Machining method for sawtooth-shaped threads of hydraulic nut of large ship shafting

Abstract

According to the machining method for the sawtooth-shaped threads of the hydraulic nut of the large ship shafting, the reasonable machining mode that X-direction layering and Z-axis tool borrowing of a straight shank arc turning tool are combined is adopted, machining of the large-pitch sawtooth-shaped threads is decomposed into machining of a plurality of sawtooth-shaped threads with the small thread height, and therefore the cutting state is improved, the cutting resistance is reduced, and the machining efficiency is improved. The huge damage to a machine tool due to the use of a forming tool and the increase of the manufacturing cost due to the turning tool breaking of a 93-degree standard external turning tool for mounting a 35-degree blade are avoided. The straight-shank arc turning tool is adopted, on one hand, the very high linear cutting speed can be achieved, the machined surface is strengthened, the surface quality is improved, on the other hand, the finish machining allowance can be precisely reserved, and the size and position precision of the straight-shank arc turning tool can be within 0.03 mm / 1000 mm.

Description

Technical field: [0001] The invention relates to a process method for turning 0° / 45° serrated threads of a large ship shafting hydraulic nut. Through the processing method, the turning processing methods of 7° / 45° and 3° / 30° serrated threads can be expanded. Background technique: [0002] The hydraulic nut of large ship shafting is an important part of the ship's shafting. Its processing quality plays a vital role in the safe and stable operation of the ship. The rough machining of its 0° / 45° serrated thread is one of the difficulties. Since there is no standard turning tool for this type of thread processing, manual sharpening and welding forming tools are usually used in early processing to complete thread processing. After the X-axis feed position is fixed, the Z-axis linear feed turns. With the continuous feeding of the tool, the contact area between the turning tool and the workpiece continues to increase, and the cutting resistance also increases, which can easily cau...

AI Technical Summary

Problems solved by technology

As the tool continues to feed, the contact area between the turning tool and the workpiece continues to increase, and the cutting resistance also increases, which can easily cause tool vibration, resulting in "knife hitting", "gnawing knife", "knife stabbing" and other situations.

At the same time, the huge cutting resistance generated when turning with forming tool affects the accuracy of the ball screw pair of the machine tool. In severe cases, the ball screw can move and deform, so that the thread being turned will be "chaotically buckled" and scrapped.

In addition, the turning speed of the forming knife is very small, which seriously affects the processing efficiency

[0003] It is possible in principle to turn 0° and 45° zigzag threads with a 93° outer circle turning tool with a 35° turning insert and a 93° corner angle of R0.8mm, but due to the 45° surface clamping between the minor cutting edge and the thread profile The angle is small, the first knife of each layer is actually the main cutting edge, the auxiliary cutting edge and the corner of the knife edge during turning. If the cutting amount is greater than 0.3mm, the blade will be broken when cutting, resulting in the inability to carry out follow-up work

The solution is to reduce the amount of back cuts on each layer, so that the overall turning efficiency of the thread will become lower, or to divide the first cut of each layer into two to complete the programming, and the programming work will become Extremely complicated, it is difficult for general CNC lathe operators to master

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