Overview of hydraulic wrench

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Overview of hydraulic wrench

the optimization design method based on finite element analysis mainly uses discrete theoretical calculation to revise the design repeatedly to achieve the optimal design. The main calculation principle is as follows:

after discretization, h-elements (further subdivision lattice) and P-elements (increasing calculation order) are adopted to achieve calculation convergence. Fig. 3 shows FEA mechanical calculation of internal pawl of hydraulic square drive wrench. It can be seen that the local stress has exceeded 1000MPa. Due to the rapid development of computer, it is not a problem that the amount of computation caused by the refinement of lattice is huge. In this respect, there is no bottleneck for the accuracy of calculation. However, because the internal parts of the hydraulic square drive wrench are complex, and the boundary conditions are difficult to be given, and the contact surface conditions are also difficult to be simulated and given, the search engine actually seeks a satisfaction in the meaning of accounting, so the calculation can only be used as a reference for design and experiment, and cannot be completely relied on. We should explore and analyze the results in the models of multiple boundary conditions, and gradually find reliable data, And compared with the corresponding experimental results

as the hydraulic wrench involves the requirements of high-strength materials and high hydraulic pressure (the mainstream pressure of the hydraulic wrench is 70MPa at present), the requirements for some basic conditions are still very high on the whole. At present, there are still some gaps between domestic products and similar foreign products in terms of weight, appearance, service life and function. In terms of manufacturing, although there are some high-quality CNC in China, there is a lack of accumulation in management and technology. At present, there are still factors of unstable quality in the components manufactured. At the same time, high-strength materials, high-pressure hydraulic seal rings, high-pressure joints and other related basic materials also rely on imports

at present, there is no product and experimental standard for hydraulic wrenches at home or abroad. Experiments (function experiments, life tests, reliability tests, etc.) are the basic requirements for determining product quality, and also the basic requirements for products before they are introduced to the market, although there is no special product and experimental standard for hydraulic wrenches. We can still find relevant technical key points from some domestic and foreign standards (such as amsi b30.1, ANSI b107, etc.) to formulate some enterprise standards on this product. This link can regulate the rapid rise of the speed valve, which is also the key point of an enterprise's R & D capability and the prerequisite guarantee of product quality and reliability

hydraulic wrenches are often used in narrow spaces and places with inconvenient transportation during construction, so the volume and weight of wrenches are the most important indicators. In order to reduce the size of components, it is common to use high-strength alloy materials and heat treatment. At the same time, it is also a very important step to reduce the size and weight of components by using finite element analysis (f sometimes inlaying special steel at the jaw, or spraying init element analysis such as steel grit on the jaw surface). This paper will analyze the size optimization of hydraulic wrench from these two aspects. At the same time, how to obtain high-quality products, this paper also expounds some basic manufacturing conditions and experimental methods

high strength alloy materials and heat treatment methods are used to reduce the size and weight of components. Due to the extensive global trade at present, it is not very difficult to find high-strength materials. However, in order to further improve the strength, heat treatment and surface treatment must also be adopted. For the parts that are expected to have a strength of more than 1000MPa and be stable, and the uniformity of material strength is also very high (mainly due to the irregular internal parts of the hydraulic square drive wrench), At present, it is difficult for domestic enterprises to reach 1000 for the strength of the internal parts of the hydraulic square drive wrench. All specimens should have the same size above MPa. Even if they can reach it individually, it is difficult to achieve batch stability. It is also necessary to learn more from similar foreign products, invest more manpower and funds in a long period of time, and explore and experiment more in material and heat treatment

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