JPS58178863A - Electromagnetic fuel injection valve - Google Patents

Abstract

PURPOSE:To enable to close an electromagnetic fuel injection valve quickly, by forming grooves in at least either one of the outer circumferential end face or the inner circumferential end face of a fixed iron core at several parts along the entire circumference of the same, and thereby improving de-energization of the electromagnetic valve. CONSTITUTION:Grooves are formed at several parts along the entire circumference of an outer circumferential fixed iron core 15b so that. when the electromagnetic force is acted, a movable iron core 22 comes into contact with an inner circumferential fixed iron core 15a and clearance is formed between the movable iron core 22 and the grooves of the outer circumferential fixed iron core 15b. That is, the movable iron core 22 does not come into contact with the entire end face of a coil assembly, so that the residual magnetism is reduced and the fluidic attractive force acted between the movable iron core 22 and the fixed iron core is rendered weak. Therefore, it is enabled to control movement of a valve element 23 excellently even if the size of the coil assembly is made small.

Description

[Detailed description of the invention] This invention relates to fuel injection valves that supply fuel.

In conventional electromagnetic fuel injection valves, when the valve body is at its maximum lift, the fixed iron b and the end face of the movable iron core are in direct contact with each other, and the contact area is as wide as a light minute, making it impossible to hold the valve in place. There is a problem in that it is difficult to close the opening P quickly and smoothly due to the difficulty in demagnetizing the magnetic field (J) and the shielding force of the current which is lost in the electrolytic layers of both iron cores.

The object of the present invention is to improve this problem. 4th, by providing grooves at several points around the entire circumference on at least one of the outer and inner end surfaces of the fixed iron core of the present invention, υ demagnetization is improved and valve closing is performed quickly; The purpose is to weaken the magnetic force by reducing the contact area and improve magnetic efficiency by reducing eddy current loss.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1-A shows its cross-sectional configuration, and this fuel injection valve 11 includes a circular housing 12 with an open tip, and a spacer 19 that seals the open tip of the housing 12. The main body of the injection valve is constructed by squeezing the sleeve 13 outside the body 27. A fixed iron core 15 is arranged concentrically inside the housing 12, and an electromagnetic coil 16 is set so as to be surrounded by the inner and outer peripheries of the fixed iron core 15. It is fixedly set within the housing 12.

That is, the central axis of the housing 12 is provided with a fuel inlet passage 17 that opens at the base end.
Pipe [8] is fixedly set to 7, and the center hole of the fixed iron core 15 is inserted into the outer periphery of this pipe 18. Further, a spacer 19 is formed on the outer periphery 15b of the fixed core 15 in the distal direction, and is set such that a rib-shaped arrow is formed, and this protrusion comes into contact with the body 13 on the inner peripheral surface of the housing 12.
and a stepped portion in the housing 12, and the coil assembly (4) is fixedly set in the housing 12. That is,
A chamber 20 is formed within the housing 12 between the fixedly configured coil assembly and the body 13.

Inside the chamber 20, there is arranged a disk-shaped movable iron core 22 made of permalloy or the like with excellent magnetic properties, and a cell assembly group consisting of a spherical cell p#23 coupled to the iron core 22 in one group. This movable iron core 22 is set opposite to the end face in the distal direction of the coil assembly, and is always subjected to a 14% force by a spring 24 in the direction of the body 13, that is, in the direction away from the coil assembly. That is, electromagnetic carp/L'
16, the movable iron core 22 is attracted and driven to the Koinon assembly against the spring 24 by the electromagnetic attraction force, and when the excitation Wi current is not present, the movable iron core 22, that is, the spherical valve The body 23 is set to be suppressed in the direction of the body 13. here,
The movable iron core 22 and the spherical valve body 23 are provided with the inlet passage 1
8 is formed in the chamber 20, and a plurality of through holes 26 are formed in the movable core 22, so that the movable core 22 is smoothly driven within the chamber 20 filled with fuel. .

Here, on the end face in the distal direction of the coil assembly, differences are provided at several places around the entire circumference of the outer peripheral end face 151 of the fixed core, so that when the movable core 22 is attracted and lifted to the maximum, a gap is formed in this vortex part. That's how it is.

The body 27 is provided with a conical valve seat 27a. The valve seat 27aK is opposed to the spherical valve body 23, and due to the pressing force of the spring 24, the spherical valve body 23 normally comes into contact with the valve seat 27a, thereby acting to close the injection passage. And the electromagnetic coil 1 of the coil assembly team
When an exciting current is supplied to 6 and the movable iron core 22 is attracted and driven, the spherical valve body 23 separates from the valve seat 27 and opens an injection passage. In this case, since the valve body z3 is spherical, the inclination of the movable iron core 22 & and the valve body 23 is #! l: It becomes like a valley. Here, the pressure of the fuel is regulated to a pressure 2 to 3 m/d lower than atmospheric pressure by a pressure regulating valve. 35 is a terminal that supplies exciting current to the electromagnetic coil 16.

(5) That is, in the fuel injection valve 11 configured as described above, fuel maintained at a pressure of about 2 to 311r/cII enters the chamber 20 from the inlet passage 17 through the passage 25 of the valve body 23. Supplied. Then, the electromagnetic coil 16 is excited and the movable iron core 22 is attracted to the square 1. +23 is valve seat 2
7, some of the fuel in the chamber 20 enters the injection passage 2.
8 to the nozzle hole 29, where it is injected into the engine. That is, by controlling the energization time to the electromagnetic coil/I/16, the amount of fuel injected can be controlled to an amount commensurate with the engine operating conditions, similar to a normal fuel injection valve.

Furthermore, the movable core 22 is shaped like a disk, and the fixed core 14.
By making the entire surface face the end face portion of the electromagnetic coil 15, the attractive force when an excitation current is supplied to the electromagnetic coil 16 can be increased. In this case, grooves are provided at several places around the entire circumference of the outer fixed core 15b, and the movable core 22 hits and contacts the inner fixed core 15a during the electromagnetic attraction.
However, a gap (6) now exists between the groove of the outer fixed core x5b and the movable core 22. In other words, the movable core 22 does not fully contact the end face of the coil assembly, resulting in a state where the residual magnetic force is reduced, and the movable core 22 and the identified core 4
The fluid adsorption force between -4 and 15 is also good. That is, even if the coil assembly is made small, the opening and closing operations of the square 23 can be controlled favorably.

It should be noted that the grooves of the fixed outer core 15b should be arranged in 4 to 12 places around the entire circumference, with a width of 0.5 to 21 m, and a depth of about 0.2 to 2 grooves, which is appropriate for the characteristics of the magnetic circuit. can do 5
In general, it is preferable to increase the number of grooves as the width becomes narrower and the depth becomes shallower.

In the above embodiment, the outer fixed core 15b is provided with a K groove, but the same effect as described above can be obtained even if #1 is provided in the inner fixed core 15a as shown in FIG. Figure 2-A, Figure 2-
In Fig. B, explanations of the same components as those in Fig. 1-A will be omitted.

In addition, in such a fuel injection valve 11, the movable iron core 22 and the fixed iron core 15 are repeatedly subjected to a collision motion f'#i tangentially during their operation, which significantly deteriorates the magnetic properties 1 of both. . For this reason, as shown in FIG. 1-B and FIG. 1-C, respectively, tlJ!
High-quality plating is applied.

In other words, iJ' ill! By applying a thin layer of hard chrome plating to the I iron L722 and H fixed iron core 15, it is difficult to peel off and can be firmly attached, and the movable iron core 2
It can prevent repeated IK-related collisions between the magnetic bodies of 2 and fixed core 15, effectively preventing deterioration of the lid and deterioration of magnetic properties, improving durability. It is possible to realize normal fuel injection.

As described above, according to the present invention, the movable core integrated with the valve body has a non-contact portion formed by a groove provided on the outer periphery or inner periphery of the fixed core when excitation current is supplied to the electromagnetic coil. There will be a gap between the parts. Therefore, compared to the case where the movable core contacts all end faces of the fixed core, the demagnetization characteristics are much better, the valve opening operation is performed quickly, and the operating performance is improved. This reduction in the contact area also has the advantage of weakening the adhesion force of the contact area.Furthermore, by applying a hard plating layer to this contact area, it is possible to reduce the magnetic non-contact. avoid collisions,
It is possible to effectively prevent deterioration of steam characteristics and provide excellent durability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1-(j+) is a sectional view showing a fuel injection valve according to an embodiment of the present invention. -(B) Figure is No.! - (A) It is a partial sectional view shown in figure. 11...fuel injection valve, 12...-housing, 27...
-Body, 15-・Fixed core, 16・-Electromagnetic coil y・1
7.-Public passageway, 20.-Room, 21..Space, 22
- Movable iron core, 23 - Valve body, 27a... Valve seat, 36
...Intake pipe. Representative Patent Attorney Takashi Okabe

Claims (1)

[Claims] II) A coil assembly including an electromagnetic coil/I/A fixed inside the injection valve body and a fixed iron core, and a fuel inflow formed at the -II end face of this coil assembly. A chamber for supplying the coil, a square for opening and closing the valve seat of the injection passage formed in a portion of this chamber facing both sides of the coil/L/assembly, and a square for opening and closing the valve seat of the injection passage, and a square for opening and closing the valve seat of the injection passage, and a square for opening and closing the valve seat of the injection passage, and A movable iron core is provided on both sides of the shaft to pull the valve body away from the valve seat, which is driven by magnetized dust, and the inner and outer peripheries of the identified iron cores are located at the four ends of one of the coils/I/assemblies. An electromagnetic fuel injection valve characterized in that grooves are provided on at least one of the end faces at several locations around the entire circumference so that the grooves can become a non-contact gap when the movable iron core is attracted to the fixed iron core. 12) The fuel injection ff according to claim 1, wherein a hard plating layer is provided on opposing surfaces of the fixed iron core and the movable iron core.
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