JP2014088699A - Shear reinforcement member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shear reinforcement member which can control not to cause excessive stress at the point where the bending moment created by the force of a main reinforcement becomes great.SOLUTION: A shear reinforcement member 2A comprises a fixing part 3, with which a shaft body 21 is hooked on main reinforcements 1 in an approximately orthogonal direction. The fixing part has an end surface 30 having an area larger than that of the cross section of the shaft body that is made to butt at and pressure-welded with friction to it, and is formed as a single unit including: a first extension part 31 extending in the direction of the axis of the shaft body with the end surface as its cross section; and a second extension part 32 formed opposite from the end surface, extending in the direction across the first extension part. The sheer reinforcement member is installed by hooking the main reinforcement at the inner corner of the first extension part and the second extension part.

Description

  The present invention relates to a shear reinforcement member for increasing the shear strength of a reinforced concrete structure.

  There is known a shear reinforcement structure that increases the shear strength by spanning a shear reinforcement member having a fixing portion attached to the end between main reinforcing bars of a reinforced concrete structure (see Patent Documents 1-4, etc.). .

  Patent Document 1 discloses a method in which a fixing plate is provided with a recess, and the shaft body made of deformed reinforcing bars is inserted into the recess while being fixed by friction welding.

  On the other hand, Patent Document 2 discloses a shear reinforcement member in which a boss is provided on a fixing plate and a shaft body is abutted against the boss and joined by flash welding.

  Patent Document 3 discloses a shear reinforcing member in which a shaft body having a threaded portion at the tip is inserted into a hole in the fixing plate, and the threaded portion at the tip is fixed to the fixing plate by a nut. Further, Patent Document 4 discloses a shear reinforcing member in which the tip of a shaft body is inserted into a hole of a fixing tool made of a ceramic sintered body and fixed with an adhesive.

  On the other hand, in Patent Document 5, the end portion of the deformed reinforcing bar is processed into a flat plate portion by forging, and the flat plate portion is bent at a substantially right angle with respect to the shaft body so as to form a recess for hooking on the main reinforcing bar. A reinforcing bar with a fixing portion is disclosed.

JP 200484312 A JP 2006-124923 A JP 2007-56670 A Japanese Patent No. 3896254 Japanese Patent No. 4866894

  By the way, when the fixing plate of the shear reinforcement member is hooked on the main reinforcing bar, the bending moment with the contact point of the main reinforcing bar with respect to the fixing plate as the point of action of the force and the arm from the point of action to the shaft body as described later, It acts on the joint that is the intersection of the fixing plate and the shaft body. That is, the largest bending moment acts near the joint portion of the shaft body.

  However, in the shear reinforcing member having a structure in which the shaft body is abutted against the plane of the fixing plate disclosed in Patent Documents 1-3, the portion where the largest bending moment acts is the shaft body having a relatively small section modulus. Therefore, the generated stress is locally increased.

  In addition, the structure in which the cylindrical protrusion is protruded from the fixing plate as disclosed in Patent Documents 3 and 4 and the tip of the shaft body is inserted into the hole and fixed with a screw or an adhesive is used for friction welding. Compared to this, the bonding strength is low, and there is a possibility that the bonded portion becomes a weak portion. Further, in the structure in which the tip of the shaft body is inserted into the hole of the protrusion, it is necessary to increase the thickness so that the protrusion is not damaged. However, when the thickness of the protrusion increases, the point of action of the force due to the main rebar moves to the outside and the arm becomes longer, so that the bending moment acting near the joint increases.

  Therefore, an object of the present invention is to provide a shear reinforcement member that can be controlled so that excessive stress is not generated at a location where a bending moment generated by a force acting from a main reinforcing bar increases.

  In order to achieve the above object, the shear reinforcing member of the present invention is a shear reinforcing member including a fixing portion that spans a shaft main body in a substantially orthogonal direction with respect to a main reinforcing bar, and the fixing portion includes: The shaft body has an end surface wider than a section of the shaft body that abuts the shaft body and is friction-welded, and a first extending portion that extends in the axial direction of the shaft body with the end surface as a section, and the first extending portion on the opposite side of the end surface A second extending portion extending in a direction intersecting with the first extending portion is integrally formed, and the main reinforcing bar is hooked on the inner angle side of the first extending portion and the second extending portion.

  Here, the end surface can be formed in a rectangular shape. Moreover, you may shape | mold so that the surface made to oppose the said main reinforcing bar of the said 1st extending | stretching part and the surface made to oppose the said main reinforcing bar of the said 2nd extending | stretching part may be substantially orthogonal. On the other hand, it can also shape | mold so that the surface facing the said main reinforcement of the said 1st extending | stretching part and the surface facing the said main reinforcing bar of the said 2nd extending | stretching part may intersect at an acute angle.

  The shear reinforcing member according to another aspect of the present invention is a shear reinforcing member including a fixing portion that spans a main shaft of the main body in a substantially orthogonal direction, and the fixing portion includes the shaft. A first extending portion extending from the end surface in the axial direction of the shaft body; and a first extending portion opposite to the end surface; A second extending portion extending in the intersecting direction and a third extending portion extending substantially parallel to the second extending portion on the end face side are integrally formed, and the main rebar is extended to the first extending portion. It inserts in the space enclosed by the part, the 2nd extending part, and the 3rd extending part.

  Here, the surface of the first extending portion that faces the main reinforcing bar may be formed according to the shape of the peripheral surface of the main reinforcing bar.

  In the shear reinforcing member of the present invention configured as described above, the shaft body and the fixing portion are firmly joined by friction welding. In the fixing unit, the first extending part and the second extending part intersecting with the first extending part are integrally formed, and the main reinforcing bar is hooked on the inner angle side of the first extending part and the second extending part.

  For this reason, the portion where the bending moment generated by the force acting from the main reinforcing bar is the largest is the first extending portion having a cross-sectional area wider than the cross section of the shaft main body, and therefore control can be performed so that excessive stress is not generated. it can. For example, when making the cross section of a 1st extending | stretching part rectangular, the stress which generate | occur | produces only by widening a width | variety can be reduced easily.

  Also, when the main reinforcing bar is inserted into the space surrounded by the first extending part, the second extending part and the third extending part of the fixing part, the bending moment generated by the force acting from the main reinforcing bar is the largest. It is possible to control so that an excessive stress does not occur at a certain point. Furthermore, the buckling suppression effect of the main reinforcing bars can be expected by surrounding the main reinforcing bars with three surfaces.

It is a perspective view for demonstrating the structure of the shear reinforcement member of embodiment of this invention. It is a figure for demonstrating the structure of a shear reinforcement member, Comprising: (a) is a side view, (b) is a top view. It is a figure explaining the bending moment and stress which generate | occur | produce in a shear reinforcement member, Comprising: (a) is explanatory drawing of the conventional shear reinforcement member, (b) is explanatory drawing of the shear reinforcement member of this Embodiment. It is a figure explaining the influence of the burr | flash part which generate | occur | produces when a shaft main body and a fixing | fixed part are friction-welded, Comprising: (a) is explanatory drawing of the conventional shear reinforcement member, (b) is the shear reinforcement of this Embodiment It is explanatory drawing of a member. It is an example of the analysis result which showed the stress which generate | occur | produces in a shear reinforcement member, Comprising: (a) is a stress distribution figure of the conventional shear reinforcement member, (b) is a stress distribution figure of the shear reinforcement member of this Embodiment. . It is a figure for demonstrating the structure of the shear reinforcement member of Example 1, Comprising: (a) is a side view, (b) is a top view. It is a perspective view for demonstrating the structure of the shear reinforcement member of Example 2. FIG. It is a figure for demonstrating the structure of the shear reinforcement member of Example 2, Comprising: (a) is a side view, (b) is a top view. It is a figure for demonstrating the structure of the shear reinforcement member of Example 3, Comprising: (a) is a side view, (b) is a top view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The shear reinforcement member 2A described in the present embodiment is disposed in a reinforced concrete structure. In the reinforced concrete structure, a reinforcing bar is disposed as a tensile resistance member. In the present embodiment, the reinforcing bars arranged as the tensile resistance member and the reinforcing bars as the main material arranged substantially parallel to the reinforcing bars are referred to as main reinforcing bars 1 and 1A.

  As shown in FIG. 1, the shear reinforcement member 2 </ b> A according to the present embodiment includes a shaft main body 21 that is oriented in a direction substantially orthogonal to the main reinforcing bar 1, and a fixing that is joined to the end of the shaft main body 21 by friction welding. It is mainly comprised by the part 3.

  The shaft body 21 is formed of a deformed reinforcing bar, a steel bar, or the like. In the present embodiment, one end of the shaft body 21 will be described in detail, but there is no limitation on the form of the other end of the shaft body 21. For example, the same fixing unit 3 may be provided at the other end of the shaft body 21, or a hook portion 23 is provided at the other end of the shaft body 21 as shown in FIG. May be.

  As shown in FIG. 1, the fixing unit 3 has an end surface 30 that abuts the end of the shaft main body 21 and causes friction welding. The friction welding is a method in which the shaft body 21 and the end face 30 are joined by frictional heat and high pressure generated when the shaft body 21 is pressed against the fixing unit 3 rotating at high speed. The joint strength by friction welding is set to be equal to or higher than the tensile strength of the shaft body 21.

  The end surface 30 of the fixing unit 3 has a larger area than the cross section of the shaft main body 21. Although the burr 22 is generated at the place where the friction welding is performed, since the amount of the burr 22 does not affect the bonding strength, it is necessary to consider the amount of the burr 22 when determining the width of the end face 30. There is no. In the present embodiment, the rectangular end face 30 will be described.

  The fixing unit 3 includes a first extending unit 31 extending in the axial direction of the shaft body 21 with the end surface 30 as a cross section, and a second extending unit extending in a direction intersecting the first extending unit 31 on the opposite side of the end surface 30. 32 is formed integrally. Such a fixing unit 3 can be formed by processing a metal material such as a steel material.

  Then, as shown in FIG. 1, the shear reinforcing member 2 </ b> A is arranged by hooking the inner corner side of the corner portion 3 a of the first extending portion 31 and the second extending portion 32 of the fixing portion 3 to the main reinforcing bar 1.

Next, details of the shape of the shear reinforcement member 2A will be described with reference to FIGS. 2 (a) and 2 (b). First, the shaft body 21 is a rod-like member having a diameter of _{D S.} The end face 30 of the fixing section 3 abutting the shaft body 21, the height A ₃ slightly larger than the diameter D _S and a short side, a rectangle wider width A ₆ than its height A ₃ and long side It is formed. The height A ₃ and the width A ₆ of the end face 30 should be at least dimensioned to allow friction welding at least the diameter D _S of the shaft body 21.

The first extending portion 31 which an end face 30 and cross-section, in the axial direction of the shaft body 21 is stretched the length of the A ₁ are formed in a quadrangular form. Since this first extending portion 31 is molded integrally with the second extending portion 32, but the length of the first extending portion 31 may also be referred to A _5, where the length A of the first extending portion 31 _Set to ₁ .

Meanwhile, the second extending portion 32 which intersects the first extending portion 31, the long side and the short side and A ₂ a rectangular cross-section and A _6, in a direction substantially orthogonal to the axial direction of the shaft body 21 of A ₇ It is stretched by a length and formed into a square columnar body. The length of the second extending portion 32 may be referred to also A _4, but here representing a length of the second extending portion 32 and the A _7.

  Since the fixing portion 3 has a quadrangular columnar first extending portion 31 and a second extending portion 32 that are substantially orthogonal to each other and formed in an L shape in a side view, the facing surface 31a of the first extending portion 31 that faces the main reinforcing bar 1. And the opposing surface 32a of the 2nd extending | stretching part 32 is also substantially orthogonal.

Then, the inner angle side of the first extending portion 31 corner portion 3a of the second extending portion 32, the main reinforcing bars 1 is accommodated a diameter D _M. Relationship between the length _{A 4} of the length _{A 1} and the opposing face 32a of the main reinforcing bar 1 having a diameter _{D M} and the facing surface 31a, the length _A 1, _{A 4} is it is sufficient that more than half of the diameter _{D M} .

  When the main reinforcing bar 1 is hooked on the fixing unit 3 in this way, a force is transmitted when the main reinforcing bar 1 comes into contact with the opposing surfaces 31a and 32a. For example, when the contact position of the main reinforcing bar 1 with respect to the facing surface 32a becomes a force application position, a bending moment acts near the corner 3a.

  Therefore, the stress generated in the shear reinforcement member 2A when the bending moment M acts will be described with reference to FIG. Here, Fig.3 (a) is a figure explaining the conventional shear reinforcement member a2 for comparing with the shear reinforcement member 2A of this Embodiment.

  In the conventional shear reinforcing member a2, a rectangular plate-shaped fixing plate a3 is joined to one end portion of a shaft main body a21 formed of a deformed reinforcing bar or the like by friction welding. Further, the other end portion of the shaft main body a21 is bent and processed into a hook portion a23, and is hooked on the main reinforcing bar 1A. Since the hook portion a23 is rotationally supported, the bending moment becomes zero.

  On the other hand, a force P in a direction substantially orthogonal to the surface of the fixing plate a3 is applied to the position where the main reinforcing bar 1 is in contact with the fixing plate a3. The distance L between the point of application of the force P and the axis of the shaft main body a21 becomes an arm, and the bending moment M = P × L acts on the joint between the shaft main body a21 and the fixing plate a3. .

Due to such a bending moment M, a stress σ ₁ is generated in the shaft main body a21. Section modulus _{Z 1} of the shaft body a21 radius r is calculated by ^{_{Z 1 = π / 4 × r}} 3, the stress sigma ₁ becomes σ ₁ = M / _{Z 1.}

As shown in FIG. 3B, the shear reinforcing member 2A of the present embodiment has a bending moment M at the corners of the first extending portion 31 and the second extending portion 32 as compared with the conventional shear reinforcing member a2. It acts near the corner 3a. Section modulus _{Z 2} of the first extending portion 31 in the vicinity of the corner portion ^{_{3a, Z 2 = b × h 2}} /6 Thus are calculated, the stress sigma ₂ becomes σ ₂ = M / _{Z 2.}

Since the section modulus is Z ₂ > Z ₁ , the generated stress is σ ₂ <σ ₁ . On the other hand, the bending moment M ₁ acting on the shaft main body 21 is reduced from the magnitude of the maximum bending moment M by the length of the first extending portion 31, so that σ ₃ <σ ₁ .

By thus increasing the section modulus Z ₂ of the first extending portion 31 of the fixing portion 3, it is possible to reduce the stress sigma ₂ occurring at a position where the maximum bending moment M is applied. Further, σ ₃ generated in the shaft main body 21 can also be suppressed.

By the way, if two members are joined by friction welding, a burr | flash will generate | occur | produce in a junction part. As shown in FIG. 4A, in the conventional shear reinforcing member a2 in which the shaft main body a21 is friction-welded to the fixing plate a3, the burr part a22 remains as it is in the joint part. The burr portion a22 mainly because the reinforcing bars 1 become an obstacle for close to the shaft body a21, length of the main reinforcement 1 and the shaft body a21 becomes L _1.

On the other hand, as shown in FIG. 4 (b), the shear reinforcement member 2 </ b> A according to the present embodiment is merely formed with the burr portion 22 by an amount that is placed on the end face 30 at a position that does not interfere with the main reinforcing bar 1. , it can be made smaller than the distance L ₁ between the shaft body 21 a distance L ₂ of the main reinforcement 1.

Since the maximum bending moment M as described above increases in proportion to the distance L _2, if it is possible to shorten the distance L _2, it is possible to reduce the stress sigma ₂ generated by that amount.

  As described above, the shear reinforcing member 2A of the present embodiment can suppress the stress generated at the location where the maximum bending moment M acts. The results of the analysis performed to confirm this effect are shown in FIG.

  The analysis was performed by a three-dimensional finite element method by creating a three-dimensional mesh analysis model for the conventional shear reinforcement member a2 and the shear reinforcement member 2A of the present embodiment.

In the analysis model of the conventional shear reinforcement member a2, the shaft body a21 has a diameter of 16 mm, and the fixing plate a3 is a rectangular plate having a plate thickness of 12 mm and a short side of 40 mm × long side of 52 mm. Also, the analysis model of the shear reinforcement member 2A of the present embodiment, the diameter _{D S} of the shaft body 21 16 mm, fixing unit 3 14mm to _{A 1,} 12 mm and _{A 2,} 20 mm of _{A 3, A 4} and 14mm, 26mm to a _5, and the _{a 6} 40 mm, the _{a 7} and 34 mm (see FIG. 2). Here, the Young's modulus of the shaft main bodies a21 and 21, the fixing plate a3, and the fixing unit 3 was set to 200 kN / mm ² .

  The analysis was performed by fixing the ends of the shaft main bodies a21 and 21 on the opposite side of the fixing plate a3 or the fixing unit 3 and loading the force P at a position corresponding to the contact position of the main reinforcing bar 1 by displacement control.

FIG. 5 shows the maximum principal stress distribution at the time point P = 5 kN. In FIG. 5A showing the analysis result of the conventional shear reinforcement member a2, the stress of the shaft main body a21 adjacent to the joint portion with the fixing plate a3 is increased to about 300 N / mm ² .

In contrast, in FIG. 5B showing the analysis result of the shear reinforcement member 2A of the present embodiment, a stress of about 100 N / mm ² is generated on the inner corner side of the corner portion 3a of the fixing portion 3. Only about 200 N / mm ² of stress is generated in the shaft body 21 in the vicinity of the joint with the fixing unit 3.

  Next, the operation of the shear reinforcement member 2A of the present embodiment will be described.

  In the shear reinforcing member 2A of the present embodiment configured as described above, the shaft body 21 and the fixing unit 3 are firmly joined by friction welding. In the fixing unit 3, the first extending portion 31 and the second extending portion 32 intersecting with the first extending portion 31 are integrally formed, and the main reinforcing bar 1 has an inner angle of the corner portion 3 a of the first extending portion 31 and the second extending portion 32. Hooked to the side.

Therefore, the area whereto the bending moment M generated by the force P becomes maximum acting from the main reinforcement 1, (a large section modulus Z ₂₎ is wider cross-sectional area than the cross-section of the shaft body 21 as a first extending portion 31 Therefore, it can be controlled so that excessive stress does not occur.

For example, when the cross section of the first extending portion 31 is rectangular like the fixing portion 3 of the present embodiment, the stress generated by simply widening the lateral width (A ₆ ) can be suppressed to a predetermined value or less.

  Moreover, in the conventional shear reinforcement member a2, since the columnar main rebar 1 crossed in the orthogonal direction is intersected with the columnar shaft main body a21, the contact portion between the shaft main body a21 and the main rebar 1 becomes a point. As a result, local stress was likely to occur. On the other hand, in the shear reinforcing member 2A of the present embodiment, the main rebar 1 is brought into contact with the opposing surface 31a that is the plane of the first extending portion 31, so that at least the contact portion becomes a line, and stress generated more than in the past. Can be reduced.

  Furthermore, if the surfaces 31a and 32a of the first extending portion 31 and the second extending portion 32 that are opposed to the main reinforcing bar 1 are substantially orthogonal to each other, the shear reinforcement excellent in the balance between the ease of being hooked on the main reinforcing bar 1 and the difficulty of coming off. The member 2A can be used.

  As described above with reference to FIG. 4, the conventional shear reinforcement member a <b> 2 increases the amount of protrusion of the fixing plate a <b> 3 in the direction perpendicular to the axis in consideration of interference with the burr part a <b> 22. If the fixing portion 3 of the shear reinforcement member 2A of the present embodiment in which the burr portion 22 and the main reinforcing bar 1 do not interfere with each other, the amount of protrusion in the direction perpendicular to the axis can be reduced. If the amount of protrusion of the fixing unit 3 in the direction perpendicular to the axis is reduced, installation is facilitated even when dense arrangement is performed, so that work efficiency can be improved.

  Next, a shear reinforcing member 2B having a form different from that of the above embodiment will be described with reference to FIG. Note that the description of the same or equivalent parts as those described in the above embodiment will be described with the same terms and the same reference numerals.

  As shown in FIG. 6, the shear reinforcing member 2 </ b> B according to the first embodiment includes a shaft main body 21 that is oriented in a direction substantially orthogonal to the main reinforcing bar 1, and a fixing unit that is joined to the end of the shaft main body 21 by friction welding. 4 is mainly composed. The fixing unit 4 has an end face 40 that abuts the end of the shaft main body 21 similar to the fixing unit 3 of the above-described embodiment and causes friction welding.

  The fixing unit 4 includes a first extending unit 41 extending in the axial direction of the shaft body 21 with the end surface 40 as a cross section, and a second extending unit extending in a direction intersecting the first extending unit 41 on the opposite side of the end surface 40. 42 is integrally formed.

  Then, as shown in FIG. 6A, the shear reinforcing member 2 </ b> B is arranged by hooking the inner corner side of the corner portion 4 a of the first extending portion 41 and the second extending portion 42 of the fixing portion 4 to the main rebar 1. .

The end face of the fixing portion 4 abutted against the shaft body 21 40 is formed in a rectangle the height B ₃ slightly larger than the diameter D _S and short sides, and the long side of the wide width B ₈ than its height B ₃ The

The first extending portion 41 which an end face 40 and cross-section, are stretched length of B ₁ in the axial direction of the shaft body 21 is formed in a quadrangular form. Since this first extending portion 41 is molded integrally with the second extending portion 42, but the length of the first extending portion 41 can be said that B _6, where B the length of the first extending portion 41 _Set to ₁ .

On the other hand, the second extending portion 42 which intersects the first extending portion 41, as shown in FIG. 6 (a), on the trapezoid to B ₄ the height to the lower base and B ₅ to the upper base and B ₂ , Each side has a side surface combining rectangles (squares) of B ₂ × B ₃ . Then the side in cross section, is stretched in a direction substantially parallel to the axial direction of the main reinforcing bar 1 as shown in FIG. 6 (b) by the length of the B _8. Although it can be said that only the trapezoidal cross-sectional portion of the second extending portion 42, a portion having a cross section obtained by combining a trapezoid with a rectangle is expressed as the second extending portion 42.

In the fixing portion 4 of the shear reinforcement member 2B of the first embodiment, the facing surface 41a of the first extending portion 41 opposed to the main reinforcing bar 1 and the facing surface 42a of the second extending portion 42 intersect at an acute angle. For example, tilting the opposing face 42a as B ₅ is about 5 mm longer than the length B _2.

Then, the inner angle side of the first extending portion 41 corner portion 4a of the second extending portion 42, the main reinforcing bars 1 is accommodated a diameter D _M. This major rebar first diameter _{D M} and the facing surface 41a of the length _{B 1} and the height _{B 4} corresponding to the opposing surface 42a relationships, the length _{B 1} and the height _{B 4} reaches or exceeds half the diameter _{D M} If it is.

  In the shear reinforcing member 2B of the first embodiment configured as described above, the opposed surfaces 41a and 42a opposed to the main reinforcing bar 1 of the first extending portion 41 and the second extending portion 42 intersect at an acute angle.

  For this reason, once the main reinforcing bar 1 is fitted to the inner corner side of the corner portion 4a of the fixing portion 4, the main reinforcing bar 1 is sandwiched between the opposing surfaces 41a and 42a and is difficult to come off. That is, when the main reinforcing bar 1 tries to move in the vertical direction in FIG. 6A, the opposing surfaces 41a and 42a become obstacles and the relative displacement is limited.

  Other configurations and operational effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  Next, a description will be given of a shear reinforcement member 2C in a form different from that of the above-described embodiment or example with reference to FIGS. Note that the description of the same or equivalent parts as those described in the embodiment or other examples will be given with the same terms and the same reference numerals.

  As shown in FIG. 7, the shear reinforcing member 2 </ b> C according to the second embodiment includes a shaft main body 21 that is oriented in a direction substantially orthogonal to the main reinforcing bar 1, and a fixing unit that is joined to the end of the shaft main body 21 by friction welding. 5 is mainly composed.

  The fixing unit 5 has an end surface 50 that abuts the end of the shaft main body 21 and frictionally contacts the end. The end surface 50 of the fixing unit 5 has a larger area than the cross section of the shaft main body 21. The end surface 50 of the second embodiment is formed in a rectangle that also serves as a side surface of a third extending portion 53 described later.

  The fixing unit 5 has a first extending unit 51 extending in the axial direction of the shaft body 21 with the upper portion of the end surface 50 as a cross section, and a second extending in a direction intersecting the first extending unit 51 on the opposite side of the end surface 50. The extending portion 52 and the third extending portion 53 extending substantially parallel to the second extending portion 52 on the end face 50 side are integrally formed. Such a fixing unit 5 is formed into a portal shape by processing a metal material such as a steel material.

  Then, as shown in FIG. 7, the shear reinforcement member 2 </ b> C is disposed so that the main reinforcing bar 1 is accommodated in the space surrounded by the first extending portion 51, the second extending portion 52, and the third extending portion 53 of the fixing unit 5. Deploy.

Next, details of the shape of the shear reinforcing member 2C will be described with reference to FIGS. 8 (a) and 8 (b). First, the end surface 50 of the fixing portion 5 abutting the shaft body 21, and the long side height C ₈ extending lower lateral width C ₇ larger than the diameter D _S and short sides, from the top, which abut against the shaft body 21 Formed into a rectangular shape. The horizontal width C ₇ of the end face 50 should be at least dimensioned to allow friction welding at least the diameter D _S of the shaft body 21.

The first extending portion 51 is a rectangular cross-section of the horizontal width C ₇ × height C ₂ in the axial direction of the shaft body 21 (C 1 _{-C 6)} to be stretched length is formed in a quadrangular form. Because it is molded integrally with the first extending portion 51 and the second extending portion 52 and the third extending portion 53, but the lengths of the first extending portion 51 can be said that such C _1, the first drawing here Let the length of the part 51 be (C ₁ -C ₆ ).

Meanwhile, the second extending portion 52 which intersects the first extending portion 51, as shown in FIG. 8 (a), a rectangular sides the long side to the short side and C ₆ to C ₈ as cross-8 ( in a direction substantially parallel to the axial direction of the main reinforcing bar 1 as shown in b) is stretched by the length of C ₇ are formed in a quadrangular form. The length of the second extending portion 52 can also be referred to as C ₃ , but here, the length of the second extending portion 52 is expressed as C ₈ .

The third extending portion 53 formed substantially parallel to the second extending portion 52, as shown in FIG. 8 (a), a rectangular side and C ₃ the long side to the short side and C ₄ in cross-section As shown in FIG. 8 (b), a rectangular columnar body is formed by extending with a length of C ₇ in a direction substantially parallel to the axial direction of the main reinforcing bar 1.

Although the thickness C ₄ of the third extending portion 53 can be set arbitrarily, the thickness C ₆ of the second extending portion 52 is made thinner in consideration of the magnitude of the force received from the main reinforcing bar 1. Can do. Incidentally, the third extending portion 53 the distance between the second extending portion 52 becomes _{C 5.}

  The fixing unit 5 has a quadrangular columnar first extending part 51, a second extending part 52, and a third extending part 53 that are formed in a gate shape substantially orthogonal to each other, and therefore the first extending part 51 that faces the main reinforcing bar 1. The opposing surface 51a, the opposing surface 52a of the second extending portion 52, and the opposing surface 53a of the third extending portion 53 are substantially orthogonal to each other.

Then, the first extending portion 51 and the second extending portion 52 third surrounded by the extending portion 53 space, the main reinforcing bars 1 is accommodated a diameter D _M. Therefore, the length C ₅ of the facing surface 51a, it is necessary to slightly larger than the diameter D _M of the main reinforcement 1. On the other hand, the relationship between the length _{C 3} of the main reinforcing bar 1 having a diameter _{D M} and the facing surface 52a and the opposing face 53a is, the length _{C 3} it is sufficient that more than half the diameter _{D M.}

  When the main reinforcing bar 1 is inserted into the inner space of the gate-shaped fixing unit 5 in this way, a force is transmitted when the main reinforcing bar 1 comes into contact with the opposing surfaces 51a, 52a, 53a. For example, when the contact position of the main reinforcing bar 1 with respect to the facing surface 52 a becomes the force application position, a bending moment acts near the corners of the first extending portion 51 and the second extending portion 52.

  The shear reinforcing member 2 </ b> C according to the second embodiment configured as described above inserts the main reinforcing bar 1 into a space surrounded by the first extending portion 51, the second extending portion 52, and the third extending portion 53 of the fixing unit 5.

  For this reason, the portion where the bending moment M generated by the force acting from the main reinforcing bar 1 is the largest is the first extending portion 51 having a larger cross-sectional area (a larger section modulus) than the cross-section of the shaft body 21, and thus is excessive. It is possible to control so that no significant stress is generated.

  Moreover, the buckling suppression effect of the main rebar 1 can be expected by configuring the main rebar 1 to be surrounded by the three opposing surfaces 51a, 52a, and 53a.

  Other configurations and operational effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  Next, a shear reinforcement member 2D having a form different from that of the above-described embodiment or example will be described with reference to FIG. Note that the description of the same or equivalent parts as those described in the embodiment or other examples will be given with the same terms and the same reference numerals.

  In the second embodiment, the fixing unit 5 in which the three facing surfaces 51 a, 52 a, and 53 a with respect to the main reinforcing bar 1 are substantially orthogonal to each other has been described. In this third embodiment, the facing surfaces matched to the peripheral surface shape of the main reinforcing bar 1. The fixing unit 6 where the 6a is formed will be described.

  The fixing unit 6 has an end surface 60 that abuts the end of the shaft main body 21 and frictionally contacts the end. The fixing unit 6 has a first extending portion 61 extending in the axial direction of the shaft body 21 with the upper portion of the end surface 60 as a cross section, and a second extending in a direction intersecting the first extending portion 61 on the opposite side of the end surface 60. The extending portion 62 and the third extending portion 63 extending substantially parallel to the second extending portion 62 on the end surface 60 side are integrally formed.

  Such a fixing portion 6 is formed into a gate shape in which the inner space is a horseshoe shape by processing a metal material such as a steel material. Then, the shear reinforcement member 2 </ b> D is arranged so that the main reinforcing bar 1 is accommodated in a horseshoe-shaped space surrounded by the first extending portion 61, the second extending portion 62, and the third extending portion 63 of the fixing unit 6.

Next, details of the shape of the shear reinforcement member 2D will be described with reference to FIGS. 9 (a) and 9 (b). First, the end surface 60 of the fixing portion 6 abutting the shaft body 21, and the long side the height D ₈ extending lower lateral width D ₇ is greater than the diameter D _S and short sides, from the top, which abut against the shaft body 21 Formed into a rectangular shape.

The first stretching unit 61, the second stretching unit 62, and the third stretching unit 63 of the fixing unit 6 of Example 3 are less likely to define boundaries than the fixing unit 5 of Example 2, but as described above, the fixing unit 6 Is integrally formed and has no meaning in defining the boundary. The fixing unit 6 according to the third embodiment and the fixing unit 5 according to the second embodiment have substantially the same outer shape, and the opposing surfaces 6a of the first extending portion 61, the second extending portion 62, and the third extending portion 63 that are opposed to the main reinforcing bar 1. Since only the shapes of are different, only the description of the corresponding dimensions is given for the outer shape. That is, the dimensions C ₁ , C ₂ , C ₃ , C ₄ , C ₅ , C ₆ , C ₇ , and C ₈ of the fixing unit 5 of Example 2 are the dimensions D ₁ and D ₂ of the fixing unit 6 of Example 3. , D ₃ , D ₄ , D ₅ , D ₆ , D ₇ , and D ₈ respectively.

  On the other hand, the facing surface 6a of the fixing unit 6 according to the third embodiment is formed in a side-view horseshoe shape having a curved surface at the top as shown in FIG. The curved surface of the facing surface 6 a has a shape that matches the peripheral surface shape of the main reinforcing bar 1.

Then, the first extending portion 61 and the second extending portion 62 space surrounded by the third extending portion 63, the main reinforcing bars 1 is accommodated a diameter D _M. Accordingly, the width D ₅ of the opening of the opposing surface 6a should be slightly larger than the diameter D _M of the main reinforcement 1. On the other hand, the relationship between the height D ₃ of the main reinforcing bar 1 having a diameter D _M and the opposing surface 6a has a height D ₃ has only to become more than half of the diameter D _M.

  Thus, when the shape of the opposing surface 6a is matched with the peripheral shape of the main reinforcing bar 1, the contact area between the main reinforcing bar 1 and the opposing surface 6a becomes wide, and the force is transmitted as a distributed load. . For this reason, it is possible to control so that excessive stress such as local stress is not generated in the fixing unit 6.

  Moreover, the buckling suppression effect of the main rebar 1 can be expected by configuring the main rebar 1 to be surrounded by the facing surface 6a. Furthermore, once the main rebar 1 is fitted into the horseshoe-shaped inner space of the fixing unit 6, the main reinforcing bar 1 is sandwiched by the facing surface 6 a and is not easily detached.

  Other configurations and operational effects are substantially the same as those of the above-described embodiment or other examples, and thus description thereof is omitted.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to the embodiment and the example, and the design change is within a range not departing from the gist of the present invention. Are included in the present invention.

1, 1A Main reinforcement 2A-2D Shear reinforcement member 21 Shaft body 3 Fixing portion 30 End surface 31 First extending portion 31a Opposing surface 32 Second extending portion 32a Opposing surface 4 Fixing portion 40 End surface 41 First extending portion 41a Opposing surface 42 2 stretching section 42a facing surface 5 fixing section 50 end surface 51 first stretching section 51a facing surface 52 second stretching section 52a facing surface 53 third stretching section 53a facing surface 6 fixing section 60 end surface 61 first stretching section 62 second stretching section 63 3rd extension part 6a Opposite surface

Claims (3)

A shear reinforcement member having a fixing portion that spans the main shaft of the shaft main body in a substantially orthogonal direction,
The fixing unit has an end surface wider than a cross section of the shaft main body that abuts the shaft main body and frictionally welds the first main body, a first extending portion that extends in the axial direction of the shaft main body with the end surface as a cross section, and A second extending portion that is extended in a direction intersecting the first extending portion on the opposite side is integrally formed, and the main reinforcing bar is hooked on the inner angle side of the first extending portion and the second extending portion. A characteristic shear reinforcement member.   The shear reinforcement member according to claim 1, wherein the end surface is formed in a rectangular shape. A shear reinforcement member having a fixing portion that spans the main shaft of the shaft main body in a substantially orthogonal direction,
The fixing portion has a wider end surface than a cross-section of the shaft main body against which the shaft main body is abutted and friction-welded, a first extending portion extending in the axial direction of the shaft main body from the end surface, and a side opposite to the end surface The second stretched portion that is stretched in the direction intersecting the first stretched portion and the third stretched portion that is stretched substantially parallel to the second stretched portion on the end face side are integrally formed, A shear reinforcing member, wherein a main reinforcing bar is inserted into a space surrounded by the first extending portion, the second extending portion, and the third extending portion.