JPH0996264A - Solenoid fuel injection valve and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve machining accuracy while complication of part shape can be eliminated, by inexpensively connecting two members constituting a fuel passage and magnetic passage in a seat carrier assembly, core, etc., in a solenoid fuel injection valve. SOLUTION: After a core 9 is press fitted to an armature guide 4, while applying irradiation of jaglaser from a direction diagonally about 30 deg. relating to a workpiece axial line, a workpiece is rotated, fillet welding of total peripheral seam is performed. Here, irradiation of the jaglaser may be applied from a single direction, and in order to improve deflection accuracy of the workpiece, irradiation may be applied from a plurality of directions, two directions or the like opposed 180 deg. in both sides of the workpiece.

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 internal combustion engine or the like.

[0002]

2. Description of the Related Art An electromagnetic fuel injection valve used in an internal combustion engine or the like is generally made of a magnetic material sheet that slidably holds an armature integrated with a needle valve or a pipe with a ball valve, and holds a valve seat at its tip. With a carrier, a non-magnetic material armature guide is joined to the sheet carrier, a magnetic material core whose inner diameter part constitutes the fuel passage is joined to the sheet carrier assembly at the armature guide part, and also on the outer periphery of the core. An electromagnetic coil is arranged. The sheet carrier and the armature guide form a sheet carrier assembly. The armature guide and the core form a core assembly.

By the way, the joining of the sheet carrier assembly and the core is generally performed by welding (Japanese Patent Publication No. Sho 5).
8-54263). This conventional joining method is as shown in FIG. 4, and after the core 9 is press-fitted into the armature guide 4 at the base end of the sheet carrier 3, the carbon dioxide gas laser (CO ₂ LASER) is irradiated from the horizontal direction to carry out the lap welding. I was going.

[0004]

The conventional method of joining the sheet carrier assembly and the core by irradiating the carbon dioxide laser requires energy of about 600 W, and both the initial cost and running cost of the welding machine are required. It was expensive. Further, since welding is performed with high energy, there is a problem that deterioration of accuracy of parts due to thermal strain cannot be avoided. There is also a problem that the shape of the parts is complicated, such as the need for grooves in the armature guide for lap welding.

The present invention has been made in view of the above problems, and is a low cost method for joining two members constituting a fuel passage and a magnetic passage such as a seat carrier assembly and a core in an electromagnetic fuel injection valve. In addition, it is an object of the present invention to reduce the complexity of the shape of parts and improve the processing accuracy.

[0006]

An electromagnetic fuel injection valve according to the present invention is one in which one of two members forming a fuel passage and a magnetic passage is press-fitted into the other and joined by fillet welding. For fillet welding, use YAG LASER (YAG LA
(SER) irradiation can be used for full-circle seam welding. In that case, the required energy is about 200 W, which is one-third that of carbon dioxide laser welding, and the influence of heat is reduced to prevent deterioration of component accuracy due to distortion. Becomes possible,
In addition, the initial cost and running cost of the welding machine can be reduced. Also, because it is fillet welding,
It is possible to eliminate the complexity of the shape of parts for lap welding, such as the need for the conventional groove of the armature guide.

Further, when one of the two members constituting the fuel passage and the magnetic passage of the electromagnetic fuel injection valve is press-fitted into the other and joined by welding, in order to improve the deflection accuracy of the work, one member is After press-fitting into the other member, for example, laser irradiation from two directions on both sides of the work, or 3
It is preferable to perform simultaneous laser irradiation from a plurality of opposing directions, such as irradiating laser from one direction, and perform seam welding around the entire circumference while rotating the work. When the laser is irradiated from one direction on one side, the phenomenon that the work (two members) is pulled toward the irradiation side and tilts occurs. It is possible to prevent distortion and deterioration of the shake accuracy.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall sectional view of an electromagnetic fuel injection valve according to the present invention, and FIG. 2 is a sectional view showing a joining structure and joining method between a seat carrier assembly and a core. This fuel injection valve is provided with a seat carrier 3 which holds a valve seat 2 forming an injection opening 1 so that the opening 1 is located at the center of the tip, and an armature guide 4 is integrally joined to the base end of the seat carrier 3. , A cylindrical armature 5 is arranged so as to be slidably held by the armature guide 4 and the sheet carrier 4, and the armature 5
Into, press-fit the pipe 7 with the slit 6 provided in a vertical split form,
A ball 8 is welded to the tip of the pipe 7. Then, the core 9 is arranged with one end facing the armature 5, and the core 9 and the sheet carrier 3 are attached to the bracket 10.
And a pipe-shaped adjuster 12 having slits 11 formed in a vertically divided shape is press-fitted inside the core 9, and a ball 8 closes the opening 1 of the valve seat 2 between the adjuster 12 and the pipe 7. A spring 13 for urging the pipe 7 in the direction is arranged. Further, an electromagnetic coil 14 capable of attracting the armature 5 in the direction in which the ball 8 opens the opening 1 of the valve seat 2 is arranged on the outer periphery of the core 9,
A connector mold 16 is provided so as to hold the terminal 15 connected to the electromagnetic coil 14, and the connector mold 16 covers almost the entire circumference of the injection valve excluding the tip portion of the sheet carrier 3. In this fuel injection valve, a drive pulse is applied to the electromagnetic coil 14 via the terminal 15. Then, the electromagnetic force generated drives the armature 5 in the opening direction against the urging force of the spring 12, and the pressurized fuel is supplied into the seat carrier 3 via the fuel passage formed by the inner diameter of the core 8. , Is ejected from the opening 1 at the tip of the valve seat 2. The armature guide 4 and the core 9 of the coil assembly form a fuel passage and a magnetic passage.

In the above fuel injection valve, the core 9 and the armature guide 4 are slanted with respect to the work axis about 3 degrees after the core 9 is press-fitted into the armature guide 4.
Work (core 9 and armature guide 4) while irradiating YAG LASER from the direction of 0 °
Rotate 360 ° + α to perform fillet welding of the entire circumference seam.

FIG. 3 is a sectional view showing another example of the joining structure and joining method of the sheet carrier assembly and the core.
In this example, after the core 9 and the armature guide 4 are press-fitted, by irradiating the laser from two directions on both sides of the work which are opposed to each other by 180 °, the deflection accuracy of the work is improved. The laser is, for example, a YAG laser, and irradiates from the direction of about 30 ° oblique to the work axis.
Then, the work is rotated 180 ° + α during laser irradiation,
After all, fillet welding of the entire circumference seam is performed. The laser also
Irradiation may be performed from three directions facing each other at 120 ° intervals, or irradiation may be performed from multiple directions. In that case, for example, in three-direction irradiation, the rotation of the work is 120 + α.
It is.

The above-described joining structure and joining method for the sheet carrier assembly and the core can be applied to joining other members.

[0013]

According to the present invention, the seat carrier assembly in the electromagnetic fuel injection valve and the core and other two members constituting the fuel passage and the magnetic passage are joined at a low cost, and the shape of the parts is complicated. It is possible to solve the problem and improve the processing accuracy.

By using a yag laser, welding can be performed with low energy, and accuracy deterioration due to thermal distortion of parts can be prevented.

Further, since the welding is of low energy, the initial cost and running cost of the welding machine can be reduced.

Further, since the fillet welding is employed, the groove of the armature guide as in the prior art is not required, and the complexity of the shape of parts for lap welding can be eliminated.

Further, by performing laser welding from a plurality of opposing directions such as two directions on both sides of the work, it is possible to prevent a phenomenon in which the work is pulled and tilted on one side, and the deflection accuracy of the work can be improved.

[Brief description of drawings]

FIG. 1 is an overall sectional view of an electromagnetic fuel injection valve according to the present invention.

2 is a cross-sectional view showing a joining structure and joining method of a seat carrier assembly and a core of the electromagnetic fuel injection valve of FIG.

FIG. 3 is a cross-sectional view showing another example of the joining structure and joining method of the sheet carrier assembly and the core.

FIG. 4 is a cross-sectional view showing a joining structure and joining method between a seat carrier assembly and a core of a conventional electromagnetic fuel injection valve.

[Explanation of symbols]

 3 Seat carrier 4 Armature guide 9 Core

Claims (4)

[Claims] 1. An electromagnetic fuel injection valve having a joint structure of two members forming a fuel passage and a magnetic passage,
An electromagnetic fuel injection valve in which one member is press-fitted into the other member and joined by fillet welding. 2. A method of manufacturing an electromagnetic fuel injection valve having a joint structure of two members constituting a fuel passage and a magnetic passage, wherein one member is press-fitted into the other member, and then both members are flesh-filled. A method for manufacturing an electromagnetic fuel injection valve, characterized by joining by welding. 3. The method for manufacturing an electromagnetic fuel injection valve according to claim 2, wherein the fillet welding is full-circle seam welding by means of YAG laser irradiation. 4. A method of manufacturing an electromagnetic fuel injection valve having a joint structure of two members constituting a fuel passage and a magnetic passage, wherein one member is press-fitted into the other member, and then the plurality of opposed members are pressed from opposite directions. A method for manufacturing an electromagnetic fuel injection valve, characterized in that both members are joined by full-circle seam welding by simultaneous laser irradiation.