JP2002357167A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability and reliability of a magnetic cylinder unit, by using ferrite stainless steel material containing titanium to form the magnetic cylinder unit. SOLUTION: A magnetic cylinder unit 2 is formed by using a ferrite stainless steel material containing titanium. The magnetic cylinder unit 2 is assembled with a valve seat member 5, a valve element 7, an electromagnetic coil 11, a resin cover 14, etc. When the magnetic cylinder unit 2 is formed, a metal plate 16 is plastically deformed by, for instance, deep drawing work or the like, a valve seat member mounting part 2A, an actuator mounting part 2B, a resin cover forming part 2C, etc., are worked to be molded into a stepped cylindrical shape. Therefore, for instance, even in the case of forming the magnetic cylinder unit 2 of slender stepped cylindrical shape in thin thickness, while ensuring its strength and corrosion resistance, flexibility can be given to the ferrite stainless steel material by titanium, workability of the magnetic cylinder unit 2 can be improved.

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. (Eg DE 195 47 406 A1)
JP, JP-A-2000-8990).

[0003] In a fuel injection valve of this type according to the related art, a main body of a valve casing is formed of a magnetic cylinder. The magnetic cylinder is made of, for example, an electromagnetic stainless steel (S
US430) or the like, and is formed by means such as drawing. In this case, in order to reduce the weight of the injection valve, the magnetic cylinder is often made as thin as possible within the range of strength.

[0004] A cylindrical valve seat member is provided on the distal end side of the magnetic cylinder via, for example, a metal holder or the like, and the valve seat inserted into the magnetic cylinder is provided on the valve seat member. A valve seat for detaching and seating is provided. A core member that magnetically attracts and opens the valve body when the electromagnetic coil is operated is provided on the inner circumference of the base end side of the magnetic cylinder. An electromagnetic coil and a resin cover are provided on the outer peripheral side of the magnetic cylinder.

[0005]

By the way, in the above-mentioned prior art, a magnetic cylinder is formed by forming a generally widely known electromagnetic stainless steel such as SUS430 into an elongated pipe shape. And
In this case, at the time of forming the magnetic cylinder, it is necessary to form the entire length of the magnetic cylinder thin while plastically deforming the metal material into a pipe shape by means such as drawing. Further, when designing the injection valve, for example, in order to provide a mounting portion and a positioning portion of each component including a valve seat member, an electromagnetic actuator, a core member, and the like on the magnetic cylinder, there is also a case where it is desired to form the magnetic cylinder into a stepped cylindrical shape. is there.

However, when forming the magnetic cylinder, if the thickness of the magnetic cylinder is reduced by means of drawing or the like, or if the magnetic cylinder is formed into a complicated stepped shape or the like, the metal material becomes thin and complicated. And the magnetic cylinder is likely to be damaged, such as cracks or breaks, during the molding process.

For this reason, in the prior art, the yield of the magnetic cylinder is reduced, and not only the injection valve cannot be manufactured efficiently, but also the strength of the magnetic cylinder may vary due to excessive deformation during molding. Yes, there is a problem that reliability is reduced.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to make it possible to easily process and form a magnetic cylinder into a thin and complicated shape. It is another object of the present invention to provide a fuel injection valve capable of stably maintaining the strength of a magnetic cylinder and improving productivity and reliability.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a magnetic cylinder having a cylindrical shape formed of a magnetic material and having a fuel passage therein, and an injection port provided in the magnetic cylinder. A fuel injection valve comprising: a valve seat member surrounding a valve seat and having a valve seat formed therein; and a valve body that is displaceably provided in the magnetic cylinder and is detachably attached to the valve seat of the valve seat member when an electromagnetic actuator is operated. Applied to

A feature of the structure adopted in the first aspect of the invention is that the magnetic cylinder is formed using a ferrite stainless steel material containing titanium.

According to this structure, the flexibility (elongation) of the magnetic cylinder can be enhanced while securing the strength and corrosion resistance of the magnetic cylinder by incorporating titanium into the ferritic stainless steel material. Therefore, at the time of forming the magnetic cylinder, the stainless material can be plastically deformed stably by, for example, press working, roll working, or the like, and the workability can be improved.

According to the second aspect of the present invention, the ferritic stainless steel material of the magnetic cylinder contains the titanium in an amount of 0.2 to 0.2.
It is configured to contain 0.6% by weight.

[0013] Thereby, the hardness of the stainless steel material forming the magnetic cylinder can be appropriately softened within an allowable range, and the elongation of the stainless steel material can be increased.
Even a magnetic cylinder having a complicated shape can be easily processed and formed.

According to the third aspect of the present invention, the ferrite-based stainless steel material of the magnetic cylinder contains 0.01 to 0.1 carbon.
It is configured to contain 12% by weight so that the titanium content is higher than the carbon content.

Thus, the ferrite-based stainless steel material can be formed while keeping the carbon content in the stainless steel material small, and the corrosion resistance can be improved.
In addition, by including more titanium than carbon, stable flexibility can be given to the stainless steel material.

Further, according to the invention of claim 4, the magnetic cylinder is formed by a stepped cylinder which forms a step at an intermediate portion in the axial direction.

Thus, a stepped magnetic cylinder can be easily formed using a ferrite-based stainless steel-containing material, and each part of the magnetic cylinder includes, for example, a valve seat member and an electromagnetic actuator. In addition, it is possible to form a mounting portion for various components.

Further, according to the invention of claim 5, the magnetic cylinder is formed by plastically deforming a metal plate into a cylindrical shape by deep drawing means.

Thus, a thin stainless steel plate can be plastically deformed into a cylindrical shape in the thickness direction by a jig such as a punch, and a magnetic cylinder can be easily formed.

According to the invention of claim 6, a core member facing the valve body with an axial gap therebetween is provided in the magnetic cylinder, and the magnetic cylinder is provided at a position where the gap is formed. The magnetic cylinder is provided with a thin portion for increasing the magnetic resistance.

Thus, a thin portion can be formed at an intermediate position in the longitudinal direction of the magnetic cylinder by means of, for example, press working, grinding, or the like. This thin portion corresponds to the portion of the magnetic cylinder where the valve element is disposed. It is possible to magnetically shut off the portion where the core member is arranged. 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.

[0022]

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 8 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 which 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 stepped cylindrical magnetic cylinder constituting a main body of the valve casing 1. The magnetic cylinder 2 is made of a ferrite stainless steel material containing titanium as will be described later. 1, etc. by pressing means such as
As shown in FIG. 7, it is formed as a thin metal pipe having a stepped shape, and has a predetermined thickness dimension of, for example, about 0.1 to 0.9 mm.

The magnetic cylinder 2 has a valve seat member mounting portion 2A located on one side (distal end side) in the axial direction and a stepped portion on the other axial side (base end side) of the valve seat member mounting portion 2A. An actuator mounting portion 2B formed through the portion 2B1 and having a diameter larger than that of the valve seat member mounting portion 2A;
And a resin cover forming portion 2C formed at the base end side with a step portion 2C1 and having a diameter larger than that of the actuator mounting portion 2B.

An annular thin portion 2D is provided at an intermediate position in the longitudinal direction of the actuator mounting portion 2B so as to surround a gap S between a valve body 7 and a core tube 8 which will be described later.
D divides the actuator mounting portion 2B into a valve body side tubular portion 2B2 in which a valve body 7 described later is displaceably accommodated and a core member side tubular portion 2B3 in which the core tube 8 is inserted. The thin-walled portion 2D increases the magnetic resistance between the valve body-side cylinder portion 2B2 and the core member-side cylinder portion 2B3 to magnetically cut off the two, and a magnetic field between these cylinder portions 2B2 and 2B3 described later. H is prevented from being short-circuited.

Here, the stainless steel material constituting the magnetic cylinder 2 will be described. For example, the stainless steel material contains 0.01 to 0.12% by weight of carbon (preferably 0.01% by weight).
-0.05% by weight) and containing 16% by weight or more of chromium,
0.08% by weight or more of nickel and 0.2 to 0.1% of titanium.
6% by weight, and the content of titanium is formed larger than the content of carbon.

In this case, in this embodiment, as shown in Example 1, 2 or 3 of Table 1 below, for example, SUS430
The magnetic cylinder 2 is formed using a ferritic stainless steel material such as M2, SUS430M3, and SUS430WD.

[0030]

[Table 1]

In the present embodiment, the strength and corrosion resistance of the magnetic cylinder 2 are secured by using a ferritic stainless steel material, and the flexibility (elongation) of the magnetic cylinder 2 is enhanced by titanium as shown in Table 2 below. Etc.) to improve the workability when performing deep drawing or the like.

Reference numeral 3 denotes a fuel passage provided in the magnetic cylinder 2. The fuel passage 3 extends in the axial direction from the resin cover forming portion 2 C of the magnetic cylinder 2 to the position of the valve seat member 5 as shown in FIG. Extending. Further, a fuel filter 4 for filtering the fuel supplied into the fuel passage 3 from the base end side of the magnetic cylinder 2 is provided in the resin cover forming portion 2C.

Numeral 5 is a cylindrical valve seat member fitted and provided 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. An injection port 5A for injecting the fuel inside to the outside and a substantially conical valve seat 5B formed surrounding the injection port 5A are provided. 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.

Numeral 7 denotes a valve body which is displaceably accommodated in the valve body side cylinder portion 2B2 of the magnetic cylinder body 2. The valve body 7 has a cylindrical valve shaft 7A extending in the axial direction as shown in FIG. And a spherical valve portion 7B fixed to the distal end side of the valve shaft 7A and detachably seated on the valve seat 5B of the valve seat member 5, and a valve shaft 7A made of, for example, a magnetic metal material.
And a cylindrical suction portion 7 </ b> C slidably inserted into the magnetic cylindrical body 2.

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. The valve is opened against the spring force of the spring 9.

Reference numeral 8 denotes a core tube as a core member formed of, for example, a magnetic metal material or the like, and the core tube 8 is inserted into the core member side tube portion 2B3 of the magnetic tube 2 by means such as press fitting. It is fitted and fixed to the magnetic cylinder 2.

Reference numeral 9 denotes an urging spring provided in the magnetic cylinder 2. The urging spring 9 includes a cylindrical spring receiver 10 fixed to the inner peripheral side of the core cylinder 8 by press-fitting or the like and a valve. 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.

Reference numeral 11 denotes an electromagnetic coil as an electromagnetic actuator which is inserted and fitted on the outer peripheral side of the actuator mounting portion 2B of the magnetic cylinder 2, and the electromagnetic coil 11 is supplied with power by using a connector 15 described later. As a result, a magnetic field H is generated, and the valve 7 is opened against the spring force of the biasing spring 9.

Numeral 12 is a magnetic cover formed in a stepped cylindrical shape from a magnetic metal material or the like.
As shown in FIGS. 2 and 3, a large-diameter cylindrical portion 12 </ b> A provided on the outer peripheral side of the electromagnetic coil 11 and a valve-body-side cylindrical portion of the magnetic cylindrical body 2 which are integrally formed at the distal end of the large-diameter cylindrical portion 12 </ b> A. A small-diameter cylindrical portion 12B fitted and fixed to the outer peripheral side of 2B2. Between the large-diameter tubular portion 12A and the core-member-side tubular portion 2B3 of the magnetic tubular body 2, a connection core 13 formed in a substantially C shape by a magnetic material or the like is inserted.

Thus, the magnetic cover 12 is magnetically connected to the magnetic cylinder 2 on both axial sides of the electromagnetic coil 11 by the small-diameter cylindrical portion 12B and the connecting core 13. When the electromagnetic coil 11 operates, the magnetic cylinder 2
The valve body-side tubular portion 2B2 and the core member-side tubular portion 2B3 are thin portions 2
D, the cylinder 2B2, 2B3, the suction portion 7C of the valve body 7, the core cylinder 8,
The magnetic field H can be stably formed along the magnetic cover 12 and the connecting core 13, 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 forming portion 2C of the magnetic cylinder 2 by means of, for example, injection molding. The resin cover 14 has an electromagnetic coil as shown in FIG. A connector 15 for supplying power to the power supply 11 is integrally molded with resin.

The fuel injection valve according to this 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.

Also, as to the assembly operation of the injection valve, first, in the magnetic cylinder forming step shown in FIGS.
For example, the magnetic cylinder 2 is formed by applying three stages of deep drawing to the metal plate 16.

In this step, as shown in FIG.
First, a thin metal plate 16 made of a ferritic stainless steel material to be the magnetic cylinder 2 is prepared. Next, as shown in FIG. 5, the metal plate 16 is disposed between the die 17A of the press working device 17 and the pressing plate 17B, and the metal plate 16 is moved in the thickness direction by a punch 17C having a predetermined outer diameter. And the metal plate 16 is plastically deformed into a cylindrical shape.
A second deep drawing process is performed to form a small-diameter portion 16A serving as a valve seat member attaching portion 2A of the magnetic cylinder 2, for example.

Next, as shown in FIG. 6, the die 17D corresponding to the actuator mounting portion 2B of the magnetic cylinder 2 and the pressing plate 17
E, by performing a second deep drawing using the punch 17F, an intermediate-diameter portion 16B serving as the actuator mounting portion 2B is formed at the base end side of the small-diameter portion 16A, and a punch corresponding to the resin cover forming portion 2C is formed. By performing the third deep drawing using the method described above, a large-diameter portion serving as the actuator mounting portion 2B is formed on the base end side of the intermediate-diameter portion 16B. Then, these cylindrical portions are separated from the metal plate 16 and a thin-walled portion 2D is provided by means of, for example, cutting, pressing, or the like, so that the magnetic cylindrical body 2 is formed as shown in FIG.
To form

In this case, the metal plate 16 serving as the magnetic cylinder 2
Is made of a ferritic stainless steel material containing titanium, as shown in Examples 1 to 3 in Table 1 above, and is compared with a stainless steel material of SUS430 listed as a comparative example, for example, as shown in Table 2 below. Then, the elongation percentage of the metal plate 16 is increased, and the hardness thereof (in Table 2 below, a measured value of Vickers hardness is exemplified as hardness) can be appropriately softened.

[0048]

[Table 2]

Thus, when the magnetic cylinder 2 is processed and formed, the metal plate 16 can be plastically deformed flexibly by the press processing device 17, and the thin magnetic cylinder 2 having the steps 2B1, 2C1, etc. is press-formed. Even in this case, it is possible to prevent the metal plate 16 from being damaged, such as cracking or breaking, due to excessive deformation or the like during the molding process.

Next, in the component assembling step shown in FIG. 8, first, the electromagnetic coil 11 and the magnetic cover 12
After the resin cover 14 is injection-molded on the outer peripheral side of the coupling core 13, the valve body 7, the core cylinder 8, the biasing spring 9, and the spring receiver 10 are assembled to the magnetic cylinder 2. Thereby, the injection valve can be assembled.

Thus, according to the present embodiment, the magnetic cylinder 2 is formed of a ferritic stainless steel material containing titanium, so that the strength and corrosion resistance of the magnetic cylinder 2 are ensured while its flexibility is maintained. Can be enhanced.
Thereby, at the time of forming the magnetic cylinder 2, the metal plate 16 can be plastically deformed stably by means of, for example, deep drawing, and its workability can be improved.

Therefore, even when a thin and long stepped cylindrical magnetic cylinder 2 is formed, the magnetic cylinder 2 can be easily processed and formed using the metal plate 16 by means of, for example, deep drawing. Seat member mounting portion 2A, actuator mounting portion 2
B, high dimensional accuracy and stable strength can be given to the resin cover forming portion 2C and the like. Thereby, the yield of the magnetic cylinder 2 can be increased, and the productivity and reliability of the injection valve can be improved.

In this case, the content of titanium contained in the magnetic cylinder 2 is, for example, 0.2 to 0.6% by weight and is formed so as to be larger than the content of carbon. As a result, the hardness of the stainless steel material can be appropriately softened within an allowable range, and its elongation can be sufficiently increased. Also, since the content of carbon can be suppressed to a small value,
The corrosion resistance of the magnetic cylinder 2 can be improved.

Further, as shown in Examples 1 to 3 in Table 1 above, the ferritic stainless steel material for forming the magnetic cylinder 2 is as follows.
Since the carbon content is suppressed to a very small amount of 0.05% by weight or less, the corrosion resistance can be further improved. In particular, since the stainless steel material of Example 2 contains, for example, 0.3% by weight or more of molybdenum, it is possible to further increase the corrosion resistance and extend the life of the injection valve.

On the other hand, 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 body 2 provided with the thin-walled portion 2D serving as a magnetically interrupted portion can be easily formed only by subjecting the metal pipe to mechanical processing such as press working or cutting work. The number of parts of the valve can be reduced and the structure can be simplified.

FIGS. 9 to 11 show a second embodiment of the present invention. The feature of this embodiment is that a metal plate is formed by bending a metal plate into a cylindrical shape and welding it. I did it.

Numeral 21 denotes a magnetic cylinder used in place of the magnetic cylinder 2 of the first embodiment. The magnetic cylinder 21 is made of a ferrite-based material containing titanium in substantially the same manner as in the first embodiment. Made of stainless steel, the valve seat member mounting portion 21A, the actuator mounting portion 21B, the resin cover forming portion 21C,
Thin portion 21D, step portions 21B1, 21C1, cylindrical portion 21B2,
21B3. However, the magnetic cylinder 2
Numeral 1 is made of a metal plate curved in a cylindrical shape, and a welding portion 22 extending over the entire length of the magnetic cylindrical body 21 is provided at one location in the circumferential direction by welding means such as seam welding. .

In this case, at the time of forming the magnetic cylinder 21, as shown in FIG. 10, a metal plate is first bent into a cylindrical shape by means of a roll process or the like, and both ends of the metal plate are brought into contact with each other by welding means such as seam welding. Is performed to form the cylindrical body 23.
Then, the cylindrical body 23 is formed into a stepped cylindrical shape by subjecting the cylindrical body 23 to drawing from outside in the radial direction using, for example, a roll 24, a rod 25, and the like. It is formed as a valve seat member attaching portion 21A, an actuator attaching portion 21B, and a resin cover forming portion 21C of the body 21.

Thus, also in the present embodiment configured as described above, it is possible to obtain substantially the same operation and effect as in the first embodiment. In the present embodiment, in particular, the elongated stepped cylindrical magnetic cylinder 21 can be easily formed by simply bending the metal plate into a cylindrical shape and performing means such as seam welding and drawing. .

In each of the above embodiments, the ferrite stainless steel containing titanium is used for the magnetic cylinders 2 and 21. However, the present invention is not limited to this. For example, the ferrite stainless steel containing titanium may be used. 0.3% by weight
Copper (Cu) and niobium (N
b) or both of these elements may be included to further enhance the corrosion resistance and strength of the magnetic cylinder.

In each of the above embodiments, for example, SU
S430M2, SUS430M3, SUS430WD and other ferritic stainless steel materials were used,
The type of element contained in the magnetic cylinder of the present invention, the specific value of the content, and the like are not limited to these examples, and the present invention provides various ferrites containing titanium while suppressing the carbon content. It is needless to say that the present invention is applied to a stainless steel material.

[0062]

As described in detail above, according to the first aspect of the present invention, since the magnetic cylinder is made of a ferrite stainless steel material containing titanium, the strength and the corrosion resistance of the magnetic cylinder can be secured. , Its flexibility can be increased. Thus, for example, even when a thin and long magnetic cylinder is formed, the stainless material can be plastically deformed stably, and its workability can be enhanced. Therefore, high dimensional accuracy and stable strength can be given to each part of the magnetic cylinder, the yield of the magnetic cylinder can be increased, and the productivity and reliability of the injection valve can be improved.

According to the second aspect of the present invention, the ferritic stainless steel material of the magnetic cylinder contains titanium in an amount of 0.2 to 0.1.
Since it is configured to contain 6% by weight, the hardness of the stainless steel material can be appropriately softened within the allowable range according to the titanium content, and the elongation can be sufficiently increased. Thus, even a magnetic cylinder having a complicated shape can be easily processed and formed.

According to the third aspect of the present invention, the ferritic stainless steel material of the magnetic cylinder contains 0.01 to 0.1 carbon.
The ferrite-based stainless steel material is formed by controlling the content of carbon in the stainless steel material to be small, since the content is 12 wt% and the content of the titanium is higher than that of the carbon. And its corrosion resistance can be improved. In addition, by including more titanium than carbon, stable flexibility can be given to the stainless steel material.

Further, according to the fourth aspect of the present invention, the magnetic cylinder is formed by a stepped cylinder which forms a step at an intermediate portion in the axial direction. Therefore, a ferrite stainless steel containing titanium is used. The stepped magnetic cylinder can be easily processed and formed by using it, and for example, a mounting portion of various parts including a valve seat member, an electromagnetic actuator and the like can be formed with high dimensional accuracy.

According to the fifth aspect of the present invention, since the magnetic cylinder is formed by plastically deforming a metal plate into a cylindrical shape by means of a deep drawing process, for example, a thin and elongated magnetic cylinder is formed. Even in this case, the ferrite stainless steel containing titanium can be easily plastically deformed in the thickness direction by a jig such as a punch, and the work forming can be easily performed.

According to the sixth 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 partially enlarged cross-sectional view showing a metal plate formed of a ferrite stainless steel material containing titanium to be a magnetic cylinder.

FIG. 5 is a partially enlarged cross-sectional view showing a state in which a portion serving as a valve seat member attachment portion of a magnetic cylinder is formed by performing a first deep drawing process on a metal plate.

FIG. 6 is a partially enlarged cross-sectional view showing a state where a portion to be an actuator mounting portion of a magnetic cylinder is formed by performing a second deep drawing process on a metal plate.

FIG. 7 is a longitudinal sectional view showing a single magnetic cylinder formed by subjecting a metal plate to a third deep drawing or the like.

FIG. 8 is a longitudinal sectional view showing a state in which the injection valve is assembled by attaching each component to the magnetic cylinder.

FIG. 9 is a longitudinal sectional view showing a magnetic cylinder of a fuel injection valve according to a second embodiment of the present invention.

FIG. 10 is a partially enlarged cross-sectional view showing a state in which a cylindrical body serving as a magnetic cylinder is formed by a metal plate.

FIG. 11 is a partially enlarged cross-sectional view showing a state where a drawing process is being performed on a cylindrical body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve casing 2, 21 Magnetic cylinder 2A, 21A Valve seat member attaching part 2B, 21B Actuator attaching part 2C, 21C Resin cover forming part 2D, 21D Thin part 3 Fuel passage 5 Valve seat member 5A Injection port 5B Valve seat 7 Valve Body 8 core cylinder (core member) 9 biasing spring 11 electromagnetic coil (electromagnetic actuator) 12 magnetic cover 13 connecting core 14 resin cover 15 connector S gap

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Okada 1370 Onna, Atsugi-shi, Kanagawa F-term in Unisia Gex Co., Ltd. (reference) 3G066 AA01 AB02 AD10 BA46 BA50 BA54 CC03 CC06U CC15 CD28 CE26 CE31

Claims (6)

[Claims] 1. A magnetic cylinder body formed of a magnetic material in a cylindrical shape and having a fuel passage inside, a valve seat member provided in the magnetic cylinder body, and a valve seat surrounding an injection port; A fuel injection valve comprising: a valve body displaceably provided in a cylinder body and a valve body detachably attached to a valve seat of the valve seat member when an electromagnetic actuator operates, wherein the magnetic cylinder body is made of a ferritic stainless steel material containing titanium. A fuel injection valve characterized by comprising: 2. The fuel injection valve according to claim 1, wherein the ferritic stainless steel material of the magnetic cylinder contains the titanium in an amount of 0.2 to 0.6% by weight. 3. The ferritic stainless steel material of the magnetic cylinder contains 0.01 to 0.12% by weight of carbon, and is formed so that the content of the titanium is higher than that of the carbon. The fuel injection valve according to claim 1. 4. The fuel injection valve according to claim 1, wherein the magnetic cylinder is formed by a stepped cylinder that forms a step at an intermediate portion in the axial direction. 5. The magnetic cylinder body is formed by plastically deforming a metal plate into a cylindrical shape by deep drawing processing means.
5. The fuel injection valve according to 2, 3, or 4. 6. A core member facing the valve body with an axial gap interposed between the magnetic cylinder and a magnetic resistance of the magnetic cylinder at a position where the gap is formed in the magnetic cylinder. 5. A thin-walled portion for increasing the thickness
Or the fuel injection valve according to 5.