What is the classification of machine tools

Summary: machine tools are mainly classified according to the processing method and the tool used, according to the national development of machine tool modeling method, machine tools are divided into 11 categories: lathes, drilling machines, boring machines, grinding machines, gear machine tools, threading machine tools, milling machines, planing and inserting machines, broaching, sawing machines and other machine tools. In each category of machine tools, and according to the scope of the process, layout and structural performance is divided into a number of groups, each group is divided into a number of departments (series) machine tool classification which machine tool model gauge detailed

Machine tool is the metal blanks processed into machine parts of the machine, it is a machine machine for manufacturing machines, so it is also known as the "master machine" or "tool machine". "or" tool machine ", customarily referred to as machine tools. Modern machinery manufacturing in the processing of machine parts in many ways: in addition to cutting, there are casting, forging, welding, stamping, extrusion, etc., but all of the higher precision requirements and surface roughness requirements of the finer parts, generally need to be in the machine tool with the method of cutting for final processing. In general, the machine tool manufacturing, machine tool processing workload accounted for 40% -60% of the total workload of machine tool manufacturing, machine tools in the modernization of the national economy plays a major role in the construction.

(A) ordinary machine tools

1, lathe

The lathe is the main rotating workpiece with a lathe tool for turning machine tools. In the lathe can also be used to drill, reaming drill, reamer, tap, plate teeth and knurling tools for corresponding processing. Lathe is mainly used for processing shafts, disks, sets and other workpieces with rotating surfaces, is the most widely used in machinery manufacturing and repair factories in a class of machine tools.

1.1 ancient pulley, bow bar "bow lathe" as early as the ancient Egyptian era, people have invented the wood around its center axis when rotating with a tool for turning technology. At first, people were using two logs as a support, set up the wood to be turned, the use of the elasticity of the branches of the rope rolled to the wood, by hand or foot pulling the rope to rotate the wood, and holding the knife and cutting.

This ancient method gradually evolved, developed in the pulley around two or three turns of the rope, the rope on the elastic rod bent into a bow, back and forth to push and pull the bow to make the object rotated so as to carry out the turning, this is the "bow lathe".

1.2 medieval crankshaft, flywheel drive "pedal lathe" to the Middle Ages, some people designed a foot pedal to rotate the crankshaft and drive the flywheel, and then drive to the spindle to make it rotate the "pedal lathe". 16th century, the middle of France, a designer named Besson designed the "pedal lathe". A designer named Besson designed a screw bar to make the tool sliding screw lathe, unfortunately, this lathe is not popularized.

1.3 The eighteenth century gave birth to the head box, chuck time to the eighteenth century, and someone designed a crankshaft rotation with a foot pedal and connecting rod, can be stored in the rotational kinetic energy on the flywheel lathe, and from the direct rotation of the workpiece to the development of the rotary head box, the head box is a chuck used to clamp the workpiece.

1.4 Englishman Maudsley invents the toolholder lathe (1797) In the story of the invention of the lathe, it is an Englishman named Maudsley who is most notable for his epochal invention in 1797 of the toolholder lathe, which came with a precision leadscrew and interchangeable gears.

Born in 1771, Mozley was 18 years old and was the right-hand man to inventor Brammer. Brammer is said to have been a farmhand, and was forced to switch to the less maneuverable trade of carpentry at the age of 16 after an accident that crippled his right ankle. His first invention was a flush toilet in 1778, and Mozley began to help Brammer design hydraulic presses and other machinery until the age of 26, when he left Brammer after Brammer brusquely refused Moritz's request to increase his wages to more than 30 shillings a week.

The very year Mozley left Brammer, he made the first threading lathe, an all-metal lathe capable of moving a toolholder and tailstock along two parallel guide rails. The guide rails had a triangular guiding surface that drove a screw to move the tool holder laterally as the spindle rotated. This is the main mechanism that modern lathes have, with this lathe can turn precision metal screws of any pitch.

Three years later, Mozley built a more complete lathe in his own workshop, with interchangeable gears to change feed speeds and the pitch of the threads being machined. 1817 saw another Englishman, Roberts, use a four-stage pulley and back-wheel mechanism to vary the speed of the spindle. Soon larger lathes were introduced, contributing to the invention of the steam engine and other machinery.

1.5 the birth of a variety of special lathes in order to improve the degree of mechanization and automation, in 1845, the United States of America's Fitch invented the turret lathe; 1848, the United States and the emergence of the wheel back to the lathe; 1873, the United States of America's Spencer made a single-axis automatic lathe, and soon he made a three-axis automatic lathe; the beginning of the twentieth century appeared by a separate motor-driven lathe with a gear transmission. Due to the invention of high-speed tool steel and the application of electric motors, the lathe was continuously improved and finally reached the modern level of high speed and high precision.

After the First World War, various kinds of high-efficiency automatic lathes and specialized lathes developed rapidly due to the needs of the arms, automobile and other machinery industries. In order to improve the productivity of small-lot workpieces, lathes with hydraulic profiling devices were popularized at the end of the 1940s, while at the same time, multi-tool lathes were also developed.In the mid-1950s, program-controlled lathes with piercing cards, pin plates and dials, etc., were developed. CNC technology began to be used in lathes in the 1960s, and was rapidly developed after the 1970s.

1.6 Classification of lathesLathes are classified into various types according to their uses and functional areas.

Ordinary lathes have a wide range of machining objects, a wide range of adjustment of spindle speed and feed, and are capable of machining the internal and external surfaces, end faces, and internal and external threads of workpieces. This kind of lathe is mainly operated manually by workers, with low productivity, and is suitable for single piece, small batch production and repair workshop.

Turret lathes and rotary lathes have turret tool holders or rotary tool holders that can hold multiple tools, and can be used by workers to complete multiple processes by using different tools sequentially in a single clamping of the workpiece, which is suitable for batch production.

Automatic lathe can automatically complete small and medium-sized workpieces according to a certain program of multi-processing, automatic loading and unloading, repeated processing of a batch of the same workpiece, suitable for mass, mass production.

Multi-tool semi-automatic lathe has single-axis, multi-axis, horizontal and vertical. The layout of single-axis horizontal lathe is similar to the ordinary lathe, but the two groups of tool holders were installed in the spindle before and after or above and below, for the processing of discs, rings and shafts, the productivity than ordinary lathes to increase by 3 to 5 times.

The imitation lathe can imitate the shape and size of the sample plate or sample parts, automatically complete the workpiece processing cycle, suitable for small batch and batch production of workpieces with more complex shapes, and its productivity is 10-15 times higher than that of ordinary lathes. There are multi-tool holder, multi-axis, chuck type, vertical and other types.

The spindle of vertical lathe is perpendicular to the horizontal plane, the workpiece is clamped on the horizontal rotary table, and the tool holder moves on the crossbar or column. It is suitable for processing larger and heavier workpieces that are difficult to be mounted on an ordinary lathe, and is generally divided into two categories: single-column and double-column.

Gear Shoveling Lathe is used for shoveling the shaped tooth surface of milling cutter, hob, etc. The tool holder periodically makes radial reciprocating motion while turning. Usually with a spade grinding attachment, a small grinding wheel driven by a separate electric motor spades the flanks.

Specialized lathes are lathes used for machining specific surfaces of certain types of workpieces, such as crankshaft lathes, camshaft lathes, wheel lathes, axle lathes, roll lathes and ingot lathes.

Combined lathe is mainly used for turning, but after attaching some special parts and accessories, it can also be used for boring, milling, drilling, inserting, grinding and other processing, with the characteristics of "one machine with multiple functions", suitable for engineering vehicles, ships or mobile repair stations on the repair work.

SAJ frequency converter on the application of machine tools

1, low-frequency torque, smooth output

2, high-performance vector control

3, torque dynamic response is fast, high precision of the speed stabilization

4, deceleration and stopping speed

5, anti-interference ability

Workshop handicrafts, although it is a relatively backward, but it has trained and produced a lot of people. But it has trained and created a lot of craftsmen, although they are not specialized

2, boring machine

Door manufacturing machine expert, but they can make a variety of handmade appliances, such as knives, saws, needles, drills, cones, grinders, and shafts, sets, gears, beds and so on, in fact, the machine is assembled from these parts and components.

2.1 The earliest boring machine designer - da Vinci boring machine is known as the "mother of all machines". When it comes to the boring machine, you have to talk about Leonardo da Vinci first. This legendary figure is probably the earliest designer of boring machines for metalworking. The boring machine he designed was powered by water power or a foot pedal, and the boring tool rotated close to the workpiece, which was fixed on a moving table driven by a crane. 1540, another artist painted a picture of "pyrotechnics" with the same picture of the boring machine, which was then used to finish hollow castings.

2.2 The First Boring Machine for Cannon Barrels (Wilkinson, 1775) In the 17th Century, due to military needs, the development of cannon manufacturing was very rapid, and how to make the barrels of cannons became a major problem for people.

The world's first true boring machine was invented by Wilkinson in 1775. In fact, to be precise, Wilkinson's boring machine was a drilling machine capable of precision machining of cannons, a hollow cylindrical boring bar with both ends mounted on bearings.

Born in America in 1728, Wilkinson moved to Staffordshire when he was 20 years old to build Bilston's first iron furnace. As a result, Wilkinson became known as the "Master Blacksmith of Staffordshire", and in 1775, at the age of 47, Wilkinson's constant efforts at his father's factory resulted in the creation of a new machine capable of drilling the barrels of cannons with rare precision. Interestingly, after Wilkinson's death in 1808, he was buried in a cast-iron coffin of his own design.

2.3The boring machine made an important contribution to Watt's steam engineIf it had not been for the steam engine, the first wave of the Industrial Revolution would not have been possible. And the development and application of the steam engine itself, in addition to the necessary social opportunities, technical prerequisites are not to be ignored, because the manufacture of steam engine parts, far from being as easy as a carpenter chipping wood, to make the metal into a number of special shapes, and machining of the precision requirements and high, without the appropriate technical equipment can not be done. For example, the manufacture of steam engine cylinder and piston, piston manufacturing process required in the accuracy of the outer diameter, can be measured from the outside side of the size of the side of the cutting, but to meet the requirements of the accuracy of the inner diameter of the cylinder, the use of general machining methods will not be easy to do.

Smithson was the best mechanical technician of the eighteenth century. Smithton designed as many as 43 pieces of watermill and windmill equipment. When making steam engines, the trickiest thing for Smithton was machining the cylinders. It was quite difficult to machine the inner circle of a large cylinder into a round shape. For this reason, a special machine tool was built at Carron Iron Works to cut the cylinders. This boring machine, driven by a waterwheel, has a tool mounted on the front of its long shaft, which can be rotated inside the cylinder so that its inner circle can be machined. Since the tool was mounted at the front end of the long shaft, problems such as shaft deflection arose, so it was very difficult to machine a truly round cylinder. For this reason, Smithton had to change the position of the cylinder several times for machining.

For this difficulty, the boring machine invented by Wilkinson in 1774 played a big role. This boring machine using a water wheel to make the material cylinder rotation, and make it against the center of the fixed tool to advance, due to the relative motion between the tool and the material, the material will be bored out of the high accuracy of the cylindrical hole. At that time, the boring machine was used to make a cylinder 72 inches in diameter, with an error of no more than the thickness of a sixpence coin. That's a big margin of error when measured by modern technology, but under the conditions of the time, it was quite a feat to achieve that level of accuracy.

But Wilkinson did not apply for patent protection for this invention, and people copied it and installed it. 1802, Watt also talked about Wilkinson's invention in his book, and copied it in his Soho Iron Works. Later, Watt also applied Wilkinson's marvelous machine in the manufacture of cylinders and pistons for steam engines. Originally, for the piston, can be outside while measuring the size, while cutting, but for the cylinder is not so simple, must use boring machine. At that time, Watt is the use of water wheels to make the metal cylinder rotating, so that the center of the fixed tool forward, used to cut the inside of the cylinder, as a result, 75 inches in diameter of the cylinder, the error is less than the thickness of a coin, which in the current pair is very advanced.

2.4The birth of the table lifting boring machine (Houghton, 1885) In the next few decades, many improvements were made to Wilkinson's boring machine. 1885, Houghton, England, made the table lifting boring machine, which has become the prototype of the modern boring machine.

3, milling machine

19th century, the British in order to steam engines and other industrial revolution needs to be invented boring machine, planing machine, and the Americans in order to produce a large number of weapons, it is dedicated to the invention of milling machine. A milling machine is a machine with a milling cutter of various shapes that cuts specially shaped workpieces, such as spiral grooves and gear shapes.

As early as 1664, the English scientist Hooker relied on a rotating circular cutter to create a machine for cutting, which can be considered the original milling machine, but at that time there was no enthusiastic response from society. In the 1840s, Pratt designed the so-called Lincoln milling machine. Of course, it was the American Whitney who really established the milling machine in machine building.

3.1 The first general milling machine (Whitney, 1818) In 1818, Whitney made the world's first general milling machine, but the milling machine patent is the British Bodmer (with the knife device of the gantry planer inventor) in 1839, the first "get". Because the milling machine is too expensive, so not many people asked for it.

3.2 The first universal milling machine (Brown, 1862) After a period of silence, the milling machine was active again in the United States. In contrast, Whitney and Pratt can only be said to have done seminal work for the invention of the milling machine application, the real invention of milling machines that can be applied to a variety of operations in the factory should be credited to the American engineer Joseph Brown.

In 1862, the United States of America's Brown made the world's first universal milling machine, this milling machine in the preparation of universal dial and integrated milling cutter is an epoch-making innovation. Universal milling machine table can rotate in the horizontal direction of a certain angle, and with vertical milling head and other accessories. He designed the "universal milling machine" in the 1867 Paris Exposition exhibition, was a great success. At the same time, Brown also designed a form of milling cutter will not be deformed even after grinding, and then also manufactured the milling cutter grinding machine, so that the milling machine has reached the present level.

4, planer

In the invention process, many things are often complementary, interlocking: in order to manufacture steam engines, the need for boring machines to help; steam engine invention after the invention of the hair, from the process requirements, and then began to call on the gantry planer. It can be said that it is the invention of the steam engine, leading to the "workhorse" from the boring machine, lathe to the design of the development of the planer. In fact, the planer is a kind of planing metal "planer".

4.1 processing large plane gantry planer (1839) because of the steam engine valve seat plane processing needs, from the early 19th century, a lot of technicians began to research in this area, among them are Richard Robert, Richard Pratt, James Fox, and Joseph Clement, etc., who began in 1814, in a 25-year period of time, each independently built the gantry planer. The gantry planer was a machine in which the workpiece was fixed on a round trip platform and the planer cut one side of the workpiece. However, this type of planer did not have a knife feeding device, and was in the process of transforming from a "tool" to a "machine". To 1839, a British named Bodmer finally designed a gantry planer with a knife device.

4.2 Processing of small surfaces of the bullhead planer another Englishman Nesmith from 1831 within 40 years from the invention of the manufacture of processing of small surfaces of the bullhead planer, which can be processed object fixed in the bed, and the tool for back and forth movement.

Since then, due to the improvement of tools, the emergence of electric motors, gantry planer on the one hand towards high-speed cutting, high precision direction, on the other hand towards the direction of large-scale development.

5, grinding machine

Grinding is an ancient technology known to mankind since ancient times, the Paleolithic era, grinding stone tools with this technology. Later, with the use of metal implements, the development of grinding technology was promoted. However, the design of a grinding machine worthy of the name is still a recent thing, even in the early 19th century, people are still by rotating the natural grinding stone, so that it touches the processing object for grinding process.

5.1 The First Grinding Machine (1864) In 1864, the United States made the world's first grinding machine, which was a device for attaching a grinding wheel to a lathe's skateboard tool holder and making it have an automatic conveyor. Twelve years later, Brown of the United States invented the universal grinder, which is close to the modern grinder.

5.2 Artificial Grinding Stones - The Birth of the Grinding Wheel (1892) The need for artificial grinding stones arose. How to develop a more wear-resistant grinding stone than the natural grinding stone? 1892, the American Atchison trial success with coke and sand made of silicon carbide, which is now known as a C abrasive artificial grinding stone; two years later, to aluminum oxide as the main ingredient of the A abrasive and the success of the trial, so that the grinder has been more widely used.

Later, due to the further improvement of the bearing and guideway parts, the precision of the grinder became higher and higher, and it developed in the direction of specialization, and there appeared internal grinder, surface grinder, roll grinder, gear grinder, universal grinder and so on.

6, drilling machine

6.1 Ancient drilling machine - "bow windlass" drilling technology has a long history. Archaeologists have now found that 4000 BC, mankind invented a device for drilling holes. Ancient people in the two columns on the frame a beam, and then from the beam down to hang a cone can rotate, and then use the bowstring winding drive cone rotation, so that in the wood and stone holes. Soon, people also designed a hole-punching device called "windlass", which also uses a flexible bowstring to make the awl rotate.

6.2 The first drilling machine (Whitworth, 1862) to around 1850, the German Matignoni first made for metal drilling twist drill; 1862 in London, England, the International Exhibition, the British Whitworth exhibition by the power-driven cast-iron cabinet drilling machine, which became the prototype of the modern drilling machine.

After that, all kinds of drilling machines appeared one after another, there are rocker arm drilling machine, equipped with automatic feed mechanism of the drilling machine, can be played at the same time at a time more than one hole multi-axis drilling machine and so on. Due to the improvement of tool materials and drills, and the adoption of electric motors, large-scale high-performance drilling machines were finally manufactured.

(B) the technical and economic indicators of machine tools

The equipment used to manufacture machine parts commonly known as metal cutting machine tools, referred to as machine tools.

The quality of the machine itself, the quality of the machine directly affects the quality of the machine. Measure the quality of a machine tool is multi-faceted, but the main requirements of good workmanship, serialization, generalization, high degree of standardization, simple structure, light weight, reliable, high productivity. Specific indicators are as follows:

1. Possibility of process

Possibility of process refers to the ability of the machine tool to adapt to different production requirements. General-purpose machine tools can be completed within a certain size range of various parts multi-processing, process possibilities are wider, and thus the structure is relatively complex, adapted to the production of small batches of a single piece. Specialized machine tools can only complete a specific process or a few parts, the possibility of its technology is narrower, suitable for mass production, can improve productivity, ensure the quality of machining, simplify the structure of the machine tool, reduce the cost of the machine tool.

2. Machining accuracy and surface roughness

To ensure the accuracy and surface roughness of the machined parts, the machine itself must have a certain geometric accuracy, motion accuracy, transmission accuracy and dynamic accuracy.

(1) geometric accuracy, motion accuracy, transmission accuracy belongs to the static accuracy

Geometric accuracy refers to the machine tool in the non-running parts of the mutual position accuracy and the main parts of the shape of the accuracy, positional accuracy. The geometric accuracy of the machine tool has an important impact on the machining accuracy, so it is the main index for evaluating the accuracy of the machine tool.

Motion accuracy refers to the machine tool in the working speed when the main parts of the geometric position accuracy, the greater the change in geometric position, the lower the motion accuracy.

Transmission accuracy refers to the coordination and uniformity of the movement between the end of the machine tool transmission chain.

(2) the above three precision indicators are detected under no-load conditions, in order to fully reflect the performance of the machine tool, the machine tool must be required to have a certain degree of dynamic accuracy and temperature rise under the role of the main components of the shape, positional accuracy. The main factors affecting the dynamic accuracy of the machine tool stiffness, vibration resistance and thermal deformation.

The stiffness of the machine tool refers to the machine tool under the action of external forces to resist the deformation of the ability to machine tool stiffness, the greater the dynamic accuracy is higher. The stiffness of the machine tool includes the stiffness of the machine component itself and the contact stiffness between the components. The stiffness of the machine component itself depends mainly on the material properties of the component itself, cross-section shape, size, etc.. The contact stiffness between the components is not only related to the contact material, contact surface geometry and hardness, but also with the surface roughness of the contact surface, geometric accuracy, processing methods, contact surface media, pre-pressure and other factors.

The vibration that occurs on the machine tool can be divided into forced vibration and self-excited vibration. Self-excited vibration is not subject to any external force, excitation force interference, by the cutting process within the continuous vibration. Under the continuous action of the excitation force, the system is forced to cause vibration for forced vibration.

The vibration resistance of the machine tool and the stiffness of the machine tool, damping characteristics, the intrinsic frequency. Due to the different coefficients of thermal expansion of various parts of the machine tool, resulting in different parts of the machine tool deformation and relative displacement, this phenomenon is called thermal deformation of the machine tool. Due to thermal deformation and the resulting error can account for up to 70% of the total error.

For the dynamic accuracy of the machine tool, there is no uniform standard, mainly through the cutting and processing of typical parts to achieve the accuracy of the machine tool to make a comprehensive evaluation of the dynamic accuracy indirectly.

(C) the classification of machine tools

Metal cutting machine tools can be divided into a variety of types according to different classification methods.

According to the processing mode or processing object can be divided into lathes, drilling machines, boring machines, grinding machines, gear processing machine tools, thread processing machine tools, spline processing machine tools, milling machines, planers, inserting machines, broaching machines, special processing machine tools, saws and scribing machines. Each category is divided into a number of groups according to its structure or processing objects, each group is divided into a number of types.

According to the size of the workpiece and the weight of the machine can be divided into instrumentation machine tools, small and medium-sized machine tools, large machine tools, heavy machine tools and ultra-heavy machine tools.

According to the machining accuracy can be divided into ordinary precision machine tools, precision machine tools and high-precision machine tools.

According to the degree of automation can be divided into manually operated machine tools, semi-automatic machine tools and automatic machine tools.

According to the automatic control of machine tools, can be divided into imitation machine tools, program control machine tools, digital control machine tools, adaptive control machine tools, machining centers and flexible manufacturing systems.

According to the scope of application of the machine tool can be divided into general-purpose, specialized and special-purpose machine tools.

Specialized machine tools have a standard general-purpose components as the basis, with a small number of specific shape of the workpiece or machining process designed for special components composed of automatic or semi-automatic machine tools, known as combined machine tools.

The processing of one or more parts, according to the process of arranging a series of machine tools, and with automatic loading and unloading devices and machine tools and machine tools and automatic transfer of the workpiece between the device, so that the formation of a group of machine tools is called the automatic production line of cutting and processing.

Flexible manufacturing system is composed of a group of digitally controlled machine tools and other automated process equipment, controlled by electronic computers, can be automatically processed with different workpieces, can adapt to the production of multiple varieties.

(D) the composition of the machine tool

The various types of machine tools are usually composed of the following basic parts: support components, used to install and support other components and workpieces, bear its weight and cutting force, such as bed and column; speed change mechanism, used to change the speed of the main movement; feed mechanism, used to change the amount of feed; spindle box for the installation of the machine tool spindle; tool racks, tool magazines; control and manipulation system; lubrication system; cooling system. Lubrication system; cooling system.

Machine tool attachments include machine tool loading and unloading devices, manipulators, industrial robots and other machine tool add-ons, as well as machine tool accessories such as chucks, suction cups spring loaded collets, vises, rotary tables and indexing heads.

(E) machine tool modeling

GB/T15375-94 and GB/T15375-2008 two naming standards to compare and learn, do not confuse

1.GB/T15375-94 "metal cutting machine tool modeling method"

Mainly mastered (1) machine tool categories of the code (2) machine tool Characteristics of the code (3) the code of the main parameters of the machine (4) the order of the machine model.

2.GB/T15375-2008 "Metal Cutting Machine Tool Modeling Methods"

Mainly master (1) machine tool category code (2) machine tool general characteristics of the code (3) machine tool group, system code and the main parameters of the representation.