CN-122007463-A - High-precision boring method and device for fixed structure in narrow space

CN122007463ACN 122007463 ACN122007463 ACN 122007463ACN-122007463-A

Abstract

The invention discloses a method and a device for boring a fixed structure in a narrow space with high precision in the technical field of anchor box and anchor hole processing, which are suitable for processing the anchor hole of an anchor box in a steel box girder box, and comprise the following steps that S1, the size of an operation space at the periphery of the anchor box is measured, and a positioning datum line is drawn on the surface of an anchor backing plate; the method comprises the steps of S2, installing a first fixing device and a second fixing device to form stable preliminary constraint on the side of a bottom plate, S3, installing a connecting seat on a gear reducer, installing a cutter head and a high alloy turning tool on the gear reducer, S4, clamping the connecting seat into the two fixing devices and installing a third fixing device on the side of a top plate, S5, installing an adjustable shoulder pole beam system on a block web and connecting the adjustable shoulder pole beam system to a lifting lug of the gear reducer, and S6, executing boring processing of an anchor hole. The invention can overcome the problems of extremely limited operation space, difficult equipment positioning, equipment dead weight in processing, vibration influence precision and the like, and finally ensures that the processing precision of the anchor holes meets the requirements within +/-0.5 mm.

Inventors

SUN HUANGQUAN
LI LEI
LI AO
XIA YIHENG
HUA LE
WU XIAOYU
DU WEI

Assignees

中铁建大桥工程局集团靖江重工有限公司

Dates

Publication Date: 20260512
Application Date: 20260401

Claims (9)

1. The method for boring the anchor holes of the anchor box in the steel box girder box with high precision in the fixed structure in the narrow space is suitable for processing the anchor holes of the anchor box in the steel box girder box, and is characterized by comprising the following steps: S1, measuring the size of an operation space around an anchor box in a welded and formed steel box girder block, and drawing a positioning datum line on the surface of an anchor backing plate according to the theoretical coordinates of an anchor point and the circle center of a foundation hole actually measured on site; S2, taking the center of the foundation hole determined in the step S1 as a reference, installing a first fixing device and a second fixing device on the bottom plate side of the anchor backing plate, wherein the connecting line included angle between the two devices and the center of the circle is 100-140 degrees, and the two devices are symmetrically arranged left and right so as to form stable preliminary constraint on the bottom plate side; S3, mounting a connecting seat on a gear reducer, and mounting a cutter head and a high alloy turning tool on a transmission shaft of the gear reducer, wherein the rated output torque of the gear reducer is larger than the actual maximum working torque; S4, hoisting the assembly in place, enabling the imperforate flange surface of the connecting seat to be attached to the anchor backing plate and clamped into the two fixing devices on the bottom plate side, then installing a third fixing device on the top plate side, enabling the three fixing devices to be distributed in an approximately regular triangle shape, and enabling the center of an anchor hole to be located at the center of the triangle; s5, installing an adjustable shoulder pole beam system on a block web, and connecting the adjustable shoulder pole beam system to a lifting lug of the gear reducer through a hanging belt so as to bear the whole self weight of the adjustable shoulder pole beam system; And S6, starting the gear reducer to bore holes, and monitoring the machining process through an observation window on the connecting seat web pipe to finish boring the anchor holes.
2. The method for boring the fixed structure in the narrow space with high precision according to claim 1, wherein in the step S1, the step of scribing the positioning line comprises the step of drawing the positioning line by taking the circle center of the anchor hole base hole as a reference and the outer circle radius of the connecting seat flange as a reference, so that the installation position of the fixing device is ensured to accurately correspond to the theoretical coordinate of an anchor point.
3. The method for boring a hole with high precision in a fixed structure in a small space according to claim 1, wherein in step S2, an included angle between a connecting line of the first fixing device and the second fixing device and a circle center is 120 °.
4. The method for boring a fixed structure in a small space with high precision according to claim 1, wherein in the step S3, the material of the connecting seat is not lower than Q235B, and the flange plate thickness is not less than 20mm.
5. The method for boring a hole with high precision in a fixed structure in a small space according to claim 1, wherein in step S3, the high alloy turning tool is made of cemented carbide YG8 or YW1.
6. The method for boring a fixed structure in a small space with high precision according to claim 1, wherein in step S5, the adjustable shoulder pole beam system realizes longitudinal position adjustment through a clamping groove, realizes transverse position adjustment through sliding of the shoulder pole beam in the sleeve, and realizes vertical position adjustment through adjusting the length of the hanging strip.
7. A boring device for carrying out the method of any one of claims 1-6, comprising: the gear reducer is provided with a lifting lug on the machine body; The connecting seat comprises a belly pipe, a first flange and a second flange which are welded at two ends of the belly pipe respectively, wherein the first flange is a non-porous smooth surface and is used for being clung to an anchor backing plate, and the second flange is provided with a plurality of bolt holes for connecting a gear reducer; Each fixing device comprises an L-shaped connecting block and a tightening bolt, wherein one side of the L-shaped connecting block is provided with a drilling and tapping structure for pressing a flange of the connecting seat through the tightening bolt; The adjustable shoulder pole beam system comprises a shoulder pole beam, sleeves, supports with clamping grooves and hanging strips, wherein two ends of the shoulder pole beam extend into the sleeves to be fixed, the bottoms of the sleeves are fixedly connected with the upper sides of the supports, and the clamping grooves of the supports are clamped on the upper edges of webs of the anchor boxes; the cutting unit comprises a cutter head and a high alloy turning tool which are arranged on the transmission shaft of the gear reducer.
8. The boring device of claim 7, wherein the gear reducer incorporates a precision screw feed mechanism for controlling the axial feed rate of the turning tool.
9. The apparatus of claim 6 wherein the cutterhead is secured to the drive shaft by a flat key and shaft end shield.

Description

High-precision boring method and device for fixed structure in narrow space Technical Field The invention relates to the technical field of anchor hole machining of anchor boxes in steel box girder boxes, in particular to a method and a device for boring a fixed structure in a narrow space with high precision. Background The precision of the anchor holes of the anchor backing plate of the anchor box structure in the steel box girder box has important importance, even decisive importance, for bridges, especially large-span cable-stayed bridges or suspension bridges, and the suspension rods of the cable-stayed bridges or suspension bridges are main bearing members of the bridges and can be compared with 'life lines' of the bridges. The force of the 'life line' is finally transmitted to the steel box girder safely and smoothly through the key force transmission component of the anchor box, and then transmitted to the whole bridge structure. The anchor pad anchor holes are the "final interface" and "throat" of the force transmission path. The precision directly determines the stress state of the inhaul cable (or the suspender) and the installation and normal operation of the anchorage device. The precision is insufficient, so that the following serious engineering problems are directly caused, namely, firstly, structural potential safety hazards are caused, brittle fracture can occur at the anchor box structure or the joint weld under the action of long-term eccentric load and fatigue, so that the anchoring failure of the inhaul cable is caused, secondly, the bridge forming line shape and the internal force state deviate from the design, the cable force of each inhaul cable is precisely calculated, the bridge reaches the designed line shape and the ideal internal force state, the additional bending moment and the cable force loss caused by the anchor hole deviation can cause the actual cable force to be inconsistent with the design value, finally, construction period delay is caused due to construction difficulty, repair work such as reaming, polishing and the like is carried out at the bridge position, time and labor are wasted, and damage is caused to the prepared anti-corrosion coating. The traditional construction process is that after the structures such as the anchor backing plate, the bearing plate and the like are machined, the structures are added into block manufacturing and segment total splicing, the process has the defects that the machining can ensure the precision of an anchor hole of the anchor backing plate, but uncontrollable factors such as welding deformation and the like in subsequent procedures can influence the precision of the anchor hole and the coordinates of an anchor point, and in addition, if the anchor hole machining is finished and the structures are added into the segment total splicing, the design is subjected to aperture change, and then secondary machining of the anchor hole is also needed to be considered. And the processing of the anchor holes is carried out after the anchor block is welded and integrated with the structures such as the web plate, the partition plate and the like, so that the precision deviation caused by welding deformation is greatly reduced. However, the internal space of the steel box girder is extremely narrow and closed, a large-scale precision machine tool cannot enter, and the precision cannot be ensured by a conventional hand-held tool. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a method and a device for boring a hole in a fixed structure in a narrow space with high precision, which can overcome the problems of extremely limited operation space, difficult equipment positioning, equipment dead weight in processing, vibration influence precision and the like, and finally ensure that the processing precision of an anchor hole meets the extremely high requirement within +/-0.5 mm. The invention aims to realize the method for boring the anchor hole of the anchor box in the steel box girder box with high precision by adopting the fixed structure in the narrow space, which comprises the following steps: S1, measuring the size of an operation space around an anchor box in a welded and formed steel box girder block, and drawing a positioning datum line on the surface of an anchor backing plate according to the theoretical coordinates of an anchor point and the circle center of a foundation hole actually measured on site; S2, taking the center of the foundation hole determined in the step S1 as a reference, installing a first fixing device and a second fixing device on the bottom plate side of the anchor backing plate, wherein the connecting line included angle between the two devices and the center of the circle is 100-140 degrees, and the two devices are symmetrically arranged left and right so as to form stable preliminary constraint on the bottom plate side; S3, mounting a connecting seat on a gear redu