Support structure for fuel injection valve

Abstract

Provided is a support structure for a fuel injection valve that can easily support a fuel injection valve on a fuel supply cap. This support structure for a fuel injection valve supports a fuel injection valve 20 on a fuel supply cap 11 in which a first recessed part 15 is formed, said support structure comprising a covering body 30 and an adapter member 50. The covering body 30 has a pair of projecting parts 35 and a second recessed part 37 provided therebetween. The adapter member 50 has a first protruding part 53 that fits into the first recessed part 15, a second protruding part 55 that fits into the second recessed part 37, and a pair of engagement parts 60 that engage with the pair of projecting parts 35 and that retain and hold the adapter member 50 to the covering body 30.

Description

Support structure for fuel injection valve

[0001] The present invention relates to a support structure for a fuel injection valve that is inserted into and supported by a cylindrical fuel supply cap provided on a fuel supply pipe that supplies fuel to the fuel injection valve.

[0002] A fuel injection valve (injector) that injects fuel into an internal combustion engine has one end inserted into a fuel supply cap provided on a fuel supply pipe and the other end inserted into a mounting hole provided in the engine cylinder, and is interposed between the fuel supply cap and the mounting holes provided in the engine cylinder.

[0003] For example, Patent Document 1 listed below describes a positioning structure for an injector that is assembled to a delivery pipe having a cylindrical fuel cap, in which an insulator is interposed between the delivery pipe and the injector, a positioning protrusion is provided on the insulator in a recess provided on the outer periphery of the fuel cap, and a recess is formed on the delivery pipe side into which the protrusion fits.

[0004] The insulator also has a ring-shaped main body and a pair of protrusions protruding from both radial sides of the ring-shaped main body.

[0005] Then, one of the convex portions of the insulator is fitted into the concave portion of the injector, and the insulator is attached to the injector in a rotation-restricted state. After that, the other convex portion of the insulator is fitted into the concave portion provided in the delivery pipe, and the injector is supported on the delivery pipe via the insulator.

[0006] Japanese Utility Model Application Laid-Open Publication No. 2-3062

[0007] In the injector positioning structure of Patent Document 1, although the rotation of the insulator and the injector is restricted by the engagement of the protrusion and recess, there is no structure to prevent the insulator from coming off in the axial direction of the injector.

[0008] Therefore, when the injector with the insulator attached is attached to the delivery pipe, it must be done carefully, and the work of supporting the injector on the delivery pipe takes time.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a support structure for a fuel injection valve that can easily support the fuel injection valve on a fuel supply cap.

[0010] To achieve the above object, the present invention provides a support structure for a fuel injection valve for supporting a fuel injection valve on a fuel supply cap having a rotation restriction structure, the fuel injection valve having a fuel supply valve with a cover covering part of the outer periphery of a housing case having a fuel passage therein, and an adapter member, the cover having a pair of protrusions and a recess that restricts rotation by recess-protrusion engagement, and the adapter member has a first protrusion that fits into the recess provided in the fuel supply cap having the rotation restriction structure, a second protrusion that fits into the rotation-restricting recess of the cover, and a pair of engaging portions that engage with the pair of protrusions protruding from the outer periphery of the cover.

[0011] According to the present invention, a pair of engaging portions engage with a pair of protrusions, and the adapter member is held in place by the covering body so as to prevent it from coming off. This reliably prevents the adapter member from falling off the covering body during the process of supporting the fuel injection valve on the fuel supply cap, and makes it easy to support the fuel injection valve on the fuel supply cap.

[0012]

[0023] Fig. 1 is a cross-sectional explanatory view showing one embodiment of a support structure for a fuel injection valve according to the present invention;

[0024] Fig. 2 is a perspective view of an adapter member constituting the support structure for the fuel injection valve;

[0025] Fig. 3 is an enlarged perspective view of a main part of the support structure for the fuel injection valve, with the adapter member removed;

[0026] Fig. 4 is an explanatory view of the support structure for the fuel injection valve;

[0013] (One embodiment of a support structure for a fuel injection valve) Hereinafter, one embodiment of a support structure for a fuel injection valve (hereinafter also simply referred to as a "support structure") according to the present invention will be described with reference to the drawings.

[0014] As shown in FIG. 1 , the present invention provides a support structure for a fuel injection valve, in which an adapter member 50 is disposed between a fuel injection valve 20 having a fuel injection cylindrical portion 21 at one end and a fuel inlet cylindrical portion 23 at the other end and a fuel supply cap 11 (hereinafter also referred to as “cap 11”), at least one of which is provided on a fuel supply pipe 10 and into which the fuel inlet cylindrical portion 23 of the fuel injection valve 20 is inserted, and the adapter member 50 has a first protrusion 53 protruding from its outer periphery. The first protrusion 53 fits into a first recess 15 formed in a recess forming portion 13 protruding from the outer peripheral end of the fuel supply cap 11, and the adapter member 50 is used to support the fuel injection valve 20 on the cap 11 via the adapter member 50.

[0015] The cover 30 covers a portion of the outside of a cylindrical case having a fuel passage of the fuel injection valve 20. The cover 30 has a pair of protrusions 35 protruding outward on its outer periphery, and the adapter member 50 has a pair of engagement portions 60 on its outer periphery that engage with the pair of protrusions 35, respectively (see FIG. 4).

[0016] Furthermore, as shown in FIG. 2, the adapter member 50 has a second protrusion 55 that fits into a second recess 37 provided at the end of the cover 30 to position the adapter member 50 relative to the cap 11 and restrict rotation.

[0017] First, as shown in FIG. 1, at least one cap 11 is provided on the outside of the fuel supply pipe 10, and the cap 11 is formed in a substantially cylindrical shape so that the fuel inlet cylindrical portion 23 of the fuel injection valve 20 can be inserted therein.

[0018] 1 and 3, the recess-forming portion 13 protrudes from the side surface of the lower opening end of the cap 11. A first recess 15 is formed by cutting out a predetermined width within the recess-forming portion 13. The ceiling surface 15a forming the inner surface of the first recess 15 and both side surfaces 15b located on both sides of the ceiling surface 15a in the width direction are flat surfaces that intersect at right angles to each other.

[0019] The fuel injection valve 20 has a substantially cylindrical shape extending a predetermined length. The fuel injection tubular portion 21 for injecting fuel is provided at the lower end of the fuel injection valve 20 in the direction of extension, and the fuel inlet tubular portion 23 into which fuel supplied from the cap 11 flows is provided at the upper end of the fuel injection valve 20 in the direction of extension.

[0020] The fuel inlet cylindrical portion 23 is inserted into the cap 11 from a lower opening thereof and disposed inside the cap 11. A filter 25 is inserted inside the fuel inlet cylindrical portion 23. Furthermore, a seal ring 27 is attached to the outer periphery of the fuel inlet cylindrical portion 23 in close contact with the inner periphery of the cap 11 to seal the gap between the outer periphery of the fuel inlet cylindrical portion and the inner periphery of the cap.

[0021] Next, the covering body 30 will be described in detail.

[0022] The covering body 30 is formed from an approximately cylindrical cover portion 31 that covers part of the outside of the cylindrical case having the fuel passage, excluding the fuel injection tube portion 21 provided at the end of the fuel injection valve 20, and a coupler portion 33 that branches off from a point midway in the extension direction of the cover portion 31 and extends, into which an electrical supply connector (not shown) is inserted.

[0023] The coupler portion 33 has a connecting portion 33a that protrudes outward from the axial direction of the fuel injection valve 20 and is connected to the cover portion 31, and an extension portion 33b that extends outward from one end of the connecting portion 33a in the axial direction of the fuel injection valve 20.

[0024] The cover portion 31 extends to a position just before the location of the fuel injection valve 20 where the seal ring 27 is attached. Furthermore, a pair of protrusions 35 protrude from a position in the circumferential direction of the cover portion 31 adjacent to the connecting portion 33a of the coupler portion 33 toward the outside in the radial direction of the cover portion 31.

[0025] 3 and 4, the protrusion 35 is arranged only on the front side of the figure, but another protrusion 35 (not shown) is arranged at a location on the covering body 30 opposite in the radial direction.

[0026] 3, a tapered surface 35a is formed at a predetermined angle on the outer surface of each protrusion 35, the surface facing the coupler portion 33. The tapered surface 35a prevents interference with both side portions of the recess-forming portion 13 when the first convex portion 53 of the adapter member 50 is engaged with the first recess 15 of the cap 11, and the recess-forming portion 13 can be disposed axially inward, enabling a compact arrangement.

[0027] Furthermore, a second recess 37, which is cut out in a concave shape, is formed on the outer periphery of the cover portion 31 between the pair of protrusions 35. Both ends of the second recess 37 extend a predetermined length along the circumferential direction of the cover portion 31, and are formed so that both ends in the circumferential direction reach the pair of protrusions 35.

[0028] A pair of upright surfaces 39 are provided on the outer surfaces of the pair of protrusions 35, at portions that face both circumferential ends of the second recess 37. That is, the upright surfaces 39 are formed by the surfaces of each of the protrusions 35 that face the engaging portion 60 of the adapter member 50 and are opposite the tapered surface 35 a.

[0029] The pair of upright surfaces 39 are formed as parallel flat surfaces along the axial direction of the fuel injection valve 20, and one end surface of the second recess 37 in the axial direction forms a stepped bottom surface 37a.

[0030] Next, the adapter member 50 disposed between the cap 11 and the fuel injection valve 20 will be described in detail.

[0031] The adapter member 50 has a first convex portion 53 that fits into the first recess 15 to position the adapter member 50 in the cap 11 and restrict rotation, a second convex portion 55 that fits into the second recess 37 to position the adapter member 50 in the cover 30 and restrict rotation, and a pair of engaging portions 60 that engage with the pair of protrusions 35 to hold the adapter member 50 in the cover 30 and prevent it from coming off in the axial direction.

[0032] More specifically, the adapter member 50 in this embodiment has a circular insertion hole 52 in the radial center, into which the fuel inlet cylindrical portion 23 of the fuel injection valve 20 is inserted, and is formed from an annular base 51 arranged between the upper end surface of the covering body 30 of the fuel injection valve 20 and the end surface of the cap 11, the first convex portion 53 protruding outward from the base 51, a second convex portion 55 extending from the lower end surface of the base 51 to the second recess 37, and a pair of engaging portions 60 protruding from the outer periphery of the base 51.

[0033] The inner diameter of the insertion hole 52 formed in the base 51 is larger than the outer diameter of the fuel inlet cylindrical portion 23. Therefore, the fuel inlet cylindrical portion 23 can be inserted into the insertion hole 52, and the base 51 is disposed (exterior-mounted) on the outside of the fuel inlet cylindrical portion 23. The base 51 has a continuous annular shape.

[0034] As shown in FIG. 1 , when the fuel inlet cylindrical portion 23 is inserted into the insertion hole 52 inside the base portion 51, an annular gap G is formed (defined) between the inner periphery of the insertion hole 52 and the outer periphery of the fuel inlet cylindrical portion 23, forming a circumferentially continuous annular gap.

[0035] Furthermore, the first convex portion 53 protrudes radially outward from the outer peripheral surface of the base 51 at a predetermined radial location on the base 51, and has an approximately rectangular shape extending circumferentially around the base 51 with a predetermined width.

[0036] The outer surface of the first protrusion 53 extends to a width along both side surfaces 15b of the first recess 15 provided in the cap 11. That is, the ceiling surface 53a of the first protrusion 53 and both side surfaces 53b located on both sides of the ceiling surface 53a in the width direction form flat surfaces that intersect at right angles.

[0037] Then, as shown in Figure 4, when the first convex portion 53 is fitted into the first recess 15 of the cap 11, the ceiling surface 53a of the first convex portion 53 is positioned opposite the ceiling surface 15a of the first recess 15, and the both side surfaces 53b of the first convex portion 53 are positioned opposite the both side surfaces 15b of the first recess 15.

[0038] As a result, the adapter member 50 is positioned in the axial direction relative to the cap 11, and rotation of the adapter member 50 is restricted in the axial direction of the cap 11. That is, movement of the adapter member 50 in the axial direction of the cap 11 is restricted, and the adapter member 50 is prevented from rotating around the axis of the fuel injection valve 20 in the axial direction of the cap 11.

[0039] The second protrusion 55 protrudes from an end face opposite to the upper end face of the base portion 51 toward the bottom surface 37 a that forms the second recess 37 of the fuel injection valve 20 .

[0040] Furthermore, the second protrusion 55 extends along the outer periphery of the fuel injection valve 20. That is, the second protrusion 55 has a generally arc-shaped protrusion shape that extends along the outer periphery of the fuel injection valve 20 and up to the pair of upright surfaces 39 that form the second recess 37 of the fuel injection valve 20.

[0041] A pair of first stopper surfaces 57 are provided at opposing positions in the circumferential direction of the second convex portion 55, and come into contact with the upright surfaces 39 of the pair of protrusions 35 of the covering body 30, respectively.

[0042] Each of the first stopper surfaces 57 is a flat surface that is parallel to and corresponds to the upright surface 39 .

[0043] As shown in FIG. 4, when the fuel inlet cylindrical portion 23 is inserted into the insertion hole 52 of the base 51 and the second convex portion 55 is fitted into the second recess 37 of the covering body 30, the pair of first stopper surfaces 57 of the second convex portion 55 can abut against the pair of upright surfaces 39 of the covering body 30, and the tip surface 55 a of the second convex portion 55 can abut against the bottom surface 37 a of the second recess 37 (see FIG. 5).

[0044] As a result, the adapter member 50 is positioned in the axial direction relative to the covering body 30, and the rotation of the adapter member 50 relative to the axial direction of the covering body 30 is restricted.

[0045] Furthermore, since the covering body 30 is covered by the fuel injection valve 20, it can be said that the fuel injection valve 20 is positioned and its rotation is restricted via the covering body 30 and the adapter member 50 by the recess-protrusion fit between the second recess 37 and the second protrusion 55.

[0046] As shown in Figure 2, the pair of engaging portions 60 have extension portions 61 that extend from the base portion 51 and abut against each of the upright surfaces 39, and engagement protrusions 63 that protrude from the tip of the extension portions 61 and engage with each of the protrusions 35.

[0047] In this embodiment, each of the extension portions 61 is a portion of the base 51 that is perpendicular to the arrangement direction of the first convex portion 53 and the second convex portion 55 (a portion that faces radially from the base 51, and can also be said to be both circumferential end portions of the second convex portion 55), and protrudes radially outward from the radial outer surface of the base 51 and extends toward one side of the opening direction of the base 51, i.e., in the same direction as the protruding direction of the second convex portion 55 (extending perpendicular to the base 51).

[0048] The engaging protrusions 63 are respectively provided to protrude from the outer surface 61a of each extending portion 61 at the tip end in the extending direction, the outer surface 61a facing the first convex portion 53. As shown in Fig. 2, the engaging protrusions 63 are configured such that a top portion is connected to a tapered surface 63a that gradually widens the engaging protrusions 63 from the top portion toward the outer surface 61a of the extending portion 61.

[0049] Furthermore, the engaging protrusion 63 is provided as follows in relation to the annular gap G (see FIG. 1) formed between the inner periphery of the insertion hole 52 and the outer periphery of the fuel inlet cylindrical portion 23.

[0050] That is, when the radial width of the annular gap G is A (see Figure 1), and the protruding height of the engaging protrusion 63 from the extension portion 61 (the protruding height from the outer surface 61a of the extension portion 61) is B, as shown in Figure 5, the engaging protrusion 63 is arranged so that A < B.

[0051] Furthermore, a part of the pair of engaging portions 60 is connected to the first stopper surface 57 of the second protrusion 55 to form a second stopper surface 62 .

[0052] Specifically, as shown in FIG. 2, the outer surface 61 a of the extension portion 61 constituting the engagement portion 60 on the side of the first convex portion 53, which is aligned with the first stopper surface 57, is connected to the first stopper surface 57, and forms a second stopper surface 62 that is a continuous flat surface with no steps relative to the first stopper surface 57.

[0053] As shown in FIG. 4 , when the fuel inlet cylindrical portion 23 is inserted into the insertion hole 52 of the base 51 and the second convex portion 55 is fitted into the second concave portion 37 of the covering body 30, the pair of second stopper surfaces 62 of the pair of engaging portions 60 can abut against the widthwise outer portions of the upright surfaces 39 of each of the pair of protrusions 35 of the covering body 30, and the engaging protrusions 63 of each of the pair of engaging portions 60 can engage with the corner peripheral portions of the pair of protrusions 35 (the peripheral portions of the bottom located on the opposite side from the cap 11).

[0054] As a result, the rotation of the adapter member 50 is restricted by the covering body 30, and the adapter member 50 is held in the axial direction so as not to come off by the covering body 30. That is, the adapter member 50 is prevented from rotating around the axis of the fuel injection valve 20 relative to the covering body 30, and the adapter member 50 is held in the covering body 30 so as not to come off so as not to move toward the fuel inlet cylindrical portion 23 of the fuel injection valve 20.

[0055] Furthermore, since the covering body 30 covers the fuel injection valve 20, it can be said that the engagement between the protrusion 35 and the engaging portion 60 prevents the fuel injection valve 20 from coming loose in the axial direction via the covering body 30 and the adapter member 50, and also restricts its rotation.

[0056] The rotation of the adapter member 50 relative to the covering body 30 (and thus the rotation of the adapter member 50 relative to the fuel injection valve 20) is restricted by two abutment structures: the abutment structure of the first stopper surface 57 of the second convex portion 55 against the widthwise inner portion of the upright surface 39 of the protrusion 35, and the abutment structure of the second stopper surface 62 of the engaging portion 60 against the widthwise outer portion of the upright surface 39 of the protrusion 35.

[0057] Furthermore, all of the components of the adapter member 50 described above (the base 51, the first convex portion 53, the second convex portion 55, the extension portion 61, and the engaging portion 60 including the engaging protrusion 63) are integrally formed from a predetermined synthetic resin material.

[0058] (Modifications) The shape, structure, layout, etc. of the support structure for the fuel injection valve in the present invention are not limited to the above-described embodiment.

[0059] In this embodiment, the base 51 of the adapter member 50 is in the shape of a circular ring having the circular insertion hole 52, but the insertion hole provided in the base may be, for example, a rectangular hole or an elliptical hole, and can be appropriately determined depending on the outer peripheral shape of the fuel inlet cylindrical portion of the fuel injection valve.

[0060] Furthermore, the base 51 does not have to have a shape with an insertion hole (it is not annular or ring-shaped), but may have, for example, a U-shaped frame shape with a portion of the periphery cut out, as long as it has a shape that can surround at least a portion of the outer periphery of the fuel inlet tube portion.

[0061] Furthermore, although the first protrusion 53 in this embodiment is a single, generally rectangular protrusion extending a predetermined length, the number and shape of the first protrusion are not particularly limited as long as it can fit into the first recess. For example, a plurality of first protrusions may be provided intermittently in the circumferential direction of the adapter member. Furthermore, the first protrusion may be, for example, a trapezoidal protrusion, and can be appropriately set depending on the inner shape of the first recess provided in the fuel supply cap.

[0062] In this embodiment, the second protrusion 55 is a single arc-shaped protrusion extending half the length of the base 51 in the circumferential direction. However, the number and shape of the second protrusion are not particularly limited as long as it can fit into the second recess. For example, multiple second protrusions may be provided protruding from predetermined locations on the adapter member. Furthermore, the outer surface shape of the second protrusion may be a rectangular block-shaped protrusion, etc.

[0063] In addition, the engaging portion 60 in this embodiment is composed of the extending portion 61 extending vertically from the radially opposing portion of the base portion 51 and the engaging protrusion 63 protruding from the tip of the extending portion 61 in the extending direction, but for example, the extending portion may extend while inclining at a predetermined angle with respect to the opening direction of the base. Furthermore, the engaging protrusion may protrude from a position midway in the extending direction of the extending portion.

[0064] (Operation and Effect) Next, the operation and effect of the support structure for the fuel injection valve configured as described above will be described.

[0065] First, the adapter member 50 is attached to the fuel injection valve 20. That is, after the second convex portion 55 of the adapter member 50 is aligned with the second concave portion 37 of the covering body 30, the fuel inlet cylindrical portion 23 is inserted into the insertion hole 52 from the opening located on the engaging protrusion 63 side of the engaging portion 60.

[0066] Then, the pair of engaging protrusions 63 are pressed against the upright surfaces 39 of the pair of protrusions 35, and the pair of engaging portions 60 are slightly flexed and deformed, while the base 51 is pushed into the fuel inlet cylindrical portion 23.

[0067] Then, when the engaging protrusion 63 gets over the bottom of the protruding portion 35, the engaging portion 60 elastically returns to its original position, and with a clicking sensation (a click sensation), the engaging protrusion 63 engages with the peripheral portion of the bottom of the protruding portion 35. At the same time, the second convex portion 55 of the adapter member 50 fits into the second concave portion 37 provided in the cover 30.

[0068] As a result, the adapter member 50 is positioned relative to the cover 30, the rotation of the adapter member 50 is restricted by the cover 30, and the adapter member 50 is held in the axial direction so as not to come off by the cover 30. Consequently, the adapter member 50 is positioned relative to the fuel injection valve 20 via the cover 30, the rotation of the adapter member 50 is restricted, and the adapter member 50 is held in the axial direction so as not to come off.

[0069] As described above, the second convex portion 55 of the adapter member 50 fits into the second concave portion 37 of the cover 30, thereby positioning the adapter member 50 on the cover 30 and restricting its rotation; further, the pair of engaging portions 60 of the adapter member 50 engage with the pair of protrusions 35 of the cover 30, thereby preventing the adapter member 50 from coming loose and allowing the adapter member 50 to be attached to the cover 30.

[0070] Then, the first convex portion 53 of the adapter member 50 is aligned with the first concave portion 15 of the cap 11, and the fuel inlet cylindrical portion 23 of the fuel injection valve 20 with the adapter member 50 attached is inserted from the lower opening of the cap 11.

[0071] As a result, the seal ring 27 fitted onto the fuel inlet cylindrical portion 23 comes into tight contact with the inner circumference of the cap 11, and the first protrusion 53 of the adapter member 50 fits into the first recess 15 of the cap 11, thereby positioning the fuel injection valve 20 relative to the cap 11 and supporting it in a rotation-restricted state (see Figures 1 and 4).

[0072] In this support structure, as described above, the pair of engaging portions 60 engage with the pair of protrusions 35, and the adapter member 50 is held in place by the covering body 30 so as to prevent it from coming off. This reliably prevents the adapter member 50 from falling off the fuel injection valve 20 during the process of supporting the fuel injection valve 20 on the cap 11, and therefore the fuel injection valve 20 can be easily supported on the cap 11.

[0073] In other words, since there is no risk of the adapter member 50 falling off from the fuel injection valve 20, the worker can quickly support the fuel injection valve 20 relative to the cap 11, making it easier to support the fuel injection valve 20 relative to the cap 11.

[0074] Furthermore, with this support structure, the fuel injection valve 20 can be supported on the cap 11 via the adapter member 50, so it is sufficient to simply form the first recess on the cap 11 side that engages with the first protrusion.

[0075] Therefore, the cap 11 does not need to be subjected to any changes in shape, size, layout, etc., or these changes can be minimized as much as possible. Therefore, by changing the shape, size, layout, etc., of the adapter member 50, it becomes possible to support various fuel injection valves on the fuel supply cap, thereby increasing the versatility of the fuel injection valve.

[0076] In addition, in this embodiment, a pair of the raised surfaces 39 are provided on the outer surfaces of the pair of protrusions 35, at portions facing both circumferential ends of the second recess 37, and the second convex portion 55 extends along the outer periphery of the fuel inlet cylindrical portion 23, and a pair of the stopper surfaces (first stopper surfaces 57) that abut against the pair of raised surfaces 39 are provided on both circumferential end surfaces thereof.

[0077] According to the above aspect, when the adapter member 50 is attached to the covering body 30, the pair of first stopper surfaces 57 provided on the second convex portion 55 abut against the widthwise inner portions of the pair of standing surfaces 39 provided on the pair of protrusions 35, thereby making it possible to position and restrict rotation of the adapter member 50 on the covering body 30 at two points: the standing surface 39 corresponding to one of the first stopper surfaces 57, and the standing surface 39 corresponding to the other first stopper surface 57.

[0078] As a result, the adapter member 50 can be more reliably positioned relative to the cover 30 and its rotation can be restricted, thereby improving the workability of attaching the adapter member 50 to the cover 30.

[0079] Furthermore, in this embodiment, a part of the pair of engaging portions 60 is connected to the stopper surface (first stopper surface 57) to form the second stopper surface (second stopper surface 62).

[0080] According to the above aspect, by connecting a portion of the pair of engaging portions 60 to the first stopper surface 57, the rigidity of the entire engaging portion 60 can be improved, so that the pair of engaging portions 60 can be engaged with the pair of protrusions 35 with a high engaging force, and the adapter member 50 can be firmly attached to the fuel injection valve 20.

[0081] Furthermore, not only the first stopper surface 57 provided on the second convex portion 55 but also the second stopper surface 62 of the engaging portion 60 abuts against the standing surface 39 of the protrusion 35 (the first stopper surface 57 abuts against the widthwise inner portion of the standing surface 39, and the second stopper surface 62 abuts against the widthwise outer portion of the standing surface 39), so the abutment area of ​​the stopper surfaces with respect to the standing surface 39 can be increased, and rotation of the adapter member 50 relative to the fuel injection valve 20 can be more reliably restricted.

[0082] In addition, in this embodiment, each of the engaging portions 60 of the adapter member 50 has the extension portion 61 extending from the base portion 51 and the engaging protrusion 63, and the protruding height B of the engaging protrusion 63 is larger than the width A of the annular gap G (A < B).

[0083] According to the above aspect, the engaging protrusion 63 is provided so that the width A of the annular gap G and the protruding height B of the engaging protrusion 63 are A < B, so that the engaging force of the engaging portion 60 with the protrusion 35 can be increased and the adapter member 50 can be firmly attached to the fuel injection valve 20.

[0084] Furthermore, by setting the width A of the annular gap G and the protruding height B of the engaging protrusion 63 as described above, when attaching the adapter member 50 to the covering body 30, the extending portion 61 is flexibly deformed and the engaging protrusion 63 is mechanically engaged with the protruding portion 35, and a clicking sensation (a sense of moderation) can be obtained when the engagement is complete (this can also be considered a snap fit), allowing the worker to clearly grasp that the attachment work of the adapter member 50 to the fuel injection valve 20 is complete.

[0085] Furthermore, by appropriately setting B while maintaining the relationship A<B, the amount of flexural deformation of the extension portion 61 can be adjusted, and therefore the clicking sensation when the attachment work of the adapter member 50 to the fuel injection valve 20 is completed can be freely changed.

[0086] It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

[0087] DESCRIPTION OF SYMBOLS 10: Fuel supply pipe 11: Fuel supply cap (cap) 15: First recess 20: Fuel injection valve 21: Fuel injection cylindrical portion 23: Fuel inlet cylindrical portion 30: Covering body 35: Protrusion 37: Second recess 39: Standing surface 50: Adapter member 51: Base 52: Insertion hole 53: First convex portion 55: Second convex portion 57: Stopper surface (first stopper surface) 60: Engagement portion 61: Extension portion 62: Stopper surface (second stopper surface) 63: Engagement protrusion G: Annular gap

Claims

1. A support structure for a fuel injection valve, in which a fuel injection valve having a fuel injection cylindrical portion and a fuel inlet cylindrical portion is supported by a fuel supply cap attached to a fuel supply pipe and formed with a first recess, the support structure for a fuel injection valve comprising: a covering body covering the fuel injection valve, and an adapter member arranged between the fuel supply cap and the fuel injection valve, the covering body having a pair of protrusions protruding from predetermined circumferential positions and a second recess provided between the pair of protrusions, the adapter member having: a first convex portion that fits into the first recess to position the adapter member on the fuel supply cap and restrict rotation, a second convex portion that fits into the second recess to position the adapter member on the covering body and restrict rotation, and a pair of engaging portions that engage with the pair of protrusions to hold the adapter member on the covering body and prevent it from coming off.

2. A support structure for a fuel injection valve as claimed in claim 1, wherein a pair of raised surfaces are provided on the outer surfaces of the pair of protrusions which face both circumferential ends of the second recess, and the second convex portion extends along the outer periphery of the fuel inlet cylindrical portion, and a pair of stopper surfaces are provided on both circumferential end faces thereof which abut against the pair of raised surfaces.

3. A support structure for a fuel injection valve according to claim 2, characterized in that a part of the pair of engagement portions is connected to the stopper surface to form a second stopper surface.

4. A support structure for a fuel injection valve as described in claim 2, wherein the adapter member has a base portion forming an insertion hole through which the fuel inflow cylindrical portion is inserted, and the first convex portion, the second convex portion, and the pair of engaging portions are provided on the base portion, and the first convex portion, the second convex portion, and the pair of engaging portions have an extending portion extending from the base portion and abutting the standing surface, and an engaging protrusion protruding from the tip of the extending portion and engaging with the protruding portion, wherein the radial width of an annular gap formed between the inner circumference of the insertion hole and the outer circumference of the fuel inflow cylindrical portion is A and the protruding height of the engaging protrusion from the extending portion is B, and the engaging protrusion is provided so that A < B.

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