JPH0680856U - Fuel injection valve - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a suitable fuel discharge foam shape when deflecting the spray by air assist. A flat sloped portion 9a is formed on a part of a wall surface of a spray passage 9 through which the spray 3 discharged from a fuel injection valve 6 passes, and a main air passage for blowing out assist air to the sloped portion 9a. The outlet 13a of 13 is opened. Exit 13a
The width in the lateral direction is made longer than the diameter of the spray 3, and assist air in the same direction is blown to the spray 3 over the entire width direction to deflect the spray 3. [Effect] Since the assist air is blown over the entire area of the spray 3 in the diameter direction, local deformation of the spray 3 can be prevented, and an appropriate fuel discharge foam shape can be obtained.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fuel injection valve for an internal combustion engine, and more particularly to a fuel injection valve having an air assist passage for appropriately deflecting the discharge direction of the spray discharged from an injector.

[0002]

[Prior art]

 2. Description of the Related Art Conventionally, in a fuel injection valve of an automobile engine as an internal combustion engine, as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-57362, two air assist passages are provided on the inner wall surface of a cylindrical spray passage. There is a structure that is formed so as to be opened, and each air assist passage is switched by a solenoid valve or the like to appropriately deflect the mist by the air blown out from the air assist passage. By doing so, for example, in a structure in which two intake valves are provided and one intake pipe branches into two intake ports, when one intake valve is deactivated, the air is sprayed. Can be sprayed to deflect the spray towards the other intake port.

However, in the above structure, as shown in FIG. 4, the air assist passage 22 is formed by forming a through hole having a circular cross section in the cylindrical wall body 21 forming the spray passage. When the cross section orthogonal to the axis of the spraying direction of the spray 23 is viewed, the air indicated by the arrow B is sprayed only on a part of the side surface of the spray 23 before spraying the air. Therefore, there is a problem that after spraying air, as shown by the imaginary line in FIG. 5, the cross-sectional shape of the spray 23 is deformed into a concave shape in which the portion on which air is hit is recessed, and it is difficult to form an appropriate fuel discharge foam. It was

[0004]

[Problems to be solved by the device]

 In view of such problems of the conventional technology, the main object of the present invention is to reduce the deformation of the spray due to the assist air for deflecting the spray, and to provide an appropriate fuel discharge foam shape even when the spray is deflected. It is to provide a fuel injection valve that can be obtained.

[0005]

[Means for Solving the Problems]

 According to the present invention, such an object is achieved by a fuel injection valve having an outlet of an air assist passage near the injection port in order to deflect the direction of the spray discharged from the injection port of the fuel injection valve by the assist air. It is achieved by providing a fuel injection valve characterized in that the outlet of the air assist passage is opened horizontally in the diametrical direction of the spray. In particular, the length of the outlet of the air assist passage in the laterally long direction is preferably longer than the diameter of the spray in the portion to which the assist air blown from the outlet is blown.

[0006]

[Action]

 In this way, by forming the assist air outlet that deflects the spray discharge direction horizontally in the spray diameter direction, the assist air can be sprayed over a wide range in the spray diameter direction. It is possible to prevent the deformation of the spray discharge foam shape due to By making the lateral length of the outlet longer than the diameter of the portion of the spray to which the air is sprayed, the entire spray can be deflected by the assist air.

[0007]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagram schematically showing a mounting state of a fuel injection valve of an automobile engine to which the present invention is applied. The engine of this embodiment shown in FIG. 1 has two intake valves and two exhaust valves for each cylinder, and is divided into one intake pipe 1 and two intake ports separately. It has each branched pipe 1a * 1b. A fuel injection valve 2 is mounted near the upstream of the branch point of both branch pipes 1a and 1b of the intake pipe 1.

The fuel injection valve 2 discharges fuel supplied to one end in the axial direction into the intake pipe 1 as a spray 3 from a nozzle end of the other end, and directs it toward both branch pipes 1a and 1b. The sprayed state and the deflected sprayed state in which one branch pipe 1a is sprayed as shown by the imaginary line in FIG. 1 can be appropriately changed depending on operating conditions. The spray 3 is deflected by air pressure, and an air supply path 4 for passing the air is connected to the nozzle end of the fuel injection valve 2.

The nozzle end portion of the fuel injection valve 2 is as shown in FIG. 2, and the injection port 6 is opened at the center of the lower end surface of the valve body 5 of the fuel injection valve 2 in the drawing. A needle valve 7 is received in the body 5 coaxially and reciprocally in the axial direction. When the needle valve 7 is reciprocated, the injection port 6 is opened and closed, and when the injection port 6 is opened, the fuel to which the predetermined fuel pressure is applied is discharged as the spray 3 which diffuses in a conical shape.

A sleeve 8 having a bottomed cylindrical shape is coaxially fitted to the valve body 5 so as to surround the lower end portion in FIG. 2, and the sleeve 8 has a mounting hole for the intake pipe 1. The fuel injection valve 2 is attached to the intake pipe 1.

A spray passage 9 penetrating in the axial direction of the injection port 6 is formed at the bottom of the sleeve 8. At the end of the sleeve 8 facing the inside of the intake pipe 1, an umbrella portion 10 having a diameter larger than that of the spray passage 8 is formed, and the spray 3 enters the intake pipe 1 from the spray passage 8 via the umbrella portion 10. Erupted.

The spray passage 9 is formed in a circular cross section in a substantially half portion on the injection port 6 side in the axial direction, but a substantially half portion on the umbrella portion 10 side is formed in a rectangular shape as shown in FIG. Has been formed. One of the four surfaces of the rectangular cross section of the spray passage 9 is formed as an inclined surface portion 9a which is inclined so as to substantially follow the spreading direction of the spray 3.

The air supply passage 4 described above communicates with an annular groove 11 formed in the wall portion of the intake pipe 1 so as to surround the nozzle end portion of the fuel injection valve 2. A pair of radial holes 8a and 8b for guiding the air that has flowed into the annular groove 11 into the sleeve 8 is formed in the peripheral wall portion of the sleeve 8, and further, the valve body 5 of the sleeve 8 shown in FIG. Communication holes 12a and 12b reaching the vicinity of the spray passage 9 are provided in the portion that receives the lower end portion, corresponding to the radial holes 8a and 8b, respectively. A main air passage 13 extending from the bottom of one communication hole 12a to the slope 9a and a sub air passage 14 extending from the bottom of the other communication hole 12b to the bottom surface of the umbrella portion 10 (the upper end surface in FIG. 2). Each is set.

In the fuel injection valve 2 configured as described above, when deflecting the spray 3, the solenoid valve (not shown) is opened to supply the assist air to the air supply passage 4. The assist air is transferred from the radial hole 8a through the communication hole 12a and the main air passage 13 to the middle portion of the side surface of the spray 3 as shown by the arrow A, as shown by the solid arrow in FIG. It is blown out toward.

According to the present invention, the slope 13 a of the main air passage 13 is formed with the outlet 13 a which is horizontally long in the diameter direction of the spray 3. The width (L) of the outlet 13a in the laterally long direction of the main air passage 13 is the spray 3 of the portion where the assist air is blown as shown in FIG. 3 (the assist air is blown as shown by the broken line in the figure). It is processed by, for example, electrical discharge machining so as to be longer (L> D) than the diameter D (when not sprayed). Since the assist air having a width wider than the diameter D of the spray 3 is blown in this manner, the assist air is pushed so as to wrap the entire spray 3, so that the assist air is only applied to a part of the spray as shown in the conventional example. Local deformation of the spray due to being sprayed can be prevented and the spray 3 can be deflected into an elliptical cross-sectional shape as shown by the phantom line in FIG.

Therefore, since the deflected spray 3 can be injected toward the one branch pipe 1 a in a shape close to a circular cross section, and the spray distribution can be maintained relatively averaged, It is possible to improve the fuel injection state when the spray is deflected. Further, since the wide outlet 13a is provided on the sloped portion 9a formed of a flat surface, compared with the case where the wide outlet is provided in the circumferential direction in the spray passage having the circular cross section, for example, the outlet having the same direction is provided. Since the air is blown out, the deflection efficiency can be suitably increased.

Further, it is desirable that the outlet 13a, which is the outlet end of the main air passage 13, be as close to the outer peripheral surface of the spray 3 as possible so as to prevent the spray 3 from adhering to improve the deflection efficiency. It is advisable to set the distance to 3 to within 1.5 mm.

The outlet of the sub air passage 14 is open to the bottom surface of the umbrella portion 10, and the sub air blown out from the outlet is on the side opposite to the main air with the spray 3 interposed therebetween. Since it is blown out substantially along with, it is possible to suitably guide the deflected spray 3 and prevent it from being excessively diffused by the main air.

[0020]

[Effect of device]

 As described above, according to the present invention, the width of the assist air can be made wider than the diameter of the portion to which the spray air is sprayed, and since the assist air is sprayed over the entire diameter direction of the spray, the air in the same direction is sprayed. By this, the entire spray can be pushed, the deformation of the spray can be prevented, and the spray can be deflected while maintaining an appropriate fuel discharge form shape that maintains the fuel distribution state relatively evenly.

[Brief description of drawings]

FIG. 1 is a view schematically showing a mounting state of a fuel injection valve of an automobile engine to which the present invention is applied.

FIG. 2 is an enlarged sectional view of a main part of a fuel injection valve according to the present invention.

FIG. 3 is an enlarged view of an essential part seen along a line III-III in FIG.

FIG. 4 is an enlarged view of a main part of a fuel injection valve showing a conventional example.

5 is an enlarged view of a main part as seen from an arrow V line in FIG.

[Explanation of symbols]

 1 Intake Pipe 1a ・ 1b Branch Pipe 2 Fuel Injection Valve 3 Spray 4 Air Supply Channel 5 Valve Body 6 Jet Port 7 Needle Valve 8 Sleeve 8a ・ 8b Radial Hole 9 Spray Path 9a Slope 10 Umbrella 11 Annular Groove 12a ・ 12b Communication Hole 13 Main air passage 13a Outlet 14 Sub air passage 21 Wall 22 Air assist passage 23 Spray

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Toshihiro Tahara 1-4-1 Chuo, Wako-shi, Saitama Stock Research Institute Honda Technical Research Institute

Claims (2)

[Scope of utility model registration request] 1. A fuel injection valve, wherein an outlet of an air assist passage is provided in the vicinity of a nozzle for deflecting the discharge direction of the spray discharged from the nozzle of the fuel injection valve by assist air. Of the fuel injection valve is opened laterally in the diameter direction of the spray. 2. The length of the outlet of the air assist passage in the laterally long direction is longer than the diameter of the spray in a portion on which the assist air blown from the outlet is blown. Fuel injection valve.