In the process of equipment design and manufacturing, manual calculation method was used, which was not only inefficient, but also prone to errors, and modern design methods could not be used, especially for local conjugate meshing gears such as spiral bevel gears and gears. Tooth design, process parameter selection, tooth contact analysis and stress-strain analysis are closely related, Such as mechanical optimization design, finite element analysis and Simulation of machining process, perfect application software and machine tools have become the necessary conditions for modern enterprise product development.
Here, we will introduce typical gear and metal materials.
Typical gear materials:
S45C (mechanical structure and carbon steel): S45C 0.45% carbon, medium carbon steel (steel). Gear, bevel gear, rack, bevel gear, worm gear use this material more.
SCM415 (chromium molybdenum alloy steel): low carbon alloy steel (C = 0.15%) represents the material. Generally speaking, after carburizing and quenching, the strength of the material after heat treatment is higher than that of S45C scm440. The service surface hardness is about 55 to 60.
Sus303 (Cr – 8 nickel steel stainless steel: 15): stainless steel, as the name implies, is not easy to rust steel (stainless steel). The austenitic stainless steel of the system is basically non-magnetic; the stainless steel gear is mainly used in the machinery which needs to avoid rusting, similar to sus303 and SUS304 stainless steel, and it is more corrosion resistant than sus303.
Casting copper alloy, casting copper alloy is the main material for manufacturing worm gear. Usually there is a phosphor bronze casting (cac502), aluminum bronze (cac702) and other meshing hands. Most of the materials used for worm meshing are S45C / scm440 / SCM415 steel, etc. Use different materials to prevent worm gear worm gear meshing tooth surface sliding agglutination and excessive wear due to etc.
Above is our original gear, typical gear selection material. CNC hobbing machine and ordinary lathe CNC lathe processing, but because of fixture, CNC hobbing, large and small modulus gear processing continuous automatic processing to complete all processes, should pay attention to the following aspects.
Choose reasonable cutting parameters
For metal processing, high efficiency, processing materials, cutting tools and cutting conditions are the three main factors. These determine the processing time, tool life and machining quality. The economical and effective treatment is to choose the cutting condition reasonably. Cutting conditions are three elements: cutting speed, cutting depth of the tool direct damage. With the increase of cutting speed, the temperature will rise, there are mechanical wear, chemical and thermal. If the cutting speed is increased by 20%, the tool life will be reduced by 1 / 2.
Back feed conditions and tool wear are kept to a minimum. But feeding is big, cutting temperature, wear. Large module gear processing. It is affected by the cutting speed of the tool. Although the cutting depth of the tool cutting speed and feed has no big impact, but in a small cutting depth and cutting, cutting material hardening layer, will also affect the tool life.
However, in practice, the selection of tool life, tool wear, machining size change, surface quality, noise, heat and related treatment is reduced. It is necessary to study according to the actual situation. Stainless steel and heat resistant alloy and other hard small modulus gear processing materials, can choose coolant or rigid blade.
Choosing the right tool for CNC gear hobbing
- Thick selection of high strength, good durability tools to meet the rough turning depth, feed requirements.
- Automobile, high selection accuracy, good tool durability, to ensure the machining accuracy requirements.
- In order to reduce the conversion time and tool convenience, machine tools and blades should be used as much as possible.
Selection of fixture for CNC gear hobbing
- In the special points of NC gear hobbing, general fixture should be used as far as possible, and special fixture should be avoided;
- The coincidence of parts positioning datum reduces the positioning error.
Determination of machining route for special points of NC Gear Hobbing
- The special points of NC Hobbing should be able to meet the requirements of machining accuracy and surface roughness;
- CNC gear hobbing processing special place should try to shorten this process, reduce the travel time of the tool.
Contact machining allowance of machining line
At present, the conditions used are not in line with the popular CNC lathe, the edge should be too rough, especially for forging, casting hard pad placed in the ordinary lathe. If you have to use CNC lathe processing, pay attention to the flexible arrangement of the program. The following points: first, use the hydraulic clamping nut wrench to clamp the hydraulic cylinder, delete the slide, take out the spindle, and then manually chuck the fixing screw, which can unload the chuck.
Effective and reasonable turning
The comprehensive index of G200 turning center processing unit is modular, with high-power dual spindle and four axis linkage function, so as to further shorten the processing time. Work axis clamping means other concepts, on the other hand, the product uses an integrated intelligent processing unit to automatically clamp the workpiece position and treatment. In other words, automatic clamping does not affect other spindle machining, and a function can shorten processing time by about 10%.
In order to improve the accuracy and production efficiency
With the improvement of productivity level, users also have high precision. The tolerance of workpiece after machining by G200 turning center and cold start is + / – 6 mm. In the process of machining, it is usually 2 mm. Therefore, index company provides customers with complete solutions with high precision, high efficiency and high precision. It also provides solutions, which requires careful selection of spindle, bearing and other characteristics
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