FUEL INJECTOR

Abstract

A fuel injection valve includes a needle (20) (valve body), a fixed core (13), a movable core (30), a main body (12) (retainer), a non-magnetic member (14) (retainer), and a stopper member (60). The movable core has an inner core (32) that contacts the stopper member, and an outer core (31) that is press-fitted into an outer peripheral surface of the inner core. The outer core has, in a moving direction of the movable core, a press-fit portion (311) that is press-fitted into the outer peripheral surface of the inner core, and a non-press-fit portion (312) that is not press-fitted into the outer peripheral surface of the inner core and is adjacent to the press-fit portion in the moving direction. Between the inner peripheral surface of the main body and the non-magnetic member and the outer peripheral surface of the movable core, the smallest gap in the press-fit portion is larger than the smallest gap in the non-press-fit portion.As a result, variation in fuel injection quantity can be reduced while simultaneously adopting a core boost structure.

Description

CROSS-REFERENCE TO SIMILAR APPLICATIONS

[0001] This application is based on Japanese Patent Application No. 2017-189885 filed on September 29, 2017, and Japanese Patent Application No. 2018-169996 filed on September 11, 2018, and incorporates the disclosures thereof. Technical area

[0002] The present disclosure relates to a fuel injector that injects fuel. BACKGROUND

[0003] A conventional fuel injector includes a fixed core that generates a magnetic attraction force when a coil is energized, a movable core that is attracted and moved by the fixed core, and a valve body that is actuated by the movable core to open the valve, ejecting fuel from a nozzle orifice. In recent years, fuel pressure has become high, and the valve closing force acting on the valve body or valve body tends to increase. Therefore, a large valve opening force is required to open the valve against the large valve closing force.

[0004] As a countermeasure to the above-mentioned points, a core boost structure described below is disclosed in Patent Literature 1. That is, for the valve-opening operation of the valve body, the movement of the movable core is first started in a state where the movable core is not engaged with the valve body. Then, when the movable core is moved a predetermined distance, the movable core is brought into contact with the valve body to start the valve-opening operation.

[0005] According to the core boost structure described above, since the movable core is not yet engaged with the valve body immediately after the start of energization, the movable core, which is not subjected to the force of fuel pressure, can quickly increase the moving speed of the movable core by an initially small magnetomotive force. Since the movable core then comes into contact with the valve body and starts the valve opening operation when the moving speed becomes sufficiently high, that is, when the movable core is moved by the predetermined distance, the valve opening operation can be performed by means of a collision force of the movable core in addition to a magnetic attraction force. Therefore, the valve opening operation of the valve body can be performed even under high fuel pressure. In addition, the magnetic attraction force required to open the valve can be reduced. LITERATURE ON THE STATE OF THE ART PATENT LITERATURE

[0006] Patent Literature 1: JP 2013-104340 A

[0007] Further prior art is disclosed in US 2016 / 0 237 966 A1, WO 2017 / 154 815 A1, JP 2004 - 346 856 A and JP 2012 - 97 728 A. SUMMARY OF THE INVENTION

[0008] However, in the core boost structure described above, the movable core moves in two stages: one movement from the start of energization to contact with the valve body; and the subsequent movement while maintaining contact with the valve body. Therefore, a new problem arises that a change in the time period from the start of energization to the start of the valve opening process is directly related to a change in the amount of fuel injected during a valve opening process. Furthermore, it is important to reduce not only the time period from the start of energization to valve opening, but also the time period from the end of energization to valve closing.

[0009] An object of the present disclosure is to provide a fuel injection valve that uses a core boost structure while reducing variation in fuel injection amount.

[0010] According to a first aspect of the present disclosure, a fuel injection valve includes: a valve body that opens and closes a nozzle opening for injecting fuel; a fixed core that generates a magnetic attraction force when a coil is energized; a movable core that has a cylindrical shape and opens the nozzle opening by moving together with the valve body due to the magnetic attraction force; a holder that has a movable chamber filled with the fuel and accommodates the movable core movable in the movable chamber; and a stopper member that contacts the movable core to limit the movement of the movable core in a direction away from the nozzle opening. The movable core includes an inner core that contacts the stopper member and an outer core that is press-fitted to an outer peripheral surface of the inner core.The outer core includes, in a moving direction of the movable core, a press-fit region where the outer core is press-fitted to the outer peripheral surface of the inner core, and a non-press-fit region where the outer core is not press-fitted to the outer peripheral surface of the inner core. The non-press-fit region is adjacent to the press-fit region in the moving direction. Between an inner peripheral surface of the holder and an outer peripheral surface of the movable core, a minimum gap in the press-fit region is larger than a minimum gap in the non-press-fit region.

[0011] In this example, a flow resistance experienced by the movable core from the fuel present in the gap between the outer peripheral surface of the outer core and the inner peripheral surface of the retainer is greatly affected by the smallest gap when the size of the gap changes according to the axial position. The gap in the press-fit region between the inner peripheral surface of the retainer and the outer peripheral surface of the movable core changes more between the products than the gap in the non-press-fit region. Therefore, contrary to the first aspect mentioned above, if the minimum gap in the press-fit region is smaller than the minimum gap in the non-press-fit region, the flow resistance is greatly affected by the gap in the press-fit region. As a result, a large variation or fluctuation in the flow resistance occurs between the products.

[0012] In contrast, according to the first aspect, since the minimum gap in the press-fit region is larger than the minimum gap in the non-press-fit region, the influence of the gap in the press-fit region on the flow resistance can be reduced and the variation in the movement speed of the movable core can be reduced. This can reduce the fluctuations in the valve opening behavior between products and thus also the fluctuations in the injection quantity.

[0013] According to a second aspect of the present disclosure, a fuel injection valve includes: a valve body that opens and closes a nozzle opening for injecting fuel; a fixed core that generates a magnetic attraction force when a coil is energized; a movable core that has a cylindrical shape and opens the nozzle opening by moving together with the valve body due to the magnetic attraction force; a holder that has a movable chamber filled with the fuel and accommodates the movable core in a movable state in the movable chamber; and a stopper member that contacts the movable core to limit the movement of the movable core in a direction away from the nozzle opening. The movable core includes an inner core that contacts the stopper member and an outer core that is press-fitted to an outer peripheral surface of the inner core.The outer core includes, in a moving direction of the movable core, a press-fit region in which the outer core is press-fitted to the outer peripheral surface of the inner core, and a non-press-fit region located adjacent to the press-fit region in the moving direction. A portion of the press-fit region that has been expanded in the radial direction by the press-fitting is removed such that a maximum outer diameter of the outer core in the press-fit region is equal to a maximum outer diameter of the outer core in the non-press-fit region.

[0014] According to the second aspect, the minimum gap in the press-fit region and the minimum gap in the non-press-fit region are equal, so that the influence of the gap in the press-fit region on the flow resistance can be reduced and the variation in the moving speed of the movable core can be reduced. This can reduce the fluctuations in the valve opening behavior between products and thus also the fluctuations in the injection quantity. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of a fuel injection valve according to a first embodiment. Fig. 2 is an enlarged view of a nozzle opening portion of Fig. 1. Fig. 3 is an enlarged view of a movable core portion of Fig. 1. Fig. Fig. 4 is a schematic diagram of the operation of the fuel injection valve according to the first embodiment, wherein (a) in Fig. 4 a closed state of the valve, (b) in Fig. 4 a state in which a movable core moving by a magnetic attraction force collides with a valve body, and (c) in Fig. 4 a state in which the movable core, which continues to move due to the magnetic attraction force, collides with a guide member. Fig. Fig. 5 is a timing chart showing the operation of the fuel injection valve according to the first embodiment, wherein (a) in Fig. 5 a change in a drive impulse, (b) in Fig. 5 a change in a drive current, (c) in Fig. 5 a change in a magnetic attraction force and (d) in Fig. 5 shows the behavior of a moving section. Fig. 6 is a flowchart showing an assembling process of the movable portion according to the first embodiment. Fig. 7 is an exploded view of a movable portion according to the first embodiment. Fig. Fig. 8 is a sectional view of the movable section showing the state of pressing a cup against a needle during the assembling process of Fig. 6 shows. Fig. Fig. 9 is a sectional view of the movable portion showing a state in which a first press fit of the Fig. 6 is completed. Fig. 10 is a perspective view of Fig. 9. Fig. 11 is a stress-strain diagram of the needle and a sleeve according to the first embodiment. Fig. 12 is a sectional view showing the shape of a communication groove provided in the movable core according to the first embodiment. Fig. 13 is a plan view of the Fig. 12, viewed from a side opposite a nozzle opening. Fig. 14 is a sectional view along a line XIV-XIV of Fig. 13. Fig. 15 is a sectional view showing the modification B1 with respect to Fig. 12 shows. Fig. 16 is a plan view of the Fig. 15, seen from the side opposite the nozzle opening. Fig. 17 is a sectional view of the modification B2 with respect to Fig. 12. Fig. 18 is a plan view of the Fig. 17, seen from the side opposite the nozzle opening. Fig. 19 is a sectional view showing the modification B3 with respect to Fig. 12 shows. Fig. 20 is a plan view of the Fig. 19, seen from the side opposite the nozzle opening. Fig. 21 is a sectional view showing the modification B4 with respect to Fig. 12 shows. Fig. 22 is a sectional view showing the modification B5 with respect to Fig. 12 shows. Fig. 23 is a sectional view showing the modification B6 with respect to Fig. 12 shows. Fig. 24 is a sectional view showing the shape of a supply flow channel provided in a needle according to the first embodiment. Fig. 25 is a plan view of the Fig. 24, seen from the side opposite the nozzle opening. Fig. 26 is a sectional view along a line XXVI-XXVI of Fig. 25. Fig. Figure 27 is a sectional view showing modification C1 compared to Fig. 26 shows. Fig. 28 is a sectional view showing the modification C2 with respect to Fig. 26 shows. Fig. 29 is a sectional view showing the modification C3 with respect to Fig. 26 shows. Fig. Figure 30 is a plan view of the needle from the side opposite the nozzle opening, showing modification C4 with respect to Fig. 25 shows. Fig. Figure 31 is a plan view of the needle from the side opposite the nozzle opening, showing modification C5 with respect to Fig. 25 shows. Fig. 32 is a sectional view through the Fig. 31, and (a) is a section along a line XXXIIa-XXXIIa and (b) is a section along a line XXXIIb-XXXIIb. Fig. 33 is a sectional view of modification C6 with respect to Fig. 24. Fig. 34 is a sectional view showing the modification C7 with respect to Fig. 24 shows. Fig. 35 is a plan view of a Fig. 34, seen from the side of the nozzle opening. Fig. 36 is a cross-sectional view showing the shape of a depressed surface provided in a guide member at the time of complete lift-off according to the first embodiment. Fig. 37 is a sectional view showing the shape of the depressed surface provided in the guide member at the time of closing the valve according to the first embodiment. Fig. 38 is a sectional view showing a gap between a movable core and a holder at the time of closing the valve according to the first embodiment. Fig. 39 is a plan view of the Fig. 38, seen from the side opposite the nozzle opening. Fig. 40 is a sectional view showing the modification E1 with respect to Fig. 38 shows. Fig. 41 is a sectional view showing the modification E2 with respect to Fig. 38 shows. Fig. 42 is a sectional view showing the modification E3 with respect to Fig. 38 shows. Fig. 43 is a sectional view of a fuel injection valve according to a second embodiment. Fig. 44 is a sectional view of a fuel injection valve according to a third embodiment. DETAILED DESCRIPTION

[0015] Hereinafter, several embodiments for implementing the present disclosure will be described with reference to drawings / figures. In the respective embodiments, a part corresponding to a subject matter described in a previous embodiment may be assigned the same reference numeral, and redundant description for the part may be omitted. When only a part of a configuration is described in one embodiment, another previous embodiment may be applied to the other parts of the configuration. The parts may be combined even if it is not explicitly described that the parts can be combined. The embodiments may be partially combined even if it is not explicitly described that the embodiments can be combined, provided that the combination is harmless. (First embodiment)

[0016] One in Fig. The fuel injection valve 1 shown in FIG. 1 is attached to a cylinder head or a cylinder block of an internal combustion engine mounted on a vehicle. Gasoline fuel accumulated in a vehicle-mounted fuel tank is pressurized by a fuel pump (not shown) and supplied to a fuel injection valve 1, and the supplied high-pressure fuel is injected directly into a combustion chamber of the internal combustion engine from the nozzle openings 11a provided in the fuel injection valve 1.

[0017] The fuel injection valve 1 includes a nozzle orifice body 11, a main body 12, a fixed core 13, a non-magnetic element 14, a coil 17, a support element 18, a first spring element SP1, a second spring element SP2, a needle 20, a movable core 30, a sleeve 40, a cup 50, a guide element 60, and the like. The nozzle orifice body 11, the main body 12, the fixed core 13, the support element 18, the needle 20, the movable core 30, the sleeve 40, the cup 50, and the guide element 60 are made of metal.

[0018] As in Fig. 2, the nozzle orifice body 11 has multiple nozzle holes 11a for injecting fuel. The needle 20 is located inside the nozzle orifice body 11, and a flow passage 11b for flowing high-pressure fuel to the nozzle orifices 11a is provided between an outer peripheral surface of the needle 20 and an inner peripheral surface of the nozzle orifice body 11. A housing-side seat 11s, on which a valve-body-side seat 20s formed on the needle 20s is separated, is seated on the inner peripheral surface of the nozzle orifice body 11. The valve-body-side seat 20s and the housing-side seat 11s are formed to extend annularly around an axis line C of the needle 20. When the needle 20 is separated and seated on the body-side seat 11s, the flow channel 11b is opened and closed and the nozzle openings 11a are opened and closed.

[0019] The main body 12 and the non-magnetic member 14 are cylindrically shaped. A cylindrical end portion of the main body 12, which is located closer to the nozzle openings 11a with respect to the main body 12 (on a nozzle opening side), is fixed to the nozzle opening body 11 by welding. A cylindrical end portion of the main body 12 on a side remote from the nozzle openings 11a with respect to the main body 12 (on a side opposite the nozzle openings) is fixed to a cylindrical end portion of the non-magnetic member 14 by welding. A cylindrical end portion of the non-magnetic member 14 on the side opposite the nozzle opening is fixed to the fixed core 13 by welding.

[0020] A nut member 15 is fastened to a threaded portion 13N of the fixed core 13 in a state where it is locked with a locking portion 12c of the main body 12. An axial force generated by the fastening generates a surface pressure that presses the nut member 15, the main body 12, the non-magnetic member 14, and the fixed core 13 in the direction of the axis line C (in the vertical direction in Fig. 1) against each other. Instead of creating such surface pressure with fastening screws, the surface pressure can also be created by pressing or interference fitting.

[0021] The main body 12 is made of a magnetic material such as stainless steel and has a flow channel 12b for allowing the fuel to flow into the nozzle openings 11a inside. The needle 20 is housed in the flow channel 12b so as to be movable in the direction of the axis line C. The main body 12 and the non-magnetic element 14 correspond to a "holder" with a movable chamber 12a filled with the fuel. A movable section M (see Fig. 9 and Fig. 10), which is an assembly in which the needle 20, the movable core 30, the second spring element SP2, the sleeve 40 and the cup 50 are assembled, is movably housed in the movable chamber 12a. Fig. 9 indicates the size of a gap between a valve closing contact surface 21b and a valve closing force transmission contact surface 52c in the direction of the axis line C. The size of the gap L1a corresponds to the size of a gap L1 formed in a column (a) of Fig. 4 is shown.

[0022] The flow channel 12b is shaped to communicate with a downstream side of the movable chamber 12a and extend in the direction of the axis line C. A center line of the flow channel 12b and the movable chamber 12a coincides with a cylindrical center line (axis line C) of the main body 12. A nozzle opening side portion of the needle 20 is slidably supported by an inner wall surface 11c of the nozzle opening body 11, and a portion of the needle 20 on a side opposite the nozzle openings is slidably supported by an inner wall surface 51b of the cup 50 (see Fig. 8 and Fig. 12). Two positions of an upstream end portion and a downstream end portion of the needle 20 are slidably supported in this manner, thereby limiting the movement of the needle 20 in the radial direction and limiting the inclination of the needle 20 relative to the axis line C of the main body 12.

[0023] The needle 20 corresponds to a "valve body" that opens and closes the nozzle holes 11a and is made of a magnetic material such as stainless steel and has a shape extending in the direction of the axis line C. The above-described valve body-side seat 20s is formed on a downstream end face of the needle 20. When the needle 20 moves to the downstream side in the direction of the axis line C (valve closing operation), the valve body-side seat 20s sits on the body-side seat 11s to close the flow channel 11b and the nozzle holes 11a. When the needle 20 moves to the upstream side in the direction of the axis line C (valve opening operation), the valve body-side seat 20s is separated from the body-side seat 11s to open the flow channel 11b and the nozzle holes 11a.

[0024] The needle 20 has an inner passage 20a and side openings 20b to allow the fuel to flow through the nozzle openings 11a (see Fig. 3). The multiple side openings 20b are provided in the circumferential direction. The multiple side openings 20b are provided at regular intervals in the circumferential direction. The internal passage 20a has a shape extending in the direction of the axis line C of the needle 20. An inflow port is provided at an upstream end of the internal passage 20a, and the side openings or

[0025] Holes 20b are connected to a downstream end of the internal passage 20a. The side openings 20b extend in a direction crossing the direction of the axis line C and communicate with the movable chamber 12a.

[0026] As in Fig. As shown in Fig. 7, the needle 20 has a contact portion 21, a core sliding portion 22, a press-fitting portion 23, an outflow portion 24, a first large-diameter portion 25, a first small-diameter portion 26, a second large-diameter portion 27, a second small-diameter portion 28, and a nozzle-hole-side bearing portion 29 in a specified order from the opposite side (upper end side) to the lower end side of the valve-body-side seat 20s. The contact portion 21 has the valve-closing contact surface 21b contacting the contact surface 52c of the cup 50 for transmitting the valve-closing force.

[0027] The cup 50 is slidably assembled with the contact portion 21, and an outer peripheral surface of the contact portion 21 slides with an inner peripheral surface of the cup 50. The movable core 30 is slidably connected to the core sliding portion 22, and an outer peripheral surface of the core sliding portion 22 slides with an inner peripheral surface of the movable core 30. A sleeve 40 is press-fitted into the press-fitting portion 23. The side openings 20b are provided in the discharge portion 24.

[0028] An outer diameter D1 of the contact portion 21 is larger than an outer diameter D2 of the core sliding portion 22, the outer diameter D2 of the core sliding portion 22 is larger than an outer diameter D3 of the press-fitting portion 23, and the outer diameter D3 of the press-fitting portion 23 is larger than an outer diameter of the discharge portion 24. A connecting part 22a between the core sliding portion 22 and the press-fitting portion 23 and a connecting portion 23a between the press-fitting portion 23 and the discharge portion 24 are each formed in a slant manner. The diameter of an inner peripheral surface 41a of the sleeve 40 in a state before press-fitting is set to be smaller than the outer diameter D3 of the press-fitting portion 23, and press-fitting can be performed.

[0029] 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 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 serve as bearing portions, respectively, when the needle 20 is cut. The second small-diameter portion 28 functions as an outlet portion, so that a cutting tool does not interfere with the cutting of the nozzle-hole-side bearing portion 29. The nozzle-hole-side bearing portion 29 is slidably supported by the inner wall surface 11c of the nozzle-hole body 11.

[0030] The cup 50 includes a circular cup portion 52 having a circular plate shape and a cylindrical portion 51 having a cylindrical shape. The circular plate portion 52 has a through-hole 52a extending in the direction of the axis line C. A surface of the circular plate portion 52 on a side opposite the nozzle openings functions as a spring contact surface 52b that contacts the first spring element SP1. A surface of the circular plate portion 52 on the nozzle opening side functions as a valve closing force transmission contact surface 52c that contacts the needle 20 and transmits a first elastic force (a valve closing elastic force or a valve closing elastic force). The circular plate portion 52 corresponds to a "valve body transmission portion" that contacts the first spring element 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 an outer peripheral end of the circular plate portion 52 toward the nozzle opening side. A nozzle opening-side end surface of the cylindrical portion 51 functions as a core contact end surface 51a that contacts the movable core 30. The inner wall surface 51b of the cylindrical portion 51 slides with the outer peripheral surface of the contact portion 21 of the needle 20.

[0031] The fixed core 13 is made of a magnetic material such as stainless steel and has a flow channel 13a to allow the fuel to flow through the nozzle openings 11a. The flow channel 13a communicates with the inner passage 20a formed within the needle 20 (see Fig. 3) and an upstream side of the movable chamber 12a, and extends in the direction of the axis line C. The flow channel 13a accommodates the guide member 60, the first spring member SP1 and the support member 18.

[0032] The support member 18 has a cylindrical shape and is press-fitted into an 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 direction of the axis line C. An upstream end face of the first spring member SP1 is supported by the support member 18, and a downstream end face of the first spring member SP1 is supported by the cup 50. A force generated by the elastic deformation of the first spring member SP1 (a first elastic force) pushes the cup 50 toward the downstream side. The degree of press-fitting of the support member 18 in the direction of the axis line C is adjusted to thereby adjust a magnitude of the elastic force for loading the cup 50 (a first set load).

[0033] As in Fig. 3, the guide member 60 has a cylindrical shape made of a magnetic material such as stainless steel and is press-fitted into an enlarged diameter portion 13c formed in the fixed core 13. The enlarged diameter portion 13c has a shape in which the flow channel 13a is enlarged in the radial direction. The guide member 60 includes a circular plate portion 62 having a circular plate shape and a cylindrical portion 61 having a cylindrical shape. The circular plate portion 62 has a through-hole 62a extending in the direction of the axis line C. A surface of the circular plate portion 62 on the opposite side to the nozzle openings contacts an 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 circular plate portion 62 to the nozzle opening side.A nozzle opening-side end surface of the cylindrical portion 61 functions as a stopper contact end surface 61a that contacts the movable core 30. An inner wall surface of the cylindrical portion 51 forms a sliding surface 61b that slides with an outer peripheral surface 51d of the cylindrical part 51 of the cup 50 (see FIG. Fig. 12).

[0034] In short, the guide member 60 has a guiding function of sliding the outer peripheral surface of the cup 50 in the direction of the axis line C, and a stopping function of contacting the movable core 30 moving in the direction of the axis line C and preventing the movable core 30 from moving to the side opposite the nozzle openings 11a. In other words, the guide member 60 corresponds to a "stopper member" that contacts the movable core 30 and prevents the movable core 30 from moving away from the nozzle openings 11a.

[0035] A resin member 16 is provided on an outer peripheral surface of the fixed core 13. The resin member 16 has a connector housing 16a, and a terminal 16b is housed in the connector housing 16a. The terminal 16b is electrically connected to the coil 17. An external connector (not shown) is connected to the connector housing 16a, and the coil 17 is supplied with electrical power via the terminal 16b. The coil 17 is wound around a bobbin 17a having an electrically insulating property to form a cylindrical shape and is arranged on a radially outer side of the fixed core 13, the non-magnetic 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 to conduct a magnetic flux generated with a power supply (excitation) to the coil 17 (see dashed arrow in Fig. 3).

[0036] As in Fig. As shown in Fig. 3, the movable core 30 is arranged on the nozzle opening side with respect to the fixed core 13 and is housed in the movable chamber 12a in a state movable in the direction of the axis line C. The movable core 30 includes an outer core 31 and an inner core 32. The outer core 31 has a cylindrical shape made of a magnetic material such as stainless steel, and the inner core 32 has a cylindrical shape made of a non-magnetic material such as stainless steel that has a magnetic property. The outer core 31 is press-fitted into an outer peripheral surface of the inner core 32.

[0037] The needle 20 is inserted into a cylindrical inner portion of the inner core 32. The inner core 32 is mounted on the needle 20 so as to be slidable relative to the needle 20 along the axis line C. A gap (inner gap) between an inner peripheral surface of the inner core 32 and an outer peripheral surface of the needle 20 is set to be smaller than a gap (outer gap) between an outer peripheral surface of the outer core 31 and an 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 the inner core 32 contacts the needle 20.

[0038] The inner core 32 contacts the guide member 60 as a stopper member, the cup 50, and the needle 20. For this reason, a material having a higher hardness than that of the outer core 31 is used for the inner core 32. The outer core 31 has a movable core surface 31c facing the fixed core 13, and a gap is provided between the movable core surface 31c and the fixed core 13. Therefore, in a state where a magnetic flux flows by energizing the coil 17 as described above, a magnetic attraction force attracted by the fixed core 13 acts on the outer core 31 by providing the gap.

[0039] The sleeve 40 corresponds to a “solid element” that is pressed or press-fitted into the needle 20. The sleeve 40 consists of a cylindrical metal with a through-bore or through-opening 40a (see Fig. 7) and includes a cylindrical insertion portion 41, a connecting portion 42, and a bearing portion 43. The cylindrical insertion portion 41 has a cylindrical shape and is press-fitted into the press-fitting portion 23 of the needle 20. The connecting portion 42 has a cylindrical shape in which the cylindrical insertion portion 41 is enlarged in the radial direction and connects the cylindrical insertion portion 41 and the bearing portion 43. The connecting portion 42 guides the second spring element SP2 to reduce a positional deviation of the second spring element SP2 in the radial direction. The bearing portion 43 has an annular flange shape extending from the nozzle opening-side end portion of the connecting portion 42 to the radially outer side.In other words, the bearing portion 43 has a plate shape extending from the nozzle opening side end portion of the connecting portion 42 to the radially outer side, and a ring shape extending around the axis line C. A surface of the bearing portion 43 on the side opposite to the nozzle opening functions as a support surface 43a for supporting the nozzle opening side end surface of the second spring member SP2.

[0040] The second spring element SP2 is a coil spring arranged on the side opposite the nozzle openings with respect to the support portion 43 and elastically deformed in the direction of the axis line C. An end surface of the second spring element SP2 on the side opposite the nozzle opening is supported by the movable core 30, specifically, by the outer core 31. A nozzle opening-side end face of the second spring element SP2 is supported by the support portion 43. The force generated by the elastic deformation of the second spring element SP2 (the second elastic force) pushes the outer core 31 toward the side opposite the nozzle openings. By adjusting the degree of interference of the cylindrical insertion portion 41 in the direction of the axis line C, a magnitude of the second elastic force for pushing the movable core 30 (a second adjustment load) at the time of valve closing is adjusted.The second adjustment load applied to the second spring element SP2 is smaller than the first adjustment load applied to the first spring element SP1. Furthermore, not only when the valve is closed, but also when the movable core 30 is urged in other situations, the magnitude of the second elastic force can be set as the second adjustment load, which is adjusted by the degree of interference fit. <Beschreibung des Vorgangs bzw. des Betriebs>

[0041] Next, the operation of the fuel injection valve 1 is explained using the Fig. 4 and Fig. 5 described.

[0042] As shown in column (a) of Fig. 4, in a state where the coil 17 is de-energized, no magnetic attraction force is generated, so that the magnetic attraction force driven toward the valve opening side does not act on the movable core 30. The cup 50, which is pressed toward the valve closing side by the first elastic force generated by the first spring element SP1, contacts the valve closing contact surface 21b of the needle 20 (see Fig. 3) and the inner cores 32 to transmit the first elastic force.

[0043] The movable core 30 is urged toward the valve closing side by the first elastic force of the first spring element SP1 transmitted from the cup 50, and the movable core 30 is urged toward the valve opening side by the second elastic force of the second spring element SP2. Since the first elastic force is greater than the second elastic force, the movable core 30 is pushed by the cup 50 and moved toward the nozzle openings (lifted downward). The needle 20 is urged toward the valve closing side by the first elastic force transmitted from the cup 50 and pushed toward the nozzle opening side (lifted downward), that is, seated on the body-side seat 11s to close the valve. In the closed state of the valve, a gap is formed between the valve opening contact surface 21a (see Fig. 3) the needle 20 and the movable core 30 (the inner core 32), and a length of the gap in the direction of the axis line C in the closed state of the valve is referred to as gap L1.

[0044] As shown in column (b) of Fig. As shown in Fig. 4, in a state immediately after the energization of the coil 17 is switched from OFF to ON, the magnetic attraction force pressed toward the valve-opening side 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 the cup 50 is pushed upward, and the amount of movement reaches the gap L1, the inner core 32 collides with the valve-opening contact surface 21a of the needle 20. At the time of collision, a gap is provided between the guide member 60 and the inner core 32, and the length of the gap in the direction of the axis line C is referred to as stroke L2.

[0045] Since the elastic force of the first spring element SP1 acts on the needle 20 only at the time of collision, the collision speed of the movable core 30 can be increased accordingly. 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 20 can be operated to open the valve even with a high-pressure fuel, preventing an increase in the magnetic attraction force required to open the valve. The elastic force of the first spring element SP1 acts on the needle 20 toward the valve-closing side in the state shown in column (a), but does not act on the needle 20 in the state shown in column (b). For this reason, inhibition of the increase in the magnetic attraction force required to open the valve can be further promoted.

[0046] After the collision, the movable core 30 continues to move by the magnetic attraction force, and when the movement amount after the collision reaches the elevator L2, the inner core 32 collides with the guide member 60 and stops the movement, as shown in column (c) of Fig. 4. A separation distance between the housing-side seat 11s and the valve body-side seat 20s in the direction of the axis line C at the time of stopping the movement corresponds to a full stroke of the needle 20 and corresponds to the stroke L2 described above.

[0047] If the process described above with reference to Fig. 5 in detail, initially starts when the excitation is switched on at a time t1, as shown in column (a) of Fig. 5, a drive current flowing through the coil 17 begins to increase (see column (b)), and the magnetic attraction force begins to increase with the increase of the drive current (see column (c)). If a value obtained by subtracting the second elastic force from the first elastic force (valve closing elastic force) is defined as the actual valve closing elasticity F0, the movable core 30 begins to move toward the valve opening side at a time t2 when the magnetic attraction force increases to the actual valve closing elasticity F0. Before the drive current reaches a peak value, the movable core 30 begins to move. A boost voltage obtained by boosting a 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 drive current reaches the peak value.

[0048] Thereafter, at a time t3, when the movement amount of the movable core 30 reaches the gap L1, the movable core 30 collides with the needle 20, and the needle 20 begins the valve opening operation (see column (d)). As a result, the fuel is injected from the nozzle openings 11a. After that, the movable core 30 lifts the needle 20 against the elastic closing force of the valve, and at a time t4, when the movable core 30 collides with the guide member 60, the stroke of the needle 20 reaches the full stroke (stroke L2). A zero point plotted on a vertical axis of column (d) indicates a collision position between the movable core 30 and the needle 20 at time t3.

[0049] After that, the needle 20 is maintained in a full lift state by the magnetic attraction force, and fuel injection continues. After that, when the excitation is turned off at time t5, the magnetic attraction force also decreases with a decrease in the drive current. At time t6, when the magnetic attraction force reaches the actual valve-closing elastic force or the valve-closing elastic force F0, the movable core 30 begins to move toward the valve-closing side together with the cup 50. The needle 20 is pushed by a pressure of the fuel filled between the needle 20 and the cup 50 to start the push-down action (the valve-closing action) simultaneously with the start of the movement of the movable core 30.

[0050] Then, at a time t7, when the needle 20 is lifted downward by the stroke L2, the valve body-side seat 20s is seated on the housing-side seat 11s to close the flow passage 11b and the nozzle holes 11a. After that, the movable core 30 continues to move toward the valve closing side together with the cup 50, and the movement of the cup 50 toward the valve closing side is stopped at a time t8 when the cup 50 contacts the needle 20. After that, the movable core 30 continues to move toward the valve closing side by an inertial force (inertial movement), and then the movable core 30 moves toward the valve opening side (rebound) 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) to the valve opening side together with the cup 50, but is quickly pushed back by the elastic closing force of the valve and converges to an initial state shown in the column (a) of . Fig. 4 is shown.

[0051] Therefore, the smaller such 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. For this reason, in multi-stage injection in which fuel is injected multiple times per combustion cycle of the internal combustion engine, an interval between injections can be shortened and the number of injections included in the multi-stage injection can be increased. Furthermore, with the shortening of the convergence time described above, the injection amount can be controlled with high precision when performing a partial lift injection or partial lift injection to be described below. In partial lift injection, due to a short valve opening time, a small amount is injected by stopping the excitation of the coil 17 and starting the valve closing operation before the needle 20, which performs the valve opening operation, reaches the full lift position. <Beschreibung des Herstellungsverfahrens>

[0052] Next, a method for manufacturing the fuel injection valve 1 will be described.

[0053] This manufacturing process includes the initial setting load adjustment process, the movable section assembly process, the welding process, the fixing process, and the resin molding process described below.

[0054] In a manufacturing process for the movable portion, the movable core 30, the second spring element SP2, the sleeve 40, and the cup 50 are assembled with the needle 20 to manufacture the movable part M. As will be described in detail later, the movable part M is manufactured so that the elastic force of the second spring element SP2 enforced by the movable core 30 becomes a target value of the second set load.

[0055] In the next welding process, the nozzle orifice body 11 is first welded and connected to the main body 12. Next, the movable portion M is arranged in the movable chamber 12a of the main body 12, and thereafter, the fixed core 13, on which the support member 18 and the first spring member SP1 are mounted, the main body 12 on which the movable portion M is arranged, and the non-magnetic member 14 are welded and coupled together.

[0056] In the next fastening process, the coil 17a or the coil support 17a is arranged between the nut member 15 and the fixed core 13 in a state in which the coil 17 is wound. Thereafter, the nut member 15 is fastened to the fixed core 13, so that the main body 12, the non-magnetic member 14, and the fixed core 13 are joined together by generating surface pressure.

[0057] In the resin molding process to be performed next, the resin member 16 with the connector housing 16a is molded into resin by pouring and solidifying molten resin onto the outer peripheral surface of the fixed core 13.

[0058] In the subsequent first adjustment load adjustment process, the first spring element SP1 is first mounted to the flow channel 13a of the fixed core 13. Then, the support member 18 is press-fitted into the flow channel 13a of the fixed core 13 to a predetermined position. The predetermined press-fit position can be determined in accordance with the variations in the elastic modulus of the first spring element SP1 and the length in the direction of the axis line C, as well as the variations in the dimensions of the respective portions of the fixed core 13. In any case, the predetermined position (press-fitting position or press-fitting position) is set so that the first elastic force imposed by the needle 20 becomes a target value of the first adjustment load. The fuel injection valve 1 is manufactured according to the manufacturing method including the above-mentioned processes. <Detaillierte Beschreibung der Konfigurationsgruppe A>

[0059] Next, among the configurations of the fuel injection valve 1 according to the present embodiment, a configuration group A including at least the press-fitting portion 23 formed on the needle 20 and the configuration associated with the press-fitting portion 23 will be described in detail.

[0060] The assembly of the movable section described above includes the Fig. 6 detailed steps S10 to S15. First, in step S10, as shown in Fig. 7, the movable core 30, the second spring element SP2 and the sleeve 40 are inserted into the needle 20s from the side (the lower end side) of the valve body side seat 20s. In this step S10, as shown in Fig. 8, the insertion of the sleeve 40 is stopped at a position of the outflow section 24 before the press-fitting section 23.

[0061] In the subsequent step S11, the needle 20 is pressed against the cup 50 in a state in which the cup 50 is assembled with the contact portion 21 of the needle 20 and the contact surface 52c for transmitting the valve closing force contacts the valve closing contact surface 21b (see Fig. 8). As a result, the core contact end surface 51a is positioned closer to the nozzle opening than the valve opening contact surface 21a by the amount corresponding to the gap L1.

[0062] In the subsequent step S12, the sleeve 40 is temporarily press-fitted into the press-fitting portion 23 with a predetermined degree of press-fitting. For example, while supporting the cup 50 in the direction of the axis line C using a support jig J1, the press-fitting load F2 is applied to the load application surface 43b of the sleeve 40 in the direction of the axis line C using the load application jig J2. During a temporary press-fitting, the movable core 30 contacts the cup 50, the second spring element SP2 contacts the sleeve 40 and the movable core 30, and the second spring element SP2 is in an elastically deformed state. Therefore, the support jig J1 has a reaction force F1 against the second elastic force by the second spring element SP2 to support the cup 50.

[0063] The temporary press-fitting is a first press-fitting, and then, in step S15 (described later), a second press-fitting (main press-fitting) is performed. The degree of press-fitting in the temporary press-fitting is a predetermined amount, regardless of a variation in machine difference, and the temporary press-fitting is performed, for example, at a location separated from the nozzle-opening-side end portion of the press-fitting portion 23 toward the side opposite the nozzle openings by a predetermined length in the direction of the axis line C.

[0064] In the subsequent step S13, the second elastic force by the second spring element SP2, that is, the second set load, is measured. For example, a force (reaction force F1) by which the support device J1 is pressed by the second elastic force is measured by means of a measuring device (not shown). In this step S13, the 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 an arrow indicating the vertical direction in Fig. 8 displays.

[0065] In the subsequent step S14, a deficiency of the measured second set load compared to a second target set load is calculated, and an additional degree of interference fit is calculated according to the deficiency. For example, a Young's modulus of the second spring element SP2 may be measured in advance, and the additional degree of interference fit may be calculated based on the measured load deficiency amount and the Young's modulus. Alternatively, the Young's modulus of the second spring element SP2 may be considered a standard value, and the additional degree of interference fit may be calculated based on the measured load deficiency amount and the standard value.

[0066] In the subsequent step S15, the sleeve 40 is further press-fitted into the press-fitting portion 23 with the additional press-fitting degree calculated in step S14 (main press-fitting). As described above, the assembly of the movable portion M is completed. In short, the second set load is measured during press-fitting, and a main press-fitting is performed according to the measured value. Each step described above is an example of the configuration group A described above.

[0067] As described above, 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 element SP1, the sleeve 40 (fixed element), and the second spring element SP2. The movable core 30 contacts the needle 20 at a time when the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount to the side opposite the nozzle openings, and opens the needle 20. The first spring element SP1 is elastically deformed during the opening operation of the needle 20 and has the first elastic force to close the needle 20. The sleeve 40 is fixed to the needle 20. The second spring element SP2 is clamped between the sleeve 40 and the movable core 30 and elastically deformed and exerts the second elastic force to urge the movable core 30 to the side opposite the nozzle opening.The needle 20 has the press-fitting portion 23 into which the sleeve 40 is press-fitted on the side opposite the nozzle openings, and the sleeve 40 is fixed to the needle 20 by press-fitting into the press-fitting portion 23.

[0068] In short, the fuel injection valve 1 according to the present embodiment has the core boost structure in which the fuel injection valve 1 contacts the needle 20 at the time when the movable core 30 is moved a predetermined distance to the side opposite the nozzle openings to open the fuel injection valve 1, and includes the sleeve 40 that supports the second spring member SP2, which urges the movable core 30 to the side opposite the nozzle openings. The sleeve 40 is fixed to the needle 20 by press-fitting the sleeve 40, and the press-fitting direction of the sleeve 40 is the press-fitting direction of the second spring member SP2. This makes it possible to adjust and fix the press-fitting degree and simultaneously measure the second elastic force that increases with the progress of the press-fitting.Therefore, the second elastic force at the time of completion of the press fit can be adjusted to the target setting load of the second spring element SP2 with high accuracy.

[0069] The adjusted load is a second elastic force exerted by the elastic deformation of the second spring element in a state where the second spring element is assembled with the fuel injection valve. Since the magnitude of the adjusted load affects the valve opening and closing timing of the valve body, adjusting the adjusted load to the target value with high accuracy contributes to reducing the variation in the fuel injection amount. Unlike the current embodiment in which the fixed element is press-fitted into the valve body, in a structure in which the fixed element is welded and fixed to the valve body, the welded portion cannot be adjusted during the measurement of the second elastic force. For this reason, the adjusted load varies due to variations between individuals, such asVariations in the machine difference of the second spring element and variations in the valve body length, as well as due to the thermal stress caused by welding.

[0070] On the other hand, in the present embodiment, since the fixed element is press-fitted into the valve body, the set load can be adjusted to the target value with high accuracy as described above. This makes it possible to reduce the variation in the fuel injection amount while adopting the core boost structure.

[0071] Furthermore, in the fuel injection valve 1 according to the present embodiment, at least a portion of the sleeve 40 that contacts the press-fitting portion 23 has a different hardness than the press-fitting portion 23. For example, metal base materials with different hardnesses may be used for the sleeve 40 and the needle 20, or a surface treatment such as heat treatment may be performed on the metal base material of the sleeve 40 to make a portion of the sleeve 40 that contacts the press-fitting portion 23 locally harder than the sleeve 40.

[0072] Unlike the present embodiment in which the sleeve 40 and the press-fitting portion 23 have the same hardness, there is a concern that the sleeve 40 and the press-fitting portion 23 will stick to each other if the press-fitting process is temporarily stopped while adjusting the press-fitting degree during measurement. When sticking occurs, the load required to repeat the press-fitting increases, and the workability of the press-fitting deteriorates. Therefore, according to the present embodiment with the different hardness, the above-mentioned sticking problem can be reduced and the workability of the press-fitting or press-fitting can be improved. The needle 20 is preferably harder than the sleeve 40. The sleeve 40 preferably has a higher hardness than that of the movable core 30. A specific example of the material of the needle 20 is martensitic stainless steel.A specific example of the material of the sleeve 40 is ferritic stainless steel.

[0073] Furthermore, in the fuel injection valve 1 according to the present embodiment, at least a portion of the sleeve 40 in contact with the press-fitting portion 23 has a lower hardness than the press-fitting portion 23.

[0074] During press fitting, at least one of the two members to be press-fitted must be plastically deformed. Since the hardness is lower, the member is easier to plastically deform, and the press-fitting load required for press-fitting or press-fitting can be reduced. Since the needle 20 requires (high) hardness to withstand collision with the body-side seat 11s (valve seat), there is a concern that the press-fitting force required for press-fitting or the press-fitting load will be increased if the sleeve 40 is provided with a harder hardness than the needle 20 to create a hardness difference. Therefore, according to the present embodiment, in which the sleeve 40 has a lower hardness than the press-fitting portion 23, the above-mentioned concern for improving press-fitting processability can be inhibited.Since the sleeve 40 according to the present embodiment is not in contact with the movable core 30, a material softer than that of the inner core 32 or the like requiring contact may be used.

[0075] For example, the solid lines A1 and A2 in Fig. Figure 11 shows the stress-σ strain-L diagrams of the needle 20 and the sleeve 40 obtained by a tensile test. As can be seen from the test result, a stress at a yield point (yield stress σ1), at which the sleeve 40 begins plastic deformation, is lower than that of the needle 20. In the case of the needle 20, a test specimen fractured once the yield stress was reached. The test result shows that the yield stress σ1 can be reduced by making the sleeve 40 harder and reducing the interference fit load required for press-fitting.

[0076] Furthermore, in the fuel injection valve 1 according to the present embodiment, even when the movable core 30 is moved toward the nozzle openings with respect to the needle 20 to the maximum relative movement, the sleeve 40 and the movable core 30 are separated from each other without contacting each other. For example, after the valve is closed, the movable core 30 continues to move toward the nozzle opening side, and the recoil occurs as described above. A state in which the further movement of the movable core 30 occurs after the valve is closed and an interval between the lines of the second spring element SP2 becomes zero, so that the elastic deformation amount of the second spring element SP2 becomes maximum, is illustrated as a specific example of a case where the relative movement is maximized.

[0077] Unlike the present embodiment, in a structure where the sleeve 40 and the movable core 30 are in contact with each other, a large interference fit clearance must be set and the plastic deformation caused by the interference fit must be increased because of the need to reinforce the interference fit of the sleeve 40. Therefore, according to the present embodiment of the structure where the sleeve 40 and the movable core 30 do not contact with each other, the need to reinforce the interference fit can be reduced, so that the interference load required for the interference fit can be reduced and the workability of the interference fit can be improved.

[0078] Furthermore, in the fuel injection valve 1 according to the present embodiment, the sleeve 40 has the cylindrical insertion portion 41 having a cylindrical shape inserted into the press-fitting portion 23, and the inner peripheral surface 41a of the cylindrical insertion portion 41 is press-fitted over the entire circumference into the outer peripheral surface of the press-fitting portion 23. Since the internal stress generated in the cylindrical insertion portion 41 can be dispersed over the entire circumference, damage to the sleeve 40 due to the concentration of internal stress can be reduced according to the above configuration.

[0079] In the method for manufacturing the fuel injection valve 1 according to the present embodiment, the fuel injection valve 1 is to be manufactured with the following structure. In other words, the needle 20 (valve body), which opens and closes the nozzle openings 11a for fuel injection, is actuated to close the valve by the first elastic force generated by the first elastically deformed and extended spring member SP1, and is actuated to open the valve by the movable core 30, which is moved by the magnetic attraction force. In addition, the movable core 30 is urged to the side opposite the nozzle openings by the second elastic force generated by the second spring member SP2. The movable core 30 is elastically deformed by being clamped between the sleeve 40 (fixed member) attached to the needle 20 and the movable core 30.The above manufacturing method includes steps S12 and S15 (press-fitting process and press-fitting process, respectively) of press-fitting the sleeve 40 (fixed member) into the press-fitting portion 23 of the needle 20, which press-fits the sleeve 40 into the press-fitting portion 23 formed in the needle 20, which contacts the movable core 30 and starts the valve-opening operation when the movable core 30 is moved by a predetermined amount by the magnetic attraction force. Furthermore, the above manufacturing method includes step S13 (load measurement process) of measuring the second elastic force in a state where the movable core 30 is immobilized during the press-fitting process. In the press-fitting process, the degree of press-fitting is adjusted based on the measurement result to complete the press-fitting.

[0080] In short, in the manufacturing method according to the present embodiment, the fuel injection valve 1 is to be manufactured with the core reinforcement structure including the sleeve 40 supporting the second spring member SP2 to urge the movable core 30 toward the side opposite the nozzle openings. While the sleeve 40 is press-fitted into the press-fitting portion 23 of the needle 20, the second elastic force is measured while the movable core 30 is not moved, and the amount of press-fitting is adjusted based on the measurement result to complete the press-fitting. Therefore, the second elastic force can be adjusted to the target setting load of the second spring member SP2 with high accuracy at the time of completion of the press-fitting.

[0081] Since, as described above, the magnitude of the set load or the set load affects the valve opening and closing timing of the needle 20, adjusting the set load to the target value with high accuracy contributes to reducing the variation in the fuel injection amount. Therefore, according to the present embodiment, in which the set load can be adjusted to the target value with high accuracy as described above, the fluctuation in the fuel injection amount can be reduced by using the core boost structure.

[0082] Furthermore, in the manufacturing method according to the present embodiment, the next fuel injection valve 1 is to be manufactured. The fuel injection valve 1 is arranged to be movable relative to the needle 20 and includes the cup 50 that contacts the needle 20 by moving relative to the fuel nozzle openings and transmits the first elastic force from the first spring member SP1 to the needle 20. In the manufacturing method described above, in step S13 (load measuring process), the cup 50 is relatively moved to contact the needle 20, and the cup 50 is brought into contact with the movable core 30 in the contacting state, thereby regulating the movement of the movable core 30.

[0083] The magnitude of the second adjustment load applied by the second spring element SP2 is important for preventing the movable core 30 from moving toward the nozzle opening after the valve closes, i.e., it is important for rapid rebound convergence. Therefore, setting the second elastic force in the closed state of the valve as the second adjustment load is beneficial for managing rebound convergence. Since the second elastic force is measured by regulating the movement of the movable core 30 through contact with the cup 50 contacting the needle 20 on the movable core 30, the second elastic force is measured in the closed state of the valve. This makes it easy to manage rebound convergence. <Detaillierte Beschreibung der Konfigurationsgruppe B>

[0084] Next, among the configurations of the fuel injection valve 1 according to the present embodiment, a configuration group B including at least the fuel storage chamber B1, which will be described below, and the configuration related to the fuel reservoir B1 will be described with reference to FIG. Fig. 12 to 14. In addition, a modification of configuration group B will be described later with reference to the Fig. 15 to 23 described.

[0085] As in Fig. As shown in Fig. 12, the fuel storage chamber B1 is a portion where the fuel is accumulated in a state surrounded by the movable core 30, the cup 50, and the needle 20. In the following description, a surface of the inner core 32 on the opposite side from the nozzle opening that contacts the needle 20 is referred to as a first core contact surface 32c, a surface of the inner core 32 that contacts the cup 50 is referred to as a second core contact surface 32b, and a surface of the inner core 32 that contacts the guide member 60 is referred to as a third core contact surface 32d.

[0086] Since the movable core 30 is pressed against the cup 50 by the second elastic force, the movable core 30 is always in contact with the cup 50, except when the movable core 30 is inertially moved and separated from the cup 50 after the valve is closed. Specifically, the second core contact surface 32b of the inner core 32 is always in contact with the core contact end surface 51a of the cup 50. The cylindrical portion 51 of the cup 50, which forms the core contact end surface 51a, separates the inside and outside of the fuel storage chamber B1. The outside is a region where the fuel exists radially outside the outer peripheral surface 51d of the cup 50, the first core contact surface 32c is located inside the fuel storage chamber B1, and the third core contact surface 32d is located outside the fuel storage chamber B1.

[0087] The fuel storage chamber B1 is a region surrounded by the outer peripheral surface of the core sliding portion 22 of the needle 20, the valve opening contact surface 21a, the inner wall surface of the through-hole 32a of the inner core 32, the first core contact surface 32c, and the inner peripheral surface of the cylindrical portion 51 of the cup 50. The fuel storage chamber B1 is a region surrounded, as described above, in a state where the movable core 30 and the cup 50 contact each other. The fuel storage chamber B1 is a region surrounded, as described above, in a state where the valve body-side valve seat 20s contacts the body-side seat 11s and the needle 20 is closed.

[0088] Communication grooves 32e are provided in the first core contact surface 32c and the second core contact surface 32b of the inner core 32. The communication grooves 32e connect the inside and outside of the fuel storage chamber B1 with each other in a state where the second core contact surface 32b contacts the core contact end surface 51a. The outside is a space other than the fuel storage chamber B1 when the can 50 and the movable core 30 contact each other.

[0089] Here, the outside of the fuel storage chamber B1 corresponds to a region exemplified below. In other words, a first region between the stopper contact end surface 61a and the third core contact surface 32d of the guide member 60 corresponds to an outside. The first region is a region formed in a state where the cup 50 and the movable core 30 contact each other, and the movable core 30 and the guide member 60 do not contact each other. A surface of the fixed core 13 facing the movable core 30 is referred to as a fixed core side surface 13b. A surface of the outer core 31 facing the fixed core 13 is referred to as a movable core surface 31c. A second region between the fixed core facing surface 13b and the movable core facing surface 31c, which communicates with the first region, corresponds to the outside.A third region, which communicates with the second region, between the inner peripheral surfaces of the main body 12 (holder) and the non-magnetic member 14 (holder) and the outer peripheral surface of the outer core 31 corresponds to the outside.

[0090] As in Fig. As shown in Figure 13, multiple (e.g., four) communication grooves 32e are provided, and the multiple communication grooves 32e are arranged at regular intervals in the circumferential direction, as viewed from the moving direction of the movable core 30. The communication grooves 32e each have a shape extending linearly in the radial direction. Each of the plurality of communication grooves 32e has the same shape. The circumferential positions of the communication grooves 32e are different from the circumferential positions of the through holes 31a.

[0091] The inner core 32 corresponds to a "contact portion" in which the first core contact surface 32c and the second core contact surface 32b are formed. The outer core 31 corresponds to a "core body portion" made of a different material than the inner core 32, on which the movable core surface 31c facing the fixed core 13 is formed. The core body portion lies outside a region where the communication grooves 32e extend. In other words, the communication grooves 32e are provided in the inner core 32 but not in the outer core 31.

[0092] The communication grooves 32e are provided over the entire surface in the radial direction of the inner core 32 and are guided via the inner peripheral surface to the outer peripheral surface of the inner core 32. In other words, the communication grooves 32e are provided over the entire surface in the radial direction of the first core contact surface 32c, the second core contact surface 32b, and the third core contact surface 32d.

[0093] As in Fig. As shown in Figure 14, the communication grooves 32e each have a bottom wall surface 32e1, a vertical wall surface 32e2, and an inclined surface 32e3. The bottom wall surface 32e1 has a shape extending perpendicular to the moving direction of the movable core 30, the vertical wall surface 32e2 has a shape extending from the bottom wall surface 32e1 in the moving direction of the movable core 30, and the inclined surface 32e3 has a shape extending from the vertical wall surface 32e2 to the groove opening 32e4 while enlarging the flow area. In a Fig. In the example shown in Fig. 14, the inclined surface 32e3 has a shape extending linearly from an upper end of the vertical wall surface 32e2.

[0094] Examples of a method for machining the communication grooves 32e include laser machining, electrical discharge machining, end mill cutting, and the like. First, a groove with a rectangular cross section including the vertical wall surface 32e2 and the bottom wall surface 32e1 is machined. At this time, a burr generated at the time of machining may remain in the peripheral portion of the groove opening 32e4 in the vertical wall surface 32e2. However, afterward, the tapered surface 32e3 with a trapezoidal cross section is machined to remove the burr. • Now, when the fuel present in the fuel storage chamber B1 is compressed while the movable core 30 moves to the side opposite the nozzle openings, the movement of the movable core 30 is hindered, so that the moving speed (collision speed) when the movable core 30 moves a predetermined amount and contacts the needle 20 becomes low. This reduces the above-mentioned effect of the core boost structure, that is, the effect that the valve body can be actuated to open even with the high-pressure fuel while reducing an increase in the magnetic attraction force required to open the valve. In addition, since the movement of the movable core 30 is hindered, a variation in the valve opening timing of the needle 20 and a variation in the fuel injection amount become large.

[0095] 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 element SP1 (spring element), and the cup 50 (valve closing force transmitting element). The movable core 30 contacts the needle 20 at a time when the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount to the side opposite the nozzle openings, and opens the needle 20. The first spring element SP1 is elastically deformed during the valve opening process of the needle 20, and the valve has an elastic closing force for closing the needle 20.The cup 50 is arranged to be movable relative to the needle 20, and when the cup 50 is moved relative to the nozzle opening side, the cup 50 contacts the needle 20 to transmit the elastic closing force of the valve to the needle 20. The movable core 30 has the first core contact surface 32c and the second core contact surface 32b, and the communication grooves 32e are provided in the first core contact surface 32c and the second core contact surface 32b to communicate the inside and outside of the fuel storage chamber B1.

[0096] When the movable core 30 moves to the side opposite the nozzle openings, the fuel accumulated in the fuel storage chamber B1 flows out through the communication grooves 32e. Therefore, the compression of the fuel accumulated in the fuel storage chamber B1 is inhibited, allowing the movable core 30 to move smoothly. For this reason, the reduction in the collision speed of the movable core 30 can be inhibited, so that the effect of reducing the magnetic attraction force by the core boost structure can be promoted. In addition, since the movable core 30 can move smoothly, the variation in the valve opening timing of the needle 20 and thus the variation in the fuel injection amount can be reduced.

[0097] Further, in the fuel injection valve 1 according to the present embodiment, the plurality of communication grooves 32e are provided, and the multiple communication grooves 32e are arranged at regular intervals in the circumferential direction as viewed from the moving direction of the movable core 30.

[0098] According to the above configuration, the portions that easily flow out of the fuel storage chamber B1 are provided at regular intervals in the axial direction. For this reason, when the movable core 30 moves in the axial direction, a change in the inclination direction of the movable core 30 with respect to the axial direction can be reduced. Since the behavior of the movable core 30 can be prevented from becoming unstable, the variation in the valve opening behavior can be further reduced. When three or more communication grooves 32e are provided at regular intervals in the circumferential direction, the effect of inhibiting behavior instability is promoted.

[0099] Furthermore, in the fuel injection valve 1 according to the present embodiment, the movable core 30 includes the inner core 32 (contact portion) and the outer core 31 (core body portion) made of a different material than the inner core 32. The inner core 32 is formed with the first core contact surface 32c and the second core contact surface 32b, and the outer core 31 is formed with the movable core surface 31c facing the fixed core 13. The outer core 31 is excluded from a region where the communication grooves 32e are provided.

[0100] Since the surface 31c of the outer core 31 facing the movable core can have a flat shape without a groove, the magnetic attraction force attracted to the fixed core 13 cannot be reduced by the communication grooves.

[0101] Furthermore, in the fuel injection valve 1 according to the present embodiment, the third core contact surface 32d of the movable core 30, which contacts the guide member 60, is located outside the fuel storage chamber B1. The communication grooves 32e are also provided in the third core contact surface 32d in addition to the first core contact surface 32c and the second core contact surface 32b.

[0102] When the needle 20 is in the full-lift position, the inner core 32 contacts the guide member 60. In the above-mentioned 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 with each other, there is a concern that a phenomenon (binding phenomenon) may occur in which the third core contact surface 32d is hardly separated from the stopper contact end surface 61a. In the present embodiment, since the communication grooves 32e are also provided in the third core contact surface 32d, in consideration of the above problems, when the movable core 30 starts to move toward the nozzle opening side with the energization off, the fuel is supplied in a state where the stopper contact end surface 61a contacts the third core contact surface 32d.Since the movable core 30 can be prevented from coming into close contact with the guide member 60 and is difficult to separate from the guide member 60, the possibility that the start of movement of the movable core 30 toward the nozzle opening side is delayed due to the above-mentioned adhesion force can be reduced. Therefore, the response time of valve closing from the energization off to the closing of the needle 20 can be reduced, and the valve closing performance can be improved.

[0103] Further, in the fuel injection valve 1 according to the present embodiment, the communication grooves 32e each have the lower wall surface 32e1 extending perpendicular to the moving direction of the movable core 30 and the vertical wall surface 32e2 extending from the lower wall surface 32e1 in the moving direction.

[0104] In order to remove burrs that occur in the groove opening 32e4 of the communication grooves 32e, it is desirable to polish the first core contact surface 32c and the second core contact surface 32b. For example, polishing is carried out by a two-point chain line in Fig. 14 to a position indicated by a solid line. In the present embodiment, after assembling the inner core 32 with the outer core 31, the communication grooves 32e and the outer communication grooves 31e are formed by cutting or the like, and thereafter, the above-mentioned polishing is performed simultaneously on the outer core 31 and the inner core 32.

[0105] In contrast to the present embodiment, in the case where the vertical wall surface 32e2 is absent and the shape is represented by a one-dot chain line, a cross-sectional area of ​​the communication grooves 32e becomes small, and a ratio of the cross-sectional area to be polished to the cross-sectional area of ​​the communication grooves 32e becomes large. As a result, an influence of the variation in the polishing depth on the cross-sectional area of ​​the communication grooves 32e becomes large, so that the variation in the cross-sectional area of ​​the communication grooves 32e becomes large. For this reason, a variation in the degree of fuel leaking out of the fuel storage chamber B1 through the communication grooves 32e becomes large, and a variation in the mobility of the movable core 30 becomes large, which hinders reduction of the variation in the valve opening timing of the needle 20.On the other hand, according to the present embodiment, since the vertical wall surface 32e2 is provided, the ratio of the cross-sectional area to be polished becomes small, and the influence of the variation in polishing depth on the cross-sectional area of ​​the communication grooves 32e becomes small. Therefore, the fluctuation in the outflow rate of the fuel from the fuel storage chamber B1 to the outside through the communication grooves 32e is reduced, and the variation in the valve opening timing of the needle 20 can be promoted. [Modification B1]

[0106] Although the Fig. 12 are not provided in the outer core 31, as shown in Fig. 15, in addition to the communication grooves 32e provided in the inner core 32, communication grooves (outer communication grooves 31e) may be provided in the outer core 31. In a Fig. 15, the inner diameter side end portion of the outer communication grooves 31e communicates directly with the outer diameter side end portion of the communication grooves 32e.

[0107] As in Fig. As shown in Figure 16, the plurality of (e.g., four) outer communication grooves 31e are provided, and the plurality of outer communication grooves 31e are arranged at regular intervals in the circumferential direction in the moving direction of the movable core 30. The outer communication grooves 31e each have a shape extending linearly in the radial direction. Each of the plurality of outer communication grooves 31e has the same shape. The position of the outer communication grooves 31e in the circumferential direction differs from the position of the through holes 31a in the circumferential direction.

[0108] The outer communication grooves 31e and the communication grooves 32e have the same position in the circumferential direction. In an example of Fig. 16, four outer communication grooves 31e are arranged at regular intervals in the circumferential direction, but six outer communication grooves 31e may be arranged at regular intervals in the circumferential direction. In this case, it is desirable to set the position of the through holes 31a in the circumferential direction so that the circumferential distance from the adjacent outer communication grooves 31e is the same.

[0109] The outer communication grooves 31e are provided over the entire surface of the outer core 31 in the radial direction and extend from the inner peripheral surface to the outer peripheral surface of the outer core 31. In other words, the outer communication grooves 31e are provided over the entire surface of the movable core-facing surface 31c in the radial direction. The cross-sectional shape of the outer communication grooves 31e is the same as that shown in Fig. 14, and the outer communication grooves 31e have the same bottom wall surface, vertical wall surface, and inclined surface as those of the communication grooves 32e. As described above, Fig. 14 a sectional view along a line XIV-XIV of Fig. 13 shows the cross-sectional shape of the communication groove 32e extending in the radial direction of the movable core 30, taken perpendicular to the extension direction. The cross-sectional shape of the outer communication grooves 31e is the same as that of the communication grooves 32e, and the cross-sectional shape includes a bottom wall surface, a vertical wall surface, and a tapered surface in a cross-section of the outer communication grooves 31e taken perpendicular to the extension direction.

[0110] As described above, according to the present modification with the outer communication grooves 31e, since the fuel flowing out from the outer diameter-side end portion of the communication grooves 32e diffuses through the outer communication grooves 31e, an increase in fuel pressure at the outer diameter-side end portion of the communication grooves 32e can be prevented, and the fuel flowing out through the communication grooves 32e can be promoted. Therefore, an increase in fuel pressure between the guide member 60 and the inner core 32 can be prevented.

[0111] In the present modification, since the end portion on the inner diameter side of the outer communication grooves 31e directly communicates with the outer diameter side end portion of the communication grooves 32e, the outflow of the fuel from the end portion on the outer diameter side can be further promoted.

[0112] In the present modification, since the outer communication grooves 31e are provided over the entire area of ​​the movable core facing surface 31c in the radial direction, the fuel leaking from the outer diameter side end portion of the outer communication grooves 31e flows directly into the gap between the inner peripheral surface of the holder and the outer peripheral surface of the outer core 31. For this reason, an increase in fuel pressure at the outer diameter side end portion of the outer communication grooves 31e can be prevented, and the fuel outflow through the communication grooves 32e and the outer communication grooves 31e can be promoted.

[0113] Furthermore, in the present modification, regarding the dimension of the outer communication grooves 31e, a width dimension (circumferential dimension) of a portion of the outer communication grooves 31e opening toward the fixed core 13 is set smaller than a depth dimension (axis line C dimension) of the outer communication grooves 31e. According to the above configuration, the cross-sectional area of ​​the flow channel of the outer communication grooves 31e can be increased, while a reduction in the movable core facing area 31c caused by the provision of the outer communication grooves 31e can be prevented. The "flow channel cross-sectional area" is an area having a cross section perpendicular to the flow direction when the fuel in the fuel storage chamber B1 flows radially outward through the outer communication grooves 31e.In other words, since the width dimension is smaller than the depth dimension as described above, the fuel discharge from the fuel storage chamber B1 at the time of the valve opening operation can be realized while preventing the reduction of the magnetic attraction force. [Modification B2]

[0114] In the present, in Fig. 17 and Fig. 18, a connecting groove 32f is provided for connecting the multiple communication grooves 31e. The connecting groove 32f has a ring-shaped shape around the through-hole 32a and connects all (four in an example of Fig. 18) Communication grooves 31e are connected to each other. The connecting groove 32f connects the outer diameter-side end portion of the communication grooves 31e. The connecting groove 32f is formed by cutting the outer diameter-side edge portion of the inner core 32. Furthermore, the inner diameter-side edge portion of the outer core 31 is cut so that the connecting groove 32f extends over both the outer core 31 and the inner core 32.

[0115] In the Fig. 15 and Fig. 16 can also be used in the Fig. 17 and Fig. 18 may be provided, and each of the plurality of communication grooves 32e and the plurality of outer communication grooves 31e may be connected to each other through the connection groove 32f.

[0116] As described above, according to the present modification with the communication groove 32f, since the fuel flowing out from the outer diameter side end portion of the communication grooves 32e diffuses through the communication groove 32f, an increase in the fuel pressure at the outer diameter side end portion of the communication grooves 32e can be prevented and the fuel flowing out through the communication grooves 32e can be promoted.

[0117] Furthermore, with the connection of the plurality of communication grooves 31e, a change in the inclination direction of the movable core 30 with respect to the axial direction can be prevented when the movable core 30 moves in the axial direction, since the fuel can be promoted to flow smoothly from the plurality of communication grooves 31e. Since the behavior of the movable core 30 can be prevented from becoming unstable, the variation in the valve opening behavior can be further reduced. [Modification B3]

[0118] The Fig. 12 are formed over the entire end face of the inner core 32. On the other hand, communication grooves 32g are formed according to the Fig. 19 and Fig. 20, the communication grooves 32g are provided over part of the first core contact surface 32c, the entire area of ​​the second core contact surface 32b, and part of the third core contact surface 32d. More specifically, the communication grooves 32g are not provided over the entire area of ​​the first core contact surface 32c in the radial direction, but partially in a portion of the first core contact surface 32c adjacent to the second core contact surface 32b. The communication grooves 32g are provided over the entire area of ​​the second core contact surface 32b in the radial direction. The communication grooves 32g are not provided over the entire area of ​​the third core contact surface 32d in the radial direction, but partially in a portion of the third core contact surface 32d adjacent to the second core contact surface 32b.

[0119] The Fig. The communication grooves 32e shown in Fig. 12 have a shape extending linearly in the radial direction, while the communication grooves 32g according to the present modification have a slanted shape. In other words, as shown in Fig. 20, the communication grooves 32g are circular as seen from the direction of the axis line C, and as shown in Fig. 19, the communication grooves 32g are triangular in sectional view.

[0120] As described above, according to the present modification having the oblique communication grooves 32g, the communication grooves 32g can be formed only by pressing a drill bit tip against the movable core 30, and therefore the communication grooves 32g can be easily machined. [Modification B4]

[0121] In the Fig. In the embodiment shown in Fig. 12, the communication grooves 32e are provided in the contact surface of the movable core 30 so that the inside and outside of the fuel storage chamber B1 communicate with each other. In the present modification shown in Fig. 21, by providing communication holes 20c in the needle 20, the interior of the fuel storage chamber B1 and the inner passage 20a of the needle 20 are connected to each other.

[0122] In a state where the cup 50 contacts the valve-closing contact surface 21b and in a state where the cup 50 contacts the second core contact surface 32b, the communication holes 20c are arranged at a position including the first core contact surface 32c in the direction of the axis line C. Alternatively, the entirety of the communication holes 20c is arranged on the side opposite the nozzle holes with respect to the first core contact surface 32c. The multiple communication holes 20c are provided, and the multiple communication holes 20c are arranged at regular intervals in the circumferential direction, as viewed from the moving direction of the needle 20. The communication holes 20c have a shape that extends linearly in the radial direction of the needle 20.

[0123] As described above, according to the present modification in which the communication holes 20c are provided in the needle 20, when the movable core 30 moves to the side opposite the nozzle holes, the fuel accumulated in the fuel storage chamber B1 flows out through the communication holes 20c into the inner passage 20a (the outer side) of the needle 20. Therefore, the compression of the fuel accumulated in the fuel storage chamber B1 is inhibited, so that the movable core 30 can move smoothly. For this reason, the reduction of the collision speed of the movable core 30 can be inhibited, so that the effect of reducing the magnetic attraction force by the core boost structure can be promoted. In addition, since the movable core 30 can move smoothly, the variation in the valve opening timing of the needle 20 and thus the variation in the fuel injection amount can be reduced. [Modification B5]

[0124] In the present, in Fig. In the modification shown in Fig. 22, sliding surface communication grooves 20d are provided in the needle 20 so that the interior of the fuel storage chamber B1 and the inner passage 20a of the needle 20 communicate with each other. The sliding surface communication grooves 20d are formed in the valve body-side sliding surface 21c (see Fig. 7) of the needle 20 on which the cup 50 slides.

[0125] A plurality of sliding surface communication grooves 20d are provided, and the plurality of sliding surface communication grooves 20d are arranged at regular intervals in the circumferential direction, as viewed from the moving direction of the needle 20. The sliding surface communication grooves 20d each have a shape that extends linearly in the direction of the axis line C of the needle 20.

[0126] As described above, according to the present modification in which the sliding surface communication grooves 20d are provided in the valve body-side sliding surface 21c, which is the sliding surface between the needle 20 and the cup 50, the fuel accumulated in the fuel storage chamber B1 flows outward through the sliding surface communication grooves 20d when the movable core 30 moves to the side opposite the nozzle openings. In the present description, the outside is a gap between the valve-closing contact surface 21b and the valve-closing force transmission contact surface 52c and the inner passage 20a. Therefore, the compression of the fuel accumulated in the fuel storage chamber B1 is inhibited, allowing the movable core 30 to move smoothly.For this reason, the reduction in the collision speed of the movable core 30 can be inhibited, thus promoting the effect of reducing the magnetic attraction force by the core boost structure. Furthermore, since the movable core 30 can be moved easily, the variation in the valve opening timing of the needle 20 and thus the variation in the fuel injection amount can be reduced. [Modification B6]

[0127] In the present, in Fig. In the modification shown in Figure 23, second sliding surface communication grooves 32h are provided in the inner core 32h, so that the interior of the fuel storage chamber B1 and the movable chamber 12a are connected to each other. The second sliding surface communication grooves 32h are provided on the surface of the inner core 32 on which the needle 20 slides, that is, on the inner peripheral surface of the inner core 32.

[0128] The multiple second sliding surface communication grooves 32h are provided, and the multiple second sliding surface communication grooves 32h are arranged at regular intervals in the circumferential direction, as viewed from the moving direction of the movable core 30. The second sliding surface communication grooves 32h each have a shape that extends linearly in the direction of the axis line C of the movable core 30.

[0129] As described above, according to the present modification in which the second sliding surface communication grooves 32h are provided on the sliding surface between the needle 20 and the inner core 32, when the movable core 30 moves to the side opposite the nozzle openings, the fuel accumulated in the fuel storage chamber B1 flows out into the movable chamber 12a (the outside) through the communication grooves of the second sliding surface 32h. Therefore, the compression of the fuel accumulated in the fuel storage chamber B1 is inhibited, allowing the movable core 30 to move smoothly. For this reason, the reduction in the collision speed of the movable core 30 can be inhibited, so that the effect of reducing the magnetic attraction force by the core boost structure can be promoted.In addition, since the movable core 30 can be moved easily, the variation of the valve opening timing of the needle 20 and thus the variation of the fuel injection amount can be reduced. <Detaillierte Beschreibung der Konfigurationsgruppe C>

[0130] Next, among the configurations of the fuel injection valve 1 according to the present embodiment, a configuration group C including at least one supply flow passage to be described below and a configuration related to the supply flow passage will be described with reference to FIG. Fig. 24 to 26 and 12. In addition, a modification of configuration group C will be described later with reference to the Fig. 27 to 35 described.

[0131] As in Fig. 24, main flow channels 20e are provided with grooves in the valve closing contact surface 21b of the needle 20. As shown in Fig. As shown in Figure 25, the valve-closing contact surface 21b is formed in a region extending annularly from the moving direction of the movable core 30, and the main flow channels 20e are each shaped to extend to connect an annular inner side and an annular outer side across an annular region in which the valve-closing contact surface 21b is formed. The main flow channels 20e each have a straight portion 201 extending linearly from the moving direction of the movable core. In the case of the present embodiment, the entirety of the main flow channels 20e corresponds to the entirety of the straight portion 201.

[0132] The annular inner side corresponds to an inner passage 20a 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 provided in a state where the valve-closing contact surface 21b contacts the cup 50. Therefore, the main flow channels 20e communicate the inner passage 20a of the needle 20 with the gap B2 in a state where the valve-closing contact surface 21b contacts the cup 50.

[0133] The main flow channels 20e (supply flow channels) each have a shape extending to connect an inner peripheral surface of the needle 20, which defines the inner passage 20a, and an outer peripheral surface of the needle 20. The outer peripheral surface of the needle 20 functions as a wall surface of a passage through which the fuel flows through the nozzle openings 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, the fuel flows into the movable chamber 12a through a gap between the inner peripheral surface of the movable core 30 and the outer peripheral surface of the needle 20 and a gap between the outer peripheral surface of the movable core 30 and the inner peripheral surface of the main body 12, and flows into the nozzle openings 11a through the flow channel 12b.

[0134] As in Fig. As shown in Fig. 25, an inner peripheral edge portion 201a and an outer peripheral edge portion 201b of the valve-closing contact surface 21b in the needle 20 are chamfered. The main flow channels 20e (supply flow channels) each have a shape connecting the inner peripheral edge portion 201a and the outer peripheral edge portion 201b.

[0135] As in Fig. 25, a plurality of (e.g., four) main flow channels 20e are provided, wherein the plurality of main flow channels 20e are arranged at regular intervals in the circumferential direction in the moving direction of the movable core 30. In other words, the plurality of main flow channels 20e are arranged at regular intervals in the circumferential direction on the valve-closing contact surface 21b of the needle 20. The main flow channels 20e each have a linear shape in the radial direction. Each of the plurality of main flow channels 20e has the same shape. As shown in Fig. As shown in Figure 26, the cross section of the straight portion 201 of the main flow channels 20e has a shape with an arcuate bottom surface convex toward the nozzle opening side. The edge portions of the outer peripheral portion and the inner peripheral portion of the contact portion 21 of the needle 20 are chamfered, and the outer peripheral portion and the inner peripheral portion of the contact portion 21 are conical in shape.

[0136] A depth dimension 201h of the main flow channels 20e is defined as a dimension of the main flow channels 20e in the direction of the axis line C, and a width dimension 201w of the main flow channels 20e is defined as a dimension of the needle 20 around the direction of the axis line C (see Fig. 24). The depth dimension 201h of the main flow channels 20e is greater than the width dimension 201w of the main flow channels 20e.

[0137] In the case of the core boost structure, in which the cup 50 contacts the needle 20 at the time when the movable core 30 starts to move together with the cup 50 by a predetermined amount due to the initiation of energization of the coil, the following concern arises. In other words, when the cup 50 and the needle 20 are in close contact with each other and touch each other, a phenomenon occurs that the cup 50 is difficult to separate from the needle 20 (chaining phenomenon), thereby delaying the start of movement of the movable core 30 by a predetermined amount, leading to a concern that the valve opening performance will be deteriorated.

[0138] To address the above-mentioned problem, the present embodiment includes the needle 20 (valve body), the fixed core 13, the movable core 30, the first spring element SP1 (spring element), and the cup 50 (valve closing force transmission element). When the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount, the movable core 30 contacts the valve-opening contact surface 21a formed on the needle 20 and actuates the needle 20 to open the valve. The first spring element SP1 is elastically deformed during the valve-opening process of the needle 20, and the valve has an elastic closing force or an elastic valve closing force for closing the needle 20. The cup 50 contacts the valve-closing contact surface 21b formed on the needle 20 and transmits the elastic valve closing force to the needle 20.When the movable core 30 begins to move together with the cup 50 by the predetermined amount, the cup 50 contacts the valve-closing contact surface 21b. The needle 20 has the main flow channels 20e (supply flow channels) for supplying fuel to the valve-closing contact surface 21b in contact with the cup 50.

[0139] Therefore, when the movable core 30 starts to move by the predetermined amount, the fuel is supplied to the valve-closing contact surface 21b in a state where the movable core 30 contacts the cup 50. For this reason, the possibility that the cup 50 does not come into close contact with the needle 20 and is difficult to separate from the needle 20 can be reduced, so that the start of movement of the movable core 30 is delayed by the predetermined amount due to the above-mentioned close contact force. Therefore, the response time of valve opening from the start of energization of the coil 17 to the start of valve opening of the needle 20 can be shortened, and the valve opening performance can be improved. In addition, the variation in the valve opening timing due to the hindrance to the movement of the movable core 30 can be reduced, and the variation in the fuel injection amount can be reduced.

[0140] Furthermore, in the fuel injection valve 1 according to the present embodiment, the main flow channels 20e (supply flow channels) are formed by the grooves provided in the valve-closing contact surface 21b of the needle 20. For this reason, the machining of the supply flow channels can be simplified, and the supply flow channels can be easily provided, compared to the case where the through holes are provided as the supply flow channels in the needle 20 or the cup 50.

[0141] Furthermore, in the fuel injection valve 1 according to the present embodiment, the valve-closing contact surface 21b is formed in a region extending annularly in the moving direction of the movable core 30, and the main flow channels 20e of the supply flow channels extend to connect the annular inner side and the annular outer side across the region. Therefore, fuel is supplied from both sides of the annular inner side and the annular outer side of the valve-closing contact surface 21b, so that the reduction of the coupling phenomenon can be promoted by the above-mentioned close contact.

[0142] Furthermore, in the fuel injection valve 1 according to the present embodiment, the multiple main flow passages 20e are provided, and the multiple main flow passages 20e are arranged at regular intervals in the circumferential direction from the moving direction of the movable core 30. According to the above configuration, the portions where a force of the cup 50 coming into close contact with the needle 20 is relieved exist at regular intervals in the axial direction. When the movable core 30 starts to move by the predetermined amount in the axial direction, the inclination direction of the movable core 30 with respect to the axial direction can no longer be changed. Since the behavior of the movable core 30 can be prevented from becoming unstable, the variation in the valve opening behavior can be further reduced.When three or more main flow channels 20e are provided at regular intervals in the circumferential direction, the effect of reducing behavioral instability is promoted.

[0143] In this example, if the depth dimension 201h of the main flow channels 20e is too small, when the flow channel cross-sectional area of ​​the main flow channels 20e becomes small as the wear of the valve-closing contact surface 21b progresses, the flow rate of the fuel flowing through the main flow channels 20e cannot be sufficiently ensured. If the width dimension 201w of the main flow channels 20e is too large, the surface pressure when the cup 50 is pressed against the needle 20 by the valve-closing elastic force becomes too large, and the pressure-bearing area of ​​the valve-closing contact surface 21b cannot be sufficiently secured. This accelerates the wear progression of the valve-closing contact surface 21b.

[0144] Considering the above points, in the fuel injection valve 1 according to the present embodiment, the depth dimension 201h of the main flow passages 20e is set larger than the width dimension 201w of the main flow passages 20e. For this reason, the flow rate of the fuel flowing through the main flow passages 20e can be sufficiently ensured, and the progression of wear of the valve-closing contact surface 21b due to excessive surface pressure can be prevented. [Modification C1]

[0145] In the present modification, the cross-sectional shape of the main flow channels 20e is modified. In other words, the straight section 201 of the Fig. 26 has a cross-sectional shape with an arcuate bottom surface. Alternatively, the straight section 201 may have a triangular cross-sectional shape, as in Fig. 27, or have a rectangular cross-sectional shape, as in Fig. 28 shown.

[0146] As in Fig. 29, the straight section 201 may have a cross-sectional shape combining a rectangle with a trapezoid. Specifically, the main flow channels 20e each have a bottom wall surface 20e1, a vertical wall surface 20e2, and an inclined surface 20e3. The bottom wall surface 20e1 has a shape extending perpendicular to the moving direction of the movable core 30, the vertical wall surface 20e2 has a shape extending from the bottom wall surface 20e1 in the moving direction, and the inclined surface 20e3 has a shape extending from the vertical wall surface 20e2 to a groove opening 20e4 while enlarging the flow area. In a Fig. 29, the inclined surface 20e3 has a shape that extends linearly from an upper end of the vertical wall surface 20e2.

[0147] As a processing method of the Fig. For the main flow channels 20e shown in Figure 29, laser machining, electrical discharge machining, end mill machining, and the like are exemplified. First, a groove with a rectangular cross section including the vertical wall surface 20e2 and the bottom wall surface 20e1 is machined. At this time, burrs generated at the time of processing or during the process may remain in a peripheral portion of the groove opening 20e4 in the vertical wall surface 20e2. However, thereafter, the above-mentioned burrs are removed by machining the inclined surface 20e3 with a trapezoidal cross section. [Modification C2]

[0148] In the present, in Fig. In the modification shown in Fig. 30, the supply flow channel includes a branch flow channel 205 branching from the main flow channels 20e and connecting the main flow channels 20e to each other, in addition to the straight portions 201 that are the main flow channels 20e. The branch flow channel 205 has an annular extending shape when 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 with the same depth as the straight portion 201. The branch flow channel 205 has a shape that extends over the entire circumference to connect all the main flow channels 20e to each other.

[0149] In an example from Fig. 25, four main flow channels 20e are provided, but in the present modification, eight main flow channels 20e are provided, and the plurality of main flow channels 20e are arranged at regular intervals in the circumferential direction, as viewed from the moving direction of the movable core 30. A branch flow channel 205 with an annular shape is provided.

[0150] In an example from Fig. 25, the valve closing contact surface 21b is divided in the circumferential direction by the straight portion 201. On the other hand, in the present modification in Fig. 30, since the branch flow channel 205 is provided in addition to the straight portion 201, the valve closing contact surface 21b is divided in the radial direction in addition to the division in the circumferential direction.

[0151] In a state where the needle 20 contacts the cup 50, a portion of the fuel flowing into the main flow passages 20e from both sides of the annular inner side and the annular outer side is supplied to the valve-closing contact surface 21b from the circumferential direction. Furthermore, the fuel flowing into the branch flow passage 205 after flowing into the main flow passages 20e is supplied to the valve-closing contact surface 21b from the radial direction.

[0152] As described above, the supply flow passage according to the present modification includes, in addition to the main flow passages 20e, the branch flow passage 205 branched off from the main flow passages 20e, connecting the annular inner side and the annular outer side. Therefore, the fuel is guided from both the main flow passages 20e and the branch flow passage 205 to the valve-closing contact surface 21b. This makes it possible to promote a reduction in the binding phenomenon through the aforementioned close contact.

[0153] Furthermore, in the fuel injection valve according to the present modification, the branch flow passage 205 has an annular shape when viewed from the moving direction of the needle 20. For this reason, both ends of the branch flow passage 205 communicate with the main flow passages 20e, so that the inflow of fuel from the main flow passages 20e to the branch flow passage 205 and the supply of fuel to the valve-closing contact surface 21b can be promoted. [Modification C3]

[0154] In the present modification, which is Fig. 31, the main flow channels 20e each have the straight sections 201 and the inflow sections 202. The straight sections 201 each have a shape that extends linearly from the moving direction of the movable core 30. The inflow section 202 communicates with the straight section 201, thus forming an inflow port 203 for the fuel to the main flow channel 20e. A flow channel cross section of the inflow section 202 has a larger shape than a flow channel cross section of the straight section 201. In particular, in the case shown in (b) in Fig. 32, the inflow section 202 has a shape in which the groove width increases towards the nozzle opening. In a plan view shown in Fig. 31, the inflow section 202 has a shape in which the groove width increases towards the radially outer side.

[0155] Of the fuel inflow ports 203 and 204 provided at both ends of the main flow passages 20e, the inflow port 203 located outside the above-mentioned annular extending portion is provided with the inflow portion 202 having an enlarged area. On the other hand, the inflow port 204 located inside the annular extending portion is not provided with an inflow portion having an enlarged area. The edge portions of the outer peripheral portion and the inner peripheral portion of the contact portion 21 of the needle 20 are chamfered, and the outer peripheral portion and the inner peripheral portion of the contact portion 21 are tapered.

[0156] The main flow channels 20e are manufactured by laser machining or a laser process. A single-point catenary line in Fig. 32 indicates the center of a laser beam. First, as shown in column (a) of Fig. As shown in Figure 32, a groove is formed by a laser in a section corresponding to the straight section 201. Specifically, laser processing is started from the inside in the radial direction, and the laser beam is moved from the inside to the outside. During processing of the straight section 201, a focal point of the laser beam is aligned with a bottom surface of the groove.

[0157] After the laser beam is moved to the outer end portion of the straight portion 201 to complete the machining of the straight portion 201, the laser beam is further moved to the radially outer side, and the groove in the portion corresponding to the inflow portion 202 is machined by the laser, as shown in column (b) of Fig. 32. The focal point of the laser beam at the time of machining the inflow portion 202 is adjusted to coincide with the focal point of the laser beam at the time of machining the straight portion 201. Since the outer peripheral portion of the contact portion 21 is tapered, the lower surface of the inflow portion 202 is cut at a position different from the focal point of the laser beam. Since a cutting width at the bottom surface of the inflow portion 202 is made larger than a cutting width at the bottom surface of the straight portion 201, the inflow portion 202 is formed in a shape in which the groove width is larger toward the nozzle opening side.

[0158] As described above, the main flow passages 20e according to the present modification include the straight portion 201 extending linearly from the moving direction of the movable core 30, and the inflow portion 202 communicating with the straight portion 201 to form the fuel inflow port 203. The flow passage cross section of the inflow portion 202 has a shape in which the area is increased compared to the flow passage cross section of the straight portion 201. For this reason, the fuel easily flows from the inflow port 203 into the straight portion 201 compared to the case where the inflow portion 202 is not provided, and therefore, the fuel supply to the valve-closing contact surface 21b can be promoted. [Modification C4]

[0159] The Fig. 24 is formed by the grooved main flow channel 20e in the needle 20. In contrast, in the present modification shown in Fig. 33, a through hole 52d is provided in the cup 50, and the through hole 52d provides a supply flow passage for supplying the fuel to the valve closing contact surface 21b.

[0160] According to the above configuration, when the movable core 30 starts to move by a predetermined amount, the fuel of the flow channel 13a is supplied to the valve closing contact surface 21b in a state where the movable core 30 contacts the cup 50 through the through hole 52d. For this reason, similar to the embodiment of Fig. 24, the responsiveness of the valve opening can be improved and the variation in the fuel injection amount due to the variation in the valve opening timing can be reduced because the cup 50 can be prevented from coming into close contact with the needle 20 and from being difficult to separate from the needle 20. [Modification C5]

[0161] In the Fig. 24, the grooved main flow channels 20e are provided in the needle 20. On the other hand, in the present Fig. 34 and Fig. 35, a grooved main flow channel 210e is provided in a plate 210, which is described below.

[0162] The plate 210 is arranged between the needle 20 and the cup 50 and is circular, plate-shaped, and made of metal. In the illustrated example, the main flow channel 210e is provided on the surface of the plate 210 on the nozzle opening side; alternatively, it may be formed on the surface of the plate 210 on the opposite side from the nozzle opening side. A plurality of (e.g., four) main flow channels 210e are provided, and the plurality of main flow channels 210e are arranged at regular intervals in the circumferential direction as viewed from the moving direction of the movable core 30. The main flow channels 210e each have a shape that extends linearly in the radial direction. The plurality of main flow channels 210e each have the same shape.

[0163] The main flow channels 210e each have a shape extending to define the annular inner side and the annular outer side over the annular region in which the valve closing contact surface 21b is formed, in the same manner as the shape shown in Fig. 25. Therefore, the main flow channels 210e each communicate the inner passage 20a of the needle 20 with the gap B2 in a state where the valve-closing contact surface 21b contacts the cup 50 through the plate 210.

[0164] The plate 210 is not coupled to the needle 20 and the cup 50, but is defined as part of the needle 20 or the cup 50. A through-hole 52a of the cup 50 and a through-hole 210a communicating with the inner passage 20a of the needle 20 are provided in the plate 210.

[0165] As described above, according to the present modification, when the movable core 30 starts to move by a predetermined amount, the fuel in the flow channel 13a is supplied to the valve closing contact surface 21b in a state where the movable core 30 contacts the cup 50 through the plate 210 through the main flow channel 210e. For this reason, similar to the embodiment of Fig. 24, the needle 20 can be prevented from coming into close contact with the plate 210 and difficult to separate from the plate 210, the response of the valve opening can be improved, and the variation in the fuel injection amount due to the variation in the valve opening timing can be reduced. [Modification C6]

[0166] The Fig. The supply flow channel shown in Fig. 24 is formed by the grooved main flow channel 20e in the valve-closing contact surface 21b of the needle 20. On the other hand, in the present modification, the main flow channel 20e is eliminated, and the supply flow channel is formed by asperities, which will be described below. In other words, shot peening to collide an abrasive material with the valve-closing contact surface 21b is performed to increase the surface roughness of the valve-closing contact surface 21b, thereby providing the valve-closing contact surface 21b with asperities. The asperities are replaced by the main flow channel 20e, which forms the supply flow channel. In other words, the surface roughness of the valve-closing contact surface 21b is made rougher than that of the inner peripheral surface of the part forming the inner passage 20a of the surface of the needle 20.Alternatively, the surface roughness of the valve closing contact surface 21b is made rougher than that of the outer peripheral surface of the needle 20.

[0167] Due to the unevenness of the supply flow channel, the hardness of the valve-closing contact surface 21b is increased by shot peening. Therefore, the abrasion resistance of the valve-closing contact surface 21b can be improved by repeated collisions between the cup 50 and the needle 20.

[0168] Instead of blasting the needle 20 to form the asperities as described above, blasting can also be performed on the contact surface 52c of the valve closing force transmission of the cup 50 to form the asperities. In this case, the supply flow channel is formed by the asperities formed on the contact surface 52c of the valve closing force transmission. <Detaillierte Beschreibung der Konfigurationsgruppe D>

[0169] Next, among the configurations of the fuel injection valve 1 according to the present embodiment, a configuration group D having at least one recessed surface 60a, which will be described below, and a configuration related to the recessed surface 60a will be described with reference to FIG. Fig. 36 and Fig. 37 described in detail.

[0170] As described above, the inner peripheral surface of the cylindrical portion 61 of the guide member 60 forms the sliding surface 61b, which slides with the outer peripheral surface 51d of the cylindrical portion 51 of the cup 50. The sliding surface 61b slides the outer peripheral surface 51d of the cup 50 to guide the movement of the cup 50 in the direction of the axis line C while simultaneously limiting the movement of the cup 50 in the radial direction. The sliding surface 61b is a surface with a shape parallel to the direction of the axis line C.

[0171] The recessed surface 60a is formed on a surface of the inner surface of the guide member 60 that is connected to the side opposite the nozzle openings of the sliding surface 61b. The recessed surface 60a is shaped to be recessed in a direction that increases the gap to the cup 50 in the radial direction. The recessed surface 60a has a shape that extends annularly around the axis line C and has the same shape in every cross section in the circumferential direction.

[0172] A surface 60a1 of the recessed surface 60a adjacent to the sliding surface 61b is a surface connected to the sliding surface 61b on the side opposite the nozzle opening and is shaped to gradually increase a gap CL1 from the cup 50 in the radial direction as the distance from the sliding surface 61b increases. The adjacent surface 60a1 includes an inclined surface 60a2 extending linearly in a cross section including the axis line C. A peripheral portion 60b of the guide member 60, which defines a boundary between the adjacent surface 60a1 and the sliding surface 61b, has a shape curved to be convex inward in the radial direction, that is, an R-shape. This can prevent the cup 50 from being supported by the guide member 60.

[0173] At a portion connecting the stopper contact end surface 61a and the sliding surface 61b, a chamfered portion 61c is provided, which is formed by chamfering in an oblique shape. The edge portion including the boundary between the chamfered portion 61c and the sliding surface 61b has a convexly curved shape in the radial direction and prevents the cup 50 from being worn by the guide member 60.

[0174] In the cup 50, an edge portion 51g connecting the outer peripheral surface 51d and the core contact end surface 51a, and an edge portion 51h connecting the transmission element-side sliding surface 51c and the core contact end surface 51a are chamfered to have an inclined shape or an R-shape. An edge portion 21d of the needle 20 connecting the valve body-side sliding surface 21c and the valve port contact surface 21a is also chamfered to have an inclined shape or an R-shape. A rim portion 21e, which includes a boundary between the tapered portion formed on the side opposite the nozzle opening with respect to the valve body-side sliding surface 21c and the valve body-side sliding surface 21c, has a shape curved to be convex outward in the radial direction and prevents wear between the cup 50 and the needle 20.

[0175] In the following description, a part of the surface of the cup 50, which includes the outer peripheral surface 51d of the cylindrical portion 51 of the cup 50 and extends parallel to the direction of the axis line C, is referred to as a parallel surface. In an example of Fig. 36, the entire outer peripheral surface 51d corresponds to a parallel surface, and an area which is in Fig. 37 indicated by the symbol M1 is a parallel surface in the surface of the cup 50.

[0176] Furthermore, a surface connected to the side opposite the nozzle openings of the parallel surface and located on the radially inner side of the parallel surface is referred to as a connecting surface 51e. The connecting surface 51e is curved so that it protrudes convexly from the cup 50 in the radial direction. In the surface of the cup 50, a region is formed which is Fig. 37, indicated by the symbol M2, is the connecting surface 51e. The surface of the connecting surface 51e connected to the side opposite the parallel surface is a spring contact surface to which the first elastic force is applied by contact with the first spring element SP1. The spring contact surface has a shape extending perpendicular to the direction of the axis line C.

[0177] A boundary line between the parallel surface and the connecting surface 51e is called connecting boundary line 51f (see circle in Fig. 37). When the movable core 30 moves in the direction of the axis line C, the cup 50 also moves in the direction of the axis line C. A movable area M3 of the connection boundary line 51f in the direction of the axis line C lies entirely within an area N1 of the depressed surface 60a in the direction of the axis line C due to the above movement.

[0178] The outer peripheral surface of the guide member 60 is press-fitted into the enlarged diameter portion 13c of the fixed core 13. Since the guide member 60 is press-fitted into the fixed core 13, the guide member 60 is not tilted relative to the fixed core 13. However, a dimensional tolerance of the outer peripheral surface of the guide member 60 or the inner peripheral surface of the enlarged diameter portion 13c is tilted. On the other hand, since the cup 50 is slidably disposed relative to the guide member 60, a sliding gap CL1 is provided between the cup 50 and the guide member 60. Accordingly, the cup 50 can be tilted relative to the fixed core 13 and the guide member 60. In other words, the axis line C of the cup 50 can be inclined with respect to the axis line C of the fixed core 13.

[0179] Since the needle 20 is slidably mounted on the cup 50, a sliding gap CL2 is provided between the needle 20 and the cup 50. Therefore, the needle 20 can be further tilted relative to the tiltable cup 50. In other words, the axis line C of the needle 20 can be further tilted relative to the axis line C of the tiltable cup 50. Therefore, an angle (maximum tilt angle) at which the needle 20 is tilted to the maximum and the cup 50 is tilted to the maximum in the same direction as the needle 20 corresponds to the assumed maximum tilt angle θ2 (see Fig. 36), in which the cup 50 is tilted. The inclined surface 60a2 is shaped so that an inclination angle θ1 (see Fig. 36), in which the inclined surface 60a2 is inclined relative to the sliding surface 61b of the guide element 60, is greater than the maximum inclination angle θ2 of the cup 50.

[0180] The gap CL1 between the parallel surface of the cup 50 and the sliding surface 61b of the guide member 60 is set larger than the gap CL2 between the cup 50 and the needle 20. Therefore, the inclination angle of the cup 50 when the gap CL2 is zero is larger than the inclination angle of the needle 20 when the gap CL1 is zero.

[0181] A sliding distance between the cup 50 and the guide member 60 in the gap CL1 is set to be longer than a sliding path or sliding distance between the cup 50 and the needle 20 in the gap CL2. In this example, the longer the sliding path or sliding distance, the smaller the inclination caused by the gap. For example, the longer the sliding path or sliding distance in the gap CL1, the smaller the inclination of the cup 50 with respect to the guide member 60. The longer the sliding path or sliding distance in the gap CL2, the smaller the inclination of the needle 20 with respect to the cup 50. Even when these two inclinations are maximum, the connecting surface 51e is set so that it does not contact the guide member 60.

[0182] The guide member 60 is made of a magnetic material, and the cup 50 is made of a non-magnetic material. Generally, a non-magnetic material has a lower hardness than a magnetic material. However, in the present embodiment, the cup 50 and the guide member 60 have the same hardness. In other words, a non-magnetic material with high hardness is used as the cup 50 instead of a general non-magnetic material. The hardness of the cup 50 (cup hardness) and the hardness of the guide member 60 (guide member hardness) are, for example, values ​​ranging from the Vickers hardness HV600 to HV700. If the deviation of the guide member hardness with respect to the cup hardness is within a range of -10% to +10% of the cup hardness, both hardnesses are considered to be equally hard.

[0183] As wear progresses due to sliding between the cup 50 and the guide member 60, the cup 50 tilts largely relative to the guide member 60, and consequently, the needle 20 tilts largely along with the cup 50. As the inclination of the needle 20 increases, the valve opening and closing timing of the needle 20 varies, and the variation in the fuel injection quantity increases.

[0184] To address the above-mentioned problem, the present embodiment includes the needle 20 (valve body), the fixed core 13, the movable core 30, the first spring member SP1 (spring member), the cup 50 (valve closing force transmitting member), and the guide member 60.

[0185] The movable core 30 contacts the needle 20 at a time when the movable core 30 is attracted by the fixed core 13 and moved by a predetermined amount, causing the needle 20 to perform the valve-opening operation. The first spring element SP1 is elastically deformed during the valve-opening operation of the needle 20, and the valve has an elastic closing force or a valve-closing elastic force for closing the needle 20. The cup 50 has a valve body transmission portion (circular plate part 52) ​​that contacts the first spring element SP1 and the needle 20 to transmit the valve-closing elastic force to the needle 20, and a cylindrical portion 51 that presses the movable core 30 toward the nozzle openings.The guide member 60 has a sliding surface 61b that slides the outer peripheral surface 51d of the cylindrical portion 51 to guide the movement of the cylindrical portion 51 in the direction of the axis line C and to limit the movement of the cylindrical portion 51 in the radial direction. The guide member 60 is provided with the recessed surface 60a, which is a surface connected to the sliding surface 61b on the side opposite the nozzle opening and recessed in a direction in which the gap with the cup 50 is increased in the radial direction. The valve body transmission portion is a circular plate part 52 having a circular plate shape, and the cylindrical portion 51 is a shape extending from the outer peripheral edge of the circular plate of the circular plate part 52 toward the nozzle opening side.

[0186] In 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 line C is the parallel surface, a surface connected to the parallel surface on the side opposite the nozzle openings and located on the radially inner side of the parallel surface is the connecting surface 51e, and a boundary line between the parallel surface and the connecting surface 51e is the connecting boundary line 51f. The movable range M3 of the connecting boundary line 51f in the axial direction is entirely within a range N1 of the depressed surface 60a in the axial direction. In other words, the position of the connecting boundary line 51f in the axial direction is within the range N1 where the depressed surface 60a is provided, regardless of whether the needle 20 is fully raised or closed.

[0187] Therefore, when the cup 50 moves in the axial direction while sliding on the guide member 60, the connection limit line 51f faces the recessed surface 60a and does not contact the sliding surface 61b. This prevents the cup 50 from being pressed against the guide member 60 in a state where the surface pressure component in the axial direction is large, and reduces wear of the cup 50. Therefore, the inclination of the cup 50 and, consequently, the inclination of the needle 20 can be reduced, so that the variation in the fuel injection amount due to the variation in the valve opening and closing timing of the needle 20 can be reduced.

[0188] Furthermore, in the fuel injection valve 1 according to the present embodiment, the adjacent surface 60a1 of the recessed surface 60a to the sliding surface 61b is shaped so that the gap CL1 between the fuel injection valve 1 and the cup 50 gradually increases in the radial direction with increasing distance from the sliding surface 61b. In this example, unlike the present embodiment, if the adjacent surface 60a1 has a shape in which the radial direction is increased in a stepwise manner, the surface pressure when the edge portion of the stepped portion is pressed against the cup 50 moving toward the nozzle opening side is increased, and there is a concern that wear will be accelerated.Since the abutting surface 60a1 according to the present embodiment has a shape gradually expanding in the radial direction, the above-mentioned surface pressure can be alleviated and the fear of promoting wear between the cup 50 and the guide member 60 can be reduced.

[0189] Furthermore, in the fuel injection valve 1 according to the present embodiment, the abutting surface 60a1 includes the inclined surface 60a2 extending linearly in sectional view. The inclination angle θ1 at which the inclined surface 60a2 is inclined relative to the sliding surface 61b is larger than the assumed maximum inclination angle θ2 at which the cup 50 is inclined. For this reason, the possibility of the tilted cup 50 coming into contact with the inclined surface 60a2 can be reduced, and the fear of promoting wear between the cup 50 and the guide member 60 can be alleviated.

[0190] Furthermore, in the fuel injection valve 1 according to the present embodiment, the restricting portion 60b including the boundary between the adjacent surface 60a1 and the sliding surface 61b has a radially inward convex curved shape. In this example, unlike the present embodiment, if the edge portion has a sharp shape, the surface pressure is increased when the edge portion is pressed against the cup 50 moving toward the nozzle opening side, and there is a fear of promoting wear. Since the edge portion 60b in the present embodiment has a radially inward convex shape, the surface pressure can be alleviated in view of the above-mentioned circumstances, and the fear of promoting wear can be reduced.

[0191] Furthermore, in the fuel injection valve 1 according to the present embodiment, the guide member 60 is made of a magnetic material, and the cup 50 is made of a non-magnetic material. According to the above configuration, the parallel surface of the cup 50 can be prevented from being pressed against the sliding surface 61b of the guide member 60 by the electromagnetic attraction force acting on the cup 50 in the radial direction. This can reduce wear between the cup 50 and the guide member 60.

[0192] Furthermore, in the fuel injection valve 1 according to the present embodiment, the cup 50 and the guide member 60 have the same hardness. Generally, a non-magnetic material has a lower hardness than a magnetic material. However, in the present embodiment, as described above, a high-hardness non-magnetic material is used as the cup 50 instead of a general non-magnetic material. For this reason, the possibility of accelerating wear of the member on the low-hardness side due to a hardness difference can be avoided, and the electromagnetic attraction force acting on the cup 50 can be avoided.

[0193] Further, in the fuel injection valve 1 according to the present embodiment, the gap CL1 between the parallel surface of the cup 50 and the sliding surface 61b of the guide member 60 is larger than the gap CL2 between the cup 50 and the needle 20.

[0194] In this example, the needle 20 can be opened and closed in a tilted state with respect to the direction of the axis line C. When the needle 20 is tilted, the cup 50 is tilted by a tilting force, and when the cup 50 is tilted, the force with which the cup 50 is pressed against the guide member 60 increases, which may cause wear. Therefore, according to the present embodiment, in which the recessed surface 60a is adopted in a configuration addressing the above-described wear, the wear-reducing effect of the recessed surface 60a can be more effectively exhibited. <Detaillierte Beschreibung der Konfigurationsgruppe E>

[0195] Next, a configuration group E including at least the press-fitting structure between the outer core 31 and the inner core 32 and the configuration related to the press-fitting structure among the configurations of the fuel injection valve 1 according to the present embodiment will be described in detail with reference to FIG. Fig. 38 and Fig. 39. In addition, a modification of configuration group E will be described later with reference to the Fig. 40 to 42 described.

[0196] As in Fig. As shown in Fig. 38, a press-fitting surface 31p formed on the inner peripheral surface of the outer core 31 and a press-fitting surface 32p formed on the outer peripheral surface of the inner core 32 are press-fitted together. The press-fitting surfaces 31p and 32p are not formed over the entire surface in the direction of the axis line C, but partially in the direction of the axis line C.

[0197] In the present embodiment, the press-fitting surfaces 31p and 32p are formed on a part of the movable core 30 on the side opposite the nozzle opening. In the following description, a portion of the outer core 31 in which the press-fitting surface 31p is formed and the entire portion in the direction of the axial line C including the press-fitting surface 31p will be referred to as a press-fitting region 311. A portion of the outer core 31 in which the press-fitting surface 31p is not formed and the entire part in the radial direction not including the press-fitting surface 31p will be referred to as a non-press-fitting region 312. In other words, in the direction of the axial line C, the outer core 31 is divided into a press-fitting region 311 on a side opposite the nozzle opening and a non-press-fitting region 312 on the nozzle opening side adjacent to the press-fitting region in the direction of the axial line C.

[0198] The non-press-fitting portion 312 is formed with a locking portion 31b that contacts a locking portion 32i of the inner core 32 in the direction of the axis line C. The locking portion 32i prevents the inner core 32 from being deflected toward the nozzle opening side with respect to the outer core 31 due to the collision of the inner core 32 with the guide member 60 and the like. In the inner peripheral surface of the non-press-fitting portion 312, a gap B3 is provided from the inner core 32 in a portion from the locking portion 31b to the boundary of the press-fitting portion 311. In other words, the gap B3 is located at the boundary between the press-fitting portion 311 and the non-press-fitting portion 312.

[0199] The gap B3 functions as a region for confining burrs generated when the inner core 32 is press-fitted into the outer core 31. Since the material of the outer core 31 is softer than that of the inner core 32, the burrs are generated on the press-fit surface 31p of the outer core 31. More specifically, the above-mentioned burrs are generated when the nozzle-opening-side end portion of the press-fit surface 32p of the inner core 32 scrapes off part of the press-fit surface 31p of the outer core 31.

[0200] In the present embodiment, after assembling the inner core 32 with the outer core 31, the communication grooves 32e and the outer communication grooves 31e are formed by cutting or the like, and then the first core contact surface 32c and the second core contact surface 32b are ground. As a result, the positions of the first core contact surface 32c and the second core contact surface 32b are aligned along the axis line C.

[0201] The outer peripheral surface of the outer core 31, which is Fig. 39, indicated by a solid line, shows a state before press-fitting with the inner core 32 and is circular (perfect circle) in plan view. On the other hand, in the state after press-fitting with the inner core 32, the outer peripheral surface of the press-fitting portion 311 of the outer core 31 expands radially outward, as indicated by a dashed line in Fig. 39. However, a portion where the through holes 31a are present (small expansion portion 331a or extension portion 311a) is less likely to expand than a portion where the through holes 31a are not present (large expansion portion 331b or extension portion 311b). Therefore, the outer peripheral surface of the press-fitting portion 311 after press-fitting is not a perfect circle, and the large expansion portion 311b has a shape with a larger diameter than the small expansion portion 311a. In the state before press-fitting, the diameter of the outer peripheral surface of the press-fitting portion 311 corresponds to the diameter of the non-press-fitting portion 312. Therefore, in the state after press-fitting, the outer peripheral surface of the press-fitting portion 311 has a larger diameter than the outer peripheral surface of the non-press-fitting portion 312 (see Fig. 38).

[0202] The holder for movably supporting the movable core 30 includes the main body 12, which is a magnetic member having magnetism, and the non-magnetic member 14 adjacent to the main body 12 in the moving direction. An end surface of the main body 12 and an end surface of the non-magnetic member 14 are welded together. A portion of the holder facing the outer peripheral surface of the press-fitting portion 311 is defined as a press-fitting portion facing portion H1, and a portion of the holder facing the outer peripheral surface of the non-press-fitting portion 312 is defined as a non-press-fitting portion facing portion H2.A minimum gap in the radial direction between the inner peripheral surface of the press-fitting portion facing portion H1 and the outer peripheral surface of the press-fitting portion 311 is defined as a press-fitting portion gap CL3, and a minimum gap in the radial direction between the inner peripheral surface of the non-press-fitting portion facing portion H2 and the outer peripheral surface of the non-press-fitting portion 312 is defined as a non-press-fitting portion gap CL4. A minimum inner diameter of the press-fitting portion facing portion H1 is set larger than a minimum inner diameter of the non-press-fitting portion facing portion H2, so that the press-fitting portion gap CL3 is larger than the non-press-fitting portion gap CL4.

[0203] The inner peripheral surface of the press-fitting portion H1 has a shape extending parallel to the moving direction of the movable core 30 (in the direction of the axis line C). The inner peripheral surface of the non-press-fitting portion H2 has a parallel surface H2a extending parallel to the moving direction and a connecting surface H2b connecting the inner peripheral surface of the press-fitting 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. Although a part of the main body 12 is included in the non-press-fitting portion H2, the non-magnetic member 14 is not included in the non-press-fitting portion H2, 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 in which the parallel surface H2a and the joint surface H2b have different inner diameter dimensions. The non-press-fitting portion gap CL4, which is the smallest gap between the non-press-fitting portion H2 and the non-press-fitting portion 312, corresponds to a gap in the parallel surface H2a formed by the main body 12.

[0204] Specifically, a flow channel cross-sectional area defined by the press-fit section gap CL3 is larger than a flow channel cross-sectional area defined by the non-press-fit section gap CL4. These flow channel cross-sectional areas are areas with a cross-section perpendicular to the axis line C of the flow channel, which are defined by the press-fit section gaps CL3 and CL4.

[0205] The inner peripheral surface H1a of the press-fitting portion H1 has a shape parallel to the movement direction. The press-fitting portion H1 includes a portion of the non-magnetic member 14 and a portion of the main body 12. The non-magnetic member 14 is shaped to have a uniform inner diameter along the entire axis line C direction. The press-fitting portion gap CL3, which is the smallest gap between the press-fitting portion H1 and the press-fitting portion 311, corresponds to a gap at a portion of the main body 12 on the opposite side from the nozzle opening with respect to the connecting surface H2b or at the non-magnetic member 14.

[0206] When the movable core 30, attracted to the fixed core 13, is configured by press-fitting 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 diameter of the outer core 31 is slightly expanded by press-fitting. As a result, the gap between the inner peripheral surface of the holder that accommodates the movable core 30 and the outer peripheral surface of the outer core 31 becomes small, and the flow resistance that the movable core 30 receives from the fuel present in the gap becomes large. Since it is difficult to cope with the amount of outer diameter expansion due to the press-fitting, a machine difference fluctuation in the magnitude of the flow resistance occurs, resulting in a change in the moving speed of the movable core 30.As a result, there is a variation in the engine difference in the response of the valve opening, which leads to a large variation in the injection quantity.

[0207] 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 (retainer), and the non-magnetic member 14 (retainer), as well as the guide member 60 (stopper member). The movable core 30 has a cylindrical shape and moves together with the needle 20 by the magnetic attraction force to open the nozzle openings 11a. The holder has a movable chamber 12a filled with fuel and accommodates the movable core 30 in the movable chamber 12a in a movable state. The guide member 60 contacts the movable core 30 and prevents the movable core 30 from moving away from the nozzle openings 11a. The movable core 30 has the inner core 32 contacting the guide member 60 and the outer core 31 press-fitted into the outer peripheral surface of the inner core 32.The outer core 31 has the press-fit portion 311, which is press-fitted into the outer peripheral surface of the inner core 32 in the moving direction of the movable core 30, and the non-press-fit portion 312, which is not press-fitted into the outer peripheral surface of the inner core 32 and is adjacent to the press-fit portion 311 in the moving direction. Of the gaps between the inner peripheral surface of the holder and the outer peripheral surface of the movable core 30, the smallest gap CL3 in the press-fit portion 311 is larger than the smallest gap CL4 in the non-press-fit portion 312.

[0208] In this example, the flow resistance that the movable core 30 receives from the fuel present in the gap between the outer peripheral surface of the outer core and the inner peripheral surface of the holder is greatly affected by the smallest gap when the size of the gap changes according to the axial position. The gap CL3 in the press-fitting region 311 in the gap between the inner peripheral surface of the holder and the outer peripheral surface of the movable cores is larger than the gap CL4 in the non-press-fitting region 312. Therefore, unlike the present embodiment, when the minimum gap CL3 in the press-fitting region 311 is smaller than the minimum gap CL4 in the non-press-fitting region 312, the flow resistance is greatly affected by the gap CL3 in the press-fitting region 311. As a result, there is a large variation in flow resistance between machines.In contrast, according to the present embodiment, the minimum gap CL3 in the press-fitting region 311 is larger than the minimum gap CL4 in the non-press-fitting region 312. For this reason, the flow resistance cannot be influenced by the gap CL3 in the press-fitting regions 311, and the moving speed of the movable core 30 cannot be varied.

[0209] This can prevent the variation of the machine difference in the valve opening behavior and thus reduce the variation in the injection quantity.

[0210] Furthermore, in the fuel injection valve 1 according to the present embodiment, the inner peripheral surface H1a of the press-fitting portion H1 has a shape parallel to the moving direction. The inner peripheral surface of the non-press-fitting portion H2 has a parallel surface H2a extending parallel to the moving direction and a connecting surface H2b connecting the inner peripheral surface of the press-fitting 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.

[0211] A boundary between a portion (large expansion portion 311b) where expansion is largely generated by press-fitting and a portion (small expansion portion 311a) where expansion is hardly generated is gradually expanded. Considering the above circumstances, according to the present embodiment, with the joint surface H2b whose inner diameter gradually decreases, the gap of the magnetic circuit formed by the portion of the joint surface H2b can be made as small as possible. As shown in Fig. 38, the connecting surface H2b may have a tapered shape in which the inner diameter changes linearly and gradually, a curved shape in which the inner diameter changes in a curved manner, or a stepped shape in which the inner diameter changes in a stepwise manner.

[0212] Furthermore, in the fuel injection valve 1 according to the present embodiment, the retainer includes the main body 12 (magnetic element) having magnetism and the non-magnetic element 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 non-magnetic element 14 are welded together. This makes it possible to perform a step of increasing or reducing the inner diameter of the retainer and a step of removing a welding mark from the inner peripheral surface of the retainer in a series of operations, thereby reducing the labor required for increasing or reducing the inner diameter of the retainer.

[0213] Furthermore, in the fuel injection valve 1 according to the present embodiment, three or more through-holes 31a extending in the moving direction are provided in the outer core 31 at regular intervals in the circumferential direction. According to the above configuration, there are three or more locations at regular intervals in the axial direction where the flow resistance that the movable core 30 receives from the fuel in the movable chamber 12a is small. For this reason, when the movable core 30 moves in the direction of the axis line C, a change in the inclination direction of the movable core 30 from the direction of the axis line C can be reduced. Since the behavior of the movable core 30 can be prevented from becoming unstable, the variation in the valve opening behavior can be further reduced. [Modification E1]

[0214] In the present, in Fig. 40, a maximum outer diameter of the outer core 31 in the press-fitting region 311 is smaller than a maximum outer diameter of the outer core 31 in the non-press-fitting region 312.

[0215] Specifically, the outer diameter of the press-fitting portion 311 is formed to be sufficiently smaller than the outer diameter of the non-press-fitting portion 312 before press-fitting, and the outer diameter of the press-fitting portion 311 is formed to be smaller than the outer diameter of the non-press-fitting portion 312 even when the press-fitting portion 311 is expanded by press-fitting. In short, in a state before press-fitting, the outer peripheral surface of the press-fitting portion 311 is cut to form a recessed portion 311c, and the cutting depth of the recessed portion 311c is set large enough to maintain the recessed portion 311c even after expansion by press-fitting. Moreover, an inner diameter dimension of the non-press-fitting portion facing portion H2 in the direction of the axis line C is the same as that of the press-fitting portion facing portion H1.

[0216] As described above, since the outer peripheral surface of the press-fitting portion 311 is smaller than the non-press-fitting portion 312, and the inner peripheral surface of the non-press-fitting portion H2 facing the non-press-fitting portion is formed equal to the press-fitted opposing portion H1, the press-fitting portion gap CL3 is larger than the non-press-fitting portion gap CL4. For this reason, in the present modification, the same effects as in the fuel injection valve 1 in Fig. 39 shown. [Modification E2]

[0217] In the present modification, which is Fig. 41, the entire press-fitting portion H1 of the holder is made of the non-magnetic member 14, and the main body 12 is not included in the press-fitting portion H1. For example, a length of the press-fitting surfaces 31p and 32p in the direction of the axis line C is smaller than the structure of Fig. 39, so that the entire section H1 facing the press-fit section consists of the non-magnetic element 14. Alternatively, in comparison to the structure in Fig. 39, the length of the non-magnetic element 14 is extended in the direction of the axis line C, so that the entire section H1 facing the press-fitting section consists of the non-magnetic element 14. Since the press-fitting section gap CL3 is provided larger than the non-press-fitting section gap CL4 in the present modification, the same effects as in the fuel injection valve 1 in Fig. 39 shown. [Modification E3]

[0218] In the present modification, which is Fig. 42, a portion of the press-fitting portion 311 which is expanded in the radial direction by the press-fitting process is removed, and the maximum outer diameter of the outer core 31 in the press-fitting portion 311 is formed to coincide with the maximum outer diameter of the outer core 31 in the non-press-fitting portion 312.

[0219] Specifically, in a state before press-fitting with the inner core 32, the outer core 31, whose outer peripheral surface is circular in plan view (perfect circle), is prepared (preparation process) and press-fitted with the inner core 32 (press-fitting process). Thereafter, the large expansion portion 311b expanded by the press-fitting (see Fig. 39) is cut after press-fitting (cutting process), whereby the outer core 31 is shaped so that the outer peripheral surface becomes circular (a perfect circle) in plan view. The inner diameter dimensions of the press-fitting portion facing portion H1 and the non-press-fitting portion facing portion H2 are the same in the direction of the axis line C. Therefore, the press-fitting portion gap CL3 and the non-press-fitting portion gap CL4 are the same. Therefore, the present modification exhibits the same effects as that of Fig. 39. (Second embodiment)

[0220] While the valve closing force transmission element according to the first embodiment is formed by the cup 50, a valve closing force transmission element according to the present embodiment is formed by a first cup 501, a second cup 502 and a third spring element SP3 (see Fig. 43), which will be described below. Except for the configuration to be described below, the configuration of a fuel injection valve according to the present embodiment is the same as the configuration of the fuel injection valve according to the first embodiment.

[0221] The first cup 501 contacts a first spring element SP1 and a needle 20 and transmits an elastic valve closing force from the first spring element SP1 to the needle 20. In short, the first cup 501 has the same function as the circular plate portion 52 of the cup 50 according to the first embodiment. The first cup 501 is formed with a through hole 52a similar to that of the first embodiment.

[0222] The third spring element SP3 is an elastic element that is elastically deformed in the axial direction to exert an elastic force. One end of the third spring element SP3 contacts a contact surface 501a of the first cup 501, and the other end of the third spring element SP3 contacts a contact surface 502a of the second cup 502. As a result, the third spring element SP3 is clamped between the first cup 501 and the second cup 502, is elastically deformed in the axial direction, and exhibits an elastic force due to the elastic deformation.

[0223] The second cup 502 contacts the movable core 30 during the valve closing operation to push the movable core 30 toward the nozzle openings. In short, the second cup 502 has the same function as the cylindrical portion 51 of the cup 50 according to the first embodiment. The third spring element SP3 performs a function of transmitting a force in the axial direction between the first cup 501 and the second cup 502.

[0224] The needle 20 includes a main body portion 2001 and an enlarged diameter portion 2002. A valve-closing contact surface 21b is formed at one end of the main body portion 2001 on the side opposite the nozzle openings. The valve-closing contact surface 21b contacts a valve-closing force transmitting contact surface 52c of the valve-closing force transmitting member (first cup 501) in the same manner as in the first embodiment.

[0225] The enlarged diameter portion 2002 is located closer to the nozzle opening side than the valve closing contact surface 21b and has a circular plate shape in which the diameter of the main body portion 2001 is enlarged. A valve opening contact surface 21a is formed on a surface of the nozzle opening side of the enlarged diameter portion 2002. The valve opening contact surface 21a contacts the first core contact surface 32c of the movable core 30 in the same manner as in the first embodiment. The length of a gap between the valve opening contact surface 21a and the first core contact surface 32c in the direction of the axis line C in the valve-closing state corresponds to a gap L1 according to the first embodiment.

[0226] In a state immediately after the energization of a coil 17 is switched from OFF to ON, a magnetic attraction force acts on the movable core 30 to start the movement of the movable core 30 toward the valve opening side. Then, when the movable core 30 moves while the second cup 502 is pushed upward, and the movement amount reaches the gap L1, the first core contact surface 32c of the movable core 30 collides with the valve opening contact surface 21a in the needle 20.

[0227] In the present embodiment, the guide member 60 is eliminated, and the movable core 30 contacts the fixed core 13, thereby regulating the valve opening operation amount or stroke of the needle 20. 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, and the length of the gap in the direction of the axis line C corresponds to a stroke L2 of the first embodiment.

[0228] The elastic force of the first spring element SP1 also acts on the needle 20 until the moment of collision. After the collision, the movable core 30 continues to move due to the magnetic attraction force, and when the movement amount after the collision reaches a stroke L2, the movable core 30 collides with the fixed core 13 and stops moving. A separation distance between the housing-side seat 11s and the valve body-side seat 20s in the direction of the axis line C at the moment of stopping the movement corresponds to a full stroke of the needle 20 and corresponds to the stroke L2 described above. (Third embodiment)

[0229] The valve closing force transmission element (cup 50) according to the first embodiment has the cup shape with the cylindrical portion 51 and the circular plate part 52. On the other hand, a valve closing force transmission element according to the present embodiment has a circular plate shape configured by a circular plate portion 52 in which the cylindrical portion 51 is eliminated (see Fig. 44). Except for the configuration to be described below, the configuration of a fuel injection valve according to the present embodiment is the same as the configuration of the fuel injection valve according to the first embodiment.

[0230] In the first embodiment, a surface (core contact end surface 51a) of the valve closing force transmitting member, with which the contact surface (second core contact surface 32b) of the movable core 30 is in contact, is formed in the cylindrical portion 51. On the other hand, in the present embodiment, a surface of the circular plate portion 52 on the nozzle opening side functions as the core contact end surface 52e (see Fig. 44), which touches the movable core 30. (Other embodiments)

[0231] The disclosure contained herein is not limited to the combinations of components and / or elements shown in the embodiments. The disclosure may include additional sections or parts that may be added to the embodiments. The disclosure includes the omission of components and / or elements of the embodiments. The disclosure includes the interchange or combination of components and / or elements between one embodiment and another. For example, the fuel injector 1 according to the first embodiment includes all of configuration groups A, B, C, D, and E, but may be a fuel injector having any combination of configuration groups A, B, C, D, and E.

[0232] In the first embodiment, the temporary press fitting is performed once as shown in Fig. 6, but the load measurement can be performed for each temporary press-fitting operation by performing the temporary press-fitting operation twice or more. According to the above configuration, the second set load can be adjusted to the target value with high accuracy. Furthermore, since the load is measured at each multiple of temporary press-fitting operations, the elastic modulus of the second spring element SP2 can be measured, and the degree of press-fitting during this press-fitting operation can be calculated with high accuracy.

[0233] In the Fig. In the press-fitting process shown in Figure 6, the second set load is measured in a state where the progress of the press-fitting is stopped and the press-fitting is completed, but the second set force can be measured during the press-fitting. In other words, the press-fitting is performed while measuring the second set load, and the press-fitting is stopped and completed when the measured second set load reaches the target value.

[0234] In the Fig. In the press-fitting process shown in Fig. 6, the second set load is measured while the cup 50 restricts the movement of the movable core 30 in the state of contact with the needle; but the second set load may be measured while the contact portion 21 of the needle 20 restricts the movement of the movable core 30.

[0235] The Fig. The communication grooves 32e shown in Fig. 12 are provided on the third core contact surface 32d in addition to the first core contact surface 32c and the second core contact surface 32b, but may not be provided on the third core contact surface 32d. Although the communication grooves 32e shown in Fig. 12 are provided over the entire area of ​​the first core contact surface 32c in the radial direction, it is sufficient that the communication grooves 32e are provided at least in a portion of the first core contact surface 32c adjacent to the second core contact surface 32b.

[0236] Although the Fig. 16 are arranged so that they do not communicate with the through holes 31a, the outer communication grooves 31e may be arranged so that they communicate with the through holes 31a. Fig. The communication grooves 32g shown in Fig. 19 are provided over the first core contact surface 32c, the second core contact surface 32b and the third core contact surface 32d, but may not be provided on the third core contact surface 32d.

[0237] In the examples of Fig. 21, Fig. 22 and Fig. 23, the communication grooves 32e are eliminated, and instead of the communication grooves 32e, the connecting holes 20c, the sliding surface communication grooves 20d, and the second sliding surface communication grooves 32h are provided. On the other hand, the fuel injection valve 1 may include two or more of the communication grooves 32e, the connecting holes 20c, the sliding surface communication grooves 20d, and the second sliding surface communication grooves 32h.

[0238] Although in one example of Fig. 22 the sliding surface communication grooves 20d are provided in the needle 20, the sliding surface communication grooves in the transmission element side sliding surface 51c (see Fig. 22) of the cup 50 on which the needle 20 slides. In an example of Fig. 23, the second sliding surface communication grooves 32h are formed in the inner core 32, but the second sliding surface communication groove may be provided in the surface of the needle 20 which slides with the inner core 32.

[0239] In an example from Fig.24, the main flow channels 20e for supplying the fuel to the valve-closing contact surface 21b in the state of contact with the cup 50 are provided by the grooves provided in the needle 20, but may be provided by the grooves provided in the cup 50. Specifically, the supply flow channel may be provided by grooves in the core contact end surface 51a of the cylindrical portion 51.

[0240] In the first embodiment, the movable portion M is supported in the radial direction at two points of the needle 20, that is, at the portion facing the inner wall surface 11c of the nozzle orifice body 11 (the needle tip portion) and the outer peripheral surface 51d of the cup 50. On the other hand, the movable portion M may be supported at two locations from the radial direction, namely, at the outer peripheral surface of the movable core 30 and at the needle tip portion.

[0241] In the first embodiment, the inner core 32 is made of a non-magnetic material, but it may be made of a magnetic material. If the inner core 32 is made of a magnetic material, the inner core 32 may be made of a weakly magnetic material that is less magnetic than the outer core 31. Likewise, the needle 20 and the guide member 60 may be made of a weakly magnetic material that is less magnetic than the outer core 31.

[0242] In the first embodiment, the cup 50 is inserted between the first spring element SP1 and the movable core 30 to realize a core boost structure in which the movable core 30 contacts the needle 20 to start the valve opening operation when the movable core 30 moves a predetermined distance. On the other hand, the cup 50 may be eliminated, and a core boost structure may be used in which a third spring element different from the first spring element SP1 is provided, and the movable core 30 is urged toward the nozzle opening by the third spring element.

[0243] In the first embodiment, to prevent a magnetic short circuit between the fixed core 13 and the main body 12, the non-magnetic member 14 is arranged between the fixed core 13 and the main body 12. Instead of the non-magnetic member 14, a magnetic member having a shape with a magnetic choke portion for preventing the magnetic short circuit may be arranged between the fixed core 13 and the main body 12. Alternatively, the non-magnetic member 14 may be eliminated, and a magnetic choke portion for preventing the magnetic short circuit may be formed in the fixed core 13 or the main body 12.

[0244] The sleeve 40 according to the first embodiment has a shape in which the connecting portion 42 extends on top of the bearing portion 43 (on the side opposite the nozzle openings) and the cylindrical insertion portion 41 extends on top of the connecting part 42. On the other hand, the sleeve 40 may have a shape in which the connecting portion 42 extends below the bearing portion 43 (on the nozzle opening side) and the cylindrical insertion portion 41 further extends below the connecting portion 42. The sleeve 40 may also be a hollow annular ring that extends 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-fitted into the press-fitting portion 23.

[0245] The cup 50 according to the first embodiment has a cup shape with the circular plate portion 52 and the cylindrical portion 51. Alternatively, the cup 50 may have a flat plate shape. In this case, the upper surface (top) of the flat plate contacts the first spring element SP1, and the lower surface (bottom) of the flat plate contacts the movable core 30.

[0246] The support element 18 has the cylindrical shape according to the first embodiment, but may have a C-shaped cross-sectional shape in which a slot running in the direction of the axis line C is cylindrical.

[0247] The movable core 30 according to the first embodiment has a two-part structure, namely, the outer core 31 and the inner core 32. The inner core 32 is made of a material with a higher hardness than the outer core 31 and has a surface that contacts the cup 50 and the guide member 60, as well as a surface that slides with the needle 20. On the other hand, the movable core 30 may have a structure in which the inner core 32 is eliminated.

[0248] When the movable core 30 has the structure in which the inner core 32 is eliminated as described above, it is preferable that 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, be plated. A specific example of a coating applied to the contact surface is chromium. A specific example of a coating applied to the sliding surface is nickel-phosphorus.

[0249] The fuel injection valve 1 according to the first embodiment has the structure in which the movable core 30 contacts the guide member 60 fixed to the fixed core 13. On the other hand, the movable core 30 is allowed to contact the fixed core 13 with the guide member 60 eliminated. In short, the inner core 32 may contact the guide member 60, or the inner core 32 may contact the fixed core 13 with the guide member 60 eliminated. Further, the structure in which the movable core 30, with the inner core 32 eliminated, contacts the guide member 60, or the structure in which the movable core 30, with the inner core 32 eliminated, contacts the fixed core 13 with the guide member 60 eliminated may be adopted.

[0250] In the case where the movable core 30 has the structure in which the inner core 32 is eliminated as described above, the surface of the movable core 30 on the opposite side from the nozzle opening that contacts the needle 20 corresponds to the first core contact surface 32c. Furthermore, in the structure in which the guide member 60 is eliminated as described above, the surface of the movable core 30 that contacts the fixed core 13 corresponds to the third core contact surface 32d.

[0251] In the first embodiment, the communication grooves 32e are provided in the portion of the inner core 32 that contacts the guide member 60. On the other hand, in the structure in which the guide member 60 is eliminated as described above, the communication grooves 32e are provided in the portion of the inner core 32 that contacts the fixed core 13. When the movable core 30 has the structure in which the inner core 32 is eliminated as described above, the communication grooves 32e are provided in the portion of the movable core 30 that contacts the fixed core 13.

[0252] The cup 50 according to the first embodiment slides in the direction of the axis line C while contacting the inner peripheral surface of the guide member 60.

[0253] On the other hand, the cup 50 may be configured to move in the direction of the axis line C while defining a predetermined gap with the inner peripheral surface of the guide member 60.

[0254] In the first embodiment, the inner peripheral surface of the second spring element SP2 is guided by the connecting portion 42 of the sleeve 40. On the other hand, the outer peripheral surface of the second spring element SP2 can be guided by the outer core 31.

[0255] In the first embodiment, one end of the second spring element SP2 is supported by the movable core 30, and the other end of the second spring element SP2 is supported by the sleeve 40 attached to the needle 20. Alternatively, the sleeve 40 may be eliminated, and the other end of the second spring element SP2 may be supported by the main body 12.

[0256] While the present disclosure has been described with reference to embodiments thereof, it is to be understood that the disclosure is not limited to the embodiments and constructions. Rather, the present disclosure is intended to cover various modifications and equivalent arrangements. In addition, the various elements shown in various combinations and configurations are exemplary, as well as other combinations and configurations including more, fewer, or only a single element are also included within the spirit and scope of the present disclosure.

Claims

[1] Fuel injection valve comprising: a valve body (20) which opens and closes a nozzle opening (11a) for injecting a fuel; a fixed core (13) which generates a magnetic attraction force when a coil (17) is excited; a movable core (30) having a cylindrical shape and opening the nozzle opening by moving together with the valve body due to the magnetic attraction force; a holder (12, 14) having a movable chamber (12a) filled with the fuel and accommodating the movable core movable in the movable chamber; and a stopper member (60) contacting the movable core to limit the movement of the movable core in a direction away from the nozzle opening, wherein the movable core comprises an inner core (32) contacting the stopper element and an outer core (31) press-fitted with an outer peripheral surface of the inner core, the outer core comprises, in a moving direction of the movable core, a press-fitting region (311) in which the outer core is press-fitted to the outer peripheral surface of the inner core, and a non-press-fitting region (312) in which the outer core is not press-fitted to the outer peripheral surface of the inner core, wherein the non-press-fitting region is adjacent to the press-fitting region in the moving direction, and between an inner peripheral surface of the holder and an outer peripheral surface of the movable core, a minimum gap in the press-fitting area is larger than a minimum gap in the non-press-fitting area. [2] The fuel injection valve according to claim 1, wherein a minimum inner diameter of a press-fitting portion (H1), which is a portion of the holder facing an outer peripheral surface of the outer core in the press-fitting portion, is larger than a minimum inner diameter of a non-press-fitting portion (H2), which is a portion of the inner peripheral surface of the holder facing an outer peripheral surface of the outer core in the non-press-fitting portion. [3] Fuel injection valve according to claim 2, wherein an inner peripheral surface of the portion facing the press-fitting area has a shape extending parallel to the direction of movement, an inner peripheral surface of the non-press-fitting portion has a parallel surface (H2a) extending parallel to the direction of movement and a connecting surface (H2b) connecting the inner peripheral surface of the press-fitting portion and the parallel surface, and the connecting surface has a shape which gradually decreases in inner diameter towards the parallel surface. [4] The fuel injection valve according to claim 1, wherein a maximum outer diameter of the outer core in the press-fit region is smaller than a maximum outer diameter of the outer core in the non-press-fit region. [5] Fuel injection valve comprising: a valve body (20) which opens and closes a nozzle opening (11a) for injecting a fuel; a fixed core (13) which generates a magnetic attraction force when a coil (17) is excited; a movable core (30) having a cylindrical shape and opening the nozzle opening by moving together with the valve body due to the magnetic attraction force; a holder (12, 14) having a movable chamber (12a) filled with the fuel and accommodating the movable core, which is movable in the movable chamber, in a movable state; and a stopper member (60) contacting the movable core to limit the movement of the movable core in a direction away from the nozzle opening, wherein the movable core comprises an inner core (32) contacting the stopper element and an outer core (31) press-fitted with an outer peripheral surface of the inner core, the outer core comprises, in a direction of movement of the movable core, a press-fitting region (311) in which the outer core is press-fitted to the outer peripheral surface of the inner core, and a non-press-fitting region (312) located adjacent to the press-fitting region in the direction of movement, and a portion of the press-fitting area that has been expanded in the radial direction by the press-fitting is removed such that the maximum outer diameter of the outer core in the press-fitting area is equal to the maximum outer diameter of the outer core in the non-press-fitting area. [6] Fuel injection valve according to one of claims 1 to 5, wherein the holder has a magnetic element (12) with magnetism and a non-magnetic element (14) next to the magnetic element in the direction of movement, and an end face of the magnetic element and an end face of the non-magnetic element are welded together. [7] A fuel injection valve according to any one of claims 1 to 6, wherein the outer core has three or more through holes (31a) penetrating the outer core in the direction of movement and arranged at regular intervals in the circumferential direction.

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