JP2012246690A - Reinforcement joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement joint capable of easily connecting ends of two reinforcements together by a coupler.SOLUTION: Two reinforcements are connected together by a coupler, by threadedly engaging the cylindrical coupler having an inner peripheral surface, on which a female screw is formed, the inner peripheral surface being threadedly engaged with an outer periphery of an end of one reinforcement, with an end of the other reinforcement while rotating the coupler with respect to one reinforcement and moving it to the other reinforcement side, in the state that respective ends of the two reinforcements used as main reinforcements for reinforced concrete abut mutually, each of the ends of the reinforcements having a male screw formed thereon. A taper surface of which diameter increases toward an opening end is provided on an inner peripheral surface of an end of the coupler on a side of insertion of the other reinforcement. A taper part of which diameter reduces toward a tip is provided at a tip of the outer periphery of the end of the other reinforcement. The inclination angle of the taper part with respect to the other reinforcement is smaller than that of the taper surface with respect to an axis of coupler.

Description

  The present invention relates to a reinforced joint that can be easily connected using a coupler in a state in which the ends of two reinforcing bars used as main bars of reinforced concrete are in contact with each other.

  In reinforced concrete, a reinforced joint is used in order to make a reinforcing bar which is a main bar of a limited standard length continuous in the field. As for the reinforcing bar joint, the present applicant has previously described a cylindrical coupler 55 in which a female thread 56 is formed on the inner peripheral surface of the two reinforcing bars 51 in a state where the end surfaces of the end portions are brought into contact with each other as shown in FIG. We proposed a rebar joint 50 to be connected by using (see Patent Document 1). In order to connect the two reinforcing bars 51, the coupler 55 is screwed into the male screw 53 formed on the outer periphery of the end 52 of the one reinforcing bar 51, and the coupler 55 is positioned so as not to protrude from the end surface of the reinforcing bar 51. (See FIG. 8A.) After the end face of the other reinforcing bar 51 is abutted and axially aligned with the end face of the reinforcing bar 51 (see FIG. 8B), the coupler 55 is rotated with respect to one reinforcing bar 51 in this state, and the one reinforcing bar 51 is rotated. The two reinforcing bars 51 are connected by the coupler 55 by being screwed into the male screw 53 on the outer periphery of the end portion 52 of the other reinforcing bar 51 while projecting from the end surface of the other reinforcing bar 51 (see FIG. 8C).

Utility Model Registration No. 3160121

  By the way, the axis | shafts of the edge part of the two rebars to connect are few, and the axis | shaft mutually has shifted | deviated in many cases, when located mutually coaxially. For this reason, when connecting the ends of two reinforcing bars using a coupler, the reinforcing bars are heavy and difficult to bend. Therefore, the coupler is rotated with the axes of the ends of the two reinforcing bars coaxially positioned. Thus, the end of the two reinforcing bars could not be easily connected by this coupler. In particular, rebar assembly used as the main reinforcing bar of reinforced concrete is, for example, a plurality of reinforcing bars bound to a hoop in a state parallel to each other (the positions of the multiple reinforcing bars are fixed) to a certain extent. 6 reference.) Is assembled in advance, and each rebar of the two rebar rods is connected to each other at the construction site. In other words, each rebar of the reinforcing bar rod is connected to each of the corresponding reinforcing bars of the reinforcing bar using a coupler. However, although each rebar of the reinforcing bar can be moved somewhat, it is difficult to move as compared with a single rebar, so the ends of the two rebars could not be easily connected by the coupler.

  Further, even when the axes of the ends of the two reinforcing bars are coaxially positioned, if the phase of the male screw at the ends of the two reinforcing bars is shifted, the coupler is not screwed as it is. The coupler cannot be screwed into the male thread at the end of the rebar. That is, the phase of the female thread of the coupler is out of phase with the male thread of the other reinforcing bar, so that the coupler cannot bite into the male thread of the other reinforcing bar, that is, cannot be screwed together, and the coupler is forcibly moved to the other reinforcing bar. When screwed into the male screw, the coupler and the other reinforcing bar screw were damaged, making it impossible to connect the reinforcing bar with the coupler. For this reason, the phase of the female thread of the coupler and the phase of the male thread of the other reinforcing bar must be matched using a special connecting jig, and the end of the two reinforcing bars cannot be easily connected by the coupler. .

  The problem to be solved by the present invention is to provide a reinforcing bar joint that can easily connect the ends of two reinforcing bars by a coupler.

  In order to solve the above-mentioned problem, a rebar joint according to the present invention is an outer periphery of an end of one reinforcing bar in a state where ends of two reinforcing bars used as main bars of reinforced concrete are abutted with each other. A cylindrical coupler having a female thread formed on its inner peripheral surface is rotated with respect to the one reinforcing bar and moved toward the other reinforcing bar while being screwed into the end of the other reinforcing bar. The two reinforcing bars are connected by the coupler, and the diameter of the coupler gradually increases toward the opening end of the coupler on the inner peripheral surface of the end of the coupler where the other reinforcing bar is inserted. A tapered surface is provided, and a tapered portion that gradually decreases in diameter toward the distal end is provided at a distal end portion of the outer periphery of the other reinforcing bar end, and an inclination angle of the tapered portion with respect to the axis of the other reinforcing bar is Before axis Characterized in that it is formed by at least 3 ° angle smaller than the inclination angle of the tapered surface.

As described above, the tapered surface is provided on the inner peripheral surface of the coupler, and the tapered portion is provided at the outer peripheral end of the other reinforcing bar, so that it is screwed to the end of the other reinforcing bar. Therefore, when the coupler is rotated with respect to one reinforcing bar and moved to the other reinforcing bar side, even if the axes of the ends of the two reinforcing bars are slightly deviated, the tapered surface of the coupler and the end of the other reinforcing bar The end of the other reinforcing bar is guided and pushed in the axial direction of the coupler by the guide action of the tapered portion, and the shafts of the ends of the two reinforcing bars are positioned substantially coaxially with each other.
Also, when the axes of the ends of the two reinforcing bars are coaxially positioned, the phase of the male thread at the ends of the two reinforcing bars is shifted, that is, the phase of the female thread of the coupler and the other reinforcing bar. When the coupler is out of phase, when the coupler is rotated relative to the end of one reinforcing bar, the other reinforcing bar is pushed and moved in the axial direction by the coupler, and the phase of the male thread of the other reinforcing bar After the phase of the female thread of the coupler is the same, the coupler is screwed into the male thread at the end of the other reinforcing bar.
Thus, when two reinforcing bars are connected by a coupler, if the inclination angle of the taper portion of the reinforcing bar with respect to the axis of the reinforcing bar is at least 3 ° smaller than the inclination angle of the tapered surface with respect to the axis of the coupler, The contact between the coupler and the reinforcing bar is a cross-section point contact because the corner of the other reinforcing bar touches the tapered surface of the coupler, or the small diameter corner of the tapered surface of the coupler hits the tapered portion of the other reinforcing bar. is there. For this reason, the coupler can be rotated with a small force compared to the case of cross-sectional line contact when the inclination angle of the taper portion of the reinforcing bar and the inclination angle of the taper surface are formed at the same angle. However, it was easy to bite into the male thread of the threaded part of the other rebar, that is, it became easy to screw. Therefore, the coupler can be rotated with a small force and screwed into the end of another reinforcing bar, so that the ends of the two reinforcing bars can be easily connected by the coupler.

  In this case, the inclination angle of the tapered portion can be set to 30 ° or less with respect to the axis of the other reinforcing bar. Moreover, a taper part can be formed in the range from the front-end | tip of the edge part of the other reinforcing bar to the place 1 to 2 times the length of the male screw pitch. Furthermore, the diameter of the end surface of the other reinforcing bar formed by the tapered portion can be formed with a dimension equal to or smaller than the diameter of the inner peripheral surface of the coupler. Further, in this case, the tapered surface is formed in a range from the tip of the end of the coupler to a location that is 1.0 to 1.6 times as long as the pitch of the female screw, and the inclination angle of the tapered surface is determined by the coupler. The diameter of the open end of the coupler formed by the tapered surface is 43 ° to 47 ° with respect to the axis, and the outer diameter of the female screw of the coupler is 1.0 to 1.1 times larger.

  According to the present invention, the ends of the two reinforcing bars can be easily connected by the coupler.

It is a partial cross section side view showing the reinforcing bar joint of an example embodiment concerning the present invention. It is a side view which shows an example of the reinforcing bar used for the reinforcing bar joint of this embodiment. It is a figure which shows an example of the coupler used for the reinforcing bar joint of this embodiment, (a) is a front view, (b) is a partial cross section side view. It is a partial cross section side view which shows the shape of the taper part of the reinforcing bar used for the reinforcing bar joint of this embodiment, and (a) is formed with a length of 1.0 times the pitch of the male screw and an inclination angle of 30 °. The figure which shows the taper part which the length is 1.5 times the pitch of the external thread, and is the figure which shows the taper part formed by the inclination angle 22 degrees, (c) is the pitch of the external thread The figure which shows the taper part formed with the inclination angle of 30 degrees with the dimension of 1.5 times of this, (d) is a dimension which is 2.0 times the length of the pitch of the external thread, and was formed with the inclination angle of 17 degrees. The figure which shows a taper part, (e) is a figure which shows the taper part formed in the dimension of 2.0 times the pitch of a male screw, and the inclination angle of 30 degrees. It is a side view which shows the other example of the reinforcing bar used for the reinforcing bar joint of this embodiment. It is a front view which shows an example of the reinforcing bar rod formed with the reinforcing bar used for the reinforcing bar joint of this embodiment. It is a partial cross section side view which shows the state which formed the inclination angle of the taper part of a reinforcing bar and the taper surface of a coupler at 45 degrees, respectively. It is explanatory drawing for connecting two reinforcing bars with the reinforcing bar joint which the present applicant proposed previously, (a) is a partial sectional side view which shows the state where the coupler was screwed in the threaded part of one reinforcing bar, b) is a partial side sectional view showing a state in which the end face of the threaded portion of the reinforcing bar shown in (a) is brought close to the end face of the threaded portion of the other reinforcing bar, and (c) is a state where the two reinforcing bars are connected by a coupler. FIG.

  Hereinafter, an embodiment of a reinforcing bar joint according to the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1, a reinforcing bar joint 1 according to an example of the present embodiment connects two reinforcing bars 2 with a coupler 3. Reinforcing bar 2 is not particularly limited as long as it is used as a reinforcing bar which is a main reinforcing bar that serves as a beam or a column of reinforced concrete. For example, a deformed reinforcing bar having a protruding portion such as a semicircular ridge and an axial ridge, Used.

  As shown in FIG. 2, the end portion of the reinforcing bar 2 is formed as a screw portion 23 having a diameter larger than that of the reinforcing bar main body 21 and having a male screw 22 formed on the outer periphery. The formation of the screw portion 23 is not particularly limited. For example, a thickened diameter-expanded portion is formed on the end portion of the reinforcing bar main body 21 by die forging that applies a compression force while performing high-frequency induction heating. Next, the outer periphery of the enlarged diameter portion is obtained by, for example, threading to form the male screw 22. The valley diameter of the male screw 22 of the screw portion 23 is formed to be larger than the maximum outer diameter of the reinforcing bar main body 21. The number of threads of the male screw 22 is arbitrarily set according to the type of the reinforcing bar 2, but the reinforcing bar 2 can be connected with sufficient strength and the axial length of the screw part 23 can be shortened, for example. It is preferably formed of 6 to 9, more specifically 8 to 9. The screw shape of the male screw 22 is not particularly limited, but is preferably formed on the basis of a JIS screw (coarse screw). Further, the corner 24 at the boundary between the reinforcing bar main body 21 and the screw part 23 prevents stress from concentrating on the corner 24 at the boundary between the reinforcing bar main body 21 and the screw part 23 when tensile stress acts on the reinforcing bar 2. Therefore, it is preferable to form R.

  A tapered portion 25 that gradually decreases in diameter toward the distal end is provided at the distal end portion of the outer periphery of the end portion that is the screw portion 23 of the reinforcing bar 2. The taper portion 25 is formed by, for example, cutting a screw portion 23 having a diameter larger than that of the reinforcing bar main body 21 and having a male screw 22 formed on the outer periphery. For this reason, in the location where a diameter is larger than the valley diameter of the male screw 22 of the taper part 25, there exists a location where a part of male screw 22 remains formed. The inclination angle α of the taper portion 25 with respect to the axis of the reinforcing bar 2 is at least 3 ° smaller than the inclination angle β (see FIG. 3) of the tapered surface 35 (see FIG. 3) with respect to the axis of the coupler 3 described later, preferably 30. It is formed at 30 ° to 17 °, more preferably 30 ° to 17 °. The axial length (length from the tip) A of the taper portion 25 is not particularly limited. For example, the taper portion 25 is preferably formed with a dimension that is one or more times the pitch of the male screw 22. More preferably, it is formed with a size of 1 to 2 times. That is, it is more preferable that the taper portion 25 is formed in a range from the tip to a location that is one to two times as long as the pitch of the male screw 22. If the length A in the axial direction of the taper portion 25 is less than one time the pitch of the male screw 22, the effect of providing the taper portion 25 is small, and the axial length A of the taper portion 25 is less than the male screw. If it is formed with a dimension exceeding twice the pitch of 22, the length of the screw portion 23 of the reinforcing bar 2 becomes longer, which is not preferable. Moreover, it is preferable that the diameter R of the end surface of the other reinforcing bar 2 formed by the taper portion 25 is formed with a dimension equal to or smaller than the diameter S (see FIG. 3) of the inner peripheral surface of the coupler 3.

  Specifically, the taper portion 25 is formed with an inclination angle α of 30 ° when the length A from the tip is formed to be 1.0 times the pitch of the male screw 22 (see FIG. 4 (a).) Further, the taper portion 25 is formed with an inclination angle α of 30 ° to 22 ° when the length A from the tip is formed to be 1.5 times the pitch of the male screw 22 (see FIG. 4 (b) and (c)). Further, the taper portion 25 is formed with an inclination angle α of 30 ° to 17 ° when the length A from the tip is formed to be 2.0 times the pitch of the male screw 22 (see FIG. 4 (d) and (e).) Thus, the taper portion 25 has an inclination angle α determined according to the length A from the tip, but the diameter R of the end surface of the other reinforcing bar 2 formed by the taper portion 25 is the diameter of the inner peripheral surface of the coupler 3. It is preferably formed with a size smaller than S, and in particular, the length A from the tip is 1.5 times the pitch of the male screw 22 and the inclination angle α is 27 ° to 25 °. It is more preferable.

  As shown in FIG. 3, the coupler 3 is formed in a cylindrical shape whose inner peripheral surface is circular in cross section. The shape of the outer peripheral surface of the coupler 3 may be circular, but is preferably polygonal, and in particular, the opposite surface is a parallel polygon (rectangle, hexagon, octagon, dodecagon, etc.). Particularly preferable are a regular hexagon, a regular octagon, and a regular dodecagon from the viewpoint that the coupler 3 can be easily rotated with respect to the reinforcing bar 2 by using a tool or the like, and a regular dodecagon is most preferable. is there. The outer shape of the coupler 3 is formed in the same shape over the entire length in the axial direction. Thus, by forming the shape of the outer peripheral surface of the coupler 3, that is, the outer shape as a regular dodecagon, the surface area becomes larger than when the outer shape is formed as a regular hexagon, for example. Can be high. In addition, when the outer shape of the coupler 3 is formed in a regular dodecagon, when the coupler 3 is rotated with respect to the reinforcing bar 1 using a tool or the like, for example, compared with a case where the outer shape is formed in a regular hexagon. Since the coupler 3 can be rotated with a fine pitch, it is easy to connect the reinforcing bars 2 with the coupler 3 in narrow places or places where the reinforcing bars 2 are adjacent. The coupler 3 is not particularly limited as long as it is used for reinforced concrete. For example, a steel pipe is used. Specifically, the coupler 3 may be cut for every 22 cylinder lengths of a thick steel pipe male screw. Further, a steel pipe having a general thickness may be increased by a thickening process in which induction heating is performed while applying a compressive force, and the thickened steel pipe may be cut off.

  On the inner peripheral surface of the coupler 3, a female screw 32 that is screwed into the male screw 22 of the screw portion 23 of the reinforcing bar 2 is uniformly formed over the entire length by, for example, threading. The length in the axial direction of the coupler 3 is equal to or greater than the total length obtained by adding the lengths in the longitudinal direction of the screw portions 23 of the two reinforcing bars 2 to be coupled using the coupler 3, and 15 mm or longer than the total length. For example, it is formed in a dimension 15 mm longer than the total length. Further, when the two reinforcing bars 2 are connected to each other by the coupler 3, it is preferable that the slip amount between the two reinforcing bars 2 is 0.3 or less.

  Tapered surfaces 35 that gradually increase in diameter toward the opening end are provided on the inner peripheral surfaces of both ends of the coupler 3, respectively. The tapered surface 35 is formed by, for example, cutting the end portion of the inner peripheral surface of the coupler 3 on which the female screw 32 is formed. The inclination angle β of the tapered surface 35 with respect to the axis of the coupler 3 is formed at the same angle as the angle of 3 ° or more than the inclination angle α of the taper portion 25 with respect to the axis of the reinforcing bar 2, for example, formed at 43 ° to 47 °. Yes. In the present embodiment, the case where the inclination angle β of the tapered surface 35 with respect to the axis of the coupler 3 is 45 ° will be described, but the present invention is not limited to this. The axial length (length from the end face) B of the taper surface 35 is not particularly limited, but is preferably formed with a dimension that is one or more times the pitch of the female screw 32, and in particular, the pitch of the female screw 32. It is more preferable that it is formed with a dimension 1.0 to 1.6 times as large as. That is, it is more preferable that the tapered surface 35 is formed in a range from the end surface to a location separated by 1.0 to 1.6 times the pitch of the female screw 32. If the length B in the axial direction of the taper surface 35 is less than 1.0 times the pitch of the female screw 32, the effect of providing the taper surface 35 is small, and the length B in the axial direction of the taper surface 35 is small. Is formed with a dimension exceeding 1.6 times the pitch of the female thread 32, the entire length of the coupler 3 is increased, which is not preferable. The diameter T of the open end of the coupler 3 formed by the tapered surface 35 is preferably 1.0 times or more the outer diameter of the female screw 32 of the coupler 3, particularly 1.0 to 1.1. More preferably, it is formed with a double size.

Next, a case where two reinforcing bars 2 are connected using the reinforcing bar joint 1 of the present embodiment will be described.
For example, one end surface of the coupler 3 (the end surface of the reinforcing bar 2 when the coupler 3 is screwed to the threaded portion 23 of the reinforcing bar 2) so as not to protrude from the end surface of the reinforcing bar 2 by screwing the coupler 3 into the threaded portion 23 of one reinforcing bar 2. Is positioned substantially flush with the end surface of the reinforcing bar 2 (see FIG. 8A). After the end face of the other reinforcing bar 2 is abutted against the end face of the reinforcing bar 2 (see FIG. 8B), the coupler 3 is rotated with respect to one reinforcing bar 2 in this state, and from the end face of the one reinforcing bar 2 The two reinforcing bars 2 are connected by the coupler 3 by being screwed into the threaded portion 23 of the other reinforcing bar 2 while protruding (see FIG. 8C).

  The end face of the other reinforcing bar 2 is brought into contact with the end face of the other reinforcing bar 2 by positioning the end face of the other reinforcing bar 2 within the open end of the coupler 3 formed by the tapered face 35 (the large diameter portion of the tapered face 35). Thus, the two reinforcing bars 2 can be connected by the coupler 3 by the guide action of the tapered surface 35 of the coupler 3 and the tapered portion 25 at the end of the other reinforcing bar 2. That is, when the end surface of the other reinforcing bar 2 is located inside the open end of the coupler 3 (large diameter portion of the tapered surface 35) and outside the inner peripheral surface of the coupler 3 (small diameter portion of the tapered surface 35). When the coupler 3 is rotated and moved to the other reinforcing bar 2 side, the corner of the tip of the other reinforcing bar 2 hits the tapered surface 35 of the coupler 3. When the coupler is further moved to the other reinforcing bar 2 side by the rotation of the coupler 3, the tip of the other reinforcing bar 2 is guided and moved in the axial direction of the coupler 3 along the tapered surface 35 of the coupler 3 by the movement of the coupler 3. The tip of the other reinforcing bar 2 reaches the small diameter portion of the tapered surface 35 of the coupler 3.

  When the diameter R of the end face of the other reinforcing bar 2 is formed with the same dimension as the diameter S of the inner peripheral surface of the coupler 3, the other reinforcing bar 2 is positioned substantially coaxially with the coupler 3. At this time, when the phase of the female screw 32 of the coupler 3 and the phase of the male screw 22 of the other reinforcing bar 2 are substantially the same, the coupler 3 is screwed into the male screw 22 at the end of the other reinforcing bar 2 by rotation of the coupler 3. Further, the two reinforcing bars 2 are connected by the coupler 3 by appropriately rotating the coupler 3 so that the screw portions 23 of the two reinforcing bars 2 are respectively covered with the coupler 3. When the phase of the female screw 32 of the coupler 3 and the phase of the male screw 22 of the other rebar 2 are different, that is, shifted, the other rebar 2 moves in the substantially axial direction of the coupler 3 due to the movement of the coupler 3 due to the rotation of the coupler 3. After the phase of the male screw 22 of the other reinforcing bar 2 becomes substantially the same as the phase of the female screw 32 of the coupler 3, the coupler 3 is screwed into the male screw 22 at the end of the other reinforcing bar 2, Further, the two reinforcing bars 2 are connected by the coupler 3 by appropriately rotating the coupler 3 so that the screw portions 23 of the two reinforcing bars 2 are respectively covered with the coupler 3.

  If the diameter R of the end surface of the other reinforcing bar 2 is smaller than the diameter S of the inner peripheral surface of the coupler 3, the tip of the other reinforcing bar 2 is connected to the coupler 3 by the movement of the coupler 3 due to the rotation of the coupler 3. The taper surface 35 of the coupler 3 moves to the back of the coupler 3, and the corner portion of the small diameter portion of the taper surface 35 of the coupler 3 hits the taper portion 25 at the tip of the other reinforcing bar 2. This is the same as the case where the end surface of the other reinforcing bar 2 is positioned inside the inner peripheral surface S of the coupler 3 (the small diameter portion of the tapered surface 35). Further, as the coupler 3 moves due to the rotation of the coupler 3, the corner of the small diameter portion of the tapered surface 35 of the coupler 3 pushes the tapered portion 25 of the tip of the other reinforcing bar 2 in the axial direction (see, for example, FIG. 4C). ). Thereby, the other rebar 2 is pushed and moved in the axial direction of the coupler 3.

  When the entire circumference of the corner of the small diameter portion of the tapered surface 35 of the coupler 3 contacts the entire circumferential direction of the tapered portion 25 of the other reinforcing bar 2, the other reinforcing bar 2 is positioned substantially coaxially with the coupler 3. . At this time, when the phase of the female screw 32 of the coupler 3 and the phase of the male screw 22 of the other reinforcing bar 2 are substantially the same, the coupler 3 is screwed into the male screw 22 at the end of the other reinforcing bar 2 by rotation of the coupler 3. Further, the two reinforcing bars 2 are connected by the coupler 3 by appropriately rotating the coupler 3 so that the screw portions 23 of the two reinforcing bars 2 are respectively covered with the coupler 3. When the phase of the female screw 32 of the coupler 3 and the phase of the male screw 22 of the other reinforcing bar 2 are different, that is, shifted, the other reinforcing bar 2 is pushed in the axial direction of the coupler 3 by the rotation of the coupler 3 and moves. After the phase of the male screw 22 of the other reinforcing bar 2 becomes substantially the same as the phase of the female screw 32 of the coupler 3, the coupler 3 is screwed into the male screw 22 at the end of the other reinforcing bar 2, and the two reinforcing bars 2 are further engaged. The two reinforcing bars 2 are connected to each other by the coupler 3 by appropriately rotating the coupler 3 so that each of the screw portions 23 is covered with the coupler 3.

  Thus, when connecting the two rebars 2 by the coupler 3, for example, when the D3 rebar 2 is connected by turning the coupler 3 having an outer diameter of 62 mm by hand, the rotational force of about 13 kg is about 100 kg. Since the propulsive force acts on the reinforcing bar, the coupler 3 can be rotated with a small force without using a special connection jig, and the other reinforcing bar 2 can be moved to be screwed onto the coupler 3. Further, when the inclination angle α of the taper portion 25 of the reinforcing bar 2 with respect to the axis of the reinforcing bar 2 is formed at least 3 ° smaller than the inclination angle β of the tapered surface 35 with respect to the axis of the coupler 3, the tapered surface 35 of the coupler 3. The contact between the coupler 3 and the reinforcing bar 2 when the corner of the tip of the other reinforcing bar 2 hits or the corner of the small diameter part of the tapered surface 35 of the coupler 3 hits the tapered part 25 of the other reinforcing bar 2 is Cross-section point contact. For this reason, especially with a small force compared with the case of cross-sectional line contact (see FIG. 7) when the inclination angle α of the tapered portion 25 of the reinforcing bar 2 and the inclination angle β of the tapered surface 35 are formed at the same angle. If the inclination angle of the taper portion 25 of the reinforcing bar 2 is 30 ° or less, the coupler 3 is rotated by hand without using a special connecting jig, so that the female screw 22 of the coupler 3 and the male screw 22 of the screw portion 23 of the other reinforcing bar 2 are used. Can be bitten (screwed together) in the first mountain. That is, when the inclination angle of the tapered portion 25 of the reinforcing bar 2 is 30 ° or less, for example, 30 ° to 17 °, the corner portion of the small diameter portion of the tapered surface 35 of the coupler 3 is the tip portion of the other reinforcing bar 2. It is easy to rotate and move the coupler 3 after hitting the taper portion 25. That is, the force for pressing the other reinforcing bar 2 in the axial direction of the coupler 3 can be reduced. For this reason, for example, the coupler 3 can be rotated manually and the internal thread 32 of the coupler 3 and the male screw 22 of the screw part 23 of the other reinforcing bar 2 can be bitten first. As a result, after the female screw 32 of the coupler 3 and the male screw 22 of the screw portion 23 of the other reinforcing bar 2 are bitten first, the coupler 3 is rotated by hand, or a general-purpose connecting jig such as a pipe wrench is used. Thus, the two reinforcing bars 2 can be connected by the coupler 3 by rotating the coupler 3.

  Therefore, according to the reinforcing bar joint 1 of the present embodiment, the coupler 3 can be screwed to the end of another reinforcing bar 2 only by rotating the coupler 3 with a small force without using a special connecting jig. Anyone can easily connect the ends of the two reinforcing bars 2 with the coupler 3 without any special technique. As a result, the reinforcing bar joint 1 according to the present embodiment has a plurality of, for example, twelve reinforcing bars 2 bound to the hoop bars 15 in parallel with each other (the positions of the twelve reinforcing bars 2 are fixed). It is effective when the rod 16 (see FIG. 6) is assembled in advance and the two reinforcing rods are connected to each other at the construction site, and the construction can be shortened and the cost can be reduced.

  Further, when the length A of the taper portion 25 of the reinforcing bar 2 is formed in a range from the tip to a place that is 1 to 2 times as long as the pitch of the male screw 22, the threaded portion 23 of the existing reinforcing bar 2; For example, when the taper portion 25 is formed in the screw portion 23 in which the number of threads of the male screw 22 is 8 to 9, and the coupler 3 is screwed to the screw portion 23 to connect the two rebars 2, the screw portion 23. The strength with the coupler 3 is not weaker than that of the rebar main body 21. As a result, since it is not necessary to lengthen the length of the screw portion 23 of the reinforcing bar 2 in the longitudinal direction, when the reinforcing bar 2 is connected using the coupler 3, the arrangement of the reinforcing bars 2 around the reinforcing bar 2 is affected. There is no.

  When the diameter R of the end surface of the other reinforcing bar 2 formed by the tapered portion 25 is not larger than the diameter S of the inner peripheral surface of the coupler 3, the other reinforcing bar 2 is placed in the opening end of the coupler 3. Since it is easy to insert the tip of the two reinforcing bars 2, it is possible to more easily connect the ends of the two reinforcing bars 2.

  Further, the taper surface 35 of the coupler 3 is formed in a range from the end surface of the coupler 3 to a portion separated by 1.0 to 1.6 times the pitch of the female screw 32, and is formed by the taper surface 35. The diameter T of the open end of the coupler 3 is formed to be 1.0 to 1.1 times the outer diameter of the female screw 32 of the coupler 3, so that the strength of the coupler 3 is reduced by the coupler 3. The rebar 2 of a book can be connected. Further, when the taper surface 35 is formed by cutting when the inclination angle β of the taper surface 35 is 43 ° to 47 ° with respect to the axis of the coupler 3, the taper surface 35 can be easily formed by an existing apparatus. be able to.

  In addition, after the reinforcing bars 2 connected by using the coupler 3 are disposed, the reinforcing bars 15 other than the main reinforcing bars such as stirrup and hoop bars around the reinforcing bars 2 near both ends of the coupler 3 (see FIG. 1). ) To prevent the coupler 3 from rotating relative to the reinforcing bar 2, the coupler 3 rotates relative to the reinforcing bar 2 due to vibration or the like, so that there is no need to worry about the coupler 3 releasing the connection of the reinforcing bar 2. .

  In the above-described embodiment, only the tapered portion 25 is provided at the outer peripheral end portion of the end portion of the rebar 2. However, the present invention is not limited to this, and as shown in FIG. The small diameter portion 26 may be formed by reducing the diameter, and the tapered portion 27 may be provided on the outer periphery on the tip side of the small diameter portion 26. In this case, the diameter U of the small-diameter portion 26 is not particularly limited. For example, it is preferable that the small-diameter portion 26 is formed with a size of 0.01 to 0.05 with respect to the outer diameter of the screw portion 23. The length (length from the tip) C of the small-diameter portion 26 is not particularly limited, but for example, it is preferably formed with a dimension that is one or more times the pitch of the male screw 22, and is 1-2 of the pitch of the male screw 22. More preferably, it is formed with a double size. The axial length D of the tapered portion 26 formed in the small diameter portion 26 is not particularly limited, and for example, it is preferably formed with a dimension 0.4 to 1.0 times the pitch of the male screw 22.

  Further, the tapered portion 25 is provided at each end portion of the two reinforcing bars 2 connected by the coupler 3, but the tapered portion 25 is provided at the end portion of one of the reinforcing bars 2 on which the coupler 3 is screwed in advance. Although not necessary, it is preferable to provide it. Moreover, although the taper surface 35 was provided in the both ends of the inner peripheral surface of the coupler 3, respectively, a taper surface is formed in the edge part by which the edge part of one rebar 2 by which the coupler 3 is screwed beforehand is inserted. 35 is not necessarily provided, but is preferably provided.

1 Reinforcing Bar Joint 2 Reinforcing Bar 3 Coupler 21 Reinforcing Bar Body 22 Male Screw 23 Screw Part (End)
25 Taper portion 32 Female thread 35 Tapered surface α Inclination angle of taper portion β Inclination angle of taper surface A Length of taper portion B Length of taper surface R Diameter of end face of reinforcing bar S Diameter of inner peripheral surface of coupler T Opening of coupler End diameter

Claims (5)

A female thread is formed on the inner peripheral surface that is screwed to the outer periphery of the end of one of the reinforcing bars while the ends of the two reinforcing bars that are used as the main reinforcing bars of the reinforced concrete face each other. A rebar joint that connects the two rebars with the coupler by rotating the cylindrical coupler with respect to the one rebar and moving it toward the other rebar while screwing it into the end of the other rebar There,
On the inner peripheral surface of the end portion on the side where the other reinforcing bar of the coupler is inserted, a tapered surface that gradually increases in diameter as it goes to the opening end of the coupler is provided,
In the tip of the outer periphery of the end of the other rebar, a tapered portion that gradually decreases in diameter as it goes to the tip,
The reinforcing bar joint, wherein an inclination angle of the tapered portion with respect to the axis of the other reinforcing bar is formed at an angle that is at least 3 ° smaller than an inclination angle of the tapered surface with respect to the axis of the coupler.   The reinforcing bar joint according to claim 1, wherein an inclination angle of the tapered portion is 30 ° or less with respect to an axis of the other reinforcing bar.   3. The reinforcing bar joint according to claim 1, wherein the tapered portion is formed in a range from a tip of an end portion of the other reinforcing bar to a place separated by a length of 1 to 2 times the pitch of the male screw.   The reinforcing bar joint according to any one of claims 1 to 3, wherein a diameter of an end face of the other reinforcing bar formed by the tapered portion is formed with a dimension equal to or smaller than a diameter of an inner peripheral face of the coupler.   The tapered surface is formed in a range from the end surface of the coupler to a location separated by 1.0 to 1.6 times the internal thread pitch, and the inclination angle of the tapered surface is relative to the axis of the coupler. And the diameter of the open end of the coupler formed by the tapered surface is 1.0 to 1.1 times the outer diameter of the female thread of the coupler. The reinforcing bar joint according to any one of claims 1 to 4.

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