Currently in the metal processing industry, the hot topics that people are most interested in are high-speed and high-precision machining. However, ten years ago, scientists and technicians focused their attention on a topic of special significance - how to reduce the vibration generated by the machine tool during processing.
The sign that the scientific and technical personnel focused their attention on the theme of reducing vibration is that each machine tool designer first considers how to go beyond the machines designed by the predecessors in the design of vertical and horizontal machining centers and other machine tools. It has a great breakthrough in solving the technical problem of vibration reduction.
They believe that the driving force is not very accurately applied to the center of gravity of the moving parts during processing. Thus there is a tendency to produce torsional motion at high cutting speeds, especially at higher feed speeds. This unavoidable torsional movement and the inertia effect due to the moving parts all cause the vibration of the machine tool and the bending and deformation of the machine tool components such as the machine bed or the column and the like.
However, people did not fully understand this point and did not solve the technical problem that has long plagued manufacturing. It is obvious that a fundamental solution to the problem lies in the design of the machine tool structure. The driving force acts as much as possible on the center of gravity of the moving part, ie, the center of gravity (DCG).
However, in reality, there is another problem. We cannot pass a ball screw directly through its center of gravity (there are machine parts in the middle, and there is no spatial position). For example, on a horizontal machining center, the fourth axis table is located exactly at the center of gravity of the Z axis, so it is not possible to install the ball screw in this optimal position.
Mori Seiki's designers deployed the Z-axis and Y-axis motion components between two ball screws on a newly developed DCG-driven vertical machining center to form an ideal but virtual center of gravity. But it can produce exactly the same effect as the actual driving force through the center of gravity. The vibration and bending caused when the respective shafts are driven are excellently suppressed, and the center of gravity does not change even when the moving components move at a high speed, thereby realizing stable driving.
According to Mori Seiki, they have made a DCG drive both theoretically and practically. They specifically embodied this design principle in the trademark of DCG.
Up to now, the company has three kinds of machining centers, using the DCG trademark: one is the NV4000 DCG vertical machining center and two horizontal machining centers NH4000 DCG and NH6300 DCG. Its main features are of course using DCG design principles and the following two design principles: All forces in the machining must be transmitted through the column to the machine bed to form a closed force transfer circuit. Under the premise of ensuring that the main components of the machine tool have sufficient strength, stiffness and good vibration damping characteristics, the main parts of the machine tool must be digitally analyzed to minimize the weight of the moving parts. Through the bold design of the machine tool by the Institute, the machine tool can reduce the vibration more than 10 times, and can significantly increase the acceleration/deceleration of the linear feed motion during machining without decreasing the surface roughness and geometrical accuracy. At the same time improve tool life.
One of the NV4000 DCG vertical machining centers, from the overall design of the machine, is indeed better than the ordinary vertical machining center. The first is the column of the arched structure and the DCG drive modes of the Y and Z axes. The arched column, with its high rigidity, has two deep holes machined from above the arched column to symmetrically install two sets of ball screws, which is a typical DCG drive structure. As a result, the Z-axis (main axis) of the machine tool is kept theoretically and virtually zero-suspended.
The double-ball screw DCG drive scheme is applied on the Y-axis (slide side), and the two sets of ball screws are mounted symmetrically on both sides of the machine bed casting. The center of the drive, which is mainly composed of two sets of ball screws, coincides with the center of the Y-axis slide, forming a DCG drive. The X-axis (table longitudinal) is designed in the center of the table and is driven by a ball screw. The ball screw is designed to be close to the center of the Y-axis ball screw. This is due to the fact that there are no other machine parts at the center of gravity of the X axis.
According to the Institute's introduction, they provide five sets of ball screw VMCs to the user at three sets of ball screw machine tool prices, and are excellent at preventing vibration, improving product quality, and greatly increasing production efficiency.
The features of the two horizontal machining centers of the series are the design of the latest box-in-box structure in which the spindle box is placed in the sports box, making the movement smooth and rigid. The double ball screw DCG drive scheme is applied to the X-axis and Z-axis (standard type). To reduce the weight of moving parts, the Y-axis is designed to be a ball screw drive scheme.
According to the development engineer, this configuration allows the machine to achieve both high acceleration machining and the best matching of the parts with high machining accuracy. The two ball screws on the X-axis are designed to be positioned on the upper and lower sides of the X-axis carriage, respectively, and coincide with the center of gravity of the slider, which has the dual effects of significant vibration reduction and high production efficiency.
According to the Institute, the series of products are mainly used in production workshops that require high-precision machining and small batch sizes. Manufacturers of cutting-edge products such as molds, medical devices and the aerospace industry will be buyers of the system's processing equipment.
The sign that the scientific and technical personnel focused their attention on the theme of reducing vibration is that each machine tool designer first considers how to go beyond the machines designed by the predecessors in the design of vertical and horizontal machining centers and other machine tools. It has a great breakthrough in solving the technical problem of vibration reduction.
This is the NV4000 DCG type vertical machining newly developed by Mori Seiki. It designs the machine's Z and Y axes to be DCG-driven by two ball screws, and the X-axis is driven by a ball screw.
The designers and engineers of the Mori Seiki in Japan proposed from the very beginning that the source of vibration that causes severe vibration in the metal processing system is mainly from the basic configuration of the machine tool itself. On the irrational. This is the conclusion drawn after they have focused on the study and analysis of the relationship between the linear motion axes and how the cutting forces act and transmit rapidly to the high-rigidity, high-rigidity machine motion components that move at high speeds.They believe that the driving force is not very accurately applied to the center of gravity of the moving parts during processing. Thus there is a tendency to produce torsional motion at high cutting speeds, especially at higher feed speeds. This unavoidable torsional movement and the inertia effect due to the moving parts all cause the vibration of the machine tool and the bending and deformation of the machine tool components such as the machine bed or the column and the like.
However, people did not fully understand this point and did not solve the technical problem that has long plagued manufacturing. It is obvious that a fundamental solution to the problem lies in the design of the machine tool structure. The driving force acts as much as possible on the center of gravity of the moving part, ie, the center of gravity (DCG).
However, in reality, there is another problem. We cannot pass a ball screw directly through its center of gravity (there are machine parts in the middle, and there is no spatial position). For example, on a horizontal machining center, the fourth axis table is located exactly at the center of gravity of the Z axis, so it is not possible to install the ball screw in this optimal position.
Mori Seiki's designers deployed the Z-axis and Y-axis motion components between two ball screws on a newly developed DCG-driven vertical machining center to form an ideal but virtual center of gravity. But it can produce exactly the same effect as the actual driving force through the center of gravity. The vibration and bending caused when the respective shafts are driven are excellently suppressed, and the center of gravity does not change even when the moving components move at a high speed, thereby realizing stable driving.
According to Mori Seiki, they have made a DCG drive both theoretically and practically. They specifically embodied this design principle in the trademark of DCG.
Up to now, the company has three kinds of machining centers, using the DCG trademark: one is the NV4000 DCG vertical machining center and two horizontal machining centers NH4000 DCG and NH6300 DCG. Its main features are of course using DCG design principles and the following two design principles: All forces in the machining must be transmitted through the column to the machine bed to form a closed force transfer circuit. Under the premise of ensuring that the main components of the machine tool have sufficient strength, stiffness and good vibration damping characteristics, the main parts of the machine tool must be digitally analyzed to minimize the weight of the moving parts. Through the bold design of the machine tool by the Institute, the machine tool can reduce the vibration more than 10 times, and can significantly increase the acceleration/deceleration of the linear feed motion during machining without decreasing the surface roughness and geometrical accuracy. At the same time improve tool life.
One of the NV4000 DCG vertical machining centers, from the overall design of the machine, is indeed better than the ordinary vertical machining center. The first is the column of the arched structure and the DCG drive modes of the Y and Z axes. The arched column, with its high rigidity, has two deep holes machined from above the arched column to symmetrically install two sets of ball screws, which is a typical DCG drive structure. As a result, the Z-axis (main axis) of the machine tool is kept theoretically and virtually zero-suspended.
The double-ball screw DCG drive scheme is applied on the Y-axis (slide side), and the two sets of ball screws are mounted symmetrically on both sides of the machine bed casting. The center of the drive, which is mainly composed of two sets of ball screws, coincides with the center of the Y-axis slide, forming a DCG drive. The X-axis (table longitudinal) is designed in the center of the table and is driven by a ball screw. The ball screw is designed to be close to the center of the Y-axis ball screw. This is due to the fact that there are no other machine parts at the center of gravity of the X axis.
According to the Institute's introduction, they provide five sets of ball screw VMCs to the user at three sets of ball screw machine tool prices, and are excellent at preventing vibration, improving product quality, and greatly increasing production efficiency.
The features of the two horizontal machining centers of the series are the design of the latest box-in-box structure in which the spindle box is placed in the sports box, making the movement smooth and rigid. The double ball screw DCG drive scheme is applied to the X-axis and Z-axis (standard type). To reduce the weight of moving parts, the Y-axis is designed to be a ball screw drive scheme.
According to the development engineer, this configuration allows the machine to achieve both high acceleration machining and the best matching of the parts with high machining accuracy. The two ball screws on the X-axis are designed to be positioned on the upper and lower sides of the X-axis carriage, respectively, and coincide with the center of gravity of the slider, which has the dual effects of significant vibration reduction and high production efficiency.
According to the Institute, the series of products are mainly used in production workshops that require high-precision machining and small batch sizes. Manufacturers of cutting-edge products such as molds, medical devices and the aerospace industry will be buyers of the system's processing equipment.