Design And Simulation Of The Small Log Planning Machine For Wooden Hexagonal Prism

The small log is always cut by saw-dry-rip method,cant sawing method,ladder-shapedmethod,triangle method and the harvest are panels with rough edge or with whole edge,triangle panel or ladder-shaped panel respectively. The disadvantage is that the recovery rate30-55%is pretty low,and the procedures are too many. Consequently,a new process thehexagonal prism glued timber with big cross section has been put forward：After the process ofbilateral trimming,rough hexagonal prism production and joint lengthwise,a planning machineis used to produce the exact hexagonal prisms with same cross section dimension so that theycan be glued together to establish a big one. So the thesis focus on the planning machine,and itis the key equipment for the above mentioned process. The main contents are as follows:(1) Firstly,the planning process of the small log hexagonal prism has been analyzed,thenthe design ideas and the overall layout of the machine has been put forward that we divide themachine into three function institutions：roller positioning section with40.89°adjustabledevice,needling apron wheel feeding section drived by chain wheel,4-shafts cutting sectionwith synchro adjusting device.(2) Secondly,we formulate and develop the main parameters and structural parameters forthe planning machine,then describe the calculation method for the general technical parametersincluding motion parameters,dynamic parameters and the spindle parameters：the power of themotor for horizontal milling cutter should be3kW,the power of the motor for verticle millingcutter should be5kW,the radio force and tangential force are110.8N and98.6N then.Theresults calculated in accordance with the above-mentioned procedures can be used as a basis ofstructural design and the simulation analysis of vertical spindle cutter model.(3) Thirdly,we summarize the concept,characteristics, commonly used software of digitaldesign, introduce the concepts and methods of the part modeling and virtual assemblytechnology. On the basis of physical prototype measurement in factory,we use the Solidworkssoftware to build up the main components of the modeling,then assemble them into thepositioning,feeding and cutting institutions. By assembly interference checking andmodification of the detected interference one by one, we get the whole assembly withoutinterference ultimately, it can be used for the follow-up analysis.(4) Fourthly,we extract the vertical cutting mechanism assembly in the SolidWorkssoftware environment. With the help of the finite element analysis module Simulation,weanalyze its natural frequency by modal analysis and get the results of natural vibration characteristics of the assembly with five orders, including each shaking mode and naturalfrequency. Based on the relationship between spindle speed and frequency,we calculate thespindle speed corresponding to each natural frequency. The analysis shows that cutting speed isfar less than the first critical speed10440rpm/min, which means the resonance would nothappen under the6000rpm/min, and the speed meets the design requirements.(5) Finally,regarding the gear transmission structure applied in positioning mechanismand vertical spindle regulating device,we import its feature-based parametric model into theSolidworks Motion,and conduct the kinematics simulation. We observe some results of thekinematics simulation,like the output gear speed,displacement and the variation of reactiontorque. The simulation results have been analyzed and they coincide with the theoretical data,which verifies the bevel gear parametric model is correctly and reasonably designed.