Several problems in the acceptance of new machine tools for CNC machine tools

In the actual inspection, many users have neglected the inspection of the accuracy of the machine tool during the acceptance of the new machine. It is considered that the new machine has been tested at the factory, and only the machine tool needs to be adjusted during the installation on site. The level of the machine, as long as the test parts are qualified, the machine is considered to pass the acceptance. These users often overlook the following questions: The new machine arrives at the scene through the transportation link. Due to the vibration and deformation caused by the transportation, the horizontal reference and the state of the factory inspection are completely different. At this time, the geometric accuracy of the machine tool deviates from the accuracy at the factory inspection. In recent years, our center has tested many imported machine tools in testing. Even famous brands have lost precision. According to statistics, there are nearly 90 CNC machine tools to make the scene re-tune, and must be re-inspected to determine the accuracy of the machine. First, even if the transportation link is not affected, large and medium-sized CNC machine tools are particularly affected by this. First, since the positional accuracy of the detecting element encoder grating or the like is directly mounted on the lead screw and the bed of the machine tool, the geometric precision adjustment has a certain influence on it. First, the positional accuracy deviation obtained by the inspection can be directly adjusted by the error compensation software of the numerical control machine tool, thereby improving the positional accuracy of the machine tool.

When testing new machine tools, it is only necessary to judge the overall quality of the machine tool by using the method of assessing the accuracy of the test part. It is not enough to use the standard as the standard of acceptance. It is necessary to comprehensively test the geometric accuracy accuracy and working accuracy of the machine tool. Only in this way can the machine work be guaranteed. In the past, there were many domestic machine tools. It is not common for all kinds of original Mu to undergo formal acceptance. Only the entire process of importing equipment can be checked and accepted. Even if there is a shortage of equipment, the quality can be quickly explained. It’s going to be successful. = Otherwise it will affect the installation and use of the equipment, resulting in greater economic losses.

The acceptance work is mainly based on the acceptance conditions specified on the machine tool's factory certificate and the test means provided by the user. The test results of the above-mentioned technical indicators of the machine tool certificate are determined, and the original data of the machine tool is stored in the technical file for future maintenance. The basis of the technical indicators.

After the CNC machine tool arrives at the factory, the equipment management department shall promptly organize the relevant personnel to open the box for inspection. The personnel participating in the inspection shall include equipment management personnel equipment planners, import business agents, customs inspection personnel, etc.

The inspection items include 1 packing list; 2 cores correspond to random operation and maintenance instructions. According to the technical documents of the paper data certificate, etc., check the quantity specifications and intact condition of the spare parts tools attached to the packing list; 4 check whether the control cabinet of the main control cabinet is damaged, such as moisture, corrosion, etc., and fill in the items one by one. The equipment is unpacked and accepted into the file.

If the unpacking inspection finds that the short parts or the model specifications are in a situation that the equipment has been seriously affected by the impact of the impact damage, such as moisture and corrosion, it should promptly report the evidence or claim to the relevant department.

The visual inspection includes the appearance of the machine and the visual inspection of the CNC cabinet. The appearance of steam detection here refers to the various inspections of the instrument 4 that can be entered into the hall with the naked eye. For example, whether the paint on the machine tool is peeled off, whether the protective covers are complete or not, and the work surface is particularly scratched and scratched.

Machine tool performance and CNC function acceptance Machine tool performance inspection Machine tool performance mainly includes spindle system performance, feed system performance, automatic tool change system electrical device safety device lubrication device gas-liquid device and various accessories. There are more than ten inspection contents of machine ice performance, and the inspection items of different types of machine tools are different. Some machine tools have pneumatic hydraulic devices, some also have automatic chip removal device automatic feeding device spindle lubrication thermostat contact type probe device, machining center also has tool magazine and automatic tool change device, work table automatic exchange device and other Attachment device. To verify that these devices are normal and reliable. The inspection is mainly through hearing and trial operation. Inspection, remote moving parts and auxiliary devices are abnormal and noise during the stop and operation of the treatment, lubrication system cooling system and whether the devices are normal. Check whether the safety device is complete and reliable, such as each motion axis over-travel protection function, current overload protection function, 卞 axis motor overheating, overload, automatic shutdown function, undervoltage and overvoltage protection.

The function of the CNC function is different depending on the type of machine being machined. The standard functions of the same type of CNC system are the same, but the control of the modern manufacturing system 2001 is more comprehensive than the advanced CNC system. For all users, all the functions are needed. Some functions can be selected by the user according to the actual needs and economic conditions of the production of this unit. This part of the function is called selective function.

Of course, the more selective features, the higher the price. The inspection and acceptance of the numerical control function shall be based on the manual of the numerical control system equipped with the machine tool and the provisions of the Ting goods contract, and the main functions that the machine tool should have are detected manually or by means of a program. The best way to verify the CNC function is to program it yourself. Let the machine run continuously 16 or 321 in the following.

In the inspection procedure, all the functions that the machine should have, as well as the various speeds of the spindle and the various feed speeds of the coordinate axes, and the automatic exchange of the table are all included.

Acceptance of CNC machine tool accuracy The acceptance of CNC machine tool accuracy must be completely dry after the installation of the foundation, and is carried out according to the general inspection rules of 13023996 gold 4 boring machine or the relevant standards. Accuracy detection content mainly includes geometric accuracy position accuracy and cutting accuracy.

The geometric accuracy of the CNC machine tool for the acceptance of geometric accuracy of the machine tool is a comprehensive reflection of the key components of the machine tool and the geometrical errors after assembly. Its detection content and method are similar to ordinary machine tools. For example, the machining center mainly detects the following items: the coordinates of the other 72 axes are perpendicular to each other, and the degree of work is 0; the movement of 1 axis is the parallelism of the blood; the parallelism of the spindle axis is the parallelism of the table; the spindle is in the direction of 172. Straightness of movement; axial runout of the main shaft; radial runout of the main shaft hole. It should be noted that the detection of geometric accuracy must be completed after the fine adjustment of the machine, and the adjustment items are not allowed. Because of the geometric precision, some items interact with each other, and at the same time, reduce the measurement tools and detection methods. Caused by mistake 2.

Inspection of machine positioning accuracy CNC machine positioning accuracy refers to the positional accuracy that the machine axes can achieve under the control of the numerical control device. According to the positional accuracy that each axis can achieve, it is possible to determine the accuracy that the part can achieve when machining the part. It mainly detects the positioning accuracy of each axis of the following contents; repeated positioning accuracy; reverse error; reversion accuracy of origin; position deviation; positioning system deviation. The main testing tools are micrometer and group block gauge standard scale optical reading microscope laser interferometer 360 tooth indexing standard turntable or multi-faceted prism.

The positioning accuracy of CNC machine tools can be understood as the running precision of the machine tool. The positioning viscosity of the CNC machine tool is determined by the CNC system and the mechanical transmission error. The moving parts of the machine tool are connected under the control of the numerical control device to reflect the precision that can be achieved by machining the parts. Positioning accuracy is an important test item.

The detection method of the positioning accuracy is generally performed according to the corresponding accuracy acceptance criteria. European machine tool manufacturers, generally adopt, 0 still, 3441 standard; Japanese machine tool manufacturers usually use 邶86201 or top 86336 or 86338 standard; China now adopts 817421.22000 21997. It should be noted that different standards have different definitions of accuracy. Very large, the definition and calculation method of the standard index should be clarified at the time of acceptance. The cutting precision of the machine tool is the comprehensive precision of the machine tool. It not only reflects the accuracy and positioning accuracy of the machine tool, but also includes the material of the test piece. The error caused by various factors such as the environmental temperature tool performance and the cutting conditions, so the amount of this element should be reduced by 4 times when cutting the test piece and the test piece. The main content of the machining center cutting test is the shape accuracy position accuracy. And the surface of the processing surface is rough. The customer machine tool manufacturer adopts the standard 菱-shaped diamond square test developed by the US National Aerospace Standard to verify the 叻 precision. The Chinese 3 American 1 Division Manufacturing Association recruits 5.54 standard using the ball bar and laser interferometer for 1 曰 test, evaluation CNC The comprehensive performance of the machine tool.

4 The standard of CNC machine tool testing is based on the standards of each country. In the test, you can refer to the following standard: 1906988 metal cutting machine general technical conditions; your 7421.998 machine tool inspection general rules in the special load into the finishing conditions of the machine tool Geometric accuracy, bamboo 7421.22000 machine tool inspection general rule of the first part of the CNC axis positioning accuracy and repeat positioning accuracy; 02301.1996 machine tool inspection general part of the machine under the no-load or finishing conditions of the geometric accuracy; this, 23021998 machine tool inspection general rules The positioning accuracy of the CNC axis and the determination of the repeat positioning accuracy, 79171998 machining center inspection conditions, the seventh part of the precision of the precision test pieces.

In the accuracy acceptance, there are technical indicators of important projects that are unqualified and affected, so that the machine tool manufacturers should negotiate, request repairs, re-adjust or seek financial compensation. If necessary, it is necessary to obtain evidence for filing, timely report to the home import and export inspection report, and make claims through the national legal procedures. At the same time, special attention should be paid to the validity period of the claim and the quality guarantee period. Knowing these basic questions is extremely beneficial to equipment acceptance management to reduce unnecessary losses.

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