JPS6185567A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To enhance productivity and reliability, by fitting an internal-toothed washer on a terminal. CONSTITUTION:After a bobbin 11 is inserted into an assembly of a yoke 2 and a core 20, an O-ring 15 for fuel sealing and a terminal guide 16 are fitted on a terminal 17. An internal-toothed washer 23 is then fitted on the terminal 17 to secure the bobbin 11 integrally coupled to the terminal 17. The inside diameter phid2 of the washer 23 and the outside diameter phid1 of the terminal are related to each other as phid2<phid1, and the washer 23 can be elastically deformed. For that reason, the washer 23 can be relatively easily fitted on the terminal 17, but cannot be easily pulled out from the terminal in the direc tion of pulling-out of the bobbin 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electromagnetic fuel injection valve, and particularly to one having a structure suitable for identifying a coil assembly.

[Background of the invention]

As shown in FIG. 4, the method of attaching the bobbin 11 wound with a coil to the center of the member that combines the core 20 and the yoke 2 is as proposed in JP-A No. 57-124174, etc. A type of welding is used in which a member such as a vibrator-shaped plastic concentric with 17 is locally heated and deformed into a buckwheat-like shape to form a hanging part 21. However, in this method, the hanging part 21 is generally There are two parts in total, and the wall thickness is about 1m, so it can be damaged by engine vibration, especially when the engine is cold (-45C to +1400).
Since the thermal expansion is large, there is a concern that the bobbin 11 may fall.

In addition, it is necessary to strictly control the welding conditions, and the sulfide in the plastic that precipitates when the hanging part 21 is melted accelerates the deterioration of the O-ring 15, making it easy for leakage to occur from the terminal 17 part. No consideration was given to productivity and reliability.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnetic fuel injection valve which eliminates the drawbacks of the prior art described above and has a suitable structure in terms of productivity and reliability.

[Summary of the invention]

The present invention incorporates a bobbin into the core and yoke assembly,
(An elastically deformable metal retaining ring smaller than the outer diameter of the terminal is attached to the terminal integrally attached to the bobbin.)
After attaching the bobbin, the attachment portion is covered with resin such as plastic to hold the bobbin.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. Fuel pumped by the fuel pump is mainly supplied from an inlet 12 opened in the yoke 2, passes through the inner and outer peripheries of the bobbin 11, flows out from the outlet 13, and is returned to the fuel tank via a fuel pressure regulator disposed nearby. . Therefore, the fuel pressure around the outer circumference of the valve 3 is held substantially constant, and the amount of injection from the nozzle 6 is controlled by the opening time of the valve 3. Bobbin 11
A current determined by the operating conditions of the engine is applied to the coil 22 at the terminal 17, and the plunger 4 integrated with the valve 3 is moved upward to open the valve. The valve 3 is guided concentrically by a pulp guide 5 to stabilize opening and closing operations. When the current to the coil 22 is cut off, the spring 8 pushes back the valve 3 and closes it. In addition, the pressing force of the spring 8 is determined by the spring adjuster 9 with an 0-ring AIO.
Adjust with. Based on the above-mentioned principle, the injected fuel is atomized from the nozzle 6 by the swirler 7 having an oblique hole.

Since the opening/closing cycle of the valve 3 reaches approximately 300 Hz, the coil 22 generates a large amount of heat, causing changes in characteristics and safety. Therefore, a method for forcibly cooling the coil 22 is provided by providing a circulation groove 18 on the outer periphery of the coil 22 and an inner surface of the bobbin 9, and a circulation path 14 on the outer periphery.

In such a configuration, the order of assembling the fuel injector 1 is to attach the bobbin 11 to the yoke 2 and tip 200 assembly, and then install the Osu/Glue B15.0 for the fuel 7-le.
The terminal guide 16 holding the ring B15 is attached to the terminal 17. After this, there will be a second terminal at Terminal 17.
The inner toothed washer 23 as shown in FIGS.

The inner diameter = φd of this inner toothed washer 23 has a relationship of φdz<φdl with respect to the outer diameter of the terminal 17 = φd, but the inner toothed washer 23 is an elastic body and can be elastically deformed. Although it is relatively easy to enter the terminal 17, it is not easy to return in the opposite direction, that is, the direction in which the bobbin comes out.

After this inner toothed washer 23 is removed, when resin is externally molded for the purpose of insulating the core 20 and the terminal 17, the inner toothed washer 23 acts as a stopper for the bobbin 11, so the bobbin 11 may fall off due to injection pressure. Prevention can be taken.

Although the embodiments of the present invention have been described using a metal retaining ring, the same effect can be expected even if a non-metallic retaining ring (such as a heat-resistant polymer material) is used.

〔Effect of the invention〕

According to the present invention, since it is only necessary to attach an inner toothed washer to the terminal portion, welding can be eliminated, which is effective in improving productivity and reliability.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of the electromagnetic fuel injection valve of the present invention, and FIG.
3 is a sectional view of FIG. 2, and FIG. 4 is a longitudinal sectional view of a conventional electromagnetic fuel injection valve. 1...Fuel injection valve, 2...Yoke, 3...Valve, 4...Plunger, 5...Valve guide, 6...
・Nozzle, 7...Swivel, 8...Spring, 9...Spring adjuster, 10...0 ring A, 11...
・Bobbin, 12...Inlet, B...Outlet, 14...
Circulation path, 15...0 ring B116...terminal guide, 17...terminal, 18...circulation groove, 1
9... Resin, 20... Core, 21... Hanging part, 22... Coil, 23... Inner toothed washer.

Claims (1)

[Claims] 1. In an electromagnetic fuel injection valve that has a coil assembly including a fixed iron core and an electromagnetic coil inside the injection valve body, and the coil assembly is attached to the fixed iron core from below, the coil assembly is integrally attached to the coil assembly. The inner diameter is d_2 and d_2≦d_ to the terminal whose outer diameter is d_1 and which is attached to
An electromagnetic fuel injection valve has a structure in which an elastically deformable retaining ring having a relationship of 1 is provided, and the retaining ring portion is covered with a resin such as plastic.