JP4306423B2 - Fuel cap - Google Patents

Description

The present invention relates to a fuel cap provided with a gasket interposed between a tank opening and a cap.

  Conventionally, as a tank cap of this type, a closing body fitted with a gasket having a C-shaped cross section is used for an automobile that opens and closes a tank opening by screwing two to three turns with a screw provided on the inner wall of the tank opening. A fuel cap is known (Patent Document 1).

Japanese Utility Model Publication No. 59-83766

  However, the conventional C-shaped gasket requires a large compressive force in the direction of advancement / retraction when the fuel cap is opened and closed, that is, the direction of bending, in order to obtain a seal surface pressure of a predetermined level or more. For this reason, a large rotational operating force is required to open and close the fuel cap, and there is a problem that the operability is not good.

The present invention solves the above-mentioned problems of the prior art, and provides a fuel cap using a gasket that can be compressed with a small amount of deformation with a large amount of deformation and that can obtain a high sealing pressure. With the goal.

The present invention made to solve the above problems
A cap body that opens and closes a tank opening having an opening-side engaging portion and has a seal holding portion, and is held by the seal holding portion and compressed in a tightening direction of the cap body, thereby to a sealing surface of the tank opening. In a fuel cap with a gasket for sealing,
The gasket is
A first lip pressed against the sealing surface; a second lip; and a connecting portion that connects the first lip and the second lip, the first lip, the second lip, and the connecting portion. A gasket body having a C-shaped cross section by
An inner periphery of the gasket body, and a detent portion projecting from a location connecting the second lip and the coupling portion toward the axial center of the gasket ;
With
The seal holding portion is an annular recess that supports the gasket,
A first sealing wall which is formed toward the second lip in the axial direction of the support vital the cap body, the first from the inner end of the first sealing wall is extended to the tightening direction A second seal wall surface that forms the annular recess together with one seal wall surface, and a plane connecting the first seal wall surface and the second seal wall surface and formed in the axial direction; and a stopper step portion for positioning said detent portion by the rotation stopper hits the plane, the second sealing wall, with separating gaps between the connecting portion, the first lip the sealing When the compression force is applied from the surface, the connecting portion is provided to narrow the gap, and when the gasket is compressed by being pushed by the seal surface, the tip of the first lip is the above To strike the first sealing wall, that it is longer than the second lip, and wherein.

In the opening and closing operation of the fuel cap of the present invention, the fastening initial fuel cap, contact the sealing surface of the first lip tank opening of the gasket, the Komu further tightened, be compressed in the bending direction. At this time, since the rotation preventing portion is positioned and stopped by the stopper portion, the gasket is deformed so as to narrow the gap with respect to the second seal wall surface as the first lip is pushed. Then, when the tip of the first lip is on the side of the tip of the second lip and hits the first seal wall surface, the compression of the gasket is completed, and the cap body closes the tank opening.

  The gasket is positioned at the stopper portion by the stopper portion and is prevented from rotating, and as the first lip is pushed by the seal surface, the connecting portion easily deforms so as to narrow the gap with respect to the second seal wall surface. A large seal surface pressure can be obtained by the tightening force, and excellent operability can be obtained.

The gasket is configured to be longer than the second lip so that when the first lip is pressed by the sealing surface and the gasket is compressed, the tip of the first lip hits the first sealing wall surface . With this configuration , the first lip hits the second lip and does not hinder deformation, and a high displacement can be obtained with a lower load.

  Furthermore, as a preferable aspect of the seal holding portion, it can be configured to have a seal recess that houses a gate end protruding from the outer peripheral portion of the connecting portion. The gasket is formed with a gate end which is a gate mark when injection molding is performed. When the gate end hits the second seal wall surface, a portion where the seal surface pressure becomes non-uniform is likely to be generated, but the seal surface pressure can be made uniform by being accommodated in the seal recess.

  In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.

(1) Schematic Configuration of Fuel Cap 10 FIG. 1 is a half sectional view showing a fuel cap 10 (cap device) according to one embodiment of the present invention. In FIG. 1, a fuel cap 10 is attached to a filler neck FN having an inlet FNb (tank opening) for supplying fuel to a fuel tank (not shown), and a cap body 20 (made of a synthetic resin material such as polyacetal). A closure body), a lid body 40 having an operation portion mounted on the upper portion of the cap body 20 and formed of a synthetic resin material such as nylon, and an inner lid for closing the upper opening of the cap body 20 to form the valve chamber 25. 30, a pressure regulating valve 50 accommodated in the valve chamber 25, a torque mechanism 80, and an annular gasket GS that is attached to the upper outer periphery of the cap body 20 and seals between the filler neck FN.

(2) Configuration of Each Part of Fuel Cap 10 Next, the configuration of each part of the fuel cap 10 according to the present embodiment will be described in detail.
(2) -1 Configuration of Cap Main Body 20 The cap main body 20 has a substantially cylindrical shape having a male threaded portion 21 that engages with a female threaded portion FNc on the inner wall of a pipe-shaped filler neck FN (opening forming member). An outer tube 20a and a valve chamber forming body 20b provided inside the lower portion of the outer tube 20a are provided. The valve chamber forming body 20b houses a positive pressure valve and a negative pressure valve that act as the pressure regulating valve 50. The inner lid 30 covers the valve chamber 25 by being press-fitted into the upper portion of the valve chamber forming body 20b.

 A gasket GS is sheathed on the lower surface of the flange portion 22 at the top of the cap body 20. The gasket GS is interposed between the seal holding portion 24 of the flange portion 22 and the seal surface FNf of the filler neck FN, and is pressed against the seal holding portion 24 when the fuel cap 10 is tightened into the inlet FNb. To achieve a sealing action.

  FIG. 2 is an explanatory view illustrating a state where the fuel cap 10 is screwed to the filler neck FN and the inlet FNb is closed. FIG. 3 is a perspective view illustrating a state before the fuel cap 10 is mounted on the filler neck FN. FIG. 2 and 3, a screwing mechanism is formed across the inner peripheral wall of the filler neck FN and the outer peripheral portion of the outer tubular body 20a. The screwing mechanism is a mechanism for screwing the fuel cap 10 to the filler neck FN, and includes a female screw portion FNc formed on the inner wall of the filler neck FN and a male screw formed on the lower outer periphery of the outer tube body 20a. Part 21. The female screw portion FNc is a ridge formed in a spiral shape from the start end portion FNc1 formed on the injection port FNb side toward the back side (fuel tank side). The male screw portion 21 includes a screw thread 21a that is a screw-shaped protrusion and a screw groove 21b of the screw thread 21a. The lower end portion of the screw thread 21a is a start end portion 21c that first engages with the start end portion FNc1 of the female screw portion FNc (FIG. 2). Further, a stopper 21d is erected so as to cross the screw groove 21b. The stopper 21d is formed at a position of about 200 ° from the start end portion 21c of the male screw portion 21, and abuts against the start end portion FNc1 of the female screw portion FNc when the fuel cap 10 is tightened into the injection port FNb. Thus, the rotation of the fuel cap 10 in the closing direction is restricted. Here, the screw pitch of the female screw portion FNc is formed by one turn advanced 6.35 mm per rotation.

  In the above configuration, when the fuel cap 10 is rotated in the closing direction from the state where the fuel cap 10 is mounted on the inlet FNb, the male screw portion 21 is screwed in along the female screw portion FNc, and the gasket GS is compressed to a predetermined displacement or more in the axial direction. Then, the stopper 21d hits the starting end portion FNc1 of the female screw portion FNc, and the rotation is restricted. In this state, the fuel cap 10 is attached to the filler neck FN.

(2) -2 Gasket GS and seal holding part 24
(2) -2-1 Configuration of Gasket GS FIG. 4 is an enlarged cross-sectional view showing the vicinity of the gasket GS attached to the seal holding portion 24 of the fuel cap. The gasket GS is made of fluororubber, has a substantially C-shaped cross section, and includes a gasket body GSa that is compressed so as to shorten the length in the bending direction. The gasket body GSa is formed in a C-shaped section so as to surround a substantially U-shaped slit GSb opened on the outer peripheral side, that is, a first lip GSc pressed against the seal surface FNf of the filler neck FN, 2 lips GSd, and a connecting portion GSe for connecting the first lip GSc and the second lip GSd, and the first lip GSc, the second lip GSd, and the second lip GSd have a C-shaped cross section.

  The first lip GSc is formed longer than the second lip GSd so that when the gasket GS is compressed by being pushed by the seal surface FNf, the tip of the first lip GSc contacts the first seal wall surface 24a. (See FIG. 5C). Further, an anti-rotation portion GSf is formed so as to protrude from the inner peripheral portion of the gasket body GSa and between the second lip GSd and the connecting portion GSe.

(2) -2-2 Configuration of Seal Holding Part 24 The seal holding part 24 is an annular recess that supports the outer peripheral surface of the gasket GS, a first seal wall surface 24a that supports the second lip GSd, and a stopper part. The stopper step portion 24b, the second seal wall surface 24c, and the seal lower surface 24d are provided. The stopper step portion 24b acts as a detent when the first lip GSc is pressed by the seal surface FNf by positioning the detent portion GSf of the gasket GS.

  The second seal wall surface 24c is formed so as to have the gap Gp between the second seal wall surface 24c and the connecting portion GSe of the gasket GS. When the first lip GSc receives a compressive force from the seal surface FNf, the gasket GS The gap Gp is narrowed by elastic deformation.

  The second seal wall surface 24c has an annular seal recess 24e that accommodates the gate end GSh projecting from the outer periphery of the connecting portion GSe. The gate end GSh is a gate mark when the gasket GS is injection molded. The seal recess 24e has an effect of eliminating a portion where the seal surface pressure is not uniform in the circumferential direction when the gate end GSh hits the second seal wall surface 24c.

(2) -2-3 Sealing Action by Gasket GS FIG. 5 is an explanatory diagram for explaining a process of compressing the gasket GS when the fuel cap 10 is closed. In the initial tightening of the fuel cap 10, the first lip GSc of the gasket GS hits the seal surface FNf (FIG. 5A), and when further tightened, the opening of the slit GSb is narrowed and compressed in the bending direction (FIG. 5 ( B)). At this time, the gasket GS has the rotation preventing portion GSf positioned and stopped by the stopper step portion 24b, so that the coupling portion GSe narrows the gap Gp with respect to the second seal wall surface 24c as the first lip GSc is pushed. It deforms as follows. When the tip of the first lip GSc is on the side of the tip of the second lip GSd and hits the first seal wall surface 24a, the compression of the gasket GS is completed (FIG. 5C), and the fuel cap 10 closes the inlet FNb.

  FIG. 6 is a graph showing the relationship between the bending allowance of the gasket GS and the reaction force, in which the solid line indicates an example and the broken line indicates a C-shaped gasket according to the prior art. Here, the bending allowance refers to a length (compression amount) in which the gasket is compressed in the bending direction and contracts. Also, the relationship between the deflection allowance and the rotation angle of the fuel cap varies depending on parameters such as the hardness and shape of the gasket, but if the 6.35 mm deflection allowance occurs due to the 360 ° rotation of the fuel cap, When the tightening angle of the fuel cap 10 is set to 198 °, a bending allowance of 3.5 mm is generated, and when the fuel cap is returned 90 ° from the closed state, a bending allowance of 1.9 mm is generated. .

  When the fuel cap is tightened, the reaction force increases because the gasket is bent. In such closing operation of the fuel cap, if the reaction force exceeds 150 N, the operability deteriorates. Therefore, it is preferable to set it to 150 N or less, particularly 130 N or less, but in the range of the reaction force of 150 N in the conventional gaskets. In this embodiment, the bending allowance of 4.5 mm or more in the fully-closed state is secured, whereas only a bending allowance of about 1.5 mm can be secured and the operability is inferior because the reaction force increases rapidly. In addition, it has excellent operability because there is no sudden increase in reaction force.

FIG. 7 is a graph showing the relationship between the deflection of the gasket and the seal surface pressure. The solid line shows the gasket of the example, and the broken line shows the C-shaped gasket according to the prior art. Here, the seal surface pressure refers to a pressure generated by the gasket on the seal surface FNf. When the fuel cap 10 is tightened, the seal surface pressure increases as the deflection of the gasket GS increases.
In addition to ensuring a seal surface pressure exceeding a predetermined level obtained by the bending allowance of the gasket GS, a tightening amount that can be tightened by the stopper 21d in FIG. 2 is 2 mm so that excessive stress is not applied to the gasket GS. As mentioned above, Preferably it is 3-5 mm.

(2) -2-4 Effect of Gasket GS (2) -2-4-1 Since the gasket GS is positioned and stopped by the stopper step 24b by the stopper 21d, and the gap Gp is provided, As the first lip GSc is pushed by the seal surface FNf, the connecting portion GSe easily deforms so as to narrow the gap Gp between the second seal wall surface 24c and the connecting portion GSe. A surface pressure can be obtained, and an excellent operability can be obtained.

(2) -2-4-2
The first lip GSc is formed longer than the second lip GSd so that, when the gasket GS is compressed by being pushed by the seal surface FNf, the tip of the first lip GSc contacts the first seal wall surface 24a. Therefore, the first lip hits the second lip GSd and the deformation is not hindered, and a higher displacement can be obtained with a lower load.

(2) -2-4-3
When the fuel cap 10 is used for a quick turn configuration that opens and closes the injection port FNb only by rotating by a predetermined angle, for example, about 180 °, the sealing surface of the gasket GS when the lid 40 receives an external force. In order to prevent the pressure from decreasing, a so-called lost motion mechanism that idles within a predetermined angle range is provided on the lid 40. However, if the gasket GS is used, the lid 40 receives an external force and rotates about 90 ° in the opening direction, and maintains a high sealing performance even if the bending allowance is reduced to about 1.6 mm. Even if a lost motion mechanism having a simple structure is not provided, a seal surface pressure exceeding a predetermined level can be ensured.

(2) -2-4-4
By using a screw with a large pitch so that the cap body 20 moves 3 mm or more in the axial direction by a rotation of 180 °, the cap body 20 can be opened and closed with a small rotation angle.

(2) -2-4-5
The gasket GS preferably has a reaction force of 100 N or less and a seal surface pressure of 0.5 MPa or more when the deflection allowance is 4 mm. In this case, it is preferable that the movement amount in the axial direction is 1.4 to 1.6 mm when the closing body is rotated 80 to 90 ° from the tightening start position. According to this configuration, even if the closing body returns from the tightened state by about 90 ° in the opening direction by an external force, high sealing performance by the gasket can be maintained.

(2) -3 Configuration of Lid 40 In FIG. 1, the lid 40 constitutes an operation mechanism, and is rotatably and detachably attached to the flange portion 22 via a torque mechanism 80. The lid 40 includes an upper wall 41, an operation part 42 protruding from the upper surface of the upper wall 41, and a side wall 43 formed on the outer peripheral part of the upper wall 41, and is integrated by injection using a conductive resin. Molded. In addition, four engaging protrusions 43a are provided on the inner side of the side wall 43 at regular intervals along the circumferential direction. The engagement protrusion 43 a is a protrusion for assembling the lid body 40 to the cap body 20 via the torque mechanism 80. The attachment structure of the lid 40 will be described later.

(2) -4 Configuration of Torque Mechanism 80 (2) -4-1 Schematic Configuration of Torque Mechanism 80 FIG. 8 is an exploded perspective view showing the torque mechanism 80 provided over the lid 40 and the upper portion of the cap body 20, and FIG. 9 is an explanatory view showing the torque mechanism 80 from above. The torque mechanism 80 includes a torque transmission unit 82 shown in FIG. 9 and a click sound generation unit 84, and is transmitted by the torque transmission unit 82 when the fuel cap 10 shown in FIG. 3 closes the inlet FNb. When the rotational torque exceeds a predetermined rotational torque, a click sound is generated by the click sound generator 84, and it can be confirmed that the fuel cap 10 is attached to the filler neck FN with the predetermined rotational torque.

  In FIG. 8, the torque mechanism 80 includes a torque plate 90 that is rotatably interposed between the lid 40 and the cap body 20. The torque plate 90 includes a disk-shaped torque main body 91 made of resin. The torque main body 91 includes a disk-shaped arm support portion 91a and an annular outer ring portion surrounding the arm support portion 91a. 91b, and a connecting portion 91c connected to the arm support portion 91a and the outer ring portion 91b. The torque body 91 is formed with a guide groove, a torque arm, a flexure spring, a spring piece, and the like. Thus, the torque transmission part 82 and the click sound generation part 84 are configured.

(2) -4-2 Torque transmission part 82
The torque transmission unit 82 includes two first transmission mechanisms that transmit rotational torque from the lid 40 to the torque plate 90, and a second transmission mechanism that transmits rotational torque from the torque plate 90 to the cap body 20.
The first transmission mechanism includes a torque transmission rib 44 formed on the lid body 40 and a bending spring 93 protruding from the torque plate 90 so as to be elastically deformable. The torque transmission ribs 44 are ribs extending in the radial direction on the lower wall 42 a of the operation unit 42, and projecting at two positions with a predetermined distance from the central axis of the lid body 40. The flexure spring 93 is integrally projected in the vertical direction in a columnar shape on the torque main body 91, enters into the recess 42 b of the operation portion 42, and an engagement end whose tip engages with the torque transmission rib 44. 93a.

  FIG. 10 is an explanatory diagram for explaining the operation of the first transmission mechanism of the torque transmission unit 82. As shown in FIG. 10A, the torque transmission rib 44 is engaged with the engagement end 93a of the bending spring 93 by the operation of the operation portion 42 in the closing direction, and as shown in FIG. The rotational torque is transmitted to the plate 90, and the spring force in the opening direction is accumulated as the elastic deformation increases by tilting the bending spring 93. The action of this spring force will be described later.

  8 and 9, the first transmission mechanism further includes a guide protrusion 46 projecting from the lower surface of the upper wall 41 of the lid 40 and a rib guide portion 95 formed on the torque plate 90. ing. The guide protrusion 46 is a cylindrical protrusion for mainly transmitting rotational torque in the opening direction. The rib guide portion 95 is an arc-shaped notch formed in the torque plate 90, and both end sides thereof are a pressing end 95 a and a pressing end 95 b, and the guide protrusion 46 is inserted into the guide protrusion 46. Is supported movably.

  The second transmission mechanism includes a guide protrusion 92 formed on the lower surface of the torque plate 90 and a main body side engaging portion formed on the upper portion of the cap body 20 in order to transmit rotational torque from the torque plate 90 to the cap body 20. 23. The main body side engaging portion 23 is arranged on the inner peripheral portion of the flange portion 22, and includes a pressing protrusion 23a and a pressing protrusion 23b spaced by a predetermined gap, and a guide step 23c is provided therebetween. . The guide protrusion 92 is inserted in the guide step 23c and hits the pressing protrusion 23a when the torque plate 90 rotates in the closing direction, while the guide protrusion 92 presses when the torque plate 90 rotates in the opening direction. Rotating torque is transmitted from the torque plate 90 to the cap body 20 by hitting the portion 23b.

(2) -4-3 Click sound generator 84
The click sound generating portion 84 includes a click engaging portion 45 projecting from the lower wall 41 of the upper wall 41 of the lid 40 and a click arm 94 formed on the torque plate 90. The click engaging portion 45 includes a pressing surface 45a formed on the outer peripheral side and an inclined surface 45b formed on the lower surface on the circumference. The click arm 94 includes an arm main body 94a that protrudes from the arm support portion 91a, and a click engagement protrusion 94c that protrudes upward from the free end of the arm main body 94a. The click arm 94 is formed of a cantilever beam having a support base 94 b as a fulcrum, and the click engagement protrusion 94 c is separated from the torque body 91 by a predetermined gap. At one end of the click engaging projection 94c, a vertical wall 94c1 that is pressed by the pressing surface 45a is formed on the inner peripheral side, and an inclined surface 94c2 that is pressed by the inclined surface 45b is formed on the circumference. Yes.

  FIG. 11 is an explanatory diagram for explaining the operation of the click sound generator 84. When the lid 40 rotates in the closing direction, the vertical wall 94c1 of the click engagement protrusion 94c is pushed by the pressing surface 45a of the click engagement portion 45 as shown in FIG. Bends in the outer circumferential direction with the support base 94b as a fulcrum and gets over the click engaging portion 45. At this time, the pressing surface 45a gets over the vertical wall 94c1, and the click engaging protrusion 94c collides with the outer periphery of the arm support portion 91a to generate a click sound. On the other hand, when the lid 40 rotates in the opening direction, the inclined surface 45b of the click engagement portion 45 pushes the inclined surface 94c2 of the click arm 94 downward as shown in FIG. Is pushed down with the support base 94b as a fulcrum. The click arm 94 is less rigid when the click arm 94 is bent downward than when the click arm 94 is bent outward, and the click engagement portion 45 and the click engagement protrusion 94c smoothly slide on the inclined surface. The click sound is smaller than when rotating in the closing direction.

(2) -4-4 Attaching Mechanism of Torque Plate 90 and Lid 40 Next, a mounting structure (plate mounting mechanism) between the cap body 20 and the torque plate 90, and a mounting structure between the torque plate 90 and the lid 40 ( The handle mounting mechanism) will be described. 12 is a perspective view showing a main part of FIG. 8, and FIG. 13 is a sectional view showing a side part of the fuel cap 10. As shown in FIG. On the inner peripheral side of the outer ring portion 91b of the torque plate 90, an engagement claw 98a of the plate engagement portion 98 is formed. The engaging claw 98a is a position that can be seen from above through the notch 98b, and is a tongue piece that protrudes from the inner wall of the outer ring portion 91b toward the central axis, and is formed to be elastically deformable in the axial direction. ing. On the other hand, an arcuate engagement protrusion 22 b is formed on the outer periphery of the upper portion of the flange portion 22 of the cap body 20. The torque plate 90 is rotatably mounted on the upper outer periphery of the cap body 20 by press-fitting the engaging claw 98a into the engaging protrusion 22b.

  A mounting portion 99 is formed on the outer peripheral portion of the outer ring portion 91b. The mounting portion 99 includes an engagement recess 99b that forms an engagement claw 99a. The engagement protrusions 99a on the inner wall of the side wall 43 of the lid 40 are engaged with the engagement recess 99b, so that the torque plate 90 supports the lid 40 so as to be rotatable (about 20 °). Where the engagement protrusion 43a is engaged with the engagement recess 99b of the mounting portion 99, the engagement claw 98a of the plate engagement portion 98 is engaged with the engagement protrusion 22b of the flange portion 22. It is arranged above the location.

  In order to assemble the torque plate 90 and the lid 40 to the fuel cap 10, the engagement claw 98 a of the plate engagement portion 98 of the torque plate 90 is press-fitted into the engagement protrusion 22 b of the cap body 20, and the torque plate 90 is capped. The lid body 40 is assembled to the torque plate 90 by assembling the main body 20 and engaging the engagement protrusion 43a of the lid body 40 with the engagement claw 99a of the torque plate 90.

(2) -4-5 Supporting Mechanism for Torque Plate 90 FIG. 14 is an explanatory view for explaining the peripheral portion of the torque plate 90. As shown in FIGS. 10 and 14, the torque plate 90 includes a first spring piece 96 for supporting the torque plate 90 between the lower surface of the upper wall 41 of the lid 40 and the upper portion of the cap body 20. A second spring piece 97 is formed. In other words, four first spring pieces 96 are formed at 90 ° in the circumferential direction on the central upper surface of the torque plate 90. The first spring piece 96 applies a vertical spring force to the lower surface of the upper wall 41 of the lid 40. The first spring piece 96 shown in FIG. 15 is the same as the upper surface of the torque plate 90 and has an arm 96a formed of a cantilever extending in the circumferential direction, and the upper surface of the torque plate 90 at the tip of the arm 96a. A pressing protrusion 96b that protrudes further is provided. The second spring piece 97 is a cantilever beam inclined slightly downward, and includes an arm main body 97a and a pressing protrusion 97b that presses against the engaging protrusion 22b of the flange portion 22 at the tip of the arm main body 97a. And one end tilts in the notch 97c on the upper surface of the torque plate 90. The second spring piece 97 is positioned in both the vertical direction and the radial direction in order to press the engaging protrusion 22b with the inclined pressing protrusion 97b.

(3) Opening / Closing Operation of Fuel Cap 10 Next, the operation of the torque mechanism 80 when an operation of opening / closing the inlet FNb of the filler neck FN with the fuel cap 10 is performed will be described. Note that the torque transmission rib 44, the guide protrusion 46, the bending spring 93, and the like of the torque mechanism 80 are provided around the rotation axis of the lid 40, and therefore will be described with reference to one side of the figure.

(3) -1 Closing Operation of Fuel Cap 10 As shown in FIG. 3, with the injection port FNb open, hold the operating portion 42 of the lid 40 by hand and place the cap body 20 on the injection port FNb. Insert in the direction. At this time, the start end portion 21c of the male screw portion 21 is aligned with the start end portion FNc1 of the female screw portion FNc. Then, when the operation unit 42 is closed by applying a clockwise turning force, the torque mechanism 80 performs a series of operations as shown in FIG. 19 from FIG. 16 through FIG. 17 and FIG.

  That is, as shown in FIG. 16, the clockwise rotational force applied to the operation unit 42 is generated when the torque transmission rib 44 is engaged with the engagement end 93a of the bending spring 93 and the bending spring 93 is tilted. When the click engagement portion 45 engages with the click engagement protrusion 94c of the click arm 94, the click engagement portion 45 is transmitted to the torque plate 90 and rotates the torque plate 90 in the same direction. As the torque plate 90 rotates, the guide protrusion 92 presses the pressing protrusion 23 a of the main body side engaging portion 23. Thereby, the cover body 40, the torque plate 90, and the cap main body 20 rotate integrally, and advance to the direction which closes the injection port FNb. At this time, as shown in FIG. 10, as the angle at which the torque transmission rib 44 deflects the spring 93 is increased, the rotational torque transmitted from the operation unit 42 to the cap body 20 increases.

  When the reaction force generated by the engaging force exceeds a predetermined rotational torque, the click engaging portion 45 gets over the click arm 94 as shown in FIG. At this time, the click engagement portion 45 gets over the click engagement projection 94c and the click engagement projection 94c collides with the outer periphery of the 94 arm support portion 91a. Can be confirmed. At the same time, the guide protrusion 46 is guided in the rib guide portion 95 and moves to a state where it hits the pressing end 95a. In this state, even if the user further rotates the operation portion 42 in the closing direction, the stopper 21d hits the start end portion FNc1 of the filler neck FN, so that the cap body 20 is not overtightened.

  When the operator removes his / her finger from the operation unit 42, as shown in FIG. 19, the bending spring 93 applies a force for rotating the lid 40 counterclockwise via the torque transmission rib 44. Then, as the cover body 40 rotates counterclockwise, the inclined surface 45b of the click engagement portion 45 pushes down the click arm 94 to follow the click engagement protrusion 94c, as shown in FIG. Get over. When the guide protrusion 46 moves along the rib guide portion 95 and comes into contact with the pressing end 95b, the rotation of the lid body 40 is stopped. In this state, the fuel cap 10 closes the inlet FNb.

(3) -2 Opening operation of the fuel cap 10 To open the fuel cap 10, the operating portion 42 of the lid 40 is grasped with a finger from the state of FIG. 19 and a force that rotates counterclockwise is applied. Accordingly, the guide protrusion 46 of the lid 40 presses the pressing end 95b of the rib guide portion 95 of the torque plate 90 to rotate the torque plate 90. As the torque plate 90 rotates, the guide protrusion 92 presses the pressing protrusion 23 b of the main body side engaging portion 23. Thereby, the rotational force applied to the lid 40 is transmitted to the cap body 20 via the guide projection 46, the torque plate 90, and the pressing projection 23 b of the main body side engagement portion 23, and the lid 40 and the torque plate 90. The cap body 20 rotates counterclockwise as a unit. Then, when the cap body 20 rotates about 180 ° integrally with the lid body 40 (state of FIG. 16), the male screw portion 21 comes off from the start end portion FNc1 of the female screw portion FNc of the filler neck FN, Release from the restraining force on the filler neck FN. Then, the fuel cap 10 can be removed from the filler neck FN, and the inlet FNb is opened.

(4) In addition to the above-described effects, the following effects are achieved by the configuration of the above embodiment.
(4) -1 In the process of closing the fuel cap 10, when the click engagement portion 45 of the lid 40 gets over the click engagement protrusion 94c, a moderation feeling can be confirmed, and the fuel cap 10 has a predetermined torque. Since it can be seen that it is tightened, it can be tightened with a constant torque regardless of the elasticity of the gasket GS or the like.

(4) -2 Since the bending spring 93 constituting the torque transmitting portion 82 is formed integrally with the torque plate 90, the coil spring as described in the prior art is not used, and the number of parts is reduced. The configuration can be simplified.

(4) -3 The bending spring 93 is erected from the torque plate 90 in a substantially vertical direction and protrudes into the recess 42b of the operation portion 42. Therefore, the bending spring 93 can be formed long in the vertical direction. The amount of elastic deformation can be increased.

  The fuel cap 10 only needs to be operated at a small rotation angle of about 180 ° due to the engagement between the male screw portion 21 and the female screw portion FNc.

(4) -4 The torque plate 90 is positioned at a normal position by the first and second spring pieces 96, 97 in a state where there is no backlash between the lid 40 and the cap body 20, so that the product Stable click sound and torque characteristics can be obtained by suppressing the variation between the two.

  The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(5) -1 In the above embodiment, the configuration in which the bending spring 93 protrudes from the torque plate 90 has been described. However, the configuration is not limited thereto, and the bending spring 93 may protrude from the lower surface of the lid 40. In this case, the lid is preferably formed from polyacetal that can generate a large spring force.

(5) -2 The click sound generation unit 84 is formed at two places, but the present invention is not limited to this, and may be one place or three or more places as long as the click sound can be generated suitably.

(5) -3 The fuel cap is configured to apply a torsional force to the gasket due to its rotational operation. However, if a force is applied in the bending direction (the direction of the rotating shaft ), the fuel cap is configured to close with an operating force in the vertical direction. There may be.

(5) -4 The rubber material of the gasket is not limited to the above-described fluororubber, and other materials such as an elastomer such as NBR / PVC can be used.

1 is a half sectional view showing a fuel cap 10 according to an embodiment of the present invention. It is explanatory drawing explaining the state which the fuel cap 10 is screwed by the filler neck FN and the inlet FNb is closed. It is a perspective view explaining the state before the fuel cap 10 is mounted | worn with the filler neck FN. It is sectional drawing which expands and shows the vicinity of the gasket GS with which the seal holding part 24 of the fuel cap was mounted | worn. It is explanatory drawing explaining the process in which the gasket GS is compressed when closing the fuel cap 10. FIG. It is a graph which shows the relationship between the bending allowance of gasket GS, and reaction force. It is a graph which shows the relationship between the bending allowance of a gasket, and a seal surface pressure. FIG. 3 is an exploded perspective view showing a torque mechanism 80 provided over a lid 40 and an upper part of a cap body 20. It is explanatory drawing which shows the torque mechanism 80 from upper direction. FIG. 10 is an explanatory diagram for explaining the operation of a first transmission mechanism of a torque transmission unit 82. FIG. 10 is an explanatory diagram for explaining the operation of the click sound generator 84. It is a perspective view which shows the principal part of FIG. 2 is a cross-sectional view showing a side portion of a fuel cap 10. FIG. FIG. 6 is an explanatory diagram for explaining a peripheral portion of a torque plate 90. It is explanatory drawing explaining the effect | action of the 1st spring piece 96 and the 2nd spring piece 97. FIG. FIG. 6 is an explanatory diagram for explaining the operation of the torque mechanism 80. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the operation | movement following FIG.

Explanation of symbols

10 ... Fuel cap 20 ... Cap body (closed body)
20a ... Outer tube body 20b ... Valve chamber forming body 21 ... Male thread portion 21a ... Thread 21b ... Thread groove 21c ... Start end portion 21d ... Stopper 22 ... Flange Part 22b ... engagement protrusion 23 ... main body side engagement part 23a ... pressing protrusion 23b ... pressing protrusion 23c ... guide step 24 ... seal holding part 24a ... first 1 seal wall surface 24b ... stopper step 24c ... second seal wall surface 24d ... seal lower surface 24e ... seal recess 25 ... valve chamber 30 ... inner lid 40 ... lid body 41 ... Upper wall 42 ... Operation part 42a ... Lower wall 42b ... Recess 43 ... Side wall 43a ... Engaging protrusion 44 ... Torque transmission rib 45 ... Click engagement Joint 45a ... Pressing surface 45b ... Inclined surface 46 ... Guide protrusion 50 ... Pressure control valve 80 ... Torque mechanism 82 ... Torque transmission part 84 ... Click sound generation part 90. .. Torque plate 91 ... Torque body 91a ... Arm support 91b ... Outer ring portion 91c ... Connecting portion 92 ... Guide protrusion 93 ... Flexible spring 93a ... Engagement end 94 ... Arm for click 94a ... Arm body 94b ... Support base 94c .. Engaging projection for click 94c1 ... vertical wall 94c2 ... inclined surface 95 ... guide portion for rib 95a ... pressing end 95b ... pressing end 96 ... first spring piece 96a .. Arm 96b ... Pressing protrusion 97 ... Second spring piece 97a ... Arm main body 97b ... Pressing protrusion 97c ... Notch 98 ... Plate engaging part 98a ... Engaging claw 98b. ..Notch 99 ... Mounting part 99a ... engagement claw 99b ... engagement recess FN ... filler neck (opening forming member)
FNb ... Inlet (tank opening)
FNb ... Injection port FNc1 ... Starting end FNc ... Female thread FNf ... Seal surface GS ... Gasket GSa ... Gasket body GSb ... Slit GSc ... First lip GSd. .. 2nd lip GSe ... Connecting part GSf ... Non-rotating part GSh ... Gate end Gp ... Gap

Claims (2)

A cap body (20) that opens and closes a tank opening having an opening-side engaging portion and has a seal holding portion (24), and is compressed in the tightening direction of the cap body (20) held by the seal holding portion (24). In the fuel cap including the gasket (GS) that seals against the sealing surface (FNf) of the tank opening.
The gasket (GS)
The first lip (GSc) pressed against the seal surface (FNf), the second lip (GSd), and the connecting portion (GSe) for connecting the first lip (GSc) and the second lip (GSd). A gasket body (GSa) formed in a C-shaped cross section by the first lip (GSc), the second lip (GSd) and the connecting portion (GSe);
Around the inner periphery of the gasket body (GSa) and projecting from the location connecting the second lip (GSd) and the connecting portion (GSe) toward the axis of the gasket (GS) A stop (GSf) ;
With
The seal holding portion (24) is an annular recess that supports the gasket (GS),
A first seal wall surface (24a) that supports the second lip (GSd) and is formed toward the axial direction of the cap body (20), and an end portion on the inner peripheral side of the first seal wall surface (24a) from being extended in the fastening direction a second sealing wall forming the annular recess with the first sealing wall (24a) (24c), said first sealing wall (24a) and the second sealing wall ( 24c), a stopper step portion for positioning the anti-rotation portion (GSf) by having a plane formed in the axial direction and contacting the anti-rotation portion (GSf) against the plane. a (24b), said second sealing wall (24c), said connecting portion with separating gaps (Gp) between the (GSe), said first lip (GSc) from the sealing surface (FNf) Receiving compressive force The connecting portion (GSe) is provided so as to narrow the gap (Gp) when the,
The first lip (GSc) is pushed by the seal surface (FNf) and the gasket (GS) is compressed so that the tip of the first lip (GSc) contacts the first seal wall surface (24a). Further, the fuel cap is formed longer than the second lip (GSd) . The fuel cap according to claim 1 , wherein
The second seal wall surface (24c) is a fuel cap having a seal recess (24e) that houses a gate end (GSh) projecting from the outer peripheral portion of the connecting portion (GSe).

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