1. Characteristics and applications of diamond rollers

Diamond roller is a newly developed dressing tool. Compared with single particle diamond pen dressing grinding wheels, it has a much shorter dressing time when performing non linear dressing and is easy to trim various messy shaped surfaces. The method of dressing grinding wheels with diamond rollers can be divided into two types: cut-in roller dressing and pendulum roller dressing. As the structure of the cut-in dressing device is simpler than that of the pendulum dressing device, it is more commonly used in practical production. In the cutting in type roller dressing, similar to the cylindrical cutting in grinding workpiece, the roller is driven by an electric motor to rotate, making a cutting motion relative to the grinding wheel, and then performing the grinding wheel dressing. The main parameters characterizing roller cut in trimming include: trimming speed ratio qd, trimming feed rate, and number of light trimming revolutions. The following introduces the application of the cut-in diamond roller dresser in HSQB885.4 channel grinding.

HSQB885.4 is a large four point contact ball bearing with a peach shaped groove. The existing TM1500 floor grinder is used to replace the vertical grinder in grinding its groove, and a TM1500 diamond roller dresser is planned.

The bracket is fixed on the front of the machine tool bed, and the base is installed on the bracket, which can be adjusted in both longitudinal and transverse directions. The roller shaft is a sleeve type spindle, and a two support shaft system structure composed of two sets of angular contact ball bearings is selected. The transmission of the spindle adopts a multi wedge belt transmission, which is stable and reliable. The driving motor is a lightweight aluminum shell wireless speed control motor, and the use of a stepless speed control motor is to ensure that the ratio qd of the linear speed between the roller and the grinding wheel remains within a certain range. Due to the consumption of the grinding wheel, its linear speed decreases. At this point, it is necessary to adjust the rotational speed of the roller appropriately to achieve a trimming effect. Change the cutting in feed for trimming to grinding wheel feed. When trimming, the roller does not move. Use the manual feed organization of the original machine tool grinding wheel feed to achieve the cutting in motion for trimming.

You can also use the method of grinding wheel not moving and roller feeding for dressing. At this time, the structure of the dressing device is relatively messy, such as using linear guides, ball screws, stepper motors, etc. The roller dressing action can be planned into a simple CNC system, with the action program planning as follows: fast forward (cannot touch the grinding wheel) → slow forward (feed according to the required cutting speed) → light dressing → exit.

2. Precautions

Due to the characteristics of short trimming time, the ability to trim various messy surfaces, good surface accuracy, and convenient trimming operations, the diamond roller forming and trimming method has gradually gained recognition for its application effect and has been increasingly widely used in production. However, in the planning, production, and application of rollers, the following points should be noted:

The particle size of diamond should be one size coarser than that of the repaired grinding wheel, and diamond particles should be selected with a size that is close to the same, and the particle shape should be approximately spherical, with commonly used particle sizes ranging from 36 # to 100 #.

Usually, the linear velocity direction at the contact point between the roller and the grinding wheel is in the same direction, and the ratio of the linear velocity of the roller to the linear velocity of the grinding wheel (qd value) should be taken as 0.3~ 0.7, which should not exceed 1; When trimming, the cutting amount of the roller is 0.5~1 per revolution of the grinding wheel μ M is appropriate, and the total amount of each grinding wheel trimming should be 0.02-0.04mm; Try to shorten the repair time as much as possible.

The manufacturing error of diamond rollers should be less than about half of the workpiece's service life, and the clearance between the roller hole and the device bearing should be 2-4 μ M

Natural or artificial diamonds can be selected, and it is necessary to use high-strength grade diamonds such as diamond SCD or high-strength diamond SMD for steel grinding.

When making rollers, general precision rollers can be made using external plating and sintering methods, while high-precision and disordered surface rollers can be made using internal plating method while undergoing grinding and trimming.

When dressing the grinding wheel with a diamond roller, it is necessary to adhere to the action program of fast forward (not touching the grinding wheel) → slow forward (feeding according to the required cutting speed) → light repair → exit, and do not step wrong, otherwise the roller will be difficult to ensure.

Article source: Diamond grinding wheelhttp://www.jm-nanhua.com