Here are some common problems of deep hole machining tools in production.
Existing problems: the aperture increases and the error is large.
1) Cause
The design value of the outer diameter of the reamer is too large or the reaming cutting edge has burrs; Cutting speed is too high; Improper feed or excessive machining allowance; The main deflection angle of reamer is too large; Reamer bending; The cutting edge of reaming is adhered with a chip lump; When grinding, the swing error of reaming cutting edge is out of tolerance; Improper selection of cutting fluid; When installing the reamer, the oil stain on the surface of the taper shank is not cleaned or the taper surface is bruised; After the flat tail of the taper handle is offset and installed into the spindle of the machine tool, the taper of the taper handle interferes with the taper; The main shaft is bent or the main shaft bearing is too loose or damaged; Reamer floating is not flexible; Different from the workpiece, the force of both hands is uneven when reaming the shaft and hand, which makes the reamer shake left and right.
2) Solutions
Reduce the outer diameter of reamer appropriately according to specific conditions; Reduce cutting speed; Adjust the feed rate appropriately or reduce the machining allowance; Properly reduce the main deflection angle; Straighten or discard the bent and unusable reamer; Carefully trim it with oilstone until it is qualified; Control the swing error within the allowable range; Choose cutting fluid with good cooling performance; Before installing the reamer, the oil stain inside the reamer taper handle and the taper hole of the machine tool spindle must be wiped off, and the bump on the conical surface must be polished with an oilstone; Grinding the flat tail of reamer; Adjust or replace the main shaft bearing; Readjust the floating chuck and adjust the coaxiality; Pay attention to correct operation.
Problem: aperture reduction
1) Cause
The design value of reamer outer diameter is too small; The cutting speed is too low; The feed rate is too large; The main deflection angle of reamer is too small; Improper selection of cutting fluid; When sharpening, the worn part of the reamer is not worn off, and the elastic recovery reduces the aperture; When reaming steel parts, the allowance is too large or the reamer is not sharp, which is easy to produce elastic recovery, so that the aperture is reduced and the inner hole is not round, and the aperture is unqualified.
2) Solutions
Change the outer diameter of reamer; Properly increase the cutting speed; Reduce the feed rate appropriately; Properly increase the main deflection angle; Choose oil-based cutting fluid with good lubricating performance; Exchange reamers regularly and grind the cutting part of reamer correctly; When designing the reamer size, the above factors should be considered, or the value should be taken according to the actual situation; Make experimental cutting, take appropriate allowance, and sharpen the reamer.
Existing problem: the reamed inner hole is not round
1) Cause
The reamer is too long and the rigidity is insufficient, causing vibration during reaming; The main deflection angle of reamer is too small; Narrow cutting edge band; Reaming allowance deviation; There are notches and cross holes on the inner hole surface; There are sand holes and pores on the hole surface; The spindle bearing is loose, there is no guide sleeve, or the clearance between the reamer and the guide sleeve is too large, and the workpiece is deformed after removal due to the clamping of the thin-walled workpiece is too tight.
2) Solutions
Reamers with unequal tooth pitch can be used for reamers with insufficient rigidity, and the installation of reamers should adopt rigid connection to increase the main deflection angle; Select qualified reamers and control the hole position tolerance of the pre machining process; Reamers with unequal tooth pitch and longer and more precise guide sleeves are used; Select qualified blank; When using equal pitch reamers to ream more precise holes, the spindle clearance of the machine tool should be adjusted, and the fitting clearance of the guide sleeve should be higher, or appropriate clamping methods should be used to reduce the clamping force.
Existing problems: there are obvious edges on the inner surface of the hole
1) causes
Reaming allowance is too large; The back angle of the reamer cutting part is too large; Reaming cutting edge band is too wide; There are pores and sand holes on the surface of the workpiece and the spindle runout is too large.
2) Solutions
Reduce reaming allowance; Reduce the back angle of the cutting part; Width of grinding blade belt; Select qualified blank; Adjust the spindle of the machine tool.