CNC Technology – Page 76 – CNC Machining & Turning, Milling, Metal parts

Precautions for CNC machining

1. The rotating speed of white steel knife shall not be too fast.

2. The copper cutter uses less white steel knife and more throwing knife or alloy knife.

3. When the workpiece is too high, it should be cut thick with different lengths of knives in layers.

4. Smooth the knife only when the margin is consistent. After the big knife is used for roughening, use the small knife to remove the surplus material.

5. The plane shall be processed with flat bottom knife and less spherical knife to reduce the processing time.

6. When the copper worker cleans the corner, first check the size of R on the corner, and then determine the size of the ball knife.

7. The four corners of the surface shall be level.

8. Where the slope is integer, it shall be processed with slope cutter, such as pipe position.

9. Before each working procedure, think about the surplus left after the previous working procedure, so as to avoid empty cutter or excessive machining.

10. Try to take a simple cutting path, such as contour, trenching, single side, less surround height.

11. When walking wcut, if you can walk finish, don’t walk rough.

12. When the shape of a smooth knife is smooth, it should be rough first, then fine. When the workpiece is too high, it should be smooth first, then the bottom.

13. Set tolerance reasonably to balance machining accuracy and computer calculation time. The tolerance is set to 1 / 5 of the allowance when opening rough, and to 0.01 when smoothing.

14. Do more processes to reduce the time of empty cutting. Think more and reduce the chance of mistakes. Do a little more auxiliary line auxiliary surface to improve the processing condition.

15. Establish a sense of responsibility and carefully check each parameter to avoid rework.

16. Be diligent in learning, good at thinking and continuous improvement.

Milling non plane, more ball knife, less end knife, do not be afraid to receive knife.

The small knife cleans the corner, the big knife is refined;

Don’t be afraid to mend the surface. Proper mending can improve the processing speed and beautify the processing effect.

High hardness of blank material: better reverse milling

Low hardness of blank material: good milling

Good accuracy, rigidity and finish machining of machine tool: it is more suitable for down milling and vice versa

It is strongly recommended to use down milling for the finishing of internal corners of parts.

Rough machining: better reverse milling, finish machining: better forward milling

Good toughness and low hardness of tool material: suitable for rough machining (machining with large amount of cutting)

Poor toughness and high hardness of tool material: suitable for finishing (machining with small cutting amount)

Operation rules of computer milling machine

Basic information of computer gong processing

1. When you enter the workshop for practice, you should wear work clothes, tie the big cuff tightly, and tie the shirt into the pants. Female students should wear safety helmets and incorporate braids into the helmets. Sandals, slippers, high heels, vests, skirts and scarves are not allowed to enter the workshop. Note: it is not allowed to operate the machine tool with gloves;

2. Be careful not to move or damage the warning signs installed on the machine tool;

3. Pay attention not to place obstacles around the machine tool, and the working space should be large enough;

4. If two or more people need to complete a certain work together, they should pay attention to the coordination and consistency between each other;

5. Compressed air is not allowed to clean the machine tool, electrical cabinet and NC unit;

6. The internship shall be conducted on the designated machine tool and computer. Without permission, other machine tools, tools or electrical switches shall not move randomly;

Preparations for computer gong processing

1. Before operation, you must be familiar with the general performance, structure, transmission principle and control program of CNC milling machine, and master the function and operation program of each operation button and indicator light. Do not operate and adjust the machine tool until you understand the whole operation process.

2. Before starting the machine tool, check whether the electrical control system of the machine tool is normal, whether the lubrication system is unblocked, whether the oil quality is good, and add enough lubricating oil according to the specified requirements, whether the operating handles are correct, whether the workpiece, fixture and cutter are firmly clamped, and whether the coolant is sufficient. Then start the idle car for 3-5 minutes, check whether the transmission parts are normal, and confirm that there is no fault After that, it can be used normally.

3. After the completion of the program debugging, it must be approved by the instructor before the step-by-step operation, and skip step execution is not allowed. Without the permission of the instructor, operate without permission or in violation of regulations. If the result is zero, the accident will be punished according to relevant regulations and the corresponding loss will be compensated

4. Before machining parts, it is necessary to strictly check whether the original point of the machine tool and the data of the cutting tool are normal and carry out the simulation operation without cutting path.

Precautions for computer gong processing

1. When processing parts, the protective door must be closed, and it is not allowed to stretch the head and hand into the protective door, and it is not allowed to open the protective door during processing;

2. During the processing, the operator shall not leave the machine tool without permission, and shall keep a high concentration of ideas and observe the operation state of the machine tool. In case of any abnormal phenomenon or accident, the program operation shall be terminated immediately, the power supply shall be cut off and the instructor shall be informed in time, and other operations are not allowed;

3. It is strictly prohibited to pat the control panel and touch the display screen. It is forbidden to knock the workbench, dividing head, clamp and guide rail;

4. It is forbidden to open the control cabinet of CNC system for viewing and touching without permission;

5. The operator shall not change the internal parameters of the machine tool at will. Students are not allowed to call or modify other programs not compiled by themselves;

6. On the machine tool control microcomputer, no other operation is allowed except for program operation and transmission and program copy;

7、 CNC milling machine belongs to large precision equipment. Except for the tools and workpieces placed on the workbench, it is strictly prohibited to stack any tools, clamps, blades, measuring tools, workpieces and other sundries on the machine tool;

8. It is forbidden to touch the tip of the knife and the iron scraps by hand. The iron scraps must be cleaned with an iron hook or a brush;

9. Do not touch the rotating spindle, workpiece or other moving parts by hand or any other means;

10. It is forbidden to measure the workpiece and change the speed manually in the process of processing, not to wipe the workpiece with cotton thread or clean the machine tool;

11. No trial operation;

12. When using the hand wheel or fast moving mode to move the position of each axis, be sure to see clearly the signs of “, -” in each direction of X, y, Z axis of the machine tool before moving. When moving, first turn the hand wheel slowly to observe whether the moving direction of the machine tool is correct before speeding up the moving speed;

13. When it is necessary to suspend the measurement of workpiece size during the operation of the program, the measurement can only be carried out after the machine tool stops completely and the spindle stops running, so as to avoid personal accidents;

14. If the machine tool is not used for several days, the NC and CRT parts shall be electrified for 2-3 hours every other day.

15. When the machine is shut down, it can only be shut down after the spindle stops for 3 minutes.

All kinds of machine tools in machining

With the development of industrial modernization, the processing and manufacturing of various parts are gradually from manual processing to mechanical processing. The development in the middle is rather tortuous. The first to realize mechanization is the textile industry in ancient China. The loom was the first processing equipment to replace the manual at that time. But in the stage of capitalist development, the industrial revolution in Britain rose because of the steam engine, and the machines in various industries of the steam engine were invented one after another. Later, the refining of oil promoted the development of engines, more mechanical products were produced one after another, and the operation speed and efficiency of machinery were greatly improved. Later, with the gradual improvement of electromagnetic theory, generators were also produced, and human beings began to use electricity, and various industries were booming. To the modern computer and other intelligent products operation and calculation has replaced a lot of human heavy work, the development of the machinery industry has also appeared the situation of the whole machinery. Baoding Honglian machine roll Co., Ltd. introduces the operation principle and development of various machine tools in detail.

The main processing in the mechanical processing industry includes turning, milling, planing, grinding and boring. But now the machining center basically contains these machining. The so-called turning is lathe machining, which uses the rotation movement of chuck and the feed movement of turning tool to cut workpiece. It mainly cuts some circular axis and symmetrical workpiece, and the machining accuracy is greatly improved. Milling is the most important machining method in mechanical processing. It processes the workpiece surface through the rotation and feed motion of milling cutter. Now, the diversification of milling machine adds more technology to milling. Both planer and grinder are used for planing and grinding the plane, groove and other processing surfaces of the workpiece to achieve a smoother and smoother surface. Boring machine is similar to drilling machine in hole processing, which is also essential in mechanical operation..

Features of sheet metal parts

1. Sheet metal has the characteristics of light weight, high strength, conductive (can be used for electromagnetic shielding), low cost, large-scale mass production performance and so on. At present, sheet metal has been widely used in the fields of electronic appliances, communication, automobile industry, medical devices and so on. For example, in computer case, mobile phone, MP3, sheet metal is an essential part.

2. With the application of sheet metal more and more widely, the design of sheet metal parts has become a very important part in the process of product development. Mechanical engineers must master the design skills of sheet metal parts, so that the designed sheet metal can not only meet the requirements of product function and appearance, but also make the stamping die manufacturing simple and low cost.

3. Sheet metal is sometimes used as trigger gold. The word comes from English sheet metal. Generally, some sheet metal is pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts by welding or a small amount of machining, such as the chimney, tin furnace, and car shell are sheet metal parts.

4. Modern sheet metal technology includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, metal plate bending forming, die forging, water jet cutting, precision welding, etc.

Advantages of copper zinc alloy in sheet metal processing

Among the materials of sheet metal processing, copper has many outstanding physical and chemical properties. For example, its thermal conductivity and conductivity are very high, its conductivity is second only to silver, and its thermal conductivity is second only to silver and gold. Chemical stability is strong, easy to dissolve, in the atmosphere, fresh water, sea water has a good corrosion resistance.

Copper zinc alloy, the color changes from yellow red to yellow with the increase of zinc content. The mechanical properties of brass are higher than that of pure copper, and it will not rust or be corroded under the same conditions. It has good plasticity and is widely used in the mechanical manufacturing industry to make various structural parts.

Moreover, it has high plasticity and can bear all kinds of cold and hot pressure sheet metal processing well. The disadvantage is that the strength and hardness are low. Generally, it does not make structural parts. Pure copper is also known as red copper, which is light rose or light red. After the copper oxide film is formed on the surface, its appearance is purple red

Source of sheet metal processing

Sheet metal processing is sometimes used for pulling metal processing. Generally, some metal sheets are pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts through welding or a small amount of machining, such as the chimney commonly used in the family, tin furnace, and automobile shell are sheet metal parts. Sheet metal processing is called sheet metal processing. For example, using plates to make chimneys, iron buckets, oil tanks, ventilation pipes, elbows, Tianyuan places, funnel-shaped and so on. The main processes are cutting, bending and buckling, bending and forming, welding, riveting and so on, which requires certain geometric knowledge. Sheet metal parts are sheet metal parts, which can be processed by stamping, bending, stretching and other means. A general definition is the parts with constant thickness in the process of processing. The corresponding parts are casting parts, forging parts, machining parts, etc. for example, the outer iron shell of the car is sheet metal parts, and some cabinets made of stainless steel are sheet metal parts..

Knowledge of machining

For processing of deformed and eccentric parts, the workpieces are generally fixed with a flower plate. Therefore, first of all, pay attention to the card. The claw and pressing plate shall not extend beyond the diameter of the disc, and it is better to install a shield. Secondly, pay attention to the counterweight of eccentric parts. It is important and appropriate. The clearance between the inner hole diameter of the counterweight and the screw diameter should be small. The rotating speed of the machine tool shall not be too high, so as to prevent the counterweight from moving outward under the centrifugal force during the rotation, colliding with the guide rail of the machine tool, breaking the screw and damaging the operator.

What safety requirements should the control system of machine tool equipment meet?

1. Easy to operate, reduce walking back and forth, avoid unnecessary bending and tiptoe.

2. The positioning is accurate and reliable to prevent misoperation due to slight vibration.

3. The movement direction of the operating parts and the movement direction of the operated parts of the machine tools shall meet the requirements, and shall be marked with simple symbols.

4. The necessary interlock mechanism shall be installed to prevent the uncoordinated action of the operating parts and the accidents caused by the uncoordinated operation of multiple persons.

5. The structure and arrangement position of handle, hand wheel and button shall meet the requirements. The start button shall be installed in the casing or equipped with a guard ring to prevent accidental touch. The handwheel and handle installed on the shaft rod will hurt people when rotating with the shaft during automatic feed, so the automatic release device shall be installed.

Basic knowledge of machining process

Basic knowledge of machining technology i. production process and production process of products refer to the whole process of transforming raw materials into finished products. The production process of mechanical products generally includes:

1. Preparation of production and technology, such as process design and design and manufacturing of special process equipment, preparation of production plan, preparation of production data, etc;

2. Manufacturing of blanks, such as casting, forging, stamping, etc;

3. Machining, cutting, heat treatment and surface treatment of parts;

4. Product assembly, such as general assembly, component assembly, commissioning inspection and paint, etc;

5. Production services such as the supply, transportation and storage of raw materials, purchased parts and tools;

The process of changing the shape, size, relative position and property of the production object in the production process to make it a finished product or semi-finished product is called process. For example, the manufacturing, machining, heat treatment and assembly of rough are all technological processes.

In the process of machining, if the shape, dimension and surface quality of the production object are directly changed by the method of machining, it is called machining process. Similarly, the process of assembling the processed parts into a machine to achieve the required assembly accuracy and obtain the predetermined technical performance is called the assembly process.

Machining process and assembly process are two main contents in the research of mechanical manufacturing technology.

2、 Composition of machining process

The machining process is composed of one or several sequential processes, which can be divided into several installation, working position, working step and cutting.

Several important steps in sheet metal processing

Sheet metal is sometimes used as trigger gold, which comes from the English word plate metal. Generally, some metal sheets are pressed by hand or die to produce plastic deformation, forming the desired shape and size, and further forming more complex parts through welding or a small amount of machining, such as the chimney commonly used in the family, tin furnace, and automobile shell are sheet metal parts.

Sheet metal processing is called sheet metal processing. For example, using plates to make chimneys, iron buckets, oil tanks, ventilation pipes, elbows, Tianyuan places, funnel-shaped and so on. The main processes are cutting, bending and buckling, bending and forming, welding, riveting and so on, which requires certain geometric knowledge.

Sheet metal parts are sheet metal parts, which can be processed by stamping, bending, stretching and other means. A general definition is the parts with constant thickness in the process of processing. The corresponding parts are casting parts, forging parts, machining parts, etc. for example, the iron shell outside the car is sheet metal parts, and some cabinets made of stainless steel are sheet metal parts.

Modern sheet metal technology includes: filament power winding, laser cutting, heavy processing, metal bonding, metal drawing, plasma cutting, precision welding, roll forming, metal plate bending forming, die forging, water jet cutting, precision welding, etc.

The surface treatment of sheet metal parts is also a very important part of the sheet metal processing process, because it can prevent parts from rusting and beautify the appearance of products. The function of surface pretreatment of sheet metal parts is mainly to remove oil, oxide skin, rust, etc. it is to prepare for surface post-treatment, and the latter treatment is mainly to spray (bake) paint, spray plastic and plating antirust layer, etc

General principles of the proposed process route for machining

1. Machining datum first

In the process of machining, the surface used as the positioning reference should be machined first, so as to provide the precision reference for the subsequent processing as soon as possible. It is called “benchmark first”.

2. Division of processing stages

Surfaces with high machining quality requirements are divided into three stages: rough machining, semi finishing and finishing. It is mainly to ensure the processing quality, to facilitate the rational use of equipment, to facilitate the arrangement of heat treatment process, and to facilitate the detection of blank defects.

3. Face before hole

For the box, bracket, connecting rod and other parts, the plane shall be machined before the hole is machined. In this way, the hole can be machined by plane positioning, ensuring the position accuracy of plane and hole, and bringing convenience to the machining of hole on plane.

4. Finishing

The finishing of the main surface of the workpiece after finishing (such as grinding, honing, fine grinding / rolling, etc.) shall be carried out at the last stage of the process route. The surface finish after finishing shall be over ra0.8um, and slight collision will damage the surface. In China, Japan, Germany and other countries, after finishing, flannelette shall be used for protection, no hands or other things are allowed Parts directly contact the workpiece, so as to avoid damage to the polished surface due to the transfer and installation between processes.