The accurate design of index plate of fixed position of ball of steel of part of the function in numerical control machine tool

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The article is in to orgnaization of index plate of steel ball fixed position numerical control machine tool, turn the modular machine tool that take form and the accurate design in all sorts of circumgyrate workbench, analysed the factor that affects precision of graduation fixed position, offerred a means of settlement and gave out to use example. Mix in numerical control machine tool turn the modular machine tool that take form and in all sorts of circumgyrate workbench, commonly used graduation workbench graduation, dislocation and position job have automatically according to the instruction that controls a system, every time the point of view with dislocation proper circumgyrate (90 ° , 60 ° , 45 ° ) , but the orgnaization that realizes workbench dislocation is very inaccessible however the requirement of graduation precision, want to special fixed position component will assure so, accordingly, graduation locates component often is the graduation workbench design, crucial part that make and adjusts. At present commonly used fixed position component has plug fixed position, rely on fixed position, tine instead dish fixed position and steel ball fixed position. To obtain the graduation of high accuracy, use orgnaization of index plate of steel ball fixed position extensively. It has a tooth-like part of anything dish a few advantages of fixed position, automatic centering and graduation precision are tall, and make simple, steel ball but outside buy, use steel ball to the workbench of circumgyrate of high accuracy graduation with lesser dimension especially fixed position is very good also. Steel ball fixed position is it is OK to use measurement of steel ball diameter preelection arrives the error is very few the principle of limits, obtain accurate graduation precision thereby. The article undertook steel ball locates the structure of index plate orgnaization is designed, analysed the element of the graduation precision that affects orgnaization of index plate of steel ball fixed position, offerred a means of settlement. The structure of orgnaization of index plate of fixed position of ball of steel of principle of 1 construction work sees a picture 1. The basic circle that it relies on high accuracy dish the precision that the 4 steel balls with high accuracy will come to raise index mechanism. With ¢ open space of 120 very close to each other arranges 8 steel ball in ¢ 297.

On the basic circle column of 61238 millimeter, contact at same end panel, impaction circle is 5 outside steel ball, the circuit inclined mouth of 30 ° to steel ball, when impaction encircles impaction, get on steel ball impaction in basic circle column and end panel. Besides, destroy graduation along circumferential roll to prevent steel ball, be opposite in some the wedge head cylinder that make it of a high strenth steel installs between steel ball is sold 12, its head is face of 45 ° wedge, in order to assure high accuracy graduation. This kind of orgnaization can use treatment tine tooth dish (namely index plate of end panel tine) etc high accuracy is graduated workpiece. When the job, when handle 7 suitable hour hand turn when, make rise fall swivel nut 9 drive main shaft and workbench 1 rise, right now impaction is encircled 5 drive steel ball to rise, can turn workbench undertakes graduation. Anticlockwise finally rotational handle 7, can make rise swivel nut 9 drop and clamp, the graduation principle of steel ball is shown 2 times like the graph. The element analysis of precision of 2 influences graduation and   of means of settlement 2.

The chooses steel ball dimension precision of 1 steel ball is the payoff of graduation precision discretion. For this, the precision of steel ball assures with the method of preelection. Those who use 1 micron measure small appearance, the steel ball that preelection diameter error is 1 micron 240, by the diametical size error of requirement steel ball and true circularity best preelection is in 0.

5 micron are the following. 2.

2 base the demand of basic circle diameter of the treatment radical disc of disc is higher, the computation of basic circle diameter is as follows: If citing pursues 3, steel ball diameter is ¢ 8 millimeter. N=120 of foregone and circumferential divide into equal parts, so ∠ AOB=3 ° , AB connects heart line for steel ball, so AB=8, OC is the bisector of the horn of AOC of the ∠ in the triangle, then △ ACO is a right-angled triangle, and 30 ′ of ∠ AOC=1 ° , criterion: AO=AC/sin1? 30? =4/0.


80619 millimeter, accordingly, base the diametical D of the basic circle column of 4 is disc: D=2 × Ao=2 (AO-Aa1) =297.

61238 millimeter   (among them Aa is steel ball radius, aa=4 millimeter)   grinding and measuring basic circle is more difficult, to solve this one difficult problem, the treatment method that we use is: First the basic circle with hard temper by dipping in water dish grind allow two plane, parallelism is in 0.

01 millimeter less than, it is the aperture inside fiducial grinding with plane, should assure plane and inside aperture center verticality is 0.

001/100 millimeter, next the arbor with tailor-made mount, less than aperture and end panel are fiducial grinding basic circle. Grinding basic circle troubles an end panel at the same time. ¢ 297.

6123 millimeter are ground + 0.

On the foundation of 1 millimeter, every are ground small 0.


02 millimeter are, be about to axis of core of workpiece along with is torn open together below (cannot dismantle the part from core axis below) . 2.

The 3 parts with hold the job good afore-mentioned treatment beforehand and impaction circle and the 120 steel ball that had picked are on stage style undertake trial assembly, measure the biggest gap of tapping ball with nice stuff feet, go up again next the 1/3; that grinder grinds small diameter to be equivalent to the biggest gap relapses for many times so grinding and trial assembly, until measure not the clearance of tapping ball, measuring the diametical measure that give at this moment should be the dimension that computation comes out. When working procedure is machined, this answers to be mixed very carefully together not tire of its are irritated, should note good cleanness and environmental temperature. The emery wheel when grinding should notice smooth, circle and end panel should be ground at the same time outside small, when spare parts outfit is rotational between the two thimble that grinding machine reachs on arbor, the a bit biggest brace up place should not exceed 0.

01 millimeter. The hardness of basic circle round cylinder had better be in HRC55 above, hardness is low, after the pine is pressed, classics steel ball is met for many times generation impress, one occurrence impress, graduation precision drops subsequently. 2.

4 basic circle dish specific means can use the measurement technique of precision of divide into equal parts body of much face arris and collimation appearance, also can contrast with collimation appearance the method of viewfinder will determine error. We are in 3 use example be in precision of steel ball preelection in this device 0.

002 millimeter are the following, what the collimation instrument that uses 1 second and viewfinder cooperate to check precision of divide into equal parts is the biggest accumulate an error to be 4 seconds. Use installation of this index plate to grind the 120 millimeter of ¢ that go out on spline grinder, the tine tooth of 120 divide into equal parts dish the pace determines at the beginning of classics, is number of computational clench the teeth counted to amount to by tine after clench the teeth 95? Above, edge tooth depth, is the interface on facewidth achieved 70? Above, tooth of this pair of tine dish installation is turning the classics on tower head is checked integratedly, error of divide into equal parts is in 0.

02 millimeter less than (repeat fixed position error) , raised the precision of treatment greatly. 4 notes   (1) when assembling impaction to encircle, when steel ball and inclined surface contact, clearance maintains between impaction circle and stage style in 0.

1 millimeter less than is more appropriate. (2) the steel ball impaction of index plate uses afore-mentioned structures, can bear after all how old turn round pitching moment, remain to make a test further. (at present from use a circumstance actually to look, this device is used at reticle of nicety of grinding divide into equal parts, get the alveolus of divide into equal parts to wait to all can achieve taller graduation precision) , to the cutting treatment with torsional or big wallop, use devoir dial and unsuited. CNC Milling CNC Machining