JPH07127691A - Connector for steel strand - Google Patents

Abstract

PURPOSE:To provide a connector which can surely and easily connect steel strands such as PC steel strands, which are exerted with a large load. CONSTITUTION:A thread-engagement in which a sleeve 3 or a female cone is screwed is used for squeezing and gripping wedges 5, 5' at ends of steel strands, instead of conventional press-gripping using a spring force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection tool for connecting a steel stranded wire, particularly a PC (prestressed concrete) steel stranded wire used for constructing a large-scale structure such as a bridge or a tank or a building. Is.

[0002]

2. Description of the Related Art Conventionally, as this type of connecting device, for example, FIG.
There is known a PC steel stranded wire connector for pretensioning as shown in FIG. In the figure, 1 is a screw 2,
2'is a joint screw, 3 and 3'each have a screw threaded to the screw 2, 2'on one end of the inner circumference, and a conical hole with a small outer end on the inner circumference of the other end. Two sleeves 4 and 4 ', 5 and 5', respectively, have an outer surface formed into an arcuate taper along the conical hole, and an inner surface formed into an arcuate shape along the outer circumference of the wire 6,6 '. It has two sets of wedges.

Reference numeral 7 is a spring inserted between two sets of wedges 5 and 5'via a presser pan 8 and 8 ', and 9 and 9'is an O-ring fitted in an outer peripheral groove of the wedge. . W and W'indicate the ends of the PC steel strands to be connected, respectively.

The use example of such a connecting tool is as follows. Plural formwork is installed between 30-50m pretensioning bench, and concrete is placed in the formwork while tensioning the PC steel wire. When the concrete solidifies and the strength of the concrete develops, the tension of the bench is removed and the solidified concrete is loaded. Splicers are used to connect PC steel strands between the bench and the formwork.

The connection is made by connecting the end W of one PC steel wire to
As shown in the figure, when the wedge 5 in the sleeve 3 is pushed inward from the outside of the center, the wedge 5 moves inward and spreads out against the force of the spring 7, and W is gripped by the entire length of the wedge 5. . Similarly, the other wire end W'of PC steel is also inserted and gripped in the sleeve 3 ', and both ends W and W'are connected to the inside of the sleeve by the wedge pressed by the spring 7. When tension is applied, the wedge slips and converges to the outside of the sleeve, firmly gripping the PC steel strand and withstanding high tension.

The PC steel stranded wire is tensioned, cast into concrete, solidified, unloaded, and then cut between the bench and the form to obtain a PC block product. If the PC steel stranded wire is a long one without connection, there is a lot of loss due to this cutting. Therefore, the PC steel stranded wire is added by a connecting tool.

[0007]

Concrete powder, rust of PC stranded wire or the like adheres to the conical hole surface of the sleeve or the tapered surface of the wedge, or oil or rust adheres to the surface of the PC stranded wire. If it does, the wedge action due to the pressing force of the spring 7 is weak, and it is difficult to grasp a plurality of wedges for W and W ′ in the same situation, and there is a case where they are misaligned and misaligned. If they are misaligned, the plurality of wedges do not slip uniformly on the conical hole surface of the sleeve as the tension of the PC steel wire increases, and therefore the wedge action due to the convergence of the wedges is not exerted.

Particularly, this unevenness is a slip phenomenon in which the wire end portions W and W'are removed from the wedge from the PC steel in the initial stage of tension,
It is easy to cause a disconnection phenomenon. This phenomenon is
This is a serious problem because it causes the steel strands to splash and lead to an accident resulting in injury or death, and the PC structure is not loaded with a predetermined tension force.

[0009]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the problem of wicking, and is characterized in that gripping is performed by screwing force of screws instead of gripping by spring force. . The screw-threading is performed between the sleeve and the female cone or between the joint screw and the sleeve, and the details thereof will be described below with reference to the illustrated embodiment.

[0010]

【Example】

(Embodiment 1) In FIG. 1, 1 is a screw 2 on both ends of the outer circumference.
2'is a joint screw, and 3'and 3'each have a screw that engages with the screw 2, 2'on one end of the inner circumference, and a conical hole with a small outer end on the inner circumference of the other end. Two sleeves with 4,4 '. Reference numerals 5 and 5'show two sets of wedges each having an outer surface formed in an arcuate taper along the conical hole and an inner surface formed in an arcuate shape 6,6 'along the outer circumference of the PC steel wire. In addition, W and W'are the ends of the PC steel strand inserted into the wedge from the outer end of the sleeve, 9 and 9'are O-rings fitted in the outer circumferential groove of the wedge, 1
0 and 10 'are parallel surfaces provided on a part of the outer circumference of the sleeve.

The connecting tool thus constructed can be securely connected and gripped in the following manner. That is, the end portion W of the PC steel strand to be connected is inserted into the arcuate shape 6 of the wedge 5 in the sleeve 3 which is not sufficiently screwed with the joint screw. Naturally wedge 5
The end is not in contact with the joint screw end, and the wedge is pushed by the strand W to slip open toward the joint screw side by the gap, and the wedge full length covers the PC steel strand. Then, apply a wrench or monkey wrench to the parallel surface of the sleeve 3 to rotate the sleeve and screw it into the joint screw side. By this screwing, a plurality of wedges converge uniformly, the ends thereof are pressed against the joint screw end, and W is uniformly held by the wedges at a predetermined position.

The opposite end W'of the PC steel wire is also gripped in the wedge 5'as described above, and both PC steel wire ends W,
W'is connected. The joint screw 1 is shown as having a stopper projecting on both the outer circumference and the inner circumference at the center of the cylinder length direction, but this can be omitted. In addition, a tooth profile of appropriate shape is provided on the wedge-shaped arcs 6 and 6 '.
The gripping of the C steel into the wire ends W and W'is ensured.

(Embodiment 2) In FIG. 2, 11 is a sleeve provided with screws 12 and 12 'at both ends of its inner circumference, and 13 and 13' are respectively screws which are screwed into the threads 12 and 12 'on the outer circumference. Two corn cones that have conical holes 14 and 14 'that have a small diameter at their outer ends. 15 and 15 'are two sets of wedges each having an outer surface formed into an arcuate taper along the conical hole and an inner surface formed into an arcuate shape 16 and 16' along the outer circumference of the PC steel wire. It is a spacing cylinder located between the two sets of wedges 15 and 15 'in the sleeve 11 and holding the wedge head to determine the spacing. W and W'represent the ends of the PC steel stranded wire inserted into the wedge from the outer end of the sleeve, and 18 and 18 'are parallel surfaces provided on the outer peripheral end side of the mescon, respectively.

The connector thus constructed is used as follows. First, the wire end W of the PC steel is inserted into the wedge in a state where the female cone 13 is not sufficiently screwed with the sleeve 11 and the interval cylinder 17 and the wedge 15 are not in contact with each other in the sleeve. Then, the wedge 15 is pushed by W and slides inward, so that the entire length thereof covers W. Then, a wrench or a monkey wrench is applied to the parallel surface of the outer circumference of the female cone to rotate the female cone, and it is screwed in so as to be completely screwed with the sleeve 11. By this screwing, the wedges are evenly slid and pushed until they come into contact with the spacing cylinder 17, and finally converge, and the reaction force causes W to be held at a predetermined position and is gripped and fixed.

The end portion W'of the PC steel strand on the opposite side is also inserted into the wedge 15 'and held and fixed, so that W and W'are connected. The center position of the sleeve 11 in the length direction and the installation position of the interval cylinder 15 are preferably marked in advance for easy understanding or have a fixed structure.

The circular arc-shaped 16 and 16 'surfaces of the wedge are provided with teeth in order to facilitate gripping and gripping the outer circumference of the PC steel wire in the same manner as in the first embodiment, and the parallel surface of the female cone has two surfaces.
It is formed by another polygon such as a piece, a piece 4, a piece 6, and the like. Each part of the connector is usually made of steel, but other materials such as a wedge made of a sintered alloy or a hard synthetic resin may be used.

(Embodiment 3) FIG. 3 is a schematic view of the case where the connecting tool as shown in Embodiments 1 and 2 is used for construction of a PC concrete floor slab for a large water storage tank. Placing concrete on a long floor slab is divided into several times as shown in the figure. In the case of the post-tensioning method, the PC steel stranded wire W is tension-fixed after the concrete is placed and solidified in the first work section A. B
In the second section, the stranded wire W end of the first section is connected to the PC steel stranded wire W'extended by the connecting tool C of Examples 1 and 2, and the same construction as in the first section is performed. The construction will be completed repeatedly. In addition, D shows a jack for tension.

[0018]

As described above, in the connector of the present invention, the end portions W and W'of the PC stranded wire to be connected are gripped and fixed, and in the first embodiment, they are screwed together by the rotation of the sleeve. In Example 2, the wedges are slid and converged along the conical holes by screwing by screwing of the measuring cone. In this way, the multiple wedges are pushed together in the convergent direction according to the movement of the sleeve or female cone by mechanical screwing, so that even if foreign matter such as concrete powder or rust is present around the wedges, the Like the one due to the spring force, the wedge portion that hits it does not stop, and there is no deviation, and the foreign matter is eliminated while proceeding in parallel.

[0019]

According to the connector of the present invention, a plurality of wedges can be screwed together to uniformly and surely converge on the wire when connecting various steel strands, particularly PC steel strands. It is possible to prevent personal injury and accident repair problems due to the slip phenomenon and disconnection phenomenon of steel stranded wire in the fields of large-capacity tanks and buildings. Also, its structure is as simple and small as the conventional product, and the connection work was rather easy and reliable by using a spanner.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a part of the first embodiment.

FIG. 2 is a partial vertical sectional side view of the second embodiment.

FIG. 3 is a schematic view showing a place where the connector of the present invention is used in concrete placing work.

FIG. 4 is a vertical sectional side view of a part of a conventional connecting tool.

[Explanation of symbols]

 1 Joint screw 2,2 'Screw 3,3' Sleeve 4,4 'Conical hole 5,5' Wedge 6,6 'Circular 7 Spring 8,8' Presser plate 9,9 'O-ring W, W' Ends of PC stranded wire 10, 10 'Parallel surface provided on part of outer circumference of sleeve 11 Sleeve 12, 12' Screw 13, 13 'Female cone 14, 14' Conical hole 15, 15 'Wedge 16, 16' Circular arc 17 Space tube 18, 18 'Parallel plane provided on part of outer circular end of female cone A 1st section for concrete placement B 2nd section for concrete placement C Connection tool D Jack for tensioning

Claims (4)

[Claims] 1. A joint screw having a screw provided on both ends of the outer circumference, and a screw screwed to the screw on one end of the inner circumference, respectively.
Two sleeves having a conical hole whose outer end has a small diameter on the inner circumference on the other end side, and an outer surface formed into an arcuate taper along the conical hole, and an inner surface having an arcuate shape along the outer circumference of the strand. A steel stranded wire connector, comprising: two sets of formed wedges, wherein the wedges are hard to fit into a steel material and are gripped by a screwing force of a screw. 2. A parallel surface is provided on a part of the outer circumference of the sleeve,
2. The connector according to claim 1, wherein a tooth shape is provided on the arcuate surface of the wedge. 3. A sleeve having threads at both ends of the inner circumference,
Two female cones each having a screw threaded to the screw on the outer circumference and having a conical hole with an outer end having a small diameter on the inner circumference, and an outer surface formed into an arcuate taper along the conical hole, respectively. Two sets of wedges whose inner surface is formed in a circular shape along the outer circumference of the stranded line and a spacing tube located between the two sets of wedges in the sleeve are provided, and the wedges are made difficult to insert into the steel and gripped by the screwing force of the screws. A connector for steel stranded wire, which is characterized in that 4. The connector according to claim 3, wherein a parallel surface is provided on a part of the outer periphery of the mescon, and / or a tooth shape is provided on the circular arc surface of the wedge.