Connection tool of PC steel stranded wire and connection method

Abstract

To easily mount a coupler sheath even when a coupler sheath fixing portion provided at a bearing plate is broken.SOLUTION: A connection tool includes: a connection tool primary side holding part for tensing a primary side PC steel stranded wire 10; a connection tool secondary side holding part for tensing a secondary side PC steel stranded wire 20; a secondary side joint 500 for connecting these; and a connection bottom plate 700 for mounting a coupler sheath. The connection bottom plate 700 includes a flange part 704 at an end part of a bearing plate 18 side. At the flange part 704, a bolt hole 700H is provided for coupler sheath mounting. An opposite side end surface (contact end surface 708) from the flange part in the longer direction is pressed by an end surface 508 on the bearing plate 18 side in the secondary side joint 500, and the connection bottom plate 700 is fixed to the bearing plate 18.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a connector and a connection method for PC steel strands used to apply prestress to post-tensioned prestressed concrete, and in particular to a connector and connection method for PC steel strands (in this invention, PC steel strands refers to PC steel strands) that can secure the coupler sheath with bolts or the like on the primary side of the connector even if the mounting portion (internal threaded hole, bolt hole) for attaching the coupler sheath provided on the primary plate (bearing plate) in a coupler sheath-type connector is filled with concrete or the internal thread is corroded and becomes unusable after primary construction.Furthermore, the present invention relates to a connector and connection method for PC steel strands that can prevent leakage of filler material filled in the coupler sheath after the coupler sheath is attached and suppress the intrusion of corrosion factors from outside the coupler sheath. [Background technology]

[0002] Conventionally, in post-tensioned prestressed concrete (PC) structures, at the concrete joints connecting the PC steel members used to prestress the concrete, after the PC steel members of the preceding section A and the following section B are connected using connectors, direct-buried connectors or coupler sheath connectors have been used to prevent the connectors from being restricted in movement by the concrete when tensioning the PC steel members of the following section B.

[0003] Japanese Patent Application Laid-Open Publication No. 2007-046313 (Patent Document 1) filed by the applicant of the present application discloses a connection method using a direct-burial type connector. The direct-burial connection method for prestressing tendons disclosed in Patent Document 1 is a method for tensioning prestressing tendons by directly burying them at concrete joints between a preceding construction section and a succeeding construction section using a connection device having a primary connection section and a secondary connection section, and is characterized in that a bearing pressure relief means is provided in association with the terminal of the secondary connection section to enable the connection device to move against the restraining force caused by the bearing pressure of the concrete when tensioning the prestressing tendons in the succeeding construction section, and an outer sheath is applied to the outer periphery of the connection device to prevent direct adhesion between the connection device and the concrete.

[0004] According to this direct burial connection method for PC steel, when connecting the PC steel under tension (meaning that the primary PC steel is already tensioned and fixed) using the direct burial method at the concrete joint between the preceding construction section A and the following construction section B, all that is required is to attach a pressure relief means of simple structure to the terminal of the secondary connection section of the connection device, and to apply an outer covering layer to the outer periphery of the connection device using a simple method such as spirally wrapping corrosion protection tape as an outer covering layer, thereby eliminating the need for a space-forming shell tube (coupler sheath) that covers the entire connection device and also eliminating the need to fill the space around the connection device with resin on site. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-046313 Summary of the Invention [Problem to be solved by the invention]

[0006] The direct burial connection method for PC tendons disclosed in Patent Document 1 has been highly praised and well-received for its significant improvement in workability, as it allows the omission of a coupler sheath and eliminates the need to fill the space around the connection device (coupler sheath) with resin on-site.However, there are cases where a coupler sheath type connection method is adopted instead of the direct burial type.

[0007] When this type of coupler sheath-type connection method is adopted, as shown in Figure 9, mounting sections for attaching coupler sheaths (bolt holes 18H with female threads, but if male threads are used instead of female threads, problems such as male threads breaking or bending will occur, as will be described later) are provided at four equally spaced locations on support plate 18, with PC steel (PC steel strand) 10 as the center point of point symmetry (this is approximately the same as the center point of the through hole provided in approximately the center of support plate 18). Then, when connecting primary PC steel (PC steel strand) 10 and secondary PC steel (PC steel strand) 20, for example, threaded fasteners are used. Here, a threaded sleeve 16 and a wedge 14 are used on the primary-side fixing device (connector primary-side holding portion) (FIG. 9(A)), and a threaded sleeve 26, a wedge 24, and a wedge holder 28, which form the secondary-side fixing device (connector secondary-side holding portion), are attached via a (secondary-side) joint 30 (FIG. 9(B)), connecting the secondary-side PC steel member (PC steel strand) 20 to the primary-side PC steel member (PC steel strand) 10. Finally, a coupler sheath 80 is placed over the primary-side fixing device, the secondary-side fixing device, and the joint 30 serving as the connecting jig. A bolt 82 is inserted into a through-hole in the flange of the coupler sheath 80, and the bolt 82 is threaded into the bolt hole 18H to attach the coupler sheath 80. The coupler sheath-type connecting device 100 is then constructed by filling the coupler sheath 80 with resin (FIG. 9(C)). The secondary side of the coupler sheath 80 is sealed with epoxy putty 34.

[0008] When connecting a coupler sheath in this manner, depending on the construction conditions (such as when concrete is poured into the exposed portion of the support plate 18), the bolt holes 18H for attaching the coupler sheath, provided in the primary plate (support plate 18), may have concrete seeping into the female threads. Or, the female threads may corrode within the several months or so between the primary construction and the connection of the coupler sheath, making it impossible to attach the coupler sheath. In such cases, on-site measures such as attaching with adhesive, re-drilling the female threads, or installing anchors in the concrete later on are considered, but they have problems such as the possibility of the adhesive coming loose, the cumbersome task of reworking the female threads, and the laborious installation of anchors. Furthermore, such measures often involve the interference of rebar or insufficient construction space, making it impossible to re-drill the female threads or install anchors later on, which can make it impossible to install the coupler sheath. Even if the coupler sheath can be installed, there are problems such as leakage of the filler material filled into the coupler sheath or the intrusion of corrosion factors from outside the coupler sheath.

[0009] The present invention was developed in consideration of the above-mentioned problems of the prior art, and its purpose is to provide a coupler sheath-type connector for PC steel strands used to apply prestress to post-tensioned prestressed concrete, a connector and connection method for PC steel strands that allows easy attachment of the coupler sheath when the coupler sheath cannot be attached to the bearing plate with bolts, etc. Another object is to provide a connector and connection method for PC steel strands that prevents leakage of filler material filled in the coupler sheath after the coupler sheath is attached, and that suppresses the intrusion of corrosion factors from outside the coupler sheath. [Means for solving the problem]

[0010] In order to achieve the above object, a PC steel strand connecting device according to the present invention and a PC steel strand connecting method according to another aspect of the present invention comprise the following technical means.

[0011] That is, a connector for PC steel strands according to one aspect of the present invention is a coupler sheath type connector that connects a primary PC steel strand and a secondary PC steel strand, and includes a connector primary holding portion that includes at least a primary sleeve that abuts against a support plate and holds the primary PC steel strand in a tensionable manner, with the direction along the PC steel strand as the longitudinal direction, and a connector that includes at least a secondary sleeve that holds the secondary PC steel strand in a tensionable manner. a connector secondary-side holding portion, a connecting jig that connects the connector primary-side holding portion and the connector secondary-side holding portion by screwing, and a connecting bottom plate that is arranged on the support plate side of the connecting jig and that connects a coupler sheath to the outer periphery of the connector, the connecting bottom plate having at least a flat flange portion that has a planar outer shape that corresponds to the planar outer shape of the support plate and has a through-hole in the center, the outer dimensions of the flange portion are equal to or smaller than the outer dimensions of the support plate, the inner diameter of the flange portion is at least equal to or larger than the outer diameter of the primary-side sleeve, and a hollow cylindrical portion having the same inner diameter as the support plate may be extended, the flange is provided with an attachment portion for attaching a coupler sheath, and the end face of the flange on the opposite side to the support plate in the longitudinal direction or the end face of the hollow cylindrical portion is configured to be able to abut against a part of the connecting jig as an abutting end face, and by changing the screwing state of the connecting jig, the connecting jig is moved toward the support plate in the longitudinal direction, and the abutting end face is pressed by a part of the connecting jig, thereby fixing the connecting bottom plate to the support plate. Here, "a flange having a planar outer shape corresponding to the planar outer shape of the support plate" means that the planar outer shapes are the same or similar (but the support plate is larger), or that the planar outer shape of the flange does not exceed the planar outer shape of the support plate.

[0012] Preferably, the connecting jig is a hollow cylindrical joint having a female thread as an internal thread on the inner circumference of the cylinder, the end face of the joint facing the support plate abutting the abutting end face, the outer circumference of the primary sleeve and the outer circumference of the secondary sleeve having male threads as external threads, the male threads of the primary sleeve and the male threads of the secondary sleeve threadingly engage with the female threads of the joint, thereby connecting the primary sleeve and the secondary sleeve and connecting the primary connector holding portion and the secondary connector holding portion, and by changing the threaded state of the joint, the joint can be moved toward the support plate in the longitudinal direction, and the abutting end face is pressed by the end face of the joint facing the support plate that has moved toward the support plate, thereby fixing the connecting bottom plate to the support plate.

[0013] More preferably, the direction of the male thread provided on the outer periphery of the primary sleeve and the female thread provided on the inner periphery of the joint on the primary sleeve side is a first direction, and the direction of the male thread provided on the outer periphery of the secondary sleeve and the female thread provided on the inner periphery of the joint on the secondary sleeve side is a second direction, and the first direction is a right-hand thread and the second direction is a left-hand thread, or the first direction is a left-hand thread and the second direction is a right-hand thread, and they are reverse threads, and as the engagement allowance of one of the threads increases, the engagement allowance of the other also increases. The advance clearance increases, bringing the primary sleeve and the secondary sleeve closer together and connecting the primary holding portion of the connector and the secondary holding portion of the connector, and by changing the threaded state at the joint while maintaining the connection state between the primary sleeve and the secondary sleeve by the joint, the joint can be moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the end surface on the support plate side of the joint that has moved toward the support plate, thereby fixing the connecting bottom plate to the support plate.

[0014] More preferably, the connecting jig is a plug having a hollow cylindrical shape, and is provided with a male thread as an external thread on the outer periphery of the cylinder, and a circular flange on the outer periphery of the cylinder at approximately the center in the longitudinal direction, the flange of the plug abutting the abutting end surface, and the inner periphery of the primary sleeve on the secondary sleeve side and the inner periphery of the secondary sleeve on the primary sleeve side are provided with a female thread as an internal thread, and the female thread of the primary sleeve and the female thread of the secondary sleeve are threadedly engaged with the male thread of the plug, thereby connecting the primary sleeve and the secondary sleeve, and connecting the connector primary-side holding part and the connector secondary-side holding part, and by changing the threaded state of the plug, the plug can be moved toward the support plate in the longitudinal direction, and the plug that has moved toward the support plate side can be threaded. The flange in the connecting base plate may be configured to press the contact end surface, thereby fixing the connecting base plate to the support plate.

[0015] More preferably, the direction of the female thread provided on the inner periphery of the primary sleeve and the direction of the male thread provided on the outer periphery of the plug on the side of the primary sleeve are a first direction, and the direction of the female thread provided on the inner periphery of the secondary sleeve and the direction of the male thread provided on the outer periphery of the plug on the side of the secondary sleeve are a second direction, and the first direction is a right-hand thread and the second direction is a left-hand thread, or the first direction is a left-hand thread and the second direction is a right-hand thread, and they are reverse threads, and as one thread advances and the engagement allowance increases, the other The threaded engagement also progresses and the engagement allowance increases, bringing the primary sleeve and the secondary sleeve closer together and connecting the primary holding portion of the connector and the secondary holding portion of the connector, and by changing the threaded state of the plug while maintaining the connection state between the primary sleeve and the secondary sleeve by the plug, the plug can be moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the flange of the plug that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

[0016] More preferably, the connection jig is a secondary sleeve having a hollow cylindrical shape and provided with a female thread as an internal thread on the inner circumference of the primary cylinder, the end face of the secondary sleeve facing the support plate abutting the abutment end face, and the outer circumference of the primary sleeve has a male thread as an external thread, and the male thread of the primary sleeve threads into the female thread of the secondary sleeve, thereby connecting the primary sleeve and the secondary sleeve and connecting the primary connector holding portion and the secondary connector holding portion, and by changing the threaded state of the secondary sleeve, the secondary sleeve can be moved toward the support plate in the longitudinal direction, and the abutment end face is pressed by the end face of the secondary sleeve facing the support plate that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

[0017] More preferably, the flange portion of the connecting bottom plate can be configured so that mounting portions for attaching the coupler sheath are provided as bolt holes at three or more locations with the PC steel strand as the central axis point-symmetrical.

[0018] More preferably, at least one of the end face of the connection bottom plate facing the support plate and the opposite face of the end face of the connection bottom plate facing the support plate can be configured to have a gasket of a shape corresponding to the shape of the flange portion of the connection bottom plate.

[0019] A method for connecting PC steel strands according to another aspect of the present invention is a connection method using a coupler sheath type connector for connecting primary PC steel strands and secondary PC steel strands, and includes a connector primary holding part including at least a primary sleeve that abuts against a support plate and holds the primary PC steel strands in a tensionable manner, with the direction along the PC steel strands as the longitudinal direction; a connector secondary holding part including at least a secondary sleeve that holds the secondary PC steel strands in a tensionable manner; a connecting jig that connects the connector primary holding part and the connector secondary holding part by screwing them together; and a coupler sheath that is positioned closer to the support plate than the connecting jig and connects the outer periphery of the connector. and a connecting bottom plate for connecting the primary side PC steel strands to the connecting jig, the connecting bottom plate having at least a flat flange portion with a planar outer shape corresponding to the planar outer shape of the support plate and a through-hole in the center, the outer dimensions of the flange portion are equal to or smaller than the outer dimensions of the support plate, the inner diameter of the flange portion is at least equal to or larger than the outer diameter of the primary side sleeve, and a hollow cylindrical portion with the same inner diameter may be extended on the secondary side of the flange portion, the flange portion is provided with an attachment portion for attaching a coupler sheath, and the end face of the flange portion or the end face of the hollow cylindrical portion on the opposite side to the support plate in the longitudinal direction is configured to be able to abut against a part of the connecting jig as an abutting end face, and the connecting method includes attaching the connecting jig to the connecting jig primary side holding portion which tensions and fixes the primary side PC steel strands. The method includes the steps of: before connecting the connector secondary side holding portion, placing the connecting bottom plate over the connector primary side holding portion with the flange portion facing the support plate; by changing the screw engagement state of the connecting jig, moving the connecting jig toward the support plate in the longitudinal direction while maintaining the connection state between the connector primary side holding portion and the connector secondary side holding portion by the connecting jig, so that a part of the connecting jig presses the abutment end surface, thereby fixing the connecting bottom plate to the support plate; and attaching a coupler sheath to an attachment portion provided on the flange portion of the connecting bottom plate. [Effects of the Invention]

[0020] The connector and connection method of the present invention are coupler sheath-type connectors for PC steel strands used to apply prestress to post-tensioned prestressed concrete, and can easily attach the coupler sheath when the coupler sheath cannot be attached to the bearing plate with bolts, etc. Furthermore, after attaching the coupler sheath in this way, it is possible to prevent the filler material filled in the coupler sheath from leaking and to suppress the intrusion of corrosion factors from outside the coupler sheath. [Brief explanation of the drawings]

[0021] [Figure 1] 1A and 1B are a side cross-sectional view and a front view seen from the secondary side of a coupler sheath type connector 1000 according to an embodiment of the present invention, showing the state after (A) primary tensioning, (B) after the secondary side is connected to the primary side after the connecting bottom plate 700 is attached, and (C) after the coupler sheath 800 is installed. [Figure 2] (A) is a side cross-sectional view of a connector 1000 (connector 1001) used in a connection method using a joint (hereinafter referred to as J method), and (B) to (H) are figures showing components used in the connector 1001. [Figure 3] (A) A side cross-sectional view of a connector 1000 (connector 1002) used in a connection method using a plug (secondary side is a wedge) (hereinafter referred to as the P1 method), and (B) to (H) are figures showing the components used in the connector 1002. [Figure 4] (A) A side cross-sectional view of a connector 1000 (connector 1003) used in a connection method using a plug (secondary side is a compression grip) (hereinafter referred to as the P2 method), and (B) to (H) are figures showing the components used in the connector 1003. [Figure 5] 3 is a side view showing the outline of the connector 1001 shown in FIG. 2 for explaining the procedure for installing the connector 1001. FIG. [Figure 6] 3 is a side cross-sectional view for explaining the procedure for installing the connector 1001 shown in FIG. 2. [Figure 7](A) A side cross-sectional view of a connector 1000 (connector 1004) used in a connection method using a secondary C-shaped sleeve (secondary side is a wedge) (hereinafter referred to as the S1 method) relating to a modified example, and (B) to (H) are figures showing components used in the connector 1004. [Figure 8] (A) A side cross-sectional view of a connector 1000 (connector 1005) used in a connection method using a secondary C-type sleeve (secondary side is a compression grip) (hereinafter referred to as S2 method) relating to a modified example, (B) to (E), (G), and (H) are figures showing components used in the connector 1005. [Figure 9] 10A and 10B are diagrams for explaining problems that arise when attaching a coupler sheath using a conventional coupler sheath-type connector 100. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Below, a coupler sheath type connector 1000 for PC steel strands according to an embodiment of the present invention (more specifically, a connector 1001 used in the J construction method, a connector 1002 used in the P1 construction method (secondary side is a wedge), and a connector 1003 used in the P2 construction method (secondary side is a grip)) and a method of connecting PC steel strands using the coupler sheath type connector 1000 (connector 1001) will be described in detail with reference to the drawings. Here, it should be noted that the secondary side joint 500 may be simply referred to as the joint 500, and the center plug 600 may be simply referred to as the plug 600.

[0023] The primary prestressing steel strand 10 (the primary steel member) is tensioned and anchored by an anchoring member (a primary-side connector retainer including a wedge 114 and a sleeve 116) before being connected to the secondary prestressing steel strand 20 (the secondary steel member) using a connecting jig (secondary joint 500, center plug 600) ( FIG. 1A ). The drawings referenced in the following explanation are generally schematic diagrams that omit detailed structural details for easy understanding of the present invention. In some cases, parts that should be depicted externally rather than internally may be depicted as see-through, parts that should be depicted as cross sections may be depicted externally rather than internally, hidden lines may be depicted as solid lines rather than dotted lines, and the same components may be hatched differently. For example, when the cross-sectional line shown by the dashed-dotted line in the left diagram of FIG. 1C is used to represent the right diagram of FIG. 1C, bolt 802 is clearly visible. Here, as described above, the coupler sheath type PC steel strand connector 1000 of this embodiment will be described in detail as connectors 1001, 1002, and 1003 (when explaining common points, connector 1000 will represent the other connectors 1001, 1002, and 1003), but the connectors of this invention are not limited to these.

[0024] A coupler sheath-type PC steel strand connector 1000 according to this embodiment and a method for connecting PC steel strands using the connector 1000 will be described in detail with reference to FIGS. 1 to 6. FIGS. 5 and 6 are diagrams for explaining the connector connection method (construction procedure). In FIGS. 1 to 6, the primary PC steel strand 10 is coated with resin and covered with a sheath 12, and the secondary PC steel strand 20 is also coated with resin and covered with a sheath 22. The connector primary holding portion (primary wedge, primary sleeve) and the connector secondary holding portion (a combination of a secondary wedge and a secondary sleeve, or a combination of a C-sleeve and a compression grip) are connected via a connecting jig (secondary joint 500 or center plug 600). In the connector secondary holding portion, the secondary wedge 124 may be restricted from longitudinal movement of the secondary PC steel strand 20 by a wedge presser 128.

[0025] This coupler sheath type connector 1000 differs from conventional connectors in that the coupler sheath 800 is not fixed to the support plate 18 by screwing a bolt 802 into an attachment portion (bolt hole 18H) provided on the support plate 18, but rather, when the bolt hole 18H cannot be used at the time of attaching the coupler sheath 800, the coupler sheath 800 is fixed to the support plate 18 by screwing a bolt 802 into an attachment portion (bolt hole 700H) provided on the connection bottom plate 700, which has been pressed and fixed to the support plate 18 instead of the support plate 18.

[0026] 1 to 4 is a coupler sheath type connector that connects a primary PC steel strand 10 and a secondary PC steel strand 20. In the following explanation, the direction along the PC steel strand is defined as the longitudinal direction.

[0027] The connector 1000 is configured to include at least a primary sleeve 116 that abuts against a support plate 18 and holds the primary PC steel strand 10 in a tensionable manner, and includes a connector primary holding portion equipped with a primary wedge 114; a connector secondary holding portion that includes at least a secondary sleeve (secondary sleeve 126, secondary sleeve 426, C-sleeve 526) that holds the secondary PC steel strand 20 in a tensionable manner and includes a secondary wedge (secondary wedge 124, secondary wedge 424, compression grip 524); and a connecting jig (secondary joint 500, center plug 600) that connects the primary sleeve 116 and the secondary sleeve (secondary sleeve 126, secondary sleeve 426, C-sleeve 526) by screwing them together. and a connecting bottom plate 700 that is disposed closer to the support plate 18 than the connecting jig (secondary joint 500, center plug 600) and that connects the coupler sheath 800 to the outer periphery of the connecting tool.

[0028] 1, 2(A), 2(G), 3(A), 3(G), 4(A), and 4(G), this connecting bottom plate 700 is a hollow cylinder 702 whose inner diameter is at least equal to the outer diameter of the primary sleeve 116, and has an annular flange 704 at the end of the hollow cylinder 702 on the support plate 18 side, the outer diameter of the flange 704 being equal to or smaller than the outer diameter of the support plate 18 (here, approximately equal to that of the support plate 18), the flange 704 is provided with an attachment portion (more specifically, a bolt hole 700H) for attaching a coupler sheath, and the end face of the hollow cylindrical shape on the opposite side of the flange in the longitudinal direction (from the support plate 18) is configured to be able to abut against a part of the connecting jig (secondary joint 500, center plug 600) as an abutment end face 708. Note that, although not limited to, these members are made of steel having properties compatible with each member. Furthermore, if the planar outer shape of the support plate 18 is not circular but is, for example, rectangular, the planar outer shape of the flange 704 of the connecting bottom plate will be rectangular or the like because it corresponds to the planar outer shape of the support plate 18. If the outer shape of the flange 704 is rectangular, it can be made smaller than if it were circular. In this case, the outer dimension (not the outer diameter) of the flange 704 will be equal to or smaller than the outer dimension (not the outer diameter) of the support plate 18. Note that "flange 704 having a planar outer shape that corresponds to the planar outer shape of the support plate 18" means that the planar outer shapes are the same or similar (however, the support plate 18 is larger), or that the planar outer shape of the flange 704 does not exceed the planar outer shape of the support plate 18. Therefore, for example, provided that the planar outer shape of flange 704 does not exceed the planar outer shape of support plate 18, combinations include the planar outer shapes of both support plate 18 and flange 704 being circular, the planar outer shapes of both support plate 18 and flange 704 being other than circular (such as polygons including rectangles), and the planar outer shape of support plate 18 being other than circular (such as polygons including rectangles) and the planar outer shape of flange 704 being circular.

[0029] Then, by changing the screwing state of the connecting jig (secondary side joint 500, center plug 600), the connecting jig (secondary side joint 500, center plug 600) is moved longitudinally toward the support plate 18, and the abutting end face 708 is pressed by a part of the connecting jig (secondary side joint 500, center plug 600) (more specifically, the end face 508 of the secondary side joint facing the support plate 18, as described later, and the annular flange 604 provided on the outer periphery of the approximately central part of the hollow cylindrical center plug 600), and the connecting bottom plate 700 is fixed to the support plate 18.

[0030] 1 and 2 is a connector using the J method, for example, and as shown in FIG. 2(D) and other figures, the connecting jig is a hollow cylinder 502 and a secondary joint 500 having a female thread 502F as an internal thread on the inner periphery of the hollow cylinder 502, and an end face 508 of the secondary joint 500 on the side of the support plate 18 abuts against the abutment end face 708. The outer periphery of the primary sleeve 116 is provided with a male thread 116M as an external thread, and the outer periphery of the secondary sleeve 126 is provided with a male thread 126M as an external thread, and the secondary sleeve 126 is provided with a mounting hole 126H for a wedge presser 128 that restricts movement of the secondary wedge 124 in the longitudinal direction.

[0031] The male thread 116M of the primary sleeve 116 and the male thread 126M of the secondary sleeve 126 are threaded into the female thread 502F of the secondary joint 500, thereby connecting the primary sleeve 116 and the secondary sleeve 126 and connecting the primary holding portion of the connector and the secondary holding portion of the connector.

[0032] Then, by changing the screwing state in the secondary joint 500, the secondary joint 500 is moved toward the support plate 18 in the longitudinal direction, and The end face 508 of the secondary joint 500 on the support plate 18 side presses against the abutting end face 708 of the connecting bottom plate 700, and the flange portion 704 is fixed to the support plate 18 via the hollow cylinder 702 (the connecting bottom plate 700 is fixed to the support plate 18).

[0033] Although this secondary side joint 500 has the same inner and outer diameters on the primary and secondary sides, it may be a stepped joint with different inner and outer diameters on the primary and secondary sides as long as it has female threads on its inner circumference that can be threaded into the primary side sleeve 116 and the secondary side sleeve 126, respectively, and the primary side sleeve 116 and the secondary side sleeve 126 can be connected.

[0034] Here, although not limited to, a description will be given of the direction of the threads when the secondary side joint 500 is employed. As a premise, the female threads 502F provided on the inner periphery of the secondary side joint 500 have different thread directions between the female threads 502F1 on the primary side sleeve 116 side and the female threads 502F2 on the secondary side sleeve 126 side (female threads 502F1 and 502F2 are not shown separately).

[0035] The thread direction of the male thread 116M provided on the outer periphery of the primary sleeve 116 and the female thread 502F1 provided on the inner periphery of the secondary joint 500 on the primary sleeve 116 side is a first direction, and the thread direction of the male thread 126M provided on the outer periphery of the secondary sleeve 126 and the female thread 502F2 provided on the inner periphery of the secondary joint 500 on the secondary sleeve 126 side is a second direction, where the first direction is a right-hand thread and the second direction is a left-hand thread, or the first direction is a left-hand thread and the second direction is a right-hand thread, and they are reverse threads, and when the engagement margin of one thread increases, the engagement margin of the other thread also increases, bringing the primary sleeve 116 and the secondary sleeve 126 closer together and connecting the connector primary holding portion and the connector secondary holding portion. The advantageous effects of this combination of a positive thread (right-hand thread) and a reverse thread (left-hand thread) will be described later.

[0036] Then, by changing the screw engagement state in the secondary joint 500 while maintaining the connection state between the primary sleeve 116 and the secondary sleeve 126 by the secondary joint 500, the secondary joint 500 is moved longitudinally toward the support plate 18, and the end face 508 of the secondary joint 500 facing the support plate 18, which has moved toward the support plate 18, presses against the abutting end face 708 of the connecting bottom plate 700, and the flange portion 704 is fixed to the support plate 18 via the hollow cylinder 702 (the connecting bottom plate 700 is fixed to the support plate 18).

[0037] The connector 1002 according to this embodiment shown in Figure 3 is, for example, a connector using the P1 method (wedge on the secondary side), and as shown in Figure 3(D) etc., the connector jig is a hollow cylinder 602 having a male thread 602M as an external thread on the outer periphery of the hollow cylinder 602, and is a center plug 600 having a circular flange 604 on the outer periphery of the hollow cylinder 602 at approximately the center in the longitudinal direction, and the flange 604 of the center plug 600 abuts against the abutment end face 708.

[0038] The inner periphery of primary sleeve 316 on the secondary sleeve 426 side has a female thread 316F as an internal thread, and the inner periphery of secondary sleeve 426 on the primary sleeve 316 side has a female thread 426F as an internal thread. Tool holes 604H (which do not have male threads 602M) are formed in several locations (preferably at equal intervals) around the annular outer periphery of flange 604 of center plug 600, into which a tool can be inserted to rotate (spin) center plug 600. A primary wedge 314 (which may be the same as primary wedge 114) is combined with the primary sleeve 316 side.

[0039] The female thread 316F of the primary sleeve 316 and the female thread 426F of the secondary sleeve 426 are threadedly engaged with the male thread 602 of the center plug 600, thereby connecting the primary sleeve 316 and the secondary sleeve 426 and connecting the connector primary holding portion and the connector secondary holding portion. can be.

[0040] Then, by changing the screwing state of the center plug 600, the center plug 600 is moved longitudinally toward the support plate 18, and the flange 604 of the center plug 600 that has moved toward the support plate 18 presses against the abutting end surface 708 of the connecting bottom plate 700, and the flange portion 704 is fixed to the support plate 18 via the hollow cylinder 702 (the connecting bottom plate 700 is fixed to the support plate 18).

[0041] Although the outer diameter of this center plug 600 is the same on the primary side and the secondary side, it may be a stepped plug with different outer diameters on the primary side and the secondary side, as long as it has male threads on its outer periphery that can be threaded into the primary side sleeve 316 and the secondary side sleeve 426, respectively, and the primary side sleeve 316 and the secondary side sleeve 426 can be connected.

[0042] Connector 1003 according to this embodiment shown in Fig. 4 is, for example, a connector using the P2 method (secondary side is a compression grip), and the only difference between the connector shown in Fig. 3 and the connector shown in Fig. 4 is that secondary side sleeve 426 shown in Fig. 3(E) is changed to C-type sleeve 526 shown in Fig. 4(E), and secondary side wedge 424 shown in Fig. 3(F) is changed to compression grip 524 (friction type instead of wedge type) shown in Fig. 4(F). The rest of the structure is basically the same (except for dimensions, etc.), so description here will not be repeated.

[0043] Here, although not limited to, the thread direction will be described when a center plug 600 is used as the connecting jig in the connectors 1002 and 1003 according to the present embodiment shown in Figures 3 and 4. As a premise, the thread direction of the male threads 602M provided on the outer periphery of the center plug 600 is different between the male thread 602M1 on the primary sleeve 316 side and the male thread 602M2 on the secondary sleeve 426 (or C-sleeve 526) side (the male threads 602M1 and 602M2 are not shown separately).

[0044] The thread direction of the female thread 316F provided on the inner circumference of the primary sleeve 316 and the male thread 602M1 provided on the outer circumference of the center plug 600 on the primary sleeve 316 side is a first direction, and the thread direction of the female thread 426F provided on the inner circumference of the secondary sleeve 426 (or the female thread 526F provided on the inner circumference of the C-type sleeve 526) and the male thread 602M2 provided on the outer circumference of the center plug 600 on the secondary sleeve 426 (or the C-type sleeve 526) side is a second direction, where the first direction is a right-handed thread and the second direction is a left-handed thread, or the first direction is a left-handed thread and the second direction is a right-handed thread, and they are reverse threads, and as the engagement allowance of one thread increases, the engagement allowance of the other thread also increases, bringing the primary sleeve 316 and the secondary sleeve 426 (or the C-type sleeve 526) closer together and connecting the connector primary side holding portion and the connector secondary side holding portion. The advantageous effects of this combination of a positive thread (right-hand thread) and a reverse thread (left-hand thread) will be described later.

[0045] Then, by changing the screwing state of the center plug 600 while maintaining the connection state between the primary side sleeve 316 and the secondary side sleeve 426 (or the C-shaped sleeve 526) by the center plug 600, the center plug 600 is moved longitudinally toward the support plate 18, and the flange 604 of the center plug 600 that has moved toward the support plate 18 presses the abutting end surface 708 of the connecting bottom plate 700, and the flange portion 704 is fixed to the support plate 18 via the hollow cylinder 702 (the connecting bottom plate 700 is fixed to the support plate 18).

[0046] Here, the advantageous effects of the combination of the positive thread (right-hand thread) and the reverse thread (left-hand thread) described above will be explained. The combination of the positive thread (right-hand thread) and the reverse thread (left-hand thread) can produce a greater effect especially when the connecting jig is a plug. The greatest advantage of combining right-handed and reverse-handed threads is that the primary and secondary sides can be connected by rotating only the plug, without rotating the secondary sleeve and PC steel strand (cable). If the plug were made with only right-handed threads, the secondary sleeve, wedge, and PC steel strand (cable) would all need to be rotated when connecting the primary and secondary sides. This is because the wedge holder holds the sleeve, wedge, and cable together as a single unit. On the other hand, by combining right-handed and reverse-handed threads, the threads can be fitted by rotating only the plug, which offers the advantage of excellent workability.

[0047] Thus, while combining right-handed and reverse-handed threads is highly advantageous in the case of plugs, combining right-handed and reverse-handed threads is often not done in the case of joints (although the present invention does not actively exclude combining right-handed and reverse-handed threads in joints). The reason for this is that even if both (primary and secondary) joints are manufactured with right-handed threads, the primary and secondary sides can be connected by rotating (rotating) the joint alone. More specifically, the joint is screwed deeply into the secondary sleeve in advance, and the primary and secondary sleeves are pulled together, allowing the joint alone to be rotated to engage and connect the threads. Therefore, even if either the primary or secondary side of the joint does not have a reverse thread, there is little chance of significant impairment of workability. For this reason, reverse threads are often not used in joints.

[0048] 1 to 4, bolt holes 700H are provided in three or more locations (four locations in this example) on the flange 704 of the connecting bottom plate 700, with the PC steel strand as the central axis and point-symmetrical thereabout. Four locations are preferred because the coupler sheath 800 can be stably attached, while three locations are preferred because the number of bolts to be tightened when attaching the coupler sheath 800 can be reduced. Furthermore, as described above, the planar outer shape of the flange of the connecting bottom plate is provided with a planar outer shape corresponding to the planar outer shape of the support plate 18. Therefore, since the support plate 18 is not limited to being circular or rectangular, the planar outer shape of the flange of the connecting bottom plate is also not limited to being circular or rectangular, and the bolt holes 700H as attachment portions are provided outside the central circular through-hole.

[0049] A coupler sheath 800 is placed over the connector primary-side holding part, the connector secondary-side holding part connected to the connector primary-side holding part by the connecting jig, and the connecting jig, and a bolt 802 is inserted into a through-hole provided in the flange of the coupler sheath 800 and screwed into a bolt hole 700H provided in the flange 704 of the connecting bottom plate 700 to attach the coupler sheath 800. Then, the inside of the coupler sheath 800 is filled with resin (a thermosetting resin for pre-grout, as an example).

[0050] A packing having a shape corresponding to the shape of the flange of the connecting bottom plate is provided on at least one of the end face of the connecting bottom plate 700 facing the support plate 18 and the opposite face of the end face facing the support plate 18. Here, the shape of the packing corresponding to the shape of the flange means that the outer diameter or outer shape of the packing provided on the end face of the connecting bottom plate 700 facing the support plate 18 and the opposite face of the end face facing the support plate 18 matches or approximately matches the outer diameter or outer shape of the flange (here, the outer diameters of packings 706 and 708, described below, match or approximately match the outer diameter of flange 704). As described above, the planar outer shape of the flange of the connecting bottom plate has a planar outer shape that matches the planar outer shape of the support plate 18, so the outer shape of the packing is not limited to being circular or rectangular, but here the outer shape of the packing will be described as being circular and the packing as being a thin ring shape.

[0051] Here, as shown in FIGS. 2(A), 3(A) and 4(A), a packing 706 is attached to the end face of the connecting bottom plate 700 on the side of the support plate 18, and a packing 708 is attached to the opposite face (the opposite side of the support plate 18, In this way, when packings are provided on both sides, the packings 706 provided on the contact surface between the existing structure (support plate 18) and the connecting bottom plate 700, and the packings 806 provided on the contact surface between the connecting bottom plate 700 and the coupler sheath 800, can prevent the resin (filler) from leaking out when filling the coupler sheath, can prevent the filler filled in the coupler sheath from leaking out before it hardens, and can suppress (more effectively than when packings are provided on only one side) the intrusion of corrosion factors from outside the coupler sheath.

[0052] It should be noted that the present invention does not explicitly exclude the case where a packing is provided on either side of the connecting bottom plate 700. As will be described later, the connecting method according to this embodiment is carried out with the packing 706 attached to the connecting bottom plate 700 and the packing 806 attached to the coupler sheath 800. One example of the material for these packings is, but is not limited to, chloroprene sponge.

[0053] Next, referring to Figure 5 (outline drawing) and Figure 6 (cross-sectional view), a method of connecting PC steel strands using the above-mentioned coupler sheath type connector 1000 (although connector 1001 is used below, connector 1000 will be used as a representative) to connect primary PC steel strand 10 and secondary PC steel strand 20 will be described.

[0054] As shown in Figures 5(A) and 6(A), before the PC strand connection method is performed (construction), the primary PC strand 10 (the primary steel member) is tensioned and fixed by the fixing member (the primary connector holding portion including the wedge 114 and sleeve 116) (before it is connected to the secondary PC strand 20 (the secondary steel member) using the connecting jig (secondary joint 500)), and the tension in the primary PC strand 10 is maintained. The primary PC strand 10 is coated with resin and covered with a sheath 12, and the secondary PC strand 20 is also coated with resin and covered with a sheath 22. The connection method according to this embodiment is preferably used when bolt holes 18H cannot be used when installing a coupler sheath 800 (described below).

[0055] Steps for installing the connection base plate As shown by the black arrows in Figures 5(B) and 6(B), before connecting the connector secondary holding part to the connector primary holding part where the primary PC steel strands 10 are tensioned and fixed, a connection bottom plate 700 is installed to cover the connector primary holding part with its flange 704 facing the support plate 18. At this time, a gasket 706 is attached to the contact surface between the existing structure (support plate 18) and the connection bottom plate 700 (the connection bottom plate 700 with the gasket 706 attached is installed to cover the connector primary holding part with its flange 704 facing the support plate 18). The state after this step is completed is shown in Figures 5(C) and 6(C).

[0056] Secondary side connection steps As shown by the black arrows in Figures 5(D) and 6(D), the connector secondary holding portion (secondary wedge 124, secondary sleeve 126, wedge presser 128) connected to the connecting jig (here, secondary joint 500) and the connected secondary PC steel strand 20 are brought close to the connector primary holding portion, which has a connecting bottom plate 700 on its outer periphery. By changing the screw engagement state in the connecting jig (here, secondary joint 500), the connecting jig (secondary joint 500) connects the primary sleeve 116 and secondary sleeve 126.

[0057] In the process of connecting the primary sleeve 116 and the secondary sleeve 126 using this connecting jig (secondary joint 500), the connecting jig (secondary joint 500) is moved in the longitudinal direction toward the support plate 18 while maintaining the connected state, 00) (here, the end surface 508 of the secondary joint 500 on the support plate 18 side) presses the abutting end surface 708. This pressing is continued until the connecting bottom plate 700 is fixed to the support plate 18.

[0058] As shown in FIGS. 1(B) and 2(A), when the secondary joint 500 is moved longitudinally toward the support plate 18, the end surface 508 of the secondary joint 500 facing the support plate 18 comes into contact with the abutment end surface 708. When the secondary joint 500 is further moved longitudinally toward the support plate 18, the end surface 508 of the secondary joint 500 facing the support plate 18 presses the abutment end surface 708 as shown by the outline arrow. A pressing force is transmitted from the pressed abutment end surface 708 through the hollow cylinder 702 to the annular flange 704 at the end on the support plate 18 side, pressing the flange 704 toward the support plate 18. Ultimately, the connecting bottom plate 700 is fixed to the support plate 18 (including becoming essentially fixed). The state after this step is completed is shown in FIGS. 5(E) and 6(E).

[0059] Coupler sheath connection steps As shown by the black arrows in Figures 5(F) and 6(F), coupler sheath 800 is brought close to connecting bottom plate 700, which is pressed by secondary joint 500 and fixed to support plate 18, and to connecting tool primary holding portion to which connecting tool secondary holding portion is connected by secondary joint 500 (these are covered with coupler sheath 800), and coupler sheath 800 is attached to an attachment portion (bolt hole 700H) provided on flange portion 704 of connecting bottom plate 700. At this time, packing 806 is attached to the abutting surface between connecting bottom plate 700 and coupler sheath 800 (coupler sheath 800 with packing 806 attached is attached so as to be close to connecting bottom plate 700). Then, bolt 802 is inserted into a through hole provided in the flange of coupler sheath 800, and bolt 802 is screwed into bolt hole 700H to attach coupler sheath 800. This state is shown in FIG. 5(G) and FIG. 6(G).

[0060] Thereafter, resin 820 (for example, a thermosetting resin for pre-grout) is filled into coupler sheath 800 through injection port 810. The secondary side of coupler sheath 800 is sealed with epoxy putty 834.

[0061] As described above, the connector and connection method for PC strands according to this embodiment can easily attach a coupler sheath to a PC strand coupler used to apply prestress to post-tensioned prestressed concrete, even when the coupler sheath cannot be attached to the bearing plate on the primary side of the connector with bolts, etc. Furthermore, after attaching the coupler sheath in this way, it is possible to prevent leakage of the filler material filled in the coupler sheath and to suppress the intrusion of corrosion factors.

[0062] More specifically, it is as described below. · The coupler sheath can be securely fixed even if there is no screw for fixing the primary side coupler sheath or if the screw is damaged and cannot be used. · Coupler sheaths can be fixed even in cases where rebar is present, space is limited, post-installed anchors cannot be installed, or screws cannot be re-opened. - It reduces the labor required to install post-installed anchors and re-drill screws, making it easier to install and shortening construction time. The labor-saving effect is particularly significant when connecting horizontally fastened steel materials, which number in the hundreds. - Easy to install and less subject to site constraints, ensuring consistent quality. The simple procedure means anyone can install it reliably, preventing problems caused by poor installation. A pad provided on at least one side (preferably both sides) of the annular flange of the connecting bottom plate The seal can prevent the resin (filler) from leaking out when filling the coupler sheath, can prevent the filler filled in the coupler sheath from leaking out before it hardens, and can prevent corrosion factors from entering the coupler sheath from outside.

[0063] <Modification> A modified example of this embodiment will be described below with reference to Figures 7 and 8. Figure 7 shows a connector 1000 (connector 1004) used in the S1 method (secondary side is a wedge) using a secondary C-shaped sleeve according to this modified example, and Figure 8 shows a connector 1000 (connector 1005) used in the S2 method (secondary side is a compression grip) using a secondary C-shaped sleeve according to this modified example. In the following description of the modified example, the same components or parts (parts) as those in the above-described embodiment (other than this modified example) are designated by the same reference numerals in this modified example, and since their structure and function are the same, they will not be described again here. Furthermore, the structure of the coupler sheath 800 is simplified in Figures 7 and 8, and accessories to the coupler sheath 800, such as the injection port 810, are not shown (unlike Figures 2 to 4).

[0064] The differences between this modified example and the above-mentioned connector 1001 used in the J method, connector 1002 used in the P1 method (secondary side is a wedge), and connector 1003 used in the P2 method (secondary side is a grip) are that the connecting bottom plate 700 is replaced with a connecting bottom plate 750, and that the connector that does not have the joint 500 and center plug 600 and connects the primary side and secondary side is replaced with a secondary side (C-type) sleeve 527 (more specifically, a short type secondary side sleeve 527S shown in Figure 7(D) or a long type secondary side sleeve 527L shown in Figure 8(D), but when the two are the same, they will be simply referred to as sleeve 527 and used as a representative). Furthermore, the only difference between connector 1004 (used for S1 method) shown in Fig. 7 and connector 1005 (used for S2 method) shown in Fig. 8 is that the secondary-side fastener is a grip (Figs. 7(E) and (F)) in connector 1004 and a compression grip (Fig. 8(E)) in connector 1005. Also, with regard to the secondary sleeve, connector 1001 used for J method shown in Fig. 2 and connector 1004 used for S1 method shown in Fig. 7 differ in that secondary sleeve 126 of connector 1001 has male threads 126M on the outer periphery, but secondary sleeve 127 of connector 1004 does not have male threads on the outer periphery.

[0065] A connecting bottom plate 750 common to the connector 1004 shown in Fig. 7 and the connector 1005 shown in Fig. 8 will be described. In short, the connecting bottom plate 750 does not have the hollow cylinder 702 of the connecting bottom plate 700 described above, and is formed only by a flange portion 704. More specifically, the connecting bottom plate 750 has at least a flat flange portion 754 with a planar outer shape (circular here) corresponding to the planar outer shape (circular here) of the support plate 18 and a circular through-hole in the center, the outer dimension (outer diameter here) of the flange portion 754 being equal to or smaller than the outer dimension (outer diameter here) of the support plate 18, and the inner diameter of the flange portion 754 is at least equal to or larger than the outer diameter of the primary-side sleeve 116. Unlike the connecting bottom plate 700, the connecting bottom plate 750 does not have a hollow cylindrical portion with the same inner diameter extended on the secondary side of the flange portion 754. The flange portion 754 has three or more (four in this case) bolt holes 750H (similar to the bolt holes 700H) as mounting portions for mounting the coupler sheath 800, and the end face 758 of the flange portion 754 on the opposite side of the support plate 18 in the longitudinal direction is configured as an abutting end face capable of abutting against a part of the connecting jig (here, the sleeve 527).

[0066] The sleeve 527 as a connecting jig is a short type secondary sleeve 527S shown in Fig. 7(D) and a long type secondary sleeve 527L shown in Fig. 8(D) and has the same basic configuration, but differs only in dimensions. This sleeve 527 is a hollow cylindrical secondary sleeve having a female thread 527F as an internal thread on the inner periphery of the primary side cylinder, and the end surface 528 of the sleeve 527 on the side of the support plate 18 is an abutting end surface (end surface 758 of the flange 754). ) The outer periphery of primary sleeve 116 is provided with male threads 116M as an external thread, and male threads 116M of primary sleeve 116 are threadedly engaged with female threads 527F of sleeve 527, thereby connecting primary sleeve 116 and (secondary) sleeve 527 and connecting the connector primary-side holding portion and connector secondary-side holding portion. By changing the threaded state of sleeve 527, sleeve 527 is moved toward support plate 18 in the longitudinal direction, and end face 528 of sleeve 527 on the support plate 18 side that has moved toward support plate 18 presses the abutting end face (end face 758 of flange portion 754), and connecting bottom plate 750 is fixed to support plate 18.

[0067] For connectors 1004 and 1005 having such a structure, the primary side and secondary side can be connected using the above-mentioned connection method, and a coupler sheath can be attached even when the bolt holes of pressure support plate 18 cannot be used. Therefore, these modified examples can also achieve the same effects as connectors 1001, 1002, and 1003 described above.

[0068] In addition, the connecting bottom plate 750 of this modified example is applicable to connecting device 1001 when it is necessary to extend the longitudinal dimension of joint 500, and in connecting devices 1004 and 1005 of this modified example, the connecting bottom plate 700 can be applied in place of connecting bottom plate 750 when it is necessary to shorten the longitudinal dimension of sleeve 527.

[0069] It should be noted that the embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Industrial Applicability]

[0070] The present invention is preferred as a connector and connection method for PC steel used to apply prestress to post-tensioned prestressed concrete, and is particularly preferred in that it allows the coupler sheath to be easily attached when it cannot be attached to the support plate with bolts or the like, prevents the filler material filled in the coupler sheath from leaking, and suppresses the intrusion of corrosion factors. [Explanation of symbols]

[0071] 10 Primary PC steel strand 20 Secondary PC steel strand 500 Secondary joint 600 center plug 700 Connection bottom plate 750 Connection bottom plate in modified example 800 Coupler Sheath

Claims

1. A coupler sheath type connector that connects a primary PC steel strand and a secondary PC steel strand, with the direction along the PC steel strand as the longitudinal direction, A connector primary side holding portion configured to include at least a primary side sleeve that abuts against a support plate and holds the primary side PC steel strand in a tensionable manner; A connector secondary holding portion configured to include at least a secondary sleeve that holds the secondary PC steel strand in a tensionable manner; a connecting jig that connects the connector primary side holding portion and the connector secondary side holding portion by screwing; a connecting bottom plate disposed closer to the support plate than the connecting jig and for connecting a coupler sheath to an outer periphery of the connecting tool; Including, The connecting bottom plate has at least a flat flange portion having a planar outer shape corresponding to the planar outer shape of the support plate and having a through-hole in the center, the outer dimensions of the flange portion are equal to or smaller than the outer dimensions of the support plate, the inner diameter of the flange portion is at least equal to or larger than the outer diameter of the primary sleeve, and a hollow cylindrical portion having the same inner diameter may be extended on the secondary side of the flange portion, the flange portion is provided with an attachment portion for attaching a coupler sheath, and the end face of the flange portion or the end face of the hollow cylindrical portion on the opposite side to the support plate in the longitudinal direction is configured to be able to abut against a part of the connecting jig as an abutting end face, A connecting device characterized in that by changing the threaded state of the connecting jig, the connecting jig is moved toward the support plate in the longitudinal direction, and a part of the connecting jig presses the abutment end surface, thereby fixing the connecting bottom plate to the support plate.

2. The connecting jig is a joint having a hollow cylindrical shape and a female thread as an internal thread on the inner periphery of the cylinder, and an end face of the joint on the support plate side abuts against the abutment end face, an outer periphery of the primary sleeve and an outer periphery of the secondary sleeve are provided with a male thread as an external thread; The male thread of the primary sleeve and the male thread of the secondary sleeve are threadedly engaged with the female thread of the joint, thereby connecting the primary sleeve and the secondary sleeve and connecting the connector primary holding portion and the connector secondary holding portion, A connector as described in claim 1, characterized in that by changing the threaded state of the joint, the joint is moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the end surface of the joint on the support plate side that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

3. The thread directions of the male thread provided on the outer periphery of the primary sleeve and the female thread provided on the inner periphery of the joint on the primary sleeve side are a first direction, and the thread directions of the male thread provided on the outer periphery of the secondary sleeve and the female thread provided on the inner periphery of the joint on the secondary sleeve side are a second direction, and the first direction is a right-handed thread and the second direction is a left-handed thread, or the first direction is a left-handed thread and the second direction is a right-handed thread, and they are reverse threads to each other, and when the engagement allowance of one thread increases, the engagement allowance of the other thread also increases, so that the primary sleeve and the secondary sleeve approach each other and the connector primary-side holding portion and the connector secondary-side holding portion are connected, A connector as described in claim 2, characterized in that by changing the threaded state of the joint while maintaining the connection state between the primary sleeve and the secondary sleeve by the joint, the joint is moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the end surface of the joint on the support plate side that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

4. the connecting jig is a plug having a hollow cylindrical shape, a male thread as an external thread on the outer periphery of the cylinder, and an annular flange on the outer periphery of the cylinder at approximately the center in the longitudinal direction, the flange of the plug abutting against the abutment end surface, an inner periphery of the primary sleeve on the secondary sleeve side and an inner periphery of the secondary sleeve on the primary sleeve side are provided with a female thread as an internal thread; The female thread of the primary sleeve and the female thread of the secondary sleeve are threadedly engaged with the male thread of the plug, thereby connecting the primary sleeve and the secondary sleeve and connecting the connector primary holding portion and the connector secondary holding portion, 2. The connector of claim 1, characterized in that by changing the threaded state of the plug, the plug is moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the flange of the plug that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

5. the direction of the female thread provided on the inner circumference of the primary sleeve and the direction of the male thread provided on the outer circumference of the plug on the primary sleeve side are a first direction, the direction of the female thread provided on the inner circumference of the secondary sleeve and the direction of the male thread provided on the outer circumference of the plug on the secondary sleeve side are a second direction, the first direction is a right-handed thread and the second direction is a left-handed thread, or the first direction is a left-handed thread and the second direction is a right-handed thread, they are reverse threads to each other, and as the engagement allowance of one thread increases, the engagement allowance of the other thread also increases, so that the primary sleeve and the secondary sleeve approach each other and the connector primary-side holding portion and the connector secondary-side holding portion are connected; A connector as described in claim 4, characterized in that by changing the threaded state of the plug while maintaining the connection state between the primary sleeve and the secondary sleeve by the plug, the plug is moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the flange of the plug that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

6. The connecting jig is a hollow cylindrical secondary sleeve having a female thread as an internal thread on the inner periphery of the primary cylinder, and an end surface of the secondary sleeve on the support plate side abuts against the abutment end surface, The primary sleeve has a male thread on its outer periphery, The male thread of the primary sleeve is threadedly engaged with the female thread of the secondary sleeve, thereby connecting the primary sleeve and the secondary sleeve, and connecting the connector primary holding portion and the connector secondary holding portion, A connector as described in claim 1, characterized in that by changing the threaded state of the secondary sleeve, the secondary sleeve is moved toward the support plate in the longitudinal direction, and the abutment end surface is pressed by the end surface of the secondary sleeve on the support plate side that has moved toward the support plate, thereby fixing the connection bottom plate to the support plate.

7. A connector as described in any one of claims 1 to 6, characterized in that the flange portion of the connection bottom plate has mounting portions for attaching coupler sheaths as bolt holes at three or more locations with the PC steel strand as the central axis of point symmetry.

8. A connector as described in any one of claims 1 to 6, characterized in that a gasket having a shape corresponding to the shape of the flange portion of the connection bottom plate is provided on at least one of the end face of the connection bottom plate facing the support plate and the opposite face of the end face of the connection bottom plate facing the support plate.

9. A connection method using a coupler sheath type connector for connecting a primary PC steel strand and a secondary PC steel strand, the direction along the PC steel strand being the longitudinal direction, A connector primary side holding portion configured to include at least a primary side sleeve that abuts against a support plate and holds the primary side PC steel strand in a tensionable manner; A connector secondary holding portion configured to include at least a secondary sleeve that holds the secondary PC steel strand in a tensionable manner; a connecting jig that connects the connector primary side holding portion and the connector secondary side holding portion by screwing; a connecting bottom plate disposed closer to the support plate than the connecting jig and for connecting a coupler sheath to an outer periphery of the connecting tool; Including, The connecting bottom plate has at least a flat flange portion having a planar outer shape corresponding to the planar outer shape of the support plate and having a through-hole in the center, the outer dimensions of the flange portion are equal to or smaller than the outer dimensions of the support plate, the inner diameter of the flange portion is at least equal to or larger than the outer diameter of the primary sleeve, and a hollow cylindrical portion having the same inner diameter may be extended on the secondary side of the flange portion, the flange portion is provided with an attachment portion for attaching a coupler sheath, and the end face of the flange portion or the end face of the hollow cylindrical portion on the opposite side to the support plate in the longitudinal direction is configured to be able to abut against a part of the connecting jig as an abutting end face, The connection method includes: Before connecting the connector secondary side holding portion to the connector primary side holding portion where the primary side PC steel strand is tensioned and fixed, the connection bottom plate is installed so as to cover the connector primary side holding portion with the flange portion facing the support plate side; a step of changing the screwed state of the connecting jig, thereby moving the connecting jig toward the support plate in the longitudinal direction while maintaining the connected state between the connecting fixture primary side holding portion and the connecting fixture secondary side holding portion by the connecting jig, so that a part of the connecting jig presses the abutment end surface, thereby fixing the connecting bottom plate to the support plate; and attaching a coupler sheath to an attachment portion provided on the flange portion of the connection bottom plate.

Images