In the maintenance process of diesel generators, it is common to encounter the phenomenon of arbitrary tightening due to the lack of important bolt tightening torque data. This result in insufficient or excessive tightening of these bolts, which can lead to unstable operation of the diesel engine. In severe cases, it may cause damage to the diesel engine due to bolt breakage. Therefore, the tightening of important bolts for diesel generators must be strictly carried out in accordance with the requirements of technical specifications.
(1) Obtain the bolt tightening torque on site. If there is no technical data such as tightening torque of relevant bolts during diesel generator maintenance, the following methods can be used to obtain on-site information. The specific method is: before or during the disassembly of the diesel engine, important bolts need to be removed. Mark the nuts and clamping bodies of the bolts, loosen two or more sets of symmetrical bolts on the outer side according to the bolt disassembly sequence, and then use a torque wrench to gradually tighten them to the marked position in stages to measure the maximum tightening torque of the bolt. If conditions permit, the above method can be used to gradually test the tightening torque of all fastening bolts, taking the average value, which can generally be used as the tightening torque of the bolt.
(2) Reference acquisition of bolt tightening torque. The bolt tightening torque obtained by the above method is often disregarded by many people due to the lack of accurate data concepts. If there are relatively authoritative high-strength bolt torque parameters, they can be compared, as long as they are within the allowable deviation range, they are all acceptable.
(3) Bolt tightening method. The commonly used bolt tightening methods include torque method, angle method, and torque slope method.
1. Torque method: The torque method is a method of tightening control in the elastic zone using the linear relationship between torque and pre tightening force. When tightening, only a certain tightening torque is controlled. This method is easy to operate and is a commonly used tightening method.
2. Angle method: The angle method is a method of controlling the initial pre tightening force by rotating the bolt and nut relative to each other by an angle (called the angle) during tightening. This method can maximize the strength of bolts when tightening the plastic zone.
3. Torque slope method: The torque slope method is a method of controlling the initial preload force based on the change in torque slope value as an indicator. This method usually takes the yield tightening axial force of the bolt as the target value for controlling the initial pre tightening force. This method is generally used when the initial pre tightening force dispersion of bolts is required to be small and the bolt strength can be maximized.
Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to firstname.lastname@example.org we will pay highly attention on your question.