JP2003028022A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost fuel injection valve having small uneveness in performance, manufactured in a machining process, an assembling process or the like wherein influence of external force is reduced without increasing a cost, having a small difference between individuals without causing magnetic distortion to a magnet core 24, and allowing improvement of accuracy and parallelism between an armature 45 and the magnet core 24. SOLUTION: In this valve, the magnet core 24 and a core installation body 41 are integrated together by welding or the like such that one side of the magnet core 24 is a free end. The core installation body 41 for installing the magnet core 24 and the magnet core 24 are integrally fixed in a fixing end (an upper circumferential part 24D) of the magnet core 24, while an end part (an attraction face 24A) of the magnet core 24 opposite to the fixing end is set to the free end.

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, and more particularly to a fuel injection valve for injecting high pressure fuel supplied from a pressure accumulator (common rail) or the like at a predetermined timing.

[0002]

2. Description of the Related Art A conventional fuel injection valve will be outlined with reference to FIG. FIG. 4 is an enlarged cross-sectional view of a main part of the fuel injection valve 1, in which the fuel injection valve 1 includes an injector housing 2
The nozzle body 3, the nozzle needle 4, the valve piston 5, the valve body 6, and the back pressure control unit 7.

A nozzle body 3 is attached to the tip of the injector housing 2, and a high-pressure fuel introduction portion 8 is provided above the nozzle body 3. This high-pressure fuel introduction section 8
The back pressure control unit 7 is provided further above. The fuel from the fuel tank 9 is stored in the common rail 11 (accumulator) as high pressure by the fuel pump 10, and the high pressure fuel is supplied from the high pressure fuel introduction portion 8 to the fuel injection valve 1. That is, from the high-pressure fuel introduction part 8 to the injector housing 2
And the fuel passage 12 is formed between the nozzle body 3 and
High pressure fuel can be supplied to the pressure receiving portion 4A of the nozzle needle 4. Further, a part of the fuel passage 12 from the high-pressure fuel introduction portion 8 extends upward in FIG. 4 to form a fuel return passage 13 from the back pressure control portion 7 so that the fuel can be recirculated to the fuel tank 9.

An arbitrary number of fuel injection holes 14 are formed at the tip of the nozzle body 3, and the tip of the nozzle needle 4 seats on the seat portion 15 connected to the injection hole 14 to close the injection hole 14. The nozzle needle 4 is seated on the seat 1.
By lifting from 5, the injection hole 14 is opened and fuel can be injected.

A nozzle spring 16 for urging the nozzle needle 4 toward the seat portion 15 in the seat direction is provided above the nozzle needle 4, and a valve piston 5 integral with the nozzle needle 4 extends further upward.

The valve body 6 has a control pressure chamber 17 formed in the upper center thereof, and the tip of the valve piston 5 faces the control pressure chamber 17 from the lower side. The control pressure chamber 17 communicates with an introduction-side orifice 18 formed in the valve body 6. The introduction-side orifice 18 communicates with the fuel passage 12 and supplies the introduction pressure from the common rail 11 to the control pressure chamber 17.

The control pressure chamber 17 is also communicated with the opening / closing orifice 19, and the opening / closing orifice 19 can be opened and closed by the valve ball 20 (control valve body) of the back pressure control section 7. The pressure receiving area of the top portion 5A of the valve piston 5 in the control pressure chamber 17 is larger than the pressure receiving area of the pressure receiving portion 4A of the nozzle needle 4.

The back pressure control unit 7 controls the lift operation of the nozzle needle 4 by controlling the pressure in the control pressure chamber 17 (that is, the back pressure of the nozzle needle 4). The armature 21 integral with the valve ball 20, the armature guide 22, the magnet 23, the magnet core 24, the core mounting body 25, the valve spring 26, the gap adjusting collar 27, the connector 28, and the control pressure chamber described above. 17
And.

The armature 21 has a rod portion 21A.
Is axially guided by the armature guide 22, and its plate portion 21B, which is orthogonal to the rod portion 21A, maintains a predetermined parallelism with the tip portion 27A of the gap adjusting collar 27 so as to maintain the first gap L1. The (lift amount) is increased, and the second gap L2 is opened between the magnet core 24 and the attraction surface 24A while maintaining a predetermined parallelism.

The magnet 23 is housed in the magnet housing portion 24B of the magnet core 24 to generate a predetermined magnetic flux in the magnet core 24, so that the armature 21
The (plate portion 21B) can be sucked.

The magnet core 24 is made of a magnetic material. Fixed body 29 made of steel, etc.
At the inner step 29A of the
Of the magnet core 24, the core mounting body 25 is disposed on the upper portion of the magnet core 24, and the magnet core 24 is disposed between the inner step portion 29A and the caulking portion 29B of the fixing body 29.
The core mounting body 25 and the magnet core 24 are fixed to the injector housing 2 by tightening the retaining nut 30 that engages the outer protruding portion 29C of the fixing body 29 with the core mounting body 25 by pressure contact and integration. Install. The core mounting body 25 is made of a non-magnetic material, and the upper open portion is closed by the plug 31.

The gap adjusting collar 27 is inserted in the center hole 24C of the magnet core 24. A shim 32 is provided between the core adjusting body 25 and the gap adjusting collar 27 and the valve spring 26 so that the first gap L1 (lift amount) and the second gap L2 can be adjusted.

The connector 28 is connected to an external control circuit (not shown) and supplies a drive signal to the magnet 23 at a predetermined timing.

In the fuel injection valve 1 having such a structure, the high-pressure fuel from the common rail 11 is supplied from the high-pressure fuel introduction portion 8 through the fuel passage 12 to the pressure receiving portion 4A of the nozzle needle 4.
And is supplied to the top portion 5A of the valve piston 5 in the control pressure chamber 17 via the introduction-side orifice 18. Therefore, the nozzle needle 4 receives the back pressure of the control pressure chamber 17 via the valve piston 5, and together with the urging force of the nozzle spring 16, seats on the seat portion 15 of the nozzle body 3 and closes the injection hole 14. ing.

By supplying a drive signal from the connector 28 to the magnet 23 at a predetermined timing, the magnet 23 attracts the armature 21 against the urging force of the valve spring 26, and the valve ball 20 is lifted to open / close the orifice 19. When is released, the high pressure of the control pressure chamber 17 is returned to the fuel tank 9 through the fuel return passage 13 through the opening / closing orifice 19, so that the high pressure acting on the top portion 5A of the valve piston 5 in the control pressure chamber 17 is released. When released, the nozzle needle 4 lifts from the seat portion 15 against the urging force of the nozzle spring 16 by the high pressure of the pressure receiving portion 4A, releases the injection hole 14 and injects fuel. When the valve ball 20 closes the opening / closing orifice 19 by demagnetizing the magnet 23, the pressure in the control pressure chamber 17 causes the nozzle needle 4 to seat at its seat position (seat portion 15) via the valve piston 5. , The injection hole 14 is closed, and the fuel injection is ended.

However, in order to stabilize the magnetic characteristics of the magnet core 24, the internal magnetism generated by cutting or other mechanical processing is removed by annealing (magnetic annealing) before assembling, and thereafter, Ideally, it should be used as a product without any mechanical force. However, in reality, when the magnet core 24 is externally tightened or compressed by the caulking operation by the fixing body 29 and the tightening operation by the retaining nut 30, the internal distortion (compression strain) occurs. Cause the deterioration of the magnetic properties and the difference between the solids.

That is, as the mounting structure of the magnet core 24, the entire magnet core 24 is integrated with the fixing body 29 (product case) through the core mounting body 25, so that subsequent processing and mounting operations are performed. The change in magnetism due to is inevitable. Although not shown, although the magnet core 24 is provided separately,
When a caulking process or the like is performed at the time of assembly, internal stress is generated in the magnet core 24, and most of them are magnetically changed. Further, in any case, since the magnet core 24 facing the armature 21 (plate portion 21B) is in contact with, for example, the inner step portion 29A of the fixing body 29, the inner step portion 29 is formed.
There is a problem that magnetic leakage and magnetic loss from the magnet core 24 via A cannot be avoided, and the magnetic leakage itself tends to vary.

As a magnetic material of the magnet core 24, a sintered material has an advantage that it is easy to prevent the generation of an eddy current due to the presence of minute voids inside, but on the other hand, it is high in cost, high in pressure and high in accuracy. In the above fuel injection valve, the occurrence of the above-mentioned magnetic strain due to the action of external force cannot be ignored. Pure iron material is easy to process at low cost, and is thermally strong and can secure magnetic force performance, but unlike sintered materials, it does not have minute voids inside, so an eddy current prevention structure is required. At the same time, there is a problem that magnetostriction is likely to occur due to the action of an external force, and the efficiency tends to decrease, and there is a great demand for any material to reduce the influence of the external force during processing and assembly. Further, in the fuel injection valve 1 connected to the common rail 11, it is necessary to control the fuel injection amount per single stroke with extremely high accuracy, but there is also a demand for making this possible at low cost. Furthermore, in addition to injecting high-pressure fuel due to the request of the fuel injection system, there is a case where pilot injection (pre-injection) and main injection are required in addition to post-injection, and the magnet can be driven at extremely high speed within a short time. When excitation and demagnetization are performed, there is also a problem that the distortion due to the heat and the magnetic change generated cannot be ignored.

Next, the parallelism between the armature 21, the gap adjusting collar 27 and the magnet core 24 will be described. The plate portion 21 of the armature 21 will be described.
The respective parallelisms in the first gap L1 between B and the front end portion 27A of the gap adjusting collar 27 and the second gap L2 between the attraction surface 24A of the magnet core 24 are determined by the magnet core 24 and the core attachment. Body 2
5, the fixing body 29, the shim 32, the gap adjusting collar 27, the armature guide 22, and the armature 21 are created by accurately stacking the respective parts. It is difficult to improve the accuracy, and there are many parts that require high accuracy, resulting in high cost. In particular, in order to stabilize the characteristics of the magnet 23 and reduce the difference between the individual bodies, the armature 21 and the magnet core 2
It is necessary to minimize or optimize the air gap (second gap L2) with respect to 4 and to improve the accuracy of parallelism, and to reduce variations in these, as described above. There is a problem that the cost of the back pressure control section 7 is increased by assembling a plurality of parts.

Further, since the armature 21 is guided by the armature guide 22 at its rod portion 21A located on the opposite side of the first gap L1 and the second gap L2, the parallelism and accuracy of the gap are improved. There is a problem that it is difficult to improve.

Regarding this type of fuel injection valve, there are JP-A-8-165965 and JP-A-11-82228.

[0022]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a fuel injection valve having an improved magnet core mounting structure.

Another object of the present invention is to provide a fuel injection valve capable of improving the magnetic characteristics of the magnet core without increasing the cost.

Further, the present invention provides a fuel injection valve capable of reducing the influence of external force in the working process or the assembling process as much as possible, and reducing the difference between solids without causing magnetic distortion in the magnet core. This is an issue.

Another object of the present invention is to provide a fuel injection valve capable of reducing magnetic leakage or magnetic loss from the magnet core.

Another object of the present invention is to provide a fuel injection valve in which an optional material can be selected as a magnetic material such as a sintered material of a magnet core or a pure iron material.

Another object of the present invention is to provide a fuel injection valve having an improved armature sliding support structure.

Another object of the present invention is to provide a fuel injection valve capable of improving mutual parallelism and accuracy between the armature and the magnet core.

It is another object of the present invention to provide a fuel injection valve having an armature and a magnet core which are inexpensive and have little variation in performance.

[0030]

That is, according to the present invention, the magnet core and the core mounting body are integrated with each other by welding, welding or bonding without using a fixing body and other members, and the magnet core We paid attention to making one side a free end or an open state (cantilevered state) and providing a sliding part of the armature inside the magnet core. That is, the first invention is
The magnet core mounting structure has been improved.The control valve body opens and closes the control pressure chamber that controls the back pressure of the nozzle needle that can open and close the fuel injection hole, and the armature that drives this control valve body. And a magnet core and a magnet for attracting the armature, and controlling the pressure of the control pressure chamber by the control valve body to enable opening and closing of the injection hole by the nozzle needle. An injection valve, wherein a core mounting body for mounting the magnet core and the magnet core are integrally fixed at a fixed end of the magnet core, and an end portion of the magnet core opposite to the fixed end. Is a free end.

The magnet core and the core mounting body can be integrated with each other by welding, welding or adhering at the fixed end.

A second aspect of the present invention is an improved sliding support structure for an armature, which includes a control valve body for opening and closing a control pressure chamber for controlling the back pressure of a nozzle needle capable of opening and closing a fuel injection hole, An armature for driving the control valve body, and a magnet core and a magnet for attracting the armature are provided, and the pressure in the control pressure chamber is controlled by the control valve body, and by the nozzle needle. A fuel injection valve capable of opening and closing an injection hole, wherein a sliding guided portion extending to the magnet core side is formed on the armature, and the sliding guided portion is provided on the inner peripheral side of the magnet core. This is a fuel injection valve characterized by being able to be guided.

The sliding guided portion may be formed so as to be orthogonal to the plate portion facing the attraction surface of the magnet core in parallel.

The magnet core is fixed to a core mounting body, and the sliding guided portion can be guided by an armature guide portion formed on the core mounting body on the inner peripheral side of the magnet core. can do.

The magnet core may be provided with a slight annular space between a member located on the outer peripheral side thereof, for example, an injector housing for mounting the core mounting body.

The magnet core may be provided with a slight annular space between it and the core mounting body (for example, an armature guide portion formed on the core mounting body) located on the inner peripheral side of the magnet core.

The magnet core may be formed with a radial groove portion in the radial direction.

In the fuel injection valve according to the present invention, by improving the mounting structure of the magnet core and the sliding support structure of the armature, the magnetic characteristics of the magnet core are stabilized and the parallelism or accuracy of the magnet core and the armature is improved. By maintaining the level at a predetermined level, it is possible to ensure cost-effective and reliable performance.

In particular, according to the first aspect of the invention, a fixed state is adopted in which the magnet core is integrated with the core mounting body only at the fixed end, which is an integral part, by welding, welding, adhesion, or the like. One side of the side magnet core is set as a free end, and the magnetic core is opened at this free end side (cantilevered state), so to speak, a structure in which the magnet core is suspended at the fixed end is realized. It is possible to prevent the external force from directly acting on the core itself during and after the assembly. Therefore, it is possible to secure stable performance without causing distortion to the magnet core, reducing magnetic leakage, enabling use in the state of the best magnetic characteristics. Further, by providing a constant annular space between the magnet core and the member on the outer peripheral side thereof, for example, the injector housing, the center of the magnet core and the armature facing the magnet core are arranged within the range of the annular housing on the injector housing side. By adjusting the delivery, it is possible to contribute to the improvement of the assembly accuracy. Further, it is possible to reduce the cost by reducing the number of parts. Therefore, in the most efficient state, it is possible to obtain stable rise and fall characteristics of the magnetic force, reduce the product variation, and obtain the required performance at the same cost as the conventional one.

In particular, according to the second aspect of the invention, contrary to the prior art, the sliding guided portion extending toward the magnet core is formed in the armature, and the sliding guided portion is guided inside the magnet core. , The mutual parallelism can be obtained at a position closer to each other and more directly between the members to be combined. Thus, the parallelism and accuracy between the armature and the magnet core are improved to improve the performance, the number of parts is reduced, the solid difference or variation in cost and performance is reduced, and the durability and the reliability are improved. You can

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a fuel injection valve 40 according to a first embodiment of the present invention will be described with reference to FIGS. However, the same parts as in FIG.
The detailed description thereof will be omitted. 1 is an enlarged cross-sectional view of a main part of the fuel injection valve 40, and FIG. 2 is a cross-sectional view of the magnet core 24 portion taken along the line II-II of FIG. 1. In the fuel injection valve 40, the core mounting body 25 is shown. The magnet core 24 is integrated with the lower part of the core mounting body 41 corresponding to the above by laser welding or the like. That is, by welding the upper circumferential portion 24D (fixed end) of the magnet core 24 to the lower circumferential portion 41A of the core mounting body 41, the core mounting body 41 and the magnet core 24 are welded.
And are integrated with each other. It should be noted that a method such as welding or adhesion utilizing a frictional action or the like can also be adopted as the integrating means.

The core mounting body 41 is mounted on the injector housing 2 with a retaining nut 42 that engages with the outward protruding portion 41B. An O-ring 43 is provided between the injector housing 2 and the upper protruding portion 2A. The shim 44 is disposed between the injector housing 2 and the main body of the injector housing 2. Further, the core mounting body 41 has an armature guide portion 41C as a skirt portion at a portion corresponding to the gap adjusting collar 27 as a stopper portion of the armature 45.
Have integrally.

The armature 45 includes the valve ball 2
A rod portion 45A having 0, a plate portion 45B orthogonal to the rod portion 45A, and a sliding guided portion 45C orthogonal to the plate portion 45B. The sliding guided portion 45C is attached to the core mounting body. The armature guide portion 41C of 41 can slide and guide in the axial direction. The armature guide portion 41C is not press-fitted into the center hole 24C of the magnet core 24, but is simply fitted therein.

As described above, the magnet core 24 is cantileveredly integrated with the core mounting body 41 in the upper circumferential portion 24D thereof, and the attraction surface 24A opposite to the upper circumferential portion 24D has a free end. The armature 45 (plate portion 45B) faces the free end (suction surface 24A) in parallel.

The magnet core 24 has a first annular gap 46 formed between the magnet core 24 and the injector housing 2 located on the outer peripheral side thereof, and the core mounting body 41 is fitted into the upper protruding portion 2A of the injector housing 2 to form a magnet. It is possible to secure an adjustment allowance in the radial direction when setting the central axis of the core 24.

The outer peripheral surface of the armature guide portion 41C is partially shaved in the radial direction to thin this portion, and the second annular gap 4 is formed between the armature guide portion 41C and the central hole 24C of the magnet core 24.
7 is formed, magnetic leakage from the magnet core 24 via the armature guide portion 41C can be reduced, and a relief portion for expansion due to processing heat of the armature guide portion 41C is formed.

The first gap L1 (lift amount)
Is formed between the attraction surface 24A of the magnet core 24 and the plate portion 45B of the armature 45, and the second gap L2 is formed between the tip portion 41D of the armature guide portion 41C and the plate portion 45B. To form this.

As shown in FIG. 2, the magnet core 2
4, a radial groove portion 24E is formed in the radial direction thereof, and a communication passage 48 communicating with the radial groove portion 2E is formed in the core mounting body 41.

In the fuel injection valve 40 having such a structure,
The magnet core 24 is fixed only to the lower circumferential portion 41A of the core mounting body 41 at the upper circumferential portion 24D thereof, and the plate portion 4 of the armature 45 is fixed.
The suction surface 24A facing 5B is an open free end that is not in contact with any member, and a first annular gap 46 is provided between the injector housing 2 and the armature guide portion 41C. Second annular gap 47
Since the magnet core 24 is formed, the magnet core 24 is attached in a cantilever manner in a suspended state, and no external force acts on the magnet core 24.

Therefore, even when an external force acts on the fuel injection valve 40 or the injector housing 2 after assembly as well as during processing or assembly, stress distortion does not occur in the magnet core 24 and its magnetic characteristics change. In addition, it is unlikely that there will be a difference in properties between solids.

Further, the armature 45 is axially guided by the armature guide portion 41C of the core mounting body 41 at the sliding guided portion 45C on the side of the magnet core 24, and the armature 45 and the magnet core 2 are guided.
The parallelism with the suction surface 24A of No. 4 can be ensured more accurately and relatively easily, and the performance can be improved and the number of parts can be reduced, and the cost can be reduced.

Since the radial groove portion 24E formed in the magnet core 24 and the communication passage 48 formed in the core mounting body 41 communicate with each other, the armature 45 is provided.
It is possible to facilitate the movement of fuel in the upstream and downstream directions of the armature 45 associated with the axial reciprocating movement of the armature 45, and to maintain the response speed of the armature 45 at a predetermined level. The magnet core 24 has a radial groove portion 2 even when a pure iron material is adopted.
The presence of 4E can prevent the generation of eddy currents in the circumferential direction.

FIG. 3 is an enlarged sectional view of a main part of a fuel injection valve 50 according to a second embodiment of the present invention. The fuel injection valve 50 has a core similar to that of the fuel injection valve 40 (FIG. 1). The integrated structure of the core mounting body 25 (FIG. 4) corresponding to the mounting body 41 and the magnet core 24 (magnet core mounting structure) has an upper circumferential portion 24D (fixed end) of the magnet core 24 and the core mounting body 25. The lower circumferential portion 25A of the core mounting body 25 is integrated with each other by welding or the like, and also as the armature sliding support structure,
The armature guide portion 25B of the armature 45
The sliding guided portion 45C is guided in the axial direction.

However, in the fuel injection valve 50,
When attaching the core attachment body 25 to the injector housing 2, the fixing body 29 having a crimping structure and the retaining nut 30 are used.

The magnet core 24 and the fixing body 29 located on the outer peripheral side thereof have the first annular gap 46.
Is formed. The second gap L2 is formed by the tip portion 25C of the armature guide portion 25B and the plate portion 45.
It forms with B.

Also in the fuel injection valve 50 having such a structure, the magnet core 24 is cantilevered with respect to the core mounting body 25 as described above, so that the magnet core 24 is not distorted and good magnetic properties are obtained. The characteristics can be obtained. Further, by guiding the armature 45 by the armature guide portion 25B of the core mounting body 25, parallelism and accuracy between the armature 45 and the magnet core 24 can be obtained at a predetermined level, and stable performance is obtained. Can be secured. Furthermore, most of the components of the conventional fuel injection valve 1 (FIG. 4) can be used as they are, and an increase in cost can be suppressed.

[0057]

As described above, according to the present invention, the magnet core is integrated with the core mounting body and the armature is guided on the side of the magnet core, so that no magnetic strain is generated in the magnet core. It is possible to reduce the cost and manufacture while ensuring the parallelism and accuracy between the respective parts, and to improve the stability and the reliability.

[Brief description of drawings]

FIG. 1 is a fuel injection valve 4 according to a first embodiment of the present invention.
It is a principal part expanded sectional view of 0.

FIG. 2 is a magnet core 2 taken along line II-II in FIG.
It is sectional drawing of 4 parts.

FIG. 3 is a fuel injection valve 5 according to a second embodiment of the present invention.
It is a principal part expanded sectional view of 0.

FIG. 4 is an enlarged cross-sectional view of a main part of a conventional fuel injection valve.

[Explanation of symbols]

1 Fuel injection valve (Fig. 4) 2 Injector housing 2A Upper protruding part of injector housing 2 (Fig. 1) 3 Nozzle body 4 Nozzle needle 4A Pressure receiving part of nozzle needle 4 Valve piston 5A Top of valve piston 5 Valve body 7 Back Pressure control unit 8 High-pressure fuel introduction unit 9 Fuel tank 10 Fuel pump 11 Common rail (accumulator) 12 Fuel passage 13 Fuel return passage 14 Injection hole 15 Seat portion 16 Nozzle spring 17 Control pressure chamber 18 Introduction side orifice 19 Opening / closing orifice 20 Valve Ball (control valve body) 21 Armature 21A Rod part 21B of armature 21 Plate part 22 of armature 21 Armature guide 23 Magnet 24 Magnet core 24A Suction surface (free end) of magnet core 24 24B Magnet core 24 Gnet accommodating portion 24C Center hole 24D of magnet core 24 Upper circumferential portion of magnet core 24 (fixed end, FIG. 1) 24E Radial groove portion of magnet core 24 (FIG. 2) 25 Core mounting body (FIG. 3, FIG. 4) 25A Lower circumference of the core mounting body 25 (Fig. 3) 25B Armature guide part of the core mounting body 25 (Fig. 3) 25C Tip of the armature guide part 25B (Fig. 3) 26 Valve spring 27 Gap adjusting collar 27A Gap adjusting collar 27 Tip part 28 connector 29 fixing body 29A fixing body 29 inner step portion 29B fixing body 29 caulking portion 29C fixing body 29 outer protruding portion 30 retaining nut 31 plug 32 shim 40 fuel injection valve ( 1st Embodiment, FIG. 1) 41 core mounting body 41A core mounting Lower circumferential portion 41B of body 41 Outer protrusion 41C of core mounting body 41C Armature guide portion 41D of core mounting body 41 Tip of armature guide portion 41C 42 Retaining nut 43 O-ring 44 Shim 45 Armature 45A Rod of armature 45 Part 45B Plate part 45C of armature 45C Sliding guided part 46 of armature 45 First annular gap 47 Second annular gap 48 Communication passage 50 Fuel injection valve (second embodiment, FIG. 3) L1 First Gap (lift amount) L2 Second gap

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI theme code (reference) H01F 7/121 H01F 7/16 E 7/16 RF (72) Inventor Kenichi Kubo Yasumimachi, Higashimatsuyama City, Saitama Prefecture 3-Chome 13-26 Co., Ltd. Bosch Automotive Systems H-Matsuyama Factory F-term (reference) 3G066 AB02 AC09 BA51 BA53 BA61 BA66 CC06T CC08T CC14 CC68U CC70 CD04 CE23 5E048 AB01 AD03 CA07

Claims (8)

[Claims] 1. A control valve body for opening and closing a control pressure chamber for controlling the back pressure of a nozzle needle capable of opening and closing a fuel injection hole, an armature for driving the control valve body, and suction for the armature. A fuel injection valve having a magnet core and a magnet for controlling the pressure of the control pressure chamber by the control valve body to enable opening and closing of the injection hole by the nozzle needle, A core mounting body for mounting the magnet core and the magnet core are integrally fixed at a fixed end of the magnet core, and an end of the magnet core opposite to the fixed end is a free end. Fuel injection valve characterized by. 2. The fuel injection valve according to claim 1, wherein the magnet core and the core mounting body are integrated with each other by welding, welding, or adhering at the fixed end. 3. A control valve body for opening and closing a control pressure chamber for controlling the back pressure of a nozzle needle capable of opening and closing a fuel injection hole, an armature for driving this control valve body, and suction for this armature. A fuel injection valve having a magnet core and a magnet for controlling the pressure of the control pressure chamber by the control valve body to enable opening and closing of the injection hole by the nozzle needle, A fuel injection valve characterized in that a sliding guided portion extending to the magnet core side is formed on the armature, and the sliding guided portion can be guided on an inner peripheral side of the magnet core. 4. The fuel injection valve according to claim 3, wherein the sliding guided portion is formed so as to be orthogonal to a plate portion facing in parallel to the attraction surface of the magnet core. 5. The magnet core is fixed to a core mounting body, and the sliding guided portion is guided by an armature guide portion formed on the core mounting body on an inner peripheral side of the magnet core. The fuel injection valve according to claim 3, wherein the fuel injection valve is made possible. 6. The fuel injection valve according to claim 1, wherein the magnet core is provided with a slight annular space between the magnet core and a member located on the outer peripheral side thereof. 7. The fuel injection valve according to claim 1, wherein the magnet core is provided with a slight annular space between the magnet core and the core mounting body located on the inner peripheral side thereof. 8. The fuel injection valve according to claim 1, wherein the magnet core is formed with a radial groove portion in a radial direction thereof.