JP2018017191A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve capable of compatibly improving joint strength between a fixed core and a non-magnetic member and suppressing magnetic short circuit while adopting a configuration to improve suction force.SOLUTION: The fuel injection valve includes a fixed core 50 having an inside core part 52 and an outside core part 51 opposed to a movable core 40, and a non-magnetic member 60 arranged between the inside core part 52 and the outside core part 51. The fuel injection valve further includes an inside weld zone W20 of the inside core part 52 and the non-magnetic member 60, and an outside weld zone W10 of the outside core part 51 and the non-magnetic member 60. In a welded surface 60b of the non-magnetic member 60 on which these weld zones are provided, at its portion between the inside weld zone W20 and the outside weld zone W10, a groove 61 is formed.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a fuel injection valve that injects fuel.

  The fuel injection valve described in Patent Literature 1 includes an annularly arranged coil, a fixed core in which a magnetic field is formed by energizing the coil, and a movable core that is attracted by forming a magnetic field between the fixed cores. And a valve body that is driven by the sucked movable core to open and close the nozzle hole. A non-magnetic member is assembled to a portion of the fixed core that faces the movable core, and an inner portion of the fixed core that is radially inward of the non-magnetic member is referred to as an inner core portion, and an outer portion is referred to as an outer core portion.

  Then, the attractive force generated by the magnetic field formed between the outer core portion and the movable core and the attractive force generated by the magnetic field formed between the inner core portion and the movable core act on the movable core, and these attractive forces The movable core is attracted to the fixed core by force. In short, the inner core portion, the nonmagnetic member, and the outer core portion are arranged side by side at a position facing the movable core, thereby generating an attractive force from both the outer core portion and the inner core portion to the movable core. Thereby, a suction | attraction force can be improved.

European Patent Application No. 2746565

  However, fuel pressure is applied to the surface of the fixed core that faces the movable core. As a result, in the conventional structure in which the inner core portion, the nonmagnetic member, and the outer core portion are arranged side by side at a position facing the movable core, the following problems are concerned. That is, when the surface of the inner core portion, the nonmagnetic member and the outer core portion facing the movable core is subjected to fuel pressure, the joint surface between the inner core portion and the nonmagnetic member, and the outer core portion and the nonmagnetic member There is a concern that the joint surface with the member is damaged.

  The nonmagnetic member and the fixed core are generally joined by welding. In the following description, the welded portion in which the inner core portion and the nonmagnetic member are melted and solidified is referred to as an inner welded portion. The welded part in which the part and the nonmagnetic member are melted and solidified is called an outer welded part. And the present inventors examined increasing the welding depth from a welding surface and improving joint strength with respect to the concern of the joint surface failure mentioned above.

  However, when the welding depth is increased, the thickness dimension of the welded portion as viewed from the weld surface side is also increased. Then, since the space | interval of an inner side welding part and an outer side welding part becomes short, there exists a concern that an inner side welding part and an outer side welding part may contact and a magnetic short circuit may occur. When such a magnetic short circuit occurs, a magnetic flux passes between the inner core portion and the outer core portion via the inner welded portion and the outer welded portion, and there is a possibility that the attractive force is reduced.

  The present invention has been made in view of the above problems, and the object thereof is to make it possible to achieve both improvement in the bonding strength between the fixed core and the nonmagnetic member and suppression of magnetic short circuit while adopting a structure that improves the attractive force. It is to provide a fuel injection valve.

  The invention disclosed herein employs the following technical means to achieve the above object. Note that the reference numerals in parentheses described in the claims and in this section indicate the correspondence with the specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

One of the disclosed inventions is
A fuel injection valve for injecting fuel from an injection hole (23a),
An annularly arranged coil (70);
A fixed core (50) that forms a magnetic field when energized to the coil;
A movable core (40) which is provided closer to the nozzle hole than the fixed core in the direction of the annular center line (C) of the coil, and is attracted to the fixed core by forming a magnetic field with the fixed core when the coil is energized. When,
A valve body (30) that is driven by the sucked movable core to open and close the nozzle hole;
An inner core part (52) which is a part of the fixed core facing the movable core;
An outer core portion (51) that is a part of the fixed core that faces the movable core and is located outside the inner core portion with respect to the annular center line;
A nonmagnetic member (60) that is disposed between the inner core portion and the outer core portion and is less magnetic than the fixed core;
A welded portion of the inner core portion and the nonmagnetic member, the inner welded portion (W20) provided on the end surface of the nonmagnetic member on the side of the movable core or the end surface opposite to the movable core;
An outer core portion and a welded portion of the nonmagnetic member, the outer welded portion (W10) provided on the welded surface (60b) which is the end surface on the same side as the inner welded portion of the nonmagnetic member,
It is a fuel injection valve by which the hollow (61) is formed in the part between an inner side welding part and an outer side welding part among welding surfaces.

  According to the said invention, an inner core part and an outer core part are provided in the part facing a movable core among fixed cores, and a nonmagnetic member is arrange | positioned between these inner core parts and outer core parts. For this reason, the formation of a magnetic path between the inner core portion and the outer core portion is avoided by the nonmagnetic member. As a result, the attractive force generated by the magnetic field formed between the outer core portion and the movable core, and the attractive force generated by the magnetic field formed between the inner core portion and the movable core, act on the movable core. These movable forces attract the movable core to the fixed core. Therefore, since the suction force is generated in the movable core from both the outer core portion and the inner core portion, the suction force can be improved.

  Furthermore, according to the said invention, the hollow is formed in the part between an inner side welding part and an outer side welding part among the welding surfaces of a nonmagnetic member. Therefore, even if the weld depth is increased to increase the joint strength and the weld thickness dimension is increased, the magnetic short circuit due to contact between the inner weld portion and the outer weld portion is suppressed by the depression. Therefore, it is possible to realize both the improvement of the joining strength by increasing the welding depth and the suppression of the magnetic short circuit.

Sectional drawing of the fuel injection valve which concerns on 1st Embodiment of this invention. The figure which looked at the fixed core, the nonmagnetic member 60, and the stopper from the nozzle hole side in 1st Embodiment. Sectional drawing which expanded FIG. Sectional drawing which expanded FIG. It is sectional drawing to which FIG. 4 was expanded, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 2nd Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 3rd Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 4th Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 5th Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 6th Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. It is sectional drawing of the fuel injection valve which concerns on 7th Embodiment of this invention, Comprising: The figure which shows a nonmagnetic member, an inner side welding part, and an outer side welding part. Sectional drawing of the fuel injection valve which concerns on 8th Embodiment of this invention.

  Hereinafter, a plurality of modes for carrying out the invention will be described with reference to the drawings. In each embodiment, portions corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals and redundant description may be omitted. In each embodiment, when only a part of the configuration is described, the other configurations described above can be applied to other portions of the configuration.

(First embodiment)
The fuel injection valve shown in FIG. 1 is mounted on an ignition internal combustion engine (gasoline engine), and directly injects fuel into each combustion chamber of a multi-cylinder engine. The fuel supplied to the fuel injection valve is pumped by a fuel pump (not shown), and the fuel pump is driven by the rotational driving force of the engine. The fuel injection valve includes a case 10, a nozzle body 20, a valve body 30, a movable core 40, a fixed core 50, a nonmagnetic member 60, a coil 70, a pipe connection portion 80, and the like.

  The case 10 is made of metal and has a bottomed cylindrical shape extending in a direction in which the annular center line C of the coil 70 extends (hereinafter referred to as an axial direction). An outflow side opening 10b is formed on the bottom surface 10a of the case 10, and an inflow side opening 10c is formed on the opposite side of the case 10 from the bottom surface 10a. The annular center line C of the coil 70 coincides with the center lines of the case 10, the nozzle body 20, the valve body 30, the movable core 40, the fixed core 50 and the nonmagnetic member 60.

  The nozzle body 20 is made of metal, and is disposed by being inserted into the case 10 from the inflow side opening 10c. The nozzle body 20 includes a main body portion 21 that is located inside the case 10 and engages with the bottom surface 10a, and a nozzle portion 22 that extends from the outflow side opening 10b to the outside of the case 10. The outer peripheral surface of the main body 21 is in contact with the inner peripheral surface of the case 10. The nozzle portion 22 has a cylindrical shape extending in the axial direction, and an injection hole member 23 is attached to the tip of the nozzle portion 22.

  The nozzle hole member 23 is made of metal and is fixed to the nozzle portion 22 by welding. The injection hole member 23 has a bottomed cylindrical shape extending in the axial direction, and an injection hole 23 a for injecting fuel is formed at the tip of the injection hole member 23. A seating surface 23 s on which the valve body 30 is seated is formed on the inner peripheral surface of the injection hole member 23.

  The valve body 30 is made of metal and has a cylindrical shape extending along the axial direction. The valve body 30 is assembled in the nozzle body 20 so as to be movable in the axial direction, and an annular fuel extending in the axial direction between the outer peripheral surface 30a of the valve body 30 and the inner peripheral surface 22a of the nozzle body 20. A passage 22b is formed. An annular seat surface 30s is formed at the end of the valve body 30 on the nozzle hole 23a side so as to be separated from and seated on the seat surface 23s. A fuel passage 30b extending in the axial direction is formed at an end portion of the valve body 30 opposite to the injection hole 23a (hereinafter referred to as an anti-injection hole side), and a fuel passage 30b inside the valve body 30 is formed. A through hole 30c communicating with the external fuel passage 22b is formed.

  The movable core 40 has a disk shape made of metal, and is accommodated in a concave accommodation chamber 21 a formed on the side opposite to the injection hole of the main body 21. The movable core 40 is fixed to the end of the valve body 30 opposite to the injection hole. Specifically, the valve body 30 is inserted and disposed in a through hole 41 formed at the center of the movable core 40. An engaging portion 31 extending in the radial direction of the valve body 30 is formed at the end of the valve body 30 on the side opposite to the injection hole. The engaging portion 31 is fitted into and engaged with the concave portion of the movable core 40, and the movable core 40 and the valve body 30 are joined by welding in a state where the engaging portion 31 is in contact with the bottom surface 42 of the concave portion. . Therefore, the movable core 40 moves integrally with the valve body 30 in the axial direction. The surfaces of the movable core 40 and the engagement portion 31 on the side opposite to the injection hole are located on the same plane and are perpendicular to the axial direction.

  The fixed core 50 has an outer core portion 51, an inner core portion 52, and a lid portion 53 described below. The fixed core 50 is fixedly disposed inside the case 10. Hereinafter, the structure of the fixed core 50 will be described with reference to FIGS. 2, 3 and 4 in addition to FIG.

  The outer core portion 51 is made of an annular metal extending around the axial direction, and the outer peripheral surface of the outer core portion 51 is in contact with the inner peripheral surface of the case 10. The lower end surface 51 a on the injection hole side of the outer core portion 51 is in contact with the upper end surface 21 b of the main body portion 21. Of the lower end surface of the outer core portion 51, a portion that receives the fuel pressure in the storage chamber 21a is referred to as an outer pressure receiving surface 51b, and a portion of the outer pressure receiving surface 51b that faces the movable core 40 is referred to as an outer facing surface 51c. The lower end surface of the nonmagnetic member 60 is referred to as a nonmagnetic facing surface 60a, and the lower end surface of the inner core portion 52 is referred to as an inner facing surface 52a. The outer facing surface 51c, the nonmagnetic facing surface 60a, and the inner facing surface 52a face the upper end surface of the movable core 40. Moreover, these opposing surfaces are located on the same plane and are perpendicular to the axial direction.

  The inner core portion 52 is made of an annular metal that is disposed radially inward with respect to the outer core portion 51 and extends around the axial direction. The inner peripheral surface of the inner core portion 52 functions as a fuel passage 52r. The nonmagnetic member 60 is an annular material disposed between the inner core portion 52 and the outer core portion 51, and is made of a material that is weaker than the outer core portion 51 and the inner core portion 52. On the other hand, the outer core portion 51, the inner core portion 52, the movable core 40, and a lid portion 53 described later are formed of a magnetic material.

  A cylindrical and metal stopper 54 is fixed to the inner peripheral surface of the inner core portion 52. The lower end surface 54a of the stopper 54 is located closer to the nozzle hole than the inner facing surface 52a in the axial direction. Therefore, when the upper end surface 31a of the engaging portion 31 of the valve body 30 is in contact with the lower end surface 54a of the stopper 54, the inner facing surface 52a, the nonmagnetic facing surface 60a, and the outer facing surface 51c do not contact the movable core 40. In this state, there is a gap G between the upper end surface of the movable core 40.

  A coil 70 is disposed on the side opposite to the injection hole of the nonmagnetic member 60 and on the radially outer side of the inner core portion 52. The coil 70 is wound around a resin bobbin 71. The bobbin 71 has a cylindrical shape centering on the axial direction. Therefore, the coil 70 is disposed in an annular shape extending around the axial direction. The lower end surface of the bobbin 71 is in contact with the nonmagnetic member 60, and the inner peripheral surface of the bobbin 71 is in contact with the inner core portion 52. The opening and the upper end surface on the outer peripheral side of the bobbin are covered with a resin cover 72. Further, in the cross section including the annular center line C, the annular outer peripheral surface of the coil 70 is located radially outside the outer peripheral surface of the movable core 40.

  The lid portion 53 is made of a metal having magnetism and is formed in an annular shape, and is disposed on the radially outer side of the inner core portion 52 and above the outer core portion 51. The outer peripheral surfaces of the lid portion 53, the outer core portion 51, and the main body portion 21 are in contact with the inner peripheral surface of the case 10 and are accommodated in the case 10.

  On the side opposite to the injection hole of the inner core portion 52, a pipe connection portion 80 that forms a fuel inflow port 80a and is connected to an external pipe is disposed. The pipe connection portion 80 is made of metal and is formed of a metal member integrated with the inner core portion 52. The fuel pressurized by the high pressure pump is supplied to the fuel injection valve from the inflow port 80a.

  A press-fitting member 82 is press-fitted and fixed in a press-fitting part 80 b provided in a part of a through hole formed in the pipe connection part 80, and an elastic member 82 s is disposed on the injection hole side of the press-fitting member 82. Yes. One end of the elastic member 82 s contacts the press-fitting member 82, and the other end contacts the engaging portion 31. Therefore, the elasticity of the elastic member 82s when the valve body 30 is opened to the full lift position, that is, when the engaging portion 31 is in contact with the stopper 54, according to the press-fitting amount of the press-fitting member 82, that is, the fixed position in the axial direction. A deformation amount is specified. That is, the valve closing force (set load) by the elastic member 82s is adjusted by the press-fitting amount of the press-fitting member 82.

  On the outer peripheral surface of the pipe connection portion 80, an annular pressing surface 80c that extends perpendicularly to the axial direction is formed. A fastening member 81 is in contact with the pressing surface 80c. The fastening member 81 is fastened to the case 10 by fastening the screw portion 81 n formed on the outer peripheral surface of the fastening member 81 to the screw portion 10 n formed on the inner peripheral surface of the case 10. By adjusting the fastening amount, a force (hereinafter referred to as an axial force F10) by which the pressing surface 80c is pressed by the fastening member 81 is adjusted. The inner core portion 52, the nonmagnetic member 60, the outer core portion 51, and the main body portion 21 are sandwiched between the bottom surface 10a of the case 10 and the fastening member 81 by the axial force F10.

  Next, the procedure for assembling the fuel injection valve will be described.

  First, the nozzle body 20 in a state where the injection hole member 23 is welded and the valve body 30 in a state where the nozzle body 20 is inserted into the through hole 41 of the movable core 40 are prepared. Next, the valve body 30 is inserted into the inner peripheral surface 22a of the nozzle body 20, and the movable core 40 is disposed in the storage chamber 21a. Next, the nozzle body 20 with the valve body 30 inserted and arranged in this way is inserted into the outflow side opening 10 b of the case 10.

  On the other hand, while the non-magnetic member 60 is disposed between the inner core portion 52 and the outer core portion 51, the inner core portion 52 and the non-magnetic member 60 are welded and fixed, and the outer core portion 51 and the non-magnetic member are fixed. 60 is fixed by welding. Further, the stopper 54 is fixed to the inner core portion 52 by welding. Thereafter, the bobbin 71 in a state where the coil 70 is wound is inserted and disposed on the outer peripheral surface of the inner core portion 52. Then, the cover 72 is resin-molded so as to cover the coil 70 and the bobbin 71, and the lid portion 53 is inserted and disposed on the outer peripheral surface of the inner core portion 52.

  Next, the fixed core 50 with the coil 70 and the lid 53 attached in this manner is inserted into the case 10 with the nozzle body 20 attached, and the fastening member 81 is fixed to the case 10 with a predetermined torque. To conclude. Then, after the elastic member 82s is inserted into the through hole formed in the inner core portion 52, the press-fitting member 82 is press-fitted and fixed to the press-fitting portion 80b while adjusting the press-fitting amount so as to obtain a predetermined set load. To do. Thus, the assembly of the fuel injection valve is completed.

  Next, a welded portion between the outer core portion 51 and the inner core portion 52 and the nonmagnetic member 60 will be described in detail with reference to FIG.

  Of the inner core portion 52 and the nonmagnetic member 60, a portion that is in contact with each other and is welded from the end surface on the side opposite to the injection hole of the nonmagnetic member 60 to a predetermined depth range. Called the inner weld W20. That is, the inner welded portion W20 is a portion with a halftone dot in FIG. 5, in which a part of the inner core portion 52 and a part of the nonmagnetic member 60 are heated and melted, and then cooled and solidified. Part.

  Of the outer core portion 51 and the nonmagnetic member 60, a portion that is in contact with each other and is welded from the end surface of the nonmagnetic member 60 on the side opposite to the injection hole to a predetermined depth range. This is referred to as an outer weld W10. That is, the outer welded portion W10 is a portion with a halftone dot in FIG. 5 in which a portion of the outer core portion 51 and a portion of the nonmagnetic member 60 are heated and melted and then cooled and solidified. Part.

  In addition, in FIG.1, FIG3 and FIG.4, illustration of these welding parts is abbreviate | omitted and the state which has not been welded is shown. Accordingly, a part of the inner tapered surface 52f and the outer tapered surface 51f illustrated in FIGS. 1, 3, and 4 is actually lost at the welded portion.

  The outer welded portion W10 and the inner welded portion W20 are provided on the same end surface (welded surface 60b) of the nozzle hole side end surface and the counter nozzle hole side end surface of the nonmagnetic member 60. A groove 61 as a recess is formed in a portion between the inner welded portion W20 and the outer welded portion W10 in the weld surface 60b. The cross-sectional shape of the groove is rectangular as shown in FIG. Specifically, it is a rectangle whose longitudinal direction is the radial direction of the fixed core 50. The groove 61 is formed in a central portion in the radial direction of the welding surface 60b, and is formed in an annular shape extending around the axial direction as shown in FIG.

  The welding depth dimension from the welding surface 60b in the inner welding portion W20 is referred to as an inner welding depth, and the welding depth dimension from the welding surface 60b in the outer welding portion W10 is referred to as an outer welding depth. The dimension up to the bottom surface 61a is called the groove depth (dent depth). In the example of FIG. 5, the welding depth direction is a direction along the outer tapered surface 51f or the inner tapered surface 52f, and the dimension of the welded portion extending in this direction corresponds to the welding depth. The groove depth corresponds to the axial dimension from the welding surface 60b to the bottom surface 61a. The groove depth is set to a size smaller than the inner welding depth and the outer welding depth. Further, the position of the bottom surface 61a in the axial direction is located on the side opposite to the injection hole than the position of the tip part W13 on the injection hole side of the outer welding part W10 and the tip part W23 on the injection hole side of the inner welding part W20.

  A part of the outer welded part W10 and a part of the inner welded part W20 are exposed at the welding surface 60b. The exposed portion has a shape extending in the radial direction along the weld surface 60b. In particular, the portions extending toward the side closer to the groove 61 are referred to as welded extensions W11 and W21, and the extended tips W12 and W22 of the welded extensions W11 and W21 are exposed from the wall surface of the groove 61. In the example of FIG. 5, the extended tips W12 and W22 are exposed from the side surfaces 61b and 61c of the groove 61, and the extended tips W12 and W22 have a shape extending in the circumferential direction along the groove 61.

  Next, the operation of the fuel injection valve will be described.

  The high-pressure fuel supplied from the high-pressure pump to the fuel injection valve flows in from the inflow port 80a, flows into the fuel passage 30b of the valve body 30 through the through-hole in the inner core portion 52, and passes from the through-hole 30c to the fuel passage 22b. Inflow. When the valve body 30 is opened as described below, the high-pressure fuel in the fuel passage 22b passes between the seat surface 30s and the seating surface 23s and is injected from the injection hole 23a. The accommodating chamber 21 a is filled with high-pressure fuel, and the pressure of the high-pressure fuel acts on the lower end surfaces of the inner core portion 52, the nonmagnetic member 60, and the outer core portion 51.

  When the valve body 30 is opened, the coil 70 is energized. Then, a magnetic field is generated around the coil 70 as indicated by the dotted arrow in FIG. That is, a magnetic field circuit through which magnetic flux passes in the order of the outer core portion 51, the movable core 40, the inner core portion 52, and the lid portion 53 is formed with energization. At this time, the nonmagnetic member 60 acts to prevent the outer core portion 51 and the inner core portion 52 from being magnetically short-circuited. When the magnetic flux passes through such a magnetic circuit, an attractive force attracted toward the fixed core 50 acts on the movable core 40. Specifically, an attractive force generated by the magnetic flux M1 passing between the outer core portion 51 and the movable core 40 and an attractive force generated by the magnetic flux M2 passing between the inner core portion 52 and the movable core 40 are generated. The inner facing surface 52 a and the outer facing surface 51 c of the fixed core 50 correspond to a fixed core suction surface that sucks the movable core 40 by energizing the coil 70.

  The movable core 40 and the valve body 30 are subjected to the valve closing force by the elastic member 82s, the valve closing force by the fuel pressure, and the valve opening force by the suction force described above. Since the valve opening force is set to be larger than the valve closing force, the movable core 40 moves toward the fixed core 50 together with the valve body 30 when a suction force is generated with energization. . As a result, the valve body 30 opens and contacts the stopper 54 so that the seat surface 30s is separated from the seating surface 23s, and high-pressure fuel is injected from the injection hole 23a.

  When the valve body 30 is operated to be closed, energization to the coil 70 is stopped. Then, since the valve opening force due to the suction force described above is lost, the valve element 30 is closed together with the movable core 40 by the valve closing force by the elastic member 82s, and the seat surface 30s is separated from the seating surface 23s. Thereby, the fuel injection from the nozzle hole 23a is stopped.

  Next, the joint surfaces of the outer core portion 51 and the inner core portion 52 and the nonmagnetic member 60 will be described in detail.

  The entire surface of the inner core portion 52 to be joined to the nonmagnetic member 60 is formed in a direction inclined with respect to the annular center line C in a cross section including the annular center line C. This is described as an inner tapered surface 52f. Further, the entire surface of the outer core portion 51 to be joined to the nonmagnetic member 60 is formed as a surface inclined with respect to the annular center line C in the cross section including the annular center line C. The surface is described as an outer tapered surface 51f.

  The inner tapered surface 52f and the outer tapered surface 51f have a shape that extends annularly around the annular center line C and that are inclined in the same direction with respect to the annular center line C. Specifically, the inner tapered surface 52f and the outer tapered surface 51f are inclined in such a direction that the radial dimension becomes smaller toward the nozzle hole side in the axial direction. In the cross section including the annular center line C, the inner tapered surface 52f and the outer tapered surface 51f are linear. In short, it can be said that the nonmagnetic member 60 has a cylindrical shape in which the radial dimension decreases as it approaches the nozzle hole side.

  The length of the inner core portion 52 in the axial direction is longer than the length of the outer core portion 51 in the axial direction. Specifically, the upper end of the outer core portion 51 is located on the lower side (the nozzle hole side) than the lower end of the coil 70, whereas the upper end of the inner core portion 52 is above the lower end of the coil 70 (on the opposite side). Located on the nozzle hole side). More specifically, the upper end of the inner core portion 52 is positioned above the upper end of the coil 70 (on the side opposite to the injection hole).

  The upper end position in the axial direction of the outer tapered surface 51f and the upper end position in the axial direction of the inner tapered surface 52f are the same, and the lower end position in the axial direction of the outer tapered surface 51f and the lower end position in the axial direction of the inner tapered surface 52f are the same. It is.

  In the cross section including the annular center line C, the inclination angle of the inner tapered surface 52f with respect to the annular center line C is referred to as an inner inclination angle 52θ, and the inclination angle of the outer tapered surface 51f with respect to the annular center line C is referred to as an outer inclination angle 51θ ( (See FIG. 3). The inner inclination angle 52θ and the outer inclination angle 51θ are set to different angles. Specifically, the inner inclination angle 52θ is set to be smaller than the outer inclination angle 51θ.

  Next, the force applied to each of the fixed core 50, the nonmagnetic member 60, and the stopper 54 will be described.

  As shown in FIG. 1, by fastening the fastening member 81 to the case 10, the inner core portion 52, the nonmagnetic member 60, the outer core portion 51, and the main body portion are provided between the bottom surface 10 a of the case 10 and the fastening member 81. 21 is sandwiched. In other words, a reaction force F30 against the axial force acting on the pressing surface 80c acts on the main body portion 21 from the bottom surface 10a, and a reaction force F20 equivalent to this reaction force F30 acts on the outer core from the upper end surface 21b of the main body portion 21. It acts on the lower end surface 51 a of the part 51. The fastening member 81 corresponds to an inner imparting portion that imparts an axial force F10 in the axial direction to the inner core portion 52, and imparts an axial force F10 in a direction in which the inner core portion 52 is pressed against the movable core 40 side. The main body portion 21 of the nozzle body 20 corresponds to an outer imparting portion that imparts a reaction force F20 against the axial force F10 to the outer core portion 51, and imparts a reaction force F30 in a direction in which the outer core portion 51 is pressed against the opposite side of the movable core 40. To do.

  Thus, although the axial force F10 by the fastening member 81 and the reaction force F20 by the main body portion 21 act on the fixed core 50, the radial position at which the axial force F10 acts is the radial direction at which the reaction force F20 acts. Since it is inside the position, a shear stress is generated inside the fixed core 50. Therefore, a shearing force acts on the joint surfaces of the inner core portion 52 and the outer core portion 51 and the nonmagnetic member 60, thereby causing a concern that welding at the joint surfaces is damaged.

  In this embodiment, in this embodiment, the inner tapered surface 52f and the outer tapered surface 51f are inclined so as to sandwich the nonmagnetic member 60 by the axial force F10 and the reaction force F20. Specifically, the inner tapered surface 52f and the outer tapered surface 51f are inclined in the direction in which the force of the compression components F11a and F21a shown in FIG. 4 is generated. In other words, the surface of the nonmagnetic member 60 that contacts the outer core portion 51 receives the reaction force F20 in the compression direction, and the surface of the nonmagnetic member 60 that contacts the inner core portion 52 receives the axial force F10 in the compression direction. It is tilted.

  Of the reaction force F20, the force F21 transmitted to the outer tapered surface 51f is divided into a compression component F21a perpendicular to the outer tapered surface 51f and a shear component F21b parallel to the outer tapered surface 51f. Of the axial force F10, the force F11 transmitted to the inner tapered surface 52f is divided into a compression component F11a perpendicular to the inner tapered surface 52f and a shear component F11b parallel to the inner tapered surface 52f. In the present embodiment, since the inner inclination angle 52θ and the outer inclination angle 51θ are different angles, the directions of the compression components F21a and F11a do not coincide with each other, and the directions of the shear components F21b and F11b do not coincide with each other.

  In a state where the inner core portion 52 and the outer core portion 51 are not receiving fuel pressure from the movable core 40 side, for example, when the fuel injection valve is not used, the inner core portion 52 and the outer core portion 51 have the axial force F10 and It is in a state of being elastically deformed by the reaction force F20. That is, the fixed core 50 is bent by screwing the fastening member 81 into the screw portion 10n with a predetermined torque.

  When the fuel injection valve is used with the prestress applied to the fixed core 50 in this way, the pressure received from the high pressure fuel in the storage chamber 21a is applied to the fixed core 50, thereby reducing the amount of elastic deformation due to the prestress. . Specifically, the outer pressure receiving surface 51b of the outer core portion 51, the inner facing surface 52a of the inner core portion 52, the nonmagnetic facing surface 60a of the nonmagnetic member 60, and the lower end surface 54a of the stopper 54 receive the pressure of high pressure fuel. . In the following description, the force that the inner core portion 52 receives on the side opposite to the injection hole due to the fuel pressure applied to the inner facing surface 52a and the lower end surface 54a is referred to as an inner fuel pressure push-up force. Then, the force F11 applied to the inner tapered surface 52f is reduced by the amount corresponding to the inner fuel pressure lifting force. Accordingly, the reaction force F20 applied to the lower end surface 51a is also reduced, and the reaction force F21 transmitted to the outer tapered surface 51f of the reaction force F20 is also reduced. The tightening torque of the fastening member 81 is set so that the force F11 caused by the axial force F10 applied to the inner tapered surface 52f does not become smaller than the inner fuel pressure.

  As described above, when the fuel injection valve is used, although the inner fuel pressure push-up force is applied to the fixed core 50 and the like, the pre-stress is applied to the fixed core 50 in advance. It is suppressed that the position is shifted by being pushed up to the upper side (reverse injection hole side). Furthermore, it can suppress that the levelness of the surface which opposes the movable core 40 among fixed cores reduces by the deformation | transformation by an inner side fuel pressure pushing-up force, and the fall of a suction force is suppressed.

  Next, the operation and effect of the configuration adopted by the present embodiment will be described.

  In the fuel injection valve according to the present embodiment, an inner core portion 52 and an outer core portion 51 are provided in a portion of the fixed core 50 that faces the movable core 40, and a nonmagnetic member 60 is disposed therebetween. Therefore, the nonmagnetic member 60 avoids the formation of a magnetic path between the inner core portion 52 and the outer core portion 51. As a result, both the attractive force generated by the magnetic flux M1 passing between the outer core portion 51 and the movable core 40 and the attractive force generated by the magnetic flux M2 passing between the inner core portion 52 and the movable core 40 are both movable core 40. To act on. That is, not only the attractive force by the magnetic flux in the direction coming out of the movable core 40 but also the attractive force by the magnetic flux in the direction going into the movable core 40 acts on the movable core 40. Therefore, the suction force can be improved.

  Now, if the attractive force is applied by the magnetic fluxes M1 and M2 in this way, the attractive force can be improved, but the radial dimensions of the movable core 40 and the fixed core 50 need to be increased. However, when the radial dimension of the fixed core 50 is increased, the pressure receiving area of the pressure that the fixed core 50 receives in the axial direction from the fuel in the storage chamber 21a increases, and the joint surface between the fixed core 50 and the nonmagnetic member 60 is damaged. This is a concern.

  In response to this concern, in the present embodiment, the fastening member 81 that applies the axial force F10 in the axial direction to the inner core portion 52 and the main body portion 21 that applies the reaction force F20 to the axial force F10 to the outer core portion 51 are provided. Prepare. When the fixed core 50 is not receiving fuel pressure from the movable core 40 side, the fixed core 50 is elastically deformed by the axial force F10 and the reaction force F20. Therefore, as described above, it is possible to suppress the damage of the joint surface due to the internal fuel pressure push-up force due to the prestress applied in advance to the fixed core 50.

  However, when such a configuration for applying prestress is adopted, there is a new concern that the joint surface is damaged by the axial force F10 that generates prestress. Therefore, in the present embodiment, after adopting such a configuration that applies prestress, the joint surface of the inner core portion 52 with the nonmagnetic member 60 is tapered and the outer core portion 51 is nonmagnetic. The joint surface with the member 60 is tapered. These joint surfaces, that is, the inner tapered surface 52f and the outer tapered surface 51f are inclined in the same direction with respect to the annular center line C. Specifically, the nonmagnetic member is caused by the axial force F10 and the reaction force F20. It inclines in the direction which clamps 60.

  Therefore, when the fastening member 81 is screwed into the screw portion 10n to apply the pre-stress described above, all of the axial force F11 transmitted to the inner tapered surface 52f of the axial force F10 due to the screwing force becomes the inner tapered surface as a shearing force. Giving to 52f can be avoided. That is, the axial force F11 is dispersed in the compression component F11a and the shear component F11b, and the shear component F11b is reduced by the amount of the compression component F11a. Similarly, the reaction force F21 transmitted to the outer tapered surface 51f is dispersed into the compression component F21a and the shear component F21b, and the shear component F21b is reduced by the amount of the compression component F21a. Accordingly, since the shearing force applied to the inner tapered surface 52f and the outer tapered surface 51f can be reduced, it is possible to suppress the concern that the joint surface is damaged by the axial force F10 that generates prestress.

  Summarizing the above effects, the inner core portion 52 and the outer core portion 51 are provided in the portion of the fixed core 50 that faces the movable core 40, and the nonmagnetic member 60 is disposed between them, thereby providing both magnetic fluxes M1. , M2 can be used to improve the suction force. Further, the fastening member 81 for applying the axial force F10 and the main body portion 21 for applying the reaction force F20 are provided, and the fixed core 50 is elastically deformed by the axial force F10 and the reaction force F20 when not receiving the fuel pressure. . Therefore, in the state which received the fuel pressure, it can suppress with a prestress that a joint surface is damaged with an internal fuel pressure pushing-up force. Further, the inner tapered surface 52f and the outer tapered surface 51f are inclined in the same direction and in the direction in which the nonmagnetic member 60 is sandwiched by the axial force F10 and the reaction force F20. Therefore, since the shearing force applied to the inner tapered surface 52f and the outer tapered surface 51f can be reduced when the axial force F10 is applied to generate the prestress, it is possible to suppress the concern that the joint surface is damaged. Therefore, it is possible to achieve both improvement in attractive force and suppression of breakage of the joint surface between the fixed core 50 and the nonmagnetic member 60.

  Here, as described above, as described above, as the fuel pressure increases, the shearing force applied to the inner tapered surface 52f and the outer tapered surface 51f increases, and there is a concern that the joint surface may be damaged. In response to this concern, the strength of the joint surface can be increased by increasing the depths of the outer welded portion W10 and the inner welded portion W20.

  However, the deeper the welded part is, the thicker the welded part is. That is, the radial dimension of the outer welded portion W10 and the inner welded portion W20 is increased. In particular, the extension lengths of the weld extensions W11 and W21 are increased. As a result, the distance between the tip of the weld extension W11 of the outer weld W10 and the tip of the weld extension W21 of the inner weld W20 is shortened. If the tips of the weld extensions W11 and W21 contact each other, the inner core portion 52 and the outer core portion 51 are magnetically short-circuited with each other. In that case, the magnetic fluxes M1 and M2 pass directly between the inner core portion 52 and the outer core portion 51 without passing through the movable core 40, and the attractive force is reduced.

  In this embodiment, the groove 61 is formed in a portion between the inner welded portion W20 and the outer welded portion W10 in the welded surface 60b of the nonmagnetic member 60 in order to deal with such a magnetic short-circuit concern. Therefore, even if the welding depth is increased to increase the joint strength and the weld thickness dimension (thickness) is increased, the inner welded portion W20 and the outer welded portion W10 are in contact with each other to cause a magnetic short circuit. 61 is suppressed. Specifically, the groove 61 restricts the weld extensions W11 and W21 from extending in the direction along the weld surface 60b. Therefore, it is possible to realize both the improvement of the joining strength by increasing the welding depth and the suppression of the magnetic short circuit.

  Furthermore, in this embodiment, the following actions and effects are also exhibited.

  In the present embodiment, the inner welded portion W20 and the outer welded portion W10 are exposed from the wall surface of the groove 61. Specifically, the extending tips W12 and W22 are exposed from the side surfaces 61b and 61c of the groove 61. This means that the weld thickness dimension (thickness) is sufficiently large that the inner welded portion W20 and the outer welded portion W10 reach the groove 61, and the strength of the joint surface by the welded portion is not magnetically short-circuited. It's big enough.

  Here, in the welding depth direction, a shallow portion in the vicinity of the welding surface 60b in the welded portion is likely to expand in the radial direction of the nonmagnetic member 60 as compared to a deep portion separated from the welding surface 60b. Therefore, the effect of avoiding a magnetic short circuit is more easily exhibited in the groove positioned with respect to the shallow portion of the welded portion than in the groove positioned with respect to the deep portion of the welded portion. In this embodiment in view of this point, the depth of the groove 61 is set to be smaller than the depth of the inner welded portion W20 and the depth of the outer welded portion W10. Therefore, it is possible to reduce the strength of the nonmagnetic member 60 by reducing the depth of the groove 61 to the necessary minimum while sufficiently exhibiting the effect of avoiding the magnetic short circuit.

  Further, in the present embodiment, the inner welded portion W20 and the outer welded portion W10 are opposite to the movable core 40 in the direction of the annular center line C, rather than the fixed core suction surface that is the surface facing the movable core 40 of the fixed core 50. Located on the side. Specifically, the inner welded portion W20 and the outer welded portion W10 are provided on the end surface of the fixed core 50 on the side opposite to the injection hole. According to this, since it can avoid that a welding part is located on the same plane as a fixed core attraction | suction surface, the attraction | suction force fall resulting from presence of a welding part can be suppressed.

  In this embodiment, the axial force F10 is applied in the direction in which the inner core portion 52 is pressed toward the movable core 40, and the reaction force F20 is applied in the direction in which the outer core portion 51 is pressed toward the opposite side of the movable core 40. In this case, the outer applying portion is located on the outer peripheral side of the movable core 40. Then, it becomes difficult to sufficiently secure the radial dimension of the movable core 40, and there is a concern that it becomes difficult to secure a large suction surface facing the outer core portion 51 of the movable core 40. In this embodiment, in this embodiment, the inner tapered surface 52f and the outer tapered surface 51f are inclined in such a direction that the radial dimension becomes smaller as the movable core 40 is approached. Therefore, it becomes easy to ensure a large suction surface facing the outer core portion 51 in the movable core 40.

  Further, in the present embodiment, in the cross section including the annular center line C, the annular outer peripheral surface of the coil 70 is located on the radially outer side than the outer peripheral surface of the movable core 40. In this case, in order to increase the passage area of the magnetic flux M1 passing between the outer core portion 51 and the movable core 40, it is necessary to increase the area of the portion facing the outer facing surface 51c in the outer core portion 51. On the other hand, in the present embodiment, the inner tapered surface 52f and the outer tapered surface 51f are inclined in such a direction that the radial dimension becomes smaller as the movable core 40 is approached. The area of the opposing part can be increased.

  Further, in the present embodiment, in the cross section including the annular center line C, the inclination angle 51θ of the outer tapered surface 51f with respect to the annular center line C is set larger than the inclination angle 52θ of the inner tapered surface 52f with respect to the annular center line C. Yes. Therefore, since the area of the part facing the outer facing surface 51c in the outer core part 51 can be increased, the passage area of the magnetic flux M1 passing between the outer core part 51 and the movable core 40 can be easily ensured.

  Further, in the present embodiment, a stopper 54 is provided that is fixed to the inner core portion 52 and regulates the amount of movement of the valve body 30 in the valve opening direction by contacting the valve body 30, and the axial length of the inner core portion 52 is provided. Is set longer than the axial length of the outer core portion 51. Therefore, the bending rigidity of the inner core portion 52 with respect to the inner fuel pressure push-up force is increased by the amount that the axial length of the inner core portion 52 is longer than the axial length of the outer core portion 51. Therefore, the amount of deformation in the axial direction of the inner core portion 52 caused by the pre-stress can be reduced, and the amount of deformation in the axial direction of the inner core portion 52 caused by the inner fuel pressure pushing force is also reduced. Therefore, the positional accuracy of the stopper in the axial direction can be improved, and as a result, the accuracy of the gap G between the fixed core 50 and the movable core 40 in the valve open state can be improved.

  Further, in the present embodiment, the inner tapered surface 52f and the outer tapered surface 51f have a shape that extends annularly around the annular center line C. Therefore, compared with the case where a tapered surface is partially formed in the circumferential direction, the above-described effect that the shearing force applied to the inner tapered surface 52f and the outer tapered surface 51f can be reduced is further exhibited.

  Further, in the present embodiment, the inner tapered surface 52f and the outer tapered surface 51f are formed on the entire surface to be joined to the nonmagnetic member 60 in the cross section including the annular center line C. Therefore, compared with the case where a part of the joint surface is partially tapered in the cross section, the above-described effect that the shearing force applied to the inner tapered surface 52f and the outer tapered surface 51f can be reduced is further exhibited. become.

(Second Embodiment)
In the first embodiment, the inner welded portion W20 and the outer welded portion W10 are exposed from the wall surface of the groove 61. On the other hand, in the present embodiment shown in FIG. 6, the inner welded portion W20 and the outer welded portion W10 are not exposed from the wall surface of the groove 61, and the extended tips W12 and W22 do not reach the groove 61. Thus, even when the welded portion does not reach the groove 61, the effect of reducing the possibility of magnetic short-circuiting is achieved as compared with the case where the groove 61 is not formed.

(Third embodiment)
In the first embodiment, the inner welded portion W20 and the outer welded portion W10 are formed on the end surface of the nonmagnetic member 60 on the side opposite to the injection hole. In contrast, in the present embodiment shown in FIG. 7, the inner welded portion W20 and the outer welded portion W10 are formed on the end surface (welded surface) on the injection hole side of the nonmagnetic member 60.

  Also in the present embodiment, the inner welded portion W20 and the outer welded portion W10 are exposed from the wall surface of the groove 61 in the same manner as in the first embodiment. Further, the position of the bottom surface 61a of the groove 61 in the axial direction is located closer to the nozzle hole side than the position of the tip part W13 on the side opposite to the nozzle hole of the outer welded part W10 and the tip part W23 on the side opposite to the nozzle hole of the inner welded part W20. To do. That is, the depth of the groove 61 is set smaller than the depth of the inner welded portion W20 and the depth of the outer welded portion W10.

  As described above, the following effects of the groove 61 are also exhibited by this embodiment. That is, even if the weld depth is increased to increase the joint strength and the weld thickness is increased, the groove 61 suppresses contact between the inner welded portion W20 and the outer welded portion W10 and magnetic short circuit. . Therefore, it is possible to realize both the improvement of the joining strength by increasing the welding depth and the suppression of the magnetic short circuit.

(Fourth embodiment)
In the said 3rd Embodiment, the surface of the inner side welding part W20 and the outer side welding part W10 is located in the fixed core attraction | suction surface. On the other hand, in the present embodiment shown in FIG. 8, the inner welded portion W20 and the outer welded portion W10 are located on the opposite side of the movable core 40 in the axial direction relative to the fixed core suction surface, that is, on the side opposite to the injection hole. Yes.

  Specifically, by reducing the length of the nonmagnetic member 60 in the axial direction, the nozzle hole side end surface of the nonmagnetic member 60 is jetted against the fixed core suction surface by the inner facing surface 52a and the outer facing surface 51c. It is located on the hole side. Thereby, although a welding part is formed in the nozzle hole side end surface of the nonmagnetic member 60, a welding part should be located in the other side (counter nozzle hole side) of the movable core 40 in an axial direction with respect to a fixed core attraction | suction surface. It becomes.

  As described above, according to the present embodiment, the welded portion is formed on the nozzle hole side end surface of the nonmagnetic member 60, but on the opposite side of the movable core 40 in the direction of the annular center line C from the fixed core suction surface. To position. Therefore, since it can avoid that a welding part is located on the same plane as a fixed core attraction | suction surface, the attraction force fall resulting from presence of a welding part, forming a welding part in the nozzle hole side end surface of the nonmagnetic member 60 Can be suppressed.

  In addition, according to the present embodiment, since the welded portion is formed on the nozzle hole side end surface of the nonmagnetic member 60, the joint surface between the inner core portion 52 and the nonmagnetic member 60, and the outer core portion 51 and the nonmagnetic member. It is possible to suppress the fuel from entering the joint surface with the member 60. Therefore, it is possible to suppress damage to the joint surface between the inner core portion 52 and the nonmagnetic member 60 and the joint surface between the outer core portion 51 and the nonmagnetic member 60.

(Fifth embodiment)
In the first embodiment, the depth of the groove 61 is set smaller than the depth of the inner welded portion W20 and the depth of the outer welded portion W10. On the other hand, in the present embodiment shown in FIG. 9, the depth of the groove 61 is set larger than the depth of the inner welded portion W20 and the depth of the outer welded portion W10. According to this, the certainty of preventing contact between the inner welded portion W20 and the outer welded portion W10 can be improved, and the certainty of preventing magnetic short circuit can be improved.

(Sixth embodiment)
In the said 1st Embodiment, the cross-sectional shape of the groove | channel 61 is a rectangle. On the other hand, in this embodiment shown in FIG. 10, the cross-sectional shape of the groove 61 is a shape combining two squares, and the width dimension, that is, the dimension in the left-right direction in FIG. 10 decreases as the distance from the welding surface 60b increases. I have to. Thus, also by this embodiment which made the cross-sectional shape of the groove | channel 61 the stepped square shape, the effect similar to the said 1st Embodiment is exhibited.

(Seventh embodiment)
In the said 6th Embodiment, the cross-sectional shape of the groove | channel 61 is made into the square with a step. On the other hand, in this embodiment shown in FIG. 11, the cross-sectional shape of the groove 61 is triangular. Also in this embodiment, the same effect as the first embodiment is exhibited. Note that the cross-sectional shape of the groove 61 in the present invention is not limited to a rectangle as in the first embodiment, a stepped rectangle as in the sixth embodiment, and a triangle as in the present embodiment.

(Eighth embodiment)
In the first embodiment, the inner tapered surface 52f and the outer tapered surface 51f that are inclined in the same direction are inclined in such a direction that the radial dimension becomes smaller as they approach the nozzle hole side in the axial direction (see FIG. 1). In this embodiment, the direction of the inclination is reversed (see FIG. 12). The technical significance will be described below.

  In the first embodiment, the force of the fuel pressure applied to the fixed core 50 is received by the prestress by the axial force F10 and the fastening member 81. In order to prevent the joint surface from being damaged by the axial force F11, a part of the axial force F11 is dispersed as a compression component on both tapered surfaces to reduce the shear component applied to the joint surface. In order to act in this way, both tapered surfaces are inclined so that the radial dimension becomes smaller as the nozzle hole side is approached.

  On the other hand, in this embodiment, in order to prevent the joint surface from being damaged by the force of the fuel pressure applied to the fixed core 50, a part of the axial force is dispersed as a compression component on both tapered surfaces, and the shear component applied to the joint surface. Is reduced. In order to act in this way, both tapered surfaces are inclined in a direction opposite to that in FIG. 1, that is, in a direction in which the radial dimension becomes smaller toward the nozzle hole side (see FIG. 9).

  Moreover, in the said 1st Embodiment, the axial force F10 is produced by screwing the fastening member 81 in the case 10, and the nonmagnetic member 60 is pinched | interposed between both taper surfaces with the axial force F10. On the other hand, in this embodiment, the fastening member 81 and the case 10 are abolished, the fastening member 810 is fastened to the nozzle body 20, and the nonmagnetic member 60 is sandwiched between both tapered surfaces by the axial force.

  Specifically, the fastening member 810 has a cylindrical shape, and is fastened by fastening a screw portion 810n formed on the inner peripheral surface of the fastening member 810 to a screw portion 21n formed on the outer peripheral surface of the main body portion 21. The member 810 is fastened to the nozzle body 20. A pressing surface 510c with which the fastening member 810 abuts is formed on the surface of the outer core portion 510 on the side opposite to the injection hole. The pressing surface 510c is located on the outer side in the radial direction from the lid portion 53, and is formed in an annular shape that extends perpendicular to the axial direction.

  When the fuel injection valve is not in use, the axial force generated by screwing the fastening member 810 acts on the pressing surface 510c. A reaction force against the axial force acts on the outer core portion 510 from the upper end surface 21 b of the main body portion 21. Accordingly, the outer core portion 510 is sandwiched between the main body portion 21 and the fastening member 810 and is restricted from moving toward the anti-injection hole in the axial direction.

  In the use state of the fuel injection valve, a reaction force against the inner fuel pressure push-up force acts on the pressing surface 510c from the fastening member 810. That is, the inner fuel pressure pushing force is transmitted to the fastening member 810 through the inner tapered surface 520f, the nonmagnetic member 60, the outer tapered surface 510f, and the pressing surface 510c. The force transmitted to the inner taper surface 520f of the inner fuel pressure push-up force is divided into a compression component perpendicular to the inner taper surface 520f and a shear component parallel to the inner taper surface 520f. Of the reaction force applied from the fastening member 810 to the inner fuel pressure pushing force, the force transmitted to the outer tapered surface 510f is a compression component perpendicular to the outer tapered surface 510f and parallel to the outer tapered surface 510f. Divided into shear components.

  In the present embodiment, of the inner core portion 520 and the outer core portion 51, the core portion having a large pressure receiving surface that receives fuel pressure from the movable core 40 side is the inner core portion 520, and the inner core portion 520 is the large pressure receiving core. The outer core portion 510 corresponds to a small pressure receiving core portion. The fastening member 810 corresponds to an outer applying portion that applies a reaction force to the force (inner fuel pressure push-up force) received by the large pressure receiving core portion from the pressure receiving surface to the small pressure receiving core portion.

  The inner tapered surface 520f and the outer tapered surface 510f are inclined in a direction to sandwich the nonmagnetic member 60 by a force (inner fuel pressure pushing force) received by the large pressure receiving core portion from the pressure receiving surface and a reaction force from the fastening member 810. ing. Specifically, both tapered surfaces are inclined in such a direction that the radial dimension becomes smaller as it approaches the nozzle hole side.

  As described above, in the present embodiment, the joint surface of the inner core portion 52 with the nonmagnetic member 60 is tapered, and the joint surface of the outer core portion 51 with the nonmagnetic member 60 is tapered. These joint surfaces, that is, the inner tapered surface 520f and the outer tapered surface 510f are inclined in the same direction with respect to the annular center line C. Specifically, the inner fuel pressure push-up force and the reaction force from the fastening member 810 are inclined. The nonmagnetic member 60 is tilted in a direction to sandwich the nonmagnetic member 60 by force.

  Therefore, it can be avoided that all of the pushing force transmitted to the inner tapered surface 520f of the inner fuel pressure pushing force is applied to the inner tapered surface 520f as a shearing force. That is, the lifting force is dispersed in the compression component and the shear component, and the shear component is reduced by the amount of the compression component. Similarly, the reaction force transmitted to the outer tapered surface 510f is dispersed into the compression component and the shear component, and the shear component is reduced by the amount of the compression component. Therefore, since the shear force applied to the inner tapered surface 520f and the outer tapered surface 510f can be reduced, it is possible to suppress the concern that the joint surface is damaged by the inner fuel pressure pushing force.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made as illustrated below. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

  In the said embodiment, although the hollow formed in the part between the inner side welding part W20 and the outer side welding part W10 among the welding surfaces 60b is made into the groove | channel 61, the said hollow is not restricted to the shape of the groove | channel 61, For example, the recess may be a recess. If a space can be formed between the inner welded portion W20 and the outer welded portion W10, it can be appropriately changed as a depression.

  Moreover, the said dent and the groove | channel 61 may be provided in the perimeter of the welding surface 60b, and may be provided partially. If it is provided on the entire circumference, it is possible to more reliably prevent the inner welded portion W20 and the outer welded portion W10 from coming into contact with each other.

  In each of the above embodiments, the inside of the groove 61 is a space, but a member such as a resin may be filled in the groove 61. However, the member to be filled needs to be a nonmagnetic member.

  In each said embodiment, although the outer side weld part W10, the inner side weld part W20, and the groove | channel 61 are formed in any one of the injection hole side end surface of the nonmagnetic member 60, and a counter injection hole side end surface, an injection hole side end surface Further, it may be formed on both of the end surfaces on the side opposite to the injection holes.

  In the first embodiment, the outer tapered surface 51f and the inner tapered surface 52f are formed on the entire surface joined to the nonmagnetic member 60 in the cross section including the annular center line C. On the other hand, at least one of the outer tapered surface 51f and the inner tapered surface 52f may be formed on a part of the surface joined to the nonmagnetic member 60 in the cross section including the annular center line C.

  In the first embodiment, the joint surface between the fixed core 50 and the nonmagnetic member 60 is formed in a tapered shape in the cross section including the annular center line C. On the other hand, you may form the said joint surface in the level | step difference shape demonstrated below. That is, an inner vertical surface that extends perpendicularly to the axial direction in the cross section including the annular center line C is formed on at least a part of the inner core portion 52 that is joined to the nonmagnetic member 60. In addition, an outer vertical surface that extends perpendicularly to the axial direction in a cross section including the annular center line C is formed on at least a part of the surface of the outer core portion 51 that is joined to the nonmagnetic member 60.

  Moreover, while forming the joint surface of one core part in the outer core part 51 and the inner core part 52 in a step shape, the joint surface of the other core part is formed in the same tapered shape as in the first embodiment. May be.

  In each of the above embodiments, in the cross section including the annular center line C, the annular outer peripheral surface of the coil 70 is located on the radially outer side than the outer peripheral surface of the movable core 40. On the other hand, the annular outer peripheral surface of the coil 70 may have the same radial position as the outer peripheral surface of the movable core 40, or may be positioned radially inward.

  In the eighth embodiment shown in FIG. 12, of the inner core portion 520 and the outer core portion 51, the core portion having a large pressure receiving surface that receives fuel pressure from the movable core 40 side is the inner core portion 520, that is, the large pressure receiving core portion. It is. On the other hand, the outer core portion 51 may have a larger pressure receiving surface than the inner core portion 520, and the outer core portion 51 may be a large pressure receiving core portion. In this case, it is necessary to reverse the direction in which the outer tapered surface 510f and the inner tapered surface 520f are inclined to the direction shown in FIG. Further, it is necessary to apply a reaction force against the force (outer fuel pressure push-up force) received by the outer core portion 51 that is the large pressure receiving core portion from the pressure receiving surface to the inner core portion 520 that is the small pressure receiving core portion by the fastening member 810 or the like. .

  In the first embodiment shown in FIG. 1, the fastening member 81 corresponding to the inner imparting portion imparts an axial force F10 in a direction in which the inner core portion 52 is pressed against the nozzle hole side, and the main body portion 21 corresponding to the outer imparting portion is provided. In this structure, the reaction force F20 is applied in the direction in which the outer core portion 51 is pressed toward the counter-injection hole. On the other hand, the inner imparting portion imparts an axial force F10 in a direction in which the inner core portion 52 is pressed against the nozzle hole side, and the outer imparting portion applies a reaction force F20 in a direction in which the outer core portion 51 is pressed against the counter nozzle hole side. The structure to provide may be sufficient. In this case, it is necessary to make the directions of inclination of the outer tapered surface 51f and the inner tapered surface 52f opposite to those in FIG.

  In the embodiment shown in FIGS. 5, 6, 7, and 12, the joint surface between the outer core portion 51 and the nonmagnetic member 60 and the joint surface between the inner core portion 52 and the nonmagnetic member 60 are inclined with respect to the axial direction. I am letting. On the other hand, you may form the said joint surface in parallel with respect to an axial direction like embodiment shown to FIG.

  DESCRIPTION OF SYMBOLS 30 ... Valve body, 40 ... Movable core, 50 ... Fixed core, 51 ... Outer core part, 52 ... Inner core part, 60 ... Nonmagnetic member, 60b ... Welding surface, 61 ... Groove (dent), 70 ... Coil, C ... annular center line, W10 ... outer weld, W20 ... inner weld.

Claims (6)

A fuel injection valve for injecting fuel from an injection hole (23a),
An annularly arranged coil (70);
A fixed core (50) that forms a magnetic field when energized to the coil;
In the direction of the annular center line (C) of the coil, it is provided closer to the nozzle hole than the fixed core. When the coil is energized, a magnetic field is formed between the coil and the fixed core. A movable core (40),
A valve body (30) driven by the movable core to be sucked to open and close the nozzle hole;
An inner core portion (52) which is a part of the fixed core facing the movable core;
Outer core part (51) which is a part facing the movable core among the fixed cores and is located outside the inner core part with respect to the annular center line;
A non-magnetic member (60) disposed between the inner core portion and the outer core portion and having weaker magnetism than the fixed core;
An inner welded portion (W20) provided on at least one of the inner core portion and the nonmagnetic member on the side of the movable core and the opposite side of the movable core of the nonmagnetic member; ,
An outer welded portion (W10) provided on a welded surface (60b) on the same side as the inner welded portion of the nonmagnetic member, the welded portion of the outer core portion and the nonmagnetic member;
With
The fuel injection valve in which the hollow (61) is formed in the part between the said inner side welding part and the said outer side welding part among the said welding surfaces.   The fuel injection valve according to claim 1, wherein at least one of the inner welded portion and the outer welded portion is exposed from the wall surface (61a, 61b, 61c) of the recess. A welding depth dimension from the welding surface of the inner welding portion is defined as an inner welding depth, a welding depth dimension from the welding surface of the outer welding portion is defined as an outer welding depth, and the bottom surface of the recess from the welding surface. When the dimension up to (61a) is the recess depth,
The fuel injection valve according to claim 1 or 2, wherein the recess depth is smaller than the inner welding depth and the outer welding depth.   At least one of the inner welded portion and the outer welded portion is more movable in the direction of the annular center line than the fixed core suction surface (52a, 51c) that is a surface of the fixed core that faces the movable core. The fuel injection valve according to claim 1, wherein the fuel injection valve is located on the opposite side of the fuel injection valve. An inner tapered surface (52f), which is a surface that is inclined with respect to the annular center line in a cross section including the annular center line, is formed on at least a part of the surface of the inner core portion that is joined to the nonmagnetic member. Formed,
An outer tapered surface (51f), which is a surface that is inclined with respect to the annular center line in a cross section including the annular center line, is formed on at least a part of the surface of the outer core portion that is joined to the nonmagnetic member. Formed,
The fuel injection valve according to any one of claims 1 to 4, wherein the inner tapered surface and the outer tapered surface are inclined in the same direction with respect to the annular center line. A stopper (54) that is fixed to the inner core portion and regulates the amount of movement of the valve body in the valve opening direction by contacting the valve body;
6. The fuel injection valve according to claim 1, wherein a length of the inner core portion in a direction in which the annular center line extends is longer than a length of the outer core portion in a direction in which the annular center line extends. .

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