JP3653269B2 - Tension fixing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tension material fixing device used for fixing a terminal of a tension material such as a PC steel strand, and particularly to fixing a tension material terminal stretched between adjacent piers and between adjacent piers and an abutment. The present invention relates to a tendon fixing device.
[0002]
[Prior art]
5 is a side view showing the configuration of the tension structure between piers, and FIG. 6 is a cross-sectional view showing the configuration in the vicinity of the fixing device shown in FIG.
When a horizontal force acts on a river bridge or a highway bridge with bridge girder 30 on pier 10 and abut 20 due to an earthquake or the like, not only the pier 10 is damaged, but also between adjacent abut 20 and pier 10 and When there is a difference in the natural period between the adjacent piers 10, the adjacent abut 20, the pier 10, and the adjacent pier 10 vibrate at different phases, causing damage that the bridge girder 30 is dropped. there is a possibility.
[0003]
Therefore, conventionally, as shown in FIG. 5, by using an abutment tension structure in which tension members 40 are stretched between adjacent abutments 20 and piers 10 and between adjacent piers 10, adjacent abutments 20 and piers are used. 10 and the gap between adjacent piers 10 are prevented from expanding and the bridge girder 30 is prevented from falling.
[0004]
As shown in FIG. 6, the tension member used in such an inter-pier tension structure includes a PC steel material 1 made of PC steel wire, a PC steel wire, and the like, and the PC steel material 1 is in contact with the abutment 20 and the pier 10. It consists of a PE pipe 2 for preventing corrosion of the PC steel material 1 due to damage or rainwater, and the PC steel material 1 is stretched in a state inserted into the PE pipe 2. Both ends of the PC steel 1 are fixed by a tension material fixing device 4 provided on the abut 20 and the pier 10, and the PE pipe 2 is a female provided in a support tube 5 attached to a steel plate 9. Only one end is fixed by a pipe fixing device including a cone 51 and a male cone 52.
[0005]
Referring to FIG. 6, the tension material fixing device 4 includes a female cone 41 in which a tapered hole gradually reducing in diameter toward the insertion port (front end side) of the PC steel material 1, a tapered cylindrical outer peripheral shape, and a parallel cylinder A male cone 42 formed into a divided cylindrical shape obtained by dividing a cylindrical body having an inner peripheral shape into a plurality of divisions (for example, three divisions), and a cap 43 screwed to an opening end surface on the rear end side of the female cone 41 And a spring 44 interposed between the male cone 42 and the cap 43 and urging the male cone 42 toward the distal end side of the female cone 41, and the support plate 8 so as to cover the female cone 41 and the cap 43. The rust prevention cap 45 is attached.
[0006]
In such a configuration, in order to attach the end portion of the PC steel material 1 to the tension material fixing device 4 of the tension material fixing device 4, the end portion of the PC steel material 1 is inserted into the insertion opening of the female cone 41 and the male cone 42. The male cone 42 is pushed in with a force greater than the urging force of the spring 44 to expand the diameter of the male cone 42, and then the PC steel material 1 is released. Then, the male cone 42 is pushed into the female cone 41 by the spring 44, and at the same time, the diameter of the male cone 42 is reduced and the end of the PC steel 1 is strongly grasped, and the end of the PC steel 1 is fixed to the tension material fixing device 4. it can. Further, the end of the PE pipe 2 can be fixed to the support tube 5 of the tension material fixing device 4 by the same operation (see, for example, Patent Document 1).
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 09-1536
[Problems to be solved by the invention]
FIG. 7 is a diagram showing a tension material fixing step of a conventional tension material fixing device.
However, in the prior art, when the PC steel material 1 is inserted into the tension material fixing device 4, the PC steel material 1 may be caught by the male cone 42 as shown in FIG. When the PC steel material 1 is pushed in while being caught by the cone 42, as shown in FIG. 7 (b), the bottom 45a of the rust prevention cap 45 is broken or cracked, and the rust prevention function is lost. However, there is a problem in that there is a risk that the PC steel material 1 falls off due to the corrosion of the tension material fixing device 4.
[0009]
In the prior art, if the distance between the adjacent abutment 20 and the pier 10 and between the adjacent piers 10 is shortened by an earthquake or the like after the PC steel material 1 is stretched, the male cone 42 is caused by the PC steel material 1. Is pushed, the fixing position is shifted, and there is a problem that the PC steel material 1 is applied with a tension more than necessary.
[0010]
The present invention has been made in view of such problems, and the object of the present invention is to prevent rust even if the PC steel is caught on the male cone when the PC steel is fixed to the tension material fixing device. Even when the cap is not damaged or cracked, and the distance between the adjacent abut 20 and the pier 10 and between the adjacent pier 10 is shortened due to an earthquake or the like, the PC steel 1 It is in the point which provides the tension | tensile_strength fixing apparatus with which the fixing position of this does not shift | deviate.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is a tension material fixing device for fixing a tension material to a bridge pier or an abutment, wherein a taper hole gradually decreasing in diameter toward a distal end side where the insertion port of the tension material is formed. The male cone formed is divided into a plurality of cylindrical bodies having a tapered cylindrical outer peripheral shape and a parallel cylindrical inner peripheral shape, and is accommodated in the tapered hole of the female cone. A cone, a cap screwed to the opening end face of the rear end side of the female cone, and interposed between the male cone and the cap, urging the male cone toward the distal end side of the female cone A first spring, a rust prevention cap for housing the female cone to which the cap is screwed, and a bottom surface of the rust prevention cap and the cap, the cap and the female cone Said first spring Consists in tendon fixing apparatus characterized by comprising a second spring biases the urging direction and the same direction.
According to a second aspect of the present invention, a convex portion for positioning the second spring is formed on a contact surface of the cap with the second spring. It exists in the tension material fixing apparatus of claim | item 1.
The gist of the invention described in claim 3 is that the urging force of the first spring is approximately twice the urging force of the second spring. Exists in the device.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0013]
FIG. 1 is a cross-sectional view showing the configuration of the embodiment of the tendon fixing device according to the present invention, and FIG. 2 is an exploded view showing the configuration of the embodiment of the tendon fixing device according to the present invention.
[0014]
1 and 2, a tendon fixing device 7 according to the present embodiment includes a female cone 41 having a tapered hole that gradually decreases in diameter toward the insertion port (front end side) of the PC steel material 1, and a taper. A male cone 42 formed into a divided cylindrical shape obtained by dividing a cylindrical body having a cylindrical outer peripheral shape and a parallel cylindrical inner peripheral shape into a plurality of divisions (such as two divisions), and an opening end surface on the rear end side of the female cone 41 Are inserted between the male cone 42 and the cap 43, and the male cone 42 is connected to the distal end side of the female cone 41. Are interposed between the bottom portion 45a of the rust prevention cap 45 and the cap 71. The spring 44 is urged to the rust, the rust prevention cap 45 is attached to the bearing plate 8 so as to cover the female cone 41 and the cap 71. , Cap 71 and female cone 4 Direction of pressing to the bearing capacity plate 8, that is, the second spring 72 that urges the urging direction and the same direction of the spring 44. A convex portion 71 a formed on the side of the cap 71 that contacts the second spring 72 is provided to position the second spring 72.
[0015]
The urging force of the spring 44 and the urging force of the second spring 72 are set such that the urging force of the second spring 72 is weaker than the urging force of the spring 44. It is preferably about 1/2 of the urging force of 44.
[0016]
The PE pipe 2 is fixed only at one end by a pipe fixing device including a female cone 51 and a male cone 52 provided in a support tube 5 attached to a steel plate 9.
[0017]
Next, the tendon fixing process of the present embodiment will be described in detail with reference to FIG.
3 and 4 are diagrams showing a tension material fixing process of the embodiment of the tension material fixing device according to the present invention.
[0018]
When the PC steel material 1 is stretched between the abut 20 and the pier 10, first, one end of the PC steel material 1 is attached to the tension material fixing device 7 attached to the abut 20. That is, as shown in FIG. 3, one end of the PC steel material 1 is inserted into the insertion opening of the female cone 41 and inserted into the male cone 42, and the male cone 42 is pushed in with a force greater than the urging force of the spring 44. After expanding the diameter of the male cone 42, the PC steel material 1 is released. Then, the male cone 42 is pushed into the female cone 41 by the spring 44, and at the same time, the diameter of the male cone 42 is reduced and the end of the PC steel material 1 is strongly grasped, and the end of the PC steel material 1 is fixed to the tension material fixing device 7. it can.
[0019]
When the PC steel material 1 is inserted into the tendon fixing device 7 and the PC steel material 1 is pushed in a state where the PC steel material 1 is caught by the female cone 41 as shown in FIG. ), The second cone 72 prevents the female cone 41 and the cap 71 from coming into contact with the bottom 45a of the rust prevention cap 45, and no sudden force is applied to the bottom 45a of the rust prevention cap 45. The bottom 45a of the rust prevention cap 45 is not damaged or cracked.
[0020]
Next, the other end portion of the PC steel material 1 is attached to the pier 10 side. As shown in FIG. 4 (a), the PC steel material 1 is passed through the tension material fixing device 7 in a state where the rust prevention cap 45 and the second spring 72 are removed, and the PC steel material 1 is removed by a tension jack (not shown). Tension in the direction indicated by the arrow in (a). Since the tension by the tension jack is performed in a state where the cap 71 and the female cone 41 are pressed, the male cone 42 is pushed into the female cone 41 by the spring 44, and at the same time, the diameter of the male cone 42 is reduced and the end of the PC steel material 1 is moved. The PC steel material 1 can be fixed in a tightly gripped and tensioned state.
[0021]
After giving a predetermined tension force to the PC steel material 1 in this manner, a tension jack (not shown) is removed, and the PC steel material 1 is cut as shown in FIG. 4 (a), as shown in FIG. 4 (b). In this manner, the second spring 72 and the rust prevention cap 45 are attached.
[0022]
As described above, according to the present embodiment, the second spring 72 is interposed between the rust prevention cap 45 and the cap 71 (female cone 41), so that the tension steel fixing device 7 is provided with the PC steel material. When fixing 1, even if the PC steel material 1 is caught on the male cone 42, the rust prevention cap 45 will not be broken or cracked, so the rust prevention function of the rust prevention cap 45 is impaired. The effect is that the PC steel material 1 can be stably fixed over a long period of time.
[0023]
Furthermore, according to the present embodiment, even when the distance between the adjacent abut 20 and the pier 10 and the distance between the adjacent piers 10 are shortened due to an earthquake or the like, the PC steel material 1 is removed by the second spring 72. Since the male cone 42 is not pushed in, the fixing position is not shifted, and the PC steel material 1 can be stably fixed over a long period of time.
[0024]
Note that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention. In addition, the number, position, shape, and the like of the constituent members are not limited to the above-described embodiment, and can be set to a number, position, shape, and the like that are suitable for implementing the present invention. In each figure, the same numerals are given to the same component.
[0025]
【The invention's effect】
In the tension material fixing device of the present invention, when a PC steel material is fixed to the tension material fixing device by interposing a spring between the rust prevention cap and the cap (female cone), the PC steel material is caught by the female cone. Even if the rust prevention cap is not damaged or cracked, the PC steel material 1 can be stably fixed over a long period of time without impairing the rust prevention function of the rust prevention cap. There is an effect that can be.
[0026]
Further, in the tension material fixing device of the present invention, the PC steel material pushes the male cone by the second spring even when the distance between the adjacent abutment and the pier and the distance between the adjacent piers are shortened due to an earthquake or the like. Therefore, the fixing position is not shifted, and the PC steel material can be stably fixed over a long period of time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of an embodiment of a tendon fixing device according to the present invention.
FIG. 2 is an exploded view showing the configuration of the embodiment of the tendon fixing device according to the present invention.
FIG. 3 is a diagram showing a tension material fixing step of the embodiment of the tension material fixing device according to the present invention.
FIG. 4 is a diagram showing a tension material fixing process of the embodiment of the tension material fixing device according to the present invention.
FIG. 5 is a side view showing a configuration of a bridge pier tension structure.
6 is a cross-sectional view showing a configuration in the vicinity of the fixing device shown in FIG.
FIG. 7 is a diagram showing a tension material fixing step of a conventional tension material fixing device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 PC steel material 2 PE pipe 4, 7 Tensile material fixing device 5 Support tube 8 Bearing plate 9 Steel plate 10 Bridge pier 20 Abut 30 Bridge girder 41, 51 Female cone 42, 52 Male cone 43 Cap (conventional)
44 Spring 45 Anti-rust cap 72 Second spring 71 Cap (present invention)

Claims (3)

A tension material fixing device for fixing a tension material to a bridge pier or an abutment,
A female cone formed with a tapered hole that gradually decreases in diameter toward the tip side where the insertion port of the tendon is formed;
A male cone that is formed into a divided cylindrical shape obtained by dividing a cylindrical body having an outer peripheral shape of a tapered cylindrical shape and an inner peripheral shape of a parallel cylindrical shape, and is accommodated in a tapered hole of the female cone;
A cap screwed to the opening end face on the rear end side of the female cone;
A first spring interposed between the male cone and the cap and biasing the male cone toward the distal end of the female cone;
A rust prevention cap for housing the female cone to which the cap is screwed;
A second spring interposed between the bottom surface of the rust prevention cap and the cap and biasing the cap and the female cone in the same direction as the biasing direction of the first spring; A tendon fixing device characterized by that. The tension material fixing device according to claim 1, wherein a convex portion for positioning the second spring is formed on a contact surface of the cap with the second spring. The tension material fixing device according to claim 1, wherein an urging force of the second spring is weaker than an urging force of the first spring.

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