JPH11210596A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of a fuel injection valve by making the length of a core shorter than conventional length. SOLUTION: This fuel injection valve injects fuel flowing from a fuel inflow port, through a fuel injection nozzle 12a. The fuel injection valve is formed of magnetic substance and is provided with a movable body 13 that can open/ close the fuel injection nozzle 12a by movement; a core 15 formed of magnetic substance and having a fuel passage 15f and moving the movable body 13 by electromagnetic force; and a passage constituent member 30 formed of different material from the core 15 and having a fuel passage 32 communicated with the fuel inflow port and the fuel passage 15f of the core 15. The length of the core 15 can therefore be shortened by the portion of the passage constituent member 30 compared to the conventional case of connecting the fuel passage 15f of the core 15 directly to the fuel in flow port.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve for injecting fuel flowing from a fuel inlet through a fuel injection port.

[0002]

2. Description of the Related Art FIG. 3 shows a longitudinal sectional view of a conventional fuel injection valve relating to this. The fuel injection valve 100 is an electromagnetic fuel injection valve, and has a substantially cylindrical body 101 at the tip thereof. A valve seat 102 having a fuel injection port 102a inside a front portion of the body 101
A movable body 103 for opening and closing the fuel injection port 102a is accommodated in an internal space of the body 101 so as to be displaceable in the axial direction. A ring 104 having an inner diameter substantially equal to that of the body 101 is fixed to a rear portion of the body 101.
The distal end of the hollow shaft-shaped core 105 is press-fitted and welded and fixed in the rear half portion of No. 4.

The core 105 functions to attract the movable body 103 by electromagnetic force and is a member constituting a fuel passage 105f. A solenoid coil 106 is mounted around the front of the core 105. The core 10
5 is provided with a connecting protrusion 105c to which a delivery pipe (not shown) is connected, and a fuel strainer 107 is press-fitted inside the connecting protrusion 105c. Further, a spring pin 108 is press-fitted inside the front portion of the core 105, and the spring pin 10
A spring 109 is mounted between the movable body 8 and the movable body 103 so as to urge the movable body 103 forward.

Therefore, when the solenoid coil 106 is not excited, the movable body 103 is
9, the fuel injection port 102a is closed by being pressed against the valve seat 102. The pressurized fuel supplied from the delivery pipe is supplied to the fuel strainer 107 and the core 1.
05, and is supplied to the inside of the body 101 via the horizontal hole 103k of the movable body 103.
In this state, when the solenoid coil 106 is excited, the movable body 103 is attracted to the core 105 against the elastic force of the spring 109, the fuel injection port 102a is opened, and the fuel enters the engine (not shown). It is injected.

[0005]

SUMMARY OF THE INVENTION The fuel injection valve 100
Since the fuel injection port 102a is opened by the attraction force between the movable body 103 and the core 105 due to the electromagnetic force, the movable body 103 and the core 105 need to be made of a ferromagnetic material. Generally, electromagnetic SUS or the like is suitably used as the material of the movable body 103 and the core 105. However, if the core 105 and the portion surrounded by the solenoid coil 106 are made of a ferromagnetic material, the function of adsorbing the movable body 103 can be sufficiently exhibited. Therefore, if the latter half of the core 105, that is, the portion used only as the fuel passage 105f, can be made of another inexpensive material, the cost of the fuel injection valve 100 can be reduced. Note that the length of the fuel passage 105f of the fuel injection valve 100 is determined by the mounting position of the fuel injection valve 100 and the position of the fuel inlet where the delivery pipe is mounted, and requires a predetermined length.

Accordingly, claims 1 to 4 of the present invention.
The object of the invention described in (1) is to reduce the cost of the fuel injection valve by shortening the core of the fuel injection valve and enabling the fuel passage between the core and the fuel inlet to be made of another material. Things. The invention described in claim 5 has the object of improving the production efficiency of the fuel passage between the core and the delivery pipe in addition to the object of the invention described in claims 2 to 4. is there.

[0007]

The above object is achieved by a fuel injector having the following features. That is, the fuel injection valve according to the first aspect of the present invention is a fuel injection valve that is formed of a magnetic material and is capable of opening and closing the fuel injection port by moving the fuel injection valve that injects fuel flowing from a fuel inlet through the fuel injection port. And a core that is formed of a magnetic material, has a fuel passage, and moves the movable body by electromagnetic force, and is formed of a material different from the core, and communicates with the fuel inlet and the fuel passage of the core. A passage component having a fuel passage.

According to the present invention, since the fuel passage of the core is connected to the fuel inlet through the passage member, the fuel passage of the core is connected to the fuel inlet directly as in the prior art. The length of the core can be shortened by the length of the passage constituting member. Therefore, by using an inexpensive material for the passage constituting member, the cost of the fuel injection valve can be reduced.

According to a second aspect of the present invention, in the fuel injection valve according to the first aspect, the passage constituting member is made of resin. Therefore, the cost of the fuel injection valve can be reduced, and the weight can be reduced.

According to a third aspect of the present invention, in the fuel injection valve according to the second aspect, the passage forming member is fitted to a resin case forming an outer wall of the fuel injection valve. Welded. For this reason, the connection structure of the passage constituting members is simplified, and the production efficiency of the fuel injection valve is improved.

According to a fourth aspect of the present invention, in the fuel injection valve according to the second aspect, the passage forming member is formed integrally with a resin case forming an outer wall of the fuel injection valve. . For this reason, the production efficiency of the fuel injection valve is further improved as compared with the case where the passage constituting member is produced alone.

According to a fifth aspect of the present invention, in the fuel injection valve according to the second, third, or fourth aspect, a resin strainer made of resin is welded to the passage constituting member. I have. That is, since the fuel strainer is fixed by welding, the structure is simpler than that of a conventional fuel strainer having a structure in which the fuel strainer is press-fitted into the core, and the cost can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fuel injection valve according to one embodiment of the present invention will be described below with reference to FIGS. The fuel injection valve according to the present embodiment is an electromagnetic fuel injection valve that injects pressurized fuel supplied from a fuel tank into an engine. FIG. 1 is a longitudinal sectional view of the fuel injection valve, and FIG. FIG. 1 is a view taken in the direction of arrows IIA and IIB-IIB. The fuel injection valve 10 has a substantially cylindrical body 11 at the tip. The body 11 is formed of a ferromagnetic material, and a valve seat 12 having a fuel injection port 12a is mounted inside the front part of the body 11.

A movable body 13 for opening and closing the fuel injection port 12a is accommodated in the inner space of the body 11 so as to be axially displaceable. The movable body 13 is composed of a hollow shaft-shaped armature 13a formed of a ferromagnetic material and a ball valve 13r attached to the tip of the armature 13a. I have. And the armature 13a
13d follows the inner wall surface of the body 11 and
The rear end face of the large diameter portion 13d is attracted to the front end face of the core 15 described later. Further, a pair of lateral holes 13k is formed in a side wall of the armature 13a, and the lateral holes 13k communicate the inside of the armature 13a with the internal space of the body 11.

Further, a ring 14 formed of a non-magnetic material is coaxially fixed to the rear end of the body 11. The ring body 14 has an inner diameter substantially equal to that of the body 11, and covers the rear part of the large-diameter cylindrical portion 13d of the armature 13a. Further, the ring body 14
The front end of the hollow shaft-shaped core 15 is housed in the rear half of the body, and is fixed by welding. That is, due to the function of the ring body 14 which is a non-magnetic material, the magnetic field of the solenoid coil 16 described later passes through the rear end face of the armature 13a and the front end face of the core 15 intensively.

The core 15 functions to attract the movable body 13 by electromagnetic force and is a member constituting a part of the fuel passage 15f. The core 15 is formed of a ferromagnetic material and has a hollow shaft shape. Further, a spring pin 18 is press-fitted into the center of the core 15, and the spring pin 1
Between the movable body 8 and the movable body 13 is mounted a spring 18b which is urged in a direction to separate the movable body 13 from the core 15, that is, to push the movable body 13 forward. As the material of the core 15, electromagnetic SUS or the like is preferably used.

A bobbin 16b made of an electrically insulating material such as a synthetic resin is mounted around the ring body 14 and the front half of the core 15. A solenoid coil 16 is wound around the bobbin 16b. Further, a terminal mounting portion 16t is provided at a rear end portion of the bobbin 16b, and a connection end portion 19s of the terminal 19 is press-fitted to the terminal mounting portion 16t.
The solenoid coil 16 is electrically connected to the connection end 19s of the terminal 19.

A magnetic path forming member 15r for forming a magnetic path of the solenoid coil 16 is attached to an outer peripheral portion of the solenoid coil 16. Further, a case 20 is formed by resin molding around the periphery from the rear half of the body 11 to the rear end of the core 15. A part of the case 20 surrounds the terminal 19, and that part functions as a connector 25. The connector 25 is connected to a power supply connector (not shown) of the electronic control unit.

In the case 20, the periphery of the rear end portion of the core 15 is formed into a tapered substantially cylindrical shape, and the portion is a convex portion 27 which fits into a passage constituting member 30 described later. . Further, a first seal ring 28 is mounted around the core 15 behind the projection 27. The passage forming member 30 is a hollow member made of resin that connects the fuel passage 15f of the core 15 to a delivery pipe (not shown), and has a length corresponding to the position of the delivery pipe and the mounting position of the fuel injection valve 10. Is set.

A fuel passage 32 is formed in the passage constituting member 30 in the axial direction, and a concave portion 34 is formed at the tip of the fuel passage 32 so as to be fitted with the convex portion 27 of the case 20. The concave portion 34 has a smaller diameter on the back side in accordance with the outer diameter of the convex portion 27 of the case 20, and the inner diameter of the deep portion is smaller than the outer diameter of the first seal ring 28. Therefore, when the convex portion 27 and the concave portion 34 are fitted, the first seal ring 28 seals the space between the fuel passage 15 f of the core 15 and the fuel passage 32 of the passage constituting member 30. Then, in a state where the two 27 and 34 are fitted, the passage constituting member 30 is ultrasonically welded to the case 20.

The rear end of the passage constituting member 30 is a portion connected to the delivery pipe, and an annular groove 36 is formed on the outer peripheral surface thereof. In addition, a second seal ring 38 that seals between the passage component 30 and the delivery pipe is mounted in the annular groove 36. The rear end face of the passage member 30 has a ring-shaped recess around the fuel passage 32, and a resin strainer 39 made of resin is set at the position of the recess 30k, and the fuel strainer 39 is attached to the passage member 30. It is ultrasonically welded (see FIG. 2).

Next, the operation of the fuel injector 10 will be briefly described. The pressurized fuel supplied from a fuel tank (not shown) via the delivery pipe is filtered by a fuel strainer 39, and then passes through the fuel passages 32 and 15f of the passage constituent member 30 and the core 15 to form a movable body. It is supplied from the inside of 13 to the internal space of body 11 via horizontal hole 13k. At this time, the ball valve 13r of the movable body 13 is pressed against the valve seat 12 by the elastic force of the spring 18b,
The fuel injection port 12a is closed. Therefore, no fuel is injected.

However, when an electric signal from the electronic control unit is input to the solenoid coil 16 and the solenoid coil 16 is excited, the movable body 13
It is attracted to the core 15 against the elastic force of 8b and retreats by a certain dimension. As a result, the fuel injection port 12a of the fuel injection valve 10 is opened, and the fuel in the body 11 is injected into the engine (not shown). Further, the electric signal is OF
When the excitation of the solenoid coil 16 is released in F, the movable body 13 moves forward by the spring force of the spring 18b, the fuel injection port 12a is closed by the ball valve 13r, and the fuel injection is stopped.

As described above, according to the fuel injection valve 10 according to the present embodiment, the fuel passages 15f and 32 are constituted by the core 15 and the passage constituting member 30, so that the
Compared to the case where the fuel passage is constituted only by the core,
Can be shortened. Here, an expensive electromagnetic SUS is generally used as a material of the core 15, and the passage constituting member 30 is used.
Since an inexpensive resin is used, the cost of the fuel injection valve 10 can be reduced by an amount corresponding to the shortening of the core 15. Further, the weight of the fuel injection valve 10 can be reduced. Furthermore, according to the fuel injection valve 10, since the resin fuel strainer 39 is attached to the resin passage constituting member 30 by welding, the fuel strainer 39 is press-fitted into the core as compared with the conventional method. The mounting structure of the fuel strainer can be simplified.

Further, in the present embodiment, the passage forming member 30 is manufactured separately from the case 20, and the recesses 34 of the passage forming member 30 are fitted to the protruding portions 27 of the case 20, and the two members 20, 30 are formed. Has been shown, but the passage constituting member 30 and the case 20 may be integrally formed. Further, the passage constituting member 30 can be made of inexpensive metal.

[0026]

According to the present invention, the cost of the fuel injection valve can be reduced because the expensive core can be made shorter than before.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a fuel injection valve according to one embodiment of the present invention.

FIG. 2 is a detailed view taken along the arrow IIA in FIG. 1 (FIG. A), and IIB-II in FIG.
FIG.

FIG. 3 is a longitudinal sectional view of a conventional fuel injection valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fuel injection valve 12a Fuel injection port 13 Movable body 15 Core 15f Fuel passage 30 Passage constituent member 32 Fuel passage 39 Fuel strainer

Claims (5)

[Claims] 1. A fuel injection valve for injecting fuel flowing through a fuel inlet through a fuel injection port, comprising: a movable body formed of a magnetic material, capable of opening and closing the fuel injection port by moving; A core having a fuel passage, the core moving the movable body by electromagnetic force, and a passage forming member formed of a material different from the core and having a fuel passage communicating with the fuel inlet and the fuel passage of the core. A fuel injection valve. 2. The fuel injection valve according to claim 1, wherein the passage forming member is made of resin. 3. The fuel injection valve according to claim 2, wherein the passage forming member is welded in a state of being fitted to a resin case constituting an outer wall of the fuel injection valve. 4. The fuel injection valve according to claim 2, wherein the passage forming member is integrally formed with a resin case constituting an outer wall of the fuel injection valve. 5. The fuel injection valve according to claim 2, wherein a resin strainer made of resin is welded to the passage constituting member.