JP2002364485A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce weight of a magnetic tube and smoothly forming a resin cover, by making thicker only the part to be strengthen out of the magnetic tube compared with the other portion. SOLUTION: The magnetic tube 2 is integrally formed of a metal pipe or the like, its valve seat member mounting portion 2A and an actuator mounting portion 2B are formed as a thin part A having the thickness a of, for example, 0.1-0.9 mm. The resin cover forming portion 2C of the magnetic tube 2 is formed as a thick part B thicker than by at least by 0.1 mm than the thin part A. Therefore, the deformation of the resin cover forming portion 2C caused by such as injection pressure of resin material is prevented when a resin cover 14 is formed. Further, the part where the valve seat member 5, a valve element 7, a solenoid coil 11 are arranged out of the magnetic tube 2 is formed as thin as possible to reduce the weight of the fuel injection valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve suitably used for injecting fuel into, for example, an automobile engine.

[0002]

2. Description of the Related Art In general, a fuel injection valve used for an automobile engine or the like has a valve body which is displaceably inserted into a valve casing. During operation of the injection valve, when the valve element is opened by operating an actuator such as an electromagnetic coil, fuel supplied to a fuel passage in the valve casing is injected toward an intake pipe of the engine. (For example, JP-A-2000-8990).

[0003] In a fuel injection valve according to this type of prior art, a magnetic cylinder serving as a valve casing is formed of a metal pipe or the like, and the magnetic cylinder is disposed at one axial end (front end side) of a valve seat member. It has an attachment portion, an actuator attachment portion located at an intermediate portion in the axial direction, and a resin cover molded portion located on the other axial side (base end side).

Further, a cylindrical valve seat member is provided at a valve seat member mounting portion of the magnetic cylinder via, for example, a metal holder or the like, and the valve seat member is inserted into the magnetic cylinder. A valve seat on which the valve element is detached and seated is provided. An electromagnetic coil is mounted on the outer peripheral side of the actuator mounting section, and a resin cover is formed on the outer peripheral side of the resin cover molding section by means of, for example, injection molding. A connector for supplying power to the power supply is integrally provided.

During operation of the injection valve, when power is supplied to the electromagnetic coil, the valve element is magnetically attracted by the magnetic field generated by the electromagnetic coil and is displaced in the axial direction, thereby displacing the valve element from the valve seat member. The valve is then opened.

[0006]

In the above-mentioned prior art, for example, when a resin cover is injection-molded on the outer peripheral side of a magnetic cylinder, a resin material is injected into a resin mold for injection molding under a high pressure (injection pressure). ), And the pressure of this resin material is applied to the magnetic cylinder having a hollow structure from the outside in the radial direction. Therefore, the magnetic cylinder needs to be formed using, for example, a thick metal pipe or the like so as not to be deformed by the injection pressure of the resin material.
In many cases, the thickness is larger than the wall thickness required to secure practical strength of the injection valve.

For this reason, in the prior art, it is necessary to provide an extra thickness to the magnetic cylinder to secure strength during injection molding, and the outer diameter and weight of the cylinder may be increased more than necessary. There is a problem that it is difficult to reduce the size of the injection valve.

The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to secure the strength of a magnetic cylinder at a mounting portion of a resin cover and the like so that the resin cover can be smoothly molded with a resin. It is another object of the present invention to provide a fuel injection valve in which the thickness of the magnetic cylinder can be reduced as much as possible, and the entire injection valve including the magnetic cylinder can be reduced in weight.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a cylinder formed of a magnetic material and having a fuel passage therein. A magnetic cylinder having a mounting portion and a resin cover molded portion on the other side, a valve seat member provided at a valve seat member mounting portion of the magnetic cylinder and having a valve seat surrounding an injection port; A valve body which is provided displaceably and detachably from a valve seat of the valve seat member, an electromagnetic actuator which is provided on an actuator mounting portion of the magnetic cylinder to open and close the valve body, and a resin cover molding part of the magnetic cylinder The present invention is applied to a fuel injection valve comprising a resin cover provided by resin molding.

A feature of the structure adopted by the first aspect of the present invention is that the magnetic cylinder has a thickness between 0.1 mm and 0.9 mm extending between the valve seat member mounting portion and the actuator mounting portion. The thickness of the resin cover molded portion is at least 0.1 mm larger than the thickness of the valve seat member mounting portion and the actuator mounting portion.

With this configuration, the portion of the magnetic cylinder extending between the valve seat member mounting portion and the actuator mounting portion can be formed as thin as possible, and the weight of the magnetic cylinder can be reduced. In addition, since the resin cover molded portion can be formed thicker than these thin portions, the resin cover molded portion can be given a sufficient strength corresponding to, for example, the pressure received when molding the resin cover.

According to the second aspect of the present invention, the thickness of the magnetic cylinder is 0.1 to 0.9 mm.
And the thickness dimension between the actuator mounting portion and the resin cover molding portion is formed to be at least 0.1 mm or more larger than the thickness dimension of the valve seat member mounting portion.

[0013] Thus, the magnetic cylinder can have the valve seat member mounting portion formed as thin as possible, and the portion between the resin cover molding portion and the actuator mounting portion can be formed thick. Therefore, for example, in the case where a part of the resin cover is arranged on the outer peripheral side of the electromagnetic actuator, even if pressure or the like at the time of molding the resin cover is applied to the actuator mounting portion through a gap or the like near the electromagnetic actuator, It is possible to prevent the actuator mounting portion from being deformed.

According to a third aspect of the present invention, a core member facing the valve body with an axial gap therebetween is provided on the inner peripheral side of the actuator mounting portion of the magnetic cylinder, and the electromagnetic actuator is provided with the actuator. A coil bobbin inserted into the outer peripheral side of the mounting portion and a coil wound around the coil bobbin. The outer peripheral side of the electromagnetic actuator is magnetically connected to the magnetic cylinder at both axial sides of the electromagnetic actuator. Is provided with a magnetic path forming member connected to the.

Accordingly, when power is supplied to the electromagnetic actuator, a closed magnetic path can be formed between the inner peripheral side and the outer peripheral side of the electromagnetic actuator via the valve element, the core member, the magnetic cylinder, the magnetic path forming member, and the like. Since the magnetic field passes through the gap between the body and the core member, the valve body can be magnetically attracted by the core member to open the valve.

Further, according to the invention of claim 4, the resin cover is provided by injection molding on the outer peripheral side of the resin cover molded portion of the magnetic cylinder, and the resin cover is integrally provided with a connector for supplying power to the electromagnetic actuator. It is configured to be provided.

[0017] Thus, the resin material can be injection-molded on the outer peripheral side of the thick resin cover molded portion of the magnetic cylinder, and the resin cover and the connector can be integrally molded with the resin.

According to the fifth aspect of the present invention, a core member is provided on the inner peripheral side of the actuator mounting portion of the magnetic cylinder so as to face the valve body with an axial gap therebetween. At a position where the gap is formed, a thin portion for increasing the magnetic resistance of the magnetic cylinder is provided.

Thus, the portion of the magnetic cylinder where the valve body is disposed and the portion where the core member is disposed can be magnetically isolated by the thin portion. Therefore, when the magnetic field generated by the electromagnetic actuator passes through the gap between the valve body and the core member, it is possible to prevent the magnetic field from being short-circuited by the magnetic cylinder.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fuel injection valve according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 7 show a first embodiment of the present invention. In this embodiment, a fuel injection valve used for an automobile engine will be described as an example.

Reference numeral 1 denotes a valve casing that forms an outer shell of the fuel injection valve. The valve casing 1 includes a magnetic cylinder 2, a magnetic cover 12, a resin cover 14, and the like, which will be described later.

Reference numeral 2 denotes a magnetic cylinder constituting a main body of the valve casing 1. The magnetic cylinder 2 is made of a metal pipe or the like made of a magnetic metal material such as an electromagnetic stainless steel, for example. By using means such as press working and grinding work, it is formed integrally in a stepped cylindrical shape as shown in FIGS.

Here, the magnetic cylinder 2 is located on one axial side (the distal end side) of the valve body, and has a valve seat member mounting portion 2A to which a valve seat member 5 described later is fitted, and a valve seat member mounting portion. An actuator mounting portion 2B to which an electromagnetic coil 11 to be described later is mounted is located on the other axial side (base end side) of 2A, and a resin cover 14 to be described below is mounted on the base end side of the actuator mounting portion 2B. And the formed resin cover molding 2C.

As shown in FIG. 4, the valve seat member mounting portion 2A and the actuator mounting portion 2B are, for example, 0.1 to
It has a predetermined thickness a of about 0.9 mm, preferably about 0.2 to 0.5 mm, and has a valve seat member mounting portion 2A
Has a smaller diameter than the actuator mounting portion 2B. Further, an annular thin portion 2D having a thickness t smaller than the thickness a is provided at an intermediate position in the length direction of the actuator mounting portion 2B (a> t).
D is arranged so as to surround a gap S between a valve body 7 and a core tube 8 described later. As a result, the actuator mounting portion 2B is provided with a valve body side tube portion 2B1 in which a valve body 7 described later is displaceably accommodated and a core tube side tube portion 2 into which a core tube 8 described later is inserted.
B2, and the thin portion 2D is divided into these cylindrical portions 2B1,
In addition to increasing the magnetic resistance between 2B2 and cylindrical portions 2B1,2
B2 is magnetically shut off.

On the other hand, the resin cover molded portion 2C is formed to have a larger diameter than the actuator mounting portion 2B. Also,
The resin cover molding portion 2C is provided with a valve seat member mounting portion 2A so as to withstand the pressure when the resin cover 14 is molded as described later.
Are formed with a predetermined thickness b larger than the thickness a such as Have been.

[0027]

## EQU1 ## b ≧ a + 0.1

In this case, if the thickness difference b of the resin cover molding 2C is 0.1 mm from the thickness a,
For example, about 0.2 to 1.0 mm, preferably 0.3 to
The dimension value is set to about 0.6 mm.

As a result, in the magnetic cylinder 2, a portion extending between the valve seat member attaching portion 2A and the actuator attaching portion 2B is formed as a thin portion A, and a resin cover molded portion 2C is formed as a thick portion B. Things. Further, a fuel passage 3 extending in the axial direction from the resin cover molded portion 2C to the position of the valve seat member 5 in the magnetic cylinder 2 and a fuel filter 4 for filtering fuel supplied into the fuel passage 3 are provided. Is provided.

Numeral 5 is a cylindrical valve seat member provided to be fitted in the valve seat member mounting portion 2A of the magnetic cylinder 2, and the fuel passage 3 is provided in the valve seat member 5 as shown in FIG. There is provided an injection port 5A for injecting fuel inside to the outside, and a substantially conical valve seat 5B formed surrounding the injection port 5A. The valve seat member 5 has its outer peripheral side welded to the valve seat member mounting portion 2A over the entire circumference. In addition, on the distal end surface of the valve seat member 5,
A nozzle plate 6 having a plurality of nozzle holes 6A is fixed at a position covering the injection port 5A.

Reference numeral 7 denotes an actuator mounting portion 2 of the magnetic cylinder 2
As shown in FIG. 2, the valve body 7 is a cylindrical valve shaft 7A extending in the axial direction, and a valve shaft 7A of the valve shaft 7A. A spherical valve body 7B fixed to the distal end side and separated from and seated on the valve seat 5B of the valve seat member 5; And a cylindrical suction portion 7C which is inserted as much as possible.

When the valve body 7 is closed, the valve portion 7 is closed.
B is held in a state of being seated on the valve seat 5B of the valve seat member 5 by the spring force of an urging spring 9 described later.
The base end face of C and the core cylinder 8 face each other with a gap S in the axial direction interposed therebetween. When a magnetic field H in FIG. 2 is formed by the electromagnetic coil 11 when power is supplied to an electromagnetic coil 11 described later, the valve body 7 is attracted magnetically by the core tube 8 so that the adsorbing portion 7C is energized. Clearance S against spring force of spring 9
Is displaced in the axial direction by the dimension of (1), thereby separating from the valve seat 5B and opening the valve.

Numeral 8 is a core tube as a core member formed of, for example, a magnetic metal material or the like, and the core tube 8 is provided with an actuator mounting portion 2B of the magnetic cylinder 2 (the core cylinder side cylinder portion 2).
B2) is fitted into the actuator mounting portion 2B at a position facing the suction portion 7C of the valve body 7 by press-fitting or the like.

Reference numeral 9 denotes an urging spring provided in the magnetic cylinder 2. The urging spring 9 is connected to a cylindrical spring receiver 10 fixed to the inner peripheral side of the core cylinder 8 by press-fitting or the like. The valve body 7 is disposed in a compressed state between the valve body 7 and constantly urges the valve body 7 in the valve closing direction.

Numeral 11 designates an electromagnetic coil as an electromagnetic actuator which is inserted and fitted on the outer peripheral side of the actuator mounting portion 2B (core cylinder side cylindrical portion 2B2) of the magnetic cylindrical body 2. The electromagnetic coil 11 is shown in FIG. As shown, a cylindrical coil bobbin 11A made of a resin material and a coil bobbin 11
The coil 11B is wound around A and is accommodated between the magnetic cylinder 2 and the magnetic cover 12. The electromagnetic coil 11 generates a magnetic field H by being supplied with power using a connector 15 described later, and opens the valve body 7 against the spring force of the biasing spring 9.

Numeral 12 denotes a magnetic cover as a magnetic path forming member formed in a stepped cylindrical shape by a magnetic metal material or the like.
As shown in FIGS. 2 and 3, the magnetic cover 12 is formed integrally with a large-diameter cylindrical portion 12A provided on the outer peripheral side of the electromagnetic coil 11 and at a distal end side of the large-diameter cylindrical portion 12A. And a small-diameter cylindrical portion 12B fitted and fixed to the outer peripheral side of the second actuator mounting portion 2B (valve-body-side cylindrical portion 2B1).

Here, in the annular space formed between the large-diameter cylindrical portion 12A and the actuator mounting portion 2B of the magnetic cylindrical body 2, there is provided a connecting core formed in a substantially C-shape of, for example, a magnetic metal material. 13 is inserted. Thus, the magnetic cover 12 is magnetically connected to the magnetic cylinder 2 on both sides in the axial direction with the electromagnetic coil 11 interposed therebetween by the small-diameter cylindrical portion 12B and the connection core 13.

When the electromagnetic coil 11 is operated, the valve body side cylinder part 2B1 and the core cylinder side cylinder part 2B2 of the magnetic cylinder body 2 are magnetically substantially shut off by the thin part 2D. Part 2B1, core cylinder side tubular part 2B2, valve body 7
Suction part 7C, core tube 8, magnetic cover 12, connecting core 1
3, the magnetic field H can be formed stably, and the valve element 7 can be magnetically attracted by the core cylinder 8 to open the valve.

Reference numeral 14 denotes a resin cover provided on the outer peripheral side of the resin cover molded portion 2C of the magnetic cylinder 2 by means of, for example, injection molding. As shown in FIG.
Resin cover molded part 2C and large diameter cylindrical part 12 of magnetic cover 12
A is covered from the outside in the radial direction. In addition, resin cover 1
4, a connector 15 for feeding power to the electromagnetic coil 11 is integrally molded with resin, and the connector 15 has a terminal pin 15A.

Here, when the resin cover 14 is injection-molded, a high injection pressure of the resin material is applied to the resin cover molded portion 2C of the magnetic cylinder 2 as shown in FIG. For this reason, in the present embodiment, by forming only the resin cover molded portion 2C of the magnetic cylinder 2 to be thick, the magnetic cylinder 2
The valve cover member mounting portion 2A, the actuator mounting portion 2B, the thin portion 2D, etc. are made as thin as possible, and the resin cover molded portion 2C is given a sufficient strength corresponding to the injection pressure of the resin material. is there.

The fuel injection valve according to the present embodiment has the above-described configuration, and its operation will be described next.

First, when the injection valve operates, the connector 15
When power is supplied to the electromagnetic coil 11 from, the magnetic field H is formed as shown in FIG. 2, and this magnetic field H passes through the gap S between the suction portion 7C of the valve body 7 and the core cylinder 8. As a result,
The valve element 7 is magnetically attracted by the core tube 8 and is displaced in the axial direction against the urging spring 9, and the valve portion 7 B is separated from the valve seat 5 B of the valve seat member 5 to open. I do. Thereby, the fuel supplied into the fuel passage 3 is injected from the injection port 5A toward the intake pipe of the engine or the like.

Referring to the operation of assembling the injection valve, first, in the step of forming a magnetic cylinder shown in FIG. 4, the magnetic cylinder 2 is formed by means such as pressing such as deep drawing or grinding. Next, in a first component assembling step shown in FIG. 5, the electromagnetic coil 11, the magnetic cover 12, and the connection core 13 are inserted into the outer peripheral side of the magnetic cylinder 2,
And the magnetic cylinder 2 are fixed by means such as welding. Also,
The valve seat member 5 is welded to the inner circumference at the distal end side of the magnetic cylinder 2 to form an assembled body 16 including the magnetic cylinder 2, the valve seat member 5, the electromagnetic coil 11, the magnetic cover 12, the connecting core 13, and the like. I do.

Next, in the resin cover molding step shown in FIG. 6, a resin mold 17 having a molding space 17A having a shape corresponding to the resin cover 14 and the connector 15 is prepared, and assembled in the resin mold 17. The body 16 is placed. In this state, the magnetic cylinder 2 is in a state where only the resin cover molding 2C is exposed in the molding space 17A. An annular gap space formed between the actuator mounting portion 2B of the magnetic cylinder 2 and the large-diameter cylinder portion 12A of the magnetic cover 12 is substantially formed by the electromagnetic coil 11 and the connection core 13 as shown in FIG. It is in the closed state.

By injecting a resin material into the resin mold 17 at a predetermined injection pressure, the resin cover molded portion 2C,
The resin cover 14 and the connector 15 can be easily injection-molded on the outer peripheral side of the magnetic cover 12 and the like. At this time, the injection pressure of the resin material is applied to the resin cover molded portion 2C, but since this portion is formed thick, the deformation of the magnetic cylinder 2 can be prevented.

Next, in a second component assembling step shown in FIG. 7, the valve 7, the core cylinder 8, the biasing spring 9, the spring receiver 10, etc. are assembled to the magnetic cylinder 2, whereby the injection is performed. The valve can be assembled.

Thus, according to the present embodiment, the portion of the magnetic cylinder 2 extending between the valve seat member mounting portion 2A and the actuator mounting portion 2B is, for example, about 0.1 to 0.9 mm,
Preferably, it is formed as a thin portion A on one side in the axial direction having a thickness dimension a of about 0.2 to 0.5 mm, and the resin cover molded portion 2C is at least 0.1 m with respect to the thickness dimension a.
The thickness is formed as a thick portion B on the other side in the axial direction having a large thickness dimension b of m or more.

Thus, the thin portion A of the magnetic cylinder 2 where the valve seat member 5, the valve 7, the electromagnetic coil 11 and the like are arranged.
Can be formed as thin as possible. Further, since the resin cover molded portion 2C of the magnetic cylinder 2 can be formed as the thick portion B, for example, when the resin cover 14 is injection molded, sufficient strength corresponding to the injection pressure at this time is applied to the resin cover molded portion 2C. This can reliably prevent the resin cover molded portion 2C from being deformed by the injection pressure of the resin material.

Therefore, according to the present embodiment, the strength of the magnetic cylinder 2 can be ensured at a necessary portion, the resin cover 14 can be smoothly molded with resin, and the magnetic cylinder 2 can be reduced in size. The entire injection valve including the cylinder 2 can be reduced in weight.

Further, since the magnetic cylinder 2 is integrally formed by a metal pipe or the like, and the thin portion 2D is provided in the middle thereof,
At the time of assembling the injection valve, the magnetic cylinder 2 provided with the thin-walled portion 2D serving as a magnetically interrupted portion can be easily formed only by performing a machining process such as a press process and a cutting process on the metal pipe. The structure can be simplified by reducing the number of parts of the valve.

FIGS. 8 and 9 show a second embodiment according to the present invention. The feature of this embodiment is that the magnetic cylinder has a thick mounting portion for mounting an electromagnetic actuator or the like. And that Note that, in the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Reference numeral 21 denotes the valve casing 1 of the first embodiment.
A valve casing 22 used in place of the magnetic casing 2 is a magnetic cylinder constituting a main body of the valve casing 21.
2 includes a valve seat member mounting portion 22A, an actuator mounting portion 22B, and a resin cover molding portion 22C, similarly to the first embodiment.
B is divided into a valve body-side cylinder portion 22B1 and a core cylinder-side cylinder portion 22B2 by a thin portion 22D.

However, as shown in FIG. 9, the valve seat member mounting portion 22A has a thin portion A having a thickness a 'of, for example, about 0.1 to 0.9 mm, preferably about 0.2 to 0.5 mm. '. Further, a portion extending between the actuator mounting portion 22B and the resin cover molding portion 22C is:
At least 0.1 with respect to the thickness dimension a 'of the thin portion A'
It is formed as a thick portion B 'having a large thickness dimension b' of not less than mm.

Thus, in the present embodiment configured as described above, substantially the same operation and effect as in the first embodiment can be obtained. In the present embodiment, in particular, the portion of the magnetic cylinder 22 extending between the actuator mounting portion 22B and the resin cover molding portion 22C is formed to be thick. 11, the magnetic cover 12, the connecting core 13 and the like, the resin material is removed from the actuator mounting portion 22 through a minute gap.
B and the pressure is applied to the actuator mounting portion 22B.
B can be reliably prevented from being deformed.

In each of the above embodiments, the magnetic cylinders 2 and 22 are formed integrally with a metal pipe or the like. However, the present invention is not limited to this. And the like may be joined to form a magnetic cylinder.

[0056]

As described in detail above, according to the first aspect of the present invention, the magnetic cylinder has a thickness of 0.1 to 0.9 mm extending between the valve seat member mounting portion and the actuator mounting portion. And
Since the thickness of the resin cover molded portion is formed to be at least 0.1 mm or more larger than the thickness of this portion, the portion of the magnetic cylinder extending between the valve seat member mounting portion and the actuator mounting portion is required. It can be formed as thin as possible. Further, since the resin cover molded portion of the magnetic cylinder can be formed to be thick, the resin cover molded portion can be given a sufficient strength according to, for example, the pressure applied when molding the resin cover. Therefore, the strength of the magnetic cylinder can be secured at a necessary portion, the resin cover can be smoothly molded with resin, the downsizing of the magnetic cylinder can be promoted, and the weight of the entire injection valve can be reduced.

On the other hand, according to the second aspect of the present invention, in the magnetic cylinder, the thickness of the valve seat member mounting portion is formed to be 0.1 to 0.9 mm, and the thickness of this portion is adjusted to the actuator. Since the thickness dimension between the mounting portion and the resin cover forming portion is formed to be at least 0.1 mm or more, the valve seat member mounting portion of the magnetic cylinder can be formed as thin as possible, and the resin cover forming portion can be formed. A portion extending between the portion and the actuator mounting portion can be formed thick. This allows
For example, even if a pressure or the like at the time of molding the resin cover is applied to the actuator mounting portion through a gap or the like near the electromagnetic actuator, it is possible to reliably prevent the deformation of this portion. Therefore, the strength of the magnetic cylinder can be secured at a necessary portion, the resin cover can be smoothly molded with the resin, and the entire injection valve including the magnetic cylinder can be reduced in weight.

According to the third aspect of the present invention, a core member is provided on the inner peripheral side of the actuator mounting portion of the magnetic cylinder.
The electromagnetic actuator is provided on the outer peripheral side of the actuator mounting portion, and the magnetic path forming member is provided on the outer peripheral side of the electromagnetic actuator. Therefore, when power is supplied to the electromagnetic actuator, the valve element, the core member, the magnetic cylinder, the magnetic path A closed magnetic path can be formed via a forming member or the like, and the valve element can be stably opened by magnetically attracting the valve element with the core member.

Further, according to the fourth aspect of the present invention, the resin cover is formed by injection molding integrally with the connector on the outer peripheral side of the resin cover molding portion of the magnetic cylinder. The resin material can be injection-molded on the outer peripheral side of the resin cover molded portion formed on the meat, and the resin can be easily molded in a state where the resin cover and the connector are integrated.

According to the fifth aspect of the present invention, the magnetic cylinder is provided with a thin portion for increasing the magnetic resistance of the magnetic cylinder at the position of the gap between the valve body and the core member. ,
For example, by simply applying mechanical processing such as pressing and cutting to the magnetic cylinder, a thin portion serving as a magnetically interrupted portion can be easily formed.When the electromagnetic actuator is activated, the valve portion and the core member are formed by the thin portion. The magnetic field can be formed stably during the period.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a fuel injection valve according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view showing a tip end side of a fuel injection valve.

FIG. 3 is an enlarged cross-sectional view of the fuel injection valve as viewed from a direction indicated by arrows III-III in FIG. 1;

FIG. 4 is a longitudinal sectional view showing the magnetic cylinder in FIG. 1 as a single body.

FIG. 5 is a longitudinal sectional view showing a state where a valve seat member, an electromagnetic coil, a magnetic cover, a connecting core, and the like are attached to a magnetic cylinder at the time of assembling the fuel injection valve.

FIG. 6 is a longitudinal sectional view showing a state where a magnetic cylinder and the like are arranged in a resin mold and a resin cover is molded with a resin.

FIG. 7 is a longitudinal sectional view showing a state where a valve body, a core cylinder, an urging spring, a spring receiver, and the like are assembled to the magnetic cylinder.

FIG. 8 is a longitudinal sectional view showing a fuel injection valve according to a second embodiment of the present invention.

9 is a longitudinal sectional view showing the magnetic cylinder in FIG. 8 as a single body.

[Explanation of symbols]

 1, 21 Valve casing 2, 22 Magnetic cylinder 2A, 22A Valve seat member attaching part 2B, 22B Actuator attaching part 2B1, 2B2, 22B1, 22B2 Tube part 2C, 22C Resin cover molding part 2D, 22D Thin part 3 Fuel passage 5 Valve seat member 5A Injection port 5B Valve seat 7 Valve 8 Core cylinder (Core member) 9 Urging spring 11 Electromagnetic coil (Electromagnetic actuator) 11A Coil bobbin 11B Coil 12 Magnetic cover (magnetic path forming member) 13 Connecting core 14 Resin cover 15 Connector a, b, a ', b' Thickness S Clearance

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hideo Kato 1370 Onna, Atsugi-shi, Kanagawa F-term in Unisia Gex Co., Ltd. 3G066 AA01 AB02 AD10 BA46 BA63 BA67 CC06U CC14 CC15 CC24 CC26 CD17 CD30 CE22 CE23 CE24 CE25 CE26 CE31

Claims (5)

[Claims] 1. A magnetic cylindrical body which is formed of a magnetic material into a cylindrical shape having a fuel passage therein, and has a valve seat member mounting portion on one side in the axial direction, an actuator mounting portion on an intermediate portion, and a resin cover molding portion on the other side. A valve seat member provided on the valve seat member mounting portion of the magnetic cylinder body and having a valve seat surrounding the injection port; and a valve seat of the valve seat member displaceably provided in the magnetic cylinder body. A valve body, an electromagnetic actuator provided at an actuator mounting portion of the magnetic cylinder to open and close the valve body, and a resin cover formed by resin molding at a resin cover molding portion of the magnetic cylinder. In the fuel injection valve, the magnetic cylinder has a thickness of 0.1 to 0.9 mm across the valve seat member mounting portion and the actuator mounting portion,
A fuel injection valve, wherein the thickness of the resin cover molding is formed to be at least 0.1 mm or more larger than the thickness of the valve seat member mounting portion and the actuator mounting portion. 2. A magnetic cylinder body formed of a magnetic material into a cylindrical shape having a fuel passage therein, one side in the axial direction being a valve seat member mounting portion, an intermediate portion being an actuator mounting portion, and the other side being a resin cover molding portion. A valve seat member provided at a valve seat member mounting portion of the magnetic cylinder body and having a valve seat surrounding an injection port; and a valve seat of the valve seat member displaceably provided in the magnetic cylinder body. An electromagnetic actuator provided on an actuator mounting portion of the magnetic cylinder for opening and closing the valve;
In a fuel injection valve comprising a resin cover formed by resin molding on a resin cover molding portion of the magnetic cylinder, the magnetic cylinder has a thickness dimension of the valve seat member mounting portion of 0.1.
To 0.9 mm, and the thickness dimension between the actuator mounting portion and the resin cover molding portion is formed to be at least 0.1 mm or more larger than the thickness dimension of the valve seat member mounting portion. Characteristic fuel injection valve. 3. A core member facing the valve body with an axial gap therebetween being provided on an inner peripheral side of an actuator mounting portion of the magnetic cylinder, and the electromagnetic actuator is inserted on an outer peripheral side of the actuator mounting portion. A magnetic path is formed by a fitted coil bobbin and a coil wound on the coil bobbin, and a magnetic path is formed on the outer peripheral side of the electromagnetic actuator so as to be magnetically connected to the magnetic cylinder on both axial sides of the electromagnetic actuator. 3. The fuel injection valve according to claim 1, further comprising a member. 4. The resin cover is provided by injection molding on an outer peripheral side of a resin cover molding portion of the magnetic cylinder, and a connector for supplying power to the electromagnetic actuator is integrally provided on the resin cover. 4. The fuel injection valve according to 2 or 3. 5. A core member facing the valve body with an axial gap interposed therebetween on the inner peripheral side of the actuator mounting portion of the magnetic cylinder, and a position where the gap is formed in the magnetic cylinder. 3. The fuel injection valve according to claim 1, further comprising a thin portion for increasing a magnetic resistance of the magnetic cylinder.