JP2010209810A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve having an installation structure reducing variation tolerance in a rotational direction to suppress a variation in an injection position in a combustion chamber by configuring the positioning pin itself of the fuel injection valve in such a manner as to be adjustable in conjunction with the phase of a valve seat. <P>SOLUTION: This fuel injection valve 100 used for a direct injection internal combustion engine and formed with a plurality of injection ports includes: a resin housing 103; a resin socket 105 integrally molded with the housing 103; and the deformable positioning member 101a with its end buried in resin between the socket 105 and the housing 103. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel injection valve (injector) used for a direct injection internal combustion engine, and more particularly to a fuel injection valve mounting structure.

  In a fuel injection valve for a direct injection gasoline engine, the fuel to be injected needs to strictly determine the position of the fuel and air during lean burn or the like. Therefore, the injected fuel is required to be injected into the combustion chamber at a predetermined angle and spread. The injection hole of the fuel injection valve is formed in the valve seat, and the valve seat is a multi-hole type as shown in FIG. 3 and has a phase in the rotation direction.

  Conventionally, when such a fuel injection valve is attached to an engine, the fuel injection valve is positioned on the fuel supply rail or the engine by a positioning pin integrally formed with a mold portion of the fuel injection valve housing. Accordingly, the phase in the rotational direction of the fuel injection valve is determined by the positioning pin.

  The positioning pin is molded on the fuel injection valve. At the time of molding, the fuel injection valves are all reversed by a predetermined machine tool or moved to a mold. When such inversion and movement are repeated, some deviation occurs. Specifically, the phase may be shifted when the fuel injection valve is reversed by the arm of the machine tool or placed on the mold. As described above, the positioning pin may be out of phase with the rotation direction of the valve seat due to the above-described problem in the assembly process of the fuel injection valve. For this reason, the tolerance in the rotation direction of the fuel injection valve has such a deviation, which causes variations in the spray position in the combustion chamber. At the stage where the valve seat is welded to the fuel injection valve, the mold has not been molded yet, that is, the positioning pin is not integrated with the fuel injection valve, so that there is no phase shift.

On the other hand, Japanese Patent Application Laid-Open No. 2006-316693 has proposed a fuel injection valve mounting structure for a direct injection gasoline engine that attempts to eliminate mounting variations.
The mounting structure is provided with an engagement pin that protrudes from the outer peripheral wall of the fuel injection valve, and an engagement groove that is formed on a plate member fixed to the cylinder head and engages with the engagement pin to position the fuel injection valve. The tip of the engaging pin moves along the inclined portion of the engaging groove in accordance with the angle of attachment tolerance of the fuel injection valve, and the engagement position changes to rotate the fuel injection valve around the axis. In this configuration, the distance between the fuel spray and the ignition point of the spark plug is kept constant.

JP 2006-316669 A

  In the mounting structure described in Japanese Patent Laid-Open No. 2006-316693, the engagement pin of the fuel injection valve moves along the inclined portion of the engagement groove of the plate member, so that a certain angle with respect to the longitudinal axis of the fuel injection valve This eliminates mounting tolerances. This mounting structure adjusts the deviation in the phase direction in the circumferential direction together with the rail for positioning the fuel injection valve, but the deviation in the phase direction cannot be adjusted by the fuel injection valve alone.

  In a direct-injection engine, the spray position in the combustion chamber affects the ignition performance, etc. The spray position variations include those due to phase variations during assembly of the fuel injection valve. There is a need to absorb variations.

  Therefore, the present invention can adjust the variation tolerance in the rotational direction by making the fuel injection valve alone, that is, the positioning pin itself of the fuel injection valve can be adjusted (deformed) in accordance with the phase of the valve seat. Thus, an object of the present invention is to provide a fuel injection valve having a mounting structure capable of suppressing variations in injection positions within a combustion chamber.

  In order to solve the above-described problems, a fuel injection valve according to the present invention includes a resin housing and a plurality of injection holes, and a fuel injection valve used in a direct injection internal combustion engine has a terminal embedded in the housing. A positioning member that can be deformed is provided. In addition, a resin socket integrally formed with the housing is provided, and an end of the positioning member is embedded between the socket and the housing during molding. Further, the positioning member extends between the socket and the housing in a direction parallel to a longitudinal axis of the fuel injection valve. The positioning member may extend between the socket and the housing toward the fuel supply end of the fuel injection valve, or may extend toward the fuel injection end of the fuel injection valve. The positioning member may be positioned on the fuel supply rail side or may be positioned on the engine side.

  With the fuel injection valve of the present invention, variations in phase (circumferential direction) caused by assembly of the fuel injection valve can be absorbed by the fuel injection valve alone. As a result, since the phase variation can be suppressed, there is no injection position variation caused by the phase variation in the combustion chamber, and more stable combustion can be obtained. In addition, phase variations occurring during assembly of the fuel injection valve can be corrected for each product. Furthermore, since the adjustment mechanism completes the adjustment with the single fuel injection valve, there is no restriction on the fuel supply rail to which the fuel injection valve is attached or on the engine side.

It is a side view of a fuel injection valve concerning one embodiment of the present invention. It is the figure which looked at the fuel injection valve which concerns on one Embodiment of this invention from the arrow A direction of FIG. It is a front view of the valve seat used as the premise of the embodiment of the present invention. It is a conceptual diagram which shows the attachment state of the fuel injection valve of FIG. It is a conceptual diagram which shows the attachment state of the fuel injection valve of deformation | transformation embodiment of this invention. FIG. 2 is an enlarged side view of the fuel injection valve on the fuel supply end side for explaining correction of phase shift in the fuel injection valve of FIG. 1.

An embodiment according to a fuel injection valve of the present invention will be described with reference to FIGS. The fuel injection valve according to the present embodiment is used for a direct injection gasoline engine.
FIG. 1 shows a side view of the fuel injection valve according to the present embodiment, and FIG. 2 shows a view of the fuel injection valve as viewed from the direction of arrow A (the fuel supply end portion 100a side) in FIG. The fuel injection valve 100 has a substantially long and thin tubular shape, and a lead (not shown) for communication with an ECU (not shown) and power supply is connected to the side surface of the housing 103 of the fuel injection valve 100. A socket 105 is provided protruding. An end of a positioning pin 101 a for fixing the fuel injection valve 100 is embedded between the socket 105 and the housing 103.

Since the housing 103 of the fuel injection valve 100 is made of resin and the socket 105 is also made of resin, both are molded integrally. At the time of this molding, the distal end portion of the positioning pin 101a which is a separate body is embedded and molded. As shown in FIG. 1, the positioning pin 101 a extends to the fuel supply end 100 a side in parallel with the longitudinal axis 100 c of the fuel injection valve 100. Positioning pins 101a is composed of a deformable metal or resin material or the like. For example, the positioning pin 101a may be formed of resin integrally with the housing 103 and the socket 105 during resin molding.

  Next, the valve seat will be described. A valve seat (valve seat) 107 having a fuel injection nozzle is welded to the fuel injection end 100 b side of the fuel injection valve 100. The shape of the valve seat 107 is shown in FIG. 3, which is a conceptual view of the valve seat 107 viewed from the arrow B side in FIG. The valve seat 107 is a multi-hole type in which a plurality of injection holes 107a having an elliptical outer edge are arranged in a ring shape. Since the valve seat 107 has a phase in the rotation direction (circumferential direction) shown in FIG. 3, the valve seat 107 needs to be welded so as to have an appropriate phase when welding to the fuel injection valve 100.

  The position of the multi-hole type hole (injection hole 107a) is determined in advance by the position of the spark plug and the like, and the position of the multi-hole formed in the valve seat 107 is important. When the valve seat 107 is attached, it is welded to the fuel injection valve 100 in accordance with a positioning point (not shown) of the valve seat 107. When the valve seat 107 is welded, the valve seat 107 is positioned and welded in a state where the fuel injection valve 100 of FIG. 1 is held by a predetermined machine tool and rotated by 180 degrees. It is held by the machine tool and rotated 180 degrees to perform molding. Thus, a welding process and a molding process are performed. Therefore, in these steps, the phase of the valve seat 107 and the position of the positioning pin 101a integrated by molding may deviate from the prescribed relationship. In the present invention, a visual check is performed for a phase shift at the final stage of the fuel injection valve production line, and when the shift is confirmed, the fuel injection valve is fixed and the positioning pin is plastically deformed to correct the shift. be able to. If this correction is performed at an angle of about several degrees, cracks and the like can be prevented from occurring in the resin portion by suppressing the force acting on the positioning pin as much as possible. As a result, the dispersion of the spray position in the combustion chamber is suppressed, the ignitability is improved, and the engine performance is stabilized.

  FIG. 4 is a conceptual diagram showing an attached state of the fuel injection valve 100 according to the present embodiment. The fuel supply end portion 100a of the fuel injection valve 100 is connected to the fuel supply rail 200 to supply the fuel, and at the same time, the fuel injection valve 100 is fixed to the rail 200 by the positioning pin 101a. The fuel injection end portion 100 b of the fuel injection valve 100 to which the valve seat 107 is attached is attached to a fuel injection valve attachment hole 301 formed in the engine head 300, and the injection hole formed in the valve seat 107 is inside the combustion chamber 400. Exposed to.

  FIG. 5 is a conceptual diagram showing an attached state of the fuel injection valve 100 according to a modified embodiment. In this embodiment, the positioning pin 101b extends in parallel to the longitudinal axis 100c of the fuel injection valve 100 toward the fuel injection end portion 100b, and is fixed by a pin fixing portion 303 formed on the engine head 300 side. .

  FIG. 6 is a main part enlarged view showing a state after the phase shift is corrected by the positioning pin, and the valve seat 107 is shifted in the left rotation direction 109a in the drawing in a plane perpendicular to the longitudinal axis 100c. In such a case, the displacement in the phase direction is absorbed by deforming the positioning pin 101a in the right rotation direction 109b by an amount corresponding to the displacement.

  The fuel injection valve of the present invention is not limited to the positioning direction, and the phase shift can be corrected regardless of whether the fuel injection valve is positioned on the rail side or the head side. Furthermore, the fuel injection valve of the present invention can correct the phase shift of about 1 to 30 degrees, and can improve the robustness of the fuel injection valve.

DESCRIPTION OF SYMBOLS 100 Fuel injection valve 100a Fuel supply end part 100b Fuel injection end part 100c Longitudinal axis 101a Positioning pin 101b Positioning pin 103 Housing 107 Valve seat 107a Injection hole 109a Left rotation direction 109b Right rotation direction 200 Rail 300 Engine head 301 Fuel injection valve attachment Hole 303 Pin fixing part 400 Combustion chamber

Claims (7)

In a fuel injection valve used for a direct injection internal combustion engine, comprising a resin housing and a plurality of injection holes,
A fuel injection valve comprising: a positioning member having a distal end embedded in the housing and deformable. The fuel injection valve according to claim 1, further comprising a resin socket integrally formed with the housing, wherein an end of the positioning member is embedded between the socket and the housing at the time of molding. Fuel injection valve. 3. The fuel injection valve according to claim 1, wherein the positioning member extends between the socket and the housing in a direction parallel to a longitudinal axis of the fuel injection valve. 4. 4. The fuel injection valve according to claim 1, wherein the positioning member extends between the socket and the housing toward a fuel supply end of the fuel injection valve. 5. Injection valve. 4. The fuel injection valve according to claim 1, wherein the positioning member extends between the socket and the housing toward a fuel injection end portion of the fuel injection valve. 5. Injection valve. 5. The fuel injection valve according to claim 4, wherein the positioning member is positioned on a fuel supply rail side. 6. The fuel injection valve according to claim 5, wherein the positioning member is positioned on the engine side.

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