JPH1073060A - Fuel injection valve for in-cylinder injection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a bobbin from deforming largely, prevent burning-damage of the bobbin from generating if short circuit of the coil is generated and then a temperature is raised, and hold an O-ring of a seal surface in a normal sealing condition by forming the bobbin around which the coil is wound of thermosetting resin. SOLUTION: A fuel injection valve 1 for in-cylinder injection is provided with a housing 2 and a valve device 3, a core 7 is installed on one end of the housing 2, and a coil ASSY 8 is arranged around the core 7. When current is carried to the coil 9 of the coil ASSY 8, an armature 19 is attracted to a core 7 side, and high pressure fuel is splayed from the top end outlet of an injection hole 15. In this case, the bobbin 10 of the coil 9 is formed of thermosetting resin, and thereby, large deformation and burning-damage of bobbin 10 are prevented even if short circuit of the coil 9 is generated and a temperature is raised. Since a normal sealing condition is held for the O-rings 11a, 11b of a seal surface, fuel leakage is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder fuel injection valve mounted on a cylinder head for directly injecting fuel into a combustion chamber of an internal combustion engine.

[0002]

2. Description of the Related Art FIG. 5 is a side sectional view showing a conventional MPI fuel injection valve. The general structure of an MPI fuel injection valve is an injection valve body having a needle valve and a valve for operating the needle valve. Are combined. In the drawing, a housing 32 is provided at one end of a core 31.
The coil winding bobbin 34 constituting the coil ASSY 33 is usually made of nylon 6 containing glass.
6. O-rings 35a and 35a are provided between the bobbin 34 and the core 31 and the housing 32, respectively.
5b is mounted to seal the fuel to the outside. A needle valve 37 movable in the axial direction is provided in the valve device 36.

[0003]

The in-cylinder fuel injection valve needs to have improved responsiveness functionally as compared with the MPI fuel injection valve. Therefore, reduce the resistance of the coil,
High responsiveness is obtained by passing overexcitation current. However, if the configuration of the coil section is the same as that of the MPI fuel injection valve, if a malfunction such as direct connection of the battery power occurs, an excessive current is supplied to the coil, the coil generates heat, and the coil is short-circuited and disconnected. Would. The bobbin also burns, deforms, etc.
There is a problem that the seal by the ring may be incomplete.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Even if the coil is short-circuited and the temperature rises, the bobbin will not be greatly deformed or burnt, and the sealing surface will not be damaged. The object of the present invention is to provide an in-cylinder fuel injection valve which does not have a fear of fuel leakage since the O-ring normally achieves sealing.

[0005]

According to a first aspect of the present invention, there is provided an in-cylinder fuel injection valve in which a bobbin around which a coil is wound is made of a thermosetting resin.

According to a second aspect of the present invention, there is provided a fuel injection valve for in-cylinder injection, wherein a bobbin around which a coil is wound is made of a phenol resin.

According to a third aspect of the present invention, there is provided an in-cylinder fuel injection valve in which an exterior mold surrounding the bobbin is made of the same material as the bobbin.

According to a fourth aspect of the present invention, there is provided a fuel injection valve for in-cylinder injection, wherein an outer mold surrounding a bobbin is provided with a press-fit portion with a core, and the outer mold is made of nylon 66.
It consists of.

According to a fifth aspect of the present invention, there is provided an in-cylinder fuel injection valve including a spacer having a claw formed between a bobbin and a housing, and the spacer being formed of nylon 66 or glass. It is composed of nylon 66.

According to a seventh aspect of the present invention, there is provided the fuel injection valve for in-cylinder injection, wherein a claw formed on the spacer is provided on the bobbin side.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a side sectional view of an in-cylinder fuel injection valve 1 according to an embodiment of the present invention. The in-cylinder fuel injection valve 1 includes a housing 2 and a valve device 3 supported at one end of the housing 2 by a coupling means such as caulking. A fuel supply pipe 4 is connected to the other end of the housing 2. Have been. The tip of the in-cylinder fuel injection valve 1 is inserted into an injection valve insertion hole 6 of a cylinder head 5 of the internal combustion engine, and is sealed and mounted. A core 7 is attached to one end of the housing 2, and a coil ASSY 8 is disposed around the core 7. A winding bobbin 10 of a coil 9 constituting the coil ASSY 8 is made of a thermosetting resin such as phenol. It is formed of resin. O-rings 11a and 11b are mounted between the bobbin 10 and the core 7 and between the bobbin 10 and the housing 2, respectively, to seal the fuel to the outside.

The valve device 3 has a stepped hollow cylindrical valve body 14 having a small-diameter cylindrical portion 12 and a large-diameter cylindrical portion 13, and a fuel injection hole 15 fixed in the valve main body 14 at the tip of a center hole. A valve seat 16, a needle valve 17 which is a valve body which opens and closes the fuel injection hole 15 by being separated from and brought into contact with the valve seat 16 by a solenoid device, and which guides the needle valve 17 in the axial direction, and radially inwards the valve seat And a revolving body 18 for imparting a revolving motion to the fuel to flow into the 16 fuel injection holes 15. The amateur 19 is formed integrally with the needle valve 17.

Next, the operation will be described. When the coil 9 is energized, a magnetic flux is generated in a magnetic path formed by the armature 19, the core 7, and the housing 2, and the armature 19 is attracted to the core 7 side, and the needle valve 17 having an integral structure with the armature 19 is a valve seat. A high pressure fuel is formed from the needle valve 17 through the revolving body 18 to form a swirling flow, and forms a swirling flow.
It enters inside and is sprayed from its tip outlet.

In the present embodiment, as described above, since the bobbin 10 is made of a thermosetting resin such as a phenol resin, the bobbin 10 is largely deformed even if the coil 9 is short-circuited and the temperature rises. The O-rings 11a and 11b on the sealing surface normally achieve the sealing without any drip or breakage, so that there is no fear of fuel leakage.

Embodiment 2 In the first embodiment,
The case where the bobbin 10 is formed of a thermosetting resin such as a phenolic resin is shown. After the coil is wound, the outside thereof is covered with an exterior mold 20.
It can be formed of a thermosetting resin such as a phenol resin. Thus, the bobbin 10 and the exterior mold 2
Constituting 0 with the same material has an effect of obtaining a product having excellent adhesion between the bobbin 10 and the exterior mold 20.

Embodiment 3 FIG. 2 is a side sectional view showing a fuel injection valve for in-cylinder injection according to a third embodiment. In the figure, a bobbin 10 is formed of a thermosetting resin such as a phenol resin, and an exterior mold 20 is made of nylon 66.
And the press-fit portion 21 is also made of nylon 66. This is because when the bobbin 10 is formed of a phenolic resin, it is harder than heat and is harder. When the press-fit portion 21 is made of nylon 66, there is an effect that the assembly of the coil ASSY 8 and the core 7 becomes easy.

Embodiment 4 FIG. 3 is a side sectional view showing a fuel injection valve for in-cylinder injection according to a fourth embodiment, and FIG. 4 is a partially enlarged side sectional view showing a bobbin portion. In addition to providing a spacer 22 between the bobbin 10 and the housing 2,
The spacer 22 is provided with an axial dimension adjusting claw 22a, and the spacer 22 is made of nylon 66 or glass-filled nylon 66. With this configuration, the claw 22a of the spacer 22 made of nylon 66 is more easily crushed than the bobbin 10, so that the dimensional adjustment becomes easier. Also, as shown in the figure, the dimension adjusting claw 22a is provided on the bobbin 10 side instead of the amateur 19 side, so that even if the claw 22a is broken and separated, it is difficult for the claw 22a to flow out to the movable component side (air gap 23 side). Become.

[0018]

According to the in-cylinder fuel injection valve according to the first aspect of the present invention, since the bobbin around which the coil is wound is made of a thermosetting resin, the coil is short-circuited and the temperature rises. However, the bobbin is not significantly deformed or burnt out, and the O-ring on the sealing surface normally seals, so that there is no fear of fuel leakage.

According to the in-cylinder fuel injection valve according to the second aspect of the present invention, the bobbin around which the coil is wound is made of phenol resin. Since the O-ring on the sealing surface achieves normal sealing without significant deformation or burning, there is no fear of fuel leakage.

According to the in-cylinder fuel injection valve according to the third aspect of the present invention, since the exterior mold surrounding the bobbin is made of the same material as the bobbin, the in-cylinder fuel injection valve having excellent adhesion can be obtained. Obtainable.

According to the fuel injection valve for in-cylinder injection according to a fourth aspect of the present invention, the press-fitting portion with the core is provided in the outer mold surrounding the bobbin, and the outer mold is made of nylon 66. And the core can be easily assembled.

According to the in-cylinder fuel injection valve according to the fifth or sixth aspect of the present invention, a spacer having a claw formed between the bobbin and the housing is provided, and the spacer is formed of nylon 66 or glass. Since the nail is made of nylon 66, the nail is more easily crushed than the bobbin, and the dimensional adjustment is easier.

According to the in-cylinder fuel injection valve according to the seventh aspect of the present invention, the claw formed on the spacer is provided on the bobbin side, so that even if the claw is broken and separated, it is provided on the movable part side. It becomes difficult to flow out.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an in-cylinder fuel injection valve according to Embodiment 1 of the present invention;

FIG. 2 is a side sectional view showing an in-cylinder fuel injection valve according to Embodiment 3 of the present invention;

FIG. 3 is a side sectional view showing a direct injection fuel injection valve according to Embodiment 4 of the present invention;

FIG. 4 is a partially enlarged side sectional view showing a bobbin portion of a direct injection fuel injection valve according to Embodiment 4 of the present invention;

FIG. 5 is a side sectional view showing a conventional in-cylinder fuel injection valve.

[Explanation of symbols]

1 In-cylinder fuel injection valve, 2 housing, 7 core, 9 coil, 10 bobbin, 14 valve body, 15 injection hole, 16 valve seat, 17 valve body, 20 exterior mold,
21 Press-fit part, 22 Spacer, 22a Claw.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location F02M 51/06 F02M 51/06 Z (72) Inventor Kensuke Imada 6-chome Hamayama-dori, Hyogo-ku, Kobe-shi, Hyogo Prefecture No. 1-2 Mitsubishi Electric Control Software Co., Ltd. (72) Inventor Masayuki Aoda 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (7)

[Claims] 1. A hollow cylindrical valve body, a valve seat provided at one end of the valve body and having a fluid injection hole in the center, and a valve body which is separated from and connected to the valve seat to open and close the injection hole. A hollow housing coupled at one end to the valve body, a core coupled to the other end of the housing to form a magnetic circuit with the housing, a bobbin arranged around the core, and a bobbin wound around the core. An in-cylinder fuel injection valve provided with a turned coil, wherein the bobbin is made of a thermosetting resin. 2. The in-cylinder fuel injection valve according to claim 1, wherein a phenol resin is used as the thermosetting resin. 3. The in-cylinder fuel injection valve according to claim 1, wherein an exterior mold surrounding the bobbin is made of the same material as the bobbin. 4. The outer mold surrounding the bobbin is provided with a press-fit portion for a core, and the outer mold is made of nylon 66.
The fuel injection valve for in-cylinder injection according to the above. 5. The device according to claim 1, wherein a spacer having a claw is provided between the bobbin and the housing, and the spacer is made of nylon 66.
The fuel injection valve for in-cylinder injection according to any one of the above. 6. The apparatus according to claim 1, wherein a spacer having a claw is provided between the bobbin and the housing, and the spacer is made of glass-filled nylon 66.
The in-cylinder fuel injection valve according to any one of claims 1 to 4. 7. The in-cylinder fuel injection valve according to claim 5, wherein a claw formed on the spacer is provided on the bobbin side.