JP2018044494A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve for improving its durability by bringing a plunger into smoother operation and at the same time reducing the abrasion loss of a stopper.SOLUTION: In a valve housing 12 as part of a fuel injection valve 10, a plunger 16 is provided movably along a guide hole 48 while facing a fixed core part 38. At the base end thereof, a stopper member 68 is provided which is formed of an elastic material. The stopper member 68 consists of a base part 70 mounted at the base end 16a of the plunger 16 and a plurality of contact parts 72 swollen from the base part 70 to the side of the fixed core part 38. The contact part 72 is formed in a hemispherical shape, for example, and provided at equal intervals along the peripheral direction of the base part 70. When the plunger 16 is moved to the side of the fixed core part 38 under the excitation effect of the solenoid part 14, the plurality of contact parts 72 abut on the front end of the fixed core part 38 to restrict the movement.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection valve for supplying fuel gas to an engine or the like.

  2. Description of the Related Art Conventionally, a fuel injection valve that supplies a fuel gas such as CNG to an internal combustion engine is known. For example, in the fuel injection device disclosed in Patent Document 1, a flow path through which fuel gas flows inside a tubular housing A coil for exciting under energization is provided on the outer peripheral side of the flow path, and a plunger made of a magnetic material is movably provided so as to face the flow path. Further, a valve body is provided at the tip of the plunger, and the communication state between the injection hole through which the fuel gas is injected and the flow path is switched by being seated and separated from the valve seat portion.

  When the coil is energized, the plunger moves in a direction away from the fuel injection hole, and the movement is restricted by coming into contact with an annular buffer member provided at the end of the housing so as to face the plunger. The valve is open. Thereby, fuel gas is supplied from a flow path to a fuel injection hole.

JP-A-8-61152

  In the fuel injection valve according to Patent Document 1 described above, since the buffer member is made of an elastic material such as rubber, there is a concern that it may be worn out over many years of use, and the plunger is moved along with the valve opening operation. There is a concern that sticking may occur when separating from the buffer member.

  The present invention has been made in consideration of the above-described problems, and provides a fuel injection valve capable of improving durability by reducing the amount of wear of a stopper while operating the plunger more smoothly. The purpose is to provide.

In order to achieve the above object, the present invention provides a housing having a flow path through which fuel gas flows, a plunger movably provided inside the housing and having a valve body at the tip, and an end of the housing. A fuel injection valve having a nozzle for injecting fuel gas and switching the open / closed state by sucking the plunger toward the fixed core under the energization action of the coil;
A stopper member provided on one end face of the plunger or the fixed core facing the plunger, and having a stopper member capable of regulating movement of the plunger toward the fixed core;
The stopper member is made of an elastic material and is formed in a circular shape, an elliptical shape, or an oval shape as viewed from the moving direction of the plunger, and a plurality of the stopper members are provided along the circumferential direction of the plunger.

  According to the present invention, a stopper member made of an elastic material is provided on one end face of either the plunger or the fixed core constituting the fuel injection valve, and is formed in a circular shape, an elliptical shape or an oval shape when viewed from the moving direction of the plunger. In addition, a plurality of them are provided side by side along the circumferential direction of the plunger.

  Therefore, when the plunger moves toward the fixed core side under the exciting action of the coil and the stopper member abuts against the fixed core or the end surface of the plunger and elastically deforms, it is formed in a circular, elliptical or oval shape. The stopper member can be deformed so as to expand substantially uniformly outward in the radial direction.

  As a result, the amount of deformation in the radial direction in the circumferential direction of the stopper member becomes substantially equal, and uneven wear such that only a specific portion of the stopper member wears or only a specific stopper member wears is prevented. In addition, since the amount of deformation is reduced, wear is suppressed and uneven wear is prevented, so that durability can be improved. Also, by arranging a plurality of stopper members along the circumferential direction of the plunger, the contact area with the plunger or the fixed core can be reduced continuously along the circumferential direction as compared with the stopper of the fuel injection valve according to the prior art. The sticking when the plunger is separated from the fixed core is prevented, and the plunger can be operated smoothly.

  Further, by making the stopper member a hemispherical shape bulging in the direction of movement of the plunger, when the fixed core or the plunger comes into contact with the stopper member and elastically deforms, the contact portion is a stopper member having a planar cross section. Since the contact amount (contact area) can be reduced in comparison, the wear is reduced and the durability can be further improved.

  Furthermore, by arranging the stopper members evenly in the circumferential direction, the impact when the plunger and the fixed core come into contact with each other is evenly buffered, so that the plunger does not tilt. Can work. At the same time, it is possible to prevent the occurrence of uneven wear in which only a specific stopper member is worn.

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

  That is, a stopper member made of an elastic material is provided on one end surface of either the plunger or the fixed core constituting the fuel injection valve, and is formed into a circular shape, an elliptical shape or an oval shape when viewed from the moving direction of the plunger. By arranging a plurality along the circumferential direction, the plunger moves toward the fixed core, and when the stopper member abuts against the fixed core or the end surface of the plunger and elastically deforms, the stopper member is directed radially outward. It can be deformed so as to spread substantially uniformly. As a result, the amount of deformation in the circumferential direction of the stopper member becomes substantially equal, and the amount of deformation is reduced, so that wear is suppressed and durability can be improved. Further, by arranging a plurality of stopper members along the circumferential direction of the plunger, the contact area can be reduced as compared with the stopper member continuously formed along the circumferential direction, so that the plunger is separated from the fixed core. Sticking is prevented and the plunger can be operated smoothly.

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 stopper member vicinity in the fuel injection valve of FIG. 3A is a plan view showing a proximal end of the plunger provided with the stopper member of FIG. 2, and FIG. 3B is a side view showing a contact portion of the stopper member in FIG. 3A. FIG. 4A is a plan view of the plunger provided with the stopper member according to the first modification, and FIG. 4B is a plan view of the plunger provided with the stopper member according to the second modification.

  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 cylindrical valve housing (housing) 12, a solenoid portion 14 provided on the outer peripheral side of the valve housing 12, and an excitation action of the solenoid portion 14. A plunger 16 that moves in the axial direction and a nozzle member (nozzle) 18 that is provided at the tip of the valve housing 12 and injects fuel are included.

  Hereinafter, the valve housing 12 side of the fuel injection valve 10 will be described as the base end side (arrow A direction), and the nozzle member 18 side will be described as the front end side (arrow B direction).

  The valve housing 12 is made of, for example, a metal material, and is formed on the first housing part 20 formed on the base end side (arrow A direction) and on the distal end side (arrow B direction) of the first housing part 20. It consists of a second housing part 22 for holding the solenoid part 14 and a third housing part 24 provided on the tip side (in the direction of arrow B) of the second housing part 22.

  A packing 26 is mounted on the outer peripheral surface of the first housing part 20 via an annular groove. On the other hand, the first housing part 20 has an opening at the base end in the axial direction (directions of arrows A and B). An extended fuel introduction hole 28 is formed, and a cylindrical filter 30 capable of removing dust and the like contained in the fuel gas is attached to the opening of the fuel introduction hole 28.

  In addition, a resin mold portion 32 is formed on the front end side of the first housing portion 20 so as to cover the outer peripheral surface, and a coupler 36 having a current-carrying terminal 34 is laterally provided in the resin mold portion 32. It is provided so as to protrude. The resin mold part 32 is formed so as to cover a part of the base end side of the second housing part 22.

  The first housing portion 20 is connected to, for example, a fuel distribution pipe C connected to a gas tank (not shown), and fuel gas is supplied to the fuel introduction hole 28. The coupler 36 is attached with a connector (not shown) connected to a controller or the like (not shown).

  The second housing portion 22 has a diameter that is increased radially outward with respect to the first housing portion 20, and a cylindrical fixed core portion 38 that extends toward the distal end side (arrow B direction) is formed at the center thereof. A through hole 40 communicating with the fuel introduction hole 28 is formed at the further center of the fixed core portion 38. A tubular retainer 42 is inserted into the through hole 40.

  A storage portion 44 that opens toward the distal end side is formed in an annular shape on the outer peripheral side of the fixed core portion 38, and a coil 50 and a bobbin 52 of the solenoid portion 14 to be described later are stored.

  The third housing portion 24 is integrally and coaxially held by crimping a flange portion 46 formed on the base end side (in the direction of arrow A) to the distal end of the second housing portion 22. A guide hole 48 is formed along the axial direction (the directions of arrows A and B). The guide hole 48 faces the front end of the second housing portion 22 and the plunger 16 is movably accommodated therein.

  The solenoid unit 14 includes, for example, a bobbin 52 that is provided in the storage unit 44 of the second housing unit 22 and holds the coil 50, and a mold unit 54 that covers the outer periphery of the bobbin 52 and the coil 50. And the outer peripheral surface of the mold portion 54 are in contact with the inner wall surface of the storage portion 44, respectively, and the coil 50 is connected to the energizing terminal 34 via a wiring (not shown). The coil 50 is energized by being energized by a control signal from a controller (not shown).

  The plunger 16 is formed of, for example, a magnetic metal material, and has a vertical hole 56 extending from the proximal end toward the distal end at the center thereof, and the proximal end side of the vertical hole 56 (in the direction of arrow A). ) Is formed with a spring receiving portion 58 whose diameter is increased outward in the radial direction.

  A spring 60 is interposed between the distal end of the retainer 42 in the fixed core portion 38 and the spring receiving portion 58. The spring 60 is formed of, for example, a coil spring, and its elastic force urges the plunger 16 in a direction away from the fixed core portion 38 (arrow B direction).

  In addition, a plurality of lateral holes 62 communicating with the longitudinal holes 56 and penetrating radially outwards perpendicular to the longitudinal holes 56 are formed at the distal end of the plunger 16, and the distal end is formed into a disk shape from an elastic material. The formed valve body 64 is attached.

  The valve body 64 is provided so as to be seated on a valve seat portion 66 formed at the proximal end of the nozzle member 18 under the movement action of the plunger 16.

  Further, as shown in FIGS. 1 to 3B, the base end (end face) 16a of the plunger 16 is formed in a plane and an annular shape perpendicular to the axial direction (directions of arrows A and B). 68 is mounted. The stopper member 68 is made of, for example, an elastic material such as rubber, and includes a base portion 70 attached to the plunger 16 and a plurality of contact portions 72 provided so as to protrude with respect to the base portion 70.

  For example, the base portion 70 is formed in an annular shape smaller than the outer peripheral diameter of the plunger 16 and is fixed to the base end 16a of the plunger 16 by adhesion or the like.

  For example, the contact portion 72 is formed in a circular shape when viewed from the axial direction of the plunger 16 (in the direction of arrow B in FIG. 1), and in a hemispherical shape in a direction away from the base portion 70 (in the direction of arrow A). The bulges are provided so as to be spaced apart from each other at equal intervals along the circumferential direction of the base portion 70 (see FIG. 3A).

  The contact portion 72 is not limited to the case where the contact portion 72 is formed in a circular shape when viewed from the axial direction of the plunger 16 as described above. For example, the contact portion 72 may have an elliptical shape or an oval shape. Also good. That is, the contact part 72 should just be a shape which has the circular arc part in the outer peripheral part.

  As shown in FIG. 1, the nozzle member 18 is formed, for example, in a cylindrical shape, and its base end is integrally crimped to the tip of the third housing portion 24, and the tip is an intake pipe (see FIG. Inserted). A nozzle hole 74 extending in the axial direction is formed at the center of the nozzle member 18, and the base end of the nozzle hole 74 is provided so as to face the valve body 64 of the plunger 16.

  The nozzle hole 74 is formed on the proximal end side (in the direction of arrow A) and faces the valve seat 66, a small diameter hole 78 adjacent to the valve hole 76, and gradually with respect to the small diameter hole 78. The diameter of the taper hole 80 is increased, and a large-diameter hole 82 is formed on the tip end side of the taper hole 80. Function as.

  The fuel injection valve 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation, action, and effect will be described. A valve closed state in which the solenoid 16 shown in FIG. 1 is de-energized, the plunger 16 is lowered, and the valve body 64 is seated on the valve seat 66 will be described as an initial state.

  In this initial state, a control signal from a controller (not shown) is input to the energization terminal 34 of the coupler 36, and the coil 50 is energized accordingly, thereby exciting and generating a magnetic flux. It is sucked and moved toward the fixed core 38 (in the direction of arrow A) against the force. The contact portion 72 of the stopper member 68 provided at the base end 16a of the plunger 16 abuts against the distal end of the fixed core portion 38, so that the movement of the plunger 16 is restricted and stopped, and the valve body 64 is moved to the valve seat. The valve is separated from the portion 66.

  At this time, as shown in FIGS. 2 and 3B, the contact portion 72 of the stopper member 68 is formed in a hemispherical shape that bulges toward the fixed core portion 38 (in the direction of arrow A), and in FIG. As shown, the adjacent contact portions 72 are spaced apart from each other by a predetermined distance. Therefore, when the contact portion 72 comes into contact with the distal end of the fixed core portion 38 (see the two-dot chain line shape in FIG. 3B), the plunger 16 As seen from the axial direction, the contact portion 72 is crushed while elastically deforming radially so as to expand substantially uniformly outward in the radial direction (in the direction of arrow D in FIG. 3A).

  Therefore, as shown in FIGS. 3A and 3B, the deformation amount E (see FIG. 3B) of the contact portion 72 in the circumferential direction in the circumferential direction becomes substantially equal, and accordingly, the deformation amount E in the radial direction outside. Less. Reducing the deformation amount E reduces the sliding contact amount between the contact portion 72 and the fixed core portion 38. Therefore, wear can be suppressed, and stress applied to the boundary portion F (see FIG. 3B) between the stopper member 68 and the base end 16a of the plunger 16 is suppressed, so that the base portion of the contact portion 72 Peeling from 70 is prevented.

  Thus, when the fuel injection valve 10 is in the valve open state, the fuel gas supplied to the fuel introduction hole 28 of the valve housing 12 passes through the guide hole 48 from the through hole 40 and the vertical hole 56 and the horizontal hole 62 of the plunger 16. It flows into the nozzle hole 74 of the nozzle member 18 and is ejected from the large diameter hole 82.

  On the other hand, when the fuel gas injection from the fuel injection valve 10 is stopped, the control signal from a controller (not shown) is stopped, whereby the coil 50 is brought into a non-excited state, and accordingly, the fixed core portion with respect to the plunger 16 is fixed. The suction force toward the 38th side (arrow A direction) disappears. Accordingly, the plunger 16 is urged and moved toward the nozzle member 18 side (in the direction of arrow B) by the elastic force of the spring 60, so that the valve body 64 shown in FIG. 1 is seated on the valve seat portion 66. Closed. As a result, the flow of the fuel gas flowing from the valve housing 12 to the nozzle member 18 is interrupted, and the fuel gas injection from the nozzle hole 74 is stopped.

  At this time, when the plunger 16 moves in a direction away from the fixed core portion 38 (in the direction of arrow B), the contact portion 72 of the stopper member 68 that is in contact with the fixed core portion 38 moves from the tip of the fixed core portion 38. The contact parts 72 provided in a plurality of hemispherical shapes and arranged in the circumferential direction have a contact area with the fixed core part 38 as compared with the annular stopper in the fuel injection valve according to the prior art. Since it is small, sticking to the fixed core portion 38 is prevented, and the plunger 16 having the stopper member 68 can be smoothly separated from the fixed core portion 38 and operated.

  As described above, in the present embodiment, the base end 16a of the plunger 16 constituting the fuel injection valve 10 is provided with the stopper member 68 made of an elastic material, and the stopper member 68 has a base portion attached to the plunger 16. A plurality of contact portions 72 that are spaced apart from each other at an equal interval along the circumferential direction with respect to 70 and swell in a semicircular cross section in a direction away from the base portion 70 are provided. Then, the plunger 16 moves toward the fixed core portion 38 (in the direction of arrow A) under the excitation action of the coil 50 constituting the solenoid portion 14, and the stopper member 68 comes into contact with the tip of the fixed core portion 38 to be elastically deformed. In this case, since each contact portion 72 is deformed so as to expand substantially uniformly toward the outer side in the radial direction, the deformation amount in the circumferential direction of the contact portion 72 is substantially equal, and the deformation amount is reduced to suppress wear. And uneven wear is also prevented. As a result, the wear amount of the stopper member 68 is reduced, and durability can be improved.

  Further, since the contact portions 72 are deformed substantially uniformly outward in the radial direction, stress applied to the boundary portion F between the stopper member 68 and the base end 16a of the plunger 16 is suppressed. Can be prevented from being peeled off from the base portion 70, and the durability of the stopper member 68 can be extended.

  Further, by providing a plurality of contact portions 72 along the circumferential direction of the stopper member 68, the contact amount with respect to the fixed core portion 38 as compared with the fuel injection valve according to the related art having an annular stopper continuous in the circumferential direction. Since (contact area) can be reduced, sticking when the plunger 16 is separated from the fixed core portion 38 is suitably prevented, and the plunger 16 can be smoothly lowered.

  Furthermore, by forming the contact portion 72 in a hemispherical shape, for example, compared to the case where the contact portion of the contact portion 72 is formed in a flat cross-section, the amount of contact (contact area) with the tip of the fixed core portion 38. Therefore, when the plunger 16 is lowered and the stopper member 68 is separated from the fixed core portion 38, the sticking of each contact portion 72 is preferably suppressed, and the plunger 16 can be smoothly operated without causing an operating resistance. Can be moved. Further, wear due to contact with the fixed core portion 38 can be reduced, and durability can be improved.

  Next, stopper members 100 and 110 according to first and second modifications will be described with reference to FIGS. 4A and 4B. As shown in FIG. 4A, the stopper member 100 according to the first modification is arranged so that a part of the adjacent contact portion 102 overlaps along the circumferential direction of the base portion 104, and according to the second modification. The stopper member 110 is different from the stopper member 68 of the fuel injection valve 10 according to the present embodiment in that the adjacent contact portions 112 are arranged so as to contact each other in the circumferential direction of the base portion 114. Yes. Even in such a configuration, substantially the same effect as the stopper member 68 described above can be obtained.

  Further, the stopper members 68, 100, 110 described above are not limited to the case where they are provided at the base end 16a of the plunger 16, but may be provided at the distal end of the fixed core portion 38 with which the plunger 16 abuts. . That is, it is only necessary that the stopper members 68, 100, 110 be provided on either the base end 16 a side of the plunger 16 facing each other or the distal end side of the fixed core portion 38.

  Further, the stopper members 68, 100, 110 are not limited to the case where the stopper members 68, 100, 110 are attached to the plunger 16 via the base portions 70, 104, 114 provided with the plurality of contact portions 72, 102, 112. The contact portions 72, 102, and 112 may be directly attached to the plunger 16 without having the portions 70, 104, and 114.

  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 ... Valve housing 14 ... Solenoid part 16 ... Plunger 18 ... Nozzle member 28 ... Fuel introduction hole 38 ... Fixed core part 50 ... Coil 60 ... Spring 64 ... Valve body 66 ... Valve seat part 68, 100, 110 ... Stopper members 70, 104, 114 ... Base part 72, 102, 112 ... Contact part 74 ... Nozzle hole

Claims (3)

A housing having a flow path through which the fuel gas flows; a plunger which is movably provided inside the housing and has a valve body at a tip; and a nozzle which is provided at an end of the housing and injects the fuel gas. A fuel injection valve for switching the open / closed state by sucking the plunger toward the fixed core under the energization action of the coil;
A stopper member provided on one end face of the plunger or the fixed core facing the plunger, and capable of regulating movement of the plunger toward the fixed core;
The stopper member is made of an elastic material, is formed in a circular shape, an elliptical shape, or an oval shape when viewed from the moving direction of the plunger, and is provided in a plurality along the circumferential direction of the plunger. Injection valve. The fuel injection valve according to claim 1, wherein
The fuel injection valve according to claim 1, wherein the stopper member is formed in a hemispherical shape that bulges in a moving direction of the plunger. The fuel injection valve according to claim 1 or 2,
The fuel injection valve according to claim 1, wherein the stopper member is disposed uniformly along the circumferential direction.

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