JP4380685B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve, and more particularly to a fuel injection valve that promotes atomization of fuel.

  The fuel is supplied to the internal combustion engine by injecting the fuel into, for example, a combustion chamber from an injection hole formed in the fuel injection valve. In the conventional fuel injection valve, the fuel is caused to flow into the entire injection hole and injected into the combustion chamber. However, in recent years, as a method for improving engine power performance and fuel consumption and reducing toxic components in exhaust gas, a technique for atomizing the fuel injected from the nozzle holes is required. Therefore, when fuel is injected from the nozzle hole into the combustion chamber, the nozzle hole is formed on a part of the nozzle hole constituting surface (the inner peripheral surface formed on the valve body when the nozzle hole is formed). A technique has been proposed in which a liquid film is formed in the nozzle hole without causing the fuel to flow into the entire nozzle hole along the fuel flowing in. When a liquid film is formed on a part of the injection hole configuration surface, fuel is more easily diffused when injected into the combustion chamber than in the case where fuel is introduced into the entire injection hole. Fuel can be atomized more.

  In order for the liquid film to be formed on a part of the injection hole surface, it is necessary to generate a fuel flow that directs the fuel filled in the fuel injection valve toward the injection hole. A fuel injection valve that generates a fuel flow mainly includes a valve body and a needle. The valve body has an injection hole formed in a portion exposed to the combustion chamber, a hollow portion communicating with the injection hole and filled with fuel, and a seating surface on which the needle is seated. The seating surface is continuous in the circumferential direction, and is formed so as to be inclined toward the injection hole side from the radially outer side toward the radially inner side. The needle is seated on the seating surface of the valve body so as to divide the hollow portion and block the inflow of fuel to the nozzle hole. When the needle is seated on the seating surface, the hollow part of the valve body is divided into a fuel filling space part filled with fuel and a communication space part communicating with the injection hole. When injecting fuel from the fuel injection valve to the combustion chamber, the needle is separated from the seating surface, and the fuel filling space and the communication space communicate with each other, so that the fuel is transferred from the fuel filling space to the communication space. Inflow. At this time, the fuel in the fuel filling space forms a seating surface fuel flow that flows along the seating surface. When the seating surface fuel flow flows into each nozzle hole, a liquid film is formed on the nozzle hole constituting surface of each nozzle hole.

In the conventional fuel injection valve according to Patent Document 1, an injection hole plate is formed on the seating surface side opposite to the combustion chamber side. The nozzle hole plate is formed with guide portions corresponding to the respective nozzle holes formed in the valve body. One end portion of the guide portion communicates with the nozzle hole, and the other end portion communicates with the communication space portion. The guide portion guides the fuel of the seating surface fuel flow to a radially inner portion of the nozzle hole constituting surface. As a result, the conventional fuel injection valve guides the fuel of the seating surface fuel flow to the injection hole by the guide portion, so that a liquid film can be formed along the radially inner portion of the injection hole constituting surface. The fuel atomization can be promoted.

JP 2005-127186 A

  However, in the conventional fuel injection valve, not only the fuel flow in one direction but also the fuel flow in the other direction other than the one direction flows into the nozzle hole. Accordingly, when the fuel flow in one direction flows into the nozzle hole, the fuel flow in the other direction flows into the nozzle hole, so that the fuel flow in the other direction collides with the fuel flow in the one direction. There was a risk of dampening the flow. Thereby, it is difficult to form a uniform liquid film, and there is a possibility that the atomization of fuel cannot be sufficiently promoted.

  This invention is made in view of the above, Comprising: By suppressing that the fuel flow of other directions other than the unidirectional fuel flow which flows into a nozzle hole flows in into a nozzle hole, it is a nozzle hole structure surface. An object of the present invention is to provide a fuel injection valve capable of forming a fuel film corresponding to only one direction of fuel flow and promoting atomization of the fuel.

In order to solve the above-described problems and achieve the object, a fuel injection valve according to the present invention includes a plurality of injection holes for injecting fuel and an injection that is continuous in the circumferential direction and goes from the radially outer side to the radially inner side. A seating surface that is inclined toward the hole side and blocks the inflow of fuel to the nozzle hole when the needle is seated; and a fuel filling space that holds the supplied fuel in a state where the needle is seated on the seating surface and the jet In a fuel injection valve including a valve body having a hollow portion that is divided into a communication space portion through which a hole communicates, a guide is provided in the communication space portion, and the needle is separated from the seating surface in the guide In the seating surface fuel flow direction flowing along the seating surface from the fuel filling space portion to the communication space portion, the seating surface fuel flow direction in which the fuel flows from the seating surface to any one injection hole is shortest. A certain shortest fuel flow direction Rami Te, guide surfaces are provided for each nozzle hole at the back side of the injection hole, both ends of each guide surface is configured to extend in the opposite direction of the shortest fuel flow direction, from the inlet side opening of any of the injection holes Is also arranged on the opposite side of the shortest fuel flow direction .

According to the present invention, the volume of the communication space when the needle is separated from the seating surface can be reduced by providing the guide surface behind the nozzle hole as viewed from the shortest fuel flow direction. Therefore, the inflow amount of the fuel flowing into the nozzle hole by the fuel flow in the other direction other than the shortest fuel flow that is the one-way fuel flow can be reduced. As a result, the fuel flow in the other direction other than the shortest fuel flow that is the one-way fuel flow is prevented from flowing into the nozzle hole, and the fuel liquid film corresponding to the fuel flow only in one direction is formed on the nozzle hole configuration surface. Since it can be formed, fuel atomization can be promoted.
Moreover, according to this invention, it can suppress inhibiting the shortest fuel flow which flows in into a nozzle hole by the provided guide surface. Accordingly, since a liquid film of fuel corresponding to only one direction of fuel flow can be formed on the nozzle hole configuration surface, atomization of fuel can be promoted.
Moreover, according to this invention, since a guide surface is formed in parallel with the shortest fuel flow direction, it can suppress inhibiting the shortest fuel flow which flows in into a nozzle hole. Moreover, it can suppress that the fuel flow of other directions other than the shortest fuel flow direction flows in into a nozzle hole from a guide surface . Accordingly, since a liquid film of fuel corresponding to only one direction of fuel flow can be formed on the nozzle hole configuration surface, atomization of fuel can be promoted.

Further, in the present invention, the guide surface is formed along the inlet side opening.

According to this invention, since the guide surface is not separated from the inlet side opening, the fuel flow in the other direction between the inlet side opening and the guide surface can be suppressed. Accordingly, it is possible to form a liquid film of fuel corresponding to only one direction of fuel flow on the nozzle hole configuration surface.

Moreover, in this invention, a guide surface surrounds 1/2 or more of the outer periphery of entrance side opening, It is characterized by the above-mentioned.

According to the present invention, by enclosing more than half of the outer periphery of the inlet side opening with the guide surface , it is possible to prevent the fuel flow in the other direction from flowing into the nozzle hole other than the shortest fuel flow that is the fuel flow in one direction. can do. Therefore, the fuel flow in the other direction other than the shortest fuel flow, which is the one-way fuel flow, is prevented from flowing into the nozzle hole, and the fuel film corresponding to the fuel flow only in one direction is formed on the nozzle hole configuration surface. Therefore, atomization of fuel can be promoted.

Further, in this invention, the guide surface is characterized by being formed even without least by extending the injection hole arrangement surface shortest fuel flow direction side portion constitutes an arbitrary nozzle hole to the guide side.

  According to the present invention, when the nozzle hole is machined in the valve body with a cutting tool such as a drill, the nozzle hole constituting surface and the guide surface can be simultaneously formed by one machining. Therefore, since the nozzle hole forming surface and the guide surface are not processed separately, the processing becomes easy. Thereby, cost reduction can be achieved.

Further, in the present invention, guide surfaces, characterized in that at least the minimum fuel flow direction side portion is formed from the inclined surface which covers the inlet side opening.

  According to the present invention, in the fuel flow in the other direction flowing into the nozzle hole from at least the opposite direction to the shortest fuel flow, the opening on the inlet side of the nozzle hole is covered by the portion on the shortest fuel flow direction side formed on the guide surface. Therefore, it becomes difficult to flow into the nozzle hole. That is, the guide surface can inhibit the fuel flow in the other direction from flowing into the nozzle hole. Thereby, since the liquid film of the fuel corresponding to the fuel flow in only one direction can be formed on the nozzle hole configuration surface, atomization of the fuel can be promoted.

  The fuel injection valve according to the present invention has an effect that the atomization of the fuel injected from the injection hole can be promoted.

  Below, the fuel injection valve concerning this invention is demonstrated in detail based on drawing. The present invention is not limited to the following examples.

  The fuel injection valve is for injecting fuel into the internal combustion engine. In the first embodiment, an in-cylinder direct injection fuel injection valve that directly injects fuel into a combustion chamber will be described as a fuel injection valve according to the present invention. The fuel injection valve according to the present invention is not limited to the in-cylinder direct injection fuel injection valve. As another example of the fuel injection valve, there is a port fuel injection valve that injects fuel into the intake path of the internal combustion engine. Specific examples of the internal combustion engine include a gasoline engine and a diesel engine.

  FIG. 1 is a diagram showing a configuration example of a fuel injection valve according to the present invention. FIG. 2-1 is an enlarged plan sectional view of the vicinity of the injection hole of the fuel injection valve according to the first embodiment. FIG. 2-2 is an enlarged side sectional view of the vicinity of the injection hole of the fuel injection valve according to the first embodiment. FIG. 2-3 is a perspective view of the vicinity of the injection hole of the fuel injection valve according to the first embodiment. FIG. 2-4 is a diagram illustrating a liquid film formed on the nozzle hole configuration surface according to the first example.

  As shown in FIG. 1, the internal combustion engine has a plurality of cylinders, and a combustion chamber A is formed in each cylinder. Each combustion chamber A is configured by a space surrounded by a cylinder block (not shown), a cylinder head 9 and a piston (not shown). The fuel injection valve 1 is attached to the cylinder head 9 in order to inject fuel directly into each combustion chamber A. The fuel injection valve 1 includes a valve body 2, a holder 3, and a valve body 4.

  As shown in FIG. 1, the valve body 2 is disposed closest to the combustion chamber A when the fuel injection valve 1 is mounted on the cylinder head 9. The valve body 2 is formed in a substantially bell shape, and includes a hollow portion 21, an injection hole 22, a seating surface 23, a guide 24, and a collar portion 25.

  The hollow portion 21 has one end, that is, the end on the combustion chamber A side, of the both ends in the axial direction of the valve body 2 closed, and the other end, that is, the end opposite to the combustion chamber A side. An opening is formed.

The nozzle hole 22 is for injecting fuel as shown in FIGS. In the first embodiment, twelve injection holes 22 are formed at equal intervals on the circumference. The valve body 2 is formed to communicate with the inner peripheral surface and the outer peripheral surface. That is, the nozzle hole 22 communicates the hollow portion 21 and the outside of the valve body 2. Accordingly, when the hollow portion 21 is filled with fuel, the fuel is injected into the combustion chamber A through the nozzle hole 22, that is, when the fuel injection valve 1 is mounted on the cylinder head 9. . The injection hole 22 is formed so as to incline in a direction away from the central axis in the injection direction, for example. Here, when the injection hole 22 is formed, a surface formed on the inner peripheral surface of the valve body 2 is referred to as an inlet side opening 22a, and a surface formed on the outer peripheral surface is referred to as an outlet side opening 22b. The injection direction C1 in which the fuel flowing into the injection hole 22 is injected into the combustion chamber A is a direction toward the combustion chamber A on a line connecting the center point of the inlet side opening 22a and the center point of the outlet side opening 22b. In the first embodiment, the injection hole 22 has an injection direction C1 opposite to the shortest fuel flow direction, which is the flow direction of the shortest fuel flow B1 corresponding to each injection hole 22, when viewed from the axial direction of the valve body 2. It is formed as follows. Moreover, when forming the nozzle hole 22, the inner peripheral surface formed in the valve body 2 is set as the nozzle hole constituting surface 22c. When a plurality of the nozzle holes 22 are formed, they may not be formed at regular intervals on the circumference as in the first embodiment.

  The seating surface 23 blocks the flow of fuel into each nozzle hole 22 when a later-described needle 5 of the valve body 4 is seated. The seating surface 23 is formed in the hollow portion 21 of the valve body 2. The seating surface 23 is formed so as to protrude toward the other side (upward in FIG. 1) in the axial direction from the surface on which the inlet side opening 22a of each nozzle hole 22 is formed. The seating surface 23 is formed continuously in the circumferential direction. In the first embodiment, it has an annular shape and is formed so as to surround all the nozzle holes 22. The seating surface 23 is formed to be inclined toward the injection hole 22 side, that is, the combustion chamber A side as it goes from the radially outer side to the radially inner side. Here, in a state where the needle 5 is seated on the seating surface 23, the hollow portion 21 is divided into the fuel filling space portion 21a and the communication space portion 21b.

  The fuel filling space 21a is formed on the opposite side of the contact surface 51 to the injection hole 22 side in the axial direction from the portion of the contact surface 51 in contact with the seating surface 23 in a state where the needle 5 is seated on the seating surface 23. . Further, the fuel filling space 21a is filled with fuel even in a state where it is separated from the communication space 21b, and holds the supplied fuel. The communication space portion 21 b is formed on the nozzle hole 22 side in the axial direction from the portion of the contact surface 51 in contact with the seating surface 23 in a state where the needle 5 is seated on the seating surface 23. The communication space portion 21 b communicates with each nozzle hole 22 via the inlet side opening 22 a of each nozzle hole 22.

  When fuel is injected from the fuel injection valve 1 into the combustion chamber A, the needle 5 is separated from the seating surface 23, whereby the fuel filling space portion 21a and the communication space portion 21b communicated with each other. Therefore, the fuel flows from the fuel filling space portion 21a into the communication space portion 21b along the seating surface 23. This fuel flow becomes the seating surface fuel flow (B1 and B2 shown in FIG. 2A). Further, the direction in which the fuel flows from the fuel filling space 21a to the communication space 21b along the seating surface 23 is defined as a seating surface fuel flow direction. The fuel that has flowed into the communication space portion 21 b flows into each nozzle hole 22.

  The guide 24 is formed in the hollow portion 21 of the valve body 2. The guide 24 is formed so as to protrude toward the other side (upward in FIG. 1) in the axial direction from the surface on which the inlet side opening 22a of each nozzle hole 22 is formed. The guide 24 is formed on the back side of each nozzle hole 22 when viewed from the shortest fuel flow direction which is the flow direction of the shortest fuel flow B1. In the first embodiment, the guide 24 has a substantially disk shape and is surrounded by all the nozzle holes 22. Therefore, in the guide 24, the peripheral portion of each nozzle hole 22 is formed by cutting away the back side of each nozzle hole 22 when viewed from the shortest fuel flow direction that is the flow direction of the shortest fuel flow B <b> 1. Note that a guide surface 24 a is formed in the notched portion of the guide 24. The guide surface 24a is configured by an inclined surface that is inclined from the opposite side to the injection hole 22 side toward the injection hole 22 side and inward in the radial direction.

  Both end portions 24b and 24b of each guide surface 24a are arranged with the opposed injection holes 22 therebetween. That is, the end portion of the guide 24 is arranged with each nozzle hole 22 interposed therebetween. Here, the shortest fuel flow B1 is a unidirectional fuel flow. Of the above-described seating surface fuel flows, the shortest fuel flows from the seating surface 23 into any one of the nozzle holes 22. The seating surface fuel flows. Further, the shortest fuel flow direction is the fuel flow in which the fuel flows in the shortest from the seating surface 23 into any one of the nozzle holes 22 among the above-described seating surface fuel flow directions, that is, the flow direction of the shortest fuel flow B1. .

  The seating surface fuel flow is composed of the shortest fuel flow B1 and a seating surface fuel flow other than the shortest fuel flow B1 (hereinafter referred to as "other seating surface fuel flow B2"). Here, even in the shortest fuel flow B1, the shortest fuel flow B1 corresponding to the other nozzle holes 22 other than the shortest fuel flow B1 corresponding to any one nozzle hole 22 is changed to the other seating surface fuel flow B2. Included (see (B2) in FIG. 2-1).

  Each guide surface 24a includes a main body portion 24c and two parallel portions 24d and 24d. The main body 24c is formed on the back side of the injection hole 22 corresponding to the shortest fuel flow B1 as viewed from the shortest fuel flow direction, that is, on the center side of the surface on which the injection holes 22 are formed. Yes. That is, the guide 24 is formed along the inlet side opening 22 a of each nozzle hole 22. Accordingly, since the guide 24 does not leave the inlet side opening 22a, the fuel flow in the other direction flows into the nozzle hole 22 corresponding to the shortest fuel flow B1 from between the inlet side opening 22a and the guide 24, that is, the guide surface 24a. Can be suppressed. Thereby, the liquid film of the fuel D1 corresponding to only the shortest fuel flow B1 which is the fuel flow in one direction can be formed on the nozzle hole constituting surface 22c of the nozzle hole 22.

  The parallel portions 24d and 24d are formed to extend in opposite directions from the both ends of the main body portion 24c as viewed from the shortest fuel flow direction. That is, the parallel portions 24d and 24d are formed in parallel to the shortest fuel flow direction. Therefore, it is possible to suppress the shortest fuel flow B1 flowing into each nozzle hole 22 from being obstructed by the parallel portions 24d and 24d. Further, since the parallel portions 24d and 24d are formed, the shortest fuel flow B1 from between the both ends of the main body portion 24c and the tips of the parallel portions 24d and 24d, that is, the ends 24b and 24b of the guide surface 24a. It is possible to suppress the fuel flow other than that, that is, the fuel flow in the other direction, from flowing into the nozzle hole 22 corresponding to the shortest fuel flow B1. As a result, the fuel of the shortest fuel flow B1 corresponding to each nozzle hole 22 can surely flow into the nozzle hole 22, and the shortest fuel flow that is a one-way fuel flow at the nozzle hole forming surface 22c of the nozzle hole 22 A liquid film of fuel D1 corresponding to only B1 can be formed.

  Further, the end portions 24b and 24b of the guide surface 24a, that is, the end portions respectively disposed across the respective injection holes 22 of the guide 24, the parallel portions 24d and 24d are formed in parallel to the shortest fuel flow direction. Therefore, it is formed without covering the inlet side opening 22a of the nozzle hole 22 sandwiched by the end portions 24b, 24b when viewed from the shortest fuel flow direction. Therefore, the guide 24 can suppress the inhibition of the shortest fuel flow B <b> 1 flowing into each nozzle hole 22. Thereby, the fuel of the shortest fuel flow B1 corresponding to each nozzle hole 22 can surely flow into the nozzle hole 22, and the shortest fuel flow that is a one-way fuel flow at the nozzle hole forming surface 22c of the nozzle hole 22 A liquid film of fuel D1 corresponding to only B1 can be formed.

  Further, the guide 24 is formed so as to surround 1/2 or more of the outer periphery L of the inlet side opening 22 a of each nozzle hole 22. In the first embodiment, each guide surface 24a is formed so as to surround 1/2 or more of the outer periphery L of the inlet side opening 22a of the injection hole 22 opposed to each guide surface 24a. Accordingly, among the fuel flows flowing into the respective nozzle holes 22, most of the fuel flow in the other direction, particularly the fuel flow in the other direction opposite to the shortest fuel flow B 1, corresponds to the shortest fuel flow B 1 by the guide 24. Inflow into the nozzle hole 22 can be suppressed. Thereby, the liquid film of the fuel D1 corresponding to only the shortest fuel flow B1 which is the fuel flow in one direction can be formed on the nozzle hole constituting surface 22c of the nozzle hole 22.

  The collar portion 25 is used to position the valve body 2 in the axial direction with respect to the holder 3 when the valve body 2 is inserted into the holder 3. The flange portion 25 is formed so as to protrude radially outward from an end portion of the valve body 2 opposite to the injection hole 22 side.

  When the fuel injection valve 1 is attached to the cylinder head 9, the holder 3 is a part into which a part of the attachment hole 91 formed in the cylinder head 9 is inserted. The holder 3 is formed in a cylindrical shape, and includes a hollow portion 31, a step portion 32, and a connector portion 33.

  The hollow portion 31 is formed by opening both end portions in the axial direction of the holder 3. The step portion 32 is a portion to which the flange portion 25 comes into contact when the valve body 2 is inserted into the hollow portion 31 of the holder 3. The step portion 32 is formed on the inner wall surface of the holder 3 constituting the hollow portion 31. The stepped portion 32 is formed such that the diameter of the hollow portion 31 on the side of the injection hole 22 relative to the stepped portion 32 is smaller than the diameter of the stepped portion 32 on the side opposite to the injection hole 22 side. The connector part 33 is electrically connected to a magnetic circuit 6 (described later) of the valve body 4. A connector electrically connected to the ECU (Engine Control Unit) 10 is connected to the connector unit 33. Thereby, the magnetic circuit 6 and ECU10 are electrically connected, and the magnetic circuit 6 can be controlled by ECU10.

  When the fuel injection valve 1 is assembled, the valve body 2 is inserted into the hollow portion 31 of the holder 3. When the valve body 2 is inserted into the hollow portion 31 of the holder 3, the collar portion 25 contacts the stepped portion 32 of the holder 3. Thereby, the valve body 2 is positioned in the axial direction with respect to the holder 3. At this time, the hollow portion 21 of the valve body 2 and the hollow portion 31 of the holder 3 communicate with each other. Further, the nozzle hole 22 side in the axial direction of the valve body 2 is exposed to the outside of the holder 3.

  The valve body 4 includes a needle 5, a magnetic circuit 6, a spring 7, and a joint portion 8.

  The needle 5 is formed in a rod shape and is disposed in the hollow portion 31 of the holder 3. The tip of the needle 5 is disposed in the hollow portion 21 of the valve body 2. A contact surface 51 is formed at the tip of the needle 5. The contact surface 51 continuously contacts the seating surface 23 in the circumferential direction when the needle 5 moves toward the nozzle hole 22 in the axial direction. The needle 5 moves in the axial direction so that the contact surface 51 comes into contact with the seating surface 23 of the valve body 2 to stop the fuel injection from each injection hole 22 into the combustion chamber A, and the contact state When the surface 51 is separated from the seating surface 23 of the valve body 2, the valve opening state in which fuel is injected from the injection holes 22 into the fuel chamber A is repeated.

  The magnetic circuit 6 is disposed between the needle 5 and the joint portion 8. The magnetic circuit 6 moves the needle 5 in the axial direction. That is, the needle 5 repeats the valve opening state and the valve closing state by the magnetic circuit 6. The magnetic circuit 6 includes a stator core 61, a moving core 62, a yoke 63, a coil 64 and a sleeve 65.

  The stator core 61 and the moving core 62 are disposed inside the sleeve 65. The stator core 61 is disposed between the joint portion 8 and the moving core 62, and the spring 7 is disposed therein.

  The moving core 62 is supported in the sleeve 65 so as to be slidable in the axial direction. The rear end portion of the needle 5 is connected to the end portion on the nozzle hole 22 side in the axial direction of the moving core 62. One end of the spring 7 is in contact with the end of the moving core 62 opposite to the nozzle hole 22 in the axial direction. Here, the spring 7 is disposed inside the stator core 61 so as to always generate an urging force even when the needle 5 is in the closed state. Therefore, the urging force on the nozzle hole 22 side is always applied to the moving core 62 by the spring 7. Thereby, even if the magnetic circuit 6 is not operated, the contact surface 51 of the needle 5 is brought into contact with the seating surface 23 of the valve body 2 by the biasing force of the spring 7, and the valve closed state can be maintained.

  The coil 64 is disposed so as to cover the outer periphery of the sleeve 65, and is electrically connected to the connector portion 33. That is, the coil 64 is connected to the ECU 10 as the control unit via the connector unit 33 so as to be controllable. The yoke 63 is arranged so as to cover the outer periphery of the coil 64. Here, when driving power is supplied from the ECU 10 to the coil 64, the magnetic circuit 6 forms a magnetic field in the magnetic circuit 6, and the moving core 62 springs in a direction opposite to the nozzle hole 22 side in the axial direction. It is moved against the urging force of 7.

  The joint portion 8 is connected to a delivery pipe to which pressurized fuel is supplied from a fuel pump. The joint portion 8 communicates with the hollow portion 31 of the holder 3 via the sleeve 65 of the magnetic circuit 6. Therefore, the fuel supplied to the fuel injection valve 1 flows into the hollow portion 31 of the holder 3 through the joint portion 8 and the sleeve 65. The fuel that has flowed into the hollow portion 31 of the holder 3 flows into the hollow portion 21 because the hollow portion 31 is connected to the hollow portion 21 of the valve body 2. Thereby, the fuel is filled in the hollow portion 21 of the valve body 2, and the fuel is supplied to the fuel injection valve 1.

  The ECU 10 determines the fuel supply amount of the fuel supplied to the internal combustion engine, that is, the fuel injection amount of the fuel injected into each combustion chamber A by each fuel injection valve 1 according to the operating state of the engine. The ECU 10 controls the energization timing and energization time to the coil 64 of the magnetic circuit 6 based on the determined fuel injection amount.

  Next, attachment of the fuel injection valve 1 to the cylinder head 9 will be described. The cylinder head 9 is formed with a mounting hole 91 that penetrates to each combustion chamber A. The holder 3 to which the valve body 2 and the valve main body 4 are inserted and fixed is inserted into each mounting hole 91 from the tip, and the mounting hole end 92 is fixed to the cylinder head 9 by a joining means such as a bolt. Thus, each fuel injection valve 1 is mounted on the cylinder head 9 corresponding to each combustion chamber A.

  Here, the operation of the fuel injection valve 1 according to the present invention will be described. The ECU 10 supplies fuel to the internal combustion engine by the fuel injection valve 1 in accordance with the operating state of the engine. When fuel is injected into the combustion chamber A by the fuel injection valve 1, the valve 5 is opened by the magnetic circuit 6 by the urging force of the spring 7. When the needle 5 changes from the closed state to the open state, the contact surface 51 that has been in contact with the seating surface 23 is separated from the seating surface 23, and the needle 5 is separated from the seating surface 23. Therefore, the fuel filling space portion 21a and the communication space portion 21b that have been blocked from communication communicate with each other. As a result, a seating surface fuel flow is generated in which the fuel filled in the fuel filling space 21 a flows into the communication space 21 b along the seating surface 23.

  Of the seating surface fuel flow, the fuel of the shortest fuel flow B1 corresponding to each nozzle hole 22 is injected from the inlet side opening 22a of the nozzle hole 22 without being blocked by the guide 24 as described above. It flows into the hole 22. That is, the fuel of the shortest fuel flow B1 corresponding to each nozzle hole 22 can be reliably introduced into the nozzle hole 22.

  FIG. 3A is an enlarged plan sectional view of the vicinity of a nozzle hole of a fuel injection valve according to a conventional example. FIG. 3-2 is an enlarged side sectional view of the vicinity of the injection hole of the fuel injection valve according to the conventional example. FIG. 3C is a perspective view of the vicinity of the injection hole of the fuel injection valve according to the conventional example. FIGS. 3-4 is a figure which shows the liquid film formed in the nozzle hole structure surface concerning a prior art example.

  As shown in FIGS. 3-1 to 3-4, the seating surface 123 of the fuel injection valve 101 according to the prior art is similar to the seating surface 23 of the fuel injection valve 1 according to the present invention from the radially outer side to the radially inner side. Is inclined toward the nozzle hole 122 formed in the valve body 102, that is, toward the combustion chamber A. Accordingly, when the valve 105 is in a state in which the needle 105 is seated on the seating surface 123 and is in a valve opening state in which the needle 105 is separated from the seating surface 123, the fuel filling space portion 121a and the communication space portion 121b that have been blocked are separated. Communicate. Accordingly, a seating surface fuel flow in which the fuel filled in the fuel filling space 121a flows into the communication space 121b along the seating surface 123 is generated in the same manner as in the present invention. Here, of the seating surface fuel flow, the fuel of the shortest fuel flow B 1 corresponding to each nozzle hole 122 flows into the nozzle hole 122.

  The seating surface fuel flow includes a fuel flow other than the shortest fuel flow B1 corresponding to each nozzle hole 22, that is, another seating surface fuel flow B2. The conventional fuel injection valve 101 does not include the guide 24 included in the fuel injection valve 1 according to the present invention. Accordingly, the other seating surface fuel flow B2 flows, for example, between the adjacent nozzle holes 122 to the inside of each nozzle hole 122, that is, into the nozzle hole inner space part surrounded by each nozzle hole 122 in the communication space part 121b. To do. As a result, turbulent flow is generated by collision of the other seating surface fuel flows B2 that have flowed into the internal space of the injection frame, and each of the injection holes 122 has a fuel flow other than the shortest fuel flow B1 corresponding to each injection hole 122. The fuel flow, that is, the fuel flow B3 in the other direction flows in.

  Therefore, since the fuel flow B3 in the other direction collides with the shortest fuel flow B1 when the shortest fuel flow B1 flows into the corresponding nozzle holes 122, the shortest fuel flow B1 flowing into the nozzle holes 122 is attenuated. Let This makes it difficult to form a liquid film on the nozzle hole constituting surface 122c constituting the nozzle hole 122, and the entire inside of the nozzle hole 122 is filled with the fuel D2 as shown in FIG. There is a possibility that the atomization of the fuel injected into the fuel cell cannot be sufficiently promoted.

  On the other hand, in the fuel injection valve 1 according to the present invention, the guide 24 is provided on the back side of each injection hole 22 when viewed from the shortest fuel flow direction. Therefore, the communication space when the needle 5 is separated from the seating surface 23. The volume of the portion 21b can be reduced as compared with the conventional fuel injection valve 101 that does not include the guide 24. Therefore, it is possible to suppress the other seating surface fuel flow B2 from flowing into the nozzle hole inner space portion of the seating surface fuel flow, so that the fuel flow in the other direction other than the shortest fuel flow B1 which is the one-way fuel flow. The inflow amount of the fuel of the fuel flow B3 flowing into the nozzle hole 22 can be reduced.

  That is, in the fuel injection valve 1 according to the present invention, by suppressing the inflow of the fuel flow B3 in the other direction other than the shortest fuel flow B1 into the injection holes 22, only the shortest fuel flow B1 corresponding to each injection hole 22 is obtained. It is possible to selectively flow into each nozzle hole 22. As a result, as shown in FIG. 2-4, a liquid film of fuel D1 can be formed along the nozzle hole constituting surface 22c, so that the entire fuel hole 122 is filled with the fuel D2 in the conventional fuel injection. Compared with the valve 101, the fuel is easily diffused when being injected into the combustion chamber A, and atomization of the fuel injected in the injection direction C1 can be promoted.

  Further, since the guide 24 is formed on the back side of the injection hole 22 when the guide surface 24a is viewed from the shortest fuel flow direction, the fuel of the shortest fuel flow B1 is on the back side of the guide surface 24a, for example, the injection hole inner space portion. It can suppress flowing into the. Therefore, the shortest fuel flow B 1 corresponding to each nozzle hole 22 is along the guide surface 24 a of the guide 24. As a result, the guide 24 can selectively guide only the shortest fuel flow B1 corresponding to each nozzle hole 22 to the nozzle hole 22, so that the liquid film of the fuel D1 along the nozzle hole constituting surface 22c can be surely provided. Since it can form, atomization of the fuel injected can be accelerated | stimulated.

  In the first embodiment, the nozzle hole constituting surface 22c and the guide surface 24a are formed separately, but the present invention is not limited to this. FIG. 4A is an enlarged plan sectional view of the vicinity of the injection hole of another configuration example of the fuel injection valve according to the first embodiment. FIG. 4-2 is an enlarged side sectional view of the vicinity of the injection hole of another configuration example of the fuel injection valve according to the first embodiment. FIG. 4-3 is a perspective view of the vicinity of the injection hole of another configuration example of the fuel injection valve according to the first embodiment.

  In the fuel injection valve 1 according to the first embodiment shown in FIGS. 4-1 to 4-3, the portion on the shortest fuel flow direction side extends the nozzle hole constituting surface 22c constituting the nozzle hole 22 toward the guide 24 side. A guide surface 24e is formed. The guide surface 24e is formed when each nozzle hole 22 is processed in the valve body 2 with a cutting tool such as a drill. Each nozzle hole 22 cuts the valve body 2 in the direction opposite to the injection direction until it penetrates from the outer peripheral surface where the outlet side opening 22b of the valve body 2 is formed to the surface where the inlet side opening 22a is formed. It is formed by doing. At this time, the cutting tool cuts the guide 24 formed on the surface on which the inlet side opening 22a is formed so as to protrude to the side opposite to the injection hole 22 side in the direction opposite to the injection direction. Thus, the guide surface 24e is formed integrally with the nozzle hole constituting surface 22c constituting the nozzle hole 22 at the shortest fuel flow direction side. That is, the portion on the shortest fuel flow direction side of the guide surface 24e can be formed by extending the portion on the shortest fuel flow direction side of the nozzle hole constituting surface 22c to the guide 24 side. Therefore, when machining the nozzle hole in the valve body 2 with a cutting tool such as a drill, the nozzle hole constituting surface 22c and the guide surface 24e can be formed simultaneously by one machining. Thereby, since the nozzle hole constituting surface 22c and the guide surface 24e are not processed separately, the processing becomes easy and the cost of the fuel injection valve 1 according to the present invention can be reduced.

  Further, the portion on the shortest fuel flow direction side of the guide surface 24e and the nozzle hole constituting surface 22c constituting the nozzle hole 22 are integrated, that is, formed without any step, so that the nozzle hole constituting surface 22c and the guide surface 22e Compared with the case where is a separate body, it is possible to suppress the inflow of the fuel toward the nozzle hole 22 along the guide surface 24e from being inhibited.

  In the first embodiment, each injection hole 22 is formed such that the injection direction C1 is opposite to the shortest fuel flow direction corresponding to each injection hole 22 when viewed from the axial direction. Is not limited to this. FIG. 5 is an enlarged plan sectional view of the vicinity of the injection hole of another configuration example of the fuel injection valve 1 according to the first embodiment. Since the injection direction is determined by the position of each injection hole 22 in the combustion chamber A or the like, it is not always the opposite direction to the shortest fuel flow direction when viewed from the axial direction. For example, as shown in the figure, each nozzle hole 22 is not positioned in the opposite direction to the shortest fuel flow direction than the inlet side opening 22a when the outlet side opening 22b is viewed from the axial direction with respect to the inlet side opening 22a. By forming, the injection direction C2 may be formed in a direction that intersects the shortest fuel flow direction as viewed from the axial direction, that is, deflected. In this case, the guide 24 is configured so that the both end portions 24g and 24g of the guide surface 24f, that is, the end portions of the guide 24 that are disposed across the nozzle holes 22 do not obstruct the shortest fuel flow B1. The inlet 22a of the injection hole 22 is formed so as not to cover the injection hole 22 when viewed from the shortest fuel flow direction corresponding to each of the holes 22.

  Next, the fuel injection valve 1 according to the second embodiment will be described. FIG. 6A is an enlarged plan sectional view of the vicinity of the injection hole of the fuel injection valve according to the second embodiment. FIG. 6B is an enlarged side sectional view of the vicinity of the injection hole of the fuel injection valve according to the second embodiment. FIG. 6-3 is a perspective view of the vicinity of the injection hole of the fuel injection valve according to the second embodiment. The fuel injection valve 1 according to the second embodiment is different from the fuel injection valve 1 according to the first embodiment in that the portion on the shortest fuel flow direction side corresponding to each injection hole 22 of the guide surface 224a is the inlet of the injection hole 22. This is a point formed by an inclined surface covering the side opening 22a. The basic configuration and operation of the fuel injection valve 1 according to the second embodiment are substantially the same as the basic configuration and operation of the fuel injection valve 1 according to the first embodiment, and therefore the same parts are omitted or simplified. explain.

  The portion of the guide surface 224a on the shortest fuel flow direction side corresponding to each nozzle hole 22 is configured by an inclined surface that is inclined from the opposite side to the nozzle hole 22 side toward the nozzle hole 22 side and radially outward. That is, the portion on the shortest fuel flow direction side corresponding to each nozzle hole 22 of the guide surface 224 a is formed to protrude toward the inlet side opening 22 a of the nozzle hole 22. Accordingly, other fuel flows other than the shortest fuel flow B1 corresponding to each nozzle hole 22, in particular, the fuel flow in the other direction flowing into the nozzle hole 22 from the opposite direction to the shortest fuel flow B1 is formed on the guide surface 224a. Since the inlet side opening 22a is covered by the shortest fuel flow direction side portion, it is difficult to flow into the injection hole 22. That is, the guide surface 224a can inhibit the fuel flow in the other direction from flowing into the nozzle hole. Thereby, the liquid film of the fuel D1 corresponding to only the shortest fuel flow B1 can be formed on the nozzle hole constituting surface 22c.

  Further, the portion on the shortest fuel flow direction side corresponding to each nozzle hole 22 of the guide surface 224a ensures that the fuel of the shortest fuel flow B1 corresponding to each nozzle hole 22 is directed along the direction toward the nozzle hole 22. Can do. Thereby, the liquid film of the fuel D1 corresponding to only the shortest fuel flow B1 can be reliably formed on the nozzle hole constituting surface 22c. Therefore, the same effects as those of the first embodiment can be obtained. In particular, when the fuel is injected into the combustion chamber A, the fuel is more easily diffused, and atomization of the fuel injected in the injection direction C1 can be further promoted.

  As described above, the fuel injection valve according to the present invention is particularly useful for a fuel injection valve that injects fuel into the combustion chamber, and is particularly suitable for promoting atomization of the injected fuel.

It is a figure which shows the structural example of the fuel injection valve concerning this invention. FIG. 3 is an enlarged plan view of the vicinity of the injection hole of the fuel injection valve according to the first embodiment. It is an expanded side sectional view of the vicinity of the injection hole of the fuel injection valve according to the first embodiment. It is a perspective view of the vicinity of the injection hole of the fuel injection valve concerning Example 1. FIG. It is a figure which shows the liquid film formed in the nozzle hole structure surface in Example 1. FIG. It is an expanded plane sectional view of the injection hole vicinity of the fuel injection valve in a prior art example. It is an expanded sectional side view of the nozzle hole vicinity of the fuel injection valve in a prior art example. It is a perspective view of the injection hole vicinity of the fuel injection valve in a prior art example. It is a figure which shows the liquid film formed in the nozzle hole structure surface in a prior art example. It is an expanded plane sectional view of the vicinity of the injection hole of the other structural example of the fuel injection valve concerning Example 1. FIG. It is an expanded flat side sectional view of the vicinity of the injection hole of another configuration example of the fuel injection valve according to the first embodiment. FIG. 6 is a perspective view of the vicinity of an injection hole of another configuration example of the fuel injection valve according to the first embodiment. It is an expanded plane sectional view of the vicinity of the injection hole of the other structural example of the fuel injection valve concerning Example 1. FIG. FIG. 6 is an enlarged plan sectional view in the vicinity of an injection hole of a fuel injection valve according to Example 2. It is an expanded flat side sectional view of the vicinity of the injection hole of the fuel injection valve according to the second embodiment. It is a perspective view of the vicinity of the injection hole of the fuel injection valve concerning Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection valve 2 Valve body 21 Hollow part 21a Fuel filling space part 21b Communication space part 22 Injection hole 22a Inlet side opening 22b Outlet side opening 22c Injection hole structure surface 23 Seating surface 24 Guide 24a Guide surface 24b End part 24c Main part 24d Parallel part 25 Collar part 3 Holder 31 Hollow part 32 Step part 33 Connector part 4 Valve body 5 Needle 51 Contact surface 6 Magnetic circuit 7 Spring 8 Joint part 9 Cylinder head 91 Attachment hole 92 Attachment hole end part 10 ECU
A Combustion chamber B1 Shortest fuel flow (unidirectional fuel flow)
B2 Other seating surface fuel flow B3 Other direction fuel flow C1, C2 Injection direction D1, D2 Fuel

Claims (5)

A plurality of injection holes for injecting fuel;
Continuing in the circumferential direction and tilting toward the injection hole side from the radially outer side toward the radially inner side,
And a seating surface that blocks the inflow of fuel into the nozzle hole when the needle is seated;
With the needle seated on the seating surface, a hollow part that is divided into a fuel filling space part that holds the supplied fuel and a communication space part that communicates with the nozzle hole;
In a fuel injection valve comprising a valve body having
A guide is provided in the communication space,
The guide has an arbitrary seating surface fuel flow direction that flows along the seating surface from the fuel filling space portion to the communication space portion in a state where the needle and the seating surface are separated from each other. A guide surface is provided for each of the injection holes on the back side of the injection hole as viewed from the shortest fuel flow direction, which is the flow direction of the seating surface fuel flow in which the fuel flows into the injection hole of the shortest,
Both ends of the guide surface extend in a direction opposite to the shortest fuel flow direction, and are arranged on the opposite side of the shortest fuel flow direction from the inlet side opening of the arbitrary injection hole. Fuel injection valve. The fuel injection valve according to claim 1, wherein the guide surface is formed along the inlet side opening . The fuel injection valve according to claim 1, wherein the guide surface surrounds a half or more of an outer periphery of the inlet side opening. The guide surface, according to claim 2 or 3, characterized in that it is formed by at least the minimum fuel flow direction side portions extending the injection hole arrangement surface constituting said arbitrary nozzle hole to the guide side Fuel injection valve. The fuel injection valve according to any one of claims 2 to 4, wherein the guide surface is formed of an inclined surface that covers at least a portion on the shortest fuel flow direction side to cover the inlet side opening .

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