CBN materials in addition to the tool used to make, but its biggest application areas or CBN abrasive made for fast and efficient grinding and honing, grinding efficiency can greatly improve the accuracy and quality of its grinding up a notch.
1 Grinding auto parts - camshafts and crankshafts
Automotive engine camshaft having a plurality of cams, cam kibble after quenching and grinding cams that affect the quality of key processes. Are generally used by imitating shaped grinding, the workpiece speed increase is limited, the workpiece is easy to produce grinding burn crack, using shaped grinding by imitating its cam surface contour curve to be affected by the impact of wheel diameter, it is difficult to ensure correct cam profile curve. Production Practice has proved that when the wheel diameter is large, grind cam lean, when wheel diameter hours, grind cam fat, only when close to or equal to the diameter of the grinding wheel cam cam roller diameter (usually φ570mm), its Profiling error close to zero, ie, the cam surface grind cam cam contour curve close. In actual production, the use of wheel diameter are generally from the D600 (or 610) is used D500, and the ideal wheel diameter (570) differ very much, so a majority of the total production of the camshaft cam curve exceeded. To solve this problem, we rely on the use of imitation cam grinder CBN grinding wheel, CBN grinding wheel diameter can be made of the D575, CBN abrasive layer thickness of 4 ~ 5mm, its smallest diameter grinding wheel D565, grinding diameter range although only 10mm, but the number was equivalent to tens of grinding parts ordinary piece wheel, not only to ensure proper cam curve, but it does not produce the phenomenon of grinding burn.
If Liton industrial automation company with CBN grinding wheel camshaft, its cost reduced by 50%, the cam surface fatigue strength increased by 30%; Xiangfan Dongfeng Motor Corporation diesel engine plant with coarse vitrified CBN wheels chilled cast iron camshaft its cam grinding allowance t = 4 ~ 5mm, υ sand = 60m / s, workpiece speed n = 100r/min, υf = 0.1mm / s, using high-speed grinding fluid, CBN grinding wheel life basically equivalent to 20 corundum abrasive.
2.CBN Grinding wheel bore applications
Internal grinding efficiency has been low, the main reason is the grinding speed, grinding wheel materials and rigid rod problem. Production process used in the dressing wheel, replace the wheel time work accounted for almost one-piece 1/3 to 1/5. If the inner circle or trench with CBN electroplated grinding wheel and the wheel speed, increasing the grinding rod diameter, can be an appropriate increase in the workpiece speed and feed rate, not only to ensure the hole (arc) diameter, width size and shape bit accuracy, surface roughness and to avoid burns, but also can be multiplied to improve processing efficiency and reduce processing costs.
Such as domestic factory processing an annual output of 600,000 sets of textile machinery bearings, grinding φ15.5 0.04 arc adjacent holes and slots in the past with chromium corundum (GG) wheel, two steps were required in two M224 internal grinding machine processing, its slot (arc) diameter difference and the size of the hole is difficult to ensure concentricity and low efficiency, the use of CBN grinding wheels, bold a grinding rod, improved feed, saving the trimming and Replace the wheel time, solve the original problem. Later changed to hole, ditch while grinding, grinding rod that is installed in two wheel, the grinding efficiency by 1 times, saving a grinder. The surface roughness of workpiece grinding process parameters used Ra0.63μm: υ sand = 36m / s, υ2 = 19m/min, f rough cut = 1μm / r, f fine cut = 0.5μm / r, light grinding time t = bs, emulsion concentration of 10% values.
3 using CBN grinding wheel gear
Gears grinding in the past is the use of a single tooth and multiple tooth surface grinding, surface grinding, although single tooth can obtain higher precision, but low efficiency, high cost, multi-tooth grinding, although high production efficiency, but its processing single tooth grinding poor quality ratio. The use of CBN grinding wheel, either single-or multi-tooth grinding, tooth grinding, electroplating or vitrified CBN grinding wheel for grinding, the effect is extremely significant:
(1) CBN grinding wheel can be made with high precision tooth, because high durability, less frequent dressing, without constantly adjust the machine, to obtain a stable tooth Gallery, lead and pitch accuracy.
(2) can be achieved with a high-speed grinding feed rate grinding tooth surface roughness is low and does not burn, you can improve the grinding efficiency obtained under the conditions of high precision gears (6 to 7).
(3) CBN grinding wheel, long life, good grinding performance, saving replacement wheel dressing, adjust the machine and the workpiece detection and many other auxiliary time.
4 Application CBN abrasive machining difficult materials and hard work surface
On hardened steel or chilled cast iron bore honing, CBN honing stone can be used for high-strength, high hardness and high heat-sensitive alloy steel, stainless steel, heat-resistant steel and alloys, should adopt high hardness, high strength CBN wheel, using extreme pressure emulsion or liquid cooled high-speed grinding. For longer rail surface or complex surfaces, cam shaft cam grinder etc. CBN grinding wheel should be used.
