2020 – Page 30 – CNC Machining & Turning, Milling, Metal parts

Machining center and drilling center

1、 What is the difference between machining center and drilling center?

In general, the manufacturers of production and processing centers will produce drilling centers, but manufacturers specializing in drilling and drilling centers may not necessarily save other types of machining centers. Drilling and drilling center is essentially a type of vertical machining center, because the drilling center itself is derived from the vertical machining center. So today mingwan machine tool will take you to understand the similarities and differences between the two.

Machining center refers to the high efficiency automatic machine tool which is composed of mechanical equipment and numerical control system, which is used to process complex shapes. I believe that we all know more about them, so we will not do more narration here. “Drilling and tapping center” is “drilling”: drilling and milling or drilling, “tapping”: tapping, “center”: machining center. (the full name is roughly several: “drilling and milling tapping center”, “drilling and tapping center”, “drilling and milling machining center” and “drilling and milling center”). It is also derived from the traditional metal cutting machine tool computer gong (machining center), so from the structure, the drilling and tapping center and the high-speed machining center are the same. The drilling center and the high-speed machining center also have the functions of drilling and tapping and high-speed milling. The advantages of drilling and tapping Center in “drilling and tapping” are better than that of high-speed machining center, and the fast moving feed of high-speed milling is faster than that of flexible high-speed processing But the model is less, the stroke is smaller than the high-speed machining center, and the cutting force is inferior to the high-speed machining center.

2、 What are the similarities between machining center and drilling center?

Processing center and drilling center, from the literal point of view, both have the word “center”. It can be seen that they are both metal cutting machines and CNC machining equipment. In style and function, machining center and drilling are very similar.

3、 What is the difference between machining center and drilling center?

Machining center is widely used, mainly for processing plane, curved surface and other shapes of equipment. The drilling and tapping center is mainly used for drilling and tapping. The machining center can be used for milling, but the drilling and tapping center can only be used for slight milling, because the power of the spindle of the drilling and tapping center is not very large, so it can not be used for strong milling and heavy load processing. In shape, the drilling center is smaller than the machining center in shape; the shape of the drilling center is similar to the form of large turntable. In the selection of tool magazine, the machining center is mainly the hat type tool library and the disc type tool library, while the drilling center is mainly the turret type tool library and the turret type tool library. In terms of fast moving speed, linear guide rail is used in drilling and tapping center, which is faster than machining center. The machining efficiency of machine tool is obvious.

Advantages of ball screw in machining center

Ball screw is composed of screw, nut, steel ball, prepress, reverser, duster and other parts. It is the best product to convert rotary motion into linear motion or linear motion into rotary motion. It is widely used in machine tools, automatic machinery, electronic machinery, aerospace and other fields. Ball screw has a variety of advantages, now by mingwan machine tool to take you to see what advantages of ball screw!

Less power

The driving force of the ball screw is only 1 / 3 of that of the sliding screw pair, so it has higher movement efficiency, so it can save more electricity.

Higher precision

Ball screws are produced by high-level mechanical equipment, and the production accuracy is higher.

Realize micro feed

The ball screw uses the ball motion, so the starting torque is very small, there will be no creeping phenomenon like sliding motion, so it can ensure the realization of accurate micro feed.

No side clearance and high rigidity

The ball screw can be preloaded, because the preload can make the axial clearance reach a negative value, and then get higher rigidity.

Realize high speed feed

The ball screw can realize high speed feed / (movement /) because of its high efficiency and low heating.

CNC computer gong vacuum sucker

1、 What is the vacuum sucker of CNC computer gong

Vacuum suction cup, also known as vacuum spreader, is one of vacuum equipment actuators. Generally speaking, it is the cheapest way to grab the product with vacuum sucker. There are various types of vacuum suction cups. Rubber suction cups can be operated at high temperature. The suction cups made of silicone rubber are very suitable for grasping products with rough surface, while those made of polyurethane are very durable. In addition, in the actual production, if the sucker is required to have oil resistance, polyurethane, nitrile rubber or polymer containing vinyl can be used to make sucker. Generally, in order to avoid scratches on the surface of the products, it is better to choose the suction cup with bellows made of nitrile rubber or silicone rubber. The material of suction cup is made of nitrile rubber, which has large breaking force, so it is widely used in various vacuum holding equipment.

2、 Vacuum sucker used in CNC computer gongs

The vacuum chuck plays the role of fixture in CNC machining center. Some workpieces require high surface smoothness, so they can’t use the fixture of common CNC computer gong. At this time, the vacuum chuck can be put into use. However, we seldom use rubber vacuum cups in CNC computer gongs. We use CNC vacuum cups more. The so-called CNC vacuum sucker is a kind of special vacuum suction cup with vacuum generator and switch. The suction principle is the same as rubber vacuum chuck, which creates a vacuum environment to make the suction cup press on the workpiece under atmospheric pressure, but CNC vacuum chuck is the only one The vacuum environment is produced by the vacuum generator. The rubber vacuum chuck is a simple vacuum component, while the CNC vacuum sucker is like a large plate.

CNC computer gongs usually use vacuum chuck because the workpiece has high requirements for surface smoothness, or when the fixture of CNC computer gong itself can not clamp the workpiece well, it is a relatively cheap special fixture in CNC machine tools

Four axis high speed machining center

1、 Four axis high speed machining center

High speed machining center and machining center have three axes, four axes and five axes. Three axis and four axis high-speed machining centers are used more, while five axis high-speed machining centers are rare because of the high price.

High speed machining center is a kind of high-speed machine tools. High speed machining center is mainly used for mass production of small parts and products. It is also one of the most used CNC machine tools. Under normal circumstances, the default axis of high-speed machining center is three axis. If the fourth axis needs to be added, the customer needs to make a request to the manufacturer. The processing range of four axis high speed machining center is wider than that of three axis high-speed machining center. For the same brand and the same type of high-speed machining center, four axis is definitely better than three axis, because it can process some complex workpieces.

2、 Characteristics of four axis high speed machining center

In the above, we said that the machining range of four axis high speed machining center is wider than that of three axis machining center, so what is the reason? Four axis high speed machining center has one more dividing head than three axis high speed machining center, which is the source of the fourth axis. Among the six degrees of freedom of the workpiece, the three axis high-speed machining center only uses three basic x, y, Z linear degrees of freedom, and the remaining three a, B, C rotation degrees of freedom are not used, and the four axis high-speed machining center selects one of these three degrees of freedom, and then installs the corresponding dividing head.

Speed of high speed machining center

High speed machining center is a common machining center in the market. It is widely used in the fields of automobile, machinery and hardware. Because the processing speed of high-speed machining center is fast, and the quality is stable, the production efficiency is greatly improved, which is the advantage of high-speed machining center. The biggest disadvantage of high-speed machining center is that it is not suitable for heavy cutting, but only suitable for finishing. For example, some workpieces with large cutting force are difficult to be processed by high-speed machining center.

Processing speed of high speed machining center

As is known to all, the cutting speed of high-speed machining center is 5-10 times faster than that of ordinary machining center. According to the hardness and strength of materials, the processing speed is different. Aluminum alloy is 1500-5500 M / min; copper alloy is 900-5000 M / min; titanium alloy is 100-1000 M / min; cast iron is 750-4500 M / min; steel is 600-800m / min. The feed speed range of high-speed cutting for various materials is 2-25m / min. From these data, we can know how fast the processing speed of high-speed machining center is, which is beyond the ability of general machining center.

The field of high speed machining center

High speed machining center involves many fields of processing, such as automobile, machinery, train, ship, aircraft, aerospace and mold. The parts in these fields can be processed by high-speed machining center. No matter how high the precision requirements are, it is difficult to defeat the high-speed machining center, because in addition to the advantages of high-speed machining, high-speed machining center also has the advantage of precision machining. High speed machining center is also called high precision high speed machining center.

Advantages of line rail machining center

Introduction to guide rail of machining center

The line rail machining center is quite common in the market, but we didn’t pay attention to it. The line rail machining center simply means that the guide rail uses the line rail. There are two types of guide rails used in machining centers, which are line rails and hard rails. There are few machining centers using hard rails in the market, while more machining centers use line rails. The line rail is called linear guide rail and linear guide rail. The line rail can be divided into ball guide rail and roller guide rail. In fact, there is no difference between the two kinds of line rail in essence. The ball guide rail is in point contact by moving friction, while the roller guide rail is in line contact by moving friction.

The line rail is generally composed of slide rail and slide block. The size of slide rail is customized according to the needs of the machine itself, and the sliding block has built-in circulating ball or roller.

Advantages of line rail machining center

The main advantages of the line rail machining center are fast running speed, small rolling friction resistance, no signs of slow crawling, high machining accuracy and convenient lubrication. After a long service time, the machining accuracy of the line rail machining center is not affected, and the damaged line rail can be disassembled and replaced. Line rail machining center is rolling friction, point or line contact, the contact area is small, the friction resistance is naturally small, more suitable for high-speed machining and small cutting capacity of workpiece processing.

Disc type tool magazine and hat type tool magazine of CNC machining center

The tool magazine commonly used in machining center includes hat type tool magazine and disc type tool magazine, and there is also a kind of chain type tool magazine. This kind of tool magazine is generally installed on gantry machining center and horizontal machining center, but rarely used in vertical machining center.

Characteristics of bamboo hat type tool magazine

The biggest feature of the bamboo hat type tool magazine is its high cost performance and simple structure. Its tool change speed can be completed in 8s. It is better to use it in small batch production. The maintenance and maintenance of the bamboo hat type tool magazine is simple and convenient. The disadvantages of the bamboo hat type tool library are that the tool change speed is slow, when the handle is placed in the magazine, the cone surface is open without protection, and the cone surface is easy to stick Dirt will directly affect the accuracy of tool repeated installation.

Characteristics of disc type magazine

Disk magazine can be called manipulator magazine and arm magazine. They are different in each place, but they are the same. They are all disc magazine. The tool change speed of disc type magazine is fast, complex and expensive. The tool change speed of disc magazine is less than 4 s because of its tool change action: the mechanical arm pulls the tool from the tool magazine and the main shaft at the same time, and installs it to the spindle and magazine through 180 ° rotation, thus completing the tool change process. The price of the magazine is much higher than that of the hat magazine. The magazine can load up to 40 tools. The disc type magazine is extremely strict on the weight of the tool. Once the loaded tool exceeds the bearing range of the magazine, the tool will be easily thrown out of the magazine, which is easy to cause accidents. If the length of the tool exceeds the specified size, it will collide with the tool in the process of tool change, which will cause damage to the magazine and the tool.

According to the characteristics of the above magazine, which is better? The problem is clear at a glance. The bamboo hat type magazine is cheap and easy to maintain, while the disc magazine is fast and expensive.

Spindle drive mode of machining center

CNC system is the control core of machining center, which is equivalent to human brain. The spindle of machining center is equivalent to human heart, which is the source of main processing power of machining center. To sum up, the spindle of machining center is essential, so the selection of spindle must be careful. There are four kinds of main shaft transmission structures, which have different characteristics and speed.

What is the main shaft drive structure of machining center and its speed and characteristics

There are four kinds of spindle of machining center according to the transmission structure, which are gear drive spindle, belt drive spindle, direct connection spindle and electric main power. These four kinds are common in the market. These four kinds of transmission structure spindle speed and characteristics are different, each has its own advantages. Gear drive spindle: its speed is generally 6000r / min, and its rigidity is good and it is suitable for heavy cutting occasions. Its main shaft is generally equipped with multi head machine tools; belt drive spindle: its speed is 8000 R / min, simple structure, easy production, strong buffer capacity, effective protection of spindle in case of spindle overload; direct spindle: its spindle and motor are connected through coupling Drive, large distortion, low energy consumption, its speed is more than 12000r / min, this kind of spindle is generally used in high-speed machining center; motorized spindle: the spindle and motor are integrated, the motor is the spindle, the spindle is the motor, it can be said that the spindle and motor are integrated into one, the transmission chain of this spindle is almost zero, and the spindle speed is between 18000-40000 R / min, and higher For example, maglev bearing and hydrostatic bearing are used in motorized spindle bearing of foreign advanced countries, and its speed can reach 100000r / min. this kind of spindle is generally used in high-speed machining center;

What are the common transmission structure spindles used in machining centers

There are three kinds of spindle with the above four kinds of transmission structure commonly used in machining center, which are belt drive spindle, straight spindle and motorized spindle. These three kinds of transmission structure spindle are commonly used in machining center, while gear drive spindle is rarely used in machining center, but there are also some, such as those used in multi head machining center. Belt drive spindle is generally used in small machining centers and large machining centers, while straight spindle and motorized spindle are commonly used in high-speed machining centers.

Spindle composition of vertical machining center

Introduction of spindle of machining center

The CNC system of machining center is the core component, which is mainly used to control the action of machining center. It usually controls the position, angle and speed of the three axes of the machining center. From the above, the CNC system of the machining center is equivalent to the human brain, so the spindle of the machining center is the cutting processing, and the output of the power is equivalent to the heart of the human body. The spindle determines the cutting ability, dynamic stiffness and machining accuracy of the machining center. The start, stop and rotation speed of the spindle are controlled by the CNC system. After the spindle is installed with a tool, it can participate in the cutting of the workpiece. The spindle is the most important mechanical part of the machining center, which has a great influence on the performance, stability and machining accuracy of the machining center.

Composition of spindle of machining center

The spindle of machining center is mainly composed of spindle, spindle support, spindle bearing, spindle drive and seal. According to the different transmission parts of the spindle, it can be divided into four types: gear driven spindle, belt driven spindle, direct coupling spindle and motorized spindle. The speed and application of these four types of spindles are different. The speed of gear driven spindle is generally 6000r / min, which is more suitable for heavy cutting; belt driven spindle is also known as synchronous belt drive spindle, which is mainly driven by belt teeth, and its spindle speed is generally at 8000r / min, which is more suitable for heavy cutting occasions; direct connected spindle is composed of motor The spindle is connected by a shaft coupler to drive. The speed of this kind of spindle is generally 12000-18000r / min. the direct connected spindle is not suitable for heavy cutting, but only suitable for processing workpieces with small cutting capacity, which is suitable for finishing. Motorized spindle: its spindle is integrated with the motor, the motor is the spindle, and the main shaft is the motor. The motor and the spindle are integrated into one, and its spindle is the most in the world For a fast spindle, its speed is more than 18000r / min. if the motorized spindle adopts aerostatic bearing and maglev bearing, the maximum speed can reach 100000r / min. this kind of spindle is generally used in finish machining, not suitable for heavy cutting.

Three axis and five axis machining center

Difference between five axis machining center and three axis machining center

The biggest difference between 5-axis machining center and 3-axis machining center is that on the motion axis, five axis machining center has five motion axes, namely XYZ linear motion axis and AC rotation motion axis; while three-axis machining center has only three motion axes, which are the conventional XYZ linear motion axis. This is the biggest difference in structure between five axis machining center and three axis machining center. There are also differences in the processing range. The processing range of the five axis machining center is relatively wide. The five axis machining center can process parts that are difficult or impossible to process with three axes. It can be generally understood that the processing range of the five axis machining center is wider than that of the three axis machining center. Today’s editor mainly introduces the advantages of five axis machining center.

Advantages of five axis machining center

Five axis machining center can process parts that cannot be processed or difficult to process by three axes, such as complex curved surface parts. Using five axis machining center to process complex curved surface parts can complete all processes processing at one time, while using three axis machining center to process complex curved surface parts is very difficult and complex, and it needs many clamping and adjustment to complete its complex processing procedures. Generally speaking, the three-axis machining center can not complete the processing of complex curved surface parts at one time. These complex curved surface parts mainly include turbine engine blades, marine propeller and other special complex curved surface parts. These parts can be processed by five axis machining center, and the angle, position and cutting path of the cutter can be adjusted freely, so the five axis machining center can be clamped and assembled at one time All processing procedures.

It is necessary to use ball end milling cutter to process complex curved surface parts with three-axis machining center. The cutting rate of parts processed by ball end milling cutter is low, and the angle of cutter can not be adjusted freely in the process of machining, so the smooth surface can not be machined. The use of five axis machining center to process complex curved surface parts does not need to use ball end milling cutter, and does not need to use special tools, because the five axis machining center can freely adjust the angle of the tool, so the surface of the workpiece processed is smooth, thus improving the quality of processing.