ROLLER BURNISHING TOOL
Abstract: this paper mainly Presents the process parameters, Technology and performance of rolling tool so as to improve the smoothness of merchandise. During the introduction of the article to describe how to improve the surface of the workpiece after rolling strain, the surface of the workpiece isn’t clean, the hints of rollingup, and so on.
Before That the roller burnishing tool was widely used, many manufacturers utilized polishing, polishing, grinding and other methods to improve the surface finish of metal products in the machining procedure. The honing procedure also has certain advantages. For some internal holes with higher hardness and small bore diameter, the honing tool is utilized to finish the honing process, but its efficacy is a lot lower than that of the roller burnishing tool.
1. Processing effect
First of all, after outside rolling, the Surface of metal workpiece is reinforced, the ultimate strength and yield point are raised, along with the hardness can be increased by 15-30%.
Abrasion resistance increased by 15 percent;
Fatigue limit improved by 30%;
10-15% by diameter calculation.
The surface roughness may reach above Ra0.2 if The overfill is suitable and matches with other procedure parameters.
Secondly, the surface micro-protuberances After rolling are smoothed, and the contact with sealing materials is smooth, which lessens the wear of sealing parts while reducing the usage of merchandise. Concerning processing efficiency, one roll can finish the processing. (finishing 100 x 300 holes at 1.5 minutes can be finished; finishing 30 x 40 holes in 10 seconds can be completed).
2. Process parameters and requirements
Level : if machining the inner hole of the workpiece with the roller burnishing tool, the tool diameter is set to be slightly bigger than the preceding machining size, rotating shaft and feeding the tool (workpiece), and rolling the inner hole. The gap value between the diameter of the tool and also the dimensions of the workpiece before processing is known as burnishing amount.
Roller Burnishing Tool is set according to this The setting of burnishing level is generally 3 to 5 days of their surface roughness prior to processing, which can be ideal. After the material is steel, the burnishing level ranges from 0.04 to 0.07mm to obtain the most perfect surface. As soon as the burnishing amount range of steel and cast iron components is 0.04~0.07mm, its inner diameter will not change.
Dimensions : as the diameter dimensions will alter after rolling, the machining allowance should be left before rolling to guarantee the dimensional tolerance. The variant of diameter and size is affected by the substance, hardness and rolling pressure of the workpiece, etc., so the determination of machining allowance should be made on the basis of the company’s reference value after many trials. It must be mentioned that the inner diameter cannot be enlarged to the identical size as the width of the tool after adjusting, cause the enlarged inner diameter is reduced after the instrument passes through due to the elastic recovery of the substance.
3) The upper limit of hardness of workpiece
4) so as to avoid the deformation of lean Wall components during rolling, the wall thickness of the machining part should reach greater than 15% to 20% of the aperture.
At the same time, once the hardness of casting materials isn’t uniform, the surface defects of rolling pressure is going to be exposed immediately. Hence, the quality of the wrapped parts is good, and also the surface defects should not be too many.
6) The result of main rolling is greatest, and The roughness can be reduced from 2-3 grades.
7) The rolling process is lubricated with
Clean machine oil or sterile with diesel oil (ratio 3:7), or using specific lubricating fluid offered by the manufacturer. A large amount of lubricating fluid ought to be used cause the lubricating fluid should clean the small metallic powder produced from the rolling procedure. Maintain the lubricating fluid sterile, listen to dust prevention and filtration.
8) Rolling effect is closely linked to this Previous process. After the present process, if the surface is too concave and Convex, the rolling pressure will also increase, and the feed amount will be Reduced, so the rolling result will not be ideal. It’s Suggested to pay Attention to the machining precision in the procedure before rolling, and pay Focus on cleaning in the same time to prevent the chip sticking to the interior