In order to meet the requirements of the gear processing industry for manufacturing precision, production efficiency, clean production and quality improvement, the following development trends have emerged in the gear making machine and the tooth making technology.

Numerical control

Since the CNC control of each motion axis of the machine tool and the linkage between some of the axes are achieved, the following advantages are obtained:

(1) It has become extremely simple to increase the functions of the machine tool, such as hobbing small taper and drum gear.

(2) Shorten the transmission chain, and adopt semi-closed loop or full closed-loop control. Through numerical control compensation, the positioning accuracy and repeat positioning accuracy of each axis can be improved, thereby improving the machining accuracy and Cp value of the machine tool and increasing the reliability of the machine tool. .

(3) When changing the variety, the time for calculating and changing the gear hanging wheel and the differential hanging wheel, the feed and the spindle shifting are omitted, and the gear shaping machine also saves the time for changing the inclined rail, thereby reducing the auxiliary machining. Time increases the flexibility of the machine.

(4) Since the mechanical structure is simple, it can be designed to be more conducive to improving the rigidity of the machine tool and reducing the thermal deformation to the bottom.

(5) There is no mechanical connection between the shafts, and the structural design becomes typical, which is more conducive to the implementation of modular design and manufacturing.

2. High speed and high efficiency

The high speed of gear processing machines such as gear hobbing machines, gear shaping machines and gear grinding machines mainly means that the machine tools have high tool spindle speed and high table speed, which are the main indicators for improving cutting efficiency.

The spindle speed of the traditional mechanical gear hobbing machine is usually up to 500r/min, and the speed of the table is up to 32r/min. With the improvement of the performance of the gear processing tool, the high-speed and high-efficiency cutting of the gear processing machine has been rapidly developed and matured. The cutting speed of the tooth is from 100m/min to 500~600m/min, and the cutting feed rate is from 3~4mm/r to 20mm/r, which makes the maximum speed of the hobbing machine spindle reach 5500r/min and the highest working table. The speed can reach 800r/min, and the moving speed of machine parts can reach up to 10m/min. The high-power spindle system enables the machine to grind with grinding wheels with large diameter and length, which is beneficial to increase the life of the grinding wheel and also helps the operator to choose the most. Excellent grinding parameters to complete the grinding process.

Efficient machining is ensured by the machine tool from all aspects: the cast bed with the best vibration absorption effect; the integrated cooling medium circulation system that makes the machine have the best thermal stability; the large inclination and smooth design of the cutting zone protection partition The chips generated by dry cutting are quickly and effectively discharged; the feed system is driven by a preloaded, non-gap ball screw; the wear-resistant linear guide or the quantitatively-lubricated cast iron guide controlled by PLC. The application of the electric spindle increases the tool spindle, while the speed of the table is increased by using a high-precision helical gear pair or a torque motor. The electric spindle and the torque motor have the advantages of high rotation precision, no backlash and no maintenance.

3. High precision

Thanks to the high-precision, pre-loaded high-rigidity linear guides, ball screws, rolling bearings, electric spindles, torque motors and CNC technology, the precision of gear processing machines under high-speed machining conditions is guaranteed and improved. The accuracy of the electric spindle is generally 0.002mm for radial runout and 0.001mm for axial direction; the positioning accuracy of the ring torque servo motor is 0.5′′, and the repeat positioning accuracy is 0.01′′; the positioning accuracy of the linear motion axis is less than 0.008mm, and the repeat positioning accuracy is less than 0.005. Mm. Hobbing and gear shaping, although rough machining, can still achieve DIN 6~7 accuracy under high-speed cutting conditions, which guarantees high precision for the subsequent finishing process.

With the improvement of the production efficiency of gear grinding machines, the reduction of the cost of single gear grinding, and the constant pursuit of precision in automotive gears, the demand for gear grinding machines is increasing. At the same time, with the development of numerical control technology, each The functional extension between machine tools is easier to implement. Therefore, under the pressure of fierce market competition, the world's major dental machine tool manufacturers have joined the ranks of gear finishing machines represented by gear grinding machines. The development of this trend will enable the future of automotive gear processing to increasingly use the roll-grinding process.

4. Functional composite

The function compound type machine tool means that the machining process can be completed in one machine or in one time, so that the machining efficiency and accuracy of the workpiece can be improved. At present, gear processing machines mainly have the following functional composite combinations:

(1) Automatic feeding, turning, hobbing, chamfering, deburring, automatic cutting.

(2) Automatic feeding, turning, hobbing, chamfering, automatic cutting.

(3) Automatic feeding, turning, hobbing, grinding, automatic cutting.

(4) Automatic feeding, grinding inner hole, car end face, grinding gear, automatic cutting.

(5) Grinding surface, grinding outer circle, grinding end surface.

(6) Automatic feeding, chamfering, deburring, shaving, automatic cutting.

(7) Automatic feeding, hobbing, chamfering, deburring, automatic cutting.

(8) Automatic feeding, milling and bevel gears, chamfering and automatic cutting.

(9) Automatic feeding, chamfering, deburring, shaving, drying, automatic cutting.

5. Green environmental protection

The use of cutting fluid during the cutting process can improve tool life, improve the quality of the machined surface and facilitate the discharge of cutting heat without causing thermal deformation of the machine tool. However, the splashing of the cutting fluid and the formation of oil mist during high-speed cutting are particularly harmful to the ecological environment, especially to the health of the operator. For this reason, it is common to close the processing area with a shield and install an oil mist separator so that only the oil-free mist is discharged, and the cutting oil is recirculated back to the machine for recycling. However, this does not solve the environmental problem fundamentally, because the replacement of the deteriorated cutting fluid will seriously pollute the environment.

The cost of cutting fluid and cutting fluid attachment device consumed in wet gear processing accounts for about 20% of the processing cost. High-speed dry cutting can improve the processing efficiency by 2~3 times. The service life of the tool is 2~5 of wet cutting. Times, therefore, dry cutting reduces the processing cost of a single piece of gear.

High-speed dry cutting not only reduces cutting fluid consumption and cooling processing equipment, but also avoids environmental pollution, and improves production efficiency and reduces the manufacturing cost of a single gear. Therefore, high-speed dry cutting has become the goal and development direction pursued by tooth processing machine manufacturers for many years. With the high speed of gear processing machines, the improvement of machine rigidity, the perfect vibration resistance and the perfection of chip removal technology, and the further development of dry high-speed cutting tools, high-speed dry cutting has been fully realized on the cutting machine.

6. Intelligent

The combination of digital control technology, sensor technology, information technology and network control technology makes the CNC gear processing machine more intelligent.

Gear processing machine tools should realize error compensation, temperature compensation, automatic balance, anti-collision function, overload protection, automatic identification of workpieces, correct clamping of workpieces, machining of workpieces, tooth engagement, machining allowance, tool wear , online precision inspection, automatic dressing grinding wheel, zero programming interface, multi-function machining software, cutting technology expert system, automatic identification, remote control, remote diagnosis and other functions when the robot transports workpieces between machine tools.

Intelligentization is the basis for gear machine tools to improve reliability, safety, stability, complex parts processing, precision machining and unmanned production, and will continue to improve and improve.