CN100359156C

CN100359156C - Fuel injector

Info

Publication number: CN100359156C
Application number: CNB2004100749577A
Authority: CN
Inventors: 千嶋正俊; 久保贤一
Original assignee: Bosch Automotive Systems Corp
Current assignee: Bosch Corp
Priority date: 2001-07-16
Filing date: 2002-07-16
Publication date: 2008-01-02
Anticipated expiration: 2022-07-16
Also published as: KR20030007145A; JP3851122B2; KR100495171B1; JP2003028022A; CN1397726A; CN1654811A; CN1270077C

Abstract

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. 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

Fuel injector

The application is Chinese patent application number dividing an application for the 02126144.X application.

Technical field

The present invention relates to fuel injector, especially relate at the fuel injector of predetermined instant injection by the high pressure fuel of accumulator supplies such as (rails altogether).

Background technique

Come the fuel injector in brief description past according to Fig. 4.

Fig. 4 is the amplification sectional view of the major component of fuel injector 1.Fuel injector 1 has oil injector body 2, nozzle body 3, nozzle needle 4, valve plug 5, valve body 6, back pressure control device 7.

Nozzle body 3 is installed on the front end of oil injector body 2, is provided with high pressure fuel input part 8 on the top of oil injector body simultaneously.Above high pressure fuel input part 8, be provided with above-mentioned back pressure control device 7.

Fuel oil from fuel tank 9 is increased to high pressure by fuel pump 10, and their savings are in being total to rail 11 (accumulator), and high pressure fuel is supplied to fuel injector 1 from high pressure fuel input part 8.

In other words, from high pressure fuel input part 8 to oil injector body 2 and nozzle body 3 ground formed fuel gallery 12, high pressure fuel can be supplied to the 4A of pressure-bearing portion of nozzle needle 4.In addition, the part of fuel gallery 12 extends to the top Fig. 4 and has formed back oil road 13 from back pressure control device 7 from high pressure fuel input part 8, and fuel oil can be got back to fuel tank 9 thus.

On the front end of nozzle body 3, be formed with the random fuel oil spray orifice 14 of quantity, the front end of nozzle needle 4 is pressed in the seat portion 15 that is communicated with spray orifice 14 and has sealed spray orifice 14 thus, and nozzle needle 4 is opened spray orifice 14 and can be sprayed fuel oil thus by being lifted away from a portion 15.

Be provided with the nozzle springs 16 that on the direction of taking a seat of pressing to a portion 15 nozzle needle 4 is applied active force on the top of nozzle needle 4, continue to extend upward with the valve plug 5 of nozzle needle 4 one.

The front end that valve body 6 is formed with pressure control chamber 17 on the central part above it and makes valve plug 5 from downside near this pressure control chamber 17.

Pressure control chamber 17 is communicated with input side opening 18 on taking shape in valve body 6.Input side opening 18 is communicated with fuel gallery 12 and handle is supplied with pressure control chamber 17 from the incoming pressure that is total to rail 11.

Pressure control chamber 17 also is communicated with keying hole 19, and opening and closing hole 19 can open and close by the valve ball 20 (control valve body) of back pressure control device 7.

And the bearing area of the valve plug 5 top 5A of pressure control chamber 17 is bigger than the bearing area of the 4A of pressure-bearing portion of nozzle needle 4.

Back pressure control device 7 is parts of controlling the rise action of nozzle needle 4 by the pressure (being the back pressure of nozzle needle 4) in the control pressure control chamber 17, and it has above-mentioned valve ball 20, the magnetic tongue (armature) 21 with valve ball 20 one, magnetic tongue guiding element 22, magnet 23, magnetic core 24, magnetic core fixing body 25, valve spring 26, gap adjustment cover 27, connector 28, above-mentioned pressure control chamber 17.

The 21A of bar portion of magnetic tongue 21 obtains guiding by magnetic tongue guiding element 22 in the axial direction, and keep between its front end 27A perpendicular to the board 21B of the 21A of bar portion and adjustment sleeve 27 predetermined parallelism ground have first gap L 1 (rise amount) and its with magnetic core 24 suction surface 24A between have second gap L 2 with keeping being scheduled to parallelism.

Magnet 23 is accommodated among the magnet accommodating part 24B of magnetic core 24, makes magnetic core 24 produce certain magnetic flux and can attract magnetic tongue (board 21B) thus.

Magnetic core 24 is made of magnetic material.

The interior ladder surface 29A of the fixed body 29 that the contact of the outward edge of the suction surface 24A of magnetic core 24 is made of steel etc., magnetic core fixing body 25 is arranged on the top of magnetic core 24, between the 29B of the portion of riveting tightly of interior ladder surface 29A and solid body 29, magnetic core 24 and magnetic core fixing body 25 are pressed into one, simultaneously, be fastened on the oil injector body 2 with the stop nut 30 that the male part 29C of fixed body 29 cooperates by handle, thereby install magnetic core fixing body 25 and magnetic core 24.

And magnetic core fixing body 25 is made of nonmagnetic substance, and its upper shed part is plugged by filling in 31.

Gap adjustment cover 27 is inserted in the center hole 24C of magnetic core 24.

Between gap adjustment cover 27 and valve spring 26 and magnetic core fixing body 25, be provided with pad 32, thus can regulate first gap L 1 (rise amount) and second gap L 2.

Connector 28 links to each other with extraneous control loop (not shown) and gives magnet 23 feed drive signals at predetermined instant.

In the fuel injector 1 that constitutes like this, arrive the pressure-bearing portion 4A of nozzle needles 4 through fuel gallery 12 from high pressure fuel input part 8 from the high pressure fuel of rail 11 altogether, simultaneously, their are supplied to the valve plug 5 top 5A of pressure control chamber 17 through input side opening 18.

Thereby nozzle needle 4 bears the back pressure of pressure control chamber 17 by valve plug 5 and presses down in the seat portion 15 that is sitting in nozzle body 3 and seal spray orifice 14 thus at the force action with the active force of nozzle springs 16.

Give magnet 23 feed drive signals by connector 28 at predetermined instant, the active force ground that magnet 23 overcomes valve spring 27 attracts magnetic tongue 21, when valve ball 20 lifts and opens keying hole 19 thus, the high pressure oil of pressure control chamber 17 is by opening and closing hole 19 and returning fuel tank 9 through back oil road 13, removed the high pressure on the valve plug 5 top 5A that act on pressure control chamber 17 thus, nozzle needle 4 is lifted away from a portion 15 by the high pressure of the 4A of pressure-bearing portion with overcoming nozzle springs 16 active forces, thereby opens spray orifice 14 ground ejection fuel oil.

If valve ball 20 has been closed keying hole 19 by making magnet 23 demagnetizations, then the pressure in the pressure control chamber 17 is positioned on its seated position (seat portion 15) nozzle needle 4 by valve plug 5, thereby has closed spray orifice 14 and finished fuel injection.

But, in magnetic core 24, in order to make its magnetic property stable, before assembling, eliminate the internal magnetization that produces because of cutting and other machining etc. by annealing (soft magnetic material annealing), subsequently, do not applying mechanically under the situation of power, it can use as finished product ideally.

And in fact when assembling, by the rivet tightly operation and the fastening operation of stop nut 30 etc. at fixed body 29, make fastening force or compressive force from external influence in magnetic core 24, thereby portion produces strain (compressive strain) within it, exist and resemble magnetic and worsen and produce the such problem of solid difference.

In other words, because the mounting structure of magnetic core 24 is that whole magnetic core 24 is by magnetic core fixing body 25 and fixed body 29 (finished product situation) all-in-one-piece structure, so can't avoid processing subsequently or magnetic that fitting operation brought to change.In addition, although not shown, magnet 24 also can be independent and the operation of riveting tightly when assembling, in this case, produces internal stress in magnetic core 24, and magnetic changes certainly.

And under any circumstance, the magnetic core 24 relative with magnetic tongue 21 (board 21B) all touches the interior ladder surface 29A as fixed body 29, therefore, magnetic core 24 leakage fields and magnetic loss by ladder surface 29A in this are unavoidable, simultaneously, exist the problem that leakage field itself also is easy to generate difference.

Magnetic material as magnetic core 24, agglomerated material has because of there is the fine pore its inside and prevents the advantage of foucault current easily, on the other hand, and except the cost height, under the situation of high pressure and highi degree of accuracy fuel injector, can not ignore the above-mentioned magnetostrictive generation that brings by the external force effect.

In addition, pure iron material low cost is easily processed and can be guaranteed magnetic property strongly at adstante febre, on the other hand, in inside micro-pore is not arranged owing to do not resemble the agglomerated material, thereby the structure of the foucault current of preventing must be arranged, simultaneously, have such problem, promptly easy generation of magneto-striction phenomenon and the efficient that is caused by the external force effect reduces easily.Concerning any material, the requirement of the influence of the external force of minimizing when adding man-hour and assembling is all very urgent.

In the fuel injector 1 that rail together 11 links to each other, must precision the fuel injection amount in the highland control one way very, but also requirement can realize fuel injector inexpensively.

In addition, requirement according to fuel injection system, the occasion of inject high pressure fuel oil just need not have been carried, under the occasion that except that oil spout in advance (pre-spray) and main injection, also needs the back to spray, when excitation of in very short time, carrying out magnet very apace and demagnetization, exist and to ignore the problem that changes the strain that causes by heating and magnetic.

Subsequently, parallelism between magnetic tongue 21, gap adjustment cover 27 and the magnetic core 24 is described, the board 21B of magnetic tongue 21 and gap adjustment overlap between the 27 front end 27A first gap L 1 and with magnetic core 24 suction surface 24A between the parallelism separately of second gap L 2 be by accumulative total magnetic core 24, magnetic core fixing body 25, fixed body 29, pad 32, gap adjustment overlap 27, the precision of each parts such as magnetic tongue guiding element 22 and magnetic tongue 21 forms, because it is relevant with a plurality of parts, so be difficult to improve gap precision, and require high-precision parts a lot, exist the problem that cost improves.

Especially, when making magnet 23 stability of characteristics, for the air gap (second gap L 2) that its solid difference dwindled must dwindle as far as possible between magnetic tongue 21 and the magnetic core 24 or make its optimization, improve parallelism precision and and then dwindle error, but the problem that the departmental cost that exists as mentioned above, the back pressure control device 7 that is caused by a plurality of parts of assembling improves.

In addition, magnetic tongue 21 is being positioned at the guiding that bar portion 21A place on that opposite side such as first gap L 1 and second gap L 2 is subjected to magnetic tongue guiding element 22, so, exist and be difficult to improve the parallelism in gap and the problem of precision.

In addition, the flat 8-165965 of Japanese Unexamined Patent Publication No, the flat 11-82228 of Japanese Unexamined Patent Publication No etc. just relate to this fuel injector.

Summary of the invention

Formulated the present invention in view of above-mentioned variety of issue, problem of the present invention is the fuel injector that will provide a kind of magnetic core mounting structure to be improved.

In addition, problem of the present invention provides a kind of can not raising the cost and just can improve the fuel injector of the magnetic of magnetic core.

And problem of the present invention provides a kind of that do one's utmost to reduce the external force influence that brought by manufacturing procedure or assembling procedure etc. and can not make magnetic core produce the fuel injector that magnetostriction ground dwindles the solid differences.

In addition, problem of the present invention provides a kind of leakage field of magnetic core or fuel injector of magnetic loss of reducing.

And problem of the present invention provides a kind ofly can select the fuel injector of magnetic material such as magnetic core agglomerated material or pure iron material arbitrarily as required.

In addition, problem of the present invention provides a kind of fuel injector that improves the slip supporting structure of magnetic tongue.

In addition, problem of the present invention provides a kind of degree of being parallel to each other between magnetic tongue and the magnetic core and fuel injector of precision of improving.

And problem of the present invention provides a kind of fuel injector with cheapness of little magnetic tongue of performance difference and magnetic core.

Promptly, the starting point of the present invention is, do not use fixed body and other parts ground magnetic core and magnetic core fixing body to be become one, make the coreplane side become free end or open state (cantilever support state) simultaneously and the magnetic tongue slide part is set in magnetic core inside by welding, mode such as deposited or bonding.

In other words, the present invention is to the magnetic core reconstruction of mounting structure of mobile, and it relates to a kind of fuel injector, and it has: open and close the control valve body of pressure control chamber, this pressure control chamber is used to control the back pressure of the nozzle needle of able to turn on or off fuel oil spray orifice; Be used to drive the magnetic tongue of this control valve body; Be used to attract the magnetic core and the magnet of this magnetic tongue, wherein, control the pressure of this pressure control chamber and can carry out keying by described control valve body by the described spray orifice of injector valve, at this, the slide-and-guide portion that extends described magnetic core side takes shape on the described magnetic tongue, simultaneously, described slide-and-guide portion can be guided in interior all sides of this magnetic core.

In fuel injector according to the present invention, described slide-and-guide portion so forms, promptly it perpendicular to the parallel relative board of the suction surface of described magnetic core.

In addition, described magnetic core is fixed on the magnetic core fixing body, and described slide-and-guide portion can all sides guide by the magnetic tongue guide portion that takes shape on this magnetic core fixing body in described magnetic core.

In fuel injector of the present invention, between described magnetic core and parts, be provided with very circlet shape gap at its outer circumferential side.

Another embodiment of fuel injector of the present invention is, is provided with very circlet shape gap at described magnetic core with in it between the described magnetic core fixing body of all sides.

In fuel injector of the present invention, on described magnetic core, directly upwards be formed with radial groove at it.

In fuel injector of the present invention, by the mounting structure of improvement magnetic core and the slip supporting structure of magnetic tongue, when the magnetic change that makes magnetic core is stable, keep predeterminated level by parallelism or the precision that makes magnetic core and magnetic tongue, can guarantee reliability at low cost.

Especially according to the present invention, differently on magnetic tongue, form the slide-and-guide portion that extends the magnetic core side with the past, slide-and-guide portion is guided in magnetic core inside, and thus one, obtaining degree of being parallel to each other on the nearer position and between the parts that more closely combine.

In addition, by between parts on magnetic core and its outer circumferential side such as oil injector body, certain annular space being set, can be that benchmark ground carries out magnetic core and the magnetic tongue relative with this magnetic core in this annular space scope centering is adjusted with the oil injector body, thereby also can be expected to improve assembly precision.

And, because reduced parts, so also can reduce cost.

Therefore, when can under the state of efficient the best, obtaining stable magnetic force increase and reducing characteristic, can reduce the product error and obtain essential performance with the cost the same with the past.

In addition, when parallelism between magnetic core and the magnetic tongue and precision being improved and realize that performance improves, reduce parts and reduced the solid difference or the error of cost and performance, can improve durability and reliability.

The invention effect

As described above, according to the present invention, by magnetic core and magnetic core fixing body being integral and at the side directed magnetic tongue of magnetic core, do not make magnetic core produce the magnetostrictive while, can guarantee parallelism and the precision between each parts and be lowered into this locality to make, and can realize the raising of stability and reliability.

Description of drawings

Fig. 1 is the amplification sectional view of major component of the fuel injector 40 of the present invention's first form of implementation.

Fig. 2 is the partial section along the magnetic core 24 of the II-II line of Fig. 1.

Fig. 3 is the amplification sectional view of major component of the fuel injector 50 of the present invention's second form of implementation.

Fig. 4 is the amplification sectional view of the major component of traditional fuel injector.

Concrete form of implementation

Below, according to Fig. 1,2 fuel injector 40 of the present invention's first form of implementation is described, but, the part the same with Fig. 4 represented with same-sign and omitted detailed description.

Fig. 1 is the amplification sectional view of the major component of fuel injector 40, and Fig. 2 cuts open figure along the office of the magnetic core 24 of the line II-II of Fig. 1.In fuel injector 40, on the bottom of the magnetic core fixing body 41 that is equivalent to described magnetic core fixing body 25, magnetic core 24 is integrated by modes such as laser beam welding.

In other words, by the last circumferential part 24D (fixed end) of magnetic core 24 is welded on the following circumferential part 41A of magnetic core fixing body 41, magnetic core fixing body 41 and magnetic core 24 are become one.And, also can adopt the mode such as deposited or bonding of utilizing rubbing action etc. as this integrated means.

Magnetic core fixing body 41 is to be installed on the oil injector body 2 by the stop nut 42 that cooperates with its male part 41B, thereby O shape circle 43 is arranged on its with oil injector body 2 and upper convex portion 2A between in, make pad 44 itself and oil injector body 2 own partly between.

In addition, magnetic core fixing body 41 has magnetic tongue guide portion 41C as purliew integratedly on corresponding to the position as the gap adjustment of magnetic tongue 45 retainers cover 27.

Magnetic tongue 45 have the band valve ball 20 the 45A of bar portion, perpendicular to the board 45B of the 45A of bar portion, perpendicular to the 45C of slide-and-guide portion of board 45B, the 45C of slide-and-guide portion can axially directed slip in the magnetic tongue guide portion 41C of magnetic core fixing body 45.

And magnetic tongue guide portion 41C is pressed in the center hole 24C of magnetic core 24, but embeds wherein simply.

As mentioned above, the last circumferential part 24D of magnetic core 24 becomes one with cantilever support mode and magnetic core fixing body 41, and become free end with the suction surface 24A of opposite that side of last circumferential part 24D, simultaneously, magnetic tongue 45 (board 45B) is parallel relative with this free end (suction surface 24A).

Magnetic core 24 forms first annular space 46 between itself and the oil injector body 2 at its outer circumferential side, magnetic core fixing body 41 is embedded on the upper convex portion 2A of oil injector body 2, the radially adjustment amount in the time of can guaranteeing thus to set magnetic core 24 central axis.

Make this part attenuation by a part that reams magnetic tongue guide portion 41C outer circumferential face diametrically, between the center hole 24C of itself and magnetic core 24, form second annular space 47, in magnetic core 24 leakage fields that can reduce, formed the Ministry of State Security that is used for the expansion that the processing heat by magnetic tongue guide portion 41C causes by magnetic tongue guide portion 41C.

And second gap L 2 is to form between the board 45B of the suction surface 24A of magnetic core 24 and magnetic tongue 45, and first gap L 1 (rise amount) is to form between the front end 41D of magnetic tongue guide portion 41C and board 45B.

As shown in Figure 2, on magnetic core 24, when radially forming radial groove 24E, on magnetic core fixing body 41, formed the communication passage 48 that is communicated with this radial groove 24E along it.

In the fuel injector 40 that constitutes like this, the last circumferential part 24D of magnetic core 24 just part is fixed on the following circumferential part 41A of magnetic core fixing body 41, its suction surface 24A relative with magnetic tongue 45 board 45B becomes the free end that is in the open state that does not contact with any parts, thereby, between itself and oil injector body 2, form first annular space 46, between itself and magnetic tongue guide portion 41C, form second annular space 47, thereby supporting magnetic core 24 at the suspended state lower cantalever, on magnetic core 24, do not having the external force effect.

Therefore, much less when processing or assembling, even if after assembling, also do not have external force to act on fuel injector 40 or the oil injector body 2, do not produce strain on magnetic core 24, when its magnetic was constant, difference unlikely appearred in the characteristic between solid.

In addition, magnetic tongue guide portion 41C by magnetic core fixing body 41 is subjected to axial lead to magnetic tongue 45 at the slide-and-guide portion 45C place of its magnetic core 24 sides, can be more accurately and more easily guarantee parallelism between magnetic tongue 45 and the magnetic core 24 suction surface 24A, when improving performance and reducing parts, can reduce cost.

And take shape in the radial groove 24E on the magnetic core 24 and the communication passage 48 that takes shape on the magnetic core fixing body 41 is interconnected, therefore, fuel oil is shifted to magnetic tongue 45 along with the axial reciprocating action of magnetic tongue 45 upstream and downstream direction has become easily, can make the speed of response of magnetic tongue 45 keep predeterminated level.

Even if magnetic core 24 usefulness pure iron are made,, also can prevent from its circumferencial direction, to produce foucault current by its radial groove 24E is set.

Fig. 3 is the amplification sectional view of major component of the fuel injector 50 of the present invention's second form of implementation, fuel injector 50 is the same with fuel injector 40 (Fig. 1), the described magnetic core fixing body 25 (Fig. 4) that is equivalent to magnetic core fixing body 41 and the integrative-structure (magnetic core mounting structure) of magnetic core 24 are that the following circumferential part 25A by last circumferential part 24D (fixed end) that makes magnetic core 24 in modes such as welding and magnetic core fixing body 25 is integral and forms, as for magnetic tongue slip supporting mechanism, also be the 45C of slide-and-guide portion that comes axial lead magnetic tongue 45 by the magnetic tongue guide portion 25B of magnetic core fixing body 25.

But, in this fuel injector 40, magnetic core fixing body 25 is installed on the oil injector body 2, and it has adopted described fixed body 29 and the stop nut 30 with the structure of riveting tightly.

Magnetic core 24 forms first annular space 46 between itself and the fixed body 29 at its outer circumferential side.

Second gap L 2 is formed between magnetic tongue guide portion 25B front end 25C and the board 45B.

In the fuel injector 50 that constitutes like this, also come cantilever support magnetic core 24 as described above by relative magnetic core fixing body 25, can not make magnetic core 24 distortion and obtain good magnetic.

And the magnetic tongue guide portion 25B by magnetic core fixing body 25 carries out magnetic tongue 45 guiding, thus one, can obtaining magnetic tongue 45 and magnetic core 24 parallelism and precision each other with predeterminated level when, can guarantee stable performance.

In addition, still can continue to use most traditional fuel injector 1 (Fig. 4) product, thereby can suppress cost and improve.

Symbol description

1-fuel oil injector (Fig. 4); 2-oil spout body; The upper convex portion (Fig. 1) of 2A-oil spout body; 3-nozzle body; 4-nozzle needle-valve; The pressure-bearing section of 4A-nozzle needle-valve 4; The 5-valve plug; 5A-valve plug 5 The top; The 6-valve body; 7-back pressure control section; 8-high pressure fuel input section; The 9-fuel tank; The 10-combustion Oil pump; 11-is rail (accumulator) altogether; 12-fuel oil passage; The 13-back oil road; The 14-spray orifice; 15-Seat section; The 16-nozzle springs; 17-pressure control chamber; 18-imports side opening; 19-opens and closes the hole; The 20-valve ball (control valve body); 21-magnetic tongue (armature); The bar section of 21A-magnetic tongue 21; 21B-magnetic tongue 21 Board; 22-magnetic tongue guide; 23-magnet; The 24-magnetic core; The suction surface of 24A-magnetic core 24 (free end); The magnet accommodation section of 24B-magnetic core 24; The centre bore of 24C-magnetic core 24; 24D-The upper circumference section of magnetic core 24 (stiff end, Fig. 1); The radial groove of 24E-magnetic core 24 (Fig. 2); 25-magnetic core fixing body (Fig. 3,4); The lower circumference section (Fig. 3) of 25A-magnetic core fixing body 25; The magnetic tongue guide part (Fig. 3) of 25B-magnetic core fixing body 25; Before the 25C-magnetic tongue guide part 25B End (Fig. 3); The 26-valve spring; 27-gap adjustment cover; The front end of 27A-gap adjustment cover 27; 28-Connector; The 29-fixed body; The interior ladder face of 29A-fixed body 29; The riveting of 29B-fixed body 29 Tight section; The male part of 29C-fixed body 29; The spacing nut of 30-; The 31-plug; The 32-pad; 40-The fuel oil injector (first form of implementation, Fig. 1); 41-magnetic core fixing body; The 41A-magnetic core is installed The lower circumference section of body; The male part of 41B-magnetic core fixing body 41; 41C-magnetic core fixing body 41 The magnetic tongue guide part; The front end of 41D-magnetic tongue guide part 41C; The spacing nut of 42-; 43-O shape circle; The 44-pad; The 45-magnetic tongue; The bar section of 45A-magnetic tongue 45; The board of 45B-magnetic tongue 45; 45C-The slide-and-guide section of magnetic tongue 45; The 46-first annular gap; The 47-second annular gap; 48-connects Circulation passage; 50-fuel oil injector (second form of implementation, Fig. 3); (rise in L1-first gap Amount); L2-second gap;

Claims

1, a kind of fuel injector, it has: open and close the control valve body of pressure control chamber, this pressure control chamber is used to control the back pressure of the nozzle needle of able to turn on or off fuel oil spray orifice; Be used to drive the magnetic tongue of this control valve body; Be used to attract the magnetic core and the magnet of this magnetic tongue, wherein, control the pressure of this pressure control chamber and can carry out the keying of described spray orifice by described control valve body by injector valve, it is characterized in that, described magnetic core is fixed on the magnetic core fixing body, the slide-and-guide portion that extends described magnetic core side takes shape on the described magnetic tongue, and described slide-and-guide portion so forms, be it perpendicular to the parallel relative board of the suction surface of described magnetic core, described slide-and-guide portion guides by the magnetic tongue guide portion that takes shape on this magnetic core fixing body in interior all sides of this magnetic core.

2, fuel injector as claimed in claim 1 is characterized in that, is provided with very circlet shape gap between described magnetic core and the parts at its outer circumferential side.

3, fuel injector as claimed in claim is characterized in that, is provided with very circlet shape gap at described magnetic core with in it between the described magnetic core fixing body of all sides.

4, fuel injector as claimed in claim 1 is characterized in that, on described magnetic core, directly upwards is formed with radial groove at it.