JP2757280B2 - PC steel rod tensioning 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 tensioning device for a PC steel bar, for example, in various concrete structures for introducing prestress into concrete by a post-tension method using a relatively short PC steel bar of about 2 m. The present invention relates to a tensioning device for a PC steel rod disposed on a side wall (support portion) for a linear track for shear reinforcement (that is, vertical prestress).

[0002]

2. Description of the Related Art When a pre-stress is introduced into a concrete structure 1 by a post-tension method, a conventional method is shown in FIG.
As shown in FIG. 1, a PC steel bar 6 is formed by using a center hole jack 25, a tension rod 26, and a reaction force receiving base 27.
I'm nervous. More specifically, in the concrete structure 1, a tubular sheath member 28 having high lubricity at the time of concrete casting and the PC steel rod 6 inserted into the sheath member 28 are integrally embedded. The outer end of the PC steel rod 6 is formed on the outer surface of the concrete structure 1 and has a bottom portion 3 of a concave portion (for example, a pyramid-shaped concave portion) 2 having a non-circular cross section whose outside diameter is enlarged.
And an anchor plate 4 disposed on the bottom 3
And projecting into the non-circular concave portion 2 through the hole 5.

After the concrete of the concrete structure 1 is hardened, the fixing nut 7 is screwed into the outer end thread portion 6a of the PC steel bar 6 protruding from the anchor plate 4 and tightened. The PC steel bar 6 is tensioned and fixed by taking a reaction force.

[0004] When tightening with the nut 7, tension is applied to the PC steel bar 6 by using the center hole jack 25 and the reaction force receiving base 27 in advance. That is, the distal end of the support leg 30 of the reaction force receiving base 27 is applied to the outer surface of the anchor plate 4, and the distal end surface of the cylinder 31 of the center hole jack 25 is in contact with the support plate 32 of the reaction force receiving base 27.

[0005] A tension rod 26 inserted through the center of the center hole jack 25 is provided with a support plate 32.
The tip of the hole 33 is connected to the PC steel bar 6 via the coupler 34. The coupler 34 has screw holes 35 at both ends thereof, and the screw portion 6a of the PC steel bar 6 and the screw portion 26a of the tension rod 26 are screwed into the screw holes 35 from both ends of the coupler, whereby the tension between the PC steel bar 6 and the tension is increased. The rod 26 is connected. Also tension rod 2
The tension rod 26 is connected to the piston 37 of the center hole jack 25 by screwing a nut 36 into the outer end screw portion 26b of the center hole jack 6. 38 is a bearing member.

[0006] The conventional post-tension type P
In the C steel rod tensioning device, the center hole jack 25 is driven to extend the piston 37, so that a reaction force is applied to the anchor plate 4 via the support leg 30 of the reaction force receiving base 27, and the tension rod 26, the coupler 34 The PC steel rod 6 can be strongly pulled outward through the through hole to give tension thereto. In this tensioned state, the operator tightens the fixing nut 7 with a torque wrench (not shown). After the fastening operation of the fixing nut 7 is completed, the jack 25 is shortened, and then the PC steel bar 6 and the tension rod 26 connected by the coupler 34 are separated, and the reaction force receiving stand 27 and the center hole jack are separated. 25
The work is completed by removing from the installation location.

[0007]

In the conventional post-tensioning type tensioning device, when using a short PC steel bar 6, a jack such as the center hole jack 25 is used for tensioning as described above. I do. In this case, after the fixing nut 7 is tightened in a tension state, when the pressure of the pump for shortening and driving the center hole jack 25 is reduced, the center hole jack 25 is released, and the tension is applied to the fixing nut 7. Will give
At this time, when the load due to the reaction force received by the reaction force receiving base 27 is transferred to the fixing nut 7, a set loss occurs due to the fixing tool such as the center hole jack 25 and the reaction force receiving base 27, and the intended tension is reduced. There is a problem that it cannot be given to the PC steel bar 6.

Further, since the degree of tightening of the fixing nut 7 depends on the feeling of the operator's hand, there is variation among the workers, and after the tensioning device is released, how much tension is introduced into the PC steel rod 6. There is a problem that you may not know.

In other words, the above-described problem inevitably occurs in the tensioning device for a PC steel bar which requires two separate operations, namely, a tensioning operation by the center hole jack 25 and a tightening operation of the fixing nut 7 by the operator. I was

As one method for solving the above problem, a fixing nut 7 is directly connected to a PC steel rod 6 by a torque wrench.
There is a method of applying tension to the PC steel bar 6 by tightening it to the screw portion 6a, but in this case, there is a disadvantage that a complicated and large-sized device for receiving the rotational reaction force of the torque wrench is required.

An object of the present invention is to provide a tensioning device for a PC steel bar which is improved in the above-mentioned disadvantages and has a characteristic in a reaction force receiving portion of a torque wrench.

[0012]

According to the present invention, there is provided a tensioning device for a PC steel bar according to the present invention, wherein a concave portion 2 having a non-circular cross section is provided on an outer surface of a concrete structure 1;
The concrete structure 1 passes through the hole 5 of the anchor plate 4 provided on the bottom portion 3 of the non-circular concave portion 2 from the concrete structure 1.
The C steel rod 6 protrudes, and the fixing nut 7 is screwed into the tip screw portion 6a of the PC steel rod 6, and the reaction force receiving frame 9 of the reaction force receiving member 8 is set in the non-circular concave portion 2. A reaction force receiving upright plate 11 stands upright from a reaction force receiving support plate 10 which is fitted non-rotatably and is provided integrally with the reaction force receiving frame 9, and is positioned inside the reaction force receiving upright plate 11. And the gear case 13 of the power transmission gear mechanism 12
Is mounted on the output gear 23 of the power transmission gear mechanism 12, and the rotation output shaft 14 and the fixing nut 7 are connected to each other by a joint member 1 having fitting square holes 15, 15a at both ends.
6, and a square hole 1 provided in a shaft portion of an input gear 24 of the power transmission gear mechanism 12.
7, a rotation drive shaft 19 of a torque wrench 18 is fitted,
The rotation locking plate 20 provided on the torque wrench 18 is configured to engage with the reaction force receiving upright plate 11. The torque wrench 18 is connected to the electric power wrench body 21
And a booster gear mechanism 22.

[0013]

According to the present invention, the reaction force of the rotation of the gear case 13 about the rotation output angle shaft 14 generated when the rotation force is transmitted from the rotation output angle shaft 14 to the fixing nut 7 via the joint member 16 is reduced. , And is received by the reaction force receiving upright plate 11 of the reaction force receiving member 8. The rotation reaction force of the torque wrench 18 for inputting the rotation force to the power transmission gear mechanism 12 about the rotation drive angular axis 19 is generated by the rotation locking plate 20 provided on the torque wrench 18 receiving the reaction force. Engagement with the plate 11 ensures the reception, and the configuration of the reaction force receiving member 8 is simple.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. The same elements as those in the conventional example will be described with the same reference numerals.

1 to 3, a PC steel rod 6 is inserted into a sheath member 28 made of a metal cylinder or a synthetic resin cylinder, etc., and is integrated with the sheath member 28 when the concrete structure 1 is poured into concrete. The concrete structure 1 is buried in the concrete structure 1 while leaving a part of the outer end. An anchor member 40 is integrally provided at the tip of the PC steel bar 6 and is embedded in the concrete structure 1.

On the outer surface of the concrete structure 1, there is formed a non-circular recessed portion 2 having a tapered outer shape, for example, a truncated pyramid shape. 4 are arranged. The PC steel bar 6 protruding from the bottom surface portion 3 penetrates the hole 5 formed in the anchor plate 4 and protrudes into the non-circular recess 2. On the outer surface of the anchor plate 4, the outer end of the PC steel bar 6 is formed. A fixing nut 7 is screwed into the screw portion 6a.

In this embodiment, the fixing nut 7 is tightened by an electric power wrench 41 shown as a specific example of the torque wrench 18 via the power transmission gear mechanism 12. At this time, the electric power wrench 41 and the power transmission The reaction force of the rotation generated in the gear mechanism 12 is received by the reaction force receiving member 8.

The reaction force receiving member 8 includes a reaction force receiving frame 9 and
The reaction force support frame 10 includes a reaction force support plate 10 integrated with the reaction force support frame 9, and a reaction force support upright plate 11 that stands up from both sides of the reaction force support plate 10.

The reaction force receiving frame 9 is provided with the non-circular recess 2.
As the simplest means for non-rotatably fitting the non-circular recess, it has a shape similar to the non-circular recess 2. In the case of the embodiment, since the non-circular concave portion 2 has a truncated pyramid shape, the
The frame is formed in a truncated pyramid shape formed by joining two frame plates in a tapered shape. Therefore, by fitting the reaction force receiving frame 9 into the non-circular concave portion 2, the reaction force receiving frame 9 is formed. Is mounted non-rotatably in the non-circular recess 2.

A reaction force receiving support plate 10 is integrally provided on one side edge 9a of the enlarged diameter end of the reaction force receiving frame 9, and when the reaction force receiving frame 9 is fitted into the non-circular concave portion 2, the reaction force is received. Receiving support plate 10
Are arranged along the flat outer surface 1a of the concrete structure 1. Then, from both sides of the reaction force receiving support plate 10,
The reaction force receiving upright plates 11 are raised in parallel.

The power transmission gear mechanism 12 is provided for taking out the rotation input of the electric power wrench 41 as a rotation output at a location remote from the input location. The gear case 13 is provided with a reaction force receiving support plate. 10. In the illustrated example, the power transmission gear mechanism 12 is composed of three gears meshing with each other. The right end gear in FIG. 3 is an input gear 24, the left end gear is an output gear 23, and the input gear 24 An intermediate gear 42 is provided between the output gears 23.

The input gear 24, the intermediate gear 42, and the output gear 23 are housed in a gear case 13 composed of a side frame 45, a top plate 46 and a bottom plate 47, and the shaft portions 23a, 2 of each gear.
4 a and 42 a are rotatably supported in the gear case 13 via bearings 43. The gear case 13 is provided with a grip portion 44, and the gear case 13 can be carried by itself by gripping the grip portion 44.

Further, the gear shaft 24a of the input gear 24 has
A square hole 17 is provided in the axial direction, and the rotation drive shaft 19 of the electric power wrench 41 is removably fitted into the square hole 17 through an opening 48 formed in the top plate 46 of the gear case 13. You can wear it. The square hole 17 is a regular quadrangle in the illustrated example.
This corresponds to the cross-sectional shape of the rotary drive angular shaft 19 of FIG.

The gear shaft 23a of the output gear 23 is provided with a polygonal hole 49 in the axial direction thereof.
The rotation output angle shaft 14 is removably fitted from below through an opening 50 formed in the bottom plate 47 of the first embodiment. Polygon hole 4
Reference numeral 9 denotes an angular wave shape in the illustrated example, and a hollow rotary output angular shaft 14 having an outer surface having a regular hexagonal cross section and a hollow shape is detachably fitted to the polygonal hole 49.

The rotary output square shaft 14 has a square hole 15 having a quadrangular cross section at one end in the axial direction, and a square hole 15 having a square wave shape at the other end.
a is removably fitted in the square hole 15 of the substantially sleeve-shaped joint member 16 having a. Further, a square wave-shaped square hole 15 a at the other end of the joint member 16 is detachably fitted to the fixing nut 7. Thus, the rotation output angle shaft 14 and the fixing nut 7 are connected via the joint member 16 so as to rotate integrally.

The electric power wrench 41 comprises an electric power wrench main body 21 and an intensifier having a power-up gear mechanism 22 composed of a plurality of gears integrally connected to the electric power wrench main body 21. Rotation drive angle axis 1
9 is connected to the output shaft of the booster gear mechanism 22.

A plurality of bolts 52 are located on the lower end face 51 of the wrench at the base end of the rotational output of the electric power wrench 41.
, The rotation locking plate 20 is attached. In FIG.
Reference numeral 53 denotes a hole for inserting the shaft of the bolt 52.

When the rotary drive shaft 19 is fitted into the square hole 17 of the input gear 24 of the power transmission gear mechanism 12, the rotation locking plate 20 is placed on the upper surface of the gear case 13 and the electric power wrench is mounted. 41, and the rotation locking plate 20
Are locked inside the reaction force receiving upright plate 11 of the reaction force receiving member 8.

According to the configuration of the embodiment, the electric power wrench 4
When the drive operation is performed, the rotational power is transmitted to the rotational drive angular axis 1.
9, the input gear 24, the intermediate gear 42, the output gear 23, the rotation output angle shaft 14, the joint member 16, and the fixing nut 7 are transmitted in this order, and the tightening force of the fixing nut 7 applies tension to the PC steel rod 6. Is done.

When the fixing nut 7 is tightened, the gear shaft 13a (that is, the gear shaft 23a of the output gear 23)
A rotation reaction force about the rotation output angle axis 14) occurs,
The gear case 13 is supported by the reaction force receiving support plate 10 and is located inside the reaction force receiving upright plate 11, and the reaction force receiving frame 9 integrated therewith is non-rotatably inserted into the non-circular recess 2. Due to the fitting, the reaction force receiving upright plate 11 receives the rotational reaction force of the gear case 13, and thus the rotation of the gear case 13 is reliably prevented.

The electric power wrench 41 also generates a rotational force about the rotational drive shaft 19, and this rotational reaction force is generated by the rotation stopping plate 20 of the reaction force receiving member 8 of the reaction force receiving member 8.
By being positioned inside the gear case 1, it is received by the reaction force receiving upright plate 11, similarly to the gear case 13, so that the rotation of the electric power wrench 41 is reliably prevented.

The power transmission gear mechanism 12 is provided with an electric power wrench 41 which is the input position of the rotational torque as described above.
The number of gears of the power transmission gear mechanism 12 is not limited to that of the embodiment, and the number of gears of the power transmission gear mechanism 12 is not limited to the embodiment.

Further, by changing the number of teeth and the meshing relationship of each gear of the power transmission gear mechanism 12, the power transmission gear mechanism 12 is added to the power-up gear mechanism 22 of the electric power wrench 41, and the second power-up gear mechanism (Not shown).

[0034]

As described above, according to the PC steel bar tensioning device of the present invention, when the fixing nut 7 of the PC steel bar 6 is tightened with the torque wrench 18, the power is centered on the rotation output angle shaft 14. The reaction force of the rotation generated in the transmission gear mechanism 12 and the reaction force of the rotation generated in the torque wrench 18 about the rotation driving angular shaft 19 are received by the reaction force receiving upright plate 11 of the reaction force receiving member 8. Luc wrench 18
And the rotation of the power transmission gear mechanism 12 is reliably prevented, and the tension of the PC steel bar 6 can be accurately and easily applied by smoothly tightening the fixing nut 7 with the torque wrench 18 and the reaction force receiving member 8 Is simple.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a post-tension type PC steel rod embedded concrete structure showing an embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view of a PC steel bar tensioning device.

FIG. 3 is an assembled sectional view of a PC steel bar tensioning device.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a perspective view of an electric power wrench.

FIG. 6 is an explanatory sectional view showing a relationship among a reaction force receiving member, a power transmission gear mechanism, and a fixing nut.

FIG. 7 is a plan view of FIG. 6;

FIG. 8 is a side view of the reaction force receiving member.

FIG. 9 is a plan view of FIG.

FIG. 10 is a rear view of the reaction force receiving member.

FIG. 11 is a vertical sectional side view of a reaction force receiving member.

FIG. 12 is a plan view of a gear case accommodating a power transmission gear mechanism.

FIG. 13 is a plan view of the gear case with a top plate removed.

FIG. 14 is a longitudinal sectional view in the central longitudinal direction of the gear case.

FIG. 15 is a plan view of a rotation output angle axis.

FIG. 16 is a side view of a rotation output angle axis.

FIG. 17 is a bottom view of the rotation locking plate.

FIG. 18 is a side view of the rotation locking plate.

FIG. 19 is a plan view of a joint member.

FIG. 20 is a side view of the joint member.

FIG. 21 is a partially sectional explanatory view of a conventional PC steel bar tensioning device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete structure 2 Non-circular concave part 3 Bottom part 4 Anchor plate 5 Hole 6 PC steel bar 6a Screw part 7 Fixing nut 8 Reaction force receiving member 9 Reaction force receiving frame 10 Reaction force receiving support plate 11 Reaction force receiving erecting plate 12 Power Transmission gear mechanism 13 Gear case 14 Rotation output square shaft 15 Engagement square hole 16 Joint member 17 Square hole 18 Torque wrench 19 Rotation drive square shaft 20 Rotation locking plate 21 Electric power wrench main body 22 Boost gear mechanism 23 Output gear 24 Input gear Reference Signs List 25 center hole jack 26 tension rod 27 reaction force receiving stand 28 sheath member 30 support leg 31 cylinder 32 support plate 33 hole 34 coupler 35 screw hole 36 nut 37 piston 38 support member 40 anchor member 41 electric power wrench 42 intermediate gear 43 bearing 44 Gripping part 45 Side plate 46 Top plate 47 Bottom plate 8 apertures 49 polygonal hole 50 opening 51 wrench large end face 52 bolt 53 holes

Claims (2)

(57) [Claims] 1. A concave portion 2 having a non-circular cross section is provided on an outer surface of a concrete structure 1. The concave portion 2 penetrates a hole 5 of an anchor plate 4 provided on a bottom portion 3 of the non-circular concave portion 2. A PC steel rod 6 protrudes from the concrete structure 1, and a fixing nut 7 is screwed into a tip screw portion 6 a of the PC steel rod 6, and a reaction force receiving member 8 is provided in the non-circular recess 2.
The reaction force receiving frame 9 is fitted non-rotatably, and a reaction force receiving erecting plate 11 stands upright from a reaction force receiving support plate 10 provided integrally with the reaction force receiving frame 9. The gear case 13 of the power transmission gear mechanism 12 is mounted on the reaction force receiving support plate 10 located inside the upright plate 11, and the rotation output angle provided on the output gear 23 of the power transmission gear mechanism 12. The shaft 14 and the fixing nut 7 are provided with engagement square holes 15,
15a, is detachably connected via a joint member 16 having an input gear 24a.
A rotary drive angular shaft 19 of a torque wrench 18 is fitted in a square hole 17 provided in a shaft portion of the shaft, and a rotation locking plate 20 provided in the torque wrench 18 is engaged with the reaction force receiving upright plate 11. A tensioning device for a PC steel bar, characterized in that it is arranged. 2. The tensioning device for a PC steel rod according to claim 1, wherein the torque wrench 18 comprises an electric power wrench main body 21 and a booster gear mechanism 22 coupled to the electric power wrench main body 21.