Fuel injection valve

Abstract

To provide a fuel injection valve for suppressing the embrittlement of a metallic component by hydrogen fuel.SOLUTION: The metallic component includes a hydrogen shielding film 20 provided covering at least part of the surface of a base material and capable of shielding hydrogen, the hydrogen shielding film 20 being a multilayer film where a first nitride film 21 formed of a first titanium nitride composite material including titanium nitride and a second nitride film 22 formed of a second titanium nitride composite material different in composition from the first titanium nitride composite material are layered.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a fuel injection valve. [Background technology]

[0002] For example, Patent Document 1 discloses an electromagnetic fuel injection valve. The electromagnetic fuel injection valve disclosed in Patent Document 1 includes a coil that generates a magnetic force when current is applied to the coil. The electromagnetic fuel injection valve disclosed in Patent Document 1 moves a valve body using the magnetic force generated by applying current to the coil, and injects fuel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6788085 Public Relations Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, in recent years, attempts have been made to use a fuel injection valve that directly injects hydrogen fuel in an internal combustion engine that uses hydrogen fuel. The fuel injection valve disclosed in Patent Document 1 is intended to inject fossil fuels such as gasoline and diesel. The components that constitute the fuel injection valve disclosed in Patent Document 1 are mainly made of metal. However, it is known that hydrogen fuel embrittles metals. For this reason, when a fuel injection valve is used to inject hydrogen fuel, it is necessary to suppress the embrittlement of metal components.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to suppress embrittlement of metal parts in a fuel injection device due to hydrogen fuel. [Means for solving the problem]

[0006] The present invention employs the following configuration as a means for solving the above problems.

[0007] One aspect of the present invention is a fuel injection valve that injects hydrogen fuel, comprising a metal component having a base material formed from a metal, the metal component comprising a hydrogen shielding film arranged to cover at least a portion of the surface of the base material and capable of shielding hydrogen, the hydrogen shielding film being a multilayer film formed by laminating a first nitride film made of a first titanium nitride composite material containing titanium nitride and a second nitride film made of a second titanium nitride composite material having a composition different from that of the first titanium nitride composite material. Effect of the Invention

[0008] The present invention provides a metal component equipped with a hydrogen barrier film that is provided so as to cover the surface of a base material. Also, in the present invention, the hydrogen barrier film is a multilayer film in which a first nitride film and a second nitride film having different compositions are laminated. Such a hydrogen barrier film can suppress hydrogen permeation. Therefore, the present invention can suppress hydrogen from coming into contact with the base material of the metal component, and suppress embrittlement of the metal component. Therefore, the present invention can suppress embrittlement of the metal component due to hydrogen fuel in a fuel injection device. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view showing a schematic configuration of a fuel injection valve according to an embodiment of the present invention. [Diagram 2] 2 is a schematic cross-sectional view of a fixed core included in the fuel injection valve according to the embodiment of the present invention. FIG. [Diagram 3] 2 is a schematic cross-sectional view of a hydrogen barrier film provided in a fuel injection valve according to an embodiment of the present invention. FIG. [Figure 4] 3 is a conceptual diagram for explaining the principle of hydrogen shielding in a hydrogen shielding film provided in the fuel injection valve according to the embodiment of the present invention. FIG. [Diagram 5] 1 is a schematic cross-sectional view including a low-friction film provided in a fuel injection valve according to an embodiment of the present invention. [Figure 6]1 is a schematic cross-sectional view including a hard chrome plating layer provided on a fuel injection valve according to an embodiment of the present invention. FIG. [Figure 7] 2 is a schematic cross-sectional view of a non-magnetic cylindrical body provided in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 8] 2 is a schematic cross-sectional view of a housing body provided in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 9] 2 is a schematic cross-sectional view of a valve seat member provided in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 10] 1 is a schematic cross-sectional view of a rod, a valve portion, a valve-opening stopper, and a valve-closing stopper provided in a fuel injection valve according to an embodiment of the present invention. [Figure 11] 2 is a schematic cross-sectional view of a movable core included in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 12] 3 is a schematic cross-sectional view of an inner collar included in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 13] 4 is a schematic cross-sectional view of a return spring provided in the fuel injection valve according to the embodiment of the present invention. FIG. [Figure 14] 3 is a schematic cross-sectional view of an auxiliary spring provided in the fuel injection valve according to the embodiment of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a fuel injection valve according to the present invention will be described with reference to the drawings.

[0011] 1 is a schematic cross-sectional view showing a schematic configuration of a fuel injection valve 1 of this embodiment. The fuel injection valve 1 of this embodiment is an electromagnetic valve device that injects and supplies hydrogen fuel to an internal combustion engine that uses hydrogen fuel. The fuel injection valve of the present invention is applicable to a direct injection type fuel injection valve that injects hydrogen fuel into a cylinder of an internal combustion engine, and a port type fuel injection valve that injects hydrogen fuel into an intake port.

[0012] As shown in Fig. 1, the fuel injection valve 1 of this embodiment includes a valve housing 2, a valve body 3, an inner collar 4, a return spring 5 (spring), an auxiliary spring 6 (spring), an orifice member 7, a filter member 8, a covering portion 9, and a coil 10. The valve housing 2, the valve body 3, the inner collar 4, the return spring 5, the auxiliary spring 6, and the orifice member 7 are metal parts mainly made of metal. Such metal parts have a base material made of metal. The base material is made of, for example, stainless steel or brass.

[0013] The valve housing 2 is a component having a fuel passage R therein for guiding the hydrogen fuel X. In this embodiment, the valve housing 2 includes a fixed core 2a, a non-magnetic cylindrical body 2b, a housing body 2c, and a valve seat member 2d. In the following description, for convenience of explanation, the direction in which the hydrogen fuel X is guided in the fuel passage R is defined as the up-down direction, with the upstream end side of the fuel passage R defined as the upper side and the downstream end side of the fuel passage R defined as the lower side. However, the installation position of the fuel injection valve 1 in this embodiment is not limited to the case where the above-mentioned up-down direction is parallel to the direction of gravity.

[0014] 2 is a schematic cross-sectional view of the fixed core 2a. The fixed core 2a is a cylindrical member located in the upper part of the valve housing 2. The fixed core 2a has a through hole 2a1 that penetrates in the vertical direction. This through hole 2a1 forms the upper part of the fuel passage R.

[0015] The lower surface of the fixed core 2a is an abutment surface 2a2 with a movable core 3e (described later) of the valve body 3. The movable core 3e abuts against the abutment surface 2a2 from below, restricting the upward movement of the valve body 3. The movable core 3e abuts against the fixed core 2a when the valve body 3 is in the valve open position.

[0016] The through hole 2a1 of the fixed core 2a accommodates the inner collar 4, the return spring 5, and the auxiliary spring 6. The through hole 2a1 of the fixed core 2a accommodates a valve-opening stopper 3c (described later) of the valve body 3 so as to be slidable in the vertical direction. In other words, the inner peripheral surface of the through hole 2a1 is a sliding surface 2a3 with the valve-opening stopper 3c.

[0017] Such a fixed core 2a is provided with a hydrogen shielding film 20 that covers at least a part of the surface of the base material. Fig. 3 is a schematic cross-sectional view of the hydrogen shielding film 20. The hydrogen shielding film 20 is a multilayer film in which first nitride films 21 and second nitride films 22 are alternately laminated, and is provided so as to cover the surface of a base material 30. Note that the base material 30 shown in Fig. 3 is not limited to the base material of the fixed core 2a, but indicates the base material of a metal part that is not limited to a specific part.

[0018] In FIG. 3, the hydrogen shielding film 20 includes two layers each of the first nitride film 21 and the second nitride film 22. However, the number of the first nitride films 21 and the second nitride films 22 included in the hydrogen shielding film 20 is not particularly limited. In FIG. 3, the layer closest to the base material 30 is the first nitride film 21, and the layer of the hydrogen shielding film 20 farthest from the base material 30 is the second nitride film 22. However, the layer closest to the base material 30 may be the second nitride film 22. In addition, the layer of the hydrogen shielding film 20 farthest from the base material 30 may be the first nitride film 21.

[0019] The first nitride film 21 is made of a first titanium nitride composite material containing titanium nitride. The first nitride film 21 is made of, for example, titanium silicon niobium nitride (TiMoN), which is a titanium nitride composite material containing molybdenum (Mo). The second nitride film 22 is made of a second titanium nitride composite material having a different composition from the first titanium nitride composite material. The second nitride film 22 is made of, for example, titanium molybdenum nitride (TiSiNbN), which is a titanium nitride composite material containing silicon (Si) and niobium (Nb). The second nitride film 22 is made of, for example, titanium aluminum nitride (TiAlN), which is a titanium nitride composite material containing aluminum (Al).

[0020] Fig. 4 is a conceptual diagram for explaining the principle of hydrogen shielding in the hydrogen shielding film 20. As shown in Fig. 4, the first nitride film 21 and the second nitride film 22 are made of a titanium nitride composite material in which an additive is added to titanium nitride (TiN), and are made of an aggregate of crystal grains that are finer than those of a film made of titanium nitride. Since the crystal grains of such first nitride film 21 and second nitride film 22 are each fine, the hydrogen trapping effect within the film is high.

[0021] Furthermore, the first nitride film 21 and the second nitride film 22 are made of titanium nitride composite materials having different compositions (i.e., different additives). Such a hydrogen barrier film 20 can trap hydrogen at the boundary between the first nitride film 21 and the second nitride film 22. Therefore, the hydrogen barrier film 20 has a higher hydrogen trapping effect than a single-layer hydrogen barrier film made of only the first nitride film 21 or the second nitride film 22.

[0022] As described above, the hydrogen shielding film 20 in this embodiment has a high hydrogen trapping effect and can prevent hydrogen from reaching the base material 30. As shown in FIG. 5, the metal part may include a low-friction film 40 provided on the surface 20a of the hydrogen shielding film 20. The low-friction film 40 has a lower hydrogen shielding performance than the hydrogen shielding film 20, but has a lower sliding resistance than the hydrogen shielding film 20. The low-friction film 40 can be made of, for example, a high-hardness fluororesin or chromium nitride material. The low-friction film 40 containing such fluororesin or chromium nitride (CrN) has a high bonding strength with the hydrogen shielding film 20.

[0023] 6, the metal part may have a hard chrome plating layer 50 disposed between the base material 30 and the hydrogen shielding film 20. The hard chrome plating layer 50 is a plating layer having a thickness of, for example, 1 μm or more. Although the hard chrome plating layer 50 has a lower hydrogen shielding performance than the hydrogen shielding film 20, it has a higher hardness than the hydrogen shielding film 20. By providing such a hard chrome plating layer 50, the impact resistance of the metal part is improved.

[0024] A hydrogen barrier film 20 is provided to cover the base material 30 at least in an area of ​​the surface of the fixed core 2a that may come into contact with the hydrogen fuel X. The hydrogen barrier film 20 may be provided on the entire surface of the fixed core 2a.

[0025] In addition, the contact surface 2a2 of the fixed core 2a is provided with a laminated hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the contact surface 2a2 in this manner, sliding wear of the contact surface 2a2 can be suppressed even if the movable core 3e rubs against the contact surface 2a2.

[0026] Also, the sliding surface 2a3 of the fixed core 2a is provided with a laminate of the hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the sliding surface 2a3 in this manner, sliding wear of the sliding surface 2a3 can be suppressed even if the valve-opening side stopper 3c rubs against the sliding surface 2a3.

[0027] Moreover, it is preferable that the hydrogen shielding film 20 and the low-friction film 40 are non-magnetic. By making the hydrogen shielding film 20 a non-magnetic material, the hydrogen shielding film 20 can have the same function as an air gap in a magnetic circuit, and the non-magnetic effect can be enhanced. By making the low-friction film 40 a non-magnetic material, the low-friction film 40 can have the same function as an air gap in a magnetic circuit, and the non-magnetic effect can be enhanced.

[0028] Furthermore, the contact surface 2a2 of the fixed core 2a and the sliding surface 2a3 of the fixed core 2a are provided with a hard chrome plating layer 50 located between the base material 30 and the hydrogen shielding film 20. By providing the hard chrome plating layer 50 on the contact surface 2a2 and the sliding surface 2a3 in this manner, the impact resistance of the fixed core 2a can be improved.

[0029] 7 is a schematic cross-sectional view of the non-magnetic cylinder 2b. The non-magnetic cylinder 2b is a cylindrical member connected to the lower part of the fixed core 2a. The non-magnetic cylinder 2b is made of a non-magnetic material and is disposed between the coil 10 and the movable core 3e.

[0030] At least an area of ​​the surface of the non-magnetic cylinder 2b that may come into contact with the hydrogen fuel X is provided with a hydrogen shielding film 20 so as to cover the base material 30. The hydrogen shielding film 20 may be provided on the entire surface of the non-magnetic cylinder 2b.

[0031] Moreover, the hydrogen shielding film 20 and the low-friction film 40 provided so as to cover the hydrogen shielding film 20 are laminated on the inner peripheral surface 2b1 of the non-magnetic cylinder 2b. The inner peripheral surface 2b1 of the non-magnetic cylinder 2b is the sliding surface on which the movable core 3e slides. By providing the low-friction film 40 on the inner peripheral surface 2b1 in this manner, sliding wear of the inner peripheral surface 2b1 can be suppressed even if the movable core 3e rubs against the inner peripheral surface 2b1.

[0032] It is preferable that both the hydrogen barrier film 20 and the low-friction film 40 provided on the surface of the non-magnetic cylinder 2b are made of non-magnetic materials, thereby enhancing the non-magnetic effect as described above.

[0033] 8 is a schematic cross-sectional view of the housing body 2c. The housing body 2c is connected to the lower part of the non-magnetic cylinder 2b. The housing body 2c is a substantially cylindrical member with a smaller diameter at the lower part than at the upper part. The housing body 2c has a through hole 2c1 that penetrates in the vertical direction. Such a through hole 2c1 forms the lower part of the fuel passage R.

[0034] A hydrogen barrier film 20 is provided to cover the base material 30 at least in an area of ​​the surface of the housing body 2c that may come into contact with the hydrogen fuel X. The hydrogen barrier film 20 may be provided on the entire surface of the housing body 2c.

[0035] The inner wall surface at the top of the through hole 2c1 is the sliding surface 2c2 along which the movable core 3e slides. A hydrogen shielding film 20 and a low-friction film 40 are laminated on the sliding surface 2c2, the low-friction film 40 being provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the sliding surface 2c2 in this manner, sliding wear of the sliding surface 2c2 can be suppressed even if the movable core 3e rubs against the sliding surface 2c2.

[0036] It is preferable that both the hydrogen barrier film 20 and the low-friction film 40 provided on the surface of the housing body 2c are made of non-magnetic materials, thereby enhancing the non-magnetic effect as described above.

[0037] 9 is a schematic cross-sectional view of the valve seat member 2d. The valve seat member 2d is formed in a cylindrical shape with a bottom, and is connected to the lower end of the housing body 2c. The internal space of the valve seat member 2d forms the lower end of the fuel passage R. This valve seat member 2d is provided with a fuel injection hole 2d1 for injecting hydrogen fuel X toward the bottom.

[0038] At least an area of ​​the surface of the valve seat member 2d that may come into contact with the hydrogen fuel X is provided with a hydrogen barrier film 20 so as to cover the base material 30. The hydrogen barrier film 20 may be provided on the entire surface of the valve seat member 2d.

[0039] A valve portion 3b of the valve body 3, which will be described later, is accommodated inside the valve seat member 2d so as to be movable up and down. An inner wall surface 2d2 of the valve seat member 2d is a sliding surface and abutting surface with the valve portion 3b. A hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20 are laminated on the inner wall surface 2d2. By providing the low-friction film 40 on the inner wall surface 2d2 in this manner, sliding wear of the inner wall surface 2d2 can be suppressed even if the movable core 3e rubs against the inner wall surface 2d2.

[0040] The valve element 3 is a member that is moved vertically inside the fuel passage R. The valve element 3 is movable between a valve-closing position where the valve portion 3b closes the fuel nozzle hole 2d1 of the valve seat member 2d and a valve-opening position where the valve portion 3b is moved upward from the valve-closing position to open the fuel nozzle hole 2d1. The valve element 3 includes a rod 3a, a valve portion 3b, a valve-opening stopper 3c (stopper), a valve-closing stopper 3d (stopper), and a movable core 3e.

[0041] 10 is a schematic cross-sectional view of rod 3a, valve portion 3b, valve-opening stopper 3c, and valve-closing stopper 3d. Rod 3a is a rod member that is housed in fuel passage R and extends linearly in the vertical direction.

[0042] A hydrogen barrier film 20 is provided to cover at least the area of ​​the surface of the rod 3a that may come into contact with the hydrogen fuel X. The hydrogen barrier film 20 may be provided on the entire surface of the rod 3a.

[0043] Furthermore, a part of the surface of the rod 3a is a sliding surface 3a1 along which the movable core 3e slides. A hydrogen shielding film 20 and a low-friction film 40 are laminated on the sliding surface 3a1, the low-friction film 40 being provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the sliding surface 3a1 in this manner, sliding wear of the sliding surface 3a1 can be suppressed even if the movable core 3e rubs against the sliding surface 3a1.

[0044] The valve portion 3b is a spherical member fixed to the lower end of the rod 3a. The valve portion 3b is welded to the lower end of the rod 3a. At least an area of ​​the surface of the valve portion 3b that may come into contact with the hydrogen fuel X is provided with a hydrogen shielding film 20 so as to cover the base material 30. The hydrogen shielding film 20 may be provided on the entire surface of the valve portion 3b.

[0045] Furthermore, a part of the surface of the valve portion 3b is a contact surface 3b1 that comes into contact with the valve seat member 2d. A hydrogen shielding film 20 and a low-friction film 40 that is provided so as to cover the hydrogen shielding film 20 are laminated on the contact surface 3b1. By providing the low-friction film 40 on the contact surface 3b1 in this manner, sliding wear of the contact surface 3b1 can be suppressed even if the movable core 3e rubs against the contact surface 3b1.

[0046] The valve-opening stopper 3c is a stopper against which the movable core 3e abuts when the valve body 3 is in the valve-open position. The valve-opening stopper 3c is disposed above the movable core 3e and is welded to the rod 3a.

[0047] The valve-opening stopper 3c has a cylindrical portion 3c1 and a flange 3c2 provided at the upper end of the cylindrical portion 3c1. The rod 3a is inserted into the cylindrical portion 3c1 and is welded to the rod 3a. The lower surface of the cylindrical portion 3c1 is an abutment surface 3c3 with the movable core 3e. The upper surface of the flange 3c2 is an abutment surface 3c4 with the return spring 5. The lower surface of the flange 3c2 is an abutment surface 3c5 with the auxiliary spring 6. The peripheral surface of the flange 3c2 is a sliding surface 3c6 with the fixed core 2a (i.e., the valve housing 2).

[0048] A hydrogen shielding film 20 is provided to cover at least an area of ​​the surface of the valve-opening stopper 3c that may come into contact with the hydrogen fuel X. The hydrogen shielding film 20 may be provided on the entire surface of the valve-opening stopper 3c.

[0049] The contact surface 3c3, the contact surface 3c4, the contact surface 3c5 and the sliding surface 3c6 are provided with a hydrogen shielding film 20 and a low friction film 40 provided so as to cover the hydrogen shielding film 20, which are laminated together. By providing the low friction film 40 on the contact surface 3c3 in this manner, even if the movable core 3e rubs against the contact surface 3c3, sliding wear of the contact surface 3c3 can be suppressed. Furthermore, by providing the low friction film 40 on the contact surface 3c4, even if the return spring 5 rubs against the contact surface 3c4, sliding wear of the contact surface 3c4 can be suppressed. Furthermore, by providing the low friction film 40 on the contact surface 3c5, even if the auxiliary spring 6 rubs against the contact surface 3c5, sliding wear of the contact surface 3c5 can be suppressed. Furthermore, by providing the low-friction film 40 on the sliding surface 3c6, even if the valve-opening stopper 3c rubs against the inner wall surface of the fuel passage R, sliding wear of the sliding surface 3c6 can be suppressed.

[0050] The valve-closing side stopper 3d is a stopper against which the movable core 3e abuts when the valve element 3 is in the valve-closed position. The valve-closing side stopper 3d is disposed below the movable core 3e and welded to the rod 3a. The valve-opening side stopper 3c and the valve-closing side stopper 3d are disposed at a distance that allows the movable core 3e to slide vertically relative to the rod 3a.

[0051] At least an area of ​​the surface of the closing side stopper 3d that may come into contact with the hydrogen fuel X is provided with a hydrogen shielding film 20 so as to cover the base material 30. The hydrogen shielding film 20 may be provided on the entire surface of the closing side stopper 3d.

[0052] An upper surface of the closing-side stopper 3d is a contact surface 3d1 of the movable core 3e. A hydrogen shielding film 20 and a low-friction film 40 are laminated on the contact surface 3d1, the low-friction film 40 being provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the contact surface 3d1 in this manner, sliding wear of the contact surface 3d1 can be suppressed even if the movable core 3e rubs against the contact surface 3d1.

[0053] In this embodiment, the hydrogen shielding film 20 is provided so as to cover a joint portion P1 between the valve portion 3b and the rod 3a, a joint portion P2 between the valve-opening stopper 3c and the rod 3a, and a joint portion P3 between the valve-closing stopper 3d and the rod 3a, as shown in Fig. 10. Such a hydrogen shielding film 20 is formed, for example, by welding the rod 3a, the valve portion 3b, the valve-opening stopper 3c, and the valve-closing stopper 3d together to form an integrated member, and then forming a film on the integrated member. Such a hydrogen shielding film 20 is formed, for example, by physical vapor deposition.

[0054] FIG. 11 is a schematic cross-sectional view of the movable core 3e. The movable core 3e is a member that is moved in the fuel passage by energizing the coil 10, and is formed in a disk shape having a certain thickness. The movable core 3e is moved upward by a magnetic force generated by energizing the coil 10. Such a movable core 3e is disposed so as to straddle the interior of the non-magnetic cylindrical body 2b and the interior of the upper part of the housing body 2c. The rod 3a penetrates the center of the movable core 3e in the vertical direction. Such a movable core 3e is movable in the vertical direction so as to slide relative to the rod 3a.

[0055] The movable core 3e is provided with a plurality of through holes 3e1 that penetrate in the vertical direction. Hydrogen fuel X passes through the movable core 3e from top to bottom through these through holes 3e1. The upper surface of the movable core 3e is an abutment surface 3e2 with the valve-opening stopper 3c and the auxiliary spring 6. The lower surface of the movable core 3e is an abutment surface 3e3 with the valve-closing stopper 3d. The outer peripheral surface of the movable core 3e is a sliding surface 3e4 with the valve housing 2 (the non-magnetic cylindrical body 2b and the housing body 2c). The outer peripheral surface without the movable core 3e is a sliding surface 3e5 with the rod 3a.

[0056] The entire surface of the movable core 3e may come into contact with the hydrogen fuel X. For this reason, the hydrogen shielding film 20 is provided so as to cover the entire surface of the base material 30 of the movable core 3e. The contact surface 3e2, the contact surface 3e3, the sliding surface 3e4, and the sliding surface 3e5 are provided with the hydrogen shielding film 20 and the low-friction film 40 provided so as to cover the hydrogen shielding film 20 in a laminated manner. By providing the low-friction film 40 on the contact surface 3e2 in this manner, even if the valve-opening side stopper 3c and the auxiliary spring 6 rub against the contact surface 3e2, the sliding wear of the contact surface 3e2 can be suppressed. By providing the low-friction film 40 on the contact surface 3e3, even if the valve-closing side stopper 3d rubs against the contact surface 3e3, the sliding wear of the contact surface 3e3 can be suppressed. Furthermore, by providing the low-friction film 40 on the sliding surface 3e4, even if the movable core 3e rubs against the inner wall surface of the fuel passage R, sliding wear of the sliding surface 3e4 can be suppressed.

[0057] Furthermore, the contact surfaces 3e2, 3e3 and the sliding surface 3e4 are provided with a hard chrome plating layer 50 located between the base material 30 and the hydrogen shielding film 20. By providing the hard chrome plating layer 50 on the contact surfaces 3e2, 3e3 and the sliding surface 3e in this manner, the impact resistance of the movable core 3e can be improved.

[0058] 12 is a schematic cross-sectional view of the inner collar 4. The inner collar 4 is a cylindrical member disposed inside the fuel passage R. The inner collar 4 is disposed above the return spring 5. The lower surface of the inner collar 4 is a contact surface 4a with the return spring 5.

[0059] The inner collar 4 is press-fitted into the through hole 2a1 of the fixed core 2a. The peripheral surface of the inner collar 4 is a pressure contact surface 4b with the valve housing 2 (fixed core 2a). The inner collar 4 is a member for adjusting the compression amount of the return spring 5 and regulating the pressure of the return spring 5.

[0060] A hydrogen barrier film 20 is provided to cover at least the area of ​​the surface of the inner collar 4 that may come into contact with the hydrogen fuel X. In this embodiment, the hydrogen barrier film 20 is provided on the entire surface of the inner collar 4.

[0061] In addition, the contact surface 4a and the pressure contact surface 4b are provided with a laminated hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the contact surface 4a in this manner, sliding wear of the contact surface 4a can be suppressed even if the return spring 5 rubs against the contact surface 4a. In addition, by providing the low-friction film 40 on the pressure contact surface 4b, sliding wear of the pressure contact surface 4b can be suppressed even if the inner collar 4 rubs against the inner wall surface of the fuel passage R.

[0062] 13 is a schematic cross-sectional view of the return spring 5. The return spring 5 is interposed between the inner collar 4 and the valve-opening stopper 3c, and biases the valve body 3 toward the valve-closed position. The return spring 5 holds the valve body 3 in the valve-closed position when the coil 10 is not energized.

[0063] The entire surface of the return spring 5 comes into contact with the hydrogen fuel X. For this reason, the return spring 5 is provided with a hydrogen shielding film 20 so as to cover the entire surface of the base material 30. The upper end surface of the return spring 5 is an abutment surface 5a with the inner collar 4. Moreover, the lower end surface of the return spring 5 is an abutment surface 5b with the valve-opening side stopper 3c.

[0064] The contact surfaces 5a and 5b are provided with a laminate of a hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the contact surface 5a in this manner, sliding wear of the contact surface 5a can be suppressed even if the inner collar 4 rubs against the contact surface 5a. Furthermore, by providing the low-friction film 40 on the contact surface 5b, sliding wear of the contact surface 5b can be suppressed even if the valve-opening side stopper 3c rubs against the contact surface 5b.

[0065] 14 is a schematic cross-sectional view of the auxiliary spring 6. The auxiliary spring 6 is inserted between the flange 3c2 of the valve-opening stopper 3c and the movable core 3e, and biases the movable core 3e downward. The auxiliary spring 6 holds the movable core 3e in the valve-closed position (position in contact with the valve-closing stopper 3d) when the coil 10 is not energized.

[0066] The entire surface of the auxiliary spring 6 comes into contact with the hydrogen fuel X. For this reason, the auxiliary spring 6 is provided with a hydrogen shielding film 20 so as to cover the entire surface of the base material 30. The upper end surface of the auxiliary spring 6 is an abutment surface 6a with the valve-opening side stopper 3c. The lower end surface of the auxiliary spring 6 is an abutment surface 6b with the movable core 3e.

[0067] The contact surfaces 6a and 6b are provided with a laminated hydrogen shielding film 20 and a low-friction film 40 provided so as to cover the hydrogen shielding film 20. By providing the low-friction film 40 on the contact surface 6a in this manner, sliding wear of the contact surface 6a can be suppressed even if the valve-opening stopper 3c rubs against the contact surface 6a. Also, by providing the low-friction film 40 on the contact surface 6b, sliding wear of the contact surface 6b can be suppressed even if the movable core 3e rubs against the contact surface 6b.

[0068] Returning to Fig. 1, the orifice member 7 is attached to the upper end opening of the fixed core 2a. In other words, the orifice member 7 is installed at the inlet portion of the fuel passage R. Such an orifice member 7 adjusts the flow speed of the hydrogen fuel X supplied to the fuel passage R.

[0069] At least an area of ​​the surface of the orifice member 7 that may come into contact with the hydrogen fuel X is provided with a hydrogen shielding film 20 so as to cover the base material 30. The hydrogen shielding film 20 may be provided on the entire surface of the orifice member 7.

[0070] The filter member 8 is disposed below the orifice member 7, and is housed inside the fuel passage R. This filter member 8 is a member for removing foreign matter contained in the hydrogen fuel X. The filter member 8 is press-fitted into the fixed core 2a via a filter collar 11. In other words, the filter collar 11 is interposed between the filter member 8 and the inner wall surface of the fuel passage R.

[0071] The filter collar 11 is a metal component having a base material 30 made of metal. A hydrogen barrier film 20 may be provided on the surface of such a filter collar 11. By providing the hydrogen barrier film 20 on the surface of the filter collar 11, it is possible to prevent the filter collar 11 from becoming embrittled by hydrogen.

[0072] The covering portion 9 is provided for machining the fixed core 2a from the radial outside. The covering portion 9 is formed of an insulator and holds the wiring connected to the coil 10. The covering portion 9 also includes a connector 9a for connecting an end of the wiring connected to the coil 10 to an external terminal. The coil 10 is fixed to the valve housing 2 for machining the movable core 3e in a state where it is molded with an insulator. The coil 10 generates a magnetic force when current is applied from the outside, and moves the movable core 3e upward.

[0073] In the fuel injection valve 1 of this embodiment, when the coil 10 is energized, the movable core 3e moves upward and comes into contact with the valve-opening stopper 3c. The movable core 3e further rises until it comes into contact with the fixed core 2a. As the movable core 3e rises toward the fixed core 2a, the valve-opening stopper 3c moves upward, and the valve body 3 moves to the valve-open position. When the valve body 3 is moved to the valve-open position in this manner, the fuel nozzle 2d1 of the valve seat member 2d is opened, and the hydrogen fuel X in the fuel passage R is injected.

[0074] On the other hand, when the current passing through the coil 10 is stopped, the movable core 3e is moved downward by the biasing force of the auxiliary spring 6 and abuts against the valve-closing stopper 3d. Furthermore, the valve body 3 is moved to the valve-closing position by the biasing force of the return spring 5. This closes the fuel injection hole 2d1 of the valve seat member 2d, and the injection of the hydrogen fuel X is stopped.

[0075] The fuel injection valve 1 of this embodiment as described above injects hydrogen fuel X. The fuel injection valve 1 of this embodiment also includes metal components (the valve housing 2, the valve body 3, the inner collar 4, the return spring 5, the auxiliary spring 6, and the orifice member 7) having a base material formed of metal. The metal components include a hydrogen shielding film 20. The hydrogen shielding film 20 is provided so as to cover at least a part of the surface of the base material 30 and is capable of shielding hydrogen. The hydrogen shielding film 20 is a multilayer film in which a first nitride film 21 made of a first titanium nitride composite material containing titanium nitride and a second nitride film 22 made of a second titanium nitride composite material having a different composition from the first titanium nitride composite material are laminated.

[0076] In this way, the hydrogen barrier film 20 is a multilayer film in which the first nitride film 21 and the second nitride film 22, which have different compositions, are laminated. Such a hydrogen barrier film 20 can suppress the permeation of hydrogen. Therefore, the fuel injection valve 1 of this embodiment can suppress the contact of hydrogen with the base material 30 of the metal component, and suppress the embrittlement of the metal component.

[0077] Although the preferred embodiment of the present invention has been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to the above embodiment. The shapes and combinations of the components shown in the above embodiment are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0078] For example, in the above embodiment, the valve housing 2, valve element 3, inner collar 4, return spring 5, auxiliary spring 6 and orifice member 7 are metal parts, and all of these metal parts have the hydrogen shielding film 20. However, the present invention is not limited to this. For example, it is also possible to adopt a configuration in which only some of the multiple metal parts are provided with the hydrogen shielding film 20. It is also possible to configure the valve housing 2, valve element 3, inner collar 4, return spring 5, auxiliary spring 6 and orifice member 7 so as not to have a metal base material 30.

[0079] The above embodiment can also be described as, for example, the following supplementary notes.

[0080] (Appendix 1) A fuel injection valve for injecting hydrogen fuel, A metal part having a base material formed of a metal, the metal component includes a hydrogen barrier film that is provided so as to cover at least a portion of a surface of the base material and is capable of blocking hydrogen; The hydrogen barrier film is a multilayer film in which a first nitride film made of a first titanium nitride composite material containing titanium nitride and a second nitride film made of a second titanium nitride composite material having a different composition from the first titanium nitride composite material are laminated. A fuel injection valve characterized by:

[0081] (Appendix 2) the first nitride film is made of the first titanium nitride composite material titanium silicon niobium nitride containing molybdenum; The second nitride film is made of titanium molybdenum nitride, which is the second titanium nitride composite material containing silicon and niobium. 2. The fuel injection valve according to claim 1.

[0082] (Appendix 3) the first nitride film is made of the first titanium nitride composite material titanium silicon niobium nitride containing molybdenum; The second nitride film is made of titanium aluminum nitride, which is the second titanium nitride composite material containing aluminum. 2. The fuel injection valve according to claim 1.

[0083] (Appendix 4) The metal part includes: a valve housing having a fuel passage therein; a valve body that moves within the fuel passage; A spring that biases the valve body to a closed position; an orifice member disposed at an inlet of the fuel passage; an inner collar disposed inside the fuel passage for adjusting the pressure of the spring; Equipped with The hydrogen barrier film is a surface of the base material on the fuel passage side of the valve housing; a surface of the base material of the valve body; a surface of the base material of the orifice member; a surface of the base material of the spring; A surface of the base material of the inner collar; is provided so as to cover at least one of 4. The fuel injection valve according to claim 1, wherein the fuel injection valve is a fuel injection valve having a diameter of 100 mm or less.

[0084] (Appendix 5) The valve housing includes a valve seat member having a fuel nozzle hole therein, the valve body includes a valve portion that opens and closes the fuel nozzle hole, The hydrogen barrier film and a low-friction film that covers the hydrogen barrier film and has a smaller sliding resistance than the hydrogen barrier film are laminated on the contact surface of the valve portion with the valve seat member. 5. The fuel injection valve according to claim 4.

[0085] (Appendix 6) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a stopper against which the movable core can come into contact; a rod to which the stopper is fixed and along which the movable core slides; Equipped with The spring is in contact with the movable core, The hydrogen shielding film and a low-friction film that is provided to cover the hydrogen shielding film and has a lower sliding resistance than the hydrogen shielding film are laminated on the contact surface of the movable core with the stopper, the contact surface of the movable core with the valve housing, the contact surface of the movable core with the spring, the sliding surface of the movable core with the rod, and the sliding surface of the movable core with the valve housing. 5. The fuel injection valve according to claim 4.

[0086] (Appendix 7) the valve housing includes a non-magnetic cylinder that is made of a non-magnetic material and is disposed between the coil and the movable core; The hydrogen barrier film and the low friction film provided on the sliding surface between the movable core and the non-magnetic cylindrical body are made of non-magnetic materials. 7. The fuel injection valve according to claim 6.

[0087] (Appendix 8) the valve housing includes a non-magnetic cylinder that is made of a non-magnetic material and is disposed between the coil and the movable core; The hydrogen barrier film and the low friction film provided on the contact surface of the movable core with the stopper, the contact surface of the movable core with the valve housing, the contact surface of the movable core with the spring, the sliding surface of the movable core with the rod, and the sliding surface of the movable core with the valve housing are made of non-magnetic material. 7. The fuel injection valve according to claim 6.

[0088] (Appendix 9) 9. The fuel injection valve according to any one of claims 6 to 8, wherein a chrome plating layer is provided between the base material and the hydrogen shielding film and has a harder layer than the hydrogen shielding film on at least one of a contact surface of the movable core with the stopper, a contact surface of the movable core with the valve housing, a contact surface of the movable core with the spring, a sliding surface of the movable core with the rod, and a sliding surface of the movable core with the valve housing.

[0089] (Appendix 10) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a valve-closing stopper that is a stopper against which the movable core abuts when the valve element is in a valve-closing position; a rod along which the valve-closing side stopper is fixed and along which the movable core slides; Equipped with The hydrogen shielding film and a low-friction film that covers the hydrogen shielding film and has a smaller sliding resistance than the hydrogen shielding film are laminated on the contact surface of the closing side stopper with the movable core. 5. The fuel injection valve according to claim 4.

[0090] (Appendix 11) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a stopper against which the movable core can come into contact; a rod on which the stopper is fixed and on which the movable core slides; Equipped with The hydrogen barrier film and a low-friction film that covers the hydrogen barrier film and has a lower sliding resistance than the hydrogen barrier film are laminated on the sliding surface of the rod that comes into contact with the movable core. 5. The fuel injection valve according to claim 4.

[0091] (Appendix 12) The valve body includes a movable core that is moved within the fuel passage by energizing a coil. The hydrogen barrier film and a low-friction film that covers the hydrogen barrier film and has a lower sliding resistance than the hydrogen barrier film are laminated on a sliding surface of the fuel passage that comes into contact with the movable core. 5. The fuel injection valve according to claim 4.

[0092] (Appendix 13) 13. The fuel injection valve according to claim 12, wherein the hydrogen barrier film is made of a non-magnetic material.

[0093] (Appendix 14) 14. The fuel injection valve according to claim 12, wherein the low friction film is a non-magnetic material.

[0094] (Appendix 15) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a valve-opening stopper that is a stopper against which the movable core abuts when the valve element is in a valve-opening position; a rod on which the valve-opening stopper is fixed and on which the movable core slides; Equipped with the spring includes a return spring having one end abutted against the valve-opening stopper and biasing the valve-opening stopper so that the valve body is in the valve-closing position, and an auxiliary spring having one end abutted against the valve-opening stopper and the other end abutted against the movable core, The hydrogen shielding film and a low-friction film that is provided to cover the hydrogen shielding film and has a lower sliding resistance than the hydrogen shielding film are laminated on a contact surface of the valve-opening side stopper with the movable core, a contact surface of the valve-opening side stopper with the return spring, a contact surface of the valve-opening side stopper with the auxiliary spring, and a sliding surface of the valve-opening side stopper with the valve housing. 5. The fuel injection valve according to claim 4.

[0095] (Appendix 16) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a valve-opening stopper that is a stopper against which the movable core abuts when the valve element is in a valve-opening position; a rod on which the valve-opening stopper is fixed and on which the movable core slides; Equipped with the valve housing accommodates the valve-opening stopper and includes a fixed core against which the movable core abuts when the valve element is in the valve-opening position, The hydrogen shielding film and a low-friction film that covers the hydrogen shielding film and has a lower sliding resistance than the hydrogen shielding film are laminated on a contact surface of the fixed core with the movable core and a sliding surface of the fixed core with the valve-opening side stopper. 5. The fuel injection valve according to claim 4.

[0096] (Appendix 17) 17. The fuel injection valve according to claim 16, wherein the hydrogen shielding film is made of a non-magnetic material.

[0097] (Appendix 18) 18. The fuel injection valve according to claim 16, wherein the low friction film is made of a non-magnetic material.

[0098] (Appendix 19) 19. The fuel injection valve according to any one of claims 16 to 18, wherein at least one of a contact surface of the fixed core with the movable core and a sliding surface of the fixed core with the valve-opening side stopper is provided with a chromium plating layer located between the base material and the hydrogen shielding film and having a harder layer than the hydrogen shielding film.

[0099] (Appendix 20) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a valve-opening stopper that is a stopper against which the movable core abuts when the valve element is in a valve-opening position; a rod on which the valve-opening stopper is fixed and on which the movable core slides; Equipped with the spring includes a return spring having one end abutted against the valve-opening stopper and biasing the valve-opening stopper so that the valve body is in the valve-closing position, and an auxiliary spring having one end abutted against the valve-opening stopper and the other end abutted against the movable core, The other end of the return spring is in contact with the inner collar, the hydrogen barrier film is provided on the entire surface of the base material of the return spring and the entire surface of the base material of the auxiliary spring; The hydrogen shielding film and a low-friction film that is provided to cover the hydrogen shielding film and has a smaller sliding resistance than the hydrogen shielding film are laminated on a contact surface of the return spring with the inner collar, a contact surface of the return spring with the valve-opening side stopper, a contact surface of the auxiliary spring with the valve-opening side stopper, and a contact surface of the auxiliary spring with the movable core. 5. The fuel injection valve according to claim 4.

[0100] (Appendix 21) The valve body is a movable core that is moved within the fuel passage by energizing a coil; a stopper against which the movable core can come into contact; a rod on which the stopper is fixed and on which the movable core slides; Equipped with the valve housing includes a non-magnetic cylinder that is made of a non-magnetic material and is disposed between the coil and the movable core; The hydrogen barrier film and a low-friction film that covers the hydrogen barrier film and has a lower sliding resistance than the hydrogen barrier film are laminated on the inner peripheral surface of the non-magnetic cylinder. 5. The fuel injection valve according to claim 4.

[0101] (Appendix 22) 22. The fuel injection valve according to claim 21, wherein the hydrogen shielding film is a non-magnetic material.

[0102] (Appendix 23) 23. The fuel injection valve according to claim 21, wherein the low friction film is a non-magnetic material.

[0103] (Appendix 24) The inner collar is pressed against the valve housing and abuts against the spring, the hydrogen barrier film is provided on a pressure contact surface of the inner collar with the valve housing, The hydrogen barrier film and a low-friction film that covers the hydrogen barrier film and has a smaller sliding resistance than the hydrogen barrier film are laminated on the contact surface of the inner collar with the spring. 5. The fuel injection valve according to claim 4.

[0104] (Appendix 25) a filter member disposed inside the fuel passage; a filter collar, which is a metal part, interposed between the filter member and an inner wall surface of the fuel passage; Equipped with The hydrogen barrier film is provided on the surface of the base material of the filter collar. 5. The fuel injection valve according to claim 4.

[0105] (Appendix 26) The valve housing includes a valve seat member having a fuel nozzle hole therein, The valve body is a valve portion that opens and closes the fuel nozzle hole; a movable core that is moved within the fuel passage by energizing a coil; a valve-opening stopper that is a stopper against which the movable core abuts when the valve element is in a valve-opening position; a valve-closing stopper that is a stopper against which the movable core abuts when the valve element is in a valve-closing position; a rod to which the valve portion, the valve-opening stopper, and the valve-closing stopper are joined and along which the movable core slides; Equipped with The hydrogen shielding film is provided so as to cover a joint portion between the valve portion and the rod, a joint portion between the valve-opening side stopper and the rod, and a joint portion between the valve-closing side stopper and the rod. 5. The fuel injection valve according to claim 4.

[0106] (Appendix 27) the metal component has a low-friction film that is provided to cover the hydrogen barrier film and has a sliding resistance smaller than that of the hydrogen barrier film, 5. The fuel injection valve according to claim 1, wherein the low friction film contains a fluororesin.

[0107] (Appendix 28) the metal component has a low-friction film that is provided to cover the hydrogen barrier film and has a sliding resistance smaller than that of the hydrogen barrier film, 5. The fuel injection valve according to claim 1, wherein the low friction film contains chromium nitride. [Explanation of symbols]

[0108] 1...fuel injection valve, 2...valve housing, 2a...fixed core, 2a1...through hole, 2a2...contact surface, 2a3...sliding surface, 2b...non-magnetic cylinder, 2b1...inner circumferential surface, 2c...housing body, 2c1...through hole, 2c2...sliding surface, 2d...valve seat member, 2d1...fuel nozzle, 2d2...inner wall surface, 3...valve body, 3a...rod, 3a1...sliding surface, 3b...valve portion, 3b1...contact surface, 3c...opening side stopper (stopper), 3c1...tubular portion, 3c2...flange, 3c3...contact surface, 3c4...contact surface, 3c5...contact surface, 3c6...sliding surface, 3d...closing side stopper (stopper), 3d1...contact surface, 3e...movable core, 3e1...through hole, 3 e2...contact surface, 3e3...contact surface, 3e4...sliding surface, 3e5...sliding surface, 4...inner collar, 4a...contact surface, 4b...pressure contact surface, 5...return spring (spring), 5a...contact surface, 5b...contact surface, 6...auxiliary spring (spring), 6a...contact surface, 6b...contact surface, 7...orifice member, 8...filter member, 9...covering portion, 9a...connector, 10...coil, 11...filter collar, 20...hydrogen shielding film, 20a...surface, 21...first nitride film, 22...second nitride film, 30...base material, 40...low friction film, 50...hard chrome plating layer, P1...joint portion, P2...joint portion, R...fuel passage, X...hydrogen fuel

Claims

1. A fuel injection valve for injecting hydrogen fuel, A metal part having a base material formed of a metal, the metal component includes a hydrogen barrier film that is provided so as to cover at least a portion of a surface of the base material and is capable of blocking hydrogen; The hydrogen barrier film is a multilayer film in which a first nitride film made of a first titanium nitride composite material containing titanium nitride and a second nitride film made of a second titanium nitride composite material having a different composition from the first titanium nitride composite material are laminated. A fuel injection valve characterized by:

2. the first nitride film is made of the first titanium nitride composite material titanium silicon niobium nitride containing molybdenum; The second nitride film is made of titanium molybdenum nitride, the second titanium nitride composite material including silicon and niobium.

2. The fuel injection valve according to claim 1.

3. the first nitride film is made of the first titanium nitride composite material titanium silicon niobium nitride containing molybdenum; The second nitride film is made of titanium aluminum nitride, which is the second titanium nitride composite material containing aluminum.

2. The fuel injection valve according to claim 1.

4. The metal part includes: a valve housing having a fuel passage therein; a valve body that moves within the fuel passage; A spring that biases the valve body to a closed position; an orifice member disposed at an inlet of the fuel passage; an inner collar disposed inside the fuel passage for adjusting the pressure of the spring; Equipped with The hydrogen barrier film is a surface of the base material on the fuel passage side of the valve housing; a surface of the base material of the valve body; a surface of the base material of the orifice member; a surface of the base material of the spring; A surface of the base material of the inner collar; is provided so as to cover at least one of 4. A fuel injection valve according to claim 1, wherein the first and second electrodes are arranged in a first direction.

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