How to choose fixture and tool in high-speed computer gongs machining

When the processing batch of parts is not large, the combined fixture, adjustable fixture or other general fixtures should be used as far as possible to shorten the production preparation time and save production costs. Only when the computer gongs are produced in batches, the use of special fixtures is considered. The selected tool setting point is combined with mathematical processing and simplified programming.
The loading and unloading of parts shall be fast, convenient and reliable, so as to shorten the pause time of the CNC lathe, and the tool point can be easily calibrated on the lathe. All parts and components on the fixture shall not interfere with the machining of parts and surfaces by the machine tool. The fixture shall be open, and the components of its positioning and clamping mechanism shall not affect the tool running during processing. It is convenient for inspection during processing.
So how to choose fixture for high-speed computer gongs processing?
Focus on the following points:
1. For single-piece small-batch production, combination fixture, adjustable fixture and other general fixtures are preferred. In order to shorten production preparation time and save production costs.
2. In mass production, high-speed computer gongs are only considered to use special fixtures and strive for simple structure.
3. The loading and unloading of parts shall be fast, convenient and reliable, so as to shorten the pause time of the machine tool and reduce the auxiliary time.
4. In order to meet the NC machining accuracy, the fixture positioning and clamping accuracy are required to be high.
5. All parts and components on the fixture shall not interfere with the machining of the parts' surfaces by the machine tool, that is, the fixture shall be set aside, and its positioning and clamping elements shall not affect the machining. Pneumatic or hydraulic fixture and multi-station fixture can be used.
6. In order to improve the efficiency of NC machining, pneumatic or hydraulic fixtures and multi-station fixtures can be used for machining parts with large batches.
Cognition of high-speed computer gongs machining tools
1 Varieties of commonly used CNC milling tools
CNC machining tools must comply with the characteristics of high-speed, efficient and high automation of CNC machine tools. Generally, they should include general tools, general connecting tool handles and a large number of common tool handles. The tool handle of high-speed computer gongs should be connected with the tool and installed on the energy head of the machine tool. Therefore, it has been gradually standardized and serialized.
(1) According to the tool layout, it can be divided into:
Integral; Mosaic type, adopting welding or machine clamp type connection, machine clamp type can be divided into two types: non-indexable and indexable; Special types, such as composite cutters, shock absorbing cutters, etc.
(2) According to the materials used for making tools, they can be divided into:
High speed steel tool; Carbide tool; Diamond tool; Other material tools, such as cubic boron nitride tools, ceramic tools, etc.
(3) The cutting process can be divided into:
Turning tools, including outer circle, inner hole, thread, cutting tools, etc; Drilling tools, including drills, reamers, taps, etc; Boring tool; Milling tools, etc.
In order to comply with the requirements of CNC machine tools for durable, stable, adjustable and replaceable tools, the clamping indexable tools have been widely used in recent years, accounting for 30% to 40% of all CNC tools in quantity, and the amount of metal removal accounts for 80% to 90% of the total.
2 Tool selection
The tool selection is carried out under the human-computer interaction of NC programming. The selection of high-speed computer gong-milling machine tool includes the selection of milling cutter diameter and the number of milling cutter teeth. Selection of milling cutter diameter: generally try to select milling cutters with small diameter specifications. Because of the large diameter of the milling cutter and the increased cutting torque, it is easy to form cutting vibration, and the cutting length of the milling cutter increases, which reduces the milling efficiency. Of course, not necessarily. When the rigidity of the milling cutter is poor, the milling cutter with larger diameter should be selected as far as possible according to the processing environment to increase the rigidity of the milling cutter.
In the processing process of economical CNC machine tools, because the sharpening, measuring and changing of tools are mostly manual and take a long time, it is necessary to reasonably allocate the order of tools.
3 Rough and finish machining tools shall be used
The numerical control milling process involves a variety of milling and processing items. The processing instruments are divided into two categories: fine and coarse. There are also great differences between different work contents and the tool examples necessary for the processing products in the detailed milling process. If only one tool is used for processing, the processed products are more equal and difficult to distinguish accurately. The processed products are also difficult to meet the use requirements and do not meet the actual use. Only by adopting different tools, combining the actual environment of processing and production, and accurately classifying tools, can we improve the quality level of products, meet the utilization scale, and ensure the effectiveness of the products produced.
Compared with ball-end cutters, flat-end cutters have a great advantage in surface processing quality and cutting efficiency. Therefore, it is necessary to ensure processing. It is better to choose flat-end cutters in both rough and finish machining. At the time of milling three-dimensional workpieces, it is also best to choose a flat-head cutter, and make a more accurate selection based on the material of the cutter and the characteristics of the processed products. In contrast to high-speed computer gongs, in order to prevent over-cutting when machining and milling curved products, the best use of ball-end cutters is to pay attention to the processing accuracy and cutting interval, so as not to reduce work efficiency.
4. Use the active tool change effect of the machining center to improve the production efficiency
With the rapid development of science and technology, the former NC milling objects and related tools can no longer meet the new requirements of practical machining, and the work efficiency can not meet the new requirements of social development.
The adoption of active tool change objects has become the general trend. In the past, most of the NC milling operations were manually operated, with low efficiency and easy to waste a large number of human, material and financial resources, which is not conducive to the promotion of the quality of the work. Adopting the active tool change technology and scientifically improving the use of tools can improve the effectiveness of tool use, quickly select tools, and adopt active means for cutting. It not only saves time, but also improves the processing quality and effect of milling to meet the new characteristics of rational use of modern technology. Of course, the use of active tool change technology is not only a simple name, it must complete the inorganic combination of itself and the object, and the time and spacing of active tool change must be accurate to improve the production efficiency.