manufacturing costs due to the need for complex surface treatments, such as the need to apply multiple layers of plating material to the entire inner surface defined by the through hole of the movable core.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electromagnetic fuel injection valve that is low cost and that prevents malfunctions due to the inclusion of foreign matter.

[0008] In order to achieve the above object, the electromagnetic fuel injection valve of the present invention comprises a rod and a movable core, and is provided with a total of two annular guide portions which form annular protrusions arranged along the circumferential direction of the inner surface defined by the through hole of the movable core and / or on the outer surface of the rod opposite the inner surface, and which are arranged spaced apart from each other in the axial direction of the rod to guide the movement of the movable core relative to the rod.

[0009] According to the present invention, it is possible to provide an electromagnetic fuel injection valve that is low in cost and that prevents malfunctions due to the inclusion of foreign matter.

[0010] Fig. 1 is a cross-sectional view of an electromagnetic fuel injection valve according to one embodiment of the present invention; Fig. 2 is an enlarged cross-sectional view of a main part of an electromagnetic fuel injection valve according to a first embodiment of the present invention; Fig. 3 is an enlarged cross-sectional view of a main part of an electromagnetic fuel injection valve according to a second embodiment of the present invention; Fig. 4 is an enlarged cross-sectional view of a main part of an electromagnetic fuel injection valve according to a third embodiment of the present invention;

[0011] [First embodiment] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 shows an electromagnetic fuel injection valve 10 according to one embodiment of the present invention.

[0012] As shown in FIG. 1 , an electromagnetic fuel injection valve 10 of the first embodiment includes a valve housing 13 in which a fuel injection hole 11 and a valve seat 12 are formed, a valve element 15 that enables fuel to be injected from the fuel injection hole 11 by lifting the valve element 15 from a valve-closed position in contact with the valve seat 12 to a valve-open position in response to excitation of a coil 14, and a return spring 16 that returns the valve element 15 to the valve-closed position in contact with the valve seat 12.

[0013] The valve element 15 is lifted to the valve open position by settling the overshoot and overshoot return that occur during the lift. The valve element 15 has a valve portion 17 that cooperates with the valve seat 12 and a rod 18 that is connected to the valve portion 17. The rod 18 is formed in a cylindrical shape that extends in the axial direction.

[0014] The electromagnetic fuel injection valve 10 also includes a hollow fixed core 19 connected to the upstream end of the valve housing 13, a movable core 21 facing an attraction surface 20 of the fixed core 19, having a through hole 30 into which the rod 18 is inserted, and movable in the axial direction of the rod 18, and a valve-opening stopper 22 fixed to the rod 18 and coming into contact with the movable core 21 attracted to the attraction surface 20 when the coil 14 is energized, thereby opening the valve body 15. A chromium (Cr) plating layer 34 is applied to the entire upper and lower surfaces of the movable core 21 (surfaces formed in a direction perpendicular to the axial direction of the rod 18).

[0015] A valve-closing stopper 23 is fixed to the rod 18, closer to the valve seat 12 than the valve-opening stopper 22. An auxiliary spring 24 is provided between the valve-opening stopper 22 and the movable core 21. The auxiliary spring 24 exerts a spring force that moves the movable core 21 away from the valve-opening stopper 22 and brings it into contact with the valve-closing stopper 23 when the coil 14 is not energized.

[0016] In this configuration, when the coil 14 is not energized, the valve portion 17 of the valve element 15 is seated on the valve seat 12 by the biasing force of the return spring 16, and the valve is in a closed state, as shown in Figure 1. The movable core 21 is brought into contact with the valve-closing stopper 23 by the biasing force of the auxiliary spring 24, and a predetermined gap is maintained between the movable core 21 and the fixed core 19.

[0017] When the coil 14 is energized in this state, the magnetic force generated thereby first attracts the movable core 21 to the fixed core 19 , compressing the auxiliary spring 24 , which is weaker than the return spring 16 , and the movable core 21 comes into contact with the valve-opening stopper 22 .

[0018] When the movable core 21 comes into contact with the valve-opening stopper 22, it quickly moves the valve-opening stopper 22 against the biasing force of the return spring 16, and then collides with the suction surface 20 to stop it. During this time, the rod 18 moves together with the valve-opening stopper 22, so that the valve portion 17 at the tip of the rod 18 lifts off the valve seat 12, and the valve is opened.

[0019] When the valve portion 17 opens, fuel is pressure-fed from a fuel pump (not shown) to a fuel supply tube 25 and passes through the inside of a pipe-shaped retainer 26, the hollow portion 27 of the fixed core 19, the side surface around the valve-opening stopper 22, the through hole 28 of the movable core 21, the inside of the valve housing 13, and the flat surface 29 around the valve portion 17, before being directly injected from the fuel injection hole 11 into the combustion chamber of the internal combustion engine.

[0020] Next, the sliding portion between the rod 18 and the movable core 21 into which the rod 18 is inserted will be described in detail. Figure 2 is an enlarged cross-sectional view of a main portion of the sliding portion between the rod 18 and the movable core 21 into which the rod 18 is inserted of the electromagnetic fuel injection valve 10 according to the first embodiment of the present invention. Note that one side (the right side in the figure) of the movable core 21 is omitted in Figure 2 (the same applies to Figures 3 and 4).

[0021] 2, two annular guide portions 31 are formed on the inner peripheral surface 21A defined by the through hole 30 of the movable core 21. The annular guide portions 31 regulate the swing range of the movable core 21 when the movable core 21 slides relative to the rod 18, and improve the linearity of the movable core 21 when it moves in the axial direction of the rod 18.

[0022] More specifically, on the inner surface 21A of the movable core 21, annular guide portions 31, 31 are respectively protruded from one axial end and the other axial end of the movable core 21 toward the radial center of the movable core 21 (which is common with the axis C of the rod 18).

[0023] Each annular guide portion 31 is a protrusion provided in an annular shape along the circumferential direction of the inner peripheral surface 21A of the movable core 21 in a direction perpendicular to the axial direction of the rod 18. In other words, the annular guide portion 31 is formed in an annular shape (circular ring shape) that is continuous and uninterrupted in the circumferential direction of the inner peripheral surface 21A of the movable core 21.

[0024] Each annular guide portion 31 is formed integrally with the movable core 21 from the inner peripheral surface 21A of the movable core 21 by injection molding or the like. Alternatively, the annular guide portion 31 may be formed by joining a separately manufactured annular guide portion 31 to the movable core 21 after the movable core 21 is manufactured.

[0025] In the cross-sectional view shown in Figure 2, each annular guide portion 31 has a first tapered surface 31A and a second tapered surface 31B that are inclined from the inner surface 21A of the movable core 21 toward the radial center of the movable core 21 (toward the rod 18), and has an arched shape in which the inner surface 21A side of the movable core 21 is wide (the axial length is large) and gradually becomes narrower (the axial length is small) toward the radial center of the movable core 21.

[0026] Each annular guide portion 31 has a top portion 31C that protrudes highest from the inner surface 21A of the movable core 21, a first tapered surface 31A (inner surface) that extends from one axial end of the top portion 31C close to the opposing annular guide portion 31 and inclined toward the inner surface 21A, and a second tapered surface 31B (outer surface) that extends from the other axial end of the top portion 31C away from the opposing annular guide portion 31 and inclined toward the inner surface 21A.It can also be said that as a whole, the annular guide portion 31 has a roughly trapezoidal, arched shape that gradually widens (the axial length gradually increases) from the top portion 31C toward the inner surface 21A of the movable core 21.

[0027] That is, in this embodiment, each annular guide portion 31 has a certain axial length at the top 31C and a wider bottom, so that it is an approximately trapezoidal annular protrusion having an upper base and a lower base.

[0028] Furthermore, it is preferable that the amount of protrusion of each annular guide portion 31 from the inner peripheral surface 21A of the movable core 21 toward the radial center of the movable core 21 be 20 to 50 μm. In this embodiment, the amount of protrusion of each annular guide portion 31 from the inner peripheral surface 21A of the movable core 21 toward the radial center of the movable core 21 is 25 μm.

[0029] Furthermore, the annular guide portion 31 may have, for example, a cross section that is approximately triangular or rectangular, curved, semicircular, or even a shape whose both side surfaces change in stages, and is not particularly limited as long as it can partially (locally) abut or be close to the outer surface 18A of the rod 18 or the inner surface 21A of the movable core 21 (it can be said that it slides when it abuts) and guide the movement (sliding movement) of the movable core 21 relative to the rod 18.

[0030] By forming a pair of annular guide portions 31, 31 at both axial ends of the inner peripheral surface 21A of the movable core 21, a radial gap 32 is formed between the tops 31C, 31C of the pair of annular guide portions 31, 31 and the outer peripheral surface 18A of the rod 18 in a direction perpendicular to the axial direction of the rod 18. The radial gap 32 is annular when the rod 18 is disposed at the radial center of the movable core 21 in the circumferential direction.

[0031] The radial dimension of the radial gap 32 (the radial length, meaning the distance from the outer peripheral surface 18A of the rod 18 to the top 31C of the annular guide portion 31) is defined as "t1".

[0032] The pair of annular guide portions 31, 31 are formed spaced apart from each other in the axial direction of the rod 18. Specifically, the pair of annular guide portions 31 are formed on the inner peripheral surface 21A of the movable core 21 near one opening of the through hole 30 (the inner peripheral edge of the one opening) and near the other opening (the inner peripheral edge of the one opening), respectively.

[0033] Therefore, an expanded gap portion 33 is formed between the pair of annular guide portions 31, 31, with a radial dimension t2 larger than the radial dimension t1 of the radial gap 32. Note that "t2" is the radial length, and refers to the distance from the outer peripheral surface 18A of the rod 18 to the inner peripheral surface 21A of the movable core 21.

[0034] The radial gap 32 and the gap expansion portion 33 are connected, and a portion of the fuel pumped by the fuel pump flows into the radial gap 32 and the gap expansion portion 33, passing between the movable core 21 and the rod 18.

[0035] Next, a description will be given of the operation and effect of the electromagnetic fuel injection valve 10 configured as described above. As described above, the two annular guide portions 31, 31 are formed on the inner circumferential surface 21A defined by the through hole 30 of the movable core 21 of the electromagnetic fuel injection valve 10.

[0036] Because these annular guide portions 31, 31 are formed, when the movable core 21 oscillates relative to the rod 18, that is, when the radial center of the movable core 21 and the axial center C of the rod 18 are not aligned (coincident) and the movable core 21 moves in a state in which it is tilted relative to the axial center C of the rod 18, only the top portion 31C of each annular guide portion 31 partially abuts against the outer peripheral surface 18A of the rod 18 (the entire inner peripheral surface 21A of the movable core 21 does not abut against the outer peripheral surface 18A of the rod 18), the contact area between the movable core 21 and the rod 18 can be reduced.

[0037] Therefore, the probability of foreign matter getting caught between the movable core 21 and the rod 18 can be reduced.

[0038] Furthermore, since each annular guide portion 31 is integrally formed from the inner surface 21A of the movable core 21, there is no need to apply multiple plating layers to prevent foreign matter from getting caught, which reduces manufacturing costs.

[0039] As a result, it is possible to provide an electromagnetic fuel injection valve 10 that is low in cost and that can suppress malfunctions caused by the inclusion of foreign matter.

[0040] Furthermore, when the movable core 21 swings relative to the rod 18, the distance between the top 31C of the annular guide portion 31 and the outer circumferential surface 18A of the rod 18 changes as the fuel passes between the movable core 21 and the rod 18. Therefore, if the movable core 21 swings in one direction perpendicular to the axial direction of the rod 18 while fuel is passing between the movable core 21 and the rod 18, the fuel present between the annular guide portion 31 and the rod 18 in that direction is pushed out (discharged) from between the annular guide portion 31 and the rod 18 by the annular guide portion 31.

[0041] As the fuel is pushed out from between the annular guide portion 31 and the rod 18 by the annular guide portion 31, the flow rate of the fuel increases, and the discharge performance of foreign matter contained in the fuel from between the rod 18 and the movable core 21 is improved.

[0042] Therefore, even if foreign matter contained in the fuel adheres to the inner peripheral surface 21A of the movable core 21 or the outer peripheral surface 18A of the rod 18, it is peeled off by the self-cleaning action of the passing fuel, thereby reducing the probability of foreign matter becoming caught between the rod 18 and the movable core 21.

[0043] Furthermore, by reducing the contact area between the rod 18 and the movable core 21, it is possible to reduce the coefficient of friction (amount of friction) between the rod 18 and the movable core 21. As a result, the movable core 21 can move (slide) smoothly relative to the rod 18.

[0044] The lubrication of the movable core 21 relative to the rod 18 is maintained by the fuel passing between the rod 18 and the movable core 21, but in a configuration in which the annular guide portion 31 is not formed on the inner surface 21A of the movable core 21, the contact area between the rod 18 and the movable core 21 is large, and it may be impossible to ensure sufficient lubrication of the movable core 21 relative to the rod 18.

[0045] In the electromagnetic fuel injection valve 10, the contact area between the rod 18 and the movable core 21 is reduced, so that the lubrication of the movable core 21 with respect to the rod 18 can be sufficiently ensured.

[0046] In addition, the annular guide portion 31 has a second tapered surface 31B that is inclined from the inner surface 21A toward the radial center, so that the fuel that collides with the annular guide portion 31 can be guided into the radial gap 32 while suppressing a decrease in its fluid pressure (suppressing pressure loss).

[0047] Therefore, the fuel pumped by the fuel pump passes between the movable core 21 and the rod 18 while maintaining its flow rate, thereby reducing the probability of foreign matter getting caught between the rod 18 and the movable core 21.

[0048] In this way, by forming the second tapered surface 31B as described above in the annular guide portion 31, the probability of foreign matter becoming caught between the rod 18 and the movable core 21 can be reduced, and measures to prevent foreign matter contained in the fuel from becoming caught can be taken at low cost.

[0049] In the electromagnetic fuel injection valve 10, the radial gap 32 and the gap expansion portion 33 are formed, so that the flow velocity of the fuel passing between the movable core 21 and the rod 18 increases (is made to increase). Therefore, it is possible to reduce the probability that foreign matter contained in the fuel will become caught between the movable core 21 and the rod 18.

[0050] More specifically, the provision of the annular guide portion 31 forms a radial gap 32 whose radial dimension t1 is shorter than the radial dimension t2 of the gap expansion portion 33, and therefore the cross-sectional area of ​​the fuel flow path temporarily decreases when the fuel passes between the rod 18 and the movable core 21. Therefore, the flow velocity of the fuel passing between the movable core 21 and the rod 18 increases when it passes through the radial gap 32.

[0051] As described above, by increasing the flow rate of the fuel passing between the movable core 21 and the rod 18, the self-cleaning action of the fuel is enhanced, and the probability of foreign matter becoming caught between the movable core 21 and the rod 18 can be reduced.

[0052] Second Embodiment A second embodiment will be described below, with the same configuration as that of the electromagnetic fuel injection valve 10 according to the first embodiment of the present invention being omitted where appropriate.

[0053] FIG. 3 is an enlarged cross-sectional view of a main part of an electromagnetic fuel injection valve 10A according to a second embodiment of the present invention, showing an enlarged sliding portion between a rod 18 and a movable core 21 into which the rod 18 is inserted.

[0054] As shown in FIG. 3, an electromagnetic fuel injection valve 10A according to the second embodiment differs from the first embodiment in that two annular guide portions 41 are formed on the outer peripheral surface 18A of the rod 18.

[0055] The annular guide portion 41 is a protrusion provided in an annular shape along the circumferential direction of the outer peripheral surface 18A of the rod 18 in a direction perpendicular to the axial direction of the rod 18. In other words, the annular guide portion 41 is formed in an annular shape (circular ring shape) that is continuous and seamless in the circumferential direction of the outer peripheral surface 18A of the rod 18.

[0056] In the cross-sectional view shown in Figure 3, the annular guide portion 41 has a first tapered surface 41A and a second tapered surface 41B that are inclined from the outer peripheral surface 18A of the rod 18 toward the movable core 21 (toward a direction away from the outer peripheral surface 18A of the rod 18), and has an arched shape that is wide on the side of the outer peripheral surface 18A of the rod 18 and gradually narrows toward the movable core 21.

[0057] Each annular guide portion 41 has a top 41C that protrudes the highest from the outer peripheral surface 18A of the rod 18 and has a slightly rounded curved shape, a first tapered surface 41A (inner surface) that is close to the opposing annular guide portion 41 and inclined from the top 41C toward the outer peripheral surface 18A, and a second tapered surface 41B (outer surface) that is away from the opposing annular guide portion 41 and inclined from the top 41C toward the outer peripheral surface 18A, and it can be said that the entire portion has a mountain-like shape that gradually widens (the axial length gradually increases) from the top 41C toward the outer peripheral surface 18A of the rod 18.

[0058] In addition, each annular guide portion 41 may be formed integrally with the rod 18 from the outer surface 18A of the rod 18 by injection molding, etc., or may be provided by joining an annular guide portion 41 manufactured separately after the rod 18 is manufactured.

[0059] A pair of annular guide portions 41, 41 is formed in the axial direction of the outer peripheral surface 18A of the rod 18, and a radial gap 42 is formed between the tops 41C, 41C of the pair of annular guide portions 41, 41 and the inner peripheral surface 21A of the movable core 21 in a direction perpendicular to the axial direction of the rod 18. The radial gap 42 is annular when the rod 18 is disposed at the radial center of the movable core 21 in the circumferential direction.

[0060] The radial dimension of the radial gap 42 (the radial length, meaning the distance from the inner circumferential surface 21A of the movable core 21 to the top 41C of the annular guide portion 41) is defined as "t1".

[0061] The pair of annular guide portions 41, 41 are formed spaced apart from each other in the axial direction of the rod 18. Specifically, the pair of annular guide portions 41, 41 are formed on the outer peripheral surface 18A of the rod 18 that faces the inner peripheral surface 21A of the movable core 21 at positions corresponding to the vicinity of one opening of the through hole 30 and the vicinity of the other opening thereof, respectively.

[0062] Therefore, an expanded gap portion 43 is formed between the pair of annular guide portions 41, 41, with a radial dimension t2 larger than the radial dimension t1 of the radial gap 42. Note that "t2" is the radial length, and refers to the distance from the outer peripheral surface 18A of the rod 18 to the inner peripheral surface 21A of the movable core 21.

[0063] The radial gap 42 and the gap expansion portion 43 are connected, and a portion of the fuel pumped by the fuel pump flows into the radial gap 42 and the gap expansion portion 43, passing between the movable core 21 and the rod 18.

[0064] Next, the operation and effect of the electromagnetic fuel injection valve 10A having the above-described configuration will be described. As described above, the two annular guide portions 41, 41 are formed on the outer peripheral surface 18A of the rod 18 of the electromagnetic fuel injection valve 10A of the second embodiment.

[0065] By providing these annular guide portions 41, 41, the electromagnetic fuel injection valve 10A of the second embodiment achieves the same effects as the electromagnetic fuel injection valve 10 of the first embodiment.

[0066] The electromagnetic fuel injection valve 10 of the first embodiment has two annular guide portions 31 formed on the inner surface 21A of the movable core 21, and the electromagnetic fuel injection valve 10A of the second embodiment has two annular guide portions 41 formed on the outer surface 18A of the rod 18, but the annular guide portions 31, 41 may be formed one on each of the inner surface 21A of the movable core 21 and the outer surface 18A of the rod 18, so that a total of two annular guide portions 31, 41 are formed.

[0067] As described above, according to the present invention, it is possible to reduce the probability of foreign matter becoming caught between the rod 18 and the movable core 21 without performing complex surface treatment on the entire inner peripheral surface of the movable core. Therefore, it is possible to provide the electromagnetic fuel injection valve 10, 10A that suppresses malfunctions due to foreign matter at low cost.

[0068] Third Embodiment A third embodiment will be described below, and the description of the same components as those of the electromagnetic fuel injection valves 10 and 10A according to the first and second embodiments of the present invention will be omitted where appropriate.

[0069] FIG. 4 is an enlarged view of a main part of an electromagnetic fuel injection valve 10B according to a third embodiment of the present invention, showing an enlarged sliding portion between the rod 18 and the movable core 21 into which the rod 18 is inserted.

[0070] 4, in the electromagnetic fuel injection valve 10B according to the third embodiment, each annular guide portion 51 is formed of a chromium (Cr) plating layer, which improves the lubricity of the movable core 21 relative to the rod 18, reduces the coefficient of friction (amount of friction) between the annular guide portion 51 and the rod 18, and ensures sufficient strength of the annular guide portion.

[0071] The annular guide portion 51 is formed of a chrome (Cr) plating layer. The chrome plating layer that becomes the annular guide portion 51 can be formed by spray-painting chrome plating on the inner circumferential surface 21A of the movable core 21 after masking the area where the gap expansion portion 33 is to be formed.

[0072] In this embodiment, each annular guide portion 51 is formed only from a chrome plating layer, and therefore, compared to a configuration consisting of multiple plating materials such as a conventional electromagnetic fuel injection valve, it is possible to reduce the occurrence of malfunctions due to the inclusion of foreign matter at a lower cost.

[0073] In this embodiment, the plated layer is formed of a chromium plated layer, but other than the chromium plated layer, a nickel plated layer or the like may also be used.

[0074] 10, 10A, 10B... Electromagnetic fuel injection valve 18... Rod 18A... Outer peripheral surface 21... Movable core Inner peripheral surface... 21A 30... Through hole 31, 41, 51... Annular guide portion 32, 42... Radial gap 33, 43... Gap expansion portion

Claims

1. 1. An electromagnetic fuel injection valve comprising: a rod; and a movable core having a through hole into which the rod is inserted and movable in an axial direction of the rod, a top portion that is annularly provided along the circumferential direction of an inner peripheral surface defined by the through hole of the movable core and that protrudes highest from the inner peripheral surface; and / or a ring-shaped guide portion provided in a circumferential direction on the outer peripheral surface of the rod facing the inner peripheral surface, the ring-shaped guide portion being spaced apart from each other in the axial direction of the rod and forming a protrusion-like shape that gradually widens from both ends of the top toward the axial direction, and the ring-shaped guide portion being spaced apart from each other in the axial direction of the rod, and guiding the movement of the movable core relative to the rod.

2. 2. The electromagnetic fuel injection valve according to claim 1, a radial gap is formed in a direction perpendicular to the axial direction of the rod between a top of the annular guide portion provided on the outer peripheral surface of the rod and an inner peripheral surface of the movable core, or between a top of the annular guide portion provided on the inner peripheral surface of the movable core and the outer peripheral surface of the rod in a radial direction, An electromagnetic fuel injection valve characterized in that a gap expansion portion is formed between the two annular guide portions in a direction perpendicular to the axial direction of the rod, the gap expansion portion being connected to the radial gap and having a radial dimension larger than that of the radial gap.

3. 3. The electromagnetic fuel injection valve according to claim 1, 10. An electromagnetic fuel injection valve, wherein the annular guide portion is formed into a protrusion shape made of a plating layer.