Monthly Archive September 25, 2020

1、 Belt type spindle of machining center

There are several kinds of spindles that can be used in machining center, such as belt type spindle, straight spindle, gear spindle and motorized spindle. Among them, the belt spindle is the most commonly used spindle form in machining centers, and it is also the standard spindle of many machining centers. Why is the standard spindle of machining center belt type? Is the belt of machining center the spindle?

Not all machining centers use belt type spindle as standard configuration, high-speed machining center and drilling center are not included. This kind of high-speed machine tool is equipped with straight spindle as standard, and belt type spindle cannot be used. The belt spindle is not as high as the direct spindle and motorized spindle, and the maximum speed can only reach 10000 rpm. However, the cutting force of belt spindle is better than that of the straight spindle and motorized spindle, next to the gear spindle. And the price will not be too high, so many machining center standard spindle are belt type spindle. Belt type spindle is enough to meet the needs of most customers and is a very good spindle.

2、 What is the belt spindle used for processing

Since the belt spindle is the most widely used spindle, what can it be processed? Belt spindle is used in both small and large machining centers. It can process large workpieces and small parts. Most of the time, large vertical machining centers are engaged in heavy cutting, including the processing of cast iron and steel castings and the processing of molds. The belt type spindle is competent in this respect, but some alloys with high hardness are not suitable for belt spindle processing, but gear spindle is selected.

Many customers of small machining centers are used for the processing and production of small hardware parts or products, and some of them are also used for the processing of small molds. In other words, the workpieces processed by small machining centers are relatively small. Generally, belt type spindles can meet the requirements of small machining centers, and their small machining centers are less used for processing alloys with high hardness, so the small ones on the market are small 99% of the machining centers use belt type spindles. It can be seen that belt type spindles are very good spindles.

3、 Model recommendation of belt spindle machining center

Most of the machining centers of mingwan machine tools use belt type spindle as standard configuration. Large vertical machining centers include vmc850, 1060, 1270, 1370, 1680, etc., and small machining centers include vmc650, 550, 420, etc., which are very good machining centers with high cost performance. The vertical machining center of mingwan machine tool can meet most of the requirements of most customers and is highly praised by customers. It is the only choice for the brand of cost-effective machining center.

1、 Characteristics of hard rail vertical machining center — hard rail

For the hard rail, we talk less, especially the vertical machining center. Isn’t it easy to use? It’s not. So, what are the characteristics of the hard rail vertical machining center? With such a question, mingwan machine tool small series for you to summarize the characteristics of the hard rail vertical machining center. Hard rail refers to the machine tool bed, column and other fixed parts of the direct processing guide rail into a whole, through the sliding seat and workbench or other moving parts connected. The rigidity of the hard rail is better, the weight it can bear is relatively large, and the ability of heavy cutting is also very strong. Through direct transmission, the three axis linkage, large axial thrust, wide base and four rail supporting structure are adopted. Therefore, the vertical machining center is suitable for large and medium-sized workpiece processing, especially for mold processing.

2、 Characteristics of hard rail vertical machining center

It has the characteristics of low damping and low friction coefficient to cast castings with mikhanna material.

The lubrication system lubricates the transmission parts to reduce the friction resistance and increase the service time of the machine tool;

Equipped with special chip removal machine for systematic chip removal;

The cooling system and oil cooler are used to cool the machining cutting and spindle, so the cooling efficiency is high;

It can be equipped with tool magazine to implement automatic tool change, saving tool changing process time;

With the fourth axis and rotary table, the horizontal / (fourth axis /) movement can be realized, and complex workpieces can be processed.

Mingwan machine tool uses Taiwan Science and technology, specializing in manufacturing high-level, cost-effective products. If you are interested in hard rail vertical machining center, you may as well contact us, we will give you the most satisfactory products.

The biggest processing attribute of vertical machining center is that the consistency of batch workpiece size should be very high. We know that the traditional processing of workpiece from one process to another has to go through a clamping process. This process is difficult to achieve the complete consistency of the processing size of each part by human operation. Of course, this does not mean that the workpiece is out of tolerance, as long as the tolerance of the workpiece is within the tolerance All parts within the band are qualified parts, which means that some workpieces may be in large difference, some parts may be in medium difference, and some parts may be in small difference, so it is difficult to ensure the consistency of workpiece size.

Therefore, at present, the utilization rate of vertical machining center is the highest in small and medium-sized processing enterprises. Of course, the vertical machining center is also the most cost-effective machine tool in CNC machine tools. It has high processing efficiency and high processing precision. From these two aspects, it also solves the problem of maintaining the size consistency of workpieces. Of course, if the numerical control parameters are not set properly or the operation is improper, the vertical machining center will also appear the phenomenon of machining out of tolerance from time to time in the actual processing. This paper briefly introduces the causes and solutions of machining out of tolerance in vertical machining center

The out of tolerance of machining accuracy of vertical machining center mainly includes: high surface roughness of inner hole, out of roundness of reamed inner hole, out of tolerance of position precision of reamed hole, obvious edge of inner surface of hole, irregularity of center line of hole after reaming, increase and decrease of hole diameter.

1、 The position accuracy of reamed hole is out of tolerance

Causes: it may be caused by the wear of the guide sleeve of the vertical machining center, the distance between the bottom end of the guide sleeve and the workpiece, the short length of the guide sleeve, the poor accuracy and the looseness of the spindle bearing.

Solution: if the position accuracy of the hole is out of tolerance during reaming of the vertical machining center, the following maintenance can be carried out according to the above-mentioned problems. The guide sleeve shall be replaced regularly and the guide sleeve shall be lengthened to improve the matching accuracy of the clearance between the guide sleeve and the reamer, the machine tool shall be maintained in time, and the spindle bearing clearance shall be adjusted.

2、 The surface roughness of inner hole is high

Causes: the surface roughness of the inner hole machined by the vertical machining center is high, and there are many reasons, which may be caused by too high cutting speed, improper selection of cutting fluid, excessive reamer main deflection angle, too large reaming allowance, uneven or small reaming allowance, unsharp edge, too wide reaming edge, poor chip removal during reaming, excessive wear of reamer, and possibly selected milling Tool and part material mismatch and other reasons.

Solution: there are many reasons for the high machining roughness, so the solution is more complex. We can start from the following aspects: reduce the cutting speed, select the cutting fluid according to the processing materials, appropriately reduce the reaming allowance, improve the position accuracy and quality of the bottom hole before reaming, or increase the reaming allowance, increase the space of chip holding groove or use the reamer with edge inclination angle to make the chip removal smooth The reamer should be changed regularly and the cutting tool should be selected reasonably. For example, when machining steel parts, the suitable tool should be selected.

3、 Increase of machining aperture

Causes: the diameter of the reamer increases gradually when machining in the vertical machining center. The causes may be: the design value of the reamer’s outer diameter is too large or the reamer edge has burr, the cutting speed is too high, the feed rate is improper or the machining allowance is too large, the reamer’s main deflection angle is too large, the reamer is bent, the reamer edge adheres to the chip, the reamer edge swing is out of tolerance during grinding, the cutting fluid is not suitable, and It may be the problem of CNC machine itself. The spindle is bent or the spindle bearing is too loose or damaged.

Solution: according to the actual situation, the following countermeasures can be made: according to the specific situation, reduce the reamer outer diameter, reduce the cutting speed, adjust the feed rate or reduce the machining allowance, properly reduce the main deflection angle, straighten or scrap the bending reamer that can not be used, select the cutting fluid with good cold performance, adjust or replace the main shaft bearing, or replace the whole spindle.

4、 The reamed inner hole is not round

Causes: the machining of the inner hole is not round and the roundness is not enough. It is mainly due to the following factors: the reamer is too long, the rigidity is not enough, the vibration is generated during reaming, the reamer’s main deflection angle is too small, the reaming allowance is too small, there are gaps on the inner hole surface, cross holes, especially sand holes and air holes on the surface of the hole, as well as the looseness of the spindle bearing of the machine tool.

Solution: we can start from the following aspects: the installation of reamer should adopt rigid connection, select qualified reamer, control the hole position tolerance of pre-processing process, adopt unequal pitch reamer, select qualified blank, timely adjust the spindle clearance of machine tool, etc.

5、 After reaming, the center line of the hole is not straight

Causes: when the vertical machining center is machining holes, the center line is not straight. The possible reasons may be: the hole is inclined when drilling, especially when the diameter is small, Due to the poor rigidity of reamer, the original bending can not be corrected, the reamer’s main deflection angle is too large and the guide is poor, so that the reamer is easy to deviate from the direction in reaming, the inverted cone of the cutting part is too large, and the reamer is displaced intermittently at the gap in the middle of the hole.

Solution: increase reaming or boring process to correct the hole, reduce the main deflection angle, adjust the appropriate reamer, replace the reamer with guide part or lengthening cutting part, and pay attention to correct operation.

The machining center has been developed from the basic CNC milling machine. It combines all the features and functions of the CNC milling machine. The only difference from the CNC milling machine is that the machining center has automatic tool changing device, which can realize the automatic tool changing function during processing. But NC milling machine has no automatic tool changing device, which can not realize the function of automatic tool change, which is the only difference between CNC milling machine and machining center.

The composition of automatic tool changing device in machining center

The automatic tool changing device of machining center is composed of tool magazine, manipulator and driving mechanism. The tool magazine is used to store the tools needed in the process. There are many types of tool banks, mainly classified according to the shape, such as the Douli type magazine, disc magazine and chain magazine, etc. the capacity of these repositories is several to hundreds of tools. In the market, there are two kinds of tool storehouses used in the common processing centers, namely, the Douli type and the disc type. However, chain type tool base is not used by any manufacturer because of its high price. Here is a small edition to introduce the way of tool change.

The way of changing the tool of the Douli type magazine

The tool changing method of the Douli type magazine is relatively simple, and there is no mechanical arm for such magazine, so it is not necessary to use the mechanical arm to complete the tool change. The tool changing mode of its magazine is that the magazine moves to the spindle to realize the tool change. This kind of tool has the advantages of high cost performance, convenient maintenance and simple structure, and the disadvantage is that the speed of tool change is slow.

The way of changing the tool of disc magazine

The tool changing mode of disc magazine is more complicated, mainly by the manipulator to complete the tool change action, and the manipulator takes the tool 180 ° from the magazine and rotates it into the spindle to complete the tool change. This kind of tool magazine has the advantage of fast tool changing, and its disadvantage is complex structure, inconvenient maintenance and high failure rate.

Although the tool changing mode, tool selection mode and tool structure of these tool banks are different, they are controlled by numerical control system, and the selection and exchange of tools are realized by motor, air pressure or hydraulic and manipulator.

As we all know, the structure of the tool magazine of machining center is very complex, especially the disc magazine. And in the normal work of the machining center, the tool magazine frequently transfers tools. Therefore, the machining center is prone to failure. According to statistics, 50% of the machine tool failures are related to the tool magazine. Therefore, when using the machining tool magazine, we must pay attention to some matters, and try to minimize the fault of the tool magazine of the machining center.

Precautions for tool magazine of machining center

1. It is forbidden to load the overweight and extra long tools into the tool magazine, which can prevent the tool from falling off or collision between the tool and workpiece and fixture during tool change.
2. When installing the tool into the tool magazine, we must pay attention to the correct installation according to the sequence of the tool magazine. After the installation, let the machining center idle to see whether the tool magazine replaced is consistent with the required tool, so as to prevent the adverse consequences caused by the wrong replacement
3. When the tool needs to be installed manually, make sure that it is installed in place and firmly. Check whether the locking device on the cutterhead is started and ensure these factors, otherwise unnecessary accidents will occur.
4. The operator of the machining center should check whether the tool magazine returns to the correct position at any time, simply return to zero, and then check whether the spindle of the machining center returns to the tool change position. If one of the two problems is found, it should be timely sorted out and fed back, otherwise the tool change can not be completed, affecting the work efficiency of the machining center.
5. The tool, handle and sleeve should be cleaned and maintained regularly. The tool, handle and sleeve must be kept clean.
6. When the machining center is started, if you want to make the machining center run at idle, check whether the tool magazine, manipulator and other moving parts are normal, especially if the travel switch and solenoid valve are working normally. The other is to check whether the hydraulic pressure value of the manipulator is within the normal range, whether the cutting tool is locked on the manipulator. If the above problems are found, they should be immediately fed back and dealt with in time.

1、 What tool magazine does five axis machining center use

Among all kinds of machining centers, five axis machining center is the most technical machining center. In the 1980s and 1990s, the five axis machining center was listed as a strategic material, and there were extremely strict restrictions on export and import. We can imagine how high the status of five axis machining center was at that time. Today, the five axis machining center still has a strong influence, and is still in an irreplaceable position in the processing of various high-end scientific and technological parts.

Although there are no clear requirements for the selection of tool magazine for five axis machining center, we will always choose a better tool magazine when selecting tool magazine of five axis machining center. This is based on the features of the five axis machining center. The workpieces processed by 5-axis machining center are generally very complex, and the requirements for precision are very high. The selection of tool magazine and tool directly affects the machining efficiency and the quality of workpiece, so the selection of tool magazine for five axis machining center cannot be ignored.

When selecting tool magazine for five axis machining center, we need to choose better tool magazine and more precise tool. A good magazine is based on the type and brand of the magazine. For example, for a five axis vmc850 machining center, we can choose the tool magazine types of hat type and tool arm type, so we’d better choose to use the tool arm type tool library. As for the magazine and the brand of the tool, there are different opinions.

2、 What are the tool magazine of five axis machining center

The five axis machining center can be a large vertical machining center or a small vertical machining center. However, the tool magazine of these two kinds of machining centers can only be selected as the hat type and the knife arm type. Generally, we can’t see the bamboo hat type tool magazine on the five axis machining center, and few people will use the hat type tool library on the five axis machining center. The type of tool magazine of five axis high speed machining center is different from that of common machining center. The tool magazine used in high-speed machining center is the tool arm type and the same motion type. Generally, the tool magazine with the same motion is better and the tool change speed is faster. The same is true for the drilling and drilling center. There is no big difference between the arm type magazine and the flying saucer type magazine. The flying saucer type magazine has faster tool changing speed than the clamping arm type one, and the capacity of the general tool magazine is larger than that of the clamping arm type, which can meet the needs of most customers.

3、 Tool magazine brand of five axis machining center

Domestic use of five axis machining center customers, almost will not use domestic tool library, the reason we all understand. Taiwan tool magazine and imported tool magazine are mostly used in domestic five axis machining center. Taiwan’s Dao warehouses, such as Shengjie, shoulun, deta, Okada, etc., are all very good brands with high cost performance. However, the imported tool magazine is not used much. Jieli from the United States, KTC and reichenbacher from Germany are all well-known brands of tool magazine. The quality is good, the precision is good, but the price is very high. How to choose the tool magazine of five axis machining center depends on the customer’s demand and economic ability.

As we all know, diamond tool is the most hard tool among all the tools, and its quality is very good. Its tool has high hardness, high wear resistance and good thermal conductivity, which is widely used in machining center tools. The main characteristics of the tool used in the machining center are high efficiency, high stability and long service life. It is indispensable to use the machining center to process the workpiece with high hardness. There are three kinds of materials used in diamond cutting tools, which are pure natural diamond, PCD diamond and CVD diamond.

1. Natural diamond tools:

Natural diamond has been used as a tool for nearly a hundred years. After fine grinding, the blade of natural diamond tool can be ground very sharp, and can be ground to ultra-thin. After investigation, natural diamond can be finely ground to the edge of 0.002 μ m radius. Using this tool to process workpieces can carry out ultra-thin cutting, and can process the ultimate machining accuracy and smooth surface Said that the surface roughness processed is very low. This kind of natural diamond tool is called irreplaceable ultra precision and ideal tool in the future. Natural diamond tools are easy to use, but they are very expensive. Few enterprises in China are willing to buy such expensive tools.

1. PCD diamond tools:

PCD diamond material is actually polycrystalline diamond, its English name is polycrystal diamond, PCD diamond is made by high temperature and high pressure synthesis technology. Because of the high price of natural diamond, there are synthetic polycrystalline diamond, its price is only one dozens of natural diamond. However, in terms of performance, polycrystalline diamond can not match, for example, natural diamond can fine grind ultra-thin blade, while polycrystalline diamond can not. In addition, in the machining center, the surface quality of workpiece processed with polycrystalline diamond tool is not as good as that of natural diamond tool. Natural diamond tool can carry out ultra-thin cutting of workpiece, while polycrystalline diamond tool cannot For ultra-thin cutting, polycrystalline diamond tools are suitable for finishing, while natural diamond tools are suitable for ultra-fine machining.

1. CVD diamond tools:

CVD diamond is also artificially synthesized. It appeared between 1970s and 1980s and was developed by Japan. CVD diamond refers to the synthesis of diamond films on heterogeneous substrates (such as cemented carbide, ceramics, etc.) by chemical vapor deposition (CVD /). The characteristics of CVD diamond are almost the same as that of natural diamond. The tool made of CVD diamond material can be regarded as perfect. It has the advantages of natural diamond and polycrystalline diamond at the same time.

The angle head of machining center is a very important part of machining center, but some friends who use machining center do not know enough about it, or even use it very little, so it can not give full play to the powerful performance of machining center.

1、 What is the angle head of machining center

The angle head of machining center is a common accessory head in CNC machining center industry in the market today. It is the only kind of accessory that can complete the side processing without secondary clamping the workpiece, especially for drilling, tapping and milling groove machining in some circular holes and small-sized cavities. It is absolutely essential tool. Because of its special and necessary function, the angle head has been widely recognized in the CNC market.

2、 What is the angle head of machining center

1. Gantry special heavy angle head BT50 output BT50
2. Light 90 degree standard angle head — the spindle is BT50 or BT40, and the output is ER40, er32, ER25, ER20, ER16, etc.
3. Non standard angle head – customized, the general cycle is 1-2 months.
4. Special heavy cutting angle head for machining center — the spindle is BT50 or BT40, and the output is BT40.
5. Universal angle head: light universal can rotate 0-180 degrees, heavy universal can rotate 360 degrees.

3、 Application field of machining center angle head

The application of machining center angle head is mainly a specific process. For example: precision workpiece, one-time fixed, need to process multiple faces; hole in hole, milling head or other tools can not probe into the hole to process small hole; machining center can not process inclined hole, inclined slot, etc., such as cylinder, box shell inner hole, when a circle of hole needs to be processed on the periphery of circular workpiece, the fourth axis processing can realize complete automation. The side needs to be processed by various processes, and automatic tool change can be realized by using multiple tools.