Although the workshop handicraft industry is relatively backward, it has trained and brought up many technicians. Although they are not experts in making machines, they can make all kinds of hand tools, such as knives, saws, needles, drills, cones, grinders, shafts, sleeves, gears, bedsteads and so on. In fact, the machine is assembled from these parts.
When it comes to boring machines, we have to talk about Leonardo da Vinci first. This legendary figure may be the designer of the earliest boring machine used for metal processing. The boring machine he designed is powered by hydraulic power or pedal, the boring cutter rotates near the workpiece, and the workpiece is fixed on the mobile platform driven by the crane. 1540, another painter painted a picture of "fireworks" and a picture of the same boring machine. At that time, the boring machine was specially used for finishing hollow castings.
/kloc-in the 0/7th century, due to military needs, the artillery manufacturing industry developed very rapidly, and how to manufacture gun barrels became a major problem that people urgently needed to solve.
The first real boring machine in the world was invented by Wilkinson in 1775. In fact, Wilkinson's boring machine is a kind of drilling machine that can accurately process cannons. It is a hollow cylindrical boring bar with two ends mounted on bearings.
Wilkinson 1728 was born in America. At the age of 20, he moved to Staffordshire and built the first ironmaking blast furnace in Bilston. Therefore, Wilkinson is called "the blacksmith master in Staffordshire". 1775, 47-year-old Wilkinson made continuous efforts in his father's factory, and finally made this new machine which can drill the gun barrel with rare accuracy. Interestingly, Wilkinson died in 1808 and was buried in a cast iron coffin designed by himself.
But Wilkinson's invention did not apply for patent protection, and people copied it and installed it. In 1802, Watt also talked about Wilkinson's invention in his book and copied it in his Su He Iron Works. Later, when Watt made the cylinder and piston of the steam engine, he also applied Wilkinson, a magical machine. Originally, for the piston, it was possible to measure the dimension while cutting the outside, but for the cylinder, it was not so simple, and a boring machine was needed. At that time, Watt used a water truck to rotate the metal cylinder, so that the tool with fixed center moved forward and cut the inside of the cylinder. As a result, the error of a cylinder with a diameter of 75 inches is less than the thickness of a coin, which is very advanced in the right place.
In the following decades, Wilkinson's boring machine was improved many times. 1885, Hutton, England, made a bench-type lifting boring machine, which became the prototype of modern boring machine.
The birth of lathe
As early as in ancient Egypt, people have invented the technology of turning wood with tools when it rotates around its central axis. At first, people used two stumps as supports to stand up the wood to be turned, used the elasticity of branches to roll the rope onto the wood, pulled the rope to turn the wood, and turned it with tools.
This ancient method has gradually evolved into a "bow car", in which the rope is wound around a pulley for two or three times, and the rope is supported on an elastic rod bent into an arch to push and pull the bow back and forth to make the processed object rotate.
In the middle ages, someone designed a kind of "bicycle bed", which used pedals to drive the crankshaft to rotate, drive the flywheel, and then transmitted it to the spindle to make it rotate. /kloc-In the middle of the 6th century, a French designer named Besson designed a lathe, which could screw screws with a threaded rod. Unfortunately, this lathe is not popular.
/kloc-in the 8th century, a crankshaft with pedals and connecting rods was designed, which can store the rotational kinetic energy of lathe on flywheel, and develop from directly rotating workpiece to rotating headstock, which is a chuck for clamping workpiece.
In the story of inventing the lathe, the most striking thing is an Englishman named Maudslay, because he invented the epoch-making tool rest lathe in 1797, which has precise screw and interchangeable gears.
Mosley was born in 177 1. 18 years old, is the right-hand man of the inventor Brammer. It is said that Brammer used to do farm work. /kloc-at the age of 0/6, he had to switch to carpentry because of an accident that disabled his right ankle. His first invention was the toilet of 1778. Maudslay began to help Brammer design hydraulic presses and other machinery, and didn't leave Brammer until he was 26 years old, because Brammer rudely refused Moritz's request to raise his salary to more than 30 shillings per week.
In the year when Maudslay left Brammer, he made the first threaded lathe, which is an all-metal lathe with a tool rest and a tailstock and can move along two parallel guide rails. The guide surface of the guide rail is triangular. When the spindle rotates, the lead screw is driven to move the tool rest laterally. This is the main mechanism of modern lathe, which can be used to turn precision metal screws with arbitrary pitch.
Three years later, Maudslay made a more perfect lathe in his workshop, and the gears on it could be replaced with each other. Soon, larger lathes came out, which made great contributions to the invention of steam engines and other machinery.
19th century, due to the invention of high-speed tool steel and the application of electric motors, lathes have been continuously improved, and finally reached the modern level of high speed and high precision.
Planer and milling machine
In the process of invention, many things are often complementary and interlocking: in order to manufacture steam engines, boring machines are needed; After the invention of the steam engine, it is also called the gantry planer technically. It can be said that it was the invention of the steam engine that led to the design and development of "working machine" from boring machine, lathe to gantry planer. In fact, the planer is a kind of "planer" for planing metal.
Since the beginning of19th century, many technicians began to study the plane machining of steam engine valve seats, including Richard Robert, Richard Pratt, james fox and Joseph Clement. They independently manufactured the planer from 18 14 in 25 years. This planer fixes the processed object on the reciprocating platform, and the planer cuts one side of the processed object. However, this planer has no feed device and is in the process of transforming from "tool" to "machine". 1839, an Englishman named Bodmer finally designed a faucet planer with a feed device.
Another Englishman, nasmyth, invented and manufactured a planer for processing small planes from 183 1 in 40 years. It can fix the object to be processed on the machine bed, and the cutter moves back and forth.
Since then, due to the improvement of tools and the appearance of motors, the gantry planer has developed in the direction of high-speed cutting and high precision on the one hand, and in the direction of large-scale on the other.
/kloc-in the 0/9th century, the British invented boring machines and planers for the needs of the industrial revolution such as steam engines, while the Americans devoted themselves to the invention of milling machines for mass production of weapons. Milling machine is a machine with milling cutters with different shapes, which can cut workpieces with special shapes, such as spiral grooves and tooth profiles.
As early as 1664, someone made a cutting machine by rotating a circular cutter, which can be regarded as the earliest milling machine. Of course, it is American Whitney who really established the position of milling machine in machinery manufacturing.
18 18, Whitney made the world's first ordinary milling machine, but the patent of the milling machine was "won" by Bodmer in Britain in 1839.
1862, Brown made the earliest universal milling machine in the world, which was an epoch-making initiative in providing universal indexing discs and comprehensive milling cutters. The worktable of universal milling machine can rotate at a certain angle in the horizontal direction, and it has accessories such as vertical milling head. At the same time, Brown also designed a shaped milling cutter that will not deform after grinding, and then made a grinder for grinding the milling cutter, which made the milling machine reach the present level.
Grinding machine and drilling machine
Grinding is an ancient technology that human beings have known since ancient times. This technology was used to grind stone tools in the Paleolithic Age. Later, with the use of metal appliances, the development of grinding technology was promoted. However, it is still a modern thing to design a veritable grinder. Even in the early19th century, people still grind natural grindstones by rotating them and bringing them into contact with the processed objects.
1864, the United States made the world's first grinding machine, which is a device to install grinding wheel on the carriage of lathe to make it have automatic speed change. 12 years later, Brown of the United States invented the universal grinder close to the modern grinder.
The demand for artificial grindstones has also increased. How to develop a grindstone that is more wear-resistant than natural grindstone? 1892, American Acheson successfully trial-produced silicon carbide made of coke and sand, which is an artificial grindstone now called C abrasive. Two years later, the abrasive A with alumina as the main component was successfully trial-produced, which made the grinder more widely used.
Later, due to the further improvement of bearings and guide rails, the accuracy of grinders became higher and higher, and they developed in the direction of specialization. Internal grinder, surface grinder, roller grinder, gear grinder and universal grinder appeared.
Similar to grinding technology, drilling technology has a long history. Archaeologists now find that in 4000 BC, humans invented a device for digging holes. The ancients put a beam on two pillars, then hung a rotatable awl from the beam, and then wrapped the awl with bowstring to drive it to rotate, so that holes could be punched in wood and stone. Soon, people also designed a punching tool called "pulley", which also uses elastic bowstring to make the awl rotate.
In about 1850, the German Martini first made a twist drill for punching metal. 1862 At the international exposition held in London, England, whitworth, an Englishman, exhibited the electric drilling machine with cast iron frame, which became the prototype of modern drilling machine.
Later, various drilling machines appeared one after another, including radial drilling machines, drilling machines with automatic feed mechanisms, and multi-spindle drilling machines that can drill multiple holes at the same time. Due to the improvement of tool materials and drill bits and the use of electric motors, a large-scale high-performance drilling rig was finally manufactured.
A constantly developing lathe
From the end of 19 to the beginning of the 20th century, a single lathe gradually evolved into milling machine, planer, grinder, drilling machine and so on. These main machine tools have been basically finalized, thus creating conditions for precision machine tools and mechanization and semi-automation of production in the early 20th century.
In the first 20 years of the 20th century, people mainly paid attention to milling machines, grinders and assembly lines. Due to the production requirements of automobiles, airplanes and their engines, when processing a large number of parts with complex shapes, high precision and high finish, precise and automatic milling machines and grinders are urgently needed. Due to the appearance of multi-spiral blade milling cutter, the difficulty that milling machine can't be developed due to the low vibration and low smoothness caused by single blade milling cutter has been basically solved, making milling machine an important equipment for processing complex parts.
Ford, who is known as the "father of cars" by the world, puts forward that cars should be "light, strong, reliable and cheap". In order to achieve this goal, it is necessary to develop an efficient grinder. For this reason, Norton, an American, made grinding wheels with large diameter and wide width from emery and jadeite in 1900, as well as heavy grinding machines with great rigidity and firmness. With the development of grinding machine, mechanical manufacturing technology has entered a new stage of precision.
30 years after 1920, mechanical manufacturing technology entered a semi-automatic period, and hydraulic and electrical components were gradually applied to machine tools and other machinery. During the period of 1938, the hydraulic system and electromagnetic control not only promoted the invention of new milling machines, but also promoted their use in planers and other machine tools. After 1930s, the travel switch-solenoid valve system was almost used for automatic control of various machine tools.
After World War II, the development of machine tools began to enter the era of automation due to the appearance of numerical control, group control machine tools and automatic lines. Numerical control machine tool is a new type of machine tool after the invention of electronic computer. It uses the principle of digital control to store the machining program, requirements, operation numbers and characters of tool changing as information, and controls the machine tool to process according to the established requirements according to the instructions issued by it.
The scheme of NC machine tool was put forward to the US Air Force by Parsons when he developed a blade processing machine to check the profile of aircraft propeller blades. With the participation and assistance of MIT, it finally succeeded 1949. 195 1 year, they formally made the first prototype of electron tube CNC machine tool, which successfully solved the automation problem of machining complex parts with multiple varieties and small batches. Later, on the one hand, the principle of numerical control extended from milling machine to milling and boring machine, drilling machine and lathe, on the other hand, it turned from electron tube to transistor and integrated circuit.
From 1970 to 1974, due to the wide application of small computers in machine tool control, there have been three technological breakthroughs. The first time was the direct digital controller, which enabled a small electronic computer to control multiple machine tools at the same time, resulting in "group control"; The second time is computer aided design, which uses light pen to design and modify the design calculation program; For the third time, according to the actual situation and unexpected changes in machining, the machining amount and cutting speed were automatically changed, and a machine tool with an adaptive control system appeared.
1968, British Moline Machinery Company developed the first automatic line composed of CNC machine tools. Soon, General Electric Company of the United States put forward that "the premise of factory automation is the numerical control of parts processing and the program control of production process". As a result, in the mid-1970s, an automation workshop appeared, and an automation factory was already under construction.
After 100 years of ups and downs, the family of machine tools has become increasingly mature and truly become a "machine tool" in the mechanical field.
Development history of lathe
The development of lathe can be roughly divided into four stages, prototype stage, basic structure stage, independent power stage and numerical control stage, which will be discussed below.
The process of the exhibition is introduced.
The birth of the lathe was not invented, but gradually evolved. As early as 4000 years ago, it was recorded that some people used the simple bow-pulling principle to complete the drilling work. This is the earliest recorded machine tool. Even now, you can still find a manual drilling machine driven by manpower. Later, lathes were derived for turning and drilling wood. This is where the English name Lath comes from. After hundreds of years of evolution, the progress of lathe is very slow. Wooden beds, with slow speed and low torque, were not suitable for metal cutting, except carpentry, until the industrial revolution. This period can be called the embryonic period of lathe.
/kloc-the industrial revolution that began in the 0/8th century marked the end of the agricultural society dominated by craftsmen and was replaced by an industrial society that emphasized mass production. Because all kinds of metal products are widely used, in order to meet the processing of metal parts, lathes become the key equipment. /kloc-At the beginning of the 0/8th century, the bed was made of metal, and its structural strength became stronger, making it more suitable for metal cutting. However, due to its simple structure, only turning and spiral machining can be carried out. It was not until the19th century that the lathe was completely composed of iron parts. Coupled with the introduction of transmission mechanism such as lead screw, a lathe with basic functions was finally developed. However, because the power can only be driven by manpower, animal power or water power, it still can't meet the demand, and it can only be regarded as just completing the construction of the basic framework.
Watt invented the steam engine to make the lathe generate electricity by steam and drive the lathe to rotate. At this time, the power of the lathe is concentrated in one place, and then distributed to the lathes of the whole factory through the transmission of belts and gears. At the beginning of the 20th century, a common lathe with independent power source was finally developed (see Figure 3), which also brought the lathe into a new field. During this period, thanks to the large-scale production of Ford cars, many auto parts have to be processed by lathes. In order to ensure the sufficient supply of parts, suppliers must purchase a large number of lathes to meet the demand. Even today, the development of lathes is still influenced by the rise and fall of the automobile industry.
In the mid-20th century, computers were invented and soon applied to machine tools. CNC lathe has gradually replaced the traditional lathe as a sharp weapon in the factory, which has doubled the production efficiency and greatly improved the machining accuracy of parts. With the progress and maturity of computer software and hardware, many technologies that were previously considered impossible to process have been overcome, and the ratio of CNC machine tools has become an important symbol of national modernization.
From a historical point of view, apart from the industrial revolution in the18th century and the rise of the automobile industry in the 20th century, the development of lathes mainly benefited from the progress of tools. The cutting tool used in the early days was carbon steel, and the cutting speed could only be limited below 20m/min, so the machining accuracy was not good. Later knives were all alloy steel, and today they are still ceramic knives. The cutting speed has increased to above 1000m/min, so the lathe speed is higher and higher, the feed speed is faster and faster, and the machining accuracy is greatly improved by 0.00 1mm from1mm a hundred years ago. In addition to the improvement of tools and technology, the cooperation of numerical control is also the biggest contributor to the rapid progress.