In the process of reaming, many problems such as out-of-tolerance hole diameter and high surface roughness of the inner hole often occur.

Cause of the problem

The aperture increases, the error is large

The design value of the outer diameter of the reamer is too large or there are burrs on the edge of the reamer; 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; Cutting edge; the reamer edge swing is out of tolerance during sharpening; the choice of cutting fluid is not suitable; the oil stain on the surface of the taper shank is not wiped clean or the taper surface is bumped when the reamer is installed; Taper shank cone interference; the main shaft is bent or the main shaft bearing is too loose or damaged; the reamer is not flexible; it is not in the same axis as the workpiece;

Aperture reduction

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 leading angle of the reamer is too small; the choice of cutting fluid is not suitable; Shrinkage; when reaming steel parts, if the margin is too large or the reamer is not sharp, it is easy to produce elastic recovery and reduce the aperture; if the inner hole is not round, the aperture is unqualified.

Reamed inner hole is not round

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 reamer edge band is narrow; the reaming hole allowance is partial; there are gaps and cross holes on the surface of the inner hole; The bearing is loose, there is no guide sleeve, or the gap between the reamer and the guide sleeve is too large; because the thin-walled workpiece is clamped too tightly, the workpiece is deformed after removal.

The inner surface of the hole has obvious facets

The reaming allowance is too large; the relief angle of the cutting part of the reamer is too large; the reamer edge is too wide; there are pores and sand holes on the surface of the workpiece; the spindle swing is too large.

Inner hole surface roughness value is high

The cutting speed is too high; the choice of cutting fluid is not suitable; the main deflection angle of the reamer is too large, and the cutting edge of the reamer is not on the same circumference; the reaming allowance is too large; the reaming allowance is uneven or too small, and the local surface is not reamed; The cutting part of the reamer is out of tolerance, the cutting edge is not sharp, and the surface is rough; the reamer margin is too wide; the chip removal is not smooth when reaming; the reamer is excessively worn; the reamer is bruised, and the cutting edge has burrs or chipping; Built-up edge on the cutting edge; due to the material, it is not suitable for zero or negative rake angle reamers.

Low service life of the reamer

The material of the reamer is not suitable; the reamer is burned during sharpening; the choice of cutting fluid is not suitable, and the cutting fluid cannot flow smoothly at the cutting place; the surface roughness value of the reamer after sharpening is too high.

The position accuracy of the reamed hole is out of tolerance

The guide sleeve is worn; the bottom end of the guide sleeve is too far away from the workpiece; the length of the guide sleeve is short and the precision is poor; the spindle bearing is loose.

Reamer tooth chipping

The reaming allowance is too large; the hardness of the workpiece material is too high; the cutting edge swing is too large, and the cutting load is uneven; the main deflection angle of the reamer is too small, which increases the cutting width; when reaming deep holes or blind holes, there are too many chips , and not removed in time; the teeth of the knife have been worn out during sharpening.
Reamer handle broken
The reaming allowance is too large; when reaming the taper hole, the distribution of rough and fine reaming allowance and the selection of cutting amount are not appropriate; the reamer tooth space is small, and the chips are blocked.
The center line of the hole after reaming is not straight
Drilling deflection before reaming, especially when the hole diameter is small, due to the poor rigidity of the reamer, the original curvature cannot be corrected; the main deflection angle of the reamer is too large; poor guidance makes the reamer easy to deviate during reaming Direction; the inverted cone of the cutting part is too large; the reamer is displaced in the gap in the middle of the intermittent hole; when hand reaming, too much force in one direction forces the reamer to deflect to one end, destroying the verticality of the reaming hole.
solution

The aperture increases, the error is large

Properly reduce the outer diameter of the reamer according to the specific situation; reduce the cutting speed; properly adjust the feed rate or reduce the machining allowance; properly reduce the main deflection angle; straighten or scrap the unusable bent reamer; Qualified; control the swing within the allowable range; choose a cutting fluid with better cooling performance; before installing the reamer, the reamer taper handle and the inside of the machine tool spindle taper hole must be wiped clean, and the taper surface with bumps should be smoothed with oil stone; Grind the flat tail of the reamer; adjust or replace the spindle bearing; re-adjust the floating chuck and adjust the coaxiality; pay attention to the correct operation.

Aperture reduction

Change the outer diameter of the reamer; properly increase the cutting speed; properly reduce the feed rate; The above factors should be taken into consideration when selecting the size of the knife, or the value should be taken according to the actual situation; for experimental cutting, take an appropriate margin and sharpen the reamer.
Reamed inner hole is not round
Reamers with insufficient rigidity can use reamers with unequal tooth pitches. The installation of the reamers should be rigidly connected to increase the lead angle; select qualified reamers to control the hole position tolerance in the pre-processing process; use unequal tooth pitches For reamers, use longer and more precise guide sleeves; select qualified blanks; when using equal pitch reamers to ream more precise holes, the clearance of the machine tool spindle should be adjusted, and the matching clearance of the guide sleeves should be higher; The clamping method reduces the clamping force.
The inner surface of the hole has obvious facets
Reduce the reaming allowance; reduce the back angle of the cutting part; repair the width of the edge band; select qualified blanks; adjust the machine tool spindle.
Inner hole surface roughness value is high
Reduce the cutting speed; select cutting fluid according to the processing material; appropriately reduce the main deflection angle, correctly sharpen the reamer edge; appropriately reduce the reaming allowance; improve the position accuracy and quality of the bottom hole before reaming or increase the reaming allowance; Select a qualified reamer; repair the width of the edge band; reduce the number of teeth of the reamer according to the specific situation, increase the space of the chip pocket or use a reamer with an edge angle to make chip removal smooth; replace the reamer regularly, and grind the During the sharpening, use and transportation of the reamer, protective measures should be taken to avoid bruising; for the bruised reamer, repair the bruised reamer with extra fine oil stone, or replace the reamer ; Use oilstone to trim to pass, using a reamer with a rake angle of 5° to 10°.

Low service life of the reamer

Select the reamer material according to the processing material, and you can use a carbide reamer or a coated reamer; strictly control the cutting amount of sharpening to avoid burns; often choose the cutting fluid correctly according to the processing material; often remove the chips in the chip groove, use enough Cutting fluid under pressure, after fine grinding or grinding to meet the requirements.
The position accuracy of the reamed hole is out of tolerance
Regularly replace the guide sleeve; lengthen the guide sleeve to improve the matching accuracy between the guide sleeve and the reamer gap; timely repair the machine tool and adjust the spindle bearing clearance.

Reamer tooth chipping

Modify the pre-processing hole size; reduce the hardness of the material or use a negative rake angle reamer or carbide reamer; control the swing error within the acceptable range; increase the main declination angle; pay attention to timely removal of chips or use a reamer with an inclination angle ; Pay attention to the quality of sharpening.
Reamer handle broken
Modify the pre-processing aperture size; modify the allowance distribution, choose the cutting amount reasonably; reduce the number of reamer teeth, increase the chip space or grind the cutter tooth gap to one tooth.
Centerline of hole after reaming is not straight
Increase the reaming or boring process to correct the hole; reduce the main deflection angle; adjust the appropriate reamer; replace the reamer with the guide part or the lengthened cutting part; pay attention to the correct operation.