Method for determining torque setting value of tightening process, bolt tightening method and system

Abstract

The invention discloses a confirmation method for tightening process torque set value, a bolt tightening method and system. The confirmation method comprises the following steps: selecting a type of bolts, and taking one bolt of the type as a sample; acquiring tightening data of a plurality of bolts of the same type with those of the selected type in the actual tightening process, and forming a sample data set, wherein the tightening data comprise corner values and torque values; by taking the corner values as transverse coordinates and the torque values as longitudinal coordinates, drawing a tightening process curve of each sample in the actual tightening process, and further confirming a yield point of each tightening process curve; setting a reference torque, a maximum torque and a step length; according to the reference torque value, aligning the tightening process curves of all samples to one corner value, and calculating a yield point distribution variance of the aligned tightening process curves; adding one step length through the reference torque value to update the reference torque value, and judging according to the maximum torque; and screening a reference torque value corresponding to a minimum variance from a series of variances, thereby obtaining an optimal torque set value.

Description

technical field [0001] The invention belongs to the field of tightening technology, and in particular relates to a method for determining a torque setting value of the tightening process, a bolt tightening method and a system. Background technique [0002] The tightening process is one of the core processes in the manufacturing industry. It mainly refers to connecting two or more parts together through bolts, and requires a certain lasting clamping force. This process is widely used in the assembly and production of trains, automobiles, heavy machinery, engines, etc. The quality of this process directly affects the quality of the product and the safe operation of the product. [0003] The torque-angle method is a high-precision bolt tightening process that is mostly used at present. Its main process is: on the basis of bolt alignment and pre-tightening, starting from a certain torque setting value for monitoring, starting to tighten the bolts. The turning angle is monitored...

AI Technical Summary

Problems solved by technology

[0004] In the bolt tightening process, the determination of the torque setting value is a key point. If the value is too large, the final tightened state will exceed the yield point, resulting in permanent elongation of the bolt and loss of elasticity, or the bolt is broken; if If the value is too small, the final tightening state will not reach the yield point, or although the yield point is reached during assembly, it will be less than the yield point after a period of time due to the vibration of the product during operation, which cannot be maintained. Durability of bolt clamping force

Theoretically, the determination of the torque setting value should be analyzed and calculated according to the attribute parameters such as the material and specification of the bolt. In practice, it is difficult to measure and obtain accurate parameter values. Therefore, most of the current processes are set by experiments or empirical values.

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