CNC Technology – Page 82 – CNC Machining & Turning, Milling, Metal parts

Automatic parts show you the function of ultrasonic cleaning

Ultrasonic cleaning is to use the cavitation effect, acceleration effect and direct inflow effect of ultrasonic in the liquid to directly and tactfully affect the liquid and dirt, so that the dirt layer is distributed, emulsified and peeled to reach the cleaning target. At present, more cavitation and direct flow are used in the ultrasonic washing machine.

According to the frequency wave, it can be divided into three types: infrasound wave, acoustic wave and ultrasonic wave. The frequency of infrasound wave is below 20Hz; the frequency of sound wave is 20Hz ~ 20kHz; the frequency of ultrasonic wave is above 20kHz. The infrasound wave and ultrasonic wave in it can’t be heard by ordinary people. Because of the high frequency and short wavelength, the ultrasonic wave has good target and strong penetration, which is the reason of designing and manufacturing the ultrasonic washing machine.

It is one of the methods for protecting teeth and cleaning teeth. In today’s society, a lot of people will do ultrasonic tooth washing.

1. Complete: the key point of ultrasonic tooth washing lies in the subgingival calculus, which is the key cause of periodontitis. Only when the area is clean, can periodontitis be prevented and gum bleeding be improved. This is one of the advantages of ultrasonic tooth washing.

2. Painless: This is also the most important advantage of ultrasonic tooth washing. Adjust the frequency of the head of the cleaning machine according to the amount of calculus of the person who washed the teeth, so as to ensure that the process of tooth washing can be completed in a painless environment.

3. Polishing after operation: it can leave microscopic tiny scratches on the surface of teeth after cleaning. After polishing, it is better to make the teeth more bright and not easy to attach calculus and tooth stains.

4. Safety: all the equipment is sterilized by high temperature and high pressure. The advantages of ultrasonic tooth washing can be used to prevent cross effects.

Discussion on the design of fixture

With the development of machining industry, fixture is more and more valued. It is used in the boundary of machining and becomes an indispensable part of machining. With the development of machine tool technology towards the goal of high speed, high efficiency, meticulous, composite, intelligent and environmental protection, fixture technology is developing towards the goal of high precision, high efficiency, module, combination, general and economic.

Problems in design and research of fixture

Generally, the structure of fixture design is single, which makes people feel that the structure is not very complex. The more we find that the hydraulic fixture is widely used, which greatly simplifies the original mechanical structure. However, if we do not conduct detailed research in the design process, we will inevitably encounter unnecessary difficulties:

1. Blank allowance of machined parts

The size of forming blank is too large, and interference occurs. So we must plan the rough drawing before design. Leave plenty of space

2. Chip removal fluency of fixture

Due to the limited machining space of the machine tool, the fixture is often designed in a compact space. At this time, the iron chips in the machining process are often ignored to accumulate at the dead corner of the fixture.

There are many difficulties in the later processing because of the poor discharge of the liquid containing chips. Therefore, at the beginning of essence, we should study the problems in the process of machining. After all, the fixture will increase efficiency and be easy to operate

3. Overall opening of fixture

Neglecting the opening, making it difficult for the operator to install the card, time-consuming and laborious, and design taboo

4. Basic comment principle of fixture design

Each set of fixture has to go through many times of clamping and loosening behavior, so it may reach the user’s requirements at the beginning, but the fixture should have its accuracy maintenance, so do not design some unreasonable equipment.

Even if you are lucky now, it will not last forever. A good design should be tempered by time.

5. Interchangeability of positioning elements

It is important to wear the positioning elements, so it is necessary to study the quick and simple replacement. It is better not to design large parts

The accumulation of fixture design experience is very important, occasionally design is one thing, and in essence use is another thing, so good design is a process of accumulation and summary.

While studying the problems that should be paid attention to in the design of tooling and fixture, we should adhere to the following basic principles in the design of tooling and fixture

1. Meet the safety and reliability of workpiece positioning in the process of application

2. Sufficient bearing or clamping force to ensure the processing process of workpiece on the fixture

3. Meet the requirements of simple and rapid operation in the clamping process

4. Vulnerable parts must be structures that can be exchanged quickly. When conditions are sufficient, it is better not to use other equipment

5. Meet the reliability of repeated positioning of fixture in the process of adjustment or exchange

6. Try to prevent complex structure and high cost

7. Try to select standard parts as component parts

8. Systematization and standardization of internal products of the company

Because of the importance of fixture, its quality and accuracy directly affect the efficiency of machining, so it is very important to control its quality and accuracy from the source and choose a reliable and capable fixture manufacturer. Shenzhen huayanghua has been focusing on automobile inspection tools, fixture, pallet and three-dimensional processing for 13 years. Our team has cooperated with each other and strictly implemented the customer’s product requirements as our guidelines. We have arranged to complete the product requirements according to the quantity and deliver the products on time.

The technique of machining thin wall parts with CNC lathe

Because it is difficult to machine the thin wall of CNC lathe, especially the inner hole, because the thin wall is affected by the cutting force in the cutting process, it is easy to produce deformation. This leads to the phenomenon of “waist shape” with small ellipse or middle and big two ends. In addition, due to the poor heat dissipation during the processing of thin-walled casing, it is very easy to produce thermal deformation, making the size and shape and position errors. How to reduce the influence of cutting force on workpiece deformation is an important problem to be solved if it can not meet the drawing requirements.

The machining of thin-walled parts in CNC lathe is a difficult problem in turning, because of the poor rigidity and strength of thin-walled parts, which are easy to deform in machining, increase the form and position error of parts, and not easy to guarantee the machining quality of parts. It can make full use of the characteristics of high machining accuracy and high production efficiency of CNC lathe, and fully consider the influence of process problems on the machining quality of parts. Therefore, it can effectively overcome the deformation in the machining process of thin-walled parts and ensure the machining accuracy by testing the square surface of workpiece clamping, tool geometric parameters, programming, etc, It provides a good basis and reference for better machining thin-walled parts in the future.

No matter what form CNC lathe uses to process parts, first of all, it must start from checking the part drawing. It can be seen from the figure that the thin-walled parts are easy to deform when they are processed. It is not only inconvenient to clamp here, but also difficult to process the parts to be processed. A special thin-walled casing and shaft guard need to be designed.

Analysis of the problem that the CNC lathe can not change the tool

Analysis of the problem that the CNC lathe can not change the cutter 1. The three-phase phase phase of the cutter head motor is reversed or the phase is missing, and the two lines of the cutter head motor are mutually adjusted or checked for external power supply 2. The positive rotation control information Tl + the outgoing terminal of the non transmission multimeter system of the CNC lathe system, measure the + 24V and Tl + contacts, and change the cutter manually together to see if the transmission voltage of these two points is + 24V, If the voltage does not exist, it is a system obstacle, which needs to be sent to the factory for repair or replacement of related IC components.

Analysis of the problem that the CNC lathe can not change the tool

The Tl + transmission of forward rotation control information of the system is normal, but there is open circuit in the control information loop or components are damaged. Check whether the forward rotation control information line is open circuit and whether the contact touch of this loop is excellent; Check whether the DC relay or talk touch device is damaged. 4. If the mechanism is stuck, the tool holder will roll by hand. If the tightness level is not stuck, disassemble the tool holder, adjust the mechanism and participate in the smooth liquid.

The machine caused by too long time of anti lock is stuck on the machine to loosen the tool holder, and then the system parameters are adjusted to maintain the tool holder. At the time of anti lock, the tool holder motor of CNC lathe is damaged. Dismantle the tool holder motor and roll it over to see if the motor is rolling. If it is not rolling, and if the circuit is OK, replace the tool holder motor and the tool holder motor with water to form the motor short-circuit drying motor, and add protection Good insulation measures.

No power supply for cutter head motor of CNC lathe check whether the power supply circuit of cutter head motor is open circuit, whether the contact is excellent, and whether the strong electrical components are damaged; Check whether the fuse is fused and the pull-up resistance is not connected. Connect the tool position input information with 2K pull-up resistance. If this resistance is not connected, the tool holder does not turn on the macro level. In essence, the behavior is to turn forward first and then turn immediately, so that the tool holder does not seem to move.

How to control the surface roughness of machined parts

In the machining industry of mechanical parts, the surface roughness of workpieces is also called brightness. Generally, the surface roughness of carefully machined parts is relatively high. In the machining process of mechanical parts, how can we control the surface roughness of machined parts? Let’s share it with everyone!

1. Cutting processing amount: it is suggested to reduce the surface processing amount properly in the cutting feed amount.

2. Select the geometric parameters of the tool: from the geometric parameters of the machining tool, it can appropriately reduce the deflection angle of the pair and increase the radius of the arc of the tool tip, and if necessary, it can grind the polishing edge. It makes the cutting simple and reduces the surface roughness.

3. Control the vibration of machine tool: start from reducing the conflict between the tool and the workpiece, extruding, sharpening the tool edge, adding cutting fluid, and properly heat treating some workpiece materials with good toughness.

4. Choose the right processing technology: in the process of machining the well-rounded mechanical parts, the processing technology process is also very important. If the process flow is not correct, it may affect the processing quality and production efficiency. A lot of carefully processed parts need the requirement of brightness after finishing.

5. Raw material selection difference: mechanical equipment parts are composed of many different raw material processing. According to the raw material density difference, the selection of cutting tools and machine tools in the process of processing is directly related to the surface roughness.

The above is how to control the machining surface roughness of mechanical hardware parts, hoping to help everyone!

How to control the surface roughness of machined parts

1. Cutting processing amount: it is suggested to reduce the surface processing amount properly in the cutting feed amount.

2. Select the geometric parameters of the tool: from the geometric parameters of the machining tool, it can appropriately reduce the deflection angle of the pair and increase the arc radius of the tool tip, and if necessary, it can grind out the polishing edge. It makes the cutting simple and reduces the surface roughness.

The above is how to control the machining surface roughness of mechanical hardware parts, hoping to help everyone!

What is the overall level of machining

How to say, the so-called machinery industry, if only the industry related to mechanical processing, can be said to be the machinery industry, which can be divided into the broad sense machinery industry and the narrow sense machinery industry. At present, the machinery industry in China can be said to be too low. Compared with the West, there are many large workshops, usually processing materials, drawings and other things are foreign, but in the coastal area, Although it is a manual workshop, most of them have their own numerical control equipment, with high processing efficiency, usually mold based, and hardware.

The automatic lathe can automatically finish the multi process processing of small and medium-sized workpieces according to a certain program, automatically load and unload materials, and repeatedly process a batch of the same workpieces, which is applicable to a large number of large-scale production. Special lathe is a kind of lathe used to process the specific surface of a certain kind of workpiece, such as crankshaft lathe, camshaft lathe, wheel lathe, axle lathe, roll lathe and ingot lathe.

(1) The development is uneven, and the overall product level is low. Although the products of some enterprises have reached or are close to the international advanced level, overall, there is still a big gap between the accuracy of the mold, the roughness of the cavity surface, the production cycle, life and other indicators and the overseas advanced level.

(2) The technology and equipment are backward, and the organization and coordination strength are poor. Although some enterprises have changed their skills in recent years, the technology and equipment level is still relatively advanced, and the equipment level of some foreign-funded enterprises is not lagging behind overseas.

Factors affecting the dimensional accuracy of CNC machining

、 Preventable factors affecting dimensional accuracy of CNC machining

1. Processing technology

Most of the essential machining deviations are formed by different machining process theories. In order to ensure the basic machining process (such as “first rough and then fine, first surface and then hole, first large surface and then small surface” in milling numerical control machining, or “reduce the number of clamping, although select combined clamp” and other basic machining process details in fixture application), the machining deviation of iron chips to aluminum parts is reduced For the aluminum is very soft, the iron scraps removed are very simple to form processing deviation. For example, in FANUC or Huazhong machining center, although the g83 instruction is used to drill deep holes, the scrap iron may be removed instead of the G73 instruction.

2. Numerical calculation in manual programming and automatic programming

3. Three factors of cutting: cutting speed VC, feed F, cutting depth AP and tool compensation

In this respect, in simple words, under the condition of ensuring the machining quality and tool wear, adjust the parameters to fully develop the tool cutting function, so that the cutting efficiency is the highest and the machining cost is the lowest.

In the CNC lathe, there are some factors such as compensation for tool wear. Because I haven’t touched the lathe for a long time, I dare not talk about it in detail. Please search by myself.

4. Inaccurate tool setting is also a factor to form dimensional deviation. Therefore, although a good edge finder is selected, if the machine tool has an automatic tool setting device, it will be better

2、 Irresistible factors:

1. Cooling deformation of workpiece after processing

This is basically impossible to prevent, although in the processing of attention to the use of coolant, and in place measurement, attention to the workpiece deformation after cooling.

2. Stability of machine tool itself

If it is not a new machine tool or the machine tool has been processed a lot without debugging, the size deviation formed by the machine tool itself will appear. There are several factors to form the deviation of machine tool itself:

Mechanical

a. Loose between servo motor and lead screw

b. Ball screw bearing or nut worn

c. Insufficient smoothness between lead screw and nut

Electrical:

a. Servomotor obstacle

b. There is dirt inside the grating ruler

c. Servo amplifier obstruction

PMC recovery can be carried out for system parameters, so it is omitted

You need to know what non-standard parts are before processing

The non-standard parts processing professionals elaborate that if the country does not set strict standards and specifications, there is no related parameter regulations, other parts are under the control of the enterprise. There are many kinds of non standard parts, and there is no standard classification at present. The general classification is as follows:

Metal non standard parts:

The drawings are provided by the customer, and the manufacturer swindles the equipment according to the drawings to produce the corresponding products. Usually, there are more molds, yamen runner’s requirements, and the brightness are all in the customer’s regulations, and there is no positive paradigm. Products from forging to finishing need corresponding quality control. The process is complex and variable, and the cost is usually higher than the standard parts.

Non metallic non standard parts:

It is the processing of some non-metallic materials. For example, plastic, wood, stone, etc., in recent years, the development of injection molding industry and plastic mold has been increasingly refined. The quotation of curved surface design and programming numerical control has greatly improved the cost of non-standard processing and the grade of yamen runner.

Some tips of CNC machining programming

1. Using computer simulation system

With the development of computer technology and the constant enlargement of NC machining education, there are more and more NC machining simulation systems and their performance is improving day by day. Therefore, it can be used to start the inspection program and watch the tool movement to determine if there is a possibility of collision.

2. Using the simulation performance of CNC machining center

Generally, the more advanced CNC machining centers have graphic performance. After inputting the program, it is advisable to call graphic simulation to show the performance and watch the moving path of the tool in detail, so as to check whether the tool may collide with the workpiece or fixture.

3. Idling performance of CNC machining center

Using the idling performance of CNC machining center, we can check the accuracy of tool path. When the program is input into CNC machining center, it is advisable to install the tool or workpiece, and then press the idle operation button. At this time, the spindle does not rotate, and the worktable automatically operates according to the program track. At this time, it is advisable to find out whether the tool may collide with the workpiece or fixture. However, in this case, it must be ensured that when the workpiece is installed, the cutter cannot be installed; when the cutter is installed, the workpiece cannot be installed, otherwise there will be collision.

4. Locking performance of CNC machining center

Generally, CNC machining centers have locking performance (full lock or single shaft lock). When the program is entered, the z-axis is locked and the collision can be inferred from the z-axis coordinate value. The use of this performance should avoid tool change and other operations, otherwise the program cannot pass.

5. The configuration of coordinate system and cutter compensation must be accurate

When starting the CNC machining center, it is sure to configure the CNC machining center reference point. CNC machining center working coordinate system should be maintained as the same as programming, which is more and more z-axis target. If there is a mistake, it is quite possible for the milling cutter to collide with the workpiece. For the rest, the configuration of tool length compensation must be accurate. Otherwise, it is either empty machining or collision.

6. Raise programming skills

Programming is an important part of NC machining. To improve programming technology, we can prevent some unnecessary collisions at a great level.

For example, when milling the inner cavity of workpiece, the milling cutter is required to return to 100mm above the workpiece quickly. If programming with N50 G00 x0 Y0 Z100, the CNC machining center will linkage the three axes, and the milling cutter may collide with the workpiece, resulting in the breakage of the cutter and the workpiece, which will affect the accuracy of the CNC machining center, the following programs N40 G00 Z100; N50 x0 Y0 can be selected; That is to say, the tool first moves back to 100 mm above the workpiece, and then returns to the programming zero point, so as to avoid collision.

In a word, to be in charge of the programming technology of CNC machining center can improve the machining efficiency and quality, and prevent unnecessary errors in machining. This requires us to constantly sum up experience in practice and constantly increase, so as to further strengthen the strength of programming and processing