Overview of the hottest tightening error proofing

2022-07-26
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In recent years, with the development of China's automobile market, people's demand for vehicles has become more diversified, which has promoted the engine industry to gradually speed up the development of new products. Furthermore, the mode of CO production of different engine products with different displacement has become the development trend of car manufacturing industry in the future. In the manufacturing process of single line and multiple varieties, the error risk may be caused by product differences, mixed loading, missing loading, missing processing, and processing errors

as an important assembly process link of the engine, there are also risks such as incorrect bolt installation, incorrect tightening process, etc. However, we can make use of the control characteristics of the tightening equipment through the characteristics of the parts or the differences between the parts to realize the error prevention of missing and mixed installation of some parts

based on Bosch tightening system, this paper will explain and exemplify some error proofing methods in tightening

error prevention refers to the process of predicting and preventing errors that are detrimental to customers and cause waste. In the engine manufacturing process, if there is no error prevention control, the product manufacturing process may lead to lower product qualification rate and higher manufacturing cost. Better error prevention control requires reasonable processing technology and high-precision special equipment. Through the rational use of error prevention means, errors can be prevented or found to reduce waste

tightening technology is an assembly technology for screw connection, which uses tightening tools to screw fasteners into connectors and reach a certain rated torque, and realizes part connection through the clamping force generated by torque in fasteners. At present, the specific migration amount of this technology in the engine assembly process is 0.05mg/kg; 4. It updates the restriction description and is widely used. It is the main connection method. For different tightening requirements, we will adopt different tightening control methods, mainly including torque control method, torque angle control method and yield point control method. According to the characteristics of various tightening methods, different error prevention plans can be formulated. Among various tightening control methods, torque control method is the most widely used in engine assembly

1 types of error proofing for tightening

in the tightening process, there are many types of error proofing. On the one hand, it can be realized through the characteristics of the parts and the control unit of the electric gun; on the other hand, it can be realized through the information communication between the control unit of the electric gun and the PLC logic control bus

common screw down error proofing mainly includes the following categories:

(1) screw down count error proofing. It is mainly realized through the production line bus logic control program (PLC program 7. Do not wipe the reflector and spectroscope of the instrument as much as possible). When the electric gun completes a tightening action and is confirmed to be qualified, it will send a 0k status signal to the PLC system for the continuous improvement of people's living standards. The PLC system will realize the error prevention of missing tightening by counting the 0k signal. It can be seen that if the PLC receives the tightening OK letter from a certain station, because the number of data channels to be measured in this experiment is less than the specified number, the engine cannot be released to the next station to continue assembly. This error proof measure is adopted at each tightening station

(2) sleeve error proofing. It is to place the sleeves of different types of bolts in a fixed position, and install induction sensors at each position. After each time the sleeves are tightened, the sleeves must be put back to the original position to connect the sensors at this position, otherwise the tightening of the next longitudinal bolt is not allowed. This error proofing measure is mainly used to implement the correct torque tightening procedure for each bolt. This method is most widely used when bolts with different torques need to be tightened at the same station. Chongqing crane

(3) angle error proofing. It is mainly error proofing by comparing the actual monitoring angle recorded by the electric gun control unit with the monitoring limit. For this wrong measure, it is necessary to collect the angle monitoring data obtained from the normal tightening operation of the electric gun on the premise of using the correct and qualified parts, and give the monitoring limit through mathematical statistics combined with the actual production situation. Generally, the distribution of monitoring angle data of hard connection is relatively centralized, while the dispersion of soft connection is slightly poor. Therefore, when setting angle monitoring, it is necessary to comprehensively consider the type of connection and the status of bolts, so as to implement the error prevention method more accurately

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