JP2903271B2 - Girder under jack - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a girder jack for tensioning a diagonal member of a cable-stayed bridge.

[0002]

2. Description of the Related Art In a cable-stayed bridge, as shown in FIG.
You need to be nervous for each book. For the tension work, a heavy jack was installed on the underside of the bridge girder,
Must move sequentially. However, moving the underside of the bridge girder has poor scaffolding, and it is not an easy task to sequentially move heavy jacks. Furthermore, depending on the structure of the cable-stayed bridge, the mounting angles of the diagonal members and the bridge girder may all differ, so it is necessary to change the pulling angle of the jack for each tensioned position, and the adjustment is also complicated. It was troublesome.

[0003]

SUMMARY OF THE INVENTION The object of the present invention is to solve the above-mentioned problems, and to provide a jack under the girder which can be easily moved and installed even on the lower surface of a bridge girder having a poor scaffold. With the goal. Still another object of the present invention is to provide a girder jack capable of easily changing the angle and tensioning the slant at an optimum angle even if the angle of attachment differs for each slant.

[0004]

That is, the present invention relates to a frame which can be moved by suspending it on a guide rail provided on the lower surface of a bridge girder, and a floor surface of the frame in a direction intersecting the guide rail. The provided crossing rail, a movable carriage mounted on the transverse rail, an upside down frame mounted on the movable upside down, a jack base movable on the upside down frame, and a jack. A girder jack consisting of a jack mounted on a table.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. <B> Structure of bridge girder A through hole penetrating the diagonal member 1 is open on both sides of the bridge girder 2. Therefore, two guide rails 3 are provided in parallel on the lower surface on both sides of the bridge girder 2, that is, on the lower surface of the through hole.

<B> Suspended Frame A movable frame 4 is suspended from the guide rail 3.
The suspension frame 4 is suspended by wheels in a monorail manner for each guide rail 3. If a part of the wheels is constituted by a gear trolley, the suspension frame 4 is extended along the guide rail 3. Can be moved. The suspension frame 4 is a frame composed of an upper frame, four columns, and a floor.

<C> Moving carriage A transverse rail 5 is provided on the floor of the suspension frame 4. The cross rail 5 is provided in a direction crossing the direction of the guide rail 3. A movable carriage 6 is mounted on the cross rail 5. The movable trolley 6 is a mount provided with wheels on a lower surface,
The motor can run on the cross rail 5.

<4> Jack stand A movable frame 6 is mounted on the movable carriage 6 via a horizontal shaft. Therefore, the raising and lowering frame 7 can be turned upside down with respect to the movable carriage 6 about the horizontal axis. For this raising and lowering operation, a telescopic cylinder 8 is installed between the movable carriage 6 and the raising and lowering frame 7,
Further, a jack stand 9 is movably mounted on the falling frame 7 which expands and contracts by hydraulic pressure. The jack base 9 is mounted on the tilting frame 7 via wheels, and moves on the tilting frame 7 by driving a motor installed at the rear end of the tilting frame 7. A jack 10 for tensioning the diagonal member 1 of the cable-stayed bridge is mounted on the jack base 9.
The jack 10 is a center-hole type jack 10 and has a structure in which the diagonal member 1 is gripped and extended inside to apply a tensile force to the diagonal member 1.

[0009]

The operation of the above-mentioned under-spar jack will now be described. <B> Movement of the suspension frame 4 The suspension frame 4 which can be suspended by moving on the guide rail 3 provided on the lower surface of the bridge girder 2 is moved to a predetermined position for giving tension to the diagonal member 1. . If you move along guide rail 3,
It almost reaches the vicinity of the penetrating position of the diagonal member 1.

<B> Movement of the mobile trolley 6 A transverse rail 5 is provided on the floor surface of the suspension frame 4 in a direction intersecting the guide rail 3, and the movable trolley 6 is mounted on the transverse rail 5. I have. Therefore, the movable carriage 6 is moved along the crossing rail 5 and is accurately arranged at a position in front of the diagonal member 1.

<C> Adjusting the tilt of the tilting frame 7 Next, the tilting frame 7 attached to the movable carriage 6 so as to be tiltable.
Extend the cylinder 8 to adjust the angle. Thus, the center line of the jack 10 on the jack base 9 is set at a position on the extension of the diagonal member 1.

<D> Extension of Jack The oblique material 1 is taken into the center hole of the jack 10, gripped and extended. As a result, the diagonal member 1 is given a tensile force in the correct direction. After applying a predetermined tensile force, the end of the diagonal member 1 is fixed by a predetermined means.

<E> Movement When fixing at one place is completed, the raising frame 7 is lowered to lower the entire height, and the suspension frame 4 is moved along the guide rail 3 to the next fixing place. Move to near. Thereafter, the subsequent diagonal member 1 is tensioned in the same manner as described above.

[0014]

As described above, the under-spar jack of the present invention has the following effects. <a> Work under a girder with a poor footing can be performed safely and smoothly. <B> Since the direction, height, and angle of the heavy jack can be freely adjusted, a tensile force can be applied to the diagonal member from an accurate direction. <C> Even in a cable stayed bridge of a type in which the mounting angle with the bridge girder differs for each diagonal member, accurate tension can be easily applied to each diagonal member.

[Brief description of the drawings]

FIG. 1 is a side view of a jack under a girder according to the present invention.

FIG. 2 is an overall perspective view.

FIG. 3 is an explanatory diagram of a state of use.

Claims (1)

(57) [Claims] 1. A frame which is movable on a guide rail provided on a lower surface of a bridge girder, a cross rail provided on a floor surface of the frame in a direction intersecting the guide rail, and a cross rail provided on the cross rail. A mobile trolley mounted on the mobile trolley, an upside down frame attached to the mobile trolley so as to be able to move up and down, a jack base that can be mounted on the upside down frame and movable, and a jack mounted on the jack base Jack under the girder