JP6606045B2 - Fuel injection valve, control device for fuel injection valve, and control method - Google Patents

Description

  The present invention relates to a fuel injection valve, a control device for a fuel injection valve, and a control method.

  In a fuel injection valve mounted on an internal combustion engine that directly injects fuel into a combustion chamber, a fuel injection device having a plurality of injection holes injects fuel in a different direction for each injection hole in the intended injection direction in the combustion chamber. By doing so, a good combustion state such as fuel consumption and exhaust is realized. On the other hand, the method of effectively using the fuel differs depending on whether the state of the fuel in the combustion chamber is homogeneously combusted or stratifiedly combusted, and the method of improving the fuel consumption and exhaust is different.

  Here, according to Patent Literature 1, a structure is disclosed in which penetration is changed depending on the injection direction of fuel injected from a plurality of injection holes and the structure of the injection holes. In particular, a method is disclosed in which fuel injected from an injection hole is injected without interfering with a countersink constituting a downstream diffusion region injected from a guide region constituting the injection hole. According to the present invention, it is disclosed that the spray is injected without interfering with the outlet end portion by decentering the center axis of the guide region farther from the center axis of the fuel injection valve.

  Further, according to Patent Document 2, a means for realizing ignition at the time of stratified combustion is disclosed by changing the form of spray supplied to the gap of the spark plug according to the lift amount of the valve body of the fuel injection valve and the structure of the injection hole. Has been.

JP 2014-1660 A JP 2006-57604 A

  In an internal combustion engine that directly injects fuel into the combustion chamber, there is a concern that fuel consumption and exhaust will deteriorate due to fuel adhering to the wall surface of the combustion chamber, spark plugs, pistons, intake valves, etc., depending on the direction in which the fuel is directed and the injection amount for each injection hole. There is.

According to Patent Document 1 (Japanese Patent Laid-Open No. 2014-1660) described above, the fuel that adheres to the injection hole itself is suppressed by decentering the countersink that constitutes the diffusion region of the injection hole of the fuel injection valve. Although it is disclosed, the method for suppressing the adhesion of the fuel in the combustion chamber to which the fuel has been injected is determined by the injection direction determined in the guide region. Further, in stratified combustion in which the air-fuel mixture in the combustion chamber is collected in layers around the ignition plug and burned in a lean state, a means for realizing combustion while suppressing adhesion of droplets of the ignition plug is required. . Further, according to Patent Document 2, the structure of the fuel injection valve that is directly supplied to the spark plug is disclosed. There is a problem in the method.
Therefore, the present invention provides a fuel injection valve for realizing stratified combustion while suppressing the fuel injected from the injection hole from adhering to the spark plug.

In order to solve the above-described object, the present invention provides a fuel injection valve in which a plurality of injection holes are formed at a tip portion, wherein at least one of the plurality of injection holes is formed on a first upstream side. A first downstream hole formed on the downstream side of the first upstream hole and formed on the downstream side of the first upstream hole, and formed on the downstream side of the first downstream hole. And a second downstream hole having a diameter larger than that of the first downstream hole, and the first downstream hole so that a part of the spray ejected from the first upstream hole is guided to the first downstream hole. Is disposed at a position eccentric with respect to the central axis of the first upstream hole, and the injection hole directed to at least one spark plug among the plurality of injection holes is in relation to the central axis of the first upstream hole. The central axis of the first downstream hole is eccentrically arranged in the direction of the spark plug .

According to the fuel injection valve and the fuel injection valve of the present invention, it is possible to provide a fuel injection valve capable of reducing fuel adhesion to the piston and the combustion chamber wall surface and improving fuel consumption and exhaust performance.
Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

The block diagram of a fuel injection valve is shown. The block diagram of the injection hole of a fuel injection valve is shown. The relationship figure of the injection hole of a fuel injection valve and spray is shown. The cross section of the surface most eccentric to the central axis of the injection hole 301a and the spark plug direction is shown. The relationship figure of the injection hole of a fuel injection valve and spray is shown.

  Embodiments of a fuel injection valve according to the present invention will be described below in detail with reference to the drawings.

  The fuel injection valve in which a plurality of injection holes are formed at the tip of the present embodiment is formed by being connected to the first upstream hole and the first upstream hole formed on the upstream side among the plurality of injection holes. The first downstream hole is formed on the downstream side having a diameter different from that of the first upstream hole. The central axis of the first downstream nozzle hole is arranged at a position eccentric with respect to the central axis of the first upstream hole so that a part of the spray ejected from the first upstream hole is guided to the first downstream hole. The injection hole directed to at least one spark plug among the plurality of injection holes is arranged eccentrically in the direction of the spark plug.

  Further, at least one of the plurality of injection holes is eccentric in a direction other than the spark plug. Further, it is characterized in that it is used for performing stratified combustion which is mounted at the center position of the combustion chamber and directly supplies fuel to the spark plug.

  In the fuel injection valve shown in FIG. 1, the valve body 102 includes a nozzle holder 103, a core 104, and a housing 105. Fuel from a high-pressure fuel pump (not shown) is discharged through a plurality of fuel injection holes 107 through a fuel passage 106. The valve body 108 is accommodated in the nozzle holder 103 so as to be slidable in the axial direction via the anchor 109. The spring 110 is disposed between the valve body 108 and the adjuster pin 111, and the position of the upper end portion of the spring 110 is restrained by the adjuster pin 111.

  The fuel injection hole 107 is closed by the spring 110 pressing the valve element 108 against the seat portion 113 of the seat member 112. The solenoid 114 is disposed on the anchor 109 and receives a drive current from a drive circuit (not shown) to the solenoid 114 and energizes the solenoid 114. As a result, the core 104 is excited to generate a magnetic attractive force. The anchor 109 is pulled up in the axial direction. Along with this, the valve body 108 is pulled up in the axial direction by the anchor 109. At this time, the valve body 108 is separated from the seat portion 113, and the guides 115 and 116 guide the valve body 108 in the sliding direction. A plurality of fuel injection holes 107 are opened, and the fuel pressurized and pumped by a high-pressure fuel pump (not shown) passes through the fuel passage 106 and injects the fuel.

  Next, the fuel spray behavior injected from the fuel injection valve will be described with reference to FIG. Sprays 201 a, 201 b, 201 c are injected from the fuel injection valve 201 into the combustion chamber 206, and at this time, 201 a is injected toward the spark plug 202. At the same time, 201 b is injected toward the combustion chamber wall surface 207. Similarly, 201c is injected toward the piston side slightly below 201b. Here, 201b and 201c are displayed as a single spray for the sake of simplicity, but it is desirable that the sprays are sprayed from two or more nozzle holes.

  The timing at which the fuel injection valve 201 injects depends on whether the state in the combustion chamber is homogeneously mixed and ignited, or stratified combustion is performed in which the air-fuel mixture is collected around the spark plug 302 and ignited in a layered manner. A description will be given using an injection mode in which fuel is stratified in the combustion chamber and ignited. Ignition is realized by concentrating the air-fuel mixture around the spark plug by inhaling air during the intake process of the engine and injecting from the fuel injection valve 201 during the period until the ignition in the compression process. Embodiments of the present invention will be described below with reference to the drawings.

When the injection is performed, the fuel diffused into the combustion chamber reaches the piston 205 and the combustion chamber wall surface 207 and becomes attached to the fuel. At this time, if the penetration can be shortened, the adhesion of the fuel can be reduced. However, if the penetration is too short for promoting the mixing, the deterioration of the mixing is caused. It is desirable to change according to the air flow in the combustion chamber that varies depending on the stroke, the opening amount of the throttle valve 4 and the intake valve 303, the tumble control valve mounted in the intake port (not shown), and the like. Since the spray 201a is sprayed closest to the spark plug 202, the spray is sprayed in the direction of the spark plug from the structure of an injection hole described later.
In FIG. 3, the plurality of injection holes are constituted by 301, 302, 303, 304, and 305. For convenience of explanation, it is represented by five holes, but it is desirable that the spray is directed to the vicinity of the spark plug and is composed of five or more holes for injection into the combustion chamber.

The injection hole 301 shows the injection hole which injects 201a which faces the spark plug direction in FIG. The injection hole 301 is formed by an upstream hole 301a formed on the upstream side and a downstream hole 301b connected to the upstream hole 301a and formed on the downstream side of the upstream hole and having a diameter different from that of the upstream hole. The central axis of the downstream hole 301b is formed eccentric to the spark plug side with respect to the central axis of the upstream hole 301a.
Subsequently, the cross section of FIG. 4 shows a cross section of the surface that is most eccentric in the direction of the spark plug and the central axis of the injection hole 301a. The injection hole 401 passes through the upstream flow path of the fuel passage 401a (not shown), then passes through the upstream injection hole 402a and flows out to the downstream injection hole 402b. At this time, the upstream injection hole 402a has a role of adjusting the injection amount by the flow direction resistance when passing through the injection direction and the injection hole.

  Subsequently, when fuel flows from the injection hole 401a to the injection hole 401b, the spray diffuses according to the flow rate in the radial direction of the fuel injection valve. At that time, the spray is prevented from diffusing due to the spray colliding with the side wall 401d whose injection hole is narrowed due to the eccentricity. At this time, since the injection hole eccentric in the spark plug direction is widened, the spray is diffused and spread without colliding with the side wall 401e. That is, the spray in the direction that collides with the side wall 401d does not spread, and the spray in the direction that does not collide with the side wall of 401e has a spray shape in which the spray spreads with spread.

By adopting the structure of this injection hole, fuel can be supplied by spraying only to the side supplied to the spark plug side of the fuel injected from one hole. Can be ignited in a lean state. 401c formed in the further downstream side of the downstream side 401b is, so as not to suppress the spraying of the formed with a diameter greater than the diameter of the injection hole 401b, the length of the injection hole 401c has a shorter than the length 401 b By doing so, it is possible to make the spray hole in which the spray directed to the spark plug hardly interferes with the spray hole.
Next, the shape of the spray supplied between the spray directed to the spark plug of FIG. 5 and the gap between the electrodes of the spark plug will be described. The spark plug 501 performs ignition when it reaches the gap of the spark plug so as to directly ignite the fuel injected into the fuel 502a injected from the tip 502 of the fuel injection valve. At this time, 502a performs ignition by supplying fuel to the gap of the spark plug by the spray injected through the injection hole configured in FIG. At this time, the discharge of the spark plug may be brought closer to the spray side. By realizing ignition with the fuel 502a supplied to the spark plug 501, the mixture ratio in the entire combustion chamber can be made lean, and fuel consumption and exhaust gas can be improved.

102 Valve body 104 Core 107 Plural fuel injection holes 108 Valve body 109 Anchor 110 Spring 112 Seat member 113 Seat portion 114 Solenoid 201 Fuel injection valve 201a Spray 201b closest to the spark plug 201b Spray toward the combustion chamber wall surface 201c Adjacent spray 301 The most downstream injection hole 401 constituting the downstream injection hole 301c 401 constituting the upstream injection hole 301b 401 constituting the injection hole 301a 401 for injecting the spray closest to the ignition plug The fuel flow 401a downstream Side injection hole 401b Side wall 401c on the narrow side of the downstream side injection hole Side wall 401d on the wide side of the downstream side injection hole Side wall of the injection hole and spray collision portion 401e Direction of spray spreading while suppressing collision of the side wall of the injection hole

Claims (4)

In the fuel injection valve in which a plurality of injection holes are formed at the tip,
At least one of the plurality of injection holes is formed to be connected to the first upstream hole formed on the upstream side and the first upstream hole, and has a large diameter downstream from the first upstream hole. A first downstream hole formed on the side and a second downstream hole connected to the downstream side of the first downstream hole and having a larger diameter than the first downstream hole ,
Is disposed at a position where the center axis of the first lower Nagareana so that a portion of the spray ejected from the first upstream hole is guided to the first downstream hole is eccentric to the central axis of the first upstream hole, the jetting holes directed at least one spark plug central axis of the first downstream hole with respect to the central axis of the first upstream hole is arranged eccentrically in the direction of the spark plug of the plurality of injection holes A fuel injection valve characterized by   2. The fuel injection valve according to claim 1, wherein at least one of the plurality of injection holes is eccentric in a direction other than the spark plug.   2. The fuel injection valve according to claim 1, wherein the fuel injection valve is used for performing stratified combustion which is mounted at a center position of a combustion chamber and directly supplies fuel to a spark plug. 2. The fuel injection valve according to claim 1, wherein the second downstream hole is formed to have a shorter axial length than the first downstream hole. 3.

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