Any machine tool builder striving to be responsive to customer interests and demands will reflect those interests and demands in the new machines it introduces. A case in point is Hitachi Seiki, which recently introduced a new horizontal machining center and a new turning center. Both of these machines pinpoint leading technology trends in milling and turning respectively. In the HMC arena, it's high speed machining with high precision contouring capability. (A flexible customer financing program and an Internet Website from Hitachi Seiki also tell you what shop owners are thinking about.)
The new horizontal machining center is designated HK630 and shows how machine tool builders around the world are dealing with two competing goals that are often difficult to achieve in the same machine design—high speed and high accuracy. Like opposing forces driving a vector, these goals are driving builders to reconfigure machine tool structures.
"Today's advanced, lightweight, resource-conserving part designs have created demand for high-efficiency machining that can handle a broad range of materials," observes Mark Leeser, vice president-general manager of Hitachi Seiki. He explains that besides handling traditional steel and cast iron, the HK630 is designed to provide extremely fast, highly accurate cutting of nonferrous workpieces, such as aluminum.
This model features a T-shaped bed, permitting column movement in the X-direction; and a rigid box column to absorb cutting forces. Standard operating features include a high-speed spindle with built-in motor to diminish vibration and deliver a smoother finished surface, while providing more responsive start-and-stop control. The built-in Seiki ATAC10 (Artificial Intelligence Thermal Accuracy Control) helps to minimize thermal distortion at high speeds. The large-capacity coolant tank and built-in chip flow jet coolant reduce thermal distortion while providing more complete chip disposal.
HK630 cutting feeds are as fast as 787 ipm, with standard spindle speeds up to 10000 rpm and a rapid traverse rate of up to 1172. Machine travels are 32 by 31.5 by 31.5 inches (X, Y, Z). Double-anchor, pre-tensioned ballscrews enable precise positioning while the standard 40-tool automatic toolchanger has a 2-second tool- to-tool time and 5-second chip-to-chip time.
The new Hitachi Seiki TF25 NC turning center, the latest upgrade to the loader-integrated TF series, has been developed for customers who require higher cutting performance, larger capacity, and increased power in a compact design. This model includes standard features designed for speed and accuracy, such as the Q-Setter, which computes and enters X and Z offsets in less than 40 seconds per tool. Square cast iron sliding guideways provide stability for heavy cuts. A built-in spindle motor minimizes vibration for increased precision and a smoother finished piece (there are no belts or gears) and is designed to reduce thermal distortion. The spindle design also minimizes interference with robotic loaders.
Machine travels measure 10.6 inches along the X-axis and 24.8 inches along the Z-axis, with spindle speeds up to 4000 rpm. Top rapid traverse rate is 1181 ipm, and maximum bar capacity is 2.5 inches. The turret features 10 tooling stations, each capable of accepting ID or OD tools.
"The TF25 can be used alone, or connected by the MR20F high-speed overhead robot with other TF25s and additional machine tools to form a versatile machining cell," Mr. Leeser notes of this model. The robot functions as an integrated loader, thus saving floor space while enabling both machining and workpiece transfer for consistent and dependable time cycles.
Hitachi Seiki's new customer financing program reflects the fact that, as shops move to flexible manufacturing technology, they need more flexible means for acquiring machine tools. Essentially, the program features a variety of fixed interest rate leasing arrangements that can be made directly with Hitachi Seiki Customer Finance, formed solely for this purpose.