When repairing low-speed trucks, the threaded joints of […]
When repairing low-speed trucks, the threaded joints of the key parts must be tightened with a torque wrench, because the tightening torque is a key factor in determining the reliability of the threaded joints. Too small a torque can easily lead to loosening of the threaded joints, and an excessive torque can easily lead to Damaged external thread.
Torque wrenches are roughly divided into two types: preset type and leaf spring type, and some have ratchet heads, which are more suitable for continuous operation. A torque wrench is also a measuring tool.
Scientific and reasonable use of torque wrenches is of great significance for improving assembly quality and extending the service life of torque wrenches. The essentials for the use and maintenance of torque wrenches are as follows:
① When using a torque wrench to tighten the bolts, the operator’s standing position should be reasonable. The operator should apply force in a horizontal direction and keep the applied force smooth and stable. Do not yank or push the torque wrench up or down. Push down the handle of the torque wrench, and if necessary, take the component force caused by the deflection force into account.
How to use torque wrench
②The tightening torque specified in the technical document refers to the tightening torque when the thread is clean and coated with anti-sintering agent. If there is dirt between the threads, the value reflected on the torque wrench may be inaccurate.
③When the tightening torque is about 60% of the maximum torque value of the torque wrench, the torque wrench has the highest display accuracy. Do not tighten the fastener with a torque exceeding the torque range of the torque wrench.
④The torque wrench cannot be used as a dead wrench, nor can it be installed with an extension sleeve.
⑤ The torque wrench should be sent to a special agency for testing or calibration on a regular basis. Although a certain cost has to be paid for this, the inspection cost is still worthwhile because of the loose or broken fasteners and the losses caused by the inaccurate torque of the torque wrench. So, how long does the torque wrench use for calibration? Under normal circumstances, the time interval is 1 year.
⑥After use, the torque wrench should be stored separately, not mixed with other tools, cannot be pressed heavily, and cannot be dropped on hard ground.