Fuel injector and method for manufacturing a fuel injector

Abstract

Fuel injector comprising: a flow-through section (60, 161, 560, 661) provided in a main body (10, 510), wherein the flow-through section (60, 161, 560, 661) has a fuel passage (60a, 161a, 560a, 661a) leading to an injection port (60b, 570b) from which fuel is injected; a valve element (51, 150, 551, 650) housed reciprocating in the main body (10, 510), wherein the valve element (51, 150, 551, 650) is adapted to open and close the fuel passage (60a, 161a, 560a, 661a) by reciprocating; an elastic element (56, 156, 556, 656), which is elastically deformable by means of a movement of the valve element (51, 150, 551, 650) in a valve closing direction when closing the fuel passage (60a, 161a, 560a, 661a), wherein the elastic element is connected at a point between the passage formation section (60, 161, 560, 661) and the valve element (51, 150, 551,650) is attached and adapted to close the fuel passage (60a, 161a, 560a, 661a) by bearing against the other of the passage formation section (60, 161, 560, 661) and the valve element (51, 150, 551, 650) when the valve element (51, 150, 551, 650) moves in the closing direction; and a movement restriction section (70, 570) provided in the main body (10, 510) to restrict the movement of the valve element (51, 150, 551, 650) in the closing direction by bearing against the valve element (51, 150, 551, 650), wherein the movement restriction section (70, 570) is made of a material different from the passage section (60, 161, 560, 661), characterized in that the movement restriction section (70, 570) is formed in a cylindrical shape having a first inner circumferential surface (70c), a second inner circumferential surface (70d) and a surface (70e),which connects the first inner circumferential surface (70c) with the second inner circumferential surface (70d), an inner diameter of the first inner circumferential surface (70c) is larger than an inner diameter of the second inner circumferential surface (70d), the valve element (51, 150, 551, 650) can abut against the surface (70e) which connects the first inner circumferential surface (70c) with the second inner circumferential surface (70d), and the movement restriction section (70, 570) is inserted by an opening (11c) of the passage formation section (60) and a relative positional relationship between the movement restriction section (70, 570) and the passage formation section (60) is fixed.

Description

The reference to related applications

[0001] This disclosure is based on Japanese Patent Application No. 2011-204724 filed on Sep. 20, 2011, Japanese Patent Application No. 2012-77236 filed on Mar. 29, 2012, and Japanese Patent Application No. 2012-159884 filed on Sep. 20, 2012 on July 18, 2012, the disclosures of which are incorporated herein by reference. technical field

[0002] The present disclosure relates to a fuel injector for injecting fuel to an internal combustion engine and a method of manufacturing the fuel injector. background

[0003] Patent Literature 1 discloses a fuel injector in which either a seat portion of a valve body or a valve seat of a valve seat formation portion is formed of an elastic member. Further, Patent Literature 1 also discloses a technique for providing a stopper for restricting a movement of the valve body toward the valve seat when a predetermined increase in the lift of the valve body is achieved, although the seat portion is repeatedly attached and detached from the valve seat to a to generate permanent compression deformation in the elastic member.

[0004] Patent Literatures 2 and 3 disclose a gas isolating valve in which a valve body is provided with a sealing member formed of an elastic material and which is attachable and detachable to and from a valve seat. As described in Patent Literature 2, a measurement portion is provided on the valve seat for defining a depressing margin of the sealing member when the sealing member is seated on the valve seat. Therefore, the indentation span of the sealing element is defined on a closing of the valve.

[0005] However, in the fuel injector disclosed in Patent Literature 1, the lift of the valve body immediately after manufacturing the fuel injector differs from that of the valve body after the compression permanent deformation occurs in the elastic member, which varies an amount of injected fuel. In particular, repeated opening and closing of the fuel injector can wear out the elastic element, so that the compression span can be varied. Also, a variation in fuel pressure can vary the compression span of the elastic member.

[0006] In the isolation valve disclosed in Patent Literature 2, upon closing of the valve, the valve body is abutted against the metering portion (protrusion) to stabilize the depressing margin of the sealing member. Even if the elastic member is used as the sealing member, the changes in stroke of the valve body can be suppressed. In the isolation valve, however, the dimensioning portion for defining the compression range of the sealing member is integral with a member for forming the valve seat on which the sealing member is to be seated. When using the metering portion to define the deflection range of the sealing member, the depressing range depends on the relative positions of the metering portion and the valve seat in the direction along the direction of movement of the valve body. When the metering portion and the valve seat are formed of one member, even if the dimensional accuracy of the metering portion and valve seat is increased, a large dimensional error of the sealing member may vary the deflection margin of an individual product. In order to set the indentation margin at the same level for each product, the dimensional accuracy of the sealing member needs to be increased in the same way as other components. However, it is basically difficult to improve the dimensional accuracy of the elastic member. Prior Art Literature Patent Literature

[0007] Patent Literature 1: JP-A No. 2002-227742 Patent Literature 2: JP-A No. 2011-132974 Patent Literature 3: JP-U No. H5(1993)-6150 Summary of the Invention

[0008] It is an object of the present disclosure to provide a fuel injector that stabilizes the amount of fuel injected without increasing the dimensional accuracy of the elastic member so much, and a method of manufacturing the fuel injector.

[0009] According to the present disclosure, a movement restriction section ( 70 , 570 ) abutted against a valve member for restricting movement of the valve member in the closing direction, from one of a passage formation portion ( 60 , 161 , 560 , 661 ) different material with a fuel passage ( 60a , 161a , 560a , 661a ) leading to an injection port ( 60b , 570b ) leads, trains.

[0010] In a prior art structure including a passage formation portion and a movement restricting portion formed of the same material, in order to set a deflection margin of an elastic member to a predetermined value in the closed state of a fuel passage, it is necessary to improve the dimensional accuracy of the To increase members for forming the passage formation portion and movement restriction portion, thereby improving the accuracy of the relative positions of the passage formation portion and the movement restriction portion, as well as increasing the dimensional accuracy of the elastic member.

[0011] In the present disclosure, the passage formation portion ( 60 , 161 , 560 , 661 ) and the movement restriction section ( 70 , 570 ) made of different materials. With this arrangement, when the passage formation portion and the movement restriction portion are provided in the main body, only by changing the relative positional relationship between the passage formation portion and the movement restriction portion, the relative positions of the passage restriction portion and the movement restriction portion can be adjusted. For this reason, the depressing margin of the elastic member can be adjusted to the predetermined value without increasing the dimensional accuracy of at least the elastic member as much as in the prior art, to thereby stabilize the amount of fuel injected.

[0012] Subsequent structures are added to the feature of the above configuration, whereby the following effects can be obtained. That is, the movement restricting portion is abutted against the valve member at a position where the crushing margin of the elastic member reaches a predetermined value due to elastic deformation of the elastic member with a fuel passage being closed by movement of the valve member to thereby restrict movement of the valve member in to restrict the closing direction.

[0013] The movement restriction section ( 70 , 570 ) rests against the valve element in a position where the deflection span of the elastic element ( 56 , 156 , 556 , 656 ) reaches a predetermined value, with a fuel passage ( 60a , 161a , 560a , 661a ), which by means of a movement of the valve element ( 51 , 150 , 551 , 650 ) is closed to thereby restrict the movement of the valve member in the closing direction, which stabilizes the depressing span of the elastic member in the closed state of the fuel passage. This arrangement suppresses the change in indentation span due to pressure variations of fuel flowing into the fuel injector, the change in indentation span due to wear of the elastic member caused by the repeated opening and closing of the fuel passage, and the effects of compression permanent deformation, therefore, changes in a lift of the valve element are restricted to stabilize the amount of injected fuel.

[0014] A general electromagnetic fuel injector in the prior art includes a valve body reciprocally installed in a body, and driving means for driving the valve body using an electromagnetic attraction force. A fuel passage is opened and closed by connecting and disconnecting a body seat portion provided in the body with respect to a movable seat portion provided in the valve body.

[0015] The body seat portion and the movable seat portion are repeatedly abutted against each other, and both are formed of metal excellent in wear resistance. If both seat portions are formed of metal to be metal seal valve portions, the high sealability is difficult to achieve.

[0016] As in figure 27, there is proposed a fuel injector having an elastic seal valve portion 91x comprises a sealing portion made of elastic material, such as. B. rubber, on the upstream side of a fuel flow with respect to a metal sealing valve portion 90x to improve the sealability (e.g., see Patent Literature 3).

[0017] However, the conventional fuel injector must strictly manage the degree of deformation of the elastic material upon valve closing in order to highly accurately meet the set load of the metal sealing valve portion 90x and the set load of the elastic seal valve portion 91x to control. For this reason, it is necessary to set a distance L1x between two seat portions of a body 92x and a distance L2x between two seat portions of a valve body 93x to be handled strictly. Therefore, the body must 92x and the valve body 93 processed with high accuracy.

[0018] In view of the foregoing points, it is an object of the present disclosure to handle the set load of the metallic sealing valve portion and the set load of the elastic sealing valve portion with high accuracy without needing the high-precision processing of the body and the valve body.

[0019] To achieve the above objective, a fuel injector includes an upstream movable seat portion ( 40x , 310x , 311x ) mounted in a metal movable section ( 3x , 4x ) is provided which moves to and fro, and a downstream movable seat portion ( 320x ) downstream of the upstream movable seat portion ( 40x , 310x , 311x ) in relation to fuel flow. An upstream body seat section ( 141x , 150x , 151x ) is attached to a metal body ( 1x ) is provided and a current collector seat portion ( 140x , 152x ) is downstream of the upstream body seat portion ( 141x , 150x , 151x ) in relation to fuel flow. One of the upstream movable seat section ( 40x , 310x , 311x ) and the upstream body seat portion ( 141x , 150x , 151x ) or one of the downstream movable seat section ( 320x ) and the current collector seat portion ( 140x , 152x ) is formed of an elastic material having more excellent elasticity than metal. A fuel passage is formed by means of connection and disconnection between the upstream movable seat portion ( 40x , 310x , 311x ) and the upstream body seat portion ( 141x , 150x , 151x ) open and closed. Also, the fuel passage is formed by means of connection and disconnection between the downstream movable seat portion ( 320x ) and the current collector seat portion ( 140x , 152x ) open and closed. The movable section ( 3x , 4x ) is set by means of a spring ( 5x ) in a direction to close the valve. The body ( 1x ) includes a first body ( 14 ax , 15x ), which is connected to the upstream body seat section ( 141x , 150x , 151x ) is provided, and a second body ( 14x , 15Ax), which is connected to the current collector seat section ( 140x , 152x ) is provided. The first body ( 14 ax , 15x ) and the second body ( 14x , 15Ax ) are formed separately and then connected to each other.

[0020] With this arrangement, in this assembly stage, the relative positions of the first body ( 14 ax , 15x ) and the second body ( 14x , 15Ax ) can be adjusted to apply a set load to a resilient sealing valve portion composed of the upstream movable seat portion ( 40x , 310x , 311x ) and an upstream body seat portion ( 141x , 150x , 151x ) is formed, easy to handle with high accuracy. Another fixed load on a metallic sealing valve section with a downstream movable seat section ( 320x ) and a current collector seat portion ( 140x , 152x ) can easily be fitted with high accuracy, although the body ( 1x ) and the movable section ( 3x , 4x ) are not designed with high accuracy. Alternatively, a set load can be applied to a resilient sealing valve portion formed from the downstream movable seat portion ( 320x ) and a current collector seat portion ( 140x , 152x ) and another set load on a metallic sealing valve portion composed of an upstream movable seat portion ( 40x , 310x , 311x ) and an upstream body seat portion ( 141x , 150x , 151x ) can be easily handled with high accuracy.

[0021] Subsequent structures are added to the feature of the above structure described above, and the following effects can be obtained. That is, the upstream body seat portion ( 150x , 151x ) and the current collector seat section ( 140x ) are chamfered and a chamfer angle of the upstream body seat portion ( 150x , 151x ) is larger than that of the downstream body seat portion ( 140 ).

[0022] Therefore, the seat diameter of the elastic seal valve portion can be smaller than that of the metal seal valve portion, which can reduce the force required to open the valve.

[0023] The upstream movable seat section ( 40x , 310x , 311x ) and the downstream movable seat section ( 320x ) can move in a reciprocating direction of the movable section ( 3x , 4x ) can be established and the fuel passage can be opened by moving the movable portion ( 3x , 4x ) in a direction from the upstream movable seat portion ( 40x , 310x , 311x ) toward the downstream movable seat portion ( 320x ) can be opened.

[0024] With this arrangement, the so-called outward opening valve can be constructed.

[0025] The upstream movable seat section ( 310x ) and the downstream movable seat section ( 320x ) can move in a reciprocating direction of the movable section ( 3x , 4x ) can be established, and the fuel passage can be opened by moving the movable portion ( 3x , 4x ) in a direction from the downstream movable seat portion ( 320x ) toward the upstream movable seat portion ( 310x ) can be opened.

[0026] With this arrangement, the so-called inward opening valve is constructed, which can provide the fuel injector with one injection port.

[0027] The first body ( 14 ax , 15x ) and the second body ( 14x , 15Ax ) can be integral with each other by means of full-circle welding.

[0028] This arrangement can be between the first body ( 14 ax , 15x ) and the second body ( 14x , 15Ax ) without using a sealing element.

[0029] The first body ( 14 ax , 15x ) and the second body ( 14x , 15Ax ) can be integral with each other by means of intermittent welding and a distance between the first body ( 14 ax , 15x ) and the second body (14x , 15Ax ) is sealed by means of a sealing element ( 8x ) sealed.

[0030] This method can reduce welding costs compared to full circle welding.

[0031] The spring ( 5x ) is a coil spring and the movable portion ( 3x , 4x ) is arranged around the spring ( 5x ) to penetrate. The upstream movable seat section ( 40x , 310x ) can be upstream of the spring ( 5x ) to be positioned in relation to the fuel flow. The downstream movable seat section ( 320x ) can be downstream of the spring ( 5x ) to be positioned in relation to the fuel flow.

[0032] When using the fuel injector for direct injection, the heat of the combustion gas at high temperatures could erode the seat portion made of elastic material. The seat portion formed of elastic material can be kept away from the heat of the combustion gas, thereby avoiding erosion of the seat portion.

[0033] The upstream movable seat section ( 40x , 310x ) can be made of elastic material.

[0034] The upstream body seat section ( 151x ) can be made of elastic material.

[0035] Gas fuel can be used as fuel.

[0036] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings is / are:

[0037] figure 1 is a sectional view showing the structure of a fuel injector and taken along a line I-I of FIG figure 4, according to a first embodiment;

[0038] figure 2 is a sectional view showing the structure of the fuel injector and taken along line II-II of FIG figure 4 is sectioned according to the first embodiment;

[0039] figure 3 is an enlarged sectional view showing the structure of the fuel injector in the first embodiment.

[0040] figure 4 is a sectional view showing the structure of the fuel injector and taken along line IV-IV of FIG figure 1 in the first embodiment.

[0041] figure 5 is a sectional view showing the structure of the fuel injector and taken along line V-V of FIG figure 1 in the first embodiment.

[0042] figure 6 is an illustration showing the flow of fuel near an injection port of the fuel injector in the first embodiment.

[0043] figure 7 is an enlarged sectional view showing the structure of a fuel injector according to a second embodiment.

[0044] figure 8 is an enlarged sectional view showing the structure of a fuel injector according to a third embodiment.

[0045] figure 9 is an enlarged sectional view showing the structure of a fuel injector according to a fourth embodiment.

[0046] figure 10 is a sectional view showing the structure of a fuel injector according to a fifth embodiment.

[0047] figure 11 is another enlarged sectional view showing the structure of the fuel injector in the fifth embodiment.

[0048] figure 12 is another enlarged sectional view showing the structure of the fuel injector according to a sixth embodiment.

[0049] figure 13 is another enlarged sectional view showing the structure of the fuel injector according to a seventh embodiment.

[0050] figure 14 is another enlarged sectional view showing the structure of the fuel injector according to an eighth embodiment.

[0051] figure 15(a) and figure 15(b) Sectional views showing the structure of a fuel injector according to a ninth embodiment.

[0052] figure16 is a sectional view showing a first modification of the ninth embodiment.

[0053] figure 17 is a sectional view showing a second modification of the ninth embodiment.

[0054] figure 18 is a sectional view showing a fuel injector according to a tenth embodiment.

[0055] figure 19 is a sectional view showing a first modification of the tenth embodiment.

[0056] figure 20 is a sectional view showing a fuel injector according to an eleventh embodiment.

[0057] figure 21 is a sectional view showing a fuel injector according to a twelfth embodiment.

[0058] figure 22(a), (b) and (c) are sectional views showing a fuel injector according to a thirteenth embodiment.

[0059] figure 23 is a timing chart showing the operation of the fuel injector in the thirteenth embodiment.

[0060] figure 24 is a test result showing the relationship between an attractive force generated by an electromagnetic force and gaps in the thirteenth embodiment.

[0061] figure 25(a), (b) and (c) are sectional views showing a fuel injector according to a fourteenth embodiment of the invention.

[0062] figure 26 is a sectional view showing a modification of the fourteenth embodiment.

[0063] figure 27 is a sectional view showing a main part of a general fuel injector. First embodiment

[0064] A fuel injector 100 , the in figure 1 is installed in an engine that functions as an internal combustion engine and serves to produce gaseous fuel such as gasoline. B. CNG (compressed natural gas), LNG (liquefied natural gas) or hydrogen gas into a combustion chamber of the engine. Now the structure of the fuel injector 100 below using figure 1 to figure 6 will be described. The fuel injector 100 includes a housing 10 , an inlet element 20 , a fixed core 30 , a moveable core 40 , a valve body 50 , a nozzle element 60 , a stopper 70 and a drive unit 90 .

[0065] The case 10 is formed entirely cylindrical and has its both ends opened in the axial direction. The case 10 has a first magnetic section 11 , a non-magnetic section 12 and a second magnetic section 13 in this order from one end to the other end in the axial direction. The first and second magnetic sections 11 and 13 , which are formed of ferritic stainless steel, which functions as a magnetic material, are connected to the non-magnetic portion by laser welding or the like 12 connected, which is formed of an austenitic stainless steel as a non-magnetic material. The non-magnetic section 12 can short circuit of a magnetic flux between the first magnetic section 11 and the second magnetic section 13 impede.

[0066] The first magnetic section 11 has a large diameter section 11d , the one with the non-magnetic section 12 connected, and a small-diameter portion 11a , which has an outer diameter smaller than that of the large-diameter portion 11d . The nozzle element 60 is at one end of the small diameter section 11a opposite to the non-magnetic section 12 provided, d. H. at the opening 11c , downstream of a fuel flow within the housing 10 is trained. The stopper 70 is between one end and the other end of the housing 10 provided in the axial direction. The inlet element 20 is at an end 13a of the second magnetic section 13opposite to the non-magnetic section 12 intended.

[0067] The inlet element 20 is cylindrical and has an inlet 20a , which is formed at the center thereof in the diametrical direction, so as to feed fuel, which is supplied from a fuel pump, through a fuel pipe to the fuel injector 100 to allow. The inlet element 20 is with the end 13a of the second magnetic section 13 connected and fixed by means of laser welding or the like.

[0068] The fixed core 30 is formed cylindrically from a ferritic stainless steel functioning as a magnetic material and coaxially on the inner side walls of the non-magnetic portion 12 and the second magnetic section 13 fixed. The fixed core 30 is with a receiving hole 31 provided which axially penetrates the center in a radial direction. A feather 80 , which is made of a coil spring as an urging element, is in the receiving hole 31 housed in an elastically deformable manner and an adjustment tube 32 for adjusting a set load on the spring 80 is fixed therein by press fitting. The spring 80 has her one end by means of the adapter tube 32 supported. The matching tube 32 is cylindrical and has a through hole 32a provided axially penetrating the center in the radial direction. With this arrangement, the fuel flows through the inlet member 20 flows into the receiving hole 31 . Then the fuel entering the receiving hole 31 flows, from the end of the fixed core 30 on the nozzle element 60 through the through hole 32a drained.

[0069] The moveable core 40 is formed cylindrically from a ferritic stainless steel serving as a magnetic material. The moveable core 40 is coaxial in the inner circumference of the housing 10 houses and rather above the nozzle element 60 than the fixed core 30 positioned.

[0070] The moveable core 40 has a core main body 41 , which is cylindrical. The core main body 41 has a guide portion on its peripheral wall 41a for guiding along the corresponding inner peripheral walls of the large-diameter portion 11d of the first magnetic section 11 and the non-magnetic section 12 . With this arrangement, the movable core goes 40 axially back and forth by means of the guide portion 41a along the respective inner peripheral walls of the large-diameter portion 11d and the non-magnetic section 12 to be led.

[0071] A seat section 41b is at the end of the core main body 41 on the fixed core 30 educated. The seat section 41b serves to end the spring 80 on the nozzle element 60 at the center in the radial direction of the seat portion. Hence the movable core 40 constant of an urging force in a direction toward the nozzle member 60 according to the one on the pen 80 subject to a specified load.

[0072] The core main body 41 is with a through hole 41c provided which axially penetrates the center thereof in a radial direction. The through hole 41c allows the fuel to flow to the nozzle element 60 of the fixed core 30 over the receiving hole 31 is discharged, to the nozzle member 60 in the moveable core 40 through the through hole 41c to flow.

[0073] The moveable core 40 has a cylindrical receiving section 42 that of the core main body 41 towards the nozzle element 60 coaxial with respect to the through hole 41c of the core main body 41 presides. The recording section 42 houses part of a coupling section 55 of the valve body50 , which will be described later. The coupling section 55 is with / at the receiving section 42 connected / fixed by means of laser welding or the like. The axial reciprocating movement of the movable core 40 causes the valve body 50 in the axial direction together with the movable core 40 going back and forth.

[0074] The valve body 50 is formed entirely in a stick-like shape coaxially on the inner circumference of the first magnetic portion 11 houses and above the nozzle member 60 with respect to the movable core 40 positioned. The valve body 50 goes back and forth in the axial direction around a fuel passage 60a to open and close in the nozzle element 60 , which will be described later, is formed while intermittently injecting the fuel from the injection port 60b injected into the combustion chamber.

[0075] As in figure 3 shown, the valve body 50 a valve main body 51 , the one with the moveable core 40 is coupled. The valve main body 51 is formed in the stick-like shape of martensitic stainless steel functioning as the non-magnetic material. The valve main body 51 includes a stick-like coupling section 55 , attached to the movable core 40 is coupled, and a support portion 52 , which is above the nozzle element 60 regarding the coupling portion 55 with the elastic section 56 , which will be described later, is appropriately positioned and fitted, the elastic portion 56 to support.

[0076] The coupling section 55 is with a fuel passage 55a to create a space inside the through hole 41c of the moveable core 40 provided to with a space between the movable core 40 and the support section 52 on the outer periphery of the coupling portion 55 connect to. Therefore, the fuel entering the fuel passage 55a through the through hole 41c flows into the space between the movable core 40 and the support section 52 on the outer periphery of the coupling portion 55 drained.

[0077] The support section 52 includes a square prism section 53 , which is above the coupling section 55 is positioned and has a pillar portion 54 , which is above the nozzle element 60 in relation to the quadrangular prism section 53 is positioned. The Leading Section 53a is at the corner of a side surface of the quadrangular prism section 53 provided along the inner peripheral wall of the stopper 70 to be guided coaxially with respect to the small-diameter portion 11a of the first magnetic section 11 is provided. Therefore, the valve body 50 along the axial direction via the guide portion 53a along the inner peripheral wall of the stopper 70 go back and forth. The corner at the bottom of the quadrangular prism section 53 on the nozzle element 60 is with a berth 53b , against which the stopper 70 by means of the movement of the valve body 50 to the nozzle element 60 , as will be described later, is created. The berth 53b is against the stopper 70 created, of the movement of the valve body 50 towards the nozzle element 60 limited, d. H. the movement of the valve body 50 in the closing direction. As in the figure 1 to figure 3 shown is the landing surface 53b to the nozzle element 60 inclined.

[0078] The Pillar Section 54 has a sectional shape in a partial portion of the quadrangular prism portion 53 plotted in the direction crossing its axial direction. The diameter of the column section 54 is set to such a size that allows the fuel to flow between the columnar section 54and the inner peripheral wall of the stopper 70 to walk through.

[0079] The elastic section 56 is at the end of the column section 54 on the nozzle element 60 appropriate. The elastic section 56 is formed in a disk-like shape around a seat portion 56a in the the nozzle element 60 provide opposite position. The elastic section 56 is made of an elastic element which can be attached and detached by means of the valve body 50 to and from the nozzle member 60 is elastically deformable. In the present embodiment, the elastic portion 56 Manufactured from fluoro rubber with excellent low temperature and oil resistance. When a fuel is injected by using gaseous fuel as the fuel, the pressure of the fuel becomes around the injection port 60b decreases, resulting in a temperature of the fuel near the injection port 60b from about -30°C to -40°C. The fluorine rubber used as the elastic portion 56 is material which is elastically deformable under the condition of very low temperatures, such as that described above, thereby ensuring the sealability. The elastic section 56 is at the end of the column section 54 and the nozzle element 60 attached by overmolding.

[0080] The outer peripheral surface of the pillar portion 54 is provided with a groove recessed in the direction that is the reciprocating direction of the valve body 50 crosses. On the other hand, the elastic section 56 anchor at its perimeter 56f , which are arranged to fit into the groove of the columnar section 54 to fit. Hence the elastic section 56 solid at the support section 52 fixed. In particular, the fixing strength in the reciprocating direction of the valve body becomes 50 elevated.

[0081] A ring-like seat section 56a is on a surface of the elastic portion 56 formed, which the nozzle element 60 opposite to the nozzle member 60 to protrude at the outer periphery of the surface. The seat section 56a has a recessed portion at its inner periphery 56b , which is opposite to the nozzle element 60 is deepened. The diameter of the inner peripheral surface 56b that at the perimeter of the floor 56c of the recessed section 56b is formed is larger than that of an opening portion 60d of the valve body 50 of the fuel passage 60a of the nozzle element 60 . The diameter of the inner peripheral surface 56d can by means of the range of the outer diameter of the elastic portion 56 be fixed. The seat section 56a is at the outer periphery of the depressed portion 56b on the surface of the elastic portion 56b formed, which the nozzle element 60 is facing. A corner 56e the inner peripheral surface 56d on the nozzle element 60 can be created so as to cover the outer perimeter of the opening 60d to include That is, the seat section 56a can be created so that it covers the outer perimeter of the opening 60d includes. In this way, the fuel passage 60a closed. The inner peripheral surface 56d of the recessed section 56b is inclined so that the depth of the recessed section 56b gradually deeper toward the center in the radial direction of the depressed portion 56b becomes.

[0082] The nozzle element 60 is cylindrically formed of martensitic stainless steel functioning as the non-magnetic material. The fuel passage 60a is formed to axially center in the radial direction of the nozzle member 60 to penetrate. In the present embodiment, the nozzle element 60 from one of the housing 10 and the stopper 70 different material formed. The nozzle element 60is from the opening 11c introduced at one end of the small-diameter section 11a of the first magnetic section 11 is formed, and on and with the opening 11c connected and fixed by means of laser welding and the like. A valve seat 60c , attached to and from the seat section 56a attachable and detachable is on the peripheral edge of the opening of the fuel passage 60a at the end face of the nozzle element 60 on the valve body 50 educated. The valve body 50 of the fuel passage 60a has the injection port 60b for injecting the fuel thereof at the end thereof leading to the valve body 50 is opposite.

[0083] The seat section 56a is adjusted to the fuel passage 60a by means of a closing operation inclusively causing the seat portion to seat on the valve seat 60c , as in figure 1 shown to close. This will increase the flow of fuel into the injection port 60b stopped. At this time, the elastic section 56 according to the amount of movement of the valve body 50 elastically deformed. On the other hand, as in figure 2 is the seat portion 56a adjusted to the fuel passage 60a by means of an opening operation involving detaching the seat portion from the valve seat 60c includes opening. In this way the fuel is allowed into the injection port 60b to flow.

[0084] The stopper 70 is formed in the cylindrical shape of martensitic stainless steel functioning as the non-magnetic material. The stopper 70 has a receiving hole 70a for receiving the support section 52 of the valve body 50 at the center in the radial direction of the stopper 70 . In the present embodiment, the stopper 70 from one of the housing 10 different material formed.

[0085] The stopper 70 is in relation to the housing 10 positioned while the end face 70b on the moveable core 40 against a stepped section 11b abuts against the inner peripheral wall of the small-diameter portion 11a is trained. The stopper 70 is with and at the small diameter portion 11a connected and fixed by means of laser welding or the like, while the stopper is in the housing 10 is positioned. The recording hole 70a has a circular cross-sectional shape in the direction crossing the axial direction. The recording hole 70a forms a first inner peripheral surface 70c on the moveable core 40 and forms a second inner peripheral surface 70d on the nozzle element 60 wherein the second inner peripheral surface has an inner diameter smaller than that of the first inner peripheral surface 70c .

[0086] As in figure 3 and figure 4 is the quadrangular prism section 53 of the valve body 50 at the inner periphery of the first inner peripheral surface 70c accommodates and the first inner peripheral surface 70c leads all leadership sections 53a , located at four corners of the outer peripheral surface 53c of the quadrangular prism section 53 are provided. As in figure 3 and figure 5 are such sections 54 of the valve body 50 and the elastic section 56 on the inner periphery of the second inner peripheral surface 70d houses. The diameter of the part from the second inner peripheral surface 70d is fixed, a distance between the outer peripheral surface 54a of the columnar section 54 and the second inner peripheral surface that allows the fuel to flow through the nozzle member 60 to flow. In the direction crossing the axial direction, the first inner peripheral surface has 70c a circular shape and the quadrangular prism section 53a quadrilateral shape showing a distance between the first inner peripheral surface 70c and a part of the outer peripheral surface 53c of the quadrangular prism section 53 , except for the guide sections 53a , forms and also a different distance between the second inner peripheral surface 70d and the outer peripheral surface 54a of the columnar section 54 trains. These distances are related to each other. Such a clearance between the outer peripheral surface of the valve body 50 and the inner peripheral surface of the stopper 70 is divided even if an inclined surface 70e of the stopper 70 against the contact surface 53b of the valve body 50 applied, as will be described later. The gap functions as a fuel passage 71 . The fuel passage 71 is constant in connection with the fuel passage 55a of the coupling section 55 and allows the fuel to flow toward the outer periphery of the coupling portion 55 is let out, to the nozzle member 60 to be led.

[0087] The recording hole 70a has the inclined surface 70e , which against the plant surface 53b of the valve body 50 between the first inner peripheral surface 70c and the second inner peripheral surface 70d can be created. The inclined surface 70e is formed in an annular shape and inclined around its diameter from the movable core 40 to the nozzle element 60 to have decreased. The inclined surface 70e is against the bearing surface 53b placed to the movement of the valve body 50 to restrict in the closing direction. The inclined surface 70e is provided at a position where the elastic portion 56 on the valve seat 60c of the nozzle element 60 seated and then in the direction along the direction of movement of the valve body 50 elastically deformed by the indentation span of the elastic portion 56 to cause it to reach a predetermined value. The predetermined value is set at such a value that changes in the lift of the valve body 50 can suppress while any damage due to the permanent compression deformation of the elastic portion 56 be avoided. Here, the predetermined value is set to a value that increases the fuel passage 60a can close even with the occurrence of permanent compression deformation of the elastic portion 56 or the inclination of the valve structure due to geometric tolerances while the damage to the elastic material 56 due to which compression is prevented. For example, the predetermined value is preferably set to the minimum value that allows a compression ratio of the elastic portion 56 from 8 to 35 percent even with occurrence of the permanent compression set of the elastic portion 56 or the inclination of the valve structure due to a geometric tolerance.

[0088] A slope angle of the sloped surface 70e , located between the central axis of the fuel injector 100 formed on the inclined surface is smaller than that of the abutment surface 53b , between the central axis and the bearing surface 53b is trained. A material for use in the stopper 70 is the same as that for use in the support section 52 of the valve body 50 , as mentioned above. Hence the beveled surface 70e of the stopper 70 substantially the same hardness as that of the abutment 53b of the valve body 50 . The plant area 53b of the valve body 50 is with a coated layer 72 provided, the z. B. DLC (diamond-like carbon) or polytetrafluoroethylene (registered trademark: Teflon). The coated layer 72 can at the beveled surface 70e of the stopper 70 be provided or on both, the contact surface 53b of the valve body 50and the beveled surface 70e of the stopper 70 , be provided. In the present embodiment, the coated layer is 72 only on the attachment surface 53b is formed, reducing the manufacturing cost as compared with the case of forming the coated layer 72 on both, the bearing surface 53b and the beveled surface 70e , be reduced. The coated layer 72 covers the outer peripheral surface of the valve body 50 what the coating of the coated layer 72 compared to the case of coating the inner peripheral surface of the stopper 70 can simplify.

[0089] With this arrangement, while the bearing surface 53 of the valve body 50 against the beveled surface 70e of the stopper 70 rests, the seat section is seated 56a of the elastic section 56 on the valve seat 60c to the fuel passage 60a to close so that the of the inlet 20a to the fuel passage 71 over the receiving hole 31 flowing fuel, through hole 32a , through hole 41c and fuel passage 55a , in that order, does not flow from the injection port 60b is injected. If the valve body 50 to the fixed core 30 along with the moveable core 40 moved by the indentation span of the elastic section 56 to pass, the seat section becomes 56a from the valve seat 60c solved the fuel passage 60a open so that the fuel leading to the fuel passage 71 leads from the injection port 60b about the distance between the elastic section 56 and the nozzle element 60 through the fuel passage 60a is injected.

[0090] As in figure 1 and figure 2 includes the drive unit 90 a magnetic coil 91 , a yoke 92 , a connecting part 93 and similar. The electromagnetic coil 91 has a metal wire rod wound around a plastic bobbin. The electromagnetic coil 91 is coaxial on the outer circumference in the radial direction of the casing 10 furnished. The connecting part 93 includes a connector 93a for electrically connecting the electromagnetic coil 91 to an external control group. By means of the external control circuit, the electromagnetic coil is powered 91 controlled.

[0091] the yoke 92 is formed cylindrically of a ferritic stainless steel functioning as a magnetic material and on the outer circumference in the radial direction of the electromagnetic coil 91 and housing 10 set up the electromagnetic coil 91 to cover. the yoke 92 has a small-diameter portion attached to the nozzle member at one end thereof 60 is trained. The small-diameter portion is with and at the small-diameter portion 11a of the first magnetic section 11 connected and fixed by means of laser welding or the like.

[0092] If the electromagnetic coil 91 welded and by supplying current to the electromagnetic coil 91 about the connection 93a is excited, a magnetic flux flows in the one magnetic circuit formed by the yoke 92 , the first magnetic section 11 , the moveable core 40 , the fixed core 30 and the second magnetic section 13 is trained together. As a result, a magnetic attraction force between the movable core 40 and the fixed core 30 generated which face each other to act as a magnetic force for driving and attracting the movable core 40 towards the fixed core 30 to serve. On the other hand, if the electromagnetic coil 91is demagnetized by stopping the energization, the magnetic flux does not flow in the magnetic circuit, thereby reducing the magnetic attraction force between the movable core 40 and the fixed core 30 is eliminated.

[0093] The operation of the fuel injector 100 will be described in detail below. When powering the electromagnetic coil 91 in the fuel injector 100 in the in figure 1 is stopped, the magnetic attraction force acting on the movable core 40 should act, eliminated, so that the contact surface 53b of the valve body 50 against the beveled surface 70e of the stopper 70 by means of an urging force of the spring 80 towards the movable core 40 is pressed. At this time, the seat portion is seated 56a of the elastic section 50 on the valve seat 60c to the injection port 60b close. Therefore, the fuel from the inlet 20a to the fuel passage 71 flows, not from the injection port 60b injected.

[0094] Then when the electromagnetic coil 91 is fed to cause the magnetic attraction force on the movable core 40 acts and the magnetic attraction force becomes greater than the urging force of the spring 80 , in which in figure 1, the movable core starts 40 towards the fixed core 30 to move. When the amount of movement of the movable core 40 to the indentation span of the elastic portion 56 exceeds, the section 56a from the valve seat 60c solved. Therefore, the fuel flows through the fuel passage 71 , as indicated by a dash-dot line from figure 2, into the fuel passage 60a about the distance between the seat section 56a and the valve seat 60c and is then from the injection port 60b injected. The moveable core 40 moves up the movable core 40 against the fixed core 30 applied (see figure 2). The stroke corresponds to a moving distance of the valve body 51 , in which the movable core 40 against the fixed core 30 rests after the seat section 56a from the valve seat 60c is solved.

[0095] With reference to figure 6, the flow of fuel becomes close to the seat portion 56a described. Therein, D is a seat diameter of the seat portion 56a , L a stroke of the valve main body 51 , S1 an opening area of ​​an opening part defined between the seat portion 56a and the valve seat 60c is formed when opening the valve, and S2 a minimum passage area in the fuel passage 60a . The seat diameter D is a diameter of an inner peripheral part of the seat portion 56a , which means the corners 56e is formed, and the opening area S1 is one determined by a following formula: S1 = D × π × L

[0096] The seat diameter D, stroke L, and passage area S2 are preferably determined so that the opening area S1 is equal to or larger than the passage area S2. Preferably, the opening area S1 is 1.4 times or more larger than the passage area S2.

[0097] When the valve main body strokes 51 for L minutes the fuel flows, which the fuel passage 51 reached, in a distance between the seat section 56a and the valve seat 60c (see in figure 6 arrows shown). The fuel in the space between the two elements 56a and 60c flows, flows into a depressed section 56b from an opened part having the opening area S1 formed in the gap and then flows into the opening 60d of the fuel passage 60a . As a result, the fuel from the injection port 60b through the fuel passage 60a boisterous. An inner peripheral surface56d of the recessed section 56b is inclined, which can reduce the pressure loss as much as possible when the fuel enters the depressed portion 56d of the distance between the two elements 56a and 60c flows. By setting the opening area S1 to be one or more times larger than the passage area S2, the distance between both members can be reduced 56a and 60c flowing fuel from the injection port 60b be left out. When the opening area S1 is set to be 1.4 times or more larger than the passage area S2, the amount of fuel flowing into the fuel passage 60a over a distance between both elements 56a and 60a flows are increased to suppress the fuel from the fuel passage 60a to be discharged, thereby reducing the pressure of the fuel within the fuel passage 60a is hindered. As a result, the pressure from the injection port 60b spilled fuel, d. H. the injection pressure, itself the pressure of fuel entering the fuel injector 100 flows as far as possible approach.

[0098] Then when the power to the electromagnetic coil 91 stopped again, the magnetic attraction force acting on the movable core 40 works, eliminated. Hence the force acting on the movable core 40 acts, only the urging force of the spring 80 , causing the movable core 40 towards the nozzle element 60 starts to move. The movement of the movable core 40 causes the seat section first 56a on the valve seat 60c stands. The seat section 56a sits on the valve seat 60c , to the inflow of fuel, the fuel passage 71 reached, into the fuel passage 60a to end what the injection of fuel from the injection port 60b stops. Even after the seat section 56a to the valve seat 60c attached, the valve body moves 50 essentially in the direction of the nozzle element 60 , while the elastic section 56 is elastically deformed. Then when the berth 53b of the valve body 50 against the beveled surface 70e of the stopper 70 is placed, the movement of the valve body 50 towards the nozzle element 60 stopped. At this time, the crushing span of the elastic portion 56 the predetermined value.

[0099] In this way, the movement of the valve body 50 towards the nozzle element 60 using the stopper 70 limited to the deflection span of the elastic section 56 to the predetermined value, which is the crushing span of the elastic portion 56 can stabilize, thereby increasing the stroke of the valve main body 51 to make stable. As a result, the amount of fuel injected is stabilized.

[0100] In the present embodiment, in a state where the fuel is not in the fuel injector 100 flows with no fuel pressure of the fuel applied to respective internal parts thereof becomes the electromagnetic coil 91 not fed. In this state, although the urging force of the spring 80 on the valve body 50 acts to cause the seat portion 56a on the valve seat 60c is attached or stands, the contact surface 53b of the valve body 50 not against the beveled surface 70e of the stopper 70 applied to form a space therebetween. When the fuel in the fuel injector 100 flows to apply a fuel pressure to the respective internal parts, such as. B. the valve body 50 , the valve body moves 50 towards the nozzle element 60 , causing elastic deformation of the elastic portion 56 is effected. In this way, the contact surface 53b against the beveled surface 70ecreated. If the electromagnetic coil 91 is in the non-energized state, the contact surface 53b constant against the beveled surface 70e be applied, regardless of whether the fuel pressure on the respective internal parts of the fuel injector 100 works or not.

[0101] The following is a method of manufacturing the fuel injector 100 described. Stopper built-in crotch

[0102] The stopper 70 is from the opening 11c of the first magnetic section 11 in the housing 10 introduced by connecting the first magnetic portion 11 , the non-magnetic section 12 and the second magnetic section 13 formed by laser welding. The stopper 70 is introduced to an end face 70b of the stopper 70 against the stepped section 11b of the first magnetic section 11 applied. After that, the stopper 70 to the housing 10 fixed by laser welding or the like. Then the stopper between one end and the other end of the case 10 provided in the axial direction. valve body forming step

[0103] The coupling section 55 of the valve body 50 with the elastic section 56 , which is attached to it, is inserted into the receiving section 42 of the moveable core 40 introduced. The clutch section 55 is to the recording section 42 fixed by laser welding or the like. distance measurement step

[0104] An integrated element of the moveable core 40 and the valve body 50 is from the second magnetic section 13 introduced and the plant surface 53b of the valve body 50 becomes against the beveled surface 70e of the stopper 70 created. With this state being held, the position of the valve body 50 in relation to the stopper 70 fixed. Therefore, in a plant state where the plant surface 53b of the valve body 50 against the beveled surface 70e of the stopper 70 a distance from the opening 11c of the first magnetic section 11 , which serves as a reference position, to the seat portion 56a of the elastic section 56 measured. Insertion Amount Calculation Step

[0105] An insertion amount of the nozzle member 60 in the first magnetic section 11 is obtained by adding a predetermined indentation margin (predetermined value) of the elastic portion 56 calculated to the result of a measurement obtained in the distance measuring step. Here, a method of joining and fixing members together by applying heat by using laser welding or the like may sometimes cause thermal expansion accompanied by heat applied to the members. In the present embodiment, the nozzle element 60 with and on the housing 10 connected and fixed by means of laser welding or the like. Therefore, the insertion amount is calculated by taking into account the thermal expansion caused by the laser welding in the nozzle member 60 and housing 10 is produced. insertion amount adjustment step

[0106] The nozzle element 60 is from the opening 11c of the first magnetic section 11 inserted by the insertion amount calculated in the insertion amount calculation step, whereby the crushing margin of the elastic portion 56 adjusted to the predetermined value. Nozzle Element Fixing Step

[0107] The nozzle element 60 comes with and attached to the first magnetic section 11 connected and fixed by laser welding. Therefore, the relative positional relationship between the nozzle member 60 and the stopper 70 in the direction along the moving direction of the valve body 50 fixed and the contact surface53b against the beveled surface 70e created so that the indentation span of the elastic area 56 can be set to the predetermined value when the seat portion 56a of the elastic section 56 on the valve seat 60c sits. In the present embodiment, a welded part is interposed between the first magnetic portion 11 and the nozzle element 60 over the entire perimeter. The welding can seal between the first magnetic section 11 and the nozzle element 60 to ensure. Installation step for the fixed core and spring

[0108] The fixed core 30 is from the second magnetic section 13 introduced. The fixed core 30 is inserted up to a position where a predetermined distance from the movable core 40 with contact surface 53b of the valve body 50 standing against the beveled surface 70e of the stopper 70 is applied, inserted and then to the housing 10 fixed by laser welding or similar (see figure 1 and figure 2). The spring 80 is in the receiving hole 31 of the fixed core 30 houses. A matching tube 32 is in the receiving hole 31 press fitted to thereby maintain the specified load of the spring 80 to adjust. Attachment step for the inlet member and the drive unit

[0109] The inlet element 20 is attached to a second magnetic section 13 appropriate. Both components are connected and fixed to one another by means of laser welding or the like. The drive unit 90 , consisting of the electromagnetic coil 91 , the connecting part 93 and the yoke 92 is in the outer perimeter of the case 10 fitted and then the yoke 92 with and on the housing 10 connected and fixed by means of laser welding or the like.

[0110] In the fuel injector 100 , which uses the upper structure described above, becomes the stopper 70 against the valve main body 51 placed in a position where the deflection span of the elastic portion 56 becomes a predetermined value, the fuel passage 60a by means of the movement of the valve main body 51 is closed. Hence the stopper serves 70 to the movement of the valve main body 51 straighten in the closing direction to stably depress the elastic portion 56 to the predetermined value with the fuel passage 60a , which is closed. This arrangement suppresses the change in impression margin due to variations in the pressure of fuel injected into the fuel injector 100 flows, the change in indentation margin due to wear of the elastic portion 56 , caused by the repeated opening and closing of the fuel passage 60a , and the influence of compression permanent deformation, causing changes in a lift of the valve main body 51 be restricted to stabilize the amount of fuel injected.

[0111] The nozzle element 60 and the stopper 70 are made of different materials. By providing the nozzle element 60 and the stopper 70 in the housing 10 can see the relative positions of the nozzle element 60 and the stopper 70 only by changing the relative positional relationship between the nozzle member 60 and the stopper 70 be adjusted. For this reason, the deflection margin of the elastic portion 56 be adjusted to the predetermined value although the dimensional accuracy of at least the elastic portion 56 is not so high to thereby stabilize the amount of fuel injected.

[0112] The method of adjusting the deflection span of the elastic section 56to the predetermined value includes adjusting the relative position of the nozzle element 60 and the stopper 70 in the direction along the moving direction of the valve body 50 , including the valve main body 51 , so as to increase the deflection span of the elastic section 56 adjust, and then fixing the nozzle member 60 on the housing 10 with the stopper 70 fixed thereto by laser welding so as to fix relative positions.

[0113] The nozzle element 60 and the stopper 70 are formed of different materials, so that the relative positional relationship between the nozzle member 60 and the stopper 70 can be changed before the nozzle element 60 on the housing 10 with the stopper fixed to it 70 is fixed. The stopper 70 becomes against the valve body 50 applied in a position where the deflection span of the elastic portion 56 becomes the predetermined value due to the elastic deformation, with the fuel passage 60a of the nozzle element 60 by means of the movement of the valve body 50 closed including the valve main body 51 , thereby restricting movement in the closing direction. Therefore, the relative positions of the nozzle element 60 and the stopper 70 in the direction along the reciprocating direction of the valve body 50 adjusted in the insertion amount adjustment step so that the depressing span of the elastic portion 56 the predetermined value becomes before the nozzle element 60 on the housing 10 is fixed. Therefore, the deflection margin of the elastic portion 56 be set to the predetermined value. After adjusting the relative position of the nozzle element 60 and the stopper 70 in the direction along the reciprocating direction of the valve body 50 in the insertion amount adjustment step, the nozzle member becomes 60 welded and attached to the housing 10 fixed in the nozzle member fixing step. Therefore, the relative positions of the nozzle member 60 and the stopper 70 be strictly fixed to the positions after the adjustment.

[0114] In the present embodiment, the nozzle element 60 on the housing 10 fixed by welding and fixing, but both the insertion amount adjustment step and the nozzle member fixing step can be performed at one time. For example, the nozzle element 60 press-fixed and into the housing 10 fixed, which can perform both steps at a time. A method of fixing the nozzle 60 can seal the nozzle element 60 to the housing 10 include.

[0115] The distance between the valve seat 60c and the injection port 60b is made as short as possible, which is preferable from the viewpoint of controllability of the combustion injection amount. This is because the fuel in a space from the position where the seat section 56a against the valve seat 60c (hereinafter referred to as the abutting position) to the injection port 60b is saved, sometimes omitted, although the seat section 56a of the valve body 50 on the valve seat 60c is seated to place the valve in the non-injecting state upon valve closing.

[0116] The present embodiment adopts the structure in which the nozzle member 60 downstream of the stopper 70 in the fuel flow toward the injection port 60b inside the housing 10 is positioned. With this structure, the stopper exists 70 at least not between the nozzle element 60 and the injection port 60b , which is the distance from the abutment position to the injection port 60b can be reduced as much as possible. Therefore, the amount of fuel to be discharged from the abutting position to the injection port 60bstored should be suppressed as far as possible when closing the valve.

[0117] In addition, in the present embodiment, the injection port 60b at the end of the fuel passage 60a formed downstream of the fuel flow. This structure can increase the distance from the abutment position to the injection port 60b shorten and therefore further suppress the amount of fuel to be discharged when closing the valve from the abutment position to the injection port 60b is saved.

[0118] In the present embodiment, the valve body 50 reciprocating in the stopper 70 houses, which is cylindrical. with the valve body 50 against the stopper 70 laid out there are clearances that act as fuel passage 71 for allowing the flow of fuel into the nozzle member 60 serve and between the first inner peripheral surface 70c of the stopper 70 and the outer peripheral surface 53c of the valve body 50 and between the second inner peripheral surface 70d and the outer peripheral surface 54a of the valve body 50 are trained. With this structure, the fuel can go to the nozzle member 60 be guided, although the valve body 50 against the stopper 70 applied. Therefore, once the valve body 50 moved to the fuel passage 60a to open, fuel from the injection port 60b injected.

[0119] In the present embodiment, the elastic portion 56 the seat section 56a towards the nozzle element 60 protruding at the outer periphery of the elastic portion 56 the nozzle element 60 facing. The seat section 56a is ajar against it, around the outer perimeter of the opening 60d of the fuel passage 60a to enclose the fuel passage 60 close. With the above structure, the seat diameter D can be larger than that of the opening 60d be fixed. When the area of ​​the elastic section 56 , which the nozzle element 60 is flat, the seat diameter is substantially the same as that of the orifice 60d . Since the seat diameter D is larger than that of the orifice 60d can be put, the part of the elastic section 56 , which corresponds to the seat diameter D, i. H. the opening area S1 formed on the inner periphery of the seat portion 56a is formed, be fixed larger. Therefore, the amount of fuel entering the fuel passage 60a flows can be increased compared to the case where the area of ​​the elastic portion 56 , which the nozzle element 60 faces is flat, thereby suppressing the increase in injection pressure.

[0120] Further, in the present embodiment, the inner peripheral surface 56d inclined so that the recessed section 56b toward the center of the recessed portion 56b becomes deeper in the radial direction, causing the loss of pressure of the fuel in the depressed portion 56b by the distance between the seat section 56a and the valve seat 60c flows, can suppress. As a result, the decrease in injection pressure due to the pressure loss of fuel can be suppressed.

[0121] In the present embodiment, the elastic portion 56 an anchor section 56f , located in the columnar section 54 of the valve body 50 in the direction which is the reciprocating direction of the valve body 50 crosses. The anchor section 56f firmly fixes the elastic section 56 to the support section 52 of the valve body 50 . In particular, the fixing force becomes in the reciprocating direction of the valve body 50 elevated.

[0122] In the present embodiment, the stopper 70 between one end and the other end of the housing 10established in the axial direction. Then the nozzle element 60 , coming out of one of the housing 10 different material is formed from the opening 11c of the first magnetic section 11 introduced. After adjustment of the insertion amount and also adjustment of the depressing margin of the elastic portion 56 becomes the nozzle element 60 at the opening 11c fixed.

[0123] In this way, the amount of insertion of the nozzle member 60 that at the opening 11c is fixed in the housing 10 adjusted to thereby increase the deflection span of the elastic section 56 to adjust, which is the adjustment operation of the indentation margin compared to the case of adjusting the position of the stopper 70 simplified, between one end and the other end of the housing 10 is set up.

[0124] In the present embodiment, the nozzle element 60 from one of the housing 10 different material formed and the stopper 70 is also from one of the housing 10 different material formed. If the nozzle element 60 and the stopper 70 each from one of the housing 10 Different material are made, can adjust the relative position of the nozzle member 60 and the stopper 70 to adjust the compression span of the elastic section 56 be complicated. In the present embodiment, the stepped portion is 11b , which is in the first magnetic section 11 of the housing 10 is formed against the end face 70b of the stopper 70 created, thereby changing the position of the stopper 70 in relation to the case 10 to determine. In this way, the adjustment of the relative position of the nozzle element 60 and the stopper 70 just by moving the nozzle member 60 be performed. Therefore, the fuel injector 100 be made easily.

[0125] The stopper 70 is a against the valve body 50 created part. Therefore, e.g. B. the material that can secure the shock by applying against the valve body 50 is effected, preferably selected as the material used for the stopper 70 is used. Since in the present embodiment the stopper 70 from one of the housing 10 different material, the material for the stopper can 70 be selected without being affected by the housing 10 material used to be limited.

[0126] Each time the valve body 50 on the valve seat 60c seated is the beveled surface 70e of the stopper 70 against the contact surface 53b of the valve body 50 created. For example, if the beveled surface 70e from one of the plant area 53b is formed of different material, the abutment between both parts is repeatedly performed, which might deform one of them having lower hardness. This might not be able to lift the valve body 50 to stabilize for a long period of time.

[0127] For this problem, the present embodiment uses the structure in which the slanted surface 70e of the stopper 70 is made of the same material as the contact surface 53b of the valve body 50 . With this arrangement, the beveled surface 70e have substantially the same hardness as that of the contact surface 53b . Therefore, deformation may occur when the stopper is abutted 70 against the valve body 50 be suppressed. The slanting surface and the abutment surface can be formed of different kinds of materials as long as both materials have the same hardness.

[0128] If the beveled surface 70e and the plant area 53b are formed of the same material, repeated application therebetween can cause baking between these surfaces 75 and 53bcause. For this problem, in the present embodiment, either has the area 75 or 53b on its front surface, the coated layer 72 , which is made of DLC or polytetrafluoroethylene. This can cause jaws to appear between the stoppers 70 and the valve body 50 suppress.

[0129] Basically, rubber is known to be a material that makes it difficult to increase dimensional accuracy compared to metallic material. As mentioned above, in the present embodiment, the crushing span of the elastic portion 56 by adjusting the relative position of the nozzle member 60 and the stopper 70 customized. In this way, it is in adjusting the compression span of the elastic section 56 not necessary, the dimensional accuracy of the elastic section 56 to improve. Therefore, rubber can be used as the elastic portion 56 be used.

[0130] In the present embodiment, rubber is for use in forming the elastic portion 56 fluoro rubber. The fluororubber is known as a material exhibiting elasticity at an ultra-low temperature (for example, in a range of -30 to -40°C). In particular, fluororubber is a material suitable when using gaseous fuel as the fuel.

[0131] In the present embodiment, that is from the fuel injector 100 handled fuel gas fuel. When using the gaseous fuel as the fuel, it is important to ensure airtightness. In the present embodiment, the seat portion 56A formed of an elastic member which maintains airtightness upon closing of the fuel injector 100 can easily ensure. The seat section 56a is suitable for gas fuel use.

[0132] In the present embodiment, the housing corresponds 10 a "main body", the fuel passage 60a corresponds to “fuel passage leading to an injection port”, the nozzle member 60 corresponds to “passage formation portion”, the valve main body 51 corresponds to a “valve element”, the elastic portion 56 corresponds to “elastic member” and the stopper 70 corresponds to a “movement restriction section”.

[0133] In the present embodiment, the process from the stopper installation step to the insertion amount adjustment step corresponds to an “adjustment step”, and the nozzle element fixing step corresponds to a “relative position fixing step”. Further, the stopper installation step corresponds to an “installation step”, and the insertion amount adjustment step corresponds to an “insertion step”. Second embodiment

[0134] Although in the first embodiment, the stopper 70 one from the case 10 different element and with / on the housing 10 connected / fixed by laser welding or the like, such as a fuel injector 200 of a second embodiment, which is figure 7, the stopper 70 in the housing 10 be formed by stamping or casting. Even with this arrangement, the nozzle element 60 one of the stopper 70 different element, so the deflection span of the elastic section 56 by adjusting the relative position of the nozzle element 60 and the stopper 70 can be adjusted. The second embodiment also adopts the same structure as that in the first embodiment with the difference of the above structure, and therefore can have the same operation and effects as those in the first embodiment. Third embodiment

[0135] In the first and second embodiments, the laser welding is applied to the entire circumference of the nozzle member 60 performed on the outer circumference in the radial direction, so that the nozzle member 60 with / on the housing 10 connected and fixed. In a fuel injector 300of a third embodiment, which is figure 8 is the nozzle member 60 with / on the housing 10 connected and fixed not by performing laser welding or the like on the entire circumference thereof, but by welding some spots (spot welding) in the circumferential direction thereof. This structure, however, allows a gap between the nozzle element 60 and the housing 10 generate between adjacent welded parts to let the fuel escape from the gap. In the present embodiment is an O-ring 61 on the outer peripheral surface in the radial direction of the nozzle member 60 intended. Even if the nozzle element 60 with / on the housing 10 connected and fixed by spot welding, the O-ring 61 the sealability between the housing 10 and the nozzle element 60 to ensure. Instead of spot welding, press fitting or caulking may be performed. The stopper 70 of the present embodiment is with the housing 10 one piece, but the stopper 70 can be separated from the housing 10 be provided as in the first embodiment. Fourth embodiment

[0136] Although in the first to third embodiments, the elastic portion 56 in the valve body 50 is provided and the seat portion 56a in the elastic section 56 provided is in a fuel injector 400 of a fourth embodiment, which is figure 9 is an elastic portion 156 on a nozzle main body 161 a nozzle element 160 appropriate.

[0137] The following are the nozzle element 160 and the valve body 150 , which have different structures from those of the first embodiment will be described in detail. The nozzle element 160 includes the nozzle main body 161 , which is formed cylindrically from martensitic stainless steel, and the elastic section 156 , which formed a disc-like shape of an elastic material, such as. B. Fluoro rubber.

[0138] The nozzle main body 161 is with a fuel passage 161a provided which axially penetrates the center thereof in the radial direction. The fuel passage 161a has on its the valve body 150 opposite end an injection port 161b to inject the fuel through it. The nozzle main body 161 is with / at the opening 11c of the small diameter section 11a in the first magnetic section 11 connected and fixed by means of laser welding or the like.

[0139] The elastic section 165 is on the end surface of the nozzle main body 161 on the valve body 150 appropriate. A through hole 156b is formed around the center in the radial direction of the elastic portion 156 to penetrate axially. The through hole 156b and the fuel passage 161a are arranged coaxially. A valve seat 156a , which is the through hole 156b surrounds is on the surface of the elastic portion 156 on the valve body 150 educated.

[0140] The elastic section 156 has an anchor section 156f for increasing the fixing force to the nozzle main body 161 . The anchor section 156f is in the nozzle main body 161 formed and arranged to bite into the groove, which is recessed in the direction that the reciprocating direction of the valve body 150 crosses. This structure increases the fixing force of the nozzle main body 161 . Specifically, the fixing force in the reciprocating direction of the valve body 150 will be raised.

[0141] The valve body 150 is formed in a stick-like shape of martensitic stainless steel functioning as a nonmagnetic material and coaxially on the inner circumference of the first magnetic portion 11 houses. The valve body 150includes a coupling portion 155 , a quadrangular prism section 153 and a columnar portion 154 .

[0142] The coupling section 155 has the same shape and function as those of the coupling portion 55 of the first embodiment and is on the movable core 40 coupled. The coupling section 155 has the same shape and function as those in the first embodiment.

[0143] The quadrangular prism 153 is on the nozzle element 160 in relation to the coupling section 155 furnished. The quadrangular prism 153 has the same shape as that of the first embodiment and has a guide portion 153a , along the inner peripheral wall surface of the stopper 70 be guided at the corners of the side surfaces. At the corners of the bottom surface of the quadrangular prism section 153 on the nozzle element 160 are investment areas 153b educated. If the valve body 150 towards the nozzle element 160 moves, every contact surface 153b against the beveled surface 70e of the stopper 70 created. The respective angle of inclination of the contact surface 153b and the beveled surface 70e are the same as those of the first embodiment.

[0144] The sectional shape and diameter of the columnar portion 154 are the same as those of the first embodiment. A seat section 154a that goes on and off the valve seat 156a attachable and detachable is at the end of the columnar portion 154 on the nozzle element 160 formed in the present embodiment.

[0145] A ring-like seat section 154a is on a face of the columnar portion 154 formed of the nozzle element 160 facing to towards the nozzle member 160 projecting from the outer perimeter of the surface. An in-depth section 154b is on the inner circumference of the seat portion 155a formed to move toward the opposite side to the nozzle member 160c to be engrossed. The diameter of the inner peripheral surface 154d that at the perimeter of the floor area 154c of the recessed section 154b is formed is larger than that of an opening 156c of the through hole 156b in the elastic section 156 . The diameter of the inner peripheral surface 154d may be in a range of the outer diameter of the columnar portion 154 be fixed. The seat section 154a is at the outer periphery of the depressed portion 154b on the surface of the columnar portion 154 the nozzle element 160 dedicated trained. corners 154e on the nozzle element 160 the inner peripheral surface 154d can be applied to the outer perimeter of the opening 156c to include That is, the corners can be created so that the seat section 154a the outer perimeter of the opening 156c includes. In this way, the fuel passage 161a closed. The inner peripheral surface 154d of the recessed section 154b is inclined so that the recessed section 154b toward the center of the recessed portion 154b gradually becomes deeper in the radial direction.

[0146] Also in the present embodiment, as in the first embodiment, when the valve opens, the seat diameter D, the stroke L and the passage area S2 are set so that the opening area S1 defined between the seat portion 154a and the valve seat 156a is formed is equal to or more than the passage area S2 of the fuel passage 161a is. Preferably, in the present embodiment, the opening area S1 is 1.4 times or more as large as the passage area S2.

[0147] By means of the nozzle element 160 and the valve body 150 in the upper arrangement becomes the contact surface 153b of the valve body 150 against the beveled surface 70e of the stopper 70applied to the movement of the valve body 150 towards the nozzle element 160 to restrict what the deflection span of the elastic section 156 , which is in the nozzle element 160 is provided, can be set to the predetermined value.

[0148] Next is the adjustment of the deflection span of the elastic section 156 are described below. In the distance measuring step, a distance from the opening 11c of the first magnetic section 11 as a reference position to the seat portion 154a of the valve section 150 measured while the plant area 153b of the valve body 150 against the beveled surface 70e of the stopper 70 is created. Then, in the insertion amount calculation step, a predetermined depressing range (predetermined value) of the elastic portion 156 is added to the measurement result in the distance measurement step, to thereby determine the amount of insertion of the nozzle member 160 to calculate. After that, the nozzle main body 161 into the opening 11c inserted by the calculated amount of insertion so that the nozzle main body 161 with and on the first magnetic section 11 is connected and fixed by means of laser welding or the like. Also, in the present embodiment, as in the first embodiment, the insertion amount is preferably determined in consideration of the occurrence of thermal expansion of the first magnetic portion 11 and nozzle main body 161 calculated due to the laser welding or the like. As mentioned in the first embodiment, the nozzle element 160 at the first magnetic section 11 fixed by press-fitting or caulking.

[0149] The stopper 70 of the present embodiment is with the housing 10 one piece, but the stopper 70 can be separated from the housing 10 be provided as in the first embodiment. In the present embodiment, like the third embodiment, a method for connecting the nozzle member 160 connecting and fixing the nozzle element 160 on the housing 10 enclose by spot welding. In this case, the O-ring 61 on the outer peripheral surface in the radial direction of the nozzle main body 161 be provided. Therefore, the sealability between the nozzle main body 161 and the housing 10 be ensured.

[0150] In particular, in the present embodiment, the columnar portion has 154 the seat section 154a towards the nozzle section 160 on the outer periphery of the face of the columnar portion 154 the nozzle element 160 face facing. The seat section 154a is applied against it around the outer periphery of the opening 156c of the through hole 156b to enclose the fuel passage 161a close. With the above structure, the seat diameter D can be set larger than that of the opening 156c . If the the nozzle element 160 facing surface of the columnar portion 154 is flat, the seat diameter is substantially the same as that of the through hole 156b . Because the seat diameter D can be set larger than that of the orifice 156c can the part of the columnar section 154 , which corresponds to the seat diameter D, i. H. the opening area S1 formed on the inner periphery of the seat portion 154a is formed, be fixed larger. Therefore, the amount of fuel entering the fuel passage 161a flows can be increased compared to the case like that of the nozzle member 160 facing surface of the columnar portion 154 is flat, thereby suppressing the decrease in injection pressure.

[0151] By setting the opening area S1 to be larger than the passage area S2 by one or more times, the fuel flowing from the distance between both the elements 154a and 156a , flows, from the injection port 161bbe left out. When the opening area S1 is set to 1.4 times or larger than the passage area S2, the amount of fuel entering the fuel passage 161a about a distance between the two, the element 154a and 156a , flows, are increased to suppress the fuel from the fuel passage 161a to be discharged, thereby reducing a pressure of the fuel within the fuel passage 161a is prevented. As a result, the pressure of a fuel flowing from the injection port 161b is omitted, d. H. the injection pressure as close as possible to the pressure of a fuel entering the fuel injector 400 flows.

[0152] In the present embodiment, the case corresponds to a “main body” described in the appended claims, the fuel passage 161a corresponds to “a fuel passage leading to an injection port”, the nozzle main body 161 corresponds to “passage formation portion”, the valve body 150 corresponds to a “valve element”, the elastic portion 156 corresponds to “elastic member” and the stopper 70 corresponds to a “movement restriction section”. Fifth embodiment

[0153] In the first to fourth embodiments described above, the shapes of the valves are the fuel injectors 100 , 200 , 300 and 400 the so-called inward opening valves. On the other hand, in a fifth embodiment shown in figure 10 shows the valve configuration of a fuel injector 500 the so-called outward opening valve. The fuel injector 500 includes a housing 510 , an inlet element 520 , a fixed core 530 , a moveable core 540 , a valve body 550 , a passage formation element 560 , a stopper 570 and a drive unit 590 .

[0154] The case 510 is entirely cylindrical and has a first magnetic section 511 , a non-magnetic section 512 and a second magnetic section 513 in this order from one end to the other end in the axial direction. The first and second magnetic sections 511 and 513 , which is formed of ferritic stainless steel functioning as a magnetic material, is laser welded or the like to the non-magnetic portion 512 , which is formed of austenitic stainless steel functions as a non-magnetic material.

[0155] The first magnetic section 511 has a large diameter section 511d , leading to the non-magnetic section 512 connected, and a small-diameter portion 511a , which has an outer diameter smaller than that of the large-diameter portion 511d . The stopper 570 is at one end of the small diameter section 511a versus the non-magnetic section 512 provided, d. H. at the opening 511c , located at one end downstream of a fuel flow within the housing 510 educated. The passage formation element 560 is between one end and the other end of the housing 510 provided in the axial direction. The inlet element 520 is at a non-magnetic portion 512 opposite end 513a of the second magnetic section 513 intended.

[0156] The inlet element 520 is cylindrical and has an inlet 520a , which is formed at the center thereof in the radial direction, so that it supplies fuel supplied from a fuel point through a fuel pipe to the fuel injector 500 permitted. The inlet element 520 is with and at the end 513a of the second magnetic section 513 connected and fixed by means of laser welding or the like.

[0157] The fixed core 530is cylindrically formed of ferritic stainless steel functioning as a magnetic material and coaxial with the inner peripheral wall of the non-magnetic portion 512 and the second magnetic section 513 fixed. The fixed core 530 is with a through hole 530a is provided which axially penetrates the center in a radial direction of the core.

[0158] The moveable core 540 is cylindrically formed of a ferritic stainless steel that functions as a magnetic material. The moveable core 540 is coaxial on the inner circumference of the housing 510 houses and between the fixed core 530 and the inlet element 520 positioned.

[0159] The moveable core 540 has guide portions on the outer peripheral wall thereof 541a , which along the respective inner peripheral walls of the second magnetic portion 530 and the non-magnetic section 512 are led. With this arrangement, the movable core 540 axially reciprocated by means of the guide portion 541a along the corresponding inner peripheral walls of the second magnetic portion 513 and the non-magnetic section 512 movable. The moveable core 540 is with a through hole 541b is provided which axially penetrates the center in a radial direction of the core. The coupling section 552 of the valve body 550 , to be described later, is press fitted and to the through hole 541b fixed.

[0160] The valve body 550 is formed entirely in the stick-like shape and coaxially on the inner circumference of the case 510 houses. The valve body 550 reciprocates in the axial direction around a fuel passage 560a , which is in the passage training section 560 to be described later is configured to open and close so that fuel is cut off from the injection port 570b injected into the combustion chamber.

[0161] As in the figure 10 and figure 11, the valve body has 550 a valve main body 551 , attached to the movable core 540 is coupled. The valve main body 551 is formed in the stick-like shape of a martensitic stainless steel functioning as the non-magnetic material. The valve main body 551 includes a stick-like coupling portion 552 , attached to the movable core 540 is coupled, a small diameter section 553 , which is above the injection port 570b in relation to the coupling section 552 is positioned and an elastic section 556 , which will be described later, attached thereto, and a large-diameter portion 554 , which is above the injection port 570b with respect to the small-diameter portion 553 is positioned and has a larger diameter than that of the small-diameter portion 553 . The coupling section 552 has its one end on the inlet member 520 , which is in the through hole 541b of the moveable core 540 set up and attached to the moveable core 540 is fixed. The coupling section 552 its other end has the through hole 530a of the fixed core 530 penetrating and the fuel passage 560a of the passage formation element 560 and is at the injection port 570b in the passage formation element 560 furnished. The coupling section 552 has a fuel passage 552a , which has a space between the inlet element 520 and the moveable core 540 with a space between the fixed core 530 and the passage formation member 560 on the outer periphery of the coupling portion 552 connects. Therefore, the fuel entering the fuel passage 552a from the inlet element 520 flows, into the space between the fixed core 530 and the passage formation member 560on the outer periphery of the coupling portion 552 boisterous.

[0162] The small diameter section 553 has a larger outer diameter than that of the coupling portion 552 and is at the injection port 570b of the coupling section 552 furnished. The outer diameter of the small diameter section 553 is smaller than the inner diameter of the inner peripheral wall of the stopper 570 . With the small diameter section 553 on the inner circumference of the stopper 570 established, a clearance is formed to allow the fuel to flow between the outer peripheral wall of the small-diameter portion 553 and the inner peripheral wall of the stopper 570 to walk through. The small diameter section 553 has a ring-like stepped section 553a , which at its end on the coupling section 552 is trained. The ring-like elastic section 556 is at the stepped section 553a appropriate. The elastic section 556 is at the stepped section 553a attached by means of an adhesive or the like. Alternatively, as in the first embodiment, the elastic portion 556 at the small-diameter portion 553 applied by overmoulding.

[0163] The large diameter section 554 has a larger outer diameter than that of the small-diameter portion 553 and is at the injection port 570b of the small diameter section 553 furnished. The large diameter section 554 has a plant area 554a , which have their diameter towards the injection port 570b gradually enlarged. The plant area 554a is against the beveled surface 570a applied, thereby controlling the movement of the valve body 550 towards the inlet element 520 limited, d. H. the movement of the valve body 550 in the closing direction. The outer diameter of the large diameter section 554 is fixed so that when the valve body 550 in the direction of movement of the contact surface 554a away from the beveled surface 570a moves the fuel between the bearing surface 554a and the beveled surface 570a has passed through, to the injection port 570b to be led.

[0164] The elastic section 556 is an elastic member which can be attached or detached to or from the passage formation member 560 is elastically deformable, and the seat portion 556a is in the passage formation element 560 facing position formed. In the present embodiment, the elastic portion 556 made of fluorine rubber with excellent resistance to low temperature and oil. With this arrangement, the valve body moves 550 also in the axial direction together with the movable core 540 , slides from the axial reciprocating movement of the movable core 540 . The elastic section 556 is upstream of the fuel flow with respect to the stopper 570 furnished.

[0165] A feather 580 , which serves as an urging member made of a coil spring, is on the outer periphery of a part of the coupling portion 552 of the valve body 550 between the fixed core 530 and the passage formation member 560 furnished. The spring 580 is coaxial with respect to the coupling portion 552 furnished. The spring 580 it has one end by means of the seat member 555 supported, which at the coupling portion 552 is fixed, and its other end by means of the stepped portion 511a propped up between the large-diameter section 551d and the small-diameter portion 511a of the first magnetic section 511 is trained. The spring 580 is between the seat element 555 and the stepped section551e arranged so that urging force toward the fixed core 530 constant on the valve body 550 is applied.

[0166] The plant area 554a of the valve body 550 is with a coated layer 571 provided, the z. B. made of DLC (diamond-like carbon) or polytetrafluoroethylene (registered trademark: Teflon). The coated layer 571 can at the beveled surface 570a of the stopper 570 be provided or on both, the contact surface 554a of the valve body 550 and the beveled surface 570a of the stopper 570 be provided. In the present embodiment, the coated layer is 571 only on the attachment surface 554a is formed, thereby reducing the manufacturing cost as compared with the case of forming the coated layer on both the abutment surface 554a and the beveled surface 570a , to be reduced. The coated layer 571 covers the outer peripheral surface of the valve body 550 what the coating of the coated layer 571 compared to the case of coating the inner peripheral surface of the stopper 570 can facilitate.

[0167] As in figure 10 and figure 11 is the passage formation member 560 from one of the housing 510 with the stopper 570 different material formed. The passage formation element 560 is cylindrically formed of a martensitic stainless steel functioning as a non-magnetic material. The passage training section 560 is with a fuel passage 560a provided penetrating its center in the axial direction. The fuel passage 560a accommodates part of the coupling section therein 552 of the valve body 550 and has a larger diameter than that of the coupling portion 552 . With this arrangement, the fuel flowing from the fuel passage 560a of the coupling section 552 was omitted by a clearance between the inner wall of the fuel passage 560a and the outer wall of the coupling portion 552 get lost. In the present embodiment, the passage formation member is 560 formed of a material different from the housing. The passage formation element 560 is in the first magnetic section 511 provided in which it into the opening 511c of the first magnetic section 511 is introduced. The passage formation element 560 is in relation to the housing 510 positioned while the end face 560c on the moveable core 540 against a stepped section 511b is applied to the inner peripheral wall of the small-diameter portion 511a is trained. The passage formation element 560 is with and at the small diameter portion 511a connected and fixed by laser welding or the like while being held by the housing 510 is positioned. A valve seat 560b , attached to and from the seat section 556a attachable and detachable is on the peripheral edge of the opening of the fuel passage 560a on the end face of the passage formation member 560 at the injection port 570b educated.

[0168] The seat section 556a is adjusted, the fuel passage 560a by means of a closing operation that includes causing the seat portion to close 556a on the valve seat 560b to deliver. This will increase the flow of fuel into the injection port 570b stopped. At this time, the elastic section 556 according to the amount of movement of the valve body 550 elastically deformed. At this time, the plant area 554a of the valve body 550 against the beveled surface 570a of the stopper 570 created. On the other hand is the seat section 556a adjusted, the fuel passage 560ato open by means of an opening operation, the loosening of the seat portion 556a from the valve seat 560b includes. At this time, the plant area 554a of the valve body 550 from the beveled surface 570a of the stopper 570 solved. Therefore, the fuel from the fuel passage 560a is left out by the distance between the abutment surface 554a and the beveled surface 570a run, thereby restricting the flow of fuel into the injection port 570b allowed, of at the top in relation to the beveled surface 570a is trained.

[0169] The stopper 570 is formed cylindrically from a martensitic stainless steel, which, as in figure 10 and figure 11 functions as a non-magnetic material. In the present embodiment, the stopper 570 from one of the housing 10 different material formed. The stopper 570 is from the small-diameter portion 511a of the first magnetic section 511 inserted and with and at the opening 511c connected and fixed by means of laser welding or the like.

[0170] The stopper 570 has a tapered surface on its inner peripheral wall 570a , which is formed to increase its inner diameter toward its tip. The beveled surface 570a is against the bearing surface 554a ajar to the movement of the valve body 550 to restrict in the closing direction. The beveled surface 570a is provided in a position where the elastic portion 556 on the valve seat 560b of the passage formation element 560 in the direction along the moving direction of the valve body 550 seated and is then elastically deformed to cause the deflection span of the elastic portion 556 reaches a predetermined value. An injection port 570b is at the top of the beveled surface 570a of the stopper 570 educated. The predetermined value is set to such a value that the stroke of the valve body changes 550 while avoiding any damage due to the permanent compression deformation of the elastic portion 556 prevented. Here, the predetermined value is set to a value that increases the fuel passage 560a even under occurrence of the compression permanent deformation of the elastic portion 556 or the inclination of the valve structure due to a geometric tolerance, while repairing the damage to the elastic material 556 prevented due to its compression. For example, the predetermined value is preferably set to a minimum value that allows sealing in a compression ratio of the elastic portion 556 from 8 to 35% is allowed even when the compression permanent deformation of the elastic portion occurs 556 or the inclination due to a geometric tolerance.

[0171] As in figure 10 includes the drive unit 590 an electromagnetic coil 591 , a yoke 592 , a connecting part 593 and similar. The electromagnetic coil 591 is formed from a metal wire rod wound around a plastic bobbin. The electromagnetic coil 591 is coaxial on the outer circumference in the radial direction of the casing 510 furnished. The connecting part 593 includes a connector 593a for electrically connecting the electromagnetic coil 591 to an external control group. By means of the external control circuit, the electromagnetic coil is powered 591 controlled.

[0172] the yoke 592 is formed cylindrically of a ferritic stainless steel functioning as a magnetic material and on the outer circumference in the radial direction of the electromagnetic coil 591 and the housing 10 set up the electromagnetic coil 591 to cover. the yoke 592has small-diameter portions formed at both ends thereof in the axial direction. The small diameter sections are with the large diameter section 511d of the first magnetic section 11 and the second magnetic section 513 each connected by means of laser welding or the like.

[0173] If the electromagnetic coil 591 by supplying current to the electromagnetic coil 591 via a connection 593a fed and excited, a magnetic flux flows in a magnetic circuit coming out of the yoke 592 , the first magnetic section 511 , the fixed core 530 , the moveable core 540 and the second magnetic section 513 is trained together. As a result, a magnetic attraction force between the movable core 540 and the fixed core 530 , which are opposed to each other, to act as a “magnetic force” for driving and attracting the movable core 540 towards the fixed core 530 to serve. On the other hand, if the electromagnetic coil 591 is demagnetized by stopping the energization, the magnetic flux does not flow in the magnetic circuit, thereby reducing the magnetic attraction force between the movable core 540 and the fixed core 530 is eliminated.

[0174] The operation of the fuel injector 500 will be described in detail below. When powering the electromagnetic coil 591 into the fuel injector 500 in the in figure 10 is stopped, the magnetic attraction force acting on the movable core 540 should act, eliminated, so that the contact surface 554a of the valve body 550 against the beveled surface 570a of the stopper 570 by means of an urging force of the spring 580 is pressed. At this time, the seat portion is seated 556a of the elastic section 556 on the valve seat 560c to the injection port 570b close. Therefore, the fuel from the inlet 520a to the fuel passage 560a through the fuel passage 522a and the space between the fixed core 35 and the passage formation member 560 flows, not from the injection port 570b injected.

[0175] Then, in the in figure 10 state shown when the electromagnetic coil 591 is fed to cause the magnetic attraction on the movable core 540 becomes, and the magnetic attractive force becomes larger than the urging force of the spring 580 , the movable core begins 540 towards the fixed core 530 to move. When the amount of movement of the movable core 540 the indentation span of the elastic section 556 exceeds, the seat section 556a from the valve seat 560b solved. Along with this becomes the plant area 554a of the valve body 550 from the beveled surface 570a solved. Therefore, the fuel leading the fuel passage 560a reached, to the level between the contact surface 554a and the beveled surface 570a about the distance between the seat section 556a and the valve seat 560a and is then from the injection port 570b injected. The moveable core 540 moves up the movable core 540 against the fixed core 530 applied. The stroke corresponds to a distance of movement of the valve body 550 , in which the movable core 540 against the fixed core 530 rests after the seat section 556a from the valve seat 560b is solved.

[0176] Then when the power to the electromagnetic coil 591 is stopped again, which is on the movable core 540 effective magnetic attraction eliminated. Therefore, the on the movable core 540 acting force only the urging force of the spring 85 , causing the movable core 540 towards the inlet element520 starts to move. The movement of the movable core 540 causes the seat section first 546a on the valve seat 560b stands. The seat section 556a sits on the valve seat 560b , to discharge the fuel from the fuel passage 560a into the injection port 570b to end what the injection of fuel from the injection port 570b stops. Even after the seat section 556a on the valve seat 556b seated, the valve body moves 550 essentially in the direction of the inlet element 520 , while the elastic section 556 is elastically deformed. Then when the plant area 554a of the valve body 550 against the beveled surface 570a of the stopper 570 is applied, the movement of the valve body 550 towards the inlet element 520 stopped. At this time, the elastic section press-in pan 556 the predetermined value.

[0177] The following is a method of manufacturing the fuel injector 500 to be discribed. passage formation element installation step

[0178] The passage formation element 560 is from the opening 511c of the first magnetic section 511 into the housing 510 introduced by connecting the first magnetic section 511 , the non-magnetic section 512 and the second magnetic section 513 is formed by laser welding. The passage formation element 560 is introduced to an end face 560c of the passage formation element 560 against the stepped section 511b of the first magnetic section 511 applied. Thereafter, the passage formation member 560 on the housing 510 fixed by laser welding or the like. Therefore, the passage formation element 560 between one end and the other end of the housing 510 provided in the axial direction. valve body forming step

[0179] The elastic section 556 will be at the graded section 553a of the valve main body 551 attached by overmolding. distance measurement step

[0180] A distance between the opening 511c of the first magnetic section 511 is used as the reference position to the valve seat 560b of the passage formation element 560 measured. Insertion Amount Calculation Step

[0181] The insertion amount of the stopper 570 in the first magnetic section 511 is based on the measurement result in the distance measurement step, the dimension of each previously measured component of the stopper 570 , especially the distance at which the stopper 570 against the contact surface 554a of the valve body 550 within a range from the end face of the stopper 570 in the axial direction to the tapered surface 570a is applied, and the predetermined indentation margin (predetermined value) of the elastic portion 556 calculated. In the present embodiment, the stopper 570 with and on the housing 510 connected and fixed by means of laser welding or the like. Therefore, the insertion amount is calculated considering the thermal expansion caused by the laser welding in the stopper 570 and the housing 510 is produced. insertion amount adjustment step

[0182] The stopper 570 is from the opening 511c of the first magnetic section 511 inserted by the insertion amount calculated in the insertion amount calculation step, whereby the depressing margin of the elastic portion 556 adjusted to the predetermined value. stopper fixing step

[0183] The stopper 570 becomes with and at the first magnetic section 511 connected and fixed by laser welding. Therefore, the relative positional relationship between the passage formation portion 560 and the stopper 570in the direction along the moving direction of the valve body 550 fixed and is the contact surface 554a against the beveled surface 570a created so that the indentation span of the elastic section 556 can be set to the predetermined value when the seat portion 556a of the elastic section 556 on the valve seat 560b sits. In the present embodiment, a welded part is interposed between the first magnetic portion 511 and the stopper 570 over the entire perimeter. The welding can seal between the first magnetic section 511 and the stopper 570 to ensure. Installation step for the spring, the fixed core and the movable core

[0184] The fixed core 580 is from the second magnetic section 513 introduced. After that, the valve body 550 from the first magnetic section 511 introduced. The seat element 555 is further from the second magnetic section 513 inserted and from the coupling portion 552 of the valve body 550 fixed. Then the fixed core 530 from the second magnetic section 513 introduced and fixed in a predetermined position. Then the movable core 540 from the second magnetic section 513 inserted and at the coupling portion 552 fixed. Inlet member and drive unit attachment step

[0185] The inlet element 520 is attached to the second magnetic section 513 attached and then both components are connected and fixed to and from each other by means of laser welding or the like. The drive unit 590 , consisting of the electromagnetic coil 591 , the connecting part 593 and the yoke 592 is in the outer perimeter of the case 510 fitted and then the yoke 592 with and on the housing 510 connected and fixed by means of laser welding or the like.

[0186] Even in the fuel injector 500 having the structure described above, like the first embodiment, are the passage formation portion 560 and the stopper 570 made of different materials. With this arrangement, as in the first embodiment, the crushing margin of the elastic portion 556 easily adjusted to a predetermined value without affecting the dimensional accuracy of parts of the elastic portion 556 to increase more than necessary, which can experience the effect and action of stabilizing the fuel injection amount while reducing the increase in manufacturing cost. The elastic section 556 is upstream of the fuel flow with respect to the stopper 570 furnished. For example, one using the fuel injector 500 for direct injection the elastic section 556 be as far away from the combustion chamber as possible. This arrangement can reduce the effect of heat of the high-temperature combustion gas in the combustion chamber, thereby reducing the damage on the elastic portion 556 to be suppressed by the heat (e.g. erosion).

[0187] In the present embodiment, the passage formation member 560 between one end and the other end of the housing 510 established in the axial direction. Then the stopper 570 coming out of one of the housing 510 different material is formed from the opening 511c of the first magnetic section 511 introduced. After adjustment of the insertion amount and also adjustment of the depressing span of the elastic portion 556 becomes the stopper 570 to the opening 511c fixed.

[0188] In this way, the insertion amount of the stopper 570 that in the opening 511c is fixed in the housing 510 adjusted to thereby increase the indentation span of the elastic clearance 556to adjust, which is the adjustment operation of the indentation margin compared to the case of adjusting the position of the passage formation member 560 , which is between one end and the other end of the housing 510 is set up, relieved.

[0189] In the present embodiment, after adjusting the relative positions of the passage formation member 560 and the stopper 570 in the direction along the reciprocating direction of the valve body 550 in the insertion amount adjustment step, the stopper 570 on the housing 510 welded and fixed at the stopper fixing step. Therefore, the relative positions of the passage formation member 560 and the stopper 570 be firmly fixed at the positions after the adjustment.

[0190] In the present embodiment, the stopper 570 on the housing 510 fixed by welding and fixing, but both the insertion amount adjustment step and the stopper fixing step can be performed at one time. For example we the stopper 570 press-fixed and into the housing 510 fixiet, which can perform both steps at a time. A method of fixing the stopper 570 can seal and fix the stopper 570 to the housing 510 lock in.

[0191] In the present embodiment, the stopper 570 from one of the housing 510 different material and is the passage formation portion 560 also from one of the housing 510 different material formed. If the passage formation element 560 and the stopper 570 each out of the housing 510 Different materials are formed, can adjust the relative positions of the stopper 570 and the passage formation member 560 to adjust the compression span of the elastic section 556 get complicated. In the present embodiment, the stepped portion 511b , which is in the first magnetic section 511 of the housing 510 is formed against the end face 560c of the passage formation element 560 applied to thereby the position of the passage formation member 560 in relation to the case 510 to determine. In this way, adjusting the relative positions of the stopper 570 and the passage formation member 560 just by moving the stopper 570 be performed. Therefore, the fuel injector 500 be made easily.

[0192] The stopper 570 is a against the valve body 550 created part. Therefore, preferably z. B. the material that can secure the shock caused by the application against the valve body 550 is produced is selected as a material used for the stopper 570 is used. Since in the present embodiment the stopper 570 from one of the housing 510 different material, the material for the stopper can 570 be selected without going through that for the housing 510 material used to be restricted.

[0193] If the valve body 550 on the valve seat 560b sits, the beveled surface lies 570a of the stopper 570 against the contact surface 554a of the valve body 554 on. For example, if the beveled surface 570a from one of the plant area 554a of different material, the abutment between both members is repeatedly performed, which may deform one of them having lower hardness. This might not be able to lift the valve body 550 to stabilize for a long period of time. For this problem, the present embodiment employs the structure in which the tapered surface 570a of the stopper 570 is made of the same material as the contact surface 554a of the valve body 550 . With this arrangement, the beveled surface 570asubstantially the same hardness as that of the abutment 554a to have. Therefore, deformation may occur when the stopper is applied 570 against the valve body 550 be suppressed.

[0194] If the beveled surface 570a and the plant surface 554a are formed of the same material, repeated engagement therebetween can cause baking between those surfaces 570a and 554a effect. For this problem, in the present embodiment, has the area 570a or 554a a coated layer on its front surface 571 , which is made of DLC or polytetrafluoroethylene. This can prevent the occurrence of baking between the stoppers 570 and the valve body 550 suppress.

[0195] In general, rubber is known as a material that makes it difficult to increase dimensional accuracy compared to metal material. As mentioned above, in the present embodiment, the relative positions of the stopper 570 and the passage formation member 560 by adjusting the compression span of the elastic section 556 customized. In this way, by adjusting the compression span of the elastic section 556 , it is not necessary the dimensional accuracy of the elastic section 556 to improve. Therefore, rubber can be used as the elastic portion 556 be used.

[0196] In the present embodiment, rubber is for use in forming the elastic portion 556 fluoro rubber. Fluorine rubber is known as a material exhibiting ultra-low temperature elasticity (e.g., in a range of -30°C to -40°C). In particular, fluororubber is a material suitable in using gaseous fuel as the fuel.

[0197] In the present embodiment, that is from the fuel injector 500 handled fuel gas fuel. By using the gaseous fuel as the fuel, the gaseous fuel can be inside the fuel injector 500 be gassed. Therefore, it is very important to ensure airtightness. In the present embodiment, the seat portion 556a formed of an elastic material that maintains airtightness upon closing of the fuel injector 500 can easily ensure. The seat section 556a is suitable for use with gas fuel.

[0198] In the present embodiment, the housing corresponds 510 a "main body", the fuel passage 560a corresponds to “fuel passage leading to an injection port”, the passage formation member 560 corresponds to “passage formation portion”, the valve main body 551 corresponds to a “valve element”, the elastic portion 556 corresponds to “elastic member” and the stopper 570 corresponds to a “movement restriction section”.

[0199] In the present embodiment, the process from the passage formation member installation step to the insertion amount adjustment step corresponds to an “adjustment step”, and the stopper fixing step corresponds to a “relative position fixing step”. Further, the passage formation member assembling step corresponds to an “assembling step”, and the insertion amount adjustment step corresponds to an “inserting step”. Sixth embodiment

[0200] In the fifth embodiment, the stopper 570 from one of the housing 510 different material. The stopper 570 is with and on the housing 510 connected and fixed by means of laser welding or the like. A fuel injector 600 one in figure The sixth embodiment shown in Fig. 12 has a stopper 570 who in the housing 510 formed by cutting or casting. Even with this arrangement, since the passage formation member 560 still one of the stopper 570 is different element, the deflection range of the elastic section 556 by adjusting the relative positions of the passage formation member 560 and the stopper 570be adjusted. The sixth embodiment uses the same structure as that in the fifth embodiment except for the upper structure, and therefore can have the same operation and effects as those of the fifth embodiment. Seventh embodiment

[0201] In the fifth and sixth embodiments, the laser welding is applied to the entire outer periphery of the passage formation member 560 performed in the radial direction, so that the passage formation portion 560 with and on the housing 560 connected and fixed. In a fuel injector 700 one in figure The seventh embodiment shown in FIG. 13 becomes the passage formation member 560 with and on the housing 510 connected and fixed not by performing laser welding or the like on the entire circumference thereof, but by welding some spots (spot welding) in the circumferential direction thereof. However, this structure can provide a clearance between the passage formation member 560 and the housing 510 generate between adjacent welded parts to drain the fuel from the gap. In the present embodiment is an O-ring 561 on the outer peripheral surface in the radial direction of the passage formation member 560 intended. Even if the passage formation element 560 with and on the housing 510 connected and fixed by spot welding, the O-ring 561 the sealability between the housing 510 and the passage formation member 560 to ensure. The stopper 570 of the present embodiment is integral with the housing 510 , but the stopper 570 can be separated from the housing 510 be provided, as in the fifth embodiment. Eighth embodiment

[0202] In the fifth to seventh embodiments, the elastic portion 656 in the valve body 650 provided and the seat portion 653b is in the elastic section 656 educated. In a fuel injector 800 one in figure 14 is an elastic portion 656 on a passage main body 561 of the passage formation element 660 appropriate.

[0203] The following are the passage formation element 660 and the valve body 650 , which have different structures from those of the fifth embodiment, will be described in detail. The passage formation element 660 includes a passage main body 661 , which is formed cylindrically from martensitic stainless steel, and an elastic section 656 , which is formed in a disk-like shape of an elastic material, such as. B. Fluoro rubber.

[0204] The passage main body 661 is with a fuel passage 661a provided which axially penetrates the center thereof in the axial direction. The inlet element 661 is with and at the small diameter portion 511a of the first magnetic section 511 connected and fixed by means of laser welding or the like.

[0205] The elastic section 656 is at the end face of the passage main body 661 of the valve body 650 appropriate. A through hole 656a is formed around the center in the radial direction of the elastic portion 656 to penetrate axially. The through hole 656a and the fuel passage 661a are arranged coaxially. A valve seat 656b , which is the through hole 656a surrounds is on the surface of the elastic portion 656 , which the valve body 650 faces, trained.

[0206] The valve body 650 is formed in a stick-like shape from martensitic stainless steel functioning as a non-magnetic material and coaxially on the inner periphery of the first magnetic portion 511 houses. The valve body 650 includes a coupling portion 652 , a small diameter section 653and a large diameter section 654 .

[0207] The coupling section 652 has the same shape and function as those of the coupling portion 652 of the fifth embodiment and is attached to the movable core 540 coupled. The coupling section 652 has the same fuel passage as that in the fifth embodiment.

[0208] The small diameter section 653 is the same as the small diameter section 553 of the fifth embodiment and is at the injection port 570b in relation to the coupling section 652 furnished. Any graded section 653a of the small diameter section 653 at the coupling section ( 652 ) is with a seat section 653b provided on and by a valve seat portion 656b attachable and detachable.

[0209] A large diameter section 654 is the same as the large diameter section 554 of the fifth embodiment and is at the injection port 570b with respect to the small-diameter portion 653 furnished. The large diameter section 654 has a plant area 654a , which gradually increase in diameter towards the injection port 570b elevated. The plant area 654a is against the beveled surface 570a applied to thereby the movement of the valve body 650 towards the inlet element 520 to restrict, d. H. the movement of the valve body 650 in the closing direction. The outer diameter of the large diameter section 654 is fixed so that when the valve body 650 in the direction of movement of the contact surface 654a away from the beveled surface 570a moves the fuel between the bearing surface 654a and the beveled surface 570a has passed, to the injection port 570b to be led.

[0210] By means of the passage formation element 660 and valve body 650 with the top arrangement becomes the abutment surface 654a of the valve body 650 against the beveled surface 570a of the stopper 570 applied to the movement of the valve body 650 towards the inlet element 520 to restrict what the deflection span of the elastic section 656 , which is in the passage formation element 660 is provided, can be set to the predetermined value.

[0211] Next is the adjustment of the deflection span of the elastic section 656 are described below. In the distance measuring step, a distance from the opening 511c of the first magnetic section 511 as the reference position to the valve seat 656b of the passage formation element 660 measured. Then, in the insertion amount calculation step, the insertion amount of the stopper 570 based on the measurement result in the distance measurement step, the dimension of each component of the stopper 570 previously measured, in particular the distance at which the stopper 570 against the contact surface 654a of the valve body 650 within a range from the end face of the stopper 570 in the axial direction to the tapered surface 570a is applied and the indentation span (predetermined value) of the elastic portion 656 calculated. After that, the stopper 570 with and on the first magnetic section 511 connected and fixed by means of laser welding or the like. Also in the present embodiment, like the fifth embodiment, the insertion amount is preferable in view of an occurrence of thermal expansion of the first magnetic portion 511 and the stopper 570 calculated due to the laser welding or the like.

[0212] The stopper 570 of the present embodiment is with the housing 510 one piece, but the stopper 570 and the housing 510of the fifth embodiment can be provided separately from each other. In the present embodiment, like the seventh embodiment, a method of connecting the passage formation member 660 connecting and fixing the passage formation member 660 with and on the housing 510 enclose by spot welding. In this case, an O-ring 561 on the outer peripheral surface in the radial direction of the passage main body 661 be provided. Therefore, the sealability between the passage main body 661 and the housing 510 be ensured.

[0213] In the present embodiment, the housing corresponds 510 a “main body” described in the accompanying claims corresponds to the fuel passage 661a a “fuel passage leading to an injection port” corresponds to the passage main body 661 a “passage formation portion” corresponds to the valve body 650 a “valve element” corresponds to the elastic portion 656 an “elastic member” and corresponds to the stopper 570 a "movement restriction section". Ninth embodiment

[0214] A ninth embodiment of the invention will be described below. figure 15a shows a cross-sectional view of a fuel injector according to the ninth embodiment; and figure 15B is an enlarged sectional view of a main part of FIG figure 15A shown fuel injector.

[0215] As in figure 15, the fuel injector includes a cylindrical body 1x , which is formed by connecting a plurality of metal components. A cylindrical coil 2x , which forms a magnetic field when fed, is on the outer circumference of the body 1x furnished. A metallic valve body 3x That which reciprocates by being propelled by means of electromagnetic force becomes inside the body 1x furnished.

[0216] Then gas fuel such. hydrogen or CNG (compressed natural gas) supplied from the fuel supply device (not shown) from the upper end of the body 1x , as on the paper plane of figure 15A into the body 1x and runs through the body 1x . Then the fuel is fed directly into the combustion chamber of the internal combustion engine (not shown) from the lower end of the body 1x , as on the paper plane of figure 15A.

[0217] The body 1x , the sink 2x and the valve body 3x are arranged coaxially. Here, a common axis line is hereinafter simply referred to as an “axis line”, the direction of the common axis line is hereinafter simply referred to as an “axial direction”, and the direction vertical to the common axis line is hereinafter simply referred to as a “radial direction”.

[0218] The body 1x includes cylindrical or substantially cylindrical first through fifth cylindrical sections 10x until 14x , which are arranged in this order from the fuel flow upstream side toward the fuel flow downstream side. The sixth cylindrical section 15x is within the fifth cylindrical section 14x furnished.

[0219] The first cylindrical section 10x is with a fuel inlet hole 100x provided, which serves as an inlet for fuel supplied from the fuel supply device. The second cylindrical section 11x is made of a magnetic metal to form a magnetic circuit. The third cylindrical section 12x is made of non-magnetic metal. The fourth cylindrical section 13x is made of a magnetic metal and includes a lift restricting portion 130x , which protrudes inward in the radial direction to form the magnetic circuit.

[0220] The fifth cylindrical section 14x, which serves as a second body, is made of a metal excellent in corrosion resistance (e.g., stainless). A current collector seat section 140x for opening and closing the fuel passage by connecting and disconnecting to and from a downstream movable seat portion (which will be described in detail below) of the valve body 3x is on the downstream side of fuel flow in the fifth cylindrical section 14x educated. The current collector seat section 140x forms a slope that widens from the upstream side of fuel flow toward the downstream side of fuel flow.

[0221] The sixth cylindrical section 15x , which serves as a first body, is made of a metal excellent in corrosion resistance (e.g., stainless steel) and upstream of fuel flow with respect to the downstream body seat portion 140x furnished. An upstream body seat section 150x for opening and closing the fuel passage by connecting and disconnecting to and from an upstream movable seat portion (which will be described in detail below) of the valve body 3x is at the downstream end of the fuel flow of the sixth cylindrical section 15x educated. The upstream body seat section 150x forms a slope extending from the upstream side of fuel flow toward the downstream side of fuel flow.

[0222] The valve body 3x includes cylindrical or substantially cylindrical first through third axial sections 30x , 31x and 32x , which are arranged in this order on the fuel flow upstream side toward the fuel flow downstream side. Among the first through third axial sections 30x , 31x and 32x has the first axial section 30x the smallest diameter and the third axial section 32x has the largest diameter.

[0223] The first axial section 30x is with a valve body vertical hole 300x is provided serving as a fuel passage extending from the end surface upstream of fuel flow in the axial direction, and a valve body transverse hole 301x , which extends in the radial direction to serve as a fuel passage around the valve body vertical hole 300x with a space of the body 1x connect to.

[0224] The end of the second axial section 31x upstream of the fuel flow is at a ring-like upstream movable seat portion 310x glued, which is made of an elastic material that has more excellent heat resistance and elasticity than metal. The upstream moveable seat section 310x is adapted to open and close the fuel passage by connecting with and from the upstream body seat portion 150x of the body 1x connected and disconnected.

[0225] In particular, the upstream movable seat section 310x formed by using fluororubber, acrylonitrile butadiene rubber (NBR), fluoroplastic, tetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), and the like.

[0226] In the upstream valve section, which consists of the upstream body seat section 150x and the upstream movable seat portion 310x is formed, one of the seat portions is formed of elastic material. Hereinafter, the upstream valve body is referred to as an “elastic sealing valve portion”.

[0227] A downstream moveable seat section 320x is at the end of the third axial section 32x formed upstream of the fuel flow. The downstream moveable seat section 320x is adapted to open and close the fuel passage by communicating with and from the downstream body seat 140x of the body 1x connected and disconnected. The downstream moveable seat section 320x is above the downstream side of fuel flow with respect to the upstream movable seat portion 310x positioned.

[0228] In the downstream valve portion, which consists of the downstream body seat portion 140xand the downstream movable seat portion 320x is formed, both seat portions are formed of metal. Hereinafter, the downstream valve portion is referred to as a “metal seal valve portion”.

[0229] The slant angle of the upstream body seat section 150x is larger than that of the current-absorption body seat portion 140x such that an area of ​​the fuel passage of the metal seal valve portion when the valve opens is smaller than that of the elastic seal valve portion when the valve opens, and such that a seat diameter D2x of the elastic seal valve portion is smaller than a seat diameter D1x of the metal seal valve portion.

[0230] The upstream moveable seat section 310x and the downstream movable seat portion 320x are along the reciprocating direction (i.e., the axial direction) of the valve body 3x arranged. The valve body 3x moves in the direction of the upstream movable seat portion 310x to the downstream movable seat portion 320x (i.e. pointed down on the paper surface of figure 15) to thereby open the fuel passage. In short, the fuel injector of the present embodiment serves as a so-called outward opening valve.

[0231] A faucet 4x , which is made of a magnetic metal, is at the end of the upstream side of the fuel flow in the first intercept 30x glued. More specifically, the faucet 4x in a through the first to fourth cylindrical section 10x until 13 of the body 1x positioned in enclosed space, i. H. upstream of the fuel flow with respect to the lift restriction section 130x of the fourth cylindrical section 13x . The valve body 3x and the faucet 4x form the movable portion of the invention.

[0232] A feather 5x for urging the valve body 3x in the direction of closing the valve is set up in a space defined by the fourth to sixth cylindrical sections 13x until 15x of the body 1x is included, d. H. downstream of the fuel flow of the fourth cylindrical section 13x in relation to the lifting restriction section 130x . In other words, the elastic seal valve portion and the metal seal valve portion are downstream of the fuel flow with respect to the spring 5x furnished. The spring 5x is a spiral spring and the valve body 3x is set up to spring 5x to penetrate.

[0233] A spring bearing 6x to pick up the spring 5x and a spacer 7x with a C-ring structure to adjust the set load on the spring 5x are on the outer periphery of the intermediate portion in the axial direction of the first axial portion 30x arranged.

[0234] Next, the operation of the fuel injector having the above structure will be described. First when the coil 2x is fed, the faucet 4x by an electromagnetic force toward the lifting restricting portion 130x dressed. The valve body 3x moves together with the valve 4x , around the upstream moveable seat section 310x from the upstream body seat portion 150x to separate, whereby the elastic seat valve portion is brought into a valve opening state, while the downstream movable seat portion 320x from the current collector seat portion 140x is separated, whereby the metal poppet valve portion is brought into a valve opening state so that the gaseous fuel is injected into the combustion chamber.

[0235] The attraction pressure required to open the valve has a relationship with the following value: (an area for receiving the pressure of the elastic seal valve portion)×(fuel pressure). A seat diameter D2x of the elastic seal valve is smaller than a seat diameter D1x of the metal seal valve, whereby the pressure-receiving area of ​​the elastic seal valve is smaller than that of the metal seal valve, resulting in a small attractive force required to open the valve.

[0236] When feeding the coil 2x is stopped, the valve body 3x towards the first cylindrical section 10x (i.e. in the direction to close the valve) by means of the spring 5x pushed. Therefore, the upstream movable seat portion comes first 310x against the upstream body seat section 150x is applied, bringing the elastic sealing valve into the valve-closing state to stop the injection of the gaseous fuel. The upstream moveable seat section 310x is made of an elastic material, which can ensure the good sealability upon closing of the valve. The upstream moveable seat section 310x is compressed in the axial direction to cause the downstream movable seat portion 320x in abutment against the downstream body seat portion 140x is, thereby bringing the metallic sealing valve into the valve-closed state.

[0237] In the internal combustion engine of a type in which gaseous fuel is directly injected into the fuel chamber, the fuel is usually ignited by means of a spark plug after the end of injection of the fuel and then burned. When the combustion gas is to flow into the fuel injector, the metallic sealing valve portion is in the valve-closed state. Therefore, by closing the metal seal valve portion, the combustion gas at high temperatures can be prevented from flowing to the elastic seal valve portion, thereby reducing the erosion of the upstream movable seat portion 310x is prevented.

[0238] In an internal combustion engine of a type in which fuel is ignited and burned during injection of the fuel, the supply pressure of the gaseous fuel is set higher than the combustion gas pressure, so that the combustion gas fills the upstream movable seat portion 310x can not reach. The metal seal valve portion allows little leakage of fuel even during valve closing. This is because when the combustion gas is to leak, the gas is expanded and then the temperature of the gas is lowered, so that even the high-temperature combustion gas is in a very low-temperature state upon reaching the upstream movable seat portion 310x can be brought, which does not lead to the erosion of the upstream movable seat portion 310x leads.

[0239] As the distance between the elastic seal valve portion and the metal seal valve portion becomes longer in the axial direction, the influence of heat of the combustion gas on the upstream movable seat portion 310x be reduced. The leakage of the fuel remaining between the elastic sealing valve portion and the metal sealing valve portion into the combustion chamber while closing the valve is undesirable from the viewpoint of controlling the combustion of the internal combustion engine. Therefore, considering both factors described above, the distance between the elastic seal valve portion and the metal seal valve portion in the axial direction is desirably set.

[0240] Next, a method of manufacturing the fuel injector having the upper structure will be described.

[0241] A set target load on the metal sealing valve portion, which consists of the downstream body seat portion 140x and the downstream movable seat portion 320x is formed is set to a set value of metal seal valve portion set load F1x. A target set load on the elastic seal valve portion extending from the upstream body seat portion 150xand the upstream movable seat portion 310x is formed is set to a set value of a sealing valve portion elastic set load F2x. The sum of the set value of a metal sealing valve portion set load F1x and the set value of an elastic seal valve portion set load Fx is set as a whole set value of a set load Fx.

[0242] The fifth cylindrical section 14x is attached to the valve body 3x assembled and the valve body 3x is urged around the downstream movable seat portion by use of a first jig (not shown). 320x against the downstream body seat portion 140x to press. At this time, the first jig urges the valve body 3x by means of a load corresponding to the whole fixed value of a fixed load FX.

[0243] Subsequently, keeping this state, the sixth cylindrical section 15x into the fifth cylindrical section 14x introduced and the sixth cylindrical section 15x is urged by a second jig (not shown) around the upstream body seat portion 150x against the upstream movable seat section 310x to press. At this time, the second jig is urging the sixth cylindrical section 15x by a load corresponding to the set value of a sealing valve portion elastic set load F2x.

[0244] In this state, a force acting on the downstream movable seat portion 320x against the downstream body seat portion 140x presses, by means of a force that presses the upstream body seat portion 150x against the upstream movable seat section 310x with respect to the urging force by means of the first jig is reduced, and thereby corresponds to the set value of the metal seal valve portion set load F1x.

[0245] Therefore, the relative positional relationship between the fifth cylindrical section increases 14x and the sixth cylindrical section 15x at this time, the optimal positional relationship between the fifth cylindrical section 14x and the sixth cylindrical section 15x from the standpoint of managing the set load on the metal seal valve portion and the set load on the elastic seal valve portion with high accuracy.

[0246] Subsequently, while maintaining the state, the fifth cylindrical section becomes 14x with the sixth cylindrical section 15x integral by welding. At this time, in full circle welding, the airtightness between the fifth cylindrical section 14x and the sixth cylindrical section 15x secured.

[0247] Below is the spring 5x on the spring bearing 6x assembled and the fixed length of the spring 5x is by means of the spacer disc 7x adjusted so that the fixed load on the spring 5x is a load corresponding to the fixed value of the total fixed load Fx. Therefore, the metal seal valve portion is subjected to the load corresponding to the set value of the metal seal valve portion set load Fix, and the elastic seal valve portion is subjected to the load corresponding to the set value of the elastic seal valve portion set load F2x. As mentioned above, in the present embodiment, the relative positions of the fifth cylindrical portion 14x and the sixth cylindrical section 15x adjusted in the assembling phase, which can easily handle the set load on the elastic seal valve portion, as well as the set load on the metal seal valve portion with high accuracy, albeit the body 1x or valve body 3x is not processed with high accuracy.

[0248] The seat diameter D2x of the elastic seal valve portion is smaller than the seat diameter D1x of the metal seal valve portion, which can reduce the attractive force required to open the valve.

[0249] Although in the above embodiments, the fifth cylindrical portion 14x and the sixth cylindrical section 15x are subjected to the full circle welding, in a first modified example of the ninth embodiment shown in FIG figure 16, the fifth cylindrical section 14x discontinuously integral with the sixth cylindrical section 15x be the distance between the fifth cylindrical section 14x and the sixth cylindrical section 15x with a sealing element 5x to seal. This method can reduce welding costs compared to full circle welding.

[0250] In the above embodiments, the upstream movable seat portion 310x formed of elastic material and the upstream body seat portion 150x is made of metal. In a second modified example of the ninth embodiment disclosed in figure 17 becomes a disc-like upstream body seat portion 151x , which is made of elastic material with more excellent elasticity and heat resistance than metal, at the end part of the sixth cylindrical section 15x glued downstream of the fuel flow. An upstream moveable seat section 311x may be at an upstream fuel flow end of the second intercept 31x be trained. The movable seat section 311x is adapted to connect and disconnect the fuel passage with or from the upstream body seat portion 151x to open and close. That is, the upstream body seat portion 151x may be formed of elastic material, whereas the upstream movable seat portion 311x can be made of metal.

[0251] The upstream body seat section 151x forms a slope extending from the upstream side of fuel flow toward the downstream side of fuel flow. The slant angle of the upstream body seat section 151x is larger than that of the current-absorption body seat portion 140x .

[0252] In the second modified example, the upstream body seat portion 151x to the sixth cylindrical section 15x , Which has a simpler structure than the valve body 3x has, glued. Gluing is easily performed. Tenth embodiment

[0253] A tenth embodiment of the invention will be described below. figure 18 is a sectional view of a fuel injector according to a tenth embodiment of the invention.

[0254] The fuel injector of the tenth embodiment is the so-called outward opening valve. On the other hand, the fuel injector of the present embodiment is the so-called inward opening valve. In the following, different parts only from the ninth embodiment will be described.

[0255] As in figure 18 is shown in the body 1x the fourth cylindrical section 13x in the second cylindrical section 11x furnished and the sixth cylindrical section 15Ax with a bottom is in the fifth cylindrical section 14 ax furnished. The fourth cylindrical section 13x is made of a magnetic metal and serves as a lift restricting portion opposed to the armature 4x is set up.

[0256] An upstream body seat section 141x is at the center of the fifth cylindrical section 14A formed as the first body in the axial direction. The upstream body seat portion is adapted to open and close the fuel passage by connecting and disconnecting with and from the upstream movable seat portion (described in detail below) of the valve body 3x . The upstream body seat section 141x forms a slope extending from the downstream side to the upstream side of the fuel flow.

[0257] The sixth cylindrical section 15Ax is as the second body downstream of the fuel flow with respect to the upstream body seat portion 141xfurnished. A current collector seat section 152x is at the upstream end of fuel flow in the sixth cylindrical section 15Ax educated. The seat section 152x is adapted to open and close the fuel passage by means of connecting and disconnecting with and from the downstream movable seat portion (described in detail below) of the valve body 3x . The current collector seat section 152x forms a slope extending from the fuel flow downstream side toward the fuel flow upstream side.

[0258] An injection port 153x is at the end of the sixth cylindrical section 15Ax formed downstream of the fuel flow. The injection port 153x serves to make the particles of the liquid fuel into very fine particles. Therefore, the fuel injector of the present embodiment is suitable for use with liquid fuel.

[0259] The valve body 3x comprises cylindrical first to third axial sections 30x , 31x and 32x , which are arranged in this order from the fuel flow upstream side toward the fuel flow downstream side. Among the first through third axial sections 30x , 31x and 32x has the first axial section 30x the smallest diameter and the second axial section 31x the largest diameter.

[0260] The end of the second axial section 31x downstream of the flow of fuel is on an annular upstream moveable seat portion 310x glued, which is made of an elastic material with more excellent heat resistance and elasticity than metal. The upstream moveable seat section 310x is adapted to connect and disconnect the fuel passage with and from the upstream body seat portion 141x of the body 1x to open and close.

[0261] In particular, the upstream movable seat section 310x can be formed using fluororubber, acrylonitrile butadiene rubber (NBR), fluoroplastic, tetrafluoroethylene (PTFE), polybutylene terephthalate (PBT), and the like.

[0262] In the upstream valve body consisting of the upstream body seat portion 141x and the upstream movable seat portion 310x is formed, one of the seat portions is formed of elastic material. Hereinafter, the upstream valve body is referred to as an “elastic sealing valve portion”.

[0263] A downstream moveable seat section 320x is at the end of the third axial section 32x formed downstream of the fuel flow. The downstream moveable seat section 320x is adapted to open and close the fuel passage by connecting with and from the downstream body seat portion 152x of the body 1x is connected and disconnected. The downstream moveable seat section 320x is above the downstream side of fuel flow with respect to the upstream movable seat portion 310x positioned.

[0264] Into the downstream valve body, which consists of the downstream body seat portion 152x and the downstream movable seat portion 320x is formed, both seat portions are formed of metal. Hereinafter, the downstream valve body is referred to as a “metallic sealing valve portion”.

[0265] The upstream moveable seat section 310x and the downstream movable seat portion 320x are along the reciprocating direction (i.e., the axial direction) of the valve body 3x arranged. The valve body 3x moves in the direction from the downstream movable seat portion 320x to the upstream movable seat portion 310x (i.e. on the paper surface of figure 18 shown upward) to thereby open the fuel passage. In short, the fuel injector of the present embodiment serves as the so-called inward opening valve.

[0266] The faucet 4x , which is made of a magnetic metal, is attached to the end of the first axle section 30xglued upstream of the fuel flow. More specifically, the faucet 4x positioned in a space defined by the second to fifth cylindrical sections 11x until 14x of the body 1x is included, d. H. downstream of the fuel flow with respect to the fourth cylindrical section 13x .

[0267] A cylindrical spring bearing 6x becomes the fourth cylindrical section 13x fitted. The spring 5x is between the spring bearing 6x and the faucet 4x set up the valve body 3x in the direction to close the valve.

[0268] Next, the operation of the fuel injector having the above structure will be described below. First when the coil 2x is fed, the faucet 4x towards the fourth cylindrical section 13x attracted by the electromagnetic force. The valve body 3x moves together with the valve 4x , around the upstream moveable seat section 310x from the upstream body seat portion 141x to separate, whereby the elastic seal valve portion is brought into a valve opening state, while the downstream movable seat portion 320x from the current collector seat portion 152x is separated, whereby the metal sealing valve portion is brought into a valve opening state, so that the fuel into the combustion chamber via the injection port 153x is injected.

[0269] When feeding the coil 2x is stopped, the valve body 3x towards the sixth cylindrical section 15Ax (i.e. in the direction to close the valve) by means of the spring 5x pushed. Therefore, the upstream movable seat portion comes first 310x against the upstream body seat section 141x is applied, bringing the elastic sealing valve portion into the valve-closing state to stop the injection of the fuel. The upstream moveable seat section 310x is made of an elastic material, which can ensure the good sealability upon closing of the valve. The upstream moveable seat section 310x is compressed in the axial direction to cause the downstream movable seat portion 320x in abutment against the downstream body seat portion 152 is what brings the metallic sealing valve into the valve-closed state. The upstream moveable seat section 310x is made of an elastic material, which can ensure the good sealability upon closing of the valve. The upstream moveable seat section 310x is compressed in the axial direction to cause the downstream movable seat portion 320x in abutment against the downstream body seat portion 152x is brought, which puts the metal sealing valve in the valve-closed state.

[0270] Next, a method of manufacturing the fuel injector having the upper structure will be described below.

[0271] A target seizing load on the metallic sealing valve portion formed from the downstream body seat portion 152x and the downstream movable seat portion 320x is formed is set to a set value of metal seal valve portion set load F1x. A target set load on the elastic seal valve portion extending from the upstream body seat portion 141x and the upstream movable seat portion 310x is formed is set to a set value of a sealing valve portion elastic set load F2x. The sum of the set value of the metal sealing valve portion set load F1 and the set value of the elastic seal valve portion set load F2x is set as a total set value of set load Fx.

[0272] First up will be the second cylindrical section 11x , the third cylindrical section 12x and the fifth cylindrical section 14 ax glued together in a one-piece element on which the valve body 3x is assembled. The valve body 3xis urged by the first constructing jig (not shown), whereby the upstream movable seat portion 310x with the upper body seat section 141x is pressed. At this time, the first jig urges the valve body 3x by means of a load equal to the total fixed value of the fixed load Fx.

[0273] Next, with this maintained state, becomes the sixth cylindrical section 15Ax into the fifth cylindrical section 14 ax introduced and the sixth cylindrical section 15Ax is urged by the second jig (not shown) around the downstream body seat portion 152 against the downstream moveable seat portion 320x to press. At this time, the second jig is urging the sixth cylindrical section 15Ax by using a load corresponding to the set value of the metallic sealing valve portion set load F1x. In this state, a force acting on the upstream movable seat portion 310x actually against the upstream body seat section 141x presses, by means of a force that presses the downstream body seat portion 152x against the downstream moveable seat portion 320x with respect to the urging force by means of the first jig, and therefore corresponds to the set value of the sealing valve elastic portion set load F2x. Therefore, the relative positional relationship between the fifth cylindrical portion increases 14 ax and the sixth cylindrical section 15Ax at this time, the optimal positional relationship between the fifth cylindrical section 14 ax and the sixth cylindrical section 15Ax from the standpoint of managing the seizing load on the metal seal valve portion and the seizing load on the elastic seal valve portion with high accuracy.

[0274] Subsequently, with the state maintained, the fifth cylindrical section becomes 14 ax integral with the sixth cylindrical section 15Ax by welding. At this time, the airtightness between the fifth cylindrical section is made by means of full-circle welding 14 ax and the sixth cylindrical section 15Ax secured.

[0275] Below is the spring 5x assembled and then the appointed length of the spring 5x adjusted by the press-fit amount of the spring bearing 6x adjusted so that the set load is on the spring 5x becomes a load corresponding to the entire fixed value of the fixed load Fx. Therefore, the metal seal valve portion is applied with the load corresponding to a set load of a metal seal valve portion set load Fix, and the elastic seal valve portion receives the load corresponding to the set value of the elastic seal valve portion set load F2x.

[0276] When a load affecting the valve body 3x urged by fuel pressure in the closing direction of the valve, indicated by reference character F3, may be the set length of the spring 5x by controlling the fitting amount of the spring bearing 6x be adjusted so that the locking load on the spring 5x Fx–F3x becomes. Therefore, when the fuel pressure on the valve body 3x is applied, the metal seal valve portion receives the load corresponding to the set value of the metal seal valve portion set load Fix, and the elastic seal valve portion receives the load corresponding to the set value of the elastic seal valve portion set load F2x.

[0277] As mentioned above, in the present embodiment, the relative positions of the fifth cylindrical portion 14 ax and the sixth cylindrical section 15Ax adjusted in the assembling stage, which can easily handle the set load on the elastic seal valve portion and the set load on the metal seal valve portion with high accuracy though the body 1x or valve body 3x are not processed with high accuracy.

[0278] In the above embodiment, the fifth cylindrical section 14 axand the sixth cylindrical section 15Ax subjected to full circle welding. As a first modified example of the tenth embodiment disclosed in FIG figure 19, the fifth cylindrical portion 14 ax and the sixth cylindrical section 15Ax be intermittently integral with each other by welding to provide a spacing between the fifth and sixth cylindrical sections 14 ax and 15Ax with a sealing element 8x to seal. This method can reduce welding cost compared to full circle welding. Eleventh embodiment

[0279] An eleventh embodiment of the invention will be described below.

[0280] figure 20 is a sectional view of a fuel injector according to an eleventh embodiment of the invention.

[0281] The present embodiment of the invention differs from the ninth embodiment in a position of the elastic seal valve portion. In other points, the present embodiment is the same as the ninth embodiment, and therefore only the different parts of the present embodiment from the ninth embodiment will be described below.

[0282] As in figure 20 are the upstream body seat portion 150x , which in the sixth cylindrical section 15x is formed, and the upstream movable seat portion 310x , attached to the second axial section 31x is glued, upstream of the fuel flow with respect to the spring 5x in the spring bearing 6x and the spacer 7x furnished. That is, the elastic seat valve portion, which consists of the upstream body seat portion 150x and the upstream movable seat portion 310x is formed is upstream of the fuel flow with respect to the spring 5x , the spring bearing 6x and the spacer 7x located.

[0283] The valve body vertical hole 300x extends to the second axial section 31x . The valve body cross hole 301x is in the second axial section 31x downstream of the fuel flow with respect to the upstream movable seat portion 310x educated.

[0284] Next, a method of manufacturing the fuel injector having the upper structure will be described below.

[0285] First up will be the fifth cylindrical section 14x , the valve body 3x , the feather 5x , the spring bearing 6x and the spacer 7x assembled to cause the spring 5x the valve body 3x urges to thereby the downstream movable seat portion 320x against the downstream body seat portion 140x to press. At this time, the appointed length of the spring 5x using the spacer 7x adjusted so that the locking load on the spring 5x is a load corresponding to the total fixed value of the fixed load Fx.

[0286] Subsequently, while maintaining this state, the sixth cylindrical section 15x into the fifth cylindrical section 14x introduced and the sixth cylindrical section 15x is urged by a jig (not shown) around the upstream body seat portion 150x against the upstream body seat section 310x to press. At this time, the building jig pushes the sixth cylindrical section 15x by a load corresponding to the set value of the sealing valve elastic portion set load F2x.

[0287] In this state, a force acting on the downstream movable seat portion 320x against the downstream body seat portion 140x presses, by means of a force that presses the upstream body seat portion 150x against the upstream movable seat section 310x in relation to the set load on the spring 5x and therefore corresponds to the set load of the metal seal valve portion set load F1x.

[0288] Subsequently, while maintaining this state, the fifth cylindrical section14x with the sixth cylindrical section 15x in one piece by welding. At this time, by means of the full circle welding, the airtightness between the fifth cylindrical portion 14x and the sixth cylindrical section 15x secured.

[0289] Therefore, the metal seal valve portion is subjected to the load corresponding to the set load of the metal seal valve portion set load F1x, and the elastic seal valve portion is subjected to the load corresponding to the set load of the elastic seal valve portion set load F2x.

[0290] As mentioned above, in the present embodiment, the relative positions of the fifth cylindrical portion 14x and the sixth cylindrical section 15x adjusted in the assembling stage, which can easily handle the set load on the elastic seal valve portion, as well as the set load on the metal seal valve portion with high accuracy though the body 1x or valve body 3x are not processed with high accuracy.

[0291] The resilient sealing valve portion is upstream of fuel flow with respect to the spring 5x or the like, and the metal seal valve portion is downstream of the flow of fuel with respect to the spring 5x or the like, which can increase the distance between the elastic seal valve portion and the metal seal valve portion in the axial direction to reduce the influence of heat of the combustion gas on the upstream movable seat portion. Twelfth embodiment

[0292] A twelfth embodiment of the invention will be described below. figure 21 is a sectional view of a fuel injector according to a twelfth embodiment of the invention. In the following, different parts only from the ninth embodiment will be described. As in figure 21 includes the valve body 3x a first axial section 30x and a third axial section 32x , without having the second axial section.

[0293] The sixth cylindrical section 15x as the first body is in the first cylindrical section 10x furnished. In other words, the sixth section is cylindrical 15x about the upstream side of the fuel flow with respect to the lift restriction section 130x or the faucet 4x of the fourth cylindrical section 13x positioned. The sixth cylindrical section 15x has a cylindrical vertical hole 154x formed therein as a fuel passage. An upstream body seat section 150x is the fuel flow downstream end of the vertical cylindrical hole 154x in the sixth cylindrical section 15x constructed and adapted to open and close the fuel passage by means of connecting and disconnecting with and from the upstream movable seat portion (which will be described later in detail below).

[0294] The end of the faucet 4x upstream of the flow of fuel is at an upstream movable seat portion 40x bonded, which is formed of an elastic material having more excellent heat resistance and elasticity than metal. The faucet 4x has a fitting cross hole 41x and a faucet vertical hole 42x , which is formed as a fuel passage.

[0295] The upstream moveable seat section 40x is adapted to open and close the fuel passage by connecting with and from the fuel body seat portion 150x of the body 1x connected and disconnected. In particular, the upstream movable seat section 40x can be formed using fluororubber, acrylonitrile butadiene rubber (NBR), fluoroplastic, tetrafluoroethylene (PTFE), polybutylene terephthalate plastic (PBT), and the like.

[0296] In the upstream valve body consisting of the upstream body seat portion 150x and the upstream movable seat portion 40xis formed, one of the seat portions is formed of elastic material. Hereinafter, the upstream valve body is referred to as an “elastic sealing valve portion”.

[0297] Next, the operation of the fuel injector having the above structure will be described below. First thing is when the coil 2x is fed, the fitting 4x towards the lift restriction section 13x attracted by the electromagnetic force. The valve body 3x moves together with the valve 4x , around the upstream moveable seat section 40x from the upstream body seat portion 150x to separate, whereby the elastic seal valve portion is brought into a valve opening state, while the downstream movable seat portion 320x from the current collector seat portion 140x is separated, whereby the metal sealing valve portion is brought into a valve opening state so that the gaseous fuel is injected into the combustion chamber.

[0298] When feeding the coil 2x is stopped, the valve body 3x towards the first cylindrical section 10x and the sixth cylindrical section 15x (i.e. in the direction that closes the valve) by means of the spring 5x pushed. Therefore, the upstream movable seat portion 40x first against the upstream body seat portion 150x is applied, whereby the elastic sealing valve portion is brought into the valve-closing state to stop the injection of the gaseous fuel. The upstream moveable seat section 40x is made of an elastic material, which can ensure the good sealability upon closing of the valve. The upstream moveable seat section 40x is compressed in the axial direction to cause the downstream movable seat portion 320x in abutment against the downstream body seat portion 140x is brought, whereby the metal sealing valve portion is brought into the valve-closed state.

[0299] Next, a method of manufacturing the fuel injector having the upper structure will be described below.

[0300] A target seizing load on the metal sealing valve portion formed from the downstream body seat portion 140x and the downstream movable seat portion 320x is formed is set to the set value of the metal seal valve portion set load Fx. A target set load on the elastic seal valve portion extending from the upstream body seat portion 150x and the upstream movable seat portion 40x is formed is set to the set value of the sealing valve portion elastic set load F2x. The sum of the set value of the metal sealing valve portion set load Fix and the set value of the elastic seal valve portion set load F2x is set as the total set value of the set load Fx.

[0301] First up will be the fifth cylindrical section 14x , the valve body 3x , the feather 5x , the spring bearing 6x and the spacer 6x assembled to cause the spring 5x the valve body 3x urges to thereby the downstream movable seat portion 320x against the downstream body seat portion 140x pushes. At this time, the appointed length of the spring 5x using the spacer 7x adjusted so that the locking load on the spring 5x is a load corresponding to the total fixed value of the fixed load Fx.

[0302] Below are the second to fourth cylindrical sections 11x until 13x at the fifth cylindrical section 14x glued and the fitting 4x , attached to the upstream movable seat section 40x is glued to the valve body 3x glued.

[0303] Below are the first cylindrical section 10x and the sixth cylindrical section 15x , which are bonded together in advance, into the second cylindrical portion 11x introduced and the first cylindrical section 10xand the sixth cylindrical section 15x are urged by a jig (not shown) around the upstream body seat portion 150x against the upstream movable seat section 40x to press. At this time, the building jig pushes the first and sixth cylindrical sections 10x and 15x by a load corresponding to the set value of the sealing valve elastic portion set load F2x.

[0304] In this state, a force acting on the downstream movable seat portion 320x actually against the downstream body seat section 140x presses, by means of a force that presses the upstream body seat portion 150x against the upstream movable seat section 40x in relation to the set load on the spring 5x and therefore corresponds to the set value of the metallic sealing valve portion set load F1x.

[0305] Next, with the state maintained, the first cylindrical section 10x with the second cylindrical section 11x in one piece by welding. At this time, the airtightness between the first cylindrical portion is achieved by means of full-circle welding 10x and the second cylindrical section 11x secured.

[0306] Therefore, the metallic sealing valve portion is subjected to the load corresponding to the set value of the metallic sealing valve portion set load F1x, and the elastic sealing valve portion is subjected to the load corresponding to the set value of the elastic sealing valve portion set load F2x.

[0307] In the present embodiment, the pressure-receiving area of ​​the elastic seal valve portion is made equal to that of the metal seal valve portion. In this way, the set load on the elastic seal valve portion and the set load on the metal seal valve portion can be set constant regardless of the pressure of a clearance between the elastic seal valve portion and the elastic seal valve portion.

[0308] As mentioned above, in the present embodiment, the relative positions of the first cylindrical portion 10x and the second cylindrical section 11x adjusted in the assembling stage, which can easily handle the set load on the elastic seal valve portion, as well as the set load on the metal seal valve portion with high accuracy though the body 1x or valve body 3x is not processed with high accuracy.

[0309] The resilient sealing valve portion is above the fuel flow upstream side with respect to the lift restriction portion 130x of the fourth cylindrical section 13x and the faucet 4x positioned, whereas the metal sealing valve portion downstream of the fuel flow with respect to the spring 5x is set up. As the distance between the elastic seal valve portion and the metal seal valve portion becomes longer in the axial direction, the influence of heat on combustion gases on the upstream movable seat portion 40x be further reduced. Thirteenth embodiment

[0310] figure 22 shows a sectional view of a fuel injector 1000 according to the present embodiment. The fuel injector 1000 , like the fuel injector 10 of the first embodiment includes the housing 10 , the inlet element 20 , the fixed core 30 , the moveable core 40 , the valve body 50 , the elastic section 56 , the nozzle element 60 , the stopper 70 and the drive unit 90 . In figure 22 are the in figure The same components shown in FIG. 1 are identified by the same reference numerals to aid in the description. That is, the stopper 70 (movement restriction portion) corresponds to “first body” according to the second invention. The nozzle element 60 (passage formation portion) corresponds to the “second body”. In the same way as in the above embodiments are the stopper 70and the nozzle element 60 separately formed from different materials, and after the formation, these components are integrated with each other by means of welding or the like.

[0311] The moveable core 40 and the valve body 50 correspond to a "movable portion". The case 10 , the inlet element 20 and the nozzle element 60 correspond to a "body". The elastic section 56 (elastic member) corresponds to “downstream movable seat portion”. The valve seat 60c of the nozzle element 60 corresponds to a “current collector seat portion”. The plant surface 53b of the valve body 50 corresponds to “downstream movable seat portion”. The beveled surface 70e of the stopper 70 corresponds to “upstream body seat portion”.

[0312] The following will mainly focus on points of the structure of the fuel injector 1000 of the in figure 22 relate to the present embodiment shown, which is different from the fuel injector 10 , the in figure 1 is shown. in the in figure 1 shown fuel injector 10 goes the valve body 50 along the axial direction together with the movable core 40 back and forth. in the in figure 22 shown fuel injector 1000 , is the valve body 50 with the moveable core 40 coupled in such a way that it is in relation to the movable core 40 is movable. That is, the movable core 40 is movable without the valve body 50 to move. The valve body is reversed 50 movable even if the movable core 40 is stopped.

[0313] More precisely, in the in figure 1 shown fuel injector 10 the coupling section 55 of the valve body 50 with the recording section 42 of the moveable core 40 connected by laser welding or the like. In contrast, in the fuel injector 1000 from figure 22 the coupling section 55 from the valve body 50 separate and with the moveable core 40 tied together. More specifically, the coupling section 55 on and with the receiving section 42 of the moveable core 40 welded and connected and the end of the valve body 50 is in the recording section 42 houses while the movable core is movable in the axial direction.

[0314] A core side engaging section 1042 who is in the recording section 42 is formed with a valve body side engaging portion 1050 , which is in the valve body 50 is formed, engaged to thereby the relative movement of the valve body 50 in the direction that closes the valve. The lower end surface 1055 of the coupling section 55 is against the top end surface 1051 of the valve body 50 applied to the relative movement of the valve body 50 in the valve opening direction.

[0315] The operation of the valve body 50 and the movable core 40 , which are constructed to be relatively movable in this way upon opening of the valve, is discussed below with reference to FIG figure 22(a), figure 22(b), figure 22(c) and figure 23 will be described. The upper part of figure 23 shows the moving amount of the movable core 40 and the lower part of figure 23 shows the amount of movement of the valve body 50 . If the valve body 50 is in the valve closing state, the amount of movement is set to zero. When powering the electromagnetic coil 91 for the drive unit 90 is switched off to the movable core 40 not tighten, the movement amount is fixed at zero.

[0316] When powering the electromagnetic coil 91 is started, the first thing to do is move the core 40 attracted and by means of the fixed core 30 emotional. The reference sign t0 in figure23 denotes a feeding start time. At the energization start time t0, as in figure 22(a), the core-side engaging portion 1042 not with the valve side engaging portion 1050 engaged so that the movable core 40 without the valve body 50 to move from the valve closed position.

[0317] After that, when the movable core 40 moved a predetermined distance, as in figure 22(b), the core-side engaging portion 1042 against the valve body engaging portion 1050 created so that both engagement sections 1042 and 1050 be brought into contact with each other. Therefore, the valve body moves 50 after the engagement also in the valve opening direction by moving by means of the movable core 40 , passing through the fixed nucleus 30 is attracted, is pulled. That is, at the time t1 when the movable core 40 is raised by 200 mm, both are engaging portions 1042 and 1050 in engagement with each other. Hence the valve body begins 50 a lift at the time t1.

[0318] A force that the valve body 50 after time t2 is due to fuel pressure (lift fuel pressure) applied to the valve body 50 from the injection port 60b in the valve body 50 is applied. That is, if the valve body 50 positioned in the valve closed position, no lift fuel pressure is applied to any part of the valve body 50 downstream with respect to the plant surface 53b upset. Nevertheless, if the valve body 50 is opened to allow the fuel into the downstream side with respect to the abutment surface 53b to flow, the high lift fuel pressure on the valve body 50 upset. Therefore, even if the movable core 40 against the fixed core 30 , which is to be stopped, is applied, the valve body 50 be lifted up.

[0319] Then, as in figure 22(c), the upper end surface becomes 1051 of the valve body 50 against the lower end face 1055 of the coupling section 55 created, thereby lifting the valve body 50 to stop. in the in figure 23 shown example is the valve body 50 at a time t3 when the valve body 50 lifted by 300 mm, thereby lifting the valve body 50 is stopped. When powering the electromagnetic coil 91 to lift off is turned off, the valve body 50 also together with the movable core 40 lifted off. in the in figure 23 start at a time t4 when the feeding is completed, both the movable core 40 and the valve body 50 to be lifted down and then, at a time t5, the down is stopped, whereby the elastic portion 56 on the nozzle element 60 seated to close the valve. When powering the electromagnetic coil 91 to lift off is turned off, the valve body 50 likewise with the movable core 40 lifted down. in the in figure 23 start at a time t4 when the power is off, both the movable core 40 and the valve body 50 , a down, and then at a time t4, the down is finished, whereby the elastic portion 56 on the nozzle element 60 seated to close the valve.

[0320] While a column G between the top end face 1043 of the moveable core 40 and the lower end face of the fixed core 30 becomes smaller, the means of the fixed core 30 induced force to move the movable core 40 to wear, to be made bigger. In short, the size of the drive unit can 90 be reduced. figure24 shows the result of a test on changes in an attractive force over time with the gap G kept at a predetermined distance when the electromagnetic coil 91 is fed. The test result was obtained by setting the predetermined distance to 100 mm and 300 mm, respectively. In a gap G of 300 mm, the attractive force is about 55 N. In a gap G of 100 mm, the attractive force is about 95 N.

[0321] As the gap G becomes smaller, the lift-up amount of the valve body becomes 50 smaller. The fuel injector 1000 is to inject the gas fuel. Therefore, the fuel injector must 1000 increase the lift amount to ensure the sufficient injection amount (mass flow rate) compared to the case where liquid fuel having a high density is injected.

[0322] In view of this point, in the present embodiment, at the elevating start time t0 of the movable core 40 the movable core lifted up without the valve body 50 to lift. Therefore, at the start time t0 with a large gap G, the necessary attraction force can be reduced. At the raising start time t1 of the valve body 50 the gap G is small compared to that at the time t0, so the necessary attractive force can be reduced as in the result of the test in figure 24 shown.

[0323] In the present embodiment, the valve body 50 continues to be lifted up even after the end time t2 of lifting up the movable core 40 . Therefore, the lifting amount of the valve body 50 be increased without setting the gap G large.

[0324] As mentioned above is the valve body 50 in the present embodiment to the movable core 40 coupled so as to be movable with respect to the movable core, which can suppress the increase in the gap G to increase the size of the drive unit 90 to prevent, and also can increase the lifting of the valve body 50 reach. Fourteenth embodiment

[0325] The fuel injector 1000 of the thirteenth embodiment has the inward opening valve structure for opening and closing the injection port 60b from the upstream side. In contrast, a fuel injector has 2000 of the present embodiment, which is figure 25, an outward opening valve for opening and closing the injection port 570b from the downstream side. The outward opening valve structure is the same as that of the fuel injector 500 , the in figure 10 is shown. In figure 25 are the same components as those in figure 10-10 are identified by the same reference numerals to aid in the description.

[0326] In contrast, in the fuel injector 2000 of the present embodiment as the fuel injector 1000 , the in figure 22, the valve body 550 to the moveable core 540 coupled in such a way that it is in relation to the movable core 540 is movable. That is, the movable core 540 is movable without the valve body 550 to move. The valve body is reversed 550 movable while the movable core 540 is stopped.

[0327] More specifically, the valve body 550 with a stream engaging section 2551 and an upstream engaging portion 2552 Mistake. The moveable core 540 is between these engaging portions 2551 and 2552 furnished. The valve body 550 can relative to the movable core 540 in an area from the in figure 25(a) where the downstream engaging portion 2551 against the lower end surface of the movable core 540 is created, to which in figure 25(c) where the upper engaging portion 2552 against the upper end surface of the movable core 540 applied.

[0328] The following is an operation for opening the fuel injector 2000 to be discribed.

[0329] When powering the electromagnetic coil 591 is started, the movable core first 540 attracted and by means of the fixed core 530 emotional. At the feeding start time as in figure 25(a), the downstream engaging portion 2551 against the moveable core 540 applied, which causes the valve body 550 against the moveable core 540 is pressed and it moves in the valve opening direction.

[0330] Then, as in figure 25(b), the lower end face of the movable core becomes 40 against the top end face of the fixed core 530 applied to thereby the movement of the movable core 540 to stop. The valve body also moves 550 further in the valve opening direction after application.

[0331] After applying the movable core 540 is the force affecting the valve body 550 moves, an elastic force of a spring 2580 . Therefore, even if the movable core 540 against the fixed core 530 applied to stop its movement is the valve body 550 movable in the valve opening direction. After that, as in figure 25(c), the upstream engaging portion 2552 against the upper end surface of the movable core 540 applied to thereby the movement of the valve body 550 to stop.

[0332] As mentioned above, in the present embodiment, moves after the movable core 540 against the fixed core 530 is applied and moving ceases, the valve element 550 also by a distance G2 between the top end face of the movable core 540 and the upstream engagement portion 2552 in the valve opening direction. Therefore, the amount of valve opening movement of the valve body 550 with respect to the gap G1 between the movable core 540 and the fixed core 530 be increased by a distance G2. Therefore, the lifting amount of the valve body 550 be increased without setting the gap G1 large. Fifteenth embodiment

[0333] In the present in figure 26 shown embodiment is a spring 2581 for urging the movable core 540 in the direction away from the fixed core 530 intended. Therefore, at a time when feeding an electromagnetic coil 591 is started, the current engagement section 2551 from the movable core 540 spaced. Therefore, at the feeding start time, like the thirteenth embodiment, the movable core becomes 540 moves without the valve body 550 to move.

[0334] After that, when the movable core 540 against a downstream engaging portion 2551 is created, then the valve body begins 550 to move by means of the movable core 540 is pressed. Then moves in the same way as the fourteenth embodiment after the movable core 540 against the fixed core 530 abuts, the valve body 550 further in the valve opening direction until the upstream engaging portion 2552 against the upper end surface of the movable core 540 applied.

[0335] As mentioned above, according to the present embodiment, at the energization start time, the movable core becomes 540 moves without the valve body 550 to move. Therefore, at the start time with the large gap G1, the necessary attraction force can be reduced. At the raising start time of the valve body 550 the gap G1 is small compared to the movement start time of the movable core 540 , so that the necessary attractive force can be reduced, as shown in the result of the test in figure 24 shown.

[0336] In the present embodiment, it also moves after the end of a movement of the movable core 540 the valve body 550 further. Therefore, the amount of movement of the valve body 550be increased without setting the gap G1 large.

[0337] As mentioned above, in the present embodiment, the valve body 550 to the moveable core 540 coupled so that it is in relation to the movable core 540 is movable, which can suppress the increase of the gap G1 to increase the size of the drive unit 90 and also the increase in lift-up amount of the valve body 550 can reach. Other embodiments

[0338] Although the first to fifteenth embodiments of the disclosure have been explained above, the disclosure is not limited to the first to fifteenth embodiments. It is to be understood that various modifications and changes can be made to the embodiments without departing from the scope of the disclosure. For example, the disclosure can be applied to a fuel injector for injecting not gaseous fuel but liquid fuel.

[0339] In the eleventh embodiment, the fifth cylindrical portion 14x and the sixth cylindrical section 15x subjected to full circle welding. In the twelfth embodiment, the first cylindrical portion 10x and the second cylindrical section 11x subjected to full circle welding. Alternatively, these parts may be integrated with each other by the intermittent welding, and a gap therebetween may be sealed with a sealing member.

[0340] In the first to eighth embodiments, the movement restriction portion is such that the movement restriction portion abuts against the valve element in a position where the pressing span of the elastic portion is a predetermined value in the state of closing the valve. Alternatively, the movement restriction portion can be positioned without considering the indentation span.

[0341] In the ninth to twelfth embodiments, one of the upstream movable seat portions 40x , 310x and 311x and the upstream body seat portions 141x , 150x and 151x made of elastic material. The downstream moveable seat section 320x and the downstream body seat portion 140x and 152x are formed of a metallic material. On the contrary, the arrangement of the elastic material and the metallic material can be reversed. That is, one of the upstream movable seat sections 40x , 310x and 311x and the upstream body seat portions 141x , 150x and 151x is formed of a metallic material. The downstream moveable seat section 320x and the downstream body seat portions 140x and 152x are made of elastic material. While the present disclosure has been described in terms of the embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. The present disclosure is intended to cover various modifications and equivalent arrangements. Additionally, while various combinations and configurations, other combinations and configurations, including more, less or only a single part, are also within the spirit and scope of the present disclosure.

Claims

[1] Fuel injector with: a transitional training phase ( 60 , 161 , 560 , 661 ), which is contained in a main body ( 10 , 510 ) is provided for, with the intermediate training section including a fuel transfer ( 60a , 161a , 560a , 661a ) has, which leads to an injection port ( 60b , 570b ) leads to the injection of fuel; a valve element ( 51 , 150 , 551 , 650 ), which is housed in the main body in a reciprocating manner, wherein the valve element is adapted to open and close the fuel passage by reciprocating; an elastic element ( 56 , 156 , 556 , 656), which is elastically deformable by means of a movement of the valve element in a valve closing direction when closing the fuel passage, wherein the elastic element is attached to and adapted to one of the passage formation section and the valve element to close the fuel passage by bearing against the other of the passage formation section and the valve element when the valve element moves in the closing direction; and a movement restriction section ( 70 , 570 ), which is provided in the main body to restrict the movement of the valve element in the closing direction by bearing against the valve element, wherein The movement restriction section is made of a material different from the transition training section. [2] Fuel injector according to claim 1, wherein the movement restriction section rests against the valve element in a position where an indentation span of the elastically deformed elastic element reaches a predetermined value with a fuel passage which is closed by means of a movement of the valve element in order to restrict the movement of the valve element in the closing direction. [3] Fuel injector according to claim 1 or 2, wherein the transition training section ( 60 , 161 ) downstream from the movement restriction section ( 70 ) in relation to a fuel flow towards the injection port ( 60b ) lies within the main body. [4] Fuel injector according to one of claims 1 to 3, wherein the injection port ( 60b ) on a power evening of the fuel passage ( 60a , 161a ) is trained. [5] Fuel injector according to claim 3 or 4, wherein The movement restriction section is cylindrically designed to accommodate the valve element on its inner circumference in a reciprocating motion, and While the valve element rests against the movement restriction section, a gap is formed between an inner circumferential surface of the movement restriction section and an outer circumferential surface of the valve element to allow the flow of fuel into the passage section. [6] Fuel injector according to any one of claims 3 to 5, wherein the elastic element is attached to the valve element the elastic element contains a seat section that projects towards the passage section on an outer circumferential surface of the elastic element opposite the passage section, and the seat section is positioned to enclose an outer circumference of an opening of the fuel passage on the valve element, so that the fuel passage is closed. [7] Fuel injector according to any one of claims 3 to 5, wherein the elastic element is attached to the passage training section, the elastic element has an opening that allows the fuel to pass through, the valve element contains a seat section that projects towards the elastic element on an outer circumferential surface of the valve element opposite the elastic element, and the seat section fits to enclose an outer circumference of the opening, so that the fuel passage is closed. [8] Fuel injector according to claim 6 or 7, wherein the seat section has a recessed section from which an inner circumferential surface is inclined such that the recessed section becomes deeper towards a center in a radial direction of the recessed section. [9] Fuel injector according to any one of claims 1 to 8, wherein the elastic element has an anchor section which is fixed to one of the passage form section and the valve element in a direction to intersect a reciprocating direction of the valve body. [10] Fuel injector according to any one of claims 1 to 9, wherein the main body ( 10 , 510 ) is cylindrical in shape and has an opening ( 11c , 511c ) has, which is formed on a current evening in relation to the fuel flow within the main body, one of the movement restriction section ( 70 , 570) and the transitional training phase ( 60 , 161 , 560 , 661 ) is arranged between one end and the other end of the main body in its axial direction, and another section, consisting of the movement restriction section and the passage training section, is made of a material different from the main body and is provided in the main body by being inserted into the opening and fixed to the opening. [11] Fuel injector according to claim 10, wherein one of the movement restriction section ( 70 , 570 ) and the transitional training phase ( 60 , 161 , 560 , 661 ) is made of a material different from the main body, and a stepped section ( 11b , 511b ) between one end and the other end of the main body ( 10 , 510) in whose axial direction is formed, and another of the movement restriction section and the passage training section lies against the stepped section in order to be positioned in relation to the main body. [12] Fuel injector according to any one of claims 1 to 11, wherein the movement restriction section ( 70 , 570 ) from one of the main body ( 10 , 510 ) is made of different materials. [13] Fuel injector according to any one of claims 1 to 12, wherein a part ( 70e , 570a ) of the movement restriction section ( 70 , 570 ), which rests against the valve element, is made of the same material as that of a part ( 53b , 153b , 554a , 654a ) of the valve element ( 51 , 150 , 551 , 650 ), which is adjacent to the section restricting movement. [14] Fuel injector according to claim 13, wherein at least one part ( 70e , 570 ) of the movement restriction section ( 70 , 570 ), which rests against the valve element, and a part ( 53b , 153b , 554a , 654a ) of the valve element ( 51 , 551 ), which abuts the movement restriction section, a coated layer ( 72 , 571 ) has, which is formed on a surface of it. [15] Fuel injector according to any one of claims 1 to 14, wherein the elastic element ( 56 , 156 , 556 , 656 ) is made of rubber. [16] Fuel injector according to claim 15, wherein the rubber contains fluorogummi. [17] Fuel injector according to any one of claims 1 to 16, wherein a gaseous fuel is injected into the main body ( 10 , 510 ) flows. [18] Fuel injector according to any one of claims 1 to 17, further comprising: a fixed core ( 30 ), which is fixed to the main body; a movable core ( 40 ), which is housed in the main body, moving back and forth; and an electromagnetic coil ( 91 ) to generate an electromagnetic force in order to attract the movable core towards the fixed core, wherein the valve element is coupled to the movable core in order to be movable relatively in relation to the movable core, when the electromagnetic coil is powered, the movable core is attracted and moved towards the fixed core, and the valve element moves in a valve opening direction, and Once the movable core is in contact with the fixed core, the valve element continues to move in the valve opening direction. [19] Fuel injector according to claim 18, wherein until the movable core moves by a predetermined distance after the start of the supply, the movable core moves without moving the valve element, and until the movable core rests against the fixed core, after it has moved by the predetermined distance, the movable core moves along with the valve element. [20] Method for manufacturing a fuel injector, the fuel injector includes: a through-flow training section provided in a main body, wherein the through-flow training section has a fuel passage leading to an injection port from which fuel is injected; a valve element that is housed in the main body in a reciprocating manner in order to close and open the fuel passage by means of a reciprocating motion; an elastic element which is elastically deformable by means of a movement of the valve element in a valve closing direction when closing the fuel passage, wherein the elastic element is attached to one of the passage formation section and the valve element in order to close the fuel passage by being pressed against another of the passage formation section and the valve element when the valve element moves in the closing direction; and a movement restriction section provided in the main body, wherein the movement restriction section is formed from a material different from the passage formation section, wherein the movement restriction section restricts movement of the valve element in a closing direction of the valve element by being applied against the valve element in a position where an indentation span of the elastically deformed elastic element is a predetermined value while the fuel passage is closed by means of the valve element, wherein the method for manufacturing the fuel injector comprises: an adjustment step that adapts the indentation span of the elastic section to the predetermined value by adjusting the relative positions of the passage formation section and the movement restriction section in one direction along the reciprocating direction of the valve element. [21] Method for manufacturing a fuel injector according to claim 20, wherein The adjustment step includes: an installation step that incorporates one of the movement restriction section and the passage formation section between one end and the other end of the main body in the axial direction; and an insertion step which inserts another of the movement restriction section and the passage training section, which are formed from a material different from the main body, into an opening of the main body which is formed at a stream end of the fuel flow within the main body in order to adapt an insertion amount of another into the main body. [22] Method for manufacturing a fuel injector according to claim 21, wherein in the installation step one of the movement restriction section and the passage formation section, which are formed from a material different from the main body, abuts a stepped section formed between one end and another end of the main body in the axial direction in order to position one of the movement restriction section and the passage formation section in relation to the main body. [23] Method for manufacturing a fuel injector according to any one of claims 20 to 22, further comprising: a relative position fixing step that fixes the relative positions of the passage training section and the movement restriction section after the adaptation step. [24] Fuel injector with: a seat section that can be moved upstream ( 40x , 310x ,311x ), which is attached to a metallic movable section ( 3x , 4x ) is provided for, which goes back and forth; a downstream movable seating section ( 320x ), which is provided on the movable section, wherein the downstream movable seat section is downstream of the upstream movable seat section ( 40x , 310x , 311x ) is set up with respect to a fuel flow; a current body seat section ( 141x , 150x , 151x ), which is attached to a metal body ( 1x ) is provided for; and a stream body seat section ( 140x , 152x ), which is provided on the metal body, wherein the downstream body seat section is located downstream of the upstream body seat section ( 141x , 150x , 151x ) is set up with regard to the fuel flow, wherein one of the upstream movable seating sections ( 40x , 310x ,311x ) and the current body seat section ( 141x , 150x , 151x ) or one of the seat sections that can be moved downstream ( 320x ) and the streambody seat section ( 140x , 152x ) is made of an elastic material with more excellent elasticity than metal, a fuel passage by means of a connection and a separation between the upstream movable seat section ( 40x , 310x , 311x ) and the current body seat section ( 141x , 150x , 151x ) is opened and closed and the fuel flow is controlled by a connection and a separation between the downstream movable seat section ( 320x ) and the streambody seat section ( 140x , 152x ) is opened and closed, with the fuel injector injecting fuel into an internal combustion engine when the fuel passage is opened, the movable section (3x , 4x ) by means of a spring ( 5x ) is forced in a closing direction, the body ( 1x ) a first body ( 14Ax , 15x ) includes, which is connected to the current body seat section ( 141x , 150x , 151x ) is provided for, as well as a second body ( 14x , 15Ax ), which is connected to the streambody seat section ( 140x , 152x ) is planned, and the first body ( 14Ax , 15x ) and the second body ( 14x , 15Ax ) are trained separately and then assembled. [25] Fuel injector according to claim 24, wherein one of the upstream movable seat section ( 40x , 310x , 311x ) and the current body seat section ( 141x , 150x , 151x ) is made of elastic material with more excellent elasticity than metal. [26] Fuel injector according to claim 24 or 25, wherein the current body seat section ( 150x , 151x ) and the streambody seat section ( 140x ) are beveled, and a bevel angle of the current body seat section ( 150x , 151x ) is larger than that of the streambody seat section ( 140x ). [27] Fuel injector according to any one of claims 24 to 26, wherein the upstream movable seat section ( 40x , 310x , 311x ) and the downstream movable seating section ( 320x ) in a back-and-forth direction of the movable section ( 3x , 4x ) are set up; and the passage of fuel by moving the movable section ( 3x , 4x ) in one direction from the upstream movable seat section ( 40x , 310x , 311x ) in the direction of the downstream movable seat section ( 320x) is opened. [28] Fuel injector according to any one of claims 24 to 26, wherein the upstream movable seat section ( 310x ) and the downstream movable seating section ( 320x ) in a back-and-forth direction of the movable section ( 3x , 4x ) are set up, the passage of fuel by moving the movable section ( 3x , 4x ) in one direction from the downstream movable seat section ( 320x ) in the direction of the upstream movable seat section ( 310x ) is opened. [29] Fuel injector according to any one of claims 24 to 28, wherein the first body ( 14Ax , 15x ) and the second body ( 14x , 15Ax ) are joined together in one piece by means of full-circle welding. [30] Fuel injector according to any one of claims 24 to 28, wherein the first body ( 14Ax , 15x ) and the second body (14x , 15Ax ) are joined together in one piece by means of interrupted welding, and a distance between the first body ( 14Ax , 15x ) and the second body ( 14x , 15Ax ) by means of a sealing element ( 8x ) is sealed. [31] Fuel injector according to any one of claims 24 to 30, wherein the spring ( 5x ) a coil spring, the movable section ( 3x , 4x ) is set up to hold the spring ( 5x to penetrate, the upstream movable seat section ( 40x , 310x ) upstream from the spring ( 5x ) is positioned in relation to the fuel flow, and the downstream movable seat section ( 320x ) downstream of the spring ( 5x ) is positioned in relation to the fuel flow. [32] Fuel injector according to one of claims 24 to 31, wherein the upstream movable seat section ( 40x , 310x ) is made of an elastic material. [33] Fuel injector according to one of claims 24 to 31, wherein the flow body seat section ( 151x ) is made of an elastic material. [34] Fuel injector according to any one of claims 24 to 33, wherein the fuel is a gaseous fuel. [35] Fuel injector according to one of claims 24 to 34, further comprising: a fixed core ( 30 ), which is fixed to the body; and an electromagnetic coil ( 91 ) to generate an electromagnetic force such that the movable section is attracted to the fixed core, wherein the movable section a valve body ( 50) comprising the upstream movable seat section, the downstream movable seat section and a movable core ( 40 ) is provided for, which is attracted by means of the electromagnetic force, the valve body is coupled to the movable core, while it is movable relative to the movable core, when the electromagnetic coil is powered, the movable core is attracted and moved towards the fixed core, and the valve element moves in a valve-opening direction and Once the movable core is in contact with the fixed core, the valve element continues to move in the valve-opening direction. [36] Fuel injector according to claim 35, wherein until the movable core moves a predetermined distance after the feed has started, the movable core moves without cooperation with the valve element, and until the movable core rests against the fixed core, after it has moved by the predetermined distance, the movable core moves in cooperation with the valve element.

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