JP7291585B2 - fuel injector - Google Patents

Description

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

2. Description of the Related Art As a background art in this technical field, an electromagnetic fuel injection valve described in Japanese Patent Laying-Open No. 2011-202613 (Patent Document 1) is known. The electromagnetic fuel injection valve disclosed in Patent Document 1 includes a cylindrical valve seat member, a magnetic cylinder fitted to the rear end of the valve seat member and welded in a liquid-tight manner, and the magnetic cylinder A non-magnetic cylinder that is abutted against the rear end and welded in a liquid-tight manner, a cylindrical fixed core that is liquid-tightly welded with the front end fitted to the inner peripheral surface of the non-magnetic cylinder, and the and a fuel inlet cylinder integrally connected to the rear end of the fixed core with the same material (see paragraph 0024). The valve seat member has a valve hole opening to its front end face, a conical valve seat continuing to the inner end of the valve hole, and a cylindrical guide hole continuing to the large diameter portion of the valve seat. A steel plate injector plate having a plurality of fuel injection holes communicating with the valve holes is liquid-tightly welded to the front end face of the seat member (see paragraph 0025).

JP 2011-202613 A

In the electromagnetic fuel injection valve (hereinafter referred to as fuel injection valve) disclosed in Patent Document 1, a valve seat member having a valve seat is fixed to a magnetic cylindrical body by welding. In such a configuration, there is a possibility that the valve seat formed in the valve seat member may be displaced in the axial direction of the fuel injection valve due to thermal expansion and contraction during welding. Misalignment of the valve seat changes the stroke of the valve body. Therefore, after fixing the valve seat member to the valve housing, it is necessary to adjust the stroke of the valve body, which complicates the manufacturing process of the fuel injection valve. Alternatively, in order to prevent the positional displacement of the valve seat member, it is necessary to add a positional displacement prevention part to the valve housing, which increases the number of parts of the fuel injection valve and the process of assembling the parts.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve in which a valve seat member can be fixed to a valve housing without welding.

In order to achieve the above object, the fuel injection valve of the present invention comprises:
a valve element and a valve seat that cooperate to open and close a fuel passage that communicates with a fuel injection hole; a first housing portion in which the valve seat is formed; a second housing portion to which the first housing portion is attached; In a fuel injection valve in which the first housing portion and the second housing portion are formed of separate members,
The first housing part and the second housing part have a locking part that locks the first housing part to the second housing part,
A seal member for sealing fuel is disposed outside the first housing portion and the second housing portion,
The first housing part has an inner peripheral surface into which the second housing part is inserted,
the locking portion on the side of the first housing portion is configured by a convex portion protruding radially inward from the inner peripheral surface of the first housing portion,
the locking portion on the side of the second housing portion is configured by a groove-shaped portion into which the convex portion is fitted;
Welds across both the first housing part and the second housing part are eliminated.

According to the present invention, the valve seat member can be fixed to the valve housing without welding.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing a cross section including a center axis 1a of a fuel injection valve 1 and parallel to the center axis 1a of an embodiment of the fuel injection valve 1 according to the present invention; 2 is an enlarged cross-sectional view showing a tip portion including a nozzle portion 8 of the fuel injection valve 1 shown in FIG. 1; FIG. 2 is an external view showing an external appearance of a tip portion including a nozzle portion 8 of the fuel injection valve 1 shown in FIG. 1; FIG. 3 is an external view showing the appearance of a valve seat member fixing portion (yoke 33) that fixes the valve seat member 15. FIG. FIG. 5B is a perspective view of the valve seat member 15 shown in FIG. 5A as seen obliquely from below; 3 is a cross-sectional view showing a cross section including a central axis 1a and parallel to the central axis 1a of the valve seat member 15 of the fuel injection valve 1. FIG. FIG. 4B is a perspective view of the valve seat member 15 shown in FIG. 4A as viewed obliquely from above; Fig. 3 is a cross-sectional view showing a cross section including a central axis 1a and parallel to the central axis 1a, showing a state where the fuel injection valve 1 is assembled to the mounting portion 109; FIG. 11 is a cross-sectional view showing a cross-sectional shape of a modified example 46' of the seal member 46; FIG. 11 is a cross-sectional view showing a cross-sectional shape of a modified example 46 ″ of the seal member 46 ; 1 is a cross-sectional view of an internal combustion engine 100 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 9. FIG.

The overall configuration of the fuel injection valve 1 will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a cross-sectional view showing a section parallel to the center axis 1a including the center axis 1a of the fuel injection valve 1 of an embodiment of the fuel injection valve 1 according to the present invention. FIG. 2 is a cross-sectional view showing an enlarged tip portion including the nozzle portion 8 of the fuel injection valve 1 shown in FIG.

In this embodiment, the center axis 1a coincides with the axis (valve axis) of the mover 27 integrally provided with the valve body 17, which will be described later, and the center axis of the tubular body 5, which will be described later. In the following description, the vertical direction may be specified, but this vertical direction is based on the vertical direction in FIG. 1 and does not specify the vertical direction when the fuel injection valve 1 is mounted. The upper end of the fuel injection valve 1 is called the proximal end, and the lower end is called the distal end. The designations proximal and distal are based on the mounting state of the fuel injection valve 1 with respect to the fuel pipe and the direction of fuel flow.

The fuel injection valve 1 is provided with a fuel supply port 2 at the base end portion of a cylindrical body 5 made of a metal material, and a fuel flow path 3 is formed inside the cylindrical body 5 so as to extend substantially along the central axis 1a. ing. A fuel filter 13 is attached to the fuel supply port 2 to remove foreign matter mixed in the fuel. An O-ring 11 is provided as a sealing member in the vicinity of the fuel supply port 2 at the proximal end of the tubular body 5 .

A valve portion 7 including a valve body 17 and a valve seat member 15 is formed at the distal end portion of the cylindrical body 5 . A through hole 15a is formed through the valve seat member 15 in a direction along the central axis 1a. A conical surface whose diameter decreases toward the downstream side is formed in the middle of the through hole 15a, and a valve seat (seat portion) 15b is formed on this conical surface. The valve body 17 opens and closes the fuel passage by contacting and separating from the valve seat 15b. That is, the valve body 17 and the valve seat 15b cooperate to open and close the fuel passage that communicates with the injection hole (fuel injection hole) 110 . The entire conical surface on which the valve seat 15b is formed may be called the valve seat surface.

An inner peripheral surface 15c of the through hole 15a above the conical surface constitutes a guide surface (guide hole) that guides the valve body 17 in the direction along the central axis 1a. A lower end portion of the valve body housing hole 15a opens to a tip surface 15t of the valve seat member 15, and this opening constitutes a fuel introduction hole (valve hole) 15d.

The valve seat member 15 is locked by a locked locking portion configured together with a yoke 33 which will be described later. The locking structure of the valve seat member 15 will be described later in detail.

In this embodiment, the nozzle portion 8 that determines the form of fuel spray includes a nozzle plate (injector plate) 21 . In this embodiment, the nozzle portion 8 is constructed by joining the nozzle plate 21 to the tip surface 15t of the nozzle portion 8 on the main body side (the valve seat member 15).

Further, in this embodiment, the valve element 17 is a spherical ball valve. The valve body 17 is provided with a plurality of cutout surfaces 17a at intervals in the circumferential direction at a portion facing the guide surface 15c, and the cutout surfaces 17a form a fuel passage. The valve body 17 is not limited to a ball valve, and for example, a needle valve may be used.

A driving portion 9 for driving the valve body 17 is arranged in the intermediate portion of the tubular body 5 . 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 cylindrical body 5, and arranged inside the cylindrical body 5 on the tip side of the fixed core 25, A mover (movable member) 27 that can move in a direction along the axis 1a and a movable core 27a formed in the mover 27 and the fixed core 25 face each other across a small gap δ. and a yoke 33 covering the electromagnetic coil 29 on the outer peripheral side of the electromagnetic coil 29 .

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 δ, in order to reduce leakage magnetic flux flowing through the cylindrical body 5 at the minute gap δ, a non-magnetic portion or a cylindrical body is provided at a position corresponding to the minute gap δ of the cylindrical body 5 . A weakly magnetic portion is provided which is less magnetic than the other portions of 5 . In this embodiment, a thin portion 5a formed by thinning the thickness of the cylindrical body 5 is provided as a weakly magnetic portion.

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 . A coil device 70 is configured by the electromagnetic coil 29, the bobbin 31, the terminal 43, and the like. 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 core 25 is press-fitted into the cylindrical body 5 and 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 mover 27 has a moveable iron core 27a on the base end side. The mover 27 has a small diameter portion (connecting portion) 27b on the tip side with respect to the movable iron core 27a, and the valve body 17 is fixed to the tip of the small diameter portion 27b by welding. The valve body 17 constitutes a part of the mover 27 and constitutes the valve portion 7 . In this embodiment, the movable iron core 27a and the connecting portion 27b are integrally formed (one member made of the same material), but they may be configured by joining two members.

As described above, in this embodiment, the movable iron core 27a is connected to the valve body 17 and drives the valve body 27 in the opening/closing direction by magnetic attraction acting between the movable iron core 27a and the fixed iron core 25. As shown in FIG. Further, since the outer peripheral surface of the movable iron core 27a is in sliding contact with the inner peripheral surface of the cylindrical body 5, the mover 27 is guided to move in the direction along the center axis 1a (the direction of the opening/closing valve).

A fuel passage 3 for supplying fuel from the fixed core 25 side to the fuel injection hole 110 side is formed inside the mover 27 .

A coil spring 39 is arranged in a compressed state between the adjuster 35 arranged in the through hole 25a of the fixed iron core 25 and the movable iron core 27a. The coil spring 39 functions as a biasing member that biases the mover 27 in the direction (valve closing direction) in which the valve body 17 contacts the valve seat 15b.

The yoke 33 is made of a magnetic metal material, has a cylindrical shape, and covers the outer circumference of the electromagnetic coil 29 . The yoke 33 is formed as a stepped cylindrical member having a large diameter portion 33a, a small diameter portion 33b, and a step surface 33d formed between the large diameter portion 33a and the small diameter portion 33b. The large diameter portion 33 a is provided on the upper end side (base end side) of the yoke 33 , and the small diameter portion 33 b is provided on the lower end side (tip end side) of the yoke 33 .

The yoke 33 is press-fitted or inserted so that the lower end portion contacts the outer peripheral surface of the cylindrical body 5 . The tip end of the yoke 33 is joined to the cylindrical body 5 by laser welding 24 over the entire circumference. The laser welding 24 is performed inside an annular groove 33c provided at the tip end of the yoke 33. As shown in FIG. Further, the annular groove 33c constitutes a locking portion that locks the valve seat member 15. As shown in FIG. The locking structure of the valve seat member 15 will be described later in detail.

The cylindrical body 5, the yoke 33, and the valve seat member 15 constitute a housing (valve housing) of the fuel injection valve 1 that accommodates the mover 27 and forms a fuel passage therein. In particular, the valve seat member 15 has a valve seat 15b and constitutes a housing portion (first housing portion) that accommodates the valve element 17. The yoke 33 is a housing portion (first housing portion) that accommodates the upper portion of the mover 27 and the electromagnetic coil 29. 2 housing portion). The first housing portion 15 and the second housing portion 33 are configured as separate members, and the first housing portion 15 is attached to the second housing portion 33 .

A valve seat member 15 having a flange portion 15f at its upper end is assembled to the distal end portion of the tubular body 5. As shown in FIG. An O-ring 46 is fitted in the annular groove 45 between the flange portion 15f and the large-diameter portion 33a of the yoke 33. As shown in FIG. When the fuel injection valve 1 is attached to the internal combustion engine, the O-ring 46 serves as a sealing member for ensuring liquid-tightness and air-tightness between the insertion port 109a formed on the internal combustion engine side and the fuel injection valve 1. It functions as a cushioning material between the mouth 109a. That is, in this embodiment, the resin protector provided for holding the O-ring 46 is eliminated, and the metallic valve seat member 15 is given the function of the resin protector.

A resin cover 47 is molded from the intermediate portion of the fuel injection valve 1 to the vicinity of the proximal end thereof, and covered with the resin cover 47 . The resin cover 47 covers the wiring member that connects the electromagnetic coil 29 and the terminal 43 , and the connector 41 is integrally formed with the resin material forming the resin cover 47 .

As shown in FIG. 2, a nozzle plate 21 is attached to the tip end face 15t of the valve seat member 15. As shown in FIG. The nozzle plate 21 is fixed to the valve seat member 15 by laser welding 23 . The nozzle plate 21 is composed of a plate-like member (flat plate) having a uniform thickness, and a projecting portion 21a is formed in the central portion so as to protrude outward. The projecting portion 21a is formed to have a curved surface (for example, a spherical surface), and a fuel chamber is formed inside the projecting portion 21a. The fuel chamber inside the protruding portion 21a communicates with the fuel introduction hole 15d, and fuel is supplied through the fuel introduction hole 15d.

Next, operation of the fuel injection valve 1 will be described.

When the electromagnetic coil 29 is in a non-energized state and no driving current flows through the electromagnetic coil 29, the movable element 27 is biased in the valve closing direction by the coil spring 39, and the valve body 17 abuts (seats) on the valve seat 15b. in a state of In this case, a gap δ exists between the distal end face of the fixed core 25 and the proximal end face of the movable core 27a. In this embodiment, the gap δ is equal to the stroke of the mover 27 (that is, the valve body 17).

When the electromagnetic coil 29 is switched to an energized state and a drive current flows through the electromagnetic coil 29, a magnetic flux is generated in a closed magnetic circuit formed by the movable iron core 27a, the fixed iron core 25, and the yoke 33. FIG. Due to this magnetic flux, a magnetic attractive force is generated between the fixed core 25 and the movable core 27a facing each other across the gap δ. When this magnetic attraction force overcomes the resultant force of the biasing force of the coil spring 39 and the fuel pressure acting on the mover 27 in the valve closing direction, the mover begins to move in the valve opening direction. When the movable element 27 moves in the valve-opening direction by a distance δ equal to the gap δ and contacts the fixed core 25, the movable core 27a stops moving in the valve-opening direction and remains stationary (valve-open stationary state). reach.

When the mover 27 moves in the valve opening direction and the valve body 17 separates from the valve seat 15b, a gap (fuel flow path) is formed between the valve body 17 and the valve seat 15b, and a protruding shape is formed through the fuel introduction hole 15d. Fuel flows into the fuel chamber inside the portion 21a. The fuel supplied to the fuel chamber through the fuel introduction hole 15d flows into the fuel injection hole 110 through the inlet opening of the fuel injection hole 110, and is injected to the outside of the fuel injection valve 1 through the outlet opening of the fuel injection hole 110. .

When the electromagnetic coil 29 is de-energized, the magnetic attractive force decreases and eventually disappears. At this stage, when the magnetic attraction force becomes smaller than the biasing force of the coil spring 39, the mover 27 starts moving in the valve closing direction. When the valve body 17 comes into contact with the valve seat 15b, the valve body 17 closes the valve portion 7 and reaches a stationary state (valve closed stationary state).

The opening is from the time when the movable element 27 moves in the valve opening direction and the valve body 17 starts to separate from the valve seat 15b to the time when the movable element 27 moves in the valve closing direction and the valve body 17 contacts the valve seat 15b again. This is referred to as the valve time or the valve open state, and the period during which the valve body 17 is in contact with the valve seat 15b to close the valve is referred to as the valve closed time or the valve closed state.

A fixing structure for the valve seat member 15 according to this embodiment will be described below.

FIG. 3 is an external view showing the appearance of the tip portion including the nozzle portion 8 of the fuel injection valve 1 shown in FIG.

In this embodiment, the tip side end of the yoke 33 covers the radially outer side of the tip side end of the tubular body 5 , and the valve seat member 15 covers the radially outer side of the tip side end of the yoke 33 . . In this case, the valve seat member 15 covers the outer peripheral surface of the small diameter portion 33b of the yoke 33, particularly the portion of the small diameter portion 33b where the annular groove 33c is formed.

The valve seat member 15 has an annular flange portion 15f formed so as to protrude radially outward from its upper end portion, and is composed of the small diameter portion 33b of the yoke 33, the stepped surface 33d, and the flange portion 15f. An O-ring 46 is fitted in the annular groove 45 . The stepped surface 33 d and the upper end surface (base end surface) 15 fa of the flange portion 15 f constitute the side surface of the annular groove 45 , and the outer peripheral surface of the small diameter portion 33 b constitutes the bottom surface of the annular groove 45 .

The valve seat member 15 is a member on which the valve seat 15b is formed, and is a member made of metal. For this reason, in this embodiment, the surface of the portion on the tip end side of the fuel injection valve 1 from the tip end portion of the large diameter portion 33a of the yoke 33 is made of metal. However, a resin O-ring 46 is fitted around the annular groove 45 . The width dimension W45 of the annular groove 45 is slightly larger than the width dimension W46 of the O-ring 46, and the clearance dimensions δ1 and δ2 between the O-ring 46 and both side surfaces 15fa and 33d of the annular groove 45 are set to small values. there is The width dimension W45 of the annular groove 45 is equal to or smaller than the width dimension W46 of the O-ring 46 within the range where the resin O-ring 46 can be fitted in the annular groove 45. may be set to In this case, the O-ring 46 contacts both side surfaces 15fa and 33d of the annular groove 45, and the gap dimensions .delta.1 and .delta.2 become zero.

FIG. 4A is an external view showing the appearance of a valve seat member fixing portion (yoke 33) that fixes the valve seat member 15. FIG. FIG. 4B is a perspective view of the valve seat member 15 shown in FIG. 5A as seen obliquely from below.

A small-diameter portion 33b of the yoke 33 is formed with an annular groove 33c recessed from the outer peripheral surface to form an annular groove in the circumferential direction. An axial groove portion 33c1, a widened groove portion (circumferential groove portion) 33c2, and a locking portion (locking groove-shaped portion or groove-shaped portion) for locking the valve seat member 15 are formed in a part of the annular groove 33c. A locking groove portion 33c3 is formed. A tapered surface 33f is provided at the tip of the yoke 33 so that the diameter of the yoke 33 decreases toward the tip.

The axial groove portion 33c1 is formed in a direction along the central axis 1a of the fuel injection valve 1 so as to penetrate from the tip end side surface 33cb of the annular groove 33c to the tip end face 33e of the yoke 33. As shown in FIG. The circumferential length (width) of the axial groove portion 33c1 is set to the dimension W33c1.

The widened groove portion (circumferential groove portion) 33c2 is formed so as to widen the groove width dimension W33c of the annular groove 33c at a portion including a position facing the axial groove portion 33c1 of the proximal side surface 33ca of the annular groove 33c. It is a groove portion, which is connected to the axial groove portion 33c1 and extends in the circumferential direction. That is, the groove width dimension W33c2 of the widened groove portion 33c2 is larger than the groove width dimension W33c of the annular groove 33c (W33c2>W33c).

The locking groove portion 33c3 is formed in a portion of the widened groove portion (circumferential groove portion) 33c2, and is formed so as to further widen the groove width W33c2 of the widened groove portion 33c2 by a dimension D33c3 on the tip side surface 33cb of the annular groove 33c. The groove width dimension W33c-2-3 of the locking groove portion 33c3 includes the groove width W33c of the annular groove 33c, the increased width portion of the increased width groove portion 33c2, and the increased width portion D33c3 of the locking groove portion 33c3. Therefore, the groove width dimension W33c-2-3 is larger than the groove width dimension W33c of the annular groove 33c and the groove width dimension W33c2 of the widened groove portion 33c2 (W33c-2-3>W33c, W33c-2-3>W33c2). The length (width) in the circumferential direction of the locking groove portion 33c3 is formed to the size of the dimension L33c3.

The locking groove shape portions (groove shape portions) 33c1, 33c2, and 33c3 are formed on the tip end side surface 33cb between the axial groove portion 33c1 and the locking groove portion 33c3, and are wider than the groove width dimension W33c-2-3 of the locking groove portion 33c3. A protrusion 33c4 is formed so that the width of the groove becomes narrower. The projecting portion 33c4 is formed so as to protrude toward the center of the annular groove 33c with respect to the side surface of the locking groove portion 33c3. formed to form

In the circumferential direction of the small diameter portion 33b of the yoke 33, the widened groove portion 33c2 is the same as the dimension L33c1-4-3 of the range in which the axial groove portion 33c1, the projection portion 33c4 and the locking groove portion 33c3 are provided, or the dimension L33c1-4-3 of this range. It is provided in a range L33c2 having dimensions larger than 4-3. That is, the circumferential length dimension L33c2 of the widening groove portion 33c2 is equal to the circumferential length dimension L33c1-4-3 of the range in which the axial groove portion 33c1, the projection portion 33c4 and the locking groove portion 33c3 are provided, or L33c1- 4-3 (L33c2≧L33c1-4-3). However, in order to ensure that the valve seat member 15 can be attached to and detached from the yoke 33, the length L33c2 of the widened groove portion 33c2 and the length of the range in which the axial groove portion 33c1, the projection portion 33c4, and the locking groove portion 33c3 are provided are The length L33c1-4-3 can be made equal, and both ends of the widening groove portion 33c2 in the circumferential direction and both ends of the range in which the axial groove portion 33c1, the projection portion 33c4 and the locking groove portion 33c3 are provided can be positioned at the same position. preferable.

In this embodiment, laser welding 24 between the yoke 33 and the cylindrical body 5 is performed inside the annular groove 33c. By performing laser welding on the bottom surface of the annular groove 33c, heat energy for laser welding can be reduced. In this embodiment, the axial groove portion 33c1, the widened groove portion 33c2, the projection portion 33c4 and the locking groove portion 33c3 are provided in a part of the annular groove 33c for the laser welding 24. As a result, the processing man-hours for forming the annular groove 33c for the laser welding 24, the axial groove portion 33c1, the widening groove portion 33c2, the projection portion 33c4, and the locking groove portion 33c3 are reduced, and the arrangement space is saved. come true.

If it is not necessary to reduce the processing man-hours and save the arrangement space, the axial groove portion 33c1, the widening groove portion 33c2, the projection portion 33c4 and the locking groove portion 33c3 are provided separately from the annular groove 33c for the laser welding 24. good too.

FIG. 5A is a sectional view showing a section of the valve seat member 15 of the fuel injection valve 1 including the central axis 1a and parallel to the central axis 1a. FIG. 5B is a perspective view of the valve seat member 15 shown in FIG. 4A as viewed obliquely from above.

The valve seat member 15 has an annular flat portion (flange surface) 15g formed radially outward from the opening edge of the through hole 15a on the upstream side of the guide surface 15c. Further, the valve seat member 15 has an inner peripheral surface 15h formed upstream from the outer peripheral edge of the annular flat portion 15g in the direction along the central axis 1a. The inner peripheral surface 15h is provided with a plurality of convex portions 15i protruding radially inward about the center axis 1a. The convex portion 15i constitutes a locking portion on the side of the valve seat member 15 that locks the valve seat member 15 to the yoke 33. As shown in FIG.

In this embodiment, the annular groove 33c of the yoke 33 constitutes a locking portion on the side of the yoke 33 that locks the valve seat member 15 to the yoke 33. and the annular groove 33c constitute a locking portion that locks the valve seat member 15 to the yoke 33. As shown in FIG. That is, the valve seat member (first housing portion) 15 and the yoke (second housing portion) 33 have locking portions that lock the first housing portion 15 to the second housing portion 33 . The locking portion is formed by a convex portion 15i in the first housing portion 15, and has a groove shape having an axial groove portion 33c1, a widened groove portion (circumferential groove portion) 33c2, and a locking groove portion 33c3 in the second housing portion 33. It consists of the department. In this embodiment, since this groove-shaped portion (locking groove-shaped portion) is configured as a part of the annular groove 33c, it can be said that a part of the annular groove 33c is a groove-shaped portion (locking groove-shaped portion). Conceivable.

The plurality of convex portions 15i are arranged at intervals in the circumferential direction around the center axis 1a. In this embodiment, four convex portions 15i are provided, and the four convex portions 15i are evenly spaced in the circumferential direction.

The circumferential length (width) dimension W15i of the convex portion 15i is smaller than the circumferential length (width) dimension W33c1 of the axial groove portion 33c1 and the groove width dimension L33c3 of the locking groove portion 33c3. Further, the length dimension L15i of the convex portion 15i in the direction along the central axis 1a is larger than the groove width dimension W33c of the annular groove 33c and smaller than the groove width dimension W33c2 of the widened groove portion 33c2.

Therefore, the convex portion 15i can be inserted from the axial groove portion 33c1 into the widened groove portion 33c2, and can move in the circumferential direction in the widened groove portion 33c2. Further, the convex portion 15i is fitted into the locking groove portion 33c3 so that the movement in the circumferential direction is restricted, and the state shown in FIGS. 2 and 3 is obtained. In the cross section of FIG. 2, the projection 15i is fitted into the locking groove 33c3 so that the circumferential end surface 33c2a of the widening groove 33c2 shown in FIG. 4 can be seen above the projection 15i. .

2 and 3, the O-ring 46 is fitted in the annular groove 45. By fitting the O-ring 46 in the annular groove 45, the protrusion 15i is prevented from coming off from the locking groove 33c3. However, the O-ring 46 is formed of a resin material so as to be elastically deformable, and when the valve seat member 15 is lifted with a strong force with respect to the yoke 33, the convex portion 15i is pulled out of the locking groove portion 33c3. However, unless the valve seat member 15 is rotated in the circumferential direction in this state, the valve seat member 15 will not come off from the yoke 33 .

In this embodiment, the mounting structure of the valve seat member 15, which is the first housing portion, to the yoke 33, which is the second housing portion, is an attachment structure using a metal locking portion (engagement portion).

As described above, the tip portion of the yoke 33 is provided with a tapered surface 33f whose diameter decreases toward the tip side. to facilitate insertion.

FIG. 6 is a cross-sectional view showing a cross section including the center axis 1a and parallel to the center axis 1a, showing the state where the fuel injection valve 1 is assembled to the mounting portion 109. As shown in FIG.

Before the fuel injection valve 1 is assembled to the mounting portion 109, as shown in FIG. Between the O-ring 46 and both side surfaces 15fa and 33d of the annular groove 45, gaps of dimensions .delta.1 and .delta.2 exist. Alternatively, the O-ring 46 is in contact with one of the side surfaces 15fa and 33d of the annular groove 45, and there is a gap of dimension .delta.1+.delta.2 between the O-ring 46 and the other side surface.

When the fuel injection valve 1 is assembled to the mounting portion 109, the O-ring 46 is compressed by the inner peripheral surface of the insertion port 109a so as to form a large contact surface with the bottom surface 33b and both side surfaces 15fa and 33d of the annular groove 45. , is elastically deformed.

In this state, at least between the O-ring 46 and the side surface 15fa of the annular groove 45, and between the O-ring 46 and the bottom surface 33b of the annular groove 45 or the side surface 33d of the annular groove 45, from the inside of the fuel injection valve 1 to the outside. A seal is provided to prevent leakage of fuel to the On the other hand, between the O-ring 46 and the side surface 15fa of the annular groove 45 and between the O-ring 46 and the inner peripheral surface of the insertion port 109a, liquid-tightness and air-tightness are provided between the inside of the intake pipe 108 and the outside air. A securing seal is configured.

In order to seal the fuel, it is necessary to form a seal portion between the O-ring 46 and the side surface 15fa of the annular groove 45. As shown in FIG. On the other hand, between the O-ring 46 and the bottom surface 33b of the annular groove 45 and between the O-ring 46 and the side surface 33d of the annular groove 45, a sealing portion may be formed on either one of them.

In this embodiment, the sealing member that prevents fuel from leaking is composed of the O-ring 46 that ensures liquid-tightness and air-tightness between the inside of the intake pipe 108 and the outside air, thereby suppressing an increase in the number of parts. can.

In this embodiment, since the O-ring 46 is brought into close contact with the bottom surface 33b and both side surfaces 15fa and 33d of the annular groove 45, as shown in FIG. It is made larger than the gap dimension .delta.1+.delta.2 between both side surfaces 15fa, 33d of the groove 45 and the O-ring .

In the present embodiment, the O-ring 46 is compressed by the inner peripheral surface of the insertion port 109a so as to come into contact with both side surfaces 15fa and 33d of the annular groove 45. 109a before being inserted (the state of FIG. 2), it may be configured to contact both side surfaces 15fa and 33d of the annular groove 45. As shown in FIG. In this case, even if a gap is formed between the O-ring 46 and the bottom surface 33b of the annular groove 45 after the fuel injection valve 1 is inserted into the insertion port 109a (the state shown in FIG. 6), the O-ring Fuel can be sealed between 46 and side surface 33 d of annular groove 45 .

In this embodiment, a seal member (O-ring) 46 for sealing fuel is disposed outside the valve seat member (first housing portion) 15 and the yoke (second housing portion) 33, and the valve seat member 15 and the yoke are separated from each other. 33 are eliminated. That is, the fuel is not sealed by the welded portion between the valve seat member 15 and the yoke 33, but is provided outside the housing of the fuel injection valve 1 composed of the valve seat member 15 and the yoke 33. It is performed by an O-ring (sealing member) 46 that In order to ensure this sealing, it is necessary to increase the packing rate of the O-ring 46 into the annular groove 45 .

FIG. 7 is a cross-sectional view showing the cross-sectional shape of a modified example 46' of the seal member 46. As shown in FIG.

The sealing member 46' of this example has a cross-shaped cross section and four projecting pieces 46'a, 46'b, 46'c, and 46'd. The sealing member 46' has a projecting piece 46'a in contact with the side surface 33d of the annular groove 45, a projecting piece 46'b in contact with the inner peripheral surface of the insertion port 109a, and a projecting piece 46'c in contact with the side surface of the annular groove 45. 15fa, and the projecting piece 46'd is arranged in the annular groove 45 so as to contact the bottom surface 33b of the annular groove 45. As shown in FIG.

The sealing member 46' of this example also has a sealing portion that prevents fuel from leaking from the inside of the fuel injection valve 1 to the outside, and a sealing portion that ensures liquid-tightness and air-tightness between the inside of the intake pipe 108 and the outside air. , can be constructed.

FIG. 8 is a cross-sectional view showing a cross-sectional shape of a modified example 46'' of the seal member 46. As shown in FIG.

The sealing member 46'' of this example has flat portions on three surfaces 46''a, 46''c, and 46''d, and between the two flat portions 46''a and 46''c ( A surface facing the flat portion 46''d) is composed of a semi-cylindrical surface (a surface obtained by cutting the cylindrical surface in half) 46''b. The sealing member 46 ″ of this example can increase the filling rate of the O-ring 46 ″ into the annular groove 45 and improve the sealing performance.

An internal combustion engine equipped with a fuel injection valve according to the present invention will be described with reference to FIG. FIG. 9 is a cross-sectional view of an internal combustion engine 100 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 this embodiment, welding for fixing the valve seat member (first housing portion) 15 and the yoke (second housing portion) 33 is eliminated. positional deviation of the first housing portion at , and stroke change of the valve body 17 due to thermal contraction can be eliminated. This eliminates the need to add a member to prevent displacement of the first housing portion due to heat shrinkage and to readjust the stroke, thereby improving the productivity of the fuel injection valve 1 and reducing the manufacturing cost of the fuel injection valve 1. Cost can be reduced. In addition, variations in the injection amount of the fuel injection valve 1 are suppressed.

REFERENCE SIGNS LIST 1 fuel injection valve 1a center axis of fuel injection valve 1 3 fuel passage 15 valve seat member (first housing portion) 15b valve seat 15h second housing portion 33 is inserted 1 inner peripheral surface of housing portion 15 15i convex portion (locking portion on first housing portion 15 side) 17 valve body 25 fixed iron core 27a movable iron core 29 electromagnetic coil 33 yoke (Second housing portion), 33c... Annular groove, 33c1... Axial groove part, 33c2... Enlarged groove part (circumferential groove part), 33c3... Locking groove part, 33c4... Projection part, 46... O-ring (sealing member), 15i , 33c1, 33c2, 33c3 . 109a: an insertion port of the fuel injection valve 1 formed on the internal combustion engine side;

Claims (5)

a valve element and a valve seat that cooperate to open and close a fuel passage that communicates with a fuel injection hole; a first housing portion in which the valve seat is formed; a second housing portion to which the first housing portion is attached; In a fuel injection valve in which the first housing portion and the second housing portion are formed of separate members,
The first housing part and the second housing part have a locking part that locks the first housing part to the second housing part,
A seal member for sealing fuel is disposed outside the first housing portion and the second housing portion,
The first housing part has an inner peripheral surface into which the second housing part is inserted,
the locking portion on the side of the first housing portion is configured by a convex portion protruding radially inward from the inner peripheral surface of the first housing portion,
the locking portion on the side of the second housing portion is configured by a groove-shaped portion into which the convex portion is fitted;
A fuel injection valve, wherein a weld extending over both the first housing portion and the second housing portion is eliminated. In the fuel injection valve according to claim 1 ,
The groove-shaped portion includes an axial groove portion formed in a direction along the central axis of the fuel injection valve, a circumferential groove portion connected to the axial groove portion and formed in the circumferential direction, and a part of the circumferential groove portion. A fuel injection valve, comprising: a locking groove formed in the fuel injection valve. In the fuel injection valve according to claim 2 ,
The groove-shaped portion is formed between the axial groove portion and the locking groove portion in the circumferential direction, and has a protrusion projecting toward the center of the groove-shaped portion with respect to the side surface of the locking groove portion. and fuel injection valve. In the fuel injection valve according to claim 3 ,
An electromagnetic drive unit that drives the valve body,
The electromagnetic drive unit includes an electromagnetic coil that is externally inserted into a cylindrical body, and a yoke that covers the electromagnetic coil on the outer peripheral side of the electromagnetic coil,
the second housing part is constituted by the yoke and has a circumferential annular groove welded to the tubular body;
The fuel injection valve, wherein the groove-shaped portion is formed in a part of the annular groove. In the fuel injection valve according to claim 4 ,
The fuel injection valve, wherein the seal member is an O-ring that secures liquid-tightness and air-tightness between an insertion port of the fuel injection valve formed on the side of the internal combustion engine and the fuel injection valve.

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