镗刀的正确使用

镗刀安装操作及如何正确使用
THE A750- MULTIFUNCTION II Rigid driving system, for simultaneous setting Two opposite micro spindle adjustment screw
Strong central screw, with tapered shape Coolant through Massive, compact and symmetrical design made from high alloyed steel
ONE GAGE PER HEAD SIZE
VIDEO (Clic on square)
Place the gage (8) over the keys. Adjust each key, Nr 1 first, i.e. starting with the dial located under the reference mark «1 » engraved on the gage (see above picture), until blocks seats against the body. Engage simultaneous mode.
A750 –CHIPS EVACUATION The most important criteria for selection of the proper twin cutter is to ensure that good chip formation and chip evacuation will occur. When you have the choice between two heads covering the same diameter, it is normal to select the one which offers the best rigidity (insert carriers in closed position).Apart when the chips are difficult to evacuated , for instance on a horizontal machine tools, a deep hole, a blind hole, or without coolant.Then select the one offering the highest clearance between the head and the bore.
Symmetrical r 90°
Symmetrical r 90°or r 80°
Staggered Each side takes DOC/2 r 90°
Rough boring, find the suitable solution
Symmetrical Setting - Boring without vibrations
No
Yes
Decrease Vc - Increase Fz
Yes
No
Use smaller radius
Yes
No
Staggered setting
Yes
No
TEST ‚sharp‘ HSS inserts
OK
A750 – MINIMAL DOC Inserts for roughing have often rounded edges. Therefore a minimal DOC is required to avoid a cut refusal, at least larger than nose radius. Depending on materials to cut, the minimal
A750- INDEPENDENT SETTING Independent setting allows to adjust each insert holder separately, for instance to work in staggered position(2 inserts in 2 different cuts). The adjustment from the simultaneous setting to the independent one, is simply achieved by loosen the little screw 2 maintaining the cogwheel engaged on the slotted setting screw.
Maximal DOC
Take in consideration following criterias:
Length of boring bar: a L/D > 5/1 will influence the DOC. With a ratio L/D =5, or greater, reduce the maximal recommended DOC to 15% to 25% of the
ISO CC or SC inserts
Setting mechanism
Massive insert holders
A750- SETTING MECHANISM
GROUND FINE PITCH SETTING SCREW DRIVING KEYS NITRITE COATED CIRCULATING BALL RUNWAY
A750- INSERT CARRIERS MOUNTING When a A750 head is first unpacked, the central screw is in place and the head is set for simultaneous adjustment. A750 boring heads are shipped without the insert holders. They have to be ordered separately.
WASHER FINE SCALE, RESOLUTION 0.1 mm /ø
LIFE GREASED MECHANISM GROUND FINE PITCH SETTING SCREW WITH SPLITTED END
COGWHEELS
COGWHEEL DISENGAGING SCREW
A750- SYNCHRONIZED SETTING
DOC is between 0.5 and 2 mm /diameter.
Minimal DOC
ENLARGED VIEW OF NOSE RADIUS
Chord of arc
Depths of cut A & B
A
B
A750 – MAXIMAL DOC DOC is determined by subtracting the original bore size from the finish hole size by 2. If stock allowance is too large, more than one tool will be required or staggered cutting method may be used. A general rule is : Max. DOC is ½ of insert width. But in optimal conditions (short bar, good chips evacuation, smooth material, rigid machine,…) this value can go up to 2/3.
DRIVING KEYS COGWHEELS SETTING SCREWS
WASHER
Synchronized setting means symmetrical movement of both insert carriers in the same way. Cogwheels, fixed on each setting screw, allow to displace simultaneously the driving keys, fitted in the slots of the insert carriers.The driving keys are strong, nitrite coated,to ensure a proper guiding.Mechanism is dust protected through washers.
VIDEO (Clic on square)
COGWHEEL TO BE DISENGAGED
A750- RESTORE SYNCHRO SETTING With no presetter available, a setting gage is used to locate keys equidistant from centreline of head.
Remove the central screw. Insert holders are placed together in roughly the position they will be when assembled. Drop them down into the slots and over the keys. Make sure the insert holders flat against the body. Reassemble the central screw, but do not fully tighten, for diameter adjustment.
inLeabharlann Baiduert width.
The diameter to bore in regard to the boring head capacity: the maximal DOC stated in above two points is true when the head is set at mid of it’s capacity. When it is set at the maximum or the minimum of it’s capacity, the maximal DOC should be 25% to 35% of the insert width. Chips evacuation: for diameters over 50 mm with a maximal DOC, you will face a high chips flow. It is highly recommended to work horizontally and if possible with coolant to avoid chips jamming. The available machine power: an important DOC requires a high feed rate to brake the chips: a powerful machine is then needed.If the power is not sufficient, you have to reduce the cutting speed.
VIDEO (Clic on square)
Rough boring, SYMMETRIC Vs. STAGGERED
DOC > 1/2 Edge length
No
Yes
L/D >6, Weak machine, Unstable workpiece
No Yes
Through hole
No Yes
SETTING SCREWS WITH SLOTTED END COGWHEEL DISENGAGING SCREW
1
2
1
While holding adjustment dial (2) steady, use disengagement screwdriver to unlock simultaneous mode from opposite side (1). Now turning adjustment dial moves only one insert holder.