Coupler for deformed reinforcement using screw node reinforcement

Abstract

To provide a coupler for a deformed reinforcement using a screw node reinforcement which dispenses with the management of a filling state, the management of injection viscosity, the management of industrial wastes remaining after construction, etc., without filling grout between tooth surfaces.SOLUTION: A coupler 10 is provided with a main cylinder 11 to which the end part of one reinforcement 4L is friction-welded and a sub-cylinder 12 screwed to the anti-friction-welded side of the bag hole 5H bored along the axis of the main cylinder 11. A bag hole female screw 5F to which a screw node 4T of the other reinforcement 4R is screwed is formed on the friction pressure contact side of the bag hole 5H, and an enlarged diameter female screw 9F formed larger in diameter than the bag hole female screw 5F and having a different pitch is provided on the anti-friction pressure contact side of the bag hole 5H. The sub-cylinder 12 is provided with a sleeve part 8 having a sleeve part male screw 8M screwed to the enlarged diameter female screw 9F, and a nut part 13 coaxial with the sleeve part 8 and integrally formed at the end of the sleeve part 8.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a coupler for deformed reinforcing bars that utilizes threaded reinforcing bars, and more particularly to a fastening coupler in which the end of one opposing reinforcing bar is friction-welded and the other reinforcing bar is inserted into the coupler, thereby preventing loosening between the reinforcing bar and the coupler and forming an enlarged reinforcing bar that transmits axial force. [Background technology]

[0002] When constructing buildings and civil engineering structures with reinforced concrete, the deformed bars (threaded bars, bamboo-knotted bars, etc.) used as concrete reinforcement are manufactured to a standard length, for example 12 meters, to allow for ease of transportation from the factory to the construction site.

[0003] However, when used, they are often extended at the construction site to suit the size of the building to which they are applied and the length of the area to which they are applied. Both screw knot rebars and bamboo knot rebars are gradually deformed and shaped by the caliber formed on the roll surface during the rolling process, but the rolls become rough and worn, albeit slightly. Although the roughness can be removed by surface grinding to allow for continued use, the diameter of the rolling rolls inevitably decreases, and the knot pitch differs slightly depending on the time of manufacture. The tooth profile formed in the coupler's connection hole is formed to match the screw knot pitch of the standard dimensions of the rebar, but with a slightly wider pitch to take into account the forming tolerance of the rebar. Therefore, although the coupler and rebar can be engaged by absorbing the difference in thread pitch, it is unavoidable that some gaps will remain when they engage.

[0004] The gap between the tooth surfaces is filled with grout (e.g., mortar) to prevent rattle, or a small screw is inserted from the outside of the coupler toward the surface of the rebar to prevent it from coming loose. Examples of the former are proposed in Patent Document 1, U.S. Patent No. 4,666,326, and Patent Document 2, JP 2018-178,365, while examples of the latter are proposed in Patent Document 3, U.S. Patent No. 5,046,878, and Patent Document 4, U.S. Patent No. 7,107,735. In both cases, the length of the coupler is increased and the fastening load is increased in order to ensure perfect fastening, so the appearance of a coupler that is easy to manage torque (realization at low torque and uniform fastening force) and that is effective in preventing rattle and coming loose is eagerly awaited.

[0005] Furthermore, there are cases where the thickness of the rebar needs to be gradually reduced or increased depending on the application area of ​​the building, or when deformed rebar needs to be changed from screw joints to bamboo joints. There are also cases where it is necessary to apply it to joints. This is because it is possible to reduce the amount of rebar used and promote the use of stock. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 4,666,326 [Patent Document 2] Patent Publication 2018-178365 [Patent Document 3] U.S. Patent No. 5,046,878 [Patent Document 4] U.S. Patent No. 7,107,735 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been developed in consideration of the above circumstances, and its object is to provide a coupler for deformed reinforcing bars that uses threaded reinforcing bars, which does not necessarily require the introduction of grout or thread locking agents into the coupler, but instead utilizes the creaking of the screw threads to make the components as small as possible, ensure fastening, and reduce the operating force. [Means for solving the problem]

[0008] The coupler for deformed reinforcing bars using threaded reinforcing bars of the present invention is applied to couplers that join the ends of opposing reinforcing bars to form an expanded reinforcing bar that transmits axial force, as shown in Fig. 1(a). Its features are as follows. The coupler 10 comprises a main cylinder 11 to which the end of one reinforcing bar 4L is friction-welded, and a secondary cylinder 12 that is screwed into the anti-friction-welded side of a pocket hole 5H drilled along the axis of the main cylinder. A pocket hole female thread 5F is formed on the friction welding side of the pocket hole 5H, into which the tip portion of the screw joint 4T of the other reinforcing bar 4R is screwed, and an enlarged diameter female thread 9F is provided on the anti-friction welding side of the pocket hole, which is concentric with the pocket hole female thread 5F but has a larger diameter than the pocket hole female thread 5F. The secondary cylinder 12 is provided with a sleeve portion 8 having a sleeve portion male thread 8M that screws into the expanding female thread 9F, and a nut portion 13 that is coaxial with the sleeve portion and is integrally formed at the end of the sleeve portion, the expanding female thread 9F is formed with a pitch different from the pitch of the thread joint 4T of the other reinforcing bar 4R, and the nut portion 13 is formed with a nut portion female thread 13F that screws into the thread joint 4T of the other reinforcing bar 4R and has the same pitch and phase as the pocket hole female thread 5F. The sleeve hole 8H of the sleeve portion 8 is formed with a sleeve portion female thread 8F that has the same pitch and phase as the nut portion female thread 13F.

[0009] In another invention, as shown in FIG. 18(b), a coupler 10X includes a main tube 11X to which an end of one reinforcing bar 4L is frictionally welded, and a secondary tube 12X that is screwed onto the outside of the main tube on the opposite side of the frictional weld. On the frictional weld side of a pocket hole 5H drilled along the axis of the main tube 11X, there is a pocket hole female thread 5F into which the tip of the screw joint 4T of the other reinforcing bar 4R is screwed. On the opposite side of the outer circumferential surface of the main tube 11X, there is an enlarged male thread 9M that is concentric with the pocket hole female thread 5F but has a larger diameter than the pocket hole female thread. The secondary cylinder 12X is provided with a sleeve portion 8X having a sleeve portion female thread 8FX that screws into the expanding male thread, and a nut portion 13 that is coaxial with the sleeve portion and is integrally formed at the end of the sleeve portion, the expanding male thread 9M is formed with a pitch different from the pitch of the thread of the other reinforcing bar 4R, and the nut portion 13 is formed with a nut portion female thread 13F that screws into the thread of the other reinforcing bar and has the same pitch and phase as the pocket hole female thread 5F. And, the sleeve hole 8H of the sleeve portion 8X is formed with a sleeve portion female thread 8FX that has the same pitch and phase as the nut portion female thread 13F.

[0010] Although it is not clear, as shown in FIG. 1(a) and FIG. 18(b), the enlarged female screw 9F or the enlarged male screw 9M has a pitch P of the thread joint 4R of the other reinforcing bar. 4 Larger pitch P 9F Or pitch P 9M is formed.

[0011] Alternatively, the enlarged female screw 9F or the enlarged male screw 9M has a pitch P of the thread joint 4R of the other reinforcing bar. 4 Smaller pitch P 9F Or pitch P 9M is formed.

[0012] As shown in Figures 3 and 16, the outer surface of the outer barrel of the cap screw 5 of the main cylinder 11 is formed with reaction force relief surfaces 11C and 11E at any location in the longitudinal direction, which serve to reduce reaction force when a desired torque is applied to the nut portion 13.

[0013] As shown in FIG. 9, the main cylinder is formed with a slit 15 extending in the longitudinal direction through which the tip position of the inserted rebar 4R can be seen.

[0014] At a position opposite to the slit 15, a slit 16 having substantially the same shape is formed in the main cylinder 11.

[0015] As shown in FIG. 13(b), the reinforcing bar to be friction welded may be a deformed reinforcing bar other than a screw joint, for example a bamboo joint reinforcing bar. Effect of the Invention

[0016] According to the present invention, it is possible to suppress the increase in the length of the coupler and the increase in the fastening load in order to ensure perfect fastening. Therefore, the burden of torque management, which is effective in preventing rattling and slipping out, is reduced. Furthermore, it is possible to gradually reduce and increase the diameter of the rebar depending on the application location of the building, and to change the deformed rebar from a screw joint to a bamboo joint, thereby reducing the amount of rebar used and promoting the use of stock. Rebar 4R, which is much longer than the coupler, can be screwed into the coupler with a light turn, and it can be firmly joined and locked with only a light turn of the secondary tube, which is much shorter than the rebar and easier to handle, and then a strong overturn. The structure of the coupler makes it ideal for application to joint construction.

[0017] The expanded female thread or expanded male thread has a pitch that is larger or smaller than the pitch of the thread of the reinforcing bar, and this pitch difference creates a large frictional force acting on the surface of the thread due to the surface contact pressure of the thread, resulting in a strong fastening due to the creaking between the threads.

[0018] If a reaction force relief surface is formed on the outer surface of the main cylinder, it becomes easy to remove the reaction force when a desired torque is applied to the nut portion.

[0019] If a slit is formed in the main cylinder that extends in the longitudinal direction, the position of the tip of the inserted rebar can be confirmed. If a slit of approximately the same shape is formed at the opposite location to this slit, it can be seen through, making it easier to confirm the position of the tip of the inserted rebar. [Brief description of the drawings]

[0020] [Figure 1] This is a vertical cross-sectional view and an overall outline drawing of the state in which the secondary cylinder is moved to the left in the latter half of the reinforcing bar fastening procedure using a reinforcing bar coupler in accordance with the present invention when P9F = P4 + 2 mm. [Diagram 2] 1 is a perspective view of the end of a threaded reinforcing bar before and after friction welding. FIG. [Diagram 3] FIG. [Figure 4]FIG. [Diagram 5] Layout diagram of coupler components in the initial stage of fastening. [Figure 6] A cross-sectional view of a main cylinder with a secondary cylinder attached to it with steel bars screwed in place. [Figure 7] A diagram of measures to prevent rotational misalignment of the main and secondary cylinders before the rebar tightening procedure. [Figure 8] A process diagram of the first half of the reinforcing bar fastening procedure using a reinforcing bar coupler after the sleeve body has been removed. [Figure 9] FIG. 4 is an overall perspective view of a coupler including a main tube showing the position of the slits. [Figure 10] FIG. 11 is an explanatory diagram showing the position and size of a paint mark. [Figure 11] An external view of the coupler used to check the end of the rebar. [Figure 12] A cross-sectional view showing the procedure for screwing the secondary cylinder onto the main cylinder. [Figure 13] Another design drawing that uses a main cylinder made of steel bars of different diameters and types friction welded together. [Figure 14] Fastening procedure and outline drawing after the procedure is completed (enlargement). [Figure 15] Outline drawing of another example after procedure completion (enlargement). [Figure 16] An external view of a coupler including a main barrel with a polyhedral central body. [Figure 17] Right-hand longitudinal section and outline drawing of the secondary tube for the latter stage of the rebar fastening procedure. [Figure 18] A diagram of the first half of the rebar fastening procedure using couplers with different secondary tubes. [Figure 19] A longitudinal cross-sectional view and an overall outline drawing of the state in which the secondary tube is moved to the left in the latter half of the rebar fastening procedure using a coupler with a different secondary tube. [Figure 20] A longitudinal cross-sectional view and an overall outline drawing of the state in which the secondary tube is moved to the right in the latter half of the rebar fastening procedure using a coupler with a different secondary tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The coupler for deformed reinforcing bars using threaded reinforcing bars according to the present invention will be described in detail below with reference to the drawings showing the embodiment. The coupler itself is used to fasten opposing threaded reinforcing bars 4L, 4R according to the part of the building as shown in FIG. 1(a). That is, whether grout is used or not, the reinforcing bars are firmly joined by utilizing the creaking of the threads described below. Of course, the coupler is intended to be applied to threaded reinforcing bars, but since it is also intended for friction-welded reinforcing bars, the reinforcing bars to be friction-welded are not limited to threaded reinforcing bars, and may be bamboo-shaped reinforcing bars described below that do not exhibit screw behavior.

[0022] The coupler 10 shown in Fig. 1(a) and (b) which joins the ends of two opposing rebars 4L and 4R prevents loosening of the threads of the rebar 4 and realizes an enlarged rebar that transmits axial force. This coupler 10 is equipped with a main tube 11 to which the end of one rebar 4L is friction-welded, and a secondary tube 12 which is screwed into the main tube 11 on the opposite side of the friction-welded side of a blind hole 5H formed along the axis of the main tube 11. Therefore, the coupler 10 brought to the construction site is a simple one consisting of two components: a component (main tube 11 with rebar) already integrated with the rebar 4L, and another component (secondary tube 12) independent of the other rebar 4R. Both are rigid bodies made of metal, but the main tube 11 and secondary tube 12 are basically cast products for reasons that will be described later.

[0023] On the friction welded side of the pocket hole 5H, the thread joint 4T (pitch P) of the other reinforcing bar 4R is 4 The same applies below.) is screwed into the female thread 5F (pitch P 5 =P 4 ) is formed, and on the opposite side of the pocket hole 5H to the friction welding side, it is concentric with the pocket hole female thread 5F, but is formed with a larger diameter (expanded diameter) than the pocket hole female thread 5F, and the pitch is P 5 Pitch P 9F (=P 4 +2mm ミリメートル It is equipped with an enlarged female screw 9F (set to 9F).

[0024] The secondary cylinder 12 is provided with a sleeve portion 8 having a sleeve portion male thread 8M that screws into the enlarged female thread 9F, and a nut portion 13 that is coaxial with the sleeve portion 8 and is integrally formed at the end of the sleeve portion 8. The sleeve portion male thread 8M is engaged with the enlarged female thread 9F, so that the pitch P 8M (=P 9F ) and the nut portion 13 is provided with a pitch P of the female screw 5F of the pocket hole, to which the threaded joint 4T of the reinforcing bar 4R is screwed. 5 The nut portion has a female thread 13F that is in phase with the nut portion 13F (pitch P 13F =P 5 The sleeve hole 8H of the sleeve portion 8 also has a sleeve portion female thread 8F (pitch P 8F =P 13F As shown in FIG. 1(a), the sleeve hole female thread 8F may be connected to the nut part female thread 13F. 4 =P 5 =P 8F =P 13F , P 8M =P 9F =P 4 +2mm (2mm is an example).

[0025] The end of the rebar is the cut edge shown in Fig. 2(b), but the welded portion of the rebar that was the subject of friction welding has a roughly hollow ring-shaped burr 1 as shown in Fig. 2(a). The welded portion of the main cylinder 11 also has a roughly hollow ring-shaped burr 2 as shown in Fig. 1(a), but it is generally small.

[0026] The main cylinder 11 is a cylinder with an external diameter, for example, about 1.5 times that of the rebar, as shown in Fig. 3, and the external shape of the left body 11C, which is a part of it, forms a polygonal (hexagonal in the figure) facet for taking counter torque, making it easy to apply torque with a wrench (not shown) hooked on the polygonal (hexagonal in the figure) facet formed on the nut part 13 of the secondary cylinder 12, the external view of which is shown in Fig. 4. Incidentally, the length of the coupler formed by applying the secondary cylinder 12 to the main cylinder 11 requires at least 4 to 6 pitches of meshing at one point when targeting, for example, a rebar 4R of D35 (nominal diameter approximately 35 mm), and the total dimension when the main cylinder 11 and secondary cylinder 12 of this coupler are combined (meshed) is at most about 200 mm.

[0027] Before describing the joining operation of the rebars, we will briefly introduce the friction welding that is performed beforehand, although it is well known. This coupler is different from the type that butts the ends of the opposing rebars inside a cylinder and fastens them with a large number of locking screws (for example, U.S. Patent No. 5,046,878 mentioned in the prior art section). Instead, the butt joint between the main cylinder 11 and the rebar 4L is pressed against each other at the joint and the heat generated by the relative high-speed rotation is used to crimp the contact parts. Since this cannot be done at the construction site, it is done before shipping based on the building design documents (drawings) at a factory with well-equipped facilities after the rebars are manufactured. In this way, the rebar 4R, which is much longer than the coupler, can be screwed into the coupler with a light rotation at the construction site, and only the secondary cylinder 12, which is much shorter than the rebar and easier to handle, can be firmly joined and locked with only a light rotation and then a strong over-rotation, which will be described later.

[0028] Incidentally, the pocket hole female thread 5F and the nut part female thread 13F are usually right-hand threads, but they are provided with a sufficient number of threads (for example, 4 to 6) for the meshing with the threads 4T of the reinforcing bar 4R (for example, the pocket hole female thread 5F in Figure 1(a) is drawn with only three threads to avoid making it too long horizontally for the convenience of creating the drawing), so there is no shortage of meshing threads even when a specified axial force is applied.

[0029] As shown in Fig. 5(c) and (d) following Fig. 5(a) and (b), the secondary tube 12 is placed against the main tube 11 to which the reinforcing bar 4L is frictionally welded, and as shown in Fig. 10 below, the paint mark 3 applied in advance for temporary setting is used as a guide, and at this point the blind hole female thread 5F, the sleeve part female thread 8F, and the nut part female thread 13F become a series of right-handed threads that are concentric and have the same pitch and phase (see Fig. 5(c) in particular), so that by rotating the main tube 11 to which the reinforcing bar 4L is welded or the reinforcing bar 4R, the reinforcing bar 4R with a right-handed thread joint can be easily screwed into the coupler (see Fig. 6). Note that if a phase shift occurs between the main tube and the secondary tube during the rotation (threading) of the reinforcing bar 4R or the main tube 11, and the threading of the reinforcing bar 4R is hindered, a rotational slippage prevention sleeve body, which will be described next, can be used. This is a sleeve body 7 having a hexagonal hole portion 11D and a circular hole portion 6 connected together as shown in Figures 7(a) and (b), which is stored on the reinforcing bar 4R and is then placed over the round body portion of the main tube 11 and the nut portion 13 of the secondary tube 12, and unexpected movement can be prevented by driving a locking screw 7a into the round body portion.

[0030] In applying the paint mark 3 (see FIG. 10), the number of unmeshed threads of the sleeve portion male thread 8M of the sleeve portion 8 and the expanded female thread 9F on the side opposite to the frictional pressure welding side of the pocket hole 5H is set to 2 or 3, allowing for at least one pitch of rightward or leftward movement of the secondary tube 12. In other words, a margin of at least one pitch of rightward or leftward movement is left to allow for a creaking operation (two threads are left in FIG. 6, FIG. 7, FIG. 8 and FIG. 10). The above operations accomplish the pre-step process of fastening (see FIG. 8).

[0031] If the reinforcing bar 4R is left screwed into the main tube 11, the reinforcing bar 4R will not be locked into the main tube 11, so the following procedure is performed. As shown in FIG. 1, the male thread 8M of the sleeve of the secondary cylinder 12 is threaded with a pitch P of the thread joint 4R of the reinforcing bar. 4 Pitch P 8M is formed, e.g., P 8M =P 4The dimensions are +2mm. The reason for the 2mm difference is to allow for creaking, and also to allow for the absorbing of several pitches even if there is some accumulation of pitch forming tolerance of the rebar (for example, ±0.2mm). It goes without saying that the 5F blind hole female thread is a female thread that has the necessary number of engagements for fastening, if the rebar allows for the forming tolerance of the thread pitch taking into account the wear of the forming roll.

[0032] Incidentally, as shown in FIG. 9, a slit 15 is formed in the outer body of the cap screw 5 of the main tube 11, which extends in the longitudinal direction and can be seen through to check the tip position of the inserted rebar 4R. Furthermore, if a slit 16 of approximately the same shape as the slit shown by the broken line is formed at the opposite position to this slit, it is convenient because it makes it easier to see through. Therefore, by looking into the slits 15 and 16, it is confirmed whether the end of the threaded rebar 4R has reached a predetermined position of the female thread 5F of the cap screw 5 as shown in FIG. 11. This operation also automatically confirms whether the number of threads required for the joint 4 to 6 described above has been achieved, and the rebar 4R is now held by the main tube 11, and the alignment between the main tube 11 and the rebar 4R is also achieved. After that, the sub-tube 12 is rotated right from the state shown in FIG. 8 and moved in the direction of the arrow 17 shown in FIG. 1(a) to approach the main tube 11. At that time, the minimum screw-in amount required to maintain fastening force is ensured in the reinforcing bar 4R in each of the pocket hole female thread 5F, the sleeve portion female thread 8F, and the nut portion female thread 13F, making it possible to transmit the desired axial force.

[0033] According to this configuration, a desired torque capable of maintaining fastening strength is applied to the hexagonal nut portion 13 of the secondary cylinder 12, and the secondary cylinder 12 is over-rotated while the left body 11C of the main cylinder 11 receives a reaction force, so that the frictional force caused by the difference in pitch between the nut portion female thread 13F of the nut portion 13 into which the thread joint 4T of the rebar is screwed and the sleeve portion male thread 8M of the secondary cylinder 12 is exerted on the contact tooth surface (creaking is generated), thereby preventing unintended rotation or axial displacement of the rebar. The coupler's structure makes it ideal for application to joint construction (not shown), etc.

[0034] By the way, it is not easy to match the phase of the sleeve female thread 8F, which meshes with the expanded female thread 9F of the cap screw hole of the main cylinder 11, with the phase of the nut female thread 13F by cutting (machining) operation. That is, even if it is easy to cut (mold) the thread, it is extremely difficult to cut the thread with the phase matched. To increase the reliability, casting is used. The core with the thread imitated is arranged so that the phase matches, a reference wall (reference surface) that should be positive is provided (not shown), and the end is abutted against this, and not only the position but also the angle posture is determined and arranged for casting, because this dramatically increases the molding efficiency. This is because, as can be seen from Figure 1 (a), it is necessary to achieve an uninterrupted phase for all the threads.

[0035] Returning to the main subject, when attempting to rotate the secondary cylinder 12, if the sleeve body 7 with the hexagonal hole portion 11D and the circular hole portion 6 connected is hung as shown in Figure 7(a), it is moved to the right side of the rebar 4R or removed from the opposite end of the rebar 4R, and then the secondary cylinder 12 is rotated rightwards to the left as shown by arrow 17 in Figure 1(a). The sleeve portion male thread 8M of the secondary cylinder 12 follows the enlarged female thread 9F of the main cylinder 11. Meanwhile, the nut portion female thread 13F also threads forward following the thread joint 4T of the rebar 4R. However, if the sleeve portion male thread 8M threads the enlarged female thread 9F by one pitch P, 8M (=P 9F =P 4 +2mm), the thread joint of the rebar 4R, which is 2mm shorter, reaches one pitch of screw thread, and this becomes a hindrance, and the thread joint of the sleeve male thread 8M along the enlarged female thread 9F of the main tube 11 is prevented from screwing in with the light rotation of the secondary tube 12 up to that point because the secondary tube 12 is rigid. Therefore, if the secondary tube 12 is forcibly rotated to the right (over-rotation), the nut female thread 13F will apply a creaking torque to the thread joint 4T of the rebar 4R before the sleeve male thread 8M completes one pitch of screwing in the enlarged female thread 9F. The thread joint 4T of the rebar 4R will damage the nut female thread 13 with which it is screwed (due to tooth surface interference), or the nut female thread 13 will damage the thread joint 4T of the rebar 4R, to the extent that it does not even allow the secondary tube 12 to rotate in the reverse direction, or they will damage each other. As shown in FIG. 17(a), the same applies when the secondary cylinder 12 is moved to the right 18. 4=P 5 =P 8F =P 13F , P 8M =P 9F =P 4 The same can be said if we use -2mm, so we will omit redundant description below.

[0036] A simple explanation will be given below with specific examples. 8M =P 9F =19mm, P 4 =P 13F = 17 mm, and the secondary cylinder 12 is first rotated 1 / 4 turn (π / 2 rad). The male thread 8M of the sleeve of the secondary cylinder 12 follows the enlarged female thread 9F of the main cylinder 11 and moves 4.75 mm. Meanwhile, the female thread 13F of the nut should move 4.25 mm following the rebar 4R. As long as the difference (difference) of 4.75 - 4.25 = 0.5 mm is within the range of the sum of the backlash on the side of the male thread 8M of the sleeve and the backlash on the side of the female thread 13F of the nut, the secondary cylinder 12 can move to the left in this manner.

[0037] Suppose the secondary cylinder 12 is rotated 1 / 12 to the right (1 / 3 rotation from the start of the right rotation, 2π / 3rad). The male thread 8M of the sleeve of the secondary cylinder 12 follows the enlarged female thread 9F of the main cylinder 11 and moves a total of 6.33mm. Meanwhile, the female thread 13F of the nut should move a total of 5.67mm. When the difference (difference) of 6.33-5.67=0.66mm cannot be absorbed by the sum of the backlash on the male thread 8M side of the sleeve and the backlash on the female thread 13F side of the nut, the secondary cylinder 12 is becoming or is no longer able to move left. Light rotation of the secondary cylinder 12 is not allowed, and if a torque exceeding the 1 / 12 rotation just performed is applied, the male thread 8M of the sleeve follows the enlarged female thread 9F of the main cylinder 11, while the female thread 13F of the nut generates creaking against the thread joint 4M of the reinforcing bar 4R. The greater the torque, the more deformation (roughening) of the meshing tooth surfaces occurs, and the resulting creaking achieves locking by the coupler. This creaking occurs on any or all of the meshing thread surfaces within the coupler. Thus, locking is achieved by a light rotation of only one component (the secondary tube 12) followed by a strong rotation operation. At this time, tension is applied to the secondary tube 12 in the axial direction, so it goes without saying that it must be able to withstand this axial force.

[0038] Incidentally, the rebar 4L that is the target of the friction welded rebar may be one with a different diameter than the rebar 4R (see Fig. 13(a)), or it may be the bamboo joint rebar 4B mentioned at the beginning (see Fig. 13(b)), which does not require screw-like behavior. This is convenient because it allows for variety in the rebars used, avoids excessive use of rebar material, and helps with inventory adjustment.

[0039] By the way, when the reinforcing bar 4R shown in FIG. 12 is screwed into the main tube 11, it should be noted that if it is screwed in before the secondary tube 12 is engaged, the secondary tube 12 cannot be screwed into the main tube 11 due to the difference in pitch. Therefore, with the secondary tube 12 engaged with the main tube 11, a substitute for the reinforcing bar 4R (a short item of about 300 mm) or a replica is screwed from the secondary tube 12 into the main tube 11. This naturally achieves phase alignment. At that time, the above-mentioned paint mark 3 (see FIG. 10(a)) is applied to the boundary between the main tube 11 and the secondary tube 12 with the number of unengaged threads of the sleeve male thread 8M and the enlarged female thread 9F set to 2 or 3. This is because it is possible to move the secondary tube 12 to the right or left by at least one pitch. It goes without saying that the substitute for the reinforcing bar 4R is then removed.

[0040] Incidentally, the position of the left barrel 11C (see FIG. 1(b)) which is a polygonal (hexagonal in the drawing) facet for taking the counter torque of the main barrel 11 may be the center barrel 11E as shown in FIG. 16. It may be in any position where the sleeve unit 7 shown in FIG. 7 or a device with the same function can be attached without getting in the way.

[0041] Incidentally, Figures 14 and 15 show some examples of fastening work carried out at construction sites. Although the figure is small, Figure 14 shows an example of repeating (i) to (iv) in the state corresponding to Figure 1(b) to reach (v). The subscripts 1, 2, 3, etc. after the reference numbers indicate the order of fastening introduction. It goes without saying that neither is limited to this example, and it is also possible to increase the length by introducing other types of couplers in the middle part. Figure 15(a) is an example corresponding to Figure 13(a), and it is natural to reduce or increase the size of the coupler 10 as necessary to match the thickness of the applicable rebar. Figure 15(b) is an example corresponding to Figure 13(b).

[0042] The above description is of the coupler 10 shown in the movements of Figures 1, 6 and 12, in which the secondary tube 12 is screwed into the main tube 11. However, we propose an example in which the secondary tube 12X is screwed into the outer surface, i.e., the periphery, of the main tube 11X as a different coupler 10X in Figures 18, 19 and 20.

[0043] The coupler 10X comprises a main tube 11X and a secondary tube 12X which is screwed onto the main tube 11X. On the friction-welded side of a pocket hole 5H drilled along the axis of the main tube 11X, there is a pocket hole female thread 5F into which the thread joint 4T of the other reinforcing bar 4R is screwed. On the opposite friction-welded side of the outer circumferential surface of the main tube 11X, there is an enlarged male thread 9M which is concentric with the pocket hole female thread 5F but has a larger diameter than the pocket hole female thread 5F. The female thread 8FX of the sleeve part of the secondary tube 12X which is screwed onto this enlarged male thread 9M has a pitch P of the thread joint 4R of the reinforcing bar. 4 Pitch P 8FX The fastening principle and behavior of this coupler 10X are almost the same as the previous example, so a duplicate explanation will be omitted. However, as mentioned above, P 4 =P 5 =P 13F , P 8FX =P 9M =P 4 +2mm. Or, P 4 =P 5 =P 13F , P 8FX =P 9M =P 4 It can be seen from the state of Fig. 18 that the creak lock is achieved by the left row 17X of Fig. 19 and the right row 18X of Fig. 20.

[0044] From the above explanation, the following can be understood. The rebar to be connected is joined with simple components, and can be fastened by lightly rotating the easy-to-handle secondary cylinder followed by strong rotation. If the rebar has a thread knot within the molding tolerance, the rebar can be fastened uniformly even if there is variation in the thread knot pitch. Since there is a difference in pitch between the expanded female thread 9F and expanded male thread 9M of the main cylinder 11 of the coupler and the female thread 13F of the nut part that engages with the rebar 4, the frictional force acting on the surface of the thread surface increases due to the increase in the surface contact pressure of the thread during threading. If roughness appears on the surface of the thread due to creaking caused by compression, further threading or retraction is prevented, and the over-threaded thread will not be released unless a reverse torque exceeding the load torque is applied.

[0045] It should be noted that there is no intention to exclude the use of grout (mortar, adhesive, thread locking agent, etc.) in combination. In other words, this does not mean that grout, etc. should not be introduced in the configuration of the present invention, but rather that in principle, injection of grout is often not necessary, and it goes without saying that it may be used in a known manner. [Explanation of symbols]

[0046] 1: rebar burrs, 2: main tube burrs, 3: paint mark, 4: rebar, 4T: screw knot, 4B: bamboo knot, 4L, 4R: screw knot rebar, 5H: blind hole, 5F: blind hole female thread, 6: circular hole portion, 7: sleeve body, 7a: locking screw, 8, 8X: sleeve portion, 8H: sleeve hole, 8M: sleeve male thread, 8F, 8FX: sleeve female thread, 9F: expanding female thread, 9M: expanding male thread, 10.10X: coupler, 11.11X: main tube, 11C: left body, 11D: hexagonal hole portion, 11E: middle body, 12.12X: secondary tube, 13: nut portion, 13F: nut female thread, 15, 16: slit, 17.17X: left arrow, 18.18X: right arrow.

Claims

1. A coupler capable of axially fastening a first reinforcing bar and a second reinforcing bar, wherein the coupler comprises a main cylinder having the first reinforcing bar frictionally press-connected to one axial end and an opening at the other axial end, and a sub-cylinder insertable through the opening of the main cylinder, wherein the main cylinder includes a first female thread portion formed on a part of the inner peripheral portion, and a second female thread portion formed on the inner peripheral portion on the other end side of the first female thread portion, wherein the sub-cylinder includes a male thread portion formed on the outer peripheral portion and screwed with the second female thread portion of the main cylinder, and a female thread portion formed on the inner peripheral portion and screwed with the thread section of the second reinforcing bar, the first female thread portion of the main cylinder and the female thread portion of the sub-cylinder are configured to have the same pitch and phase, the second female thread portion of the main cylinder and the male thread portion of the sub-cylinder are screwed together, and the first female thread portion of the main cylinder, the female thread portion of the sub-cylinder, and the thread section of the second reinforcing bar are screwed together, the thread pitch of the male thread portion of the sub-cylinder is configured to be different from the thread pitch of the second reinforcing bar, a coupler.

2. The coupler according to claim 1, wherein a male thread with a pitch larger than the pitch of the thread section of the second reinforcing bar is formed on the male thread portion of the sub-cylinder. The coupler according to claim 1.

3. The coupler according to claim 1, wherein a male thread with a pitch smaller than the pitch of the thread section of the second reinforcing bar is formed on the male thread portion of the sub-cylinder. The coupler according to claim 1.

4. A coupler capable of axially fastening a first reinforcing bar and a second reinforcing bar, wherein the coupler comprises a main cylinder having the first reinforcing bar frictionally press-connected to one axial end and an opening at the other axial end, and a sub-cylinder having an opening into which the main cylinder can be inserted, wherein the main cylinder includes a male thread portion formed on the outer peripheral portion, and a female thread portion formed on the inner peripheral portion, wherein the sub-cylinder includes a first female thread portion formed on the inner peripheral portion on the main cylinder side and screwed with the male thread portion of the main cylinder, and a second female thread portion formed on the inner peripheral portion on the side opposite to the main cylinder side and screwed with the thread section of the second reinforcing bar, the female thread portion of the main cylinder and the second female thread portion of the sub-cylinder are configured to have the same pitch and phase, the male thread portion of the main cylinder and the first female thread portion of the sub-cylinder are screwed together, and the female thread portion of the main cylinder, the second female thread portion of the sub-cylinder, and the thread section of the second reinforcing bar are screwed together, the thread pitch of the male thread portion of the main cylinder is configured to be different from the thread pitch of the second reinforcing bar, a coupler.

5. On the male screw portion of the main cylinder, a male screw having a pitch larger than the pitch of the screw threads of the second reinforcing bar is formed. The coupler according to claim 4.

6. On the male screw portion of the main cylinder, a male screw having a pitch smaller than the pitch of the screw threads of the second reinforcing bar is formed. The coupler described in claim 4.

7. On the outer surface of the central portion in the longitudinal direction of the main cylinder, a reaction force receiving surface is formed when applying a desired torque to the sub-cylinder. The coupler according to claim 1 or 4.

8. The nominal diameters of the first reinforcing bar and the second reinforcing bar are different. The coupler according to claim 1 or 4.

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