2021 – Page 40 – CNC Machining & Turning, Milling, Metal parts

Features of precision grinder – computer gong

So what are the characteristics of gantry precision grinder processing?

Taiwan ball screw is equipped on the bed, beam and end milling head, which is driven by servo motor.
The unique cross beam lifting safety interlock device ensures the repeated positioning accuracy of the machine tool.
The side milling head is equipped with V5 gantry milling head, the computer gong processing is equipped with independent lubrication device, the lifting is driven by ordinary reducer, and the frequency control is adopted.
The end milling head of gantry precision grinder is equipped with tx400 heavy gantry milling head, double rectangular guide rail and strong rigidity; the milling head is equipped with ball screw, pneumatic broach device and driven by servo motor.
The general milling / NC milling one key conversion three-axis CNC system of gantry precision grinding machine is programmable and can be operated manually by using the extended panel, which has strong practicability in the actual machining process.

Do not cut off the connection of protective device when overhaul the electrical equipment of large water mill.

Electrical maintenance personnel should wear insulating gloves and rubber shoes to avoid electric accidents. And do not wear metal jewelry and other conductive articles that may lead to false electric shock.

Before overhauling the electrical equipment, pay attention to follow the instructions of the relevant warning plate, and use the appropriate three watt hour meter to confirm that the circuit is open circuit.

When overhauling the electrical equipment of the large gantry grinder, the main power switch must be cut off, and warning signs must be erected, so as to avoid the accidental injury caused by the reactivation of the large water mill without the knowledge of others.

When the motor is activated in the grinding machine, there may be sparks at the contact point of the electrical box, so the machine can not be used in dust, gas explosion and flammable places.

The electric box of large water mill is designed for the safe operation of the machine. No one is allowed to modify the structure and circuit design of the electric box without the authorization of our company.

The operator must be familiar with the position of emergency stop switch and main power activation switch of large water mill. In case of emergency, the machine can be stopped and the power can be cut off at the first time.

Process specification is one of the process documents that stipulate the machining process and operation method of parts. It is written into the process in accordance with the specified form for the machining of mechanical parts under the specific production conditions. The large-scale computer CNC machining center is a kind of CNC machining center with tool magazine and can automatically replace the tool, which can control the workpiece at a certain speed CNC machine tools for a variety of processing operations.

Large computer gong machining center is usually classified by the relative position of spindle and worktable, which is divided into horizontal, vertical and multi axis linkage machining center.

A horizontal machining center: it refers to the machining center with the spindle axis parallel to the workbench, which is mainly suitable for machining box parts.

B vertical machining center: it refers to the machining center with the spindle axis perpendicular to the worktable, which is mainly suitable for processing plate, plate, mold and small shell complex parts. C multi axis linkage machining center, also known as universal machining center, refers to the machining center that can control linkage change through the angle between the spindle axis and the rotary axis of the worktable to complete the machining of complex spatial surface. It is suitable for machining impeller rotor, mould, cutting tool and other workpieces with complex space surface.

After the machined parts are clamped once, the CNC system can control the machine tool to automatically select and replace the cutting tools according to different processes; automatically change the spindle speed of the machine tool, the feed rate of Dongguan CNC machining center, the movement path of the cutting tool relative to the workpiece and other auxiliary functions, and continuously carry out multiple processes such as drilling, countersinking, reaming, boring, tapping, milling, etc Processing.

Because the early CNC system of milling machine does not have the function of function calculation, it is difficult to work out the processing program of function equation curve directly with G code, and the CAD / CAM software (with lower version) usually does not have the function of inputting graph directly from equation, so it is very difficult to process the contour of function equation curve.

The programming method of machining center: the contour composed of simple contour line and arc is directly programmed with G code of NC system. In this paper, the complex outline of three-dimensional curved surface is drawn with CAD / CAM software in the computer. According to the type of curved surface, the corresponding parameters are set, and the NC machining program is automatically generated. The above two programming methods can basically meet the requirements of NC machining.

The process of large-scale mechanical parts processing plant is to change the shape, size, relative position and nature of the production object on the basis of the process, so as to make it into finished or semi-finished products. It is the detailed description of each step and each process,

The specific technical requirements are as follows: ‘

(1) Remove oxide scale from parts.

(2) The unmarked shape tolerance shall meet the requirements of gb1184-80, and the allowable deviation of unmarked length dimension shall be ± 0.5mm. The tolerance zone of casting is symmetrical to the basic dimension configuration of blank casting.

(3) When assembling rolling bearings, it is allowed to use oil heating for hot charging, and the oil temperature shall not exceed 100 ℃. There should be no scratch, scratch and other defects on the surface of parts.

(4) When assembling the hydraulic system, it is allowed to use sealing packing or sealant, but it should be prevented from entering the system. Before assembly, the main fit dimensions of parts and components, especially the interference fit dimensions and relevant accuracy shall be rechecked.

(5) The parts and components to be assembled must have the certificate of inspection department before they can be assembled. Parts must be cleaned and cleaned before assembly, without burr, flash, oxide scale, rust, chip, oil stain, colorant and dust.

(6) Parts shall not be knocked, touched, scratched or rusted during assembly. When fastening screws, bolts and nuts, it is strictly forbidden to strike or use improper screwdrivers and spanners. After tightening, the screw groove, nut, screw and bolt head shall not be damaged. For fasteners with specified tightening torque requirements, torque wrench must be used and tightened according to specified tightening torque. After bonding, the excess adhesive should be removed. The semicircular holes of the bearing outer ring, the open bearing seat and the bearing cover shall not be stuck; the semicircular holes of the bearing outer ring, the open bearing seat and the bearing cover shall be in good contact, and they shall be in uniform contact with the bearing seat within the range of 120 ° symmetrical to the center line, and the machining of Dongguan Mechanical parts and the bearing cover within the range of 90 ° symmetrical to the center line. When checking with a feeler gauge within the above range, the 0.03mm feeler gauge shall not be inserted into 1 / 3 of the outer ring width. After assembly, the outer ring of the bearing shall contact the end face of the bearing cover at the locating end evenly.

In the process of processing large parts, we still need to pay attention to the safety aspects

The cutting tool must be clamped firmly, otherwise it is not allowed to drive.
When moving the worktable and tool rest, loosen the fixing screw first.
When milling various workpieces, especially during rough milling, slow cutting should be carried out at the beginning.
When loading and unloading tools, use copper hammer or wooden mallet to gently hit to prevent tool fragments from flying out and injuring people.
Before work, check the operation of the transmission part of the machine tool, and install the baffle of the machine tool before operation.
The work object should be clamped with pressing plate, screw or special tool. The general wrench is not allowed to add casing, so as to avoid slipping and injury.

Computer gong processing – bakelite

The chemical name of bakelite is phenolic plastics, which is the first variety of plastics put into industrial production. Because of its high mechanical strength, good insulation, heat resistance and corrosion resistance, it is often used in the manufacture of electrical materials, such as switches, lamp caps, earphones, telephone cases, instrument cases, etc.

Phenolic resin can be prepared by condensation polymerization of phenols and aldehydes with acid or basic catalyst. Bakelite powder was obtained by mixing phenolic resin with sawdust, talc (filler), urotropine (curing agent), stearic acid (lubricant), pigment, etc. and heating in a mixer. Thermosetting phenolic resin products were obtained by heating and pressing bakelite powder in mold. The disadvantages of phenolic resin are poor mechanical properties, oil resistance and chemical corrosion resistance,

People have modified phenolic resin, adding different fillers in phenolic resin can get modified phenolic plastics with different functions. For example, adding asbestos and mica in ingredients can increase its acid resistance, alkali resistance and wear resistance, which can be used as materials for chemical equipment and accessories for motor and automobile; adding glass fiber can increase hardness, which can be used as machine parts, etc.; using nitrile rubber After modification, the oil resistance and impact strength are greatly improved; after modification with PVC, the mechanical strength and acid resistance are improved.

The characteristics of bakelite are non absorbent, non-conductive, high temperature resistant and high strength. It is often used in electrical appliances. Because of its high insulation and good plasticity, it is called “bakelite”. Bakelite is made of powdered phenolic resin, mixed with sawdust, asbestos or clay, and then pressed out in a mold at high temperature. Among them, phenolic resin is the first synthetic resin in the world.

Phenolic plastic (bakelite): the surface is hard, brittle and fragile. There is a sound of wood when knocking. It is mostly opaque and dark (brown or black). It is not soft in hot water. It is an insulator, and its main component is phenolic resin.

When the formaldehyde / phenol (molar ratio) is less than 1, the thermoplastic product can be obtained, which is called thermoplastic phenolic resin, that is, linear phenolic resin. It does not contain further condensation groups, and can be cured only by adding curing agent and heating. Such as hexamethylene tetramine as curing agent, curing temperature 150 ℃, mixed with filler made of molding powder, commonly known as bakelite powder. When the formaldehyde / phenol (molar ratio) is greater than 1, the thermosetting phenolic resin, which is soluble in organic solvents, can be obtained first under the catalysis of alkali. The resin in stage a contains hydroxymethyl which can be further condensed, so it can be cured without adding curing agent. The resin in stage B, also known as semi soluble phenolic resin, can be obtained under the reaction of heating, which is insoluble and insoluble, but can swell and soften. Further reaction can obtain insoluble and insoluble structure c resin, also known as insoluble phenolic resin. The resin at stage a can also self cure after long-term storage.

The curing forms of thermosetting phenolic resin can be divided into room temperature curing and heat curing.

Non toxic room temperature curing agent NL, benzene sulfonyl chloride or petroleum sulfonic acid can be used for room temperature curing, but the latter two materials are more toxic and irritating.

The main purpose of phenolic resin modification is to improve its brittleness or other physical properties, improve its adhesion to fiber reinforced materials and improve the molding process conditions of composites. Generally, the modification is carried out by the following ways:

① Blocking phenol hydroxyl. Phenolic hydroxyl group of phenolic resin does not take part in chemical reaction in the process of resin manufacturing. The phenolic hydroxyl left in the molecular chain of the resin is easy to absorb water, which reduces the electrical properties, alkali resistance and mechanical properties of the cured products. At the same time, phenolic hydroxyl groups are easy to form quinones or other structures under the action of heat or ultraviolet light, resulting in uneven color changes.

② Introduce other components. In order to change the curing speed and reduce the water absorption, the components which have chemical reaction with phenolic resin or good compatibility with phenolic resin are introduced to separate or surround hydroxyl groups. The introduction of other polymer components can combine the advantages of the two polymer materials.

Polyvinyl acetal modified phenolic resin is widely used in the industry. It can improve the adhesion of resin to glass fiber, improve the brittleness of phenolic resin, increase the mechanical strength of composite materials, reduce the curing rate, and reduce the molding pressure. The modified phenolic resin is usually synthesized with ammonia or magnesium oxide as catalyst. Polyvinyl acetal used as modification is a polymer with different proportion of hydroxyl, acetal and acetyl side chains

① The molecular weight of polyvinyl acetal;

② The relative content of hydroxyl group, acetyl group and acetal group in the molecular chain of polyvinyl alcohol acetal;

③ The chemical structure of the aldehyde used. Due to the addition of polyvinyl acetal, the concentration of phenolic resin in the resin mixture decreases correspondingly, which slows down the curing rate of the resin and makes low-pressure molding possible, but the heat resistance of the product decreases.

Polyamide modified phenolic resin the impact toughness and adhesiveness of phenolic resin were improved by polyamide modified phenolic resin, and the fluidity of the resin was improved, while the advantages of phenolic resin were still maintained. Polyamide used for modification is a kind of hydroxymethyl polyamide, which can be modified by the reaction of hydroxymethyl or active hydrogen in the process of resin synthesis or curing.
Epoxy modified phenolic resin is a composite made of 40% first-order thermosetting phenolic resin and 60% diphenolpropane epoxy resin, which can have the advantages of both resins and improve their disadvantages, so as to achieve the purpose of modification. The mixture has excellent adhesion of epoxy resin, which improves the brittleness of phenolic resin. Meanwhile, it has excellent heat resistance of phenolic resin, which improves the disadvantage of poor heat resistance of epoxy resin. This modification is achieved by the chemical reaction of hydroxymethyl group in phenolic resin with hydroxyl group and epoxy group in epoxy resin, and the chemical reaction of phenolic hydroxyl group in phenolic resin with epoxy group in epoxy resin, and finally cross-linking into a complex body structure.
Silicone modified phenolic resin has excellent heat resistance and moisture resistance. The heat resistance and water resistance of phenolic resin can be improved by reaction of phenolic hydroxyl or hydroxymethyl groups in linear phenolic resin with silicone monomer.

Modified phenolic vinegar resins with different properties can be obtained by modifying phenolic resin with different organosilicon monomers or their mixed monomers, which have wide selectivity. The composite prepared by silicone modified phenolic resin can work at 200 ~ 260 ℃ for a long time, and can be used as instantaneous high temperature resistant material for rocket, missile and other ablative materials.

Boron modified phenolic resin has better heat resistance, instantaneous high temperature resistance and mechanical properties than phenolic resin due to the introduction of inorganic boron into the molecular structure of phenolic resin. The heat resistance, instantaneous high temperature resistance and ablation resistance of boron modified phenolic resin are much better than those of common phenolic resin. They are widely used as excellent ablative materials in space technology fields such as rockets, missiles and space vehicles.
Xylene modified phenolic resin xylene modified phenolic resin is the introduction of hydrophobic xylene ring into the molecular structure of phenolic resin,

The water resistance, alkali resistance, heat resistance and electrical insulation properties of the modified phenolic resin were improved.

It can also be used as insulation material of diphenyl formaldehyde and diphenyl ether.

Lathe processing – computer gong processing

Lathe processing is a part of mechanical processing. There are two main processing forms of computer gong processing: one is to fix the turning tool to process the unformed workpiece in rotation, and the other is to fix the workpiece to carry out precision processing through the high-speed rotation of the workpiece and the horizontal and vertical movement of the turning tool (tool holder).

It is easy to ensure the accuracy of each processing surface of the workpiece; during processing, the workpiece rotates around a fixed axis, and each surface has the same rotation axis, so it is easy to ensure the requirements of coaxiality between processing surfaces;
The cutting process is relatively stable; in addition to the intermittent surface, generally, the processing process of Dalang lathe is continuous, unlike milling and planing, in the process of one tool feed, the cutter teeth have multiple cuts in and out, resulting in impact;
It is suitable for finish machining of non-ferrous metal parts; for some non-ferrous metal parts, because of the low hardness and good plasticity of the material itself, it is difficult to obtain a smooth surface with other machining methods;
The cutting tool is simple; turning tool is the simplest one of the cutting tools, which is very convenient for manufacturing, grinding and installation, so it is convenient to select a reasonable angle according to the specific processing requirements

Operation safety of lathe

It is forbidden to put on the protective clothing when the machine is operating. It is forbidden to put on the protective clothing when the machine is operating. It is forbidden to put on the protective clothing when the machine is operating. Must wear a helmet, braids should be put into the hat, not to wear skirts, slippers. Wear protective glasses to prevent eye injury caused by splashing iron chips.
It is necessary to carefully check whether the machine tool operates safely and reliably according to the requirements of no-load operation for 2 ~ 3 minutes, and carefully check whether the machine tool operates safely and reliably.
When loading and unloading chucks and large pieces, check whether there are obstacles around, pad wood to protect the bed surface, and block, hold firmly and frame well. When the car is too heavy, balance should be done according to the weight. The clamping of workpieces and tools should be tightened to prevent workpieces or tools from flying out of the fixture. The chuck wrench and socket wrench should be removed.
When the machine tool is running, it is strictly forbidden to wear gloves to operate; it is strictly forbidden to touch the rotating part of the machine tool with hands; it is strictly forbidden to transfer objects across the lathe during the operation of the lathe. The machine should be stopped to load and unload the workpiece, install the cutter, refuel and clean the chip. Brush or hook shall be used to remove iron filings. Hand cleaning is forbidden.
When the machine tool is running, it is not allowed to measure the workpiece, and it is not allowed to use the hand to brake the rotating chuck; when using sandpaper, it should be placed on the file, and it is strictly prohibited to wear gloves to operate with sandpaper. It is not allowed to use the worn sandpaper, it is not allowed to use the file without handle, it is not allowed to use the brake of the front and back brake, it should go through the intermediate braking process.
The cutting parameters are selected according to the technical requirements of the machine tool to avoid accidents caused by overload of the machine tool.
When cutting, the cutter should be withdrawn when stopping. The center frame must be used for machining long axis of mechanical parts to prevent the workpiece from bending and deforming to hurt people; the length of the bar extending into the head of the bed shall not exceed the vertical axis of the head of the bed, and it shall be processed slowly, and attention shall be paid to protection when extending.
When cutting at high speed, there should be a protective cover. The workpiece and tools should be fixed firmly. When the iron chips splash seriously, a baffle should be installed around the machine tool to isolate it from the operation area.
When the machine tool is running, the operator can’t leave the machine tool. If the machine tool doesn’t work properly, stop the machine immediately and ask the repairman to check and repair it. In case of sudden power failure, shut down the machine immediately and exit the tool from the working position.
When working, you must stand sideways in the operating position, and it is forbidden to face the rotating workpiece.
At the end of the work, cut off the power supply of the machine tool or the main power supply, withdraw the cutting tool and workpiece from the working position, clean and place the tools, clamps and measuring tools used, and clean the machine tool. Now because the automatic lathe processing market is not perfect and sound, small stamping parts market is very mature in some areas.

From the current situation, there are some problems in the automatic lathe processing market, some production capacity is oversupplied, and some stamping plants in the main engine factory can’t put it or hold it.

Is Internet marketing the way out for computer gong processing

In recent years, the machining center is becoming more and more powerful. Among all kinds of imported CNC metal cutting machine tools, the machining center has become the most important import product, and its quantity and amount account for one third of the imported CNC metal cutting machine tools. Its rapid growth rate reflects the great demand for this product in our country.

The situation that most of the domestic demand processing centers depend on foreign imports has not fundamentally changed, and the domestic market share is still low, about 27%. The main reason for the low market share of domestic products is that there are many gaps in product level, delivery time, quality and reliability compared with foreign similar products. So the products we import mainly come from Japan, South Korea and Taiwan. In the face of these foreign countries, we use CNC machine tools, flexible manufacturing cells and flexible manufacturing systems to achieve large-scale production. Relatively speaking, foreign products have shorter delivery time and better quality stability. Due to the small production scale of domestic popular vertical machining center, the annual output of most enterprises is about hundreds, and individual enterprises can reach about 500. There is a gap between domestic and foreign similar products in terms of delivery time and quality, and the price advantage is not big, so they lose the market in the competition.

The Internet is closely related to our life now. We will use the Internet for many things, especially now that many young people are staying at home and almost do not go out. We call this kind of people “otaku men and otaku women”. From the perspective of the general quadrant of society, we know that the Internet has almost completely occupied our life. Now that the Internet has become the mainstream of our life, we can see that the Internet has become the mainstream of our life Network is so popular, so many of our enterprises think of doing business on the Internet, which is what we call network marketing. Many enterprise owners will do network marketing now, so as to eliminate the traditional way of sales. Network marketing can make you worry and labor-saving, and also earn an apology. Why not? So if our machining center wants to develop better, the network must be a breakthrough.

Machining center machine can be said to be the mechanical equipment used in numerical control, and this equipment is really the same as the name of this equipment. It is the application center control system of mechanical equipment, which plays a great role in the application of mechanical equipment, and we also play a great role in the application of this equipment.

Now many enterprises are doing this processing center, the market competitiveness is very strong, and generally are small and medium-sized enterprises to do, their products and this approach are roughly the same, so the competitiveness between peers will be more powerful, so many manufacturers change to price this piece of sales, peers have reduced the price, but for a long time this is not the case What kind of sales method is still not good, we still need to change the sales method. In the current situation, e-commerce is the only way out for enterprises. Compared with the cost of traditional exhibitions, magazines, newspapers and TV promotion, the cost of e-commerce is nothing.

Measurement error classification – computer gong processing

When manufacturing large batch parts, there are many factors that affect the accuracy of the data in the measurement process. The following small series for us to introduce the measurement error, measurement error can be divided into three categories: random error, systematic error, gross error.

Random error. Under the same condition, the size and direction of the error change when measuring the same measurement, and there is no change rule, this kind of error is random error. The causes of the random errors are the gap and deformation of the measuring instrument, the change of the measuring force, and the judgment error of the visual measurement or estimation. The elimination method is mainly from the source of the error to eliminate (reduce the temperature fluctuation, control measurement force, etc.), but also according to the normal distribution probability budget random error size.
System error. Under the same conditions, the size and direction of errors in repeated measurement of the same measurement remain unchanged. Maybe when the measurement conditions change, the errors change according to certain rules. This kind of error is a system error. The causes of system errors include inaccurate calibration of measuring tools or measuring instruments, errors in proofreading of measuring tools or measuring instruments, and the ambient temperature is not at 20 ℃ during fine measurement. There are several ways to eliminate system errors. Before measurement, it is necessary to verify all measuring instruments, which should be corrected according to regulations to eliminate errors. Dongguan high speed computer gong processing, to ensure that the scale alignment zero, it is necessary to measure before carefully checking measuring tools to ensure the accuracy of the requirements.
Gross error. Gross errors are errors that obviously distort the measurement results. The reason for this kind of error is that the measuring staff will not concentrate and ignore the carelessness, such as reading error, recording error, calculation error, and other abnormal disturbing factors from the outside world. Measurement values with gross errors are called bad values, which probably need not be eliminated.
The oxide scale of the parts shall be removed. There shall be no scratch, scratch and other defects on the surface of the parts, and the burr and flash shall be removed;
After quenching and tempering, the parts are subjected to high-frequency quenching, tempering at 350-370 ℃, hrc40-45, carburizing depth of 0.3mm, and high-temperature aging treatment.
The undeclared shape tolerance should meet the requirements of gb1184-80, the allowable deviation of undeclared length dimension is ± 0.5mm, and the casting tolerance zone is symmetrical to the basic dimension configuration of the blank casting;
The fillet radius R5 is not noted, the chamfer is 2 × 45 ° and the acute angle is blunt;
The temperature shall not exceed 100 ℃. After the gear is assembled, the contact spot and backlash on the tooth surface shall comply with the provisions of GB10095 and gb11365;
When assembling the hydraulic system, it is allowed to use sealing filler or sealant, but it should be prevented from entering the system. The parts and components (including purchased parts and outsourcing parts) that enter the assembly must have the qualification certificate of the inspection department before they can be assembled.