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The working principle of hydraulic wrench

2018-04-27

Hydraulic torque wrench (hydraulic wrench for short) is a professional bolt tightening tool powered by hydraulic pressure and provides large torque output. It is used for bolt installation and disassembly. It is often used to tighten and loosen bolts larger than one inch.
hydraulic torque wrench (hydraulic wrench for short) is a professional bolt tightening tool powered by hydraulic pressure and provides large torque output. It is used for bolt installation and disassembly. It is often used to tighten and loosen bolts larger than one inch. The maximum output torque of the hydraulic torque wrench can reach 110000Nm, which not only improves the work efficiency, reduces the labor intensity, but also greatly improves the installation quality, and is also conducive to the site safety management.
 
The use of hydraulic wrench is very wide. In the ship engineering, petrochemical, construction, electric power, mining, metallurgy and other industries in the construction, maintenance, repair and other work, the hydraulic wrench is a very important tool for the installation and removal of large bolts. Irreplaceability of other tools. Not only is it easy to use and light, but the torque provided is huge and very accurate. Torque repeat accuracy of ± 3% or so. According to relevant statistics, about 50% of the equipment operation failures are caused by bolt problems, and the number of major equipment accidents caused by bolt problems is also very alarming. Therefore, in the process of equipment installation, maintenance and gun repair, the torque for bolt fastening and disassembly is relatively strict in most cases, and it is difficult to meet the requirements by manual methods. For bolts to provide large specifications of torque, hydraulic wrench is the ideal choice. Hydraulic torque wrench is composed of working head, hydraulic pump and high pressure oil pipe. Through the high-pressure oil pipe, the hydraulic pump transmits the power to the working head, and drives the working head to tighten or loosen the rotating nut. The hydraulic pump may be driven by electricity or compressed air.
The working head of the hydraulic wrench is mainly composed of three parts, the frame (also called the shell), the oil cylinder and the transmission parts. The output force of the oil cylinder, the piston rod of the oil cylinder and the transmission part form a motion pair. The distance from the center of the oil cylinder to the center of the transmission part is the amplification arm of the hydraulic wrench. The output of the oil cylinder multiplied by the arm is the theoretical output torque of the hydraulic wrench. Due to the existence of frictional resistance, the actual output torque of the hydraulic wrench is less than the theoretical output torque.
 
Hydraulic wrench has two series of driven hydraulic torque wrench and hollow hydraulic wrench. The driven hydraulic torque wrench is used with standard socket. It is a universal hydraulic wrench and has a wide range of applications. Hollow hydraulic wrench thickness is thin, especially suitable for space is relatively small place. Suitable for electric power (nuclear power, wind power, hydropower, thermal power), ships, metallurgy, transportation, cement, construction, aviation and other fields.
 
Because hydraulic wrenches are often used in narrow spaces and inconvenient locations during construction, the volume and weight of wrenches are the most important indicators. In order to reduce the size of parts, the use of high-strength alloy materials and heat treatment is a common method.
For the use of high-strength alloy materials and heat treatment methods to achieve the purpose of reducing the size and weight of components. Due to the current extensive global trade, it is not very difficult to find high-strength materials. However, in order to further improve the strength of a part, heat treatment and surface treatment must be adopted. For the desired component strength to reach more than 1000MPa and be stable, and the uniformity of material strength is also extremely high (mainly due to the influence of the irregularity of the internal parts of the hydraulic square drive wrench), at present, it is difficult for domestic enterprises to achieve the strength of the internal parts of the hydraulic side drive wrench above 1000MPa, even if it can be achieved individually, it is difficult to achieve batch stability. It is also necessary to learn more from similar foreign products, invest more manpower and capital in a long period of time, and explore and experiment more in the aspects of material and heat treatment.