Also on the determination of the diameter of the rolling thread

Pressure processing Zhao Hongmin - Tow company standard parts factory technical section (Luoyang 471004) Table 2, the pitch deviation 'x can be found in Table 1 t standard parts industry in the processing of external threads generally used the rolling process.

In the production process, whether the thread diameter is selected properly not only affects the quality of the threaded parts after forming, but also affects the cost of the parts.

The calculation of the blank diameter before the thread is introduced in many books. There are also many methods used in actual production. The thread diameter of the thread determined by these methods cannot cover the thread precision and the needs of special industries. However, the most produced 6g thread in the standard parts industry has basically met the requirements. For example, we apply thread pitch, mm-thread diameter, mm-maximum and minimum diameter of the blank before rolling, pitch deviation, mm tooth profile deviation, mm tooth profile deviation accounted for Table 1 pitch 8 gas 4h accuracy 6g or 6h Accuracy 4h accuracy 6g or 6h accuracy according to the formula calculated by the diameter of the thread see Table 2. Nominal diameter pitch force Our factory actually uses the blank diameter pressure processing bolt head head material consumption process to determine the rationality of the development of China's fasteners There are six or seven thousand manufacturing enterprises, and the annual consumption of steel is more than 3 million tons. As the consumption quota of process materials, the enterprises are not the same. It is a subject of deep research by all enterprises to strive to save raw materials under the premise that the quota data is reasonable and accurate. In this paper, the calculation of the material consumption quota of the fastener bolt head of M20~M60 for die forging is taken as an example for calculation, comparison and analysis.

The nominal size SmaxSmin is specified; at the same time, the standard size ruler is specified for the thickness of the head. The uniform standardized series size provides convenience for the manufacturing industry and design application units. According to this regulation, selecting a suitable size range to achieve the minimum material consumption process quota, and being able to manufacture reasonable, reduce material consumption, and increase enterprise efficiency are the process technicians to formulate the process, and must combine the actual production with the theory. Explore and think about topics.

It can be seen from Table 2 that the calculated diameter of the thread blank is basically the same as that actually used in the process.

In mass production, due to mold manufacturing and normal wear and other reasons, the phenomenon that the blank diameter exceeds the specified range of the process often occurs, and the final rolled thread is qualified. This presents us with a process to determine the size of the blank, especially if the tolerance range is appropriate. This problem is a common problem for our factory and the entire standard parts industry. We have been exploring for this for a long time. Through the process verification, we have come to the conclusion that the above-mentioned public is used to re-determine the diameter of the thread blank.

The size of the spiral blank thus determined is shown in Table 3. The diameter of the thread blank thus determined satisfies the actual production needs, and more importantly, the application range of the blank diameter is expanded. This has great practical significance for the cold heading die using the reduced diameter process, which can increase the life of the cold heading die and greatly reduce the cost of the die.

Table 1 shows the specifications for the S-face size and the head thickness K in GB5780'5785-86.

Table 1 Bolt head S surface size, degree size K (mm) specification s surface size thickness size specification S surface size thickness size table nominal diameter pitch eve

1)   Bulldozer Spare Parts , Engine spare parts ,Cylinder Head, Cylinder Block, Turbocharger, Piston, Piston Ring, Metal, Crankshaft, Oil Pump, Injector, Fuel injection Pump, filter, Water Pump, Belt, Alternator, Starting Motor, CPU-