In order to meet the requirements of manufacturing precision, production efficiency, clean production and improve the quality of gear processing industry, the following development trend of tooth machine and tooth making technology has appeared.
As the machine through the movement of the axis of CNC control and part of the axis between the linkage, has the following advantages:
1) increased the function of the machine, such as hobbing small taper and drum gear, etc. become extremely simple.
2) shorten the transmission chain, while the use of semi-closed-loop or closed-loop control, through the NC compensation can improve the positioning accuracy of each axis and repeat the positioning accuracy, thereby improving the machining accuracy and Cp value, increased machine reliability.
3) For the variety, due to the need to calculate and replace the tooth wheel and differential wheel, feed and spindle shift time, the gear machine also eliminates the need for changing the timing of the guide rail, thus reducing the auxiliary processing Time, increased the flexibility of the machine.
4) As the mechanical structure becomes simple, can be designed to be more conducive to improve the rigidity of the machine and the thermal deformation to the bottom.
5) There is no mechanical connection between the shafts, structural design has become typical, more conducive to the implementation of modular design and manufacturing.
Gear machining machines such as hobbing machines, gear shaper and high speed of the grinding machine mainly refers to the machine has a high tool spindle speed and high table speed, they are the main indicators to improve the cutting efficiency. Conventional mechanical hobbing machine hob spindle speed is usually up to 500r / min, table speed up to 32r / min. Metal processing micro letter, the content is good, worthy of attention. With the improvement of the gear machining tool performance, the high speed and efficient cutting of the gear machining machine has been developed rapidly and mature. The gear hobbing cutting speed has been increased from 100m / min to 500 ~ 600m / min, the cutting feed speed is from 3 ~ 4mm / r to 20mm / r, which makes the maximum speed of the hobbing machine spindle up to 5500r / min, the maximum speed of the table up to 800r / min, machine parts moving speed is also up to 10m / min; high-power spindle system allows the machine can use diameter and The length of the grinding wheel are grinding, is conducive to increasing the wheel life, but also help the operator to choose the best grinding parameters to complete the grinding process.
As a result of the use of high precision, with preloaded high-rigidity linear guide, ball screw, rolling bearing, spindle, torque motor and CNC technology, high-speed machining conditions under the gear machining machine accuracy is guaranteed and improved. Electric spindle accuracy is generally radial vibration 0.002mm, axial 0.001mm; ring torque servo motor positioning accuracy of 0.5 ", repeat positioning accuracy of 0.01"; linear motion axis positioning accuracy of less than 0.008mm, repeat positioning accuracy of less than 0.005 mm. Hobbing and gear teeth, although rough, but in high-speed cutting conditions can still achieve DIN 6 ~ 7 precision, for the subsequent finishing process to obtain high accuracy to provide a guarantee. With the increase in the production efficiency of the grinding machine, the reduction of the cost of the single gear grinding and the constant pursuit of the accuracy of the gears of the automobile gears, the demand for the grinding machine is increasing. At the same time, with the development of numerical control technology, The extension of the machine tool is easier to implement. Therefore, in the fierce market competition pressure, the world's major manufacturers of tooth-making machine manufacturers have joined the production of grinding machine as the representative of the gear finishing machine ranks. The development of this trend will make the future of automotive gear processing more and more rolling - grinding process.
The choice of gear material is a vital part of the current universal universal gear in the following several categories:
The properties of steel impact resistance, good toughness, the surface after a specific heat treatment greatly enhance its hardness, the most suitable for the manufacture of gear materials.
The alloy steel can improve the toughness, impact resistance, abrasion resistance and anti-gluing properties of the alloy according to the composition and properties of the metal, and improve the mechanical properties and improve the hardness of the tooth surface by heat treatment or chemical heat treatment The So for both high-speed, heavy load and requires small size, low-quality aviation gear, with excellent performance of the alloy steel to manufacture.
Cast steel wear resistance is better, it is used for large gears.