Category Archive CNC Technology

With the continuous development of industry, people’s living standards continue to improve. When Xiaobian talks about CNC processing, we feel very familiar, mainly because it is often carried out. As a skilled CNC programming operator, after understanding the machining requirements, process routes and machine characteristics of precision mechanical parts, he can operate the CNC machining machine to complete the task. Therefore, the working principle of CNC machining is divided into several points:

Firstly, in the clamping process, in order to simplify the machining origin of each positioning surface relative to CNC machining center, there should be accurate coordinate size. Secondly, the direction of mechanical parts installation is consistent with the workpiece coordinate system and machine coordinate system selected in programming, and directional installation. In the production and processing of batch precision mechanical parts, it is necessary to consider the fixture which can be disassembled in a short time and changed into a fixture suitable for new workpiece. Because the auxiliary time of CNC machining center has been compressed very short, the loading and unloading of supporting fixture can not take up too much time.

In the production of the fixture, should have as few workpieces as possible and higher stiffness. The fixture should be open as far as possible, the space position of clamping workpiece can be low or low, and the installation fixture can not interfere with the tool path. In order to avoid affecting the processing process, ensure that the processing content of the workpiece is completed within the stroke range of the spindle!

When there is an interactive worktable in CNC machining, the fixture design must prevent the spatial interference between the fixture and the machine tool due to the movement, up support, down support and rotation of the worktable. Try to finish all the processing contents in one clamping. When it is necessary to replace the clamping point, special attention should be paid not to damage the positioning accuracy due to the replacement of the clamping point. If necessary, it should be explained in the drawing processing technology

In order to improve our work efficiency, we often carry out CNC processing, we are familiar with it. Pay attention to details when processing to avoid problems. Today, I’d like to discuss the cover parts of CNC machining process with you

1. Process analysis of parts

The material of cover plate is cast iron, and the blank is casting. The cover plate needs to be processed for the plane, hole and thread are concentrated on a, B surface, the four sides of the edge do not need to be processed, the highest accuracy should reach it7 level. Then we can take the A-side as the positioning reference, and process it in the previous process. Select the B-side and the hole on the B-side to process on the machining center.

1. Design process

(1) Select processing method

Rough milling can be used for surface B_ Finish milling: the dimension accuracy of Φ 60h7 hole is it7, The roughness is ra0.8um, and the blank hole has been cast, so rough boring and semi precision boring can be carried out+ Fine boring: the dimension accuracy of Φ 12h8 hole is required to be grade it8, and the roughness is ra0.8um. In order to prevent the drilling deviation, we can drill the center hole, drill the hole, enlarge the hole, ream the hole; when the thread hole is between M6 and M20, we can drill the bottom hole first and then tap the thread.

(2) Determine the processing sequence

In order to reduce the frequency of tool change and according to the principle of rough before finish and face to hole, the processing route is as follows: rough and finish milling B surface – coarse, semi finish, finish boring Φ 60h7 – drilling the center hole of each smooth hole and threaded hole – drilling, expanding 4 × Φ 2h8 hole – countersinking 4 × Φ 16 hole – twisting 4 × Φ 12h8 hole – M16 screw hole, drilling bottom hole, chamfering and tapping.

For the long-term development trend of industry, there will be a variety of modern scientific and technological development, to get different industrial products production and processing. In the process of getting new processing procedures, the processing of “CNC processing” will get new operation procedures. Then in the development of modern industry, any trend change will get new technological innovation, making life begin to move towards a better direction. Therefore, for the development stage of CNC processing, there will be more appropriate trend processing process. Similarly, more technical operations will be carried out according to different processes.

Facing the development of various science and technology, it can be said that this era has begun to enter a prosperous stage. In different countries, different regions, the industrial development field is also constantly expanding to get better technology operation process. Then, in the development process of different industrial projects, more work will be carried out according to different national science and technology Industrial processing, also for different machinery and equipment, different industrial technology to get a simple but efficient technical operation process. Therefore, in the process of slow historical changes, the development of industry will get more changes and technological updates.

The process of “CNC processing” is to get more operation according to more process operation. For the current industrial development, will get more functional changes, to carry out different processing procedures, for the simplified operation of CNC processing, mainly for the development of high-tech processes, but also will get different scientific and technological processing process. So in the process of different industrial technology capacity changes, there will be a new processing trend.

rous operation, Dongguan CNC processing will also have new process processing changes.

But in different steps to carry out the specified CNC processing process, will be based on the better development trend, to get the processing change trend of different processes. Then, in the process of more steps, there will be different change operations. Therefore, in the process of CNC machining operation steps, the appropriate technology operation will be obtained, and the appropriate functional operation trend will be carried out. But in the process of specified steps processing, for CNC (computer gongs) processing trends, will be carried out in different steps.

Different processing routes will have better development and Realization of operation process, can carry out different change trend, and also can get better step processing trend according to the actual processing process. Therefore, for the CNC processing steps in the process of operation, to carry out a better function. In order to ensure the realization of various high-tech processing, it is necessary to ensure the process of determining the processing route to carry out better function operation. In the process of determining the CNC processing route, different processes will be carried out.

As the saying goes, people should learn to be lazy. Today, I’m going to tell you how to learn these skills when working with CNC. It’s much easier for us to learn these skills. Moreover, we can greatly improve the quality of our products. The following editor will tell you what skills CNC machining has when programming?

1. Computer simulation system for CNC machining application

With the development of computer technology and the expansion of NC machining teaching from time to time, there are more and more NC machining simulation systems, and their functions are becoming more and more perfect. Therefore, it can be used in the preliminary inspection procedure to observe the movement of the tool to determine whether there is a possibility of collision.

1. Locking function of CNC parts machining center

The common CNC machining center has locking function (full lock or single axis lock). When the program is input, the z-axis is locked and the collision can be judged by the coordinate value of z-axis. The application of this function should avoid the operation of tool change, otherwise the program can not pass through.

1. Improve programming skills

It is very important to be able to prevent some programming skills from collision in NC programming.

1. Application of the imitation function of CNC parts machining center

Common and more advanced CNC parts processing center has graphic display function. After inputting the program, it can call the graphic imitation display function to observe the movement track of the tool carefully, so as to check whether the tool may collide with the workpiece or fixture.

1. The coordinate system and cutter compensation must be set correctly

When starting CNC machining center, it is necessary to set reference point of CNC machining center. The working coordinate system of CNC machining center should be different from that of programming, especially in the direction of Z axis. If there is a mistake, the possibility of collision between milling cutter and workpiece is very large. In addition, the setting of tool length compensation must be correct, otherwise, it is either empty machining or collision.

1. The application of CNC parts machining center in idle running

The correctness of tool path can be checked by using the function of idle running of CNC parts machining center. When the program is input into CNC parts machining center, the tool or workpiece can be installed, and then the idle operation button is pressed. At this time, the spindle does not rotate, and the workbench runs automatically according to the program path. At this time, it can be found whether the tool may collide with the workpiece or fixture. However, in this case, it is necessary to ensure that when the workpiece is installed, the cutter cannot be installed; when the cutter is installed, the workpiece cannot be loaded, otherwise there will be collision.

In general, when the fault occurs, the alarm indicator light on the speed unit in the numerical control is abnormal, the fuse is blown out, and all kinds of jump switch for protection are given an alarm. After the failure, our work can not continue, which greatly delays our work efficiency. In fact, a lot of times, we can solve the problems by ourselves, but many people do not know what method can be used to deal with the sudden fault of CNC parts processing system. Today, the editor will teach you a few simple methods.

1. The protection switch of CNC parts processing system starts alarm. The protection switch is a device to protect the machine tool. For example, high voltage will burn some components and other emergency measures that cannot be controlled by the machine tool. When meeting these conditions, the protection switch will start to avoid unnecessary component damage, similar to safe stop and so on.
2. If the voltage is too low, the machine tool will give an alarm. The probability of this kind of occurrence in the machining center is very rare. This may be caused by the input voltage being lower than 85% of the rated value, or due to poor power connection.
3. The alarm is caused by the broken feedback line of the detection speed, which is an error alarm, because there is no problem in the airport, and there is a problem in the detection and feedback system. Most of the alarms are caused by the broken speed feedback line of the CNC servo motor of the machining center or the poor contact of the detection feedback line.
4. Overload alarm, the cause of overload alarm is that the CNC mechanical load of the machining center is abnormal, or the upper limit value of motor current on the speed control unit is set too low. The permanent magnet falling off on the permanent magnet motor will also cause overload alarm. If the CNC motor without brake in the machining center can’t rotate by hand or it is very hard to rotate the shaft when it is no-load, it means that the permanent magnet has fallen off completely.
5. The fuse on the CNC speed control unit of machining center is blown or the circuit breaker trips.
6. In general, there are two possibilities of high current alarm, that is, high current alarm caused by damage and short circuit of power drive element on CNC speed control unit of machining center.
7. High voltage will also cause alarm of machine tool. Generally, there are three possible situations of high voltage alarm, which may be that the input voltage of CNC of machining center exceeds 10% of rated value, or insulation performance of servo motor decreases, or high voltage caused by circuit of speed control unit of machining center.

The quality of repair work depends on the personnel condition. It is necessary for repair workers to have the following basic conditions: a high sense of responsibility and outstanding professional ethics; a wide range of knowledge, grasp the basic knowledge of computer skills, analog and digital circuits, automatic control and motor drive, inspection skills and mechanical processing technology and a certain level of foreign language; through outstanding skills training, master the work of CNC, drive and PLC Professional principle, understand CNC programming and programming language; understand the structure, have experimental skills and strong ability to operate; grasp a variety of commonly used (especially on-site) testing instruments, appearance and various maintenance tools.

2、 The conditions of CNC machining center maintenance methods

Prepare common spare parts and accessories; get practical assistance or supply of micro electronic components at any time; repair necessary things, instruments, appearance, wiring and microcomputer. The best way is to have a small programming system or programmer to assist equipment debugging; complete materials, manuals, circuit diagrams, repair instructions (including CNC operation instructions), interface, adjustment and diagnosis, driver instructions, PLC instructions (including PLC user program list), component forms, etc

“CNC parts processing” sequence

In our CNC machining parts, there are often several surfaces that need to be processed. Machining on the surface not only has certain accuracy requirements, but also is very important for the position requirements. In addition, the sequence of processing can not be disordered.

1. In order to ensure the important surface finish of CNC parts, it is necessary to finish the surface of important parts.
2. After finishing datum machining, roughing, semi finishing and finishing should be carried out on the main surfaces with high precision requirements. The surface with high precision needs to be finished.
3. The surface as a precision reference should be machined at the beginning of the CNC part processing process, because it is used to locate other surfaces in subsequent processes. That is, “benchmark first, then others”.
4. It is necessary to use coarse datum to locate the precise datum plane of CNC parts. In single piece production, small batch production and even batch production, for castings and forgings with complex shape or large size, as well as blanks with large size error, the marking process should be arranged before the machining process, so as to provide alignment reference for precision reference processing.
5. For the process prone to waste products, finishing and finishing can be appropriately placed in front, and some minor surface processing can be placed behind.

CNC machining, CNC machining refers to the processing with CNC machining tools. So what is the composition and characteristics of machine tools for processing?

CNC index controlled machine tool is programmed by NC machining language, usually G code. NC machining G code language tells CNC machine tool which Cartesian position coordinates, and controls the tool feed speed and spindle speed, as well as tool converter, coolant and other functions. Compared with manual machining, CNC machining has great advantages, such as the parts produced by CNC machining are very accurate and repeatable; CNC machining can produce parts with complex shapes that cannot be completed by manual processing. CNC machining technology has been widely promoted, most of the machining workshops have the ability of NC machining. The most common NC machining methods in typical machining workshops are CNC milling, CNC lathe and CNC EDM wire cutting (WEDM). The tool for NC milling is called CNC milling machine or CNC machining center. CNC turning lathe is called CNC lathe center. NC machining G code can be manually programmed, but usually the machining workshop uses CAM software to automatically read CAD file and generate G code program to control NC machine tool.

All kinds of machine tools are usually composed of the following basic parts: supporting parts, which are used to install and support other parts and workpieces to bear their weight and cutting force, such as bed and column; speed changing mechanism, which is used to change the speed of main motion; feed mechanism, which is used to change feed rate; headstock for installing machine tool spindle; tool holder, tool magazine; control and control system; lubrication system; cooling System. The accessory devices of machine tool include loading and unloading device, manipulator, industrial robot and other machine tool accessories, as well as chuck, suction cup spring chuck, vise, rotary table and dividing head and other machine tool accessories.

CNC machine tools have the following characteristics:

1、 High machining precision and stable machining quality;

2、 The complex shape of the parts can be processed by linkage;

3、 When the machining parts are changed, only the NC program needs to be changed, which can save the production preparation time;

4、 The machine tool itself has high precision and rigidity. It can choose favorable processing amount and high productivity (generally 3 ~ 5 times of ordinary machine tool);

5、 High degree of automation of machine tools can reduce labor intensity;

6、 Mass production, product quality is easy to control;

7、 The requirements for the quality of operators are low, and the technical requirements for maintenance personnel are high.

CNC machining refers to the processing with CNC machining tools. CNC index controlled machine tool is programmed by NC machining language, usually G code. NC machining G code language tells CNC machine tool which Cartesian position coordinates, and controls the tool feed speed and spindle speed, as well as tool converter, coolant and other functions. In CNC machining, the determination of processing route should follow the following principles.

1、 The accuracy and surface roughness of the workpiece to be processed shall be guaranteed.

2、 It can shorten the processing route, reduce the idle travel time and improve the processing efficiency.

3、 Simplify the workload of numerical calculation and simplify the processing program.

4、 For some reusable programs, subroutines should be used.