Category Archive CNC Technology

The milling machine used in machining is very complex, and there are many kinds of milling cutters. “Milling” workpiece is: the workpiece is placed on the worktable and clamped with fixture, and the milling cutter is installed on the spindle. The spindle drives the cutter to rotate at high speed (main motion). The workpiece is driven by the worktable, which can realize the horizontal and vertical movement (feed motion). Under the joint action of the main motion and feed motion of the machine tool, the redundant part of the workpiece is removed. It can process plane, groove and curved surface on milling machine. The strengthening methods of aluminum alloy are as follows:

1. Solution strengthening

The addition of alloy elements into pure aluminum forms aluminum based solid solution, which causes lattice distortion, hinders the movement of dislocations, and plays a role of solution strengthening, which can improve its strength. According to the general law of alloying, when forming infinite solid solution or high concentration solid solution alloy, not only high strength, but also excellent plasticity and good press workability can be obtained. Al Cu, Al Mg, Al Si, Al Zn, Al Mn binary alloys can generally form finite solid solutions and have high limit solubility (see table 9-2), so they have great solution strengthening effect.

2

Another strengthening effect of alloying elements on aluminum is achieved by heat treatment. However, the transformation of aluminum during heat treatment is different from that of steel because there is no isomeric transformation of aluminum. The heat treatment strengthening of aluminum alloy is mainly due to the high solid solubility of alloy elements in the aluminum alloy, which decreases sharply with the decrease of temperature. Therefore, the supersaturated aluminum based solid solution can be obtained after the aluminum alloy is heated to a certain temperature and quenched. When the supersaturated aluminum based solid solution is placed at room temperature or heated to a certain temperature, its strength and hardness increase with time, but the plasticity and toughness decrease. This process is called aging. Aging at room temperature is called natural aging, and aging under heating conditions is called artificial aging. The phenomenon of increasing the strength and hardness of aluminum alloy during aging is called aging strengthening or aging hardening. The strengthening effect depends on the aging hardening phenomenon in the aging process.

1. Excess phase strengthening

If the amount of alloying elements in aluminum exceeds the limit solubility, there will be a part of the second phase which can not be dissolved into the solid solution, which is called excess phase. In aluminum alloys, these excess phases are usually hard and brittle intermetallic compounds. They hinder dislocation movement in the alloy and strengthen the alloy, which is called excess phase strengthening. This method is often used to strengthen cast aluminum alloy and heat resistant aluminum alloy in production. The more the amount of excess phase and the more dispersed the distribution, the greater the strengthening effect. However, if there are too many excess phases, the strength and plasticity will be reduced. The more complex the structure of the excess phase and the higher the melting point, the better the thermal stability at high temperature.

1. Refine the structure and strengthen it

Many aluminum alloys are composed of α solid solution and excess phase. If the microstructure of aluminum alloy can be refined, including refining α solid solution or refining excess phase, the alloy can be strengthened.

Because of the coarse structure of cast aluminum alloy, modification is often used to refine the alloy structure in actual production. Computer gong machining | mechanical parts processing | CNC machine tool processing | Dongguan high-speed computer gong machining modification is to add 2-3% modifier (commonly used sodium salt mixture: 2 / 3naf + 1 / 3nacl) to the molten aluminum alloy before pouring, so as to increase the crystal core and refine the microstructure. After modification, fine and uniform eutectic and primary α solid solution structure can be obtained, which can significantly improve the strength and plasticity of aluminum alloy.

It is found that there is abnormal sound in the spindle and gearbox when the spindle speed is below 500r / min. observing the power meter of the motor, it is found that the output power of the motor is unstable and the pointer swings greatly. However, the abnormal sound disappeared when it was used above 1201r / min. After startup, the power meter of the motor will swing automatically without rotation command, and the motor will drift and rotate automatically. After normal operation, the braking time is too long, and the machine tool has no alarm.

According to the phenomenon observed, the main shaft controller may be out of control, and the mechanical transmission or motor can not be eliminated. Due to the heavy workload of dismantling the mechanical part, the spindle controller of the electrical part is checked first. The controller is Siemens 6sc-6502. First, check the preset parameters in the controller, and then check the control board, all of which are normal. After checking that the circuit board is dirty, clean the circuit board according to the requirements, but after it is installed, the machine fails as usual. Therefore, the fault causes in the controller can be eliminated temporarily. In order to determine whether the fault is in the motor or in the mechanical transmission part, it is necessary to separate the motor from the machinery. After the separation, it is found that when the motor speed command is close to 450R / min, the abnormal sound starts to appear continuously, but when the instruction of 1201r / Min is given, the abnormal sound disappears again. For this reason, we analyzed the spindle part. The original 450 R / min command given at low speed and 4500r / min command at high speed are the same to the motor at the highest speed, but the gear decelerates at low speed, so the fault can be basically determined in the motor part. After analysis, the abnormal sound may be caused by poor bearing.

When the motor was disassembled for inspection, it was found that the bearing was damaged. When the bearing was stuck at high speed, the load was increased, which made the power meter swing and deflect. But after stopping, the motor drifted and the brake was too slow. After checking, the encoder disc was scratched. After replacing the bearing and encoder, all the faults were eliminated. This fault is mainly due to the abnormal sound when the spindle rotates. Therefore, it is necessary to find out the sound source before checking. Abnormal sound is common for mechanical rubbing, jamming and bearing damage.

CNC machining center spindle orientation usually adopts three ways: magnetic sensor, encoder and mechanical orientation. When using magnetic sensor and encoder, in addition to adjusting the position of components, it can also adjust the machine parameters. There is no alarm when the orientation error occurs, and it can only be detected when there is an interruption in the process of tool change.

Once in a refitted CNC machining center, there was a fault of inaccurate orientation. At the beginning, the machine tool was often interrupted in the work, but the frequency was not many. The machine could work again after restarting, and the fault occurred repeatedly. After careful observation of the machine tool after the fault occurred, it was found that the real cause of the fault was the position deviation of the spindle after orientation. It is strange that if the spindle is touched by hand after orientation (similar to the situation when the tool is inserted into the spindle during tool change), the spindle will drift in the opposite direction. Check the electrical part without any alarm, and the mechanical part is very simple.

The orientation of the machine tool uses encoder, so from the fault phenomenon and possible parts, the possibility of electrical part is relatively small, the most important mechanical connection. Therefore, it was decided to check the mechanical connection part. When checking the connection of the encoder, it was found that the set screw of the coupling sleeve on the encoder was loose, which caused the coupling sleeve to retreat, resulting in excessive clearance between the coupling part and the spindle, and the rotation was not synchronous. The failure was eliminated after the set screw was fixed as required. In case of spindle orientation failure, the analysis and treatment shall be carried out according to the specific structure of the machine tool. The electrical part shall be checked first, and then the mechanical part shall be considered if it is confirmed to be normal.

Mechanical processing cost calculation must understand the process, in order to estimate the processing time, to quote.

The calculation of machining cost can be said to be very simple or complex. The key depends on your company’s situation. For a large company, you should consider various cutting efficiency, tool performance, machinery and equipment performance, etc. if it is a small mechanical processing plant, according to your expenses, including rent, water and electricity, master’s wages, tool wear, equipment loss, etc., how much should you spend a day, plus your own estimated profit.

You’ll have to finish your parts in three hours. If your profit is 5%, your profit on this part is 15 yuan. In this way, it is very simple. In addition, mechanical processing cost calculation must know the process, in order to estimate the processing time, to quote.

Wire cutting processing fee is generally calculated according to the total cutting area, 0.xx yuan / square millimeter

For example, according to the processing area / 1200 * 8 yuan

There are usually two calculation methods

1. 01 yuan / mm2,
2. Parts that are too small are generally calculated by piece

In most places, it’s 5cm / m2!

The machining cost of ordinary WEDM is generally calculated according to the wire cutting area, and the workpiece height is also high, and the corresponding price will be high

The price of slow wire cutting is about 10 times that of ordinary wire cutting

In Jiangsu and Zhejiang provinces, slow wire processing generally costs 60 yuan per hour (the average cutting efficiency is 40-60mm / min), but the higher precision die cutting costs 80 yuan, because once scrapped, it needs to pay the material cost

Processing time calculation: Processing cross-section area / (1200-1800) = the required time, 1200-1800 is an adjustable parameter, generally taken as 1500, and then multiplied by the hourly processing fee

Fast silk words some can 0.015 yuan mm, also have 0.005 yuan mm

There are also 10 yuan hours

Slow wire cutting tool 0.03mm

Slow wire cutting two cutters 0.038mm

Slow wire cutting with three cutters 0.045mm

Slow wire cutting four cutters 0.055mm

Fast wire is 5 yuan per hour. Generally, each machine can cut 2.5 hours per hour

The cost of WEDM here is basically 10 yuan / hour

WEDM is divided into fast wire and slow wire, and their processing accuracy is different, such as computer gong processing, mechanical parts processing, CNC machine tool processing, Dongguan high-speed computer gong processing

The slow wire can reach 0.001 mm, but the fast wire can’t. I’ve made Sadik’s slow silk. The processing fee is calculated according to the area and also depends on the number of knives. The price of cutting one repair is obviously different from that of cutting a few. If the height of parts processed exceeds one, it will be doubled. If the processed materials are different, their prices are not the same. For example, cutting tungsten steel is twice as much, usually 2-3 times. They can process at least 50 yuan a piece (excluding batch)

Standard charging method: 0.08 yuan / square millimeter

Common wire cutting; sectional area / 1200 * man hour unit price

Standard charging method: batch processing 0.08 yuan / square millimeter, mould 0.12 yuan / square millimeter

The fast one is 8 yuan / hour

Generally, Sodick aq550ls is used to make the first cutting, and the second cutting is about 5 times of the first cutting. The third one is faster!!

Fastwire is about 1200-1800

And then take your own set fee!!

Wire cutting is divided into fast wire and slow wire

Ordinary wire cutting is generally calculated by wire cutting area, and the workpiece height is also high, and the corresponding price will be high

The price of slow wire cutting is about 10 times that of ordinary wire cutting

In Jiangsu and Zhejiang provinces, slow wire processing generally costs 60 yuan per hour (the average cutting efficiency is 40-60mm / min), but the higher precision die cutting costs 80 yuan, because once scrapped, it needs to pay the material cost

Processing time calculation: Processing cross-section area / (1200-1800) = the required time, 1200-1800 is an adjustable parameter, generally take 1500, and then multiply the hourly processing fee.

In the case of fast wire, some can be 0.015 yuan mm, and there are 0.005 yuan mm

There are also 10 yuan hours

Slow wire cutting 0.03mm

Two cutting tools 0.038mm

Slow wire cutting three cutters 0.045mm

Professional mechanical processing fee calculation, mechanical processing fee calculation formula, mechanical processing fee calculation method.

The general principle of non-standard parts processing and cutting process arrangement is: the front work must be ready for the later work, lay a good foundation, and do a good service. The working principle of non-standard parts processing can be divided into four aspects

Just like building a house, the foundation determines the height. Only when the foundation is built well can the house be built high. The same is true for precision mechanical parts processing, which always processes the precise datum first, and then processes other surfaces by the precise datum positioning. For example, for box parts, the main hole is generally used as the rough datum to process the plane, and then the plane is used to process the hole system; for the shaft parts, the outer circle is generally used as the rough datum to process the central hole, and then the center hole is used as the fine datum to process the outer circle, end face and other surfaces. If there are several precision datum, the machining of base surface and main surface should be arranged according to the sequence of datum transformation and the principle of gradually improving machining accuracy.

Secondly, the processing sequence of non-standard parts should be determined, and the sequence should be done well. Generally, the main part should be done first

A part of an electronic or electrical device or equipment that is processed by a computer gong. It is used as the two terminals of input or output current in a conductive medium (solid, gas, vacuum or electrolyte solution). One pole of input current is called anode or positive pole, and the other pole of discharging current is called cathode or negative pole. There are various types of electrodes, such as cathode, anode, welding electrode, electric furnace electrode, etc.

In the battery, the electrode generally refers to the position where the redox reaction occurs with the electrolyte solution. The electrode can be divided into positive and negative. Generally, the positive electrode is the cathode, which obtains electrons and reacts with reduction. The negative electrode is the anode, which loses electrons and reacts with oxidation. The electrode can be metal or nonmetal. As long as it can exchange electrons with electrolyte solution, it is called electrode. The concept of electrode was put forward by M. Faraday in 1834 after the systematic electrolysis experiment. The original meaning only refers to the metal rod inserted in the electrohydraulic system to form the battery. The component of a battery, which consists of a series of phases in contact with each other. One end of the battery is an electronic conductor metal (including graphite) or a semiconductor, and the other end must be an ionic conductor electrolyte. The electrode with the simplest structure should consist of two phases and a phase interface, i.e., [metal electrohydraulic]. The electrode defined above in machining mechanical parts is also called “half cell”. The naming method is very complicated. Some are named according to the metal part of the electrode, such as copper electrode and platinum electrode; some are named according to the characteristic substances in the redox pair of electrode activity, such as calomel electrode and hydrogen electrode; some are named according to the shape of the metal part of the electrode, such as drop mercury electrode and rotary electrode; some are named according to the shape of the metal part of the electrode The function of the electrode is named. These names, such as reference electrode and sodium ion selective electrode (see ion selective electrode), are conventional. Any metal in contact with electrolyte will produce potential (potential), which is the most important characteristic property of electrode.

electrode

If there is a fast electron exchange of a single redox pair on the electrode interface, that is, there is a single electrode reaction with a large exchange current (see transition overpotential), this kind of electrode can quickly establish an electrochemical equilibrium, which is called reversible electrode. The potential energy of the reversible electrode is stable for a long time, and it has strong anti-interference ability and can be measured accurately. It is a necessary part of the reversible battery and the core part of the potential analysis measuring device. Reversible electrodes have the following types:

① Metal electrodes, such as copper electrodes (Fig. 2), are characterized by the fact that redox pairs can migrate across the phase interface.

② Redox electrodes, such as Pt | Fe, Fe electrode (Fig. 3), Pt | Mn, MnO 嬄 h electrode, etc. Its redox pair can not move across the electrode phase interface. The platinum pt of the electrode only indicates that the electrode metal is inert. It only provides a place for electron exchange. Any inert metal can be used in practical application.

electrode

③ The gas electrode is a component of redox pair, and the redox electrode when it is composed of gas (Fig. 4), such as hydrogen electrode (pt| h2| h), chlorine electrode (pt| Cl2 | CL), etc. In order to accelerate the equilibrium, platinum black is needed to be plated on platinum to increase the surface area and act as electrocatalysis.

electrode

④ One component of redox pair is insoluble salt or other solid phase. Therefore, Dongguan CNC machining center consists of three phases and two interfaces (Fig. 1). There is a single rapid transition process at each phase interface, such as calomel electrode (hg| Hg2Cl2 | CL) and mercury oxide electrode (Hg | HGO | oh). In the calomel electrode, the dissolution equilibrium of calomel and electrolyte is completely controlled by the higher concentration of CL in the electrolyte. The exchange rate of CL on the interface of Hg2Cl2 | is also very fast, so its electrode potential is very stable. It is the most commonly used reference electrode. Some books and periodicals call this kind of electrode the second type.

electrode

Membrane electrode a device for measuring the activity of specific ions in an electrohydraulic system (Fig. 5), such as a glass electrode or an ion selective electrode, using the permeability of the membrane to a single ion or the potential established by the ion exchange equilibrium between the membrane surface and the electrolyte (Fig. 5).

Chemically modified electrodes attach active groups and catalytic substances to the surface of electrode metals (including graphite and semiconductors) by adsorption, coating, polymerization, chemical reaction and other methods to make them have strong characteristic functions. This is a new development of electrode preparation methods since 1970s.

Single electrode and multiple electrode: if there is only one dominant electrode reaction on the metal electro-hydraulic interface of the electrode, it is a single electrode; if there is not only one electrode reaction, it is multi electrode. For example, there may be two kinds of electrode reactions on the zinc electrode (zn| ZnSO4 aqueous solution)

Zn─→Zn+2e ⑴

2H+2e─→H2 ⑵

electrode

However, due to the high Superpotential of hydrogen on the metal zinc, the rate of reaction (2) is too small, and the reaction (1) is dominant. The above zinc electrode is considered as a single electrode and is a typical reversible electrode. When the impure zinc is immersed in sulfuric acid, the reaction rate of (1) and (2) is fast, so [Zn | H2SO4] electrode is a double electrode, and its static potential can be judged according to the polarization curve and polarization law of reaction (1) and (2). Metal corrosion system is often a double electrode. Multiple electrodes cannot be reversible

In practical application, the studied electrode is called working electrode W, which is also called indicator electrode in electrochemical analysis. Its potential can be measured by two electrode measurement battery composed of reference electrode R. When the working electrode needs to be polarized, another auxiliary electrode (or corresponding electrode, represented by C) should be used to form a three electrode measuring battery system (Fig. 6)

Drilling and tapping center is a kind of metal cutting equipment. Its style and function are basically similar to the machining center, but it is smaller than the machining center. The general stroke is not more than (x / y) 800 × 400mm. Its main purpose is to process drilling and tapping processes such as nonferrous metals, 3C industry and aluminum substrate. Although boring and milling can be realized, due to the low power of the main motor, ferrous metal can not be used Cutting, but the efficiency and quality of drilling and tapping speed is more than 10 times that of ordinary machining center. It is the most ideal processing equipment for 3C, communication industry and other industrial customers.

At present, the overall market analysis is as follows:

Due to the rise of mobile phone industry, communication industry and tablet computer industry in recent years and the continuous upgrading to please consumers, the following supporting processing industry is also rising, especially the demand for drilling machines is growing.

At present, the common well-known brands include Japan fanco, Japan brother, British jiamite, including Korea Kia and so on.

Fanaco α – T21: FANUC α – T21 mainly produces X-axis stroke 500 with independent system + turret type tool magazine as its main products: fanaco drilling machine is the only machine tool manufactured by fanaco company in Japan, and its market share is in the forefront in Japan. Its core technology is fanuc-31 system, which is matched with the machine tool, and has high performance in spindle acceleration and high-speed displacement. The machine tool is very popular in China, especially in Guangdong electrode market, known as “the king of copper”. The biggest drawback of the machine is that the overall rigidity is insufficient, it can not carry out load cutting, and the use efficiency is not high. In addition, the price of the machine tool is also quite expensive, especially the technical support and accessories price after the warranty period is beyond the ordinary enterprises’ affordability.

Japan brother tc-s2d: Japan’s brother tc-s2d series mainly focuses on X-axis travel of 500 and 700, and has exchange worktable options: brother group was first known as a machinist sewing machine, and later developed printer equipment and machine tool drilling machine equipment. Japan brother drilling and tapping machine is the only one in Japan that can compete with fanco in system calculation. However, brother’s overall workmanship is more rigorous, and the main shaft is different from fanco. The main shaft adopts JIS form and short nose structure, which is stable in high-speed tapping and is not easy to break the tap. In recent years, the sales volume of brother drilling machine in some areas of China has been increased Hold the top position.

Camit t-fm600: jamit is the latest European brand drilling and tapping machine to enter the Chinese market. The most widely used drilling machine in the European market is jamitt drilling machine, with pure European processing technology. The tool change speed and overall mechanical structure of the drilling machine are stronger than those of Japanese machine tools, and the casting of bed body is subject to secondary aging treatment. Its advanced servo tool magazine and optical fiber panel technology is the biggest bright spot advantage of the machine tool. At the same time, it can be combined with BT40 simultaneous action tool library to realize drilling, milling, boring, tapping and other processes, and the price is cheaper than Japanese machine tools, and the comprehensive cost performance ratio is the strongest.

Hyundai Weiya vx380: Hyundai Kia drilling and attack center and Hyundai Weiya belong to Hyundai Group, the largest group in South Korea, and its technology basically comes from Japan. The brand entered the Chinese market late, but its excellent performance price ratio has been favored by enterprises, but after-sales service has always been a short board of the brand, which can not meet the needs of Chinese users. At the beginning of using the drilling and tapping center, the cutting fluid (water-based) was used in the separate cooling water tank, which was used in both stations. However, after a period of time, it was found that the water-based cutting fluid in the drilling and tapping center was not good for drilling and thread tapping. Especially for the tap, it was “astringent” during processing, which was easy to break, and the quality of the finished screw hole was poor. Therefore, we changed the drilling of this drilling center to dry machining. When we arrived at the tapping station, we used kerosene lubrication (kerosene was supplied by the pump separately, and electrical control) the quality of the thread was good, and the tap was rarely broken. Computer gong processing | mechanical parts processing | CNC machine tool processing | Dongguan high-speed computer gong processing drilling and tapping center processing form: manually pushing the material to the conveying position, pressing the “swing up” button will start to enter the automatic cycle, and the two headstock will act at the same time. After the second working feed of the two headstock, they return to the original position.

CNC machine tools are widely used in drilling and tapping center. CNC machine tool is a kind of advanced equipment with excellent performance, wide range of technology, high precision of drilling and tapping center and high production efficiency. It can complete drilling, reaming, boring, groove cutting and plane milling processing at one time. In addition, it can also carry out hole series processing with high precision. CNC machining is heavy machinery, engineering machinery, locomotive and rolling stock, mining equipment, large motor and water turbine , steam turbine, ship, iron and steel, military and other industrial sectors of essential processing equipment. The CNC machine tool has the characteristics of good rigidity, high precision, strong reliability, convenient operation and beautiful appearance. Especially, various accessories can be installed on the end face of the square ram or used with the rotary table, which can further expand the application range of the CNC machine tool. CNC machine tools are mainly used for boring holes of large and medium-sized parts, and can also complete drilling, expanding, reaming, milling plane and other work. The CNC machine tool is equipped with change gear device, which can process metric or British internal thread. The radial tool holder of flat rotating disc can be used to process internal thread

The chemical name of bakelite is phenolic plastic, which is the first variety of plastics put into industrial production. It has high mechanical strength, good insulation, heat resistance, corrosion resistance, so it is commonly used in the manufacture of electrical materials, such as switches, lamp caps, earphones, telephone case, instrument case, etc. “bakelite” is named from this. Its appearance is of great significance to industrial development. Phenolic resin can be prepared by polycondensation of phenols and aldehydes in the presence of acidic or alkaline catalysts. Bakelite powder was obtained by mixing phenolic resin with sawdust, talcum powder, urotropine, stearic acid and pigment in mixer. Bakelite powder is heated and pressed in the mold to obtain thermosetting phenolic plastic products. The disadvantages of phenolic resin are poor mechanical properties, oil resistance and chemical corrosion resistance. In order to overcome the above defects, people have modified phenolic resin. Adding different fillers into phenolic resin can obtain modified phenolic plastics with different functions. For example, adding asbestos and mica in the ingredients can increase the mechanical properties of phenolic resin With its acid, alkali and wear resistance, it can be used as the material of chemical equipment and the accessories of motor and automobile; the hardness can be increased by adding glass fiber, which can be used as machine parts; the oil resistance and impact strength of the modified NBR are greatly improved; the mechanical strength and acid resistance can be improved after the modification with PVC.

Bakelite is non absorbent, non conductive, high temperature resistant and high strength. It is mostly used in electrical appliances. Like wood, it has high insulation and good plasticity, so it is called “bakelite”. Bakelite is a kind of powdered phenolic resin mixed with sawdust, asbestos or clay. It is extruded with a mold at high temperature. Phenolic resin is the first synthetic resin in the world.

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

When formaldehyde / phenol (molar ratio) is less than 1, thermoplastic products can be obtained, which is called thermoplastic phenolic resin, namely linear phenolic resin. It does not contain further condensation groups, and can be cured by adding curing agent and heating. Such as hexamethylene tetramine as curing agent, curing temperature 150 ℃, mixed with fillers made of molding powder, commonly known as bakelite powder. When the molar ratio of formaldehyde to phenol is greater than 1, the first step resin, namely thermosetting phenolic resin, is obtained under the catalysis of alkali. It can be dissolved in organic solvents. The first stage resin contains hydroxymethyl which can be further polycondensated, so it can be cured without adding curing agent. The second stage resin, also known as semi soluble phenolic resin, is insoluble and insoluble, but can be swelling and softening. Then, the insoluble phase C resin, also known as insoluble phenolic resin, was obtained by further reaction. Phase a resin can also self cure after long-term storage.

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

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

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

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

② Other components were introduced. In order to change the curing rate and reduce the water absorption of phenolic resin, the components which react with phenolic resin or have good compatibility with it are introduced to separate or surround hydroxyl groups. The advantages of the two polymer materials can be obtained by introducing other polymer components.

1. Polyvinyl acetal modified phenolic resin is widely used in industry. It can improve the adhesive force of the resin to glass fiber, improve the brittleness of the phenolic resin, increase the mechanical strength of the composite, reduce the curing rate, so as to reduce the molding pressure. Phenolic resin used for modification is usually phenol formaldehyde resin synthesized with ammonia or magnesium oxide as catalyst. The modified polyvinyl acetal is a polymer with different proportions of hydroxyl, acetal and acetyl side chains. Its properties depend on: 1) the molecular weight of polyvinyl acetal; 2) the relative content of hydroxyl, acetyl and acetal groups in the molecular chain of polyvinyl 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 is reduced correspondingly, which slows down the curing rate of the resin and makes it possible to form under low pressure, but the heat resistance of the products is reduced.
2. Polyamide modified phenolic resin the impact toughness and adhesiveness of the phenolic resin are improved, and the fluidity of the resin is improved, and the advantages of the phenolic resin are still maintained. Polyamide used for modification is a kind of hydroxymethyl polyamide, which is modified by the reaction of hydroxymethyl or active hydrogen to form chemical bond in the process of resin synthesis or resin curing.
3. Epoxy modified phenolic resin composites made of 40% first-order thermosetting phenolic resin and 60% bisphenol propane type epoxy resin can have two kinds of composite materials

High efficiency and economic hobs must have a lot of grooves and not too large. The cutting surface of the top of the diameter hob should exceed the face of the central cutter tooth and the tooth undercut. To meet the above needs, the hob developed by Hanjiang Tools Co., Ltd., has a new structure and high efficiency, and each adjacent double cutter hob tooth has a row of teeth with complete tooth profile, and the other effective department only has 1 / 3 tooth height row teeth.

The promise of the case hob diameter about 20 exhaust groove, computer gongs processing and ordinary hob is 2 times. According to the requirements of workpiece quality, the new structure and efficient system of double cutter hob shovel can also be polished. Because the complete gear hob is about 10 lines, it can be used not only for rough, but also for gear machining. In rough machining, rake hob can also be used to reduce cutting force and wear.

The new structure double cutter hob can be effectively ground on any scale hob grinder. Before the blade accuracy can be ensured after clamping, what is needed is an adjusted depth grinding wheel hob groove. The design principle of hob is not only limited to module or diameter measuring involute gear hob, but also used for the tooth profile of special gear hob. According to different requirements, the company can also make three or four cutting hobs, but it is still the most effective cutter with new structure.

The new structure is suitable for the field of gear undercutting hob with high requirements. Because the number of teeth (usually 20 teeth) of gear hob tip is used in small module gear processing, the number of gears is processed in gear processing. Therefore, the high-efficiency double cutter hob processing gear and the new structure can get a good end of circular arc gear.

New structure double cutting hob for effective utilization

The new high-efficiency double cutter hob structure is mainly used for processing large module gears in many fields of energy, ship, cement, mining, metallurgy, building materials and machinery industries. In order to quickly occupy the market and expand the production scale, many industrial enterprises still buy large hobbing machines, high-speed and high-efficiency double cutting hobs and the characteristics of new structure, this kind of efficient cutting. The new high efficiency double cutting hob structure has the same specification of ordinary hob, and the cutting efficiency has been improved 3 ~ 4 times. Therefore, the development of new efficient double cutter structure mapping tool needs to be satisfied, which can replace the import. It is a high-speed and efficient cutting for industrial gear processing requirements in China. It can give full play to the function of CNC equipment and accelerate the pace towards high-end products. It has a very broad market prospect and social and economic benefits.

1. Application materials

The structure and high efficiency function of the new double cutting hob are made of high speed steel and powder metallurgy high speed steel. By adjusting the basic chemical composition and adding other alloy elements, the mechanical function and cutting function of ordinary high speed steel have been greatly improved. At room temperature, the hardness of high-performance high-speed steel can reach hrc67-69, and the high-temperature hardness can also be improved accordingly. It can be used for machining high-strength steel, superalloy, titanium alloy and other difficult to machine materials, and can improve the service life of tools.

The manufacturing quality of high speed steel is affected by many factors, including the effect of influencing factors and the difficulty to improve. The average is the size control of carbide distribution and thickness.

In smelting high speed steel, carbide segregation is serious, which can be completely eliminated by powder metallurgy. The basic principle is that molten steel is melted in high frequency induction furnace and atomized into powder by high pressure inert gas. Powder metallurgy high speed steel and smelting high speed steel have many advantages, such as high toughness and hardness, grinding function can be significantly improved, average material, heat treatment and small deformation, the quality is unreliable, so the service life of the product is longer. It can be used to cut various kinds of P / M high-speed steel, especially suitable for manufacturing precision cutting tools and complex shaped knives. Self lubricating bearing

1. Hob coating

Coating technology is used to solve the contradiction between strength and toughness. By optimizing the lattice structure of the coating, adding alloy elements and multi-layer coating combination, it has made progress. It has strong toughness, and greatly improves the tool cost and cutting speed under the premise of adapting to different cutting conditions. Multi layer structure and nano composite coatings are the development of new tool coating materials. The research field of tool coatings and special functional coatings will become a new tool.

Coating technology mainly includes chemical coating (CVD) and physical (PVD) coating technology. The characteristics of contemporary CVD coatings are multilayer coatings, including TiCN, tic, tin, zncn and alumina. Through good control of CVD process, tool manufacturers can now provide quality coating tools with coating thickness ranging from 5 μ m to 20 μ m, which can be used for workpiece processing of high hardness materials, and multi-layer coating alloy tools with single layer coating thickness less than 0.2 μ M.

PVD coating technology in cermet, cemented carbide substrate thickness of 2 ~ 5 μ m, this hard coating has entered the trade. Typical trades include tin, TiCN coating methods, TiAlN, CrN, TiB2 plastic industry networks, such as tin TiAlN multilayer coatings. The unique advantages of PVD coating process can provide sharp cutting edge, ultra-fine particles, smooth surface, low friction and high temperature cracking resistant coating.

New developments in externally coated cemented carbide tools include bonding with internal tin, tin or tialnpvd coatings TiCN / tincvd coatings. Internal CVD coating can provide excellent substrate adhesion and wear resistance, large modulus gear machining and external PVD coating provide solid, not brittle fracture, smooth surface, surface ultrafine grain tools. The combination of CVD and PVD coating can prolong the service life of tool refractory metal materials and steel in intermittent cutting.

Tin, TiCN or TiAlN coatings are mainly used for gear cutting tools and their chemical composition is not random,

报错 笔记

Do CNC deep hole processing friends should know that CNC processing, deep hole processing is the most difficult. The so-called deep hole machining is the processing that the ratio of the length of the hole to the diameter of the hole is greater than 10 times. The deep hole processing is applied in some industrial fields of the country, such as the national military rocket body and the barrel of various guns. In these application fields, some require very high quality and precision of machining, and some require high cutting ability of processing materials The so-called CNC is the abbreviation of computer numerical control machine tool, which is the technology required for programmed control, automation and high-tech.

The use of CNC technology in deep hole processing, because of its processing technology and method is very complex, so few people use CNC machining center for deep hole processing. If using this technology, first of all, we should reform the CNC machining center vibration deep hole drilling machine, combine the advanced deep hole machining vibration cutting technology and AC frequency conversion speed control technology organically It has become a kind of precise professional processing technology. This kind of precise CNC deep hole processing technology effectively applies the vibration cutting technology to the drilling process. On the basis of the traditional deep processing technology, the vibration amplitude and frequency of regular vibration are given to the tool. In the process of cutting tool running, the cutting work is completed by vibration at the same time, and the cutting thickness changes periodically, so as to achieve the purpose of NC cutting according to the predetermined shape and size. Thus, the problem of chip removal interruption in CNC deep hole machining is effectively solved, and the quality and efficiency of deep hole processing are improved!

With the rapid development of computer technology, the degree of automation control, intelligent control and other technologies are more and more applied in the field of technology. Computer technology auxiliary functions are more and more applied to automobile manufacturing, home appliance manufacturing, aerospace and communication electronics. Nowadays, most of the labor steps that need manual processing are more and more moving to use computer programming Process can be automatically completed, in the processing lathe, CNC lathe, tool system, and other related technologies efficient organic combination, such as CNC thin-walled processing technology is one of them. Next, the CNC thin-walled processing technology in the CNC machining parts of the size data and structure technology two aspects to talk about its characteristics.

The design of dimension data should accord with the principle of convenient programming. The drawings in the industrial field are very important, but at the same time, they should also be strictly combined with the actual operation needs. If the dimensions on the part drawings are marked, they should adapt to the characteristics of NC machining, that is, they should be guided by the same datum to give the coordinate dimensions directly. This method is suitable for programming and also suitable for the coordination between dimensions, which brings great convenience to the follow-up work. At the same time, the part designer can change the local scattered marking method to the same datum dimension when designing, instead of only considering the assembly characteristics.

The structure process should be in line with the characteristics of NC machining, and the shape and inner cavity of the parts should adopt the unified geometric type and size. In this way, the number of tool change and tool specifications can be reduced in the process of operation, which makes programming convenient and production efficiency higher. In addition, CNC thin-walled machining should also consider the accuracy and dimensional tolerance of parts.

CNC five axis machining is a way of CNC machining. In the machine tool industry, the axis number of CNC machine tools is usually taken as the standard. The axis number below three axis is the resistance, the three to five axis is medium and high-grade, and the five axis machining is higher and higher. Now the modern equipment products represented by CNC five axis machining are developing towards the extreme manufacturing method, which is more and more high, more and more slender and more miscellaneous As the production process is highly centralized, what are the extraordinary strategic significance of China’s CNC five axis machining linkage automation and intelligent CNC machine tools for China’s equipment manufacturing industry

In recent years, with the rapid development of China’s national economy and the needs of national defense construction, more urgent requirements have been put forward for high-grade CNC machine tools. This requirement is not only in quantity, but also in the quality, accuracy, automation and mechanization of their products. The developed western industrial countries, led by the United States, have always regarded the five axis CNC machine tool system as an important strategic material basis, and implemented the export license system, especially the blockade system implemented to China during the cold war. In recent years, with the strong support of the state in this respect, China’s CNC five axis machining technology has been greatly developed on the basis of reference Exhibition, five axis CNC machine tool system for a country’s aerospace, precision instruments, heavy

Machine parts, you can add components to increase the risk of collision in the limited space of the machine, computer gong processing and precision machine model can ensure the reliability of the system processing. 3.5.1 num’s new version of the drum optimization function model and impact testing machine, the existing digital drum system can be upgraded to the latest version.

Numrto programming system has been used for more than 20 years and has been widely used in more than 2500 tool grinders in the world. Because the tool software is wide, the tool grinding process can be developed independently and the collision safety test can be selected by the grinding machine manufacturer. With the continuous development of computer performance, the influence of the whole tool grinder and grinding process can be simulated most accurately. Today, numrto is the most widely used machine for machining machine parts. It is equipped with 3-D simulation. Due to the application of three-dimensional CAD technology and high-speed computer gong machining, the structure design of modern tool grinder is more compact. The internal space of the machine must be optimized to grind different shapes and sizes of knives. More difficult machine parts are usually only used for machining tools or programs, which hinder other processes. Because of these obstacles, the programming system must constantly calculate the grinding path to avoid collision, which requires an accurate and realistic machine model. Numrto 3.5.1 tracks the version of the machine model with easy to use to ensure that the machine’s computer modeling and conform to the actual machine movement.

At present, traditional grinding system programming tools are used in computer gongs machining tools and basic models. Machine tools are usually equipped with machine parts such as seat, moving frame, tail and head. Special chuck is used for sintering or blade casting, cutting device, passive components and high frequency shaft. For fixed installed machine components, such as complete unit test and high frequency spindle, click once to select machine parts from munroto list. Before canceling, these accessory machine models are always visible. Mobile scaffold mechanical accessories, motion state and other corresponding parameter editor. Position variable machine components can handle step stop positions when in the workplace and subsequent processing steps. All of these are operated using electrical, hydraulic and pneumatic drive attachments, which activate the corresponding NC commands. The model is the most complex axis to control the moving parts of the machine, such as the moving center running to the specified position and exiting the specified position.

You can add numrto. Machine parts and components are stored in the database, so you can make database backup. Because the range of options added is unlimited, even very complex machines can display actual details.

The machine tool model is integrated into the programming system, and the new generation of tool grinder tool program before large module gear processing, and the software can conduct detailed collision safety test. High speed computer gong processing collision test runs at high resolution, even in very small components can detect collisions. When grinding workpiece with block grinder, elastic clamping mechanism will be used for positioning and clamping thin workpiece with large modulus gear. A layer of 0.5mm thick rubber is placed between the workpiece and the magnetic meter. When the magnetic attraction of the workpiece, the rubber compression and elastic deformation are very small, so the surface grinding of the workpiece is carried out. Repeat several times, can meet the accuracy requirements.

1. Using temporary measures to strengthen the rigid sheet workpiece

The computer gong processing uses epoxy resin glue, and the wafer plane workpiece is in the free state. Tablet computer chip in electromagnetic chuck. The smooth skinny face, then from the tablet will be removed, the chip and smooth electromagnetic chuck, workpiece grinding sliced on the other side of the workpiece on the plane. Because before the quenchant epoxy resin, computer gong processing can bridge the gap between the chip workpiece and the tablet computer. The epoxy resin, the workpiece and the plate are bonded together as a whole, thus greatly improving the stiffness. According to the magnetic gravity, the chip will not produce clamping deformation, creating conditions for ground aircraft. It is also possible to use concentrated oil instead of epoxy resin to fill the space between the flake workpiece and the electromagnetic chuck, so as to improve the hardness of the workpiece and obtain good results.

1. Mechanical clamping mode

The use of other pliers will borrow a small magnetic table vise to absorb thin pieces of workpiece, because there is a certain height of the pliers, therefore, through the magnetic small jaw. In order to reduce the gradual smooth feed sheet workpiece surface, get off the car, and then the grinder has a good plane magnetic table, and then another plane grinding chip part, repeat several times, two plane flatness.

1. Vacuum clamping mode

Its working principle is: the rubber seal ring on the concrete, the rubber seal, and the workpiece concrete sealing chamber formed between the thin pieces of workpiece processed by small module gear. Use the air hole in the vacuum pump chamber when the workpiece is clamped. Because of the small clamping force, the grinding method of circular grinding. After the wafer is ground, ground and cut the other side of the workpiece on the plane, you can use the above method, and you can get satisfactory results.

Common chip components such as gasket, friction plate and template are easy to warp and grind after bending heat treatment due to poor rigidity and heat dissipation. High speed CNC gear hobbing machine usually uses electromagnetic chuck to grind on surface grinder. After grinding, the magnetic attraction is removed and the sheet workpiece is restored to its original state, which is difficult to ensure the machining accuracy. Computer gong processing, such as the use of clamping methods to ensure chip positioning and clamping of the workpiece in a free country, the use of double-sided grinding, can achieve good results to meet the requirements of precision parts processing.

In 1959, Richard P. Feynman (1965 Nobel Prize winner in Physics) proposed the idea of micromachining. In 1962, the first silicon micro pressure sensor came into being in computer gongs processing. After that, micromechanics such as gears, gear pumps, pneumatic turbines and connecting pieces with dimensions of 50-500 μ m were developed. In 1965, Stanford University developed a silicon brain electrode probe, and then succeeded in scanning tunneling microscope and micro sensor. In 1987, the University of California, Berkeley, developed a silicon micromotor with a rotor diameter of 60-12 μ m, which shows the potential of using silicon micromachining technology to make small movable structures compatible with integrated circuits to manufacture micro systems.

Large machinery and micro machinery have been attached great importance by government departments, enterprises, universities and research institutions abroad. At the end of 1980s, 15 scientists from MIT, Berkeley and Stanford / at & T in the United States put forward the national proposal of “small machine, big opportunity: report on emerging field micromechanics”, claiming that “due to the urgency of micromechanics (microsystem) in the United States, it should take the lead in the competition with other countries in this new and important technical field”, and suggested that the central government should advance expenses For five years, it has been valued by the leading organizations of the United States, continuously invested heavily, and regarded aerospace, information and MEMS as the three major priorities of science and technology development. NASA has invested 100 million US dollars to develop the “discovery microsatellite”. The National Science Foundation of the United States takes MEMS as a new rising research field and formulates a plan to support the research and development of micro electromechanical systems. Since 1998, it has funded eight universities such as MIT, University of California and Bell Laboratories to engage in research and development in this field, with annual funding of 100 Two million, two million to five million dollars in 1993. MEMS is listed as a key technology project in the report of “DOD technology plan” released in 1994. The advanced research projects agency of the U.S. Department of defense has actively led and supported the research and military application of MEMS. A standard MEMS process line has been built to promote the research and development of new components / devices. American industry is mainly engaged in the research of sensors, displacement sensors, strain gauges and accelerometers. Many organizations have participated in the research of micromechanical systems, such as Cornell University, Stanford University, University of California, Berkeley, University of Michigan, University of Wisconsin, old lunzdermore national research, etc. The Berkeley Center for sensors and actuators (BSAC) of the University of California has established a 1115m2 ultra clean laboratory for MEMS Research and development after receiving 15 million yuan from the Department of defense and more than a dozen companies.

In 1991, Japan’s Ministry of industry and industry started a 10-year, 25 billion yen micro large-scale research program, developing two prototypes, one for medical treatment, human body diagnosis and micro surgery, the other for industry, to repair the tiny cracks in aircraft engines and atomic energy equipment. Dozens of units, including Tsukuba University, Tokyo University of technology, Northeast University, Waseda University and Fujitsu Research Institute, participated in the project.

Grinding machine processing, European industrial developed countries have also invested heavily in the research and development of microsystems. Since 1988, Germany has started the 10-year plan for micromachining. From 1990 to 1993, its Ministry of science and technology allocated 40000 marks to support the research of “microsystem project”, and listed microsystems as the focus of scientific and technological development at the beginning of this century. The Liga process initiated by Germany provides a new technical means for the development of MEMS, And has become the preferred process of three-dimensional structure. France launched the 70 million franc “microsystem and technology” project in 1993. The European community formed the “multi-functional microsystem research network nexus”, which jointly coordinated the research of 46 research institutes. Switzerland has also invested in the development of MEMS on the basis of its traditional watch and clock manufacturing industry and small precision machinery industry, with an investment of US $10 million in 1992. The British government has also developed a nanoscience program. Eight projects are listed for research and development in the fields of mechanics, optics and electronics. In order to strengthen the development of MEMS in Europe, some European companies have formed MEMS development groups.

Grinding machine processing, At present, a large number of micromachines or micro systems have been developed. For example, a micro tweezer with a tip diameter of 5 μ M can clamp a red blood cell, a micro pump with a size of 7mm × 7mm × 2mm can run a car, a robot butterfly flying in a magnetic field, and a miniature inertial unit (MIMU) which integrates a micro speedometer, a micro gyroscope and a signal processing system. Germany created Liga process, which made cantilever beam, CNC machining center actuator, micro pump, micro nozzle, humidity, flow sensor and a variety of optical devices. Dongguan machine parts processing, California Institute of technology in the United States, a considerable number of 1 mm micro beams on the wing surface, to control its bending angle to affect the aerodynamic characteristics of the aircraft. High speed computer gongs process silicon accelerometers produced in large quantities in the United States. The micro sensors (mechanical parts) and integrated circuits (electrical signal sources, amplifiers, signal processing and calibration circuits, etc.) are integrated into the silicon chip within the range of 3mm × 3mm. The micro lathe developed in Japan with a square of several centimeters can process micro shafts with an accuracy of 1.5 μ M.