Automatic bolt pre-tightening method for narrow-opening deep-cavity environment

Abstract

The invention belongs to the technical field of automatic assembly, and particularly relates to an automatic bolt pre-tightening method for a narrow-opening deep-cavity environment. According to the method, a mechanical auxiliary positioning and automatic nut pre-tightening mode is adopted, a visual sensor is adopted to feed back an internal image in real time, and therefore the operation process and the nut assembly result can be visible; and a strain gauge sensor is adopted to measure and feed back the torsion information, and therefore the controllability and the safety of the nut pre-tightening force can be ensured. The method comprises the steps that an automatic pre-tightening device is assembled firstly, a wrench assembly is eccentrically and vertically fed into a cavity of a narrow-opening deep-cavity type structure, a base assembly is arranged, and a torque motor is started to carry out automatic pre-tightening. The method has the advantages that the precision and the efficiency of automatic pre-tightening of a connecting bolt of the narrow-opening deep-cavity type structure environment can be improved, and the influence of other human factors on the loading and unloading processes can be eliminated; and a manual positioning and automatic loading and unloading combined mode is adopted, and therefore real-time visibility can be achieved, control can be easy, and efficient and flexible operation can be realized.

Description

technical field [0001] The invention belongs to the technical field of automatic assembly, in particular to an automatic pre-tightening method for bolts facing the environment of narrow mouth and deep cavity. Background technique [0002] With the development of equipment manufacturing technology and process innovation, there is a kind of preload assembly task in the narrow mouth and deep cavity structure environment in the modern high-end equipment manufacturing process. This type of task has the characteristics of narrow, narrow, and invisible working space, and has high requirements on the uniformity and consistency of bolt preload force, making the preload operation difficult. However, considering the requirements of the assembly process, most of the actual preloading operations have to be done inside the deep cavity. Taking the bolt connection of a rotary body structure as an example, the diameter of the operation entrance is less than 100mm and the operation depth is ...

AI Technical Summary

Problems solved by technology

However, considering the requirements of the assembly process, most of the actual preloading operations have to be done inside the deep cavity

Taking the bolt connection of a rotary body structure as an example, the diameter of the operation entrance is less than 100mm and the operation depth is more than 400mm, and there are other parts above the assembly position. It is necessary to complete the circumferentially uniform nuts and bolts in this narrow and limited deep cavity structure environment. Preload assembly is extremely difficult to implement

Considering that the narrow-mouth and deep-cavity structural environmental assemblies usually have the characteristics of long manufacturing cycle and high cost, in order to take into account the safety and ease of operation, it is necessary to integrate design ideas such as mechanical assisted operation, visualization, and automatic control to carry out narrow-mouth and deep-cavity Research on automatic pre-tightening method of bolts in cavity environment, and develop special equipment

[0003] In 2013, Wang Chuan et al. proposed a deep-type bolt tightener with nut nested parts in the patent application number 201320288424.3 "A Deep-type Bolt Fastener", but the precision is not enough and visualization cannot be realized

In 2014, Huang Hongzhan and others proposed a ratchet wrench tightening device that can move along the arc-shaped hole in the patent "Aero-engine rotor assembly deep cavity bolt loading and unloading force-limiting adapter wrench" with application number 201410612525.0, but the degree of automation is low , higher requirements for workers to operate

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