JPH083274B2 - PC steel rod tension device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PC steel rod tensioning device, and more particularly to a device for tensioning a PC steel rod used for connecting concrete blocks and the like by bolting.

[0002]

2. Description of the Related Art When paving a road surface, there is a method in which precast pavement boards made of concrete are spread and joined to each other by PC steel rods.
There is shown in FIG.

In FIG . 3 , reference numerals 1a and 1b denote precast concrete precast pavement plates 2a and 2b connected to each other, and vertical holes 3a and 2a and 2a formed at positions closer to the center than the joint end faces of the precast pavement plates 1a and 1b. Three
Reference numeral b is an expanded portion formed on the end face portion of the precast pavement boards 1a and 1b, and reference numeral 4 is a pair of two short rods 4a and 4b, and a coupler 5
It is a PC steel rod that is formed by connecting with each other and connects the precast pavement boards 1a and 1b.

The PC steel rod 4 is coated with an unbonded material such as asphalt on the surface and housed in the precast pavement boards 1a and 1b. Then, both ends thereof are projected into the vertical holes 2a, 2b, penetrate the pressure plate 6, and the fixing nut 7 is screwed to fix both ends in the vertical holes 2a, 2b, and at the same time, the fixing is performed in one vertical hole 1a. Nut 7
By tightening with a torque wrench, the PC steel rod 4 is tensioned and prestressed.

[0005]

However, in such a conventional PC steel rod tensioning method, when the fixing nut 7 screwed onto the PC steel rod is tightened, the vertical hole 1
Since it is necessary to insert a torque wrench into one of a and 1b and tighten the fixing nut 7,
The vertical hole 1a, the at least one hand of 1b, the
To take enough space to accommodate the (hand torque wrench and the operator, as the case may be) a torque wrench, such it is necessary to set the diameter <br/> dimensions to a large value, the vertical hole 1a
When the PC steel bar is strained because the diameter is set to a large value
There was a problem that cracks tended to occur and the amount of mortar used for filling the vertical hole 1a after tensioning the PC steel rod increased.

The present invention has been made in view of the above problems, and an object thereof is to provide a PC steel rod tensioning device which can easily tighten a nut of a PC steel rod even in a narrow vertical hole space.

[0007]

In order to achieve the above object, the present invention has a driving side gear having a torque wrench fitting hole, a driven side gear meshing with the driving side gear, and a PC steel rod screwed together. It consists of a toothed fixing nut, and a torque wrench is fitted to the drive side gear while the driven side gear is PC.
Operatively connected to a screwed toothed fixing nut to the steel rod, the gist of the PC steel rod tensioning device for transmitting to the toothed fixing nut via a drive-side gear the torque of the torque wrench.

[0008]

As described above, since the PC steel rod tensioning device is composed of the gear trains meshed with each other, the PC steel rod and the toothed gear are engaged .
Even if narrow space of the vertical hole screwing a tree fixing nut,
If even the driven gear of the PC steel rod tensioning device can be accommodated in the vertical hole, insert this driven gear into the vertical hole and add the above teeth.
Engage with the fixing nut . Then, transmitted to the toothed fixing nut through the drive-side gear and the driven gear from the outside of the vertical hole, since tightening the toothed fixing nut, P
The C steel rod can be tensioned. In addition, as the action of tensioning the PC steel bar, the tensile force applied to the PC steel bar is
Both compressive force is included.

[0009]

1 and 2 are views showing a first embodiment of a PC steel rod tensioning device according to the present invention. Of these, FIG. 1 is a front view showing the internal structure of the PC steel rod tensioning device, and FIG. 2 is a side view of the essential parts showing the operating state of the first embodiment. In FIG. 1, reference numeral 10 is a PC steel rod tensioning device, and 11 is a PC.
A housing that houses each functional component of the steel rod tensioning device 10,
Reference numeral 12 is a drive side gear to which the rotational torque is input, 13 is a driven side gear, and 14 is a toothed fixing nut. Drive side gear 1
Reference numeral 2 is composed of a spur gear and other external gears, and has a torque wrench fitting hole 15 into which the tip of the torque wrench can be inserted in the central portion. The driven gear 13 is composed of a gear having the same structure as the driving gear 12, and is meshed with the driving gear 12. Toothed fixing nut 1
Reference numeral 4 is a nut member formed with meshing teeth 16 on the outer circumference.
Is bitten by.

The operation of the PC steel rod tensioning device having the above structure will be described below. In FIG. 2, reference numeral 17 is a precast member made of prestressed concrete and used for bridge girders, and 18 is a vertical hole for tightening a nut formed in the precast member 17. Also, reference numeral 19
Is a PC steel rod that connects a plurality of precast members 17, and 20 is a steel rod through hole into which the PC steel rod 19 is inserted. In this embodiment, the steel rod through hole 20 of the vertical hole 18
A pressure support plate 21 that is fastened by the toothed fixing nut 14 is attached to the opening. If it is desired to tighten the nut of the PC steel rod to give a tension force, the toothed fixing nut 14 is screwed into the threaded portion 19a formed at the end of the PC steel rod 19, and the PC is fixed to the toothed fixing nut 14. The driven gear 13 of the steel rod tensioning device 10 is engaged. Then, the electric torque wrench 2 is inserted into the torque wrench fitting hole 15 of the drive side gear 12.
When the distal end of 2 is fitted and the electric torque wrench 22 is actuated, the rotational torque is transmitted from the driving gear 12 to the toothed fixing nut 14 via the driven gear 13.
The toothed fixing nut 14 rotates by receiving the rotation torque, moves in the direction of arrow S in FIG.
A tensile tension is applied to the C steel rod 19.

As described above, when the toothed fixing nut 14 is fastened to the PC steel rod 19, the electric torque wrench 22 can be operated from the outside of the vertical hole 18.
No. 8 is required to have a space for mounting the toothed fixing nut 14 on the PC steel rod 19, and this space can be reduced.

[0012] Note that as the torque wrench is used torque wrench 22 of the motorized may perform tightening toothed fixing nut 1 4 with a manual torque wrench. Further, as the torque wrench, when a tension force is applied to the PC steel rod 19 by the electric torque wrench 22, a method of applying a tensile force to the PC steel rod 19 is adopted, but not limited to this. , it is also possible to adopt an additional embodiment of the tensioning force as compressive force is applied against the PC steel bars 1 9.

[0013]

As described above, according to the present invention,
The PC steel rod tensioning device constructed in accordance with the gear train, the driven gear and inserted the installed toothed fixing nut into the vertical hole in order to fastening the PC steel bars, in the toothed fixing nut
So that the driven side gear is engaged.
It is possible to easily tighten the nut of the PC steel rod in a space with a narrow vertical hole. The vertical hole was made small like this
As a result, cracks that tend to occur when the PC steel bar is strained
Prevents cracks as much as possible, and is a model for filling vertical holes in the field.
The amount of rutar used can be kept small.

[Brief description of drawings]

FIG. 1 is a front view showing the internal structure of a PC steel rod tensioning device according to an embodiment of the present invention.

FIG. 2 is a side view of an essential part showing an operating state of the embodiment.

[Fig. 3] Precast pavement plates are connected by PC steel rods.
It is sectional drawing which shows the prior art example of the opened state.

[Explanation of symbols]

10 PC steel rod tensioning device 1 1 Housing 1 2 Drive side gear 1 3 Driven side gear 14 Toothed fixing nut 1 5 Torque wrench fitting hole 1 7 Precast pavement board 1 8 Vertical hole 1 9 PC steel rod 2 0 Through hole 2 1 Pressure plate 35 Fixing nut

Claims (1)

[Claims] 1. A drive-side gear comprising a drive-side gear having a torque wrench fitting hole, a driven-side gear meshing with the drive-side gear, and a toothed fixing nut screwed to a PC steel rod. While the wrench is fitted, the driven gear is PC
A PC steel rod tension device that meshes with a toothed fixing nut screwed to a steel rod and transmits the rotational force of the torque wrench to the toothed fixing nut via a drive side gear and a driven side gear .