2020 – Page 51 – CNC Machining & Turning, Milling, Metal parts

What are some small problems in machining?

Metal parts processing, most of the use of mechanical equipment to complete the work, the effect is good, and the processing speed is fast, in a certain range involved is also relatively wide, the era is changing, we need to apply the mechanical equipment is also increasing, different industries, then the types of mechanical equipment, or classification, model are different, precisely because with the times Change, machining precision, requirements are higher and higher. So we must pay attention to the craftsmanship! What are the skills of turning simple shaft in machining knowledge?

Mechanical processing, Dongguan machining skills have what

(1) Before operation, check whether the machine tool operates normally and whether the workpiece and cutter are clamped firmly.

(2) The chuck wrench should be removed immediately after use.

(3) Before turning by hand, the relevant motorized handle should be put in neutral position.

(4) The lathe rotation speed should be suitable and the manual feed rate should be uniform.

(5) When cutting, start the machine first and then feed the tool. After cutting, the tool should be withdrawn first and then stop.

(6) When testing the workpiece, the shift handle should be in neutral position.

What are the machining skills

What is the axial datum in machining knowledge?

Compared with shaft, the expression scheme of sleeve is roughly the same as that of shaft. Generally, only one basic view and a small number of auxiliary views are needed. Only because the sleeve is hollow structure, it is necessary to carry out sectional representation (whether to use full section, half section or partial section depends on the complexity of the internal and external structure shape of the part). The dimension datum only has radial datum and axial datum. The axial datum should be the axial positioning surface when the sleeve is fitted to other parts, that is, the right end face of the left-hand 040 cylinder. The surface roughness requirement is such as the ring plane with Gen value of 0.8.

Mechanical processing, Dongguan machining skills have what

What is the method of threading in machining common sense?

If the diameter of the round rod is too large, it is difficult to insert the die and the thread is not complete if it is too small. The diameter of round rod can be calculated by consulting the manual or empirical formula: the diameter of round rod is 4 = (nominal diameter of thread) – 0.13p (pitch). The end of round rod with thread set shall be chamfered (15 ° ~ 20 °), and the diameter of small end of round rod after chamfering shall be less than the minor diameter of thread, so as to facilitate thread setting. The process of threading is similar to tapping. When threading, the die end face should be strictly vertical to the round rod. When starting to rotate the die, a little pressure should be evenly applied; after 3-4 turns of threading, the die can only be rotated without pressure. In the process of thread setting, it is necessary to reverse frequently for chip breaking. The thread of steel parts should be lubricated with oil.

Hardware processing design process to pay attention to what?

Metal parts, parts processing, is now very common, mainly related to our development, the better, the faster the development, the more research and development of mechanical equipment, the effect is better, the role is obvious, automation era, hardware accessories in a wide range, market development in recent years, however, hardware processing need to pay attention to the details Many, for example?

Dongguan Hardware processing, Dongguan Hardware processing effect is how

The designed stamping parts must meet the product use and technical performance, and be easy to assemble and repair.
The designed stamping parts must be conducive to improving the utilization rate of metal materials, reducing the varieties and specifications of materials, and reducing the consumption of materials as far as possible. If allowed, low-cost materials should be used to make the parts as much as possible to achieve no waste and less waste blanking.
The designed stamping parts must be simple in shape and reasonable in structure, so as to simplify the die structure and simplify the number of working procedures. In other words, the least and simplest stamping process is used to complete the processing of the whole part, reduce the use of other processing methods, and facilitate the stamping operation, facilitate the organization of mechanized and automatic production, and improve labor productivity.
Under the condition of ensuring normal use, the stamping parts designed should have lower requirements for dimensional accuracy and surface roughness, and be conducive to product exchange, reduce waste products and ensure product quality stability.
The design of stamping parts should be conducive to the use of existing equipment, process equipment and process flow to process them, and to extend the service life of the die.

What are the five evaluation indexes of precision hardware processing quality?

Our staff, in the production of anything, we should pay attention to whether its quality is up to the standard. We need to achieve some specified indicators. Tangxia precision hardware processing is the same. What are the five evaluation indicators of precision hardware processing quality?

Surface texture morphology: including surface waviness and surface texture direction in surface roughness,
Surface defects: including machining burr, flash, macro crack, surface tear and wrinkle.
Microstructure, surface metallurgy and chemical properties. It includes metallographic structure, micro crack and surface chemical properties.
Surface mechanical properties: including the degree and depth of work hardening, the size, direction and distribution of residual stress.
Other engineering and technical characteristics of the surface, including changes in electronic properties and optical properties.

What are the safety precautions in machining?

For our technicians, it’s very good for us to be familiar with various safety precautions, which can prevent and reduce the problems in this respect. The same is true for machining. What are the safety precautions in Dongguan machining?

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

(2) The positioning is accurate and reliable, so as to prevent misoperation caused by slight vibration.

(3) The movement direction of the operating parts of the machine tool and the moving direction of the operated parts shall meet the requirements, and there shall be 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 many people.

(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 with a guard ring to prevent accidental touch. The hand wheel and handle installed on the shaft rod will rotate along with the shaft to hurt people when feeding automatically, so the automatic release device should be installed.

Operation principle of precision hardware processing control system

In the same processing, there will be a variety of principles. For example, our machines will have working principles and operating principles, and our precision hardware processing is the same. So what is the operation principle of precision hardware processing control system?

Generally, CNC computer lathe processing control system can control the machine tool to automatically start and stop, change direction and change speed of the spindle according to the digital program instruction. It can automatically control the feed speed, direction and processing road, stop the processing, select the tool and adjust the cutting amount and walking path according to the tool size, and complete various auxiliary actions required in the processing. When using CNC machine tool to process parts, it only needs to program the part graphics, process parameters and processing steps in the form of digital information, and input them into the machine tool control system, and then turn them into the command signal driving the servo mechanism after the processing of the stop operation, so as to control the harmonious action of all parts of the machine tool and automatically process the parts. When changing the processing object, only need to rewrite the program code, input to the machine tool, can be installed by numerical control instead of human brain and hands of the overall function, control the whole process of processing, manufacturing arbitrary complex parts. When we use machine tools to process parts, CNC computer lathe processing usually needs to stop the various actions of the machine tool, one is to control the sequence of action, the other is to control the displacement of each moving part of the machine tool. When the CNC computer lathe is processed by ordinary machine tools, such operations as start-up, parking, tool moving, reversing, spindle speed changing and cutting fluid switching are all controlled by manual. When automatic machine tool and copying machine tool are used, the processing operation and motion parameters of the above CNC computer lathe are controlled by imitating quantity through the installation of designed cam, profiling and block. Although they can process complex parts, and have certain sensitivity and generality, the machining accuracy of parts is affected by the manufacturing accuracy of cam and profiling, and the process is also affected It took a long time to prepare

报错笔记

What are the processing principles of Dongguan machining?

When we are processing, it’s better to operate according to its processing principles. After all, this will not affect our Dongguan machining. So what are the processing principles of Dongguan machining? Let’s talk about it for us!

(1) In order to ensure the machining accuracy, the roughing and finishing should be carried out separately. During rough machining, the cutting amount is large, the cutting force and clamping force on the workpiece are large, the heat generation is more, and the machining surface has obvious work hardening phenomenon. There is a large internal stress in the workpiece. If the rough machining and rough machining are carried out continuously, the precision of the parts after finishing will be lost quickly because of the redistribution of stress. For some parts with high machining accuracy. After rough machining and before finishing, low temperature annealing or aging treatment should be arranged to eliminate internal stress.

(2) Reasonable selection of equipment. Rough machining is mainly to cut off most of the machining allowance and does not require high machining accuracy. Therefore, rough machining should be carried out on machine tools with high power and low precision, while the finishing process requires high-precision machine tools. Rough machining and finish machining are processed on different machine tools, which can not only give full play to the equipment capacity, but also extend the service life of precision machine tools.

(3) In machining process route, heat treatment process is often arranged. The arrangement of heat treatment process is as follows: in order to improve the cutting performance of metal, such as annealing, normalizing, quenching and tempering, it is generally arranged before machining. In order to eliminate internal stress, such as aging treatment, quenching and tempering treatment, it is generally arranged after rough machining and before finishing. In order to improve the mechanical properties of parts, such as carburizing, quenching, tempering, etc., they are generally arranged after machining. If there is large deformation after heat treatment, the final processing procedure must be arranged.

The above is a small series of Dongguan machining processing principle is which some of the analysis, more details please consult the site address.

What problems do you often encounter in CNC processing?

In this era of rapid development, the use of mechanical equipment processing, CNC processing, has been very common, but to achieve the quality, or accuracy, or the details of the processing, or the level of operators, many people will have doubts, what are these CNC, in fact, CNC, which we often say processing center, plays an increasingly important role in modern furniture production The more important the position is, you can say that it is the “production line standard configuration”, or you can think of it as a “necessary good tool”.

CNC processing, CNC processing economy will be affected by what factors

What principle should the arrangement of processing sequence follow? The arrangement of machining sequence should be considered according to the structure and blank condition of the parts, as well as the need of positioning and clamping. The key point is that the rigidity of the workpiece will not be damaged. Generally, the sequence should be carried out according to the following principles:

① The processing of the previous process cannot affect the positioning and clamping of the next process, and the machining process of general machine tool should be considered comprehensively.

② The inner shape and inner cavity processing sequence is carried out first, and then the contour processing process is carried out.

③ In order to reduce the times of repeated positioning, tool changing and pressing plate moving, it is better to connect the processes with the same positioning, clamping mode or the same tool.

④ For multiple procedures in the same installation, the process with less damage to the rigidity of the workpiece should be arranged first.

How to determine the tool setting point is reasonable? The tool setting point can be set on the part to be processed, but the tool setting point must be the reference position or the position that has been finished. Sometimes the tool setting point is damaged after the first process, which will lead to the second process and subsequent tool setting point can not be found. Therefore, in the first process of tool setting, it is necessary to set up a relative tool setting position where there is a relatively fixed dimension relationship with the positioning datum, so that the original tool setting point can be retrieved according to the relative position relationship between them. This relative tool setting position is usually set on the machine tool table or fixture, and the selection principle is as follows:

① Easy to find

② Programming is convenient

③ Small tool setting error

④ Inspection during processing

Problems caused by improper arrangement of CNC processing technology

With the continuous improvement of our science and technology, our various processing technologies, in the industry, are still used more, but if not done well, it will cause a series of problems, CNC processing is the same, so what are the problems caused by improper arrangement of CNC processing technology?

CNC machining process is too scattered

The reason for this problem lies in the fear of complexity, simple programming, simplified operation and processing, easy adjustment of tool setting with one tool, and being used to ordinary processing. In this way, the product quality is not easy to guarantee and the production efficiency can not be well developed. Therefore, CNC processing personnel and operators should be fully familiar with the knowledge of CNC machining, try more to master the relevant knowledge, as far as possible to use the method of process concentration for processing, more use, will naturally reflect its advantages. After adopting the centralized process, the unit processing time increases. We arrange two equipment face-to-face to realize the operation of two equipment by one person, which greatly improves the efficiency and ensures the quality.

CNC machining sequence is unreasonable

Some CNC processing operators consider some problems in preparation, and often arrange the processing sequence irrationally. NC machining is usually carried out according to the requirements of general machining process planning, such as first coarse and then fine (tool change), first inside and then outside, reasonable selection of cutting parameters, so that the quality and efficiency can be improved.

The above is the problem of improper arrangement of CNC processing technology introduced by Xiaobian. I hope it can help you. If you want to know more about it, you can consult us.

The content and scope of self inspection of computer gong processing

Self inspection content:

Stretching must be carried out on the drawing frame after the aluminum alloy profile is cooled to below 50 degrees. If the temperature is too high, the drawing will not only damage the human body and the wool top, but also cause twists and turns, twisting, poor function and other absolute waste products before and after aging due to the failure to completely eliminate the internal stress of aluminum alloy profiles.
The control of stretching amount is controlled at 1%, and it should be noted that if the stretching amount is too high, the scale error of head, middle and tail will occur, and the appearance of water ripple like twist (fish scale) mark, low elongation, high hardness and brittle (low plasticity). If the tensile strength is too low, the compressive strength and hardness of the profile will be low, even aging (quenching) can not improve the hardness, and the profile is easy to curve (commonly known as big knife bend).
In order to control the tensile deformation and the scale change of the whole profile, appropriate special clamp pad and appropriate method should be selected. In particular, the opening material, arc material, cantilever material, as well as the bending shape of the profile should pay more attention to the reasonable and useful use of stretch clamp pad.
Pay attention to the stress conditions of small feet, thin teeth, long legs, arc surface, inclined surface, opening and viewpoint of profiles with high width thickness ratio, long cantilever wall, large radian, great wall thickness difference and strange shape, so as to avoid the defects such as deformation, twisting and spiral of section or point scale.
Due to the heat blocking effect of wool top, the aluminum profiles with high demand for decorative appearance must be turned up and down, back and forth, so as to facilitate uniform heat dissipation and reduce the transverse bright spot defects caused by uneven heat dissipation and different crystallinity. Especially for aluminum profiles with large width and thick wall, more attention should be paid to them.
In the process of reclaiming, moving and stretching, it is not allowed to touch, pull, stack, jam and entangle with each other, and a certain space shall be reserved between them. The aluminum alloy profiles with easy twists and turns and the length of discharge shall be disposed in time, and the maintenance and disposal between them shall be done when necessary.

Self test range:

Before processing, the processor must clearly see the content of the process card, clearly know the parts, shapes and dimensions of the workpiece to be processed, and know the processing content of the next process.
Before clamping the workpiece, the blank size should be measured to see if it meets the requirements of the drawing, and the placement of the workpiece must be carefully checked whether it is consistent with the programming operation instruction.
Self inspection should be carried out in time after rough machining, so as to adjust the data with errors in time. The self inspection content mainly includes the position and size of the processing parts. For example:

(1) Whether the workpiece is loose;

(2) Whether the workpiece is correctly divided;

(3) Whether the dimension from the processing part to the reference edge (reference point) meets the drawing requirements;

(4) The position and size between the processing parts. After checking the position and size, measure the rough machined shape ruler (except arc).

After rough machining self inspection, finish machining is carried out. After finishing, the workers should check the shape and size of the processing parts: check the basic length and width of the vertical processing parts; measure the base point size marked on the drawing for the processing parts of the inclined plane.
The worker can remove the workpiece and send it to the inspector for special inspection after completing the self inspection of the workpiece and confirming that it meets the drawing and process requirements.

The route and advantages of computer gong processing

Computer gong processing route:

(1) the shortest cutting feed route. The cutting feed path is the shortest, which can effectively improve the production efficiency and reduce the tool loss. When arranging the shortest cutting feed route, the rigidity of the workpiece and processing technology should be ensured.

(2) the shortest empty route.

① Use the starting point skillfully. A general example of rough turning with rectangular circulation. The setting of tool setting point a takes into account the need for convenient tool change in the process of finishing turning, so it is set far away from the blank, and at the same time, the tool starting point and tool setting point are overlapped together

② Skillfully set up tool changing point. In order to consider the convenience and safety of tool change, sometimes the tool change point is also set far away from the blank. Then, when the second tool is replaced, the empty travel route of finishing turning must be longer; if the tool change point of the second tool is also set at the no point position in the middle, the empty travel distance can be shortened.

③ The route of “returning to zero” should be arranged reasonably. In order to simplify the calculation process and facilitate the verification, the programmer sometimes returns the end point of each tool to the position of tool setting point by executing the “return to zero” operation command, and then execute the subsequent program. This will increase the distance of the feed path and reduce the production efficiency. Therefore, in order to meet the requirement of the shortest feed path, the distance between the end point of the previous cutter and the starting point of the next cutter should be as short as possible or zero when arranging the “return to zero” route reasonably. In addition, when selecting the command to return to the tool point, on the premise of no interference, the direction of “return to zero” in both directions of x-axis and z-axis is adopted as far as possible, and the “return to zero” route of this function is the shortest.

(3) step cutting feed route of large surplus blank. Two kinds of cutting feed routes of too much stock are listed. It is the wrong step cutting route. Cutting in the order of one bucket and five times is the correct step cutting feed route. Because in the same amount of back knife.

(4) the continuous cutting feed route of the part contour finishing. One or several finishing operations can be arranged for the finish machining of part contour. The finished contour shall be machined continuously by the last tool. At this time, the advance and retreat position of the tool shall be selected appropriately. It is not necessary to arrange cutting, cutting out, tool changing and stopping in the continuous contour, so as to avoid damaging the balance state of the process system due to the sudden change of cutting force, resulting in scratches on the part contour Injuries, abrupt changes in shape or retention of knife marks.

(5) special feeding route. In the NC turning process, in general. The longitudinal feed of the tool is along the negative direction of the coordinate, but sometimes it is not reasonable to arrange the feed path according to the conventional negative direction. It may even damage the workpiece.

2、 Advantages of computer gong processing:

① A large number of tooling is reduced, and complex tooling is not needed to process parts with complex shapes. If you want to change the shape and size of parts, you only need to modify the part processing program, which is suitable for the development and modification of new products.

② The machining quality is stable, the machining precision is high, and the repetition precision is high, which can meet the processing requirements of aircraft.

③ In the case of multi variety and small batch production, the production efficiency is higher, the time of production preparation, machine tool adjustment and process inspection can be reduced, and the cutting time is reduced due to the use of the best cutting amount.

④ It can machine complex surface which is difficult to process by conventional method, and even can process some parts which cannot be observed. The disadvantage of NC machining is the high cost of machine tools, which requires maintenance personnel to have a high level.