WO2019065406A1 - Fuel injection valve and method for manufacturing fuel injection valve - Google Patents

Abstract

This fuel injection valve is provided with a needle (20) (valve body) for opening and closing an injection hole for injecting fuel, a fixed core, a movable core (30), a first spring member, a sleeve (40) (fixed member), and a second spring member (SP2). The movable core is attracted to the fixed core, abuts the needle at the point in time that the movable core has moved a prescribed amount to a counter-injection hole side, and causes the needle to perform a valve opening operation. The first spring member elastically deforms in association with the valve opening operation of the needle, and exerts a first elastic force that causes the needle to perform a valve closing operation. The second spring member is sandwiched between the sleeve fixed to the needle and the movable core, elastically deforms, and exerts a second elastic force that biases the movable core to the counter-injection hole side. Furthermore, the needle has a press-fitting part (23) onto which the sleeve is press-fitted, and the sleeve is fixed to the needle by being press-fitted to the press-fitting part. As a result, variations in the fuel injection amount can be suppressed while adopting a core boost structure.

Description

Fuel injection valve and method of manufacturing fuel injection valve Cross-reference to related applications

The present application is based on Japanese Patent Application No. 2017-189882 filed on September 29, 2017, and Japanese Patent Application No. 2018 filed on September 11, 2018, the disclosure contents of which are incorporated by reference into the present application. It is based on -169992.

The present disclosure relates to a fuel injection valve that injects fuel and a method of manufacturing the same.

In the conventional fuel injection valve, the fuel is released from the injection hole by opening the valve by the fixed core which generates magnetic attraction force when the coil is energized, the movable core which is attracted and moved by the fixed core, and the movable core which moves. And a valve body to be injected. In recent years, the valve closing force for urging the valve body tends to increase with the increase in fuel pressure, which requires a large valve opening force in order to open the valve against a large valve closing force. Come.

As a measure against this, Patent Document 1 discloses a core boost structure described below. That is, when opening the valve body, first, movement of the movable core is started in a state not engaged with the valve body, and thereafter, when the movable core moves a predetermined amount, the movable core is pressed against the valve body. It is a structure which makes it open and starts valve opening operation.

According to such a core boost structure, since the movable core is not yet engaged with the valve body immediately after the start of energization, the movable core not receiving the force of the fuel pressure has an initial small magnetomotive force of the movable core. The moving speed can be raised quickly. Then, when the moving speed becomes sufficiently fast, that is, when the movable core moves by a predetermined amount, the movable core abuts on the valve body to start the valve opening operation, so in addition to the magnetic attraction force, The valve can be opened using a collision force. Therefore, it is possible to open the valve body even with high-pressure fuel while suppressing an increase in the magnetic attraction force required to open the valve.

JP, 2013-104340, A

However, in the above-mentioned core boost structure, the movable core moves in two steps of movement from the start of energization to contact with the valve body and movement thereafter in contact with the valve body. Therefore, the problem that the time variation from the energization start to the valve opening start is directly linked to the variation in the amount of fuel injected by one valve opening arises anew. Furthermore, it is important to suppress the time variation from the end of energization to the closing of the valve while suppressing the variation in time from the start of energization to the opening of the valve.

One object of the present disclosure is to provide a fuel injection valve that uses a core boost structure and suppresses variation in fuel injection amount.

Another object of the present disclosure is to provide a method of manufacturing a fuel injection valve, which suppresses variation in fuel injection amount while adopting a core boost structure.

According to the first aspect of the present disclosure, the fuel injection valve includes a valve body for opening and closing an injection hole for injecting fuel, a fixed core for generating a magnetic attraction force with energization to a coil, and a fixed core The movable core which abuts against the valve body when moving a predetermined amount to the injection hole side and opens the valve body, and elastically deforms with the valve opening action of the valve body to close the valve body A first spring member that exerts an elastic force, a fixed member fixed to the valve body, and a second elastic member that is elastically deformed by being sandwiched between the fixed member and the movable core to urge the movable core to the opposite side of the injection hole. And a second spring member that exerts a force. The valve body has a press-fitting portion in which the fixing member is press-fitted to the counter injection hole side, and the fixing member is fixed to the valve body by being press-fitted in the press-fitting portion.

In short, the fuel injection valve according to the first aspect has a core boost structure in which the movable core abuts against the valve body at the time when the movable core has moved a predetermined amount to the reverse injection hole side to open the valve. A fixing member is provided which supports a second spring member for biasing. And it is a structure which press-fits and fixes the fixing member in a valve body, and the pressing-in direction is the energizing direction of the 2nd spring member. Therefore, it becomes possible to adjust and fix the amount of press-in, measuring the 2nd elastic force which increases with advancing of press-in. Therefore, it is possible to realize with high accuracy the second elastic force at the time of completion of press-fitting and fixing to the target set load of the second spring member.

The set load is a second elastic force exerted by elastic deformation of the second spring member in a state where the second spring member is assembled to the fuel injection valve. Since the magnitude of the set load affects the on-off valve timing of the valve body, setting the set load to the target value accurately contributes to the suppression of the variation in the fuel injection amount. Then, in contrast to the first aspect in which the fixing member is press-fitted and fixed to the valve body, in the case of adopting a structure in which the fixing member is welded and fixed to the valve body, adjusting the welding location while measuring the second elastic force. Can not Therefore, due to inter-individual variation such as machine difference variation of the second spring member and valve body length variation, the set load also varies due to thermal strain due to welding.

On the other hand, in the first aspect, the set load can be accurately set to the target value as described above because the fixing member is press-fitted and fixed to the valve body. Therefore, it is possible to suppress the variation of the fuel injection amount while adopting the core boost structure.

According to the second aspect of the present disclosure, the fuel injection valve causes the valve body for opening and closing the injection hole for injecting the fuel to close by the first elastic force by the first spring member that is elastically deformed and exhibited, The movable core is structured to be opened by the movable core which moves by suction, and the second elastic force by the second spring member which is elastically deformed by being held between the fixed member fixed to the valve body and the movable core. It is a manufacturing method of the fuel injection valve of the structure made to urge to the counter injection hole side. The manufacturing method includes a press-fitting step of press-fitting the fixing member into a press-fitting portion formed on the valve body which abuts on the movable core at the time of movement by a predetermined amount by magnetic attraction and starts valve opening. And a load measuring step of measuring the second elastic force in a state in which the movable core can not be moved. In the press-in process, the amount of press-in is adjusted based on the measurement result to complete the press-in.

In short, the manufacturing method according to the second aspect is directed to a fuel injection valve having a core boost structure provided with a fixing member for supporting a second spring member that biases the movable core to the counter injection hole side. Then, while the fixed member is press-fitted to the press-fit portion of the valve body, the second elastic force is measured in a state in which the movement of the movable core is restricted, and the press-fit amount is adjusted based on the measurement result to complete the press-fit. . Therefore, it is possible to realize with high accuracy the second elastic force at the time of completion of press-fitting and fixing to the target set load of the second spring member.

As described above, since the magnitude of the set load affects the on-off valve timing of the valve body, setting the set load to the target value accurately contributes to the suppression of the variation in the fuel injection amount. Therefore, according to the second aspect in which the set load can be accurately set to the target value as described above, it is possible to suppress the variation in the fuel injection amount while adopting the core boost structure.

Sectional drawing of the fuel injection valve concerning 1st Embodiment. The enlarged view in the injection hole part of FIG. The enlarged view in the movable core part of FIG. It is a schematic diagram which shows the action | operation of the fuel injection valve which concerns on 1st Embodiment, (a) in a figure shows a valve closing state, (b) is a state where the movable core which moves by magnetic attraction collides with a valve body. (C) shows a state in which the movable core, which is further moved by magnetic attraction, collides with the guide member. It is a time chart which shows operation of a fuel injection valve concerning a 1st embodiment, and (a) in a figure shows change of a drive pulse, (b) shows change of drive current, (c) shows magnetic attraction power (D) shows the behavior of the movable part. 5 is a flowchart showing an assembling work procedure of the movable part according to the first embodiment. The exploded view of the movable part concerning a 1st embodiment. Sectional drawing of the movable part which shows the state of the operation | work which presses a cup on a needle in the assembly operation of FIG. FIG. 7 is a cross-sectional view of the movable portion showing a state in which the first press-in of FIG. 6 is completed. FIG. 10 is a perspective view of FIG. BRIEF DESCRIPTION OF THE DRAWINGS The stress-distortion diagram of the needle which concerns on 1st Embodiment, and a sleeve. Sectional drawing which shows the shape of the communicating groove formed in the movable core in 1st Embodiment. FIG. 13 is a top view of the movable core shown in FIG. 12 as viewed from the side opposite to the injection hole. Sectional drawing which follows the XIV-XIV line of FIG. FIG. 13 is a cross-sectional view showing a modification B1 to FIG. 12; FIG. 16 is a top view of the movable core shown in FIG. FIG. 13 is a cross-sectional view showing a modified example B2 of FIG. 12; FIG. 18 is a top view of the movable core shown in FIG. 17 as viewed from the side opposite to the injection hole. FIG. 13 is a cross-sectional view showing a modified example B3 of FIG. 12; FIG. 20 is a top view of the movable core shown in FIG. 19 as viewed from the side opposite to the injection hole. FIG. 13 is a cross-sectional view showing a modified example B4 with respect to FIG. 12; FIG. 13 is a cross-sectional view showing a modified example B5 with respect to FIG. 12; FIG. 13 is a cross-sectional view showing a modified example B6 with respect to FIG. 12; Sectional drawing which shows the shape of the supply flow path formed in the needle in 1st Embodiment. FIG. 25 is a top view of the needle shown in FIG. 24 viewed from the side opposite to the injection hole. FIG. 26 is a cross-sectional view along the line XXVI-XXVI in FIG. 25. FIG. 27 is a cross-sectional view showing a modified example C1 with respect to FIG. 26. FIG. 27 is a cross-sectional view showing a modified example C2 of FIG. 26. FIG. 27 is a cross-sectional view showing a modified example C3 of FIG. 26. FIG. 26 is a top view of a needle viewed from the side opposite to the injection hole, showing a modified example C4 with respect to FIG. 25. FIG. 26 is a top view of a needle viewed from the side opposite to the injection hole, showing a modified example C5 with respect to FIG. 25. It is a sectional view of Drawing 31, and (a) is a sectional view which meets a XXXIIa-XXXIIa line, (b) is a sectional view which meets a XXXIIb-XXXIIb line. FIG. 25 is a cross-sectional view showing a modified example C6 with respect to FIG. 24. FIG. 25 is a cross-sectional view showing a modified example C7 with respect to FIG. 24; The top view which looked at the plate shown in FIG. 34 from the injection hole side. Sectional drawing at the time of full lift which shows the shape of the hollow surface formed in the guide member in 1st Embodiment. Sectional drawing at the time of valve closing which shows the shape of the hollow surface formed in the guide member in 1st Embodiment. Sectional drawing at the time of valve closing which shows the clearance gap between a movable core and a holder in 1st Embodiment. FIG. 39 is a top view of the needle shown in FIG. 38 as viewed from the side opposite to the injection hole. FIG. 39 is a cross-sectional view showing a modification E1 to FIG. 38; FIG. 39 is a cross-sectional view showing a modification E2 to FIG. 38; FIG. 39 is a cross sectional view showing a modification E3 to FIG. 38; Sectional drawing of the fuel injection valve which shows 2nd Embodiment. Sectional drawing of the fuel injection valve which shows 3rd Embodiment.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. The same referential mark may be attached | subjected to the part corresponding to the matter demonstrated by the form preceded in each form, and the overlapping description may be abbreviate | omitted. When only a part of the configuration is described in each form, the other forms described above can be applied to other parts of the configuration. Not only combinations of parts which clearly indicate that combinations are possible in each embodiment, but also combinations of embodiments even if they are not specified unless there is a problem with the combination. Is also possible.

First Embodiment
The fuel injection valve 1 shown in FIG. 1 is attached to a cylinder head or a cylinder block of an ignition ignition type internal combustion engine mounted on a vehicle. The gasoline fuel stored in the on-vehicle fuel tank is pressurized by a fuel pump (not shown) and supplied to the fuel injection valve 1, and the supplied high-pressure fuel is injected from the injection hole 11 a formed in the fuel injection valve 1 to the internal combustion engine Directly into the combustion chamber of the

The fuel injection valve 1 includes an injection hole body 11, a body body 12, a fixed core 13, a nonmagnetic member 14, a coil 17, a support member 18, a first spring member SP1, a second spring member SP2, a needle 20, a movable core 30, A sleeve 40, a cup 50, a guide member 60 and the like are provided. The injection hole body 11, the main body 12, the fixed core 13, the support member 18, the needle 20, the movable core 30, the sleeve 40, the cup 50 and the guide member 60 are made of metal.

As shown in FIG. 2, the injection hole body 11 has a plurality of injection holes 11 a for injecting fuel. A needle 20 is positioned inside the injection hole body 11, and a flow passage 11b is formed between the outer peripheral surface of the needle 20 and the inner peripheral surface of the injection hole body 11 to allow high pressure fuel to flow to the injection hole 11a. ing. On the inner peripheral surface of the injection hole body 11, a body side seat 11s is formed on which the valve element side seat 20s formed on the needle 20 is released and seated. The valve body side seat 20s and the body side seat 11s are shaped to extend annularly around the axis C of the needle 20. When the needle 20 is separated from and seated on the body side seat 11s, the flow passage 11b is opened and closed, and the injection hole 11a is opened and closed.

The main body 12 and the nonmagnetic member 14 have a cylindrical shape. The cylindrical end of the main body 12 on the side closer to the injection hole 11 a (the injection hole side) with respect to the main body 12 is welded and fixed to the injection hole body 11. The cylindrical end of the main body 12 on the side (the opposite side to the injection hole) in the direction away from the injection hole 11 a with respect to the main body 12 is welded and fixed to the cylindrical end of the nonmagnetic member 14. The cylindrical end of the nonmagnetic member 14 on the side opposite to the injection hole is welded and fixed to the fixed core 13.

The nut member 15 is fastened to the screw portion 13 N of the fixed core 13 in a state of being locked to the locking portion 12 c of the main body 12. The axial force generated by the fastening generates a surface pressure that presses the nut member 15, the main body 12, the nonmagnetic member 14 and the fixed core 13 in the direction of the axis C (vertical direction in FIG. 1). Note that, instead of generating such a surface pressure by screw fastening, it may be generated by press-fitting.

The main body 12 is formed of a magnetic material such as stainless steel, and has a flow passage 12b for allowing fuel to flow to the injection hole 11a. The needle 20 is accommodated in the flow path 12b so as to be movable in the axis C direction. The main body 12 and the nonmagnetic member 14 correspond to a "holder" having a movable chamber 12a filled with fuel. In the movable chamber 12a, the movable portion M (see FIGS. 9 and 10), which is an assembled body in which the needle 20, the movable core 30, the second spring member SP2, the sleeve 40, and the cup 50 are assembled, is movable. It is housed. Note that the gap L1a shown in FIG. 9 indicates the size of the gap in the direction of the axis C between the valve contact surface 21b at the valve closing time and the valve closing force transmission contact surface 52c. The size of the gap L1a is the same as the gap amount L1 shown in the column of FIG. 4 (a).

The flow path 12 b communicates with the downstream side of the movable chamber 12 a and has a shape extending in the direction of the axis C. The center lines of the flow path 12 b and the movable chamber 12 a coincide with the cylinder center line (axis C) of the main body 12. The injection hole side portion of the needle 20 is slidably supported on the inner wall surface 11c of the injection hole body 11, and the non-injection hole side portion of the needle 20 is the inner wall surface 51b of the cup 50 (see FIGS. 8 and 12). Slidingly supported). By thus slidingly supporting the upstream end portion and the downstream end portion of the needle 20, the radial movement of the needle 20 is limited, and the tilting of the needle 20 with respect to the axis C of the main body 12 is limited. Be done.

The needle 20 corresponds to a "valve body" for opening and closing the injection hole 11a, is formed of a magnetic material such as stainless steel, and has a shape extending in the axial line C direction. On the downstream side end face of the needle 20, the valve body side seat 20s described above is formed. When the needle 20 moves to the downstream side in the direction of the axis C (valve closing operation), the valve body side seat 20s is seated on the body side seat 11s, and the flow path 11b and the injection hole 11a are closed. When the needle 20 moves to the upstream side in the direction of the axis C (valve opening operation), the valve element side seat 20s is separated from the body side seat 11s, and the flow path 11b and the injection hole 11a are opened.

The needle 20 has an internal passage 20a and a lateral hole 20b that allow fuel to flow to the injection hole 11a (see FIG. 3). A plurality of lateral holes 20b are formed in the circumferential direction. The plurality of lateral holes 20b are formed at equal intervals in the circumferential direction. The internal passage 20 a is shaped to extend in the direction of the axis C of the needle 20. An inlet is formed at the upstream end of the inner passage 20a, and a lateral hole 20b is connected to the downstream end of the inner passage 20a. The lateral hole 20b extends in a direction intersecting the direction of the axis C and communicates with the movable chamber 12a.

As shown in FIG. 7, in the needle 20, the contact portion 21, the core sliding portion 22, the press-fit portion 23, the outflow portion 24, the first portion are sequentially arranged from the opposite side (upper end side) to the lower end side A large diameter portion 25, a first small diameter portion 26, a second large diameter portion 27, a second small diameter portion 28 and an injection hole side support portion 29 are provided. The contact portion 21 has a valve closing contact surface 21b at the time of valve closing that contacts the valve closing force transmission contact surface 52c of the cup 50.

The cup 50 is assembled to the contact portion 21 in a slidable state, and the outer peripheral surface of the contact portion 21 slides on the inner peripheral surface of the cup 50. The movable core 30 is assembled to the core sliding portion 22 in a slidable state, and the outer peripheral surface of the core sliding portion 22 slides on the inner peripheral surface of the movable core 30. A sleeve 40 is press-fitted and fixed to the press-fit portion 23. A lateral hole 20 b is formed in the outflow portion 24.

The outer diameter D1 of the contact portion 21 is set larger than the outer diameter D2 of the core sliding portion 22, and the outer diameter D2 of the core sliding portion 22 is set larger than the outer diameter D3 of the press-fit portion 23. The diameter D3 is set to be larger than the outer diameter of the outflow portion 24. Further, a connection portion 22a between the core sliding portion 22 and the press-fit portion 23 and a connection portion 23a between the press-fit portion 23 and the outflow portion 24 are formed in a tapered shape. The diameter of the inner peripheral surface 41a of the sleeve 40 before the press-fitting is set smaller than the outer diameter D3 of the press-fitting portion 23, and the press-fitting can be performed.

The outer diameters of the first large diameter portion 25 and the second large diameter portion 27 are larger than the outer diameters of the first small diameter portion 26 and the second small diameter portion 28. Weight reduction is achieved by having the first small diameter portion 26 and the second small diameter portion 28. The first large diameter portion 25 and the second large diameter portion 27 function as a support when cutting the needle 20. The second small diameter portion 28 functions as a relief portion so that the cutting tool does not interfere when the injection hole side support portion 29 is cut. Further, the injection hole side support portion 29 is slidably supported by the inner wall surface 11 c of the injection hole body 11.

The cup 50 has a disc-shaped disc portion 52 and a cylindrical portion 51. The disc portion 52 has a through hole 52 a penetrating in the direction of the axis C. The surface of the disc portion 52 on the side opposite to the injection hole functions as a spring contact surface 52b that contacts the first spring member SP1. The surface on the injection hole side of the disc portion 52 functions as a valve closing force transmission contact surface 52c that contacts the needle 20 and transmits the first elastic force (valve closing elastic force). The disc portion 52 corresponds to a “valve body transmitting portion” which abuts on the first spring member SP1 and the needle 20 to transmit the first elastic force to the needle 20. The cylindrical portion 51 has a cylindrical shape extending from the outer peripheral end of the disc portion 52 to the injection hole side. The injection hole side end face of the cylindrical portion 51 functions as a core contact end face 51 a that contacts the movable core 30. The inner wall surface 51 b of the cylindrical portion 51 slides on the outer peripheral surface of the contact portion 21 of the needle 20.

The fixed core 13 is formed of a magnetic material such as stainless steel, and has a flow passage 13a for allowing the fuel to flow to the injection hole 11a. The flow path 13a communicates with the inner passage 20a (see FIG. 3) formed inside the needle 20 and the upstream side of the movable chamber 12a, and extends in the direction of the axis C. The guide member 60, the first spring member SP1, and the support member 18 are accommodated in the flow path 13a.

The support member 18 has a cylindrical shape and is press-fitted and fixed to the inner wall surface of the fixed core 13. The first spring member SP1 is a coil spring disposed on the downstream side of the support member 18, and elastically deforms in the axis C direction. The upstream end surface of the first spring member SP1 is supported by the support member 18, and the downstream end surface of the first spring member SP1 is supported by the cup 50. The cup 50 is biased downstream by a force (first elastic force) generated by the elastic deformation of the first spring member SP1. By adjusting the press-fit amount in the direction of the axis C of the support member 18, the magnitude (first set load) of the elastic force for biasing the cup 50 is adjusted.

As shown in FIG. 3, the guide member 60 has a cylindrical shape formed of a magnetic material such as stainless steel, and is press-fitted and fixed to the enlarged diameter portion 13 c formed on the fixed core 13. The enlarged diameter portion 13 c has a shape in which the flow path 13 a is expanded in the radial direction. The guide member 60 has a disk portion 62 in the shape of a disk and a cylindrical portion 61 in the shape of a cylinder. The disc portion 62 has a through hole 62 a penetrating in the direction of the axis C. The surface on the side opposite to the injection hole of the disc portion 62 abuts on the inner wall surface of the enlarged diameter portion 13c. The cylindrical portion 61 has a cylindrical shape extending from the outer peripheral end of the disc portion 62 to the injection hole side. The injection hole side end face of the cylindrical portion 61 functions as a stopper abutting end face 61 a that abuts on the movable core 30. The inner wall surface of the cylindrical portion 51 forms a sliding surface 61b that slides on the outer peripheral surface 51d of the cylindrical portion 51 related to the cup 50 (see FIG. 12).

In short, the guide member 60 has a guide function to slide the outer peripheral surface of the cup 50 moving in the direction of the axis C, and movement of the movable core 30 to the counter injection hole side while in contact with the movable core 30 moving in the direction of the axis C And a stopper function to regulate That is, the guide member 60 corresponds to a “stopper member” that abuts on the movable core 30 and restricts the movement of the movable core 30 in the direction away from the injection hole 11 a.

A resin member 16 is provided on the outer peripheral surface of the fixed core 13. The resin member 16 has a connector housing 16a, and a terminal 16b is accommodated inside the connector housing 16a. The terminal 16 b is electrically connected to the coil 17. An external connector (not shown) is connected to the connector housing 16a, and power is supplied to the coil 17 through the terminal 16b. The coil 17 is wound around an electrically insulating bobbin 17 a to form a cylindrical shape, and is disposed radially outside the fixed core 13, the nonmagnetic member 14 and the movable core 30. The fixed core 13, the nut member 15, the main body 12 and the movable core 30 form a magnetic circuit that allows the magnetic flux generated by the power supply (energization) to the coil 17 to flow (see dotted arrow in FIG. 3).

As shown in FIG. 3, the movable core 30 is disposed on the injection hole side with respect to the fixed core 13, and is accommodated in the movable chamber 12 a so as to be movable in the direction of the axis C. The movable core 30 has an outer core 31 and an inner core 32. The outer core 31 has a cylindrical shape formed of a magnetic material such as stainless steel, and the inner core 32 has a cylindrical shape formed of a nonmagnetic material such as stainless steel having magnetism. The outer core 31 is press-fitted and fixed to the outer peripheral surface of the inner core 32.

The needle 20 is inserted and disposed inside the cylinder of the inner core 32. The inner core 32 is assembled to the needle 20 so as to be slidable with respect to the axis C with respect to the needle 20. The gap (inner gap) between the inner peripheral surface of the inner core 32 and the outer peripheral surface of the needle 20 is set smaller than the gap (outer gap) between the outer peripheral surface of the outer core 31 and the inner peripheral surface of the main body 12. These gaps are set so that the outer core 31 does not contact the main body 12 while allowing the inner core 32 to contact the needle 20.

The inner core 32 abuts on the guide member 60 as a stopper member, the cup 50 and the needle 20. Therefore, the inner core 32 is made of a material having a hardness higher than that of the outer core 31. The outer core 31 has a movable side core facing surface 31 c facing the fixed core 13, and a gap is formed between the movable side core facing surface 31 c and the fixed core 13. Therefore, as described above, in the state where the coil 17 is energized and the magnetic flux flows, the magnetic attraction force attracted to the fixed core 13 acts on the outer core 31 because the gap is formed.

The sleeve 40 corresponds to a “fixing member” press-fitted and fixed to the needle 20. The sleeve 40 is made of a cylindrical metal having a through hole 40 a (see FIG. 7), and has an insertion cylindrical portion 41, a connecting portion 42 and a support portion 43. The insertion cylindrical portion 41 has a cylindrical shape and is press-fitted and fixed to the press-fit portion 23 of the needle 20. The connection portion 42 is a cylindrical shape in which the insertion cylindrical portion 41 is expanded in the radial direction, and connects the insertion cylindrical portion 41 and the support portion 43. Further, the connecting portion 42 guides the second spring member SP2 to suppress the positional deviation of the second spring member SP2 in the radial direction. The support portion 43 is in the shape of an annular ridge extending radially outward from the injection hole end of the connection portion 42. In other words, the support portion 43 is in the form of a plate extending radially outward from the injection hole side end of the connection portion 42, and in the form of a ring extending around the axis C. The surface on the side opposite to the injection hole of the support portion 43 functions as a support surface 43a that supports the injection hole side end face of the second spring member SP2.

The second spring member SP2 is a coil spring disposed on the side opposite to the injection hole of the support portion 43, and elastically deforms in the axis C direction. The end face of the second spring member SP <b> 2 on the side opposite to the injection hole is supported by the movable core 30. Specifically, the end face is supported by the outer core 31. The injection hole side end surface of the second spring member SP2 is supported by the support portion 43. The outer core 31 is biased to the opposite side of the injection hole by the force (second elastic force) generated by the elastic deformation of the second spring member SP2. By adjusting the press-fit amount in the direction of the axis C of the insertion cylindrical portion 41, the magnitude (second set load) of the second elastic force that biases the movable core 30 at the time of valve closing is adjusted. The second set load of the second spring member SP2 is smaller than the first set load of the first spring member SP1. Further, the magnitude of the second elastic force when the movable core 30 is biased in other situations as well as when the valve is closed may be set as the second set load adjusted by the press-fit amount.

<Description of operation>
Next, the operation of the fuel injection valve 1 will be described using FIGS. 4 and 5.

As shown in the column (a) in FIG. 4, when the coil 17 is deenergized, no magnetic attractive force is generated, so the movable core 30 is urged toward the valve opening side. Does not work. Then, the cup 50 biased toward the valve closing side by the first elastic force by the first spring member SP1 abuts on the valve body abutting surface 21b (see FIG. 3) of the needle 20 and the inner core 32, 1) Transmitting elastic force.

The movable core 30 is urged toward the valve closing side by the first elastic force of the first spring member SP1 transmitted from the cup 50, and is urged toward the valve opening side by the second elastic force of the second spring member SP2. ing. Since the first elastic force is larger than the second elastic force, the movable core 30 is pushed by the cup 50 and moved (lifted down) to the injection hole side. The needle 20 is urged toward the valve closing side by the first elastic force transmitted from the cup 50, pushed by the cup 50 and moved (lifted down) to the injection hole side, that is, seated on the body side seat 11s It will be in the closed state. In this valve closed state, a gap is formed between the valve-member abutting surface 21a (see FIG. 3) of the needle 20 and the movable core 30 (inner core 32). The length in the direction of the axis C is called the gap amount L1.

As shown in the column (b) in FIG. 4, in the state immediately after switching the energization of the coil 17 from off to on, the magnetic attraction force biased toward the valve opening side acts on the movable core 30, The movable core 30 starts moving to the valve opening side. Then, the movable core 30 moves while pushing up the cup 50, and when the movement amount reaches the gap amount L1, the inner core 32 collides with the valve opening contact surface 21a of the needle 20. At the time of this collision, a gap is formed between the guide member 60 and the inner core 32, and the length in the direction of the axis C of this gap is called the lift amount L2.

Since the valve closing force by the fuel pressure applied to the needle 20 does not act on the movable core 30 in the period until the collision point, the collision velocity of the movable core 30 can be increased accordingly. And since such a collision force is added to the magnetic attraction force and used as the valve opening force of the needle 20, the needle of even a high pressure fuel while suppressing the increase of the magnetic attraction force necessary for the valve opening. 20 can be opened.

After the collision, the movable core 30 continues to move by the magnetic attraction force, and when the amount of movement after the collision reaches the lift amount L2, as shown in the (c) column in FIG. Clash and stop moving. The separation distance between the body side seat 11s and the valve body side seat 20s in the direction of the axis C at the time when the movement is stopped corresponds to the full lift amount of the needle 20 and matches the lift amount L2 described above.

When the operation described above is described in detail with reference to FIG. 5, first, as shown in the column (a) of FIG. 5, when switched on at time t1, the drive current flowing through the coil 17 starts to rise ((b) As the column rises, the magnetic attraction also starts to rise (see column (c)). When the value obtained by subtracting the second elastic force from the first elastic force (valve-closing elastic force) is taken as the actual valve-closing elastic force F0, at time t2 when the magnetic attraction force is increased to the actual valve-closing elastic force F0, The movable core 30 starts moving to the valve opening side. The movable core 30 starts moving before the drive current reaches the peak value. The boost voltage obtained by boosting the battery voltage is applied to the coil 17 until the drive current reaches the peak value, and the battery voltage is applied to the coil 17 after the peak value is reached.

Thereafter, at time t3 when the moving amount of the movable core 30 reaches the gap amount L1, the movable core 30 collides with the needle 20 and the needle 20 starts the valve opening operation (see (d) column). Thus, the fuel is injected from the injection holes 11a. Thereafter, the movable core 30 lifts up the needle 20 against the valve closing elastic force, and at t4 when the movable core 30 collides with the guide member 60, the lift amount of the needle 20 reaches the full lift amount (lift amount L2). . In addition, the zero point shown on the vertical axis | shaft of (d) column shows the collision position of the movable core 30 and the needle 20 at the time of t3.

Thereafter, the full lift state of the needle 20 is maintained by the magnetic attraction force, and the fuel injection is continued. Thereafter, when the current supply is switched off at time t5, the magnetic attraction force also decreases with the decrease of the drive current. Then, at time t6 when the magnetic attraction force reaches the actual valve closing elastic force F0, the movable core 30 starts to move together with the cup 50 toward the valve closing side. The needle 20 is pushed by the pressure of the fuel filled between it and the cup 50, and starts lifting down (close valve operation) simultaneously with the start of movement of the movable core 30.

Thereafter, at time t7 at which the needle 20 is lifted down by the lift amount L2, the valve body side seat 20s is seated on the body side seat 11s, and the flow path 11b and the injection hole 11a are closed. Thereafter, the movable core 30 continues the movement toward the valve closing side together with the cup 50, and the movement toward the valve closing side of the cup 50 is stopped at time t8 when the cup 50 abuts against the needle 20. Thereafter, the movable core 30 continues to move (inertial movement) to the valve closing side by inertia force, and then moves (rebound) to the valve opening side by the elastic force of the second spring member SP2. Thereafter, the movable core 30 collides with the cup 50 at time t9 and moves (rebounds) together with the cup 50 toward the valve opening side, but is quickly pushed back by the valve closing elastic force, and is shown in column (a) of FIG. It converges to the initial state.

Therefore, the smaller the rebound and the shorter the time required for convergence, the shorter the time from the end of the injection to the return to the initial state. Therefore, when performing multistage injection in which the fuel is injected a plurality of times per one combustion cycle of the internal combustion engine, the interval between the injections can be shortened, and the number of injections included in the multistage injection can be increased. Further, by shortening the convergence time as described above, it is possible to control the injection amount when performing partial lift injection described below with high accuracy. Partial lift injection refers to the injection of a small amount by a short valve opening time by stopping the energization of the coil 17 and starting the valve closing operation before the valve opening needle 20 reaches the full lift position. is there.

<Description of manufacturing method>
Next, a method of manufacturing the fuel injection valve 1 will be described.

This manufacturing method includes a first set load adjusting process, a movable part assembling process, a welding process, a fastening process and a resin molding process described below.

In the movable part manufacturing process, the movable core 30, the second spring member SP2, the sleeve 40 and the cup 50 are assembled to the needle 20 to manufacture the movable part M. As will be described in detail later, the movable portion M is manufactured such that the elastic force by the second spring member SP2 biased to the movable core 30 becomes the target value of the second set load.

In the welding step to be performed next, first, the injection hole body 11 is welded and coupled to the main body 12. Next, the movable portion M is disposed in the movable chamber 12a of the main body 12, and thereafter, the fixed core 13 to which the support member 18 and the first spring member SP1 are assembled, and the main body 12 in which the movable portion M is disposed; The nonmagnetic member 14 is welded and joined.

In the fastening step to be performed next, the bobbin 17 a in a state in which the coil 17 is wound is disposed between the nut member 15 and the fixed core 13. Thereafter, by fastening the nut member 15 to the fixed core 13, surface pressure is generated on the main body 12, the nonmagnetic member 14 and the fixed core 13 for assembly.

In a resin molding process to be performed next, the molten resin is poured into the outer peripheral surface of the fixed core 13 and solidified to resin-mold the resin member 16 having the connector housing 16a.

In the first set load adjustment process performed thereafter, first, the first spring member SP1 is assembled to the flow path 13a of the fixed core 13. Thereafter, the support member 18 is pressed into the flow path 13a of the fixed core 13 to a predetermined position. The predetermined position relating to the press-fit may be determined according to the variation of the elastic coefficient of the first spring member SP1 and the length in the direction of the axis C, or the dimension variation of each portion of the fixed core 13. In any case, the predetermined position (press-fit position) is set such that the first elastic force biased by the needle 20 becomes the target value of the first set load. The fuel injection valve 1 is manufactured by the manufacturing method including the above steps.

<Detailed Description of Configuration Group A>
Next, among the configurations of the fuel injection valve 1 according to the present embodiment, a press-fit portion 23 formed on the needle 20 and a configuration group A including at least a configuration related to the press-fit portion 23 will be described in detail.

The movable part assembling step described above includes the respective steps S10 to S15 shown in FIG. 6 in detail. First, in step S10, as shown in FIG. 7, the movable core 30, the second spring member SP2, and the sleeve 40 are inserted into the needle 20 from the side (lower end side) of the valve body sheet 20s. In this step S10, as shown in FIG. 8, the insertion of the sleeve 40 is stopped at the position of the outflow portion 24 in front of the press-fit portion 23.

In the subsequent step S11, with the cup 50 assembled to the contact portion 21 of the needle 20, the needle 20 is pressed against the cup 50, and the valve closing force transmission contact surface 52c is in contact with the valve contact surface 21b. (See FIG. 8). As a result, the core contact end surface 51a is positioned closer to the injection hole side than the valve opening contact surface 21a by the gap amount L1.

In the subsequent step S12, the sleeve 40 is temporarily press-fit into the press-fit portion 23 by a predetermined press-fit amount. For example, while supporting the cup 50 in the axis C direction using the support device J1, the press-fit load F2 is applied in the axis C direction to the load application surface 43b of the sleeve 40 using the load application device J2. In temporary press-fit, the movable core 30 is in contact with the cup 50, and the second spring member SP2 is in contact with the sleeve 40 and the movable core 30, and the second spring member SP2 is elastically deformed. Press fit until it is Accordingly, the support device J1 exerts and supports the reaction force F1 against the second elastic force by the second spring member SP2.

The temporary press-fit is a first press-fit, and then a second press-fit (main press-fit) is performed in step S15 described later. The press-in amount in the temporary press-in is a predetermined amount regardless of the machine difference variation. For example, the injection hole side end of the press-in portion 23 is separated from the injection hole side end by a predetermined length in the axis C direction Temporarily press-fit to the position.

In the subsequent step S13, the second elastic force by the second spring member SP2, that is, the second set load is measured. For example, the force (the reaction force F1) with which the supporting device J1 is pressed by the second elastic force is measured using a measuring device (not shown). In this step S13, measurement is performed in a state in which the cup 50 is positioned above the needle 20, that is, in a state in which the direction of the movable portion M is set in the direction of the arrow indicating the vertical direction in FIG.

In the subsequent step S14, an insufficiency with respect to the target second set load of the measured second set load is calculated, and an additional press-fit amount corresponding to the insufficiency is calculated. For example, the elastic coefficient of the second spring member SP2 may be measured in advance, and the additional press-fit amount may be calculated based on the measured load deficiency and the elastic coefficient. Alternatively, the elastic coefficient of the second spring member SP2 may be regarded as a standard value, and the additional press-fit amount may be calculated based on the measured load deficiency and the standard value.

In the subsequent step S15, the sleeve 40 is further press-fit (final press-fit) into the press-fit portion 23 by the amount of the additional press-fit amount calculated in step S14. Thus, the assembly of the movable portion M is completed. In short, the second set load is measured in the middle of the press fit, and the main press fit is performed according to the measured value. And each process demonstrated above is an example of the composition group A mentioned previously.

-As mentioned above, fuel injection valve 1 concerning this embodiment is needle 20 (valve body), fixed core 13, movable core 30, 1st spring member SP1, sleeve 40 (fixed member), and the 2nd And a spring member SP2. The movable core 30 abuts on the needle 20 at the time when the movable core 30 is attracted by the fixed core 13 and moves by a predetermined amount to the counter injection hole side, and opens the needle 20. The first spring member SP1 elastically deforms with the valve opening operation of the needle 20, and exerts a first elastic force for closing the needle 20. The sleeve 40 is fixed to the needle 20. The second spring member SP2 is sandwiched between the sleeve 40 and the movable core 30 to be elastically deformed, and exerts a second elastic force that biases the movable core 30 to the counter injection hole side. The needle 20 has a press-fitting portion 23 in which the sleeve 40 is press-fitted to the opposite side of the injection hole, and the sleeve 40 is fixed to the needle 20 by press-fitting in the press-fitting portion 23.

In short, the fuel injection valve 1 according to the present embodiment has a core boost structure in which the movable core 30 is moved in contact with the needle 20 at the time when the movable core 30 moves a predetermined amount to the reverse injection hole side to open the valve. A sleeve 40 supporting a second spring member SP2 biased toward the hole side is provided. The sleeve 40 is press-fitted and fixed to the needle 20, and the press-fitting direction is the biasing direction of the second spring member SP2. Therefore, it becomes possible to adjust and fix the amount of press-in, measuring the 2nd elastic force which increases with advancing of press-in. Therefore, it is possible to realize with high accuracy the second elastic force at the time of completion of press-fitting and fixing to the target set load of the second spring member SP2.

The set load is a second elastic force exerted by elastic deformation of the second spring member in a state where the second spring member is assembled to the fuel injection valve. Since the magnitude of the set load affects the on-off valve timing of the valve body, setting the set load to the target value accurately contributes to the suppression of the variation in the fuel injection amount. And, in contrast to the present embodiment in which the fixing member is press-fixed to the valve body, in the case of adopting a structure in which the fixing member is welded and fixed to the valve body, adjusting the welding location while measuring the second elastic force become unable. Therefore, due to inter-individual variation such as machine difference variation of the second spring member and valve body length variation, the set load also varies due to thermal strain due to welding.

On the other hand, in the present embodiment, since the fixing member is press-fitted and fixed to the valve body, the set load can be accurately set to the target value as described above. Therefore, it is possible to suppress the variation of the fuel injection amount while adopting the core boost structure.

Further, in the fuel injection valve 1 according to the present embodiment, at least a portion of the sleeve 40 in contact with the press-fit portion 23 has a hardness different from that of the press-fit portion 23. For example, a metal base material of different hardness may be used for the sleeve 40 and the needle 20, or the metal base material of the sleeve 40 is subjected to surface treatment such as heat treatment to contact the press-fit portion 23 of the sleeve 40. The portion may be locally harder than the sleeve 40.

Now, contrary to the present embodiment, when the sleeve 40 and the press-fit portion 23 have the same hardness, when adjusting the press-fit amount while measuring, when the press-fit is temporarily stopped, the sleeve 40 and the press-fit portion 23 adhere It is a concern to do. If adhesion occurs, the load required to resume press-in increases, and the workability of press-in deteriorates. Therefore, according to this embodiment having different hardness, the concern of the above-mentioned adhesion can be reduced, and the workability of press-fitting can be improved. Preferably, the needle 20 is harder than the sleeve 40. It is desirable that the sleeve 40 be harder than the movable core 30. Specific examples of the material of the needle 20 include martensitic stainless steel. Specific examples of the material of the sleeve 40 include ferritic stainless steel.

Further, in the fuel injection valve 1 according to the present embodiment, at least a portion of the sleeve 40 in contact with the press-fit portion 23 is lower in hardness than the press-fit portion 23.

Now, in the press-fitting, at least one member of the two members to be press-fit needs to be plastically deformed. The lower the hardness, the more easily plastic deformation occurs, and the press-in load required for press-in can be reduced. In view of this point, the needle 20 needs to have a hardness to endure a collision with the body side seat 11s (valve seat), and if the hardness of the sleeve 40 is made higher to make the hardness difference higher than that hardness, There is concern that the load will increase. Therefore, according to the present embodiment in which the sleeve 40 has a hardness lower than that of the press-fit portion 23, the above-mentioned concern can be suppressed to improve the workability of press-fit. Furthermore, since the sleeve 40 of the present embodiment does not contact the movable core 30, it is possible to use a softer material than the inner core 32 or the like which requires the contact.

For example, each of solid lines A1 and A2 in FIG. 11 shows a stress σ strain L diagram of the needle 20 and the sleeve 40 obtained by the tensile test. As shown in the test results, the stress at the yield point (yield stress σ 1) at which the sleeve 40 starts plastic deformation is lower than that of the needle 20. In the case of the needle 20, the test sample is broken as soon as the yield stress is reached. The test results show that by making the sleeve 40 low in hardness, the yield stress σ 1 can be lowered and the press-in load required for press-in can be lowered.

Further, in the fuel injection valve 1 according to the present embodiment, the sleeve 40 and the movable core 30 contact each other even when the movable core 30 moves relative to the needle 20 to the injection hole side as much as possible. There is no separation. For example, as described above, the movable core 30 is further moved to the injection hole side after the valve is closed to cause a rebound. Then, the movement of the movable core 30 after such valve closure occurs, and a state in which the distance between the lines of the second spring member SP2 becomes zero and the amount of elastic deformation of the second spring member SP2 becomes maximum It is mentioned as a specific example of “when moving relatively to the limit”.

Now, in the case of a structure in which the sleeve 40 and the movable core 30 contact each other contrary to the present embodiment, it is necessary to make the press fit and fixation of the sleeve 40 strong. Needs to be increased. Therefore, according to this embodiment of the structure which does not contact each other, it is possible to reduce the need for strengthening the press fit, so the press fit load required for the press fit can be reduced, and the workability of the press fit can be improved.

Further, in the fuel injection valve 1 according to the present embodiment, the sleeve 40 has the cylindrical insertion cylindrical portion 41 inserted into the press-fit portion 23, and the inner peripheral surface 41a of the insertion cylindrical portion 41 covers the entire circumference. And the outer peripheral surface of the press-fit portion 23. According to this, since the internal stress generated in the insertion cylindrical portion 41 can be dispersed over the entire circumference, damage to the sleeve 40 due to concentration of the internal stress can be suppressed.

-Moreover, the manufacturing method of the fuel injection valve 1 which concerns on this embodiment makes the fuel injection valve 1 of the following structures manufacture object. That is, the needle 20 (valve body) for opening and closing the injection hole 11a for injecting the fuel is closed by the first elastic force by the first spring member SP1 which is elastically deformed and exhibited, and movable by the magnetic attraction force The core 30 is configured to be opened. Further, the movable core 30 is urged toward the reverse injection hole side by the second elastic force by the second spring member SP2 which is elastically deformed by being sandwiched between the sleeve 40 (fixed member) fixed to the needle 20 and the movable core 30. Structure. According to the above manufacturing method, the press-fit portion of the needle 20 which press-fits the sleeve 40 into the press-fit portion 23 formed on the needle 20 which contacts the movable core 30 and starts the valve opening operation when moving a predetermined amount by magnetic attraction. 23 includes steps S12 and S15 (press-in step) in which the sleeve 40 (fixing member) is pressed into 23. In addition, step S13 (load measurement step) of measuring the second elastic force in a state in which the movable core 30 can not be moved is included in the middle of press-fitting. In the press-in process, the press-in amount is adjusted based on the measurement result to complete the press-in.

In short, the manufacturing method according to the present embodiment targets the fuel injection valve 1 of the core boost structure including the sleeve 40 that supports the second spring member SP2 that biases the movable core 30 to the counter injection hole side. . Then, while the sleeve 40 is press-fit into the press-fit portion 23 of the needle 20, the second elastic force is measured in a state in which the movable core 30 is not movable, and the press-fit amount is adjusted based on the measurement result. To complete. Therefore, it is possible to realize with high accuracy the second elastic force at the time of completion of press-fitting and fixing to the target set load of the second spring member SP2.

As described above, since the magnitude of the set load affects the on-off valve timing of the needle 20, setting the set load to the target value accurately contributes to the suppression of the variation in the fuel injection amount. Therefore, according to the present embodiment that can set the set load to the target value accurately as described above, it is possible to suppress the variation of the fuel injection amount while adopting the core boost structure.

Further, in the manufacturing method according to the present embodiment, the following fuel injection valve 1 is manufactured. The fuel injection valve 1 is disposed so as to be movable relative to the needle 20, and abuts against the needle 20 by moving relatively to the injection hole side to transmit the first elastic force from the first spring member SP1 to the needle 20. The cup 50 is provided. In the above-described manufacturing method, in step S13 (load measurement step), the cup 50 is moved relative to contact the needle 20, and the cup 50 in the contact state is brought into contact with the movable core 30. Regulate 30 movements.

Now, the magnitude of the second set load by the second spring member SP2 is important in suppressing the movement of the movable core 30 to the injection hole side after the valve is closed, that is, in rapidly converging the rebound. is important. Therefore, setting the second elastic force in the valve closed state as the second set load is advantageous in managing rebound convergence. Therefore, the second elastic force is measured by restricting the movement of the movable core 30 by bringing the cup 50 in a state of coming into contact with the needle 20 into contact with the movable core 30, so that the second elastic force in the valve closed state Will be measured. Therefore, it is easy to manage rebound convergence.

<Detailed Description of Configuration Group B>
Next, among the configurations included in the fuel injection valve 1 according to the present embodiment, a fuel storage chamber B1 described below and a configuration group B including at least a configuration related to the fuel storage chamber B1 will be described with reference to FIGS. This will be described in detail using FIG. In addition, modified examples of the configuration group B will be described later with reference to FIGS.

As shown in FIG. 12, the fuel reservoir chamber B <b> 1 is a portion surrounded by the movable core 30, the cup 50 and the needle 20 and the fuel is accumulated. In the following description, among the surfaces of the inner core 32 on the side opposite to the injection hole, the surface in contact with the needle 20 is called a first core contact surface 32c, and the surface in contact with the cup 50 is called a second core contact surface 32b. The surface in contact with the guide member 60 is referred to as a third core contact surface 32d.

Since the movable core 30 is biased toward the cup 50 by the second elastic force, the movable core 30 always abuts the cup 50 except when the movable core 30 inertially moves away from the cup 50 after valve closing. ing. In detail, the second core contact surface 32 b of the inner core 32 is always in contact with the core contact end surface 51 a of the cup 50. The cylindrical portion 51, which is a portion forming the core contact end surface 51a of the cup 50, divides the inside and the outside of the fuel reservoir chamber B1. The outside is a region where fuel exists radially outward of the outer peripheral surface 51d of the cup 50, the first core contact surface 32c is located inside the fuel reservoir chamber B1, and the third core contact surface 32d is It is located outside the fuel reservoir chamber B1.

The fuel reservoir chamber B1 includes the outer peripheral surface of the core sliding portion 22 related to the needle 20 and the valve open valve body contact surface 21a, the inner wall surface of the through hole 32a related to the inner core 32, and the first core contact surface 32c. It is a region surrounded by the inner peripheral surface of the cylindrical portion 51 related to the cup 50. The fuel reservoir chamber B1 is an area surrounded as described above in a state where the movable core 30 and the cup 50 are in contact with each other. The fuel storage chamber B1 is an area surrounded as described above in a state where the valve body side seat 20s is in contact with the body side seat 11s and the needle 20 is closed.

A communication groove 32 e is formed in the first core contact surface 32 c and the second core contact surface 32 b of the inner core 32. The communication groove 32e allows the inside and the outside of the fuel reservoir chamber B1 to communicate with each other with the second core contact surface 32b in contact with the core contact end surface 51a. The outside is a space other than the fuel reservoir chamber B1 when the cup 50 and the movable core 30 are in contact with each other.

The outside of the fuel storage chamber B1 referred to here corresponds to the region exemplified below. That is, the first region between the stopper abutting end surface 61a of the guide member 60 and the third core abutting surface 32d corresponds to the outside. The first area is an area formed in a state where the cup 50 and the movable core 30 are in contact with each other and the movable core 30 and the guide member 60 are not in contact with each other. The surface of the fixed core 13 opposed to the movable core 30 is referred to as a fixed side core facing surface 13 b. The surface of the outer core 31 facing the fixed core 13 is called a movable side core facing surface 31 c. The second region between the fixed core facing surface 13b and the movable core facing surface 31c, which is a region in communication with the first region, corresponds to the outside. A third region between the inner peripheral surface of the main body 12 (holder) and the nonmagnetic member 14 (holder) and the outer peripheral surface of the outer core 31, which is a region in communication with the second region, corresponds to the outside.

As shown in FIG. 13, a plurality of (for example, four) communication grooves 32 e are formed, and the plurality of communication grooves 32 e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30. The communication groove 32e has a shape extending linearly in the radial direction. The plurality of communication grooves 32e have the same shape. The circumferential position of the communication groove 32e is different from the circumferential position of the through hole 31a.

The inner core 32 corresponds to the “contact portion” in which the first core contact surface 32 c and the second core contact surface 32 b are formed. The outer core 31 corresponds to a “core main body portion” made of a material different from the inner core 32 in which the movable side core facing surface 31 c facing the fixed core 13 is formed. The core main body is excluded from the formation range of the communication groove 32e. That is, although the communication groove 32 e is formed in the inner core 32, the communication groove 32 e is not formed in the outer core 31.

The communication groove 32 e is formed over the entire area of the inner core 32 in the radial direction, and is formed over the inner peripheral surface to the outer peripheral surface of the inner core 32. That is, the communication groove 32e is formed over the entire area in the radial direction of the first core contact surface 32c, the second core contact surface 32b, and the third core contact surface 32d.

As shown in FIG. 14, the communication groove 32 e has a bottom wall surface 32 e 1, an upright wall surface 32 e 2 and a tapered surface 32 e 3. The bottom wall surface 32e1 is shaped to expand perpendicularly to the moving direction of the movable core 30, the standing wall surface 32e2 is shaped to extend in the moving direction of the movable core 30 from the bottom wall surface 32e1, and the tapered surface 32e3 is a standing wall surface 32e2 Extending toward the groove opening 32e4 while expanding the flow area. In the example shown in FIG. 14, the tapered surface 32 e 3 has a shape that linearly extends from the upper end of the upright wall surface 32 e 2.

Examples of a method of processing the communication groove 32e include laser processing, electric discharge processing, cutting with an end mill, and the like. First, a groove having a rectangular cross-sectional shape, including the upright wall surface 32e2 and the bottom wall surface 32e1, is processed. At this time, there may be a case where burrs generated during processing remain in the peripheral portion of the groove opening 32e4 of the upright wall surface 32e2. However, thereafter, the burr is removed by processing the tapered surface 32e3 having a trapezoidal cross-sectional shape.

The movement of the movable core 30 is impeded when the fuel present in the fuel reservoir B1 is compressed with the movement of the movable core 30 to the counter injection hole side, so the movable core 30 moves by a predetermined amount. As a result, the moving speed (collision speed) when coming into contact with the needle 20 is reduced. As a result, the aforementioned effect by the core boost structure, that is, the effect that "the valve body can be operated to open even with high pressure fuel while suppressing the increase of the magnetic attraction force necessary for valve opening" is reduced. Do. Further, the movement of the movable core 30 is impeded, whereby the valve opening timing variation of the needle 20 becomes large, and the variation of the fuel injection amount becomes large.

On the other hand, the fuel injection valve 1 according to the present embodiment includes the needle 20 (valve body), the fixed core 13, the movable core 30, the first spring member SP1 (spring member), and the cup 50 (valve closing force transmission). Member) and. The movable core 30 abuts on the needle 20 at the time when the movable core 30 is attracted by the fixed core 13 and moves by a predetermined amount to the counter injection hole side, and opens the needle 20. The first spring member SP1 elastically deforms with the valve opening operation of the needle 20, and exerts a valve closing elastic force that causes the needle 20 to close. The cup 50 is disposed so as to be movable relative to the needle 20, and contacts the needle 20 by moving relative to the injection hole side to transmit the valve-closing elastic force to the needle 20. The movable core 30 has a first core contact surface 32c and a second core contact surface 32b, and the first core contact surface 32c and the second core contact surface 32b form the inside of the fuel reservoir chamber B1. A communication groove 32e is formed to communicate the outside with the outside.

Therefore, when the movable core 30 moves to the counter injection hole side, the fuel stored in the fuel storage chamber B1 flows out through the communication groove 32e. Therefore, the compression of the fuel accumulated in the fuel reservoir chamber B1 is suppressed, so that the movable core 30 can be easily moved. Therefore, since the collision velocity reduction of the movable core 30 can be suppressed, the effect of magnetic attraction force reduction by the core boost structure can be promoted. In addition, since the movable core 30 can be easily moved, variations in the valve opening timing of the needle 20 can be suppressed, and in turn, variations in the fuel injection amount can be suppressed.

Further, in the fuel injection valve 1 according to the present embodiment, a plurality of communication grooves 32e are formed, and the plurality of communication grooves 32e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30.

According to this, the portions that easily flow out of the fuel reservoir chamber B1 are present at equal intervals around the axial direction. Therefore, when the movable core 30 moves in the axial direction, it is possible to suppress a change in the tilting direction of the movable core 30 with respect to the axial direction. Thus, the behavior of the movable core 30 can be prevented from becoming unstable, so that the valve opening response can be further suppressed from being dispersed. In addition, if the communicating groove 32e is formed in three or more equal intervals in the circumferential direction, the effect of behavioral instability suppression will be promoted.

Further, in the fuel injection valve 1 according to the present embodiment, the movable core 30 includes the inner core 32 (abutment portion) and the outer core 31 (core main body portion) made of a material different from that of the inner core 32. A first core contact surface 32 c and a second core contact surface 32 b are formed in the inner core 32, and a movable side core facing surface 31 c facing the fixed core 13 is formed in the outer core 31. And the outer core 31 is excluded from the formation range of the communication groove 32e.

According to this, since the movable side core opposing surface 31c of the outer core 31 can be formed into a flat shape without a groove, reduction in the magnetic attraction force attracted to the fixed core 13 by the communication groove can be suppressed.

Further, in the fuel injection valve 1 according to the present embodiment, the third core contact surface 32d of the movable core 30 that contacts the guide member 60 is located outside the fuel reservoir chamber B1. The communication groove 32e is also formed on the third core contact surface 32d in addition to the first core contact surface 32c and the second core contact surface 32b.

The inner core 32 is in contact with the guide member 60 when the needle 20 is in the full lift position. In this contact state, when the stopper contact end surface 61a of the guide member 60 and the third core contact surface 32d of the inner core 32 are in close contact, the third core contact surface 32d is from the stopper contact end surface 61a. There is a concern that the phenomenon of becoming difficult to separate (linking phenomenon) may occur. With respect to this concern, in the present embodiment, the communication groove 32e is also formed on the third core contact surface 32d, so that the movable core 30 starts moving to the injection hole side when the current is turned off. The fuel is supplied to the third core contact surface 32d in a state of being in contact with the contact end surface 61a. Therefore, the movable core 30 can be prevented from coming into close contact with the guide member 60 and difficult to be separated, so that the possibility of delaying the start of the movement of the movable core 30 to the injection hole side can be reduced. Therefore, the valve closing response time from the energization OFF to the valve closing of the needle 20 can be shortened, and the valve closing response can be improved.

Further, in the fuel injection valve 1 according to the present embodiment, the communication groove 32e includes a bottom wall surface 32e1 extending perpendicularly to the moving direction of the movable core 30, and an upright wall surface 32e2 extending in the moving direction from the bottom wall surface 32e1. Have.

Now, it is desirable to polish the first core contact surface 32c and the second core contact surface 32b in order to remove burrs generated in the groove opening 32e4 of the communication groove 32e. For example, polishing is performed from the position indicated by the two-dot chain line in FIG. 14 to the position indicated by the solid line. In the present embodiment, after the inner core 32 is assembled to the outer core 31, the communication groove 32e and the outer communication groove 31e are formed by cutting or the like, and then the polishing is simultaneously performed on both the outer core 31 and the inner core 32. .

In contrast to the present embodiment, in the case of a shape shown by the alternate long and short dash line without the upright wall surface 32e2, the cross-sectional area of the communication groove 32e decreases, and the ratio of the cross-sectional area to be polished to the cross-sectional area of the communication groove 32e Becomes larger. As a result, since the influence of the variation in the polishing depth on the cross-sectional area of the communication groove 32e becomes large, the variation in the cross-sectional area of the communication groove 32e becomes large. Therefore, the variation in the degree of outflow of the fuel from the fuel storage chamber B1 to the outside through the communication groove 32e becomes large, and the variation in the easiness of movement of the movable core 30 becomes large. Become. On the other hand, in the present embodiment, since the rising wall surface 32e2 is provided, the ratio of the cross-sectional area to be polished is reduced, and the influence of the variation in polishing depth on the cross-sectional area of the communication groove 32e is reduced. Therefore, the variation in the degree of the fuel flowing out from the fuel reservoir chamber B1 to the outside through the communication groove 32e is reduced, and the suppression of the valve opening timing variation of the needle 20 can be promoted.

[Modification B1]
Although the communication groove 32e shown in FIG. 12 is not formed in the outer core 31, as shown in FIG. 15, in addition to the communication groove 32e being formed in the inner core 32, the communication groove (outer communication groove 31e) is formed in the outer core 31. ) May be formed. In the example shown in FIG. 15, the inner diameter side end of the outer communication groove 31e is in direct communication with the outer diameter side end of the communication groove 32e.

As shown in FIG. 16, a plurality (for example, four) of outer communication grooves 31 e are formed, and the plurality of outer communication grooves 31 e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30. The outer communication groove 31e has a shape extending linearly in the radial direction. The plurality of outer communication grooves 31e have the same shape. The circumferential position of the outer communication groove 31e is different from the circumferential position of the through hole 31a.

The outer communication groove 31e and the communication groove 32e have the same circumferential position. In the example of FIG. 16, the four outer communication grooves 31 e are equally spaced in the circumferential direction, but the six outer communication grooves 31 e may be equally spaced in the circumferential direction. In this case, it is desirable that the circumferential positions of the through holes 31a be set so that the circumferential distances to the adjacent outer communication grooves 31e become the same.

The outer communication groove 31 e is formed over the entire area of the outer core 31 in the radial direction, and is formed over the inner peripheral surface to the outer peripheral surface of the outer core 31. That is, the outer communication groove 31e is formed over the entire area in the radial direction of the movable side core facing surface 31c. The cross-sectional shape of the outer communication groove 31e is the same as the cross-sectional shape of the communication groove 32e shown in FIG. 14, and the outer communication groove 31e has the same bottom wall surface, vertical wall surface and tapered surface as the communication groove 32e. As described above, FIG. 14 is a cross-sectional view taken along the line XIV-XIV in FIG. 13 and has a shape of a cross section of the communicating groove 32 e extending in the radial direction of the movable core 30 taken perpendicularly to the extending direction. Indicates The cross-sectional shape of the outer communication groove 31e is the same as that of the communication groove 32e, and is a cross-sectional shape having a bottom wall surface, an upright wall surface, and a tapered surface in a cross section perpendicular to the extension direction of the outer communication groove 31e.

As described above, according to the present modification having the outer communication groove 31e, the fuel flowing out from the outer diameter end of the communication groove 32e is diffused through the outer communication groove 31e, so the outer diameter end of the communication groove 32e It is possible to suppress the fuel pressure increase at the time of fuel injection and to promote the fuel outflow through the communication groove 32e. That is, the fuel pressure increase between the guide member 60 and the inner core 32 can be suppressed.

Furthermore, in the present modification, since the inner diameter side end of the outer communication groove 31e is in direct communication with the outer diameter side end of the communication groove 32e, the fuel outflow from the outer diameter side end can be further promoted.

Furthermore, in this modification, since the outer communication groove 31e is formed over the entire area in the radial direction of the movable side core facing surface 31c, the fuel flowing out from the outer diameter side end of the outer communication groove 31e is the inside of the holder. It flows directly into the gap between the circumferential surface and the outer circumferential surface of the outer core 31. Therefore, the fuel pressure rise at the outer diameter side end of the outer communication groove 31e can be suppressed, and the fuel flow out through the communication groove 32e and the outer communication groove 31e can be promoted.

Furthermore, in the present modification, regarding the dimension of the outer communication groove 31e, the width dimension (circumferential dimension) of the portion of the outer communication groove 31e that opens toward the fixed core 13 is the depth dimension of the outer communication groove 31e (axis It is set smaller than the dimension in the C direction. According to this, it is possible to increase the flow passage cross-sectional area of the outer communication groove 31e while suppressing the reduction in the area of the movable side core facing surface 31c resulting from the formation of the outer communication groove 31e. The “flow passage cross-sectional area” is an area of a cross section perpendicular to the flow direction of the fuel in the fuel reservoir chamber B1 to flow radially outward through the outer communication groove 31e. That is, since the width dimension is smaller than the depth dimension as described above, it is possible to realize the fuel discharge from the fuel reservoir chamber B1 at the time of the valve opening operation while suppressing the reduction of the magnetic attraction force.

[Modification B2]
In the present modification shown in FIGS. 17 and 18, a connecting groove 32f for connecting a plurality of communicating grooves 31e is formed. The connection grooves 32f are shaped to extend annularly around the through holes 32a, and connect all (four in the example of FIG. 18) communication grooves 31e. The connection groove 32 f connects the outer diameter side end of the communication groove 31 e. The connection groove 32 f is formed by cutting the outer diameter side corner portion of the inner core 32. Further, by cutting the inner diameter side corner portion of the outer core 31, the connection groove 32f is formed across both the outer core 31 and the inner core 32.

Also in the embodiment shown in FIGS. 15 and 16, the connecting grooves 32f shown in FIGS. 17 and 18 are formed, and the plurality of communicating grooves 32e and the plurality of outer communicating grooves 31e are connected by the connecting grooves 32f. You may

As described above, according to the present modification having the connection groove 32f, the fuel flowing out from the outer diameter end of the communication groove 32e is diffused through the connection groove 32f, and hence the fuel at the outer diameter end of the communication groove 32e The fuel pressure rise can be suppressed, and the fuel outflow through the communication groove 32e can be promoted.

Further, by connecting the plurality of communication grooves 31e, it is possible to promote that the fuel flows out uniformly from the plurality of communication grooves 31e, so that when the movable core 30 moves in the axial direction, the movable core 30 in the axial direction It is possible to suppress the change in the tilting direction. Thus, the behavior of the movable core 30 can be prevented from becoming unstable, so that the valve opening response can be further suppressed from being dispersed.

[Modification B3]
A communication groove 32 e shown in FIG. 12 is formed over the entire end surface of the inner core 32. On the other hand, the communication groove 32g of this modification shown in FIGS. 19 and 20 includes a part of the first core contact surface 32c, the entire area of the second core contact surface 32b, and the third core contact surface 32d. It is formed across a part. More specifically, the communication groove 32g is not formed over the entire area in the radial direction of the first core contact surface 32c, and is adjacent to the second core contact surface 32b of the first core contact surface 32c. Partially formed in the The communication groove 32g is formed over the entire area in the radial direction of the second core contact surface 32b. The communication groove 32g is not formed over the entire area in the radial direction of the third core contact surface 32d, and is partially formed in a portion of the third core contact surface 32d adjacent to the second core contact surface 32b. Is formed.

Further, while the communication groove 32e shown in FIG. 12 has a shape extending linearly in the radial direction, the communication groove 32g according to this modification has a conical shape. That is, as shown in FIG. 20, it is circular as viewed from the direction of the axis C, and as shown in FIG. 19, it is triangular in cross sectional view.

As described above, according to the present modification having the conical communication groove 32g, the communication groove 32g can be formed simply by pressing the tip of the drill bit against the movable core 30, so the communication groove 32g can be easily processed.

[Modification B4]
In the embodiment shown in FIG. 12, the communication groove 32 e is formed on the contact surface of the movable core 30 so that the inside and the outside of the fuel reservoir chamber B <b> 1 are communicated. On the other hand, in the present modification shown in FIG. 21, the communication hole 20 c is formed in the needle 20 so that the inside of the fuel reservoir chamber B 1 and the internal passage 20 a of the needle 20 are in communication.

In the state where the cup 50 is in contact with the valve body abutting surface 21b at the valve closing time and the cup 50 is in contact with the second core abutting surface 32b, the communication hole 20c is the first core in the axis C direction. It is arrange | positioned in the position containing the contact surface 32c. Alternatively, the entire communication hole 20c is disposed on the side opposite to the injection hole of the first core contact surface 32c. A plurality of communication holes 20 c are formed, and the plurality of communication holes 20 c are arranged at equal intervals in the circumferential direction when viewed from the movement direction of the needle 20. The communication hole 20 c has a shape that linearly extends in the radial direction of the needle 20.

As described above, according to the present modification in which the communication hole 20c is formed in the needle 20, when the movable core 30 moves to the counter injection hole side, the fuel accumulated in the fuel reservoir chamber B1 is transmitted through the communication hole 20c. It flows out to the internal passage 20a (outside). Therefore, the compression of the fuel accumulated in the fuel reservoir chamber B1 is suppressed, so that the movable core 30 can be easily moved. Therefore, since the collision velocity reduction of the movable core 30 can be suppressed, the effect of magnetic attraction force reduction by the core boost structure can be promoted. In addition, since the movable core 30 can be easily moved, variations in the valve opening timing of the needle 20 can be suppressed, and in turn, variations in the fuel injection amount can be suppressed.

[Modification B5]
In the present modification shown in FIG. 22, the sliding surface communication groove 20 d is formed in the needle 20 so that the inside of the fuel storage chamber B 1 and the internal passage 20 a of the needle 20 are in communication. The sliding surface communicating groove 20d is formed on the valve body sliding surface 21c (see FIG. 7) of the needle 20 on which the cup 50 slides.

A plurality of sliding surface communication grooves 20 d are formed, and the plurality of sliding surface communication grooves 20 d are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the needle 20. The sliding surface communication groove 20 d has a shape extending linearly in the direction of the axis C of the needle 20.

According to the present modification in which the sliding surface communicating groove 20d is formed on the valve element side sliding surface 21c, which is the sliding surface between the needle 20 and the cup 50, as described above, when the movable core 30 moves to the reverse injection hole side. Then, the fuel accumulated in the fuel reservoir chamber B1 flows out through the sliding surface communication groove 20d. The term "outside" as used herein means a gap between the valve closing surface 21b at the valve closing time and the valve closing force transmission contacting surface 52c, and the internal passage 20a. Therefore, the compression of the fuel accumulated in the fuel reservoir chamber B1 is suppressed, so that the movable core 30 can be easily moved. Therefore, since the collision velocity reduction of the movable core 30 can be suppressed, the effect of magnetic attraction force reduction by the core boost structure can be promoted. In addition, since the movable core 30 can be easily moved, variations in the valve opening timing of the needle 20 can be suppressed, and in turn, variations in the fuel injection amount can be suppressed.

[Modification B6]
In the present modification shown in FIG. 23, the second sliding surface communicating groove 32h is formed in the inner core 32 to connect the inside of the fuel reservoir chamber B1 with the movable chamber 12a. The second sliding surface communication groove 32 h is formed on the surface of the inner core 32 on which the needle 20 slides, that is, the inner peripheral surface of the inner core 32.

A plurality of second sliding surface communication grooves 32 h are formed, and the plurality of second sliding surface communication grooves 32 h are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30. The second sliding surface communication groove 32 h has a shape extending linearly in the direction of the axis C of the movable core 30.

As described above, according to the present modification in which the second sliding surface communicating groove 32h is formed on the sliding surface between the needle 20 and the inner core 32, the fuel reservoir chamber B1 is moved when the movable core 30 moves to the reverse injection hole side. The fuel accumulated in the fuel flows out to the movable chamber 12a (outside) through the second sliding surface communication groove 32h. Therefore, the compression of the fuel accumulated in the fuel reservoir chamber B1 is suppressed, so that the movable core 30 can be easily moved. Therefore, since the collision velocity reduction of the movable core 30 can be suppressed, the effect of magnetic attraction force reduction by the core boost structure can be promoted. In addition, since the movable core 30 can be easily moved, variations in the valve opening timing of the needle 20 can be suppressed, and in turn, variations in the fuel injection amount can be suppressed.

<Detailed Description of Configuration Group C>
Next, among the configurations provided in the fuel injection valve 1 according to the present embodiment, the supply flow channel described below and the configuration group C including at least the configuration related to the supply flow channel are shown in FIGS. This will be described in detail using 12. In addition, modified examples of the configuration group C will be described later with reference to FIGS.

As shown in FIG. 24, a supply flow path (main flow path 20 e) for forming a groove is formed in the valve closing surface 21 b of the needle 20 when the valve is closed. The supply flow passage is a flow passage for supplying fuel to the valve closing valve contact surface 21b in a state of being in contact with the cup 50, and is described as a main flow passage 20e in the following description. As shown in FIG. 25, the closing valve body contact surface 21b is formed in a region extending annularly as viewed from the moving direction of the movable core 30, and the main flow passage 20e contacts the closing valve body. The shape is extended so as to connect the annular inner side and the annular outer side across the annular region in which the surface 21 b is formed. The main flow passage 20 e has a straight portion 201 extending linearly when viewed from the moving direction of the movable core. In the case of the present embodiment, the entire main flow passage 20 e coincides with the entire straight portion 201.

The annular inner side corresponds to the internal passage 20 a of the needle 20. The annular outer side corresponds to a gap B2 (see FIG. 12) between the inner surface of the cup 50 and the outer surface of the needle 20, which is formed in a state where the valve body abutting surface 21b abuts on the cup 50 at valve closing. Therefore, the main flow passage 20 e brings the internal passage 20 a of the needle 20 into communication with the gap B 2 in a state where the valve element abutting surface 21 b is in contact with the cup 50 at the valve closing time.

The main flow passage 20 e (supply flow passage) has a shape extending so as to connect the inner circumferential surface of the needle 20 forming the inner passage 20 a and the outer circumferential surface of the needle 20. The outer peripheral surface of the needle 20 functions as a wall surface of a passage that allows fuel to flow to the injection hole 11a. The fuel flowing through the passage formed by the gap between the outer peripheral surface of the needle 20 and the inner peripheral surface of the cylindrical portion 51 flows into the fuel storage chamber B1. Thereafter, it flows through the gap between the inner circumferential surface of the movable core 30 and the outer circumferential surface of the needle 20 and the gap between the outer circumferential surface of the movable core 30 and the inner circumferential surface of the main body 12 and flows into the movable chamber 12a. It flows into the injection hole 11a through 12b.

As shown in FIG. 25, the inner peripheral edge portion 201 a and the outer peripheral edge portion 201 b of the valve closing surface 21 b of the needle 20 at the valve closing time are chamfered. The main flow passage 20 e (supply flow passage) has a shape connecting the inner peripheral edge portion 201 a and the outer peripheral edge portion 201 b.

As shown in FIG. 25, a plurality of (for example, four) main channels 20 e are formed, and the plurality of main channels 20 e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30. That is, on the valve closing surface 21b of the needle 20 at the valve closing time, a plurality of main flow channels 20e are arranged at equal intervals in the circumferential direction. The main flow passage 20 e has a shape extending linearly in the radial direction. The plurality of main channels 20e have the same shape. As shown in FIG. 26, the cross section of the straight portion 201 of the main flow passage 20e has a shape having an arc-shaped bottom surface which is convex toward the injection hole side. The outer peripheral edge and the inner peripheral edge of the contact portion 21 of the needle 20 are chamfered, and the outer peripheral edge and the inner peripheral edge of the contact portion 21 are tapered. There is.

The depth dimension 201h of the main flow passage 20e is defined as the dimension in the direction of the axis C of the main flow passage 20e, and the width dimension 201w of the main flow passage 20e is defined as the dimension around the direction of the axis C of the needle 20 (FIG. 24) reference). The depth dimension 201h of the main flow passage 20e is set larger than the width dimension 201w of the main flow passage 20e.

In the case of the core boost structure in which the cup 50 is in contact with the needle 20 at the time when the movable core 30 starts moving by a predetermined amount with the cup 50 by the start of energization of the coil, the following concerns arise. That is, when the cup 50 and the needle 20 are in close contact and in contact with each other, a phenomenon (linking phenomenon) in which the cup 50 becomes difficult to separate from the needle 20 occurs. As a result, the start of movement of the movable core 30 by a predetermined amount is delayed. As a result, there is a concern that the valve opening responsiveness may deteriorate.

To address this concern, in the present embodiment, the needle 20 (valve body), the fixed core 13, the movable core 30, the first spring member SP1 (spring member), and the cup 50 (valve-closing force transmission member) Equipped with When the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount, the movable core 30 abuts on the valve opening contact surface 21 a formed on the needle 20 to open the needle 20. The first spring member SP1 elastically deforms with the valve opening operation of the needle 20, and exerts a valve closing elastic force that causes the needle 20 to close. The cup 50 abuts on the valve closing surface 21 b formed at the needle 20 at the valve closing time to transmit the valve closing elastic force to the needle 20. Then, at the time when the movable core 30 starts to move by a predetermined amount together with the cup 50, the cup 50 is in contact with the valve closing surface 21b. And the needle 20 has the main flow path 20e (supply flow path) which supplies a fuel to the valve element contact surface 21b at the time of valve closing which is in contact with the cup 50.

Therefore, when the movable core 30 starts to move by a predetermined amount, fuel is supplied to the valve closing contact surface 21b in the state of being in contact with the cup 50. Therefore, it is possible to suppress that the cup 50 is in intimate contact with the needle 20 and difficult to separate, so that the possibility of delaying the start of the movement of the movable core 30 by a predetermined amount due to the force of the intimate contact can be reduced. Therefore, the valve opening response time from the start of energization of the coil 17 to the start of the valve opening of the needle 20 can be shortened, and the valve opening response can be improved. In addition, variations in the valve opening timing due to the movement of the movable core 30 being hindered can be suppressed, and variations in the fuel injection amount can be suppressed.

Further, in the fuel injection valve 1 according to the present embodiment, the main flow passage 20 e (supply flow passage) is provided by the groove formed on the valve closing surface 21 b of the needle 20 at the valve closing time. Therefore, as compared with the case where the through hole as the supply flow channel is formed in the needle 20 or the cup 50, the processing of the supply flow channel can be simplified, and the supply flow channel can be easily provided.

Further, in the fuel injection valve 1 according to the present embodiment, the valve closing surface 21b is formed in a region extending annularly as viewed from the moving direction of the movable core 30, and the supply flow passage is It has a main flow passage 20 e extending across the region to connect the annular inner side and the annular outer side. Therefore, since fuel is supplied to the valve closing surface 21b from both sides of the annular inner side and the annular outer side, the suppression of the linking phenomenon due to the close contact can be promoted.

Further, in the fuel injection valve 1 according to the present embodiment, a plurality of main channels 20e are formed, and the plurality of main channels 20e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30 . According to this, places where the force by which the cup 50 adheres to the needle 20 is relaxed are present at equal intervals around the axial direction. Therefore, when the movable core 30 starts moving a predetermined amount in the axial direction, it is possible to suppress a change in the tilting direction of the movable core 30 with respect to the axial direction. Thus, the behavior of the movable core 30 can be prevented from becoming unstable, so that the valve opening response can be further suppressed from being dispersed. In addition, if the main flow path 20e is formed in three or more at equal intervals in the circumferential direction, the effect of behavioral instability suppression is promoted.

· Here, if the depth dimension 201h of the main flow passage 20e is too small, if the flow passage cross-sectional area of the main flow passage 20e becomes smaller as the wear of the valve contact surface 21b progresses at the valve closing time, the main It is not possible to ensure a sufficient flow rate of the fuel flowing through the flow path 20e. Further, when the width dimension 201w of the main flow passage 20e is excessive, the contact pressure when the cup 50 is pressed against the needle 20 by the valve closing elastic force becomes excessive, and the valve contact surface 21b of the valve closing time. It will not be possible to secure a sufficient pressure receiving area. Then, the progress of wear of the valve contact surface 21b at the valve closing time is accelerated.

In view of these points, in the fuel injection valve 1 according to the present embodiment, the depth dimension 201h of the main flow passage 20e is set larger than the width dimension 201w of the main flow passage 20e. Therefore, the flow rate of fuel flowing through the main flow passage 20e can be sufficiently secured, and the progress of wear of the valve contact surface 21b at the time of closing the valve due to excessive surface pressure can be suppressed.

[Modification C1]
In the present modification, the cross-sectional shape of the main flow passage 20e is deformed. That is, although the straight portion 201 of the main flow passage 20e shown in FIG. 26 has a cross-sectional shape having an arc-shaped bottom surface, it may have a triangular cross-sectional shape as shown in FIG. And may have a rectangular cross-sectional shape.

In addition, as shown in FIG. 29, the cross-sectional shape may be a combination of a rectangle and a trapezoid. Specifically, the main flow passage 20e has a bottom wall surface 20e1, an upright wall surface 20e2, and a tapered surface 20e3. The bottom wall surface 20e1 is shaped to expand perpendicularly to the moving direction of the movable core 30, the standing wall surface 20e2 is shaped to extend in the moving direction from the bottom wall surface 20e1, and the tapered surface 20e3 is formed from the standing wall surface 20e2 to the groove opening 20e4. It is a shape that extends while expanding the distribution area toward the In the example shown in FIG. 29, the tapered surface 20e3 has a shape that linearly extends from the upper end of the upright wall surface 20e2.

Examples of a method of processing the main flow path 20e shown in FIG. 29 include laser processing, electric discharge processing, cutting with an end mill, and the like. First, a groove having a rectangular cross-sectional shape, including the standing wall surface 20e2 and the bottom wall surface 20e1, is processed. At this time, there may be a case where burrs generated during processing remain in the peripheral portion of the groove opening 20e4 of the upright wall surface 20e2. However, thereafter, the burr is removed by processing the tapered surface 20e3 having a trapezoidal cross-sectional shape.

[Modification C2]
In the present modification shown in FIG. 30, the supply flow channel has a branch flow channel 205 which branches from the main flow channel 20e and connects the main flow channels 20e together, in addition to the straight portion 201 which is the main flow channel 20e. The branch flow channel 205 has a shape extending annularly as viewed from the moving direction of the movable core 30. Specifically, the branch flow channel 205 has an annular shape surrounding the inner passage 20a. The branch flow channel 205 has a groove shape having the same depth as that of the straight portion 201. The branch flow channel 205 is shaped to extend over the entire circumference so as to connect all the main flow channels 20 e.

Although four main channels 20e are provided in the example of FIG. 25, eight main channels 20e are provided in this modification, and the plurality of main channels 20e are circumferentially viewed from the moving direction of the movable core 30. It is arranged at equal intervals in the direction. The number of annular branch channels 205 is one.

In the example of FIG. 25, the valve closing contact surface 21 b is divided in the circumferential direction by the straight portion 201. On the other hand, in the present modification shown in FIG. 30, since the branched flow passage 205 is provided in addition to the straight portion 201, the valve closing surface 21b is closed also in the radial direction in addition to the division in the circumferential direction. It is divided.

When the needle 20 is in contact with the cup 50, a part of the fuel flowing into the main flow passage 20e from both the annular inner side and the annular outer side is supplied from the circumferential direction to the valve contact surface 21b at valve closing time. . Further, the fuel flowing into the branch flow channel 205 after flowing into the main flow channel 20 e is radially supplied to the valve closing surface 21 b during valve closing.

-According to this modification, in addition to the main flow path 20e which connects an annular inner side and an annular outer side according to this modification, it has the branch flow path 205 branched from the main flow path 20e. Therefore, fuel is supplied from both the main flow passage 20 e and the branch flow passage 205 to the valve closing surface 21 b during valve closing. Therefore, suppression of the linking phenomenon due to the close contact can be promoted.

Further, in the fuel injection valve according to the present modification, the branch flow passage 205 has a shape extending annularly as viewed from the moving direction of the needle 20. Therefore, since both ends of the branch flow channel 205 communicate with the main flow channel 20 e, it is possible to promote the inflow of fuel from the main flow channel 20 e to the branch flow channel 205 and consequently to the valve contact surface 21 b at valve closing time. Fuel supply can be promoted.

[Modification C3]
In the present modification shown in FIG. 31, the main flow passage 20 e has a straight portion 201 and an inflow portion 202. The straight portion 201 has a shape extending linearly when viewed from the moving direction of the movable core 30. The inflow portion 202 communicates with the straight portion 201 to form an inflow port 203 of the fuel to the main flow passage 20 e. The flow passage cross section of the inflow portion 202 has a shape in which the area is enlarged compared to the flow passage cross section of the straight portion 201. Specifically, in the cross-sectional view shown in FIG. 32 (b), the inflow portion 202 has a shape in which the groove width increases as it approaches the injection hole side. In the top view shown in FIG. 31, the inflow portion 202 has a shape in which the groove width is expanded toward the radially outer side.

Of the fuel inlets 203 and 204 formed at both ends of the main flow passage 20e, the inlet 203 located outside the above-described annularly extending region is provided with an inlet 202 having an enlarged area. There is. On the other hand, the inlet 204 located inside the annularly extending region is not provided with the inflow portion having an enlarged area. The outer peripheral edge and the inner peripheral edge of the contact portion 21 of the needle 20 are chamfered, and the outer peripheral edge and the inner peripheral edge of the contact portion 21 are tapered. There is.

The main flow passage 20 e is formed by laser processing. The dashed-dotted line in FIG. 32 shows the center of a laser beam. First, as shown in the column (a) of FIG. 32, a groove corresponding to the straight portion 201 is formed by laser. Specifically, laser processing is started from the inner side in the radial direction, and laser light is moved from the inner side to the outer side. In the processing of the straight portion 201, the focal point of the laser light is made to coincide with the bottom of the groove.

After the laser beam is moved to the outer end of the straight portion 201 to complete the processing of the straight portion 201, the laser beam is further moved radially outward, and the inflow portion as shown in the column (b) of FIG. A groove in a portion corresponding to 202 is processed by a laser. The focus of the laser light when processing the inflow portion 202 is set to be the same as the focus of the laser light when processing the straight portion 201. And since the outer peripheral edge part of the contact part 21 is formed in the taper shape, the bottom face of the inflow part 202 will be cut in the position which shifted from the focus of a laser beam. Thus, the cutting width at the bottom of the inflow portion 202 is larger than the cutting width at the bottom of the straight portion 201, so that the inflow portion 202 is formed in a shape in which the groove width widens closer to the injection hole side.

As described above, according to the present modification, the main flow passage 20 e communicates with the straight portion 201 extending linearly as viewed from the moving direction of the movable core 30 and the straight portion 201 to form the fuel inlet 203. And an inflow portion 202. The flow passage cross section of the inflow portion 202 has a shape in which the area is enlarged compared to the flow passage cross section of the straight portion 201. Therefore, compared with the case where the inflow portion 202 is not provided, the fuel can easily flow from the inflow port 203 into the straight portion 201, and the fuel supply to the valve contact surface 21b can be promoted.

[Modification C4]
The supply flow channel shown in FIG. 24 is provided by a groove-shaped main flow channel 20 e formed in the needle 20. On the other hand, in the present modification shown in FIG. 33, the through hole 52d is formed in the cup 50, and the through hole 52d provides a supply flow path for supplying fuel to the valve contact surface 21b at valve closing time.

According to this, when the movable core 30 starts to move by the predetermined amount, the fuel in the flow path 13a is supplied to the valve closing surface 21b in contact with the cup 50 through the through hole 52d. . Therefore, as in the embodiment of FIG. 24, it is possible to suppress the cup 50 from coming into close contact with the needle 20 and making it difficult to separate, so the valve opening response can be improved and variation in fuel injection amount due to variation in valve opening timing It can be suppressed.

[Modification C5]
In the supply flow path shown in FIG. 24, a groove-shaped main flow path 20 e is formed in the needle 20. On the other hand, in the present modification shown in FIGS. 34 and 35, a groove-shaped main flow passage 210e is formed in the plate 210 described below.

The plate 210 is disposed between the needle 20 and the cup 50, has a disk shape, and is made of metal. In the illustrated example, the main flow passage 210 e is formed in the surface on the injection hole side of the plate 210, but may be formed on the surface on the counter injection hole side of the plate 210. A plurality of (for example, four) main channels 210 e are formed, and the plurality of main channels 210 e are arranged at equal intervals in the circumferential direction when viewed from the moving direction of the movable core 30. The main flow passage 210 e has a shape extending linearly in the radial direction. The plurality of main channels 210e have the same shape.

Similarly to the main flow passage 20e shown in FIG. 25, the main flow passage 210e extends so as to connect the annular inner side and the annular outer side across the annular region where the valve element abutting surface 21b is formed. It is a shape. Therefore, the main flow passage 210e causes the internal passage 20a of the needle 20 to communicate with the gap B2 in a state where the valve element abutting surface 21b is in contact with the cup 50 via the plate 210.

Although plate 210 is not coupled to needle 20 and cup 50, it is defined herein as a portion of needle 20 or cup 50. The plate 210 is formed with a through hole 210 a communicating with the through hole 52 a of the cup 50 and the internal passage 20 a of the needle 20.

As described above, according to the present modification, when the movable core 30 starts moving by the predetermined amount, the main valve flow path to the valve close contact surface 21b in the state of being in contact with the cup 50 via the plate 210. The fuel of the flow path 13a is supplied through 210e. Therefore, as in the embodiment of FIG. 24, since the needle 20 can be prevented from coming into close contact with the plate 210 and difficult to be separated, the valve opening response can be improved and variation in fuel injection amount due to variation in valve opening timing can be reduced. It can be suppressed.

[Modification C6]
The supply flow path shown in FIG. 24 is provided by a groove-shaped main flow path 20 e formed on the valve element abutting surface 21 b of the needle 20 at the time of valve closing. On the other hand, in the present modification, the main flow path 20 e is eliminated, and the supply flow path is provided by the unevenness described below. That is, a shot blast is made to cause the abrasive to collide with the valve closing surface 21b at the valve closing time, and the surface roughness of the valve closing surface 21b at the valve closing time is increased. Make the surface uneven. This unevenness is used as a substitute for the main flow path 20e which provides the supply flow path. In other words, the surface roughness of the valve contact surface 21b at the time of closing the valve is made rougher than the inner peripheral surface of the portion forming the internal passage 20a among the surfaces of the needle 20. Alternatively, the surface roughness of the valve contact surface 21b at the time of valve closing is made rougher than the outer peripheral surface of the needle 20.

According to the supply flow path by the above-mentioned unevenness, the hardness of the valve closing surface 21b at the time of valve closing is increased by the shot blast. Therefore, it is possible to improve the wear resistance of the valve contact surface 21b during valve closing due to the cup 50 repeatedly colliding with the needle 20.

It should be noted that, instead of applying the shot blast to the needle 20 to form the asperity as described above, the valve closing force transmission contact surface 52c of the cup 50 may be subjected to the shot blast to form the asperity. In this case, the supply flow channel is provided by the unevenness formed on the valve closing force transmission contact surface 52c.

<Detailed Description of Configuration Group D>
Next, among the configurations provided in the fuel injection valve 1 according to the present embodiment, using FIG. 36 and FIG. 37 for configuration group D including at least a recess surface 60a described below and a configuration related to the recess surface 60a. Will be described in detail.

As described above, the inner peripheral surface of the cylindrical portion 61 of the guide member 60 forms a sliding surface 61 b that slides on the outer peripheral surface 51 d of the cylindrical portion 51 related to the cup 50. The sliding surface 61 b slides the outer peripheral surface 51 d of the cup 50 so as to guide the movement in the direction of the axis C while restricting the movement of the cup 50 in the radial direction. The sliding surface 61 b is a surface that is shaped to extend in parallel to the direction of the axis C.

A recess surface 60 a is formed on the surface of the inner surface of the guide member 60 which is connected to the side of the sliding surface 61 b opposite to the injection hole. The recessed surface 60 a is shaped to be recessed in a direction in which the gap with the cup 50 is expanded in the radial direction. The recessed surface 60a has a shape extending annularly around the axis C, and has the same shape in any cross section in the circumferential direction.

The adjacent surface 60a1 adjacent to the sliding surface 61b of the recessed surface 60a is a surface connected to the side of the sliding surface 61b opposite to the injection hole, and the clearance CL1 with the cup 50 is gradually increased in the radial direction as it goes away from the sliding surface 61b. It is a shape to be enlarged. The adjacent surface 60a1 includes a tapered surface 60a2 extending linearly when viewed in a cross section including the axis C. Further, the boundary portion 60b of the guide member 60, which includes the boundary between the adjacent surface 60a1 and the sliding surface 61b, has a shape curved in a radially inward projecting direction, that is, an R shape. Thereby, the wear of the cup 50 by the guide member 60 can be suppressed.

At a portion connecting the stopper abutting end surface 61a and the sliding surface 61b, a chamfered portion 61c formed in a tapered shape by chamfering is provided. The boundary portion including the boundary between the chamfered portion 61c and the sliding surface 61b has a shape which is curved in a radially inward projecting direction, and suppresses the wear of the cup 50 by the guide member 60.

In addition, the corner portion 51g connecting the outer peripheral surface 51d and the core contact end surface 51a of the cup 50, and the corner portion 51h connecting the transmission member side sliding surface 51c and the core contact end surface 51a have a tapered shape or an R shape. Chamfering processing is given to become. A chamfering process is performed on the corner portion 21d connecting the valve body side sliding surface 21c and the valve opening side valve contact surface 21a of the needle 20 so as to have a tapered shape or an R shape. The boundary 21e including the boundary between the chamfer formed on the side opposite to the injection hole of the valve-side sliding surface 21c and the valve-side sliding surface 21c has a shape curved in a direction projecting radially outward. The wear of the needle 50 and the needle 20 is suppressed.

In the following description, among the surfaces of the cup 50, a surface that includes the outer peripheral surface 51d of the cylindrical portion 51 of the cup 50 and extends parallel to the direction of the axis C is referred to as a parallel surface. In the example of FIG. 36, the whole of the outer peripheral surface 51d corresponds to a parallel surface, and of the surface of the cup 50, the range indicated by the symbol M1 in FIG. 37 is a parallel surface.

Further, a surface that is connected to the opposite surface of the parallel surface opposite to the injection hole and is located radially inward of the parallel surface is referred to as a connection surface 51e. The connecting surface 51 e has a curved shape that protrudes outward in the radial direction of the cup 50. Of the surface of the cup 50, the range indicated by the symbol M2 in FIG. 37 is the connecting surface 51e. In addition, the surface connected on the opposite side to the parallel surface in the connecting surface 51e is a spring contact surface which is in contact with the first spring member SP1 and to which a first elastic force is applied. The spring contact surface is shaped to expand perpendicularly to the direction of the axis C.

The boundary between the parallel surface and the connecting surface 51e is called a connecting boundary 51f (see the circle in FIG. 37). As the movable core 30 moves in the direction of the axis C, the cup 50 also moves in the direction of the axis C. The entire range M3 in which the connecting boundary line 51f moves in the direction of the axis C by this movement is included in the range N1 in which the recessed surface 60a is formed in the direction of the axis C.

The outer peripheral surface of the guide member 60 is press-fit into the enlarged diameter portion 13 c of the fixed core 13. As described above, since the guide member 60 is press-fitted and fixed to the fixed core 13, the guide member 60 does not tilt with respect to the fixed core 13. However, dimensional tolerances of the outer peripheral surface of the guide member 60 and the inner peripheral surface of the enlarged diameter portion 13c are inclined. On the other hand, since the cup 50 is disposed slidably with respect to the guide member 60, a gap CL1 for sliding is formed between the cup 50 and the guide member 60. Therefore, the cup 50 can be tilted relative to the fixed core 13 and the guide member 60. That is, the axis C of the cup 50 can be inclined with respect to the axis C of the fixed core 13.

Further, since the needle 20 is disposed slidably with respect to the cup 50, a clearance CL2 for sliding is formed between the needle 20 and the cup 50. Thus, the needle 20 can be further tilted relative to the cup 50 which can be tilted. That is, the axis C of the needle 20 can be further inclined with respect to the axis C of the cup 50 which can be inclined. Therefore, the angle (maximum inclination angle) when the needle 20 is maximally inclined and the cup 50 is maximally inclined in the same direction as the needle 20 is the maximum inclination angle assumed among the angles at which the cup 50 is inclined. This corresponds to θ 2 (see FIG. 36). The tapered surface 60a2 is formed such that the inclination angle θ1 (see FIG. 36) at which the tapered surface 60a2 is inclined with respect to the sliding surface 61b of the guide member 60 is larger than the maximum inclination angle θ2 of the cup 50. ing.

The clearance CL1 between the parallel surface of the cup 50 and the sliding surface 61b of the guide member 60 is set larger than the clearance CL2 between the cup 50 and the needle 20. Therefore, the inclination angle of the cup 50 when the clearance CL2 is zero is larger than the inclination angle of the needle 20 when the clearance CL1 is zero.

The sliding distance between the cup 50 and the guide member 60 in the gap CL1 is set longer than the sliding distance between the cup 50 and the needle 20 in the gap CL2. Here, the longer the sliding distance, the smaller the inclination due to the gap. For example, the inclination of the cup 50 with respect to the guide member 60 decreases as the sliding distance in the gap CL1 increases. The longer the sliding distance in the clearance CL2, the smaller the inclination of the needle 20 with respect to the cup 50. The connecting surface 51 e is set so as not to hit the guide member 60 even if the inclination of both of them is maximum.

The guide member 60 is formed of a magnetic material, and the cup 50 is formed of a nonmagnetic material. In general, non-magnetic materials have lower hardness than magnetic materials. Nevertheless, in the present embodiment, the cup 50 and the guide member 60 have the same hardness. In other words, for the cup 50, not a general nonmagnetic material but a high hardness nonmagnetic material is used. The hardness of the cup 50 (cup hardness) and the hardness of the guide member 60 (guide member hardness) are, for example, values in the range of Vickers hardness HV600 to HV700. If the deviation of the guide member hardness with respect to the cup hardness falls within the range of -10% to + 10% of the cup hardness, both hardnesses are regarded as having the same hardness.

Now, if the wear progresses due to the sliding between the cup 50 and the guide member 60, the cup 50 is largely inclined with respect to the guide member 60, and consequently, the needle 20 together with the cup 50 is largely inclined. And if inclination of the needle 20 becomes large, the on-off valve timing of the needle 20 will vary, and the fuel injection amount variation will become large.

To address this concern, in the present embodiment, the needle 20 (valve body), the fixed core 13, the movable core 30, the first spring member SP1 (spring member), and the cup 50 (valve-closing force transmission member) And a guide member 60.

When the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount, the movable core 30 abuts on the needle 20 to open the needle 20. The first spring member SP1 elastically deforms with the valve opening operation of the needle 20, and exerts a valve closing elastic force that causes the needle 20 to close. The cup 50 abuts on the first spring member SP1 and the needle 20 to urge the valve body transmission portion (disc portion 52) for transmitting the valve closing elastic force to the needle 20, and the movable core 30 toward the injection hole side. It has a cylindrical portion 51 of cylindrical shape. The guide member 60 has a sliding surface 61b for sliding the outer peripheral surface 51d of the cylindrical portion 51 so as to guide the movement in the direction of the axis C while restricting the movement of the cylindrical portion 51 in the radial direction. The guide member 60 is formed with a recessed surface 60a which is a surface connected to the side of the sliding surface 61b opposite to the injection hole, and which is recessed in a direction in which the gap with the cup 50 is expanded in the radial direction. The valve body transmitting portion is a disc portion 52 having a disc shape, and the cylindrical portion 51 has a shape extending from the outer peripheral end of the disc portion 52 to the injection hole side.

Of the surface of the cup 50, a surface including the outer peripheral surface of the cylindrical portion 51 and extending parallel to the direction of the axis C is a parallel surface, and is a surface connected to the opposite side of the parallel surface opposite to the injection hole. The surface located on the surface is referred to as a connection surface 51e, and the boundary between the parallel surface and the connection surface 51e is referred to as a connection boundary 51f. Then, the entire range M3 in which the connecting boundary 51f moves in the axial direction is included in the range N1 in which the depression surface 60a is formed in the axial direction. That is, the axial position of the connection boundary 51f is in the range N1 in which the recessed surface 60a is formed, regardless of whether the needle 20 is fully lifted or closed.

Therefore, when the cup 50 moves in the axial direction while sliding on the guide member 60, the connection boundary 51f faces the recessed surface 60a and does not contact the sliding surface 61b. Therefore, it can suppress that the cup 50 presses on the guide member 60 in the state where the surface pressure component in the axial direction is large, and the wear of the cup 50 can be suppressed. Therefore, since the inclination of the cup 50 can be suppressed and the inclination of the needle 20 can be suppressed, the fuel injection amount variation due to the variation of the on / off valve timing of the needle 20 can be suppressed.

Further, in the fuel injection valve 1 according to the present embodiment, the adjacent surface 60a1 adjacent to the sliding surface 61b of the recessed surface 60a is gradually separated in the radial direction from the clearance CL1 with the cup 50 as it goes away from the sliding surface 61b. It is a shape to be enlarged. Here, in the case where the adjacent surface 60a1 is shaped to expand the radial direction in a step-like manner contrary to the present embodiment, the surface pressure when the corner portion of the step presses against the cup 50 moving to the injection hole side is increased. And there is a concern about wear promotion. In view of this point, since the adjacent surface 60a1 according to the present embodiment is shaped to be gradually expanded in the radial direction, the above-mentioned surface pressure can be relieved, and concern about promoting wear of the cup 50 and the guide member 60 can be reduced.

Further, in the fuel injection valve 1 according to the present embodiment, the adjacent surface 60a1 includes the tapered surface 60a2 that linearly extends in a cross sectional view. And inclination-angle (theta) 1 which taper-shaped surface 60a2 inclines with respect to the sliding face 61b is larger than the largest inclination-angle (theta) 2 assumed among the angles which the cup 50 inclines. Therefore, the possibility of the inclined cup 50 coming into contact with the tapered surface 60a2 can be reduced, and the concern of promoting the wear of the cup 50 and the guide member 60 can be reduced.

Further, in the fuel injection valve 1 according to the present embodiment, the boundary portion 60b including the boundary between the adjacent surface 60a1 and the sliding surface 61b has a shape curved in a radially inward projecting direction. Here, in the case where the boundary portion has a sharp shape contrary to the present embodiment, the surface pressure at the time when the boundary portion presses against the cup 50 moving to the injection hole side is increased, and wear acceleration is promoted. Are concerned. In the present embodiment in view of this point, since the boundary portion 60b has a shape that is curved in a radially inward projecting direction, the surface pressure can be relaxed, and the concern of wear promotion can be reduced.

Further, in the fuel injection valve 1 according to the present embodiment, the guide member 60 is formed of a magnetic material, and the cup 50 is formed of a nonmagnetic material. According to this, it can be avoided that the electromagnetic attraction force acts on the cup 50 in the radial direction, and the parallel surface of the cup 50 is pressed against the sliding surface 61 b of the guide member 60. Therefore, wear of the cup 50 and the guide member 60 can be suppressed.

Further, in the fuel injection valve 1 according to the present embodiment, the cup 50 and the guide member 60 have the same hardness. In general, non-magnetic materials have lower hardness than magnetic materials. Nevertheless, in the present embodiment, as described above, not the general nonmagnetic material but the high hardness nonmagnetic material is used for the cup 50. Therefore, while avoiding the electromagnetic attraction force acting on the cup 50, it is possible to avoid the concern that the member on the low hardness side is accelerated by wear when there is a difference in hardness.

Further, in the fuel injection valve 1 according to the present embodiment, the clearance CL1 between the parallel surface of the cup 50 and the sliding surface 61b of the guide member 60 is larger than the clearance CL2 between the cup 50 and the needle 20.

Here, the needle 20 may open and close in a state of being inclined with respect to the direction of the axis C. When the needle 20 is tilted, the cup 50 is also tilted by the tilting force, and when the cup 50 is tilted, the force by which the cup 50 presses against the guide member 60 becomes large, and there is a concern of wear. Therefore, according to the present embodiment in which the depression surface 60a is applied to the configuration in which the wear is concerned, it can be said that the wear suppressing effect by the depression surface 60a is more effectively exhibited.

<Detailed Description of Configuration Group E>
Next, among the configurations of the fuel injection valve 1 according to the present embodiment, FIG. 38 and FIG. 39 are applied to a configuration group E including at least a press-fit structure of the outer core 31 and the inner core 32 and a configuration related to the press-fit structure. This will be described in detail. In addition, modified examples of configuration group E will be described later with reference to FIGS. 40 to 42.

As shown in FIG. 38, a press-fit surface 31p formed on the inner peripheral surface of the outer core 31 and a press-fit surface 32p formed on the outer peripheral surface of the inner core 32 are mutually press-fitted and fixed. The press- fit surfaces 31p, 32p are not formed over the entire area in the direction of the axis C, but are formed in a part of the direction of the axis C.

In the present embodiment, the press- fit surfaces 31p and 32p are formed on a part of the movable core 30 on the side opposite to the injection hole, and in the following description, the press-fit surface 31p of the outer core 31 is formed. A portion in the entire axial direction C including the press-fit surface 31 p is referred to as a press-fit region 311. A portion of the outer core 31 in which the press-fit surface 31 p is not formed and which does not include the press-fit surface 31 p is called a non-press-fit area 312. That is, the outer core 31 is divided into the press-in area 311 on the side opposite to the injection hole and the non-press-in area 312 on the injection hole side adjacent to the press-in area in the axis C direction.

In the non-press-fit area 312, a locking portion 31b that contacts the locking portion 32i of the inner core 32 in the direction of the axis C is formed. The locking portion 32i prevents the inner core 32 from shifting to the injection hole side with respect to the outer core 31 due to the collision of the inner core 32 with the guide member 60 or the like. A gap B3 with the inner core 32 is formed in a portion of the inner peripheral surface of the non-press-fit area 312 from the locking portion 31b to the boundary between the press-fit area 311. In other words, the gap B3 is located at the boundary between the press-fit area 311 and the non-press-fit area 312.

The clearance B3 functions as a region for confining a burr generated as a result of pressing the inner core 32 into the outer core 31. In addition, since the material of the outer core 31 is softer than the inner core 32, the burrs are generated on the press-fit surface 31 p of the outer core 31. In detail, the injection hole side end of the press-fit surface 32 p of the inner core 32 scrapes off a part of the press-fit surface 31 p of the outer core 31 to generate the burr.

In the present embodiment, after the inner core 32 is assembled to the outer core 31, the communication groove 32e and the outer communication groove 31e described above are formed by cutting or the like, and then the first core contact surface 32c and the second core contact The surface 32b is being ground. Thus, the positions of the first core contact surface 32 c and the second core contact surface 32 b in the axis C are aligned.

The outer peripheral surface of the outer core 31 shown by the solid line in FIG. 39 shows a state before press-fitting with the inner core 32, and is circular (perfect circle) in top view. On the other hand, in a state after press-fitting with the inner core 32, the outer peripheral surface of the press-fit area 311 in the outer core 31 bulges radially outward as shown by the dotted line in FIG. However, the portion where the through hole 31a exists (small inflating portion 311a) is less likely to expand than the portion where the through hole 31a does not exist (large inflating portion 311b). Therefore, the outer peripheral surface of the press-fit area 311 after the press-fit deformation does not become a perfect circle, and the large expansion portion 311 b has a diameter larger than the small expansion portion 311 a. Moreover, in the state before press-fitting, the diameters of the outer peripheral surface in the press-fit area 311 and the non-press-fit area 312 are the same. Therefore, in the state after press-fitting, the outer peripheral surface of the press-in area 311 has a diameter larger than the outer peripheral surface of the non-press-in area 312 (see FIG. 38).

The holder accommodating the movable core 30 in a movable state has a main body 12 which is a magnetic member having magnetism and a nonmagnetic member 14 adjacent to the main body 12 in the moving direction, and the end face of the main body 12 And the end face of the nonmagnetic member 14 are welded to each other. In the holder, a portion facing the outer circumferential surface of the press-fit area 311 is referred to as a press-in facing portion H1, and a portion facing the outer circumferential surface of the non-press-in area 312 is referred to as a non-press-in facing portion H2. Further, of the radial gaps between the inner circumferential surface of the press-in facing portion H1 and the outer circumferential surface of the press-in area 311, the smallest gap is a press-in portion gap CL3. The inner circumferential surface of the non-press-in facing portion H2 and the non-press-in area 312 Of the gaps in the radial direction with the outer peripheral surface of the above, the smallest gap is taken as a non-press-fit portion gap CL4. Then, the minimum inner diameter of the press-in facing portion H1 is formed larger than the minimum inner diameter of the non-press-in facing portion H2 so that the press-in portion gap CL3 becomes larger than the non-press-in portion clearance CL4.

The inner peripheral surface of the press-in facing portion H1 has a shape that expands in parallel with the moving direction (axis C direction) of the movable core 30. The inner circumferential surface of the non-press-in facing portion H2 has a parallel surface H2a extending parallel to the moving direction, and a connecting surface H2b connecting the inner circumferential surface of the press-in facing portion H1 and the parallel surface H2a. The connecting surface H2b has a shape in which the inner diameter gradually decreases as it approaches the parallel surface H2a. Although the non-press-in facing portion H2 includes a part of the main body 12, the nonmagnetic member 14 is not included, and the parallel surface H2a and the connecting surface H2b are formed by the main body 12. In other words, the main body 12 has a shape having parallel surfaces H2a and connecting surfaces H2b having mutually different inner diameter dimensions. The non-press-fit portion gap CL4, which is the minimum gap between the non-press-fit opposing portion H2 and the non-press-fit region 312, corresponds to the gap in the parallel surface H2a formed by the main body 12.

More specifically, the flow passage cross-sectional area formed by the press-fit portion clearance CL3 is larger than the flow passage cross-sectional area formed by the non-press-fit portion clearance CL4. These flow path cross-sectional areas are areas of cross sections perpendicular to the axis C direction among the flow paths formed by the press-in portion gaps CL3, CL4.

The inner circumferential surface H1a of the press-in facing portion H1 has a shape that expands in parallel with the movement direction. The press-in facing portion H1 includes a part of the nonmagnetic member 14 and a part of the main body 12. The nonmagnetic member 14 is formed to have a uniform inner diameter over the entire axis C direction. A press-fit portion gap CL3 which is a minimum gap between the press-fit opposing portion H1 and the press-fit region 311 corresponds to a portion of the main body 12 opposite to the injection hole of the connecting surface H2b or a gap at the nonmagnetic member.

When the movable core 30 attracted to the fixed core 13 is formed by press-fitting and fixing the inner core 32 for collision with the guide member 60 and the like and the outer core 31 for the magnetic circuit, the outer side of the outer core 31 is press fitted. The diameter slightly swells. As a result, the gap between the inner peripheral surface of the holder accommodating the movable core 30 and the outer peripheral surface of the outer core 31 becomes smaller, and the flow resistance that the movable core 30 receives from the fuel present in the gap becomes larger. Then, since it is difficult to control the amount of expansion of the outer diameter by press-fitting, machine resistance variation occurs in the magnitude of flow resistance, and variation in the moving speed of the movable core 30 occurs. As a result, machine difference variation occurs in the valve opening response, and the injection amount variation becomes large.

On the other hand, the fuel injection valve 1 according to the present embodiment includes the needle 20 (valve body), the fixed core 13, the movable core 30, the main body 12 (holder) and the nonmagnetic member 14 (holder), and the guide member 60 (stopper member). The movable core 30 has a cylindrical shape, and opens with the injection hole 11a by moving with the needle 20 by the magnetic attraction force. The holder has a movable chamber 12 a filled with fuel, and accommodates the movable core 30 in a movable state in the movable chamber 12 a. The guide member 60 abuts on the movable core 30 to restrict the movement of the movable core 30 in the direction away from the injection hole 11 a. The movable core 30 has an inner core 32 in contact with the guide member 60 and an outer core 31 press-fitted and fixed to the outer peripheral surface of the inner core 32. In the movement direction of the movable core 30, the outer core 31 is not pressed into and fixed to the outer peripheral surface of the inner core 32 in the movement direction of the movable core 30, and is not pressed into the outer peripheral surface of the inner core 32. It has a press-fit area 312. Then, among the gaps between the inner circumferential surface of the holder and the outer circumferential surface of the movable core 30, the minimum gap CL3 in the press-fit area 311 is larger than the minimum gap CL4 in the non-press-fit area 312.

Here, the flow resistance that the movable core 30 receives from the fuel present in the gap between the outer core outer peripheral surface and the holder inner peripheral surface becomes the smallest in the case where the size of the gap changes according to the axial position. Greatly affected by the gap. Then, among the gaps between the inner circumferential surface of the holder and the outer circumferential surface of the movable core, the gap CL3 in the press-fit area 311 has a large machine difference variation compared to the gap CL4 in the non-press-fit area 312. Therefore, contrary to the present embodiment, when the minimum clearance CL3 in the press-fit region 311 is smaller than the minimum clearance CL4 in the non-press-fit region 312, the flow resistance is largely affected by the clearance CL3 in the press-fit region 311. . Therefore, the machine difference of the flow resistance is largely generated. On the other hand, according to the present embodiment, the minimum clearance CL3 in the press-fit area 311 is larger than the minimum clearance CL4 in the non-press-fit area 312. Therefore, it can suppress that flow resistance receives to the influence of clearance gap CL3 in the pressing-in area | region 311, and can suppress that the movement speed of the movable core 30 produces dispersion | variation. As a result, it is possible to suppress the machine difference variation in the valve opening response and to make the injection amount variation smaller.

Further, in the fuel injection valve 1 according to the present embodiment, the inner circumferential surface H1a of the press-in facing portion H1 is shaped so as to expand in parallel with the movement direction. The inner circumferential surface of the non-press-in facing portion H2 has a parallel surface H2a extending parallel to the moving direction, and a connecting surface H2b connecting the inner circumferential surface of the press-in facing portion H1 and the parallel surface H2a. The connecting surface H2b has a shape in which the inner diameter gradually decreases toward the parallel surface H2a.

The boundary between the portion (large expansion portion 311b) where the expansion is largely generated by the press-in and the portion (small expansion portion 311a) which is hardly expanded is in a shape of gradually expanding. In view of this point, according to the present embodiment having the connecting surface H2b in which the inner diameter gradually decreases, the gap of the magnetic circuit formed by the portion of the connecting surface H2b can be made as small as possible. The connecting surface H2b may have a tapered shape in which the inner diameter gradually changes linearly as shown in FIG. 38, or may have a curved shape in which the inner diameter changes by curving, or changes in a stepwise manner It may be a stepped shape.

-Furthermore, in the fuel injection valve 1 according to the present embodiment, the holder has the main body 12 (magnetic member) having magnetism, and the nonmagnetic member 14 adjacent to the main body 12 in the moving direction, and the main body The end face 12 and the end face of the nonmagnetic member 14 are welded to each other. According to this, it is possible to carry out the processing for increasing and decreasing the inner diameter of the holder and the processing for removing the welding mark in the inner peripheral surface of the holder by a series of operations, so it is possible to reduce the time and effort of the processing for increasing and decreasing the inner diameter of the holder.

Further, in the fuel injection valve 1 according to the present embodiment, the outer core 31 is formed with the through holes 31a penetrating in the movement direction at equal intervals of three or more in the circumferential direction. According to this, three or more places where the flow resistance received by the movable core 30 from the fuel of the movable chamber 12a is low are present at equal intervals around the axial direction. Therefore, when the movable core 30 moves in the direction of the axis C, it is possible to suppress a change in the tilting direction of the movable core 30 with respect to the direction of the axis C. Thus, the behavior of the movable core 30 can be prevented from becoming unstable, so that the valve opening response can be further suppressed from being dispersed.

[Modification E1]
In the present modification shown in FIG. 40, the maximum outer diameter of the outer core 31 in the press-fit area 311 is smaller than the maximum outer diameter of the outer core 31 in the non-press-fit area 312.

Specifically, the outer diameter of the press-fit region 311 is formed sufficiently smaller than the outer diameter of the non-press-fit region 312 before the press-fit, and the press-fit is also performed even if the press-fit region 311 is expanded by the press-fit. The outer diameter of the region 311 is smaller than the outer diameter of the non-press-in region 312. In short, in the state before press-fitting, the outer peripheral surface of the press-fit area 311 is cut to form the recess 311 c, and the cutting depth of the recess 311 c is sufficiently large so that the recess 311 c remains even after press-fitting and swelling. Keep it. Further, the inner diameter dimension of the non-press-in facing portion H2 is the same along the axis C direction in the same manner as the press-in facing portion H1.

As described above, the outer circumferential surface of the press-fit region 311 is smaller than the non-press-fit region 312, and the inner circumferential surface of the non-press-in facing portion H2 is formed identical to the press-in facing portion H1. It is larger than the press-in part clearance CL4. Therefore, also in this modification, the same effect as the fuel injection valve 1 shown in FIG. 39 is exhibited.

[Modification E2]
In the present modification shown in FIG. 41, the entire press-in facing portion H1 of the holder is formed of the nonmagnetic member 14, and the main body 12 is not included in the press-in facing portion H1. For example, by shortening the axial C direction length of the press- fit surfaces 31p and 32p as compared with the structure of FIG. 39, the entire press-fit opposing portion H1 is formed of the nonmagnetic member 14. Alternatively, the length of the nonmagnetic member 14 in the direction of the axis C is made longer as compared with the structure of FIG. 39, so that the entire press-in facing portion H1 is formed of the nonmagnetic member 14. Also in this modification, since the press-in portion gap CL3 is formed larger than the non-press-in portion gap CL4, the same effect as the fuel injection valve 1 shown in FIG. 39 is exerted.

[Modification E3]
In the present modification shown in FIG. 42, the radially expanded portion of the press-fit area 311 is removed by press-fitting, and the maximum outer diameter of the outer core 31 in the press-fit area 311 is the maximum outer diameter of the outer core 31 in the non-press-fit area 312. It is formed to be identical to

Specifically, in a state before press-fitting with the inner core 32, the outer core 31 whose outer peripheral surface is circular (perfect circle) in top view is prepared (preparation process) and press-fit with the inner core 32 (press-fit process). Thereafter, the large expanded portion 311b (see FIG. 39) expanded by press-fitting is cut after press-fitting (cutting step), whereby the outer core 31 is formed so that the outer peripheral surface becomes circular (perfect circle) in top view. ing. Further, the inner diameter dimensions of the press-in facing portion H1 and the non-press-in facing portion H2 are the same along the axis C direction. Therefore, the press-in portion gap CL3 and the non-press-in portion gap CL4 are the same. Therefore, the same effect as that of FIG.

Second Embodiment
While the valve-closing force transmission member according to the first embodiment is provided by the cup 50, the valve-closing force transmission member according to the present embodiment includes a first cup 501, a second cup 502, and the like, which will be described below. It is provided by the third spring member SP3 (see FIG. 43). The configuration of the fuel injection valve according to the present embodiment is the same as the configuration of the fuel injection valve according to the first embodiment except for the configuration described below.

The first cup 501 is in contact with the first spring member SP1 and the needle 20, and transmits the valve closing elastic force by the first spring member SP1 to the needle 20. In short, the first cup 501 exerts the same function as the disc portion 52 of the cup 50 according to the first embodiment. In the first cup 501, a through hole 52a similar to that of the first embodiment is formed.

The third spring member SP3 is an elastic member that elastically deforms in the axial direction to exert an elastic force. One end of the third spring member SP3 abuts on the abutment surface 501a of the first cup 501, and the other end of the third spring member SP3 abuts on the abutment surface 502a of the second cup 502. As a result, the third spring member SP3 is sandwiched between the first cup 501 and the second cup 502 so as to be elastically deformed in the axial direction, and exerts an elastic force by the elastic deformation.

The second cup 502 abuts on the movable core 30 at the time of valve closing operation to bias the movable core 30 toward the injection hole side. In short, the second cup 502 exhibits the same function as the cylindrical portion 51 of the cup 50 according to the first embodiment. Then, the third spring member SP3 exerts a function of transmitting a force in the axial direction between the first cup 501 and the second cup 502.

The needle 20 has a main body portion 2001 and an enlarged diameter portion 2002. At the end of the main body portion 2001 opposite to the injection hole, a valve closing surface 21b is formed. As in the first embodiment, the valve closing contact surface 21b contacts the valve closing force transmitting contact surface 52c of the valve closing force transmitting member (first cup 501).

The enlarged diameter portion 2002 is located closer to the injection hole side than the valve body abutting surface 21b at the time of valve closing, and has a disk shape in which the diameter of the main portion 2001 is enlarged. A valve opening contact surface 21 a is formed on the injection hole side surface of the enlarged diameter portion 2002. The valve opening contact surface 21a abuts on the first core contact surface 32c of the movable core 30 in the same manner as in the first embodiment. The length in the axis C direction of the gap between the valve opening surface 21a and the first core contact surface 32c in the valve closed state corresponds to the gap amount L1 according to the first embodiment.

In a state immediately after switching the current supply to the coil 17 from off to on, the magnetic attraction force acts on the movable core 30, and the movable core 30 starts to move toward the valve opening side. Then, when the movable core 30 moves while pushing up the second cup 502, and the amount of movement reaches the gap amount L1, the valve open surface 21a of the needle 20 at the valve opening surface 21a of the needle 20 contacts the first core contact surface of the movable core 30. 32c collides.

In the present embodiment, the guide member 60 is eliminated, and the movable core 30 abuts on the fixed core 13, whereby the valve opening actuation amount of the needle 20 is regulated. When the movable core 30 collides with the needle 20 as described above, a gap is formed between the fixed core 13 and the movable core 30. The length of the gap in the direction of the axis C is the first embodiment. It corresponds to the lift amount L2 of the form.

The elastic force of the first spring member SP1 acts on the needle 20 also in the period up to the point of collision. After the collision, the movable core 30 continues to move by the magnetic attraction force, and when the amount of movement after the collision reaches the lift amount L2, the movable core 30 collides with the fixed core 13 and stops moving. The separation distance between the body side seat 11s and the valve body side seat 20s in the direction of the axis C at the time when the movement is stopped corresponds to the full lift amount of the needle 20 and matches the lift amount L2 described above.

Third Embodiment
The valve-closing force transmission member (cup 50) according to the first embodiment has a cup shape having a cylindrical portion 51 and a disc portion 52. On the other hand, the valve-closing force transmission member according to the present embodiment has a disc shape constituted by the disc portion 52 in which the cylindrical portion 51 is eliminated (see FIG. 44). The configuration of the fuel injection valve according to the present embodiment is the same as the configuration of the fuel injection valve according to the first embodiment except for the configuration described below.

In the first embodiment, the surface (core contact end surface 51a) of the valve-closing force transmission member to which the contact surface (second core contact surface 32b) of the movable core 30 contacts is formed in the cylindrical portion 51. It is done. On the other hand, in the present embodiment, the surface on the injection hole side of the disk portion 52 functions as a core contact end surface 52 e (see FIG. 44) that contacts the movable core 30.

(Other embodiments)
The disclosure in this specification is not limited to the combination of parts and / or elements shown in the embodiments. The disclosure can have additional parts that can be added to the embodiments. The disclosure includes those in which parts and / or elements of the embodiments have been omitted. The disclosure includes replacements or combinations of parts and / or elements between one embodiment and another embodiment. For example, although the fuel injection valve 1 according to the first embodiment includes all of the constituent groups A, B, C, D, and E, even if it is a fuel injection valve provided with an arbitrarily combined constituent group Good.

In the first embodiment, as shown in FIG. 6, the temporary press-fit is performed once, but the temporary press-fit may be performed twice or more and the load measurement may be performed for each temporary press-fit. According to this, it is possible to achieve the target value of the second set load with high accuracy. Moreover, since the load is measured for each of a plurality of temporary press-fits, the elastic coefficient of the second spring member SP2 can be measured, and the press-fit amount in the main press-fit can be calculated with high accuracy.

Further, in the press-fitting operation shown in FIG. 6, the second set load is measured in a state in which the progress of the press-fit is stopped and interrupted, but the second set load may be measured while press-fitting. In other words, press-in may be performed while measuring the second set load, and the press-in may be stopped and completed when the measured second set load becomes the target value.

Further, in the press-fitting operation shown in FIG. 6, the second set load is measured while restricting the movement of the movable core 30 by the cup 50 in a state of being in contact with the needle. It may be measured while restricting the movement of the core 30.

The communication groove 32e shown in FIG. 12 is formed not only on the first core contact surface 32c and the second core contact surface 32b but also on the third core contact surface 32d. May not be formed. In addition, although the communication groove 32e shown in FIG. 12 is formed over the entire area in the radial direction of the first core contact surface 32c, at least the second core contact surface 32b of the first core contact surface 32c. It may be formed in the adjacent part.

The outer communication groove 31e shown in FIG. 16 is disposed so as not to communicate with the through hole 31a. However, the outer communication groove 31e may be disposed so as to communicate with the through hole 31a. The communication groove 32g shown in FIG. 19 is formed across the first core contact surface 32c, the second core contact surface 32b and the third core contact surface 32d, but the third core contact surface 32d is It does not have to be formed.

In the examples of FIGS. 21, 22 and 23, the communication groove 32e is eliminated and the communication hole 20c, the sliding surface communication groove 20d and the second sliding surface communication groove 32h are provided instead of the communication groove 32e. On the other hand, the fuel injection valve 1 may include any two or more of the communication groove 32e, the communication hole 20c, the sliding surface communication groove 20d, and the second sliding surface communication groove 32h.

In the example of FIG. 22, the sliding surface communication groove 20d is formed in the needle 20, but the sliding surface communication groove is on the transmission member side sliding surface 51c (see FIG. 22) of the cup 50 on which the needle 20 slides. May be formed. Although the second sliding surface communication groove 32 h is formed in the inner core 32 in the example of FIG. 23, the second sliding surface communication groove may be formed on the surface of the needle 20 that slides on the inner core 32.

In the example of FIG. 24, although the main flow path 20e which supplies a fuel to the valve element contact surface 21b at the time of valve closing in the state contact | abutted with the cup 50 is provided by the groove formed in the needle 20, A groove formed in 50 may be provided. Specifically, the supply flow channel may be provided by forming a groove in the core contact end surface 51 a of the cylindrical portion 51.

In the first embodiment, the movable portion M is supported in the radial direction at two points of the needle 20 facing the inner wall surface 11c of the injection hole body 11 (the needle tip) and the outer peripheral surface 51d of the cup 50. It is done. On the other hand, the movable portion M may be supported from the radial direction at two points of the outer peripheral surface of the movable core 30 and the tip end of the needle.

In the first embodiment, the inner core 32 is formed of a nonmagnetic material, but may be formed of a magnetic material. When the inner core 32 is formed of a magnetic material, the inner core 32 may be formed of a weak magnetic material that is weaker in magnetism than the outer core 31. Similarly, the needle 20 and the guide member 60 may be formed of a weakly magnetic material that is less magnetic than the outer core 31.

In the first embodiment, when the movable core 30 is moved by the predetermined amount, the movable core 30 is brought into contact with the needle 20 to realize the core boost structure for starting the valve opening operation. A cup 50 is interposed between the core 30 and the core 30. On the other hand, even if it is the core boost structure which abolishes the cup 50, provides the 3rd spring member different from 1st spring member SP1, and urges the movable core 30 to the injection hole side by the 3rd spring member. Good.

In the first embodiment, the nonmagnetic member 14 is disposed between the fixed core 13 and the main body 12 in order to avoid a magnetic short circuit between the fixed core 13 and the main body 12. Instead of the nonmagnetic member 14, a magnetic member having a shape with a magnetic throttling portion that suppresses the magnetic short circuit may be disposed between the fixed core 13 and the main body 12. Alternatively, the nonmagnetic member 14 may be eliminated, and a magnetic throttling portion for suppressing the magnetic short circuit may be formed in the fixed core 13 or the main body 12.

The sleeve 40 according to the first embodiment has a shape in which the connecting portion 42 extends on the upper side (anti-injection hole side) of the support portion 43, and the insertion cylindrical portion 41 extends on the upper side of the connecting portion 42. On the other hand, the sleeve 40 may have a shape in which the connecting portion 42 extends to the lower side (the injection hole side) of the support portion 43 and further the insertion cylindrical portion 41 extends to the lower side of the connecting portion 42. The sleeve 40 may also be a hollow shaped ring extending annularly around the needle 20. In this case, the upper surface of the ring supports the second spring member SP2, and the inner peripheral surface of the ring is press-fit into the press-fit portion 23.

The cup 50 according to the first embodiment has a cup shape having a disc portion 52 and a cylindrical portion 51. On the other hand, the cup 50 may have a flat plate shape. In this case, the upper surface (upper surface) of the flat plate abuts on the first spring member SP1, and the lower surface (lower surface) of the flat plate abuts on the movable core 30.

Although the support member 18 according to the first embodiment has a cylindrical shape, it may have a C-shaped cross section in which a slit extending in the direction of the axis C is formed in a cylinder.

The movable core 30 according to the first embodiment has a structure having two parts, an outer core 31 and an inner core 32. The inner core 32 is a material having a hardness higher than that of the outer core 31 and has a surface in contact with the cup 50 and the guide member 60 and a surface in sliding contact with the needle 20. On the other hand, the movable core 30 may have a structure in which the inner core 32 is eliminated.

When the movable core 30 has a structure in which the inner core 32 is eliminated as described above, plating is applied to the contact surface of the movable core 30 that contacts the cup 50 and the guide member 60 and the sliding surface that slides with the needle 20. It is desirable that it is done. One particular example of plating applied to the contact surface is chromium. Nickel phosphorus is mentioned as one of the examples of plating given to a sliding face.

The fuel injection valve 1 according to the first embodiment has a structure in which the movable core 30 abuts on the guide member 60 attached to the fixed core 13. On the other hand, the movable core 30 may be in contact with the fixed core 13 without the guide member 60. In short, the inner core 32 may be in contact with the guide member 60, or the inner core 32 may be in contact with the fixed core 13 without the guide member 60. Alternatively, the movable core 30 with the inner core 32 removed may be in contact with the guide member 60, or the movable core 30 with the inner core 32 removed may be in contact with the fixed core 13 with the guide member 60 removed. It may be.

As described above, when the movable core 30 has a structure in which the inner core 32 is eliminated, the surface of the movable core 30 on the side opposite to the injection hole that abuts the needle 20 corresponds to the first core contact surface 32c. Further, in the case where the guide member 60 is abolished as described above, the surface of the movable core 30 that abuts on the fixed core 13 corresponds to the third core contact surface 32 d.

In the first embodiment, the communication groove 32 e is formed in a portion of the inner core 32 that contacts the guide member 60. On the other hand, when it is the structure which abolished the guide member 60 as mentioned above, the communicating groove 32e is formed in the part which contact | abuts on the fixed core 13 among the inner core 32. As shown in FIG. Further, in the case where the movable core 30 has a structure in which the inner core 32 is eliminated as described above, the communication groove 32 e is formed in the portion of the movable core 30 that abuts on the fixed core 13.

The cup 50 according to the first embodiment slides in the direction of the axis C while in contact with the inner peripheral surface of the guide member 60. On the other hand, the cup 50 may be configured to move in the direction of the axis C while forming a predetermined gap with the inner circumferential surface of the guide member 60.

In the first embodiment, the inner circumferential surface of the second spring member SP <b> 2 is guided by the connecting portion 42 of the sleeve 40. On the other hand, the outer peripheral surface of the second spring member SP2 may be guided by the outer core 31.

In the first embodiment, one end of the second spring member SP2 is supported by the movable core 30, and the other end of the second spring member SP2 is supported by the sleeve 40 attached to the needle 20. On the other hand, the sleeve 40 may be abolished, and the other end of the second spring member SP2 may be supported by the main body 12.

Although the disclosure has been described with reference to examples, it is understood that the disclosure is not limited to the disclosed examples or structures. Rather, the present disclosure includes various modifications and variations within the equivalent range. In addition, although various elements of the present disclosure are illustrated by various combinations and forms, other combinations and forms including more elements, fewer elements, or only one of these elements Are also within the scope and scope of the present disclosure.

Claims (7)

1. A valve body (20) for opening and closing an injection hole (11a) for injecting fuel;
   A fixed core (13) that generates a magnetic attraction upon energization of a coil (17);
   A movable core (30) which is brought into contact with the valve body when it is sucked by the fixed core and moved by a predetermined amount to the counter injection hole side to open the valve body;
   A first spring member (SP1) that elastically deforms with the valve opening operation of the valve body to exert a first elastic force that causes the valve body to close the valve operation;
   A fixing member (40) fixed to the valve body;
   A second spring member (SP2) that exerts a second elastic force that is elastically deformed between the fixed member and the movable core to urge the movable core to the side opposite to the injection hole;
   Equipped with
   The valve body has a press-fitting portion (23) in which the fixing member is press-fitted to the opposite side of the injection hole,
   The fuel injection valve fixed to the valve body by pressing the fixing member into the press-fitting portion.
2. The fuel injection valve according to claim 1, wherein at least a portion of the fixing member in contact with the press-fit portion has a hardness different from that of the press-fit portion.
3. The fuel injection valve according to claim 2, wherein at least a portion of the fixing member in contact with the press-fit portion has a hardness lower than that of the press-fit portion.
4. The fixed member and the movable core are separated without contact with each other even when the movable core is moved relative to the valve body to the injection hole side as much as possible. The fuel injection valve as described in 1 or 2.
5. The fixing member has a cylindrical insertion cylindrical portion (41) inserted into the press-fit portion,
   The fuel injection valve according to any one of claims 1 to 4, wherein the inner peripheral surface of the insertion cylindrical portion is press-fitted to the outer peripheral surface of the press-fit portion over the entire circumference.
6. The valve body (20) for opening and closing the injection hole (11a) for injecting the fuel is closed by the first elastic force by the first spring member (SP1) which is elastically deformed and exhibited, and is moved by the magnetic attraction force A structure in which the movable core (30) opens the valve, and
   The second elastic force by the second spring member (SP2), which is elastically deformed between the fixed member (40) fixed to the valve body and the movable core, urges the movable core to the side opposite to the injection hole A method of manufacturing a fuel injection valve (1) having a structure
   Press-fit process for press-fitting fixed member (40) into press-fit portion (23) formed on the valve body to abut the movable core at the time of movement by a predetermined amount by the magnetic attraction force and start the valve opening operation (S12, S15),
   A load measuring step (S13) of measuring the second elastic force in a state in which the movable core can not be moved in the middle of the press fitting;
   Including
   The method for manufacturing a fuel injection valve according to claim 1, wherein in the press-in step, the amount of the press-in is adjusted based on the result of the measurement to complete the press-in.
7. The fuel injection valve is disposed so as to be movable relative to the valve body, and abuts against the valve body by moving relatively to the injection hole side, and the first elastic force is transmitted from the first spring member to the valve It has a closing force transmission member (50) for transmission to the body,
   In the load measurement step, the valve-closing force transmission member is relatively moved to be in contact with the valve body, and the valve-closing force transmission member in a state of being in contact with the movable core is brought into contact with the movable core. The method of manufacturing a fuel injection valve according to claim 6, wherein movement of the core is restricted.

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