JP2009227294A - Cap for tank - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cap can prevent operability from being decreased caused by swelling with a fuel and simplify the shape of a screw. <P>SOLUTION: The fuel cap 10 opens and closes a bung hole FNb of a filler neck FN with a female screw part FNc, and is equipped with a cap body 20, an operating part 42 and a gasket GS, and is opened and closed through a screw mechanism. The screw mechanism is equipped with a male screw part 21, a stopper 21d and a running-on preventing rib 21e. The running-on preventing rib 21e is at the opposite side to the stopper 21d around a shaft of the cap body 20 as a center and is arranged at a position with no screw channel 21b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tank cap that opens and closes an injection port by being screwed to an opening forming member (filler neck) connected to a fuel tank.

  Conventionally, the technique of Patent Document 1 is known as a fuel cap that opens and closes a filler neck inlet connected to a fuel tank. That is, the fuel cap includes a resin cap body with a gasket and an operation section for rotating the cap body. The fuel cap is rotated by the operation section, and the external thread portion of the outer periphery of the cap body is filled with filler. The inlet is sealed with a gasket by screwing into the female threaded portion of the inner wall of the neck. A stopper is formed at the end of the male screw portion of the fuel cap. The stopper stops the rotation of the cap body when it hits the starting end of the filler neck, and the operability is improved by fixing the direction of the operation part when the gasket is overtightened or tightened. However, when the stopper rides on the start end of the filler neck, the cap body may be eccentric and the sealing performance may be lowered, or the cap body may be difficult to remove from the filler neck. A restraining portion projects from the screw groove of the male screw portion of the cap body on the opposite side.

  However, the constraining portion protruding from the screw groove narrows the gap between the filler neck and the female screw portion due to fuel swelling, which increases the rotational operation force and may impair the operability. In addition, the restraining portion needs to have a large allowance between the male screw portion and the female screw portion by the height, and there is a problem that the shape of the screw is complicated.

JP 2006-182421 A

  An object of the present invention is to solve the above-described problems of the prior art, and to provide a tank cap that can prevent a decrease in operability due to fuel swelling and can simplify the shape of a screw.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
Application Example 1 is a tank cap that opens and closes an opening forming member having a female screw portion.
A cap body for opening and closing the inlet,
An operating portion provided on the cap body for rotating the cap body in a closing direction or an opening direction;
A gasket for sealing between the outer periphery of the cap body and the sealing surface of the opening forming member;
A male screw part formed on an outer peripheral part of the cap body and screwed into the female screw part is provided, and the male screw part is moved from the start end of the female screw part to the female screw by rotation of the operation part in a closing direction. A screwing mechanism for screwing the cap body in the axial direction by screwing it in accordance with the portion, and screwing the cap body to the opening forming member;
With
Further, the screwing mechanism is formed in a thread groove of the male screw portion, and a stopper that restricts rotation of the cap main body in the closing direction by contacting the start end portion of the female screw portion; A ride-up preventing rib that is formed on the outer periphery and prevents the axial displacement of the cap body by hitting the inner wall around the injection port when the stopper is about to ride over the start end,
With
The riding-up preventing rib is arranged on the opposite side of the stopper body with respect to the stopper as a center and on the inlet side in the axial direction.

  In the tank cap described in Application Example 1, the cap body is inserted into the injection port with the operation unit, and the cap body is screwed in via the screwing mechanism to close the injection port with the cap body. The screwing mechanism includes a male screw portion that is screwed into a female screw portion formed on the inner wall of the opening forming member. By rotating the cap body in the closing direction, the start end portion of the male screw portion is connected to the female screw portion. Align with the start end, screw the male thread into the female thread, and complete the tightening when the stopper formed near the end of the male thread contacts the start end of the female thread To do.

  In the configuration of Application Example 1, the position of the operation portion at the start of tightening of the tank cap is determined at the start end of the female screw portion, and the position of the operation portion at the end of tightening of the cap is determined by the stopper. Therefore, the operation unit is excellent in operability because it is set at a fixed position in the rotation direction in both the closing operation and the opening operation.

  Further, according to the tightening operation of the tank cap, the gasket interposed between the cap body and the inner wall of the opening forming member is compressed and displaced in the axial direction and sealed with a seal surface pressure of a predetermined level or more at the position where it hits the stopper. Seal against the surface. At this time, since the amount of displacement of the gasket in the axial direction is regulated by a stopper formed on the cap body, the gasket is not subjected to excessive compression, and durability is improved.

  Further, the riding-up preventing rib is provided on the opposite side of the stopper, that is, on the outer peripheral portion of the cap body which is rotationally symmetric with respect to the axis of the cap body, and is protruded from a portion which is not the male screw portion above the stopper. When it is going to ride on the starting end of the opening forming member, the stopper hits the inner wall of the opening forming member and prevents the stopper from riding on the starting end of the opening forming member. As a result, when the cap body is stopped from rotating by the stopper, the entire cap body does not move toward one of the inlets of the opening forming member or the shaft is not tilted. Therefore, the gasket attached to the cap body is not excessively elastically deformed, so that the sealing performance is not lowered and the cap body is not easily removed from the opening forming member.

  Moreover, since the riding-up preventing rib is not provided in the thread groove of the male screw portion unlike the restraint portion described in the prior art, in order to secure a desired allowance between the male screw portion and the female screw portion. There is no need to deepen the thread groove of the male screw part by the amount of the restraining part or increase the inner diameter of the male screw part or the opening forming member.

  Further, since the riding-up preventing rib is not formed in the thread groove of the male screw portion, the gap between the opening forming member and the female screw portion is not narrowed due to fuel swelling, and the opening / closing operability is not hindered.

[Application Example 2]
The riding-up preventing rib of the application example 2 is a screw thread of the male screw portion and is formed on the protrusion continuously from the stopper. As an aspect of the riding-up preventing rib, it can be easily formed by taking advantage of the conventional shape by being continuously formed on the thread of the male screw portion. In addition to this configuration, any portion that is effective for riding on the stopper may be divided.

[Application Example 3]
Application Example 3 is provided with a seal holding portion that protrudes in an annular shape from the outer peripheral portion of the upper portion of the cap body and holds the gasket, and the climbing prevention rib is disposed below the seal holding portion in the axial direction. It is what has been configured.

  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 (tank cap) according to an embodiment of the present invention. In FIG. 1, a fuel cap 10 is attached to a filler neck FN (opening forming member) having an inlet FNb (tank opening) for supplying fuel to a fuel tank (not shown), and is formed from a synthetic resin material such as polyacetal. The cap body 20, the lid body 40 having an operation portion 42 that is mounted on the upper portion of the cap body 20 and made of a synthetic resin material such as nylon, and the valve chamber 25 is formed by closing the upper opening of the cap body 20. The lid 30, the pressure regulating valve 50 housed in the valve chamber 25, the torque mechanism 80 for transmitting the rotational torque in the closing direction of the lid body 40 to the cap body 20 within a predetermined range, and the upper outer periphery of the cap body 20 And an annular gasket GS that 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. The cap body 20 is provided in a substantially cylindrical outer tube body 20a having a male screw portion 21 engaged with a female screw portion FNc on the inner wall of the pipe-shaped filler neck FN, and on the lower inner side of the outer tube body 20a. And a valve chamber forming body 20b. 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 inlet FNb is closed by the fuel cap 10. 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 on the outer peripheral portion of the cap body 20. The screwing mechanism is a mechanism for screwing the fuel cap 10 to the female screw portion FNc of the filler neck FN, and includes a male screw portion 21 formed at the lower outer periphery of the outer tube body 20a. 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 between the screw threads 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.

  Further, as shown in FIG. 2, a ride-up preventing rib 21e is formed on the outer peripheral portion of the cap body 20 and on the opposite side of the stopper 21d with the axis of the cap body 20 as the center. The climbing prevention rib 21e is disposed on the injection port FNb side in the axial direction of the cap body 20 with respect to the stopper 21d, that is, disposed at a location other than the screw groove 21b, and the stopper 21d rides on the start end portion FNc1 of the filler neck FN. This is a projection that prevents the axial displacement of the cap body 20 when it hits the inner wall around the inlet FNb. The riding-up preventing rib 21e is formed at the same height or slightly lower in the circumferential direction than the thread 21a of the male screw portion 21.

(3) Operation of the fuel cap 10 As shown in FIG. 3, the cap body 20 is inserted into the inlet FNb in the axial direction by holding the operating portion 42 of the lid 40 with the hand with the inlet FNb open. To do. 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. When the clockwise rotation is applied to the operation unit 42 and the closing operation is performed, the cap body 20 rotates via the torque mechanism 80 (FIG. 1).

  4 is a cross-sectional view taken along line 4-4 of FIG. 2 is a line parallel to the screw thread 21a. When the fuel cap 10 is rotated in the closing direction from the state where the fuel cap 10 is attached to the inlet FNb (FIG. 4), 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, as shown in FIG. 5, the stopper 21d hits the start end portion FNc1 of the female screw portion FNc to restrict the rotation. In this state, the fuel cap 10 is attached to the filler neck FN.

(4) Effects and effects of the embodiment The configuration of the above embodiment provides the following effects in addition to the effects described above.
(4) -1 The position of the operating portion 42 at the start of tightening of the fuel cap 10 is determined at the start end of the female screw portion FNc, and the position of the operating portion 42 at the end of tightening of the cap is determined by the stopper 21d. Therefore, the operation unit 42 is excellent in operability because it is set at a fixed position in the rotation direction in both the closing operation and the opening operation.

(4) -2 According to the tightening operation of the fuel cap 10, the gasket GS interposed between the cap body 20 and the inner wall of the filler neck FN is compressed and displaced in the axial direction, and at a predetermined position or more at the position where it hits the stopper 21d. It seals with respect to a sealing surface with the sealing surface pressure of. At this time, since the amount of displacement of the gasket GS in the axial direction is restricted by the stopper 21d formed on the cap body 20, the gasket GS is not subjected to excessive compression, and durability is improved.

(4) -3 As shown in FIGS. 4 and 5, the riding-up prevention rib 21e is located on the opposite side (180 °) of the stopper 21d around the axis of the cap body 20 and above the stopper 21d. When the stopper 21d tries to ride on the start end FNc1 of the filler neck FN, the stopper 21d hits the inner wall of the filler neck FN and rides on the start end FNc1 of the filler neck FN. To prevent. Further, since the riding-up preventing rib 21e is formed at the same height or a slightly lower height above the thread 21a and without the thread, the gap with the inner wall of the filler neck FN is substantially the same. Thus, even when a tilting force is applied to the cap main body 20, the cap main body 20 is prevented from tilting by hitting the inner wall of the filler neck FN by supporting the upper and lower two points together with the thread 21a. Therefore, when the cap main body 20 is stopped from rotating by the stopper 21d, the entire cap main body 20 does not move toward one of the inlets FNb of the filler neck FN or cause an axial shift that tilts. Therefore, the gasket GS attached to the cap body 20 is not excessively elastically deformed, and the sealing performance is not lowered, and the cap body 20 is not easily removed from the filler neck FN.
Absent.

(4) -4 FIG. 6 is an explanatory view for explaining the operation of the riding-up preventing rib 21e. FIG. 6 (A) shows this embodiment, and FIG. 6 (B) shows a conventional technique. As shown in FIG. 6 (A), since the riding-up preventing rib 21e is not provided in the screw groove 21b of the male screw portion 21, a desired engagement allowance La between the male screw portion 21 and the female screw portion FNc is ensured. Therefore, it is not necessary to deepen the thread groove 21b of the male screw portion 21 by the amount of the restraining portion or increase the inner diameter of the male screw portion 21 or the filler neck FN. On the other hand, in the conventional fuel cap shown in FIG. 6B, the restraint portion RM protrudes in the thread groove SWa of the male screw portion SW, so that the male screw portion SW and the female screw portion FNc are separated from each other. In order to secure the desired engagement allowance Lb, the thread groove SWa of the male screw part SW is deepened by the amount of the restraint part RM, or the inner diameter of the male screw part SW or filler neck FN is increased. Become.

(4) -5 The climbing prevention rib 21e is not formed in the thread groove 21b of the male threaded portion 21, so that the gap between the filler neck FN and the female threaded portion FNc is not narrowed due to fuel swelling, and the opening / closing operability is reduced. Will not be disturbed.

(5) Other Embodiments 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.

  FIG. 7 is an explanatory view illustrating a state in which the fuel cap 10B according to another embodiment is screwed to the filler neck FN and the inlet is closed. The riding-up preventing rib 21Be of the present embodiment is characterized in that the thread 21Ba of the male screw portion 21B is formed by a ridge continuous from the stopper 21Bd. The riding-up preventing rib 21Be can be easily formed by making use of the conventional shape by being formed continuously with the thread 21Ba of the male screw portion 21B.

  In the above-described embodiment, the configuration suitable for the fuel cap used in the fuel tank of the automobile has been described. However, the configuration is not limited to this, and the cap may be used for another cap, for example, the cap of the radiator tank.

It is a half sectional view showing a fuel cap (cap) concerning one example of the present invention. It is explanatory drawing explaining the state which the fuel cap is screwed by the filler neck and the inlet is closed. It is a perspective view explaining the state before a fuel cap is mounted | worn with a filler neck. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the effect | action of a fuel cap. It is explanatory drawing explaining the state which the fuel cap concerning another Example is screwed by the filler neck and the injection port is closed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cap 20 ... Cap main body 20a ... Outer tube body 20b ... Valve chamber formation body 21 ... Male screw part 21a ... Screw thread 21b ... Screw groove 21c ... Starting end part 21d ... Stopper 21e ... Riding prevention rib 22 ... Flange part 24 ... Seal holding part 25 ... Valve chamber 30 ... Inner lid 40 ... Lid 42 ... Operation part 50 ... Pressure regulating valve 80 ... Torque mechanism FN ... Filler neck FNb ... Injection port FNc ... Female thread part FNc1 ... Start end part FNf ... Seal surface GS ... gasket

Claims (3)

In the tank cap for opening and closing the opening forming member having the female screw portion (FNc),
A cap body (20) for opening and closing the inlet (FNb);
An operation portion (42) provided on the cap body (20) for rotating the cap body (20) in a closing direction or an opening direction;
A gasket (GS) for sealing between the outer peripheral portion of the cap body (20) and the sealing surface (FNf) of the opening forming member;
The male threaded portion (21) formed on the outer peripheral portion of the cap body (20) and screwed into the female threaded portion (FNc), and the male threaded portion by rotating the operating portion (42) in the closing direction. The cap body (20) is moved in the axial direction by screwing (21) from the start end portion (FNc1) of the female screw portion (FNc) along the female screw portion (FNc), thereby moving the cap main body (20 ) To the opening forming member;
With
Further, the screwing mechanism is formed in the screw groove (21b) of the male screw portion (21), and comes into contact with the start end portion (FNc1) of the female screw portion (FNc), so that the cap body (20) A stopper (21d) for restricting rotation in the closing direction and an outer peripheral portion of the cap body (20), and when the stopper (21d) is about to ride on the start end (FNc1), the injection port A ride-up preventing rib (21e) that hits the inner wall around (FNb) and prevents axial displacement of the cap body (20);
With
The riding-up prevention rib (21e) is disposed on the side opposite to the stopper (21d) with respect to the axis of the cap body (20) and on the inlet (FNb) side in the axial direction. A tank cap characterized by that. The tank cap according to claim 1,
The climbing prevention rib (21e) is a thread cap (21a) of the male threaded portion (21), and is a tank cap formed on the protrusion continuously from the stopper (21d). The tank cap according to claim 2,
A seal holding part (24) that protrudes in an annular shape from the outer periphery of the upper part of the cap body (20) and holds the gasket (GS);
The riding-up preventing rib (21e) is a tank cap that is disposed below the axial direction with respect to the seal holding portion (24).

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