JP4194990B2 - Fastener - Google Patents

Description

The present invention relates again and again fastened to fix the two members without significant displacement load to the bearing surface of the fastening bolt or member applied.

Conventionally, a fastening bolt has a structure composed of a rod-shaped bolt main body provided with a male screw and a head provided at an end of the bolt main body, and is used for various machine elements. In such a fastening bolt, for example, a bolt main body is passed through a bolt through hole provided in the first member, and the bolt main body is screwed into a screw hole provided in the second member, thereby fixing these two members.
Also, the fastening bolt is used for shaft coupling as fasteners such as shown in FIG. 8 (a). In this case, the fastening bolt 501 is used for fastening a fastening body 507 for fixing the shaft 505 in a shaft coupling that connects the two shafts 505 (Patent Document 1). The fastening body 507 is provided with a shaft hole portion 571 through which a shaft 505 (another member) is inserted in the central portion, a slit groove 572 in the radial direction, and one end portion of the slit groove 572 facing each other. A bolt through hole 530 is provided in 503 (first member) and a screw hole 540 is provided in the other end portion 504 (second member). The fastening bolt 501 is passed through the bolt through hole 530 to the screw hole 540. Screwed together. Therefore, when the fastening bolt 501 is screwed in, the gap between the slit grooves 572 is narrowed to reduce the diameter of the shaft hole portion 571 of the tightening body 507, and the shaft 505 is caused by the surface pressure of the shaft hole portion 571 due to this diameter reduction. Tighten and fix.
JP 2001-295851 A JP-A-11-125265

  By the way, when fixing the two members 503, 504, etc. with the fastening bolt 501, the screw holes 540 provided in the members 503, 504 may actually be formed slightly inclined rather than at right angles. The lower surface corner 522 of the head 520 of the fastening bolt 501 is substantially in contact with the seat surface 531 of the member 503 provided with the bolt through-hole 530, and a large displacement load or bending stress is applied to the seat surface 531 or the fastening bolt 501. It becomes a state. Therefore, the fastening force by the fastening bolt 501 becomes insufficient, and problems such as easy loosening of tightening occur. In addition, the fastening bolt 501 itself may be formed by bending the head 520 and the bolt main body 510, and even in that case, the fastening force of the fastening bolt 501 becomes insufficient as described above, and the fastening is easy to loosen. Problems arise.

On the other hand, in the shaft coupling 600 shown in FIG. 8 (a), opposite the ends 503, 504 of the sliding separation grooves 572 of the clamping member 507 in accordance with screwing the fastening bolt 501 is an inclined posture, along with this The seating surface 531 of the one end 503 is also inclined. For this reason, as shown in FIG. 8B , the lower surface corner 522 of the head 520 of the fastening bolt 501 is substantially in contact with the seating surface 531 to cause local tight contact and the fastening bolt 501 and the seating surface 531. A large displacement load is applied. Therefore, a strong force is required for screwing the fastening bolt 501, and further, when the fastening bolt 501 is tightened, local contact between the seating surface 531 and the lower surface corner portion 522 is caused to occur in the contacted portion. As a result, the tightening force of the fastening bolt 501 was not stable and was not sufficiently converted to an axial force. In addition, when the thickness of one end portion 503 forming the seat surface 531 is thin or when the fastening body 507 is formed of a soft material such as aluminum, the seat surface 531 is depressed (see FIG. 8 (b) in broken line K), tightening of the fastening bolt 501 may be weakened, and the fastening force of the shaft 505 may be insufficient.

Further, when the corner 522 of the lower surface of the head of the fastening bolt 501 comes into contact with the seat surface 531, a large bending stress is applied to the seat surface 531 and the fastening bolt 501. Therefore, when the fastener 507 during rotation of the shaft coupling is vibrated, the added further seating surface 531 and fastening bolts 501 loads due to vibrations, as a result, or generated on the seat surface 531 cracking V (see FIG. 8 (b)) is In addition, problems such as loosening of tightening of the fastening bolt 501 occur due to vibration.
In addition, when the slit is provided in two places and the fastening body is divided into two parts and tightened with two fastening bolts 501 (FIG. 1 of Patent Document 1), the fastening bolts 501 are evenly tightened. Is difficult in practice, and the same problem as described above may occur.
This invention implement | achieves the fastener by which the loosening of a fastening bolt is prevented and the fastening force with respect to a member is strengthened.

(1) The fastener according to the present invention is
A shaft hole portion through which the rotating shaft is inserted is provided at the center portion, a slit groove is provided in the axial direction, a bolt through hole having a seating surface is provided at one end portion facing the slit groove, and the other end portion is provided. A fastening body provided with a screw hole;
In a fastener including a fastening bolt that tightens the fastening body in a circumferential direction by screwing into a screw hole at the other end through a bolt through hole at one end of the fastening body.
The seat surface of the bolt through hole in the tightening body is a tapered seat surface formed in a tapered groove,
The fastening bolt includes a rod-shaped bolt main body having a male screw provided on the outer periphery thereof, and a head provided at an end of the bolt main body and having a larger diameter than the bolt main body and abutting against a seat surface of the bolt through hole. And
The lower surface of the head of the fastening bolt is formed into a tapered surface that is reduced in diameter toward the front end side of the bolt body, and this tapered surface is formed into a tapered curved surface with a curved surface finish that swells outward ,
In the fastening bolt, the tapered curved surface is in contact with the tapered seat surface all around even if the opposed end surfaces of the slit of the fastening body are inclined and the tapered seat surface of the bolt through hole is inclined. And screwed together.

As a result, even if the opposing end surface of the slit groove of the tightening body is inclined and the seat surface of the bolt through hole is inclined as the fastening bolt is tightened, the bottom surface of the head of the fastening bolt and the seat surface of the bolt through hole are Because of the tapers, local tight contact is prevented, and the displacement load during tightening is received by the tapered seat surface. Therefore, the displacement load and seizure acting on the seat surface during bolt tightening can be greatly reduced.
Further, when fixing the one end and the other end of the tightening body, even if the screw hole of the other end is inclined, or the fastening bolt itself is bent, The tapered curved surface of the lower surface of the head is appropriately slid on the tapered seating surface of the bolt through hole at the one end so that the posture of the bolt body is substantially coincident with the axial direction of the screw hole. Therefore, the screwing of the bolt main body is substantially coincident with the axial direction of the screw hole, and the fastening bolt can be allowed to enter concentrically with the screw hole. Therefore, even when the screw hole is inclined, the tapered curved surface of the fastening bolt is brought into contact with the tapered seat surface of the bolt through-hole at the time of bolt tightening, so that local one-side contact does not occur.

  Since seizure acting on the seating surface during tightening is greatly relieved, the tightening force of the fastening bolt can be stabilized and sufficiently converted to an axial force. Further, since the displacement load on the tapered seating surface is greatly relaxed, the strength of one end of the fastening body forming the tapered seating surface is improved, so that the one end can be thinned. Moreover, since the taper surface of the lower surface of the head of the fastening bolt is immersed in the tapered seat surface of the bolt through hole, the head of the fastening bolt can be deeply embedded in one end of the tightening body.

  On the other hand, when this fastener is used for a rotating body such as a shaft joint, the fastening bolt receives a centrifugal force during rotation. Then, since the taper surface of the lower surface of the head of the fastening bolt is taper-fitted with the taper seat surface of the bolt through hole, the taper surface of the head of the fastening bolt receiving the centrifugal force is tapered of the bolt through hole. A force in the pulling direction is applied when pressed against the seating surface. Accordingly, during rotation, the axial force due to the screwing of the male screw of the fastening bolt and the screw hole of the fastening body is amplified, and the fastening force of the fastening body with respect to the shaft is strengthened to increase the transmission torque. Can do.

( 2 ) The bolt through hole and the screw hole may be formed so that the fastening bolt is disposed on an outer side than an intermediate portion of the slit groove.
As a result, it is possible to increase the tightening force of the shaft by the tightening body by moving the tightening point of the shaft disposed in the central shaft hole portion away from the shaft center of the shaft. As a result, the torque transmitted to the shaft can be further increased. Can be improved.
In addition, when the fastener is used for a rotating body such as a shaft joint, the centrifugal force at the time of rotation described above acts greatly on the fastening bolt, and as a result, the axial force of the fastening bolt at the time of rotation is further amplified. The tightening force of the tightening body with respect to the shaft is further strengthened, and the reduction in transmission torque can be reduced.

( 3 ) The bolt through hole and the screw hole may be offset so that the center line of the bolt through hole is arranged outward with respect to the center line of the screw hole.
As a result, even if the first member and the second member are inclined as the fastening bolt is tightened, the posture of the fastening bolt is accommodated by the offset space. It is possible to make contact with the taper-shaped seating surface almost entirely without causing any trouble. Therefore, seizure acting on the seating surface during tightening is greatly relieved, so that the tightening force of the fastening bolt can be stabilized and sufficiently converted to an axial force.

( 4 ) The taper surface of the lower surface of the head of the fastening bolt may be coated with a stabilizer that reduces frictional resistance.
As a result, seizure acting on the seating surface during tightening is greatly relieved, so that the tightening force of the tightening bolt can be stably converted into an axial force.

According to the fastener according to the present invention, seizure and displacement load at the time of bolt tightening acting on the bearing surface of the bolt through hole in the tightening body are greatly reduced, so that the tightening force of the fastening bolt is stable and sufficient. Therefore, the fastening force can be sufficiently secured .

Embodiments of the present invention will be described below with reference to the accompanying drawings.
( Reference example )
As shown in FIG. 1A, the fastener includes a first member 3 provided with a bolt through hole 30 and a tapered seat surface 31, a second member 4 provided with a screw hole 40, and these members 3. , 4 are fastened with fastening bolts 1.
The fastening bolt 1 includes a rod-shaped bolt body 10 having a male screw 11 provided on the outer peripheral portion thereof, and a columnar head portion 20 provided at an end portion of the bolt body 10 and having a diameter larger than that of the bolt body 10. . The fastening bolt 1 is a hexagon socket head cap screw, and is provided with a hexagon socket (see FIG. 2) for fitting a hexagon wrench on the top surface of the head 20 and knurled on the side of the head 20. Has been. In addition, the lower surface of the head 20 is a tapered surface 21 having a diameter that decreases toward the tip of the bolt body 10 and a tapered curved surface 21 that is provided with a crowning (curved surface) that expands outward. The tapered curved surface 21 is brought into contact with a tapered seat surface 31 formed of a tapered groove formed in the bolt through hole 30.

  The taper angle θ1 of the taper curved surface 21 may be larger than the taper angle θ2 of the taper-shaped seat surface 31 serving as a seat surface as shown in FIG. 1A, or substantially equal to the taper angle θ2. It can be arbitrarily set. The curvature of the tapered curved surface 21 can be arbitrarily set. For example, in order to improve the slidability of the tapered curved surface 21 on the tapered seat surface 31, the size of the head 20 and the tapered curved surface 21 Although it depends on the length of the taper portion and the taper angle thereof, it is set to about 5R to 1200R.

The fastening bolt 1 is processed by a press or a lathe so that the lower half of the head 20 of an existing hexagon socket head bolt (for example, M6 size <head diameter φ10 mm>) becomes the tapered curved surface 21. Thus, the protrusion of the head 20 to the side is smaller than the countersunk screws of the same size, and the head 20 can be made compact.
The fastening bolt 1 is a hexagon socket head bolt having a head portion 20 in a columnar shape, but may be a hexagon bolt in which the head portion 20 is formed in a hexagonal column shape.

According to the fastening bolt 1, as shown in FIG. 1A, the first member 3 provided with the bolt through hole 30 and the tapered seat surface 31 and the second member 4 provided with the screw hole 40 are overlapped. Even when the screw hole 40 of the second member 4 is not perpendicular to the upper surface but inclined to the angle θ, the posture of the fastening bolt 1 (the screwing direction of the bolt body 10) is set to the second. The axial direction of the screw hole 40 of the member 4 can be substantially matched. That is, when the fastening bolt 1 is screwed, the tapered curved surface 21 on the lower surface of the head 20 is brought into contact with the tapered seat surface 31 of the first member 3 and appropriately slides on the tapered seat surface 31.
Thereby, the fastening bolt 1 can be made to approach concentrically with the screw hole 40 without difficulty. Therefore, even if the screw hole 40 of the second member 4 into which the fastening bolt 1 is screwed is inclined, a large displacement load is not applied to the fastening bolt 1 or the tapered seat surface 31, and the first member 3 and The second member 4 can be fixed without loosening.

Moreover, as shown in FIG.1 (b), this fastener may clamp the 1st member 3 and the 2nd member 4 by inserting | pinching the other member 5. As shown in FIG. In this case, even if the first member 3 and the second member 4 are inclined as the fastening bolt 1 is screwed in, the tapered curved surface 21 is the tapered seat as in the above case (FIG. 1A). By appropriately sliding on the surface 31, the posture of the fastening bolt 1 can be made to substantially coincide with the axial direction of the screw hole 40 of the second member 4. Therefore, even when the other member 5 is sandwiched between the first member 3 and the second member 4 and fastened, the fastening bolt 1 can be allowed to enter concentrically with the screw hole 40 without difficulty. A large displacement load is not applied to the fastening bolt 1 or the tapered seat surface 31, and the first member 3 and the second member 4 can be fixed without loosening with the member 5 interposed therebetween.
In addition, the fastening bolt 1 has a small surface pressure and can be easily screwed because the tapered curved surface 21 of the head 20 and the tapered seating surface 31 of the first member 3 are substantially in line contact with each other. That is, the screwing torque efficiency of the fastening bolt is good.

Also, the conventional fastening bolts 501 (FIG. 8 (a), the FIG. 8 (b)) in, when screwing is completed, the lower surface of the bolt head 520 is only contact with the seating surface 531, the fastening bolt 1 When the screwing of the fastening bolt 1 is completed, the taper curved surface 21 of the fastening bolt 1 and the taper-shaped seat surface 31 of the first member 3 are taper-fitted. Is done.
Moreover, even when the fastening bolt 1 is screwed into the inclined screw hole 40, the contact position of the tapered curved surface 21 on the tapered seat surface 31 is substantially the same height on the entire circumference (in FIG. 1A). 1, the symbol h in FIG. 1B, and the taper fitting force acts evenly at substantially the same height position h of the head 20. Therefore, the above-described loosening prevention effect is reliably exhibited, and a strong fastening force between the members 3 and 4 can be reliably exhibited.

  When the taper angle θ1 of the tapered curved surface 21 in the fastening bolt 1 is larger than the taper angle θ2 of the tapered seat surface 31 of the first member 3, the contact position h of the tapered curved surface 21 on the tapered seat surface 31 is high. And approaches the upper surface side of the head 20 (the contact position h in FIG. 1A is higher than the contact position h in FIG. 1B). Thereby, since the head 20 of the fastening bolt 1 is taper-fitted at the thick portion of the tapered seat surface 31, the taper fitting force between the fastening bolt 1 and the taper seat surface 31 can be increased. Therefore, the above-described loosening prevention effect is remarkably exhibited, and a strong fastening force between the members 3 and 4 is reliably exhibited. Thereby, even when the material of the 1st member 3 is brittle like aluminum die-casting, since the intensity | strength of the seating surface 31 is strengthened, the effect which becomes difficult to damage is also acquired.

On the other hand, the fastening bolt 1 is such that the tapered bearing surface 31 of the first member 3 has an acute angle (the taper angle θ2 is a small angle with respect to the axis of the bolt through hole 30, for example, 90 degrees or less). Since the direction of the taper fitting force between the taper curved surface 21 and the taper seat surface 31 approaches the direction perpendicular to the axis of the fastening bolt 1, the above-described loosening prevention effect and strong fastening are further exerted. Can be made.
In the example shown in FIG. 1 described above, the screw hole 40 of the second member 4 is described as being inclined. However, although the screw hole 40 is formed at a substantially right angle without being inclined, the head of the fastening bolt 1 itself. Even when the portion 20 and the bolt main body 10 are bent, the tapered curved surface 21 of the bent fastening bolt 1 is slid appropriately on the tapered seat surface 31 in the same manner as described above. 10 can be made to substantially coincide with the axial direction of the screw hole 40 of the second member 4. Therefore, even such a bent fastening bolt 1 can be forced to enter concentrically with the screw hole 40 and a large displacement load is not applied to the tapered seat surface 31 or the fastening bolt 1. The first member 3 and the second member 4 can be fixed without difficulty.

( Embodiment )
The embodiment is a shaft coupling as a fastener according to the present invention.
As shown in FIG. 2, this shaft coupling 6 is obtained by connecting two C-shaped tightening bodies 7 provided with a slit groove 72 reaching a central shaft hole 71 by a leaf spring intermediate body 8. It is. In the two tightening bodies 7, a shaft 5 a serving as a drive shaft is disposed on one tightening body 7, and a shaft 5 a serving as a driven shaft is disposed on the other tightening body 7. Thus, the two shafts 5a and 5a are connected by the shaft coupling 6.
As shown in FIG. 3A, the tightening body 7 is provided with a bolt through hole 30 at one end 3a (first member 3) facing the slit groove 72 and the other end. The part 4a (second member 4) is provided with a screw hole 40a into which the fastening bolt 1 is screwed. Further, the bolt through hole 30a is provided with a tapered seat surface 31a which is a tapered groove having an enlarged diameter on the inlet side. The tapered seat surface 31a contacts the tapered curved surface 21 of the fastening bolt 1 all around. Then, the fastening bolt 1 is threaded into the screw hole 40a of the other end 4a through the bolt through hole 30a of the one end 3a of the fastening body 7.

When the shaft 5 a is fastened to the shaft joint 6, the shaft 5 a is inserted into the shaft hole portion 71 of the tightening body 7 and then the fastening bolt 1 attached to the tightening body 7 is screwed. Then, the lower surface of the head 20 which becomes the tapered curved surface 21 in the fastening bolt 1 presses the tapered seat surface 31a formed in the bolt through hole 30a of the tightening body 7, and the space between the slits 72 is reduced. The diameter of the hole 71 is reduced, and the shaft 5a is firmly fastened by the surface pressure due to the reduced diameter.
At this time, as shown in FIG. 3B, the opposing ends 3a and 4a of the slit groove 72 are inclined, but the taper curved surface 21 of the fastening bolt 1 is tapered at one end 3a. By sliding appropriately on the seating surface 31a, the posture of the fastening bolt 1 substantially coincides with the axial direction of the screw hole 40a, and the fastening bolt 1 can be forced to enter concentrically with the screw hole 40a. . Therefore, no displacement load is applied to the fastening bolt 1 or the tapered seat surface 31a, and the fastening bolt 1 can be screwed in smoothly without requiring a strong force (a large fastening torque).

  Even if the opposing end surface of the slit groove 72 of the tightening body 7 is inclined and the tapered seat surface 31a of the bolt through hole 30a is inclined as the fastening bolt 1 is tightened, the tapered curved surface 21 of the fastening bolt 1 and the bolt Since the tapered seating surface 31a of the through-hole 31a is tapered, local tight contact is prevented, and the displacement load during tightening is received by the tapered seating surface 31a. Therefore, the displacement load and seizure that act on the tapered seating surface 31a during bolt tightening can be greatly reduced. Since seizure acting on the tapered seat surface 31a during tightening is greatly relieved, the tightening force of the fastening bolt 1 can be stabilized and sufficiently converted to an axial force.

Further, even after tightening is completed, no displacement load is applied to the fastening bolt 1 or the tapered seat surface 31a, and the taper curved surface 21 of the fastening bolt 1 presses the entire circumference of the tapered seat surface 31a. It becomes a state. As a result, as in the conventional case shown in FIG. 8B , the fastening of the fastening bolt is weakened by the depression of the seating surface, and the shaft can be firmly fixed without impairing the fastening force of the shaft. It is also possible to prevent the fastening bolt 1 from loosening due to the accompanying vibration. In addition, since a state in which stress is applied to the tapered seat surface 31a and the fastening bolt 1 is avoided, the taper seat surface 31a is cracked (see FIG. 8) even if a further load is applied due to vibration caused when the shaft joint 6 rotates. (B) can be prevented, and the fastening bolt 1 can be broken. Therefore, the strong fastening of the shaft 5a by the fastening body 7 can be stably maintained over a long period of time.

  On the other hand, the fastening bolt 1 receives centrifugal force when the shaft coupling 6 rotates. Then, since the taper curved surface 21 on the lower surface of the head 20 is taper-fitted to the taper seat surface 31a of the bolt through hole 30a, the fastening bolt 1 receives the centrifugal force and the taper curved surface of the head 20 21 is pressed against the tapered seat surface 31a of the bolt through hole 30a, and a force in the pulling direction acts. Accordingly, during rotation, the axial force due to the screwing of the male screw 11 of the fastening bolt 1 and the screw hole 40a of the fastening body 7 is amplified, and the fastening force of the fastening body 7 with respect to the shaft 5a is strengthened. The transmission torque can be increased.

(Other embodiments)
(1) As for the shaft coupling as the fastener of the present invention, for example, as in the shaft coupling 6a shown in FIG. 4 (a), the fastening body 7a is provided with two slits 72a and 72b at 180 degrees. The present invention may be applied to a semi-circular divided piece that is divided into two. In this case, one divided piece of the fastening body 7a divided into two includes one end 3a (first member 3) or the other end 4a (second member 4).
Further, like the shaft coupling 6b shown in FIG. 4 (b), the tightening body 7b is formed of a semicircular divided piece that is divided into two by providing two slit grooves 72a and 72b at 180 degrees. You may apply to things. In this case, one divided piece of the fastening body 7b divided into two includes both one end 3a (first member 3) and the other end 4a (second member 4). Accordingly, this is advantageous in manufacturing because the pair of divided pieces to be the fastening body 7b have the same structure.

(2) Further, as the shaft coupling of the present invention, the intermediate connecting two fastening members is not limited to the leaf spring intermediate 8 shown FIG 2, as shown in FIG. 5, provided with a central hole 81 The block intermediate body 8a may be integrally formed with the two fastening bodies 7 ′ and 7 ′.

(3) Further, as the fastening bolt according to the present invention, as the fastening bolt 1d shown in FIG. 6 may be those corners 22 of the head 20d upper surface is formed in an R shape, also, the corner portion 22 It may be chamfered. Thus, by forming the corner portion 22 on the upper surface of the head 20d of the fastening bolt 1d in an R shape or the like, coupled with the immersion of the head 20d of the fastening bolt 1d into the tapered seat surface 31d of the bolt through hole 30d. Furthermore, it can suppress that the head 20d protrudes from the outer peripheral surface of the fastening body 7d.

(4) Further, as shown in FIG. 6 , the shaft coupling of the present invention has the above bolt penetration so that the fastening bolt 1 d is disposed on the outer side of the intermediate line 720 (intermediate portion) of the slit groove 72. The hole 30d and the screw hole 40d may be formed. Even in this case, the head portion 20d of the fastening bolt can be disposed in the bolt through hole 30d without projecting to the outer periphery due to the taper shape or the like.
Accordingly, it is possible to increase the tightening force of the shaft 5d by the tightening body 7d by moving the tightening point of the shaft 5d disposed in the central shaft hole portion 71 away from the shaft core of the shaft 5d, and as a result, the shaft 5d. This is advantageous in that the transmission torque to the can be further improved.
In addition, the centrifugal force at the time of rotation of the shaft coupling is greatly exerted by the fastening bolt 1d, and as a result, the axial force of the fastening bolt 1d at the time of rotation is further amplified, so that the fastening force of the fastening body 7d with respect to the shaft 5d Is further strengthened, and the transmission torque can be further increased.

(5) Also, as shown in FIG. 7 (a), as the tightening body 7e, the bolts are arranged such that the center line 300 of the bolt through hole 30e is disposed outward from the center line 400 of the screw hole 40e. The through hole 30e and the screw hole 40e may be offset.
Thus, even if the opposing ends 3e, 4e (first member 3e and second member 4e) of the slit groove 72 are inclined as the fastening bolt 1a is tightened, the posture of the fastening bolt 1a by the amount of the offset space described above. Therefore, the tapered curved surface 21a on the lower surface of the head 20a of the fastening bolt 1a can be brought into contact with the tapered seat surface 31e almost entirely without causing a single contact. Therefore, seizure and displacement load on the tapered seating surface 31e during tightening are greatly relieved, so that the tightening force of the tightening bolt 1a can be stabilized and sufficiently converted to an axial force.

(6) Moreover, the stabilizers which reduce frictional resistance may be coated on the lower surfaces ( tapered curved surfaces 21, 21a ) of the heads 20, 20a of the fastening bolts 1, 1a. As a result, seizure acting on the tapered seating surface 31 during tightening is greatly relieved, so that the tightening force of the tightening bolts 1 and 1a can be stabilized and sufficiently converted to an axial force. In addition, the said stabilizer may be coated entirely including not only the lower surface of the heads 20 and 20a of the fastening bolts 1 and 1a but also the male screw 11 portion. Examples of the stabilizer include n-butene, isobutene, a single polymer or copolymer of these, and the like. More specifically, examples of the polyisobutylene include a trade name “Glossopal” and a trade name “Opanol” manufactured by BASF, and examples of a polymer of isobutene and n-butene (polybutene) include, for example, Nippon Oil. Trade names “Tetrax”, “High Mall”, “Evertac”, “Nisseki Polybutene”, “SV-7000” manufactured by Kagaku Co., Ltd., “VISTANEX” manufactured by Exxon, Idemitsu Petrochemical ( The product name “Idemitsu Polybutene” manufactured by Nihon Yushi Co., Ltd., the product name “Polyvis” manufactured by Nippon Oil & Fats Co., Ltd., the product name “Indopol” manufactured by Amoco, the product name “Napvis” manufactured by BP, and the like.

(7) In addition, the fastener of the present invention is not limited to a shaft coupling, but is a piping joint for connecting two pipes, or a collar for attaching a sensor or the like to other members such as columns, frames, and shafts. In addition, the present invention can be applied to various fasteners including the first member 3 and the second member 4 that are integrally formed or separately formed.

(Example)
Lower surface fastening bolts of the tapered curved surface of the bolt head as Examples 1 to 3 using a (fastening bolt 1 in FIG. 1 (a)), these clamping body is sandwiched shaft by a fastening bolt The transmission torque when tightened was measured. Here, the transmission torque means that after the fastening bolt is tightened with a predetermined tightening torque, the shaft is fixed so as not to rotate, and the tightening body rotates when a load is applied in the rotational direction. The torque value at the beginning.
In Example 1, the fastening bolts, used as a size head size is M5 (head diameter 8.5 mm), the clamping body, the C-ring type shown in FIG. 3 (a) clamping The appendage 7 was used.

Example 2 is the same as Example 1 except that a fastening bolt having a head size of M6 (head diameter: 10 mm) is used.
Example 3, the fastening bolts, used as a size M6 head size (10mm the head diameter), the clamping body, a pair of semicircular split pieces shown in FIG. 4 (a) The tightened body 7a was used. Thus, in this third embodiment, the fastening bolts are used two.
In the fastening bolts used in Examples 1 to 3, the curvature of the tapered curved surface on the lower surface of the head is 7R for the fastening bolt of Example 1 of the M5 size, and each fastening of the Examples 2 and 3 of the M6 size. The bolt is 8R.

On the other hand, as Comparative Examples 1 to 3, the fastening bolt, using a fastening bolt 501 which shows the structure in Figure 8 (b).
In Comparative Example 1, the head size of the fastening bolt is M5 size (head diameter is 8.5 mm), and the fastening body is of the C ring type shown in FIG. This Comparative Example 1 corresponds to Example 1 .
In Comparative Example 2, the head size of the fastening bolt is M6 size (head diameter is 10 mm), and the fastening body is of the C ring type shown in FIG. This Comparative Example 2 corresponds to Example 2 .

In Comparative Example 3, the head size of the fastening bolts in M6 size (10mm the head diameter), the clamping body with clamping member 7a that a pair of semicircular split pieces shown in FIG. 4 (a) . Therefore, in this comparative example 3, two fastening bolts are used. This Comparative Example 3 corresponds to Example 3 .
The material of the fastening member and the fastening bolt, Example 1-3, any of Comparative Examples 1 to 3, a steel.
Then, in Comparative Example 1 and Contact Example 1, tightened by the force of the fastening bolt tightening torque 7.6N · m. In Example 2, 3 Contact and Comparative Examples 2 and 3, clamping the two fastening bolts with a force of tightening torque 13.4 N · m, respectively.

  Next, after tightening the fastening bolt, the shaft is fixed so as not to rotate, a force in the rotational direction is applied to the tightening body, and the torque value (transmission torque) is measured when the tightening body starts to rotate. . The measurement results are shown in Table 1.

From Table 1, in the transmission torque value, each of Examples 1 to 3 is larger at a ratio of about 50% to 90% than Comparative Examples 1 to 3 to which each corresponds .
Therefore, according to the fastening bolt of the tapered curved surface used in Examples 1-3, the head lower surface conventional fastening bolt of the flat surface shape as compared with the (FIG. 8 (b)), strongly fastening the shaft It can be seen that the transmission torque can be increased.

It is a side view which shows the structure of the fastener by a reference example . It is a side view which shows the whole structure of the shaft coupling as a fastener by embodiment . It is a partial cross section figure which shows the structure of the shaft coupling in embodiment . It is sectional drawing which shows the other example of the shaft coupling in embodiment . It is a side view which shows the further another example of the shaft coupling in embodiment . It is sectional drawing which shows the structure of the shaft coupling as a fastener by other embodiment. It is sectional drawing which shows the structure of the shaft coupling as a fastener by other embodiment. It is a partial cross section figure which shows the structure of the shaft coupling as a conventional fastener.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fastening bolt 3 1st member 3a One edge part (1st member)
4 Second member 4a The other end (second member)
5 Other member 5a Shaft (other member)
6 Shaft joint 7 Fastening body 10 Bolt body 11 Male screw 20 Head 21 Tapered curved surface 31, 31a Tapered seat surface 30, 30a Bolt through hole 40, 40a Screw hole 72 Slot groove h Tapered curved surface at tapered seat surface Contact position height

Claims (4)

A shaft hole portion through which the rotating shaft is inserted is provided at the center portion, a slit groove is provided in the axial direction, a bolt through hole having a seating surface is provided at one end portion facing the slit groove, and the other end portion is provided. A fastening body provided with a screw hole;
In a fastener including a fastening bolt that tightens the fastening body in a circumferential direction by screwing into a screw hole at the other end through a bolt through hole at one end of the fastening body.
The seat surface of the bolt through hole in the tightening body is a tapered seat surface formed in a tapered groove,
The fastening bolt includes a rod-shaped bolt main body having a male screw provided on the outer periphery thereof, and a head provided at an end of the bolt main body and having a larger diameter than the bolt main body and abutting against a seat surface of the bolt through hole. And
The lower surface of the head of the fastening bolt is formed into a tapered surface that is reduced in diameter toward the front end side of the bolt body, and this tapered surface is formed into a tapered curved surface with a curved surface finish that swells outward ,
In the fastening bolt, the tapered curved surface is in contact with the tapered seat surface all around even if the opposed end surfaces of the slit of the fastening body are inclined and the tapered seat surface of the bolt through hole is inclined. Fasteners that are screwed together. The fastener according to claim 1,
The fastener, wherein the bolt through hole and the screw hole are formed so that the fastening bolt is disposed on an outer side than an intermediate portion of the slit groove. The fastener according to claim 1 or 2,
The fastener, wherein the bolt through hole and the screw hole are offset so that a center line of the bolt through hole is arranged outward with respect to a center line of the screw hole. The fastener according to any one of claims 1 to 3,
The fastener according to claim 1, wherein a tapered surface of the lower surface of the head of the fastening bolt is coated with a stabilizer for reducing frictional resistance.

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