Summary：The modern mechanical manufacturing technology and precision machining technology are briefly discussed，and the welding technology and processing technology commonly used in industrial are listed. It points out the specific method of error adjustment in machine tool and the concrete way of precision error compensation, so that to improve the precision of industrial machinery manufacturing and processing.

Key words: Modern; mechanical manufacturing technology; precision machining technology; discussion

With the growth of the national economy, industrial technology has made obvious progress.  At the same time, modern machinery manufacturing technology and precision machining technology have been widely used in machinery, electronics, metallurgy and other industrial aspects. However, with the continuous development of industrial technology, higher requirements for machinery manufacturing technology and machining processing technology have been put forward. In the process of product production, different processing techniques and mechanical equipment will produce different quality grades of products. In order to ensure the production quality of the enterprise and produce better products for consumers, Mechanical manufacturing technology and precision machining technology need to be further studied. At the same time, we should strengthen the exploration of mechanical technology and processing technology, it can effectively improve the production efficiency of enterprises, so as to enhance the market competitiveness of enterprises, and lay a good technical foundation for the long-term development of enterprises.

1. modern mechanical manufacturing process

At present, from the actual situation of China's industrial production, the mechanical manufacturing process has the wide cover range, high professionalism and complexity. This article will briefly discuss several commonly used processes in modern machinery manufacturing. Gas shielded welding process is a modern welding technology which is implemented by arc heat source, it mainly relies on gas as a protection medium, thus effectively protecting welding materials, so that the material will not appear cracks during the welding process and other problems.  Through the gas protection welding process, the gas protection layer of the arc can be formed during the welding process, which blocks the contact between the arc and the molten pool and the air, and reduces the influence of the harmful gas on the welding material, and ensures the quality of the welding process. At present, the commonly used protective gas is carbon dioxide in our nation, and because of its good protective effect, it has received warm welcome in modern machinery manufacturing. The resistance welding process is mainly to press the welding objects between the positive and negative electrodes, and to electrify them, and then the resistance heat effect is formed on the contact surface of the welded stage with the help of the current, until the object is melted, and the metal is integrated into one. This kind of resistance welding technology, which can be called pressure welding process, can be used in the environment with high mechanization, and is widely used by modern manufacturing industry because of its high quality, high production efficiency and heating time

2.Modern precision machining technology

With the continuous development of modern construction technology, various processing technologies have also made significant progress and become more and more precise, the following will be a brief analysis of the commonly used precision machining technology in China.

Precision cutting technology:  At present, the precision machining technology commonly used in industrial production is precision cutting technology. For example, in the process of machining tool, in order to ensure the rigidity of the machine tool and the thermal deformation performance can meet the demand of industrial production, the micro feed technology and precision control technology have been used to achieve the product precision.

Mold forming technology is mainly applied to the processing of electronic products, and even 1/3 of electronic products are realized by die processing. This is mainly because mold molding technology can improve the accuracy of abrasive tools and meet the accuracy requirements of electronic products. Ultra precision grinding technology is commonly used in the centralized processing of electrical circuit substrate silicon wafer. However, as the pace of industrial production is accelerating, the precision of the product is constantly improved, and the traditional grinding method has been unable to meet the actual needs of modern industrial processing, therefore, in the actual processing, the technical personnel need to do atomic level polishing treatment, so as to improve the result of ultra precision grinding technology and improve the precision of industrial manufacturing.  As a new technology, nanofabrication technology has been widely used in mechanical production, and with the progress of nanotechnology, nanometer processing technology has also developed obviously. At present, the global technology level nanometer processing technology can describe the Nanometer-scale line on the silicon chip, so as to achieve the purpose of improving the density of silicon chip information storage. Micro processing technology, as a new processing technology, is actually reducing the volume of electronic components and to improve the frequency of the use of electronic components, thus reducing the energy loss of the components. In the energy saving society, micro processing technology has been widely used in mechanical processing, which has promoted the precision of semiconductors and promoted the development of precision machining technology.

3. Machining tools in modern machinery manufacturing should be constantly adjusted

Machining is as the main production mode in modern manufacturing, it is also an important part of mechanical manufacturing. However, the machining process in modern machinery manufacturing, there is still a certain accuracy deviation, mainly caused by the spindle, guide rail and transmission chain. After a period of use, the machining tools will wear out, which will cause the machining accuracy to decrease, and ultimately cause the machining accuracy of the workpiece reduced. In order to ensure the accuracy of machine tool and improve the machining accuracy of workpiece , the technical personnel should solve the error problems in the machine tools, and ensure the precision of the machining tool through the precision control and the adjustment method. The rotary precision of the spindle of the machine tool will be reduced in the continuous running, and the rotation precision of bearing will also be reduced caused by other environmental factors. Therefore, the spindle rotation precision of the machine tool should be adjusted, the clearance of the bearing shall be strictly controlled, and the bearing can bear certain pressure and resistance during the rolling process, and so the bearing can bear certain pressure and resistance during the rolling, and make sure the elastic pressure in bearing balls are always the unchanged status. Only by this way can ensure that spindle rotation f machining tools does not appear accuracy error, so that the machining accuracy of mechanical equipment can be guaranteed. The adjustment of the guide precision of the machine tool can be achieved by adjust the clearance by moving the press plate. In this way, there will be a certain gap in the operation of the guide rail, when the parts slide on the guide rail, the tightness of the screws can be detected, Then, through corresponding adjustment, ensure the movement clearance of the guide rail can operate normally. in addition, technicians can adjust the clearance between the guides by grinding the scraper plate. During the adjustment process, attention should be paid to the tightness of the screws , and the screws should be fixed on the pressing plate.

4.Compensation for precision error

In order to ensure the precision of the mechanical equipment, the technicians also need to take some measures to compensate the precision error of the equipment so as to ensure the quality of the precision machining technology. Therefore, technicians can compensate for the accuracy of mechanical equipment by displacement compensation. Displacement compensation, technicians can compensate for the accuracy error through the radial run-out and axial shift compensation method, and to ensure the precision of machining. First, the technical personnel measure the parts assembled on the bearing, and detect the specific radial run-out value of the parts on the outer circle at the position of shaft assemble the parts, and determine the highest position point. In assembly, the two parts with highest radial run-out can be properly adjusted to make it in the opposite direction at 180 degrees, so as to achieve the purpose of counteracting radial run-out value each other partially. The Axial movement compensation should measure the vertical error and the specific direction between the bearing section of the spindle and the center line of the spindle, and measure the value and the highest point of the radial run-out error of the thrust bearing, and then move the bearing to the highest point of the shaft section of bearing position, so as to realize the reclosing of the lowest point of the thrust bearing section radial run-out.