Common problems with tools during deep hole machining

In the deep hole processing process, the dimensional accuracy, surface quality and tool life of the workpiece are often encountered. How to reduce or even avoid these problems is an urgent problem we need to solve. Here are some of the more common deep hole machining tools in production.

There is a problem: the aperture is increased, the error is large

1) Cause

The reamer outer diameter dimension design value is too large or the hinge cutting edge has burrs; the cutting speed is too high; the feed rate is improper or the machining allowance is too large; the reamer main deflection angle is too large; the reamer is bent; the hinge cutting edge is stuck Attached to the cutting edge; the sharpening of the cutting edge of the cutting edge is too poor; the cutting fluid is not suitable for selection; when the reamer is installed, the oil on the surface of the taper shank is not wiped clean or the cone is bumped; the flat tail of the taper shank is loaded The rear taper shank of the machine tool spindle has interference; the spindle is bent or the spindle bearing is too loose or damaged; the reamer is not flexible; when the shaft is different from the workpiece and the hand is reamed, the force of the two hands is uneven, so that the reamer shakes left and right.

2) Solution

According to the specific circumstances, reduce the outer diameter of the reamer; reduce the cutting speed; adjust the feed amount or reduce the machining allowance; properly reduce the lead angle; straighten or scrap the curved reamer; carefully repair with the oil stone Qualified; control the swing within the allowable range; select the cutting fluid with better cooling performance; before installing the reamer, the reamer taper shank and the oil splash inside the taper hole of the machine tool must be cleaned, and the cone surface is bumped with oil stone; Grind the reamer flat tail; adjust or replace the spindle bearing; re-adjust the floating chuck and adjust the coaxiality; pay attention to correct operation.

There is a problem: the aperture is reduced

1) Cause

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 yaw angle of the reamer is too small; the cutting fluid is not properly selected; the wear of the reamer is not worn off during sharpening, and the elastic recovery makes the aperture Reducing; when reaming steel, the margin is too large or the reamer is not sharp, it is easy to produce elastic recovery, the aperture is reduced and the inner hole is not round, and the aperture is unqualified.

2) Solution

Replace the outer diameter of the reamer; appropriately increase the cutting speed; appropriately reduce the feed rate; appropriately increase the lead angle; select the oily cutting fluid with good lubrication performance; interchange the reamer regularly, correct the cutting part of the reamer; design the hinge When the size of the knife is used, the above factors should be considered, or the value should be taken according to the actual situation; for the experimental cutting, take the appropriate margin and sharpen the reamer.

There is a problem: the hinged inner hole is not round

1) Cause

The reamer is too long, the rigidity is insufficient, and the vibration occurs when reaming; the main yaw angle of the reamer is too small; the hinge cutting edge is narrow; the reaming margin is biased; the inner hole surface has a notch and a cross hole; the hole surface has blisters and air holes; 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 due to the tight clamping of the thin-walled workpiece.

2) Solution

The reamer with insufficient rigidity can adopt the reamer with unequal pitch. The reamer should be installed with rigid connection to increase the lead angle. The qualified reamer is used to control the hole position tolerance of the pre-processing. The unequal pitch is adopted. Reamer, use longer, more precise guide sleeve; use qualified blank; when reaming more precise holes with equal pitch reamer, adjust the machine shaft clearance, the matching clearance of guide sleeve should be higher or appropriate The clamping method reduces the clamping force.

There is a problem: the inner surface of the hole has a distinct facet

1) Cause

The reaming allowance is too large; the back angle of the reamer cutting part is too large; the reaming cutting edge is too wide; the surface of the workpiece has pores, blisters, and the spindle pitch is too large.

2) Solution

Reduce the reaming allowance; reduce the back angle of the cutting part; trim the width of the cutting edge; select the qualified blank; adjust the machine tool spindle.