Basic analysis of processing conditions of rolling cutter:

1. Appearance before processing

Because the rolling processing is the processing method of roller rolling, the surface roughness after processing is affected by the height and shape of the convex part (i.e. the state before processing).

If the appearance is rough before processing (the convex part is high and the depression part is deep), the convex part cannot be completely buried in the depression part to form a rough processing appearance.

In addition, the shape of the convex part also affects the appearance after processing. When the regular concave convex shape obtained by single point cutting of lathe or boring machine is the height of simple rolling, the most ideal appearance can be obtained. Generally, the better the appearance before processing, the better the appearance after processing, and the less wear of the rolling head. If required, an operation can be added.

2. Dimensions before processing

Because rolling is the processing method of roller rolling, Therefore, the diameter of the workpiece will change before and after processing (the inner diameter will expand and the outer diameter will decrease). In order to be processed to the scale range, this change amount should be considered to determine the scale of the previous process. The change amount of diameter is related to the material, hardness and rolling amount of the workpiece, so the scale should be determined after 2 ~ 3 trial processing.

3. Driving machinery

The standard types of rolling head include Morse conical clamping part and parallel clamping part. Rolling processing is different from cutting processing. It does not need high torque. Small power machine tools can also be used. It can be installed on drilling machines, lathes, hexagonal lathes, boring machines, drillers and other equipment for processing without special equipment.

4. Smoothing and cleaning

Because the rolling process is processed by roller rolling, fine dust will occur. Dust not only affects the appearance quality, but also accelerates the loss of rolling head, so it is necessary to inject a large amount of cutting fluid to remove dust. Cutting fluid with low viscosity shall be used during rolling. Although the cutting fluid with high viscosity has good smoothness, it has poor cleaning function and is not suitable for rolling processing. The company has special rolling smooth oil for rolling processing. As long as 5% rolling smooth oil is added to low viscosity cutting fluid, its outstanding function can be brought into play.

5. Wall thickness of processing part

Rolling processing is to use rollers to roll the surface of the processed part to densify it. Therefore, in order to accept the processing pressure, the part to be processed should have sufficient wall thickness (20% of the inner diameter). When the wall thickness is too thin or part of it is too thin, there will be ruggedness or decrease of true roundness after processing.

This problem is usually solved by the following methods: ① reduce the rolling amount; ② Support the outer circumference with fixture; ③ Rolling shall be carried out before cutting thin wall thickness.

6. Hardness of processing part

The upper hardness limit of the workpiece that can be processed by the rolling head is 40HRC, but the rolling head for processing high hardness workpiece (the upper hardness limit is 55HRC) is also specially designed. When rolling high hardness workpiece, the service life of things is shortened because of the high pressure. Therefore, in order to obtain the machining surface with the required accuracy, the main method is to reduce the rolling amount.

7. Speed and feed rate

Rotate the rolling head to the right for rolling processing; The rolling head can also be fixed, and the same result can be obtained by workpiece rotation. The rotation speed and feed speed vary according to the machining diameter.

8. Parts that cannot be rolled

When rolling the blind hole and step shaft with the rolling head, there are the following parts that cannot be machined: ① the arc part at the front end of the roller; ② The distance from the front end of the roller to the front end of the support; ③ The gap from the front end of the support to the end face of the processing part; In order to minimize the part that cannot be rolled, after setting the East-West diameter, grind off the spindle at the front end of the roller or keep the protrusion of the head at the same position as the front end of the roller.