JP3135757B2 - Electromagnetic fuel injection valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve mainly used for an electronic fuel injection device in a vehicle engine.

[0002]

2. Description of the Related Art A conventional example of an electromagnetic fuel injection valve will be described with reference to FIG. As shown in FIG. 5, the body 1 is made of a metal, for example, an electromagnetic SUS having magnetism. The body 1 is made of a magnetic material at the axis of the body 1 and has a hollow shape having a flange 2a on the outer periphery of the center. The core 2 is assembled from the rear of the body 1 (right side in FIG. 5). A bobbin 4 made of an electrically insulating material such as a synthetic resin and formed by winding a coil 5 in a multilayer shape is provided on the outer periphery of the first half of the core 2.

[0003] A power receiving connector 7 in which a terminal 6 electrically connected to the coil 5 is inserted is resin-molded on the outer periphery of the core 2. Specifically, the connector 7 is resin-molded with, for example, a polyamide resin so as to cover the joint between the body 1 and the core 2. The connector 7 is connected to a power supply connector of an electronic control unit (not shown), and the coil 5 is energized and released in response to an input from the electronic control unit.

A valve seat 8 having a fuel injection port 9 is provided in the front part (left part of FIG. 5) of the body 1 with an adapter 1.
Included with 0. A valve 12 is incorporated in the axial center of the valve seat 8 so as to be slidable in the axial direction. In addition, a stopper plate 11 for regulating a retreat position of the valve 12 is inserted into the body 1 prior to the valve seat 8. An armature 13 made of a magnetic material is fixed to a rear end of the valve 12. The armature 13 receives an attractive force from the core 2 when the coil 5 is energized.

A pipe 14 is press-fitted and fixed in the core 2. A valve spring 15 is incorporated between the pipe 14 and the valve 12. Valve 12
The fuel injection port 9 of the valve seat 8 is normally kept closed by the elasticity of the valve spring 15.
A fuel passage 16 is formed between the rear end of the core 2 (the right end in FIG. 5) and the fuel injection port 9 of the valve seat 8, and the fuel passage 16 is located behind the core 2 corresponding to the inlet of the fuel passage 16. A strainer 17 is incorporated in the end. At the rear end of the core 2 is fitted a grommet 18 that functions as a buffer between the connector 7 and a delivery pipe (not shown).

The operation of the thus-configured electromagnetic fuel injection valve will be briefly described. The fuel supplied under a predetermined pressure from a fuel tank (not shown) is filtered by a strainer 17 and then filtered. The fuel passage 16 extends to the inside of the valve seat 8. However,
Since the valve 12 is held in a state where the fuel injection port 9 of the valve seat 8 is closed by the elasticity of the valve spring 15, fuel injection from this injection port 9 does not occur. Here, when the coil 5 is energized by the input of an electric signal from the electronic control unit, the armature 13 is retracted together with the valve 12 by the attraction force of the core 2 as described above. As a result, the valve 12 opens the fuel injection port 9 of the valve seat 8, from which fuel is injected. And
When the electric signal to the coil 5 is turned off and the suction force of the core 2 acting on the armature 13 is released, the valve 12 is kept closed with the fuel injection port 9 again by the elasticity of the valve spring 15, The fuel injection from the injection port 9 stops.

[0007] An outline of the assembly of the electromagnetic fuel injection valve will be described. Assembling parts such as a valve 12, a valve seat 8 and an adapter 10 are assembled at a front portion of the body 1.
A bobbin 4 around which a coil 5 is wound is attached to the rear of the body 1 together with the core 2 inserted therein, and a power receiving connector 7 into which the terminal 6 of the coil 5 is inserted is formed by resin molding. The power receiving connector 7 is illustrated in FIG. In the figure, (a)
Is a sectional view, and (b) is a perspective view. 6, a flat surface 70 is formed at the front of a cylindrical portion surrounding the terminal 6 of the connector 7, and a stepped recess 7 is formed at the lower end thereof.
0b is formed, and a corner 70a is formed around a plane excluding the recess 70b. It is considered that the flat surface 70 is a flat surface because of ease of manufacturing a resin mold. An electromagnetic fuel injection valve provided with a connector having a flat surface is disclosed in, for example, Japanese Patent Application Laid-Open No. 63-36060.

[0008]

According to the conventional electromagnetic fuel injection valve, the concave portion 70b is formed at the lower end of the flat surface 70 of the connector 7 so that the peripheral portion of the concave portion has a square pin shape, and the rigidity is low. Since the upper edge of the corner 70a also has a pin square shape, the rigidity is weak,
Vibration is likely to occur at the corner 70a of the plane 70, and it is expected that the operating noise will increase. Also the plane 70
When the vibration wave propagates through this part, this part (plane 70)
It is also expected that operating noise due to vibration will be generated from the vibration.
Since this operation noise includes harsh high-frequency sounds,
The improvement is demanded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electromagnetic fuel injection valve capable of reducing operating noise due to a flat corner of a power receiving connector. Is to do.

[0010]

According to the present invention, there is provided an electromagnetic fuel injection valve having a power receiving connector formed by resin molding by inserting a terminal of a coil, wherein the outer shape of the connector is continuous by a curved surface. The planes forming the corners and the recesses are excluded from the outer shape.

[0011]

According to the above-mentioned means, the plane which causes vibration of the conventional power receiving connector is eliminated from the outer shape of the connector.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. 1 showing a sectional view of a fuel injection valve and FIG. 2 showing a main part thereof. FIG. 2 shows a power receiving connector.
(A) is a sectional view, and (b) is a perspective view. In this example,
Since a part of the conventional example is modified, the modified part will be described in detail, and the same parts as those of the conventional example will be denoted by the same reference numerals in the drawings, without redundant description. In the following and subsequent embodiments, the same description will not be repeated. As shown in FIGS. 1 and 2, in the power receiving connector 7,
Its outer shape is continued by a curved surface. That is, in the connector 7 of the present example, the flat surface 70 forming the front corner 70a and the concave portion 70b of the cylindrical portion surrounding the terminal 6 in the conventional example (see FIG. 6) is excluded from the outer shape of the connector 7. It has a convex curved surface 7a in which the corner 70a is chamfered, a concave curved surface 7b in which the concave portion 70b is rounded, and a curved surface 7c connecting the curved surfaces 77a and 7b. As shown in the cross-sectional view of FIG. 3, a power supply connector 19 is connected to the power receiving connector 7 of the fuel injection valve.
The connection of the power supply connector 19 does not cause any trouble even if the connection is made by the steps a to 7c.

According to the electromagnetic fuel injection valve, since the plane causing the vibration of the conventional power receiving connector does not exist on the outer shape of the connector 7, the operation which has conventionally occurred at the corner of the plane is not performed. Noise will be reduced. FIG. 4 is a characteristic diagram showing the relationship between the frequency of the fuel injection valve and the sound pressure level. The horizontal axis in the drawing indicates the frequency, the vertical axis indicates the sound pressure level, the solid line in the figure indicates the frequency characteristics of the product of the present embodiment, and the dotted line indicates the conventional product (see FIG. 5). ) Is the frequency characteristic. The measurement conditions were as follows: the drive voltage of the fuel injection valve was 14 V;
The opening and closing frequency of the valve 12 is 12.5 Hz, and the measurement distance is about 3 mm from the flat portion of the connector or a curved portion corresponding to the flat portion. As is clear from FIG. 4, according to the product of the present embodiment, a significant reduction in noise was observed in a sound range of approximately 4 kHz or more including a harsh high-frequency sound range as compared with the conventional product.

[0014]

According to the present invention, since there is no flat surface on the outer shape of the power receiving connector as compared with the conventional one, the operation noise which has been conventionally generated due to the vibration of the corner of the flat surface is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an electromagnetic fuel injection valve of an embodiment.

FIG. 2 is an explanatory view showing a connector part of FIG. 1;

FIG. 3 is a cross-sectional view showing a connection state of a power supply connector.

FIG. 4 is a characteristic diagram showing a relationship between a frequency of an electromagnetic fuel injection valve and a sound pressure level.

FIG. 5 is a sectional view showing a conventional example.

FIG. 6 is an explanatory view showing a connector part of FIG. 5;

[Explanation of symbols]

 5 Coil 6 Terminal 7 Power receiving connector 7a, 7b, 7c Curved surface

Claims (1)

(57) [Claims] 1. An electromagnetic fuel injection valve having a power receiving connector formed by resin molding by inserting a terminal of a coil, wherein an outer shape of the connector is continuous by a curved surface, and a plane forming a corner portion and a concave portion from the outer shape. Electromagnetic fuel injectors that have been eliminated.