JPH05164017A - Electromagnetic type fuel injection valve - Google Patents

Abstract

PURPOSE:To reduce production costs and lighten a valve by simplifying the shapes of the housing and core of an electromagnetic type fuel injection valve and molding process. CONSTITUTION:A housing 6 holding the valve assembly 5 of an electromagnetic fuel injection valve 1 and core 7 are jointed to each other by two magnetic plate materials 15 spacedly arranged in the peripheral direction. Coil assemblies 10 are arranged inside the plate materials 15, and a non-magnetic member 16 is secured between the endfaces of a coil bobbin 8 and housing 6, and an O-ring is secured at the end of the side of the housing 6 whose non-magnetic member 16 has a step. During the mold of a connector mold section 13a, a coil external peripheral mold section 13b covering all over the external periphery of the coil assembly 10 and a housing external periphery mold section 13c covering the external periphery of the housing 6 to the midway of it in the axial direction are formed of the same resin in a body.

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 used in an electronically controlled fuel injection type internal combustion engine.

[0002]

2. Description of the Related Art As an electromagnetic fuel injection valve used in an electronically controlled fuel injection type internal combustion engine, one having a structure as shown in FIG. 5 is conventionally known. This conventional electromagnetic fuel injection valve 1 controls the injection amount of fuel by the pulse width of a drive pulse applied to an electromagnetic coil. A valve assembly 5 is constituted by a needle 4 slidably mounted inside the valve body 3 so as to open and close. Further, a housing 6 for holding the valve assembly 5 at one end is provided, and a collar portion of a core 7 arranged to face the needle 4 is fixed to the other end side of the housing 6 by caulking. An annular space is formed inside the housing 6 between the core 7 and the core 7. In the annular space, a coil bobbin 8 mounted on the core 7 is provided with an electromagnetic coil 9.
A coil assembly 10 formed by winding is disposed.
An outer mold 11 made of resin is formed so as to cover the outer circumference of the coil assembly 10. Also,
The terminal 12 connected to the electromagnetic coil 9 is held by a connector mold 13 made of resin. A spring 14 for biasing the needle 4 in the closing direction is held at the tip of the core 7. In such a configuration, when a drive pulse is applied to the electromagnetic coil 1 via the terminal 11, the needle 4 is driven in the opening direction against the biasing force of the spring 14.

Further, in the electromagnetic fuel injection valve described in Japanese Utility Model Publication No. 3-32781, the entire outer peripheral surface of the housing is integrally mold-coated with the same resin material as that of the connector portion to improve the soundproofing property and the heat insulating property. I am trying.

[0004]

In the conventional electromagnetic fuel injection valve constructed as described above, the housing and the core are particularly complicated in shape, and they are processed with high precision by cold forging or shaving and assembled. Since it is necessary, there is a problem that the manufacturing cost is unavoidably increased and the weight is unavoidably increased. In addition, a separate step of forming an outer mold so as to cover the outer circumference of the coil assembly is required, which also contributes to the high cost.

Even if the mold for the outer peripheral surface of the housing is integrally molded with the same resin material as the connector portion as described in Japanese Utility Model Publication No. 3-32781, the coil exterior mold is still formed. A separate process is required.

The present invention has been made to solve the above-mentioned problems, and achieves a reduction in manufacturing cost and a reduction in weight by simplifying the shapes of the housing and core of the electromagnetic fuel injection valve and the molding process. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION In an electromagnetic fuel injection valve according to the present invention, a plurality of magnetic plate members are arranged on the outer circumference of a coil assembly, the plate member joins a housing and a core, and an outer peripheral surface of the coil assembly is formed. In addition, a mold part made of the same resin is integrally formed with the connector mold part.

[0008]

In the present invention, the housing and the core are connected to each other by a plurality of simple-shaped magnetic plate members, and
The mold part on the outer periphery of the coil assembly also encloses a plurality of plate materials and is molded integrally with the connector mold part by the same resin simultaneously. Therefore, the housing does not need a part that covers the coil assembly, and has a simple and compact shape only for the part that holds the valve assembly, and the core does not need a collar part, which is also a simple and compact shape. In addition, the manufacturing cost is reduced in terms of workability and assembling, and the weight is reduced. In addition, the molding process is simplified, which also reduces the cost.

[0009]

1 is a sectional view showing a first embodiment of an electromagnetic fuel injection valve according to the present invention (cross section AA in FIG. 2), and FIG. 2 shows this electromagnetic fuel injection valve in the direction of arrow B in FIG. FIG. 3 is a perspective view for explaining a partial structure of this electromagnetic fuel injection valve. In the figure, the same or corresponding parts as those of FIG. 5 according to the conventional device are designated by the same reference numerals.

In this embodiment, the electromagnetic fuel injection valve 1
The valve assembly 5 is composed of a valve body 3 having an opening 2 at the center of the tip and a needle 4 slidably mounted inside the valve body 3 so as to open and close the opening 2. Further, a housing 6 for holding the valve assembly 5 is provided, and a core 7 is arranged on the other end side of the housing 6 so as to face the needle 4, and the housing 6 and the core 7 are arranged in a circumferential direction. Two magnetic plate members 15 arranged with a gap therebetween are coupled to each other.
Both ends of each plate member 15 are joined to the outer peripheral surfaces of the housing 6 and the core 7 by spot welding or the like.

Further, a gap is formed between the core 7 and the inside of the plate member 15 connecting the housing 6 and the core 7, and in this gap, the coil bobbin 8 which is externally mounted on the core 7 is formed.
A coil assembly 10 formed by winding an electromagnetic coil 9 therein is arranged, and a non-magnetic member 16 is mounted between the coil bobbin 8 and the end surface of the housing 6.

An O-ring 17 is attached to the stepped housing 6 side end of the non-magnetic member 16, and the coil assembly side end has a stepped coil bobbin 8 inner peripheral surface and a core. It is fitted in an annular gap with 7. A spring 14 for biasing the needle 4 in the closing direction is held at the tip of the core 7. Then, the connector mold portion 13a for holding the terminal 12 connected to the electromagnetic coil 9 is formed by resin molding, and at the same time when the connector mold portion 13a is molded, the entire outer peripheral surface of the coil assembly 10 is made of the same resin. A coil outer peripheral mold part 13b and a housing outer peripheral mold part 13c that covers the outer periphery of the housing 6 partway in the axial direction are molded, and these are integrated into a mold 13.

According to the configuration of this embodiment, the housing 6
Has a simple shape that only holds the valve assembly 5, and has a simple shape with no core 7 flanks, and both are compact and lightweight members. Moreover, each mold part 3a-
Since 3c can be integrally formed of the same resin, the number of steps is reduced.

FIG. 4 is a sectional view showing a second embodiment of the electromagnetic fuel injection valve according to the present invention. The second embodiment corresponds to a modification of the seal structure between the end surface of the housing 6 and the end surface of the non-magnetic member 16 in order to further reduce the weight, based on the first embodiment. That is, in this embodiment, the abutting portions of the housing 6 and the non-magnetic member 16 are formed in a stepped shape so that the non-magnetic member 16 side is inside and overlapped, and the O-ring is removed to overlap. The diameter of the portion is made small and the axial dimension of the overlapping portion is made large, thereby facilitating weight reduction. The structure and operation of the other parts of this embodiment are not different from those of the first embodiment. In the drawings, common or corresponding parts are designated by the same reference numerals.

In the above embodiment, the housing and the core are connected by the two magnetic plate members, but the number of the magnetic plate members can be changed appropriately.

[0016]

As described above, according to the present invention, it is possible to simplify the shapes of the housing and the core of the electromagnetic fuel injection device, and reduce the manufacturing cost and the weight. Further, by integrally forming the coil exterior mold with the connector mold, the number of steps can be reduced and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an electromagnetic fuel injection valve according to the present invention (cross-section AA in FIG. 2).

FIG. 2 is a view showing the first embodiment of the electromagnetic fuel injection valve according to the present invention, as viewed from the direction of arrow B in FIG.

FIG. 3 is a perspective view illustrating a partial structure of the first embodiment of the electromagnetic fuel injection valve according to the present invention.

FIG. 4 is a sectional view showing a second embodiment of the electromagnetic fuel injection valve according to the present invention.

FIG. 5 is a sectional view showing a conventional electromagnetic fuel injection valve.

[Explanation of symbols]

 1 Electromagnetic Fuel Injection Valve 2 Opening 3 Valve Body 4 Needle 5 Valve Assembly 6 Housing 7 Core 8 Coil Bobbin 9 Electromagnetic Coil 10 Coil Assembly 13 Mold 13a Connector Mold 13b Coil Exterior Mold 14 Spring 15 Magnetic Plate Material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Kasue 313 Takada, Odawara, Kanagawa Japan Injector Co., Ltd.

Claims (1)

[Claims] 1. A valve assembly in which a needle is slidably mounted to open and close an opening at the tip of the valve body, a housing holding the valve assembly at one end side, and the other end of the housing. Between the core and the needle, a core that is coupled to the side and is arranged to face the needle, a coil assembly formed by winding an electromagnetic coil around a coil bobbin that is packaged on the core, a resin-molded connector mold part, and the core and the needle. In an electromagnetic fuel injection valve equipped with a spring for urging the needle in a closing direction, a plurality of magnetic plate members are arranged on the outer circumference of the coil assembly, and the housing and the core are coupled by the plate members. At the same time, a mold part made of the same resin is integrally formed on the outer peripheral surface of the coil assembly with the connector mold part. An electromagnetic fuel injection valve characterized in that