Jméno společnosti:BEIJING DEMINA PRECISION MACHINERY CO., LTD Tel 0086-10-62965622 0086-13910819265 E-mailem:[email protected] Adresa: No.1034, Building A, Hongfu Science Park, Beiqijia Town, Changping District, 102209, Beijing, China
Instructions for purchasing CNC grinder
CNC grinder this kind of grinder, it's in the purchase is a notice. It is: should take into account all the relevant factors. Including the product detailed parameters, performance indicators, origin, price, quality, manufacturers and after-sales service these seven necessary factors to consider, not one. Moreover, these factors should be taken into comprehensive consideration in order to have accurate judgment and correct selection results. And then, to choose the right products.
The difference between ordinary grinder and CNC grinder
Common grinder, which is driven by a hydraulic cylinder, is a two-axis drive cylindrical grinding machine. With two cylinders respectively control the grinding wheel frame and the work table feed. And through the dial changes to manually control the grinder. In the process of measurement is also the use of measuring instruments for manual control.
CNC grinder manufacturers of CNC grinder, which is the use of a CNC system to achieve control. Servo drive instead of the common grinder cylinder drive. In addition, linkage control is realized through a servo system and on-line measuring instrument, and the linear grating is realized as a whole closed-loop control.
Therefore, to sum up, these two grinding machines are very different, they can not be equated. Therefore, its selection and use can not wrong, so as not to cause problems or unnecessary trouble.
Comparison of CNC peripheral grinder and CNC tool grinder
CNC peripheral grinder and CNC tool grinder, both of which are specific types of CNC grinders. However, to compare them, there are some differences, is:
Difference 1: the freedom of the working part of the equipment is not the same, CNC tool grinder freedom is more.
Difference 2: The machining range is not the same, CNC peripheral grinder is used for grinding workpiece with a certain Angle. Such as the edge of the complex contour grinding Angle, and CNC tool grinder, it can also change the Angle of grinding.
Difference 3: in the scope of application, CNC tool grinder's scope of application than CNC peripheral grinder a few wider.
Warning Of Operating Tool Grinding MachineIf you do not strictly comply with the operation rules and procedures, personal injury may result. So the operator needs to note these warnings.1. Wear appropriate safety clothing.2. Wear glasses and gloves to prevent metal debris damage to your body.3. Do not be used when the machine is broken down.4. Eliminate safety problems before powering on.5. Report to your supervisor in case of any operational problems.6. Daily checks whether every part work normally and the protective measures is taken.7. Daily operation and maintenance areas must be dry and clean. Make sure you have all maintenance tools, and they are in good condition.8. Any repairs must be done under the circumstances that the machine is not working and the power is off.9. Obey the operation procedures and use the information.Must not use detergents, gasoline, solvents, or other flammable liquids, for cleaning but the use of non-flammable, non-toxic commercial solvent.10. Do not use compressed air to clean the machine and its components. Please wear a protective glass and limit the pressure bellow 2bar if you won’t do this.11. Don’t use bare wire for lighting during leak inspection and test.Do not lubricate while the machine is running.12. Before making electrical connections, make sure the voltage and frequency meet the requirements.13. Electrical power must be connected to the ground for protection.Any electrical operation, for example replacing the fuse, replacing the overload protection, etc., must be handled by professionals, and only after the power cut off.
The world's largest exhibition in metal processing and machine tools
Exhibition Date: Sep.16 to Sep.21 2019
European machine tools exhibition EMO is launched by the European machine tool industry cooperation committee (CECIMO) and sponsorship, founded in 1951, has so far held the nineteenth session, held once every two years, two famous exhibition cities in Europe, in accordance with the "Hanover, Hanover, Milan" pattern on tour, extension by eight days to shorten to 6 days.
Internationalization: exhibitors travel to EMO Hanover from all over the world and from all areas of metalworking technology.EMO Hannover is one of the world's most international metal processing trade fairs, with about 60% of foreign exhibitors. As the leading exhibition of its kind, it serves as the hub of the network, embodying a high level of expertise between the provider and the user.EMO Hannover is the only trade fair to enter the global market - located in the heart of Germany, EMO is one of the world's leading markets for machine tool sales.
Extensive exhibition scope: EMO is the world's leading machinery manufacturing technology exhibition. Covering the whole process of metal processing such as machine tools, tools, mold manufacturing, software, surface treatment, accessories, waste disposal, and related services, it has the reputation of being a vane of innovative production of engineering technology. Considering the number of exhibitors, the quality of exhibitors, the release of new products and technologies, the introduction of new ideas and other aspects, EMO is the epitome and barometer of the international machine tool market and a superb exhibition in the field of metal processing and machine tools in the world.
What is the cause of the burn of the workpiece during the grinding of the high-speed CBN wheel?1. The hardness of the CBN grinding wheel is too high or the grain size is too fine;2. The speed of the grinding wheel is too high for the workpiece;3. Insufficient cutting fluid supply, too much feed, and poor heat dissipation conditions;4. The CBN grinding wheel is not dressed in time or the dressing quality is poor;5. The excessive vibration swing of the grinding wheel may cause burns due to the constantly changing grinding depth of the workpiece;6. The clamping of the grinding bow and arrow is not firm enough, and the workpiece stops when grinding;7. The burn is too deep during rough grinding, and the fine grinding reserve is too small to wear off;So how do we tell if a piece is burned? Quite simply, it can be checked out by regular pickling. When the surface of the workpiece is wet, we should quickly carry out a visual inspection under the fluorescent lamp. The normal workpiece without burn is a uniform dark gray.If the crack is cracked, it is a grinding crack. If gray or dark spots, it is decarbonization. If the software point, if there is a cloud-like dark spot, and the boundary is indefinite, it is a soft point. If there are dark patches, continuous lines, or discontinuous lines on the surface of the workpiece along the grinding direction of the grinding wheel, it is considered as a burn.When grinding the workpiece, if there is a burn, we must find out the reason in time, and take limited measures to solve, only in this way can grinding out the standard quality products.
The function of guide lubricant
(1) Make guide rail work as close as possible to liquid friction state, so as to reduce friction resistance, reduce driving power and improve efficiency.
(2) Reduce guide rail wear and prevent guide rail corrosion. The flowing lubricating oil also serves as flushing.
(3) Avoid crawling at low speed and heavy load, and reduce vibration.
(4) Reduce friction heat at high speed and reduce thermal deformation.
Selection of lubricating oil for guide rail of machine tool
According to experience and data, the following factors should be considered when selecting lubricating oil for a machine guide.
(1) Both as a hydraulic medium and guide oil lubricating oil. According to the needs of different types of machine guides, the guide oil can be used as a hydraulic medium at the same time to meet the requirements of the guide and hydraulic system. For example, machine tools, such as coordinate boring machine guide rail oil viscosity (50 ℃) should choose high (40 ~ 90 was/s). But like all kinds of grinding machines, often will guide rail lubricating oil supply by hydraulic system, and higher requirements of the hydraulic system must satisfied. The guides rail of a hydraulic oil viscosity (50 ℃) elected to lower (20 ~ 40 was/s), namely the viscosity in the hydraulic system.
(2) Select viscosity according to sliding speed and average pressure.
(3) According to the actual application of machine guide lubrication at home and abroad to choose. When choosing to use guide lubricant, we can also refer to the practical application of guide lubrication of existing machine tools at home and abroad.
Domestic lubrication equipment XHZ series thin oil centralized lubrication device. The device is composed of a quantitative lubrication pump, a precision oil filter, a level detector, a feed oil detector, a pressure relay, a progressive oil distributor and a fuel tank. To guide the surface of a fixed amount of oil supply.
Solid lubrication is the solid lubricant that will cover on the friction surface of the guide. Forming a cohesive solid lubrication film, to reduce friction, reduce wear. According to the basic raw materials, solid lubricants can be divided into metal, metal compounds, inorganic and organic substances. The bearing capacity, aging performance and high and low-temperature performance of lubricating oil can be enhanced or improved by adding solid lubricant powder to lubricating oil.
The machining accuracy of CNC machine tools ultimately depends on the accuracy of the machine tools themselves to ensure the accuracy of CNC machine tools, including geometric accuracy, positioning accuracy, repeatable positioning accuracy, and cutting accuracy.Geometric precision: also known as static precision, is a comprehensive reflection of the key parts of the CNC machine tool after the assembly of the comprehensive geometric shape error.Positioning accuracy: indicates the accuracy of the motion of the measuring machine under the control of the numerical control device. According to the measured positioning accuracy value, the best machining accuracy can be judged in the automatic machining process of the machine tool. It refers to the difference between the actual position of parts or tools and the standard position (theoretical position, ideal position). The smaller the difference, the higher the accuracy. It is the premise that machining precision of parts can be guaranteed.Repeated positioning accuracy: refers to the consistency of position accuracy obtained by repeatedly running the same program code on a CNC machine tool. It is the consistency of continuous results obtained by processing a batch of parts under the same conditions (for example, on the same CNC machine tool, if the same part program is applied, but the operation method is different, the results will be consistent).Cutting accuracy: it is a comprehensive check of the geometric accuracy and positioning accuracy of the machine tool under the condition of cutting.It can be seen from the above, CNC machine tool precision of high and low mechanical and electrical aspects, mechanical aspects such as spindle precision, such as jumping, bus, etc.. Precision of lead screw. The precision of the fixture, the rigidity of the machine tool, and so on. In the electrical field, the control mode is mainly semi-closed loop, full closed-loop, feedback and compensation mode, interpolation accuracy during machining, etc. So the accuracy of the machine does not depend on whether the machine is a fully closed loop.
PCD tool in the automobile manufacturing industry
In Europe, according to research published by the European aluminum Association (EAA), the amount of aluminum used in a new car in 1990 was 50kg. By 2005, that number had risen to 132 kilograms. A further 25kg of aluminum is expected to be used in each new car by 2010. According to the study, two million tons of aluminum parts were made in new cars made in Europe in 2005. Using aluminum parts to make cars lighter could save 1 billion liters of fuel a year and reduce carbon dioxide emissions by about 40 million tons over the life of those cars.
In the body of a car, most aluminum parts are concentrated on the air conditioning system, engine cover, shock absorber parts, and steering column. In automobile chassis and suspension assembly, aluminum parts are mainly concentrated on wheel hub, suspension bracket, and steering system assembly parts. In the power transmission system, most aluminum parts are located on the cylinder head, cylinder body, hood, pump, and cooler. In addition, aluminum alloy seals, body shell and chassis applications are also increasing.
Replacing steel with a denser material as a conventional structural material is also important in other industries such as general machinery manufacturing and aviation. However, because the hardness of aluminum alloy is not too high, and has a higher toughness, so its cutting is more difficult. In processing, aluminum alloy is easy to bond with the tool material and appear cold work hardening phenomenon, so in low-speed cutting, the tool's front edge is easy to produce chip tumor.
Due to sensitivity to environmental impacts, automotive parts are increasingly being cut dry or machined with minimal coolant. The cooling cost savings (including associated waste liquid recovery and treatment costs) are also driving a significant increase in cutting speed that is not possible with conventional cemented carbide tools.
When using a conventional tool or tool material for dry cutting, the surface finish of the workpiece is poor due to the change in the geometry of the cutting edge of the tool and the increase of heat caused by friction in the cutting area.
Higher machine speed
Last but not least, the development of machine tool technology makes its spindle speed and feed constantly improve, so as to achieve faster machining. Only a few years ago, the spindle speed of the machine tool was only 6000r/min, but now it has reached 30,000-40000r /min, and the movement acceleration of the shaft can reach 2G. This machine, supported by powerful computer power, is capable of achieving the movement required for machining (e.g., screw interpolation in thread milling).In order to convert this speed advantage into a machining advantage at the point of action, the corresponding tool material is required. However, with carbide cutting tools, the cutting speed can only reach 400m/min. Tools with polycrystalline diamond (PCD) cutting edges can cut up to 3000m/min(depending on the cutting process).In addition to higher machining speed, the main benefits of PCD tools include longer tool life and (in many cases) better surface machining quality.
JEL precision tools, part of the German Komet group, offer a wide range of PCD tools to the market, including DRILLCUT and DRILLMAX for high-efficiency PCD drills with carbide body. These two drills are capable of drilling holes up to a depth of 5D. The DRILLCUT is a straight groove bit with 2 cutting edges and 4 guide edges and is provided with a coolant channel for internal cooling.DRILLMAX also USES the same internal cooling design, but it is a spiral grooved bit with 2 guide edges.DRILLMAX bit positioning accuracy, drilling accuracy up to it8-it9 and can obtain a long tool life and good surface finish. The company also includes PCD slot cutters in its product line. During machining, the PCD cutting edge of the tool is drilled into the center hole from the upper part of the workpiece and then cut off the center. The maximum cutting depth is up to twice the diameter of the tool. These tools can also be used for suitable milling, as well as for machining circular geometry to achieve the good surface finish and burpless cutting edges. Standard 2-edge PCD cutters have a minimum diameter of 6mm and 3-edge cutters have a diameter of 16-20mm.
High-reliability thread milling
JEL is one of the few technical authorities in the field of complex internal threading, particularly when it comes to thread milling or developing specialized solutions for specific processing. The famous MGF and TO MILL thread mills are the most commonly used machining tools.MGF thread milling cutter with PCD tip has a sunk hole in the shank, and the cutter body is made of hard alloy material, especially suitable for processing aluminum alloy and other materials usually processed by PCD. The tool can mill m6-m12 standard thread sizes with a cutting edge length of 2 times a nominal diameter. Similarly, TO MILL(GWF) thread milling cutters with diameters of 16mm and 20mm can mill threads with diameters ≥20mm.In addition, JEL offers process-oriented solutions that include as many processing operations as possible.PCD tip drills and thread milling cutters (BGF) have also been developed that, in addition to producing screw holes, 90° chamfers and threads, can also produce protective countersunk holes in a single machining operation.
Examples of auto parts processing
One example of the vabos-k modular tool concept (variable drilling, counterboring and thread cutting system) with bit and thread milling cutters is machining spark plug threads on die-cast aluminum. With this tool, the machining of the screw hole, 90° chamfering, spot-facing, face facing with diameter 22mm and M14×1.25 thread can be completed through one processing. All cutting elements of the tool use PCD tips. The values-k modular tool system was developed for processing where the use of indexable blades in tool clips is not possible due to shape, size, or precision requirements. To process 90° chamfering, spot facing, and face facing, the PCD cutting edge is welded directly to the vabos-k head and the head is then fixed to the cutter body or clamp, and the cutter body or clamp can be easily removed to install the new PCD cutting edge. This knife clip is a one-time purchase of accessories. Center drills and thread mills can be easily installed in place without time-consuming adjustments.
Another example of a specialized tool developed by JEL is also a vabos-k tool system. The system consists of a solid carbide bit and thread milling cutter (BGF) for drilling through holes with internal threads, counter facing holes and M6 threads on aluminum shell workpiece. The salient feature of the tool is that it can process countersunk holes with a diameter of 50mm. Only the PCD tip can be used for machining at a steady maximum speed of 10000r/min (equivalent to a cutting speed of 1570m/min at a diameter of 50mm). Only in this way can a very short total processing time (3.9 seconds) be achieved.
The vabos-m tool system for finishing prefabricated holes in fuel filter housings has a PCD Tomill thread mill. The process of machining countersunk hole contour, counter facing hole, outer edge deburring and milling S80×3 sawtooth thread can be completed with one machining operation. Processing time per hole can be reduced to an incredible 8.8 seconds. One of the features of the tool is that the design of the thread milling cutter enables the first thread processed on the workpiece to be a complete thread.
Circular cutting and groove cutting machining
When contour machining is required on the inner and outer diameter of the workpiece (such as grooving in the hole and machining cavity), circular milling and turning can only be realized on the flexible machining center, and circular cutting and grooving is a feasible alternative processing method. This kind of processing will be in the lathe insert the principle of processing upside down and turning the workpiece rotation, tool static way is different, it is the workpiece static, tool movement. The tool is processed by the circular interpolation path generated by the CNC system of the machine tool into the stationary workpiece. In this process, the cutting edge of the tool is perpendicular to the tangent of the cylinder of the hole at each point in the circular interpolation path. The result is that for every turn the tool makes around the workpiece, it only turns around its axis once. The surface machined by circumferential cutting and grooving will not produce the special cutting mark surface of circumferential milling. Such tools with PCD cutting edges are also available for aluminum parts.
German Komet group is composed of the Komet precision tool company, Dihart precision tool company and JEL precision tool company. The group has approximately 1500 employees around the world, engaged in the production and sales of precision cutting tools, its main technical areas are a hole, thread general processing and precision processing, special thread cutting, standard, and special PCD tools and turning tools. Komet is a market leader in mechatronics (tools with built-in NC axis for cutting edge positioning and tools with NC contorting).
What is a grinding burn? During grinding, due to the instantaneous high temperature in the grinding area (generally 400-1500 ℃), the surface layer of the workpiece tissue changes locally, and some parts of the surface appear discoloration (namely the color of the oxide film – yellow, brown, purple, green and other colors), this phenomenon is called grinding burn.Grinding burns can be distinguished according to appearance, properties of surface microstructure changes, and depth. Depending on the appearance of the burn, there are total burns (where the entire surface of the part is burned), porphyritic burns (where there are scattered burns on the surface), and linear burns (where there are streaks on the entire surface of the part), which are the most common burns in production.According to the properties of surface microstructure, there are tempering burns: when the surface layer temperature of the workpiece does not exceed the phase transition temperature Ac3 but exceeds the transition temperature of martensite, the martensite will change into the tempered trostenite or Soxhlet with lower hardness. Quench burn – when the surface layer temperature of the workpiece exceeds the phase transition temperature Ac3, the martensite is converted into austenite. And then there is sufficient cooling fluid, the surface layer will be quickly cooled to form a secondary quench Martensite, hardness higher than the tempered Martensite. But very thin (only a few microns), and the lower layer is the tempered Soxhlet and trostenite with lower hardness. Annealing burn – When the surface layer temperature of the workpiece exceeds phase transition temperature Ac3, the martensite is converted into austenite. And at this time, if there is no coolant, the surface hardness drops sharply, causing the surface of the workpiece to be annealed. This can easily happen in dry grinding.Burns can also be classified as shallow (up to 0.005mm), medium (up to 0.001mm), and deep (up to 0.01mm), depending on the depth of the surface microstructure.
Machining Tools have many types of classification
1. According to the application, they can be divided into special and universal tools, also called standard and non-standard tools.
2. According to the tool material, there are high-speed steel, cemented carbide, metal ceramic, ceramic material, CBN, and PCD machining tools.
3. According to the manufacturing process of machining tools, there are welding, coated and non-re-sharpening machine clamped tools.
4. According to the appearance, they can be divided into translation type, rotary type, sizing adjustable tools.
5. According to the equipment using, there are turning the tool, milling cutter, drill, boring cutter, planer, grinding wheel and so on. Hob, gear slotting cutter, razor, and other special tools
6. According to the processing parts, hole processing tools such as drilling, reaming, boring, grinding so on. Plane processing tools mainly for all kinds of the milling cutter such as face milling cutter, end milling cutter, corn milling cutter and so on. In addition, there are groove class, cylindrical class, curved surface, cavity and so on.
7. It seems to be various, but in fact, it is only according to the components and different needs, management, manufacturing and application to classify.
We should choose a suitable grinding tool according to the type of machining tools used. A series of tool grinding machines developed and manufactured by our company can basically meet the grinding and manufacturing of most of the machining tools above. Customers can contact us and tell us your needs through the following information, and we will help you choose the most suitable program.
In order to reasonably select the grinding amount, the relationship between the surface temperature of the grinding area and the grinding amount must be analyzed first. Taking plane grinding as an example, the calculation problem of reducing the grinding area to a semi-infinite heat field with a continuous uniform heat source AB conducting only below the surface of the workpiece is simplified according to the actual machining situation (see Figure 1). Through the theoretical analysis and calculation of temperature field, the heat generated by the continuous uniform heat source AB in the grinding zone in unit time Q = c0VI0.2AP0.35V sand 0.35F-0.3 (C0 is constant) can be obtained. From the relation between the surface temperature of the grinding zone and the grinding dosage, it can be seen that:1. Grinding depth AP When the grinding depth AP increases, the heat generated will increase, which will increase the surface temperature of the workpiece and increase the degree of burn. Therefore, AP cannot be selected too large.2. Transverse feed F When the transverse feed F increases, the surface temperature of the grinding zone decreases on the contrary, and the grinding burn decreases. The reason is that with the increase of F, the contact time between the grinding wheel and the workpiece surface is relatively reduced, so the action time of heat is reduced and the heat dissipation condition is improved. In order to make up for the increase of surface roughness caused by the increase of lateral feed, a wider grinding wheel can be used.When the workpiece velocity vI increases, the surface temperature of the grinding zone rises. However, the further study found that the larger vI was, the larger the temperature gradient near the grinding surface was, as shown in Table 1.This is because although vI increases, the action time of heat is reduced, that is, although the temperature of the grinding area is high, the workpiece surface is not burned before it is effectively cooled out of the grinding area. According to the data in Table 1, choosing a larger vI can reduce the burn on the grinding surface and improve productivity at the same time.Of course, increasing vI will lead to increased surface roughness, and in order to make up for this defect, the speed of the grinding wheel can be improved accordingly. In fact, according to relevant studies, if vI is increased by 3 times, resulting in increased surface roughness, only a 39% increase in V sand can be compensated. The practice has proved that increasing vI and V sand simultaneously can avoid grinding burns. As shown in figure 2 is 18 crniwa steel grinding, vI, and v sand not burn the critical ratio curve. Here is the right of the curve is prone to burn the danger zone (Ⅰ area), the curve of the upper left for safe (Ⅱ area).