CN100494038C - Restoration method for deflection of main girder of girder crane and its girder crane - Google Patents

Abstract

The present invention relates to beam crane, and is especially one kind of self-repaired pre-stressed beam crane and the method of applying external pre-stress to repair the downwards bent beam of beam crane. The method of the present invention includes the following steps: 1. fixing stretching bearing and fixed bearing separately on two ends below the lower cover of the crane beam; 2. stringing steel strands separately in the fixing anchor beside the fixed bearing and the stretching anchor beside the stretching bearing to anchor the fixed end and to pressing the stretching anchor to the outer side of the stretching bearing; 3. regulating the initial stress of each steel strand with jack for equalized stress; 4. fixing 1-4 staying devices on the lower cover of the crane beam and setting the steel strands; and 5. stretching the steel strand of the stretching anchor with jack for the beam to bend upwards, anchoring the stretching end and regulating the staying devices for proper stress.

Description

Restoration method for deflection of main girder of girder crane and its girder crane

technical field

The invention relates to a method for repairing the deflection of the main girder of a beam crane and the girder crane thereof, in particular to a method for repairing the deflection of the main girder of the girder crane by applying prestress outside the body and the prestressed self-repairing girder crane.

Background technique

Beam cranes are widely used in industrial and mining enterprises, and have a large social stock. In order to prevent the "climbing" and "rolling" of the trolley due to the working load when the beam crane is in use, GB/T14405-93 "General Bridge Cranes" stipulates that the main beam should have an upper camber, but the beam crane After a period of use, due to various reasons, the camber of the main girder gradually decreases, or even deflects, which affects the use performance and safety performance of the crane, and makes the crane lose its use value. Since the crane is a large-scale equipment, if it is scrapped and replaced, it will lose Therefore, it is very important to repair the deflection of the main girder of the crane. Chinese patent CN1069952A discloses a method of using a "prestressed tensioner" to repair and transform the main girder of a crane, but the tensioner used in this method has the disadvantages of complex structure, large parts, difficult manufacture and high cost.

Contents of the invention

An object of the present invention is to overcome the deficiencies in the prior art and provide a method for repairing the deflection of the main girder of a girder crane.

Another object of the present invention is to provide a prestressed self-repairing beam crane.

The purpose of the present invention is achieved like this:

The method for repairing the deflection of the main girder of the girder crane of the present invention comprises the following steps:

a. Fix the tension end support and the fixed end support at the two ends of the lower cover plate of the main girder of the crane respectively;

b. Thread the steel strands into the fixed anchor and the tension anchor respectively placed on the outside of the fixed end support and the tension end support, and anchor the fixed end so that the tension anchor is pressed against the outside of the tension end support;

c. Use a jack to adjust the initial stress of each steel strand to make it evenly stressed;

d. Fix 1-4 top props upwards under the lower cover of the main beam, and place them downwards on the steel strands;

e. Use a jack to stretch the steel strand of the anchor to force the main girder to bend and deform upwards. After stretching to the set camber value, anchor the stretched end and adjust the supporter to make it bear the force.

The tension end support and the fixed end support are composed of a reinforcement plate fixed under the lower cover plate of the main beam, 2-5 ribs parallel to and perpendicular to the main beam fixed to the reinforcement plate, and a crossbeam fixed at one end of the rib constitute.

The outer side of the crossbeam of the tension end support and the fixed end support is provided with a groove for matching the tension anchor and the fixed anchor.

The supporter is composed of a top plate fixed under the main beam, 2-6 sets of screw rods fixed under the top plate and an arc-shaped bracket provided with screw holes for use with the screw rods. The arc-shaped bracket consists of nuts and The adjusting nut is adjustable and fixed on the screw rod.

The girder crane of the present invention is a prestressed self-repairing girder crane, comprising a main girder, a sub-beam is arranged under the main girder, and the sub-beam is composed of fixed ends fixed to the lower two ends of the lower cover plate of the main girder, tension The tension end and the steel strand that can be stretched and fixed between the fixed end and the tension end are composed of 1-4 jacking devices between the main girder and the auxiliary girder.

The fixed end is composed of a fixed end support and a fixed anchor anchored on the fixed end support, and the tension end is composed of a tension end support and a tension anchor anchored on the tension end support.

The fixed end support and the tension end support are composed of a reinforcement plate fixed under the lower cover plate of the main beam, 2-5 ribs parallel to and perpendicular to the main beam fixed to the reinforcement plate, and a crossbeam fixed at one end of the rib constitute.

The outer side of the crossbeam of the tension end support and the fixed end support is provided with a groove for matching the tension anchor and the fixed anchor.

The supporter is composed of a top plate fixed under the main beam, 2-6 sets of screw rods fixed under the top plate and an arc-shaped bracket provided with screw holes for use with the screw rods. The arc-shaped bracket consists of nuts and The adjusting nut is adjustable and fixed on the screw rod.

After the crane is repaired by the method of the present invention, the auxiliary beam is left in place and works together with the main beam to maintain the repair effect and enhance the strength, stiffness and bearing capacity of the main beam; after the crane is repaired for a period of time, if the camber of the main beam changes , and then adjust the prop nut to obtain a satisfactory camber.

The method of the present invention sets the sub-beam in the deflection or deformation direction of the main girder, and by adjusting the adjustable nut of the sub-beam supporter, the supporter is expanded, and the upward expansion drives the main beam to bend and deform upwards, and the downward expansion is transmitted through the steel strand At the supports at both ends, it is transformed into eccentric pressure acting on the main beam, which compresses the main beam to deflect and deform. The deflection deformation of the main beam is used to repair the camber, the bending stress of the main beam is used to offset the working load, and the jack is used to restrain the working deformation of the main beam and improve the stress of the main beam.

The method of the present invention is to use the auxiliary beam to make the main girder deflected downward into a negative bending moment, because it is opposite to the positive bending moment caused by the working load, so offset part of the working load stress of the main beam.

The auxiliary beam added by the method of the present invention makes the neutral axis of the main beam move down correspondingly, the cross-sectional area of the compression zone increases, and the cross-sectional area of the tension zone decreases, but the steel strand is the farthest from the neutral axis, and most of the tensile stress , are all concentrated on the steel strand, and because the steel strand has superior tensile properties, the tensile and compressive capabilities of the repaired main girder are enhanced. At the same time, the additional sub-beams increase the moment of inertia of the section and the modulus of the flexural section, and the changes in the camber, modulus of the flexural section, and bending moment of the main beam are similar, making the original Constant cross-section beams are improved to approximate constant strength beams.

Compared with the prior art, the method of the present invention has the advantages of labor saving, labor saving, time saving, low repair cost, small increase in repair weight, long-term repair effect, significant reinforcement effect, and the improvement of equal-section beams to approximate equal-strength beams. Simultaneously, the present invention not only can repair and reinforce the large-tonnage and large-span cranes, but also is especially suitable for repairing low-value small-tonnage cranes.

Description of drawings

Fig. 1 is the structural representation of girder crane of the present invention;

Fig. 2 is a schematic diagram of the tension end structure of the girder crane of the present invention;

Fig. 3 is the structural representation of the supporter of the inventive method;

Fig. 4 is a schematic diagram of the arrangement of the flat anchor of the box-type positive rail beam repaired by the method of the present invention;

Fig. 5 is a schematic diagram of the honeycomb anchor layout of the box-shaped off-rail beam repaired by the method of the present invention;

Fig. 6 is a schematic diagram of the layout of honeycomb anchors for repairing I-beams using the method of the present invention.

Detailed ways

Specific embodiments of the present invention are described below with reference to the accompanying drawings:

Referring to Fig. 1--6, the method for repairing the deflection of the girder girder of the girder crane of the present invention comprises the following steps:

a. Fix the tension end support 21 and the fixed end support 31 at both ends of the lower cover plate 11 of the main beam 1 of the crane respectively, and the tension end support 21 and the fixed end support 31 are fixed on the lower cover plate of the main beam 1 The reinforcing plate 211 under 11 is composed of two ribs 212 fixed to the reinforcing plate 211 parallel to and perpendicular to the main beam 1, and a beam 213 fixed at one end of the two ribs;

b. Penetrate the prestressed steel strand 4 into the tension anchor 22 and the fixed anchor 32 respectively placed on the outside of the tension end support 21 and the fixed end support 31, and anchor the fixed end 3 so that the tension anchor 22 is pressed against On the outside of the tension end support 21, the outer side of the crossbeam 213 of the tension end support 21 and the fixed end support 31 is provided with a groove that cooperates with the tension anchor 22 and the fixed anchor 32, so that the tension anchor 22 and the fixed anchor 32 are matched. The fixed anchor 32 is placed in the tension end support 21 and the outer beam 213 of the fixed end support 31;

c. Use a special small jack with an oil pump to adjust the initial stress of each steel strand 4 to make it evenly stressed;

d. Fix two top props 5 upwards under the lower cover plate 11 of the main beam 1 and place them downward on the steel strand 4; the top props 5 are fixed on the top plate 51 fixed under the main beam 4 sets of screw rods 52 under the top plate 51 and arc brackets 55 provided with screw holes for use in cooperation with the screw rods 51 are formed. The arc brackets 55 are adjustably fixed on the screw rods 52 by lock nuts 53 and adjustment nuts 54. The lower arc end of the arc support 55 cooperates with the prestressed steel strand 4;

e. Use a special large jack to stretch the tension end 2, the steel strand 4, and force the main beam 1 to bend and deform upwards. After tensioning to the set camber value, anchor the tension end 2, and adjust the supporter 5 to adjust the nut 54, make it stressed, and then tighten the lock nut 53.

When the method of the present invention is used to repair the box-type rail girder crane, in step b, the tension anchor 22 and the fixed anchor 32 are flat anchors 221 or multiple single anchors, arranged in pairs.

When the method of the present invention is used to repair the box-type off-rail girder crane, in step b, the tension anchor 22 and the fixed anchor 32 are two honeycomb anchors 222 arranged in parallel, arranged in pairs.

When the method of the present invention is used to repair the I-beam crane, in step b, the tension anchor 22 and the fixed anchor 32 are a single honeycomb anchor 222 arranged in pairs.

The girder crane of the present invention is a prestressed self-repairing girder crane, comprising a main girder 1, a sub-beam 6 is arranged under the main girder 1, and the sub-beam 6 is fixed under the cover plate 11 of the main girder 1 The fixed end 3 at both ends, the tension end 2 and the steel strand 4 that can be stretched and fixed between the fixed end 3 and the tension end 2 are composed of: the fixed end 3 is composed of a fixed end support 31 and an anchored support at the fixed end. The fixed anchor 3 on the seat 31 is composed of the tension end 2 composed of the tension end support 21 and the tension anchor 22 anchored on the tension end support 21; the fixed end support 31 and the tension end The support 21 is composed of a reinforcing plate 211 fixed under the lower cover plate 11 of the main beam 1, two ribs 212 fixed to the reinforcing plate 211 parallel to and perpendicular to the main beam 1, and a beam 213 fixed at one end of the two ribs 212 ; The outside of the beam 213 of the tension end support 21 and the fixed end support 31 is provided with a groove 214 that cooperates with the tension anchor 22 and the fixed anchor 32; between the main beam 1 and the auxiliary beam 6, there are two Supporter 5.

The supporter 5 is composed of a top plate 51 fixed under the main girder 1, four groups of screw rods 52 fixed under the top plate 51 and an arc-shaped support 55 that is provided with a screw hole in cooperation with the screw rod 52. The shaped bracket 55 is adjustable and fixed on the screw rod 52 by a lock nut 53 and an adjustment nut 54 .

When the method of the present invention is used to repair the box-type rail girder crane, in step b, the tension anchor 22 and the fixed anchor 32 are flat anchors 221 or multiple single anchors, arranged in pairs.

When the method of the present invention is used to repair the box-type off-rail girder crane, in step b, the tension anchor 22 and the fixed anchor 32 are two honeycomb anchors 222 arranged in parallel, arranged in pairs.

When the method of the present invention is used to repair the I-beam crane, in step b, the tension anchor 22 and the fixed anchor 32 are a single honeycomb anchor 222 arranged in pairs.

The girder crane of the present invention, after a long period of use, when the deflection of the main girder 1 occurs, the deflection of the main girder 1 can be automatically repaired by applying prestress to the sub-beam 6 through actions on the sub-beam 6. The specific repair includes the following steps :

a1. Use a special small jack with an oil pump to adjust the initial stress of each steel strand 4 to make it evenly stressed;

a2. Use a special large jack to stretch the steel strand 4 at the tension end 2 to force the main girder 1 to bend and deform upwards. After stretching to the set camber value, anchor the tension end 2;

a3. Adjust the supporter 5 downwards and adjust the nut 54 to make the supporter 5 expand and receive force, and then tighten the locking nut 53 to complete the repair operation.

Claims (14)

1. A method for repairing the deflection of the main girder of a beam crane, characterized in that it comprises the following steps: a. Fix the tension end support and the fixed end support at the two ends of the lower cover plate of the main girder of the crane respectively; b. Thread the steel strands into the fixed anchor and the tension anchor respectively placed on the outside of the fixed end support and the tension end support, and anchor the fixed end so that the tension anchor is pressed against the outside of the tension end support; c. Use a jack to adjust the initial stress of each steel strand to make it evenly stressed; d. Fix 1-4 top props upwards under the lower cover of the main beam, and place them downwards on the steel strands; e. Use a jack to stretch the steel strand of the anchor to force the main girder to bend and deform upwards. After stretching to the set camber value, anchor the stretched end and adjust the supporter to make it bear the force. 2. The repair method according to claim 1, characterized in that, the tension end support and the fixed end support are composed of reinforcement plates fixed under the lower cover plate of the main beam, 2-5 pieces parallel and perpendicular to the main beam. The beam is composed of a rib plate fixed to the reinforcement plate and a beam fixed at one end of the rib plate. 3. The repairing method according to claim 2, characterized in that, the outer sides of the beams of the tension end support and the fixed support are provided with grooves to cooperate with the tension anchor and the fixed anchor. 4. The repair method according to claim 1, characterized in that, the supporter is composed of a top plate fixed under the main beam, 2-6 sets of screws fixed under the top plate, and a set of screws used in conjunction with the screws. The arc-shaped support of the screw hole is formed, and the arc-shaped support is adjustable and fixed on the screw rod by a lock nut and an adjustment nut. 5. The repair method according to any one of claims 1 to 4, characterized in that the fixed anchor and the tension anchor are flat anchors arranged in pairs. 6. The repair method according to any one of claims 1 to 4, characterized in that, the fixed anchor and the tension anchor are single honeycomb anchors arranged in pairs. 7. The repair method according to any one of claims 1 to 4, characterized in that the fixed anchor and the tension anchor are two honeycomb anchors arranged in parallel, arranged in pairs. 8. A beam crane comprising a main girder, characterized in that a sub-beam is provided under the main girder, and the sub-beam consists of a fixed end fixed to the lower two ends of the lower cover plate of the main girder, a tension end and its It is composed of steel strands that can be stretched and fixed between the fixed end and the tensioned end. There are 1-4 jacking devices between the main beam and the auxiliary beam; the fixed end is supported by the fixed end support and anchored at the fixed end. The fixed anchor on the support is composed of the tension end support and the tension anchor anchored on the tension end support. 9. The crane according to claim 8, characterized in that, the fixed end support and the tension end support are composed of reinforcement plates fixed under the lower cover plate of the main girder, 2-5 pieces parallel and perpendicular to the main girder It consists of ribs fixed to the stiffener and beams fixed at one end of the rib. 10. The crane according to claim 9, characterized in that, the outer sides of the beams of the tension end support and the fixed support are provided with grooves to cooperate with the tension anchor and the fixed anchor. 11. The crane according to claim 8, characterized in that, the supporter is composed of a top plate fixed under the main girder, 2-6 sets of screw rods fixed under the top plate, and a set of screw rods that are used in conjunction with the screw rods. The arc bracket of the hole is formed, and the arc bracket is adjustable and fixed on the screw rod by a lock nut and an adjustment nut. 12. The crane according to any one of claims 8 to 11, wherein the fixed anchor and the tension anchor are flat anchors arranged in pairs. 13. The crane according to any one of claims 8 to 11, characterized in that, the fixed anchor and the tension anchor are single honeycomb anchors arranged in pairs. 14. The crane according to any one of claims 8 to 11, characterized in that the fixed anchor and the tension anchor are two honeycomb anchors arranged in parallel, arranged in pairs.

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