JPS62258161A - Structure of electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To eliminate an annular groove and prevent a foreign matter from remaining by cutting a plane on the coupling part of a needle valve to a plunger and leaving a cylindrical surface on said coupling part other than the plane cut part and making said coupling part caught into a plunger. CONSTITUTION:In an electromagnetic fuel injection valve, a needle valve 1 which is coupled to a plunger 4 and attracted to an electromagnetic coil is brought into contact with or separated from the valve seat of a nozzle body, to open or close the valve, thereby, intermittently injecting fuel. In such a structure, in order to couple the needle valve 1 to the plunger 4, any annular groove, etc. is not provided on the coupling part of the needle valve 1 but a cylindrical surface 10 is left as it is, while a plane is cut to secure a fuel passage. That is, when the needle valve 1 is inserted into the plunger 4, the outside diameter of the needle valve 1 is made smaller than the inside diameter of the plunger 4, preventing a burr, etc. from being produced. And, the outer periphery of the plunger 4 is squeezed by a drawing ring and, then, polished and finished.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electromagnetic fuel injection valve, and in particular to an electromagnetic fuel injection valve suitable for a structure that easily and reliably connects a plunger and a needle valve and does not generate foreign matter. related to type fuel injection valves.

[Conventional technology]

As shown in FIG. 1, a conventional injection valve of this type known from Japanese Patent Publication No. 56-11071 has an annular groove 2 at the connecting portion of the needle valve 1, and a plunger 4 is attached to a protrusion 3 formed by the groove. It is crimped.

[Problem that the invention seeks to solve]

However, since the plunger 4 that has been crimped does not completely fill the annular groove 2, foreign particles that have entered the groove before and after crimping
It is difficult to remove with simple cleaning or air blowing. Also, as shown in cross section AA in Fig. 2, both ends of the groove are not closed, so
There is a problem that foreign matter 5 in the groove comes out inside the plunger 4 while the electromagnetic fuel injection valve (hereinafter referred to as the injection valve) is operating.
The outer periphery of the plunger 4 may disturb the opening/closing time of the needle valve 1, or may enter between the stopper 6 and the stopper 7 of the needle valve 1 to change the stroke.
It enters between the needle valve 1 and the seat portion 9 of the nozzle body 8 to change the injection amount.

There is a problem where the fuel keeps blowing out.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide a simple caulking method with a structure that does not leave any foreign matter.

[Means for deciding a problem or problem]

The above object is achieved by eliminating the conventional annular groove and leaving one cylindrical surface.

[Effect]

The present invention prevents foreign matter from remaining between the plunger 4 and the needle valve 1 by eliminating the annular groove, and even if the foreign matter enters the gap, the plunger 4 is bitten into the entire circumference of the cylindrical surface 10, so the foreign matter will not run away.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. The injection valve injects fuel by opening and closing the seat portion 9 in response to an ON-OFF signal, and an electric signal is given to the coil 10 as a pulse. A magnetic circuit is formed by the core 11 through which current is passed through the coil 10, the yoke 12, and the plunger 4, and the plunger 4 is attracted to the right side. The plunger 4 is connected to a needle valve 1 which also serves as a sliding guide inside the nozzle body 8, and when the plunger 4 moves, the seat portion 9 is opened and fuel is injected. The pressure of the fuel is adjusted by a fuel pump or fuel pressure regulator, and the fuel flows into the interior through a filter 14 from a fuel inlet pipe 13 that is integrated with the core 11 of the injection valve.
The spring 16. passes through the spring adjuster 15 provided inside. The liquid is injected into the engine through the gap between the inside and outer circumference of the plunger 4, the needle valve, and the nozzle body 8.

The needle valve 1 and the plunger 4 are connected by leaving the cylindrical surface 10 without providing an annular groove or the like in the connecting part of the needle valve 1, cutting a flat surface to secure a fuel passage, and crimping the inner wall of the plunger there. The work I am doing-X! The order is as follows: (1) Insert the needle valve 1 into the plunger 4.

However, the outer diameter of the connecting part of needle valve 1; φdz, plunger 4
When the inner diameter of the valve is φd2, set φdz<φd2 to prevent burrs or burrs from appearing during insertion6■ Needle valve 1
After positioning the plunger 4, pull out the outer periphery of the plunger 4 and squeeze it with the ring.

■ After completing step (2), the outer periphery and end face of the plunger 4 are polished and finished.

According to this embodiment, since the plunger 4 is bitten into the entire circumference of the cylindrical surface 10 without any gaps, the pulling force is reduced.

The torsional force is sufficient to withstand the load during durability and processing, and the injection It does not cause problems such as volume changes or fuel blown out.

〔Effect of the invention〕

According to the present invention, the needle valve and the plunger can be easily and reliably connected without any gaps.

This has the effect of preventing problems caused by foreign matter contamination.

[Brief explanation of drawings]

1st Iy! 1(a) is a drawing showing a connecting portion between a needle valve and a plunger formed by a conventional crimping method, and FIG.
b) is an enlarged view of part P in FIG. 1(a), FIG. 2 is a cross-sectional view taken along the line A-A in FIG. FIG. 4 shows a joint between the needle valve and plunger shown in FIG. 3. DESCRIPTION OF SYMBOLS 1... Needle valve, 2... Annular groove, 3... Protrusion part, 4... Plunger, 5... Foreign object.

Claims (1)

[Claims] 1. An electromagnetic fuel injection valve that intermittently injects fuel by opening and closing a needle valve that is fixedly connected to a plunger that is attracted by an electromagnetic coil and moves relative to a valve seat provided in the nozzle body. In this method, the connecting part of the needle valve is cut into a flat surface with a predetermined width, leaving a cylindrical surface except for the flat cut part, and the plunger material is bitten into the cylindrical part and the flat cut part, thereby forming the needle valve. The structure of an electromagnetic fuel injection valve that combines a plunger and a plunger.