WO2020148821A1

WO2020148821A1 - Fuel injection device

Info

Publication number: WO2020148821A1
Application number: PCT/JP2019/001068
Authority: WO
Inventors: 啓祐伊藤; 恭輔渡邉; 宗実　毅
Original assignee: 三菱電機株式会社
Priority date: 2019-01-16
Filing date: 2019-01-16
Publication date: 2020-07-23
Also published as: JP7031020B2; JPWO2020148821A1; CN113260783B; CN113260783A

Abstract

The present invention is configured so as to have, in an upstream end surface of an injection hole plate (13), a fuel passage (17) which introduces fuel from a valve seat opening part (12b) to a center part, and discharges the fuel to a plurality of swirl chambers (18a, 18b) that are joined at an end part and impart a swirling force to the fuel, wherein: injection holes (14a, 14b) are opened in the swirl chambers (18a, 18b); the swirl chambers (18a, 18b) and the injection holes (14a, 14b) are disposed in a point symmetrical manner with respect to a center (17c) of the fuel passage; and a center axis (40) of the fuel passage is offset with respect to a center (12c) of the valve seat opening part, whereby the direction of main flows (30a, 30b) of fuel flow introduced from the valve seat opening part (12b) to the injection holes (14a, 14b) via the fuel passage (17) becomes two directions including a direction separating from the injection holes and a direction heading toward the injection holes.

Description

Fuel injector

The present application relates to a fuel injection device.

In recent years, exhaust gas regulations for internal combustion engines mounted on automobiles have been tightened, and as a part thereof, atomization of fuel spray injected from a fuel injection device of an internal combustion engine is required, and swirling flow is used. Various studies have been made on a method for achieving atomization.

The conventional fuel injection device disclosed in Patent Document 1 has a valve body that moves in response to a control signal from an internal combustion engine control module, a valve seat on which the valve body is seated or separated, and a valve in the fuel flow direction. A fuel injector nozzle disposed immediately downstream of the seat, the fuel injector nozzle having a plurality of groove-shaped channels communicating with each other at a central portion, and communicating with the downstream side of each channel. A plurality of swirl chambers are provided, and each swirl chamber is provided with an injection hole for ejecting fuel.

According to the conventional fuel injection device disclosed in Patent Document 1, the fuel flowing from the valve seat into the central portion of the fuel injection nozzle uniformly flows into the plurality of groove-shaped flow passages and is rectified in the flow passages. Then, it flows into the swirl chamber and flows into the injection hole while generating a swirling flow. The swirling flow of the fuel flowing into the injection hole is maintained even inside the injection hole, and a thin liquid film is formed along the inner wall of the injection hole. The thin liquid film formed on the inner wall of the injection hole is atomized by being injected into the combustion chamber of the internal combustion engine in a hollow conical shape from the injection hole, and atomization of the fuel is promoted.

JP-A-2002-98028

In recent years, in the method of injecting fuel in the intake port of an internal combustion engine, cases of injecting fuel in the intake stroke of the internal combustion engine are increasing in order to improve fuel efficiency. As is well known, in the injection of fuel in the intake stroke, fuel injection is performed with the intake valve open, and the fuel spray is made to flow directly into the combustion chamber of the internal combustion engine to enhance the evaporative cooling effect in the combustion chamber. It is a method that improves fuel economy by improving knock resistance and increasing the compression ratio of the internal combustion engine.

The conventional fuel injection device disclosed in the above-mentioned Patent Document 1 has good atomization performance of the fuel spray, but has a small penetration force of the fuel spray, and therefore, at the time of fuel injection in the intake stroke of the internal combustion engine. Due to the influence of the intake flow generated in the intake port, the fuel spray is made to flow toward the ceiling side of the intake port, and a part of the fuel spray adheres to the inner wall surface of the ceiling part of the intake port, and the inflow amount of the fuel spray into the combustion chamber. May decrease. Therefore, the vaporization cooling effect in the combustion chamber becomes insufficient, the knock resistance cannot be improved, and the compression ratio of the internal combustion engine cannot be increased, so that a sufficient fuel efficiency improvement effect cannot be obtained. was there.

Further, in the above-mentioned conventional fuel injection device, even in the case of the exhaust stroke injection in which the fuel is injected with the intake valve closed, the influence of the intake pulsation generated between the intake ports of the multi-cylinder internal combustion engine. , And when the injection amount is large and the injection period is long, the required amount of fuel cannot be injected in the exhaust stroke, and the latter half of the fuel injection operation shifts to the intake stroke, which is affected by the intake flow. There is a problem that the spray is apt to flow to the ceiling portion of the intake port and easily adhere to the inner wall of the ceiling portion of the intake port, which hinders improvement in fuel consumption.

The present application has been made in order to solve the problems in the conventional fuel injection device as described above, and it is possible to reduce the adhesion of fuel to the inner wall of the intake port and promote the improvement of fuel efficiency. An object is to provide an injection device.

The fuel injection device according to the present application is
Having a valve body for opening and closing the valve seat, and operating the valve body by receiving an operation signal from a control device, so that fuel passes between the valve body and the valve seat seat portion, and then the valve seat downstream side A fuel injection device that injects from a plurality of injection holes provided in an injection hole plate attached to the valve seat opening of
On the upstream end surface of the injection hole plate, a plurality of swirl chambers are arranged radially outside the valve seat opening, and impart swirl force to the fuel; and fuel flows from the valve seat opening to the center. The swirl chamber joined to an end has a fuel passage for flowing out fuel, and the swirl chamber is provided with the injection hole for injecting fuel to the outside,
When the upstream end surface of the injection hole plate is viewed from the upstream side in the central axis direction of the valve seat opening, the plurality of swirl chambers and the injection holes are arranged point-symmetrically with respect to the center of the fuel passage. , The central axis of the fuel passage is offset with respect to the center of the valve seat opening,
At least one injection hole of the plurality of injection holes is provided offset to the center side of the valve seat opening with respect to the center axis of the fuel passage, and at least one injection hole of the fuel passage is provided. It is provided offset to the side opposite to the center of the valve seat opening with respect to the central axis,
It is characterized by

A fuel injection device according to the present application has a valve body for opening and closing a valve seat, and operates the valve body by receiving an operation signal from a control device, so that fuel flows between the valve body and the valve seat seat portion. After passing, the fuel injection device is injected from a plurality of injection holes provided in an injection hole plate attached to a valve seat opening on the downstream side of the valve seat, wherein the upstream end surface of the injection hole plate has A plurality of swirl chambers are arranged radially outward of the valve seat opening to impart swirl force to the fuel, and fuel flows into the swirl chamber from the valve seat opening to the center and is joined to the end of the swirl chamber. It has a fuel passage that flows out, is provided with the injection hole that is opened to the swirl chamber and injects fuel to the outside, and has an upstream end surface of the injection hole plate from the upstream side in the central axis direction of the valve seat opening. When viewed, the plurality of swirl chambers and the injection holes are arranged point-symmetrically with respect to the center of the fuel passage, and the central axis of the fuel passage is offset with respect to the center of the valve seat opening. Of the plurality of injection holes, at least one injection hole is provided offset to the center side of the valve seat opening with respect to the center axis of the fuel passage, and at least one injection hole is provided in the fuel passage. Is provided on the side opposite to the center of the valve seat opening with respect to the central axis of the fuel injection device, so that it is possible to reduce the adhesion of fuel to the intake port wall and promote the improvement of fuel efficiency. can do.

3 is a vertical sectional view of the fuel injection device according to the first embodiment. FIG. FIG. 3 is a vertical cross-sectional view of a part of the fuel injection device according to the first embodiment. FIG. 3 is a transverse cross-sectional view of a cross section taken along the line AA of FIG. 2 viewed from the arrow direction. 5 is an explanatory diagram of an upstream end surface of an injection hole plate of the fuel injection device according to the first embodiment. FIG. 7 is an explanatory diagram of an upstream end surface of an injection hole plate of the fuel injection device according to the second embodiment. FIG. FIG. 7 is a vertical cross-sectional view of a part of the fuel injection device according to the third embodiment. FIG. 7 is a transverse cross-sectional view of a cross section taken along the line BB of FIG. 6 viewed from the arrow direction. FIG. 11 is an explanatory view showing an upstream end surface of an injection hole plate of the fuel injection device according to the third embodiment. FIG. 13 is an explanatory diagram when the fuel injection device according to the fourth embodiment is installed in an intake port of an internal combustion engine. FIG. 11 is an explanatory view of an upstream end surface of an injection hole plate of the fuel injection device according to the fourth embodiment when the cross section taken along the line CC of FIG. 9 is viewed from the arrow direction.

Embodiment 1.
1 is a vertical cross-sectional view of the fuel injection device according to the first embodiment, FIG. 2 is a vertical cross-sectional view of a part of the fuel injection device according to the first embodiment, and FIG. 3 is a cross-sectional view taken along line AA of FIG. It is the cross-sectional view which looked at from the arrow direction. 1, 2, and 3, the fuel injection device 1 is composed of a solenoid device 4 and a valve device 9. The solenoid device 4 includes a resin frame 71 having flanges at both ends in the axial direction, a coil 7 wound around the outer periphery of the frame 71, and a yoke arranged on the outer periphery of the coil 7. Of the metal housing 5, the inner peripheral surface of the frame body 71 and the core 6 as a metal fixed iron core inserted into the inner peripheral surface of the housing 5, the coil 7, the frame body 71, the core 6 and the housing 5. It is constituted by a resin-made insulating jacket 41 embedded inside.

The valve device 9 includes a valve body 10, an armature 8 made of a magnetic metal, a valve seat 12, a valve holder 11, and an injection hole plate 13. The valve holder 11 is fixed to the core 6 by welding after one end portion in the axial direction is press-fitted into the outer peripheral portion of the one end portion in the axial direction of the core 6. The valve holder 11 is provided with an annular guide portion 11a protruding from the inner peripheral surface on the inner peripheral surface on the one end side in the axial direction. The armature 8 is press-fitted into one end of the valve body 10 in the axial direction and then fixed to the valve body 10 by welding. The armature 8 is axially slidably supported by the guide portion 11a of the valve holder 11, and when sucked by the core 6 as will be described later, the armature 8 slides axially so that the end surface 8a of the armature 8 is cored. It contacts the end face of 6. The ball 15 is fixed to the other axial end portion of the valve body 10 by welding, and has a flat surface 15a formed by a plurality of chamfers.

The valve seat 12 is formed in a hollow cylindrical shape, one end of which is open in the axial direction and the other end of which is closed by an end wall 121. Inside the valve seat 12, the above-mentioned ball 15 fixed to the other axial end of the valve body 10 by welding is arranged so as to be movable in the axial direction. An annular seat portion 12a on which the ball 15 is seated is formed on the inner surface of the end wall portion 121 of the valve seat 12. Further, a valve seat opening 12b penetrating the end wall portion 121 is provided at the center of the end wall portion 121 of the valve seat 12. The valve seat opening 12b is closed when the ball 15 is seated on the seat portion 12a of the valve seat 12, and the ball 15 is separated from the seat portion 12a to be released from the blockage so that the inside and the outside of the valve seat 12 are separated from each other. Communicate.

The dish-shaped nozzle hole plate 13 has its upstream end face fixed to the downstream side of the valve seat 12 by welding. The welded portion 50 indicates the welding point. The peripheral edge portion of the valve seat 12 and the peripheral edge portion of the injection hole plate 13 are fixed by abutting on the inner peripheral portion of the other axial end portion of the valve holder 11.

As shown in FIG. 3, the injection hole plate 13 has a first swirl chamber 18a, a second swirl chamber 18b, and a fuel passage connected to the first swirl chamber 18a and the second swirl chamber 18b. 17, a first injection hole 14a that penetrates the injection hole plate 13 in the plate thickness direction, and a second injection hole 14b are provided. The first swirl chamber 18a, the second swirl chamber 18b, and the fuel passage 17 are formed by recessing the upstream end surface of the injection hole plate 13, and the bottom surfaces of the first swirl chamber 18a and the fuel passage 17 are substantially flush with each other. Is configured to. Details of the structure of the injection hole plate 13 will be described later.

The first injection hole 14a is formed in the center of the first swirl chamber 18a, and the second injection hole 14b is formed in the center of the second swirl chamber 18b. The center 13c of the injection hole plate 13 and the center 12c of the valve seat opening 12b of the valve seat 12 are located on the central axis X of the fuel injection device 1. The compression spring 16 inserted into the core 6 has one end fixed to the core 6 and the other end abutting on one end of the valve body 10 in the axial direction. Pushing in the direction.

Next, the operation of the fuel injection device according to the first embodiment will be described. When an operation signal is sent from a control device (not shown) of the internal combustion engine to a drive circuit (not shown) of the fuel injection device 1, a current is passed through the coil 7 of the fuel injection device 1, and the armature 8, the core 6, A magnetic flux is generated in the magnetic circuit composed of the housing 5 and the valve holder 11, and the armature 8 is attracted to the core 6 side and moves against the pressing force of the compression spring 16. As the armature 8 is sucked and moved toward the core 6, the ball 15 of the valve body 10 fixed to the armature 8 separates from the seat portion 12a of the valve seat 12, and the valve seat opening 12b is formed by the ball 15. Release from blockage.

When the valve seat opening 12b is released from the blockage by the ball 15, the high-pressure fuel filling the inside of the valve holder 11 is discharged between the flat surface 15a of the ball 15 of the valve body 10 and the inner peripheral surface of the valve seat 12. Between the seat portion 12a of the valve seat 12 and the outer peripheral surface of the ball 15 and the valve seat opening portion 12b, and the gas flows into the central portion of the fuel passage 17 of the injection hole plate 13. .. The fuel that has flowed into the central portion of the fuel passage 17 is branched from the central portion of the fuel passage 17 and flows into the first swirl chamber 18a and the second swirl chamber 18b, and the first swirl chamber 18a ejects the fuel. It is injected into the intake port of the internal combustion engine through the hole 14a, and at the same time, is injected from the second swirl chamber 18b into the intake port of the internal combustion engine through the second injection hole 14b.

Next, when a stop signal for stopping the fuel injection operation is sent from the control device of the internal combustion engine to the drive circuit of the fuel injection device 1, the current of the coil 7 is cut off and the armature 8, the core 6, the housing 5, the valve The magnetic flux of the magnetic circuit formed by the holder 11 decreases, and the armature 8 moves toward the valve seat 12 by sliding on the surface of the guide portion 11a of the valve holder 11 by the pressing force of the compression spring 16. As a result, the ball 15 of the valve body 10 is seated on the seat portion 12a of the valve seat 12 and closes the valve seat opening 12b. As a result, fuel injection from the first injection hole 14a and the second injection hole 14b is stopped.

Here, the structure of the injection hole plate 13 will be described in more detail. FIG. 4 is an explanatory diagram of an upstream end surface of the injection hole plate of the fuel injection device according to the first embodiment. As shown in FIG. 4, a first swirl chamber 18a and a second swirl chamber 18b for imparting a swirl force to the fuel are provided on the upstream end surface of the injection hole plate 13 on the radially outer side of the valve seat opening 12b. Is formed in.

The first injection hole 14a is provided at the center of the first swirl chamber 18a, and the second injection hole 14b is provided at the center of the second swirl chamber 18b. A fuel passage 17 having a central portion facing the valve seat opening 12b is provided on the upstream end surface of the injection hole plate 13. The fuel flowing out from the valve seat opening 12b is branched into the first swirl chamber 18a and the second swirl chamber 18b joined to both ends of the fuel passage 17 after flowing into the fuel passage from the central portion of the fuel passage 17. Is configured to.

Further, when the upstream end face of the injection hole plate 13 is viewed from the upstream side of the central axis X passing through the center of the valve seat opening 12b, the center 12c of the valve seat opening 12b and the center 13c of the injection hole plate 13 are It is arranged to match. The first swirl chamber 18a and the second swirl chamber 18b are arranged so as to be point-symmetric with respect to the center 17c of the fuel passage 17. The first injection hole 14a and the second injection hole 14b are formed so as to be point-symmetric with respect to the center 17c of the fuel passage 17.

Further, the central axis 40 of the fuel passage 17 is provided so as to be offset by a predetermined amount from the center 12c of the valve seat opening and the center 13c of the injection hole plate 13. As a result, the first injection hole 14a provided in the first swirl chamber 18a is offset from the central axis 40 of the fuel passage 17 toward the center 12c of the valve seat opening 12b by a predetermined amount, and The second injection hole 14b provided in the second swirl chamber 18b is offset by a predetermined amount on the side opposite to the center 12c of the valve seat opening 12b with respect to the central axis 40 of the fuel passage 17.

The fuel flowing from the valve seat opening 12b of the valve seat 12 into the upstream end surface of the injection hole plate 13 radially flows into the center of the fuel passage 17 around the center 12c of the valve seat opening 12b. Since the first injection hole 14a provided in the swirl chamber 18a of the valve is offset with respect to the central axis 40 of the fuel passage 17 in the direction of the center 12c of the valve seat opening 12b, the first injection hole 14a passes through the fuel passage 17 through the first injection hole 14a. The main flow 30a of the fuel flowing into the first injection hole 14a provided in the swirl chamber 18a is a side wall 17w of the fuel passage 17 on the side opposite to the first injection hole 14a with respect to the center 17c of the fuel passage 17. Flow toward. For this reason, it becomes difficult for the fuel to directly enter the first injection holes 14a, the first swirling flow 30a1 of strong fuel is generated inside the first swirling chamber 18a, and the penetrating force is small and the fuel is sufficiently atomized. A spray is formed, and the fuel spray is injected from the first injection hole 14a into the intake port of the internal combustion engine.

On the other hand, the second injection hole 14b provided in the second swirl chamber 18b is offset from the center axis 40 of the fuel passage 17 to the side opposite to the center 12c of the valve seat opening 12b. The main flow 30b of the flow of the fuel flowing in the direction of the second injection hole 14b provided in the second swirl chamber 18b through the passage 17 flows toward the second injection hole 14b, It becomes easy for fuel to directly flow into 14b. Therefore, the second swirl flow 30b1 weaker than the above-described first swirl flow 30a1 is generated inside the second swirl chamber 18b, and a fuel spray having a large penetration force is formed. The fuel is injected from the injection hole 14b into the intake port of the internal combustion engine.

In this way, the fuel flowing into the swirl chamber from the valve seat opening flows into the injection hole while generating a swirl flow, and the swirl flow is maintained even inside the injection hole, so that the fuel along the inner wall of the injection hole is thin. A liquid film is formed, and atomization of the fuel is promoted by injecting a thin liquid film from the injection hole into a hollow cone shape.

In the fuel injection device according to the first embodiment, in one nozzle hole plate, the main flow direction of the fuel flow flowing from the valve seat opening through the fuel passage into the nozzle hole provided in the swirl chamber is directed toward the nozzle hole. It is possible to set two directions, a weak swirling flow and a strong swirling flow in the swirling chamber, and it is possible to set the fuel spray with a large penetration force and the atomization force to a small atomization. It is possible to form two types of fuel sprays that are good fuel sprays. Therefore, even when the fuel is injected when the intake flow is present in the intake port, it becomes difficult for the fuel spray to flow due to the intake flow, and it is possible to reduce the adhesion of the fuel spray to the intake port wall. Therefore, the direct injection rate of the fuel spray into the combustion chamber can be improved, the vaporization cooling effect in the combustion chamber can be enhanced, the knock resistance can be improved, and the compression ratio can be increased, and the fuel consumption can be improved.

On the other hand, in the case of the conventional fuel injection device disclosed in the above-mentioned Patent Document 1, the center of the valve seat opening and the center of a plurality of radially extending fuel passages provided on the upstream end surface of the injection hole plate are The main flow direction of the fuel flowing from the valve seat opening into each fuel passage toward the injection hole is substantially parallel to the central axis of the fuel passage, and is the same in each swirling chamber. A swirling flow of fuel having such strength is generated, and fuel spray having the same penetrating force is injected from each injection hole. Therefore, the above-described effects of the fuel injection device according to the first embodiment of the present application cannot be obtained.

Further, in a fuel atomizing system fuel injection system that uses a general swirling flow of fuel, when fuel sprays having different penetration forces are formed by one injection hole plate, the fuel sprays having different penetration forces are used. Different injection holes, swirl chambers, fuel passages, etc. corresponding to each need to be formed in one injection hole plate, which complicates the fuel flow path structure and deteriorates workability. According to the fuel injection device of the first aspect, the injection hole, the swirl chamber, and the fuel passage corresponding to different penetrating forces of the fuel spray have the same shape, and the central axis of the fuel passage is arranged with respect to the center of the valve seat opening. Since only the offset is required, the fuel flow passage structure can be simplified and the workability can be improved.

Embodiment 2.
Next, a fuel injection device according to a second embodiment of the present application will be described. In the fuel injection device according to the first embodiment, two injection holes are provided on the upstream end surface of the injection hole plate, but in the fuel injection device according to the second embodiment, four injection holes are provided on the upstream end surface of the injection hole plate. Is provided. FIG. 5 is an explanatory diagram of the upstream end surface of the injection hole plate of the fuel injection device according to the second embodiment.

In FIG. 5, a first fuel passage 17 and a second fuel passage 171 are provided on the upstream end surface of the injection hole plate 13 so as to intersect with each other at a common center 17c and to be orthogonal to each other. ing. The first swirl chamber 18a is connected to one end of the first fuel passage 17, and the second swirl chamber 18b is connected to the other end of the first fuel passage 17. The third swirl chamber 18c is connected to one end of the second fuel passage 171 and the fourth swirl chamber 18d is connected to the other end of the second fuel passage 171. The first swirl chamber 18a, the second swirl chamber 18b, the third swirl chamber 18c, and the fourth swirl chamber 18d are respectively formed outside the valve seat opening 12b in the radial direction.

The first fuel passage 17, the second fuel passage 171, the first swirl chamber 18a, the second swirl chamber 18b, the third swirl chamber 18c, and the fourth swirl chamber 18d are the same as those described above. The injection hole plate 13 is formed by denting the upstream end surface, and the bottom surfaces of the injection hole plate 13 are formed to be substantially continuous with each other.

A first injection hole 14a penetrating the injection hole plate 13 in the plate thickness direction is opened in the center of the first swirl chamber 18a, and the injection hole plate 13 is opened in the center of the second swirl chamber 18b. The second injection hole 14b penetrating in the plate thickness direction is opened, and the third injection hole 14c penetrating the injection hole plate 13 in the plate thickness direction is opened at the center of the third swirl chamber 18c. A fourth injection hole 14d that penetrates the injection hole plate 13 in the plate thickness direction is opened at the center of the fourth swirl chamber 18d.

When the upstream end face of the injection hole plate 13 is viewed from the upstream side of the central axis X passing through the center 12c of the valve seat opening 12b, the center 12c of the valve seat opening 12b and the center 13c of the injection hole plate 13 are aligned. I am doing it. The first swirl chamber 18a and the second swirl chamber 18b are arranged so as to be point-symmetric with respect to the common center 17c of the first fuel passage 17 and the second fuel passage 171. The injection holes 14a and the second injection holes 14b are arranged so as to be point-symmetric with respect to the common center 17c of the first fuel passage 17 and the second fuel passage 171. The third swirl chamber 18c and the fourth swirl chamber 18d are arranged so as to be point-symmetric with respect to the common center 17c of the first fuel passage 17 and the second fuel passage 171. The injection hole 14c and the fourth injection hole 14d are arranged so as to be point-symmetric with respect to the common center 17c of the first fuel passage 17 and the second fuel passage 171.

Further, the central axis 40 of the first fuel passage 17 and the central axis 401 of the second fuel passage 171 are provided offset from the center 12c of the valve seat opening 12b by a predetermined amount. Further, the first injection hole 14a provided in the first swirl chamber 18a and the third injection hole 14c provided in the third swirl chamber 18c respectively have the central axis 40 of the first fuel passage 17. And a second shaft provided in the second swirl chamber 18b so as to be offset from the central axis 401 of the second fuel passage 171 by a predetermined amount in the direction of the center 12c of the valve seat opening 12b. Of the injection hole 14b and the fourth injection hole 14d provided in the fourth swirl chamber 18d with respect to the central axis 40 of the first fuel passage 17 and the central axis 401 of the second fuel passage 171 respectively. The valve seat opening 12b is provided so as to be offset by a predetermined amount in the direction opposite to the center 12c.

The fuel that has flowed into the upstream end surface of the injection hole plate 13 from the valve seat opening 12b is radially centered on the center 12c of the valve seat opening 12b and is located at the central portion between the first fuel passage 17 and the second fuel passage 171. However, the first injection hole 14a provided in the first swirl chamber 18a is offset with respect to the central axis 40 of the first fuel passage 17 in the direction of the center 12c of the valve seat opening 12b. Therefore, the main flow 30a of the flow of fuel flowing into the first injection hole 14a provided in the first swirl chamber 18a through the first fuel passage 17 is the main flow 30a with respect to the central axis 40 of the first fuel passage 17. It flows toward the side wall 17w of the first fuel passage 17 opposite to the first injection hole 14a. For this reason, it becomes difficult for the fuel to directly enter the first injection holes 14a, the first swirling flow 30a1 of strong fuel is generated inside the first swirling chamber 18a, and the penetrating force is small and the fuel is sufficiently atomized. The spray is formed and injected from the first injection hole 14a into the intake port of the internal combustion engine.

Similarly, the third injection hole 14c provided in the third swirl chamber 18c is offset in the direction of the center 12c of the valve seat opening 12b with respect to the central axis 401 of the second fuel passage 171. Therefore, the main flow 30c of the fuel flowing into the third injection hole 14c provided in the third swirl chamber 18c through the second fuel passage 171 is less likely to flow with respect to the central axis 401 of the second fuel passage 171. The current flows toward the side wall 171w of the second fuel passage 171 opposite to the third injection hole 14c. For this reason, it becomes difficult for the fuel to directly enter the third injection hole 14c, a strong third fuel swirl flow 30c1 is generated inside the third swirl chamber 18c, and the penetration force is small and the fuel is sufficiently atomized. The spray is formed and injected from the third injection hole 14c into the intake port of the internal combustion engine.

On the other hand, the second injection hole 14b provided in the second swirl chamber 18b is offset in the direction opposite to the center 12c of the valve seat opening 12b with respect to the central axis 40 of the first fuel passage 17. Therefore, the main flow 30b of the fuel flowing in the direction of the second injection hole 14b provided in the second swirl chamber 18b through the first fuel passage 17 is directed toward the second injection hole 14b. The fuel easily flows directly into the second injection hole 14b. Therefore, the second swirl flow 30b1 weaker than the above-described first swirl flow 30a1 is generated inside the second swirl chamber 18b, and fuel spray having a large penetrating force is formed and the second swirl hole 14b is formed. It is injected into the intake port of the internal combustion engine.

Similarly, the fourth injection hole 14d provided in the fourth swirl chamber 18d is offset with respect to the central axis 401 of the second fuel passage 171 in the direction opposite to the center 12c of the valve seat opening 12b. Therefore, the main flow 30d of the fuel flow flowing in the direction of the fourth injection hole 14d provided in the fourth swirl chamber 18d through the second fuel passage 171 is directed toward the fourth injection hole 14d. The fuel easily flows directly into the fourth injection hole 14d. Therefore, the fourth swirl flow 30d1 weaker than the above-described third swirl flow 30c1 is generated inside the fourth swirl chamber 18d, and fuel spray having a large penetrating force is formed to cause the fourth swirl flow 14d to flow from the fourth injection hole 14d. It is injected into the intake port of the internal combustion engine.

As described above, according to the fuel injection device of the second embodiment, the number of the injection holes is four, and one injection hole plate has two types of fuel sprays having different penetrating forces, that is, penetration holes. It is possible to form two types of fuel sprays, that is, a fuel spray having a large force and a fuel spray having a small penetration force and well atomized, and the same effect as that of the fuel injection device of the first embodiment can be obtained. You can

Further, the first injection hole 14a and the third injection hole 14c, which form the fuel spray that is small in penetrating power and is well atomized, are arranged in close proximity to each other in a lump, and the fuel spray that forms a large penetrating power is formed. The second injection hole 14b and the fourth injection hole 14d are arranged in a block in close proximity to each other, and the first injection hole 14a, the third injection hole 14c, the second injection hole 14b and the fourth injection hole 14b No. 14 d of the fuel spray nozzles are arranged in line symmetry with respect to the common center 17 c of the first fuel passage 17 and the second fuel passage 171. Are less likely to interfere with each other, and deterioration of atomization can be suppressed.

In the fuel injection device according to the second embodiment described above, the number of injection holes is four, but the number of injection holes may be further increased to form a plurality of fuel sprays having different penetrating forces. The same effect as described above can be obtained, the injection flow rate can be increased by increasing the number of injection holes, and it is possible to cope with the case where the flow rate required for the fuel injection device is large.

Embodiment 3.
Next, a fuel injection device according to a third embodiment of the present application will be described. In the fuel injection device according to the first embodiment described above, the center of the fuel passage does not coincide with the center of the injection hole plate, and the center of the fuel passage is provided offset from the center of the injection hole plate. In the fuel injection device according to the third aspect, when the upstream end face of the nozzle hole plate is viewed from the upstream side of the central axis passing through the center of the valve seat opening, the center of the nozzle hole plate and the center of the fuel passage are aligned, The center of the injection hole plate and the center of the fuel passage are offset from the center of the valve seat opening. Other configurations are similar to those of the fuel injection device according to the first embodiment.

6 is a vertical cross-sectional view of a portion of the fuel injection device according to the third embodiment, FIG. 7 is a cross-sectional view of a cross-section taken along the line BB of FIG. 6 as seen from the direction of the arrow, and FIG. 3 is an explanatory view of an upstream end surface of an injection hole plate of the fuel injection device according to FIG. 6, FIG. 7, and FIG. 8, the center 17c of the fuel passage 17 coincides with the center 13c of the injection hole plate 13, and the first injection hole 14a provided in the injection hole plate 13 The two injection holes 14b, the first swirl chamber 18a, the second swirl chamber 18b, and the fuel passage 17 are arranged point-symmetrically with respect to the center 13c of the injection hole plate and the center 17c of the fuel passage. The injection hole plate 13 is formed in a flat disc shape, and the outer diameter of the injection hole plate 13 is smaller than the outer diameter of the valve seat 12.

In the first embodiment described above, the injection hole plate 13 was formed in a dish shape, but in the third embodiment, the injection hole plate 13 is formed in a flat disk shape. Therefore, the manufacture of the injection hole plate 13 Alternatively, there is an advantage that processing becomes easy. Further, in the third embodiment, the outer diameter of the injection hole plate 13 is formed smaller than the outer diameter of the valve seat 12. Therefore, even if the valve seat 12 and the injection hole plate 13 are not fixed strictly concentrically, the outer edge of the injection hole plate 13 does not contact the inner wall of the valve holder 11, and the valve seat 12 and the valve holder 11 Can be easily assembled.

Further, according to the third embodiment, the center 13c of the injection hole plate 13 and the center 17c of the fuel passage 17 are different from the center 12c of the valve seat opening 12b provided on the central axis X of the valve seat 12. The fuel passage 17 is arranged with a predetermined offset in the direction orthogonal to the central axis 40.

Therefore, the fuel flowing from the valve seat opening 12b of the valve seat 12 into the upstream end surface of the injection hole plate 13 radially flows into the central portion of the fuel passage 17 about the center 12c of the valve seat opening 12b. The first injection hole 14a provided in the first swirl chamber 18a is offset in the direction of the center 12c of the valve seat opening 12b with respect to the central axis 40 of the fuel passage 17, so that the first injection hole 14a passes through the fuel passage 17 through the first injection hole 14a. The main flow 30a of the fuel flowing into the first injection hole 14a provided in the first swirl chamber 18a is the main flow path 30a of the fuel passage 17 on the side opposite to the first injection hole 14a with respect to the central axis 40 of the fuel passage 17. Flows toward the side wall 17w of the. For this reason, it becomes difficult for the fuel to directly enter the first injection holes 14a, the first swirling flow 30a1 of strong fuel is generated inside the first swirling chamber 18a, and the penetrating force is small and the fuel is sufficiently atomized. The spray is formed and injected from the first injection hole 14a into the intake port of the internal combustion engine.

On the other hand, the second injection hole 14b provided in the second swirl chamber 18b is offset in the direction opposite to the center 12c of the valve seat opening 12b with respect to the central axis 40 of the fuel passage 17. The main flow 30b of the fuel flowing through the fuel passage 17 in the direction of the second injection hole 14b provided in the second swirl chamber 18b flows in the direction of the second injection hole 14b, It becomes easier for fuel to directly flow into the injection holes 14b. Therefore, the second swirl flow 30b1 weaker than the above-described first swirl flow 30a1 is generated inside the second swirl chamber 18b, and fuel spray having a large penetrating force is formed and the second swirl hole 14b is formed. It is injected into the intake port of the internal combustion engine.

As described above, according to the fuel injection device of the third embodiment, the fuel flow flowing from the valve seat opening 12b into the first injection hole 14a and the second injection hole 14b is the same as in the case of the first embodiment. In addition, it is possible to set the main flow 30b in the direction toward the injection hole and the main flow 30a in the direction away from the injection hole, and the fuel spray having a large penetration force and the fuel spray having a small penetration force and sufficiently atomized. It is possible to form the two types of fuel spray described above, and it is possible to obtain the same effect as that of the first embodiment.

Furthermore, in the fuel injection device according to the third embodiment, the shape of the flow passage formed by the fuel passage 17, the first swirl chamber 18a, and the second swirl chamber 18b formed on the upstream end surface of the injection hole plate 13 is changed. Instead, the center of the valve seat 12 and the center of the injection hole plate 13 are offset from each other and fixed to each other, so that the amount of fuel can be adjusted by simply adjusting the offset amount of the central axis 40 of the fuel passage 17 with respect to the center 12c of the valve seat opening. Since the direction of the fuel flow from the seat opening 12b to the first injection hole 14a and the second injection hole 14b can be adjusted, the amount of the optimum penetration force of the fuel spray corresponding to various internal combustion engines can be adjusted. Can be adjusted to. Therefore, in the fuel injection device of the atomization system using the general swirl flow, when the penetrating force of the fuel spray is adjusted, the swirl flow is imparted to the fuel formed on the upstream end surface of the injection hole plate. The design man-hour required for the adjustment can be reduced compared with the case where the shape of the flow path such as the injection hole, swirl chamber, fuel passage, etc. is changed, and the cost for changing the injection hole plate die is not necessary and the cost is reduced. can do.

Fourth Embodiment
Next, a fuel injection device according to Embodiment 4 of the present application will be described. FIG. 9 is an explanatory view of a case where the fuel injection device according to the fourth embodiment is installed in an intake port of an internal combustion engine, and FIG. 10 is a third embodiment in which a cross section taken along the line CC of FIG. 9 is viewed from an arrow direction. FIG. 4 is an explanatory view showing an upstream end face of an injection hole plate of the fuel injection device. In FIG. 9, the fuel injection device 1 according to any one of the first to third embodiments described above is mounted on the ceiling portion 70b of the intake port 70 that communicates with the combustion chamber 60 of the internal combustion engine. Fuel is injected from the fuel injection device 1 toward the intake valve 80 of the engine.

In the case of the intake stroke injection in which the fuel is injected in the intake stroke of the internal combustion engine, the intake flow 90 is generated in the intake port 70 from the upstream side to the downstream side in the fuel flow direction. Since the penetrating force of the fuel spray is small in the injector, the fuel spray is caused to flow to the ceiling part 70b of the intake port 70 by the intake flow 90 and adheres to the inner wall surface of the ceiling part 70b, so that the amount of fuel flowing into the combustion chamber 60 is increased. Therefore, the vaporization cooling effect in the combustion chamber 60 becomes insufficient, the knock resistance does not improve, and the compression ratio cannot be increased, so that a sufficient fuel efficiency improving effect cannot be obtained.

In the fuel injection device according to the fourth embodiment, as shown in FIG. 10, the first injection hole 14a that is offset with respect to the central axis 40 of the fuel passage 17 in the direction of the center 12c of the valve seat opening 12b is It is arranged so as to be on the side Y1 closer to the bottom 70a of the intake port with respect to the center 17c of the fuel passage 17, and is offset in the direction opposite to the center 12c of the valve seat opening 12b with respect to the central axis 40 of the fuel passage 17. The second injection hole 14b is arranged on the side Y2 closer to the ceiling portion 70b of the intake port with respect to the center 17c of the fuel passage 17. Therefore, the first fuel spray F1 having a small penetration force and sufficiently atomized is injected from the first injection hole 14a toward the bottom portion 70a side of the intake port 70, and the penetration force is large from the second injection hole 14b. The second fuel spray F2 is injected toward the ceiling portion 70b side of the intake port 70.

According to the fourth embodiment, due to the intake air flow 90 generated in the intake stroke injection, the first fuel spray F1 which has a small penetration force and is sufficiently atomized is flowed to the ceiling portion 70b of the intake port 70 and adhered to the wall surface. This can be suppressed by the second fuel spray F2 having a large penetration force.

Although the present application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more of the embodiments are applicable to the particular embodiment. However, the present invention is not limited to the above, and can be applied to the embodiments alone or in various combinations. Therefore, innumerable variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, it is assumed that at least one component is modified, added or omitted, and at least one component is extracted and combined with the components of other embodiments.

The fuel injection device according to the present application can be used in the field of internal combustion engines, and thus in the field of the automobile industry.

1 fuel injection device, 4 solenoid device, 5 housing, 6 core, 7 coil, 8 amateur, 9 valve device, 10 valve body, 11 valve holder, 12 valve seat, 12b valve seat opening, 13 injection hole plate, 14a No. 1 injection hole, 14b 2nd injection hole, 14c 3rd injection hole, 14d 4th injection hole, 15 balls, 16 compression springs, 17 fuel passage, 17 1st fuel passage, 171 2nd fuel passage , 18a first swirl chamber, 18b second swirl chamber, 18c third swirl chamber, 18d fourth swirl chamber, 50 weld, 60 combustion chamber, 70 intake port, 80 intake valve, 90 intake flow, F1 1st fuel spray, F2 2nd fuel spray

Claims

Having a valve body for opening and closing the valve seat, and operating the valve body by receiving an operation signal from a control device, so that fuel passes between the valve body and the valve seat seat portion, and then the valve seat downstream side A fuel injection device that injects from a plurality of injection holes provided in an injection hole plate attached to the valve seat opening of
On the upstream end surface of the injection hole plate, a plurality of swirl chambers are arranged radially outside the valve seat opening, and impart swirl force to the fuel; and fuel flows from the valve seat opening to the center. The swirl chamber joined to an end has a fuel passage for flowing out fuel, and the swirl chamber is provided with the injection hole for injecting fuel to the outside,
When the upstream end surface of the injection hole plate is viewed from the upstream side in the central axis direction of the valve seat opening, the plurality of swirl chambers and the injection holes are arranged point-symmetrically with respect to the center of the fuel passage. , The central axis of the fuel passage is offset with respect to the center of the valve seat opening,
At least one injection hole of the plurality of injection holes is provided offset to the center side of the valve seat opening with respect to the center axis of the fuel passage, and at least one injection hole is provided in the fuel passage. A fuel injection device, wherein the fuel injection device is provided on the side opposite to the center of the valve seat opening with respect to the central axis.
Of the plurality of injection holes, at least two injection holes that are offset toward the center of the valve seat opening with respect to the center axis of the fuel passage, and the valve seat opening with respect to the center axis of the fuel passage. The fuel injection device according to claim 1, wherein the at least two injection holes offset to the opposite side of the center of the portion are arranged in proximity to each other.
When the upstream end surface of the injection hole plate is viewed from the upstream side in the central axis direction of the valve seat opening, the center of the injection hole plate and the center of the fuel passage are aligned,
The fuel injection device according to claim 1 or 2, wherein a center of the injection hole plate is offset from a center of the valve seat opening.
The fuel injection device installed on the ceiling side of an intake port communicating with a combustion chamber of an internal combustion engine,
Among the plurality of injection holes, an injection hole offset to the center side of the valve seat opening with respect to the central axis of the fuel passage is arranged on the bottom side of the intake port on the injection hole plate,
The injection hole offset to the side opposite to the center of the valve seat opening with respect to the central axis of the fuel passage is arranged on the ceiling side of the intake port on the injection hole plate. The fuel injection device according to any one of 1 to 3.