Study On102-meter-high Multi-stage Hydraulic Cylinder Scaling Ladder

With the rapid development of cities, the constructions are getting higher and higher. Although we take many advantages of them, the high-rise fire is becoming a great threat to life and properties. Once high-buildings catch fire, it burns fiercely and spread quickly, thus making it difficult to control, so it lead to heavy casualties and property losses easily. Now most of the fire truck that fire brigade are using are made in china, their low level of technology are making them difficult to pull out high-rise fire effectively. Compared to domestic products, foreign fire truck are expensive, so it can’t promote in domestic market. To solve this problem, we take advantage of the fast, stable and accurate characteristics of the hydraulic cylinder to design a new hydraulic cylinder scaling ladder. Around this technology, the main research works of this paper are as follows:Firstly, this paper reviews the existing problems of fire safety in city constructions, introduces the main technology of domestic and foreign fire trucks, describes the features and development trend of the fire truck and elaborates the topic research significance.Secondly, the paper describes the composition of fire trucks. On the basis of referring to the existing technology, this paper designs the upper structure of the102-meter-high multi-stage hydraulic cylinder scaling ladder, using the existing ladder truck chassis. According to the designed height and strength requirements, this paper design the distribution pattern and connection type of the multi-stage hydraulic cylinder scaling ladder, determining the size of the hydraulic cylinder and the connection clamp.Thirdly, this paper designs the hydraulic system of the multi-stage hydraulic cylinder scaling ladder. Based on technical requirements of the scaling ladder, this paper designs the system pressure、quantity of flow and other parameters of the system. In order to satisfy the requirements of running smoothing, we choose the appropriate synchronous hydraulic cylinder. The multi-stage hydraulic cylinder ladder of three hydraulic cylinders require synchronization, so on the basis of the comparison of several common advantages and disadvantages of synchronous circuit, we select a suitable ladder synchronization loop.Fourthly, according to the wind load theory, we calculate the value of wind loading on the hydraulic multi-stage cylinder scaling ladder. Referring to the high wind load on high structures, we analysis the response of the hydraulic multi-stage cylinder scaling ladders under wind referring to the existing literature. Based on the manual, we calculate the stability of scaling ladder under wind.Finally, according to the contents of the structural design, this paper model and analysis the multi-stage hydraulic cylinder scaling ladder using ANSYS. We use3D modeling software to model the scaling ladder and then imported into ANSYS. We applied the force to the model and analysis the stress distribution and deformation of the cylinder, so we can find the dangerous section in order to improve the structure design. ANSYS results show that the ladder is feasible both in theory and practice.