Parametric modeling and simulation of the cylindrical Indexing cam mechanism based on Pro/E and ADAMS

Shun-hong LIN1*，Xin-cai ZHU2，Chang-jian LI1，Ming XU1（1Chongqing University of Science and Technology，Chongqing 401331，China）（2Chongqing Real Estate College，Chongqing 401331，China）

Parametric modeling and simulation of the cylindrical Indexing cam mechanism based on Pro/E and ADAMS

Shun-hong LIN1*，Xin-cai ZHU2，Chang-jian LI1，Ming XU1
（1Chongqing University of Science and Technology，Chongqing 401331，China）
（2Chongqing Real Estate College，Chongqing 401331，China）

By the spatial coordinate transformation theory and conjugate theory，the mathematic model of cylindrical indexing cam mechanism is established.Using Pro/E software for three dimensional parametric modelling capabilities for a specific and precise modelling of cylindrical indexing cam design，its 3D solid model is built.And its dynamics and kinematics simulation was analyzed by ADAMS software.Simulation results show that the Correctness of the agency model，Be of great practical value conclusion，It has the guidance to the cylindrical indexing cam mechanism design，processing，installation.

Cylindrical indexing cam，Pro/E，Parametric modelling，ADAMS simulation

Hydromechatronics Engineering

http：//jdy.qks.cqut.edu.cn

E-mail：jdygcyw@126.com

1 Introduction

Indexing cam mechanism in automated machinery occupies a very important position，it can be a continuous rotary motion of the input shaft into the actuator to move or rotate the gap，so that the system can complete the scheduled technological action during the stop segment［1］.Cylindrical indexing cam mechanism for two staggered vertical gap between the indexing axis stepper motion，with high positioning accuracy，load capacity Japanese smooth motion，which is widely used in machine tools，light industry，packaging，pharmaceuticals，tobacco and chemical industries the automatic machine，is automated，efficient production of preferred core component，so the exact design of the cam profile of the motion analysis is crucial［2］.

Using two-dimensional software modeling tools for cylindrical indexing cam for three-dimensional modelling is more difficult，but after the hit reality modeling accuracy，many users are using UG NX，SOLIDWORKS，VC and pro/Toolkit its secondary development［3］，to a certain extent，able to meet the requirements of use and design，but also failed to achieve the integration of modeling and programming，and the derivation of mathematical formulas and programming process is complex，cylindrical indexing cam many parameters，technical personnel to master more difficulty［4］.In this paper，Pro/E for cylindrical indexing cam mechanism parametric modeling and assembly，the model file as“x_t”file into the virtual prototype for further ADAMS virtual simulation analysis，for cylindrical indexing cam mechanism design and assembly provide a strong basis［5］.

2 A virtual prototype modeling

2.1 Cylindrical indexing cam model construction principle

Cylindrical indexing cam profile is calculated in two ways，first is to simplify the analysis and design，both the cylindrical indexing cam contour expanded into a flat curve to design，a series of points calculated by the formula，the resulting point generation line，the last line of the generated by wrapping method，the wire wrap on the cylinder for rotary cutting，resulting model.The second is the accurate design modeling methods，spatial envelope surface by conjugation principle calculations［4］，through parametric modeling，as shown in Fig.1.We established a theoretical curve roller，the roller two theoretical curves，theoretical curve rollers 3.left contour，contour the right，depending on the pitch circle of angle θ and an engagement point on the roller to the plate plane indexing distance r create a series of curves，the curve to create surfaces，create an entity through the curve，the last roller radius under Boolean operations on entities to obtain the final accurate cam model.In this paper，the second method uses Pro/E software，its three-dimensional parametric modelling［5］.

Fig.1 CyIindricaI indexing cam mechanism and expanded view

2.2 Cylindrical indexing cam model building

First，you need to calculate the exact theory of cylindrical indexing cam contour surface spatial coordinates，cylindrical indexing cam to get the actual work contour surfaces.Now with a automatic production line of the cylindrical indexing cam mechanism for the column，the basic parameters are：cam speed n= 80 r/min，turntable station Z=8，the center distance C=120 mm，substrate distance A=122.5 mm，roller radius Rr=27.5，width of 20，cam indexing profiles for a single head clockwise rotation，rotation coefficient p=-1，r in the range of 22.5-47.5.requirements set according to the motion of the cam indexing angle θf=120°，the cam stop phase angle θd=240°，by calculating the radius of the pitch circle of the cam Rp1=100 mm，the radius of the pitch circle wheel Rp2=130 mm，under lighter loads，so the use of improved sinusoidal acceleration motion，such movement of the consists of three segments：the middle section of the trip was a long cycle sinusoidal acceleration motion，and the whole story of the trip for the two shorter cycle sinusoidal acceleration motion.Cylindrical indexing cam material taken 38CrMoAlA steel，were 45 in indexing plate steel，by spatial envelope principle conjugate，cam contour coordinate the work equation：

Where，Φ is wheel angular position；Φ0is roller initial angular position；Φiis turntable indexing of angular displacement.

Where，r is roller engages on a point-to-point distance dial datum；

2.3 Based on Pro/E modeling process

1）Create cylindrical indexing cam base，using a tensile or rotary tool can be directly stroke entity cylindrical cam base having a radius of 100mm，a height of 200mm［6］.

2）Generate 5 theoretical contour lines，respectively roller 1，the roller 2，the roller 3 of the contour line indexing，and two stop contour of the theory.The“insertion reference curve”command，select the Cartesian coordinate system，to the Pro/E default origin as the center，according to the formula（1），（2），（3），（4），for parametric modeling，the establishment of 5 theory of the contour line thereof，respectively，corresponding to the establishment of the initial angular displacement of roller establishment，as used in this paper is to improve the sinusoidal acceleration motion，the roller 1，the roller 2 and the roller 3 are theoretical contour lines by three line segments，the first paragraph of 0＜t＜1/8*T，second to 1/8* T＜t＜6/8*T，the third paragraph 6/8*T＜t＜T，each section has a corresponding dimensionless displacement velocity V S and the corresponding dimen-sionless.According to the step of establishing the cam，after the theoretical contour is established is a smooth curve，since each r corresponding to a curve only，can not generate the standard surface，so this 2.5 units each corresponding to create a curve，r in the range of 22.5 to 47.5［7］.

Fig.2 Pro/E parameter editing window

Fig.3 CyIindricaI indexing cam profiIe curve theory

3）Create a theoretical contour surface，using the“border hybrid instruments”，select the corresponding curves to generate 12 surfaces，and the resulting theoretical contour lines，creating a theoretical outline surfaces，use the“merge”tool，let the 12 surfaces doing Boolean operations，merged into a surface.

4）Generate cam body.A cam created based on the first step the substrate surface and the creation of the theoretical contour operation for removing material，the use of“thick”tool，select the surface of the substrate and the thick，symmetrical thickening width 35 mm，the substrate removal of the excess material will complete cylindrical indexing cam accurate modeling.

Fig.4 CyIindricaI indexing cam profiIe curve theory

Fig.5 Thickened cyIindricaI indexing cam surface formation modeIs

2.4 Cylindrical indexing cam mechanism to establish three-dimensional solid

According to design requirements，using Pro/ED software to establish a turnable which the diameterd of 300mm，the pitch circle radius R of 130mm，diameter of roller 35，the thickness of the 20.And cylindrical indexing cam for assembly，when assembly，the plate center plane and the cylindrical indexing cam would coincide，the gap of the roller underside and the cam is 5mm，turntable and cylindrical indexing cam center distance of 120mm，the vertical axis，the assembly complete，open the Pro/E analysis menu tool interference checking and analysis，to detect design flaws，and make effective repair and improvement.After the assembly，you can get cylindrical indexing cam mechanism，as shown in Fig.7［8］.

Fig.6 CyIindricaI indexing cam compIete modeI

Fig.7 CyIinder indexing mechanism assembIy drawing

3 Cylindrical indexing cam mechanism simulation analysis

3.1 ADAMS cylindrical indexing cam mechanism in the constraints and driver added

Cylindrical indexing mechanism model which was established by Pro/E software saved as“X_T”format file，use the Import command of ADAMS to edit and import.Because the model is imported without any quality，after import，the turntable and cylindrical indexing camwilladdthematerialpropertiesof 38CrMoAlA steel and 45 steel.cylindrical indexing cam between the earth and the turntable between the earth were added revolute joint，so that it can rotate around its own axis；in order to facilitate analysis，the roller and the turntable will as an entity modeling to analysis；add a contact pairs（solid-solid contact），solid1 for the turntable，solid2 as cylindrical indexing cam，contact pairs of contact stiffness coefficient，power index，damping，fathom depth using the system default.In the cylindrical indexing cam between the earth add drive，the size of n=80 r/min.Through constraint the cylinder indexing mechanism and add the driven，form a complete model of the cylindrical indexing cam mechanism，create a virtual prototype model shown in Fig.8.

Fig.8 CyIindricaI indexing cam modeI after appIying constraints and drivers

3.2 Virtual prototype simulation

For the establishment of a virtual prototype simulation analysis，it is assumed that the agency work in the no-load conditions，that is the reverse torque is 0. Setting the simulation time t=500 s，simulation steps =1 000，through the“MEASURE”respectively the turntable and cylindrical indexing cam analysis，can be obtained indexing plate and the cam angular displacement，velocity，acceleration，force of the cam in contact with the turntable.

From the angle of the turntable plus curve can be seen，the left sharp curve is a roller and the state has not been engaged，no effect on the results，completely ignored；in each roller indexing time period，there is a mutation of accelerometer，but this acceleration is maintained in a relatively small range，the effect on the whole body is negligible.The angular velocity of the turnable from curve can be seen，the angular speed variation is uniform，and is has cyclical changes and is smooth curve，realistic when the angular velocity changes.Cam velocity，acceleration，angular displacement output curve can be seen，the angular displacement in a fixed period can be a sine curve similar to the movement cycle.Constant acceleration，the acceleration is 0.To one of the rollers establish a MARKER point can get the corresponding angular displacement of the roller，the angular velocity，angular acceleration.

From the speed of the roller can be seen，in the indexing of roller speed from 0 increased to maximum and then start reducing to 0，from acceleration to deceleration stage is a relatively smooth curve，which is to stop the movement of the rest.Roller acceleration output curve shows the acceleration roller is divided into three stages，namely in the roller from the indexing to the rest of the middle experienced three changes of speed，effectively reduce the impact of the cam on the roller also verified the accuracy of the model.

Cylindrical indexing cam and turnable through the contact force to transfer force，in ADAMS contact force can not be measured directly，a function expression is required to be measured.The following figure is a function of the contact force output curve.

Fig.17 shows the contact force can be generated so as to drive the rotation of turntable regular，and kept a relatively stable level and in a small level，verified cylindrical indexing cam feasible.

Fig.9 TurntabIe anguIar dispIacement，veIocity，acceIeration output curve

Fig.10 TurntabIe acceIeration output curve

Fig.11 TurntabIe anguIar veIocity output curve

Fig.12 Cam veIocity，acceIeration，anguIar dispIacement

Fig.13 Cam anguIar acceIeration

Fig.14 RoIIer veIocity，acceIeration，dispIacement output curve

Fig.15 RoIIer speed output curve

Fig.16 RoIIer acceIeration output curve

Fig.17 Contact force output curve

4 Conclusions

For cylindrical indexing cam mechanism design complexity，proposed cylindrical indexing cam mathematical model，the use of Pro/E parametric modeling a precise three-dimensional solid cylindrical indexing cam model and according to the parameters established a turntable and the agency has been assembled，

through the ADAMS software to build a virtual prototype of the institution and conduct of angular kinematics and dynamics simulation.The simulation analysis shows that，from the stage to the rest of the indexing process，angular acceleration of the turntable to the less stable acceleration transform，within a smaller range，has smaller impact on this institution.Rollers during the indexing of different levels of acceleration change，effectively reduce the vibration of the roller，and the contact force is maintained at a relatively small range，and is relatively stable，so that the cylindrical indexing cam verified the correct model sex. Since the cylindrical indexing cam mechanism is lubricated environment，so this article do not consider the impact of friction.

Acknowledgements

1）This research on gasification of municipal solid wastes（MSW）with mechanic grate was funded by Chongqing Municipal Program for key science and technology research.The program number is cstc2012 gg-yyisB0206.

2）The research was funded by the capacity improvement program of Chongqing Technology Center of Municipal Solid Wastes to Energy.Its program number-is-cstc2014pt-gc0016.

3）This research was funded by the program of the Waste to Energy Technology Interactive Experiencing Center.Theprogramnumberiscstc2014kp-2jpyfb0005.

4）The research on technology transformation of mechanic-grate-based MSW combustion and gasification was funded by Chongqing municipal program for transformation of key researches conducted by higher institutions of Chongqing.The program number is KJZH14108.

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基于Pro/E和ADAMS的圓柱分度機(jī)構(gòu)參數(shù)化建模及仿真

林順洪1*，朱新才2，李長江1，徐 明1
1.重慶科技學(xué)院，重慶 401331
2.重慶房地產(chǎn)職業(yè)學(xué)院，重慶 401331

利用空間包絡(luò)曲面的共軛原理建立了圓柱分度凸輪的數(shù)學(xué)模型，使用Pro/E三維軟件的參數(shù)化建模功能對特定的圓柱分度凸輪進(jìn)行設(shè)計和精確建模，建立了圓柱分度凸輪機(jī)構(gòu)虛擬樣機(jī)模型，使用ADAMS軟件對其進(jìn)行動力學(xué)和運動學(xué)仿真分析。仿真結(jié)果表明：該機(jī)構(gòu)模型建立的正確性，得到了具有實際應(yīng)用價值的結(jié)論，對圓柱分度凸輪機(jī)構(gòu)的設(shè)計、加工、安裝起到了一定的指導(dǎo)作用。

圓柱分度凸輪；Pro/E；參數(shù)化建模；ADAMS仿真分析

10.3969/j.issn.1001-3881.2015.12.019Document code：A

TM743

12 January 2015；revised 27 February 2015；accepted 15 March 2015

*Corresponding author：Shun-hong LIN，Professor.

E-mail：cqutljh@163.com