JP2000142738A - Cap fastening structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a cap fastening characteristic by a method wherein there is provided a second threaded section engaged with a female thread of a capped member under rotation of a first threaded section from its inserted state. SOLUTION: There is provided a cap fastening structure in which a cap 8 having a male thread is fastened to a capped body 3 having a female thread 4. At least a part of the female thread 4 at the capped body 3 is cut with a predetermined width to arrange a recess 5. The cap 8 is provided with a first threaded section 12 having a width where the recess 5 can be inserted and a second threaded section 13 threadably engaged with the female thread 4 of the capped body 3 under rotation of the first threaded section 12 from its inserted state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap tightening structure for tightening a cap having a male screw to a cap body such as a filler tube having a female screw.

[0002]

2. Description of the Related Art Conventionally, as a structure for tightening a cap in the above-described example, there is a structure as shown in FIG.

That is, a cap 83 in which a shaft 83 is formed integrally with a flange 82 having an operation protrusion 81 formed integrally therewith, and a continuous male screw 84 having a relatively small pitch P is formed on the outer periphery of the shaft 83. 85, and this cap 85
Is fastened to a body to be capped (not shown) having a female screw.

However, in this conventional structure, since the pitch P is small, the tightening operation cannot be completed unless the entire cap 85 is rotated many times, and the tightening operation becomes complicated. There is a problem that the tightening rotation angle becomes large.In addition, if the tightening is not completed, good sealing performance is not obtained.In particular, when this cap tightening structure is applied to that of a vehicle fuel tank, However, there is a problem that the fuel vapor leaks.

The fuel tank cap disclosed in Japanese Patent Application Laid-Open No. 7-186744 has the same problem as described above.

In order to solve such a problem, for example, a structure as shown in FIGS. 9 and 10 can be considered.

That is, a cap body 93 is internally fitted into the filler box 91 via a filler tube 92 made of a metal pipe. The cap body 93 has a discontinuous and symmetrical structure projecting radially inward. Two female screws 94, 94 are formed, and cutouts 95, 95 are formed between both ends of the female screws 94, 94.

On the other hand, two projections 10 having a symmetrical structure corresponding to the notches 95, 95 are formed on the outer periphery of the shaft 98 of the cap 99 having the operation projection 96, the flange 97, and the shaft 98.
After the two projections 100, 100 are inserted into the notches 95, 95, the entire cap 99 is rotated by a predetermined angle in the tightening direction. It is configured so that the cap 99 can be screwed together and tightened easily.

According to this conventional structure, there is an advantage that the tightening operability is improved, but the seal member 101 such as an O-ring is provided.
The screw pitch becomes large in relation to the compression allowance of
The contact surface at the time of tightening is only the upper surface of the two protrusions 100, 100, and there is a problem that the tightening torque is reduced and the cap 99 is easily loosened because the contact surface is small.

[0010]

According to the first aspect of the present invention, at least one of the internal threads of the body to be capped is notched with a predetermined width to provide a notch, and the cap has a width through which the notch can be inserted. By providing a first screw portion and a second screw portion that is rotated from a state where the first screw portion is inserted to be screwed into the female screw of the cap-receiving body, the notch portion and the first screw portion The corresponding configuration not only improves the operability of tightening the cap, but also increases the contact area between the second thread and the internal thread even if the rotation angle of tightening the cap is reduced, thus lowering the tightening torque. It is an object of the present invention to provide a cap tightening structure capable of preventing occurrence of cracks.

According to a second aspect of the present invention, a notch is provided by notching at least one portion of a female screw in a cap body in a vertical direction with a predetermined width, and the cap has a width in which the notch can be inserted in a vertical direction. By providing a lower screw part of the above and an upper screw part which is screwed into the female screw of the capped body by rotating the cap from a state where the lower screw part is inserted, a corresponding configuration of the notch part and the lower screw part In addition to improving the operability of tightening the cap, the contact area between the upper thread and the internal thread can be set longer even if the tightening rotation angle of the cap is made smaller, which reduces the tightening torque. An object of the present invention is to provide a cap tightening structure that can be prevented.

According to a third aspect of the present invention, in addition to the object of the second aspect of the present invention, the upper screw portion is set to be longer than the lower screw portion, so that the upper screw portion is formed. It is an object of the present invention to provide a cap tightening structure capable of securing a longer contact area with a female screw and preventing a reduction in tightening torque more favorably.

According to a fourth aspect of the present invention, in addition to the object of the second aspect, the screwing position of the lower screw portion with the upper screw portion is set at a diagonal position. It is another object of the present invention to provide a cap tightening structure that can secure a balanced and uniform tightening force when tightening the cap and does not easily loosen.

According to a fifth aspect of the present invention, in addition to the object of the second aspect, an insertion guide portion is provided below the above-mentioned lower screw portion (before the insertion), so that the cap-covered portion is provided. An object of the present invention is to provide a cap tightening structure in which a lower thread portion of a cap is easily inserted into a notch of a body.

According to a sixth aspect of the present invention, in addition to the object of the second aspect, by providing a rotation guide portion on the rotation leading side of the lower screw portion, the female member of the capped member is provided. An object of the present invention is to provide a cap tightening structure capable of improving operability of tightening a lower screw portion of a cap with respect to a screw.

According to a seventh aspect of the present invention, in addition to the object of the second aspect of the present invention, a stopper for restricting rotation of the cap is provided on the above-mentioned body to be capped, thereby turning the cap. To prevent the so-called overrun,
An object of the present invention is to provide a cap tightening structure capable of holding a cap at an appropriate position and maintaining the durability of a seal member.

According to an eighth aspect of the present invention, in addition to the object of the second aspect, by setting the above-mentioned cap to a filler cap for a vehicle, it is possible to reliably prevent the leakage of fuel vapor. It is an object of the present invention to provide a cap tightening structure that can be used.

[0018]

According to a first aspect of the present invention, there is provided a cap fastening structure for fastening a cap having a male thread to a cap body having a female thread, the female cap being provided with a female thread. A notch is provided by notching at least one portion of the screw with a predetermined width, and the cap has a first screw portion having a width capable of inserting the notch portion, and a cap to be capped by rotating from a state where the first screw portion is inserted. It is characterized by a cap fastening structure provided with a second screw portion to be screwed into the female screw.

According to a second aspect of the present invention, there is provided a cap fastening structure for fastening a cap having a male thread to a cap body having a female thread, wherein at least one of the female threads in the cap body is provided. A notch is provided by notching at a predetermined width in the up-down direction, the cap has a lower screw portion having a width that allows the notch to be inserted in the up-down direction, and the cap is rotated by rotating the cap from a state where the lower screw portion is inserted. And an upper screw portion to be screwed into the female screw.

According to a third aspect of the present invention, in addition to the structure of the second aspect of the present invention, there is provided a cap tightening structure in which an upper screw portion is set longer than the lower screw portion. Features.

According to a fourth aspect of the present invention, in addition to the configuration of the second aspect of the present invention, a cap is tightened in which a screw position of the upper screw portion with respect to the lower screw portion is set at a diagonal position. It is characterized by having a structure.

According to a fifth aspect of the present invention, in addition to the configuration of the second aspect of the present invention, there is provided a cap fastening structure in which an insertion guide portion is provided below the lower screw portion. Features.

According to a sixth aspect of the present invention, in addition to the configuration of the second aspect of the present invention, there is provided a cap fastening structure in which a rotation guide portion is provided on the rotation leading side of the lower screw portion. It is characterized by the following.

According to a seventh aspect of the present invention, in addition to the configuration of the second aspect of the present invention, there is provided a cap tightening structure in which a stopper for restricting rotation of the cap is provided on the cap body. It is characterized by the following.

According to an eighth aspect of the present invention, in addition to the configuration of the second aspect, the cap is a cap tightening structure provided on a vehicle filler cap.

[0026]

According to the first aspect of the present invention, when the cap is fastened to the object to be capped, the first screw portion of the cap is inserted into the notch of the object to be capped. When the cap is rotated in the tightening direction, the first screw portion is screwed into the female screw, and the second screw portion is also screwed into the female screw, so that the cap can be tightened.

As described above, by the configuration corresponding to the notch and the first screw portion, the operability of tightening the cap can be improved, and the second screw portion can be formed even when the rotation angle of tightening the cap is reduced. The contact area between the screw and the female screw portion can be set long, and there is an effect that occurrence of a reduction in tightening torque can be prevented.

According to the invention described in claim 2 of the present invention,
When tightening the cap to the cap body, the cap is moved downward through a notch of a predetermined width of the cap body, the lower screw portion thereof is inserted, and in this state, the cap is rotated in the tightening direction. Since the portion is screwed into the female screw and the upper screw is also screwed into the female screw, the cap can be tightened.

As described above, by the structure corresponding to the above-mentioned notch and the lower screw portion, not only the operability of tightening the cap can be improved, but also the upper screw portion can be formed even when the tightening rotation angle of the cap is reduced. Contact area with female screw (screw distance)
Can be set long, and there is an effect that occurrence of a reduction in tightening torque can be prevented.

According to the third aspect of the present invention,
In addition to the effect of the second aspect of the present invention, since the upper screw portion is set longer than the lower screw portion, the contact area (screw distance) of the upper screw portion with the female screw can be further secured. As a result, there is an effect that the occurrence of a reduction in the tightening torque can be more effectively prevented.

According to the invention described in claim 4 of the present invention,
In addition to the effect of the second aspect of the present invention, since the screwing position of the upper screw portion with respect to the lower screw portion is set at a diagonal position, a balanced and uniform tightening force is secured when tightening the cap. And has the effect of making it difficult to loosen.

According to the invention described in claim 5 of the present invention,
In addition to the effect of the invention described in claim 2, since the insertion guide portion is provided below (before insertion) the lower screw portion, the lower screw portion of the cap is inserted into the cutout portion of the cap body. According to the invention described in claim 6 of the present invention, which has the effect of making it easier, in addition to the effect of the invention described in claim 2,
Since the rotation guide portion is provided on the rotation leading side of the lower screw portion, there is an effect that the operability of tightening the lower screw portion of the cap with respect to the female screw of the capped body can be improved.

According to the invention described in claim 7 of the present invention,
In addition to the effect of the invention described in claim 2, a stopper for restricting rotation of the cap is provided on the above-mentioned capped body, so that excessive rotation of the cap, so-called overrun, is prevented,
There is an effect that the cap can be tightened and held at an appropriate position, and the durability of the seal member can be maintained.

According to the eighth aspect of the present invention,
In addition to the effect of the second aspect of the present invention, since the above-mentioned cap is set as a filler cap for a vehicle, there is an effect that leakage of evaporated fuel from the fuel tank can be reliably prevented.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a cap tightening structure. In FIG. 1, a cap body 3 is fitted inside a filler box 1 via a filler tube 2 made of a metal pipe.

An internal thread 4 is formed on the cap body 3 by a roller pressing means or the like so as to protrude radially inward from the inner wall surface. This female screw 4 is shown in FIGS.
As shown in FIG. 5, a part of a continuous screw (a continuous pitch screw having a relatively small pitch) is cut out in a vertical direction at a predetermined width L2 to form a first cutout portion 5, and the other part is formed in a vertical direction in a predetermined width L1.
(Where L1 <L2) to form a second notch 6,
The female screw 4 is divided into a female screw long part 4L and a female screw short part 4S.

In this embodiment, as shown in FIG. 3, the angle formed by the center of the first notch 5 and the center of the second notch 6, that is, the opening angle θ is set to about 113 degrees. It is not limited. In FIG. 2, one end a of the female screw short portion 4S is located at the uppermost position, and the other end b of the female screw long portion 4L is located at the lowermost position.

Further, the other end b of the above-described female screw long portion 4L
A stopper 7 is provided below the upper surface of the cover 7 so as to restrict rotation (over-rotation) of the filler cap 8 described below.

As shown in FIGS. 1 and 2, the above-mentioned filler cap 8 has an operation projection 9, a flange 10 and a shaft 11, and the outer periphery of the shaft 11 of the filler cap 8 is covered with a cap. A lower screw portion 12 (male screw) having a width that allows the first notch portion 5 of the body 3 to be inserted in the up-down direction is formed so as to protrude, and the filler cap 8 is moved from a state where the lower screw portion 12 is inserted through the first notch portion 5. The upper screw portion 13 (male screw) which is screwed into the female screw short portion 4S by the female screw 4 of the capped body 3 by rotating the in the tightening direction is formed.

Here, as shown in FIGS. 2 and 4, the upper screw portion 13 is set to be longer than the lower screw portion 12, and as is apparent from FIG. Are arranged in a diagonal direction with a shaft portion 11 therebetween. When the filler cap 8 is screwed into the cap body 3, the screwing position of the upper screw portion 13 with respect to the lower screw portion 12 becomes a diagonal position. Is set to

A guide piece 14 is integrally provided at the lower end of the upper screw portion 13 on the side of the leading end of the tightening.
The guide piece 14 has a small width and can be vertically inserted through the second cutout 6 of the body 3 to be capped, and is oriented vertically as shown in FIG.

Further, the lower portion of the lower screw portion 12 is formed in a round shape to provide an insertion guide portion 12a, and the corner portion on the rotation leading side of the lower screw portion 12 is formed in a round shape to form a rotation guide portion 12b. Is provided. In FIG. 1, reference numeral 15 denotes a sealing member such as an O-ring provided between the upper end of the filler tube 2 and the lower surface of the flange portion 10 of the filler cap 8.

The operation of the thus structured cap tightening structure will be described in detail below. In order to fasten the filler cap 8 to the cap body 3, as shown in FIG. 2, first, the lower screw portion 12 is vertically opposed to the first notch portion 5, and the guide piece 14 is vertically opposed to the second notch portion 6. When the filler cap 8 is moved toward the cap body 3 in such a way that
, The lower screw portion 12 passes through the first notch portion 5,
The guide piece 14 passes through the second cutout 6.

When the filler cap 8 is rotated in the tightening direction (clockwise in FIG. 5) from the state where the insertion is completed, the upper surface 12c of the lower screw portion 12 is screwed into the lower surface of the long female screw portion 4L, and at the same time, the upper screw portion 13 is rotated. Is screwed over a long distance to the lower surface of the female screw short part 4S, for example, about 60 to 90
As shown in FIG. 6, the filler cap 8 can be fastened to the cap body 3 at a predetermined fastening rotation angle.

When the above-mentioned filler cap 8 is excessively rotated, the short surface of the lower screw portion 12 on the leading side of the tightening is used as the stopper 7.
, And so-called overrun of the filler cap 8 can be prevented.

On the other hand, when the filler cap 8 is removed from the cap body 3 when supplying fuel to the fuel tank, the filler cap 8 (see FIG. 6) in the tightened state is removed in the removing direction (counterclockwise in FIG. 6). When rotated, as shown in FIG. 5, the guide piece 14 on the cap 8 side
Abuts the stopper 7 on the side.

In this state, the lower screw portion 12 is
2 and the upper and lower screw portions 13, 1
Since the thread 2 is released, overrun when removing the cap is prevented, and the filler cap 8 can be easily removed and removed.

In short, according to the cap tightening structure of the above embodiment, when the filler cap 8 is tightened to the cap body 3, the first notch 5 having a predetermined width of the cap body 3 is provided.
When the filler screw 8 is moved downward, the lower screw portion 12 is inserted through the first notch 5 and the filler cap 8 is rotated in the tightening direction in this state. The upper screw portion 13 is screwed into the female screw 4 while being screwed into the portion, so that the filler cap 8 can be tightened.

As described above, the structure corresponding to the first notch portion 5 and the lower screw portion 12 can improve the tightening operability of the filler cap 8 as well as the tightening rotation angle of the filler cap 8. Even if it is small, upper screw part 13
The contact area (screw engagement distance) between the screw and the female screw 4 can be set longer, and the contact resistance between the two 13, 14 and 12, 4 is greatly increased as compared with the conventional example. This has the effect of preventing the occurrence of blemishes.

Further, since the upper screw portion 13 is set to be longer than the lower screw portion 12, a contact area (screw distance) of the upper screw portion 13 with the female screw 4 can be further secured, and tightening is performed. There is an effect that the occurrence of torque down can be more favorably prevented.

Further, since the screwing position of the upper screw portion 13 with respect to the lower screw portion 12 is set at a diagonal position, there is no one-side contact or the like, and a balanced and uniform tightening force is obtained when the filler cap 8 is tightened. It can be secured, and it has the effect of making it difficult to loosen.

In addition, since the insertion guide portion 12a is provided below the above-mentioned lower screw portion 12 (before the insertion), the lower screw portion 12 of the filler cap 8 is formed with respect to the first cutout portion 5 of the body 3 to be capped. In addition, since the rotation guide portion 12b is provided on the rotation leading side of the lower screw portion 12, the tightening operability of the lower screw portion 12 of the filler cap 8 with respect to the female screw 4 of the capped body 3 is provided. There is an effect that can be improved.

Furthermore, since the stopper 7 for restricting the rotation of the filler cap 8 is provided on the above-mentioned capped body 3, the overrun of the filler cap 8 is prevented, so-called overrun is prevented, and the filler cap 8 is tightened and held at an appropriate position. Therefore, there is an effect that the durability of the seal member 15 can be maintained. Further, since the above-mentioned cap is set to the filler cap 8 for the vehicle, there is an effect that leakage of the evaporated fuel from the fuel tank can be reliably prevented.

FIG. 7 shows another embodiment of the cap tightening structure, in which the restricting piece 1 is located at a position on the inner wall of the cap body 3 which exceeds the predetermined tightening rotation angle of the filler cap 8.
6, when the end surface of the lower threaded portion 12 on the leading side of the tightening abuts on the regulating piece 16 at a position on the front side of the stopper 7, so that the filler cap 8 is turned too much. It is configured to prevent overrun.

With such a configuration, there is an effect that the durability of the seal member 15 can be maintained more favorably. In addition, in the embodiment shown in FIG. 7, in other respects, the operation and effects are almost the same as those of the previous embodiment. Therefore, the same reference numerals in FIG. Detailed description is omitted.

In the correspondence between the configuration of the present invention and the above-described embodiment, the cap of the present invention corresponds to the vehicle filler cap 8 of the embodiment. The notch corresponds to the screw 13, the notch corresponds to the first notch 5, the first screw corresponds to the lower screw 12, and the second screw corresponds to the upper screw 13. The invention is not limited only to the configuration of the above-described embodiment.

For example, in the above-described embodiment, the filler cap 8 for the fuel supply port is exemplified as the cap, but it is needless to say that the filler cap 8 may be applied to another supply port cap.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a cap tightening structure of the present invention.

FIG. 2 is an exploded perspective view of a main part of FIG.

FIG. 3 is a cross-sectional view of the capped object taken along line AA in FIG. 2;

FIG. 4 is a sectional view of the cap taken along the line BB of FIG. 2;

FIG. 5 is a cross-sectional view of a main part along line CC in FIG. 1;

FIG. 6 is an explanatory view when tightening is completed.

FIG. 7 is a sectional view showing another embodiment of the cap tightening structure of the present invention.

FIG. 8 is a side view showing a conventional cap structure.

FIG. 9 is a cross-sectional view showing a conventional cap tightening structure.

FIG. 10 is a sectional view taken along line DD in FIG. 9;

[Explanation of Symbols] 3 ... Capped object 4 ... Female screw 5 ... First notch (notch) 7 ... Stopper 8 ... Filler cap (cap) 12 ... Lower screw (first screw) 12a ... Introduction guide 12b: rotation guide 13: upper screw (second screw)

Claims (8)

[Claims] 1. A cap fastening structure for fastening a cap having a male screw to a cap body having an internal thread, wherein at least one of the internal threads of the cap body is cut out at a predetermined width to form a notch. A cap provided with a first screw portion having a width capable of inserting the notch portion into the cap, and a second screw portion which is screwed into the male screw of the cap body by rotating from a state where the first screw portion is inserted; Tightening structure. 2. A cap fastening structure for fastening a cap having a male screw to a cap body having a female thread, wherein at least one of the female threads in the cap body is cut out in a vertical direction at a predetermined width. A lower screw portion having a width that allows the notch portion to be vertically inserted into the cap, and an upper screw that is screwed into the female screw of the object to be capped by rotating the cap from a state where the lower screw portion is inserted. Tightening structure of the cap provided with parts. 3. The cap tightening structure according to claim 2, wherein an upper screw portion is longer than said lower screw portion. 4. The cap tightening structure according to claim 2, wherein a screw position of the upper screw portion with respect to the lower screw portion is set at a diagonal position. 5. The cap tightening structure according to claim 2, wherein an insertion guide portion is provided below said lower screw portion. 6. The cap fastening structure according to claim 2, wherein a rotation guide portion is provided on the rotation leading side of said lower screw portion. 7. The cap tightening structure according to claim 2, wherein said cap body is provided with a stopper for restricting rotation of said cap. 8. The cap tightening structure according to claim 2, wherein said cap is a vehicle filler cap.