JP2018087518A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a manufacturing time while surely preventing the leakage of fuel at valve-closing, in a fuel injection valve.SOLUTION: A recess 52 of a valve seat member 16 constituting a fuel injection valve 10 is formed into a substantially-conical shape which is gradually contracted in a diameter toward a base end side, and an injector plate 56 is inserted into the recess 52, and fixed by entire-circumferential welding. The injector plate 56 is formed into the substantially-conical shape, and a communication part 58 facing a valve hole 50 of the valve seat member 16 is formed at an apex of the injector plate. A plurality of flow passages 62 radially extending along a conical face 60 are connected to the communication part 58, and end parts of the flow passages 62 are connected to injection holes 64 which penetrate in an axial direction in the vicinity of an outer edge of the injector plate 56.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection valve that has a valve body that moves under an energization action of a coil and injects fuel into an internal combustion engine by opening the valve body.

  2. Description of the Related Art Conventionally, a fuel injection valve that opens a valve under the excitation action of a solenoid and injects supplied fuel into an internal combustion engine is known. In such a fuel injection valve, for example, as disclosed in Patent Document 1, an injection hole-shaped member is fixed to the tip of a cylindrical nozzle holder by diffusion bonding, plasma bonding, or the like, and formed on the peripheral surface thereof. The fuel supplied to the nozzle holder through the nozzle hole forming groove flows to the opening and is injected to the outside.

  Further, in the fuel injection valve disclosed in Patent Document 2, an annular valve seat is attached to the tip of a cylindrical valve body, and a conical spray tip is attached to the center thereof. A groove is formed along the peripheral surface of the spray tip, and fuel in the valve body is injected from the tip to the outside through the groove.

JP 2009-174398 A Japanese Patent No. 3907627

  In the fuel injection valve of Patent Document 1 described above, the peripheral surface of the nozzle hole-shaped member is brought into contact with the inner peripheral joint surface of the nozzle holder and heated, so that the joint surface is fixed by diffusion bonding, plasma bonding, or the like. It is fixed. However, since the inner peripheral joint surface is close to the valve seat on which the needle serving as the valve body is seated, the valve seat is distorted by heat generated when the nozzle holder and the nozzle hole-shaped member are fixed. There is a concern that the fuel leaks from the gap formed between the valve body and the valve seat when the valve is closed.

  On the other hand, the fuel injection valve of Patent Document 2 is configured to be fixed to the valve seat by laser welding from the lower surface side of the spray tip in a state where the spray tip is inserted into the conical inner surface portion of the valve seat. Since the peripheral surface has a plurality of grooves spaced apart by a predetermined distance and extends to the lower surface side, it is difficult to weld the entire circumference along the circumferential direction of the spray tip, and a portion where no groove is formed is selected. Therefore, there is a problem that the time required for the welding operation is increased as compared with the case of the entire circumference welding, and the manufacturing time is accordingly increased.

  The present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a fuel injection valve capable of reducing the manufacturing time while reliably preventing fuel leakage when the valve is closed. To do.

In order to achieve the above object, the present invention provides a valve seat member having a valve seat and a valve hole penetrating through the center of the valve seat, and a valve that opens and closes the valve hole by being seated and separated from the valve seat. In a fuel injection valve having a body and a plate member having an injection hole that is attached to an end of a valve seat member and injects fuel,
The plate member is formed in a conical shape, and is formed at the top of the plate member and communicates with the valve hole,
A flow path extending along the conical surface from the communicating portion and connected to the nozzle hole;
With
In the plate member, the vicinity of the outer edge portion, which is on the outer peripheral side of the flow path and the nozzle hole, is fixed to the valve seat member by all-around welding.

  According to the present invention, the fuel injection valve has a conical shape, a communication portion formed at the top thereof and communicating with the valve hole, and a flow extending from the communication portion along the conical surface and connected to the injection hole. A plate member having a passage is provided, and the vicinity of the outer edge portion on the outer peripheral side of the flow path and the nozzle hole in the plate member is fixed by being welded to the valve seat member all around.

  Accordingly, by welding the plate member to the valve seat member all around, the manufacturing time can be shortened as compared with the conventional fuel injection valve that is partially welded. Further, since the welded portion (outer edge portion) of the plate member in the valve seat member and the valve seat on which the valve body is seated are separated from each other, the thermal effect due to welding does not reach the valve seat, so Is avoided. As a result, when the valve is closed, the valve body can be reliably seated on the valve seat and fuel leakage can be prevented.

  Furthermore, the plate member may be inserted into a conical recess formed at the tip of the valve seat member. Thus, the plate member can be easily and reliably positioned coaxially with respect to the valve seat member simply by inserting the plate member into the recess.

  According to the present invention, the following effects can be obtained.

  That is, a plate member having a conical shape, a communication portion formed at the top thereof and communicating with the valve hole, and a flow path extending from the communication portion along the conical surface and connected to the injection hole, In this plate member, the vicinity of the outer edge portion, which is on the outer peripheral side of the flow path and the nozzle hole, is fixed by being welded all around the valve seat member having the valve seat and the valve hole. As a result, it is possible to shorten the manufacturing time by welding all around at once as compared with the conventional fuel injection valve in which the plate member is partially welded, and the outer edge portion to which the plate member is welded Since the valve seat on which the valve body is seated is separated from the valve seat, heat effects from welding do not reach the valve seat, and distortion of the valve seat can be avoided. It is possible to reliably seat and prevent fuel leakage.

1 is an overall cross-sectional view of a fuel injection valve according to an embodiment of the present invention. It is an expanded sectional view which shows the front-end | tip vicinity of the valve seat member in the fuel injection valve of FIG. It is a front view of the injector plate which comprises the fuel injection valve of FIG. FIG. 4A is an enlarged cross-sectional view showing the vicinity of the tip of the valve seat member before the injector plate is mounted on the valve seat member, and FIG. 4B shows the injector plate of FIG. 4A with respect to the valve seat member. FIG. 6 is an enlarged cross-sectional view showing a state where the entire circumference is welded and fixed.

  Preferred embodiments of the fuel injection valve according to the present invention will be described below and described in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 10 indicates a fuel injection valve according to an embodiment of the present invention.

  As shown in FIG. 1, the fuel injection valve 10 includes a body 12 formed in a cylindrical shape along the axial direction, a valve housing 14 provided at the tip of the body 12, and a tip of the valve housing 14. A valve seat member 16 provided, a valve body 20 seated on a valve seat 18 of the valve seat member 16, and a resin mold portion 22 covering the outer peripheral side of the body 12 and the valve housing 14 are included.

  In the following description, the body 12 side of the fuel injection valve 10 is referred to as a base end side (arrow A direction), and the valve seat member 16 side is referred to as a distal end side (arrow B direction).

  The body 12 is made of, for example, a magnetic material, and a supply port 24 to which fuel is supplied opens on the base end side (in the direction of arrow A), and impurities and the like contained in the fuel are removed from the supply port 24. A filter member 26 for mounting is attached. The filter member 26 has a base end engaged with the base end of the body 12, and a cylindrical portion to which a mesh-like filter 28 is attached is inserted into the supply port 24.

  A fixed core portion 30 is formed on the distal end side (in the direction of arrow B) of the body 12, and a through hole 32 is formed in the interior thereof along the axial direction (in the directions of arrows A and B). The through hole 32 communicates with the supply port 24 and penetrates to the tip, and a cylindrical retainer 34 is provided therein. Further, a spring 36 is accommodated in the through hole 32 so as to abut the tip of the retainer 34.

  The valve housing 14 is formed, for example, in a cylindrical shape from a magnetic material, and a movable core 38 is provided in the inside thereof so as to be movable along the axial direction (arrows A and B directions), and at the base end side (arrow A direction). Similarly, a cylindrical spacer 40 is connected so as to be coaxial by welding or the like.

  The spacer 40 is made of, for example, a nonmagnetic material, and is connected to the valve housing 14 by being inserted into a stepped portion 42 formed on the outer peripheral surface of the fixed core portion 30 in the body 12. The outer diameters of the valve housing 14 and the spacer 40 are formed to be the same as the outer diameter of the body 12.

  On the other hand, the proximal end side of the valve seat member 16 is inserted into and fixed to the distal end of the valve housing 14.

  The movable core 38 is made of, for example, a magnetic material, and is formed on the base end side (in the direction of arrow A) and is in sliding contact with the valve housing 14, and a small diameter portion formed on the distal end side of the large diameter portion 44. 46, and a communication hole 48 is formed in the inside of the large-diameter portion 44.

  The communication hole 48 extends from the proximal end of the movable core 38 toward the distal end side (in the direction of arrow B), and extends radially outward at the small diameter portion 46 and opens to the outer peripheral surface. The base end of the communication hole 48 is engaged with one end of the spring 36 accommodated in the through hole 32 of the body 12, so that the elastic force of the spring 36 is biased against the movable core 38. And pressed in a direction away from the body 12 (arrow B direction).

  The tip of the small diameter portion 46 is recessed in a substantially conical shape toward the large diameter portion 44 side (arrow A direction), and the valve body 20 described later is connected by welding or the like.

  The movable core 38 has a predetermined interval between the proximal end of the movable core 38 and the distal end of the fixed core portion 30 in a state where the elastic force of the spring 36 is biased toward the distal end side (arrow B direction). Arranged in a state.

  As shown in FIGS. 1 and 2, the valve seat member 16 is provided on the most distal side (in the direction of arrow B) in the fuel injection valve 10, and a valve hole 50 is formed at the center of the distal end. A recessed portion 52 that is recessed toward the proximal end side (in the direction of arrow A) is formed further on the distal end side than the hole 50. The concave portion 52 is formed in a substantially conical shape that gradually decreases in diameter toward the valve hole 50 side, and has a tapered surface 54. An injector plate (plate member) 56 to be described later is housed in the concave portion 52, and all-around welding W is performed. (See FIG. 4B, for example, laser welding).

  As shown in FIGS. 1 to 3, the injector plate 56 is formed in a substantially conical shape, and a circular and flat communication portion 58 is formed at the top of the injector plate 56, and from the communication portion 58 to the conical surface 60. A plurality of flow paths 62 are formed radially outward along the radial direction.

  As shown in FIG. 3, the flow path 62 has one end connected to the communication portion 58 having the same width as the diameter of the communication hole 48 and the other end on the outer edge side of the conical surface 60. It is formed so that the width dimension gradually decreases toward the part.

  The other end of the flow path 62 is formed with an injection hole 64 penetrating from the other end of the flow path 62 to the end face 56a along the axial direction of the injector plate 56 (directions of arrows A and B). ing.

  When the injector plate 56 is inserted into the recess 52, the communication portion 58 faces the valve hole 50, and the conical surface 60 contacts the tapered surface 54 of the recess 52, thereby covering the plurality of flow paths 62. The end surface 56 a is mounted so as to be substantially flush with the tip of the valve seat member 16.

  On the other hand, inside the valve seat member 16, as shown in FIGS. 1 and 2, a conical valve seat 18 whose diameter decreases toward the distal end side (arrow B direction) is formed so as to be continuous with the valve hole 50. At the same time, a guide hole 66 is formed from the valve seat 18 toward the base end side (in the direction of arrow A). As shown in FIG. 1, the guide hole 66 has substantially the same diameter and opens to the proximal end side. Inside the guide hole 66 and the valve seat 18, a later-described valve body 20 is axially (arrow A, (B direction) is accommodated movably.

  In addition, a fuel collecting chamber 68 is formed on the proximal end side of the guide hole 66 and gradually expands with respect to the guide hole 66 and then extends with substantially the same diameter. The fuel collecting chamber 68 accommodates the small-diameter portion 46 of the movable core 38, communicates with the inside of the valve housing 14 and communicates with the communication hole 48 of the movable core 38.

  The valve body 20 is a sphere made of, for example, a metal material, and is connected to the tip of the small-diameter portion 46 in the movable core 38 and has a plurality of fuel holes through which the fuel can flow through the guide hole 66. A flat portion 70 is formed. The flat portions 70 are provided so as to be spaced apart from each other at equal intervals along the circumferential direction of the valve body 20, and the valve body 20 moves integrally along with the movement of the movable core 38 along the axial direction to open the valve. At this time, the fuel flows between the guide hole 66 and the flat portion 70.

  The resin mold part 22 is formed of, for example, a resin material, and a main body part 72 that covers the outer peripheral side of the body 12 and the valve housing 14, and a coupler part 76 that protrudes from the side of the main body part 72 and accommodates the connection terminal 74. A coil housing 78 is provided inside the main body 72, and a coil assembly 80 is provided further inside the coil housing 78.

  The coil assembly 80 functions as a solenoid portion that is excited under energization, and includes a bobbin 82 that contacts the outer peripheral surface of the fixed core portion 30 and the spacer 40, and a coil 84 that is wound around the outer peripheral side of the bobbin 82. The outer periphery of the coil housing 78 is surrounded by the coil housing 78, and the tip of the coil housing 78 is fixed to the outer peripheral surface of the valve housing 14.

  An annular O-ring 86 is provided at the base end of the main body 72 so as to be on the outer peripheral side of the body 12, and when an unillustrated fuel supply pipe is connected to the base end of the body 12, the O-ring The fuel 86 is prevented from leaking by contacting the inner peripheral surface of the fuel supply pipe 86.

  The coupler portion 76 is formed in, for example, a rectangular cross section and protrudes obliquely upward so as to be inclined at a predetermined angle with respect to the axial direction (arrow A, B direction) of the main body portion 72. One end of the connection terminal 74 is provided so as to be exposed. The other end of the connection terminal 74 extends into the coupler section 76 and is electrically connected to the coil 84.

  The coupler unit 76 is connected to a connector (not shown), whereby a control signal from a controller (not shown) is input to the connection terminal 74 and the coil 84 is energized.

  The fuel injection valve 10 according to the embodiment of the present invention is basically configured as described above. Next, the case where the injector plate 56 is attached to the valve seat member 16 will be described with reference to FIGS. This will be described with reference to 4B.

  First, as shown in FIG. 4A, the injector plate 56 and the valve seat member 16 are coaxially inserted into the recess 52, so that the conical surface 60 becomes a tapered surface 54 as shown in FIG. 4B. And the communicating portion 58 faces the valve hole 50, and the end surface 56a is housed in a state substantially flush with the tip of the valve seat member 16.

  Next, as shown in FIG. 4B, the outer edge of the end face 56a of the injector plate 56 is welded by laser welding to the outer edge of the end surface 56a, whereby the outer edge and the tip of the valve seat member 16 are welded and fixed. Is done. Thereby, the injector plate 56 is firmly fixed to the valve seat member 16 in a state where the injector plate 56 is housed in the recess 52.

  At this time, the entire circumference welding W is performed easily and efficiently by rotating the valve seat member 16 in which the injector plate 56 is accommodated with respect to a laser welding machine (not shown).

  In addition, heat generated during laser welding is generated near the outer edge portion at the tip of the valve seat member 16, and the valve seat 18 on which the valve body 20 is seated is separated in both the radial direction and the axial direction, which may affect the heat. Avoided. Therefore, distortion or the like does not occur in the valve seat 18 due to the thermal effect of welding.

  Next, the operation of the fuel injection valve 10 in which the injector plate 56 is fixed to the valve seat member 16 as described above will be described with reference to FIGS. 1 and 2.

  First, when a control signal from a controller (not shown) is input to the connection terminal 74 of the coupler unit 76, the coil 84 is energized and excited to generate magnetic flux. This magnetic flux flows around the fixed core portion 30, the coil housing 78, the valve housing 14 and the movable core 38, and the generated magnetic force causes the movable core 38 to move together with the valve body 20 toward the fixed core portion 30 (arrow A direction). As a result, the valve seat 18 is opened.

  Then, by opening the valve seat 18 in this way, it flows from the supply port 24 of the body 12 to the communication hole 48 of the movable core 38 through the through hole 32 and reaches the fuel collecting chamber 68 of the valve seat member 16. The fuel flows between the flat portion 70 of the valve body 20 and the guide hole 66 through the valve seat 18 and flows into the valve hole 50. The fuel flows from the valve hole 50 to the communicating portion 58 of the injector plate 56, then flows radially through the plurality of flow paths 62, and is supplied to the injection hole 64. Through the injection hole 64, the tip side (in the direction of arrow B). Is injected into.

  On the other hand, by stopping energization of the coil 84, the attractive force toward the fixed core portion 30 (in the direction of arrow A) with respect to the movable core 38 is extinguished, and the movable core 38 is fixed by the elastic force of the spring 36. When the valve body 20 is pressed in the direction away from 30 (arrow B direction) and seats on the valve seat 18, the flow of the fuel to the valve hole 50 is interrupted and the injection stops.

  As described above, in the present embodiment, the valve seat member 16 constituting the fuel injection valve 10 is provided with the substantially conical injector plate 56 in the concave portion 52 at the tip, and the communication portion communicating with the valve hole 50 at the top. 58 and a plurality of flow passages 62 extending radially from the communication portion 58 along the conical surface 60, and a plurality of nozzle holes 64 penetrating to the end surface 56 a of the injector plate 56 at the end thereof. Provided. As a result, when the injector plate 56 is inserted into the recess 52 and the vicinity of the outer edge thereof is fixed by welding all around, the valve seat 18 of the valve seat member 16 on which the valve body 20 is seated is connected to the welded portion, the radial direction and the shaft. Since they are separated from each other in the direction, the heat effect due to welding does not reach the valve seat 18, and the occurrence of distortion or the like of the valve seat 18 is avoided. Therefore, the valve body 20 can be reliably seated on the valve seat 18 when the valve is closed, and fuel leakage can be reliably prevented.

  Further, since the injector plate 56 can be welded to the valve seat member 16 all around, the manufacturing time can be shortened and the joint strength can be increased as compared with the conventional fuel injection valve that is partially welded. Is possible.

  Further, the injector plate 56 is formed in a substantially conical shape, and the recess 52 of the valve seat member 16 into which the injector plate 56 is inserted is also recessed in a substantially conical shape, whereby the injector plate 56 is inserted into the recess 52. The injector plate 56 can be positioned coaxially easily and reliably.

  In addition, the fuel injection valve according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Fuel injection valve 12 ... Body 14 ... Valve housing 16 ... Valve seat member 18 ... Valve seat 20 ... Valve body 52 ... Recess 56 ... Injector plate 58 ... Communication part 62 ... Flow path 64 ... Injection hole

Claims (2)

A valve seat member having a valve seat and a valve hole penetrating the center of the valve seat, a valve body that opens and closes the valve hole by being seated and separated from the valve seat, and an end portion of the valve seat member And a fuel injection valve having a plate member having an injection hole for injecting fuel.
The plate member is formed in a conical shape, and is formed at the top of the plate member and communicates with the valve hole;
A flow path extending along a conical surface from the communication portion and connected to the nozzle hole;
With
The fuel injection valve according to claim 1, wherein the plate member has an outer edge near the flow path and the nozzle hole that is fixed to the valve seat member by welding all around. The fuel injection valve according to claim 1, wherein
The fuel injection valve according to claim 1, wherein the plate member is inserted into a conical recess formed at a tip of the valve seat member.

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