The choice of raw materials for tubing coupling.

1. Choice of steel: tubing coupling is a steel pipe that supports the well shaft. The deeper the well, the greater the tension or pressure of the tubing coupling in the well, and the service life of the tubing coupling determines the life of the well. High difficulty technical Wells such as deep Wells and complex structural Wells put forward new and higher requirements for the performance of oil casing.
2. Selection of blank specifications: According to the part drawing, the outer diameter of the part is 153.5. Therefore, we choose a blank with an outer diameter of 154.5. By calculating the coordinates of the 23 points (129.4, -107.96), the required diameter of the fine car is not less than 129.4, and a certain margin is reserved for processing. Therefore, the price list of TPCQ tubing nipple should choose a blank with an inner diameter of 128.

Tubing coupling processing technology

1. The car is round
   For this kind of workpiece, for the outer ring of the vehicle, this is a very simple and important process. The following is a detailed description of this process: The coupling we produce is a type of petroleum pipe fitting, and the outer round part of the tubing coupling is a smooth surface without steps. In the absence of auxiliary tools, we can only deal with one end. Using the method of machining the other end to complete the outer circle turning, the curved part of the collar will produce a small step, thus greatly reducing the surface quality of the product. In this case, we can machine a pair of conical auxiliary clamping tools. Abbreviated as assistive tool. The left auxiliary tool is fixed on the three-grip chuck, and the right auxiliary tool is supported by the center. When processing, put the billet between the two auxiliary tools, turn the hand wheel, and the billet will be tightly fixed together. Now you can turn.
   The outer diameter of the billet obtained with the caliper is 154.4, and the required outer diameter is 153.5. We need this car to drop about a millimeter.
   After rotation, turn the handwheel to the left and remove the workpiece. This method not only improves the surface roughness, but also has a certain influence on the concentricity of the surface, because this clamping method is not reliable, so that the concentricity of the parts after the spindle is rotated is reduced.
   Advantages: Save time, improve surface roughness. Disadvantages: reduced workpiece concentricity.
2. car tail, cylinder diameter, internal thread
3. Workpiece clamping Workpiece clamping is an important part of machine tool processing. The accuracy of the clamping position directly determines the machining accuracy of the parts. The gap between the workpiece and the bottom surface of the chuck indicates that the clamping position is incorrect, which has a certain impact on the machining accuracy. It can even cause size errors.
4. A machine tool fixture is a device that clamps the workpiece (and guide tool) on the machine tool. Its function is to position the workpiece, to obtain the correct position of the workpiece relative to the machine tool and the tool, and to clamp the workpiece reliably.
5. The content of the workpiece installation includes: positioning: make the workpiece in the correct position relative to the machine tool and the tool. Clamping: After the workpiece is positioned, the workpiece is fixed, so the position of the workpiece does not change during processing. The relationship between positioning and clamping: In the installation process of the workpiece, positioning and clamping are two interrelated processes, the first is positioning, and then clamping.