PH10 swing tower decides the correction of horny error

Firstly, the Positional Relationship Between The PH10 Rotating-center And The Red Ruby Sphere Centre Is Obtained By The Measurement Of The Sphere With A Coordinate Measuring Machine (CMM) .

Then Based On The Restults, the Reference Coordinate System Around Which Axes PH10 Rotates Is Created.

Also, the Calculation Of Absolute Angles And The Angle Errors Are Presented.

Finally, the Causes Of The Indexing Angle Errors Are Analyzed.

Keywords: ? The high accuracy circumgyrate that swing tower of PH10 of 　 of 　 of Reference Coordinate System of 　 of 　 of CMM of 　 of 　 of Angle Error of 　 of 　 of  H10 Probe is production of British RENISHAW company measures a head. If the graph is shown 1 times, it has A, B two rotor, two axes are vertical intersect, point of intersection is the centre of turning circle of PH10. The circumgyrate angle limits that circles A axis 0 ° ～ 105 ° , the circumgyrate angle limits that circles B axis - 180 ° ～ + 180 ° , step pitch horn is 7.

5 ° , there are 720 places inside whole slew space. Graph 　 RENISHAW company assures outline drawing of swing tower of 1 　 PH10 only PH10 the angle repeatability precision of each position, and the error that gives angle and actual circumgyrate point of view is sealed. When use TP6 measures a head to provide the measuring staff with senior 21mm, the positional repeatability error that ruby measures ball center to fall in same corner is less than ± 0.

5 μ M. The center that measure a ball is 117mm to the total length of PH10 centre of turning circle, criterion error of PH10 angle repeatability is less than ± 0.

9" . Normally, PH10 is measured with 3 coordinate of machine spark join of the photograph that measure a head, before undertaking metrical, PH10 circumgyrate comes the angle of the requirement, after undertaking demarcate to surveying head system, finish measure, the PH10 in measuring a process namely does not produce circumgyrate. This kind of circumstance just measures need to satisfy and make measure a head to be in the pose that secures, need not consider to decide the effect of horny error. When measuring complex body, the PH10 in measuring a process needs to produce circumgyrate, so that can measure each place of workpiece. Below this kind of circumstance, must know the accurate angle of each circumgyrate horn, such ability are in PH10 what each angle falls measure data to undertake normalization is handled, be about to these data alternate same in measuring fiducial coordinate to fasten. So, be necessary to undertake detect and be correctioned to the deviation of the circumgyrate horn of PH10. Use ZOO2 of centre of turning circle of 1 　 PH10 and relation of position of the center that measure a ball above all certainly the method that 3 coordinate measure machine mark to follow a ball decides He Gongbao stone measures PH10 centre of turning circle the dimensional coordinate of ball ball heart. If the graph is shown 2 times, PH10 installation is measuring the Z axis of machine to go up, TP2 sparks measure head and PH10 photograph join. Establish the position the circumgyrate horn of 1 place PH10 is θ A1 and θ B1, measure so that the ball heart coordinate of standard ball is O1; position the circumgyrate horn of 2 place is θ A2 and θ B2, measure so that the ball heart coordinate of standard ball is O2. In fact, the position of standard ball is changeless, ball heart coordinate also does not have a change, however the position of centre of turning circle of PH10 produces change. If ruby measures the ball heart coincide of the ball heart of the ball and standard ball, criterion PH10 by the position 1 circumgyrate comes the position 2 when, can think the coordinate of its centre of turning circle turns into by O1 O2. Press this method, the circumgyrate point of view that changes PH10 will get a ball heart O with standard ball be ball heart, be apart from the ball that is radius to heart of the ball that measure a ball with PH10 centre of turning circle, the centre of turning circle of PH10 is in spherical on, if pursue,3 are shown. Graph 2 determine PH10 centre of turning circle and the dimensional coordinate plan that survey ball ball heart sketch map of centre of turning circle of 3 　 PH10 is in the graph, when θ B=0 ° , PH10 circles A axis circumgyrate only, set O0 to be the position of centre of turning circle of the PH10 when ° of B=0 of θ of A= of circumgyrate horn θ , o1, O2... Oi... the position that is the centre of turning circle after circling A axis circumgyrate. When can begging a PH10 centre of turning circle to be in either position Oi by the graph, the included angle between the OOi connecting a line of Oi and heart of standard ball ball and OO0, the Aj of circumgyrate horn θ that this horn moves to be in PH10 to circle A axis to positional Oi for centre of turning circle namely. Visible, the ball heart of the centre of turning circle of PH10 and standard ball (heart of the ball that measure a ball) positional relation is opposite, accordingly, we can think the O in the graph is the centre of turning circle of PH10, and O0, O1, O2... Oi... the heart of the ball that measure a ball that for PH10 different circumgyrate angle leaves. Centre of turning circle of such OK and affirmatory PH10 and the measure ball ball heart space of the correspondence below all corner mutual position affects. The builds the each circumgyrate part to describe PH10 accurately size that fiducial coordinate is 2 circumgyrate, fiducial coordinate is the circumgyrate that must build PH10, get the absolutely circumgyrate point of view of PH10 from which. Want to build fiducial coordinate department to want to decide actual rotor B and A above all. The direction connecting a line of centre of turning circle of the PH10 when the way that sees B spindle from the exterior and θ A=0 ° and heart of the ball that measure a ball is consistent, measure the presence of a mounting error as a result of the sum of errors that decide part actually, centre of turning circle of the PH10 when θ A=0 ° connects line and B axis with what measure ball ball heart not coincide, if graph 4(a) place is shown, o is the centre of turning circle of PH10, the place of ball head center is measured when O0 is ° of B=0 of θ A= θ . Right now, make PH10 winds a week of B axis circumgyrate, draft 48 a little bit when measure syncretic round, of Q of this round the centre of a circle and O can consider as even the line B the axis. Graph the builds 　 A axis way that fiducial coordinate is 4 circumgyrate and B axis are vertical, be like graph 4(b) , when θ B=0 ° , the place that ball ball heart measures after PH10 circles A axis circumgyrate is O1, O2... Oi... , allow to take among them a bit Oi, join OOi, OOi and B axis fix one plane, cross O and as perpendicular as this plane can consider as A the axis point-blank. After A axis and B axis are affirmatory, building fiducial coordinate is OxCyAzB. Among them, the direction of YA and A axis is consistent, the direction of ZB and B axis is consistent, the direction of XC is decided by right hand department. The coordinate of heart of the ball that measure a ball of correspondence of place of angle of PH10 either circumgyrate measures machine machine coordinate to fasten next) for Oi(, in OxCyAzB coordinate department, part Oi to 3 reference axis umbriferous the directional number that gets it is {li, mi, ni} , the absolutely corner that circles A axis is: (1) circles the absolutely corner of B axis to be: (2) 　 basis afore-mentioned principles, by formula (1) and (the size of horn of each circumgyrate of 2) demarcate PH10. Place issueing a list is shown measure partial data for place, among them θ A and θ B are spent to give circumgyrate role, θ A and θ B are the absolutely point of view that measures actually, Δ θ A and Δ θ B are the error that decide part. Angle of partial actual measurement and its error watch give angle to measure angle actually to decide B0 of θ of Δ of A of θ of Δ of B of θ of A of θ of B of θ of A of horny error θ .

0 ° 0.

0 ° 0.

0072 ° 0.

0061 ° 0.

430.

367.

5 ° 0.

0 ° 7.

5015 ° 0.

0023 ° 0.

090.

1415.

0 ° 0.

0 ° 15.

0170 ° 0.

0058 ° 1.

020.

3590.

0 ° 7.

5 ° 90.

0051 ° 7.

4788 ° 0.

31-1.

2790.

0 ° 15.

0 ° 90.

0354 ° 14.

9998 ° 2.

12-0.

0190.

0 ° 30.

0 ° 90.

0135 ° 29.

9925 ° 0.

81-0.

4515.

0 ° 45.

0 ° 14.

9732 ° 14.

9974 ° - 1.

61-0.

1622.

5 ° 67.

5 ° 22.

4837 ° 67.

5193 ° - 0.

981.

1660.

0 ° 82.

5 ° 59.

9983 ° 82.

5343 ° - 0.

102.

The repeatability precision that PH10 already mentioned before 063 errors analysis is very tall, that is to say PH10 circles A, B the reappearance of angle of two same circumgyrate is good, because this and photograph of the error that decide part are compared, repeatability error is negligible. Make the circumgyrate angle of one axis changeless now, change the circumgyrate point of view of another axis only, if the watch is medium, ° of your θ B=0, change θ A, right now θ B should is worth to be secured from beginning to end (do not be certainly 0) , and the θ B in the watch each are unequal. Because θ A changes,this is when, PH10 circles A axis circumgyrate not only, and circle B axis and XC axis to have tiny swing. Secure the circumgyrate role that confuses B axis consequently, circle A axis circumgyrate to be able to produce angle deviation in 3 reference axis; Manage together, circle B axis circumgyrate to also can circle A axis and XC axis to have only tiny swing; If circle A, B at the same time two axes circumgyrate, the circumgyrate that circles every axis can be on 3 reference axis generation deviation. The definition is the following 6 corner error: ε X(A): ? The on XC axis corner error when Pi axis circumgyrate. ε Y(A): ? The on YA axis corner error when Pi axis circumgyrate. ε Z(A): ? The on ZB axis corner error when Pi axis circumgyrate. ε X(B): ? The on XC axis corner error when Pi axis circumgyrate. ε Y(B): ? The on YA axis corner error when Pi axis circumgyrate. ε Z(B): ? The on ZB axis corner error when Pi axis circumgyrate. The A of θ of corner error Δ that PH10 is in either pose and Δ θ B are by above 6 errors complex. In PH10 Y(B) of X(B) of the ε when circling A axis circumgyrate only, ε is mixed ε Z(B) is changeless, what Y(A) of ε X(A) , ε and ε Z(A) follow θ A is different and change; Y(A) of X(A) of the ε when circling B axis circumgyrate only, ε and ε Z(A) are changeless, what Y(B) of ε X(B) , ε and ε Z(B) follow θ B is different and change; Circle A, B at the same time Y(B) of X(B) of Z(A) of Y(A) of X(A) of the ε when two axes circumgyrate, ε , ε , ε , ε and ε Z(B) are mixed as θ A of θ B differ to produce change. The experiment proves, the error of horn of the biggest circumgyrate that bypasses two axes of A, B is: Δ θ Amax=2.

68, Δ θ Bmax=2.

24. Additional, the size that PH10 decides horny error and installation pose and place suffer pitching moment size to concern, when installation pose is certain, what get moment of force the bigger error that decide part is bigger. Accordingly, the pose when PH10 is used actually and place suffer pitching moment to must be mixed with the pose when to its the error that decide part is amended pitching moment is identical. CNC Milling CNC Machining