JP2011094632A - Solenoid fuel injection valve and method for assembling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the stroke adjustment of the needle of a fuel injection valve. <P>SOLUTION: The maximum outer diameter of the needle arranged between a fixed core and a fuel injection port and having a valve element at the front end for opening/closing the fuel injection port is set smaller than the minimum inner diameter of a through-hole provided at the center of the fixed core. The needle is driven depending on the movement of the movable core as part of a solenoid drive mechanism, but both can be moved independently. The fuel injection port is provided at the front end of a small-diameter cylindrical portion of a metallic cylindrical container. After the fixed core is fixed to the inner periphery of a large-diameter cylindrical portion, the needle having the valve element at the front end for opening/closing the fuel injection port is mounted through the through-hole of the fixed core. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetically driven fuel injection valve for an internal combustion engine and an assembling method thereof, and in particular, a fixed core and a mover are arranged in a metallic cylindrical container, and the mover is driven by an electromagnetic drive device. The present invention relates to an electromagnetic fuel injection valve for opening and closing a fuel injection port provided at the tip of the metallic cylindrical container with a valve body provided at the tip of the metal material, and an assembling method thereof.

  This type of electromagnetic fuel injection valve includes a cylindrical container made of a metal material with a fuel injection port attached to the tip side. A fixed core having a through hole serving as a fuel introduction passage at the center is attached to the inner peripheral portion on the rear end side of the metallic cylindrical container. A mover is disposed between the fixed core and the fuel injection port. The mover includes a plunger, and includes a movable core provided at the end of the plunger on the fixed core side so as to face the end surface of the fixed core. Further, a valve body for opening and closing the fuel injection port is provided at the other end of the plunger. A cylindrical electromagnetic coil device is attached to the outer periphery of the metallic cylindrical container, and a magnetic path passing through the fixed core and the movable core is formed around the electromagnetic coil device. A metallic cylindrical container that is long in the axial direction is provided with a fixed core after the mover is incorporated, and then a spring that biases the mover in a direction in which the valve body of the mover closes the fuel injection port and its spring A regulator for adjusting the biasing force of the spring is disposed in this order in the fuel introduction passage of the fixed core.

Japanese Patent No. 3734702

  In the conventional electromagnetic fuel injection valve and its assembling method, the mover is first assembled in the metallic cylindrical container, and then the fixed core is fixed to the inner peripheral portion of the opening end of the metallic cylindrical container. For this reason, there has been a problem that the stroke of the mover is difficult to adjust. An object of the present invention is to provide an electromagnetic fuel injection valve in which the stroke of a mover can be easily adjusted, and an assembling method thereof.

  The above object of the present invention is to provide a minimum inner diameter of a through-hole provided between the fixed core and the fuel injection port, and having a maximum outer diameter of a mover having a valve body at the tip for opening and closing the fuel injection port at the center of the fixed core. This is achieved by making it smaller. Further, after fixing the fixed core to the inner periphery of the rear end of the metallic cylindrical container having the fuel injection port at the tip, the mover having a valve body for opening and closing the fuel injection port at the tip is passed through the through hole of the fixed core. Achieved by wearing.

  In the present invention configured as described above, since the mover is incorporated after the fixed core is fixed, it is easy to adjust the stroke of the mover.

It is a longitudinal cross-sectional view of the electromagnetic fuel injection valve of a 1st Example. It is a partial expanded sectional view of the electromagnetic fuel injection valve of a 1st Example. It is a partial expanded sectional view of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is drawing for demonstrating the assembly of the electromagnetic fuel injection valve of a 1st Example. It is a longitudinal cross-sectional view of the electromagnetic fuel injection valve of 2nd Example. It is a longitudinal cross-sectional view of the electromagnetic fuel injection valve of a 1st Example.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  In this embodiment, the present invention is applied to a fuel injection valve having an electromagnetic coil used for an internal combustion engine.

  By energizing and deactivating the electromagnetic coil, the movable core is attracted to the fixed core or separated from the fixed core. The mover provided with a valve element at the tip is reciprocated by the movement of the movable core at this time.

  The reciprocating motion of the mover opens and closes the fuel injection port provided at the tip of the nozzle portion, and fuel is injected from the injection port.

  Specifically, the present invention relates to an electromagnetic fuel injection valve of a type that has a long dimension from a fuel introduction port at one end to a fuel injection port at the other end, and as a result, has a long mover length, that is, a so-called long type electromagnetic fuel injection valve. Has been implemented.

  FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve according to an embodiment. 2 and 3 are partial enlarged views of FIG. 1 for explaining the operating state of the electromagnetic fuel injection valve of the embodiment, FIG. 2 is a drawing showing a valve opening state, and FIG. 3 shows a valve closing state. It is a drawing.

  Hereinafter, the overall configuration of the electromagnetic fuel injection valve according to the embodiment will be described with reference to FIGS. 1 to 3.

  The metallic cylindrical container 20 includes a small-diameter cylindrical portion 21 having a small diameter and a large-diameter cylindrical portion 23 having a large diameter, and the two are connected by a conical cross section 22.

  A nozzle body 30 is formed at the tip of the small diameter cylindrical portion 21.

  A guide member 35 and an orifice plate 36 are stacked and inserted in this order into the cylindrical portion 31 formed at the other end of the nozzle body 30 and fixed to the cylindrical portion 31 by welding around the orifice plate 36. .

  The guide member 35 guides the outer periphery of the plunger 11 or the valve body 12 of the mover 10 to be described later, and also serves as a fuel guide for guiding the fuel from the radially outer side to the inner side as indicated by an arrow F in the figure. The orifice plate has a plurality of fuel injection ports 37 that are inclined with respect to the central axis of the plunger. The plurality of through holes are formed of stepped holes having different diameters, the inlet side (valve element side) having a small diameter and the outlet side having a large diameter.

  A conical valve seat 39 is formed on the orifice plate 36 on the side facing the guide member 35. A valve body 12 provided at the distal end of a plunger 11 described later contacts this valve seat 39 to guide or block the fuel flow indicated by the arrow F to the fuel injection port 37.

The thickness T ₁ of the nozzle body 30 is formed to be thicker than the other thicknesses T _{2 to} T ₄ of the metal cylindrical container 20. The reason is that a groove 32 is formed on the outer periphery, and a seal member 32A represented by a resin-made chip seal or a gasket in which rubber is baked around a metal is fitted into the groove 32.

  An annular small protrusion 32B is provided at the center of the groove 32, whereby the movement of the seal member 32A in the thrust direction is restricted, and the fuel injection valve is mounted in the mounting hole of the cylinder head or cylinder block of the engine. It plays the function of preventing the coming off.

  The outer diameter of the seal portion after mounting the seal member 32A is larger than the outer diameter of the nozzle body 30. For this reason, the seal member 32A comes into pressure contact with the inner wall of the mounting hole of the cylinder head or cylinder block. Thus, the function of the seal is achieved in the state where the high pressure of the combustion chamber acts.

  On the other hand, the outer diameter of the nozzle body 30 and the outer diameter of the small-diameter cylindrical portion 21 of the metallic cylindrical container 20 are configured to be slightly smaller than the diameter of the mounting hole of the cylinder head or cylinder block, and the gap is fitted. Attach to the mounting hole.

  The inner diameter of the nozzle body 30 is maintained at a uniform small diameter up to the beginning of the cylindrical portion 31, and a fuel passage having a uniform cross-sectional area is formed on the outer periphery of the plunger 11 of the mover 10.

  The inner diameter of the nozzle body 30 increases at the cylindrical portion 31 to form an insertion portion for the guide member 35 and the orifice plate 36.

The outer diameter of the cylindrical portion 31 of the nozzle body 30 is uniform up to the tip, and the wall thickness T ₄ is formed thinner than the other portions T _{1 to} T _3. A cylindrical portion to which the plate 36 is attached is formed.

  A plunger guide 11A for guiding the plunger 11 of the mover 10 is press-fitted and fixed to the drawing portion 25 of the large-diameter cylindrical portion 23 at the lower end of the inner periphery of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20. Yes.

  The plunger guide 11A is provided with a guide hole 11B for guiding the plunger 11 in the center, and a plurality of fuel passages 11C are perforated around the guide hole 11B.

  Further, a recess 11D is formed on the upper surface of the center by extrusion. A spring described later is held in the recess 11D.

  A protrusion corresponding to the recess 11D is formed by extrusion on the lower center surface of the plunger guide 11A, and a guide hole 11B of the plunger 11 is provided at the center of the protrusion.

  Thus, the elongated plunger 11 is guided to reciprocate straight by the guide hole 11B of the plunger guide 11A and the guide hole of the guide member 35.

  Thus, since the metallic cylindrical container 20 is integrally formed of the same member from the front end portion to the rear end portion, the parts can be easily managed and the assembly workability is good.

  The mover 10 includes an elongated plunger 11. A valve body 12 is fixed to one end of the plunger 11 by welding. A concave portion is formed at the distal end portion of the plunger, and a part of the outer periphery of the ball valve is fitted into the concave portion and welded at the contact portion between the two.

  A cylindrical head portion 13 having an outer diameter larger than the diameter of the plunger 11 is press-fitted to the other end, and welded 13A at the outer peripheral portion of the press-fitting portion.

  This welded portion may weld the contact portion of the upper end surface of the plunger 11 with the head portion 13 in an annular shape. In this case, it is necessary to prevent the seating surface of the first spring 52 described later from becoming uneven due to the welded portion, or to make the inner diameter of the spring larger than the diameter of the welded portion.

  Moreover, you may weld a contact part with the plunger 11 of the lower end surface inner peripheral part of the head 13 cyclically | annularly. In this case, an annular recess is provided in the inner periphery of the head 13 or the outer periphery of the plunger 11 so as to prevent the upper end surface of the movable core 15 and the welded portion from being buffered, and the recess is recessed in the annular recess. So that the contact portion between the two is formed, and welding is performed in the recess of the annular recess, or an annular recess that accommodates the unevenness of the annular weld is provided on the inner peripheral portion of the upper end surface of the movable core 15. good.

  The mover 10 has a movable core 15 having a through hole 14 through which the plunger 11 passes in the center. The movable core 15 has a spring receiving recess 15A at the center of the surface facing the plunger guide 11A, and the spring 16 is held between the recess 11D of the plunger guide 11A and the recess 15A.

  Since the diameter of the through hole 14 is smaller than the diameter of the cylindrical head portion 13, the biasing force of the spring 52 (first spring) that presses the plunger 11 toward the valve seat 39 of the orifice plate 36 or the action of gravity. Below, the inner peripheral lower end surface of the head 13 of the plunger 11 is in contact with and engaged with the upper end surface of the movable core 15 held by the spring 16 (second spring).

  Thus, both of the upward movement of the movable core 15 against the urging force or gravity of the spring 52 (first spring) or the downward movement of the plunger 11 along the urging force of the spring 52 or gravity are both. They will work together to work together.

  However, when the force for moving the plunger 11 upward or the force for moving the movable core 15 downward independently of each other regardless of the biasing force of the spring 52 or gravity, the two move independently in both directions. And

  At this time, the fluid film existing in the minute gap of 5 to 15 microns between the outer peripheral surface of the plunger 11 and the inner peripheral surface of the movable core 15 in the through-hole 14 portion moves in a different direction. This causes friction and suppresses both movements. In other words, the brake is applied to the rapid displacement of both. Shows little resistance to slow movements. Thus, such momentary movement in the opposite direction of both is attenuated in a short time.

  The effect based on this phenomenon will be described later.

  Here, the movable core 15 is not formed between the inner peripheral surface of the large-diameter cylindrical portion 23 and the outer peripheral surface of the movable core 15 but by the inner peripheral surface of the through hole 14 of the movable core 15 and the outer peripheral surface of the plunger 11. The center position is maintained. The outer peripheral surface of the plunger 11 functions as a guide when the movable core 15 independently moves in the axial direction.

  The lower end surface of the movable core 15 faces the upper end surface of the plunger guide 11A, but the spring 16 is interposed so that they do not contact each other.

  Although the plunger 11 of the mover 10 is entirely made of solid metal, a fuel passage hole 17 is formed at the center from the upper end where the cylindrical head 13 is fixed to the plunger guide 11A. Perforated and communicated with the fuel passage 15 </ b> B on the outer periphery of the plunger 11 through a plurality of radial lateral holes 17 </ b> A provided at the position of the recess 15 </ b> A for the spring 16 of the movable core 15.

  A minute gap gA is provided between the outer peripheral surface of the movable core 15 and the inner peripheral surface of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20. The minute gap gA is formed between the outer peripheral surface of the plunger 11 and the inner peripheral surface of the movable core 15 in the portion of the through hole 14 in order to allow the movement of the movable core 15 in the axial direction. For example, it is about 0.1 millimeter larger than the minute gap. If the magnetic resistance is too large, the magnetic resistance becomes large, so this gap is determined in consideration of the magnetic resistance.

  A fixed core 50 is press-fitted into the inner peripheral portion of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20 and is welded 51A at the press-fit contact position. The inside of the large-diameter cylindrical portion 23 of the metal-made cylindrical container 20 passes between the inner surface of the large-diameter cylindrical portion 23 of the metal-made cylindrical container 20 and the outer peripheral surface of the fixed core 50 by this welding joint. A fuel leak gap formed between the air and the outside air is sealed.

  An annular flange 58 is formed on the outer periphery of the fixed core 50, and the upper end surface of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20 abuts on the lower end surface of the flange 58, so that both are positioned. Is done.

  The AA surface on which the upper end surface of the flange portion 58 (the shoulder portion 55 of the fixed core 50) and the upper end surface of the annular yoke are held so as to be in the same plane, and the contact portion 44 between the annular yoke 42 and the fixed core 50 is retained. Are welded in an annular shape.

  The fixed core 50 has a through hole 51 having a diameter slightly larger than the diameter of the head 13 of the plunger 11 at the center.

  A cylindrical head portion 13 of the plunger 11 is inserted in a non-contact state into the inner periphery of the lower end portion of the through hole 51 of the fixed core 50. The gap between the inner peripheral surface of the through-hole 51 of the fixed core 50 and the outer periphery of the head 13 of the mover 10 is provided with a gap similar to the above-described minute gap gA. This is to prevent extra resistance from being applied to the reciprocating motion of the mover 10.

  One end of an initial load setting spring 52 (second spring) is in contact with the upper end surface of the head portion 13 of the plunger 11, and the other end is received by a regulator 54 press-fitted into the upper end portion of the through hole 51. Thus, it is fixed between the cylindrical head 13 and the adjuster 54.

  By adjusting the fixing position of the adjuster 54, the initial load by which the spring 52 presses the plunger 11 against the valve seat 39 can be adjusted.

  2 and 3, with the initial load of the initial load setting spring 52 adjusted, the lower end surface of the fixed core 50 is about 20 to 100 microns with respect to the upper end surface of the movable core 15 of the mover 10. It is configured to face each other with a magnetic gap Ga (exaggerated in the drawing).

  The outer diameter of the movable core 15 and the outer diameter of the fixed core 50 are only small (about 0.1 millimeter), and the outer diameter of the movable core 15 is small. On the other hand, the inner diameter of the through hole 14 located at the center of the movable core 15 is slightly larger than the outer diameters of the plunger 11 and the valve body 12 of the movable element 10. Further, the inner diameter of the through hole 51 of the stator core 50 is slightly larger than the outer diameter of the cylindrical head 13. The outer diameter of the head 13 is larger than the inner diameter of the through hole 14 of the movable core 15.

  As a result, the radial width of the annular end surface of the movable core 15 facing the magnetic gap Ga is larger than the radial width of the annular end surface of the fixed core 50. As a result, while securing a sufficient magnetic path area in the magnetic gap Ga, an axial engagement margin between the lower end surface of the head 13 of the mover 10 and the upper end surface of the movable core 15 of the mover 10 is secured. Yes.

  A groove 13 </ b> B is provided on the outer peripheral surface of the plunger 11 facing the edge portion at the upper end of the inner periphery of the movable core 15. This groove 13B is designed so that the two do not come into contact with each other even if the edge of the inner peripheral upper end of the movable core 15 has irregularities caused by burrs or the like at the time of processing so as not to adversely affect the relative movement of the two. It is for making.

  Returning to FIG. 1, the portion projecting upward from the shoulder portion 55 of the fixed core 50 does not need a function as a magnetic path, and thus the thickness in the radial direction is reduced. A flange portion 56 is formed at an intermediate position between the shoulder portion 55 and the tip of the portion protruding from the shoulder portion 55, and an annular groove 57 is formed between the shoulder portion 55 and the flange portion 56.

  The thickness in the radial direction is further reduced beyond the flange portion 56. The inner peripheral surface of the lower end of the fuel introduction pipe 61 is press-fitted outside the portion where the thickness is reduced, and is welded to the fixed core 50 at the outer periphery 61A of the lower end of the fuel introduction pipe 61.

  On the other hand, a fuel filter 62 is mounted on the inner periphery of the upper end of the fuel introduction pipe 61, and an O-ring 63 is mounted on the outer periphery.

  A cup-shaped yoke 41 and an annular yoke 42 provided so as to close the opening on the open side of the cup-shaped yoke are fixed to the outer periphery of the large-diameter tubular portion 23 of the metallic container 20.

  A through hole 41A is provided at the center of the bottom of the cup-shaped yoke 41, and the large-diameter cylindrical portion 23 of the metallic cylindrical container 20 is inserted into the through hole 41A.

  A portion of the peripheral wall of the cup-shaped yoke 41 faces the outer peripheral surface of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20.

  The outer periphery of the flange portion 58 of the metallic cylindrical container 20 and the inner diameter of the annular yoke 42 are formed to be substantially the same diameter, and the inner periphery of the annular yoke 42 is press-fitted into the outer periphery of the flange portion 58, and is the contact surface of the upper end surface. It is welded in an annular shape.

  The outer diameter of the annular yoke 42 and the outer diameter of the cup-shaped yoke 41 are formed to have substantially the same diameter.

  The cup-shaped yoke 41 is positioned with the upper end surface of the cup-shaped yoke 41 in contact with the lower end surface of the annular yoke 42.

  A cylindrical electromagnetic coil 43 is disposed in a cylindrical space formed by the cup-shaped yoke 41 and the annular yoke 42.

  The electromagnetic coil 43 is composed of an annular coil bobbin 43A having a U-shaped groove that opens outward in the radial direction, and an annular coil 43B formed of a copper wire wound in the groove. Yes.

  The electromagnetic coil device 40 includes an electromagnetic coil 43, a cup-shaped yoke 41 and an annular yoke 42.

  The cup-shaped yoke 41 is fixed to the annular yoke 42 by welding in an annular manner along the joint surface 45 between the upper peripheral edge of the cup-shaped yoke 41 and the lower peripheral edge of the annular yoke 42.

  Further, the cup-shaped yoke 41 is welded in a ring shape along the joint surface 46 between the inner peripheral edge of the lower end of the cup-shaped yoke 41 and the outer peripheral surface of the large-diameter cylindrical portion 23, so that the cup-shaped yoke 41 has a large diameter of the metallic cylindrical container 20. It is fixed to the outer peripheral part of the cylindrical part 23.

  Thus, a toroidal magnetic path BH indicated by the arrow BH is formed around the electromagnetic coil 43.

  A rigid conductor 43C is fixed at the winding start and winding end of the electromagnetic coil 43, and the conductor 43C is drawn out from a through hole provided in the annular yoke.

  The conductor 43C, the fuel introduction pipe 61, the groove 57 of the fixed core 50, the flange portion 56, and the reference plane AA are molded with resin and covered with a resin molded body 71.

  A plug for supplying power from a battery power source is connected to the connector 71 formed at the tip of the conductor 43C, and energization / non-energization is controlled by a controller (not shown).

  As shown in FIG. 2, while the electromagnetic coil 43 is energized, a magnetic attractive force is generated between the movable core 15 and the fixed core 50 of the mover 10 in the magnetic gap Ga by the magnetic flux passing through the magnetic circuit BH. Is moved upward by being attracted with a force exceeding the set load of the spring 52. At this time, the movable core 15 engages with the head portion 13 of the plunger, moves upward together with the plunger 11, and moves until the upper end surface of the movable core 15 collides with the lower end surface of the fixed core 50.

  As a result, the valve body 12 at the tip of the plunger 11 is separated from the valve seat 39, and the fuel passes through the fuel passage F and is ejected from the plurality of injection ports 37 into the combustion chamber.

  When the energization to the electromagnetic coil 43 is cut off, the magnetic flux in the magnetic circuit BH disappears, and the magnetic attractive force in the magnetic gap Ga also disappears.

  In this state, the spring force of the initial load setting spring 52 that pushes the cylindrical head 13 of the plunger 11 in the opposite direction overcomes the force of the spring 16 and acts on the mover 10.

  As a result, the mover 10 that has lost the magnetic attractive force is pushed back to the closed position where the valve 12 contacts the valve seat 39 by the spring force of the initial load setting spring 52.

  At this time, the cylindrical head 13 is engaged with the movable core 15 and the movable core 15 overcomes the force of the spring 16 and moves toward the plunger guide 11A.

  When the valve 12 collides with the valve seat 39 vigorously, the plunger 11 rebounds in the direction in which the initial load setting spring 52 is compressed.

  However, since the movable core 15 is separate from the plunger 11, the plunger 11 tends to move away from the movable core 15 in the direction opposite to the movement of the movable core 15. At this time, friction due to fluid is generated between the outer periphery of the plunger 11 and the inner periphery of the movable core 15, and the energy of the rebounding plunger 11 is still moving in the opposite direction (valve closing direction) due to inertial force. Absorbed by the inertial mass of the core 15.

  Since the movable core 15 having a large inertial mass is separated from the plunger 11 at the time of rebound, the rebound energy itself is also reduced.

  Further, since the inertial force of the movable core 15 that absorbs the rebound energy of the plunger 11 is reduced accordingly, the energy for compressing the spring 16 is reduced, the repulsive force of the spring 16 is reduced, and the movable core 15 itself is reduced. The phenomenon that the plunger 11 is moved in the valve opening direction due to the rebound phenomenon does not occur.

  Thus, the rebound of the plunger 11 is suppressed to a minimum, and the so-called secondary injection phenomenon in which the valve is opened after the energization of the electromagnetic coil device 43 is cut off and the fuel is randomly injected is suppressed.

  According to the embodiment configured as described above, since the thickness and diameter of the material other than the members constituting the magnetic path are made as thin or small as possible, a small and lightweight long nozzle type electromagnetic fuel injection valve is obtained. It was.

  In addition, since the metallic cylindrical container portion can be configured seamlessly and with sufficiently short dimensions, it has a configuration with good magnetic properties and excellent moldability, and a small and inexpensive fuel injection valve can be provided.

  Furthermore, after assembling the fixed core and the movable core to the metal material cylindrical container, the mover is inserted into the through hole of the fixed core and the movable core so that the mover is placed inside the metal material cylindrical container. Since it can be assembled, the assembly work is simplified.

  To adjust the stroke of the mover, the head of the mover dropped from the through-hole of the fixed core is pushed with a jig, it is confirmed that the valve element contacts the valve seat, and the position is measured. The upper end position of the movable core is measured in advance, and the dimensional difference between the upper end position of the movable core and the upper end position of the head of the fixed core is obtained. An adjustment spacer (shim) prepared in advance is attached between contact portions between the lower end of the head of the plunger and the upper end surface of the movable core so that the difference becomes a preset value, and the plunger is reassembled.

  Alternatively, a plurality of plungers having different lengths are prepared, and the plungers whose dimensional differences described above are allowed are selected and reassembled.

  Finally, the initial load setting spring is dropped, and then the adjuster is inserted into the through hole of the fixed core and adjusted so that the initial load becomes a predetermined value to fix the adjuster, and the spring and the mover are fixed.

  Hereinafter, the assembly method of the electromagnetic fuel injection valve of the present embodiment and the material of each component will be described in detail with reference to FIGS.

  FIG. 4 shows a cross-sectional view of the metallic cylindrical container 20 after processing, and a cross-sectional view of the plunger guide 11A, the guide member 35, and the orifice plate 36 assembled thereto. FIG. 5 shows an overall cross-sectional view of the plunger guide 11A, the guide member 35 and the orifice plate 36 assembled to the metallic cylindrical container 20.

  In the embodiment, the metallic cylindrical container 20 is made of a ferritic stainless steel specified by JIS SUS430F, which is a magnetic material, and a large-diameter cylindrical portion 23 and a conical section are formed by repeating press molding and drawing multiple times. The part 22, the small diameter cylindrical part 21, and the nozzle body 30 are integrally formed. Further, SUS430 series, SUS420J2 or other martensitic stainless steel can be used if the magnetic properties are adjusted by changing the wall thickness of the cylinder, or if a necessary part is subjected to weak magnetic or non-magnetic treatment. It is also possible to use austenitic stainless steel, which is a non-magnetic material. In this case, a magnetic path is formed by magnetizing a necessary part contrary to the above. The following other characteristics are considered when selecting materials.

1. Excellent bending, deep drawing and burring.
2. Good corrosion resistance against moisture in gasoline.
3. Good workability and corrosion resistance of welds.
4). Resistant to oxidation and thermal deformation at high temperatures.

  The inner and outer diameters and wall thicknesses of the large-diameter cylindrical portion 23, the conical section 22, the small-diameter cylindrical portion 21, and the nozzle body 30 change in a complicated manner rather than monotonously increasing or decreasing. Good moldability is one major reason for selection.

Specifically, in the nozzle portion, φ2 and φ4 portions with larger inner diameters are formed on both sides of the portion with the minimum inner diameter φ3. Further, the wall thickness changes from the large diameter cylindrical portion 23 toward the nozzle body 30 as T ₃ <T ₂ <T _1, and the end portion cylindrical portion 31 is formed thinner (T ₄ ) than anywhere else. .

Since the large-diameter cylindrical portion 23 is used at a position where the magnetic path of the electromagnetic coil device 40 is divided (the magnetic flux passes at a right angle), its thickness T _{3 is set} so as not to deteriorate the magnetic characteristics of the electromagnetic coil device 40. Is formed thinner than other portions.

  A press-fit surface 23F into which the outer peripheral surface of the fixed core 50 is press-fitted and a press-in surface 25F into which the outer periphery of the plunger guide 11A is press-fitted are formed on the inner peripheral surface of the large-diameter cylindrical portion 23, and corresponds to the press-in surface 25F. The outer peripheral portion is drawn, and the drawn portion 25 is slightly smaller in diameter than the large-diameter cylindrical portion 23.

  A groove 23K is formed on the outer periphery of the portion where the lower end surface of the fixed core 50 is located. The groove 23K is for reducing the passage cross-sectional area of the large-diameter cylindrical portion 23 serving as a leakage magnetic flux passage so that the magnetic flux flowing between the fixed core 50 and the movable core 15 is difficult to leak.

The portion of the nozzle body 30 following the small-diameter cylindrical portion 21 has a thickness T ₁ thicker than any portion. This is because it is necessary to form a groove for attaching the seal member on the outer peripheral portion thereof, and to form a step surface 31S having a diameter φ4 for inserting and holding the guide member 35 and the orifice plate 36 on the inner peripheral portion thereof.

  The guide member 35 and the orifice plate 36 are inserted into and fixed to the cylindrical portion 31 having a diameter φ4 which is the thinnest formed at the tip of the metallic cylindrical container 20.

  The guide member 35 has an outer diameter slightly smaller than the inner diameter φ4 of the cylindrical portion 31, and a gap of about 100 microns is provided between the guide member 35 and the inner diameter portion of the cylindrical portion 35 when positioned at the center.

  The orifice plate 36 is press-fitted into the inner diameter portion of the cylindrical portion 31. At the final stage of processing, an employment for centering is inserted inside, and when the employment is inserted into the guide hole 35G at the center of the guide member 35, the guide member 35 is automatically aligned and centered within a range of 100 microns. The

  In this state, the orifice plate 36 is welded at the contact surface with the cylindrical portion 31. For the orifice plate 36, for example, stainless steel having excellent wear resistance and corrosion resistance specified by JIS 420SUS can be used.

  Since the valve body 12 collides with the valve seat 39, wear resistance is required, and the material is selected as a material having good compatibility with the material of the cylindrical portion 31.

  For example, a sintered alloy made of a nickel alloy material can be used for the guide member 35. The guide member 35 has a sliding surface as a guide for the plunger 11 (or the valve body 12) in the center, and has a complicated uneven surface on the upper surface and the lower surface. Selected as material.

  A step surface 35 </ b> A is provided on the upper surface of the guide member 35, and a radial fuel passage is formed between the stepped surface 31 </ b> A of the cylindrical portion 31 and directed from the inside to the outside. Several cut-off surfaces are formed on the side surface of the guide member 35, and a vertical fuel passage is formed between the cut-off surface and the inner peripheral surface of the cylindrical portion 31.

  Further, a plurality of radial grooves 35B are formed on the lower surface of the guide member 35, and a fuel passage is formed from the longitudinal passage toward the inside by the grooves.

  If the radial groove 35B is provided offset from the central axis of the guide hole 35G, the fuel reaches the valve seat 39 of the orifice plate 36 while turning away from the valve seat 39 as soon as the valve body 12 leaves the valve seat 39. If the radial groove 35B is provided toward the central axis of the guide hole 35G, the fuel flows straight toward the center of the valve seat 39 of the orifice plate 36. The fuel that has flowed into the valve seat 39 is ejected from the plurality of injection ports 37.

  The plunger guide 11A has a guide surface 11B as a sliding surface for guiding the plunger 11 in the center, and a recess 11D for receiving a spring is formed around the guide surface 11B. Further, the outer periphery is press-fitted into the inner surface of the drawing portion 25.

  Under such conditions, for example, a stainless alloy specified by SUS420J2 of JIS standard is used as a material that is easy to press work, has wear resistance, and is corrosion resistant to moisture in gasoline.

  The upper and lower ends of the guide hole 11B are chamfered to form R surfaces 11R1 and 11R2. This is formed in a narrow range of the sliding contact surface between the plunger 11 and the inner surface of the guide hole 11B, and has an aim of making it difficult to hit one side and an aim of deburring that occurs during processing.

  6 shows the movable core 15, the second spring 16, and the fixed core 50 assembled to the metallic cylindrical container 20 to which the plunger guide 11 </ b> A, the guide member 35, and the orifice plate 36 described in FIGS. 4 and 5 are assembled. FIG. 7 is a view illustrating a state in which they are assembled.

  In the recess 11D provided at the center of the plunger guide 11A fixed to the cylindrical container 20 made of metal, for example, a spring specified by JIS standard SUS631-WPC as a material having high strength and corrosion resistance to moisture in gasoline. 16 (second spring) is set, and the movable core 15 is arranged in the large-diameter cylindrical portion 23 so that the upper portion of the spring 16 fits into the recess 15A provided at the lower center of the movable core 15. . At this time, the upper end surface of the movable core 15 exactly matches the position of the annular groove 23K. The movable core 15 is made of magnetic stainless steel with good workability suitable for forging, and at least the end surface that collides with the fixed core 50 and the surrounding surface thereof are plated with chromium (Cr) or Ni (nickel).

  The outer diameter D15 of the movable core 15 and the inner diameter D23 of the large-diameter cylindrical portion 23 are configured so that the outer diameter D15 of the movable core 15 is reduced by about 0.2 millimeters. A gap gA of about 0.1 millimeter is formed between the inner periphery of the cylindrical portion 23.

  This gap gA is very important. When the fuel injection valve is mounted on the vehicle, the mounting state varies. When the fuel injection valve is mounted inclined with respect to the vertical direction, the movable core 15 placed on the spring 16 is inclined under the influence of gravity. When the movable core 15 is inclined and the outer peripheral upper and lower end edges of the movable core 15 come into contact with the inner peripheral surface of the large-diameter cylindrical portion 23, the movable core 15 cannot move smoothly up and down.

  In order to avoid such a state, the gap between the plunger 11 and the inner peripheral surface of the through hole 14 of the movable core 15 is set to 5 to 15 microns, for example, as described above so that the gap gA is 0.1. Set to millimeters. Thereby, even when the inclination of the movable core 15 becomes the worst inclination state in the actual use state, the movable core 15 can smoothly move up and down. Further, the chrome plating layer on the inner peripheral surface of the through hole 14 functions as a protective film against sliding with the plunger 11.

  Next, the press-fitting surface 50F of the fixed core 50 is press-fitted into the inner peripheral surface 23F of the large-diameter cylindrical portion 23. The outer diameter D50F of the press-fit surface 50F of the fixed core 50 is formed larger than the outer diameter D50 of the end portion of the fixed core 50 on the movable core 15 side.

  By providing this press-fitting surface on the fixed core 50, unnecessary stress is not applied to the large-diameter cylindrical portion 23 during press-fitting, and even when the large-diameter cylindrical portion 23 is formed thin, this portion is not affected when the fixed core 50 is press-fitted. No longer deformed. The gap gB formed by the difference between the outer diameter D5 of the end of the fixed core 50 on the movable core 15 side after the press-fitting of the fixed core 50 and the inner diameter D23 of the large-diameter cylindrical portion 23 is a metallic cylindrical container 20. This part is formed as a weak magnetic or non-magnetic part, and further has a function of suppressing leakage magnetic flux leaking from the opposed surfaces of the fixed core 50 and the movable core 15 in cooperation with the annular groove 23K. Yes.

The thickness D58 of the flange 58 provided on the stationary core 50 is set equal to the thickness T ₃ of the large-diameter cylindrical portion 23.

  Thus, the fixed core 50 press-fitted into the large-diameter cylindrical portion 23 is welded 51 </ b> A at the entire outer periphery thereof facing the press-fitting surface 50 </ b> F. In this state, the end surfaces of the fixed core 50 and the movable core 15 are in a light contact state. And the annular groove 23K is located in the outer peripheral part corresponding to the position of the contact part.

The fixed core 50 is made of the same material as the movable core 15, and similarly to the movable core 15, the collision surface with the movable core 15 and the surrounding surface are plated with chromium. (In the embodiment, chromium plating is used, but nickel plating may be used.)
This chrome plating has a function of relieving a shock when the fixed core and the movable core collide, and suppressing the secular change of the surface state.

  Thereafter, the annular yoke 42 is pressed into the outer periphery of the flange portion 58 of the fixed core 50 so that the surface of the shoulder 55 of the fixed core 50 and the upper end surface of the annular yoke 42 are flush with each other. The thickness of the collar portion 58 and the thickness of the annular yoke 42 are set to the same value. Both are fixed by welding the entire circumference at the contact portion of the upper end surface.

  The annular yoke 42 is formed into an annular shape by press-molding the same material as the fixed core 50 and the movable core 15. A punched portion 42B is provided in a part of the circumferential direction, and a coil terminal is later pulled out from the punched portion 42B.

  Next, the fuel introduction pipe 61 is press-fitted into the outer periphery of the protruding portion at the upper end of the fixed core 50 up to the position of the flange portion 56 and welded at the outer periphery 61A of the press-fit portion. The fuel introduction pipe 61 is a material that is resistant to moisture in gasoline, and is specified as, for example, JIS 304 SUS304 as a material that can be press-molded (deep-drawn) (magnetic properties do not need to be considered). Stainless steel is used.

  FIG. 8 is a diagram illustrating a process of attaching the electromagnetic coil device 40 to the outer periphery of the assembly described in FIG. Moreover, the assembly drawing of the state in which the electromagnetic coil device 40 is assembled is shown in FIG.

  The electromagnetic coil device 40 includes an electromagnetic coil 43 in which a coil 43B is wound around an annular bobbin 43A and an outer yoke 41.

  The electromagnetic coil 43 is inserted into the assembly from the nozzle body 30 side. At this time, the terminal 43C is pulled out through the punching hole 42B of the annular yoke 42.

  The cup-shaped yoke 41 is inserted from the nozzle body 30 side, and the inner peripheral surface of the bottom through-hole 41 </ b> A is press-fitted into the outer periphery of the large-diameter cylindrical portion 23. The cup-shaped yoke 41 is press-fitted until the upper end surface contacts the lower end surface of the annular yoke 42. As shown in FIG. 10, the entire circumference is welded 45 at the contact portion between the lower outer periphery of the annular yoke 42 and the upper outer periphery of the annular yoke 41.

  Similarly, the entire circumference is welded 46 at the contact portion between the inner peripheral edge at the lower end of the cup-shaped yoke 41 and the outer peripheral surface of the large-diameter cylindrical portion 23.

  The inner peripheral surface of the bottom of the cup-shaped yoke 41 is located at a position facing the outer peripheral surface of the movable core.

  Thus, a toroidal magnetic path BH surrounding the annular coil 43 through the cup-shaped yoke 41, the movable core 15, the fixed core 50, the annular yoke 42, and the cup-shaped yoke 41 is formed.

  The cup-shaped yoke 41 is made of magnetic stainless steel with good workability in consideration of magnetic characteristics.

  After being assembled in this state, as shown in FIG. 10, the periphery of the fuel introduction pipe 61, the periphery of the upper end protruding portion including the flange portion 56 of the fixed core 50, the coil terminal 43C, and the periphery of the electromagnetic coil 43 (inside the cup-shaped yoke 41) The upper end surface of the annular yoke 42 and the shoulder 55 of the fixed core are molded with a resin material.

  FIG. 9 is a cross-sectional view showing a state where the assembly of the mover 10 is completed, and FIG. 10 is a view for explaining a state where the mover 10 is assembled to the assembly after resin molding.

  The plunger 11 of the mover 10 is made of the same material (SUS420J2) as the plunger guide 11A as a weak magnetic material that is wear resistant and resistant to moisture in gasoline. Thereby, since the sliding part of the plunger guide 11A becomes a sliding contact of the same material, durability is good. At the upper end of the plunger 11, a hole 17 serving as a fuel passage and a plurality of small holes 17A preceded in the radial direction from the hole 17 are formed at the center. A cylindrical head portion 13 made of the same material is press-fitted into the outer peripheral portion of the plunger 11 where the hole 17 is formed, and the outer periphery of the press-fit portion is welded around the entire circumference 13A.

  A concave portion 11Q is formed at the tip of the plunger 11, and a part of the outer periphery of the ball-shaped valve body 12 made of the same material is fitted into the concave portion 11Q, and the entire circumference of the contact portion is welded 12A.

  The diameter of each part of the mover 10 is the largest in the diameter S1 of the head 13, followed by the diameter S2 of the plunger 11 and the diameter S3 of the valve body 12, both of which are the diameters of the through holes 51 of the fixed core 50. It is smaller than the inner diameter.

  The diameters of the valve body 12 and the plunger 11 are smaller than the diameters of the through hole 14 of the movable core 15, the guide hole 11B of the plunger guide 11A, and the guide hole 35G of the guide member 35. As a result, after the fixed core 50, the movable core 15, the plunger guide 11A, and the guide member 35 are assembled, the movable element 10 can be finally assembled.

  The mover 10 is inserted through the assembly and the stroke is measured. A stroke adjusting shim having an appropriate thickness sandwiched between the lower end surface of the head 13 and the upper end surface of the movable core 15 is selected according to the measured value.

  Moreover, you may replace with the needle | mover of suitable length according to a measured value. In any method, since the stroke can be adjusted after the fixed core 50 and the movable core 15 of the electromagnetic drive mechanism are incorporated, the stroke adjustment is simple.

  Thus, after the movable element having the optimum stroke is set, the first spring 52 is dropped onto the head 13 of the movable element 10.

  Finally, the adjuster 54 is press-fitted into the through-hole 51 of the fixed core 50, the initial load is adjusted, and the spring 52 is fixed to complete the assembly.

  A second embodiment in which the present invention is used will be described with reference to FIG. First, only portions different from the embodiment will be specifically described below.

  One end of the nozzle body 30 is formed with a cylindrical portion 33 to be inserted into the inner diameter portion of the tip opening portion of the small diameter cylindrical portion 23, and is fixed by the all-around welding 33 </ b> A at the stamping fitting portion 34.

  The outer diameter of the nozzle body 30 is the same as the outer diameter of the small-diameter cylindrical portion 21 of the metallic cylindrical container 20. For this reason, the dimension which added the thickness of the cylindrical part 33 of the nozzle body 30 and the thickness of the small diameter cylindrical part 21 of the metal-made cylindrical container 20 is the thickness of the main-body part of the nozzle body 30. .

  The outer diameter of the cylindrical portion 31 of the nozzle body 30 is uniform up to the tip, but the thickness thereof is formed thinner than the other portions. As a result, the most distal portion of the nozzle body 30 is the cylindrical portion 31. The inner diameter is widened at the portion, and an insertion portion for the guide member 35 and the orifice plate 36 is formed.

  In this way, the portion of the nozzle body 30 having a complicated shape is formed separately from the metallic cylindrical container 20 and is joined and integrated later, thereby processing the metallic cylindrical container 20 and the nozzle body. 30 and the work of inserting and assembling the guide member 35 and the orifice plate 36 are facilitated.

  In particular, since the processing of the nozzle body 30 and the work of inserting and assembling the guide member 35 and the orifice plate 36 and the processing of the metallic cylindrical container 20 can be performed simultaneously on separate work lines, the final joining work is considered. Even so, the overall work time is reduced.

  The elongated plunger 11 of the mover 10 is integrally formed by cutting a valve body 12 at the tip, and a cylindrical head 13 having an outer diameter larger than the diameter of the plunger 11 is integrally formed at the other end.

  When the mover 10 is formed as a single piece from the same member in this way, it is easy to manage the parts of the mover and the assembly work is simplified.

  The plunger 11 and the cylindrical head 13 of the mover 10 are entirely made of solid metal, but the fuel passage hole 17 is formed in the center from the upper end of the cylindrical head 13 to the position of the plunger guide 11A. Are communicated with the fuel passage 15B on the outer periphery of the plunger 11 through a plurality of radial holes 17A provided at the position of the recess 15A for receiving the spring of the movable core 15.

  In this embodiment, the fixed core 50 is press-fitted in the axial direction until the shoulder portion 55 of the fixed core 50 coincides with the AA surface where the upper end surface of the large-diameter cylindrical portion 23 of the metal-made cylindrical container 20 is located. Thus, axial positioning between the fixed core 50 and the large-diameter cylindrical portion 23 of the metallic cylindrical container 20 is achieved.

  The inner diameter of the annular yoke 42 through which the large-diameter cylindrical portion 23 of the metal-made cylindrical container 20 is inserted is formed to be substantially the same as the outer diameter of the large-diameter cylindrical portion 23 of the metallic-material cylindrical container 20. The outer diameter of 42 is formed to be substantially the same as the outer diameter of the cup-shaped yoke 41.

  Axial positioning of the electromagnetic coil device 40 and the large-diameter cylindrical portion 23 of the metallic cylindrical container 20 is achieved by fixing the upper end surface of the annular yoke 42 so as to coincide with the reference plane AA. Is done.

  As a result, the upper end surface of the annular yoke 42, the upper end surface of the large-diameter cylindrical portion 23 of the metallic cylindrical container 20, and the shoulder portion 55 of the fixed core 50 are all located in the same plane as the reference plane AA. .

  The annular yoke 42 is welded in a ring shape along the joint surface 44 between the upper inner peripheral edge of the annular yoke 42 and the upper outer peripheral edge of the large-diameter cylindrical portion 23 of the metal cylindrical container 20, so that the annular yoke 42 is in the metal cylindrical shape. It is fixed to the outer peripheral part of the large-diameter cylindrical part 23 of the container 20.

  By positioning the fixed core and the electromagnetic coil device in the axial direction with respect to the cylindrical container made of metal material on one reference plane, an electromagnetic fuel injection valve with small assembly error and good assembly property was obtained.

  Note that the same reference numerals as those in the first embodiment and those not described as the second embodiment have the same functions even if they are not the same shape, and therefore the description of the first embodiment is followed.

  A third embodiment in which the present invention is used will be described with reference to FIG. Only the parts different from the first embodiment will be specifically described below.

  The plunger 11 is composed of a hollow member. The hollow member may be either a pipe material obtained by curling a plate material and welding the mating surfaces, or a pipe material processed into a hollow shape.

  In this embodiment, a plurality of through holes are formed in the hollow pipe material to reduce the weight of the plunger itself. This is useful for speeding up the operation of the mover 10. In addition, since a sufficient fuel passage cross-sectional area can be secured, fuel pressure loss can be reduced, and the operation of the mover 10 can be accelerated.

  The fuel is guided to the position of the nozzle body 30 through the hollow plunger 11.

  The movable core 15 has a concave portion 15H that receives the head portion 13 of the movable element 10 at the center, and the head portion 13 and the movable core 15 are brought into contact with and engaged with each other at the bottom portion of the concave portion 15H.

  The diameter R2 of the hole formed in the bottom of the recess 15H of the movable core 15 is larger than the diameter R4 of the hollow plunger 11 and the diameter R1 of the valve body 12, and smaller than the diameter R3 of the head 13. According to this fairness, the inclination of the movable core 15 is reduced, and a fuel injection valve with a smooth movement of the movable element 10 can be obtained regardless of the mounting posture.

  In this embodiment, the large-diameter cylindrical portion 23 extends further upward beyond the end portion of the fixed core 50. The diameter of the head 13 is smaller than the diameter D of the through-hole 51 of the fixed core 50 as in the other embodiments, but before fixing the fuel introduction pipe 61 to the upper end of the large-diameter cylindrical portion 23, The stroke adjustment of the mover 10 is completed, and the spring 52 and the adjuster 54 are fixed.

  After fixing the fuel introduction pipe 61 to the upper end of the large-diameter cylindrical portion 23, the electromagnetic coil device 40, the upper outer periphery of the large-diameter cylindrical portion 23, and a part of the fuel introduction pipe 61 are molded with a resin material.

  In this embodiment, the outer diameter of the fixed core 50 is configured to be the same outer diameter between the press-fit portion of the large-diameter cylindrical portion 23 and the press-fit portion of the annular yoke 42. With this configuration, there is an effect that the shape of the fixed core 50 can be simplified. In the case of this embodiment, the upper end surface of the large-diameter cylindrical portion 23 is press-fitted to the lower end surface of the annular yoke 42 with an adjusted interval, and is welded 51A at the press-fit portion.

  In any of the embodiments, the head 13 of the mover 10 and the plunger 11 as a whole are described as being made of a non-magnetic material or a weak magnetic material, but the portion between the plunger guide 11A and the head 13 is partially. If it is non-magnetic or weak magnetism, the leakage of magnetic flux and the magnetization phenomenon of the mover 10 can be suppressed. Therefore, the material may be partially changed, or it may be subjected to non-magnetization or weak magnetizing treatment.

  In any of the embodiments, the metallic cylindrical container 20 is described as being a non-magnetic material or a weak magnetic material. However, the fixed core 50 and the movable core 15 are opposed to each other across the gap Ga. If the part that can become the surrounding leakage magnetic flux path is non-magnetic or weak magnetic, the leakage magnetic path is difficult to form. Therefore, this part is either subjected to demagnetization or weak magnetic treatment or is made of such a member. May be.

  In the embodiment shown in FIGS. 1 and 3, the metallic cylindrical container is fixed to the fixed core 50 until the upper end surface of the large-diameter cylindrical portion 23 comes into contact with the flange portion 58 of the fixed core 50 or the lower end surface of the annular yoke 42. Although what is press-fitted has been described, in practice, the metal-made cylindrical container 20 is press-fitted to a predetermined position on the basis of the AA plane, and thus does not necessarily come into contact. In order not to be able to press-fit normally, an interval of a specific dimension is provided. As a result, the end surface of the large-diameter cylindrical portion 23 faces the flange portion 58 or the lower end surface of the annular yoke 42 at a specific interval. Furthermore, in any of the embodiments, the coil bobbin 43A of the electromagnetic coil device 40 has been described as having a U-shaped groove. However, the shape of the groove is a stepped shape at the bottom. It may be a mixture of a place with many winding layers and a place with few winding layers. In this case, the coil can be wound without any waste in the internal surplus space, and the coil occupancy is increased, and a powerful electromagnetic coil is obtained.

  The same reference numerals as those of the first embodiment and those not described as the third embodiment have the same functions even if they are not of the same shape, and therefore follow the description of the first embodiment.

  In the first to third embodiments described above, the guide member 35 has been described as guiding the distal end portion of the plunger 11 of the movable element 10. However, the guide member 35 may be configured to guide the side surface of the valve body 12. . In the former, the diameter (outer diameter) of the valve body 12 is smaller than the outer diameter of the plunger tip portion. In the latter, the diameter (outer diameter) of the valve body 12 is larger. However, in any case, the diameter is smaller than the inner diameter of the guide hole of the plunger guide 11A.

  The present invention can be used as a fuel injection valve for an internal combustion engine. Although it is suitable for use in a fuel injection valve of a so-called in-cylinder injection type internal combustion engine in which fuel is directly injected into a cylinder, it is not limited to this.

  It can be used for a so-called port injection type fuel injection valve that is attached to the inlet port and injects fuel toward the intake valve.

  Moreover, although it is suitable when it uses for a fuel injection valve with a long plunger, it can also be used for the thing with a short plunger, without restricting to it.

  Further, the through hole 51 as a fuel passage is provided in the fixed core, and it is suitable to be applied to a structure in which the movable element is incorporated using the through hole 51 as the fuel passage, but the fuel passage is not necessarily required. There is no. For example, even if a fuel supply passage called a side feed type is provided at the side of the tip of the fuel injection valve, the technique of the present invention can be applied if a through hole for incorporating a mover is provided in the fixed core. .

  Furthermore, it can also be used as an electromagnetic mechanism for variable displacement control that is provided at the suction port or overflow port of a high-pressure fuel pump and adjusts the fuel intake amount or overflow flow rate (return amount).

  In addition to the internal combustion engine, it can be widely used as an electromagnetic operation plunger such as a fluid metering mechanism or a movable plunger mechanism of other actuators.

  DESCRIPTION OF SYMBOLS 10 ... Movable element, 11 ... Plunger, 11A ... Plunger guide, 12 ... Valve body, 13 ... Head, 15 ... Movable core, 16, 52 ... Spring, 20 ... Metal-made cylindrical container, 21 ... Small diameter cylindrical part , 23 ... large-diameter cylindrical portion, 30 ... nozzle body, 35 ... guide member, 36 ... orifice plate, 40 ... electromagnetic coil device, 50 ... fixed core, 51 ... through hole.

Claims (35)

A cylindrical container made of a metal material provided with a fuel injection port at the tip and closed with a fixed core having a through hole at the other end,
A mover that is disposed between the fixed core and the fuel injection port and has a valve body that opens and closes the fuel injection port at the tip, and a maximum outer diameter smaller than the minimum inner diameter of the through hole,
An electromagnetic drive mechanism for reciprocating the mover;
An electromagnetic fuel injection valve comprising: Attach a fixed core with a through-hole at the center to the inner periphery of the other end of the metallic cylindrical container with a fuel injection port at the tip,
After that, a mover provided with a valve body for opening and closing the fuel injection port at the tip is assembled by inserting the through hole,
Furthermore, the assembly method of the electromagnetic fuel injection valve by which the spring and the regulator which press the rear-end part of the said needle | mover are assembled | attached in this order in the said through-hole. 2. The guide element according to claim 1, further comprising a guide element that is fixed to an inner periphery of the cylindrical container made of the metal material between the fixed core and the fuel injection port and has a hole for guiding the mover at the center thereof. Electromagnetic fuel injection valve. The electromagnetic drive mechanism includes a movable core that faces the fixed core and reciprocates in cooperation with the stator core, and the movable core has a through-hole through which the movable element is inserted, The mover has an engagement portion that engages with the fixed core side engagement surface around the through hole of the movable core, and the outer diameter of the engagement portion is that of the mover guided by the guide element. The electromagnetic fuel injection valve according to claim 3, wherein the electromagnetic fuel injection valve is larger than the outer diameter of the portion. A spring that is mounted in the through hole and presses the rear end of the mover;
The electromagnetic fuel injection valve according to claim 1, further comprising an adjuster for adjusting the position of the spring. The mover is formed entirely or partially in the vicinity of the magnetic path formed by the electromagnetic drive mechanism, and is made of a non-magnetic material or a weak magnetic material, or subjected to a non-magnetic or weak magnetic treatment. The electromagnetic fuel injection valve according to claim 1. The metal cylindrical container is entirely or near the magnetic path formed by the electromagnetic drive mechanism is made of a non-magnetic material or a weak magnetic material, or is subjected to a non-magnetic or weak magnetizing treatment. The electromagnetic fuel injection valve according to claim 1. A cylindrical container made of a metal material provided with a fuel injection port at the tip and closed with a fixed core having a through hole at the other end,
A movable body that includes a valve body that opens and closes the fuel injection port at a tip, and extends from the fixed core to the fuel injection port;
In an electromagnetic fuel injection valve provided with an electromagnetic drive mechanism for reciprocating the mover,
An electromagnetic fuel injection valve in which a maximum outer diameter of the mover is smaller than a minimum inner diameter of the through hole. After the fixed core is attached to the cylindrical container made of metal material, the mover is assembled by inserting the through hole, and a spring and an adjuster are assembled in this order above the mover of the through hole. The method for assembling an electromagnetic fuel injection valve according to claim 7 attached. A metallic cylindrical container having a small diameter cylindrical part on one side and a large diameter cylindrical part on the other side,
A fuel injection port provided at the tip of the small-diameter cylindrical portion;
A fixed core fixed inside the large-diameter cylindrical portion;
An electromagnetic coil device comprising an electromagnetic coil device provided on the outer periphery of the large-diameter cylindrical portion and a movable core that is spring-loaded in a direction away from the fixed core and is attracted to the fixed core by energizing the electromagnetic coil device. Drive mechanism,
A mover that is housed between the fixed core and the fuel injection port and reciprocates between the fixed core and the fuel injection port in response to movement of the movable core of the electromagnetic drive mechanism;
Provided at the tip of the movable element, and a valve body for opening and closing the fuel injection port,
The movable element extends through the through hole provided in the movable core to the fuel injection port, and its head is inserted into the through hole provided in the fixed core,
The maximum outer diameter of the mover excluding the head is smaller than the minimum inner diameter of the fixed core and the through hole provided in the movable core, and the maximum outer diameter of the head is the minimum inner diameter of the through hole provided in the movable core. An electromagnetic fuel injection valve that is larger and smaller than the minimum inner diameter of the through hole provided in the fixed core. The electromagnetic coil device includes a cup-shaped yoke fixed to the outer periphery of the large-diameter cylindrical portion of the metal-made cylindrical container;
An annular coil provided between the outer periphery of the large-diameter cylindrical portion of the metallic cylindrical container and the inner periphery of the cup-shaped yoke;
The electromagnetic fuel injection valve according to claim 10, comprising an annular yoke that covers an open end side of the cup-shaped yoke. The fixed core includes an annular flange on the outer periphery,
11. The electromagnetic fuel injection valve according to claim 10, wherein one end face of the flange portion and an end face of the large-diameter cylindrical portion of the metallic cylindrical container are in contact with each other and both are fixed. The fixed core includes an annular flange on the outer periphery,
The one side end face of the collar part and the end face of the large-diameter cylindrical part of the metallic material cylindrical container face each other or contact each other, and both are fixed.
The electromagnetic fuel injection valve according to claim 10, wherein one end surface of the annular yoke is positioned on the same plane as an end surface on the other side of the flange portion of the fixed core and is fixed to the outer periphery of the flange portion. . The metallic cylindrical container is formed from the same member as one part of an integrated object,
The thickness of the large-diameter cylindrical portion is thinner than the thickness of the small-diameter cylindrical portion, and further, the tip portion of the small-diameter cylindrical portion is integrally formed with a thicker portion than the other portions, The electromagnetic fuel injection valve according to claim 10, wherein a groove for attaching the seal member is formed on the outer periphery of the thick portion. The metallic cylindrical container is formed from the same member as one part of an integrated object,
A thin tubular portion is integrally formed at the most distal end portion of the small-diameter tubular portion with any thickness of any portion of the metallic tubular container,
The electromagnetic fuel according to claim 10, wherein a guide element having a guide hole for guiding the tip of the movable element and an orifice plate having the fuel injection port are assembled in this order in the cylindrical portion. Injection valve. 11. The electromagnetic fuel injection valve according to claim 10, wherein the large-diameter cylindrical portion of the metal-made cylindrical container has an annular groove on an outer periphery of a portion where the fixed core and the movable core face each other. The outer periphery of the fixed core is formed in a cylindrical shape and is fixed to the inner periphery of the large-diameter cylindrical portion of the metallic cylindrical container,
The movable core faces the end face on one end side of the fixed core, and the projecting cylinder having an outer diameter smaller than the inner diameter of the large-diameter tubular portion of the metallic cylindrical container on the other end face The shape part is formed,
A fuel passage is formed at the center of the fixed core including the protruding cylindrical portion,
11. The electromagnetic fuel according to claim 10, wherein a first spring for applying a preload to the movable element in a direction to close the fuel injection port is attached to the movable element together with an adjuster for adjusting the preload. Injection valve. A fuel introduction pipe is fixed to the outer periphery of the protruding cylindrical portion,
Covers the end surface of the large-diameter cylindrical portion of the cylindrical container made of metal material, the axial end surface of the electromagnetic coil device, the axial end surface of the fixed core, and the periphery of the protruding cylindrical portion and the fuel introduction pipe portion The electromagnetic fuel injection valve according to claim 17, further comprising a resin molded body portion that molds an electric terminal of the electromagnetic coil device. A flange portion for receiving an axial end surface of the fuel introduction pipe is formed on the outer periphery of the protruding cylindrical portion,
The electromagnetic fuel injection valve according to claim 18, wherein an outer diameter of the flange portion is larger than an outer diameter of the protruding cylindrical portion and the fuel introduction pipe. The mover includes a plunger portion that connects the head and the valve body,
The head of the mover reciprocates within the through hole of the fixed core and is spring loaded by the first spring,
The movable core is received at the other end of the second spring, one end of which is held by the metallic cylindrical container, and is disposed so as to be reciprocally movable around the plunger.
The movable core is sandwiched between the head of the movable element spring-loaded by the first spring and the second spring, and cooperates with the movable element with respect to axial movement. The electromagnetic fuel injection valve according to 17. The outer periphery is press-fitted into the inner peripheral part of the large-diameter cylindrical part of the metallic cylindrical container, and includes a plunger guide in which a hole for guiding the outer periphery of the plunger is formed in the center.
The electromagnetic fuel injection valve according to claim 20, wherein one end of the second spring is held by the plunger guide. The electromagnetic fuel injection valve according to claim 21, further comprising a drawing portion on an outer periphery of a large-diameter cylindrical portion of the metal-made cylindrical container corresponding to a press-fitting position of the plunger guide. The electromagnetic fuel injection valve according to claim 20, wherein a valve body formed of a separate member is fixed to the tip of the plunger. The electromagnetic fuel injection valve according to claim 23, wherein the plunger is formed of a hollow member. 21. The electromagnetic fuel injection valve according to claim 20, wherein the head portion, the plunger portion, and the valve body portion are an integrated member formed from the same member. The electromagnetic fuel injection valve according to claim 20, wherein the head is formed separately from the plunger and is fixed to the plunger. A nozzle body formed as a separate object is attached to the small-diameter cylindrical portion of the metallic cylindrical container,
The nozzle body has an insertion cylindrical portion that is inserted into the inner periphery of the small-diameter cylindrical portion of the metallic material cylindrical container on one end side,
11. The distal end cylindrical portion in which a guide element having a guide hole for guiding the distal end portion of the movable element and an orifice plate having the fuel injection port are assembled in this order on the other end side. Electromagnetic fuel injection valve. 28. The electromagnetic fuel injection valve according to claim 27, wherein the nozzle body has an annular groove for mounting a seal member on an outer periphery between the plug-in cylindrical portion and the tip cylindrical portion. The wall thickness of the nozzle body excluding the plug-in cylindrical portion, the tip cylindrical portion, and the annular groove portion is greater than the thickness of the large-diameter cylindrical portion and the small-diameter cylindrical portion of the metallic material cylindrical container. The electromagnetic fuel injection valve according to claim 28, which is thicker. The electromagnetic fuel injection valve according to claim 10, wherein an end face of the large-diameter cylindrical portion, an axial end face of the electromagnetic coil device, and an axial end face of the fixed core are located on the same plane. A movable core that reciprocates in cooperation with the fixed core by electromagnetic force generated by the electromagnetic coil device;
In an electromagnetic fuel injection valve that includes a mover that reciprocates between the stator and the fuel injection port by the movement of the movable core, and that opens and closes the fuel injection port by a valve provided at the tip of the mover.
A metal-made cylindrical shape having a large-diameter cylindrical portion in which the fixed core is fixed inside and the electromagnetic coil device is attached to an outer peripheral portion, and a small-diameter cylindrical portion in which the fuel injection port is provided at a tip portion. An electromagnetic fuel injection valve comprising a container. The large-diameter cylindrical portion and the small-diameter cylindrical portion of the metal-made cylindrical container are formed from the same member as a single component,
The thickness of the large-diameter cylindrical portion is thinner than the thickness of the small-diameter cylindrical portion, and further, the tip portion of the small-diameter cylindrical portion is integrally formed with a thicker portion than the other portions,
A thin tubular portion is integrally formed at the most distal end portion of the small-diameter tubular portion with any thickness of any portion of the metallic tubular container,
32. The electromagnetic fuel according to claim 31, wherein a guide element having a guide hole for guiding the tip of the movable element and an orifice plate having the fuel injection port are assembled in this order in the cylindrical portion. Injection valve. The electromagnetic fuel injection valve according to claim 32, wherein a groove for attaching a seal member is formed on an outer periphery of the thick portion. 32. The electromagnetic fuel injection valve according to claim 31, wherein the large-diameter cylindrical portion of the cylindrical container made of metal material has an annular groove at a portion of the outer periphery thereof where the fixed core and the movable core face each other. A method for assembling a fuel injection valve according to claim 31,
Forming a fuel injection port at an end of the small-diameter cylindrical portion of the metallic cylindrical container having a small-diameter cylindrical portion on one side and a large-diameter cylindrical portion on the other side;
Mounting a fixed core and movable core assembly inside the large-diameter cylindrical portion;
Fixing an electromagnetic coil device to an outer peripheral portion of the large-diameter cylindrical portion;
Molding the electrical terminals of the electromagnetic coil device and a part of the fixed core with resin;
Inserting the movable element by inserting the through hole of the fixed core and the movable core;
Adjusting the stroke of the mover;
A method for assembling an electromagnetic fuel injection valve.

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