JP2023057255A - Fuel injection valve - Google Patents

Abstract

To provide a fuel injection valve having a reduced dead water region that is formed around a coil spring arranged in a penetration hole of a fixed iron core.SOLUTION: A fuel injection valve comprises: a movable element 27 having a valve body 27c arranged at one end and a movable iron core 27a arranged at the other end; a valve seat 15b against which the valve body 27c abuts in valve closing; a valve body energization member 39 for energizing the valve body 27c in a valve-closing direction; and a fixed iron core 25 which generates a magnetic suction force between it and the movable iron core 27a. The valve body energization member 39 is formed of a plate spring which is arranged at a lower end part of the movable iron core 27a.SELECTED DRAWING: Figure 3

Description

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

BACKGROUND ART As background art in this technical field, a fuel injection valve described in Patent Document 1 is known. This fuel injection valve is provided with a fuel passage that communicates the upstream side and the downstream side of the guide portion in the central axis direction at the same angular position as the downstream side communication hole in the circumferential direction of the mover. This fuel injection valve has a through-hole passing through the center of the fixed iron core in a direction along the central axis, and a coil spring is provided in this through-hole. The mover is urged in the (valve closing direction) (see paragraphs 0023-0028).

JP 2016-169674 A

In the fuel injection valve of Patent Document 1, if foreign matter enters the fuel passage during the manufacturing process, it is possible to discharge the foreign matter from the fuel passage with a short run-in. Consideration is given to reducing water areas. However, in the fuel injection valve of Patent Literature 1, no consideration is given to the dead water area generated around the coil spring arranged in the through hole of the fixed iron core.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve in which a dead water area generated around a coil spring arranged in a through hole of a fixed iron core is reduced.

In order to achieve the above object, the fuel injection valve of the present invention comprises:
a mover having a valve body provided at one end and a movable iron core provided at the other end;
a valve seat against which the valve element abuts when the valve is closed;
a valve body biasing member that biases the valve body in a valve closing direction;
A fixed iron core that generates a magnetic attraction force between itself and the movable iron core;
with
The valve body biasing member is composed of a leaf spring arranged at the lower end of the movable iron core.

According to the present invention, by using a leaf spring instead of a coil spring, it is possible to provide a fuel injection valve in which a dead water area generated around the coil spring disposed in the through-hole of the fixed iron core is reduced. can.

1 is a cross-sectional view showing a cross-section along a valve axis (center axis) of an embodiment of a fuel injection valve according to the present invention; FIG. 2 is an enlarged cross-sectional view showing the vicinity of a nozzle portion 8 shown in FIG. 1; FIG. It is a longitudinal cross-sectional view which expands and shows the mover 27 vicinity. It is a figure which shows one Example of the valve body biasing spring used for the fuel injection valve which concerns on this invention. FIG. 5 is a schematic diagram showing an overview of the function of the valve body biasing spring shown in FIG. 4; FIG. 9 is a diagram showing analysis results of fuel flow around a coil spring 390 in a comparative example with the present invention in which a coil spring 390 is arranged in a through-hole 25a of a fixed iron core 25; 1 is a cross-sectional view of an internal combustion engine in which a fuel injection valve 1 is mounted; FIG.

An embodiment according to the present invention will be described with reference to FIGS. 1 to 3. FIG.

The overall configuration of the fuel injection valve 1 will be described with reference to FIG. FIG. 1 is a cross-sectional view showing a cross-section along the valve axis (central axis) of an embodiment of the fuel injection valve according to the present invention. The central axis 1a coincides with the axis (valve axis) of the movable element 27 integrally provided with the valve body 27c, the rod portion (connecting portion) 27b, and the movable iron core 27a. aligned with the central axis.

In FIG. 1, the upper end portion (upper end side) of the fuel injection valve 1 may be called the base end portion (base end side), and the lower end portion (lower end side) may be called the tip portion (tip end side). The names of the base end (base end side) and the tip end (front end side) are based on the direction of fuel flow or the mounting structure of the fuel injection valve 1 with respect to the fuel pipe. Also, the vertical relationship described in this specification is based on FIG. 1, and does not necessarily match the vertical direction when the fuel injection valve 1 is mounted in an internal combustion engine.

The fuel injection valve 1 has a tubular body 5 made of a metallic material, and a fuel passage (fuel passage) 3 is formed inside the tubular body 5 so as to extend substantially along the central axis 1a. The cylindrical body 5 is made of a metal material having magnetism, such as stainless steel, and is formed into a stepped shape along the central axis 1a by press working such as deep drawing. As a result, the diameter of the cylindrical body 5 on the one end side 5a is larger than the diameter on the other end side 5b.

A fuel supply port 2 is provided at the proximal end of the cylindrical body 5, and a fuel filter 13 is attached to the fuel supply port 2 for removing foreign matter mixed in the fuel. An O-ring 11 is arranged on the outer periphery of the proximal end portion 5d of the cylindrical body 5. As shown in FIG.

A valve portion 7 composed of a valve body 27c and a valve seat member 15 is formed at the tip of the cylindrical body 5. As shown in FIG. The valve seat member 15 is inserted inside the tip end of the tubular body 5 and fixed to the tubular body 5 by laser welding 19 . The laser welding 19 is performed from the outer peripheral side of the cylindrical body 5 over the entire circumference. In this case, the valve seat member 15 may be press-fitted inside the tip end of the tubular body 5 and then fixed to the tubular body 5 by laser welding.

A driving portion 9 for driving the valve body 27c is arranged in the intermediate portion of the tubular body 5. As shown in FIG. The drive unit 9 is composed of an electromagnetic actuator (electromagnetic drive unit). Specifically, the drive unit 9 includes a fixed core 25 fixed inside (inner peripheral side) of the tubular body 5, and a front end side of the fixed core 25 inside the tubular body 5. A mover (movable member) 27 that can move in a direction along the axis 1a and a mover core 27a and a fixed core 25 formed in the mover 27 face each other across a minute gap δ1. and a yoke 33 covering the electromagnetic coil 29 on the outer peripheral side of the electromagnetic coil 29 .

A mover 27 is accommodated inside the cylindrical body 5, and the cylindrical body 5 constitutes a housing that surrounds the movable core 27a so as to face the outer peripheral surface of the movable core 27a.

The movable iron core 27a, the fixed iron core 25, and the yoke 33 form a closed magnetic circuit through which magnetic flux generated by energizing the electromagnetic coil 29 flows. Although the magnetic flux passes through the minute gap δ1, in order to reduce leakage magnetic flux flowing through the cylindrical body 5 at the minute gap δ1, a non-magnetic portion or a cylindrical body is provided at a position corresponding to the minute gap δ1 of the cylindrical body 5. A weakly magnetic portion 5c, which is weaker than the other portions of 5, is provided. Hereinafter, the nonmagnetic portion or the weakly magnetic portion 5c will be simply referred to as the nonmagnetic portion 5c. The non-magnetic portion 5 c can be formed by subjecting the cylindrical body 5 to a non-magnetic treatment or by forming an annular concave portion on the outer peripheral surface of the cylindrical body 5 .

The electromagnetic coil 29 is wound around a bobbin 31 formed of a resin material in a cylindrical shape, and is externally inserted on the outer peripheral side of the cylindrical body 5 . The electromagnetic coil 29 is electrically connected to terminals 43 provided on the connector 41 . An external drive circuit (not shown) is connected to the connector 41 , and a drive current is applied to the electromagnetic coil 29 via the terminal 43 .

The fixed core 25 is made of a magnetic metal material. The fixed iron core 25 is formed in a cylindrical shape and has a through hole 25a passing through the central portion in a direction along the central axis 1a. The fixed iron core 25 is press-fitted and fixed to the base end side of the small diameter portion 5 b of the cylindrical body 5 and is positioned in the intermediate portion of the cylindrical body 5 . The fixed iron core 25 may be fixed to the cylindrical body 5 by welding, or may be fixed to the cylindrical body 5 using both welding and press-fitting.

The movable element 27 is composed of a movable iron core 27a, a rod portion (connecting portion) 27b, and a valve body 27c. The movable iron core 27a has an annular shape. The valve body 27c is a member that contacts the valve seat 15b (see FIG. 2). The valve seat 15b and the valve body 27c cooperate to open and close the fuel passage. The rod portion 27b has an elongated cylindrical shape and is a connection portion that connects the movable iron core 27a and the valve body 27c. The movable iron core 27a is a member that is connected to the valve body 27c and drives the valve body 27c in the opening/closing direction by a magnetic attraction force acting between the movable iron core 27c and the fixed iron core 25 .

In this embodiment, the rod portion 27b and the valve body 27c are formed of separate members, and the valve body 27c is fixed to the rod portion 27b. Fixation of the rod portion 27b and the valve body 27c is performed by welding. The rod portion 27b and the valve body 27c may be integrated as one member.

The rod portion 27b has a cylindrical shape, and has a central hole 27ba that opens at the upper end of the rod portion 27b and extends in the axial direction. A communication hole (opening) 27bo is formed in the rod portion 27b to communicate between the inside (center hole 27ba) and the outside. A fuel chamber 37 is formed between the outer peripheral surface of the rod portion 27 b and the inner peripheral surface of the cylindrical body 5 . The fuel passage 3 in the through hole 25a of the fixed core 25 communicates with the fuel chamber 37 through the recess 27aa of the movable core 27a, the hole 27ba of the rod portion 27b, and the communication hole 27bo. The recessed portion 27aa, the central hole 27ba, and the communication hole 27boa form a fuel passage 3 that communicates the fuel passage 3 and the fuel chamber 37 in the through hole 25a.

The yoke 33 is made of a magnetic metal material and also serves as a housing for the fuel injection valve 1 . The yoke 33 is formed in a stepped cylindrical shape having a large diameter portion 33a and a small diameter portion 33b. The large-diameter portion 33a covers the outer periphery of the electromagnetic coil 29 and has a cylindrical shape. The small-diameter portion 33b is press-fitted or inserted into the outer circumference of the small-diameter portion 5b of the tubular body 5. As shown in FIG. The inner peripheral surface of the small diameter portion 33b is in close contact with the outer peripheral surface of the cylindrical body 5. As shown in FIG. At this time, at least a portion of the inner peripheral surface of the small diameter portion 33b faces the outer peripheral surface of the movable iron core 27a via the cylindrical body 5, thereby reducing the magnetic resistance of the magnetic path formed in this facing portion. ing. The tip end of the yoke 33 is joined to the cylindrical body 5 by laser welding 24 over the entire circumference.

A cylindrical protector 49 is fitted around the tip of the tubular body 5 , and the tip of the tubular body 5 is protected by the protector 49 . An annular groove 34 is formed by the flange portion 49a of the protector 49, the small-diameter portion 33b of the yoke 33, and the step surface between the large-diameter portion 33a and the small-diameter portion 33b of the yoke 33, and an O-ring 46 is fitted in the annular groove 34. It is The O-ring 46 provides liquid-tightness and air-tightness between the inner peripheral surface of the insertion port formed on the internal combustion engine side and the outer peripheral surface of the small diameter portion 33b of the yoke 33 when the fuel injection valve 1 is attached to the internal combustion engine. Acts as a securing seal.

A resin cover 47 is molded over a range from the intermediate portion of the fuel injection valve 1 to the vicinity of the proximal end. The distal end of the resin cover 47 covers part of the proximal end of the large diameter portion 33 a of the yoke 33 . Further, the connector 41 is integrally formed with the resin forming the resin cover 47 .

In this embodiment, a plate spring 39 is attached to the mover 27, and the plate spring 39 urges the mover 27, ie, the valve body 27c, to contact the valve seat 15b (see FIG. 2). That is, a plate spring 39 is provided on the mover 27 as a valve body biasing member that biases the valve body 27c in the valve closing direction. This valve body biasing member 39 will be described later in detail.

Next, referring to FIG. 2, the configuration of the nozzle portion 8 will be described in detail. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the nozzle portion 8 shown in FIG.

Through holes 15d, 15c, 15v, and 15e are formed in the valve seat member 15 so as to extend therethrough along the central axis 1a. A conical surface 15v whose diameter decreases toward the downstream side is formed in the middle of this through hole. A valve seat 15b is formed on the conical surface 15v, and the opening and closing of the fuel passage is performed by the valve body 27c coming into and out of contact with the valve seat 15b. Note that the conical surface 15v on which the valve seat 15b is formed may be called a valve seat surface. The valve seat 15b constitutes a sealing portion on the side of the valve seat surface 15v that contacts the valve body 27c.

Hole portions 15d, 15c, and 15v of the through-holes 15d, 15c, 15v, and 15e above the conical surface 15v constitute a valve body accommodation hole that accommodates the valve body 27c. A guide surface 15c for guiding the valve body 27c in the direction along the central axis 1a is formed on the inner peripheral surfaces of the valve body housing holes 15d, 15c, and 15v. Of the two guide surfaces that guide the mover 27, the guide surface 15c constitutes the downstream guide surface located on the downstream side.

The downstream guide surface 15c and the sliding contact surface 27cb of the valve body 27c that slides on the downstream guide surface 15c constitute a downstream guide portion 50A that guides the displacement of the mover 27. As shown in FIG.

On the upstream side of the guide surface 15c, an enlarged diameter portion 15d whose diameter is enlarged toward the upstream side is formed. The lower end of the valve seat surface 15v is connected to the fuel introduction hole 15e, and the lower end surface of the fuel introduction hole 15e opens to the tip surface 15t of the valve seat member 15. As shown in FIG.

A nozzle plate 21n is attached to the tip surface 15t of the valve seat member 15. As shown in FIG. The nozzle plate 21n is fixed to the valve seat member 15 by laser welding 23. As shown in FIG. The laser welded portion 23 surrounds the injection hole formation region in which the plurality of fuel injection holes 110 are formed, and goes around the injection hole formation region.

The nozzle plate 21n is made of a plate-like member (flat plate) having a uniform thickness, and has a plurality of fuel injection holes 91 formed therein. The form of the plurality of fuel injection holes 91 is not particularly limited. A swirling chamber that imparts a swirling force to the fuel may be provided on the upstream side of the fuel injection hole 91 . The center axis 91a of the fuel injection hole may be parallel to the center axis 1a of the fuel injection valve, or may be inclined.

In this embodiment, the valve portion 7 that opens and closes the fuel injection hole 91 is composed of the valve seat member 15 and the valve body 27c, and the fuel injection portion 21 that determines the form of fuel spray is composed of the nozzle plate 21n. The valve portion 7 and the fuel injection portion 21 constitute a nozzle portion 8 for injecting fuel. That is, the nozzle portion 8 in this embodiment is constructed by joining the nozzle plate 21n to the tip surface 15t of the nozzle portion 8 on the main body side (valve seat member 15).

Further, in this embodiment, a ball valve having a spherical shape is used as the valve body 27c. For this reason, a plurality of cutout surfaces 27ca are provided at intervals in the circumferential direction at a portion of the valve body 27c facing the guide surface 15c. 3) is configured. The valve body 27c can also be configured with a valve body other than a ball valve. For example, a needle valve may be used.

A configuration near the mover 27 will be described in detail with reference to FIG. FIG. 3 is a longitudinal sectional view showing the vicinity of the mover 27 in an enlarged manner.

In this embodiment, the movable iron core 27a and the rod portion 27b are integrally formed as one member. A concave portion 27aa recessed toward the lower end side is formed in the central portion of the upper end surface 27ab of the movable iron core 27a. An opening 27af communicating with the center hole 27ba of the rod portion 27b is formed in the bottom portion 27ag of the recess 27aa. The opening 27af constitutes a fuel passage through which fuel flowing into the space (fuel passage) in the recess 27aa from the through hole 25a of the fixed core 25 flows into the space (fuel passage) 27bi of the center hole 27ba of the rod portion 27b.

That is, the movable element 27 includes a rod portion 27b extending between a valve body 27c provided at one end and a movable iron core 27a provided at the other end and having a diameter smaller than that of the movable iron core 27a, and the center of the rod portion 27b. and a fuel passage 27bi formed with a hole 27ba.

In this embodiment, the rod portion 27b and the movable iron core 27a are configured as one member, but they may be configured as separate members and assembled together.

An upper end surface 27ab of the movable core 27a faces a lower end surface 25b of the fixed core 25. As shown in FIG. An upper end surface 27ab of the movable iron core 27a and a lower end surface 25b of the fixed iron core 25 constitute magnetic attraction surfaces on which magnetic attraction forces act on each other. A cylindrical member 30 is provided between the outer peripheral surface 27ac of the movable iron core 27a and the inner peripheral surface 5e of the tubular body 5 .

The cylindrical member 30 is configured to be magnetic on the distal end side and non-magnetic on the proximal end side. That is, the cylindrical member 30 has a magnetic portion 30b and a non-magnetic portion 30a. The magnetic portion 30b improves the flow of magnetic flux between the yoke 33 and the movable iron core 27a, and the non-magnetic portion 30a reduces leakage magnetic flux flowing through the cylindrical member 30 between the yoke 33 or the movable iron core 27a and the fixed iron core 25. . Thereby, a decrease in the magnetic attraction force between the movable core 27a and the fixed core 25 can be suppressed.

The presence of the non-magnetic portion 30a of the cylindrical member 30 enhances the effect of reducing the leakage magnetic flux flowing from the movable core 27a to the fixed core 25 through the cylindrical body 5 at the minute gap δ1. If this leakage magnetic flux can be sufficiently reduced, the non-magnetic portion 5c of the cylindrical body 5 can be omitted, and the strength of the cylindrical body 5 can be improved.

The outer peripheral surface 27ac of the movable iron core 27a is configured to slide on the inner peripheral surface 30e of the cylindrical member 30 interposed between the inner peripheral surface 5e of the tubular body 5 and the outer peripheral surface 27ac. An inner peripheral surface 30e of the cylindrical member 30 constitutes an upstream guide surface, and an outer peripheral surface 27ac of the movable iron core 27a is in sliding contact with the upstream guide surface 30e formed by the cylindrical member 30. As shown in FIG. The upstream guide surface 30e and the outer peripheral surface 27ac of the movable iron core 27a form an upstream guide portion 50B that guides the displacement of the mover 27. As shown in FIG.

The mover 27 is guided by two points, an upstream guide portion 50B and a downstream guide portion 50A (see FIG. 2), and reciprocates along the central axis (valve axis) 1a. As described above, the rod portion 27b of the mover 27 is formed with the communication hole 27bo that communicates the inside (center hole 27ba) and the outside. That is, in the fuel injection valve 1 of this embodiment, the movable element 27 has a rod portion 27b between the valve body 27c and the movable iron core 27a. It has a communicating fuel passage.

A plate spring 39 is provided at the lower end of the movable iron core 27a as a valve body biasing member that biases the valve body 27c in the valve closing direction. That is, the fuel injection valve 1 of this embodiment includes a movable element 27 having a valve element 27c provided at one end and a movable iron core 27a provided at the other end, and a valve seat with which the valve element 27c abuts when the valve is closed. 15b, a valve body biasing member 39 that biases the valve body 27c in the valve closing direction, and a fixed core 25 that generates a magnetic attraction force between the movable core 27a. , and a plate spring 39 arranged at the lower end of the movable iron core 27a.

For this reason, a recess 27ad is formed in the outermost peripheral surface 27ac of the lower end portion of the movable iron core 27a, and the plate spring 39 is press-fitted into the recess 27ad and fixed to the movable iron core 27a. That is, the plate spring 39 is fixed to an outer peripheral surface portion 27ad having a smaller diameter than the outermost peripheral surface 27ac of the movable iron core 27a.

That is, the fuel injection valve of this embodiment has a cylindrical member 30 on the outer peripheral side of the core of the movable iron 27a. It is arranged so as to abut against the lower end.

As shown in FIG. 3, a fuel filter 36 for collecting foreign matter mixed in the fuel may be arranged at the bottom 27ag of the concave portion 27aa of the movable iron core 27a. As a result, the effect of collecting foreign matter contained in the fuel is enhanced, and the reliability of the fuel injection device is improved.

4 and 5 together with FIG. 3, a detailed description will be given of the configuration related to the biasing of the mover 27 by the plate spring 39. FIG. FIG. 4 is a diagram showing an embodiment of a valve element biasing spring used in the fuel injection valve according to the present invention. FIG. 5 is a schematic diagram showing an overview of the function of the valve body biasing spring shown in FIG.

In this embodiment, the leaf spring 39 is constructed by a disc spring. The leaf spring 39 has a hole in its center and is tapered such that the outer diameter 39o side is located closer to the base end side of the fuel injection valve 1 than the inner diameter 39i side. It abuts on the lower end of the magnetic portion 30b. As described above, since the leaf spring 39 is press-fitted into the recess 27ad of the movable core 27a and fixed, the dimension (inner diameter dimension) D39i of the inner diameter 39i of the leaf spring 39 is larger than the outer diameter dimension of the recess 27ad of the movable core 27a. small. On the other hand, the dimension (outer diameter dimension) D39o of the outer diameter 39o of the leaf spring 39 is larger than the inner diameter dimension of the cylindrical member 30 so that the leaf spring 39 functions as a spring. It is set to a value smaller than the diameter (inner diameter dimension) of 5e.

The length h of the cylindrical member 30 in the direction along the central axis 1a is set to such a length that the leaf spring 39 can always generate a biasing force that biases the mover 27 in the valve closing direction. That is, the length h of the cylindrical member 30 is such that the outer diameter portion (peripheral portion) of the leaf spring 39 always contacts the lower end portion of the cylindrical member 30 and the inner diameter portion always compresses the leaf spring 39 fixed to the movable iron core 27a. It is set to a size that can be maintained in a closed state.

Since the cylindrical member 30 is held by the plate spring 39, it need not be fixed to the cylindrical body 5, but may be fixed to the inner peripheral surface 5e of the cylindrical body 5 by press fitting or the like. In the fuel injection valve 1 of this embodiment, the cylindrical member 30 is sandwiched between the fixed core 25 and the leaf spring 39 . More specifically, the cylindrical member 30 is sandwiched between the leaf spring 39 and the lower end surface 25 b of the fixed core 25 . In this case, the fuel injection valve 1 of the present embodiment includes the cylindrical body 5 containing the mover 27, and the cylindrical member 20 is loosely fitted inside the cylindrical body 5. As shown in FIG.

Therefore, the upper end of the cylindrical member 30 contacts the lower end surface 25 b of the fixed core 25 , and the lower end of the cylindrical member 30 contacts the outer diameter portion of the leaf spring 39 . In this case, the urging force of the mover 27 is set within a predetermined numerical range depending on the length h of the cylindrical member 30 . Further, when the cylindrical member 30 is fixed to the inner peripheral surface 5e of the tubular body 5, the biasing force of the mover 27 can also be set by the fixing position of the cylindrical member 30. FIG.

In FIG. 5, the movable core 27 indicated by the solid line indicates the movable core in the valve closed state, and the movable core 27' indicated by the broken line indicates the movable core in the valve open state. A plate spring 39 indicated by a solid line indicates a plate spring in the valve closed state, and a plate spring 39' indicated by a broken line indicates a plate spring in the valve open state. The inner diameter side of the leaf spring 39 is positioned lower than the outer diameter side, and the lowest end of the leaf spring 39 in the valve closed state is positioned lower than the lowest end of the leaf spring 39 in the valve open state. In the valve open state (the state indicated by the broken line 39 ′) in which the upper surface of the leaf spring 39 is displaced to the highest position, there is a gap between the upper surface of the leaf spring 39 ′ and the lower end surface of the cylindrical member 30 . Of course, the outermost diameter portion of the leaf spring 39 is in contact with the lower end surface of the cylindrical member 30 .

As shown in FIG. 4, the leaf spring 39 does not need to be in a perfect circular ring shape, and may have a shape in which a notch 39a is partially provided. As with the leaf spring 39, the cylindrical member 30 does not need to be a perfect cylinder, and may be partially provided with a notch similar to the notch 39a.

Here, with reference to FIG. 6, the difference between the fuel flow of this embodiment and the comparative example will be described. FIG. 6 is a diagram showing analysis results of the fuel flow around the coil spring 390 for a comparative example with the present invention, in which the coil spring 390 is arranged in the through hole 25a of the fixed iron core 25. As shown in FIG.

Generally, a coil spring 39' is provided in the through hole 25a of the fixed iron core 25 to bias the valve body 27c into contact with the valve seat 15b (see FIG. 2). One end (lower end) of the coil spring 39 ′ abuts against a spring seat provided inside the movable iron core 27 a , and the other end (upper end) of the coil spring 39 ′ contacts an adjuster (adjuster) arranged inside the through hole 25 a of the fixed iron core 25 . It is provided so as to abut on the lower end portion of 35 (end face on the distal end side). That is, in a general fuel injection valve, a coil spring 39' is provided inside the through hole 25a of the fixed iron core 25 as a valve body biasing member that biases the valve body 27c in the valve closing direction. An adjuster 35 is also provided for installation.

In the comparative example, due to the coil spring 39' and the adjuster 35, a large dead water area is formed around the coil spring 39'. As a result, foreign matter stays in this dead water area, and a long break-in operation is required to discharge the foreign matter from the fuel passage.

In this embodiment, by providing the leaf spring 39 on the lower end side of the movable iron core 27a, it is possible to suppress the generation of dead water areas inside the through hole 25a of the fixed iron core 25. FIG. As a result, in this embodiment, the ability to discharge foreign matter from the fuel injection valve 1 is improved.

Further, in the present embodiment, by providing the leaf spring 39 on the lower end side of the movable iron core 27a where a dead water area is likely to occur structurally, no new dead water area is formed and the size of the conventional dead water area is reduced. can do.

An internal combustion engine equipped with a fuel injection valve according to the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view of an internal combustion engine in which the fuel injection valve 1 is mounted.

A cylinder 102 is formed in an engine block 101 of an internal combustion engine 100 , and an intake port 103 and an exhaust port 104 are provided at the top of the cylinder 102 . The intake port 103 is provided with an intake valve 105 for opening and closing the intake port 103 , and the exhaust port 104 is provided with an exhaust valve 106 for opening and closing the exhaust port 104 . An intake pipe 108 is connected to an inlet side end portion 107 a of an intake passage 107 formed in the engine block 101 and communicating with the intake port 103 .

A fuel pipe 110 is connected to the fuel supply port 2 (see FIG. 1) of the fuel injection valve 1 .

A mounting portion 109 for the fuel injection valve 1 is formed in the intake pipe 108, and an insertion port 109a into which the fuel injection valve 1 is inserted is formed in the mounting portion 109. As shown in FIG. The insertion port 109a penetrates to the inner wall surface (intake passage) of the intake pipe 108, and the fuel injected from the fuel injection valve 1 inserted into the insertion port 109a is injected into the intake passage. In the case of bidirectional spraying, an internal combustion engine having two intake ports 103 in an engine block 101 is targeted, and each fuel spray is directed toward each intake port 103 (intake valve 105) and injected.

In the internal combustion engine 100 of this embodiment, it is possible to suppress the occurrence of a dead water area in the fuel injection valve 1 . As a result, even if foreign matter enters the fuel flow path 3, the foreign matter can be quickly discharged from the fuel flow path 3, and the break-in time can be shortened.

It should be noted that the present invention is not limited to the above-described embodiments, and it is possible to delete some configurations and add other configurations that are not described.

REFERENCE SIGNS LIST 1 fuel injection valve 5 cylindrical body 15b valve seat 25 fixed iron core 27 mover 27a movable iron core 27b rod portion 27c valve body 30 cylindrical member 39 valve Body biasing member (leaf spring).

Claims (7)

a mover having a valve body provided at one end and a movable iron core provided at the other end;
a valve seat against which the valve element abuts when the valve is closed;
a valve body biasing member that biases the valve body in a valve closing direction;
A fixed iron core that generates a magnetic attraction force between itself and the movable iron core;
with
The valve body biasing member is a fuel injection valve configured by a leaf spring arranged at the lower end of the movable iron core. In the fuel injection valve according to claim 1,
A cylindrical member is provided on the outer peripheral side of the movable core,
The leaf spring is a fuel injection valve arranged such that an inner diameter portion thereof is press-fitted into an outer peripheral portion of the movable iron core, and an outer diameter portion thereof abuts against a lower end portion of the cylindrical member. In the fuel injection valve according to claim 2,
The fuel injection valve, wherein the cylindrical member is sandwiched between the fixed core and the leaf spring. In the fuel injection valve according to claim 3,
The inner diameter side of the leaf spring is positioned below the outer diameter side, and the lowest end of the leaf spring in the valve closed state is positioned lower than the lowest end of the leaf spring in the valve open state,
A fuel injection valve in which a gap exists between the upper surface of the leaf spring and the lower end surface of the cylindrical member in an open state in which the upper surface of the leaf spring is displaced to the highest position. In the fuel injection valve according to claim 4,
The mover includes a rod portion between the valve body and the moveable iron core,
A fuel injection valve having a fuel passage communicating with the upstream side of the movable iron core inside the rod portion. In the fuel injection valve according to claim 3,
A cylindrical body containing the mover,
The cylindrical member is a fuel injection valve that is loosely inserted inside the cylindrical body. The fuel injection valve according to any one of claims 1 to 6,
The fuel injection valve, wherein the plate spring is a disc spring.

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