JP2006118415A - Method for manufacturing electromagnetic fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable correction of axial direction dimension of a magnetic cylindrical body and correction of eccentricity of a valve seat member in relation to the magnetic cylindrical body by relatively small laser radiation energy in a manufacturing process of an electromagnetic fuel injection valve. <P>SOLUTION: An annular welding part W is formed between the valve seat member 3 and the magnetic cylindrical body 4 mutually fitted to close a valve housing 2 storing a valve assembly V. After that laser is irradiated on an outer circumference surface of the magnetic cylindrical body 4 over whole circumferences to form annular fake weld part w1, w2 in which weld penetration does not reach an inner circumference surface of the magnetic cylindrical body 4. Consequently, correction of axial direction dimension of the magnetic cylindrical body 4 and correction of eccentricity of the valve seat member 3 in relation to the magnetic cylindrical body 4 are performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a valve seat member having a valve seat and a valve hole penetrating through the center of the valve seat at a front end portion thereof, a magnetic member that is fitted to the rear end portion of the valve seat member and is coaxially coupled through an annular welded portion. A valve housing having a cylindrical body and a fixed core that is coaxially coupled to the rear end of the magnetic cylindrical body via a non-magnetic cylindrical body, and a movable body disposed in the valve housing so as to be close to and away from the fixed core A valve assembly consisting of a core and a valve body coupled to the movable core and separated from and seated on the valve seat according to its movement, and disposed on the outer peripheral surface of the valve housing. Correction of the axial dimension of the magnetic cylinder (that is, correction of the valve opening stroke) and the valve for the magnetic cylinder during the manufacturing process of the electromagnetic fuel injection valve including a coil for generating a suction force Electromagnetic fuel injection that enables correction of seat member eccentricity A method for manufacturing a valve.

Conventionally, in such a method of manufacturing an electromagnetic fuel injection valve, when a valve seat member and a magnetic cylinder that are fitted to each other are joined together by welding, a partial weld is formed on the overlapping portion of the valve seat member and the magnetic cylinder. It has already been known to correct the axial dimension of the magnetic cylinder and to correct the eccentricity of the valve seat member with respect to the magnetic cylinder (see Patent Documents 1 and 2 below).
JP 2001-246487 A JP 2001-252778 A

  In the conventional manufacturing method described above, since partial welding for correction is applied to the overlapping portion of the valve seat member and the magnetic cylinder, penetration due to welding penetrates the outer magnetic cylinder to the inner valve seat member. As a result, a large amount of welding energy is required, and as a result, a large amount of distortion occurs after welding. Therefore, it is extremely difficult to correct the distortion amount.

  The present invention has been made in view of such circumstances. In the manufacturing process of an electromagnetic fuel injection valve, the axial dimension of the magnetic cylinder is corrected and the valve seat with respect to the magnetic cylinder is corrected with relatively little laser irradiation energy. It is an object of the present invention to provide a method of manufacturing an electromagnetic fuel injection valve that can correct the eccentricity of a member.

  In order to achieve the above object, the present invention provides a valve seat member having a valve seat and a valve hole penetrating through the center of the valve seat at the front end portion, and fitted to the rear end portion of the valve seat member and via an annular welded portion. A magnetic cylindrical body coupled coaxially, and a valve housing having a fixed core coaxially coupled to the rear end of the magnetic cylindrical body via a non-magnetic cylindrical body, and in the vicinity of the fixed core in the valve housing・ A valve assembly consisting of a movable core that can be separated from each other and a valve body that is coupled to the movable core and moves away from and seats on the valve seat according to the movement, and is arranged on the outer periphery of the valve housing. In a method of manufacturing an electromagnetic fuel injection valve having a coil for generating an attractive force between a fixed and a movable core, a valve seat member and a magnetic cylinder fitted to each other so as to close a valve housing containing a valve assembly After forming an annular weld between the bodies, By irradiating the entire outer circumference of the magnetic cylinder with laser, and forming an annular pseudo weld that prevents the penetration of the laser from reaching the inner circumference of the magnetic cylinder, the axial direction of the magnetic cylinder The first feature is to correct the dimensions and to correct the eccentricity of the valve seat member with respect to the magnetic cylindrical body.

  In addition to the first feature, the second feature of the present invention is that the laser irradiation energy at the time of forming the annular pseudo weld is 0.1 to 1.5 J / P.

  Furthermore, in addition to the first or second feature, the present invention forms a plurality of the annular pseudo welds on the outer peripheral surface of the magnetic cylinder by making laser irradiation start points different from each other in the circumferential direction of the magnetic cylinder. This is the third feature.

  Furthermore, in addition to the first feature of the present invention, after connecting the magnetic cylindrical body and the valve seat member so that the valve opening stroke of the valve body exceeds the specified stroke, the specified stroke of the valve opening stroke is increased. Measure and calculate the excess and the eccentric direction and amount of eccentricity of the valve seat member with respect to the magnetic cylinder, and form the annular pseudo weld on the outer peripheral surface of the valve seat member in order to bring these measured values close to zero And determining the laser irradiation energy, the number of the annular pseudo welds, and the laser irradiation start point, and forming the annular pseudo welds on the outer peripheral surface of the valve seat member based on the determination. .

  According to the first feature of the present invention, in the manufacturing process of the electromagnetic fuel injection valve, an annular weld is formed between the valve seat member and the magnetic cylinder fitted to each other so as to close the valve housing. By irradiating the entire circumference of the magnetic cylinder with laser and forming an annular pseudo weld that prevents the penetration of the laser from reaching the inner circumference of the magnetic cylinder, the axial dimension of the magnetic cylinder can be reduced. Since the correction and the eccentricity of the valve seat member with respect to the magnetic cylindrical body are performed, the laser irradiation energy required for forming the annular pseudo welded portion is extremely small, and there is almost no distortion of the magnetic cylindrical body after the formation of the annular pseudo welded portion. The above correction can be made accurate.

  Further, according to the second feature of the present invention, the laser irradiation energy at the time of forming the annular pseudo-welded portion is 0.1 to 1.5 J / P, so that the penetration by the laser irradiation at the time of forming the annular pseudo-welded portion. Can be reliably prevented from reaching the inner peripheral surface of the magnetic cylinder, and the strength of the relatively thin magnetic cylinder is not impaired.

  Further, according to the third feature of the present invention, when a plurality of annular pseudo welds are formed on the outer peripheral surface of the magnetic cylinder, the laser irradiation start points are made different in the circumferential direction of the magnetic cylinder. Thus, the correction amount of the eccentricity of the valve seat member with respect to the magnetic cylinder can be freely adjusted.

  Furthermore, according to the fourth aspect of the present invention, the correction can be made more accurate.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve manufactured by the method of the present invention, FIG. 2 is an enlarged view of part 2 of FIG. 1, and FIG. 3 is a view of a magnetic cylinder performed in the manufacturing process of the electromagnetic fuel injection valve. FIG. 4 is an explanatory diagram for measuring the axial shrinkage, FIG. 4 is an explanatory diagram for measuring the eccentric direction and the eccentric amount of the valve seat member with respect to the magnetic cylinder, and FIG. Fig. 5-5 is an exaggerated cross-sectional view taken along line 5-5, (A) shows the state when the magnetic cylindrical body and the valve seat member are press-fitted, (B) shows the state when the two are welded, and (C) shows (D) shows the correction | amendment process by formation of the 2nd cyclic | annular pseudo-welded part, (D) shows the correction | amendment process by formation of the 2nd cyclic | annular pseudo-welded part. 6 is a diagram showing the relationship between the laser irradiation energy and the axial contraction amount of the magnetic cylinder, and FIG. 7 is a diagram showing the relationship between the laser irradiation energy and the eccentric amount of the valve seat member with respect to the magnetic cylinder. .

  First, referring to FIGS. 1 and 2, the structure of an electromagnetic fuel injection valve I manufactured by the manufacturing method of the present invention will be described.

  The valve housing 2 of the electromagnetic fuel injection valve includes a cylindrical valve seat member 3 having a valve seat 8 at the front end, a magnetic cylinder 4 coupled coaxially to the rear end portion of the valve seat member 3, A nonmagnetic cylinder 6 coaxially coupled to the rear end of the magnetic cylinder 4, a fixed core 5 coaxially coupled to the rear end of the nonmagnetic cylinder 6, and a rear end of the fixed core 5 It is comprised with the fuel inlet tube 26 connected coaxially.

  The valve seat member 3 has a connecting tube portion 3a protruding from the outer peripheral surface to the magnetic cylinder 4 side with an annular shoulder portion 3b at the rear end portion. The front end surface of the magnetic cylinder 4 is butted against the annular shoulder 3b, and an annular welded portion W1 is formed by laser welding at the butted portion. Thus, the valve seat member 3 and the magnetic cylindrical body 4 are connected to each other coaxially and in a liquid-tight manner.

  Further, the magnetic cylindrical body 4 and the nonmagnetic cylindrical body 6 are coaxially and liquid-tightly coupled to each other by forming an annular welded portion W2 by laser welding similarly between the opposed end faces.

  The valve seat member 3 includes a cylindrical guide hole 9, a conical valve seat 8 connected to the front end of the guide hole 9, and a valve hole 7 penetrating through the central portion of the valve seat 8. A circular recess 45 that concentrically surrounds the valve hole 7 is formed on the front end surface of the valve seat member 3, and the injector plate 10 is liquid-tightly welded to the valve seat member 3 in the recess 45. The injector plate 10 is provided with a plurality of annular fuel injection holes 11, 11... Concentrically surrounding the center line of the valve hole 7.

  The valve seat 8 of the valve seat member 3 is formed in a conical shape. Between the valve seat 8 and the valve hole 7, the fuel that has passed through the valve seat 8 is collected and guided to the valve hole 7. A collective recess 35 is formed.

  A flat fuel diffusion chamber 36 for diffusing the fuel that has passed through the valve hole 7 radially outward is formed between the opposed surfaces of the valve seat member 3 and the injector plate 10. The fuel diffusion chamber 36 is formed as a recess in the front end surface of the valve seat member 3 in the illustrated example. The injector plate 10 is provided with a plurality of fuel injection holes 11, 11... That open to the fuel diffusion chamber 36 at positions radially away from the valve hole 7. Therefore, the valve hole 7 and each fuel injection hole 11 communicate with each other via the fuel diffusion chamber 36.

  A hollow cylindrical fixed core 5 is press-fitted into the inner peripheral surface of the nonmagnetic cylindrical body 6 from the rear end side, and the rear end of the nonmagnetic cylindrical body 6 and the annular shoulder 5b of the fixed core 5 are butted together. An annular welded portion W3 is formed on the portion by laser welding, whereby the nonmagnetic cylindrical body 6 and the fixed core 5 are coaxially and liquid-tightly coupled to each other. At this time, a portion that does not fit with the fixed core 5 remains at the front end portion of the nonmagnetic cylindrical body 6, and the valve assembly V is accommodated in the valve housing 2 extending from the portion to the valve seat member 3.

  The valve assembly V is connected to the valve rod portion 17 including a valve portion 16 that opens and closes with respect to the valve seat 8 and a valve rod portion 17 that supports the valve portion 16, and is connected to the valve rod portion 17. It consists of a movable core 12 straddling the cylindrical body 6 and inserted into them and confronted with the fixed core 5 coaxially. The valve rod portion 17 is formed to have a smaller diameter than the guide hole 9, and the journal portion 17 a that protrudes radially outward at the outer periphery thereof and is slidably supported on the inner peripheral surface of the guide hole 9. Are integrally formed. In addition, a journal portion 17b that is slidably supported on the inner peripheral surface of the magnetic cylindrical body 4 is formed on the outer periphery of the movable core 12.

  The valve assembly V includes a vertical hole 19 that ends from the rear end surface of the movable core 12 before the valve portion 16, and a plurality of first horizontal holes 20 a that communicate with the outer peripheral surface of the movable core 12. A plurality of second lateral holes 20b are provided to communicate the vertical hole 19 with the outer peripheral surface of the valve rod part 17 between the journal part 17a and the valve part 16. At that time, an annular spring seat 24 facing the fixed core 5 is formed in the middle of the vertical hole 19.

  The fixed core 5 has a vertical hole 21 that communicates with the vertical hole 19 of the movable core 12, and a fuel inlet cylinder 26 that communicates internally with the vertical hole 21 is integrally connected to the rear end of the fixed core 5. The fuel inlet cylinder 26 is composed of a reduced diameter portion 26a connected to the rear end of the fixed core 5 and a subsequent enlarged diameter portion 26b, and a slotted pipe shape press-fitted into the vertical hole 21 from the reduced diameter portion 26a. A valve spring 22 for biasing the movable core 12 toward the valve closing side of the valve body 18 is provided between the retainer 23 and the spring seat 24. At that time, the set load of the valve spring 22 is adjusted by the depth of fitting of the retainer 23 into the vertical hole 21. A fuel filter 27 is mounted in the expanded diameter portion 26b, and a seal member 49 is mounted on the outer periphery of the expanded diameter portion 26b.

  The fixed core 5 is made of a ferrite-based high hardness magnetic material. On the other hand, in the movable core 12, a collar-like high-hardness stopper element 14 surrounding the valve spring 22 is embedded in a suction surface opposite to the suction surface of the fixed core 5. The stopper element 14 has its outer end slightly protruded from the suction surface of the movable core 12, and usually faces the suction surface of the fixed core 5 with a gap S corresponding to the valve opening stroke of the valve body 18. Is done.

  A coil assembly 28 is fitted to the outer periphery of the valve housing 2 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 from the rear end portion of the magnetic cylindrical body 4 to the fixed core 5 and a coil 30 wound around the bobbin 29. The front end of the coil housing 31 that surrounds 28 is welded to the outer peripheral surface of the magnetic cylindrical body 4, and the rear end is welded to the outer peripheral surface of the yoke 5 a that protrudes in a flange shape from the outer periphery of the rear end portion of the fixed core 5. The coil housing 31 has a cylindrical shape, and a slit 31a extending in the axial direction is formed on one side.

  A part of the magnetic cylinder 4, the coil housing 31, the coil assembly 28, the fixed core 5, and the front half of the fuel inlet cylinder 26 are embedded in a synthetic resin cylindrical mold part 32 by injection molding. At that time, the mold portion 32 is filled into the coil housing 31 through the slit 31a. A coupler 34 protruding in one side is integrally formed in the middle portion of the mold portion 32, and the coupler 34 holds a current-carrying terminal 33 connected to the coil 30.

  Thus, when the coil 30 is demagnetized, the valve assembly V is pressed forward by the urging force of the valve spring 22, and the valve body 18 is seated on the valve seat 8. In this state, the fuel pumped from the fuel pump (not shown) to the fuel inlet cylinder 26 passes through the pipe-like retainer 23, the vertical hole 19 of the valve assembly V, and the first and second horizontal holes 20a and 20b. 3 is put on standby and used for lubrication around the journal portions 17a and 17b of the valve assembly V.

  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 magnetic cylindrical body 4, and the movable core 12, and the movable core 12 of the valve assembly V is set to the valve spring 22 by the magnetic force. Since the valve portion 16 of the valve body 18 is separated from the valve seat 8 of the valve seat member 3 against the load, the high pressure fuel in the valve seat member 3 passes through the valve seat 8. Thereafter, the fuel collecting recess 35 is guided to the valve hole 7, the flow is reversed at the valve hole 7, the gas is transferred to the fuel diffusion chamber 36, diffused outward in the radial direction, and the plurality of fuel injection holes 11 of the injector plate 10. , 11..., And fuel spray foam F can be formed.

  In assembling such an electromagnetic fuel injection valve I, the non-magnetic cylindrical body 6 and the magnetic cylindrical body 4 are sequentially coupled to the fixed core 5 and then the coil assembly 28 is assembled, and the mold portion 32 and the coupler are mounted on the outer periphery thereof. 34 is integrally formed.

  Next, after inserting the valve assembly V into the nonmagnetic cylinder 6 and the magnetic cylinder 4, the connecting cylinder portion 3 a of the valve seat member 3 is press-fitted into the inner peripheral surface of the front end portion of the magnetic cylinder 4, and the valve seat The valve housing 2 is closed by abutting the annular annular shoulder 3b of the member 3 with the front end surface of the magnetic cylinder 4. As shown in FIGS. 2 and 5B, the laser torch Ta irradiates the butted portion between the annular annular shoulder 3b of the valve seat member 3 and the front end surface of the magnetic cylinder 4 while irradiating the laser with the magnetic cylinder. 4 and the valve seat member 3 are rotated once in the direction of the arrow R around the axis (see FIG. 5B) to form the annular welded portion W1 at the butted portion, and the magnetic cylindrical body 4 and the valve seat member 3 are Bonds firmly and liquid tightly. The laser irradiation energy at this time is 2.0 J / P.

  By the way, when the magnetic cylinder 4 and the valve seat member 3 are press-fitted together, as shown in FIG. 5 (A), both of the centers C1 of the magnetic cylinder 4 and the center C2 of the valve seat member 3 are made high. Although concentric accuracy is maintained, if the annular welded portion W1 is formed after the press-fitting, the valve opening stroke S of the valve body 18 due to the axial contraction of the magnetic cylindrical body 4 as shown in FIG. A deviation (decrease) occurs, and an eccentricity e of the valve seat member 3 with respect to the magnetic cylindrical body 4 occurs in a direction A at an angle α≈45 ° before the end of laser irradiation.

  As shown in FIG. 2, the present invention forms one or a plurality of pseudo welded portions w1a and w2 on the outer peripheral surface of the magnetic cylindrical body 4 by laser irradiation with a laser torch Tb. Since the correction of the direction dimension (that is, the correction of the valve opening stroke of the valve body) and the eccentricity of the valve seat member 3 with respect to the magnetic cylinder 4 are performed, the valve body accompanying the formation of the annular welded portion W1. Even if the valve opening stroke is reduced, the axial dimensions of the magnetic cylinder 4 and the valve seat member 3 are set in advance so that the valve opening stroke S of the valve body 18 slightly exceeds the specified stroke.

  3 and FIG. 3 for the fuel injection valve semi-finished product I ′ assembled at the annular welded portion W1 (the valve spring 22, the retainer 23, and the fuel filter 27 are not assembled at this stage). 4, the valve opening stroke S of the valve body 18 is measured, and the eccentric direction A and the eccentric amount e (see FIG. 5B) of the valve seat member 3 with respect to the magnetic cylindrical body 4 are measured.

  That is, as shown in FIG. 3, when measuring the valve opening stroke S of the valve element 18, first, the fuel injection valve semi-finished product I ′ is held in the upright state by the measuring stand 50, and the measuring piece 51 a of the digital gauge 51 is The tip is inserted into the fuel inlet cylinder 26 and brought into contact with the spring seat 24 of the valve assembly V, a predetermined voltage is applied to the coil 30 from the energizing terminal 33 of the coupler 34, and the valve body 18 is opened. The valve opening stroke S is read from the digital gauge 51, and an excess ΔS with respect to the specified stroke is calculated.

  As shown in FIG. 4, when measuring the eccentricity e of the valve seat member 3 with respect to the magnetic cylindrical body 4, first, the fuel inlet cylinder 26 of the semi-fuel injection valve product I ′ and the inner peripheral surface of the fixed core 5 are matched. A rotation measurement jig 53 having a shaft 53 a to be obtained is prepared, and the fuel inlet cylinder 26 and the fixed core 5 of the fuel injection valve semifinished product I ′ are fitted to the shaft 53 a, and the rotation measurement jig 53 is clamped by a clamp 54. By pressing the valve seat member 3 against the upper elastic member 55, the fuel inlet cylinder 26 and the fixed core 5 are held concentrically with the shaft portion 53a. On the other hand, the probe 52a of the digital gauge 52 is brought into contact with the outer peripheral surface of the valve seat member 3 of the fuel injection valve semifinished product I ′. In this state, the rotation measuring jig 53 is rotated around the center of the shaft portion 53 a, and the eccentric direction A and the eccentric amount e of the valve seat member 3 are read from the digital gauge 52.

  Next, in order to bring these measured values close to zero, the laser irradiation energy and the annular pseudo welded portion w1 when the annular pseudo welded portions w1 and w2 are formed on the outer peripheral surface of the magnetic cylindrical body 4 by laser irradiation with the laser torch Tb. , W2 is read from the following tables 1 and 2, and the charts of FIGS.

これら表１及び表２，並びに図６及び図７の図表は，レーザの照射条件を色々変えて試験的に磁性円筒体４の外周面に環状疑似溶接部を形成することで，得たデータを纏めたものである。尚，表１及び表２において，環状疑似溶接部の条数を複数とした場合，レーザ照射開始点は同位相である。

Tables 1 and 2 and FIGS. 6 and 7 show the data obtained by experimentally forming an annular pseudo weld on the outer peripheral surface of the magnetic cylinder 4 under various laser irradiation conditions. It is a summary. In Tables 1 and 2, when the number of annular pseudo welds is plural, the laser irradiation start point is in phase.

  Further, the laser irradiation energy for forming the annular pseudo welded portion is less than the laser irradiation energy (2.0 J / P) required for forming the annular welded portion W1 between the valve seat member 3 and the magnetic cylindrical body 4 and melts. Is limited to a range of 0.1 to 1.5 J / P so as not to reach the inner peripheral surface of the magnetic cylindrical body 4.

  As is apparent from Table 1 and FIG. 6, the amount of contraction in the axial direction of the magnetic cylinder 4 is the magnitude of the laser irradiation energy applied to the magnetic cylinder 4 and the annular pseudo weld formed in the magnetic cylinder 4 thereby. It is proportional to the number of articles.

As is apparent from Table 2 and FIG. 7, the amount of eccentricity e of the magnetic cylinder 4 with respect to the valve seat member 3 is proportional to the laser irradiation energy.
[Example of correction]
As a result of the measurement, the excess ΔS of the valve opening stroke S of the valve body 18 is 0.014 mm, the eccentricity e of the valve seat member 3 with respect to the magnetic cylinder 4 is 0.006 mm, and these are corrected.

  First, when the condition for contracting the magnetic cylindrical body 4 in the axial direction is found from Table 1 in order to make the valve opening stroke excess ΔS = 0.014 mm zero, laser irradiation energy = 1.3 J / P, annular pseudo welded portion The number of articles is 2. Next, in Table 2, the amount of eccentricity when the laser irradiation energy = 1.3 J / P and the number of strips = 2 is 0.008 mm. Therefore, if two annular pseudo welds are formed with the laser irradiation energy = 1.3 J / P and the irradiation start point in the same phase, the excess ΔS of the valve opening stroke S can be made zero. , The correction of the eccentricity e is overcorrection, and e = 0.006−0.008 = −0.002 mm.

  Therefore, first, as shown in FIG. 5C, the laser irradiation with the irradiation energy = 1.3 J / P from the laser torch Tb is completed and the laser irradiation is completed when the annular welded portion W1 is formed on the outer peripheral surface of the magnetic cylindrical body 4. Before point P1 (which is also the laser irradiation start point), a laser with irradiation energy = 1.3 J / P is irradiated by a laser torch Tb from a point P2 of approximately 135 °, and the same direction R as in the formation of the annular welded portion W1. Then, the fuel injection valve semi-finished product I ′ is rotated once to form the first annular pseudo welded portion w1. As a result, the magnetic cylinder 4 is contracted by 0.007 mm in the axial direction, and the center C2 of the valve seat member 3 is set to 0. 0 on the opposite side to the laser irradiation start (end) point P1 when the annular welded portion W1 is formed. Displace 004 mm.

  Next, as shown in FIG. 5D, with respect to the diameter line passing the laser irradiation start (end) point P1 when the annular welded portion W1 is formed, the laser irradiation start when the annular pseudo welded portion w1 is formed ( End) From the point P3 symmetrical to the point P2, the outer surface of the magnetic cylindrical body 4 is irradiated with a laser having a laser irradiation energy of 1.3 J / P from the laser torch Tb, and the same direction A as in the formation of the annular weld W1. Then, the fuel injection valve semifinished product I ′ is rotated once to form the second annular pseudo welded portion w2. As a result, the magnetic cylinder 4 is further contracted by 0.007 mm in the axial direction, and the center C2 of the valve seat member 3 is connected to a diameter line passing through the laser irradiation start (end) point P1 when the annular welded portion W1 is formed. It is displaced by 0.004 mm along the perpendicular diameter line on the side opposite to the initial eccentric direction A.

As a result, the amount of axial contraction of the magnetic cylindrical body 4 due to the formation of the two annular pseudo welds w1, w2 is 0.007 × 2 = 0.014 mm, and the valve opening stroke S is excessive. The minute ΔS can be zero. At the same time, the amount of movement of the center C2 of the valve seat member 3 toward the center side of the magnetic cylinder 4 is 0.004 ² × 2 square root = 0.0005657 mm, and therefore the eccentricity of the valve seat member 3 with respect to the magnetic cylinder 4 The quantity e is 0.006-0.005657 = 0.000343 mm, which can be regarded as substantially zero.

  The electromagnetic fuel injection valve I is completed by assembling the valve spring 22, the retainer 23, and the fuel filter 27 to the fuel injection valve semifinished product I 'that has been subjected to such a correction process.

  As described above, in the process of manufacturing the electromagnetic fuel injection valve I, the annular welded portion W1 is formed between the valve seat member 3 and the magnetic cylinder 4 fitted to each other so as to close the valve housing 2, and then the magnetic By irradiating a laser over the entire outer periphery of the cylindrical body 4 and forming the annular pseudo welds w1 and w2 that do not reach the inner peripheral surface of the magnetic cylindrical body 4, the axis of the magnetic cylindrical body 4 is Since the correction of the directional dimension and the correction of the eccentricity of the valve seat member 3 with respect to the magnetic cylindrical body 4 are performed, the laser irradiation energy required for forming the annular pseudo welded portions w1 and w2 is extremely small. The distortion of the magnetic cylinder 4 after the formation can be almost eliminated, and the above correction can be made accurate.

  In this case, the laser irradiation energy for forming the annular pseudo welds w1 and w2 is limited to a range of 0.1 to 1.5 J / P, so that the penetration by the laser irradiation is caused on the inner peripheral surface of the magnetic cylindrical body 4. It can be surely prevented from reaching, and the strength of the relatively thin magnetic cylinder 4 is not impaired.

  Further, when a plurality of annular pseudo welds w1 and w2 are formed on the outer peripheral surface of the magnetic cylindrical body 4, the laser irradiation start (end) points P1 and P2 are made different in the circumferential direction of the magnetic cylindrical body 4. Thus, the correction amount of the eccentricity of the valve seat member 3 with respect to the magnetic cylindrical body 4 can be freely adjusted.

  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.

The longitudinal cross-sectional view of the electromagnetic fuel injection valve manufactured with the method of this invention. FIG. 2 is an enlarged view of part 2 of FIG. 1. Explanatory drawing of the measurement process of the axial direction shrinkage | contraction amount of the magnetic cylindrical body performed in the manufacture process of the said electromagnetic fuel injection valve. Explanatory drawing of the measurement process of the eccentric direction and eccentric amount of the valve-seat member with respect to a magnetic cylinder performed in the manufacture process of the said electromagnetic fuel injection valve. 2A and 2B are exaggeratedly drawn, (A) shows a state when the magnetic cylindrical body and the valve seat member are press-fitted, (B) shows a state when both of them are welded, ( C) shows a correction process by forming the first annular pseudo welded portion, and (D) shows a correction process by forming the second loop pseudo welded portion. The diagram which shows the relationship between laser irradiation energy and the axial direction shrinkage of a magnetic cylindrical body. The diagram which shows the relationship between laser irradiation energy and the eccentric amount of the valve seat member with respect to a magnetic cylinder.

Explanation of symbols

B ... Laser beam I ... Fuel injection valve S ... Center 2 of the abutting part ... Valve housing 3 ... Valve seat member 3b ... Axial facing surface (annular shoulder)
4 ... Magnetic cylindrical body 4a ... Axial facing surface (front end face)
7 ... Valve 8 ... Valve seat 18 ... Valve 30 ... Coil 50 ... Abutting portions 51, 52 ... Annular groove 53 ... Annular weld

Claims (4)

A valve seat member (3) having a valve seat (8) and a valve hole (7) penetrating through the center of the valve seat (8) at the front end, and fitted to the rear end of the valve seat member (3) and an annular welded portion (W ) And a fixed core (5) coaxially coupled to the rear end of the magnetic cylinder (4) via a non-magnetic cylinder (6). A valve housing (2) having a movable core (12), which is opposed to the fixed core (5) in the valve housing (2) so as to be capable of approaching and separating, and the movable core (12). Correspondingly, a valve assembly (V) comprising a valve body (18) that is separated from and seated on the valve seat (8) and a valve housing (2) are disposed on the outer periphery of the valve assembly (5). 12) In the manufacturing method of an electromagnetic fuel injection valve provided with a coil (30) for generating an attractive force between
An annular weld (W) is formed between the valve seat member (3) and the magnetic cylinder (4) fitted to each other so as to close the valve housing (2) containing the valve assembly (V). Irradiate the entire circumference of the outer surface of the magnetic cylinder (4) with laser to form an annular pseudo weld (w1, w2) in which the penetration does not reach the inner surface of the magnetic cylinder (4). A method for manufacturing an electromagnetic fuel injection valve, comprising: correcting the axial dimension of the magnetic cylinder (4) and correcting the eccentricity of the valve seat member (3) with respect to the magnetic cylinder (4). In the manufacturing method of the electromagnetic fuel injection valve according to claim 1,
A method for manufacturing an electromagnetic fuel injection valve, characterized in that a laser irradiation energy in forming the annular pseudo welded portion (w1, w2) is 0.1 to 1.5 J / P. In the manufacturing method of the electromagnetic fuel injection valve of Claim 1 or 2,
A plurality of the annular pseudo welds (w1, w2) are formed on the outer peripheral surface of the magnetic cylinder (4) by making the laser irradiation start points (P2, P3) different from each other in the circumferential direction of the magnetic cylinder (4). A method for manufacturing an electromagnetic fuel injection valve. In the manufacturing method of the electromagnetic fuel injection valve according to claim 1,
After connecting the magnetic cylinder (4) and the valve seat member (3) so that the valve opening stroke (S) of the valve body (18) exceeds the specified stroke, the specified stroke of the valve opening stroke (S) To measure and calculate the excess (ΔS) exceeding the value, the eccentric direction (A) and the eccentric amount (e) of the valve seat member (3) with respect to the magnetic cylinder (4), and bring these measured values close to zero When forming the annular pseudo welded portion (w1, w2) on the outer peripheral surface of the valve seat member, the laser irradiation energy, the number of the annular pseudo welded portion (w1, w2) and the laser irradiation start point (P2, P3) And the annular pseudo welded portion (w1, w2) is formed on the outer peripheral surface of the valve seat member (3) based on the determination.

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