JP3819741B2 - Electromagnetic fuel injection valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic fuel injection valve mainly used for a fuel supply system of an internal combustion engine, and in particular, a valve seat member having a valve hole and a conical valve seat and a guide hole connected to the inner end of the valve hole ; The valve housing has one end connected to the other end of the valve seat member, a fixed core connected to the other end of the valve housing, and is movable in the axial direction to the valve housing so as to face the fixed core. A valve core made of a steel ball that opens and closes the valve hole in cooperation with the valve seat, and a valve stem that integrally connects the movable core and the valve body. provided, the valve assembly, the outer periphery and the outer periphery of the valve stem of the valve body, axially spaced, first and second sliding shaft which is guided by the guide hole of the valve seat member The present invention relates to an improvement of an electromagnetic fuel injection valve having a portion .
[0002]
[Prior art]
Such an electromagnetic fuel injection valve is already known as disclosed in, for example, FIG. 1 of JP-A-56-107956.
[0003]
[Problems to be solved by the invention]
In Such an electromagnetic fuel injection valve of the valve assembly, a valve body cooperating with the valve seat, the valve stem you abuts against the valve housing, both high hardness material to the need of imparting abrasion resistance However, if both are made of high-hardness materials, cracks often occur in the welded portion if both are to be efficiently and firmly joined by laser beam or electron beam welding. The main reason for this is thought to be that the high-hardness material becomes re-quenched due to the above-mentioned welding and generates a large strain.
[0004]
The present invention has been made in view of the mentioned circumstances, the portion that requires wear resistance of the valve assembly while using the high hardness material without the occurrence of cracks, the valve assembly It is an object of the present invention to provide an electromagnetic fuel injection valve capable of coupling the constituent members of each other by a laser beam or an electron beam.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a valve seat member having a valve hole , a conical valve seat connected to the inner end of the valve hole, and a guide hole, and one end portion at the other end portion of the valve seat member. A valve core that couples to the other end of the valve housing, a movable core that is accommodated in the valve housing so as to be axially movable so as to face the fixed core, and the valve seat. A valve body made of a steel ball that operates to open and close the valve hole and a valve stem that integrally connects the movable core and the valve body, the valve assembly including the valve body An electromagnetic fuel injection valve in which first and second sliding shaft portions guided by guide holes in the valve seat member are formed on the outer periphery of the valve stem and the outer periphery of the valve stem at an axial interval. in the valve, the valve stem, a high hardness material made of the valve body and the timber, before A first valve stem element for coupling at one end to said movable core which has integrally a positioning shaft portion which projects toward the valve seat side from the second sliding shaft portion and the second sliding shaft portion, the valve body which is made of low-hardness material than, constituted by a second valve stem element that binds both ends by welding with a laser beam or an electron beam to the positioning shaft portion and the valve body of the first valve stem element, each section thereof The first feature is that the valve assembly is constructed by welding by heat input from the second valve stem element side during welding .
[0006]
According to the first feature, by the valve body及beauty first valve stem element in the valve assembly and hardened materials made, it is possible to increase their abrasion resistance. In addition, the second valve stem element made of low hardness material is interposed between the first valve stem element made of high hardness material and the valve body, and they are joined by laser welding or beam welding. Heat input from the side of the second valve stem element made of material avoids re-quenching of the first valve stem element made of high-hardness material and the valve body and reduces distortion that occurs somewhat at each weld. It can be absorbed by the second valve stem element made of a hard material to prevent cracking at each weld. Further, since the positioning shaft portion is provided on the first valve stem element, positioning when coupled with the second valve stem element can be easily performed. As a result, a highly durable valve assembly can be efficiently manufactured.
[0007]
The present invention, in addition to the first feature, forming said the second valve stem element, said first valve stem component and positioning hole into which the positioning shaft portion so as to temporarily fixed coaxially is press-fitted When welding the first and second valve stem elements, the irradiation point of the laser beam or electron beam is offset from the boundary line of the first and second valve stem elements toward the second valve stem element side. A second feature is that the second valve stem elements are heated and connected by melting .
[0008]
According to the second feature, prior to the welding of the first and second valve stem elements, the respective positioning shaft portions and the positioning holes are pressed into each other to maintain high coaxial accuracy of both valve stem elements. In other words, the following welding operations can be easily performed, which can contribute to improving the accuracy of the valve assembly. And since welding is performed by inputting heat from the second valve stem element side made of a low hardness material, the penetration is performed relatively slowly, and the occurrence of weld cracks can be prevented as described above. it can.
[0009]
Further, according to the present invention, in addition to the first or second feature, the guide hole of the valve seat member includes first and second guide holes arranged coaxially with the valve seat at a distance from each other. and the second sliding shaft portion have been adapted to slidably fitted to the first and second guide holes, provided fuel flow part respectively to the first and the outer periphery of the second sliding shaft This is a third feature.
[0010]
According to the third feature, the opening and closing posture of the valve assembly is properly maintained by sliding the first and second sliding shaft portions along the first and second guide holes of the valve seat member. In combination with this, an appropriate valve opening stroke can be obtained by contact of the first valve stem element with the valve housing. Moreover, the valve body having a first sliding shaft, and a first valve stem element having a second sliding shaft portion, because both are made of hardened materials, their abrasion resistance is high, the valve assembly It can greatly contribute to the improvement of durability.
[0011]
Furthermore, the present invention is characterized in that, in addition to any of the first to third features, the opposed portions of the first valve stem element and the movable core are coupled to each other by press-fitting and caulking. .
[0012]
According to the fourth feature, the first valve stem element and the movable core can be firmly coupled without changing the magnetic characteristics of the movable core.
[0013]
The fuel circulation portion corresponds to first and second chamfered portions 18 ₁ and 18 ₂ in an embodiment of the present invention described later.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.
[0015]
FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve for an internal combustion engine according to an embodiment of the present invention, FIG. 2 is an enlarged view of the valve assembly peripheral part (part 2 of FIG. 1) of FIG. 1, and FIG. 4 is an exploded longitudinal sectional view of the valve assembly, FIG. 4 is an enlarged view of a part 4 in FIG. 2, and FIG. 5 is an enlarged view of a part 5 in FIG.
[0016]
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 a cylindrical valve housing 2 (magnetic material) and a lower end portion of the valve housing 2. The valve seat member 3 has a bottom cylindrical shape, and a cylindrical fixed core 5 that is liquid-tightly coupled to the upper end of the valve housing 2 with an annular spacer 4 interposed therebetween.
[0017]
The 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 on both end faces of the spacer 4 and are welded all around the liquid.
[0018]
A first fitting tube portion 3a and a second fitting tube portion 2a are formed at opposite ends of the valve seat member 3 and the valve housing 2, respectively. The first fitting cylinder 3a is press-fitted together with the stopper plate 6 into the second fitting cylinder 2a, and the stopper plate 6 is sandwiched between the valve housing 2 and the valve seat member 3. At that time, in particular, the valve seat member 3 and the stopper plate 6 are made of martensitic stainless steel (for example, JIS SUS440C) because of the need for wear resistance. After that, by performing laser welding or beam welding over the entire circumference of the corner sandwiched between the outer peripheral surface of the first fitting tube portion 3a and the end surface of the second fitting tube portion 2a, the valve housing 2 and the valve seat member 3 Are liquid-tightly coupled to each other.
[0019]
The valve seat member 3 includes a valve hole 7 opened at a lower end surface thereof, a conical valve seat 8 connected to the inner end of the valve hole 7, and a valve seat 8 connected to a large diameter portion of the valve seat 8. a first guide hole 9 ₁ coaxial cylindrical, and a cylindrical second guide hole 9 of ₂ arranged from the first guide hole 9 ₁ coaxially therewith away upwards.
[0020]
A steel plate injector plate 10 having a plurality of fuel injection holes 11 communicating with the valve hole 7 is welded to the lower end surface of the valve seat member 3 in a liquid-tight manner.
[0021]
In the valve housing 2, the valve seat member 3 and the spacer 4, a valve assembly V which cooperates with the fixed core 5, the valve seat 8 and the stopper plate 6 is accommodated.
[0022]
As shown in FIGS. 2 and 3, the valve assembly V includes a movable core 12 that faces the lower end surface of the fixed core 5, a steel ball valve body 16 that can be seated on the valve seat 8, and these movable cores. 12 and a valve stem 15 integrally connecting the valve body 16. The valve stem 15 includes a first valve stem element 15 a coupled to the movable core 12, and a second valve stem element 15 b that connects the first valve stem element 15 a and the valve body 16. At this time, the first valve stem element 15a and the valve body 16 are made of a hard material such as martensitic stainless steel (JIS SUS440C) because of the necessity of wear resistance, and on the contrary, the second valve stem element 15b. Is made of a low hardness material such as ferritic stainless steel (JIS SUS410L).
[0023]
The outer peripheral surface of the valve body 16, a first sliding shaft 17 ₁ slidably fitted in the first guide hole 9 _1, the fuel be in the first outer circumference of the sliding shaft portion 17 _{1 1} a plurality of first chamfered portion 18 to allow the flow is formed. The first valve stem element 15a includes a large-diameter connecting shaft portion 40, a stopper flange 42 connected to the lower end of the connecting shaft portion 40 via a first neck portion 41, and a second neck portion connected to the lower end of the stopper flange 42. a second sliding shaft portion 17 ₂ continuous through the part 43, configured by arranging a small-diameter positioning shaft portion 44 projecting from the lower end surface of the second sliding shaft portion 17 ₂ coaxially. Then, after the connecting shaft portion 40 is press-fitted into the connecting hole 45 formed in the lower end surface of the movable core 12, the lower end peripheral portion 12 a of the movable core 12 is caulked toward the first neck portion 41, thereby the first valve stem. Element 15a and movable core 12 are joined together.
[0024]
The stopper flange 42 is opposed to the lower surface of the stopper flange 42 by inserting the first neck portion 41 into the U-shaped notch 6 a of the stopper plate 6.
[0025]
The second sliding shaft portion 17 _2, the valve seat member 3 and the second guide hole 9 ₂ slidably fitted in the, in its outer peripheral surface, the second chamfered portion more to allow the flow of fuel 18 ₂ is formed.
[0026]
The second valve stem element 15b is formed with a bottomed positioning hole 46 opened at its upper end surface and a conical positioning recess 47 opened at its lower end surface. And after stopping by press-fitting the position-decided Me shank 44 of the first valve stem element 15a provisional positioning holes 46, by performing laser welding or beam welding in the press-fitting the periphery, the first and second valve stem element 15a and 15b are integrally connected to each other. Further, after engaging a part of the spherical surface of the valve body 16 with the positioning recess 47, laser welding or beam welding is applied to the peripheral edge of the engagement so that the second valve stem element 15b and the valve body 16 are integrated with each other. Combined.
[0027]
As shown in FIG. 4, in welding between the first and second valve stem elements 15a and 15b by laser welding or a beam, the irradiation point P of the beam B is set to the first and second valve stem elements 15a and 15b. The second valve stem element 15b made of a low hardness material is offset from the boundary line toward the second valve stem element 15b made of a low hardness material, and the penetration W by the beam B is changed from the second valve stem element 15b made of a low hardness material to the first valve stem element 15a side made of a high hardness material. It is better to spread it.
[0028]
Further, as shown in FIG. 5, also in welding between the second valve stem element 15b and the valve body 16 by laser welding or a beam, the irradiation point P of the beam B is defined as the boundary between the second valve stem element 15b and the valve body 16. The second valve stem element 15b made of low hardness material is offset from the line toward the second valve stem element 15b side, so that the penetration W by the beam B spreads from the second valve stem element 15b made of low hardness material to the valve body 16 side made of high hardness material. Good.
[0029]
In this case, the first valve stem element 15a and the valve body 16 made of a hard material are not subjected to direct heat input by the beam B, so that the melting is performed relatively slowly, and therefore, re-quenching is performed. The state is suppressed, and the distortion that occurs more or less is absorbed by the second valve stem element 15b made of a low-hardness material, thereby preventing the weld from cracking.
[0030]
The first and second sliding shaft portions 17 ₁ , 17 ₂ and the first and second chamfered portions 18 ₁ , 18 ₂ are processed after the completion of the welding operation of each of the above parts. Desirable for ensuring high accuracy.
[0031]
1 and 2 again, a gap g corresponding to the valve opening stroke of the valve element 16 is provided between the stopper plate 6 and the stopper flange 42 when the valve element 16 is closed, that is, when the valve element 16 is seated. It is done. On the other hand, there is a gap between the fixed core 5 and the movable core 12 to avoid contact between the cores 5 and 12 even when the valve body 16 is opened, that is, when the valve body 16 is separated from the valve seat 8. Provided.
[0032]
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 in the hollow portion 21 in the closing direction of the valve body 16, that is, in the seating direction on the valve seat 8. A coiled valve spring 22 and a pipe-shaped retainer 23 that supports the upper end of the valve spring 22 are accommodated.
[0033]
At this time, a positioning recess 24 for receiving the lower end portion of the valve spring 22 is formed on the upper end surface of the movable core 12. The set load of the valve spring 22 is adjusted by the press-fitting depth of the retainer 23 into the hollow portion 21.
[0034]
An inlet cylinder 26 having a fuel inlet 25 communicating with the hollow portion 21 of the fixed core 5 via a pipe-shaped retainer 23 is integrally connected to the upper end of the fixed core 5, and a fuel filter 27 is connected to the fuel inlet 25. Installed.
[0035]
A coil assembly 28 is fitted on the outer periphery of the spacer 4 and the fixed core 5. The coil assembly 28 includes a bobbin 29 fitted to the outer peripheral surfaces of the spacer 4 and the fixed core 5 and a coil 30 wound around the bobbin 29. A coil housing 31 surrounding the coil assembly 28 is provided. One end is joined to the outer peripheral surface of the valve housing 2 by welding.
[0036]
Coil housing 31, the coil assembly 28 and the fixed core 5 is embedded in the synthetic resin of the cover 32, the intermediate portion of the covering member 32, a coupler 34 which example Bei connection terminal 33 connected to the coil 30 It is connected continuously.
[0037]
A seal positioning ring 36 made of synthetic resin that contacts the lower end of the covering body 32 is fitted to the outer periphery of the valve housing 2 exposed downward from the covering body 32. A synthetic resin cap 35 is elastically fitted to the front end of the valve seat member 3, and an O-ring 37 that is in close contact with the outer peripheral surface of the valve seat member 3 is interposed between the cap 35 and the seal positioning ring 36. Installed. The O-ring 37 is in close contact with the inner peripheral surface of the mounting hole when the electromagnetic fuel injection valve I is mounted in a fuel injection valve mounting hole of an intake manifold (not shown) of the engine.
[0038]
Next, the operation of this embodiment will be described.
[0039]
As shown in FIG. 2, when the coil 30 is demagnetized, the movable core 12 and the valve body 16 are pressed forward by the urging force of the valve spring 22, and the valve body 16 is seated on the valve seat 8. Therefore, the high-pressure fuel supplied into the casing 1 through the fuel filter 27 and the inlet cylinder 26 stands by in the casing 1.
[0040]
When the coil 30 is energized by energization, the magnetic flux generated by the coil 30 sequentially travels through the fixed core 5, the coil housing 31, the valve housing 2, and the movable core 12, and the magnetic core is attracted to the fixed core 5 together with the valve body 16 by the magnetic force. since the valve seat 8 is opened, the high pressure fuel in the casing 1 passes through the second chamfered portion 18 ₂ and the first chamfered portion 18 _first valve hole 7 through the valve body 16 of the valve stem 15, the fuel injection holes 11 From the engine toward the intake valve of the engine. At this time, when the stopper flange 42 of the valve assembly V abuts against the stopper plate 6 fixed to the valve housing 2, the valve opening stroke of the valve body 16 is defined.
[0041]
When the coil 30 is returned to the demagnetized state again, the valve assembly V is returned to the state shown in FIG. 2 by the urging force of the valve spring 22, the valve body 16 is seated on the valve seat 8, and the fuel injection is stopped.
[0042]
During this time, the valve assembly V is opened and closed by sliding the first and second sliding shaft portions 17 ₁ and 17 ₂ along the first and second guide holes 9 ₁ and 9 ₂ of the valve seat member 3. Since the posture is properly maintained, the valve seat 8 can be accurately opened and closed, and the fuel injection amount can be accurately controlled according to the valve opening time.
[0043]
Moreover, the valve seat 8, the first and second guide holes ₉ 1, _{9 2} valve seat member 3 having a first sliding shaft part 17 _first valve body 16 having a second sliding shaft portion 17 ₂ and the stopper flange the first valve stem element 15a having 42 and stopper plate 6, because all is made high hardness materials, high their abrasion resistance, cotton proper closing position and valve opening stroke of the valve assembly V in the long-term Can be maintained.
[0044]
Further, the second valve stem element 15b made of low hardness material is interposed between the first valve stem element 15a made of high hardness material and the valve body 16, and they are coupled by laser welding or beam welding as described above. By avoiding the re-quenched state of the first valve stem element 15a and the valve body 16 made of a high hardness material, the second valve stem element 15b made of a low hardness material absorbs distortion generated in each welded portion. , It is possible to prevent the occurrence of cracks in each weld.
[0045]
Further, when the first and second valve stem elements 15a and 15b are welded, the respective positioning shaft portions 44 and the positioning holes 46 are press-fitted into each other and temporarily fixed, so that the high coaxial accuracy of both valve stem elements 15a and 15b is achieved. This makes it possible to easily perform the welding operation. As a result, the valve assembly V having high welding strength and high accuracy can be provided.
[0046]
Furthermore, the first valve stem element 15a and the movable core 12 are coupled to each other by press-fitting of the positioning shaft portion 44 and the positioning hole 46 formed on the respective opposing surfaces and caulking of the lower peripheral edge of the movable core 12. The coupling between the two can be made strong without changing the magnetic characteristics of the movable core 12.
[0047]
The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention .
[0048]
【The invention's effect】
As described above, according to the first feature of the present invention, the valve seat member having the valve hole, the conical valve seat connected to the inner end of the valve hole, and the guide hole, and the other end portion of the valve seat member. A valve housing coupled to one end of the valve housing, a fixed core coupled to the other end of the valve housing, a movable core accommodated in the valve housing so as to be axially movable so as to face the fixed core, the valve A valve body made of a steel ball that opens and closes the valve hole in cooperation with a seat, and a valve assembly that integrally connects the movable core and the valve body, the valve assembly includes: An electromagnetic fuel injection valve solenoid having first and second sliding shaft portions formed in the outer periphery of the valve body and the outer periphery of the valve stem at axial intervals and guided by guide holes in the valve seat member. in formula fuel injection valve, the valve stem, a high hardness material made of the valve body and the timber A first valve stem element for coupling at one end to the movable core and having a second sliding shaft portion and the second sliding shaft portion integrally positioning shaft portion which projects toward the valve seat side, the valve than the body be made of a low hardness material, constituted by a second valve stem element that binds both ends by welding with a laser beam or an electron beam to the positioning shaft portion and the valve body of the first valve stem element, the When welding each part, the valve assembly is configured by welding and joining by applying heat from the second valve stem element side . Therefore, the valve body in the valve assembly and the first valve stem element having the stopper flange are raised. The wear resistance can be enhanced by using a hard material. In addition, the second valve stem element made of low hardness material is interposed between the first valve stem element made of high hardness material and the valve body, and they are joined by laser welding or beam welding. Heat input from the side of the second valve stem element made of material avoids re-quenching of the first valve stem element made of high-hardness material and the valve body and reduces distortion that occurs somewhat at each weld. It can be absorbed by the second valve stem element made of a hard material to prevent cracking at each weld. Further, since the positioning shaft portion is provided on the first valve stem element, positioning when coupled with the second valve stem element can be easily performed. As a result, a highly durable valve assembly can be efficiently manufactured.
[0049]
According to a second aspect of the present invention, in addition to the first feature, wherein the second valve stem element, the positioning shaft portion so as to temporarily fixed at the first valve stem element and coaxially press-fitted When the first and second valve stem elements are welded, the irradiation point of the laser beam or the electron beam is set to be higher than the boundary line of the first and second valve stem elements. Since the heat is input by offsetting to the element side and the second valve stem element is melted and joined , the positioning shaft and the positioning hole are press-fitted into each other prior to welding of the first and second valve stem elements. By doing so, while maintaining the high coaxial accuracy of both valve stem elements, the next welding operation can be easily performed, which can contribute to the improvement of the accuracy of the valve assembly. And since welding is performed by inputting heat from the second valve stem element side made of a low hardness material, the penetration is performed relatively slowly, and the occurrence of weld cracks can be prevented as described above. it can.
[0050]
Further, according to the third feature of the present invention, in addition to the first or second feature, the first and second guides in which the guide hole of the valve seat member is arranged coaxially with the valve seat at a distance from each other. consists hole, said first and second sliding shaft portion have been adapted to slidably fitted to the first and second guide holes, the first and the outer periphery of the second sliding shaft since fuel flow part are respectively provided, by sliding along the first and second sliding shaft to the first and second guide hole of the valve seat member, properly opening and closing position of the valve assembly In combination with this, an appropriate valve opening stroke can be obtained by the contact of the stopper flange with the stopper plate. Moreover, since the valve body having the first sliding shaft portion, the second sliding shaft and the first valve stem element having the stopper flange are all made of a hard material, their wear resistance is high, and the valve assembly This can greatly contribute to the improvement of solid durability.
[0051]
Furthermore, according to the fourth feature of the present invention, in addition to any of the first to third features, the opposing portions of the first valve stem element and the movable core are coupled by press-fitting and caulking. The first valve stem element and the fixed core can be firmly coupled without changing the magnetic characteristics of the core.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve for an internal combustion engine according to an embodiment of the present invention.
FIG. 2 is an enlarged view of the periphery of the valve assembly in FIG. 1 (part 2 in FIG. 1).
FIG. 3 is an exploded vertical sectional view of the valve assembly.
4 is an enlarged view of part 4 in FIG. 2;
FIG. 5 is an enlarged view of part 5 in FIG. 2;
[Explanation of symbols]
I ... Electromagnetic fuel injection valve V ... Valve assembly 2 ... Valve housing 3 ... Valve seat member 5 ... Fixed core 6 ... · Stopper plate 7 ··· Valve hole 8 ··· Valve seat 9 ₁ ··· First guide hole 9 ₂ ··· Second guide hole 12 ··· movable core 15 ··· · Valve stem 15a · · · first valve stem element 15b · · · second valve stem element 16 · · · valve body
17 ₁ ... First sliding shaft
17 ₂ ... 2nd sliding shaft part 1 8 ₁ ... Flowing part of fuel (first chamfered part)
1 8 ₂ ... Fuel distribution part (second chamfer)
42 ... Stopper flange 44 ... Positioning shaft part 46 ... Positioning hole

Claims (4)

A valve seat member (3) having a valve hole (7), a conical valve seat (8) connected to the inner end of the valve hole (7), and guide holes (9 ₁ , 9 ₂ ), and the valve seat member A valve housing (2) having one end connected to the other end of (3), a fixed core (5) connected to the other end of the valve housing (2), and facing the fixed core (5) A valve body made of a steel ball that opens and closes the valve hole (7) in cooperation with the movable core (12) accommodated in the valve housing (2) so as to be axially movable and the valve seat (8) 16), as well as these movable core (12) and the valve body (16) and a valve assembly comprising a valve stem (15) connecting together (V) between said valve assembly (V), wherein Guide holes (9 ₁ , 9 ₂ ) of the valve seat member (3) are spaced axially around the outer periphery of the valve body (16) and the outer periphery of the valve stem (15). In the electromagnetic fuel injection valve formed with the first and second sliding shaft portions (17 ₁ , 17 ₂ ) guided by
Said valve stem (15),
The valve body (16) is made of the same material as the hard material, and the second slide shaft portion (17 ₂ ) and the second slide shaft portion (17 ₂ ) are disposed on the valve seat (8) side. A first valve stem element (15a) integrally having a positioning shaft portion (44) projecting toward the end and having one end coupled to the movable core (12);
Which is made of low-hardness material than the valve body (16), the positioning shaft portion of the first valve stem element (15a) (44) and the laser beam both end to said valve body (16) (B) or electronic A second valve stem element (15b) joined by welding with a beam,
The electromagnetic fuel injection valve is characterized in that the valve assembly (V) is configured by welding and joining the respective parts by welding from the second valve stem element (15b) side . The electromagnetic fuel injection valve according to claim 1,
Wherein the second valve stem element (15b), forming the first valve stem element (15a) and the positioning hole into which the positioning shaft portion so as to temporarily fixed coaxially (44) is press-fitted (46) In the welding of the first and second valve stem elements (15a, 15b), the irradiation point (P) of the laser beam (B) or electron beam is set to the first and second valve stem elements (15a, 15b). An electromagnetic fuel injection valve characterized in that heat is input by being offset to the second valve stem element (15b) side with respect to the boundary line, and the second valve stem element (15b) is coupled by melting (W) . The electromagnetic fuel injection valve according to claim 1 or 2,
Guide hole of the valve seat member (3) ₍₉ 1, _{9 2)} comprises a first and a second guide hole the valve seat (8) arranged at intervals coaxially _{(9 1, 9} 2) the first and second sliding shaft portion ₍₁₇ 1, 17 ₂₎ have been adapted to slidably fitted to the first and second guide holes ₍₉ 1, _{9 2),} these first An electromagnetic fuel injection valve characterized in that fuel circulation portions (18 ₁ , 18 ₂ ) are respectively provided on the outer circumferences of the first and second sliding shaft portions (17 ₁ , 17 ₂ ). The electromagnetic fuel injection valve according to any one of claims 1 to 3,
Electromagnetic fuel injection valve, wherein the opposing portions mutually the first valve stem element (15a) and the movable core (12) is coupled by press-fitting and caulking.

Images