JP2001059344A - Prestressing device for prestressing strand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely, surely and efficiently achieve prestressing work by improving a driving means of a gripper into a cone, and provide a prestressing device for prestressing strands to obtain the safe, sure and efficient prestressing and releasing work even in a temporary coupling by improving the drive-coupling of the gripper into an anchor head and its release. SOLUTION: In this prestressing device for prestressing strands 25 etc., a rear portion of each gripper 4 is uniformly pressed and fitted into a cone 3 by a flat portion provided on a pressing member 8 in coupling a prestressing piece to the strands 25, and concrete bodies (a) and (b) are firmly prestressed to each other. During the temporary coupling of the prestressing piece comprising each gripper 4 and the cone 3 for the PC strands 25, each gripper 4 is uniformly driven into an anchor head 23 by the flat portion provided on one end side of a jig 9 for attachment/detachment, and attached to the anchor head 23 and each gripper 4 via an open hole on the other end side of the jig for attachment/detachment, and the jig for attachment/detachment is driven to relatively move the anchor head 23 from each gripper 4 and to release the prestressing to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of constructing a structure made of materials such as wood, stone, concrete, and the like, when it is necessary to connect each material with an appropriate compressive force to a PC stranded wire or the like. The present invention relates to a tensioning device capable of applying a load.

[0002]

2. Description of the Related Art As a conventional technique, for example, when a concrete structure such as a box culvert is to be tensioned by a PC stranded wire, a prestress is introduced to tension the PC stranded wire, and then, a tapper and a hammer are used. There are tensioning devices that drive the gripper into the cone to join the PC strands. For example, a PC for connecting two concrete bodies with a required tension to form a concrete structure.
An example of the stranded wire tensioning device will be described with reference to FIGS.

In FIG. 4, a tension device for a PC stranded wire is as follows.
First and second fasteners 1a and 1b each comprising a washer 2, a cone 3 having a conical hole 31 having a central hole 32, and split grooved grippers 4 and 4 which are arc-shaped wedges, and a pedestal at one end. 6
Is formed on the inner surface near the other end.
And a hydraulic cylinder 1 having an extensible cylinder portion 11 and a through hole 12 formed therein.
0, a pressure washer 21 and a conical hole 2 with a central hole 32
Temporary fastener 20 including anchor head 23 with two and grippers 4 and 4 with split grooves as arc-shaped wedges and PC stranded wire 2
5 is comprised.

Here, an application of the above-described conventional tensioning device for a PC stranded wire will be described.

[0005] Concrete bodies A and B to be tightened are provided with through holes 1 and 1 and mortar-shaped recesses 2 and 2 beforehand.
The PC stranded wire 25 is inserted through the through-holes 1 and 2 of B, and the washer 2 and the conical hole 31 are inserted into the PC stranded wire 25 so as to fit into the mortar-shaped recess 2 of one concrete body A. The attached cone 3 is inserted in advance (see FIG. 4). Then, the gripper 4 is hammered into the conical hole 31 of the cone 3 with the rag B and the hammer C, so that the teeth (not shown) formed on the inner surfaces of the grippers 4 and 4 are cut into the PC stranded wire 25,
The cone 3 is connected to the stranded wire 25.

Subsequently, a washer 2 and a cone 3 having a conical hole 31, a ram chair 5, a hydraulic cylinder 10, a pressure washer 2 are connected to a PC stranded wire 25 located on the other concrete body B side.
1. An anchor head 23 with a conical hole 22 and the like are sequentially inserted without any gap, and the pedestal 6 is bolted to the side surface of the concrete body B as necessary to fix the ram chair 5 (see FIG. 4). Then, as shown in FIG. 5, the gripper 4 is hammered into the conical hole 22 of the anchor head 23 with a rag and a hammer to temporarily couple the anchor head 23 to the PC stranded wire 25.

Under such a connection, the hydraulic cylinder 10
Is operated to extend the ram 11 (see FIG. 4), since the one end surface of the hydraulic cylinder 10 is fitted and abutted on the concave portion 57 of the ram chair 5, the ram 11 of the hydraulic cylinder 10 is The anchor head 23 is pressed via the pressure washer 21. By this pressing action, the anchor head 23 holding the PC stranded wire 25 is moved (to the right in FIG. 4 ), and the PC stranded wire 25 is moved.
Required tension. Then, under the tension of the PC stranded wire 25, the washer 2 and the cone 3 with the conical hole 31 are pressed against the inner end face of the mortar-shaped concave part 2 of the concrete body B, and the opening 51 of the ram chair 5 and the pedestal 6 are pressed. The gripper 4 is fitted to the conical hole 31 through the insertion hole 61, and the opening 51 of the ram chair 5 and the insertion hole 61 of the pedestal 6 are further inserted.
5 and the hammer C is applied as shown in FIG. 5, and the gripper 4 is beaten to join. After the concrete body b is tightened and connected to the concrete body b by this connection, the tension is released by pulling in the ram 11 to release the ram chair 5, the hydraulic cylinder 10, the pressure washer 21 and the like, and the anchor head 23 Is loosened by hitting the hammer to release the connection by the grippers 4 and 4 (see the dotted hammer in FIG. 6). When the pedestal 6 is bolted to the side surface of the concrete body B and the ram chair 5 is fixed, the bolting may be released to be free. When further another concrete body is to be continuously provided, each of the members 10, 21, 2,
After removing 3 and the like from the PC stranded wire 25, another new concrete body is inserted into the PC stranded wire 25 so as to be adjacent to the concrete body B, and the above-described operation is repeated.

[0008]

However, in such a conventional technique, it is troublesome to drive each of the plurality of grippers at one location through each of the narrow openings formed at two locations on the side of the ram chair. Work is required, and the gripper may come off and fly away without evenly driving the gripper, resulting in an accident. Such disengagement of the gripper also occurs during the temporary connection of the anchor head to the stranded wire, causing an accident.

The present invention has been made in view of the above-mentioned problems of the conventional tensioning device, and achieves a safe, reliable and efficient tightening operation by improving means for driving a gripper to a cone. An object of the present invention is to provide a tensioning device for a PC stranded wire or the like that improves the means for driving and releasing the gripper to and from the anchor head to obtain a safe, reliable and efficient tightening / releasing operation even in a temporary connection. Things.

[0010]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems. Firstly, at the time of connecting the fastener to the PC stranded wire, each of the grippers is provided by a flat portion provided on the pushing member. The rear part was evenly pressed and fitted into the cone to provide a tensioning device such as a PC stranded wire for strongly tightening the concrete body b. Secondly, at the time of temporary connection of the fastener consisting of each gripper and the cone to the PC stranded wire, evenly driving each gripper into the anchor head by the flat portion provided at one end of the attachment / detachment jig. On the other hand, when loosening / releasing the tightening, it is inserted into the anchor head and each gripper through the opening provided on the other end side of the attachment / detachment jig, and the attachment / detachment jig is struck to release the anchor head from each gripper. Was used as a tensioning device such as a PC stranded wire for relative movement to release the mutual tightening.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The first aspect of the present invention is a P-type tightening device comprising a cone and a gripper located on a concrete body.
Tightening to the C stranded wire or the like is achieved by operating the pushing member by the pushing operation member and pushing the rear portion of the gripper by the flat portion of the pushing member. A second aspect of the present invention is a P-type tightening device comprising an anchor head and a gripper.
Temporary tightening to the C stranded wire or the like is achieved by driving the rear part of the gripper with the flat part of the attaching / detaching jig, and the loosening / releasing of the temporary tightening is performed by the attachment / detachment inserted into the anchor head and the gripper. This is achieved by hitting a jig.

Here, an embodiment of a tensioning device for a PC stranded wire or the like according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an overall view of, for example, a PC stranded wire tensioning device based on the conventional tensioning device shown in FIG.
A tightening tool 1b including the cone 3 and the grippers 4 and 4, a cylinder 100 surrounding the gripper 4, a pushing force transmission cylinder 7 having flanges 71 and 72 at both ends, and a gripper 4 and 4 for the cone 3. Ram chair 5 with push-in member 8, hydraulic cylinder 10 with ram 11, anchor head 23
And a jig 9 for attaching / detaching the gripper 4 to / from the anchor head 23 are sequentially provided through the stranded wire 25.

Here, the ram chair 5 will be described. A pedestal 6 having an opening 61 and a positioning piece 62 is provided.
And a cylindrical body having a concave portion 57 at an end of a bottom portion 53 having a central hole 52, and a side wall on which the pivotal support piece 81 is fixed is provided with one locking member 83 and a pair of long groove holes 54, 55 and a pair of long groove holes. The push-in member 8 having a pair of swelling pieces 84, 84 fixed at the center thereof is inserted into the long slots 54, 55 and the pivot support piece 81. Are pivotally supported by a pivoting member 82 provided in the robot. As shown in FIG. 2, which is a cross-sectional view taken along the line AA in the PC stranded wire tensioning device of FIG. 1, the pushing member 8 has a through hole 87 of the stranded wire 25 and a pair of bulging portions protruding on one side. And a bulging portion 84, 84, which is a rod-shaped member provided with a central portion 88 having pieces 84, 84.
Corresponding to the other flange 71.

The jig 9 for attachment and detachment will be described. An opening 92 having a large opening 91 and a bottom 94 with an insertion hole 93 for the stranded wire 25 constitute each side end. A hole 95 having a diameter smaller than the large opening 91 and larger than the insertion hole 93 extends between the insertion hole 91 and the insertion hole 93, and the stepped portion 9 is formed.
6 are formed.

Referring now to FIG. 1, a description will be given of an arrangement structure of a PC stranded wire tensioning device provided with the ram chair 5 and the detachable jig 9 having the above-described structure. In order to attach each member to the PC stranded wire 25 inserted into the concrete body B (see the concrete body A and B in FIG. 4), first, the inside of the mortar-shaped concave part 2 of the concrete body B In a state where the tip portions of the grippers 4 and 4 are fitted into the cone 3, the cylindrical body 100 is fitted into the cone 3 so as to surround the grippers 4 and 4, and furthermore, a transmission having flanges 71 and 72 at both ends. The cylinder 7 is positioned at the rear of the grippers 4, 4 so that it can enter and exit the cylinder 100. Next, after the cylindrical body 7 is passed through the opening 61 of the pedestal 6, the positioning piece 62 of the pedestal 6 is fitted and positioned in the mortar-shaped concave part 2,
The pedestal 6 is bolted to the side of the concrete body
Tighten to 0 and install the ram chair 5. Then, the hydraulic cylinder 10 is fitted into the concave portion 57 at the end of the bottom portion 53 of the ram chair 5, and the pressure-resistant washer 21 and the anchor head 23 are inserted in that order, and the tips of the grippers 4, 4 are inserted into the conical hole 22 of the anchor head 23. After the portion is fitted, the attachment / detachment jig 9 is inserted so that the outer flat surface of the bottom portion 94 corresponds to the rear end surface of the conical hole 22.

Subsequently, the tensioning device having the above-described arrangement structure is applied to the mutual tightening action between the concrete body A and the concrete body B in a state where the PC strand 25 is tightened to one concrete body A (see FIG. 4). (See FIG. 1).

First, when the jig 9 is grasped by hand and struck from the side of the opening 92 (see arrow C), the jig 9 is attached.
While being guided and moved by the insertion hole 93, the bottom surface 94 hits the rear end of each of the grippers 4 and 4 so that the gripper 4 is fitted into the conical hole 22 of the anchor head 23 (see arrow D).
The PC stranded wire 25 is strongly and uniformly held and joined. Thereafter, when the ram 11 is extended (see arrow E) through the pressure washer 21 by the operation of the hydraulic cylinder 10, the end of the ram 11 pushes the anchor head 23 (see arrow F), and this movement is performed. Take the PC stranded wire 25
Is nervous.

Under such a tensioned state of the PC strand 25, the pushing member 8 released by releasing the locking of the locking member 83 is swung in the direction of arrow G via the pivoting member 82. Due to this swinging, in a state where the stranded wire 25 is loosely fitted in the insertion hole 87, the pushing member 8 is guided by the long slots 54, 55, and the pair of bulging portions 84, 84 is fitted to the one flange 71. Acts to move the cylinder 7 along the stranded wire 25 and the cylinder 100 (to the left in FIG. 1). In such a movement of the cylinder 7, the other flange 72 of the cylinder 7 acts on the rear end of each gripper 4, 4 to fit the gripper 4 into the conical hole 31 of the cone 3, and the PC stranded wire 25 Are strongly and uniformly held together. The fastening of the fastener 1 to the PC stranded wire 25 strongly tightens the concrete bodies A and B. Thereafter, the pushing member 8 is swung / returned in the direction indicated by the arrow H through the pivotal support member 82. It is locked by the stop member 83 to prevent the pushing member 8 from being carelessly operated.

FIG. 3 shows the conical hole 2 of the anchor head 23.
FIG. 8 is an explanatory view of an operation of the attachment / detachment jig 9 when the grippers 4 are removed from the inside 2, and is an operation necessary when the tensioning device is removed after the concrete body b is tightened.
The grippers 4 and 4 are removed by retracting the ram 11 by the operation of the hydraulic cylinder 10 (see the direction of arrow R in FIG. 1) to relax the tension of the tensioning device by the PC stranded wire 25. The attachment / detachment jig 9 is inserted into the PC stranded wire 25 in a state opposite to the direction in which the grippers 4 and 4 are driven, so that the large opening 91 is loosely fitted to the anchor head 23. Next, the end of the anchor head 23 is hit by grasping the attachment / detachment jig 9 by hand (see a dotted line state). Due to this striking action, the contact surface 96 of the attachment / detachment jig 9 is moved to the anchor head 23.
The anchor head 23 is moved relative to the grippers 4 and 4 at a time.
Tightening by the frictional forces of 4 and 4 can be released very easily.

The anchor head 23 and the PC stranded wire 2
After releasing the engagement with the ramchair 5, the bolts 200, 200 on the side of the concrete body B are removed, the ram chair 5 with the pedestal 6 is released from the side of the concrete body B in FIG. 9, 20, 10,
Release in the order of 5 and 7. If necessary, mortar is buried in the mortar-shaped concave part 2 of the concrete body B to terminate the connection of the concrete body A and B, and when it is necessary to tighten and connect a new concrete body, What is necessary is just to repeat the connection by a tensioning device.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the above-described embodiments.
Various changes in design may be made without departing from the spirit of the invention as set forth in the appended claims. In the embodiment of the present invention, it is described that the concrete body is to be tightened, but as the material to be tightened, it is possible to employ wood, synthetic resin, a mixture of various materials, and the like.
Although it is described that a PC stranded wire is adopted as the tightening means, it is also possible to apply a PC steel wire alone, and the gripper is pushed in by a pushing member provided in the ram chair and a tubular body provided with flanges at both ends. Although it is stated,
A hydraulic cylinder can be provided on the ram chair, and the gripper can be pushed in by extending the ram of the hydraulic cylinder, so that various designs can be changed.

[0023]

The first aspect of the present invention is that when a fastener is connected to a PC stranded wire or the like, the rear portion of each gripper is uniformly pressed and fitted to the cone by a flat portion provided on a pushing member, thereby forming a concrete body. Since a tensioning device such as a PC stranded wire that strongly tightens the two parts a and b was used, reliable and efficient tightening work could be achieved. Also, a second aspect of the present invention is a tensioning device for a PC stranded wire or the like, wherein a temporary portion provided on one end side of an attaching / detaching jig is used for temporarily connecting a fastener comprising each gripper and a cone to the PC stranded wire. The gripper evenly drives each gripper into the anchor head, so that reliable and efficient temporary connection work can be achieved, while it is inserted into the anchor head through the opening provided on the other end of the attachment / detachment jig. By uniformly hitting the end face of the anchor head with the attachment / detachment jig, each gripper can be easily loosened / released from the anchor head, and the tightening tool including the anchor head and each gripper and P
The work of releasing the temporary connection with the C stranded wire and the like was also achieved safely, reliably and efficiently.

[Brief description of the drawings]

FIG. 1 is an overall view of a tension device for a PC stranded wire according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line AA of the tensioning device of FIG.

FIG. 3 is an operation explanatory view of the attaching / detaching jig of FIG. 1;

FIG. 4 is an overall view of a conventional tension device for a PC stranded wire.

FIG. 5 is an explanatory view of an operation of tightening the PC stranded wire by a tightening tool including a cone and each gripper in FIG.

FIG. 6 is an explanatory view of a temporary connection / disconnection operation of the attachment / detachment jig shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1a, 1b 1st, 2nd tightening tool 3 cone 4 gripper 5 ram chair 7 pushing force transmission cylinder 8 pushing member 9 attachment / detachment jig 10 hydraulic cylinder 20 temporary fastener 23 anchor head 25 PC twisted wire b, concrete body b 2, b2 mortar-shaped recess

Claims (2)

[Claims] 1. A tensioning device applied to a PC stranded wire or the like for tightening objects to be tightened with a PC stranded wire or the like,
A fastening device comprising a cone and a plurality of grippers, a pushing force transmitting member, a pushing operating member, a tension applying member, and a temporary fastener, each of which is provided after the plurality of grippers in the fastening device by the pushing force transmitting member. A tensioning device for a PC stranded wire or the like, characterized in that the end face is pressed in evenly. 2. A tensioning device applied to a PC stranded wire or the like for tightening objects to be tightened with a PC stranded wire or the like,
A fastening device comprising a cone and a plurality of grippers, a pushing force transmitting member, a pushing operating member, a tension applying member, and a temporary fastener are provided, and temporary fastening or temporary fastening of the temporary fastener is enabled. A tensioning device for a PC stranded wire or the like, which is also provided with a detachable jig.