These early Vertical Lathe machines were essentially horizontal turning centers configured in a vertical orientation. Over time, like most classes of machine tools, the inverted vertical lathe has evolved to add numerous multi-task machining capabilities that earlier machines did not have.
Going back to the origins of the VTL, inverted risers are built around the portal design; only reduced in size due to the diameters of the workpiece for which it is intended. The nominal size of the V160 chuck is 160 mm (6.5 inches) or 200 mm (8 inches), which is far from the meter / foot blanks that traditional VTLs are designed to handle.
Placing the main spindle on the X-axis bridge that connects the cantilever brackets creates a box-frame structure that is rigid regardless of the spindle's X-axis extreme travels. The spindle carrier is fully supported throughout its stroke.
Overall, the inverted cnc vertical lathe design is very well suited for automatic loading in various ways. The vertical spindle of the motor performs the "handling" and "machining" functions.
The self-loading inverted spindle concept eliminates the need to add automation systems as the movable spindle serves the dual function of an integral gate loader. Short traversing paths combined with high rapid traverse speeds significantly reduce unproductive times.
X-axis travel allows the main spindle to travel outside the machine's work area to "pick up" the blank from single or multiple conveyor systems located outside of the cutting area. The work area is easily accessible, allowing the use of many types of conveyor systems. The open front of this compact machine provides access for operator comfort and quick set-up and changeover.
The cnc vertical lathe machines use linear drives on the X axis, which is the usual manipulation axis on inverted risers. Linear motors achieve dynamics, speed and short handling times, which improves the loading / unloading function of the machine. The maximum rapid traverse speed of the relatively long X axis is 80 m / min or 3150 ipm and the acceleration speed is 1g.
The portal structure of the inverted vertical machine creates an open work zone, which gives greater possibilities for multi-task machining. It also uses gravity for simple and effective chip evacuation.
For some turning center configurations, as many as four heads are available with as many as 48 tool stations in which VDI preset tools for quick change can be fixed or movable. Two tool carriers can be configured with the optional Y and B axes. There are also other ways to configure this class of machine tools that can extend its production capabilities well beyond turning.
Overall, the open-front design concept significantly reduces set-up times and results in lower production costs, especially for small and medium-sized batches. Whether it is a compact version with one spindle and up to two tool carriers and an auxiliary tool clamping plate, or a version with main and counter spindles and as many as four tool carriers, productivity is a key feature. Index and other builders use a block system where various modules can be integrated into the work area to increase flexibility, allowing automation and other accessories that can be customized to obtain a process oriented solution optimized for the application.
As it developed from the 1980s, a cnc vertical lathe has evolved into a versatile and efficient metal machining center. In-process and post-process measurement can be easily added with minimal investment. By using the spindle as a gantry loader, you can integrate control into your process. On some computers Y/B axis is available, which permits angular and off-center drilling, milling and gaging.
The relatively large open work area allows the integration of special machining units such as internal or external grinding spindles, high power multi-spindle drilling heads, polygonal turning units or high frequency drilling and milling spindles, as well as large milling heads. All of these are in addition to standard VDI energized tools in the turret.
In the version with the counter spindle, both X axes are perpendicular to each other and intersect at the point of transfer of the workpiece. For backward machining operations, the workpiece can be transferred with a minimal loss of clamping precision to the counter spindle to machine the opposite end. This ensures the highest concentricity from one side to the other. The transfer point is programmable down to microns and provides the ability to process op 10 and op 20 in one work zone.
For small to medium and even large batches, the vertical lathe is very productive due to simultaneous machining with two tools. The proven concept also ensures process reliability, reduced set-up times, excellent availability and great tool possibilities in one or more heads. When using a glass balance, diameter tolerances of up to 0.003 mm can be achieved.
For larger volume continuous production, the vertical inverted machine concept allows several machines to be combined into a production line, cell or system, simply by extending the workpiece conveyor.
For external grinding, the grinding spindle supports grinding wheels up to 400 mm / 16 inch in diameter. It is driven by a programmable motor spindle with intercooled speed up to 6,000 rpm and a maximum power of 15 kW / 22 HP.
All kinds of metalworking plants are struggling with the acute shortage of qualified employees. Automation is one of the directions many stores are looking for to compensate for this shortage.
As the inverted riser concept has evolved, many of the metalworking options at its core are a fundamental step forward for a self loading / unloading machine tool. These machines do this without the need for external material handling equipment. It is a built-in automation that is included in the design of the machine.
By using a relatively simple conveyor system to supply blanks and remove entire parts, the system is ready for unattended or unattended machining. Capacity is determined by a conveyor system that can be expanded.
Freeing skilled machine operators is a key goal for many stores. The concept of an inverted vertical machine can be as simple or complex as the requirements of a workshop application, but regardless of the complexity of the setup, its inherent productivity benefits are free.
Thanks to the modular design and optional possibilities, the configuration of the inverted vertical lathe to your production strategy is almost unlimited.
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