The connection of the steel bar straight thread sleeve is to peel off a part of the longitudinal and transverse ribs at the end of the steel bar to be connected by cutting with a thread rolling machine, and then directly roll it into an ordinary straight thread and connect it with a straight thread sleeve. The technology is efficient, convenient, fast, saves energy and reduces consumption, improves efficiency, and the connection quality is stable and reliable.

Rebar straight thread connection technology

1. Rib stripping and rolling process: the end of the steel bar is cut flat; a professional rib stripping and thread rolling machine strips the end of the rib and rolls the wire; use the connecting sleeve to connect the steel bar.

2. Features

(1)High joint strength;

(2) The operation is simple, no professional technicians are required, and the on-site connection speed is fast;

(3) High production efficiency, each shift can produce 300-500 silk heads, which are prefabricated in advance and do not account for the construction period;

(4) Economical, less equipment investment, and low cost;

(5) Environmental protection, and safety, are not affected by the environment and climate.

Sleeve extrusion connection is to insert the end of the steel bar (which should be a ribbed steel bar) to be connected into the steel sleeve and use the extruder to compress the steel sleeve to make it plastically deform. The mechanical occlusal tightening force of the ribbed steel bar is used to realize the connection of the steel bar. This connection method is generally used for grade II and grade III steel bars (including residual heat treatment steel bars) with a diameter of 16 to 40 mm. It is divided into the radial extrusion and axial extrusion.

Operation Gists

1. Before using the extrusion equipment (extruder, oil pump, oil hose, etc.), the extrusion force should be calibrated (the extrusion force is controlled by the reading of the oil pressure gauge).

It should be calibrated in one of the following situations: before the extrusion equipment is used; after the old extrusion equipment is overhauled; after the oil pressure gauge is damaged and vibrated; when the sleeve indentation is abnormal and for other reasons; the extrusion equipment has been used for more than one year; The number of extruded joints exceeds 5000.

2. It is necessary to check in advance whether the die and the sleeve are matched with the steel bar, and the corresponding connecting bar specification mark should be marked on the die.

The extrusion force, die width, indentation diameter, or the fluctuation range of the sleeve length after extrusion, and the number of extrusion passes used in the extrusion operation should all meet the technical parameter requirements determined by the joint technology provider.

3. Use a toothless saw for cutting and cutting the steel bar, so that the end face of the steel bar is perpendicular to its axis. Do not use a steel bar cutter or gas cutting.

4. The oil used in the high-pressure pump should be filtered and kept clean, and the oil tank should be sealed to prevent rainwater and dust from mixing into the oil tank.

5. The matching steel bars and sleeves should be checked before use, and the uncleanness (rust, sand, oil, etc.) of the crimping part should be cleaned; Bending, horseshoe shape (such end faces will only appear when individual violations are cut with a steel bar cutting machine) or the size of longitudinal ribs is too large, it should be corrected or ground with a hand-stretched grinding wheel.

6. Insert the steel bar into the sleeve, so that the depth of the steel bar meets the predetermined requirements, that is, the end of the steel bar should not exceed 10mm from the midpoint of the length of the sleeve (mark on the steel bar to be flush with the end face of the sleeve); for positive pressure, The position of the die, and the direction of movement of the die is perpendicular to the plane where the two longitudinal ribs of the steel bar are located, so as to ensure that the large crimping surface can be located on the transverse rib of the steel bar.

7. Two crimping sequences can be used: one is to crimp two steel bars through the sleeve at the work station on the construction site (should start from the sleeve and extrude to both ends in turn); The first is to crimp the sleeve with a steel bar in advance, then install it on the working station, insert the steel bar to be connected, and then squeeze the other end of the sleeve.

8. During the operation, special attention should be paid to construction safety, and the safety regulations for working at heights and the use regulations of various equipment should be followed. Drag under load or pressurized conditions and being scored by sharp objects, tight reliability of contacts everywhere, etc.).

9. It is required that the crimping operation and the completed steel bar joints are free of defects. If abnormal phenomena occur during the construction process or the joints are defective, they should be treated and prevented. The occurrence of abnormal phenomena and defects is not only directly related to operational factors but also related to the equipment used.