The most popular navigation system for machine too

2022-07-26
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The navigation system for machine tools

the length of time to complete orders is a decisive factor in the level of productivity. The modern navigation system can significantly reduce the non production downtime on the machine tool and greatly liberate the operators

with the increasingly fierce market competition, production-oriented enterprises must survive among competitors. The types of products are becoming more and more abundant, but the technological innovation and product life cycle are constantly shortening, the market saturation is becoming higher and higher, and the preparation time of products is becoming longer and longer. The production interruption due to the introduction of new processes is also increasing

STAMA Machine Tool Co., Ltd. located in schlierbach not only produces vertical machining centers, but also provides "turnkey" solutions. In the past, the "turnkey" program included not only manufacturing fixtures and tools, but also providing the entire process technology. In the future, by shortening the product life cycle and reducing the production batch, the downtime will be minimized with the help of equipment with improved performance. The different navigation system for machine tools can significantly improve the production efficiency

"smart" clamping of tools

standardization is the decisive factor in preparing and importing workpieces. All standardized tools, such as end mills, reaming drills and thread drills, can be kept in the tool magazine of the machine tool. It still takes a relatively long time to install additional tools into the tool magazine and remove unnecessary and redundant tools

too short tool engagement time will lead to adverse consequences: even the high-performance machine tool magazine cannot prepare the follow-up tool in a sufficiently short time. This creates additional operating time that is not related to production. Once the follow-up tool cannot be prepared, the shortest clamping time cannot be obtained. This requires the tool magazine of the machine tool to unload the tools in the order of program execution

however, the method of manually sequencing and loading the tools into the magazine involves two serious weaknesses. One weakness is that the existing tool in the magazine needs to be moved to another position first. Another weakness is that the sister tools necessary for production cannot be correctly positioned. With the help of the buffer station, the STAMA navigation system can correctly sequence the tools. Use the first program to arrange the corresponding storage space in the tool magazine, and then use the tools to complete the machining tasks according to the order of use. From the second stage of the program, the tools can be classified in the order of stopping in place. When the tool reaches its service life, the system can automatically call the corresponding sister tool to be clamped to the correct position in the tool magazine. If different programs need to call the same tool in the tool library at the same time, the navigation system can also arrange a reasonable machining sequence to achieve the shortest clamping time. The downtime of the machine tool depends only on the number of tools to be clamped. In addition, the modern machining method allows the machine tool to clamp the tools required by the next process while one process is being carried out. This "fastest" tool magazine is not based on the existing NC program, and it can hold other tools while the machine performs the main process (Fig. 1). While switching the NC program and changing the clamping equipment, the machine tool can still transport the required tools independently in the tool magazine. In this way, the part family can be automatically replaced and the processing method can be switched without human being on duty within the shortest downtime

Figure 1 even when the machine tool is still in the previous process, the tool can be installed and closed:

the "fastest" tool magazine can install and clamp other tools while executing the main process.

the statistical software of the "fastest as pneumatic fixture" tool magazine can count the use frequency of different tools and clear the tool with the lowest use rate out of the main tool magazine. In this way, The clamping times and the resulting non productive and satisfactory long-term cooperation can be reduced by 70%

in a stable machining process, the optimization of tool operation mode is of decisive significance for increasing output, reducing supply time and unit cost. In addition to reducing the failure rate of parts, the period from production interruption to system restart is an important but rarely involved step

dynamic navigation that can return to the "starting point" of the system

in the past, maintainability, quick change of parts and good service were equally important for machine tools. In fact, the error correction function of the system does not fully consider the operation of the machine tool when it is started

once there is interference between tools, the production process must be stopped immediately, which will also have a very serious negative impact. In case of thread idling or undercut, several feed shafts shall rotate at the same time. These cannot be operated manually. When drilling the thread, if the drill bit is stuck in the threaded hole, loosen the clamping washer and reset the machine tool in Z direction

if the tool is stuck in the undercut, the tool cannot be taken out even if it is operated manually. The operator can change several axial feeds to "squeeze" the tool from the undercut. This is, of course, an emergency measure in case of tool operation errors, but it is easy to damage the spindle of the machine tool. In many cases, the continuous damage of the spindle and the resulting downtime are the real reasons why the machine tool stops working

this requires a navigation system that can reset the tool to a safe initial position. Special machine tools also have special processes and tools. Each group of NC programs must have a tool withdrawal program. Machining centers also need a universally applicable dynamic navigation system. The performance of the system depends on the tool type and each feed action that will lead to production interruption. The patented STAMA initial position program (HPP) can meet these requirements. The programmer shall store the tool identification number related to the tool type in the NC program. Tool slopes are divided into different categories (e.g. drill, end mill, thread drill, T-shaped keyway mill). The machine tool should independently navigate the tool according to the tool type and the feeding action that leads to production interruption, and ensure that the tool cannot collide with the workpiece. Remove unnecessary tools and put them into the tool magazine. Obviously, this function is effective for emergency stop signal and power failure. For this, the operator only needs to press the "HPP" button (Fig. 2). In this case, idling is a fast and very important normal operation mode

Figure 2 one button reset: the operator presses the "reset sequence" button

event monitoring

the strict consequences of production interruption and excessive extension of interruption time can be avoided by using collision free idling. However, the navigation system cannot manage and eliminate the causes of production interruption. The alarm and error recording of modern high-performance CNC systems allow short-term grounding before production interruption. However, the operator can often restart or rewrite the process with the help of the self diagnostic function of the existing ring memory. Sporadic errors are not recorded

for example, if compressed air is used to clean the workpiece, the change of pressure will affect the cleaning effect. If some specific functions are mixed together, it may lead to function failure and production interruption. If the pressure of compressed air fluctuates for a short time and then becomes sufficient, it is very difficult to identify the cause of the fault. A similar situation occurs when the clamping device air pressure leaks. Oil spillage during wet processing is not easy to detect, and the pressure loss can be balanced by the hydraulic system. Unless the system treats an error as a fault signal, if the "clamped" signal is lost in a short time, the machine tool will not stop, which puts forward high requirements for the operator. Before the fault is identified and cleared, the fault should be identified in advance. The length of order completion time is becoming more and more decisive to the level of productivity. The modern navigation system can significantly reduce the non production downtime on the machine tool and greatly liberate the operators

the "slama event monitoring" function can identify the real fault causes in the form of mileage recorder according to the statistical preparation related to the status function. In this way, switch vibration, poor contact and similar shutdown causes can be identified and eliminated in time

the three-level navigation system can guide the operator to find the cause of machine tool shutdown. The system has specially opened up a section of non erasable storage space for recording the state of the machine tool from the equipment commissioning stage. It is also possible to compare the number of events recorded in the erasable storage space with the absolute number if the manufacturing conditions permit. In this way, before the current production interruption occurs, the system can analyze the frequent events and failure rates in a specific period of time (one day or one week)

Figure 3 identify and timely eliminate the causes of machine tool shutdown:

the event monitoring system is mainly used for error analysis

the navigation system can avoid non productive auxiliary time

the dynamic navigation system can help machine tool operators reduce very time-consuming or difficult production tasks. Contrary to the navigation system on the automobile, the machine tool can complete the guidance instructions independently with the help of the numerical control system. This system is not only effective for independently dividing the tools in the tool magazine of the machine tool, but also effective for idling without collision. This system can avoid the wrong operation that may be very expensive under special circumstances, and the large radian can reduce the non productive auxiliary time, but it does not put forward higher requirements for the dynamic load of the machine tool. (end)

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