JP2002122114A - Bolt and method for fastening and releasing fasteners using the bolt - Google Patents

Abstract

(57) [Problem] To provide a bolt capable of securely fastening two members separated from each other while absorbing dimensional variations. SOLUTION: A cylindrical collar bolt 2 having a male screw portion 9 screwed to a first member on an outer peripheral surface and a female screw portion 11 on an inner peripheral surface, and a bolt screwed to a second member at a lower end portion. A bolt body 1 having a male screw portion 7 to be fitted and a head 4 at the upper end capable of engaging with the first member. The male screw portion 7 of the bolt body 1 and the collar bolt 2
By forming a special thread portion 8 such as a trapezoidal thread portion on at least one of the female thread portions 11, the bolt body 1 is screwed to the center of the collar bolt 2 so as to be detached with a predetermined torque to form a bolt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt capable of fastening two members having a dimensional variation in the interval or center position between the members while absorbing the variation, and a fastening of the member using the bolt. It relates to a method and a fastening release method.

[0002]

2. Description of the Related Art As shown in FIG. 14, for example, when fastening both ends of a long member called an instrument panel reinforcement 52 to an end face of an automobile body 51 by bolts,
Due to variations in the press and assembly accuracy of the body 51 and the instrument panel reinforcement 52, the bolt assembly position varies with the body 51 and the instrument panel reinforcement 52. Therefore, conventionally, an adjustment member 53 having an L-shaped horizontal cross section is interposed on one side of the instrument panel reinforcement 52, and the adjustment member 53 and the instrument panel reinforcement 5 are provided.
The bolt is fastened to the body 51 while adjusting the relative position to the body 2 using the elongated hole 54 of the adjusting member 53. However, when such an adjusting member 53 is used, there is a problem that the number of parts is increased and the number of bolts to be fastened is increased as compared with a case where the instrument panel reinforcement 52 is directly fastened by bolts.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a bolt and a bolt capable of securely fastening two members having dimensional accuracy variations while absorbing the variations. The purpose of the present invention is to provide a fastening method and a fastening release method for the members used.

[0004]

A bolt according to the present invention for solving the above-mentioned problem is a bolt for integrally fastening a first member and a second member which are separated from each other. A cylindrical collar bolt having a male screw portion to be screwed to the first member and having a female screw portion on the inner peripheral surface, and a male screw portion to be screwed to the second member at one end and A bolt body having a head engaged with one member, and a special thread portion is formed on at least one of the male thread portion of the bolt body and the female thread portion of the collar bolt, thereby detaching the bolt body with a predetermined torque. It is characterized by being screwed into the center of the collar bolt so that

[0005] A small diameter portion having a diameter smaller than the root diameter of the special thread portion can be provided on a shaft portion between the head portion of the bolt body and the external thread portion. Also, the special thread part is 10-5
It may be trapezoidal in cross section with a thread angle of 0 ° and may have threads that are usually larger or smaller than the pitch of the threads. further,
The special thread portion can be formed by forming a thin layer made of plastic on the normal thread, and the shape of the thread is usually a thread, but this normal thread is formed by an elastic body such as an elastomer. Things.

On the other hand, in the method of fastening a member using a bolt according to the present invention, the outer peripheral portion of the collar bolt is inserted into the female screw hole of the first member, and the bolt is rotated by torque so that the outer peripheral portion of the collar bolt and the male screw portion of the outer peripheral portion of the collar bolt are rotated. After screwing the female screw portion of the first member and bringing the lower end of the collar bolt into contact with the second member, the bolt is further rotated by torque to release the screwing between the bolt body and the collar bolt, thereby removing the collar bolt. By detaching from the bolt body, and then screwing the male screw part of the bolt body with the female screw part of the second member, the dispersion of the relative position is adjusted and the two members separated from each other are integrally fastened. It is. Further, the method for releasing the fastening of the two members separated from each other according to the present invention includes the steps of: Disengagement of the screw with the female screw portion, re-threading of the male screw of the bolt main body with the female screw of the collar bolt, and release of the screwing of the male screw of the collar bolt and the female screw of the first member are sequentially performed. It is characterized by being detached from the second member.

In the bolt of the present invention, a small diameter portion and a male screw portion are formed on the shaft portion of the bolt body, and a normal screw thread is formed on a part of the upper end portion of the male screw portion or the female screw portion on the inner peripheral surface of the collar bolt. By forming a special screw thread such as a trapezoidal cross section different from the above, screwing the female screw part of the color bolt or the male screw part of the bolt body to this special screw part, and combining the bolt body and the collar bolt integrally, A function of releasing the screwing when a predetermined load is applied to the color bolt can be provided, and a shift in the center position can be absorbed by the small-diameter portion. Even when a dimensional variation occurs at the center position, the two members separated from each other by absorbing the variation in the relative position can be integrally fastened.

[0008]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial sectional view of a bolt of the present invention, FIG. 2 is a plan view of a bolt head, and FIG. 3 is a plan view of a collar bolt. A bolt 20 is a washer inserted into the bolt. The bolt body 1 is provided with a circular head 4 which is a round head close to a hemisphere at the upper end of the shaft 3, and this head 4 has a hexagonal recess 5 for torque transmission.
Are formed. The shaft portion 3 is formed with a small-diameter portion 6 having a slightly reduced shaft diameter, and a lower portion than the center of the bolt body 1 is a male screw which is a normal thread formed by thread rolling. The part 7 is formed. And
A special screw thread 8 is formed at a part of the upper end (head side) of the male screw portion 7 so as to be able to screw with a female screw with a predetermined torque. The small diameter portion 6 is thinner than the root diameter of the special thread portion 8.

A washer insertion portion 23 having a diameter larger than that of the small-diameter portion 6 is provided directly below the head 4 of the bolt body 1 to reduce the contact area between the seat surface of the head 4 and the washer 20,
When the bolt is fastened, the washer 20 is prevented from rotating together with the rotation of the bolt body 1. Further, the lower end of the washer insertion portion 23 is chamfered or rounded so as to be inclined so that the washer 20 can be smoothly inserted into the washer insertion portion 23.

On the other hand, as shown in FIG. 3, the collar bolt 2 has an external thread portion 9 formed on its outer peripheral surface to be screwed to the first member. A hexagonal concave portion 10 for rotating the bolt 2 is formed, and a female screw portion 11 is formed on the inner peripheral surface of the collar bolt 2. The female screw portion 11 is a special screw thread portion of the bolt body 1. Screw with 8. The recesses 5 and 10 provided in the bolt body 1 and the collar bolt 2 may be of any shape capable of transmitting torque. In addition to polygons such as hexagons, tools such as a plus, minus screwdriver and a Torx screwdriver can be set. Any suitable shape can be used. FIG. 4 shows an example of the concave portion 5 in which the convex portions 24 are arranged at predetermined intervals on the inner peripheral surface of the circular hole of the bolt head 1.

As a typical example of the above-described special thread portion 8, as shown in FIG. 5, a trapezoidal screw whose top is pressed by a rolling die and deformed into a trapezoidal cross section by plastic flow of metal. There is a mountain 25. The mechanism of screwing the collar bolt 2 with the female thread 11 by the trapezoidal thread 25 will be described below. The angles of the hills and valleys (flanks) of ordinary bolts are formed at approximately 60 °, respectively.
By screwing the 60 ° male thread and the 60 ° female thread valley, it is possible to smoothly fasten the bolt and the nut or the like. The top of an external thread, which is a thread of °, is pressed by a rolling die, and the metal flows plastically on both slopes of the thread, so that the thread angle (angle formed by the flank) is approximately 40 °. Things. When the male screw is formed into a trapezoidal cross section in this way, when it is screwed into a female screw having a valley flank angle of 60 °, as shown in FIG. 6, plastic flow occurs from the flank of the original thread. The protruding part wraps with the female screw valley flanks, and the female screw 1
1 and the collar bolt 2 can be screwed into the trapezoidal thread portion 25 with a predetermined torque.

The thread angle of the trapezoidal thread portion 25 is 10
~ 50 ° is desirable. If the thread angle is less than 10 °, the meshing portion 19 becomes large and the screwing torque becomes high, resulting in poor workability. In addition, when high-speed screw tightening is performed by an air motor or the like, the frictional heat becomes large and the screw is seized. Problem. On the other hand, when the thread angle exceeds 50 °, the meshing portion 19 becomes small, the meshing torque is reduced, and the bolt is easily loosened. Therefore, the required torque can be stably obtained by setting the thread angle of the trapezoidal thread portion 25 to 10 to 50 °.

Such a trapezoidal thread portion 25 can be formed on the male thread portion 7 of the bolt shaft portion 6 or by pressing the thread of the female thread portion 11 on the inner peripheral surface of the collar bolt 2. By screwing the trapezoidal thread portion 25 with the female thread portion 11 or the male thread portion 7, the collar bolt 2 can be attached to the bolt main body 1 with a predetermined torque to form an integral bolt. When a predetermined torque is applied, the color bolt 2
Can be detached from the bolt body 1. The step of forming the trapezoidal thread 25 by pressing the thread of the external thread 7 or the internal thread 11 is desirably performed simultaneously with the step of processing the external thread or the internal thread from the viewpoint of improving productivity. Further, the formation range of the trapezoidal thread portion 25 is sufficient if the number of threads is 1 to 10 threads and the angle around the axis is 10 to 360 °, and the trapezoidal thread portion 25 is not necessarily formed by bolts. It is not necessary to provide it over the entire circumference, and it is sufficient if at least one portion is formed around the axis. In the present invention,
Trapezoidal thread part 2 having a constant thread angle without variation
5 can be easily formed, and the detachment torque of the collar bolt 2 from the bolt main body 1 can be a predetermined one with small variation.

Further, as shown in FIG. 7, the special thread portion 8 is formed with a pitch lock portion 26 having a pitch L2 larger than the pitch L1 of the normal thread or a smaller pitch L3.
It can be. Here, the pitch lock unit 26 is 1
Up to four normal threads are provided on the tip side or head 4 of the bolt shaft 3.
It can be formed by shifting the pitch L1 by 10 to 30% to the side. For example, 4 regular threads 20%
When shifted upward, a pitch lock thread 27 having a pitch L2 that is 20% larger than the pitch L1 of the normal thread is formed at the bottom of the four threads, and the pitch lock thread 27 is usually formed at the top of the four threads. A pitch lock thread 27 having a pitch L3 that is 20% smaller than the thread pitch L1 is formed, so that the pitch lock portion 26 can be formed on the shaft portion 3.

Further, another special thread portion 8 can be used. For example, the shape, angle, and pitch of the thread of the portion are usually the same as those of the thread, but a thin layer made of plastic such as nylon can be formed only on the portion. Once this thin layer is formed, it is preferable that the thin layer does not easily fall off from the place where it is formed unless it is intentionally peeled off. "Nylok" (trademark) of Nyloc.
The formation of the thin layer is carried out by a conventional method, for example, US Pat.
71,604 / 1964; 398,495 / 1964; 599,042 / 19
66; 628,683 / 1967; 821,178 / 1969; 20
3,130 / 1972; 400,502 / 1973 and US patent: RE2
8,812 / 1978; 3,995,074 / 1976; 4,054,688
No./1977; 4,100,882 / 1978; 4,012,993 / 1978
The method may be performed according to the method described in the year. Further, as the special thread portion 8, the shape of the thread is usually a thread, but the material of the ordinary thread can be an elastic body such as general-purpose rubber, special rubber, and elastomer. Although the special thread 8 is provided on the bolt body 1 in the drawings and the above description, the purpose of providing the special thread 8 is to engage the bolt body 1 with the collar bolt 2. State is
In order not to cancel the torque unless a torque exceeding a predetermined value is applied, it goes without saying that the special thread portion 8 may be provided on the collar bolt side.

8 to 12, a description will be given of a method of integrally fastening two members in which the relative positions between the members vary by using the bolt of the present invention. In order to simplify the explanation, an example in which the special thread 8 is provided in the bolt body 1 will be described as an example. The first member and the second member shown in the drawing have dimensional variations in the distance s between the first member and the second member.
The position of the central axis 22 of the first and second members may be shifted. In fastening such two members, first, a washer 20 is inserted into the bolt body 1 and a bolt in which the collar bolt 2 is screwed with a predetermined torque is applied to the first member 13 and the second member 14. At the required position above the. (See FIG. 8) Next, the color bolt 2
Is inserted into the female screw hole 15 of the first member from above. (See Fig. 9)

Then, the bolt is torque-rotated to screw the male screw portion 9 on the outer peripheral portion of the collar bolt 2 with the female screw portion 16 of the first member 13, and the lower end of the collar bolt 2 is attached to the upper surface of the second member 14. Contact. (See Fig. 10)
Even if the bolt is further rotated by torque, the lower end of the collar bolt 2 is stopped by abutting on the upper surface of the second member 14, so that the lower end cannot be further lowered. Is special thread 8
The collar bolt 2 is detached from the special thread portion 8 by applying a load higher than that screwed into the threaded portion, and the tip of the bolt main body 1 is inserted into the female screw hole 17 of the second member 14. (See Fig. 11)

Further, by rotating the bolt body 1 by torque, the male screw portion 7 of the bolt body 1 can be screwed into the female screw portion 18 of the second member 14, and the bolt head 4 is connected to the first head portion 4 via the washer 20. By suppressing the member 13,
The first member 13 and the second member 14 can be integrally bolted. Here, when the bolt body 1 is sufficiently long, the special thread portion 8 formed on the bolt body 1 can be screwed into the female thread portion 18 of the second member 14, and the bolt tip By forming the special screw thread 8 on the male screw part 7 of the first member 13, it can be screwed with the female screw part 18 of the second member 14, and the first member 13 is provided with a predetermined torque with the effect of preventing loosening.
And the second member 14 can be integrally bolted. For the purpose of preventing loosening, the special thread portion 8 may be further formed on either the male thread portion 9 of the collar bolt 2 or the female thread portion 16 of the first member 13. However, the torque value for releasing the engagement between the collar bolt 2 and the first member 13 by the additional special thread portion is smaller than the torque value required for releasing the engagement between the bolt body 1 and the collar bolt 2. As it is, it is necessary to form a special thread 8. Further, it is desirable to form serrations or irregularities on the lower end surface of the color bolt 2. That is, FIG.
When the state shown in the figure is shifted to the state shown in FIG. 11, the collar bolt 2 is moved by the torque applied to the bolt body 1 (which is extremely large compared to the torque normally required for screwing the threads together). 1 and the first member 13
This is because the gap between the second member 14 and the second member 14 can be prevented from being expanded.

Even if the center axis 21 of the female screw hole 15 and the center axis 22 of the female screw hole 17 are misaligned, the bolt body 1 is provided with the small-diameter portion 6 and there is a gap between the bolt body 1 and the female screw portion 11. As a result, the displacement between the members can be absorbed by the displacement of the bolt body 1 and the bolt can be tightened. In this way, the two members 1 can be used both when the size of the interval s varies and when the positions of the central axes 21 and 22 vary.
3, 14 can be integrally fastened by bolts.

The first member 13 and the second member 1 are used for repair or the like.
In order to remove the bolt from 4, the bolt can be removed by rotating the bolt in a direction opposite to the tightening direction.
That is, the bolt body 1 is reversely rotated to release the screwing of the bolt body 1 and the second member 14 as shown in FIG. 12 → FIG. 11, and the collar bolt 2 is screwed into the bolt body 1 again as shown in FIG. Let it. However, when the bolt is tightened, there is a possibility that the thread of the female thread 11 of the collar bolt 2 is deformed by the special thread 8 of the bolt body 1 and the engagement torque is reduced. In such a case, the bolt body 1 is further rotated in the reverse direction so that only the bolt body 1 is
It can be removed from the member 14. In addition, since the collar bolt 2 has a recess 10 such as a hexagon for transmitting torque, the collar bolt 2 is removed from the first member 13 by attaching a tool to the recess 10 and rotating it in the reverse direction. be able to.

As described above, the bolt of the present invention has a function of absorbing the variation in the distance s between the first member 13 and the second member 14 and the relative position between the center axes 21 and 22 of the screw holes. As shown in FIG. 2, if the modularized unit 30 including the instrument panel reinforcement or the instrument panel reinforcement is used for bolting to the body 51, the two can be directly connected without using another adjusting member as in the related art. Can be bolted.

[0022]

As described above, the bolt of the present invention is provided with a collar bolt on the bolt body capable of absorbing variations in the distance between the first member and the second member separated from each other and the relative position of the center axis. Therefore, the first member and the second member can be securely fastened and can be removed. Further, according to the method for fastening members using bolts of the present invention, members such as instrument panel reinforcements can be easily fastened and fastened to the body only by bolts without using an adjusting member. Performance can be greatly improved. Further, according to the fastening release method of the present invention, the bolt can be easily removed from the two members separated by rotating the bolt in a direction opposite to the tightening direction. Therefore, the present invention is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing the overall configuration of a bolt according to the present invention.

FIG. 2 is a plan view of a bolt head.

FIG. 3 is a plan view of a color bolt.

FIG. 4 is a plan view of a bolt head in which a hole having a convex portion is formed.

FIG. 5 is an explanatory diagram of a function of a trapezoidal thread portion.

FIG. 6 is an enlarged sectional view showing a state in which a female thread portion of a collar bolt is screwed into a trapezoidal thread portion;

FIG. 7 is an enlarged sectional view of a pitch lock portion.

FIG. 8 is a partial sectional view showing a state before the bolt of the present invention is mounted on the first member.

FIG. 9 is a partial cross-sectional view showing a state where the collar bolt is being inserted into the first member.

FIG. 10 is a partial cross-sectional view showing a state where a lower end of a collar bolt is in contact with a second member.

FIG. 11 is a partial cross-sectional view showing a state where the bolt main body is detached from the collar bolt.

FIG. 12 is a partial cross-sectional view illustrating a state where a bolt body is screwed into a second member.

FIG. 13 is a perspective view illustrating a state in which the instrument panel reinforcement is attached to the body by the bolt of the present invention.

FIG. 14 is a perspective view illustrating a state in which an instrument panel reinforcement is attached to a body according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Bolt main body 2 Color bolt 3 Shaft part 4 Head 5, 10 Recess 6 Small diameter part 7, 9 Male screw part 8 Special thread part 11 Female screw part 13 First member 14 Second member 15, 17 Female screw hole 16 First member Female screw part 18 female screw part of the second member 19 meshing part with female screw 20 washer 21 central axis of female screw hole 15 22 central axis of female screw hole 17 washer insertion part 24 convex part 25 trapezoidal thread 26 pitch lock part 27 pitch Lock thread 30 Modularized unit including instrument panel reinforcement 51 Body 52 Instrument panel reinforcement 53 Adjusting member 54 Slotted hole

Continuing from the front page (72) Inventor Hiromichi Mizuno 1-8-8 Takahashi, Oguchi-machi, Niwa-gun, Aichi Prefecture Inside the Oguchi Plant of Aoyama Seisakusho (72) Inventor Shuji Ito 1-8-8 Takahashi, Oguchi-machi, Niwa-gun, Aichi Prefecture Aoyama Plant Oguchi Plant (72) Inventor Masafumi Takahashi 1-8-1 Takahashi, Oguchi-machi, Niwa-gun, Aichi Prefecture Co., Ltd. Inside Aoyama Plant Oguchi Plant (72) Inventor Kenji Inagaki 1-8-1, Takahashi, Oguchi-cho, Niwa-gun, Aichi Prefecture Inside the Oguchi Plant of Aoyama Manufacturing Co., Ltd.

Claims (16)

[Claims] 1. A bolt for integrally fastening a first member and a second member which are separated from each other, comprising a male screw portion screwed to the first member on an outer peripheral surface and a female screw portion on an inner peripheral surface. A cylindrical collar bolt having a male screw portion screwed to the second member at one end and a head body having a head engaged with the first member at the other end. A bolt characterized in that a special thread portion is formed in at least one of the male thread portion and the female thread portion of the collar bolt, and the bolt body is screwed to the center of the collar bolt so as to be detached with a predetermined torque. 2. The bolt according to claim 1, wherein a thin portion having a diameter smaller than a root diameter of the special thread portion is provided on a shaft portion between the head portion of the bolt body and the male screw portion. 3. The bolt according to claim 1, wherein the special thread portion has a trapezoidal cross section having a thread angle of 10 to 50 °. 4. The special thread portion is 1 to 10 in number of threads.
4. The bolt according to claim 3, wherein at least one ridge having a range of 10 to 360 [deg.] Around the axis is formed around the axis. 5. The bolt according to claim 1, wherein the special thread portion has a thread which is larger or smaller than a pitch of the normal thread. 6. The pitch of the special thread portion is 10 to 30% larger than the pitch of the normal thread as a pitch, or 10 to 30%.
The bolt according to claim 5, wherein the number of the ridges is smaller by 1% and the number of ridges is 1 to 4%. 7. The bolt according to claim 1, wherein the special thread portion is formed by forming a thin layer made of plastic on the normal thread. 8. The bolt according to claim 1, wherein the special thread portion has a normal thread shape, and the normal thread portion is formed by an elastic body. 9. The bolt according to claim 8, wherein an elastomer is used as the elastic body. 10. A position where the special thread portion is on the bolt body side and can be screwed with a female thread portion formed in a screw hole of the second member at the time of completion of fastening of the first member and the second member. The bolt according to any one of claims 1 to 9, wherein the bolt is provided in a bolt. 11. The bolt according to claim 1, wherein a recess for transmitting a torque into which a tip of a tool can be inserted is formed in a head portion of the bolt body and a bolt penetrating surface of the collar bolt. 12. The bolt according to claim 11, wherein the head of the bolt body has a circular shape. 13. The bolt according to claim 2, wherein a washer insertion portion having a larger diameter than the small diameter portion is provided immediately below the head of the bolt body. 14. The bolt according to claim 13, wherein the lower end of the washer insertion portion is chamfered or rounded. 15. An outer peripheral portion of a collar bolt is inserted into a female screw hole of a first member by using the bolt according to any one of claims 1 to 14, and the bolt is torque-rotated. After the male screw portion and the female screw portion of the first member are screwed together, and the lower end of the collar bolt is brought into contact with the second member, the bolt is further rotated by torque to release the screwing between the bolt body and the collar bolt. By separating the collar bolt from the bolt body and then screwing the male thread portion of the bolt body with the female thread portion of the second member, the dispersion of the relative position is adjusted, and the two members separated from each other are integrally fastened. A method of fastening members using bolts. 16. The method according to claim 15, wherein the bolt that fastens the first member and the second member is rotated in the reverse direction, so that the male screw portion of the bolt body and the female screw portion of the second member are unlocked. The male screw of the bolt body and the female screw of the collar bolt are re-threaded, and the screwing of the male screw of the collar bolt and the female screw of the first member are sequentially released to remove the bolt from the first member and the second member. To release the fastening of two members separated from each other.