Common problems and solutions of grinding wheel in the process of grinding

Published: 2020-06-18 Publisher: FUNIK R&D Center

Grinding is a processing method of removing excess materials from the workpiece with super abrasives, which can process materials of any hardness. As a traditional machining model, it can obtain high workpiece precision and surface quality, high processing efficiency and low cost. It occupies a very high proportion in the field of advanced manufacturing. Different grinding methods will produce different grinding defects in the application process, and the most influential factor on grinding defects is grinding wheel. This paper describes in detail the defects caused by the specific grinding wheel factors and the corresponding dressing methods, as shown in the table below.

Table 1 Common problems and solutions of grinding wheel in the process of grinding

Serial number

Name of grinding method

Grinding defect name

Grinding defects caused by grinding wheel factors

Dressing method

1

External circular grinding

Straight ripples occur on the surface of the workpiece

Poor balance

Correctly balance grinding wheel

2

External circular grinding

Straight ripples occur on the surface of the workpiece

Too high or uneven hardness

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

3

External circular grinding

Straight ripples occur on the surface of the workpiece

Have been used blunt, not sharp, uneven wear

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time.

4

External circular grinding

Straight ripples occur on the surface of the workpiece

The newly trimmed grinding wheel is not sharp

If the dressing is too fine or the diamond has been worn, choose the correct dressing method and dosage according to the grinding requirements

5

External circular grinding

There is a spiral shape on the surface of the workpiece

The hardness of the grinding wheel is too high and the dressing of the grinding wheel is too fine

The grinding wheel should be selected correctly according to the characteristics of the workpiece and the grinding requirements and the selection rules of the grinding tool. Select correct dressing method and dosage according to grinding requirements

6

External circular grinding

There is a spiral shape on the surface of the workpiece

The thermal deformation of machine tool is unstable when dressing grinding wheel

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

7

External circular grinding

There is a spiral shape on the surface of the workpiece

The dressing is not timely, the wear is not uniform, and the grinding fluid is insufficient when dressing the grinding wheel

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

8

External circular grinding

The surface of the workpiece is brushed and scratched

Shedding of abrasive

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

9

External circular grinding

The surface of the workpiece is brushed and scratched

Improper selection of abrasive and grain size of grinding wheel

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

10

External circular grinding

The surface of the workpiece is brushed and scratched

Empty abrasive left or embedded on the surface after dressing the grinding wheel

When grinding softer metals and non-ferrous metals with coarse-grained grinding wheels, the specimens should be ground first so that the protruding abrasives fall off before grinding

11

External circular grinding

Workpiece surface burn

The hardness is too hard or the grain size is too fine

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

12

External circular grinding

Workpiece surface burn

Improper selection of abrasives and bond

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

13

External circular grinding

Workpiece surface burn

The dressing is too fine and the grinding wheel is blunt and not trimmed in time

According to the grinding requirements, the correct dressing method and dosage should be selected, and the characteristics of the workpiece and the changing law of precision should be grasped and the grinding wheel should be trimmed in time

14

External circular grinding

The workpiece is tapered

Poor finishing, uneven wear or sharpness

According to the grinding requirements, the correct dressing method and dosage should be selected, and the characteristics of the workpiece and the changing law of precision should be grasped and the grinding wheel should be trimmed in time

15

External circular grinding

The workpiece is in the shape of a drum or a saddle

 

Poor forming accuracy

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

16

External circular grinding

The workpiece is in the shape of a drum or a saddle

 

The grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

17

External circular grinding

The surface of the workpiece is brushed and scratched

The corner is worn or the busbar is not straight

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

18

External circular grinding

The verticality of the end face of the workpiece is over-poor

The contact between the end face of the grinding wheel and the workpiece is too large

Trim the grinding wheel to reduce the contact surface and select the appropriate grinding wheel

19

External circular grinding

The verticality of the end face of the workpiece is over-poor

The wear of grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

20

External circular grinding

Workpiece roundness error

The grinding wheel is not sharp or worn unevenly

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

21

Internal circular grinding

Straight ripples occur on the surface of the workpiece

The connecting shaft is long and thin, and the rigidity is poor

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

22

Internal circular grinding

Straight ripples occur on the surface of the workpiece

The grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

23

Internal circular grinding

Straight ripples occur on the surface of the workpiece

Vibration caused by too large diameter of grinding wheel

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

24

Internal circular grinding

Straight ripples occur on the surface of the workpiece

The vibration is caused by the excessive connection length between the grinding wheel and the workpiece

grinding wheel to reduce the contact surface and select the appropriate grinding wheel

25

Internal circular grinding

There is a spiral shape on the surface of the workpiece

Bad contact between grinding wheel and workpiece

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

26

Internal circular grinding

The surface of the workpiece is brushed and scratched

The contact area between grinding wheel and workpiece is too large

Trim the grinding wheel to reduce the contact surface and select the appropriate grinding wheel

27

Internal circular grinding

The workpiece is tapered

The hardness of grinding wheel is too low

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

28

Internal circular grinding

The workpiece shows taper and burns on the workpiece surface

The grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

29

Internal circular grinding

Workpiece surface burn

The diameter of grinding wheel is too large

Reduce the diameter of tested wheel

30

Internal circular grinding

The workpiece is in the shape of a trumpet

When there is a through-hole of countersunk grooves in the middle of grinding,

 the groove is in the shape of a trumpet due to the insufficient width of the grinding wheel

Increase the width of grinding wheel

31

Internal circular grinding

The workpiece is in the shape of a trumpet

When grinding the short shoulder hole, the grinding wheel comes out of the workpiece too much and causes the trumpet shape

Choose a narrower grinding wheel or trim the diameter of the passing part of the grinding wheel a little smaller.

32

Internal circular grinding

The workpiece is in the shape of a trumpet

When grinding the inner hole with keyway, the groove edge angle is caused because the grinding wheel is too wide.

Appropriately reduce the width of the grinding wheel or embed a cushion (Bakelite or metal) in the workpiece slot

33

Plane mill

Ripples occur on the surface of the workpiece

Grinding wheel  is imbalance

Correctly balance grinding wheel

34

Plane mill

Ripples occur on the surface of the workpiece

The hardness of grinding wheel is too high

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

35

Plane mill

Ripples occur on the surface of the workpiece

Uneven hardness on the circumferential surface of the grinding wheel

Select high quality grinding wheel

36

Plane mill

There are ripples on the workpiece surface and straight marks on the workpiece surface

The grinding wheel has been used blunt, not sharp, and the grinding wheel has been used blunt, not sharp

The characteristics of the workpiece and the law of precision change should be mastered, and the grinding wheel should be trimmed in time, and the characteristics of the workpiece and the law of precision change should be mastered

37

Plane mill

Workpiece surface burn

The grain size is too fine or the hardness is too high

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

38

Plane mill

Workpiece surface burn

The grinding wheel is  obtuse and not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

39

Plane mill

Workpiece surface burn

Grinding wheel dressing is too fine

Choose the correct dressing method and dosage according to the grinding to be repaired

40

Plane mill

The workpiece squashes the horn, or the angle or side of the workpiece is in the shape of a horn, and the parallelism or flatness of the two surfaces of the workpiece is over-difference

Improper selection of grinding wheel

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

41

Plane mill

The workpiece squashes the horn, or the angle or side of the workpiece is in the shape of a horn, and the parallelism or flatness of the two surfaces of the workpiece is over-difference

The grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

42

Centerless mill

Workpiece roundness error

The grinding wheel is not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

43

Centerless mill

Workpiece roundness error

The surface of the guide wheel is not clean

Clean the surface of the guide pulley in time

44

Centerless mill

Workpiece roundness error

The guide pulley is not round or the working time is too long to lose the circle

Pay attention to timely repair

45

Centerless mill

The workpiece is prismatic and round

The imbalance between grinding wheel and guide wheel is too large

Rebalance grinding wheel and guide wheel

46

Centerless mill

Workpiece straightness error

The grinding wheel is too soft and poorly trimmed during cut-in grinding

Select the harder grinding wheel, pay attention to timely dressing, reduce the feed rate, increase the number of polishing times, adjust the dresser position according to the taper direction of the workpiece, and re-trim the grinding wheel

47

Centerless mill

Workpiece cylindricity error

The hardness of the grinding wheel is too low during cut-in grinding

Choose a harder grinding wheel, pay attention to timely dressing, reduce the feed rate, and increase the number of polishing times

48

Centerless mill

Workpiece cylindricity error

The grinding wheel and guide wheel have been worn out and lost their original correct shape

Trim the grinding wheel and guide wheel in time to ensure the correct shape

49

Centerless mill

Workpiece cylindricity error

Imbalance of grinding wheel or guide wheel

Balance grinding wheel or guide wheel

50

Centerless mill

There are vibration marks on the surface of the workpiece

The hardness of the grinding wheel is too high or has been used bluntly

Correctly select the hardness of the grinding wheel according to the material characteristics of the workpiece and trim the grinding wheel in time

51

Centerless mill

There are vibration marks on the surface of the workpiece

The grain size of grinding wheel is too fine

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

52

Centerless mill

There are vibration marks on the surface of the workpiece

The dressing of the grinding wheel is too rough or too smooth

Choose the correct dressing method and dosage according to the grinding to be repaired

53

Centerless mill

Workpiece surface burn

The grinding wheel is too fine or blunt

Choose the correct dressing method and dosage according to the grinding to be repaired

54

Centerless mill

Workpiece surface burn

The hardness of grinding wheel is too high

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

55

Centerless mill

Numerical error of surface roughness of workpiece

The grain size of the grinding wheel is too coarse, and the dressing of the grinding wheel is too coarse

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

56

Centerless mill

Numerical error of surface roughness of workpiece

The hardness of grinding wheel is too soft

The grinding wheel should be correctly selected according to the characteristics of the workpiece and the grinding requirements and according to the characteristics of the grinding tool and its selection rules

57

Centerless mill

Workpiece size dispersion

The grinding wheel just finished grinding is not sharp and the diamond has been worn

Diamond should change direction or replace new one in time.

 

58

Cam mill

The accuracy of cam lift curve is too bad

The diameter of the grinding wheel has exceeded the allowable range of use

Replace the grinding wheel

59

Guide rail mill

Workpiece deformation or fault error

Improper selection of grinding wheel

Select the appropriate grinding wheel according to the material and hardness of the workpiece. When the hardness of the workpiece is ≥ HRC64, the CBN grinding wheel should be selected

60

Guide rail mill

Workpiece deformation or fault error

The grinding wheel is used blunt and not sharp

The characteristics of the workpiece and the law of precision change should be mastered and the grinding wheel should be repaired in time

Grinding is a complex system engineering, and the grinding wheel and grinding process should be correctly selected according to the material characteristics of the workpiece. When there are different grinding defects in the working conditions, the correct dressing method should be adopted, so that the workpieces with good machining quality and high dimensional accuracy can be obtained, so as to improve the production efficiency and reduce the production cost.

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