Fuel injection device

Abstract

The present invention provides a fuel injection device that can improve the waterproof performance of the coil portion. The fuel injection device (1) includes: a coil tube (51) disposed within a housing (70), having a wire tube outer peripheral surface (51a) that holds a coil (50) and a wire tube inner peripheral surface (51b) on the side opposite to the wire tube outer peripheral surface (51a); and a first outer peripheral surface (46a) and a first outer peripheral surface (10b) (a guiding portion) that are in contact with the wire tube inner peripheral surface (51b). A first space (S1) and a second space (S2) (inner spaces) are formed by the first outer peripheral surface (46a), the first outer peripheral surface (10b), and the wire tube inner peripheral surface (51b), and the first space (S1) and the second space (S2) communicate with the space of a filling connection portion (80).

Description

Technical Field

[0001] The present invention relates to a fuel injection device. Background Art

[0002] Conventionally, as an internal combustion engine, an in-cylinder injection type internal combustion engine that directly injects fuel into a cylinder through a fuel injection device has been used. As a technology related to an existing fuel injection device, for example, there is a technology described in Patent Document 1.

[0003] In the fuel injection device described in Patent Document 1, a cup-shaped outer shell 103 is fixed to the outer periphery of a large-diameter cylindrical portion 23 of a nozzle seat 101. A through hole is provided at the center of the bottom of the outer shell 103, and the large-diameter cylindrical portion 23 of the nozzle seat 101 is inserted through the through hole. A part of the outer peripheral wall of the outer shell 103 forms an outer peripheral yoke portion facing the outer peripheral surface of the large-diameter cylindrical portion 23 of the nozzle seat 101.

[0004] A coil 105 wound in a ring shape is disposed in a cylindrical space formed by the outer shell 103. The coil 105 is formed by a ring-shaped coil tube 104 having a U-shaped groove in a cross section opening toward the outer side in the radial direction, and a copper wire wound in the groove. Rigid conductors 109 are fixed to the winding start end portion and the winding end portion of the coil 105, and each end portion is led out from a through hole provided in a fixed core 107.

[0005] Insulating resin is injected from the inner periphery of the upper end opening portion of the outer shell 103 to mold the conductors 109 and the fixed core 107, and the outer periphery of the large-diameter cylindrical portion 23 of the nozzle seat 101. Therefore, the conductors 109 and the fixed core 107, and the outer periphery of the large-diameter cylindrical portion 23 of the nozzle seat 101 are covered with a resin molded body 121. An annular magnetic circuit is formed around the coil 105.

[0006] In addition, the coil tube 104 around which the coil 105 is wound is installed between the nozzle seat 101 (holding member) and the outer shell 103. The nozzle seat 101 is provided with a guiding portion facing the inner peripheral surface of the coil tube 104. This guiding portion suppresses a case where the coil tube 104 is deformed due to a filling pressure of a sealing resin member filled in a space between the outer shell 103 and the coil 105.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Laid-Open No. 2013-151915 Summary of the Invention

[0010] Technical Problem to be Solved by the Invention

[0011] In addition, a fuel injection device (sometimes also referred to as a fuel injection valve) used in an internal combustion engine is exposed to harsh environments such as water pouring and temperature cycling. In a harsh environment where the fuel injection device is immersed in water, water sometimes enters the coil portion and forms an electrically conductive path between the inner peripheral surface of the housing and the coil. As a result, there may be a problem of a decrease in the insulation resistance of the coil. Therefore, it is desirable to improve the waterproof performance of the coil portion.

[0012] In the fuel injection valve of Patent Document 1, guide portions are provided near the lower end portion of the large-diameter portion (flange portion) of the fixed core 107 and near the upper end portion of the small-diameter portion of the housing 103. In this case, when the sealing resin member is filled into the space between the housing 103 and the coil 105, the air existing in the space between the housing 103 and the coil 105 remains in the filling range of the sealing resin member (the space between the housing 103 and the coil 105). As a result, a portion where the sealing resin member is not filled is generated, which may affect the basic characteristics (flow rate, injection amount, generation of magnetic field, etc.) of the fuel injection device.

[0013] An object of the present invention is to provide a fuel injection device that can improve the waterproof performance of the coil portion in consideration of the above problems.

[0014] Technical means for solving technical problems

[0015] To solve the above problems and achieve the object, the fuel injection device includes: a movable core; a fixed core opposed to the movable core; a coil that generates a magnetic attraction force between the fixed core and the movable core when energized; a housing that covers the radial outer side of the coil; and a resin member that is filled into the housing and covers the coil. In addition, the fuel injection device includes: a bobbin that is disposed in the housing and has an outer peripheral surface that holds the coil and an inner peripheral surface that is opposite to the outer peripheral surface; and a guide portion that contacts the inner peripheral surface of the bobbin. An internal space is formed by the guide portion and the inner peripheral surface of the bobbin, and the internal space communicates with the space filled with the resin member.

[0016] Advantages of the invention

[0017] According to the fuel injection device having the above structure, the waterproof performance of the coil portion can be improved.

[0018] Technical problems, structures, and effects other than the above are further clarified by the description of the following embodiments. Description of the drawings

[0019] Figure 1 is a cross-sectional view including a central axis of a fuel injection device according to an embodiment of the present invention.

[0020] Figure 2 is an enlarged Figure 1 cross-sectional view showing the periphery of the housing and the coil.

[0021] Figure 3 is Figure 1 a sectional view taken along line A-A as shown. Detailed implementation manners

[0022] Hereinafter, with reference to Figures 1 to 3 the implementation manners of the fuel injection device will be described. In addition, in each figure, the same reference numerals are assigned to common components.

[0023] 1. An embodiment of the fuel injection device

[0024] 1-1. Structure of the fuel injection device

[0025] First, with reference to Figure 1 the structure of an embodiment of the fuel injection device (hereinafter referred to as "this embodiment") will be described.

[0026] Figure 1 is a sectional view including the central axis of the fuel injection device according to this embodiment.

[0027] Figure 1 The fuel injection device 1 shown is used as an internal combustion engine for a four-cycle engine that repeatedly performs four strokes: an intake stroke, a compression stroke, a combustion (expansion) stroke, and an exhaust stroke. In addition, the fuel injection device 1 is applied to an in-cylinder injection type internal combustion engine that injects fuel into the cylinder of each cylinder.

[0028] In this embodiment, the central axis AX1 of the fuel injection device 1 coincides with the central axes of the following components: the nozzle body 10, the injection hole forming member 12, the valve body 20, the movable core 30, and the fixed core 40. In this embodiment, the central axis AX1 is sometimes referred to as the central axis of each component 10, 12, 20, 30, 40 for description.

[0029] In addition, in the following description, the up-down direction is sometimes specified for description. This up-down direction is based on Figure 1 the up-down direction in, and does not specify the up-down direction in the installed state of the fuel injection device 1. In addition, the end of the fuel injection device 1 on the side where the following injection hole 11 is provided is referred to as the front end, and the end on the opposite side is referred to as the base end. In addition, the center line axis AX1 is a line segment parallel to and passing through the central axis, and includes not only the central axis but also the line segment after extending the central axis. In addition, the direction along the center line axis AX1 is referred to as the axis direction Da for description.

[0030] As shown in Figure 1As shown, the fuel injection device 1 includes a nozzle body 10, a valve body 20, a movable core 30, a fixed core 40, a coil 50, a housing 70, a connecting portion 80, and a filter 90. In addition, the fuel injection device 1 includes a first spring 61, a second spring 63, and an adjustment member 62.

[0031]

Nozzle Body

[0032] The nozzle body 10 is formed in a substantially cylindrical shape extending along the axial direction Da. The nozzle body 10 has a cylindrical hole 16. The injection hole forming member 12 is installed at one end, i.e., the front end, in the axial direction Da of the nozzle body 10 by insertion or press-fitting. The injection hole forming member 12 is fixed to the nozzle body 10 by welding over the entire circumference on the inner peripheral edge of the opening at the front end of the nozzle body 10.

[0033] The injection hole forming member 12 has a seat portion 124. A plurality of injection holes 11 for injecting fuel are formed in the seat portion 124. The seat portion 124 is formed in a substantially hemispherical shape protruding toward the front end side in the axial direction Da. A seat surface 124a that contacts and separates from a later-described spherical surface portion 230 of the valve body 20 is formed inside the seat portion 124. The seat surface 124a is formed in a frustum shape that tapers as it goes toward the front end side in the axial direction Da.

[0034] In addition, a plurality of (two in this example) grooves 131 are formed on the outer peripheral surface on the front end side of the nozzle body 10. The grooves 131 are continuously formed along the circumferential direction of the outer peripheral surface of the nozzle body 10. A sealing member 15 is fitted into the grooves 131. When the fuel injection device 1 is installed in a cylinder (not shown) of an internal combustion engine, the sealing member 15 seals the gap between the cylinder and the fuel injection device 1.

[0035] In addition, at the other end, i.e., the base end, in the axial direction Da of the nozzle body 10, a large diameter portion 14 having a larger outer diameter than the front end is formed. An internal space 140 is formed in the large diameter portion 14. The internal space 140 is formed in a bottomed cylindrical shape having an opening that opens toward the base end side.

[0036] A part of the later-described movable core 30 and fixed core 40 is disposed in the internal space 140. A spring housing portion 141 is formed at the center of the bottom in the internal space 140, and the spring housing portion 141 is formed on a circle concentric with the internal space 140. The spring housing portion 141 is a concave portion that is cylindrically recessed from the bottom of the internal space 140 toward the front end. One end of the second spring 63 is housed in the spring housing portion 141.

[0037]

Valve Body

[0038] The valve body 20 is movably disposed inside the nozzle body 10 along the axial direction Da. The valve body 20 is formed in a round bar shape or a cylindrical shape. The valve body 20 has a rear end portion 21, a front end portion 23, and an intermediate portion 22 representing the middle between the rear end portion 21 and the front end portion 23. The front end portion 23 is formed on the front end side in the axial direction Da of the valve body 20, and the rear end portion 21 is formed on the base end side in the axial direction Da of the valve body 20.

[0039] The front end portion 23 is received in the injection hole forming member 12 provided at the front end portion of the nozzle body 10. By moving the valve body 20 along the axial direction Da, the front end portion 23 opens and closes the injection holes 11 provided in the injection hole forming member 12. The front end portion 23 has a spherical surface portion 230. The spherical surface portion 230 is formed in a substantially hemispherical shape. The spherical surface portion 230 faces the seating surface 124a of the seating portion 124 and approaches and separates from the seating surface 124a.

[0040] When the spherical surface portion 230 of the valve body 20 contacts the seating surface 124a, the flow path FC leading to the plurality of injection holes 11 is closed. In addition, if the spherical surface portion 230 separates from the seating surface 124a, a flow path FC for fuel to pass through is formed between the spherical surface portion 230 and the seating surface 124a. As a result, the fuel is ejected from the plurality of injection holes 11.

[0041] The intermediate portion 22 is continuously provided on the base end side in the axial direction Da of the front end portion 22. The intermediate portion 22 is disposed in the cylindrical hole 16 of the nozzle body 10. A gap is formed between the outer peripheral surface of the intermediate portion 22 and the inner peripheral surface of the cylindrical hole 16. The rear end portion 21 is continuously provided on the base end side in the axial direction Da of the intermediate portion 22.

[0042] The rear end portion 21 is disposed in the internal space 140 in the nozzle body 10. The rear end portion 21 is formed in a substantially cylindrical shape larger than the outer diameter of the intermediate portion 22. The rear end portion 21 is inserted into the cylindrical hole of a fixed core 40 described later. The rear end portion 21 is provided with an engaging portion 213. The engaging portion 213 projects outward in the radial direction from the outer peripheral surface of the rear end portion 21. This engaging portion 213 engages with a movable core 30 described later during the opening and closing valve operation of the valve body 20.

[0043] In addition, one end portion of the first spring 61 abuts against the end surface on the rear end side in the axial direction Da of the rear end portion 21. The valve body 20 is biased by the first spring 61 toward the front end side (valve closing side) in the axial direction Da.

[0044] The valve body 20 having the above structure is formed of a metal material such as SUS.

[0045]

Movable Core

[0046] The movable core body 30 is disposed between the rear end portion 21 of the valve body 20 and the bottom of the internal space 140 in the internal space 140 of the nozzle body 10. Further, a minute gap is formed between the outer peripheral surface of the movable core body 30 and the inner peripheral surface of the large-diameter portion 14 forming the internal space 140. Therefore, the movable core body 30 is configured to be movable along the axial direction Da in the internal space 140.

[0047] The movable core body 30 is formed in an annular shape. The movable core body 30 is formed with an insertion through-hole 31 and an eccentric through-hole 32. The insertion through-hole 31 and the eccentric through-hole 32 are through-holes that penetrate from one end portion in the axial direction Da of the movable core body 30 to the other end portion. The insertion through-hole 31 is formed on the central axis of the movable core body 30. The intermediate portion 22 of the valve body 20 is inserted into the insertion through-hole 31.

[0048] The eccentric through-hole 32 is formed at a position eccentric from the central axis of the movable core body 30. The eccentric through-hole 32 communicates with the flow path FC formed by the outer peripheral surface of the valve body 20 and the inner peripheral surface of the fixed core body 40. Then, the eccentric through-hole 32 forms a flow path FC for fuel to pass through.

[0049] The other end portion of the second spring 63 abuts against the end surface on the front end side in the axial direction Da of the movable core body 30. Therefore, the second spring 63 is interposed between the movable core body 30 and the spring housing portion 141 of the nozzle body 10. Further, the fixed core body 40 abuts against the end surface on the base end side in the axial direction Da of the movable core body 30.

[0050]

Fixed Core Body

[0051] The fixed core body 40 is a member that attracts the movable core body 30 by magnetic attraction force. The fixed core body 40 is formed in a substantially cylindrical shape having irregularities on the outer peripheral surface. The front end portion in the axial direction Da of the fixed core body 40 is press-fitted inside the large-diameter portion 14 of the nozzle body 10, that is, into the internal space 140. Then, the nozzle body 10 and the fixed core body 40 are joined by welding. Thereby, the gap between the nozzle body 10 and the fixed core body 40 is sealed, and the space inside the nozzle body 10 is sealed.

[0052] Further, the front end portion of the fixed core body 40 faces the end surface on the base end side in the axial direction Da of the movable core body 30 disposed in the internal space 140. The front end portion of the fixed core body 40 that faces the movable core body 30 can be covered by plating such as hard chromium plating or electroless nickel plating. Thereby, the durability and reliability of the front end portion of the fixed core body 40 that collides with the movable core body 30 can be improved.

[0053] In addition, the rear end portion of the movable core 30 that faces the fixed core 40 can be covered by plating such as hard chromium plating or electroless nickel plating. Thereby, even when a relatively soft soft magnetic stainless steel is used as the movable core 30, the durability and reliability of the movable core 30 can be ensured.

[0054] In addition, the rear end portion side in the axial direction Da of the fixed core 40 protrudes from the internal space 140 of the nozzle body 10 toward the rear end in the axial direction Da.

[0055] The fixed core 40 is formed with a through hole 42. The through hole 42 is formed coaxially with the central axis AX1. Then, the through hole 42 forms a flow path FC through which fuel passes. In addition, an opening 43 communicating with the through hole 42 is formed at the rear end portion of the fixed core 40 in the axial direction Da. Fuel is introduced into the through hole 42 from the opening 43. In addition, the filter 90 is inserted into the through hole 42 from the opening 43.

[0056] In addition, a first spring 61 and an adjustment member 62 are disposed on the front end portion side of the through hole 42 in the axial direction Da. The first spring 61 is disposed on the front end portion side of the through hole 42 relative to the adjustment member 62. The adjustment member 62 is press-fitted into the through hole 42 and fixed to the inside of the fixed core 40. In addition, the rear end portion 21 of the valve body 20 is inserted into the front end portion of the through hole 42. The first spring 61 is interposed between the adjustment member 62 and the rear end portion 21 of the valve body 20. Then, the first spring 61 applies a force to the valve body 20 in the axial direction Da toward the front end portion of the nozzle body 10.

[0057] In addition, by adjusting the fixing position of the adjustment member 62 relative to the fixed core 40, the force applied by the first spring 61 to the valve body 20 can be adjusted. Thereby, the initial load at which the front end portion 23 of the valve body 20 presses the seat surface 124a of the injection hole forming member 12 provided in the nozzle body 10 can be adjusted.

[0058] The force applied by the first spring 61 to the valve body 20 toward the front end portion of the nozzle body 10 is set to be greater than the force applied by the second spring 63 to the movable core 30 toward the fixed core 40.

[0059]

Coil

[0060] The coil 50 is wound around a cylindrical coil tube 51. The coil 50 wound around the coil tube 51 is disposed to cover a part of the outer peripheral surface of the large diameter portion 14 in the nozzle body 10 and a part of the outer peripheral surface of the front end portion of the fixed core 40. The winding start end portion and the winding end portion of the coil 50 are connected to the power supply terminal 811 of the connector 81 of the connection portion 80 described later via wiring (not shown). The housing 70 is fixed to the outer peripheries of the coil 50 and the coil tube 51.

[0061]

Housing

[0062] The housing 70 is formed into a bottomed cylindrical shape. A through-hole 71 is formed at the front end portion in the axial direction Da of the housing 70, i.e., at the bottom. The through-hole 71 is formed at the center portion of the bottom. The large-diameter portion 14 of the nozzle body 10 is inserted into the through-hole 71. Then, welding is performed, for example, over the entire circumference between the opening edge of the through-hole 71 and the outer peripheral surface of the nozzle body 10. Thus, the nozzle body 10 is fixed to the housing 70.

[0063] In addition, the housing 70 is arranged to surround the front end portion side of the fixed core 40, the outer peripheries of the coil tube 51 and the coil 50. The inner peripheral surface of the housing 70 faces the large-diameter portion 14 of the nozzle body 10 and the coil 50, and forms an outer peripheral magnetic yoke portion. Thus, an annular magnetic circuit including the fixed core 40, the movable core 30, the nozzle body 10, and the housing 70 is formed around the coil 50.

[0064]

Connection portion

[0065] The connection portion 80 is formed of resin. The connection portion 80 is filled between the fixed core 40, the coil 50, the coil tube 51, and the housing 70. In addition, the connection portion 80 covers the outer peripheral surface except the rear end portion of the fixed core 40 on the base end side in the axial direction Da with respect to the housing 70. Then, the connection portion 80 is molded so that a connector 81 having a power supply terminal 811 is formed. The terminal 811 is connected to a connection terminal (not shown) of a plug. Thus, the fuel injection device 1 is connected to a high-voltage power supply or a battery power supply. Then, energization of the coil 50 is controlled by an engine control unit (ECU) not shown.

[0066] 1-2. Operation example of the fuel injection device

[0067] Next, with reference to Figure 1 an operation example of the fuel injection device 1 having the above structure will be described.

[0068] The fuel injection device 1 is provided on the wall surface of a cylinder constituting an internal combustion engine. In the fuel injection device 1, the front end portion of the nozzle body 10, which is the front end portion for injecting fuel, is arranged in a combustion chamber formed by the inner wall surface of the cylinder and the piston. In addition, the front end portion of the nozzle body 10 in the fuel injection device 1 faces the spark plug.

[0069] As described above, the force applied by the first spring 61 is set to be larger than the force applied by the second spring 63. Therefore, in a state where the coil 50 is not energized, the front end portion 23 of the valve body 20 is pressed against the seat surface 124a of the injection hole forming member 12. As a result, the flow path FC leading to the plurality of injection holes 11 is closed by the valve body 20 and becomes a closed valve state.

[0070] Next, if the ECU energizes the coil 50, magnetic flux flows through the magnetic circuit including the fixed core 40, the movable core 30, the nozzle body 10, and the housing 70. Then, a magnetic attractive force that attracts the movable core 30 is generated in the fixed core 40. If the magnetic attractive force of the fixed core 40 exceeds the force applied by the first spring 61, that is, the set load, the movable core 30 moves toward the fixed core 40 until the end face of the movable core 30 facing the fixed core 40, that is, the base end side end face, collides with the front end side end face of the fixed core 40.

[0071] When the movable core 30 moves, the engaging portion 213 provided at the rear end portion 21 of the valve body 20 engages with the movable core 30. Therefore, the valve body 20 and the movable core 30 move together toward the fixed core 40 on the base end side along the axial direction Da.

[0072] As the valve body 20 moves toward the fixed core 40, the front end portion 23 of the valve body 20 separates from the injection hole forming member 12. Therefore, the flow path FC leading to the plurality of injection holes 11 formed between the valve body 20 and the injection hole forming member 12 is opened, and an open valve state in which the plurality of injection holes 11 are opened is achieved.

[0073] When the valve body 20 is in the open valve position (open valve state), fuel is introduced into the opening 43 of the fixed core 40 via the filter 90. Then, the fuel flows through the through hole 42 of the fixed core 40 toward the nozzle body 10. Further, the fuel passes through the adjustment member 62 and the first spring 61 disposed in the through hole 42 and flows in the flow path FC formed between the inner peripheral surfaces of the valve body 20 and the fixed core 40. Then, the fuel flows into the internal space 140 of the nozzle body 10 via the eccentric through hole 32 of the movable core 30.

[0074] The fuel flowing into the internal space 140 passes through the gap between the cylindrical holes 16 of the valve body 20 and the nozzle body 10 and flows to the front end side of the nozzle body 10. Then, the fuel flows in the flow path FC formed between the front end portion 23 of the valve body 20 and the injection hole forming member 12 and is injected into the combustion chamber of the internal combustion engine via the plurality of injection holes 11.

[0075] In addition, if the ECU interrupts the energization of the coil 50, the magnetic flux flowing through the magnetic circuit including the fixed core 40, the movable core 30, the nozzle body 10, and the housing 70 disappears. Then, the magnetic attractive force of the fixed core 40 that attracts the controllable core 30 also disappears. Therefore, the elastic force with which the first spring 61 biases the valve body 20 toward the injection hole forming member 12 of the nozzle body 10 is restored to an initial state in which it is greater than the elastic force with which the second spring 63 biases the movable core 30 toward the fixed core 40.

[0076] Accordingly, the valve body 20 biases the injection hole forming member 12 of the nozzle body 10 via the first spring 61 and moves forward along the axial direction Da. In addition, the movable core 30 engaged with the engaging portion 213 of the valve body 20 moves forward along the axial direction Da together with the valve body 20. As a result, the front end portion 23 of the valve body 20 is pressed against the seat surface 124a of the injection hole forming member 12, and the flow paths FC of the plurality of injection holes 11 are closed by the valve body 20 and enter the closed valve state. As a result, the fuel injection by the fuel injection device 1 is stopped.

[0077] 2. Detailed structures of the nozzle body, the fixed core, and the coil tube

[0078] Next, with reference to Figure 2 and Figure 3 the detailed structures of the nozzle body 10, the fixed core 40, and the coil tube 51 will be described.

[0079] Figure 2 is an enlarged Figure 1 cross-sectional view showing the periphery of the housing 70 and the coil 50. Figure 3 is Figure 1 the cross-sectional view taken along line A-A shown in

[0080] As shown in Figure 2 the fixed core 40 faces the movable core 30. Hereinafter, the direction (axial direction Da) in which the movable core 30 faces the fixed core 40 is defined as the vertical direction. Then, in the vertical direction, the side where the fixed core 40 is disposed is defined as the upper side, and the side where the movable core is disposed is defined as the lower side.

[0081] A first inner peripheral surface 70a is formed on the upper end side of the housing 70, and a second inner peripheral surface 70b is formed on the lower side of the first inner peripheral surface 70a. The second inner peripheral surface 70b is formed to have a smaller diameter than the first inner peripheral surface 70a. The second inner peripheral surface 70b faces the coil 50 via the connecting portion 80. In addition, a stepped surface 70c is formed between the first inner peripheral surface 70a and the second inner peripheral surface 70b. Further, the housing 70 has an inner bottom surface 70d continuous with the second inner peripheral surface 70b. The inner bottom surface 70d is formed as a plane substantially perpendicular to the vertical direction.

[0082] The coil tube 51 has a tube outer peripheral surface 51a around which the coil 50 is wound, and a surface opposite to the tube outer peripheral surface 51a, i.e., a tube inner peripheral surface 51b. In addition, the coil tube 51 has an end surface orthogonal to the axial direction of the coil 50, i.e., a tube upper end surface 51c and a tube lower end surface 51d.

[0083] The bobbin 51 is arranged such that the axis of the coil 50 is parallel to the vertical direction. Then, the axis of the coil 50 coincides with the central axis AX1. The upper end face 51c of the bobbin faces the later-described large-diameter portion 45 of the fixed core 40. The lower end face 51d of the bobbin abuts against the inner bottom face 70d of the housing 70.

[0084] The fixed core 40 has a large-diameter portion 45 and a small-diameter portion 46. The large-diameter portion 45 is formed on the upper side in the vertical direction of the small-diameter portion 46. The large-diameter portion 45 is formed as a flange portion that protrudes more radially outward than the small-diameter portion 46. The large-diameter portion 45 has an outer peripheral face 45a, an upper end face 45b which is the upper-side end face, and a lower end face 45c which is the lower-side end face. The lower end face 45c of the large-diameter portion 45 abuts against the stepped face 70c of the housing 70. Thereby, it is fixed to the housing 70, and the relative position of the nozzle body 10 and the fixed core 40 is determined.

[0085] As Figure 3 shown, a notch 45d is formed in the large-diameter portion 45. The resin member forming the connecting portion 80 is filled into the housing 70 through the notch 45d from above the large-diameter portion 45. Then, the resin member filled into the housing 70 travels around the coil 50 (bobbin 51). Therefore, the resin member is finally filled into the side that is symmetric with respect to the central axis (central axis AX1) of the coil 50 and the notch 45d.

[0086] The small-diameter portion 46 faces the movable core 30. The small-diameter portion 46 has a first outer peripheral face 46a, a second outer peripheral face 46b, and a recessed portion 46c.

[0087] The first outer peripheral face 46a is formed in the middle portion in the vertical direction of the small-diameter portion 46. The first outer peripheral face 46a contacts the inner peripheral face 51b of the bobbin of the bobbin 51. The first outer peripheral face 46a of the fixed core 40 corresponds to the first guiding portion according to the present invention. The first outer peripheral face 46a (first guiding portion) contacts the inner peripheral face 51b of the bobbin on the upper side with respect to the central position in the axial direction (vertical direction) of the coil 50.

[0088] The second outer peripheral face 46b is formed between the first outer peripheral face 46a and the outer peripheral face 45a (notch outer peripheral face 45d) of the large-diameter portion 45. The diameter of the second outer peripheral face 46b is smaller than the diameter of the first outer peripheral face 46a. Thereby, the first outer peripheral face 46a forms a groove portion that is continuous in the circumferential direction of the small-diameter portion 46. As a result, a first space S1 is formed between the second outer peripheral face 46b and the inner peripheral face 51b of the bobbin of the bobbin 51. That is, the first space S1 is formed on the upper side of the first outer peripheral face 46a.

[0089] A first space communication groove 51e is formed on the upper end face 51c of the bobbin 51 of the coil tube. The first space communication groove 51e communicates the space filled with the filling connection part 80 (resin member) with the first space S1. That is, the first space S1 communicates with the space filled with the resin member.

[0090] In addition, in this embodiment, a gap is provided between the lower end face 45c of the large diameter portion 45 and the upper end face 51c of the bobbin. Therefore, even if the first space communication groove 51e is not provided on the upper end face 51c of the bobbin, the first space S1 also communicates with the space filled with the resin member. In the case where no gap is provided between the lower end face 45c of the large diameter portion 45 and the upper end face 51c of the bobbin, by providing the first space communication groove 51e on the upper end face 51c of the bobbin, the first space S1 communicates with the space filled with the resin member.

[0091] The recessed portion 46c forms the lower end portion of the small diameter portion 46. The diameter of the recessed portion 46c is smaller than the diameter of the first outer peripheral surface 46a. The recessed portion 46c is inserted into the nozzle body 10. In addition, a third outer peripheral surface 46d and a stepped surface 46e are formed between the first outer peripheral surface 46a and the recessed portion 46c. The third outer peripheral surface 46d is larger than the diameter of the recessed portion 46c and smaller than the diameter of the first outer peripheral surface 46a.

[0092] The large diameter portion 14 of the nozzle body 10 is arranged more inside the coil tube 51. The large diameter portion 14 has an inner peripheral surface 10a, a first outer peripheral surface 10b, a second outer peripheral surface 10c, a third outer peripheral surface 10d, and an upper end surface 10e.

[0093] The recessed portion 46c of the fixed core 40 is press-fitted into the inner peripheral surface 10a of the nozzle body 10. The first outer peripheral surface 10b of the nozzle body 10 is formed at the middle portion in the vertical direction of the large diameter portion 14. The first outer peripheral surface 10b contacts the inner peripheral surface 51b of the bobbin of the coil tube 51. The first outer peripheral surface 10b of the nozzle body 10 corresponds to the second guiding portion according to the present invention. The first outer peripheral surface 10b (the second guiding portion) contacts the inner peripheral surface 51b of the bobbin at a lower side with respect to the central position in the axial direction (vertical direction) of the coil 50.

[0094] Thus, the first outer peripheral surface 46a of the fixed core 40 and the first outer peripheral surface 10b of the nozzle body 10 contact the inner peripheral surface 51b of the bobbin at the upper side and the lower side of the central position in the axial direction (vertical direction) of the coil 50. Thus, when the connecting portion 80 (resin member) is filled inside the housing 70, the coil tube 51 can be prevented from being deformed by the pressure of the resin member. As a result, the coil 50 wound around the coil tube 51 can be prevented or suppressed from being disordered, and the coil 50 can be stably covered by the connecting portion 80 (resin member). Therefore, the waterproof performance of the coil 50 can be improved, and the influence on the basic characteristics (flow rate, injection amount, magnetic field generation, etc.) of the fuel injection device 1 can be suppressed.

[0095] The second outer peripheral surface 10c of the nozzle body 10 is formed on the lower side of the first outer peripheral surface 10b. The diameter of the second outer peripheral surface 10c is smaller than the diameter of the first outer peripheral surface 10b. Thus, the second outer peripheral surface 10c forms a groove portion continuous in the circumferential direction of the nozzle body 10. As a result, a second space S2 is formed between the second outer peripheral surface 10c and the inner peripheral surface 51b of the coil tube 51 of the coil tube. That is, the second space S2 is formed on the lower side of the first outer peripheral surface 10b.

[0096] A second space communication groove 51f is formed in the lower end surface 51d of the coil tube 51 of the coil tube. The second space communication groove 51f communicates the space filled with the connection portion 80 (resin member) with the second space S2. That is, the second space S2 communicates with the space filled with the resin member.

[0097] The first space communication groove 51e and the second space communication groove 51f are provided at positions symmetric with respect to the filling port (cutout 45d) where the resin member is filled into the housing 70 with the central axis (central axis AX1) of the coil 50 as the axis. That is, the first space communication groove 51e and the second space communication groove 51f are provided on the upper end surface 51c and the lower end portion 51d of the coil tube on the side opposite to the cutout 45d side across the central axis AX1.

[0098] Most of the air between the housing 70 and the coil 50 before filling the resin member escapes from the filling port (cutout 45d) when filling the resin member, but there is also air that does not escape from the filling port (cutout 45d). The air that does not escape from the filling port (cutout 45d) travels together with the resin member to surround the periphery of the coil 50 (coil tube 51). Then, it is sealed into the first space S1 or the second space S2 through the first space communication groove 51e or the second space communication groove 51f.

[0099] Thus, it is possible to prevent air from remaining between the housing 70 and the coil 50, and the coil 50 can be stably covered by the connection portion 80 (resin member). As a result, the waterproof performance of the coil 50 can be improved, and the influence on the basic characteristics (flow rate, injection amount, magnetic field generation, etc.) of the fuel injection device 1 can be suppressed.

[0100] The third outer peripheral surface 10d of the nozzle body 10 is formed on the upper side of the first outer peripheral surface 10b and reaches the upper end surface 10e. The third outer peripheral surface 10d is larger in diameter than the second outer peripheral surface 10c and smaller in diameter than the first outer peripheral surface 10b. In addition, the third outer peripheral surface 10d is substantially equal to the third outer peripheral surface 46d of the fixed core 40. The upper end surface 10e of the nozzle body 10 abuts against the stepped surface 46e of the fixed core 40 in the vertical direction. Thus, the relative position of the fixed core 40 and the nozzle body 10 is determined. Then, the boundary portion between the nozzle body 10 and the fixed core 40 is joined by welding.

[0101] As described above, the diameter of the third outer peripheral surface 46d of the fixed core 40 is smaller than that of the first outer peripheral surface 46a, and the diameter of the third outer peripheral surface 10d of the nozzle body 10 is smaller than that of the first outer peripheral surface 10b. Thus, even if the boundary portion between the third outer peripheral surface 46d of the fixed core 40 and the third outer peripheral surface 10d of the nozzle body 10 is welded, the welded portion will not protrude radially outward relative to the first outer peripheral surface 46a of the fixed core 40 and the first outer peripheral surface 10b of the nozzle body 10.

[0102] In addition, the nozzle body 10 is loaded in the outer diameter direction and in the downward direction in the vertical direction due to the fuel pressure in the flow path FC. Therefore, in the present embodiment, the upper end surface 10e of the nozzle body 10 abuts against the stepped surface 46e of the fixed core 40 in the vertical direction. That is, the upper end surface 10e and the stepped surface 46e are in contact with each other in a direction substantially perpendicular to the direction in which the load caused by the fuel pressure is applied.

[0103] Thus, the downward load caused by the fuel pressure can be borne substantially evenly on the upper end surface 10e and the stepped surface 46e. Therefore, when the boundary between the upper end surface 10e and the stepped surface 46e is welded along the circumferential direction, the maximum stress generated is smaller than when the overlapping portion (press-fitted portion) is welded in a direction parallel to the direction in which the load is applied. As a result, the joint strength between the nozzle body 10 and the fixed core 40 can be improved.

[0104] In the existing nozzle body, the large-diameter portion is formed such that the length of the end face reaches the large-diameter portion 45 of the fixed core 40 (see Japanese Patent Publication No. 2013-151915). On the other hand, in the present embodiment, a first guiding portion (the first outer peripheral surface 46a) is provided on the fixed core 40, and a second guiding portion (the first outer peripheral surface 10b) is provided on the large-diameter portion 14 of the nozzle body 10. Thus, the length of the large-diameter portion 14 of the nozzle body 10 is shorter than that of the existing one, and therefore, the machining amount required to form the nozzle body 10 (the large-diameter portion 14) can be made smaller than that of the existing one. In addition, the nozzle body 10 can be miniaturized, the material used (the member before machining) can be reduced, and cost reduction can be achieved.

[0105] In addition, in the present embodiment, the first outer peripheral surface 46a is provided as the first guiding portion on the fixed core 40, and the first outer peripheral surface 10b is provided as the second guiding portion on the nozzle body 10. However, the first guiding portion and the second guiding portion according to the present invention may be provided on the fixed core. In this case, the joint portion between the fixed core and the nozzle body is provided on the lower side in the vertical direction compared to the embodiment. In addition, in this case, the first guiding portion and the second guiding portion are preferably in contact with the inner peripheral surface 51b of the coil bobbin on the upper side and the lower side of the central position in the axial direction (vertical direction) of the coil 50.

[0106] In addition, in the case where the joint portion between the fixed core and the nozzle body is offset downward in the vertical direction compared to the embodiment, one guiding portion may be provided for the fixed core. In this case, the guiding portion preferably contacts the upper side and the lower side with the center position of the axial direction (vertical direction) of the coil 50 interposed therebetween.

[0107] In addition, the first guiding portion and the second guiding portion according to the present invention may be provided on the nozzle body 10. In this case, the joint portion between the fixed core and the nozzle body is provided at the press-fitting portion on the upper side in the vertical direction compared to the embodiment. In this case, the first guiding portion and the second guiding portion preferably contact the inner peripheral surface 51b of the coil tube at the upper side and the lower side of the center position of the axial direction (vertical direction) of the coil 50.

[0108] In addition, in the case where the joint portion between the fixed core and the nozzle body is provided at the press-fitting portion on the upper side in the vertical direction compared to the embodiment, one guiding portion may be provided for the nozzle body. In this case, the guiding portion preferably contacts the upper side and the lower side with the center position of the axial direction (vertical direction) of the coil 50 interposed therebetween.

[0109] 3. Summary

[0110] As described above, the fuel injection device 1 (fuel injection device) according to the above embodiment includes: a movable core 30 (movable core); a fixed core 40 (fixed core) opposed to the movable core 30; a coil 50 (coil) that generates a magnetic attraction force between the fixed core 40 and the movable core 30 when energized; a housing 70 (housing) that covers the radially outer side of the coil 50; and a connecting portion 80 (resin member) that is filled into the housing 70 and covers the connecting portion of the coil 50. In addition, the fuel injection device 1 includes: a coil tube 51 (coil tube) that is disposed in the housing 70 and has an outer peripheral surface 51a (outer peripheral surface) of the coil tube that holds the coil 50 and an inner peripheral surface 51b (inner peripheral surface) of the coil tube that is opposite to the outer peripheral surface 51a; and a first outer peripheral surface 46a and a first outer peripheral surface 10b (guiding portion) that contact the inner peripheral surface 51b of the coil tube. The first space S1 and the second space S2 (internal space) are formed by the first outer peripheral surface 46a, the first outer peripheral surface 10b, and the inner peripheral surface 51b of the coil tube, and the first space S1 and the second space S2 communicate with the space filled with the connecting portion 80.

[0111] As a result, no air remains between the housing 70 and the coil 50, and the connection portion 80 can stably cover the coil 50. As a result, the waterproof performance of the coil 50 can be improved, and the influence on the basic characteristics (flow rate, injection amount, magnetic field generation, etc.) of the fuel injection device 1 can be suppressed. In addition, since the first outer peripheral surface 46a and the first outer peripheral surface 10b are in contact with the inner peripheral surface 51b of the coil tube, when the connection portion 80 is filled inside the housing 70, the coil tube 51 will not be deformed by the pressure of the resin member. As a result, it is possible to prevent or suppress the coil 50 wound around the coil tube 51 from being disordered, and the coil 50 can be stably covered by the connection portion 80.

[0112] In addition, in the fuel injection device 1 (fuel injection device) according to the above-described embodiment, the direction in which the movable core 30 (movable core) faces the fixed core 40 (fixed core) is set as the vertical direction, the side where the fixed core 40 is disposed is set as the upper side, and the side where the movable core 30 is disposed is set as the lower side. In this case, the internal space has a first space S1 (first space) and a second space S2 (second space). The first space S1 is formed above the first outer peripheral surface 46a (guide portion) in the vertical direction with respect to the first outer peripheral surface 46a by the first outer peripheral surface 46a and the inner peripheral surface 51b (inner peripheral surface) of the coil tube. The second space S2 is formed below the first outer peripheral surface 10b (guide portion) in the vertical direction with respect to the first outer peripheral surface 10b by the first outer peripheral surface 10b and the inner peripheral surface 51b of the coil tube. At least one of the first space S1 and the second space S2 communicates with the space filled with the connection portion 80. As a result, the space between the housing 70 and the coil 50 can be easily sealed in the first space S1 or the second space S2.

[0113] In addition, the axial direction of the coil 50 (coil) in the fuel injection device 1 (fuel injection device) according to the above-described embodiment is parallel to the vertical direction. The guide portion has a first outer peripheral surface 46a (first guide portion) that faces the upper side of the central position of the coil 50 in the vertical direction and is in contact with the inner peripheral surface 51b (inner peripheral surface) of the coil tube 51 (coil tube); and a first outer peripheral surface 10b (second guide portion) that faces the lower side of the central position of the coil 50 in the vertical direction and is in contact with the inner peripheral surface 51b. As a result, the pressure of the filling member does not concentrate on a part of the inner peripheral surface 51b of the coil tube. As a result, when the connection portion 80 (resin member) is filled inside the housing 70, the coil tube 51 will not be deformed by the pressure of the resin member.

[0114] In addition, the fuel injection device 1 (fuel injection device) according to the above-described embodiment includes: a valve body 20 (valve body) that moves in the vertical direction by a movable core 30 (movable core); and a nozzle body 10 (nozzle) that movably houses the valve body 20. A first outer peripheral surface 46a (first guide portion) is provided on a fixed core 40 (fixed core) disposed inside a coil tube 51 (coil tube). In addition, a first outer peripheral surface 10b (second guide portion) is provided on the nozzle body 10 disposed inside the coil tube 51. As a result, a reduction in the processing amount for forming the nozzle body 10 is achieved. In addition, the nozzle body 10 can be miniaturized, the materials used (components before processing) can be reduced, and cost reduction is achieved.

[0115] In addition, the fuel injection device according to the present invention may include: a valve body 20 (valve body) that moves in the vertical direction by a movable core 30 (movable core); and a nozzle body 10 (nozzle) that movably houses the valve body 20, and a first outer peripheral surface 46a (first guide portion) and a first outer peripheral surface 10b (second guide portion) are provided on the nozzle body 10 disposed inside a coil tube 51 (coil tube). As a result, processing for making the diameters (heights) of the first guide portion and the second guide portion the same becomes easy. In addition, when the first guide portion and the second guide portion are provided on the nozzle body 10, instead of forming a recess (second outer peripheral surface 10c) between the first guide portion and the second guide portion, the first guide portion and the second guide portion may be formed as one guide portion. As a result, processing for forming the guide portion becomes simple.

[0116] In addition, in the fuel injection device according to the present invention, a first outer peripheral surface 46a (first guide portion) and a first outer peripheral surface 10b (second guide portion) may be provided on a fixed core 40 (fixed core) disposed inside a coil tube 51 (coil tube). As a result, processing for making the diameters of the first guide portion and the second guide portion the same becomes easy. In addition, when the first guide portion and the second guide portion are provided on the fixed core 40, instead of forming a recess (second outer peripheral surface 10c) between the first guide portion and the second guide portion, the first guide portion and the second guide portion may be formed as one guide portion. As a result, processing for forming the guide portion becomes simple.

[0117] In addition, the first space S1 (first space) in the fuel injection device 1 (fuel injection device) according to the above-described embodiment communicates with the space of the filling connection portion 80 (resin member). The coil tube 51 (wire tube) has a first space communication groove 51e (first space communication groove) that communicates the space of the filling connection portion 80 with the first space S1. Thereby, the space of the filling connection portion 80 can be reliably communicated with the first space S1. As a result, no air remains between the housing 70 and the coil 50, and the coil 50 can be stably covered by the connection portion 80.

[0118] In addition, the second space S2 (second space) in the fuel injection device 1 (fuel injection device) according to the above-described embodiment communicates with the space of the filling connection portion 80 (resin member). The coil tube 51 (wire tube) has a second space communication groove 51f (second space communication groove) that communicates the space of the filling connection portion 80 with the second space S2. Thereby, the space of the filling connection portion 80 can be reliably communicated with the second space S2. As a result, no air remains between the housing 70 and the coil 50, and the coil 50 can be stably covered by the connection portion 80.

[0119] In addition, the first space communication groove 51e (first space communication groove) or the second space communication groove 51f (second space communication groove) in the fuel injection device 1 (fuel injection device) according to the above-described embodiment is provided at a position symmetric to the filling port where the connection portion 80 (resin member) is filled into the housing 70 (housing) with the central axis of the coil tube 51 (wire tube) as the axis. Thereby, in the portion where the connection portion 80 is finally filled, the air remaining between the housing 70 and the coil 50 can be sealed into the first space S1 or the second space S2. As a result, no air remains between the housing 70 and the coil 50, and the coil 50 can be stably covered by the connection portion 80.

[0120] As described above, the embodiments of the fuel injection device of the present invention have been described including their effects. However, the fuel injection device of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention described in the claims. In addition, the above-described embodiments are detailed descriptions for easily understanding the present invention, and the present invention is not limited to including all the structures described.

[0121] For example, the fuel injection device 1 according to the above-described embodiment forms a recess between the first outer peripheral surface 46a (first guide portion) and the first outer peripheral surface 10b (second guide portion) by providing the third outer peripheral surface 46d and the third outer peripheral surface 10d. However, as the fuel injection device according to the present invention, the first guide portion and the second guide portion may form a continuous one guide portion. Further, the fuel injection device 1 according to the above-described embodiment is provided with the first space S1 and the second space S2. However, as the fuel injection device according to the present invention, a configuration in which either the first space S1 or the second space S2 is provided may be employed.

[0122] In addition, in this specification, words such as "parallel" and "orthogonal" are used, but they do not only mean strict "parallel" and "orthogonal", but include both "parallel" and "orthogonal", and may also be in a state of "substantially parallel" and "substantially orthogonal" within a range where their functions can be exerted.

[0123] Reference Numeral Explanation

[0124] 1 Fuel injection device

[0125] 10 Nozzle body

[0126] 10a Inner peripheral surface

[0127] 10b First outer peripheral surface (second guide portion)

[0128] 10c Second outer peripheral surface

[0129] 10d Third outer peripheral surface

[0130] 10e Upper end surface

[0131] 11 Injection hole

[0132] 12 Injection hole forming member

[0133] 14 Large diameter portion

[0134] 16 Cylindrical hole

[0135] 20 Valve body

[0136] 21 Rear end portion

[0137] 22 Intermediate portion

[0138] 23 Front end portion

[0139] 30 Movable core

[0140] 40 Fixed core

[0141] 42 Through hole

[0142] 43 Opening

[0143] 45 Large-diameter part

[0144] 45a Outer peripheral surface

[0145] 45b Upper end surface

[0146] 45c Lower end surface

[0147] 45d Cutout outer peripheral surface

[0148] 46 Small-diameter part

[0149] 46a First outer peripheral surface (first guide part)

[0150] 46b Second outer peripheral surface

[0151] 46c Recessed part

[0152] 46d Third outer peripheral surface

[0153] 46e Step surface

[0154] 50 Coil

[0155] 51 Coil tube

[0156] 51a Outer peripheral surface of the tube

[0157] 51b Inner peripheral surface of the tube

[0158] 51c Upper end surface of the tube

[0159] 51d Lower end surface of the tube

[0160] 51e Connecting groove for the first space

[0161] 51f Connecting groove for the second space

[0162] 62 Adjusting member

[0163] 70 Housing

[0164] 70a First inner peripheral surface

[0165] 70b Second inner peripheral surface

[0166] 70c Step surface

[0167] 70d Inner bottom surface

[0168] 71 Through hole

[0169] 80 Connecting part

[0170] 81 Connector

[0171] 90 Filter

[0172] 124 seat part

[0173] 124a seat surface

[0174] 230 spherical part

[0175] 811 terminal

[0176] AX1 central axis

[0177] S1 first space

[0178] S2 second space.

Claims

1. A fuel injection device, comprising: A movable core; A fixed core opposite to the movable core; A coil that generates a magnetic attraction force between the fixed core and the movable core when energized; A housing covering the radial outer side of the coil; And a resin member filled into the housing and covering the coil. The fuel injection device is characterized in that it includes: A bobbin, which is arranged in the housing and has an outer peripheral surface for holding the coil and an inner peripheral surface on the side opposite to the outer peripheral surface; And A guiding portion that contacts the inner peripheral surface of the bobbin, An internal space is formed by the guiding portion and the inner peripheral surface of the bobbin, The internal space communicates with the space filled with the resin member.

2. The fuel injection device according to claim 1, wherein When the direction in which the movable core faces the fixed core is set as the vertical direction, the side where the fixed core is arranged is set as the upper side, and the side where the movable core is arranged is set as the lower side, The internal space has: A first space formed on the upper side in the vertical direction of the guiding portion through the guiding portion and the inner peripheral surface of the bobbin; And A second space formed on the lower side in the vertical direction of the guiding portion through the guiding portion and the inner peripheral surface of the bobbin, At least one of the first space and the second space communicates with the space filled with the resin member.

3. The fuel injection device according to claim 2, wherein The axial direction of the coil is parallel to the vertical direction, The guiding portion has: A first guiding portion that faces the upper side of the central position of the coil in the vertical direction and contacts the inner peripheral surface of the bobbin; And a second guiding portion that faces the lower side of the central position of the coil in the vertical direction and contacts the inner peripheral surface of the bobbin.

4. The fuel injection device according to claim 3, characterized in that, Comprising: A valve body that moves in the vertical direction through the movable core; And A nozzle that movably houses the valve body, The first guiding portion is provided on the fixed core arranged inside the bobbin, The second guiding portion is provided on the nozzle arranged inside the bobbin.

5. The fuel injection device according to claim 3, characterized in that, Comprising: A valve body that moves in the vertical direction through the movable core; And A nozzle having a through hole for the valve body to pass through, The first guiding portion and the second guiding portion are provided on the nozzle arranged inside the bobbin.

6. The fuel injection device according to claim 3, wherein The first guiding portion and the second guiding portion are provided on the fixed core arranged inside the bobbin.

7. The fuel injection device according to claim 2, wherein The first space communicates with the space filled with the resin member, The bobbin has a communication groove for the first space, and the communication groove for the first space communicates the space filled with the resin member with the first space.

8. The fuel injection device according to claim 2, wherein The second space communicates with the space filled with the resin member, The bobbin has a communication groove for the second space, and the communication groove for the second space communicates the space filled with the resin member with the second space.

9. The fuel injection device according to claim 7 or 8, characterized in that the communication groove for the first space or the communication groove for the second space is provided at a position that is axially symmetric with respect to the central axis of the coil and symmetric to the filling port where the resin member is filled into the housing.

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