PC Steel Connector

Abstract

To improve working efficiency when a first PC steel material and a second PC steel material are connected.SOLUTION: A connector (1) for connecting a first PC steel material (C1) and a second PC steel material (C2) has a connector body (10) and a connector lid (20). One end of the connector body (10) is connected to an anchoring tool (30) fixed to the first PC steel material (C1), and the other end of the connector body (10) has an opening (12) for passing a coupler (40) fixed to the second PC steel material (C2). The connector lid (20) is detachably connected to the opening (12) of the connector body (10). In the state where the connector lid (20) is connected to the opening (12) of the connector body (10), the coupler (40) is stored inside the connector body (10), and the second PC steel material (C2) passes through the connector lid (20).SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a connector used to connect two prestressing tendons and a method for connecting two prestressing tendons. [Background technology]

[0002] In PC structures, which use prestressed concrete (PC) steel members to introduce prestress into a concrete skeleton, anchors are fixed to both ends of the PC steel members. When widening the PC structure, new PC steel members may be connected to existing PC steel members. Below, we will explain how to connect new PC steel members to existing PC steel members using Figures 12 to 14.

[0003] 12 is a cross-sectional view of a connector 100 used to connect existing and new prestressing steel members, taken along the longitudinal direction of the prestressing steel members. The connector 100 is cylindrical, and a threaded portion 110 is formed on the inner peripheral surface of one end of the connector 100 (the end on the left side in FIG. 12). A stopper portion 120 is integrally formed on the other end of the connector 100 (the end on the right side in FIG. 12), and a through-hole 121 is formed in the stopper portion 120 for passing the new prestressing steel member through.

[0004] 13 and 14 are diagrams illustrating a method of connecting a new PC steel member C2 to an existing PC steel member C1.

[0005] As shown in Figure 13, a prestressing steel member C1 is embedded in an existing concrete body CS, and a fixing device 200 is fixed to one end of the prestressing steel member C1. The fixing device 200 has a bearing plate 210, a sleeve 220, and a plurality of wedges 230. The plurality of wedges 230 are inserted into through holes 221 of the sleeve 220 together with the prestressing steel member C1, thereby fixing the prestressing steel member C1 to the fixing device 200. A threaded portion 222 is formed on the outer peripheral surface of the sleeve 220.

[0006] Meanwhile, a coupler (crimping grip) 300 is fixed to one end of the newly installed prestressing steel C2. When connecting the prestressing steels C1 and C2, first, the connector 100 is attached to the coupler 300. Specifically, the other end of the prestressing steel C2 is inserted into the inside of the connector 100 from the side of the threaded portion 110 and passed through the through-hole 121. Then, by moving the coupler 300 relative to the connector 100 in the direction of arrow D10 shown in FIG. 13, the coupler 300 is accommodated inside the connector 100 and the coupler 300 is brought into contact with the stopper portion 120.

[0007] Next, as shown in Figure 14, while engaging the threaded portion 110 of the connector 100 with the threaded portion 222 of the sleeve 220, the connector 100 is moved relative to the fixing device 200 in the direction of arrow D11 shown in Figure 14. This secures the connector 100 to the fixing device 200, and the prestressing steel members C1 and C2 can be connected to each other. At this point, if a tensioning jack (not shown) is connected to the other end of the prestressing steel member C2 (the end opposite the coupler 300) and the prestressing steel member C2 is pulled, tension can be applied to the prestressing steel members C1 and C2. Summary of the Invention [Problem to be solved by the invention]

[0008] 13 and 14, coupler 300 must be accommodated inside connector 100 while holding connector 100. Furthermore, with coupler 300 accommodated inside connector 100, connector 100 must be fixed to fixing device 200. These operations are complicated, and there is room for improvement in work efficiency. [Means for solving the problem]

[0009] The first invention of the present application is a connector for connecting first and second prestressing steel members, comprising a connector body and a connector lid. One end of the connector body is connected to a fixing device fixed to the first prestressing steel member, and the other end of the connector body has an opening through which a coupler fixed to the second prestressing steel member passes. The connector lid is detachably connected to the opening of the connector body. When the connector lid is connected to the opening of the connector body, the coupler is housed inside the connector body, and the second prestressing steel member passes through the connector lid.

[0010] The connector lid can be formed with a threaded portion that can engage with a threaded portion formed in the opening of the connector body. The connector lid can be provided with an inner circumferential surface that follows the outer circumferential surface of the second prestressing steel member and a notch for guiding the second prestressing steel member to the inner circumferential surface. The outer circumferential surface of the connector lid can then be connected to the opening.

[0011] A threaded portion can be formed on one end of the connector body, and this threaded portion can be engaged with a threaded portion formed on the fixing device. This allows the one end of the connector body to be connected to the fixing device of the first prestressing steel member. Alternatively, the one end of the connector body can be connected to the fixing device of the first prestressing steel member via a wedge. Here, the wedge can be held down by a holding cover that is sandwiched between the fixing device and the coupler.

[0012] The second invention of the present application is a connection method for connecting first and second prestressing steel members. In this connection method, one end of a connector body is connected to a fastener fixed to the first prestressing steel member (connection step). Then, a coupler fixed to the second prestressing steel member is inserted into the connector body through an opening formed in the other end of the connector body (insertion step). After the insertion step, a connector cover, which passes through the second prestressing steel member, is connected to the opening of the connector body. [Effects of the Invention]

[0013] According to the present invention, with the connector body connected to the fastener for the first prestressing steel member, the coupler for the second prestressing steel member can be housed inside the connector body through the opening of the connector body. Then, by connecting the connector cover to the connector body, the first prestressing steel member and the second prestressing steel member can be connected via the connector. This improves work efficiency compared to conventional methods. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a cross-sectional view of the connector main body in the first embodiment. [Figure 2] FIG. 2 is a view showing one end face of the connector main body in the first embodiment. [Figure 3] 3A and 3B are external views of a connector cover according to the first embodiment. [Figure 4] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 5] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 6] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 7] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 8] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 9] 3A to 3C are diagrams illustrating a method for connecting new prestressing steel members to existing prestressing steel members in the first embodiment. [Figure 10] FIG. 10 is a diagram showing a connection structure of PC steel members in the second embodiment. [Figure 11] FIG. 10 is an exploded view of the PC steel connecting structure in the second embodiment. [Figure 12] FIG. 10 is a cross-sectional view of a conventional connector. [Figure 13]FIG. 1 is a diagram illustrating a conventional method for connecting new prestressing tendons to existing prestressing tendons. [Figure 14] FIG. 1 is a diagram illustrating a conventional method for connecting new prestressing tendons to existing prestressing tendons. DETAILED DESCRIPTION OF THE INVENTION

[0015] (First embodiment) A connector 1 used to connect a new prestressing steel member (second prestressing steel member) C2 to an existing prestressing steel member (first prestressing steel member) C1 will be described with reference to Figures 1 to 3. The connector 1 has a connector main body 10 shown in Figures 1 and 2 and a connector cover 20 shown in Figure 3. Figure 1 is a cross-sectional view of the connector main body 10 taken along the longitudinal direction of the prestressing steel members C1 and C2, and Figure 2 is a view of the connector main body 10 as viewed from the direction of arrow D1 shown in Figure 1.

[0016] The connector body 10 is formed in a cylindrical shape. A threaded portion 11 is formed on the inner peripheral surface of one end (the end on the left side in FIG. 1) of the connector body 10, and a threaded portion 12 is formed on the inner peripheral surface of the other end (the end on the right side in FIG. 1) of the connector body 10.

[0017] Furthermore, a plurality of viewing windows (through holes) 13 are formed in the connector body 10, and the viewing windows 13 penetrate the connector body 10 in the radial direction of the connector body 10. As shown in Fig. 2, the plurality of viewing windows 13 are arranged at predetermined intervals in the circumferential direction of the connector body 10. The viewing windows 13 are used to visually check components housed inside the connector body 10 (such as a part of the fixing device 30 and the coupler 40, which will be described later) from the outside of the connector body 10.

[0018] The connector lid 20 is attached to the threaded portion 12 of the connector body 10. As shown in Fig. 3(A), the connector lid 20 is formed in a substantially U-shape and has a notch 21. Fig. 3(B) is a view of the connector lid 20 as viewed from the direction of arrow D2 shown in Fig. 3(A). The inner peripheral surface 22 of the connector lid 20 is formed along the outer peripheral surface of the prestressing steel C2, and the space surrounded by the inner peripheral surface 22 is used to allow the prestressing steel C2 to pass through.

[0019] A threaded portion 23 is formed on the outer peripheral surface of the connector lid 20, and the threaded portion 23 engages with the threaded portion 12 of the connector body 10. Here, the outer peripheral surface of the connector lid 20 (threaded portion 23) is formed in a shape that follows the inner peripheral surface of the connector body 10 on which the threaded portion 12 is formed. By rotating the connector lid 20 relative to the connector body 10, the threaded portions 12, 23 engage with each other, thereby fixing the connector lid 20 to the connector body 10.

[0020] The shape of the connector lid 20 is not limited to the shape shown in Fig. 3. As will be described later, it is sufficient if the prestressing steel C2 can pass through the connector lid 20 when the connector lid 20 is attached to the connector main body 10. For example, the connector lid 20 can be formed in a ring shape, and the prestressing steel C2 can be passed through an opening in this ring shape. Also, the connector lid 20 may be divided into multiple lid parts (for example, half lid parts), and these lid parts may be attached to the connector main body 10.

[0021] Next, a method for connecting prestressing steel members C1 and C2 to each other using the above-mentioned connector 1 will be described with reference to Figures 4 to 9. As shown in Figure 4, a prestressing steel member C1 and an anchoring device 30 are installed in an existing concrete skeleton CS. The anchoring device 30 has a bearing plate 31, a sleeve 32, and a plurality of wedges 33.

[0022] One end of the PC steel C1 passes through a through hole 31a formed in the bearing plate 31 and protrudes outside the concrete body CS. A plurality of wedges 33 are arranged on the outer periphery of the end of the PC steel C1 protruding from the concrete body CS, and the inner peripheral surface 33a of each wedge 33 contacts the outer peripheral surface of the PC steel C1. Here, the inner peripheral surface 33a of the wedges 33 can be configured as a flat surface, or the inner peripheral surface 33a of the wedges 33 can be formed with uneven teeth that bite into the outer peripheral surface of the PC steel C1.

[0023] The multiple wedges 33 are inserted into through holes 32a formed in the sleeve 32. The through hole 32a of the sleeve 32 has a tapered surface, and the diameter of the through hole 32a continuously decreases from one end of the sleeve 32 (the right end in FIG. 4) to the other end of the sleeve 32 (the left end in FIG. 4). The outer peripheral surface 33b of the wedge 33 is formed along the through hole 32a of the sleeve 32 (i.e., the tapered surface). By inserting the multiple wedges 33 into the through hole 32a of the sleeve 32 together with the prestressing steel C1, the end of the prestressing steel C1 can be fixed to the fastener 30. A threaded portion 32b is formed on the outer peripheral surface of the sleeve 32.

[0024] First, as shown in Fig. 4, the connector body 10 is moved in the direction of arrow D3 to engage the threaded portion 11 of the connector body 10 with the threaded portion 32b of the sleeve 32. Specifically, by rotating the connector body 10 along the threaded portions 11, 32b relative to the sleeve 32, the connector body 10 can be fixed to the sleeve 32 as shown in Fig. 5. This causes the sleeve 32 to be housed inside the connector body 10.

[0025] Next, as shown in Fig. 6, the coupler (crimping grip) 40 fixed to one end of the newly installed PC steel C2 is moved in the direction of arrow D4 relative to the connector body 10, thereby housing the coupler 40 inside the connector body 10. The coupler 40 enters the inside of the connector body 10 from the end of the connector body 10 where the threaded portion 12 is formed. Here, the diameter of the inner circumferential surface where the threaded portion 12 is formed is larger than the outer diameter of the coupler 40.

[0026] After the coupler 40 is housed inside the connector body 10, the connector lid 20 is placed on the outer periphery of the prestressing steel C2, as shown in Fig. 7. As described above, the connector lid 20 has the cutout portion 21, so that the connector lid 20 can be placed on the outer periphery of the prestressing steel C2 by passing the prestressing steel C2 through the cutout portion 21.

[0027] Next, by moving the connector lid 20 in the direction of arrow D5 shown in Fig. 7, the connector lid 20 can be attached to the connector body 10 as shown in Fig. 8. Specifically, the connector lid 20 can be fixed to the connector body 10 by engaging the threaded portion 23 formed on the outer peripheral surface of the connector lid 20 with the threaded portion 12 formed on the inner peripheral surface of the connector body 10. Here, the connector lid 20 is rotated relative to the connector body 10 along the threaded portions 23, 12.

[0028] 9, a coupler sheath 50 is placed on the outside of the connector 1 (connector body 10 and connector lid 20), and after covering the connector 1 with the coupler sheath 50, a filler is injected into the inside of the coupler sheath 50. Specifically, an injection pump (not shown) is connected to an injection port 51 formed in the coupler sheath 50, and the filler is injected into the inside of the coupler sheath 50 from the injection port 51. This allows the connector 1 to be covered with the filler, and makes it possible to protect the connector 1 and the components housed inside the connector 1 (such as the sleeve 32, wedge 33, and coupler 40).

[0029] The filler may be the same as the filler filled around the PC steel strands C1 and C2. The PC steel strands C1 and C2 may be covered with a cylindrical sheath (not shown), and the inside of this sheath may be filled with a filler to protect the PC steel strands C1 and C2. For example, a resin may be used as the filler.

[0030] In this embodiment, a coupler sheath 50 is placed outside the connector 1 (connector body 10 and connector lid 20) and a filler is injected into the inside of the coupler sheath 50, but the coupler sheath 50 may be omitted and the injection of the filler into the coupler sheath 50 may be omitted.

[0031] After injecting a filler into the coupler sheath 50, concrete can be poured around the coupler sheath 50 and the PC steel C2 to add to the concrete structure. Then, a tensioning jack or the like is used to pull the other end of the PC steel C2 (the end opposite the end where the coupler 40 is installed).

[0032] When the PC steel C2 is pulled by a tensioning jack or the like, the coupler 40 comes into contact with the connector cover 20, and the tensile force (tension) of the PC steel C2 is transmitted to the connector 1. Furthermore, because the connector body 10 is fixed to the sleeve 32 of the fixing device 30, the tensile force of the PC steel C2 transmitted to the connector 1 is transmitted to the PC steel C1 via the fixing device 30. This allows both PC steels C1 and C2 to be tensioned.

[0033] After tensioning both PC tendons C1 and C2, a fixing device (not shown) is attached to the other end of PC tendon C2, thereby introducing prestress into the concrete body in which the PC tendons C1 and C2 are embedded. Here, the fixing device 30 described in this embodiment can be used as the fixing device attached to the other end of PC tendon C2.

[0034] In this embodiment, new prestressing steel C2 is connected to prestressing steel C1 already installed in the concrete skeleton CS during construction to widen the concrete skeleton CS, but the present invention is not limited to this. That is, the connector 1 of this embodiment can be used in any structure that connects two prestressing steels C1 and C2. For example, when constructing the concrete skeleton CS in sections, the connector 1 of this embodiment can be used to connect prestressing steel embedded in one concrete skeleton CS to prestressing steel embedded in the other concrete skeleton CS.

[0035] According to this embodiment, as shown in Figures 6 and 7, when the connector main body 10 is attached to the sleeve 32 of the fixing device 30, the coupler 40 can be housed inside the connector main body 10. This eliminates the need to attach the connector 100 to the sleeve 220 of the fixing device 200 when the coupler 300 is housed inside the connector 100, as in the conventional case (Figures 13 and 14), thereby improving workability.

[0036] In the conventional method (FIGS. 13 and 14), when connecting the connector 100 to the sleeve 200, the entire connector 100 must be rotated relative to the sleeve 200 with the coupler 300 housed inside the connector 100. In this embodiment, after the coupler 40 is housed inside the connector main body 10, it is only necessary to rotate the connector lid 20 relative to the connector main body 10, thereby improving workability.

[0037] (Second embodiment) A second embodiment of the present invention will be described with reference to Figures 10 and 11. In this embodiment, components having the same functions as those described in the first embodiment are designated by the same reference numerals, and detailed descriptions thereof will be omitted. Below, differences from the first embodiment will be mainly described.

[0038] The sheath S1 covers the existing prestressing steel C1, and the sheath S2 covers the new prestressing steel C2. The sheaths S1 and S2 are filled with the above-mentioned filler. A spacer 31b is disposed between the outer surface of the sheath S1 and the through-hole 31a of the support plate 31.

[0039] In the first embodiment, the coupler (crimping grip) 40 is fixed to one end of the PC steel C2, but in this embodiment, a coupler 60 is fixed to one end of the PC steel C2. The coupler 60 has a plurality of wedges 61 and a sleeve 62. The plurality of wedges 61 are arranged on the outer peripheral surface of the PC steel C2 and are inserted into a through hole (including a tapered surface) 62a of the sleeve 62 together with the PC steel C2. In this way, the coupler 60 is fixed to the PC steel C2.

[0040] In the first embodiment, the coupler 60 (wedge 61 and sleeve 62) of this embodiment can be used instead of the coupler (crimping grip) 40. In the present embodiment, the coupler 60 (wedge 61 and sleeve 62) can be used instead of the coupler (crimping grip) 40 of the first embodiment.

[0041] In this embodiment, the connector body 10 is connected to the sleeve 32 via a plurality of wedges 14. The plurality of wedges 14 are arranged along the outer circumferential surface of the sleeve 32, and the inner circumferential surfaces 14a of the wedges 14 are in contact with the outer circumferential surface of the sleeve 32. Note that threaded portions that engage with each other can be formed on the inner circumferential surfaces 14a of the wedges 14 and the outer circumferential surface of the sleeve 32. The inner circumferential surface 15 of the connector body 10 is configured as a tapered surface and is in contact with the outer circumferential surfaces 14b of the wedges 14.

[0042] As shown in Fig. 10 , a pressure cover 70 is disposed in a space formed inside the connector body 10. In the assembled state shown in Fig. 10 , the pressure cover 70 presses down on the wedge 14, thereby preventing the wedge 14 from slipping off the inner peripheral surface 15 of the connector body 10. Here, as shown in Fig. 10 , the pressure cover 70 is sandwiched between the wedge 33 of the fixing device 30 and the wedge 61 of the coupler 60. One end face of the pressure cover 70 (the end face on the left side in Fig. 10 ) contacts the end face of the wedge 33, and the other end face of the pressure cover 70 (the end face on the right side in Fig. 10 ) contacts the end face of the wedge 61. Furthermore, through holes 71 are formed in the pressure cover 70, and the ends of the PC steel members C1 and C2 are inserted into the through holes 71, respectively.

[0043] The connector body 10 has an opening in which a threaded portion 12 is formed. The coupler 60 can be moved from the outside of the connector body 10 to the inside of the connector body 10 via this opening (threaded portion 12). After the coupler 60 is housed inside the connector body 10, the connector lid 20 can be placed on the outer periphery of the sheath S2 and connected to the connector body 10. Specifically, as in the first embodiment, the connector lid 20 can be connected to the connector body 10 by engaging the threaded portion 23 formed on the outer periphery of the connector lid 20 with the threaded portion 12 of the connector body 10.

[0044] In this embodiment as well, the coupler 60 can be housed inside the connector main body 10 in a state where the connector main body 10 is attached to the sleeve 32 of the fixing device 30 via the wedge 14. This eliminates the need to attach the connector 100 to the sleeve 220 of the fixing device 200 in a state where the coupler 300 is housed inside the connector 100, as in the conventional case (FIGS. 13 and 14), thereby improving workability.

[0045] Furthermore, in the conventional method (FIGS. 13 and 14), when fixing the connector 100 to the sleeve 200, the entire connector 100 must be rotated relative to the sleeve 200 with the coupler 300 housed inside the connector 100. In this embodiment, after the coupler 60 is housed inside the connector main body 10, it is only necessary to rotate the connector lid 20 relative to the connector main body 10, thereby improving workability.

[0046] In the first and second embodiments, the screw portions 23, 12 are used to detachably connect the connector lid 20 to the connector main body 10, but this is not limiting. For example, the connector lid 20 can be detachably connected to the connector main body 10 using a structure in which a convex portion engages a concave portion. Here, one of the convex portion and the concave portion can be provided on the connector lid 20, and the other of the convex portion and the concave portion can be provided on the connector main body 10. Furthermore, it is only necessary that the convex portion can be inserted into the concave portion and that the convex portion can come into contact with the concave portion after the connector lid 20 is rotated relative to the connector main body 10, preventing the connector lid 20 from coming off the connector main body 10. [Explanation of symbols]

[0047] 1: Connector, 10: Connector body, 11, 12: Threaded portion, 13: Viewing window, 14: Wedge, 20: Connector cover, 30: Fixing device, 31: Support plate, 32: Sleeve, 33: Wedge, 40: Coupler (crimping grip), 50: Coupler sheath, 60: Coupler, 61: Wedge, 62: Sleeve, C1, C2: PC steel, CS: Concrete body, S1, S2: Sheath

Claims

1. A connector for connecting a first PC steel member and a second PC steel member, a connector body having one end connected to a fastener fixed to the first PC steel member and having an opening at the other end through which a coupler fixed to the second PC steel member passes; a connector cover that is detachably connected to the opening and that, when connected to the opening, accommodates the coupler inside the connector body and allows the second PC steel member to pass through; A connector comprising:

2. 2. The connector according to claim 1, wherein the connector cover has a threaded portion that engages with a threaded portion formed in the opening.

3. The connector cover has an inner peripheral surface formed along an outer peripheral surface of the second PC steel member and a notch portion for guiding the second PC steel member to the inner peripheral surface, 3. The connector according to claim 1, wherein an outer peripheral surface of the connector cover is connected to the opening.

4. 4. The connector according to claim 1, wherein the connector body has a threaded portion at the one end thereof that engages with a threaded portion formed on the fixing device.

5. the connector body is connected at the one end to the fixing device via a wedge; 4. The connector according to claim 1, wherein the wedge is held down by a holding cover sandwiched between the fixing tool and the coupler.

6. A connection method for connecting a first PC steel member and a second PC steel member, a connecting step of connecting one end of a connector body to a fastener fixed to the first PC steel member; an insertion step of inserting a coupler fixed to the second PC steel into the connector body through an opening formed in the other end of the connector body; After the inserting step, a step of connecting a connector cover through which the second PC steel member passes to the opening; A method for connecting PC steel members, comprising:

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