In recent years in the manufacturing industry, working population and the number of skilled workers has been decreased. There are the demands for production method that maintain high-precision with few setup changes. From this kind of circumstance, we have switched from the conventional method of dividing the process to the method that integrate process with the multi-functional 5-axis/multitasking machine. In order to shortens the lead time, efficiently produces wide variety of workpieces, and saving production lines by reducing number of machines (Fig. 1).
Process Integration Technology
Gear machining technology
For OKUMA 5-axis/multitasking machine with turning function, we offer the “gear machining package” that enables gear machining with precision equivalent to gear special-purpose machine through power skiving and hobbing. The gear machining by power skiving with the 5-axis machining center MU-4000V-L (Fig.2). In this machining, B-axis (trunnion table) is indexed, C-axis (circular table) and tool spindle are synchronously controlled to machining the gear using gear special-purpose cutter. In this example, in addition to gear machining, other processes such as turning, milling, and drilling can be achieved in one chucking.
Measurement technology
◆ Process-intensive 3D measurement “NC gauging”
To measure large workpiece outside the machine requires time-consuming work such as removing and transporting the workpiece. There is an “NC gauging” as a function that performs 3D measurement on the machine without removing workpiece. With this function, it is possible to automatically generate the measurement program with simple teaching, and in addition to measure the diameter and longitudinal dimension of workpiece, it is also support various geometric precision measurements such as roundness and straightness.
◆ Measurement on gear “NC gear measurement”
“NC gear measurement” an application that performs gear-specific measurements on the machine such as tooth profile, tooth trace, pitch, runout, etc. It is possible to judge the accuracy immediately after machining by inputting the data of measurement point from the gear specification on the PC, and measure the gear with the NC gauging (Fig.3).
Turning Cut
Turning cut
This function enables process integration including machining of inclined shaft part by turning the cylindrical part of workpiece that is not on the main spindle center axis. This function is effective because the sealing surfaces and grooves that improve airtightness require for lathe machining, not endmill machining. The workpiece is fixed, and turning is performed by synchronizing the circular motion of the feed axis (X-Y axis, Y-Z axis, X-Y-Z axis) and M-axis indexing angle (Tool edge position control). It is achieved by wide Y-axis stroke and high followability (Fig.4).
Application of Laser Technology
We have proposed various process integration technologies as described above. It was not possible to solve the problem of requiring. Therefore, we have developed the “LASER EX” series of ultra-multitasking machines that combine metal additive manufacturing, coating, and precision quenching by applying cutting-edge laser technology that will be the core of next “manufacturing innovation.” The model lineup includes the multitasking machine “MULTUS U LASER EX” series and the 5-axis machining center “MU-V LASER EX” series.
Metal additive manufacturing
We have adopted the LMD (Laser Metal Deposition) method as our additive manufacturing technology (Fig.5). The LMD is a method in which metal powder is supplied from nozzle with inert gas, melted and bonded with laser beam. By arbitrarily switching and mixing metal powder, it is possible to easily change the material for additive manufacturing. It can be used for machining integrated parts of multiple material including coating, repairing, and correction machining. In addition, the control device OSP which was developed in-house, not only controls the laser output and the operation of powder device, but also programmatically control the laser spot diameter within the range of φ0.4 to 8.5 mm. This enables a wide range of applications, from high-definition additive manufacturing to high-efficiency manufacturing.
Laser hardening
The LASER EX series can stably supply high-quality laser light. Therefore, it supports not only additive manufacturing but also laser hardening. Laser hardening can raise the temperature of irradiation area only with laser light. The temperature of heated area exceeding the transformation point is rapidly lowered by the self-cooling effect of material. Therefore, it is possible to obtain hardened structure (Fig.6).
Article by: Okuma Techno (Thailand) Ltd. & MEGA Tech