RU2527597C2 - Method to increase resource of crane girder - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to crane structures. To increase resource of a crane girder comprising upper and lower belts from T bars connected to each other by a vertical wall, where a longitudinal stiffening rib and inclined support ribs are fixed from a pair of angle profiles with horizontal flanges, elements of the crane girder structure are prepared, K-shaped processing of the T bar wall edges is carried out, through holes are pierced in the shelf of the T bar and in the sheet of the braking beam with regular pitch, using a rolling and bending machine, they process a sheet and form a pair of channel sections by longitudinal bends, forming a Z-shaped profile of cross section of the braking beam. Through holes are pierced and calibrated in design points with a regular pitch in the wall of the crane girder, which respond to the holes in the braking beam and in the T bar of the lower belt. Using gravity roll carriers, finished parts are transported to a line. In the lower position the wall of the T bar of the upper belt and the wall of the T bar of the lower belt are connected with a continuous seam with a wall of a crane girder, the connected elements are manipulated, burr and slag are removed from the root of both seams. Connected elements are transported to the next post of automatic welding, and in the lower position they finally connected the wall of the T bar of the upper belt and the wall of the T bar of the lower belt with the wall of the crane girder. The crane girder is connected with a Z-shaped braking beam, their calibrated holes are matched, alloyed pins are installed, and nuts are tightened in a mechanised manner using a wrench for the rated value, support ribs from angles or T bars are installed, using high-resource connections, and the finished crane girder is sent to a finished goods warehouse.

EFFECT: invention achieves increased resource of a crane girder.

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Description

The present invention relates to crane structures with intensive operation in the shops of ferrous and non-ferrous metallurgy with the operating mode of cranes 8K, 7K.

Crane beams in such workshops lose their life and working capacity due to fatigue cracks arising from defects in welds in the rail under-wall zone [1], [2].

The endurance of the under-rail zone of the wall is highly affected by the connection resource and effective stress concentration factors [3, p.136]. These coefficients show how many times the endurance of the compound decreases with respect to the steel rolling sheet without any treatment (i.e., with the rolling crust).

In the 30s of the last century [4, p.51] the technology of manufacturing steel structures was changed. Rivet joints have been intensively replaced by welded joints. Unfortunately, in structures subject to dynamic stresses, riveted joints were replaced by welded joints. A technical error was made - riveted joints in crane beams with a high resource were replaced by welded joints with several times lower resource [3, p.136]. This gave rise to the problem of low operability of the under-rail zone of crane beams.

It should be noted that during the construction of railway bridges, also subject to dynamic effects from trains, such a technical error was not made! In the construction of railway bridges, up to the present time, joints with a high service life are used, namely riveted joints and joints with high-resource alloyed bolts (steel 40X "Select") [5, p.40].

For the prototype we take a technical solution developed by Nezhdanov K.K. and Nezhdanov S.K. [6, patent No. 1594118]. The crane beam contains an upper and lower belt connected to each other by a vertical wall on which a longitudinal stiffening rib and supporting ribs are fixed. The supporting ribs are placed obliquely and made of a corner profile with horizontal flanges, which are connected with corresponding belts by means of high-strength bolts. Connections of elements are made using high-strength bolts.

The technical task of the invention is to increase the resource of crane structures by 2.5 ... 3 times with intensive operation and the operating mode of bridge cranes 8K, 7K, as well as automation and reducing the complexity of manufacturing structures on the production line.

The technical problem on the method of increasing the resource of a crane beam containing the upper and lower zones of the Tauri, connected with each other by a vertical wall on which a longitudinal stiffening rib and supporting ribs from a pair of corner profiles are fixed, is solved as follows.

The structural elements of the crane beam are prepared [7, p.28], K-shaped edges of the Tauri wall are produced, pyrotechnically [9] are sewn through the template in the shelf of the Taurus of the upper belt and through the same pattern through holes in the sheet of the brake beam through holes with a regular step.

A sheet is processed on a bending machine and a pair of channel sections is formed by longitudinal bends, forming a Z-shaped section profile of the brake beam.

Through the pyrotechnic method [9], through holes in the design points are pierced through holes with a regular step in the wall of the crane beam, the response holes in the brake beam and in the lower belt brand, all holes are calibrated to the design diameter.

According to the roller tables [8, p. 387] finished parts are transported to the production line. At the automatic welding station in the lower position, connect the wall of the Taurus of the upper belt and the wall of the Taurus of the lower belt with a continuous seam to the wall of the crane beam, connect the connected elements.

Grat and slag are removed [7, p. 180] from the root of one and the other seam. The connected elements are transported along the rolling table to the next automatic welding station and in the lower position “into the boat”, the wall of the brand of the upper belt and the wall of the brand of the lower belt are finally connected to the wall of the crane beam. Connected elements are transported along the rolling table to the next assembly post and a crane beam is connected to a Z-shaped brake beam.

Their calibrated holes are combined, alloyed studs are installed and mechanized, guaranteed to tighten the nuts with a wrench by the calculated value. Set supporting ribs from corners or brands using high-resource connections, and send the finished crane beam to the finished goods warehouse.

Figure 1 shows the implementation of a method of increasing the resource of a crane beam. The crane beam contains an upper belt 1 from the brand, a wall 2 provided with a longitudinal rib 3, and a lower belt 4 from the brand. All parts were shot blasted [8, p. 387].

The edges of the walls of the upper 1 and lower 4 zones of the Tauri processed and have a K-shaped cutting [7, p. 173], [8, p. 117]. Such processing of the walls of the Tauri was performed for high-quality automatic welding on the production line [10, p. 387] with penetration to the entire thickness.

The brake beam 5 is formed from a sheet on a bending machine. Through the sheet using the pyrotechnic method [9], through holes in the design points are stitched through the holes on the production line at regular intervals in the shelves of brands 6 and brands 1, corresponding to the holes in the brake beam 5. The holes are sewn in the pyrotechnic method [9] according to the template and in the lower brand 4 belts for attaching crane beams to columns, and then deployed to the design diameter by reamer.

Finished parts are transported via live rolls to the production line [10, p. 387]. At the automatic welding station in the lower position “into the boat”, the wall of the top 1 brand 1 is connected by a continuous automatic seam with the wall 2 of the crane beam, to which the longitudinal rib 3 is welded automatically. The wall 2 is joined in the same way with the wall of the 4 brand of the lower belt.

Grat and slag are removed [7, p. 180] from the root of one and the other joints. The connected elements are transported along the rolling table to the next post, the beam is turned over, and the wall of the brand 1 of the upper belt and the wall of the brand 4 of the lower belt are automatically connected by welding the wall 2 of the crane beam.

The brake beam 5 is formed by longitudinal bends on a bending machine [7, p. 73 ... 80] from a sheet and gives it a Z-shaped section profile, and a pair of channel profiles are formed on the left and right sections. Then, the Z-shaped brake beam 5 is transported along the rolling table to the production line and, at the assembly post, the holes in the connected elements are combined, the holes are calibrated to the design diameter. Set alloy studs 7, mechanically, guaranteed to tighten the nuts with a wrench to the calculated value and connect the crane and brake beams 5 with alloy studs 7 (steel 40X "Select") to each other in a single monolithic, high-life design. Then install the upper removable brand 6 in the design place and in a similar way connect it to the brake beam 5 on the one hand and the rolling channel 8 on the other hand. The upper removable brand 6 has a milled end of the wall for tight contact with the surface of the shelf of the brand 1, which is the upper belt of the I-beam crane beam. Ready high-resource crane beam is sent to the finished goods warehouse.

The economic effect arose due to the following:

1. The resource of the crane beam is increased by 4 ... 6 times in comparison with the I-beam welded beam, since the connections with a high resource are used - alloyed studs or bolts with a guaranteed tightness. This effect is achieved due to the principle of equal endurance in the design. Vertical supporting ribs are also attached to the wall by high-resource bolted joints, which allowed to reduce the stress concentration in the crane beam to a minimum [3, T 1, p. 140]. Under the rail in the zone of transition of the wall into the belt, the continuity of the metal is not broken and the mates at the t-joints are made in radius.

2. Automated assembly technology of the crane beam on the production line, since high-tech bolted joints were used.

3. The longitudinal waist seam is removed from the zone of dynamic, cyclic impacts of the wheels of the cranes.

4. The stress concentrators at the support rib are eliminated, since a connection with a high resource is used [3, T.I, p.138].

5. The longitudinal rib is welded to the wall and is in a low-stress zone; accordingly, the appearance of fatigue cracks in this zone is impossible.

6. The proposed design of a high-resource crane beam allows you to completely solve the problem of increasing the endurance of the crane zone of the wall. This design will work in the zone of so-called "unlimited endurance."

Bibliography

1. Nezhdanov K.K. Improvement of crane structures and methods of their calculation / diss ... Dr. tech. sciences. - Penza, 1992.349 s.

2. Nezhdanov K.K. Improvement of crane structures and methods for their calculation [Text]; monograph / K.K. Nezhdanov. - Penza: PTU AC, 2008-288 p.

3. Handbook of cranes: In 2 t. T.I. Characteristics of materials and loads. Fundamentals of calculation of cranes, their drives and metal structures // V.I. Braude, M.M. Gokhberg, I.E. Zvyagin et al.: Ed. M.M. Gokhberg - M .: Engineering, 1988 - 536 p.

T.2. Characteristics and design schemes of cranes. Crane mechanisms, their parts and components. Technical operation of cranes // M.P. Aleksandrov, M.M. Gokhberg, A.A. Kovin et al.: Ed. M.M. Gokhberg - L .: Engineering, 1988 .-- 559 p.

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9. Nezhdanov K.K., Vasiliev A.V., Kalmykov V.A., Nezhdanov A.K. Method and device for fixed connection. Patent of Russia No. 2114328. Bull. No. 18 - 06/27/1998.

10. Nikolaev G.A., Kurkin S.A., Vinokurov V.A. Calculation, design and manufacture of welded structures: A manual for engineering universities. - M.: Higher School, 1971-760 p.

11. Metal structures: a textbook for students. higher training institutions / [Yu.I. Kudishin, E.I. Belenya, B.C. Ignatyev, etc.]; under the editorship of Yu.I. Kudishina. - 9th ed. erased. M.: Publishing Center "Academy", 2007. - 688 p.

Claims (1)

A method of increasing the resource of a crane beam containing the upper and lower chords from the Tauri, connected with each other by a vertical wall, on which a longitudinal stiffening rib and inclined support ribs are fixed from a pair of corner profiles with horizontal flanges, characterized in that the structural elements of the crane beam are prepared, The K-shaped processing of the edges of the wall of the Tauri is pyrotechnically stitched according to the template in the shelf of the Tauri of the upper belt and through the same template in the sheet of the brake beam through holes with with a regular step, a sheet is processed on a bending machine and a pair of channel sections are formed with longitudinal bends, forming a Z-shaped section profile of the brake beam, pyrotechnically stitch through holes in the design points with regular steps in the wall of the crane beam, the corresponding holes in the brake beam and in brand of the lower zone, calibrate all the holes to the design diameter, transport the finished parts to the production line using the live rolls, connect the wall at the automatic welding station in the lower position Avra of the upper belt and the wall of the lower belt brand with a continuous seam with the wall of the crane beam, turn over the connected elements, remove grata and slag from the root of one and the other seam, transport the connected elements along the live table to the next automatic welding station and in the lower position finally connect the wall of the upper belt brand and the wall of the lower belt brand with the wall of the crane beam, the connected elements are transported along the rolling table to the next assembly post and the crane beam is connected to the Z-shaped brake bulk second, combine their calibrated holes, set alloy studs and mechanized guaranteed tighten the nut wrench to the calculated value, set the supporting ribs of the corners or brand using High yield compound, and send the finished crane beams to the warehouse of finished products.