What are the honing processes at Dongguan CNC Precision Machining Factory

From the cutting process of honing at Dongguan CNC Precision Machining Factory, honing can be divided into three processes: constant pressure feed honing, constant maximum feed honing, and constant pressure quantitative composite feed honing.

(1) Constant pressure feed honing can be divided into three stages: shedding cutting, crushing cutting, and blocking cutting.

1. Falling off cutting stage. At the beginning of this constant pressure honing, due to the roughness of the hole wall, the contact area between the oil stone and the hole wall is very small, and the contact pressure is high. The protruding part of the hole wall is quickly ground off. Due to the high contact pressure on the surface of the oilstone and the wear of the oilstone binder by chips, the bonding strength between the abrasive particles and the binder decreases. Therefore, some abrasive particles fall off on their own under the action of cutting pressure, exposing new abrasive particles on the oilstone surface, which is called oilstone self sharpening.

2. Crushing and cutting stage. As the honing work progresses, the surface of the hole becomes smoother and the contact area with the oilstone becomes larger. The contact pressure per unit area decreases, and the cutting efficiency gradually decreases. The chips cut simultaneously are small and fine. These chips also have minimal wear on the adhesive. Therefore, the oil stone abrasive particles fall off very little, and at this time, grinding does not rely on new abrasive particles, but on cutting at the tip of the abrasive particles. Therefore, the load at the tip of the abrasive particles is high, and the abrasive particles are prone to fracture and collapse, forming new cutting edges.

3. Block the cutting stage. As the honing continues, the contact area between the oil stone and the hole surface becomes larger and larger, and extremely fine chips accumulate between the oil stone and the hole wall, making it difficult to eliminate them, causing the oil stone to block and become very smooth. Therefore, at this point, the cutting ability of the oilstone is extremely low, equivalent to polishing. If honing continues, if the oilstone is severely blocked and causes adhesive blockage, the oilstone will completely lose its cutting ability and generate severe heat, which will affect the accuracy and surface roughness of the hole. At this time, honing work should be completed as soon as possible.

(2) Quantitative feed honing. During quantitative feed honing, the feed mechanism expands the feed at a constant speed, forcing the abrasive particles to enter the workpiece. Therefore, the honing process only involves detachment and fragmentation cutting, and it is impossible to produce cold cutting phenomenon. Because when the cutting force decreases due to the blockage of the oilstone, the feed rate is greater than the actual grinding amount, and the honing pressure increases, causing the abrasive particles to fall off and break, enhancing the cutting effect. When honing with this method, in order to improve the machining accuracy of the hole and reduce surface roughness, the final method is to honing for a certain period of time without feeding to improve the machining accuracy of the hole.

(3) Constant pressure and quantitative composite feed honing. At the beginning, constant pressure feed honing is used, and when the oilstone enters the clogging cutting stage, it is converted to quantitative feed honing to improve efficiency. Finally, non feed honing can be used to improve the accuracy of honing holes and reduce surface roughness at Dongguan CNC Precision Machining Factory.