JPS61265351A - Solenoid-operated fuel injection valve - Google Patents

Abstract

PURPOSE:To make reduction in the number of parts items and work processes and improvement in fixed positioning accuracy for a yoke and a core promotable, by locking the yoke and the core tight by means of plastic flow bonding. CONSTITUTION:A solenoid-operated fuel injection valve 1 consisting of an orifice 2, a turning force generating part 3, a valve guide 4, a ball valve, a plunger 6, an exciting coil 8, a core 9 and a yoke 7 installs a groove 31 in a cylindrical part of the core 9, locally pressurizing an end part 30 of the yoke 7 lower in hardness than the core 9 with a metal mold, and the yoke 7 is made into plastic flowing, making it bite into the groove 31 of the core 9, and they are coupled together. Thus, an O-ring being so far interposed between the yoke 7 and the core 9 is eliminable so that it will do that only the O-ring of a terminal part is attached, therefore the number of parts items becomes reduced and, what is more, positioning accuracy at the time of assembling is also improved.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to an electromagnetic fuel injection valve.

[Background of the invention]

As described in Japanese Patent Publication No. 58-54263, conventional devices include a sleeve inside the bobbin to prevent leakage from the joint between the fuel supply socket and the yoke or the joint between the nozzle body casing and the yoke. is provided, and both ends are welded to the connection casing of the fuel supply socket and the nozzle body, respectively.

However, there are concerns about deformation due to welding and the effect on magnetic flux.

Further, no consideration was given to workability during mass production.

[Purpose of the invention]

An object of the present invention is to provide an electromagnetic fuel injection valve that is inexpensive and has excellent productivity by utilizing plastic flow coupling.

[Summary of the invention]

The present invention relates to an electromagnetic fuel injection valve whose main components include an excitation coil, a magnetic yoke, a core, a valve guide, and a plunger rod. In order to prevent fuel leakage from the crimped part, OIJ songs were used on the inner and outer circumferences of the bobbin, but by using plastic flow bonding, leakage from the crimped part was eliminated and one O-ring could be omitted. This made it possible to reduce costs and improve productivity.

[Embodiments of the invention]

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

First, FIG. 3 is a cross-sectional structural diagram of the electromagnetic fuel injection valve 1. As shown in FIG. A core 9 including an orifice 2 and a turning force generating member 3, a yoke 7, a plunger 6 forming a magnetic circuit with the core 9, a ball valve 5, and a rod that connects and fixes the plunger 6 to form a movable part. 10. It has a seat surface 11 for seating fuel therein and a guide surface 12 for guiding the rod 10 at two places, and a plurality of fuel passages 13 are provided downstream of the seat surface 11, with the fuel passage 13 being the geometric center. A turning force generating member 3 provided eccentrically relative to the valve guide 4 fixedly equipped with an orifice 2 for metering the fuel to which the turning force is applied and uniformizing the spray using a metal flow, determines the stroke of the movable part. A stop bar 14 to press the seat surface 11Vc, a spring 15 to press the ball valve 5, and a spring 15 to adjust the spring force of the spring 15 by
It is composed of an adjuster 16 that is movably provided inside, a twin connector 1f that divides the inflow and outflow of fuel, and the like.

The fuel is pressurized by a fuel pump, passes through a pressure pulsation absorber and a fuel filter, and is then pressure regulated by a regulator and supplied to the electromagnetic fuel injection valve IK.

FIG. 4 shows a conventional state in which the yoke 7 and core 9 are fixed. Conventionally, the yoke 7 and the core 9 are fixed by bending the end 21 of the yoke 7 inward over the entire circumference so as to wrap around the core 9. A caulking method is adopted to prevent fuel from leaking from the gap between the yoke 7 and the core and from the terminals.
IJ songs 0 and 22 are used.

FIG. 1 shows the state of identification of the yoke 7 and the core 9 using the present invention. In the metal flow joining method, a groove 31 is carved in the cylindrical part of the core, and the yoke 7 has a lower hardness than the core 9. The end portion 3o of the entire mold is locally pressurized to cause the yoke 7 to flow laminarly, bite into the groove of the core 9, and join together.

According to this embodiment, the O-ring for security purposes interposed between the yoke 7 and the core 9 can be removed, and only the O-ring for preventing leakage from the terminal portion needs to be attached, thereby reducing the number of parts. This can reduce costs. It also improves positioning accuracy during coupling.

The circumferential VC groove is formed by locally pressurizing and bonding the core 940.

In addition, Fig. 2 (to) shows that the coupling shown in Fig. 1 has been further modified to improve the airtightness of the gap between the yoke and the core.
A metal 43, which has lower hardness than the yoke and core and has excellent corrosion resistance, is put into an annular gap 42 provided between the yoke and the core and pressurized to form grooves 44 on the inner circumferential surface of the yoke and the outer circumferential surface of the core, respectively. .45 to be bonded by plastic flow.

〔Effect of the invention〕

According to the present invention, it is effective to reduce the number of parts and the number of manufacturing steps of an electromagnetic fuel injection valve, improve the fixing positioning accuracy of the yoke and core, and reduce the size of the electromagnetic fuel injection valve.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of one embodiment of the present invention, Figure 3 is a vertical cross-sectional view of an injector, and Figure 4 is a vertical cross-sectional view of a conventional method of fixing a yoke and a core. be. Figure 1'V 30

Claims (1)

[Claims] 1. A magnetic circuit is constituted by a yoke surrounding the excitation coil, a core located at the center of the excitation coil and having one end fixed to the yoke, and a plunger coaxially with the yoke and core and capable of reciprocating movement. The fuel passes through the center of the core, passes through the gap between the valve guide and the plunger rod, and is guided to the seat section.In an electromagnetic fuel injection valve, the measured amount of fuel is supplied to the internal combustion engine by the movement of the plunger rod. An electromagnetic fuel injection valve characterized by being fixed by coupling.