1. Structure determines equipment performance
There are many structural forms of five-axis machining centers, and their basic design fundamentally shapes the performance characteristics of the equipment, which are directly related to essential elements such as the robustness of the machine tool, the processing accuracy, operational stability and ease of use.
The following aspects should mainly be taken into account:
1) Linear axis movement method
2) Rigidity of equipment
3) Tilt rotation axis
4) Whether it is a five-axis linkage
5) Proximity on five axes
Makino’s D200Z, D800Z and a500Z series five-axis machining centers adopt an innovative “Z”-shaped high-rigidity bench architecture design. What is unique about this design is that the workbench does not rest on a stand at each end, but uses large diameter tilt bearings for added stability. Under this structure, the center of gravity B of the workpiece is exactly within the range of the fulcrum A. Compared with the traditional single support structure, this design greatly reduces the amount of bending d of the workbench, making the shorter moment arm L.
The tilt axis structural design ensures that its machining accuracy is comparable to 3-axis machining centers. Even when transporting and rotating heavy workpieces, the deformation of the workbench can be controlled to an extremely low level. At the same time, through the use of high rigidity bearings and direct drive motors, low vibration and high precision smooth rotation are achieved. In addition, it also has excellent spatial proximity performance, providing more possibilities for processing complex parts.
Angled axis construction for excellent spatial proximity
2. Accuracy of inclined rotation axis
In order to deeply understand the impact of inclined rotation axis accuracy on machining accuracy, we take Makino D800Z machine tool as an example.
First, you need to understand the conversion of base units of angles: 1 degree is 60 minutes and 1 minute is 60 seconds, so 1 degree is 3,600 seconds.
In the D800Z machine tool, the minimum resolution of its B and C axes reaches an extremely high level of 0.0001 degrees, which is equivalent to 0.36 seconds. Positioning accuracy is ±3 seconds.
Through the specific calculation chart, we can intuitively see what impact it will have on the machining accuracy when there is such a difference in accuracy in the inclined rotation axis. Specifically, even small angular deviations can result in significant errors between the machined part and the intended design.
Therefore, the accuracy of the inclined rotation axis is crucial to the machining accuracy of the machine tool. When selecting machine tools, we must pay special attention to this indicator to ensure that the processed parts can meet our precision requirements.
3. Avoidance of interference and collisions
In the field of five-axis machining, interference and collision prevention is an issue that must be taken seriously. To meet this challenge, Makino’s five-axis machining center is not only equipped with a computer-side software interference checking function, but also comes standard with an online real-time simulation CSG function. This function can also be effective in manual mode. to effectively prevent the occurrence of interference.
The working principle of the CSG function is quite advanced: it can pre-check possible errors such as tool setup or tool length adjustment before machining begins, thus minimizing errors. emergency stops during machining. Specifically, this function will predict the possibility of interference in real time based on pre-calibration and adjustment data, as well as position information such as coordinates and offset values in the CNC system.
Once the machine tool is stopped due to potential interference during operation, the CSG function immediately presents a status screen to help the operator quickly locate and confirm the expected interference location and direction of movement of the machine tool. the axis concerned. This way, operators can quickly take action to resolve the problem and restore normal machine operation.
4. Correction of the center of rotation
Due to factors such as environmental and temperature fluctuations, the position of the center of rotation may change, which poses a challenge to the precision of five-axis machining. To solve this problem, machine tools must have the ability to automatically correct via probes. This correction mechanism ensures that machining accuracy is verified and maintained during 3-axis, indexing and 5-axis machining. In addition, the tool assembly error must be strictly controlled within ±4 microns to ensure high standards of processing quality.
Automatically corrects the center of rotation on 5 axes using a probe
3-axis/indexing/5-axis machining accuracy verification processing
5. Link Accuracy
The linkage accuracy of a five-axis machining center is the result of a combination of factors. In order to provide specific reference, we can take Makino D200Z as an example to demonstrate its performance in bonding accuracy through actual processing cases.
Processing equipment: D200ZCAM: FFCAM Workpiece material: NAK80 (40HRC) Workpiece size: 140x140x35mm Cavity: Clear corner R0.22mm, depth 20mm Processing time: 1H35min/pocket Tools: 7 6 types
Bonding accuracy: position accuracy ±2 μm, shape accuracy ±3 μm
6. Support for the process
The ability to fully exploit the performance of a five-axis machining center depends on the choice of machining technology. For example, the use of special-shaped tools for processing can greatly improve the processing efficiency and fully demonstrate the potential of the equipment.
Treatment case: efficiency multiplied by 6!
Material: YXR33 (58HRC) Shape and size: as shown below, depth 30mm, draft angle 2°, free angle R3mm
Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.
