This document discusses the application of CBN grinding wheels in various industrial grinding processes. It describes how CBN wheels can be used to grind camshafts and crankshafts with tighter tolerances compared to conventional wheels. The document also discusses how CBN wheels improve efficiency when grinding internal holes and gears. CBN abrasive tools are also said to be better for machining hardened materials due to their high hardness and strength. While CBN tools provide benefits, the document notes there are still problems to address with their widespread adoption.

1. 河 南 磨 澳 超 硬 材 料 有 限 公 司
H e n a n M o r e S u p e r H a r d P r o d u c t s C o . , L t d .
Office: B-906,Wanda Plaza Office Building,NO. 171 Zhongyuan Rd, Zhongyuan
District,450000,Zhengzhou City, Henan Province 450001,China
Tel/Fax: +86(371)86545906 Mob: +8615093391569 Email:Julia@moresuperhard.com
The Application Of CBN Wheel In Grinding
1. Grinding Automotive Parts-Camshaft and Crankshaft
There are many cams on the camshaft of an auto engine, the rough and fine grinding of quenched cams are the
key processes of the cam quality. Usually, we adapt imitating shape grinding, the increasing of the workpiece
speed is limited and easy to burn out. And the camber curve of cam surface is strongly affected by the diameter of
grinding wheel. So it is hard to promise the accuracy of cam profile. The production practice proves that when the
wheel diameter is large, the cam that ground is thin; and when the wheel diameter is small, the cam that ground is
fat. Only when the wheel diameter is similar or equal to the roller diameter (usually φ570mm)of grinding cam, its
profile tolerance is almost zero, which means the camber curve of cam surface is near imitated cam. In real
production, the wheel diameter is generally from D600 to D500, while is far from the ideal grinding wheel
diameter(φ570mm), so in production there always have most camshafts are out of standard line. In order to solve
this problem, we use CBN wheel grinding on the imitated shaping cam grinding machine, we can make the
diameter of CBN wheel D575mm, the thickness of CBN layer 4-5mm, while the smallest diameter of grinding
wheel is D565 and the diameter range of grinding is only 10mm, meanwhile the numbers of grinding parts is
equivalent to dozens of ordinary wheels. Through CBN wheel grinding , can not only promise the curve of
camshaft but also won’t cause burns.
For example, Liton company uses CBN grinding wheel to grind camshaft, its cost decreased 50%, while the
fatigue strength of the camshaft surface increased 30%; Dongfeng Motor Corporation Xiangfan Diesel Engine
Works uses vitrified CBN grinding wheels to rough grind of Cold-shock cast iron camshaft, its grinding tolerance is
t=4~5mm, v=60m/s(grinding wheel), the rotating speed of workpiece n=100r/min, vf=0.1mm/s. By using high
speed grinding fluid, the life span of CBN wheel equals 20pcs Corundum abrasive wheels.

2. 河 南 磨 澳 超 硬 材 料 有 限 公 司
H e n a n M o r e S u p e r H a r d P r o d u c t s C o . , L t d .
Office: B-906,Wanda Plaza Office Building,NO. 171 Zhongyuan Rd, Zhongyuan
District,450000,Zhengzhou City, Henan Province 450001,China
Tel/Fax: +86(371)86545906 Mob: +8615093391569 Email:Julia@moresuperhard.com
2. Application of CBN Grinding Wheel in Internal Hole Grinding
The efficiency of internal grinding is always low, its mail reason is the grinding speed, the rigidity of grinding
wheel material and grinding rod. The time spent in dressing and changing grinding wheels during the production
process accounted for almost 1/3~ 1/5 of the production time per piece. If grind inside circle or groove with
electroplated CBN wheel,by increasing the wheel speed and grinding rod diameter, the rotate speed and feed speed
can be appropriately increased. In this way not only can guaranteed hole(arc) diameter, groove width
size ,geometric tolerance, surface roughness and not easy to burn, but also can greatly increased the working
efficiency and decrease production cost.
For example: One factory processes an annual output of 600,000 spinning machine rolling bearing sleeve, they
used to use GC grinding wheel to grind φ15.5+0.04 hole and adjacent arc slots, need to machining in two steps in
two different M224 internal grinding machine. The groove (arc) diameter difference and size and hole coaxiality is
difficult to ensure, and the efficiency is very low. After using CBN wheel, the grinding rod is thickened, the feed
amount is improved and the time of dressing and changing grinding wheel is shortened, which completely solved
the original issues. Afterwords,the machining way changed to grind hole and groove in the same time, which means
install two grinding wheels on the grinding rod, increased one time grinding efficiency and saved one grinding
machine. The processed surface roughness of workpiece is RA0.63um. The adopted grinding parameters are as
follows: V=36m/s(grinding wheel), V2=19m/min, f=1um/r(rough machining),f=0.5um/r(fine machining).
3. Using CBN Wheel for Grinding Gear
Gear grinding usually adapt single tooth face grinding and multi-tooth surface grinding. Single tooth face
grinding can achieve higher machining accuracy,but its efficiency is lower and cost is higher; While multi-tooth
surface grinding can get higher production efficiency but its machining quality is worse than single tooth face
grinding. If using CBN wheel grinding, no matter use single tooth face grinding or multi-tooth surface grinding,
when using electroplated CBN wheel or vitrified CBN wheel , its performances are very amazing:
(1) CBN grinding wheel can be made into high precision tooth profile, without frequent dressing and adjusting
machine,and because of high durablity, it can achieve steady tooth profile, lead and pitch accuracy.

3. 河 南 磨 澳 超 硬 材 料 有 限 公 司
H e n a n M o r e S u p e r H a r d P r o d u c t s C o . , L t d .
Office: B-906,Wanda Plaza Office Building,NO. 171 Zhongyuan Rd, Zhongyuan
District,450000,Zhengzhou City, Henan Province 450001,China
Tel/Fax: +86(371)86545906 Mob: +8615093391569 Email:Julia@moresuperhard.com
(2) Can realize high speed grinding and high feed amount when grind gear face. It is not easy to burn and
roughness is low, under the condition of improving grinding efficiency can achieve higher gear accurancy(level
6~7).
(3) Longer lifespan and better grinding efficiency, it saves the time of dressing and changing of grinding wheel,
also shorten the time of adjusting machine and measurement of workpiece.
4. Application of CBN abrasive tools to process hard materials and hard surface
For honing holes of hardened steel or chilled cast iron, we can use CBN honing stones. For machining alloy steel,
stainless steel, heat-resistant steel and alloy with high strength, high hardness and high heat sensitivity, it is better to
choose high hardness and high strength CBN grinding wheel, meanwhile use extreme pressure emulsion or high
speed grinding fluid for cooling. It is advisable to use CBN grinding wheel for long guide or complex surface and
cam-grinding machine
CBN material, whether it is used to make tools or abrasives, can be used in high speed cutting or grinding to
improve product quality, improve processing efficiency, shorten the processing cycle and reduce the processing cost.
Therefore, in the processing, vigorously promote CBN cutting (grinding) tools is a powerful measure to improve
the manufacturing technology. However, if it is widely used, there are still exist .many problems.