April 12, 2021
FAQ of CNC machining center
1. The aperture increases and the error is large
1) Causes
The results show that the design value of the outer diameter of the reamer is too large or the reaming cutting edge has burr; the cutting speed is too high; the feed rate is improper or the machining allowance is too large; the main deflection angle of the reamer is too large; the reamer is bent; the chip lump is adhered on the reaming cutting edge; the swing error of the reaming cutting edge is out of tolerance during grinding; the selection of cutting fluid is inappropriate; the oil stain on the taper shank surface is not cleaned or the taper surface is bumped when the reamer is installed; After the flat tail of the taper shank is installed into the spindle of the machine tool, the taper of the taper shank interferes; the spindle is bent or the bearing of the spindle is too loose or damaged; the reamer floats inflexibly; different from the workpiece, the force of the two hands is not uniform when reaming the shaft and hand, which makes the reamer shake left and right.
2) Solutions
According to the specific situation, reduce the outer diameter of the reamer; reduce the cutting speed; adjust the feed rate or reduce the machining allowance properly; reduce the main deflection angle properly; straighten or scrap the bending reamer that can not be used; carefully trim the reamer with the oilstone; control the swing within the allowable range; select the cutting fluid with better cooling performance; Before installing the reamer, the oil stain inside the reamer taper shank and the taper hole of the machine tool spindle must be cleaned, and the bumps on the taper surface shall be polished with oilstone; the flat end of the reamer shall be polished; the spindle bearing shall be adjusted or replaced; the floating chuck shall be readjusted and the coaxiality shall be adjusted; and the correct operation shall be paid attention to.
2. The aperture is reduced
1) Causes
The results show that the design value of the outer diameter of the reamer is too small; the cutting speed is too low; the feed rate is too large; the main deflection angle of the reamer is too small; the selection of cutting fluid is not appropriate; when grinding, the worn part of the reamer is not worn off, and the elastic recovery reduces the hole diameter; when reaming steel parts, if the allowance is too large or the reamer is not sharp, it is easy to produce elastic recovery, which reduces the hole diameter, and the inner hole is not round, and the hole diameter is not qualified. 2) Solutions
Change the outer diameter of the reamer; increase the cutting speed properly; reduce the feed rate properly; increase the main deflection angle properly; select the oil-based cutting fluid with good lubrication performance; exchange the reamer regularly and grind the cutting part of the reamer correctly; consider the above factors or take the value according to the actual situation when designing the size of the reamer; make experimental cutting and take the appropriate allowance to sharpen the reamer.
3. The reamed inner hole is not round
1) Causes
The results show that the reamer is too long, the rigidity is insufficient, and vibration occurs during reaming; the main deflection angle of the reamer is too small; the reaming cutting edge is narrow; the reaming allowance is partial; there are defects and fork holes on the surface of the inner hole; there are sand holes and air holes on the surface of the hole; the spindle bearing is loose, there is no guide sleeve, or the fit clearance between the reamer and the guide sleeve is too large, and the workpiece is deformed after unloading due to the tight clamping of the thin-walled workpiece.
2) Solutions
The reamer with insufficient rigidity can adopt the reamer with unequal pitch. The installation of the reamer should adopt rigid connection to increase the main deflection angle. The qualified reamer should be selected to control the hole position tolerance in the pre-processing process. The unequal pitch reamer should be adopted to adopt the longer and more precise guide sleeve. The qualified blank should be selected; When the equal pitch reamer is used to ream more precise holes, the spindle clearance of the machine tool should be adjusted, the matching clearance of the guide sleeve should be higher, or the appropriate clamping method should be adopted to reduce the clamping force.
