JPH1151026A - Bolt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bolt capable of surely removing paint adhered to the screw thread of a female screw, and the following flank of the screw thread in particular. SOLUTION: In this bolt 1 which is composed of a head part 2, and of a shaft part 3, and is provided with a screw part 4 at the shaft part 4, an irregular pitch part 4 provided with a portion having pitch P1 larger than normal pitch or having irregular pitch smaller than normal pitch, is provided for the tip end or the intermediate part of the screw part 4, and furthermore, a cut-out 5 is provided for the circumferential surface of the irregular pitch part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt which can be screwed in while removing paint when the paint adheres to a screw hole.

[0002]

2. Description of the Related Art Products requiring high rust prevention performance, such as automobiles, have many screw holes into which bolts are to be incorporated after painting. For such screw holes, in order to ensure the reliability of fastening, masking is performed with a masking material before painting so that paint does not enter, and the masking material is removed when installing the bolt, or After the coating, a paint removal tap is performed, and after the paint in the screw hole is removed, installation is performed. However, there is a problem that the work of attaching and detaching the masking material or the operation of the paint removing tap is complicated, and the workability of assembling the bolt is reduced, and the cost is increased.

[0003] Therefore, a bolt provided with a notch has been proposed so that the paint can be directly incorporated into the screw hole into which the paint has entered without removing the paint.
No. 56-65213, No. 63-18610, No. 63-128309,
No. 3-6114). 6 to 8 show an example of such a notched bolt 31. FIG. The bolt 31 includes a head portion 32 and a tapered shaft portion 33 whose front end portion decreases in diameter toward the front end.
Three notches 35 are provided at the tip of 34 along the axial direction. When the bolt 31 is incorporated into the female screw 7 to which the paint is attached, a sharp edge portion 36 which is a boundary between the screw portion 34 and the notch 35 scrapes the paint attached to the thread 71 of the female screw 7 and scrapes the paint. The removed paint is taken into the notch 35. When such a bolt 31 is tightened to the female screw 7, an axial force is applied to the bolt 31, and the thread of the bolt 31
37 of chase flank F _f is pressed against the chase flank f _f of the threads 71 of the female screw 7. Therefore, in order to improve the reliability of the bolt, it is necessary to remove the particular paint adhering to the chase flank f _f of the threads 71 of the female screw 7.

[0004]

The above conventional bolt 31
Since only a notch is provided in a bolt having an ordinary screw portion, the threads 37 of all the screw portions 34 have a regular pitch, and the screw portion 34 in which the notch 35 is provided is provided. Each of the pitches Q _{1 to} Q ₄ has the same size. Even if such a bolt 31 is incorporated into the female screw 7, the axial force is still applied to the bolt 31 when the notch 35 provided at the tip of the screw portion 34 advances in the female screw 7. Instead, as shown in FIG. 6, the thread 37 of the bolt 31 and the thread 71 of the female screw 7
Even if there is play between them and there is no play, the paint adhered to the thread 71 of the female screw 7 can be sufficiently removed because there is no close contact, much less pressure contact. Did not. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a bolt capable of reliably removing paint adhering to a thread of an internal thread, in particular, a flanking flank of the thread.

[0005]

In order to solve the above-mentioned problems, the present invention provides a bolt 1 comprising a head 2 and a shaft 3, and having a screw 4 provided on the shaft 3. An irregular pitch portion 4a having a portion having a pitch (P ₁ ) larger than the regular pitch and / or a portion having a pitch (P ₄ ) smaller than the regular pitch is provided at a tip end portion or an intermediate portion of the screw portion 4. The bolt 1 is provided, and a notch 5 is provided on a peripheral surface of the irregular pitch portion 4a. The irregular pitch portion 4a includes a portion having a larger pitch (P ₁ ) than the regular pitch, a portion having a regular pitch (P ₂ , P ₃ ) from the tip side of the shaft portion 3, and a portion having a regular pitch. preferably comprising a portion having a even smaller pitch (P ₄₎ is, the cutout portion 5 is preferably inclined to the screw rotation opposite directions toward the front end of the bolt 1. Further, a guide boss 18 having a diameter slightly smaller than the root diameter of the screw 4 may be provided at the tip of the screw 4.

[0006]

The thread portion 4 of the bolt 1 of the present invention has an irregular pitch having a portion having a pitch (P ₁ ) larger than the regular pitch and / or a portion having a pitch (P ₄ ) smaller than the regular pitch. A portion 4a is provided, and a notch 5 is provided on the peripheral surface of the irregular pitch portion 4a. When such a bolt 1 is incorporated into a female screw 7 to which paint is attached, the thread M in the irregular pitch portion 4a has a force to push the gap between the threads 71 of the female screw 7 and / or A force is generated to pinch the thread 71, and the thread M of the bolt 1 comes into pressure contact with the thread 71 of the female screw 7. As described above, since the bolt 1 advances while being pressed against the female screw 7, the paint adhered to the thread 71 of the female screw 7 is formed at the boundary between the irregular pitch portion 4 a of the bolt 1 and the notch 5. The sharp edge portion 6 can reliably scrape off.

The irregular pitch portion 4a is divided into a portion having a pitch (P ₁ ) larger than a regular pitch from a tip side of the shaft portion 3, a portion having a regular pitch (P ₂ , P ₃ ),
When such a bolt 1 is incorporated into the female screw 7 to which the paint is attached in a case where it is composed of a portion having a pitch (P ₄ ) smaller than the regular pitch, the pitch (P ₄ ) is larger than the regular pitch (P ₄ ). Due to the large pitch (P ₁ ), the trailing flank F _{f of} the head-side thread (M ₂ ) constituting the large pitch (P ₁ ) becomes the thread 71 of the female screw 7.
Pressed against the nephew flank f _f, the pitch of normal following a large-pitch _{(P 1) (P 2,} P 3), the thread (M ₃ constituting the regular pitch (P _2, P ₃₎ , follow flank F _f of M ₄₎ is, for pressure to follow flank f _f of the threads 71 of the thread (M ₂₎ in the same manner as the female screw 7, the threads (M ₂ of the continuous, M ₃ , M ₄ ), the edge 6 at the trailing flank F _f , in particular the internal thread 7
Paint adhering to the chase flank f _f of the thread 71 of the can to take reliably scraped. After the threads (M ₁ , M ₂ , M ₃ , M ₄ ) pressed against the thread 71 of the internal thread 7 pass through the threaded hole of the internal thread 7, when an axial force is applied to the bolt 1 also, the end of the thread in the irregular pitch region 4a (M ₅₎ and normal and follow flank F _f of the thread M _n in the thread portion 4b, chasing side of the thread 71 of the female screw 7, which is the removal of the paint since the and Frank f _f to press, is very high reliability of the bolt.

When the notch 5 of the bolt 1 is inclined in the direction opposite to the screw rotation toward the tip of the bolt 1, the wedge effect of the edge portion 6 for scraping the paint efficiently allows the female screw 7 to be efficiently removed. The paint adhered to the screw holes can be scraped off. Further, in the above-mentioned bolt 1, when the irregular pitch portion 4a which comes into pressure contact with the thread 71 of the female screw 7 is provided at the tip end of the screw portion 4, depending on the amount of paint adhered to the screw hole of the female screw 7, In some cases, it is difficult to screw 1 into the female screw 7. In such a case, a guide boss 18 having a diameter slightly smaller than the root diameter of the screw portion is provided at the tip of the screw portion 4, or the irregular pitch portion 4a is formed at an intermediate portion of the screw portion 4. If a portion 24c having a regular pitch is provided at the tip of the bolt shaft 3, the bolt 1 can be easily screwed into the female screw 7 to which a large amount of paint has adhered.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
A bolt according to one embodiment of the present invention is shown in FIGS. The bolt 1 includes a head portion 2 and a shaft portion 3, and a screw portion 4 is formed on a tip end side of the shaft portion 3. The tip side of the screw portion 4 is an irregular pitch portion 4a, and a plurality (five) of notches 5 are provided on the peripheral surface of the irregular pitch portion 4a. At the boundary between the screw portion 4 and the notch 5, a sharp edge portion 6 capable of scraping paint is formed. As shown in the enlarged view of FIG.
In a, from the front end side, the pitch P ₁ between the first and threads M ₁ and the second thread M ₂ is normal is larger than the pitch, the second thread M ₂ Third thread M
₃ pitch P ₃ between the pitch P ₂ and the third thread M ₃ and fourth thread M ₄ between is adapted to the normal pitch, a fourth thread M ₄ second pitch P ₄ between the threads M ₅ 5 is smaller than the normal pitch. The pitch between the threads _Mn in the normal thread portion 4b other than the irregular pitch portion 4a has a regular pitch.

The ratio between the pitch P ₁ larger than the regular pitch and the regular pitches P ₂ and P ₃ and the ratio between the pitch P ₄ smaller than the regular pitch and the regular pitches P ₂ and P ₃ are determined by the following formulas. The amount is appropriately set in consideration of the amount of the paint adhered to the screw hole of the female screw 7 into which the bolt 1 is to be incorporated, the ease of assembling the bolt 1 into the female screw 7, and the like. 1.05 × P ₁ ≦ P ₂ , P ₃ ≦ 1.25 × P ₁ 0.75 × P ₄ ≦ P ₂ , P ₃ ≦ 0.95 × P ₄ .

In the bolt 1 of this embodiment, the notch 5 is inclined in the direction opposite to the screw rotation toward the tip of the bolt 1. The angle of inclination of the notch 5 is not particularly limited, but is preferably 5 to 30 ° with respect to the axis of the bolt 1.

The bolt 1 is connected to the female screw 7 to which paint is attached.
In the case of assembling, the irregular pitch portion 4a provided with the notch 5
In the first thread M₁And the second thread M_TwoWith
Pitch P between₁Is larger than the regular pitch,
Thread M₁The leading side of Frank F_lIs the screw of the female screw 7
Frank f on the leading side of mountain 71_lTo the second thread M _Two
Follower Frank F_fIs the trailing side of the thread 71 of the female screw 7
Frank f_fPress against Also, the second thread M_TwoAnd the second
3 thread M_ThreePitch P between_TwoAnd the third thread M
_ThreeAnd the fourth thread M_FourPitch P between_ThreeIs a regular pick
The third thread M_ThreeAnd the fourth
Thread M_FourIs the second thread against the thread 71 of the female screw 7.
Jiyama M_TwoAnd thus the third screw
Mountain M_ThreeFollower Frank F_fAnd the fourth thread M_Fourof
Follower Frank F_fIs the second thread M_TwoThe follower
Rank F_fIn the same manner as above,
Link f_fPress against Further, the fourth thread M_FourAnd the fifth
Thread M_FivePitch P between_FourIs more than the regular pitch
The fifth thread M_FiveOn the leading side
Pressing or pressing against the thread 71 of the internal thread 7
But between the threads 71 of the female screw 7. Here,
Switch P_FourIs larger than the fifth thread M as in the former case._Fiveof
Leading Frank F_lIs the leading end of the thread 71 of the female screw 7.
Rank f_lIf the size is such that it can be pressed against
Thread M_FourFollower Frank F_fIs the screw of the female screw 7
The trailing flanking f of mountain 71_fTo press against
You. On the other hand, the pitch P_FourThe size of the fifth, like the latter,
Thread M_FiveIs not pressed against the thread 71 of the female screw 7
If it is large, the fifth thread M_FiveFrom regular pitch
Thread M in the ordinary threaded portion 4b continuous with_n
Also the fifth thread M_FiveSimilarly, the thread 71 of the female screw 7
Thread M₁~ M_FourBy scraping paint
While applying the scraping, without adding extra resistance
The bolt 1 can be screwed into the female screw 7.

[0013] or the bolt 1 in a pressed state, such as is for traveling within the internal thread 7, paint adhering to the chase flank f _f of the threads 71 of the female screw 7, in the bolt 1 3
Continuous second thread M ₂ , third thread M ₃ and fourth thread M ₃
Edge 6 at the trailing flank F _f of the thread M ₄
Can be scraped off reliably by coating adhering to the stabbing flank f _l of the threads 71 of the female screw 7, the edge portion 6 of the stabbing flank F _l first thread M ₁ of the bolt 1 Can be scraped. The scraped paint is stored in the notch 5. The above thread M ₁ , M
_{If the second} , M ₃ and M ₄ have passed through the screw holes of the female screw 7, even if an axial force is applied to the bolt 1, the fifth screw thread M ₅ and the screw thread in the ordinary screw portion 4 b since the M _n of the follow-side flank F _f, and follow flank f _f of the threads 71 of the female screw 7, which is the removal of the paint is pressed, an extremely high reliability bolting. Further, in the bolt 1 in this specific example, since the notch 5 is inclined in the direction opposite to the screw rotation toward the tip of the bolt 1, the female screw 7 is efficiently produced by the wedge effect of the edge portion 6 that scrapes the paint. Paint can be scraped off.

In the bolt 1 of the present invention described above, the screw portion 4 is formed from the tip of the shaft portion 3 and the irregular pitch portion 4a is provided at the tip of the screw portion 4. Is not limited to these embodiments. In the case where the irregular pitch portion 4a which presses against the thread 71 of the female screw 7 is provided at the tip of the screw portion 4, the bolt 1 may be attached to the female screw 7 depending on the amount of paint adhered to the screw hole of the female screw 7. It may be difficult to screw into the cable and may be installed diagonally.
In such a case, the bolt of the present invention can be in a mode as shown in FIGS. 4 and 5, for example.

The bolt 11 shown in FIG. 4 comprises a head portion 12, a shaft portion 13, and a guide boss portion 18 provided at the tip of the shaft portion 13. A screw portion 14 is formed on the distal end side of the shaft portion 13, and the guide boss portion 18 has a slightly smaller diameter than the root diameter of the screw portion 14. The tip side of the screw portion 14 is an irregular pitch portion 14
In the peripheral surface of the irregular pitch portion 14a, a plurality (five) of notches 15 are provided which are inclined toward the tip of the bolt 11 in the direction opposite to the screw rotation. The notch
The irregular pitch portion 14a provided with 15 is a portion having a pitch larger than the regular pitch from the tip side of the shaft portion, a portion having a regular pitch, and a portion having a pitch smaller than the regular pitch. Consists of When the bolt 11 is incorporated into a female screw to which paint is attached, the bolt 11 is provided with a guide boss 18 having a diameter slightly smaller than the root diameter of the screw part 14 at the tip of the shaft part 13. Even if a large amount of paint adheres to the screw hole, the bolt 11 can be incorporated at an appropriate angle by inserting the guide boss 18 into the screw hole.

On the other hand, the bolt 21 shown in FIG.
And a shaft portion 23, and a screw portion is provided at the tip end side of the shaft portion 23.
The screw portion 24 is provided with a normal screw portion 24c, an irregular pitch portion 24a, and a normal screw portion 24b in this order from the tip side. On the peripheral surface of the irregular pitch portion 24a,
A plurality (five) of notches 25 are provided which are inclined toward the tip of the screw 21 in the direction opposite to the screw rotation. The notch 25
The irregular pitch portion 24a provided with a portion having a pitch larger than the regular pitch from the tip side of the shaft portion,
It has a portion having a regular pitch and a portion having a smaller pitch than the regular pitch. When the above-mentioned bolt 21 is incorporated into a female screw to which paint is attached, the bolt 21 is provided with a regular thread portion 24c having a regular pitch at the tip side of the irregular pitch portion 24a having the notch 25. Even if a large amount of paint adheres to the screw hole of the female screw, the screw 11c is screwed into the female screw, so that the bolt 11 can be incorporated into the female screw at an appropriate angle in the initial stage. Therefore, the irregular pitch portion 24a can be appropriately incorporated into the female screw.

The bolt of the present invention is not limited to the embodiment shown in the drawings, and various modifications can be made without departing from the scope of the present invention. For example, although the number of threads in the irregular pitch portion of the bolt of this specific example was 5,
There is no particular limitation. Although five notches are provided in the bolt of this specific example, the number is not particularly limited, and may be set as appropriate according to the amount of paint adhered to the female screw. Similarly, the length, width and depth of the notch may be appropriately set in consideration of the amount of the paint adhered to the female screw and the strength of the bolt.

[0018]

According to the bolt of the present invention, the paint adhered to the screw hole of the female screw can be reliably scraped off.
Very high bolt fastening reliability.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a bolt according to an example of the present invention.

FIG. 2 is an AA end view of the bolt in FIG. 1;

FIG. 3 is a partially enlarged view of a screw portion of a bolt in FIG. 1;

FIG. 4 is a perspective view showing a bolt according to another example of the present invention.

FIG. 5 is a perspective view showing a bolt according to another example of the present invention.

FIG. 6 is a side view showing a conventional bolt.

FIG. 7 is a BB end view of the bolt in FIG. 6;

FIG. 8 is a partially enlarged view of a screw portion of a bolt in FIG. 6;

[Explanation of symbols]

 1, 11, 21, 31 ... bolt 2, 12, 22, 32 ... head 3, 13, 23, 33 ... shaft 4, 14, 24, 34 ... screw 4a, 14a, 24a ... irregular pitch 4b, 14b, 24b, 24c: Normal thread 5, 15, 25, 35 ... Notch 6, 16, 26, 36 ... Edge 7 ... Female thread 71: Female thread 18: Guide boss 37: Bolt thread

Claims (4)

[Claims] 1. A bolt comprising a head portion and a shaft portion, wherein a screw portion is provided on the shaft portion, and a tip portion or an intermediate portion of the screw portion has a portion having a pitch larger than a regular pitch. And / or an irregular pitch portion having a portion having a pitch smaller than the regular pitch is provided, and a notch is provided on a peripheral surface of the irregular pitch portion. 2. The irregular pitch portion includes a portion having a pitch larger than a regular pitch, a portion having a regular pitch, and a portion having a pitch smaller than the regular pitch from the tip side of the shaft portion. The bolt according to claim 1, wherein 3. The bolt according to claim 1, wherein the notch is inclined in a direction opposite to the screw rotation toward a tip of the bolt. 4. A guide boss having a diameter slightly smaller than a root diameter of the threaded portion is provided at a tip of the threaded portion.
Any of the bolts described.