Common defects and treatment methods of internal grinding

1、 There are vibration marks on the workpiece surface of internal grinder, the surface roughness value is large, and the surface is burned.

Reason for resolution:
1. The diameter of the internal grinding wheel of the internal grinder is small;
2. Due to the looseness of the head spindle of the internal grinder, the bending of the grinding wheel spindle of the internal grinder and the non-circular dressing of the grinding wheel, strong vibration occurs, resulting in ripples on the workpiece surface.
3. The internal grinding wheel of the internal grinder is blocked;
4. Poor heat dissipation;
5. The grinding wheel grain of the internal grinder is too fine, the hardness is high or the dressing is not timely;
6. The feed rate of internal grinder is large, and the grinding heat increases.

Preventive measures:
1. The grinding wheel diameter of internal grinder shall be larger as far as possible.
2. To adjust the bearing clearance, the main thing is to correctly trim the grinding wheel of internal grinder to reduce runout and vibration.
3. Select the grinding wheel with coarse strength, loose structure and soft hardness to make it self sharpening;
4. Select the coarse and soft grinding wheel of internal grinder and trim it in time;
5. When grinding with internal grinder, sufficient grinding fluid shall be supplied;
6. Reduce the feed rate of the internal grinder.

2、 When grinding a workpiece with an internal grinder, the workpiece has a bell mouth.

Reason for resolution:
1. Uneven feed of internal grinder;
2. The grinding wheel of internal grinder has taper;
3. The grinding wheel shaft of the internal grinder is slender.
Preventive measures:
1. Properly control the dwell time and adjust the length of the internal grinding wheel shaft of the internal grinding machine, which shall not exceed half of the width of the grinding wheel;
2. Correct dressing of grinding wheel of internal grinder;
3. Select the thickness of the grinding wheel shaft according to the size and length of the inner hole of the workpiece.

3、 Conical hole defect in internal grinding

Reason for resolution:
1. The adjustment angle of internal grinder head frame is incorrect;
2. The longitudinal feed of the internal grinder is uneven and the transverse feed is too large;
3. The extension of grinding wheel shaft of internal grinder is unequal at both ends;
4. The grinding wheel of internal grinder is seriously ground.

Preventive measures:
1. Readjust the angle of the head frame of the internal grinder;
2. Reduce the feed rate of internal grinder;
3. Adjust the extension of grinding wheel of internal grinder to make it equal;
4. Timely repair the grinding wheel of NC internal grinder.

4、 The roundness error and internal and external coaxiality error after internal grinding are too large

Reason for resolution:
1. The workpiece of the internal grinder is not firmly clamped and moves;
2. Elastic deformation occurs due to too tight clamping of thin-walled workpiece to be processed by internal grinder;
3. Inaccurate adjustment of internal grinder leads to excessive coaxiality error of internal and external surfaces;
4. The chuck of the internal grinder is loose on the main shaft, and the clearance between the main shaft and bearing of the internal grinder is large.

Preventive measures:
1. Fasten the workpiece of internal grinder;
2. The clamping force shall be appropriate;
3. Be careful when adjusting the internal grinder;
4. Adjust the tightness and the clearance between the spindle and bearing of the internal grinder.

5、 Perpendicularity error between end face and hole occurs in internal grinding

Reason for resolution:
Workpiece clamping of internal grinder is not firm;
Inaccurate alignment of internal grinder;
When grinding the end face of the internal grinder, the feed is large, resulting in the loosening of the workpiece.

Precautions:
Before the internal grinder works, the workpiece shall be clamped and grinded after confirmation;
Be careful in the alignment process;
Try to control the feed rate of the internal grinder when grinding the end face.

6、 Spiral marks appear in the grinding process of internal grinder.
Reason for resolution:
The longitudinal feed of internal grinder is too fast;
The internal grinding wheel of internal grinder is passivated in the process of use;
The extension shaft of the internal grinder is bent.

Precautions:
Reduce the table speed of internal grinder;
In the process of internal grinding, the grinding wheel shall be trimmed in time;
Replace the extension shaft with good rigidity.