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Fabrication and evaluation of HDDS cells. Mechanical evaluation of HDDS cells and estimation toward HDDS1 (H60VG3S18). Dec. 10—12, ISG9, KEK T. Kume, KEK (Presented by T. Higo). HDDS1 Machining procedure 1/3. 1. Cut (logging) 2. Rough cut (turning) finish allowance of 0.2-0.5 mm - PowerPoint PPT Presentation
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Fabrication and evaluation of HDDS cells
Dec. 10—12, ISG9, KEK
T. Kume, KEK(Presented by T. Higo)
Mechanical evaluation of HDDS cells and
estimation toward HDDS1 (H60VG3S18)
HDDS1 Machining procedure 1/3
1. Cut (logging)2. Rough cut (turning)– finish allowance of 0.2-0.5 mm
3. Anneal– at 500oC, 2 hours by N2 substitution or vacuum furnace
4. Machine tuning holes (drilling)5. Finish OD (turning)– with a soft jaw
6. Semi-finish cup side & finish nesting ID (turning) – with a collet chuck (tong hold of ~3 mm)– constant circumferential speed (2000 rpm, 20-30 m/rev)– one-stroke-turning for ellipse & cup end– start cutting from the ellipse top (2a)– semi-finishing with an allowance of 20 m on end surface– Finish inside cup
HDDS1 Machining procedure 2/3
7. Semi-finish disk side & finish nesting OD (turning)– with a collet chuck (tong hold of ~7 mm)– check the deflection of the disk end (< 4 m)– constant circumferential speed (2000 rpm, 20 - 30 m/rev)– start cutting from the ellipse top (2a)– semi-finishing with an allowance of 20 m
8. Dimension check9. Milling– 8o relief angle of milling tool(R0.5-flat <12o)– large radius of tool path (R2 and 2b <5o)
10. Finish cup side (turning)– finish end surface
11. Stamp the number on the disk side
HDDS1 Machining procedure 3/3
12. Finish disk side (turning)– same as “10” but together with the elliptical part
13. Clean & check dimensions
14. Ultraprecision turning of the both end surfaces – at KEK
Fabrication status
Quality estimation on HDDS cell fabrication in studying test cells for following two cases
1. HDDS0
dia. 45mm 6 replacement cells for H60VG3N
2. HDDS1
dia. 61mm H60VG3S18
Measurement positionsfor turning evaluation –radial direction
Turning error-radial direction(samples: HDDS1-052-1,2,4 for cutting test)
Tolerance: +/-0.02 mm
Accuracy: +/-0.01 mm
Repeatability: +/-0.005 mm
Limited by accuracy of lathe
0.0
1.0
2.0
3.0
4.0
5.0
6.0
-0.03 -0.02 -0.01 0 0.01 0.02 0.03
ODNest-ID2a2a+0.1(disk side)2a-0.1(cup side)2b
Error (mm)
Measurement positions
for Turning evaluation -axial direction
Turning Error-axial direction(samples: HDDS1-052-1,2,4 for cutting test)
Tolerance: p +/-0.01 mm
t +/-0.02 mm
Accuracy: +/-0.02 mm
Limited by operator skill, caused by scratch correction after finish
0.0
2.0
4.0
6.0
8.0
10
-0.03 -0.02 -0.01 0 0.01 0.02 0.03
tp
Error (mm)
Measurement positions for Milling evaluation
Milling Error(samples: HDDS1-052-1,2,4 for cutting test)
0.0
2.0
4.0
6.0
8.0
10
12
-0.03 -0.02 -0.01 0 0.01 0.02 0.03
hHOM
Error (mm)
Tolerance: h +/- 0.02 mm
HOM +/-0.05 mm
Accuracy: ~0.02 mm
Repeatability: ~0.005 mm
h: Caused by work alignment error
HOM: tool diam.
Angle measurement positions
r=2r=b
r=b
r=b- del ta
l i ne
3deg
Sepa
r at i
on
Mi l l i ng tool path
Milling tool path Intersection between 2b and r2
Escape circle radius 2mm for HDDS0 (45mm dia.)
9mm for HDDS1 (61mm dia.)
2b – r2 Typical in HDDS0
Angle between R2 and 2b(samples: HDDS0-026-0, 7 for RF test,
and HDDS0-026-1 for SLAC)
0.0
1.0
2.0
3.0
4.0
5.0
0 5 10
Angle (deg)
Tolerance: <= 5 deg
Results: 5-11 deg
Caused by work alignment error and tool path along an escaping circle with radius 2mm
Shift to escaping circle radius at 9mm for HDDS1, close to “b”.
R0.5—flat tool
Milling radius tool for HDDS0
Tool reliaf angle was changed to 8 degrees for HDDS1
In case of HDDS0Too severe depth control to get rid of edge mark at end of 3 degree wing
Escape towards less cutting (floating) side
Crossing at circular part
Uncontrollable crossing angle
Between flat surface to r0.5mm rounding
R0.5 – flat shape in HDDS0RF test cell #7 cup side
Elliptical
Slot end point
R0.5
Angle between R0.5 and flat(samples: HDDS0-026-0, 7 for RF test,
and HDDS0-026-1 for SLAC)
0.0
1.0
2.0
3.0
4.0
5.0
0 4 8 12 16 20 24
cup sidedisk side
Angle (deg)
Tolerance: <= 12 deg
Caused by tool positioning (axial) error , relief angle of the tool (3 deg), and correction turning after finish against scratch
Change relief angle to 8 deg for HDDS1
Elliptical shape and connectionRF test cell #7 cup side connection
2a top
Elliptical to flat
Angle between ellipse and flat end(samples: HDDS0-026-0, 7 for RF test,
and HDDS0-026-1 for SLAC)
0.0
1.0
2.0
3.0
4.0
5.0
0 1 2 3 4 5
cup sidedisk side
Angle (deg)
Tolerance: <= 1deg
Results: 1-3 deg
Limited by accuracy of lathe and/or additional flat-part cut without continuous cutting to elliptical part
For HDDS1, require continuous cutting between flat part and elliptical part
Turning roughness
Elliptical shape Ry=1.7trace due to tool shape?
Flat part Ry=0.5
RF test cell #7 cup side
Roughness of the turned surface(samples: HDDS0-026-00, 0, 7 for RF test,
HDDS0-026-1 for SLAC,HDDS1-052-4 for cutting test)
Tolerance: Ry 0.7 m
Roughness: ~0.6 m (straight, 1D), ~1.6 m (curve, 2D)
Difference of ~1.0 m is caused by tool periphery shape
0.0
1.0
2.0
3.0
4.0
5.0
0 0.5 1 1.5 2
Straight (1D) turning-cup endStraight turning-disk endCurve (2D) turning-cup sideCurve turning-disk side
Ry roughness (m)
0.7
Milling roughness
Roughness Ry 1.6m
Wave 3m/2mm
Slot end turning point with r=1.1mm
Roughness of the milled surface(sample: HDDS0-026-7 for RF test)
0.0
1.0
2.0
3.0
4.0
5.0
0 0.5 1 1.5 2
Milling-side cutMilling-face(R) cut
Ry roughness (m)
Tolerance: Ry 1 m
Results: 1.3-1.9 m
(seems to be) caused by tool mark
Disk flatness(samples: HDDS1-053-1,2 and
HDDS1-052-1,2,4 for cutting test)
Tolerance: 2 m
More than 30 pts by CMM
Result: 1—3 m
(seems to be) limited by lathe accuracy and deformation due to chucking and turning0.0
1.0
2.0
3.0
4.0
0 0.001 0.002 0.003 0.004 0.005
Turning onlyCompelete machining
Flatness (mm)
Cup-side flatness(samples: HDDS1-053-1,2 and
HDDS1-052-1,2,4 for cutting test)
Tolerance: 2 m
More than 30 pts by CMM
Result: 2—3 m
(seems to be) limited by lathe accuracy and deformation due to chucking
(“Turning only” is with copper without annealing)
0.0
1.0
2.0
3.0
4.0
0 0.001 0.002 0.003 0.004 0.005
Turning only
Compelete machining
Flatness (mm)
Parallelism between disk and cup (samples: HDDS1-053-1,2 and
HDDS1-052-1,2,4 for cutting test)
Tolerance: 5 m
Result: 2—5 m
(seems to be) limited by lathe accuracy and chucking
0.0
1.0
2.0
3.0
4.0
0 0.001 0.002 0.003 0.004 0.005
Turning onlyComplete machining
Parallelness (mm)
Conclusion to make H60VG3S18
•Mechanical dimension: OK within tuning range
•Junction angle: should be OK
•Surface finish: Acceptable
•Surface flatness: Improve with diamond turning at KEK