Axle workpiece
Lathe turning is also a commonly used and common processing method for shaft workpiece, which is one of the typical parts often encountered in machines. Shaft workpiece is a rotating part, whose length is greater than the diameter, and is composed of cylindrical surface, cross-section and steps.
1. Cylindrical turning tools: common cylindrical turning tools include straight head cylindrical turning tools, 90 ° offset tools and 45 ° offset tools.
2. Turning excircle: straight head excircle turning tool has good strength; It is often used for rough turning of outer circle. The main deflection angle of 90 ° offset cutter is large, which is suitable for turning of outer circle, section and steps; The 45 ° elbow turning tool is suitable for turning smooth shafts without steps.
End face and step
The plane at both ends of the cylinder is called the end face. The part connected by two cylinders with different diameters is called a step.
1. The method of turning the end face: turning the end face by turning the tool to the right is to feed the tool from the outside to the inside, which is easy to plunge into the workpiece and form a concave surface; Turning the end face from the center to the outside with a right offset cutter, the turning is smooth, and it is not easy to produce a concave surface. The cutting conditions are improved by turning the end face from the outside to the center with the left offset cutter and cutting with the main cutting edge. Turning the end face of the elbow turning tool is carried out with the main cutting edge, which is very smooth. It can be used not only for turning the end face, but also for turning the outer circle and chamfer.
2. Step turning method: turning the workpiece with a step lower than 5mm can be completed at one time with the offset cutter on the outer circle of the turning. Turning workpieces with steps higher than 5mm will cause vibration due to excessive shoulder. Therefore, the workpiece with high bench can be roughly shaped by the cylindrical turning tool, and then cut by the eccentric tool layer by layer.
3、 Grooving and cutting
1. Grooving: the method of grooving on the surface of the workpiece is called grooving. The shape of the groove includes outer groove, inner groove and end groove.
(1) Grooving knife: high speed steel grooving knife is often used.
(2) Grooving method
·For rectangular grooves with low accuracy and narrow width, a slotting knife with a knife width equal to the groove width can be used, and the straight in method can be used to turn out at one time.
·Turning a wide groove, you can cut many times by straight forward method, and leave a certain amount of finish turning allowance on both sides of the groove.
·Turning small circular arc grooves can be turned with formed turning tools.
·For large circular arc grooves, you can use two hand linkage turning, and check and repair with a template.
2. Cutting: the shape of the cutting knife is similar to that of the grooving knife. The commonly used cutting methods include straight cutting method and left-right borrowing method. The straight cutting method is used for brittle materials such as cast iron; The left and right knife borrowing method is used for plastic materials such as steel.