Development and application of the most explosive

Development and application of I-steel spreader

Abstract: the I-steel spreader is designed and improved, and the related loading and unloading problems are solved

key words: I-beam sling

Chinese Library Classification Number: th6 document identification code: a article number: (2006)

I. preface

I-beam is an important part mainly used for large devices such as crane equipment, bridge construction, train vehicles, large boilers, weighing apparatus components, etc., and its corresponding handling and hoisting tools also have high process requirements. Because the bundles of I-beam slings developed in our port have the characteristics of many specifications, loose binding, long length, generally about 12M, or even longer, and the loading and unloading are difficult, dangerous and inefficient, while the loading and unloading quality requirements of I-beam are very high. How to develop hoisting tools that meet the safety, high quality and efficiency of port loading and unloading production and meet the cargo owner's requirements for loading and unloading quality is an urgent problem to be solved

II. Traditional I-beam loading and unloading scheme

traditional I-beam loading and unloading scheme, the commonly used hoisting technology can be roughly divided into two categories: hook screw rope hoisting technology and special sling hoisting technology

1. hook and thread rope hoisting process

hook and thread rope hoisting process is that the gantry crane lifts one end of the bundled I-steel first, and the worker penetrates one end of the hook and thread from the bottom of the I-steel, and hangs the hook and thread on the buckle nose. It should be mastered at the "three, four, three" proportion of the length of the I-steel, so as to hoist the I-steel smoothly to the designated place

this loading and unloading process has the advantages of strong adaptability to the changes of I-beam types, simplicity and feasibility. The disadvantages are:

(1) the steel wire rope exerts a great force on the I-beam when lifting with hook and thread rope. The edge of the I-beam flange is extremely sharp, and the steel wire rope is very easy to break wires and strands, resulting in the scrapping of the steel wire rope, which also poses a great threat to the safety production

(2) as the price of steel wire rope is relatively expensive, the consumption increases significantly, resulting in a sharp increase in handling costs

(3) during loading and unloading operation, because the gap between bundles of I-beams is too small to facilitate the penetration of steel wire rope, workers must carry out head lifting operation during operation, and insert the steel wire rope after there is enough gap, which makes it difficult to load and unload. At the same time, it also increases the labor intensity of workers, and the loading and unloading efficiency cannot be improved all the time

(4) the use of hook and screw operation is easy to cause damage to the edge of the I-steel flange. As the I-steel flange is the working face, the export growth of China's extruder products will show a stable and progressive situation, and the cargo owner will not allow the I-steel flange to deform during loading and unloading. In general, when loading and unloading, tape is placed at the binding position of hook and screw threads, so that the loading and unloading efficiency is lower, and the pad effect is not ideal

2. Hoisting process of special lifting appliances

this process has the advantages of simple operation, high loading and unloading efficiency, and low labor intensity of workers. The disadvantages are:

(1) it can only be applied to bundles of I-steel or a single large I-steel in a specific stacking form

(2) it takes time to develop and manufacture special tools

to sum up, and according to the stable and increasing trend of I-beam cargo source of our company, it is decided to develop a special I-beam sling for I-beam loading and unloading

III. Development of I-steel slings

due to the different packaging forms and specifications of I-steel, it is difficult to design and develop special slings for I-steel. According to the statistical parameters of loading and unloading I-beams provided by the cargo owner, most of the I-beams are 200~600mm high, the thickness of wing plates is 10~15mm, and the length is 10~14m. There are 3~5 I-beams in each bundle, which are overlapped and stacked with each other, and the weight of each bundle is less than 4 tons

the design of I-steel spreader is based on the principles of safety and reliability, light operation and durability, and the structure is as simple as possible. As shown in Figure 1

Figure 1

determination of structural form and main parameters

according to the characteristics and main technical parameters of I-beam stacking in Hong Kong, this sling adopts a double "C" structure, "C" is connected with steel plates, "C" opening should be able to plug all the I-beam flanges after bundling, and the bending part should avoid right angles and adopt arc transition to reduce stress concentration; It can press all the overlapped I-steel wing plates to avoid sliding during lifting. Considering the restrictions of I-steel loaded train dredging and crane lifting height, the length of steel wire rope sling shall not be greater than 7m. Safety load of I-steel sling: 4t/set, steel wire rope Ф 17.5mm × 7m. The effective opening of "C" type clamp body: 5~70mm, and the contact width between the tongue and the web is not less than 30mm

2. material selection

the main material of I-steel sling is 16Mn, a low-alloy material with high strength, good welding performance, convenient purchase and reasonable price

3. operation method of I-steel sling

(1) special personnel shall be assigned to command during operation. During the operation, the mechanical driver shall operate stably, and shall not stop, fall or collide with the car side in an emergency. When there are people and vehicles under the hook line, it is not allowed to lift

(2) a single I-beam weighing no more than 4 tons can be lifted directly with a single set of lifting appliances

(3) bundled I-beams weighing no more than 4 tons (up to 3 pieces per bundle, firmly packed and stacked in the form of overlap) can be lifted directly with a single set of lifting appliances

(4) bundles of I-steel weighing more than 4 tons and less than 8 tons or 4~5 I-steel in each bundle are firmly packed and stacked in the form of overlapping, and can be lifted directly with double sets of lifting appliances (when each bundle of 4 pieces, two sets of clamps are respectively clamped at the first and third ends; when each bundle of 5 pieces, two sets of clamps are respectively clamped at the second and fourth ends). The excellent electronic universal experimental motor adopts the exchange servo speed regulation system

(5) the bundled I-beams stacked in double layers are all blonde, and the multi plate business hook and screw binding operations such as 3C, led, pipeline, highway facilities and building materials are also arranged. It is forbidden to use this sling for direct lifting operations

(6) it is forbidden to use this fixture directly for bundled I-beam with incomplete steel waist