Fuel cap

Abstract

The present disclosure provides a fuel cap capable of preventing blow-off by, inter alia, air ejected from an oil supply port even if the fuel cap is removed in a state in which the internal pressure of a fuel tank has increased. A fuel cap (1) is provided with a plurality of stoppers (18) facing in an axial direction (Da) toward a fastening inclined surface inside an oil supply port in a state in which the fuel cap (1) can be pulled up in the axial direction (Da) from the tip of a fuel tank filler.

Description

fuel cap

[0001] The present disclosure relates to a fuel cap.

[0002] Conventionally, fuel tank caps for sealing relatively large fuel tanks used in civil engineering vehicles and the like have been known (for example, see Patent Document 1). The conventional fuel tank cap described in Patent Document 1 has a notch and an engagement portion, and is removably attached to a cylindrical cap attachment opening provided on the fuel tank.

[0003] More specifically, the cap attachment opening has a flange bent inward at its upper end. Three radially outwardly recessed notches are formed in this flange. The tip of the flange faces downward, and its lower end serves as an engagement part.

[0004] When attaching the fuel tank cap to the cap mounting opening, the engaging protrusions of the latching pieces attached to the operating cap are inserted from above into the notches formed in the flange of the cap mounting opening, and the operating cap is then placed over the cap mounting opening from above.Then, the operating cap is rotated in the LOCK direction.

[0005] This causes the latching protrusions on the latching piece to engage with the lower end of the flange from below, fastening the fuel tank cap to the cap mounting opening. As a result, the packing on the operating cap comes into close contact with the upper end surface of the flange of the cap mounting opening and elastically deforms, sealing the cap mounting opening.

[0006] Japanese Patent Application Laid-Open No. 2006-103466

[0007] The present disclosure provides an improved fuel cap.

[0008] A fuel cap according to an embodiment of the present disclosure is a fuel cap that is fastened to a cylindrical fuel tank filler by rotating it in a fastening direction around an axis to close a fuel filler opening at the axial tip of the fuel tank filler, and is provided with a plurality of stoppers that face the fastening inclined surface on the inside of the fuel filler opening in the axial direction, while allowing the fuel cap to be pulled up axially from the tip of the fuel tank filler.

[0009] A fuel cap according to another embodiment of the present disclosure is a fuel cap that is fastened to a cylindrical fuel tank filler by rotating it in a fastening direction around an axis to close a fuel filler opening at the axial tip of the fuel tank filler, and is equipped with a plurality of fastening protrusions that engage with the inside of the fuel filler opening of the fuel tank filler, and a plurality of interference prevention portions that prevent interference between the plurality of fastening protrusions and the fuel tank filler.

[0010] According to the above-described embodiments, an improved fuel cap can be provided.

[0011] Fig. 4 is a perspective view of a fuel tank including a fuel cap according to an embodiment of the present disclosure; Fig. 5 is an enlarged perspective view showing a state in which the fuel cap of Fig. 1 has been removed; Fig. 6 is an enlarged perspective view of the fuel cap of Fig. 2 as viewed from diagonally below; Fig. 7 is an enlarged perspective view showing a state in which the fuel cap of Fig. 2 is being installed; Fig. 8 is a perspective view of the fuel cap of Fig. 4 as cut by a disk cap; Fig. 9 is an enlarged perspective view of a fuel cap according to another embodiment of the present disclosure as viewed from diagonally below;

[0012] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0013] Fig. 1 is a perspective view of a fuel tank FTK to which a fuel cap 1 according to an embodiment of the present disclosure is attached. Fig. 2 is an enlarged perspective view showing a state in which the fuel cap 1 of Fig. 1 has been removed. Fig. 3 is an enlarged perspective view of the fuel cap 1 of Fig. 2 as seen obliquely from below.

[0014] The fuel cap 1 of this embodiment is used in a fuel tank FTK mounted on a work machine such as a hydraulic excavator, asphalt finisher, or crane. The fuel tank FTK stores fuel such as diesel oil to be supplied to an engine mounted on the work machine. The fuel tank FTK is provided, for example, with a cylindrical fuel tank filler FTF at its top. A fuel filler opening FO opens at the tip of the fuel tank filler FTF.

[0015] The fuel cap 1 is fastened to the cylindrical fuel tank filler FTF by rotating it in a fastening direction Dt about its axis, and closes the fuel filler opening FO that opens at the tip of the fuel tank filler FTF in the axial direction Da.

[0016] 2, the fuel tank filler FTF includes a fuel filler opening FO, a leading annular surface TAF provided around the fuel filler opening FO, and a plurality of notches C provided in the leading annular surface TAF. The fuel tank filler FTF also includes, for example, an inner circumferential wall ICW, a fastening inclined surface TIF, and a rotation stopper WS.

[0017] The inner circumferential wall ICW is provided, for example, so as to hang down in the axial direction Da from the inner peripheral edge of the tip annular surface TAF. The fastening inclined surface TIF is provided, for example, at the lower end of the inner circumferential wall ICW and is inclined with respect to the tip annular surface TAF so that the height H of the inner circumferential wall ICW in the axial direction Da increases toward the front in the fastening direction Dt. The rotation stop WS is provided, for example, at the lower end of the end of the inner circumferential wall ICW on the front side in the fastening direction Dt, adjacent to the fastening inclined surface TIF.

[0018] The tip annular surface TAF and the inner circumferential wall ICW are formed, for example, by bending the circumferential wall at the tip of the fuel tank filler FTF, which is a cylindrical straight pipe, in the axial direction Da inward in the radial direction and then further bending it in the axial direction Da opposite to the tip. The tip annular surface TAF is, for example, an annular flat surface perpendicular to the axial direction Da, and is provided at the tip of the fuel tank filler FTF to surround the fuel filler opening FO.

[0019] When the fuel cap 1 is fastened to the tip of the fuel tank filler FTF, the tip annular surface TAF comes into close contact with a packing 15 (see FIG. 3) of the fuel cap 1, which will be described later, thereby sealing the periphery of the fuel filler opening FO and ensuring the airtightness of the fuel tank FTK. Therefore, it is extremely important not to scratch or otherwise damage the tip annular surface TAF when attaching the fuel cap 1 to the fuel tank filler FTF.

[0020] The inner circumferential wall ICW is provided, for example, so as to extend downward in the axial direction Da from the inner circumferential edge of the tip annular surface TAF toward the inside of the fuel filler opening FO and surround the fuel filler opening FO. The inner circumferential wall ICW is a cylindrical inner wall of the fuel tank filler FTF that defines the outer circumferential edge or opening edge of the fuel filler opening FO.

[0021] The plurality of cutouts C are formed, for example, by cutting out a recessed portion of the tip annular surface TAF and the inner circumferential wall ICW from the inside to the outside in the radial direction. The plurality of cutouts C are provided, for example, at equal angular intervals in the circumferential direction of the tip annular surface TAF, i.e., in the fastening direction Dt of the fuel cap 1. In the example shown in FIG. 2 , three cutouts C are provided in the tip annular surface TAF of the fuel tank filler FTF at 120° intervals in the circumferential direction. Note that the number of cutouts C provided in the tip annular surface TAF is not particularly limited.

[0022] The shape of the notch C as viewed in the axial direction Da of the fuel tank filler FTF and the shape of the notch C as viewed in the radial direction of the fuel tank filler FTF are, for example, generally rectangular. That is, both end edges of the notch C in the circumferential direction of the tip annular surface TAF are parallel to each other and generally parallel to the radial direction of the fuel tank filler FTF as viewed in the axial direction Da of the fuel tank filler FTF. Furthermore, both end edges of the notch C in the circumferential direction of the inner circumferential wall ICW are parallel to each other and generally parallel to the axial direction Da of the fuel tank filler FTF as viewed in the radial direction of the fuel tank filler FTF.

[0023] The fastening inclined surface TIF is provided at the lower end of the inner circumferential wall ICW, extends in the circumferential direction of the fuel tank filler FTF, and is inclined at a predetermined angle relative to the leading annular surface TAF. The fastening inclined surface TIF is provided between two adjacent notches C in the fastening direction Dt of the fuel cap 1, which is the rotational direction of the fuel tank filler FTF around its axis. Therefore, the number of fastening inclined surfaces TIF is the same as the number of notches C. The fastening inclined surface TIF is inclined at a predetermined angle relative to the leading annular surface TAF so that the height H of the inner circumferential wall ICW in the axial direction Da of the fuel tank filler FTF increases toward the front in the fastening direction Dt of the fuel cap 1. Note that the fastening inclined surface TIF may be entirely inclined at a predetermined angle relative to the leading annular surface TAF, as shown in FIG. 2 , or may be partially inclined at a predetermined angle relative to the leading annular surface TAF.

[0024] In other words, in the axial direction Da of the fuel tank filler FTF, the height H of the fastening inclined surface TIF relative to the tip annular surface TAF is smallest at the end of the fastening inclined surface TIF adjacent to the rear notch C in the fastening direction Dt of the fuel cap 1. Also, the height H of the fastening inclined surface TIF is largest at the end of the fastening inclined surface TIF adjacent to the front detent WS in the fastening direction Dt of the fuel cap 1.

[0025] The detent WS is provided on the front side of the fastening inclined surface TIF in the fastening direction Dt, so as to protrude downward from the fastening inclined surface TIF in the axial direction Da. The height of the detent WS from the tip annular surface TAF is greater than the maximum height H of the fastening inclined surface TIF. The detent WS has, for example, a generally rectangular shape when viewed radially from the fuel tank filler FTF.

[0026] Fig. 4 is an enlarged perspective view showing the fuel cap 1 of Fig. 2 being attached to the tip of the fuel tank filler FTF. Fig. 5 is an enlarged perspective view showing the fuel cap 1 of Fig. 4 cut at the upper end surface of the guide portion 16g of the disc cap 16. As shown in Figs. 2 to 5, the fuel cap 1 has a cap body 11, a retainer 12, multiple fastening protrusions 13, and multiple stoppers 18. The fuel cap 1 also has, for example, multiple interference prevention portions 14, a packing 15, a disc cap 16, and a fastening member 17.

[0027] 2, the cap body 11 is a cylindrical member with a bottom, having a peripheral wall 11p in the shape of a short cylinder and an upper wall 11u provided at the upper end of the peripheral wall 11p. The upper wall 11u has, for example, an annular flat portion, an annular inclined portion, an annular stepped portion, and a cylindrical convex portion from the outer edge toward the center, and the height from the lower end of the peripheral wall 11p is higher at the center than at the outer edge.

[0028] As shown in Fig. 1, when the fuel cap 1 is attached to the fuel tank filler FTF, the cap body 11 covers the tip of the fuel tank filler FTF. Note that when the fuel cap 1 is attached to the tip of the fuel tank filler FTF, the central axis a of the cylindrical cap body 11 with a bottom shown in Figs. 2 and 3, i.e., the central axis a of the fuel cap 1, roughly coincides with the central axis A of the fuel tank filler FTF. Furthermore, a gap may be provided between the inner peripheral surface of the peripheral wall 11p of the cap body 11 and the fuel tank filler FTF.

[0029] The retainer 12 is, for example, an annular or disc-shaped member as shown in Fig. 3. The retainer 12 is, for example, made of an elastic metal plate and has a hardness equal to or greater than the hardness of the leading annular surface TAF of the fuel tank filler FTF. The retainer 12 is, for example, fixed to the top wall bottom surface 11b of the cap body 11 that faces the fuel filler opening FO when the fuel cap 1 is attached to the fuel tank filler FTF. The top wall bottom surface 11b is the underside of the top wall 11u of the cap body 11.

[0030] The multiple fastening protrusions 13 are provided to protrude radially outward from the outer peripheral edge of the retainer 12. The multiple fastening protrusions 13 are provided on the retainer 12 at positions, sizes, and shapes that correspond to multiple notches C formed in the leading annular surface TAF of the fuel tank filler FTF, and are configured to be able to pass through the multiple notches C in the axial direction Da. As will be described in detail later, the multiple fastening protrusions 13 pass through the multiple notches C in the axial direction Da and are rotated in the fastening direction Dt to engage with the fastening inclined surface TIF on the inside of the fuel filler opening FO.

[0031] 3 and 4, the fastening protrusions 13 have a curved shape that is convex toward the fastening inclined surface TIF when engaged with the fastening inclined surface TIF, and are configured to elastically deform in the axial direction Da when engaged with the fastening inclined surface TIF. The fastening protrusions 13 are provided on the inner side of the peripheral wall 11p of the cap body 11, for example, as shown in FIG.

[0032] In other words, the multiple fastening protrusions 13 are provided between the lower end of the peripheral wall 11p of the cap body 11 and the upper wall bottom surface 11b in the direction along the central axis a of the fuel cap 1, as shown in Fig. 3, for example. In this case, the peripheral wall 11p of the cap body 11 may have a slit 11s at a position corresponding to at least one fastening protrusion 13, as shown in Fig. 4, for example. This configuration makes it easy to align the multiple fastening protrusions 13 of the fuel cap 1 with the multiple cutouts C of the fuel tank filler FTF when attaching the fuel cap 1 to the fuel tank filler FTF.

[0033] The distance d1 in the axial direction Da from the multiple fastening protrusions 13 shown in Fig. 3 to the packing 15 disposed on the top wall bottom surface 11b of the cap body 11 is, for example, slightly smaller than the maximum height H of the fastening inclined surface TIF of the fuel tank filler FTF from the leading annular surface TAF shown in Fig. 2. With this configuration, when the multiple fastening protrusions 13 are engaged with the fastening inclined surface TIF and the cap body 11 is rotated in the fastening direction Dt until each fastening protrusion 13 abuts against the rotation stopper WS, the multiple fastening protrusions 13 elastically deform in the axial direction Da. The elastic force of the multiple fastening protrusions 13 compresses the packing 15 between the top wall bottom surface 11b of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF, ensuring a seal between the top wall bottom surface 11b of the cap body 11 and the leading annular surface TAF.

[0034] The multiple stoppers 18 have a size and shape that allows them to pass through the multiple cutouts C of the fuel tank filler FTF in the axial direction Da, for example. That is, as shown in Figures 2 and 3, for example, the multiple stoppers 18 are provided at positions and with sizes that correspond to the multiple cutouts C of the fuel tank filler FTF, and are configured to be able to pass through the multiple cutouts C in the axial direction Da. As shown in Figures 3 and 5, for example, each stopper 18 has a generally trapezoidal shape that is smaller than the cutouts C of the fuel tank filler FTF when viewed in the axial direction Da.

[0035] 3, the plurality of stoppers 18 are provided at positions farther from the upper wall bottom surface 11b than the lower end of the cap body 11. Here, the distance Da in the axial direction between the upper wall bottom surface 11b of the cap body 11 and the plurality of stoppers 18 is set, for example, as follows: That is, this distance is set so that, when the plurality of stoppers 18 are in contact with the fastening inclined surface TIF of the fuel tank filler FTF shown in FIG. 2, a gap Ga is formed between the lower end of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF, as shown in FIG.

[0036] The stoppers 18 are provided at positions facing the fastening inclined surface TIF of the fuel tank filler FTF shown in FIG. 2 when the fastening protrusions 13 pass through the notches C in the axial direction Da. In other words, the stoppers 18 are provided at angular positions different from the fastening protrusions 13 in the fastening direction Dt of the fuel cap 1, and are provided at positions not overlapping with the fastening protrusions 13 in the axial direction Da. The stoppers 18 are provided to protrude radially from, for example, the outer peripheral surface of the disc cap 16, specifically, from the outer peripheral surface of a guide portion 16g of the disc cap 16, which will be described later.

[0037] The stoppers 18 are made of a material that is lower in hardness than the leading annular surface TAF of the fuel tank filler FTF. The material of the stoppers 18 is not particularly limited, but may be, for example, metal, resin, ceramic, etc. The hardness may be, for example, Vickers hardness, Rockwell hardness, Brinell hardness, etc. In this embodiment, the stoppers 18 are made of a resin material such as plastic, similar to the disc cap 16.

[0038] 3, the centers of the multiple fastening protrusions 13 and the multiple interference prevention portions 14 coincide with each other in the fastening direction Dt of the fuel cap 1. Therefore, the center line perpendicular to the axial direction Da of each fastening protrusion 13 is at the same angular position in the fastening direction Dt of the fuel cap 1 as the center line perpendicular to the axial direction Da of each interference prevention portion 14 shown in FIG.

[0039] 5 , the angle between the center line perpendicular to the axial direction Da of each stopper 18 and the center line perpendicular to the axial direction Da of the interference prevention part 14 adjacent to the rear side in the fastening direction Dt among the multiple interference prevention parts 14 is defined as the angular interval θb. Also, the angle between the center line perpendicular to the axial direction Da of each stopper 18 and the center line perpendicular to the axial direction Da of the interference prevention part 14 adjacent to the front side in the fastening direction Dt among the multiple interference prevention parts 14 is defined as the angular interval θf.

[0040] In this case, for example, the angular interval θb between each of the plurality of stoppers 18 and the adjacent interference prevention portion 14 on the rear side in the fastening direction Dt among the plurality of interference prevention portions 14 is narrower than the angular interval θf between each of the plurality of stoppers 18 and the adjacent interference prevention portion 14 on the front side in the fastening direction Dt. In other words, for example, the angular interval θb between each of the plurality of stoppers 18 and the adjacent fastening protrusion 13 on the rear side in the fastening direction Dt among the plurality of fastening protrusions 13 is narrower than the angular interval θf between each of the plurality of stoppers 18 and the adjacent fastening protrusion 13 on the front side in the fastening direction Dt. In the present embodiment, the angular interval θb on the rear side in the fastening direction Dt is smaller than ½ the angular interval θf on the front side in the fastening direction Dt and smaller than ⅓ the angular interval θf on the front side in the fastening direction Dt, for example.

[0041] The multiple interference prevention portions 14, like the multiple stoppers 18, have a size and shape that allows them to pass through the multiple cutouts C of the fuel tank filler FTF in the axial direction Da. That is, as shown in FIGS. 2 and 3, the multiple interference prevention portions 14 are provided at positions, sizes, and shapes that correspond to the multiple cutouts C of the fuel tank filler FTF, and are configured to be able to pass through the multiple cutouts C in the axial direction Da. As shown in FIGS. 3 and 5, each interference prevention portion 14 has a generally rectangular shape when viewed in the axial direction Da that corresponds to the shape of the cutouts C and the fastening protrusion 13 of the fuel tank filler FTF. Note that the fuel cap 1 of this embodiment does not necessarily have to have the interference prevention portion 14.

[0042] 3 and 4, the multiple interference prevention portions 14 are provided at positions interposed between the leading annular surface TAF of the fuel tank filler FTF and the multiple fastening protrusions 13 when the retainer 12 of the fuel cap 1 is placed opposite the filler opening FO of the fuel tank filler FTF. That is, as shown in Figures 2 to 4, when the cap body 11 is moved toward the leading annular surface TAF of the fuel tank filler FTF in the axial direction Da, the multiple interference prevention portions 14 come into contact with the leading annular surface TAF before the multiple fastening protrusions 13. This prevents contact between the multiple fastening protrusions 13 and the leading annular surface TAF of the fuel tank filler FTF.

[0043] Furthermore, in the circumferential direction of the cap body 11, the positions of both end edges of the interference prevention portion 14 are, for example, equal to the positions of both end edges of the fastening protrusions 13 or are located outward of the positions of both end edges of the fastening protrusions 13. Therefore, after the multiple fastening protrusions 13 have passed through the multiple notches C provided in the leading annular surface TAF of the fuel tank filler FTF in the axial direction Da, when the cap body 11 is further moved in the axial direction Da, the multiple fastening protrusions 13 pass through the multiple notches C. This prevents contact between the multiple fastening protrusions 13 and the leading annular surface TAF of the fuel tank filler FTF.

[0044] The interference prevention portions 14 are made of, for example, a material having a lower hardness than the leading annular surface TAF of the fuel tank filler FTF. The material and hardness of the interference prevention portions 14 may be the same as those of the stopper 18. In this embodiment, the interference prevention portions 14 are made of, for example, a resin material such as plastic. In this embodiment, the interference prevention portions 14 are provided so as to protrude radially outward from the outer peripheral surface of the disc cap 16.

[0045] The disc cap 16 is attached to the top wall bottom surface 11b of the cap body 11, for example, inside the retainer 12. The disc cap 16 is made of a resin material, for example, plastic. As shown in Figures 3 to 5, the disc cap 16 has a cylindrical guide portion 16g that has an outer diameter corresponding to the inner diameter of the fuel filler opening FO and engages with the inside of the fuel filler opening FO.

[0046] The guide portion 16g is, for example, a disk-shaped portion provided on the lower side of the disc cap 16, and has a short-axis cylindrical outer peripheral surface and a bottom surface with a concave recess on the inside of the periphery. The outer peripheral surface of the guide portion 16g may have, for example, a tapered shape whose diameter decreases as it gets farther away from the upper wall bottom surface 11b of the cap body 11. This allows the tapered outer peripheral surface to guide the guide portion 16g so that the center of the guide portion 16g coincides with the center of the fuel filler opening FO when engaging the guide portion 16g with the fuel filler opening FO, making it easier to engage the guide portion 16g with the inside of the fuel filler opening FO.

[0047] The disc cap 16 has, for example, a small-diameter portion above the lower guide portion 16g, the diameter of which is smaller than that of the guide portion 16g. The disc cap 16 is fixed to the upper wall bottom surface 11b of the cap body 11 by fastening members 17, e.g., three screws, that pass through the guide portion 16g and the small-diameter portion. The fastening members 17 are disposed, for example, in the center of a recess provided in the bottom surface of the guide portion 16g.

[0048] The plurality of interference prevention portions 14 are provided, for example, at the upper end of the guide portion 16g. The plurality of stoppers 18 are provided, for example, at the lower end of the guide portion 16g. That is, the plurality of stoppers 18 are provided at positions farther away from the upper wall bottom surface 11b of the cap body 11 in the axial direction Da than the plurality of interference prevention portions 14.

[0049] The plurality of interference prevention portions 14 and the plurality of stoppers 18 each protrude radially outward from the outer peripheral surface of the guide portion 16g. The plurality of interference prevention portions 14 and the plurality of stoppers 18 are provided at positions farther in the axial direction Da from the upper wall bottom surface 11b than the lower end of the peripheral wall 11p of the cap body 11, as shown in Figures 3 to 5. As a result, the plurality of interference prevention portions 14 and the plurality of stoppers 18 are exposed on the lower side of the cap body 11 when viewed from the radial direction of the cap body 11 perpendicular to the central axis a, as shown in Figures 3 to 5.

[0050] 3 and 4, a gap G in the axial direction Da is formed between the plurality of fastening protrusions 13 and the plurality of interference prevention portions 14. This gap G has a dimension that allows elastic deformation of each fastening protrusion 13 in the axial direction Da when, for example, each fastening protrusion 13 of the fuel cap 1 is engaged with each fastening inclined surface TIF of the fuel tank filler FTF.

[0051] 3 is greater than, for example, the height H in the axial direction Da of the fastening inclined surface TIF and the height in the axial direction Da of the anti-rotation stopper WS provided on the fuel tank filler FTF shown in Fig. 2. This allows the stoppers 18 of the fuel cap 1 to pass through the notches C of the fuel tank filler FTF, and allows the cap body 11 to freely rotate in the fastening direction Dt and the opposite loosening direction with the interference prevention portions 14 abutting against the tip annular surface TAF.

[0052] The packing 15 is, for example, an annular flat rubber plate. As shown in Fig. 3, the packing 15 is disposed on the outermost periphery of the upper wall bottom surface 11b of the cap body 11. The packing 15 is fixed to the upper wall bottom surface 11b of the cap body 11 with, for example, an adhesive, and is provided integrally with the cap body 11. When the upper wall bottom surface 11b of the cap body 11 is facing downward, the packing 15 is disposed above the retainer 12, the plurality of fastening protrusions 13, and the plurality of interference prevention portions 14.

[0053] The packing 15 functions, for example, as a sealing portion that seals the gap between the cap body 11 and the fuel filler opening FO of the fuel tank filler FTF. Specifically, the packing 15 is compressed between the upper wall bottom surface 11b of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF when the interference prevention portion 14 of the fuel cap 1 engages with the fastening inclined surface TIF of the fuel tank filler FTF and abuts against the rotation stopper WS. This causes the packing 15 to closely contact the upper wall bottom surface 11b of the cap body 11 and the leading annular surface TAF, sealing the gap between the cap body 11 and the fuel filler opening FO of the fuel tank filler FTF. Note that the fuel cap 1 does not necessarily have to include the packing 15. In this case, the upper wall bottom surface 11b of the cap body 11 can be closely contacted with the leading annular surface TAF of the fuel tank filler FTF to function as a sealing portion.

[0054] The operation of the fuel cap 1 of this embodiment will be described below in comparison with the conventional fuel tank cap described in the aforementioned Patent Document 1.

[0055] The conventional fuel tank cap described in Patent Document 1 has the risk of being blown off and lost by air escaping from the cap mounting opening of the fuel tank when it is loosened for removal when the internal pressure of the fuel tank is elevated.

[0056] In contrast, the fuel cap 1 of this embodiment is fastened to the cylindrical fuel tank filler FTF by rotating it in a fastening direction Dt about its axis, and closes the fuel filler opening FO that opens at the tip of the fuel tank filler FTF in the axial direction Da. The fuel cap 1 is provided with a plurality of stoppers 18 that face the fastening inclined surface TIF on the inside of the fuel filler opening FO in the axial direction Da, in a state in which the fuel cap 1 can be pulled up in the axial direction Da from the tip of the fuel tank filler FTF.

[0057] With this configuration, the fuel cap 1 of this embodiment can be removed from the tip of the fuel tank filler FTF by following the procedure below. First, the cap body 11 of the fuel cap 1 is rotated in the loosening direction opposite to the fastening direction Dt. Then, the engagement between the fuel cap 1 and the fastening inclined surface TIF of the fuel tank filler FTF in the axial direction Da of the fuel tank filler FTF is released, making the fuel cap 1 removable in the axial direction Da from the tip of the fuel tank filler FTF.

[0058] Here, the internal pressure of the fuel tank FTK may increase due to, for example, an increase in temperature inside the fuel tank FTK when the filler opening FO of the fuel tank filler FTF is closed by the fuel cap 1, an expansion of the fuel volume due to an increase in fuel temperature, or a decrease in the volume of the air in the fuel tank FTK when fuel is filled with fuel while the fuel cap is attached to the fuel tank FTK. In such a case, as described above, if the fuel cap 1 is made removable in the axial direction Da from the tip of the fuel tank filler FTF, a gap will be formed between the fuel cap 1 and the tip of the fuel tank filler FTF.

[0059] When this happens, gas such as air that has expanded inside the fuel tank FTK will burst out from the gap, exerting an axial force that will blow off the fuel cap 1. As a result, there is a risk that the fuel cap 1 will be blown off from the tip of the fuel tank filler FTF.

[0060] However, with the fuel cap 1 of this embodiment, the multiple stoppers 18 of the fuel cap 1 are provided in positions facing the tip annular surface TAF of the fuel tank filler FTF in the axial direction Da, in a state in which the fuel cap 1 can be pulled up in the axial direction Da from the tip of the fuel tank filler FTF. Therefore, by engaging the multiple stoppers 18 of the fuel cap 1 with the tip annular surface TAF of the fuel tank filler FTF, the fuel cap 1 is prevented from being blown off by gas spraying out from the fuel filler opening FO.

[0061] More specifically, the fuel cap 1 of this embodiment further includes a cap body 11 that covers the tip of the fuel tank filler FTF, an annular retainer 12 fixed to the top wall bottom surface 11b of the cap body 11 that faces the fuel filler opening FO, and a plurality of fastening protrusions 13 that protrude radially outward from the outer circumferential edge of the retainer 12. The plurality of fastening protrusions 13 pass through a plurality of notches C formed in a tip annular surface TAF around the fuel filler opening FO in the axial direction Da and are rotated in the fastening direction Dt to engage with a fastening inclined surface TIF on the inside of the fuel filler opening FO. The plurality of stoppers 18 have a size and shape that allows them to pass through the plurality of notches C in the axial direction Da, and are positioned so as to face the fastening inclined surface TIF when the plurality of fastening protrusions 13 pass through the plurality of notches C in the axial direction Da.

[0062] With this configuration, the fuel cap 1 of this embodiment can be removed from the tip of the fuel tank filler FTF by following the procedure below. First, the cap body 11 of the fuel cap 1 is rotated in the loosening direction opposite to the fastening direction Dt, causing the multiple fastening protrusions 13 of the fuel cap 1 to slide along the fastening inclined surface TIF of the fuel tank filler FTF. Then, the multiple fastening protrusions 13 of the fuel cap 1 are passed through the multiple notches C provided in the tip annular surface TAF of the fuel tank filler FTF.

[0063] Next, the cap body 11 of the fuel cap 1 is pulled up in the axial direction Da, and the stoppers 18 are further rotated in the loosening direction while abutting against the fastening inclined surfaces TIF of the fuel tank filler FTF. Then, the stoppers 18 of the fuel cap 1 are slid along the fastening inclined surfaces TIF of the fuel tank filler FTF, and the stoppers 18 pass through the notches C of the fuel tank filler FTF in the axial direction Da. This allows the fuel cap 1 to be removed from the tip of the fuel tank filler FTF.

[0064] As described above, the internal pressure of the fuel tank FTK may increase. In such a case, as described above, when the cap body 11 of the fuel cap 1 is rotated in the loosening direction, the multiple fastening projections 13 of the fuel cap 1 slide along the fastening inclined surface TIF of the fuel tank filler FTF. As a result, a gap is formed between the upper wall bottom surface 11b of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF.

[0065] Then, gas such as air expanded inside the fuel tank FTK is ejected from the gap, exerting an axial force that pushes the cap body 11 up in the axial direction Da. As a result, the multiple fastening protrusions 13 of the fuel cap 1 may slide further along the fastening inclined surface TIF of the fuel tank filler FTF, and the multiple fastening protrusions 13 of the fuel cap 1 may pass through the multiple notches C of the fuel tank filler FTF in the axial direction Da.

[0066] However, according to the fuel cap 1 of this embodiment, when the multiple fastening projections 13 pass through the multiple cutouts C of the fuel tank filler FTF in the axial direction Da, the multiple stoppers 18 are provided in positions facing the fastening inclined surfaces TIF of the fuel tank filler FTF. Therefore, even when the multiple fastening projections 13 of the fuel cap 1 pass through the multiple cutouts C of the fuel tank filler FTF in the axial direction Da, the multiple stoppers 18 of the fuel cap 1 engage with the fastening inclined surfaces TIF of the fuel tank filler FTF.

[0067] This prevents the fuel cap 1 from being blown off by gas escaping from the fuel filler opening FO. Also, by engaging the multiple stoppers 18 of the fuel cap 1 with the fastening inclined surface TIF of the fuel tank filler FTF, the gap between the upper wall bottom surface 11b of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF is larger than when the multiple fastening protrusions 13 are engaged with the fastening inclined surface TIF. As a result, the gas is more easily ejected from the fuel filler opening FO, and the internal pressure of the fuel tank FTK can be rapidly reduced.

[0068] Therefore, according to this embodiment, it is possible to provide a fuel cap 1 that can be prevented from being blown off by air spraying out from the fuel filler opening FO, even if it is removed when the internal pressure of the fuel tank FTK is elevated.

[0069] In addition, the fuel cap 1 of this embodiment is provided with a gasket 15 as a sealing part that seals the gap between the cap body 11 and the fuel filler opening FO, and when multiple stoppers 18 are in contact with the fastening inclined surface TIF of the fuel tank filler FTF, a gap is formed between the lower end surface of the gasket 15, which is the sealing part, and the tip annular surface TAF of the fuel tank filler FTF.

[0070] With this configuration, gas that is ejected from the fuel filler opening FO when the internal pressure of the fuel tank FTK rises can be released into the atmosphere from the gap Ga between the lower end surface of the packing 15 and the leading annular surface TAF of the fuel tank filler FTF. Specifically, when gas is ejected from the fuel filler opening FO, the cap body 11 is pushed up in the axial direction Da, and the multiple stoppers 18 come into contact with the fastening inclined surface TIF of the fuel tank filler FTF.

[0071] In this state, a gap is formed between the bottom end surface of the packing 15, which serves as the sealing portion, and the leading annular surface TAF of the fuel tank filler FTF. As a result, gas ejected from the fuel filler opening FO passes through the gap between the bottom end surface of the packing 15 and the leading annular surface TAF of the fuel tank filler FTF and is released into the atmosphere. This reduces the internal pressure of the fuel tank FTK, preventing the fuel cap 1 from being blown off.

[0072] In the fuel cap 1 of this embodiment, the plurality of stoppers 18 are made of a material that is lower in hardness than the leading annular surface TAF of the fuel tank filler FTF.

[0073] With this configuration, when the fuel cap 1 is fastened to the tip of the fuel tank filler FTF to close the fuel filler opening FO, it is possible to prevent damage to the tip annular surface TAF of the fuel tank filler FTF and prevent a decrease in the sealing performance of the fuel filler opening FO. Specifically, when fastening the fuel cap 1 to the tip of the fuel tank filler FTF, as shown in Figures 2 and 3, first, the plurality of stoppers 18 are aligned with the plurality of notches C provided in the tip annular surface TAF of the fuel tank filler FTF and passed through in the axial direction Da.

[0074] At this time, there is a risk that each stopper 18 of the fuel cap 1 may interfere with, contact, collide with, or slide against the leading annular surface TAF of the fuel tank filler FTF. However, even in such a case, the hardness of the multiple stoppers 18 is lower than the hardness of the leading annular surface TAF, so that the leading annular surface TAF can be prevented from being damaged. As a result, the packing 15 provided on the upper wall bottom surface 11b of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF are tightly fitted together, preventing a decrease in the sealing performance of the fuel filler opening FO.

[0075] Furthermore, in the fuel cap 1 of this embodiment, for example, as shown in Figures 3 and 5, the angular interval θb between each of the multiple stoppers 18 and the fastening protrusion 13 adjacent to it on the rear side in the fastening direction Dt among the multiple fastening protrusions 13 is narrower than the angular interval θf between each of the multiple fastening protrusions 13 adjacent to it on the front side in the fastening direction Dt among the multiple fastening protrusions 13.

[0076] This configuration makes it easy to attach and detach the fuel cap 1 to the tip of the fuel tank filler FTF. Specifically, when fastening the fuel cap 1 to the tip of the fuel tank filler FTF, first, as described above, the multiple stoppers 18 are aligned with the multiple cutouts C and passed through in the axial direction Da. Then, as shown in Figure 4, the multiple fastening protrusions 13 of the fuel cap 1 and the tip annular surface TAF of the fuel tank filler FTF face each other in the axial direction Da.

[0077] In this state, by rotating the cap body 11 in the fastening direction Dt by an angle equal to the angular interval θb, the multiple fastening protrusions 13 can be passed axially through the multiple cutouts C. At this time, the angular interval θb between each stopper 18 and the fastening protrusion 13 adjacent thereto on the rear side in the fastening direction Dt is smaller than the angular interval θf between each stopper 18 and the fastening protrusion 13 adjacent thereto on the front side in the fastening direction Dt.

[0078] This allows the rotation angle of the cap body 11 to be smaller when the multiple fastening protrusions 13 are passed through the multiple notches C after the multiple stoppers 18 have passed through the multiple notches C, making it easier to attach the fuel cap 1. The same applies to the removal of the fuel cap 1. Note that the angular interval θb can be made as small as possible within a range in which, for example, the multiple stoppers 18 do not pass through the multiple notches C during the period from when the multiple fastening protrusions 13 pass through the multiple notches C until the internal pressure of the fuel tank FTK decreases when removing the fuel cap 1.

[0079] The fuel cap 1 of this embodiment also includes a plurality of interference prevention portions 14 that are sized and shaped to pass through the plurality of notches in the fuel tank filler FTF in the axial direction Da. These interference prevention portions 14 are provided at positions that are interposed between the leading annular surface TAF of the fuel tank filler FTF and the plurality of fastening projections 13 when the retainer 12 of the fuel cap 1 is placed opposite the fuel filler opening FO.

[0080] With this configuration, when the fuel cap 1 is fastened to the tip of the fuel tank filler FTF to close the fuel filler opening FO, the tip annular surface TAF around the fuel filler opening FO is prevented from coming into contact with the fastening protrusion 13, thereby preventing damage to the tip annular surface TAF. Specifically, when the fuel cap 1 is attached to the tip of the fuel tank filler FTF, as shown in Figure 2, the retainer 12 attached to the top wall bottom surface 11b of the cap body 11 is opposed to the fuel filler opening FO that opens at the tip of the fuel tank filler FTF.

[0081] In this state, as described above, the multiple stoppers 18 of the fuel cap 1 are aligned with and passed through the multiple cutouts C provided in the leading annular surface TAF of the fuel tank filler FTF. At this time, each of the multiple interference prevention portions 14 is interposed between each of the multiple fastening projections 13 protruding from the outer peripheral edge of the retainer 12 and the leading annular surface TAF of the fuel tank filler FTF. Therefore, when the multiple stoppers 18 of the fuel cap 1 are passed through the multiple cutouts C of the fuel tank filler FTF, each interference prevention portion 14 comes into contact with the leading annular surface TAF of the fuel tank filler FTF, thereby preventing interference, contact, collision, or sliding between all of the fastening projections 13 and the leading annular surface TAF.

[0082] Furthermore, in order to interpose the plurality of interference prevention portions 14 between the plurality of fastening protrusions 13 and the tip annular surface TAF of the fuel tank filler FTF, the plurality of fastening protrusions 13 and the plurality of interference prevention portions 14 are provided at positions where they overlap with each other in the axial direction Da. Therefore, when the plurality of interference prevention portions 14 are aligned with the plurality of notches C provided in the tip annular surface TAF, the plurality of fastening protrusions 13 also become aligned with the plurality of notches C.

[0083] Therefore, when the multiple interference prevention portions 14 are passed through the multiple notches C in the axial direction Da, the multiple fastening protrusions 13 also pass through the multiple notches C in the axial direction Da. Therefore, during the time when the multiple fastening protrusions 13 are aligned with the multiple notches C and passed through in the axial direction Da, the fastening protrusions 13 are prevented from contacting, colliding with, or sliding against the tip annular surface TAF, and damage to the tip annular surface TAF is prevented.

[0084] Thereafter, by rotating the cap body 11 in the fastening direction Dt, each fastening protrusion 13 rotates in the fastening direction Dt and engages with each fastening inclined surface TIF provided on the inside of the fuel filler opening FO. When the cap body 11 is further rotated in the fastening direction Dt, each fastening protrusion 13 moves in the fastening direction Dt along each fastening inclined surface TIF, and a force acts from each fastening inclined surface TIF to elastically deform each fastening protrusion 13 in the axial direction Da.

[0085] Ultimately, each fastening projection 13 abuts against a rotation stop WS provided at the end of each fastening inclined surface TIF, restricting rotation of the cap body 11 in the fastening direction Dt, and the fuel cap 1 is fastened to the tip of the fuel tank filler FTF. To remove the fuel cap 1 from the fuel tank filler FTF, the procedure for attaching the fuel cap 1 to the fuel tank filler FTF is reversed. This allows the fuel cap 1 to be attached to and removed from the fuel tank filler FTF while preventing damage to the tip annular surface TAF of the fuel tank filler FTF.

[0086] The fuel cap 1 of this embodiment further includes a disc cap 16 attached to the top wall bottom surface 11b of the cap body 11 inside the retainer 12. The disc cap 16 has a cylindrical guide portion 16g that has an outer diameter corresponding to the inner diameter of the fuel filler opening FO and engages with the inside of the fuel filler opening FO.

[0087] With this configuration, when aligning the multiple fastening projections 13 (and interference prevention portion 14) with the multiple notches C provided in the leading annular surface TAF of the fuel tank filler FTF, the guide portion 16g of the disc cap 16 can be engaged with the fuel filler opening FO. This prevents tilt of the central axis a of the fuel cap 1 with respect to the central axis A of the fuel tank filler FTF and prevents radial rattle of the cap body 11, making alignment easier. This therefore makes it easier to attach and detach the fuel cap 1 to and from the fuel tank filler FTF.

[0088] 3 and 4, in the fuel cap 1 of this embodiment, the multiple fastening protrusions 13 are provided on the inside of the peripheral wall 11p of the cap body 11. The multiple stoppers 18 are provided at positions farther from the upper wall bottom surface 11b than the lower end of the cap body 11. With the multiple stoppers 18 in contact with the fastening inclined surface TIF of the fuel tank filler FTF, as shown in FIG. 4, a gap Ga is formed between the lower end surface of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF.

[0089] With this configuration, the position of the stopper 18 can be visually confirmed when attaching the fuel cap 1 to the fuel tank filler FTF, facilitating circumferential alignment of the fuel cap 1. This facilitates attachment of the fuel cap 1 to the fuel tank filler FTF. Furthermore, compared to a case in which the cap body 11 covers the tip of the fuel tank filler FTF, including the tip annular surface TAF and the fuel filler opening FO, this configuration makes it easier to release gas ejected from the fuel filler opening FO into the atmosphere. Furthermore, compared to a case in which the cap body 11 covers the tip of the fuel tank filler FTF, including the tip annular surface TAF and the fuel filler opening FO, this configuration makes it easier to release gas ejected from the fuel filler opening FO into the atmosphere.

[0090] Furthermore, in the fuel cap 1 of this embodiment, the plurality of stoppers 18 are provided at positions farther away from the upper wall bottom surface 11 b of the cap body 11 in the axial direction Da than the plurality of interference prevention portions 14 .

[0091] With this configuration, when fastening the fuel cap 1 to the fuel tank filler FTF, the stoppers 18 are passed through the notches C of the fuel tank filler FTF, causing the interference prevention portions 14 to abut against the leading annular surface TAF. Then, by rotating the fuel cap 1 in the fastening direction Dt and aligning the interference prevention portions 14 with the notches C and passing them through, the fastening protrusions 13 can also pass through the notches C. Then, by rotating the fuel cap 1 in the fastening direction Dt, the fastening protrusions 13 each engage with the fastening inclined surfaces TIF, and the fuel cap 1 is fastened to the fuel tank filler FTF.

[0092] When loosening the fuel cap 1 and removing it from the fuel tank filler FTF, the cap body 11 is rotated in the loosening direction opposite to the fastening direction Dt, causing the fastening projections 13 and interference prevention portions 14 to pass through the notches C. In this state, the stoppers 18 each face the fastening inclined surfaces TIF. Therefore, when the internal pressure of the fuel tank FTK increases, the stoppers 18 each engage with the fastening inclined surfaces TIF, preventing the fuel cap 1 from being blown off.

[0093] As described above, according to this embodiment, it is possible to provide a fuel cap 1 that can be prevented from being blown off by air spraying out from the fuel filler opening FO, even if it is removed when the internal pressure of the fuel tank FTK is elevated.

[0094] To summarize the above-described embodiment, the following procedure is followed to remove the fuel cap according to this embodiment from the tip of the fuel tank filler. First, the cap body of the fuel cap is rotated in the loosening direction, which is opposite to the fastening direction. Then, the engagement between the fuel cap and the fastening inclined surface of the fuel tank filler in the axial direction of the fuel tank filler is released, making the fuel cap detachable in the axial direction from the tip of the fuel tank filler.

[0095] For example, a fuel tank may be filled with fuel by a fuel pump attached to the side of the fuel tank while the filler opening at the tip of the fuel tank filler is closed with a fuel cap. In such a case, the air inside the fuel tank may be compressed, causing an increase in internal pressure. In such a case, if the fuel cap is made axially removable from the tip of the fuel tank filler as described above, a gap will be formed between the fuel cap and the tip of the fuel tank filler.

[0096] This can cause gases such as air expanding inside the fuel tank to escape through the gap, creating an axial force that can blow the fuel cap off, potentially blowing it off the tip of the fuel tank filler.

[0097] However, according to the above-described embodiment, the fuel cap can be pulled up axially from the tip of the fuel tank filler, and the stoppers of the fuel cap are provided in positions that axially face the fastening inclined surfaces of the fuel tank filler. Therefore, the stoppers of the fuel cap engage with the fastening inclined surfaces of the fuel tank filler, thereby preventing the fuel cap from being blown off by gas spraying out from the fuel filler opening.

[0098] In addition, by engaging the multiple stoppers of the fuel cap with the fastening inclined surfaces of the fuel tank filler, the gap between the fuel cap and the tip of the fuel tank filler is enlarged, promoting the escape of gas from the fuel filler opening and rapidly reducing the internal pressure of the fuel tank.

[0099] Therefore, according to the above-described embodiment, it is possible to provide a fuel cap that can be prevented from being blown off by air spraying out from the fuel filler opening, even if it is removed when the internal pressure of the fuel tank is elevated.

[0100] Next, with reference to FIG. 6, an embodiment of a fuel cap according to another embodiment of the present disclosure will be described.

[0101] Fig. 6 is an enlarged perspective view of a fuel cap 1 according to another embodiment of the present disclosure, viewed from diagonally below. As shown in Fig. 6, the fuel cap 1 of this embodiment includes a cap body 11, a retainer 12, a plurality of fastening protrusions 13, and a plurality of interference prevention portions 14. The fuel cap 1 also includes, for example, a packing 15, a disc cap 16, and a fastening member 17.

[0102] The fuel cap 1 of this embodiment shown in Figure 6 differs from the fuel cap 1 according to the first embodiment shown in Figure 3 in that it does not have a stopper 18. The other configuration of the fuel cap 1 of this embodiment is similar to that of the fuel cap 1 according to the first embodiment described above, so similar parts are denoted by the same reference numerals and descriptions thereof will be omitted.

[0103] The operation of the fuel cap 1 of this embodiment will be described below in comparison with the conventional fuel tank cap described in the aforementioned Patent Document 1.

[0104] As described above, the conventional fuel tank cap described in Patent Document 1 has a notch and an engaging portion and is removably attached to a cylindrical cap mounting opening provided on a fuel tank. However, when this conventional fuel tank cap is attached to the cap mounting opening, the engaging protrusions of the latching pieces may interfere with, contact, collide with, or slide against the upper end surface of the flange portion of the cap mounting opening, which may cause damage such as scratches on the upper end surface of the flange. Such damage may reduce the sealing ability of the fuel tank cap around the cap mounting opening and may cause fuel to leak from the fuel tank.

[0105] On the other hand, the fuel cap 1 of this embodiment is fastened to the cylindrical fuel tank filler FTF by rotating it in a fastening direction Dt about its axis to close the fuel filler opening FO that opens at the tip of the fuel tank filler FTF in the axial direction Da. The fuel cap 1 is equipped with a plurality of fastening protrusions 13 that engage with the inside of the fuel filler opening FO of the fuel tank filler FTF, and a plurality of interference prevention portions 14 that prevent interference between the plurality of fastening protrusions 13 and the fuel tank filler FTF.

[0106] With this configuration, when the fuel cap 1 is fastened to the tip of the fuel tank filler FTF to close the fuel filler opening FO at the tip of the fuel tank filler FTF, the multiple fastening protrusions 13 are prevented from interfering with, contacting, colliding with, or sliding against the tip annular surface TAF of the fuel tank filler FTF, thereby preventing damage to the tip annular surface TAF of the fuel tank filler FTF. As a result, it is possible to prevent a decrease in the sealing performance between the fuel cap 1 and the tip annular surface TAF of the fuel tank filler FTF.

[0107] The fuel cap 1 of this embodiment also includes a cap body 11 that covers the tip of the fuel tank filler FTF and an annular retainer 12 fixed to the top wall bottom surface 11b of the cap body 11 that faces the fuel filler opening FO. A plurality of fastening protrusions 13 protrude radially outward from the outer peripheral edge of the retainer 12. The fastening protrusions 13 pass through a plurality of notches C formed in a tip annular surface TAF around the fuel filler opening FO in the axial direction Da and are rotated in the fastening direction Dt to engage with the fastening inclined surface TIF on the inside of the fuel filler opening FO. Furthermore, the plurality of interference prevention portions 14 have a size and shape that allows them to pass through the multiple notches C in the axial direction Da. The plurality of interference prevention portions 14 are located between the tip annular surface TAF and the multiple fastening protrusions 13 when the retainer 12 faces the fuel filler opening FO.

[0108] With this configuration, when the fuel cap 1 is fastened to the tip of the fuel tank filler FTF to close the fuel filler opening FO, the tip annular surface TAF around the fuel filler opening FO is prevented from coming into contact with the fastening protrusion 13, thereby preventing damage to the tip annular surface TAF. Specifically, when the fuel cap 1 is attached to the tip of the fuel tank filler FTF, as shown in Figure 2, the retainer 12 attached to the top wall bottom surface 11b of the cap body 11 is opposed to the fuel filler opening FO that opens at the tip of the fuel tank filler FTF.

[0109] In this state, each of the multiple interference prevention portions 14 is interposed between each of the multiple fastening projections 13 projecting from the outer peripheral edge of the retainer 12 and the leading annular surface TAF of the fuel tank filler FTF. Therefore, when the cap body 11 is moved in the axial direction Da and brought closer to the fuel filler opening FO, each of the interference prevention portions 14 comes into contact with the leading annular surface TAF of the fuel tank filler FTF, thereby preventing interference, contact, collision, or sliding between all of the fastening projections 13 and the leading annular surface TAF.

[0110] Furthermore, in order to interpose the plurality of interference prevention portions 14 between the plurality of fastening protrusions 13 and the tip annular surface TAF of the fuel tank filler FTF, the plurality of fastening protrusions 13 and the plurality of interference prevention portions 14 are provided at positions where they overlap with each other in the axial direction Da. Therefore, when the plurality of interference prevention portions 14 are aligned with the plurality of notches C provided in the tip annular surface TAF, the plurality of fastening protrusions 13 also become aligned with the plurality of notches C.

[0111] Therefore, when the multiple interference prevention portions 14 are passed through the multiple notches C in the axial direction Da, the multiple fastening protrusions 13 also pass through the multiple notches C in the axial direction Da. Therefore, during the time when the multiple fastening protrusions 13 are aligned with the multiple notches C and passed through in the axial direction Da, the fastening protrusions 13 are prevented from contacting, colliding with, or sliding against the tip annular surface TAF, and damage to the tip annular surface TAF is prevented.

[0112] Thereafter, by rotating the cap body 11 in the fastening direction Dt, each fastening protrusion 13 rotates in the fastening direction Dt and engages with each fastening inclined surface TIF provided on the inside of the fuel filler opening FO. When the cap body 11 is further rotated in the fastening direction Dt, each fastening protrusion 13 moves in the fastening direction Dt along each fastening inclined surface TIF, and a force acts from each fastening inclined surface TIF to elastically deform each fastening protrusion 13 in the axial direction Da.

[0113] Ultimately, each fastening projection 13 abuts against a rotation stop WS provided at the end of each fastening inclined surface TIF, restricting rotation of the cap body 11 in the fastening direction Dt, and the fuel cap 1 is fastened to the tip of the fuel tank filler FTF. To remove the fuel cap 1 from the fuel tank filler FTF, the procedure for attaching the fuel cap 1 to the fuel tank filler FTF is reversed. This allows the fuel cap 1 to be attached to and removed from the fuel tank filler FTF while preventing damage to the tip annular surface TAF of the fuel tank filler FTF.

[0114] The fuel cap 1 of this embodiment further includes a disc cap 16 attached to the upper wall bottom surface 11b of the cap body 11 inside the retainer 12. The plurality of interference prevention portions 14 are provided so as to protrude radially outward from the outer peripheral surface of the disc cap 16.

[0115] This configuration makes it easy to attach the multiple interference prevention portions 14 to the cap body 11. In addition, the multiple interference prevention portions 14 can be arranged at positions where they overlap the multiple fastening protrusions 13 in the axial direction Da, making it easy to arrange the multiple interference prevention portions 14 at positions interposed between the tip annular surface TAF of the fuel tank filler FTF and the multiple fastening protrusions 13.

[0116] Furthermore, in the fuel cap 1 of this embodiment, the plurality of interference prevention portions 14 are made of a material that is lower in hardness than the leading annular surface TAF of the fuel tank filler FTF.

[0117] This configuration prevents damage such as scratches to the leading annular surface TAF of the fuel tank filler FTF even if each interference prevention portion 14 interferes with, contacts, collides with, or slides against the leading annular surface TAF of the fuel tank filler FTF when attaching the fuel cap 1. In particular, when the interference prevention portion 14 is made of a resin such as plastic, damage to the leading annular surface TAF can be more effectively prevented.

[0118] In the fuel cap 1 of this embodiment, the fastening projections 13 have a curved shape that convexly extends toward the fastening inclined surface TIF of the fuel tank filler FTF so as to elastically deform in the axial direction Da when engaging with the fastening inclined surface TIF of the fuel tank filler FTF. Gaps G in the axial direction Da are formed between the fastening projections 13 and the interference prevention portions 14, allowing elastic deformation of the fastening projections 13.

[0119] With this configuration, when the fastening projections 13 of the fuel cap 1 are engaged with the fastening inclined surfaces TIF of the fuel tank filler FTF and the fuel cap 1 is fastened to the leading end of the fuel tank filler FTF, an elastic force acts on the fastening inclined surfaces TIF from the fastening projections 13. This allows the fuel cap 1 to be securely fastened to the fuel tank filler FTF and prevents the fuel cap 1 from falling off the fuel tank filler FTF.

[0120] In the fuel cap 1 of this embodiment, the fastening protrusions 13 are provided on the inside of the peripheral wall 11p of the cap body 11. The interference prevention portions 14 are provided at positions farther in the axial direction Da from the upper wall bottom surface 11b than the lower end of the peripheral wall 11p of the cap body 11.

[0121] With this configuration, when the multiple fastening projections 13 of the fuel cap 1 are engaged with the multiple fastening inclined surfaces TIF of the fuel tank filler FTF, the lower end of the peripheral wall 11p of the cap body 11 is positioned below the leading annular surface TAF of the fuel tank filler FTF. As a result, as shown in Figure 1, the leading end of the fuel tank filler FTF can be covered by the cap body 11, protecting the leading end of the fuel tank filler FTF and the leading annular surface TAF.

[0122] 4, when the fuel cap 1 of this embodiment is attached, the multiple interference prevention portions 14 can be exposed from the lower end of the peripheral wall 11p of the cap body 11. Therefore, the multiple interference prevention portions 14 can be easily aligned with the multiple notches C provided in the leading annular surface TAF of the fuel tank filler FTF, and the multiple interference prevention portions 14 and the multiple fastening protrusions 13 can easily pass through the multiple notches C.

[0123] In the fuel cap 1 of this embodiment, the disc cap 16 has a cylindrical guide portion 16g that has an outer diameter corresponding to the inner diameter of the fuel filler opening FO and engages with the inside of the fuel filler opening FO.

[0124] With this configuration, when aligning the multiple interference prevention portions 14 with the multiple notches C provided in the leading annular surface TAF of the fuel tank filler FTF, the guide portion 16g of the disc cap 16 can be engaged with the fuel filler opening FO. This prevents tilt of the central axis a of the fuel cap 1 with respect to the central axis A of the fuel tank filler FTF and prevents radial rattle of the cap body 11, making alignment easier. This makes it easier to attach and remove the fuel cap 1 to and from the fuel tank filler FTF.

[0125] In the fuel cap 1 of this embodiment, the plurality of interference prevention portions 14 are provided on the upper end portion of the guide portion 16g.

[0126] With this configuration, by engaging the lower end of the guide portion 16g with the fuel filler opening FO and inserting the guide portion 16g into the fuel tank filler FTF, the multiple interference prevention portions 14 provided on the upper end of the guide portion 16g come into contact with the leading annular surface TAF of the fuel tank filler FTF. By rotating the cap body 11 in the fastening direction Dt in this state, the multiple interference prevention portions 14 and the multiple fastening projections 13 can be simultaneously passed through the multiple notches C of the fuel tank filler FTF. This makes it possible to easily attach the fuel cap 1 to the fuel tank filler FTF while preventing contact between the multiple fastening projections 13 and the leading annular surface TAF of the fuel tank filler FTF.

[0127] As described above, according to this embodiment, it is possible to provide a fuel cap 1 that can prevent a decrease in sealing performance when the fuel cap 1 is fastened to the tip of a cylindrical fuel tank filler FTF and the fuel filler opening FO at the tip of the fuel tank filler FTF is closed. Note that fuel caps according to other embodiments of the present disclosure are not limited to the configuration of the fuel cap 1 according to the above-described embodiment. Below, a modified example of the fuel cap 1 according to the above-described embodiment will be described with reference to FIG. 3.

[0128] Figure 3 is an enlarged perspective view showing a fuel cap 1 according to an embodiment of the present disclosure as a modified example of the fuel cap 1 according to another embodiment of the present disclosure shown in Figure 6. The fuel cap 1 in Figure 3 differs from the fuel cap 1 according to the other embodiment shown in Figure 6 in that it includes a plurality of stoppers 18. The other configuration of the fuel cap 1 shown in Figure 3 is similar to that of the fuel cap 1 shown in Figure 6, and therefore the same parts are designated by the same reference numerals and description thereof will be omitted.

[0129] The stoppers 18, like the interference prevention portions 14, have a size and shape that allow them to pass through the notches C of the fuel tank filler FTF in the axial direction Da. The stoppers 18 are provided at positions that face the fastening inclined surfaces TIF of the fuel tank filler FTF when the fastening protrusions 13 pass through the notches C in the axial direction Da. The stoppers 18 are provided at the lower end of the guide portion 16g of the disc cap 16, for example, and protrude radially from the outer peripheral surface of the guide portion 16g.

[0130] With this configuration, when attaching the fuel cap 1 shown in Fig. 3 to the tip of the fuel tank filler FTF, the retainer 12 attached to the bottom surface 11b of the upper wall of the cap body 11 is opposed to the fuel filler opening FO that opens at the tip of the fuel tank filler FTF, similar to the fuel cap 1 shown in Fig. 6. Thereafter, first, the plurality of stoppers 18 are aligned with the plurality of notches C of the fuel tank filler FTF and passed through in the axial direction Da.

[0131] 4, the multiple interference prevention portions 14 come into contact with the tip annular surface TAF of the fuel tank filler FTF, preventing interference, contact, collision, and sliding between the multiple fastening protrusions 13 and the tip annular surface TAF. Furthermore, when the cap body 11 is rotated in the fastening direction Dt, the multiple interference prevention portions 14 and the multiple cutouts C are aligned, allowing the multiple interference prevention portions 14 and the multiple fastening protrusions 13 to pass through the multiple cutouts C in the axial direction.

[0132] Thereafter, when the cap body 11 is further rotated in the fastening direction Dt, each of the multiple fastening protrusions 13 engages with each of the multiple fastening inclined surfaces TIF, and the fuel cap 1 is fastened to the tip of the fuel tank filler FTF. Thereafter, the internal pressure of the fuel tank FTK may increase due to, for example, an increase in air temperature or fuel volume expansion due to an increase in fuel temperature, or a decrease in the volume of air in the fuel tank FTK when refueling the fuel tank FTK with the fuel cap 1 attached.

[0133] In this way, if the fuel cap 1 is removed from the fuel tank filler FTF when the internal pressure of the fuel tank FTK is elevated, gas may be ejected from the fuel filler opening FO, blowing off the fuel cap 1 and causing it to be lost.

[0134] In contrast, as described above, the fuel cap 1 according to this modified example further includes a plurality of stoppers 18 having a size and shape that allows them to pass through the plurality of cutouts C of the fuel tank filler FTF in the axial direction Da. Furthermore, these plurality of stoppers 18 are provided in positions that face the fastening inclined surfaces TIF when the plurality of fastening protrusions 13 pass through the plurality of cutouts C in the axial direction Da.

[0135] With this configuration, when the fuel cap 1 fastened to the tip of the fuel tank filler FTF is rotated in the loosening direction opposite to the fastening direction Dt and the multiple fastening protrusions 13 align with the positions of the multiple cutouts C, the cap body 11 is pushed up in the axial direction Da by the internal pressure of the fuel tank FTK. However, in this state, because each of the multiple stoppers 18 faces the fastening inclined surface TIF, each stopper 18 engages with the fastening inclined surface TIF, preventing the fuel cap 1 from falling off or being blown off.

[0136] During this time, gas inside the fuel tank FTK is discharged from the gap formed between the packing 15 fixed to the bottom surface 11b of the upper wall of the cap body 11 and the leading annular surface TAF of the fuel tank filler FTF, causing the internal pressure of the fuel tank FTK to decrease. After that, by further rotating the cap body 11 in the loosening direction to align the multiple stoppers 18 with the multiple notches C, the fuel cap 1 can be removed from the fuel tank filler FTF.

[0137] To summarize the above-described another embodiment of the present disclosure, according to the above-described another embodiment, when fastening a fuel cap to the front end of a fuel tank filler to close the filler opening at the front end of the fuel tank filler, the fastening protrusions are prevented from interfering with, contacting, colliding with, or sliding against the front annular surface of the fuel tank filler, and the front annular surface of the fuel tank filler is prevented from being scratched, thereby preventing a decrease in the sealing ability between the fuel cap and the front annular surface of the fuel tank filler.

[0138] The preferred embodiments of the present invention have been described above in detail. However, the present invention is not limited to the above-described embodiments. Various modifications or substitutions may be applied to the above-described embodiments without departing from the scope of the present invention. Furthermore, features described separately may be combined unless technical contradictions arise.

[0139] For example, in the fuel cap of the present disclosure, the interference prevention portions may be integral with the fastening protrusions. Specifically, the interference prevention portions may be coatings provided on the lower surfaces of the fastening protrusions that face the annular front surface of the fuel tank filler. In this case, the fuel cap does not need to have a disc cap.

[0140] In addition, this international application claims priority based on Japanese Patent Application Nos. 2023-217025 and 2023-217026 filed on December 22, 2023, and the entire contents of Japanese Patent Application Nos. 2023-217025 and 2023-217026 are incorporated by reference into this international application.

[0141] REFERENCE SIGNS LIST 1 fuel cap 11 cap body 11b upper wall bottom surface 11p peripheral wall 12 retainer 13 fastening protrusion 14 interference prevention portion 16 disc cap 16g guide portion 18 stopper C notch Da axial direction Dt fastening direction FO fuel filler opening FTF fuel tank filler G gap Ga gap TAF tip annular surface TIF fastening inclined surface θb angular interval θf angular interval

Claims

1. A fuel cap that is fastened to a cylindrical fuel tank filler by rotating it in a fastening direction about an axis to close a fuel filler opening that opens at the axial tip of the fuel tank filler, the fuel cap having a plurality of stoppers that face the fastening inclined surface on the inside of the fuel filler opening in the axial direction while allowing the fuel cap to be pulled up in the axial direction from the tip of the fuel tank filler.

2. The fuel cap according to claim 1, further comprising: a cap body covering the tip of the fuel tank filler; a circular retainer fixed to a bottom surface of an upper wall of the cap body facing the fuel filler opening; and a plurality of fastening protrusions protruding radially outward from the outer circumferential edge of the retainer and engaging with the fastening inclined surface on the inside of the fuel filler opening by passing in the axial direction through a plurality of notches formed in a tip annular surface around the fuel filler opening and rotating in the fastening direction; wherein the plurality of stoppers have a size and shape enabling them to pass through the plurality of notches in the axial direction, and are provided in positions facing the fastening inclined surface when the plurality of fastening protrusions pass through the plurality of notches in the axial direction.

3. The fuel cap according to claim 2, further comprising a sealing portion that seals between said cap body and said fuel filler opening, and a gap is formed between a lower end surface of said sealing portion and said tip annular surface when said multiple stoppers are in contact with said fastening inclined surface.

4. The fuel cap according to claim 2, wherein said plurality of stoppers are made of a material having a lower hardness than said tip annular surface.

5. A fuel cap as described in claim 2, wherein the angular interval between each of the plurality of stoppers and an adjacent fastening protrusion on the rear side in the fastening direction among the plurality of fastening protrusions is narrower than the angular interval between each of the plurality of stoppers and an adjacent fastening protrusion on the front side in the fastening direction among the plurality of fastening protrusions.

6. The fuel cap as set forth in claim 2, further comprising a plurality of interference prevention portions having a size and shape enabling them to pass through said plurality of cutouts in the axial direction, and provided at positions interposed between said tip annular surface and said plurality of fastening projections when said retainer is opposed to said fuel filler opening.

7. A fuel cap as described in claim 2, wherein the multiple fastening protrusions are provided on the inside of the peripheral wall of the cap body, the multiple stoppers are provided at a position farther from the upper wall bottom surface than the lower end of the cap body, and a gap is formed between the lower end surface of the cap body and the tip annular surface when the multiple stoppers are in contact with the fastening inclined surface.

8. The fuel cap as set forth in claim 1, comprising: a plurality of fastening protrusions that engage with the inside of the fuel filler opening of the fuel tank filler; and a plurality of interference prevention portions that prevent interference between the plurality of fastening protrusions and the fuel tank filler.

9. The fuel cap according to claim 8, further comprising: a cap body covering the tip of the fuel tank filler; and a circular retainer fixed to a bottom surface of an upper wall of the cap body facing the fuel filler neck, wherein the multiple fastening protrusions protrude radially outward from the outer circumferential edge of the retainer and engage with an inner fastening inclined surface of the fuel filler neck by passing in the axial direction through multiple notches formed in a tip annular surface around the fuel filler neck and rotating in the fastening direction, and the multiple interference prevention portions have a size and shape that enable them to pass through the multiple notches in the axial direction, and are provided at a position interposed between the tip annular surface and the multiple fastening protrusions when the retainer is opposed to the fuel filler neck.

10. The fuel cap according to claim 9, further comprising a disk cap attached to the bottom surface of the upper wall of the cap body inside the retainer, and the plurality of interference prevention portions are provided so as to protrude radially outward from the outer peripheral surface of the disk cap.

11. The fuel cap according to claim 9, wherein the plurality of interference prevention portions are made of a material having a lower hardness than the tip annular surface.

12. A fuel cap as described in claim 9, wherein the multiple fastening protrusions have a curved shape that is convex toward the fastening inclined surface so as to elastically deform in the axial direction when engaging with the fastening inclined surface, and axial gaps that allow the elastic deformation are formed between the multiple fastening protrusions and the multiple interference prevention portions.

13. A fuel cap as described in claim 9, wherein the plurality of fastening protrusions are provided on the inside of the peripheral wall of the cap body, and the plurality of interference prevention portions are provided at a position farther in the axial direction from the bottom surface of the upper wall than the lower end of the peripheral wall of the cap body.

14. The fuel cap according to claim 10, wherein the disk cap has a cylindrical guide portion having an outer diameter corresponding to an inner diameter of the fuel filler opening and engaging with the inside of the fuel filler opening.

15. The fuel cap according to claim 14, wherein the plurality of interference prevention portions are provided on an upper end portion of the guide portion.

16. A fuel cap that is fastened to a cylindrical fuel tank filler by rotating it in a fastening direction about an axis to close a fuel filler opening that opens at the axial tip of the fuel tank filler, the fuel cap comprising: a plurality of fastening protrusions that engage with the inside of the fuel filler opening of the fuel tank filler; and a plurality of interference prevention portions that prevent interference between the plurality of fastening protrusions and the fuel tank filler.

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