In the processing of mechanical parts, the proportion of hole machining is quite large. Similar to high-speed milling, high-speed and high-precision drilling has been put on the agenda. High-efficiency hole machining is indispensable for the fair production of parts and components Important process. In recent years, the production of parts and components mostly adopts the production mode centered on the CNC numerical control drilling machine. When machining the holes, most of the advanced equipments such as the machining center and the CNC EDM drilling machine are also used. No matter which area of the hole processing, to achieve high precision and speed are important means of obtaining customer orders. CNC plane drilling
High-speed hole machining center (MC) conditions
A prerequisite for high-speed hole machining is the need to use high-speed machining centers, while the high-speed CNC drilling machine must meet the following conditions.
1. Equipped with high-speed rotary spindle
The drill bit has a center tooth like an end mill. Since the circumferential speed of the center tooth has a peripheral speed, the speed of the main shaft must also be increased when the cutting speed is increased. Especially in the use of small diameter drill, the spindle speed is indispensable. In the future, with the progress of high-speed hole machining, it is estimated that the demand of the spindle with the speed up to 30000 ~ 100000r / min will continue to increase. At the same time, the high-speed spindle is indispensable for high-speed and high-precision hole machining due to the short time required to reach the specified high-speed rotation and the requirement for the Z-axis (bit cutting direction) spindle extension to be kept to a minimum. condition.
2. The movable part has the action-sensitive function
The movable parts such as the main shaft and table should reduce the weight as much as possible in order to realize the quick action. This is also the condition that must be possessed for high-speed hole machining. 1 hole processing time only a few seconds, it is necessary to shorten the hole between the hole and the tool moving time, which is the key to achieving high efficiency cutting, the solution to this problem is the first move the movable part must be flexible Fast. For example, even if the high-precision positioning accuracy is achieved, if the movable part of the CNC drilling machine is not fast and sensitive, it is impossible to meet the current requirements of users for processing high-speed holes. The acceleration characteristic (G value) is usually used to determine the quick performance of the movable part of the CNC drilling machine. When G = 0.8 ~ 1.5, the numerical control drilling machine can be judged as a machining center with high and quick performance. CNC plane drilling
3. Table and the proportion of the overall area of CNC drilling should be small
As a user of the machining center, they would like to see as little space as possible on the workbench and on the workbench. In particular, hole processing such processing costs higher and lower added value of the processing field, it is best to use the kind of compact machining center. Such as the Japan Institute of Physics and Technology trial high-speed CNC milling machine, the processing range of 300mm2, CNC drilling machine body area of ?? 950mm2, CNC drilling machine about the maximum working area of about three times the size of the workpiece, the entire structure is very compact. The milling spindle speed 45000r / min, for high-speed cutting. The main axis is XY movement structure (the workbench is limited to Z axis movement). Its acceleration characteristic value G = 1.5, which indicates that this CNC drilling machine has the quick action function.
4. The spindle can supply coolant directly
In the drilling process, the processing L / D (drill diameter and hole depth ratio) in the hole above 5 must pay special attention to chip removal problems, the best choice of drill with a hole for stable processing. Adopting the method of supplying coolant from the center of the spindle is more convenient for changing the clamp bolts.
5. With CNC machining tool hole interpolation function
CNC cutting is characterized by the tool can be controlled by the fair path processing, in the hole for CNC cutting, spiral cutting, contour cutting, cutting tools such as interpolation, CNC control system with these functions can be In the hole processing to be applied.
High-speed hole machining center (MC) conditions
A prerequisite for high-speed hole machining is the need to use high-speed machining centers, while the high-speed CNC drilling machine must meet the following conditions.
1. Equipped with high-speed rotary spindle
The drill bit has a center tooth like an end mill. Since the circumferential speed of the center tooth has a peripheral speed, the speed of the main shaft must also be increased when the cutting speed is increased. Especially in the use of small diameter drill, the spindle speed is indispensable. In the future, with the progress of high-speed hole machining, it is estimated that the demand of the spindle with the speed up to 30000 ~ 100000r / min will continue to increase. At the same time, the high-speed spindle is indispensable for high-speed and high-precision hole machining due to the short time required to reach the specified high-speed rotation and the requirement for the Z-axis (bit cutting direction) spindle extension to be kept to a minimum. condition.
2. The movable part has the action-sensitive function
The movable parts such as the main shaft and table should reduce the weight as much as possible in order to realize the quick action. This is also the condition that must be possessed for high-speed hole machining. 1 hole processing time only a few seconds, it is necessary to shorten the hole between the hole and the tool moving time, which is the key to achieving high efficiency cutting, the solution to this problem is the first move the movable part must be flexible Fast. For example, even if the high-precision positioning accuracy is achieved, if the movable part of the CNC drilling machine is not fast and sensitive, it is impossible to meet the current requirements of users for processing high-speed holes. The acceleration characteristic (G value) is usually used to determine the quick performance of the movable part of the CNC drilling machine. When G = 0.8 ~ 1.5, the numerical control drilling machine can be judged as a machining center with high and quick performance. CNC plane drilling
3. Table and the proportion of the overall area of CNC drilling should be small
As a user of the machining center, they would like to see as little space as possible on the workbench and on the workbench. In particular, hole processing such processing costs higher and lower added value of the processing field, it is best to use the kind of compact machining center. Such as the Japan Institute of Physics and Technology trial high-speed CNC milling machine, the processing range of 300mm2, CNC drilling machine body area of ?? 950mm2, CNC drilling machine about the maximum working area of about three times the size of the workpiece, the entire structure is very compact. The milling spindle speed 45000r / min, for high-speed cutting. The main axis is XY movement structure (the workbench is limited to Z axis movement). Its acceleration characteristic value G = 1.5, which indicates that this CNC drilling machine has the quick action function.
4. The spindle can supply coolant directly
In the drilling process, the processing L / D (drill diameter and hole depth ratio) in the hole above 5 must pay special attention to chip removal problems, the best choice of drill with a hole for stable processing. Adopting the method of supplying coolant from the center of the spindle is more convenient for changing the clamp bolts.
5. With CNC machining tool hole interpolation function
CNC cutting is characterized by the tool can be controlled by the fair path processing, in the hole for CNC cutting, spiral cutting, contour cutting, cutting tools such as interpolation, CNC control system with these functions can be In the hole processing to be applied.
