Forging blanks on the lathe mainly rely on the rotation of the main movement and tool feed movement to complete the cutting action. Therefore, the choice of the angle of the tool is reasonable, the angle of the vehicle blade grinding is correct, will directly affect the processing quality and cutting efficiency of forgings.
Forging in the cutting process, due to the knife's front face and knife face in the intense friction and cutting heat of the role, will make the cutting edge of the tool blunt and lose the cutting ability, only through sharpening to restore the cutting edge of the sharp and correct angle of the car. Therefore, the lathe operator should not only know the cutting principle and the reasonable choice of the angle of the tool, but also must master the sharpening skill of the lathe knife.
The blade grinding of the tool is divided into two kinds: mechanical sharpening and manual grinding, and the machine has high efficiency, good quality and convenient operation. At present, small and medium-sized forgings production plant is still commonly used by hand-grinding, so the lathe operator must master the technology of hand-grinding vehicles.
At present, the commonly used grinding wheel has alumina and sic two types, knife grinding must be based on the cutting tool material to choose the wheel.
1. Alumina Grinding Wheel
Alumina grinding Wheel is more white, its grit toughness is good, relatively sharp, but slightly lower hardness (refers to abrasive particles easily from the grinding wheel off), suitable for grinding high-speed steel car knives and carbide shaft parts. Alumina grinding wheel is also called corundum grinding wheel.
2. Silicon Carbide Grinding Wheel
SIC grinding wheel is green, its grit is high, its cutting performance is good, but it is more brittle, it is suitable for sharpening cemented carbide lathe tool.
The thickness of the grinding wheel is expressed in grain size. GB 2477-83 stipulates 41 size number, coarse grinding with coarse grain size (the basic size of large), fine grinding with fine-grained (basic size small).
Precautions for cutting edge grinding in forging process
1. Wear protective goggles when sharpening.
2, the new installed grinding wheel must undergo a rigorous inspection, after the test transfer qualified to use.
3. Grinding surface of grinding wheel must be constantly trimmed.
4, when sharpening, the operator should try to avoid the grinding wheel, to stand on the side of the wheel is advisable. This will not only prevent the sand particles from flying into the eye, but more importantly, can avoid the damage caused by the grinding wheel. A grinder for a person to operate as well, not allow more people to gather together on lookers.
5, when sharpening, do not force too hard to prevent slipping and hurt hands.
6, the use of flat-type grinding wheel, should try to avoid grinding on the end of the wheel.
7, the Force mill high-speed steel car knife, should be timely cooling to prevent the blade annealing, resulting in reduced hardness. While sharpening the carbide knife, the knife body part can not be placed in the water cooling. In case the blade cracks because of sudden cold.
8, force grinding knot reined, should with Yin close the wheel electromechanical source.