并聯(lián)機(jī)床中工件安裝定位系統(tǒng)的開(kāi)發(fā)外文文獻(xiàn)翻譯@中英文翻譯@外文翻譯

1、<p>　　Development of a Workpiece Location Determ ination System in Parallel Mechanism Type Machine Tools</p><p>　　ZHAO Xiao ming , SHAO Hua, 　HATTORI Kazuya, 　TSUTSUMIM asaom i</p><p>　

2、　School of Mechanical Eng, Shanghai Jiao tong Univ, Shanghai 200030,China;</p><p>　　Technical Research Dept,Toyoda Machine Works, Kariya 44828652,Japan;</p><p>　　Bio Applications and Systems

3、Eng, Tokyo Univ of A griculture and Technology, </p><p>　　Tokyo 18428858, Japan.</p><p>　　Abstract: This paper uses HexaM made by ToyodaMachine Works Co.as an analyticalmodel of parallel&l

4、t;/p><p>　　mechanism type machine tools. Much collision may be generated for its complicated </p><p>　　structure and working space, when a workpiece is mach inedusing this machine. For <

5、;/p><p>　　example, those collisions are generated.between the moving components of the parallel </p><p>　　mechanism ,between the moving components and a workpiece and between themoving </p>

6、<p>　　components and the tool storage for autom atic changing.In th is paper,an algorithm </p><p>　　for detecting and avoiding those collision swasproposed. The method for avoiding the</p><p&

7、gt;　　collisions was conducted by readjusting the location of the workpiece without am ending </p><p>　　the toolpath.It is confirmed through experim ent that the proposed algorithm is </p><p>　

8、　useful for detecting the collisions and determining the location of the workp ieceprior </p><p>　　to the actual machining.</p><p>　　Keywords: parallel machine tools;ollision check; avoidance

9、; toolpath; in stallation site</p><p>　　In recent years, the PMT development and application of the growing, but because of its structure and working space is very complicated, use it for processing the work

10、piece, it is very possible the machine components themselves interfere with the workpiece and the machine interference. Also, if like PMT HexaM [1], work on stage in the installation of automatic tool change devices and

11、 other peripheral equipment, the installation of the workpiece. It may limit the installation of the workpiece lo</p><p>　　PMT on their way to check interference and machine work space has been much research

12、 [2 ~ 5]. Among them, This writer and other Japanese companies Toyota Machine Works of PMT HexaM [1] as a model. Discussion of PMTs their interference in the inspection, the work space approximate expression [5]. the oth

13、er hand, 5-axis NC machining, cutting tool (knife, Chuck and Spindle) and the workpiece (workpiece and fixture) interference methods also have many. Among them, Takeuchi, etc. [6] tool system from</p><p>　　T

14、hese studies are discussed in detail PMT their interference in the machine tool and workpiece and the interference checking and evasive methods, However, the use of PMT ago, but there are several problems : </p>&

15、lt;p>　?、?working platform for peripheral devices such as a barrier Machine [1] should consider the machines and peripheral equipment possible interference;</p><p>　?、?the inspection machine and the interf

16、erence of the workpiece. Consideration should also be given spindle plywood, plywood hinge link with the workpiece and the possibility of interference, However, the existing CAM software does not include such interferenc

17、e detection;</p><p>　?、?machine when there is interference with the workpiece. General Tool always postural adjustments to avoid interference. In fact, PMT, in addition to postural adjustment tool, You can a

18、lso adjust the location of the workpiece to avoid all interference. Moreover, This approach avoided the biggest advantage is not to change the existing CAM software. </p><p>　　Based on common CAM software to

19、ol path of the output-based, shorten the time to interfere in the inspection checkpoints document composition, By adjusting the location of the installation of the workpiece to avoid the possibility of all kinds of inter

20、ference, of the workpiece can test for processing at the workpiece and machinability best installation location calculation. </p><p>　　1.Interference checking and avoid interference </p><p>　　Us

21、ing the PMT HexaM, peripheral equipment (the knife) and the workpiece installation diagram shown in Figure 1. Therefore, For the machine, during processing and installation of the workpiece at the possibility of interfer

22、ence with his interference, machine tool and workpiece interference machines and the peripheral equipment, and interference with the surrounding devices workpiece interference. </p><p>　　If you are using a p

23、arallel machine table without peripheral devices or devices placed around the far more, will not affect the location of the workpiece machining process or there will not be machines and peripheral equipment interference,

24、 can be omitted from the workpiece and the machine and equipment around the interference checking. </p><p>　　F ig. 1　Schemat ic of the parallelmechanism HexaM</p><p>　　1.1 Their interference <

25、;/p><p>　　1.1.1 The composition checkpoints During processing, All tools can be applied to position literature [5] described method to check whether their intervention will happen. if there is interference, ca

26、n be used in the adjustment of the workpiece location to avoid interference. Parts of the installation location changes, Processing Tool position will naturally be changed. Therefore, the need to conduct another inspecti

27、on, not occur until the date their interference. As an installation at each loca</p><p>　　From the z-axis cutter farther, the higher the position, the greater the degree of tilt, the more prone they interfer

28、e in [5]. Therefore, wait for the processing of the workpiece, the tool path from the outside to share the measurement point, the higher the cutter location, tool tilt angle larger point as to determine whether they inte

29、rfere in the check points. </p><p>　　1.1.2 Interfere with the inspection methods Tool position and posture straight at the moon and the space rotary disk space, it would be interference in its own [5]. Ther

30、efore, they interfere with the inspection methods : ① read all checkpoints, obtained a checkpoint each corresponding to the straight and rotating space Yuan Yuan space [5]. ② cutter position and posture in response The s

31、traight round space and space Rotary Circle, convicted of the checkpoint will not interfere in their occurrenc</p><p>　　1.1.3 Avoid interference method As in the same horizontal plane, the cutter in the z-a

32、xis location at the least prone to his interference. Therefore, If a checkpoint in a self-interference then we check points and the z-axis direction connectivity as evasive. Then, Parts of the installation location along

33、 the direction of movement of evading 10 mm. If two consecutive evade direction of the angle is greater than 150 °. that could have been avoided reversed direction in the horizontal plane does </p><p>　

34、　1.2 Machine interfere with the workpiece </p><p>　　1.2.1 The composition checkpoints As shown in figure 2, machine and workpiece possible interference between parts of a knife, chuck, spindle head, spindle

35、 splint, Hinges and plywood link. workpiece can be seen from the surface and surface composition. Among them, Surface processing from the point with machine might happen to the non-interference by non-machined surface pr

36、ocessing point is, here, processing and point and non-point processing collectively referred inquiries to the point. </p><p>　　F ig. 2　Check method of the collision betw een the parallelmechanism and wo rkp

37、iece</p><p>　　Inquiries point with knives, and Chuck, The first spindle axis and the splint interference known as a category interference. Such interference only with knives, the posture, and workpiece posit

38、ion unrelated to the installation. Therefore, if the screening of such interference, and only postural adjustment tool for evasive, This requires changes CAM software, beyond the scope of this discussion.</p><

39、p>　　Inquiries point splint hinge connecting rod or interfere in the resolution as interference in two categories. Such interference can be adjusted through the installation of the workpiece - Purchase avoided. Below t

40、hese two types of intervention on the check points formed. </p><p>　　With a cone, its center point for the tool, cone angle of H0 included knives, and Chuck, The first spindle axis and the minimum angle of p

41、lywood; Tool center hinge splint to the minimum distance of d002; Tool axis in the direction of the minimum distance of h0, H0, d002 and h0 machine parts according to the size and structure of plywood hinge back corner o

42、f the largest such parameters obtained. </p><p>　　For the processing of a point P, P calculated with all inquiries Q-point connectivity PQ and the tool axis angle H, d line segment and the length of the segm

43、ent PQ tool axis direction on the length of the projection h. Therefore, satisfy conditions H "H 0 inquiries point as a kind of interference in check; satisfy conditions d "h and d 0" h0 inquiries points a

44、s Class 2 interfere in the check points. As with all the processing points have obtained two checkpoints, and deposited checkpoints docume</p><p>　　1.1.2 Interfere with the inspection methods Checking wheth

45、er there was interference in Category 1, the first knife, Chuck, The first spindle axis and splint (referred to as Tool System), and a type of intervention checkpoints x z plane to the projection, then, Tool checks into

46、the projection system checks whether the point system and tool interference [7]. As the No. 1 category interfere with the workpiece unrelated to the installation location, in the calculation of the workpiece location, on

47、l</p><p>　　Due to the location of the installation of the workpiece, which will definitely lead to splint hinge and link the position and posture change. Therefore, Parts of each installation location adjust

48、ments, we must check whether there will be interference in the first two categories. Therefore, How to reduce interference in the first two categories of the inspection is to shorten the clearance time of the key. In thi

49、s paper, judgment Category 2 interference check point is to satisfy the conditions d</p><p>　　1.2.3 Avoid interference method When interference, and its method of avoiding interference in its own when there

50、 are evading the same method. </p><p>　　1.3 Machine and equipment around the interference </p><p>　　1.3.1 The composition checkpoints Figure 3 for PMT HexaM of peripheral equipment, workpiece m

51、achining and tool path when the vertical view. From Figure 3, we can see that peripheral equipment installed in the workstations to a quadrant, so Tool path to the center of a quadrant of the outer (.), as interference i

52、n the check points.</p><p>　　Fig. 3　Check po ints and avo idance vecto r of the co llisionbetw een the parallelmechanism and magazine</p><p>　　1.3.2 Interfere with the inspection methods And pe

53、ripheral equipment may interfere with the parts of a machine tool, chuck, spindle head, plywood hinge connecting rod and spindle splint, Their shape of a cylinder and the plane circles constitute the polyhedron, and peri

54、pheral equipment for the many facets of the shape. Therefore, peripheral equipment and machine parts will be used between "bounded plane and cylinder" and "bounded plane and bounded plane" interferenc

55、e method [5]. That is, in all</p><p>　　1.3.3 Avoid interference method If the machine occurred with the surrounding equipment interference, peripheral equipment will surface before the normal direction as t

56、o evade direction, and the occurrence of evading their own methods of avoiding interference in the same way. </p><p>　　1.4 Workpiece and the interference of neighboring devices </p><p>　　In orde

57、r to be able to quickly detect when installing the workpiece and the existence of peripheral equipment interference, the first of the workpiece to the xy plane projection, and bounded by polygons workpiece envelope proje

58、ction. Then, use "bounded plane and bounded plane" [5] to check the workpiece and the interference of neighboring devices. each installation location given workpiece after, the need for such interference checki

59、ng. </p><p>　　If the workpiece and interfere with the surrounding equipment, peripheral equipment will surface before the normal direction as to evade direction, and the occurrence of evading their own metho

60、ds of avoiding interference in the same way.</p><p>　　1.5 Interpolation of check points </p><p>　　From the above content aware that apart from the workpiece and the interference of neighboring e

61、quipment checks, other checks are interfering in the inspection point in terms of interference. Therefore, if the check points between the distance is too large, There were at checkpoints without interference, while at c

62、heckpoints will happen between interference, But such interference has not been found possible. in actual processing time is absolutely impermissible. </p><p>　　To solve checkpoints may exist between the int

63、erference problem, there are two major ways : First, a simple function with polyhedron intersection method [8]; two is to check the distance between the point narrowing. No. 1 methods for screening machine and the interf

64、erence of the workpiece particularly effective, But they can not be used to solve interference; 2 methods for the various types of interference in the inspection applies to all, But if the checkpoints between the distanc

65、e is too small</p><p>　　Conducting two objects judgment interference, One of the first objects to expand 5 mm. If the expanded intersection of two objects. was convicted of two objects there is interference.

66、 If the intersection from the surface of objects within 5 mm. In fact, this is still no interference. If convicted of two objects there is no interference, then the distance between the two objects in more than 5 mm. Her

67、e, this 5 mm called safe distance. </p><p>　　CAM system for output from the reference point and tool path, If adjacent to the inquiry or the distance tool path is greater than the distance between a safe dis

68、tance Inquiries points in the tool path between or among some interpolation points. that is, after inquiries after the interpolation between the points and tool path is the distance between less safe distance. So, when t

69、he two checkpoints there are no interference. in between them would not have happened interference. Thus, a safe dista</p><p>　　2. Workpiece location of the installation method of calculation </p><

70、;p>　　2.1 Parts of the best installation location </p><p>　　In this paper, "Pad of the minimum height; from the shortest distance from the center stage "as a measure of the workpiece best install

71、ation location standards. Specifically, First to the workpiece is placed in the bottom table (At this point, the height of the pan 0) Tool tracks in the xy plane projection center and the center coincides workstations (d

72、istance from the center of the worktable 0) Workpiece as the best installation location. If there is interference in the location to be installed</p><p>　　2.2 Best installation location method of calculation

73、 </p><p>　　Based on the best parts of the installation location concept, this paper presents a workpiece machining installation location calculation steps are as follows : </p><p>　　1) Read the

74、basic data. Include : knives, and Chuck extend the radius and length; Inquiries; Tool path; peripheral equipment and the location of the xy plane with the other projector. </p><p>　　(2) to determine whether

75、the machine processing. According to the workpiece Inquiries point and the tool path, Calculation workpiece xy z direction in the shape and size of the cutter Mobile distance. When the workpiece size or shape of the move

76、ment distance Tool too large, given the workpiece on the machine can process of warnings. the end of the operation. </p><p>　　(3) various types of interference generated inspection checkpoints document. Amon

77、g them : checking their interference, The machine tool and workpiece Class 1 and Class 2 interference, Machine interfere with peripheral equipment check-point document. </p><p>　　(4) to check whether there a

78、re machine the workpiece with a type interference. If depositors in, due to the interference by not moving the workpiece to avoid the installation location, so given the "unavoidable existence of a category of inter

79、ference" warning, the end of the system. </p><p>　　(5) to set the tool path Center C (x, y, z) of the initial position. To meet the workpiece best installation location definition, C (x, y, z) of the in

80、itial set of home : x = 0; y = 0; z = s. Among them, 's center for the tool path to the bottom of the workpiece distance. </p><p>　　(6) Calculation tool path C center position. According to interfere in

81、the inspection Methods and evasive methods, and keep track of mobile tool center installation location, until they found no interference or location of the installation is not in the workpiece on the machine processing w

82、arning to date. </p><p>　　(7) loser workpiece location of the installation. (6) If there will not seek to interfere in the tool path of the center position, based on the value of the structure and size of th

83、e workpiece, calculated and output workpiece installation location. </p><p>　　3. Analysis of the experimental results </p><p>　　For the map shown in the four dimensions of 350 mm × 150 mm &

84、#215; 350mm workpiece, When using vertical machining, The use of a common software CAMAND CAM generated at the processing location Tool and Tool Posture (with the normal processing point is the same). maps, tool path of

85、the location points to 123 201 points. Tool for ball milling, diameter 10 mm, Collet, which stretches out from the length of 50 mm and 60 mm in diameter chuck, which extend from the main shaft 45 mm. </p><p>

86、;　　Fig. 4　The workpiece and tool path</p><p>　　Based on the above algorithm, This paper developed PMT workpiece machining time calculation system installation location. calculated as shown in Figure 4 proces

87、sing workpieces installation location, computing time (computer CPU : 850MHz AMD THLON A), about 15 min. </p><p>　　3.1 Inspection Points</p><p>　　CAMAND software in the tool path generation, bec

88、ause there is no tool path than the adjacent safe distance, so no interpolation point of support. Also, as shown in Figure 4 on the workpiece, in addition to processing face, The remaining surface and the machine is unli

89、kely to happen interference, therefore, All inquiries from point to point tool path. Inquiries from the point out of their interference check points to 2382 points. Machine interfere with peripheral equipment for the ins

90、pection of 2</p><p>　　3.2 Installation location analysis, the experimental results</p><p>　　Workpiece location of the installation process of change as shown in Figure 5. Know from the calculati

91、on process, When the workpiece is low installation location near the center stage, prone machines and peripheral equipment interference; If the workpiece location distant from the center, the machine itself prone to inte

92、rference. Finally, When the workpiece installation height of 70 mm, only to find no interference by the installation location. </p><p>　　Fig. 5　Change of p rocess of the locat ion of workpiece</p><

93、;p>　　Figure 6 workpiece to be installed in Figure 5 ★ location of the installation diagram. From Figure 6 shows, Workpiece bottom center is not the center of the table, but from the center, from workstations (-42. 05.

94、 - 42. 05, 70) mm. This is because, to avoid the machine and placed in a quadrant of the first stage of the peripheral equipment interference, it must workpiece to the first three workstations Quadrant Mobile, and also u

95、pward movement installation of the workpiece to be placed under 70 m</p><p>　　Fig. 6　The final locat ion of workpiece</p><p>　　To check the installation shown in Figure 6 position and to make ap

96、propriate location for the entire whether there will be interference, Using machine HexaM experiments, installation location and experimental results, as shown in table 1. Among them, the smallest gap is the method of vi

97、sual observation. </p><p>　　Table 1, except for the line 3 position (x =-35, y =-35, z = 70) mm installed outside the workpiece, Analytical and experimental results the same, ie no interference. and the thir

98、d line position shown in the installation of the workpiece, by the experimental knowledge, Machine and equipment surrounding the smallest gap is 3 mm, as compared with the analytic system created a safe distance from the