About Crane common sense

Detailed introduction
   1. Lifting the basic institutions use a variety of lifting different structures are very different, but all have the basic actions to achieve lift hoisting mechanism. Some crane also has run institutions, luffing, slewing, or other body of work. Material can be flexible rope or lifting items such as hanging a chain movements, may also be a screw or other rigid pieces held the top. Characterization of performance parameters crane lifting capacity of the basic work is the most important performance parameters from the weight and work level. ① from the weight is permitted under specified conditions of work of the heavy lifting the maximum weight that the load does. Generally with electromagnetic chuck (see lifting heads) or grab the crane, its lifting capacity should also include electromagnetic disk or grab the weight. Boom-type crane hook from the weight includes the weight group. ② lifting the working level to reflect the general working conditions of the performance parameters of the design and selection of an important basis for lifting. It consists of lifting the required use of the work needs to be done during the period the total number of cycle and load state to decide. International Organization for Standardization (iso) provides for lifting the working level is divided into eight. China only requires the crane is divided into eight, light a small lifting equipment, lifts, overhead monorail system has no division level. Operating procedures for regular and reproducible large crane, for example, cargo ship docks loading and unloading cranes, overhead crane used for storage and for blast furnace feed hopper lift, duty cycle is also an important parameter. Work cycle to complete a work cycle that the time required, it depends on the pace of work organization and with transport distance. The crane productivity is sometimes used as an important parameter, usually an hour to complete the lifting capacity to represent. Working-level concept. Cranes level is determined by two factors, one characterized by crane in use throughout the design lifetime frequency of use rating, the second is that the loading of the extent of crane load condition, considering the use of grade and load conditions, according to diagonal principle, Cranes level is divided into ai ~ a8 8, crane crane components level is zero, ministry, an important basis for component design, but also safety checks to determine the zero, Ministry of standard components are scrapped and the basis for quantitative analysis of the accident. In general, the working-level difference, the safety factor is different, and disposal standards are different. Cranes in different extents, their safety lifting the load is different from the calibration plate weight is the biggest lifting capacity crane is not in any case can be the biggest load lifting, hydraulic telescopic boom cranes only in the basic arm (short arm length), maximum elevation, the legs under the conditions fixed firmly to secure lifting the weight from the calibration plate, which is to bracket the difference between cranes and crane one. The question of test centers is the largest truck crane lifting the weight from the conditions to be met. A crane type and type of working-level 1.1 Cranes Cranes Cranes type is that busy work load level and degree of change parameters. The extent of work busy hours of work, including cranes and crane bodies duty cycle.Degree of load changes, since the whole year with the crane and lifting the weight of the average nominal weight ratio.Also includes the number of cycles per hour of work. According cranes busy loading level and degree of change the crane into light, intermediate, heavy duty and extra heavy duty. Table 1 is the crane type table. Table 1 Type of Cranes busy work sheet type of work load level of the degree of change the number of hours of work organization crane operating time rate (jc%) body of work load cycles per hour range n regular lifting of Class 100 015 1 / 3 rated load 5 Intermediate200025 regular lifting (1 / 3 to 1 / 2) Rated load weight class 400 040 10 regular lifting rated load 20 special heavy duty lifting rated load 700 060 40 for more opportunities for safe use of cranes, the type of work must be considered a reasonable use of the crane. 1.2 Cranes-level work crane level (gb3811-83) is based on use levels and loading cranes are divided into a1 ~ a8-class status. Grade level is used cranes used crane in its useful life characterized by the use of the frequency of the period, the total work cycle times with n said. According to the total number of cycles n, the crane into u0 ~ u910 using grade level. Table 2 is used crane scale. Table 2, the use of crane utilization level of the overall level of work cycles n Note u0u1u2u31.6 × 1043.2 × 1046.3 × 1041.25 × 105 is not often used lightly to u42.5 × 105 regular use u55 × 105 regular moderate use of u61 × 106 is not always heavy use of u7u8u92 × 1064 × 106> 4 × 106 heavy use of the crane's load status of the crane load state and the two factors, one is the actual lifting load and maximum load ratio (pi / pmax), and the other is lifting The role of loading frequency and the total work cycle times than (ni / n) about. That (pi / pmax) and (ni / n) relationship between the value of the load spectrum as the number of kp, which was expressed as: kp = type of pi - the first i-lifting load, i = 1,2,3, ... n ; ni - the role of load times pi; n - the total work cycle times, n =; pmax - nominal weight; m - index; Table 3 is the crane's load status and the nominal load spectrum tables. Table 3 crane load state and its nominal load spectral kp load state description of nominal load spectral kp q2-q1-light weight in q3-q4-special weight 0.1250.250.51.0 little lift rated load, lifting a small general load sometimes lifting load, medium load hoisting the regular general lifting rated load, lifting heavy loads usually frequent lifting rated load under the crane used crane working-level hierarchy (Table 2) and loading conditions (Table 3) to Crane is divided into eight working-level a1 ~ a8. Table 4 is the division of cranes working-level table.Table 4 crane load state level on behalf of the division of spectral load (kp) using rating u0u1u2u3u4u5u6u7u8u9q1-light 0.125a1a2a3a4a5a6a7a8q2-in 0.25a1a2a3a4a5a6a7a8q3-weight 0.5a1a2a3a4a5a6a7a8q4-special weight 1.0a2a3a4a5a6a7a8 sector-level sector-level use in accordance with institutional level (Table 5 ) and institutional load status (Table 6) is divided into m1 ~ m8 level (7). Table 5 rating agencies use rating agencies to use the total service life (h) Notes to the t0200 does not often use t1400t2800t31600t43200 often lightly to moderate the use of regular use t56300 t612500 t725000 infrequent use of heavy use with heavy loads t850000t9100000 Table 6 state agencies and the nominal load spectrumnumber of spectral loading state of nominal load (km) Note l1-light 0.125 agencies often bear the light of the load, the occasional bear the largest load of 0.25 l2-medium agencies often bear the load, and less subject to the greatest load l3-weight 0.50 organizations often bear heavier loads, often by the largest load of l4-special agencies often bear the greatest weight 1.00 load Table 6 in the nominal load spectral km km = the formula for the m - body parts test curve of fatigue index; pi - - The body of work 8 hours exposure to the different loads; pi = p1, p2, p3, ..., pn; ti - the institution to withstand the various load duration (t1, t2, t3, ..., tn) ; Table 7, the state agency on behalf of the working-level load spectral loading (km) agencies use rating t0t1t2t3t4t5t6t7t8t9l1-light 0.125m1m3m3m4m5m6m7m8l2-in 0.25m1m2m3m4m5m6m7m8l3-weight 0.50m1m2m3m4m5m6m7m8l4-special weight 1.00m2m3m4m5m6m7m8