JPS6076248A - Injection nozzle of fuel injector - Google Patents

Abstract

PURPOSE:To provide a titled injection nozzle having high coupling accuracy in the stage of fixing a swirl tip into the aperture, of a nozzle holder by fitting the swirl tip and an injection port into the aperture and deforming locally and plastically the injection port or the nozzle holder thereby coupling the holder and the swirl tip. CONSTITUTION:The production of the above-described nozzle is accomplished by placing a swirl tip 8 to the fitting step part 6 in the aperture of a nozzle holder 1 consisting of a metallic body then fitting an injection port 9 thereto. The outside circumferential step part 11 of the port 9 in the fitted state is leveled equal to the top surface of the holder 1 or below the same. When an outside circumferential stepped surface 11 is pressed by using an annular punch 12 in this state, the material of the port 9 has the hardness equal to or lower than the hardness of the material of the holder 1 and therefore said material is locally and plastically deformed in the direction of a coupling groove 10 where resistance is low, i.e., in the perpendicular direction thus the material fits tightly to the projecting part generated by the groove 10. The injection port and the holder and thus securely coupled by tightening force and shearing force. The product having high coupling accuracy is easily and surely obtd. according to the above- mentioned invention. The intended injection nozzle of the fuel injector is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an injection nozzle of a fuel injection device, and more particularly to a coupling structure between a nozzle holder and an injection port.

[Background of the invention]

For example, the injection nozzle of the fuel injection device is manufactured by Japanese Patent Publication No. 55-121
It is known from Publication No. 904. This kind of structure is pig2
As can be seen from the above, in most cases, the swirl tip and the injection port are placed in the opening of the nozzle holder, and then the edges of the opening of the nozzle holder are caulked to fix the injection port. A structure that screws into the opening is also known.

However, in the former case, the opening edge was tightened around the entire circumference, resulting in poor installation accuracy and problems with airtightness. On the other hand, the screw-in method required thread processing and a lock to prevent loosening, and was inferior in terms of productivity and reliability.

[Purpose of the invention]

An object of the present invention is to provide an injection nozzle for a fuel injection device with high coupling accuracy.

[Summary of the invention]

In this invention, when fixing the swallow tip to the opening of the nozzle holder, the swallow tip and the injection port are fitted into the opening,
This is a fuel injection nozzle of a fuel injection device in which the injection port or nozzle holder is locally plastically deformed and connected.

[Embodiments of the invention]

FIG. 1 is a mid-longitudinal cross-sectional view of an injection nozzle showing an embodiment of the present invention, and the nozzle holder 1 is made of a cylindrical body, with a valve seat 2 provided in the middle part and a fuel inlet passage 3 penetrating laterally in the lower part thereof. is forming. A ball valve 4 driven by an electromagnetic device (not shown) is pressed against the valve seat 2 via a rod. On the other hand, a stepped portion 6 is formed in the upper opening, and a souffle tip 8 having a mandrel 7 implanted therein is placed on this stepped portion, and an injection port 9 is further placed and fitted on the upper surface of the souffle tip 8.

A plurality of annular coupling grooves 10 are formed in the inner circumferential wall near the opening of the nozzle holder, and are coupled by biting into a protrusion formed by plastically deforming the material of the injection port to form the grooves. This type of nozzle is constructed so that the fuel is introduced from the inlet passage 3 and is injected from the injection port through the entire souffle tip 8 only when the ball valve 4 is open.

Next, to explain the manufacturing process of the above nozzle with reference to FIG. 2, the souffle tip 8 is placed on the fitting step 6 in the opening of the nozzle holder 1 made of a metal body, and then the injection port 9 is fully fitted. . In the fitted state, the outer circumferential working surface 11 of the injection port 9 is equal to or lower than the upper surface of the nozzle holder 1. Here, when the annular punch 12 is used to suppress the outer circumferential working surface 111, the material of the injection port 9 has a hardness equal to or lower than that of the nozzle holder ρ material, so it is localized in the direction of the coupling groove 10 with less resistance, that is, in the vertical direction. It is plastically deformed and tightly adheres to the protrusion created by the bonding groove, and is firmly bonded with tension and shear force.

With this connection, deformation pressure is simultaneously applied to the annular shape to cause plastic deformation, so centering accuracy is stable, and since the connection groove is formed near the opening, plastic deformation can be easily achieved with a small pressure force. , it can be combined without affecting other components, resulting in a highly accurate product from the perspective of the entire product.

In the above embodiment, the coupling groove is formed in the nozzle holder, but the same effect can be obtained by forming the coupling groove on the outer periphery of the injection port and locally plastically deforming the nozzle holder member.

〔Effect of the invention〕

As described above, according to the present invention, products with high bonding accuracy can be easily and reliably provided.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical cross-sectional view of a main part of an injection nozzle, and FIG. 2 is an illustrative assembly view of the same. 1... Nozzle holder, 8... Souffle tip, 9
...Injection port, 10...Joining groove. 2nd mouth

Claims (1)

[Claims] 1. A fuel injection system in which a swallow tip that gives fuel injection swirl to the opening of a nozzle holder and an injection port that diffuses the swirl flow of the swallow tip in a conical shape are fitted, and these kings are fixed together. In the injection nozzle of the device, the material of the component facing the coupling groove is vertically plastically deformed into the coupling groove formed on either the inner wall surface near the opening or the outer circumferential surface of the injection port, and tension force and shear are generated. An injection nozzle of a fuel injection device characterized in that it is coupled to a force.