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1、Received 21 February 2007 Development of a TestM achine for IVECO DriveAxle WANG Liang- mo, WANG H e-fu, CHEN Jin-rong, LI NG Zhi-liang, CAO Yu-hua School ofMechanicalEngineering , Nanjing University of Science and Technology , Nanjing 210094 ,P. R. China Abstract: To i mprove the automation level o

2、f the vehicle drive axle test and better simulate a vehiclecs actual operation, an advanced testmachine has been developed. The load system of themachine consists of hand brakes and electric cylinders. It is si mple-structured and low-cost. Themajormotor of thema- chine is controlled by a transducer

3、 and its speed can be adjusted easily. In addition,the programmed machine can auto matically test such parameters as the grinding condition,the differential speed,the noise level, etc. It can also adjust the test procedures according to different requirements. Detailed dis- cussion of the structure

4、and mechanis m of the testmachine is given in this paper . Key words : vehicle ,testmachine ,drive axle ,IVECO 1 Introduction The drive axle of a vehicle is composed of a final drive ,a differentia,la shel,lhal- f axles and brakes ,etc .It comes into play at the last transm ission stage of the vehic

5、le transm ission system. The grinding functionality ,the transm ission stability ,the braking capability ,and the noise volume , etc. ,of the drive axlew ill all affect a vehiclecs quality and perfor mance . Therefore ,after the drive axle is assembled ,it is necessary to test such functionalities a

6、s the grinding,differential speeding , and noise levels ,etc . Currently,only a few manufacturers test the functionalities of vehicle drive axles in their domestic assembly lines .In addition,the automation level of these manufacturersc testmachines is relatively low.For example ,the YuejinMotor Gro

7、up Corporation uses am anually-operated and single -speed drive axle testmachine . Thism achine does not have ameasuring syste m for testing the speed ,load , and noise levels . Thus,themachine can not control its test ti me accurately. Further more ,the si mu - lated operation deviates quite far fr

8、om the actual operation ,so that it can not ensure the perfor mance and quality of the drive axle . However ,the drive axle testmachine of the I VECO vehicle has a relatively high level of automation and provides some advanced functionalities .It enables a better si mulation of a vehiclecs actual op

9、er - ation and also increases the accuracy of the tes. t This paper introduces the advanced functionalities of the I VECO testm achine by illustrating them achinecs structure , mechanism,aswell as the design features of themachinecsmechanical and electrical controlling system. International Journal

10、of P lantEngineering andM anagement Vo.l 12 No. 1 March 2007 2 The structure andmechanis m of the testmachine F igure 1 Illustration of the I VECOcs drive axle testmachine F igure 1 illustrates I VECOcs drive axle test ma - chine . The test m achine pri marily consists of a transm ission device,a lo

11、cating and holding de - vice ,a loading device ,and an oil intake and re - lease device ,etc . ( 1) The transm ission device The transm ission device consists of a drive shaft w ith a spline ,amovable spline liner ,a b- i direc - tional acting cylinder ,universal joints and pegs, etc. The transm iss

12、ion device joins themotorw ith the test drive axle . This device ispneumatic . V ia the displacement sensor and the programmable controller ,the transm ission device not only can automatically transm it the motorcs force to the tested drive axle ,but also can automatically separate the t wo. I VECOc

13、s testmachine for the first ti me uses the transducer and has achieved the stepless speed regu - lation bet ween 0 and 3000 r/m in ,thus allow ing a better si mulation of a vehiclecs actual operation . Further more,the transm ission deviceworks fas, t easily,and reliably w ithout noticeable shocks,v

14、- i brations and noises . ( 2) Locating and holding device W hen the transm ission device and the drive axle are joined ,it is required that the axis of the drive shaft be alignedw ith the axis of the final gear in order to reduce shocks,vibrations and noises . To meet this requiremen, ta locating d

15、evice is designed for the testm achine . Based on the principle of complete location,the locating device uses three V-shaped pieces for locating .Among the m,t wo pieces are positioned on the edges of the hal- f axle liner , while the third piece is positioned under the drive axle , w ithin the li m

16、 it of 6 degrees of freedom. During the tes, tthe drive axle vibrates violently because of the high speed of the hal- f axle and wheels . To reduce the vibration ,a pneumatic board is installed above the two V-shaped pieces which are positioned outside the hal- f axle liner ,holding the drive axle t

17、ightly . ( 3) Loading device The drive axle testmachine generally uses the electric eddy current brake , or the asynchronous gen - erator ,as its loading device. The loading effectsw ill be i mposed when the brake or the generator is joinedw ith the left and rightwheels of the drive axle .This type

18、of test machines have notable and lasting loading effects ,and can perfor m loading testson the drive axle for a long ti me. H owever ,the arrange m ent of thesem achines is crowded and the cost of thesem achines is also relatively high ,be - cause two electric eddy current brakes ,or t wo asynchron

19、ous generators , w ill be added into the test machines for the loading. 25Development of a T estM achine for I VECO Drive Axle Comparedw ith the conventional loading device ,the loading device of I VECOcs testmachine is inno- vative in two aspects. Firs, titworksw ith hand brakes . Second ,it adopts

20、 the domestically newly in - troduced and developed electric cylinders.These cylinders are si mple-structured ,and their loads can be easily adjusted . When the loading device isworking,the electric cylinders tighten the hand brakesc steel rope andmove the brakes . The load levels can be changed by

21、adjusting themove m ents of the hand brakescsteel rope . Concurrently,differential transm issions of the drive axle can also be achieved w ith the hand brakes . ( 4) Oil intake and release device Before the tes, t kerosene needs to be fed into the oil intake device and then themachine is cleaned . A

22、fter the cleaning ,kerosene needs to be released completely and then engine oil is added . Engine oil can be recycled during the tes. t The critical technique of the oil intake device is the design of the quick oil intake and release joints . The principles and structures of these two joints are bas

23、ically the same .During the operation ,the cylinder pushes the intake and release device to connect quickly and accurately through a connecting rod .In addition ,a special device is also used to ensure the sealing perfor m ance of the intake and release device . In the oil release syste m,oil is fir

24、st released from a releasing hole into an oi- l separating box . Then , through an oi- l separating valve , which is connectedw ith the oi- l separating box,kerosene is separa - ted from the engine oi. l 3 Controlling system F igure 2 The controlling system of the testmachine Currently,there are thr

25、ee types of wel- l developed me - chanical and electrical controlling systems :the relay contact controlling system,the programmable contro- l ling system,and the industrially-controlled computer system. The relay controlling syste m is slow,clum sy , and only allows for si mple contro. lThe industr

26、ially - controlled computer system is expensive ,and difficult to program, while the programm able controlling system is smal,lreliable ,wel- l functioned ,and easy to pro - gram. Therefore ,the programm able controlling system is selected here for the test machine .F igure 2 shows the controlling s

27、ystem of the test machine . The design procedure of the test machinecs controlling system is as follow s : ( 1) Analyzing the workflows The drive axlecs testm achine operates in t wo phases :the preparation and the tes. t The preparation phase proceeds in the sequence of installing the drive shaf, t

28、connecting the drive axlew ith the drive 26International Journal of P lantEngineering andM anagement Vo.l 12 No. 1 March 2007 shaft ,feeding kerosene,rotating the generator clockw ise and counter -clockw ise ( cleansing the drive axle) and releasing kerosene through air pressure . The test phase pro

29、ceeds in the sequence of feeding engine oi, lrotating the generator clockw ise ,a- l ternative loading or si multaneous loading w ith the left hand brake and right hand brake,differential and delayed transm ission,grinding , measuring noise ,rotating the generator counter -clockw ise ,a- l ternative

30、 loading w ith the left hand brake and right hand brake ,differential and delayed transm is- sion ,restoring the left hand brake and right hand brake ,stopping the generator ,testing the oil sea- l ing perfor mance of the oil intake and release device ,releasing engine oil through air pressure ,rest

31、o- ring the oil intake join, trestoring the drive shaf, trestoring the holding device to the end of the tes. t ( 2) Deter m ining the input bits and output bits The input bits prm i arily include the signal of the drive shaftc s position ,the signal of the holding devicec s position ,the signal of t

32、he oil intake and release jointscposition ,aswell as the signals of the automatic stopping button and stepping button ,etc . Altogether ,there are 53 input bits. The output bits prm i arily include the start signal of the generator ,the start signal of each valve of the pneumatic system,aswell as th

33、e start signals of the electric cylinders ,etc . Altogether ,there are 33 output bits . ( 3) Selecting the program controller Currently,there aremany types of progra m controllers .In terms of their bit numbers and functiona- l ities ,they can be classified into three categories :sm al- l sized , me

34、dium-sized ,and large -sized . The smal- l sized controlling system is selected heremostly for the purpose of producing such on -off actions as sequential controlling ,ti m e controlling and warning and locking ,etc . The total number of input and output bits is 86 . M itsubishics F1 series of progr

35、a mmable controllers are used ,w ith a 60 -bit main engine F1-60MR and a 40 -bit extended engine F1 -40 ER. Altogether ,they generate 100 input and output bits , w ith amargin of 14 bits. ( 4) Drawing the input and output ter m inal distribution chart and defining each input and output nu mber . ( 5

36、) Draw ing the workflow diagram and programm ing the process based on thework flows . The syste m thus designed has the follow ing features:( a) The system allows flexible control and sw itching a mong variousmodes ( such as automatic contro,l stepping contro, l etc . );( b) The sys- te m provides t

37、he stepping contro. l This controlmode is easy to operate . The test programsw ill pro- ceed to the next stepwhen the stepping button is pressed . The procedures are si mple and clear . All of thesew ill be useful for adjusting the test progra m s ;( c) The system also allows diagnosing m a - chine

38、breakdowns on the line. When the input and output lights of the progra m controller are dis- played ,then the progra m stopsworking at this poin,tindicating breakdowns occur ,thusm aking d- i agnostics and repairs easy. Using the relay controller can not achieve this. 4 Conclusions Practical experie

39、nce has shown that IVECOcs driving shaft test m achine is wel- l functioned ,and highly automatic .It has good stability,suitable for testing the five types of the IVECOcs vehicle drive axles. At the same ti me ,its test programs can be adjusted according to different requirements . 27Development of

40、 a T estM achine for I VECO Drive Axle This testm achine is relatively cheap and si mple -structured .It also allows stepless speed ,and load - ing w ith hand brakes .Thus,the test machine enables the drive axle test to better si mulate a vehiclecs actual operation. The successful development of this testmachine not only increases