Definition of Grinding Machine?
A grinder is a machine tool that uses abrasive tools to grind the surface of a work piece. Most grinding machines use high-speed rotating grinding wheels for grinding, and a few use oil stone, abrasive belts and other abrasives and free abrasives for processing, such as honing machines, super finishing machines, belt grinders, grinding machines and polishing machine, etc.
The grinding machine can process materials with higher hardness, such as hardened steel, cemented carbide, etc.; it can also process brittle materials, such as glass and granite. The grinder can perform high-precision grinding with small surface roughness, as well as high-efficiency grinding, such as strong grinding.
The relationship between supply and demand is a prerequisite for the rapid development of an industry. The market demand is huge, but the supply is slightly insufficient, especially the enterprises with core intellectual property rights and excellent product quality are not many, and the industry as a whole lacks brand effect. In the stage of strong demand, the industry has huge demand and good development prospects, which is beyond doubt. However, how to maintain the healthy, stable and sustainable development of the industry requires the joint efforts of enterprises in the industry, especially the spirit of excellence in research and development, to further improve the production process, reduce costs, truly solve the actual difficulties of customers, strictly control the quality, and provide the best Reliable product.
Energy Saving Application
Grinders used in standard machining, the grinding wheel motors operate according to the conventional starting circuit. After the motor is started, it runs at the rated speed. Due to certain fluctuations in the grid voltage, the friction load of the grinding wheel work piece is constantly changing, which will affect the speed error of the motor. The standard grinding wheel motor starting circuit generally only has one processing speed, which is difficult to adapt to different work piece sizes. Different processing relative lines The speed is so high that it is difficult to guarantee the machining precision of the processed work piece. Therefore, considering the aspects of improving processing quality and processing efficiency and saving energy, the application of frequency conversion speed regulation technology to grinding machines can achieve satisfactory results. There are many kinds of products processed in the machining industry, and the work pieces are of different sizes and require different machining accuracy. Relatively, the rotational speed of the grinding wheel is different from the linear speed of the main shaft. It is difficult to adjust the rotational speed of the main shaft to meet the machining line speed of the work piece to an ideal state.In addition, due to the stress bending caused by the shaft processing process, the grinding process will produce different feed torque of the grinding wheel, which will bring about different changes in the output speed/torque of the grinding wheel, and correspondingly will produce vibration pattern/burnt pattern, etc., grinding accuracy. It is difficult to guarantee, resulting in low production efficiency and low quality rate. With the development of power electronic technology, frequency conversion speed regulation technology is becoming more and more popular, and the application of frequency converter in the machining industry has received good results. Among them, the step less speed regulation of frequency converter, soft start and constant torque output greatly meet the constant speed/constant torque requirements of mechanical processing equipment.
Grinding Machine Classification
With the increase in the number of high-precision, high-hardness mechanical parts, as well as the development of precision casting and precision forging processes, the performance, variety and output of grinding machines are constantly improving and growing.
(1) Cylindrical grinder: It is a common basic series, mainly used for grinding cylindrical and conical outer surfaces.
(2) Internal grinding machine: It is a common basic series, mainly used for grinding cylindrical and conical inner surfaces. In addition, there are grinding machines with both internal and external cylindrical grinding.
(3) Coordinate grinder: an internal cylindrical grinder with a precise coordinate positioning device.
(4) Center less grinder: The work piece is center less clamped, generally supported between the guide wheel and the bracket, and the guide wheel drives the work piece to rotate. It is mainly used for grinding machines on cylindrical surfaces. For example, bearing shaft support, etc.
(5) Surface grinder: a grinder mainly used for grinding the plane of the work piece. a. The hand grinder is suitable for processing small size and high precision work pieces, and can process various special-shaped work pieces including camber, plane, groove, etc. b. The large water mill is suitable for the processing of larger work pieces, and the processing accuracy is not high, which is different from the hand grinder.
(6) Abrasive belt grinder: a grinder that grinds with a fast-moving abrasive belt.
(7) Honing machine: It is mainly used to process various cylindrical holes (including smooth holes, axial or radial discontinuous surface holes, through holes, blind holes and multi-step holes), and can also process conical holes, elliptical holes, Trochoidal hole.
(8) Grinding machine: a grinding machine used to grind the flat or cylindrical inner and outer surfaces of the work piece.
(9) Guide rail grinder: a grinder mainly used for grinding the guide rail surface of machine tools.
(10) Tool grinder: a grinder for grinding tools.
(11) Multi-purpose grinder: a grinder used for grinding cylindrical, conical inner and outer surfaces or planes, and can grind various work pieces with follow-up devices and accessories.
(12) Special grinder: a special machine tool engaged in grinding certain types of parts. According to its processing objects, it can be divided into: spline shaft grinder, crankshaft grinder, cam grinder, gear grinder, thread grinder, curve grinder, etc.
(13) End face grinder: a grinder for grinding the end face of gears.
According to the movement characteristics and process requirements of the grinding machine, the following requirements are required for electric drive and control: 1. The rotational movement of the grinding wheel generally does not require speed regulation, and can be driven by a three-phase asynchronous motor, and only requires one-way rotation. When the capacity is large, the Y-delta step-down start can be used. 2. In order to ensure the machining accuracy, make it run smoothly, and ensure that the reciprocating motion of the worktable has little inertia and no impact, so hydraulic transmission is used to realize the reciprocating motion of the worktable and the lateral feed of the grinding wheel box.
In the 1830s, in order to adapt to the hardened processing of clocks, bicycles, sewing machines and firearms, the United Kingdom, Germany and the United States developed grinding machines using natural abrasive grinding wheels. These grinding machines were rebuilt by adding grinding heads on the existing machine tools such as lathes and planers at that time. They have simple structures, low rigidity, and are prone to vibration during grinding. Operators are required to have high skills to grind precision. Work piece. In 1876, the universal cylindrical grinder manufactured by Brown-Sharp Corporation of the United States exhibited at the Paris Exposition was the first machine with the basic characteristics of modern grinders. Its work piece head stock and tail stock are mounted on a reciprocating table, a box-shaped bed increases machine rigidity, and it has an internal grinding attachment. In 1883, the company made a surface grinder with a grinding head mounted on a column and a reciprocating table.Around 1900, the development of artificial abrasives and the application of hydraulic transmission had a great impetus to the development of grinding machines. With the development of modern industry, especially the automobile industry, various types of grinding machines have come out one after another. For example, in the early 20th century, planetary internal cylindrical grinders, crankshaft grinders, camshaft grinders, and piston ring grinders with electromagnetic chucks were successively developed for processing cylinder blocks. Automatic measuring devices began to be applied to grinding machines in 1908. Around 1920, center less grinders, double-end grinders, roll grinders, guideway grinders, honing machines and ultra-finishing machine tools were successively manufactured and used; in the 1950s, high-precision cylindrical grinders that could be used for mirror grinding appeared; in the 1960s At the end of the year, high-speed grinders with a grinding wheel linear speed of 60-80 m/s and surface grinders with large depth of cut and slow feed appeared; in the 1970s, technologies such as digital control and adaptive control of microprocessors were widely used on grinders. Applications.
Grinding is widely used and is one of the main methods of precision machining of machine parts. However, due to the high rotational speed of the grinding wheel of the grinding machine, the grinding wheel is relatively hard, brittle, and cannot withstand heavy impacts. Accidental improper operation, breaking the grinding wheel will cause very serious consequences. Therefore, the safety and technical work of grinding processing is particularly important. Reliable safety protection devices must be adopted, and the operation must be concentrated to ensure foolproof. In addition, the fine sand and metal chips splashed from the work piece of the grinding wheel during grinding will hurt the eyes of the workers. If the workers inhale a large amount of this dust, it will be harmful to the body, and appropriate protective measures should also be taken. The following safety technical issues should be paid attention to when grinding. Before starting the machine, a comprehensive inspection of the machine tool should be carried out, including the inspection of the operating mechanism, electrical equipment, and magnetic chucks and other fixtures. After inspection, it is lubricated, and after lubricating, a test run is carried out to confirm that everything is in good condition before it can be used. When loading the work piece, pay attention to the clamping and clamping. The work piece loosening during the grinding process will cause the work piece to fly out and hurt people or break the grinding wheel and other serious consequences. When starting to work, the manual adjustment method should be used to make the grinding wheel approach the work piece slowly, the initial feed should be small, and excessive force should not be used to prevent the grinding wheel from colliding.When it is necessary to use the stopper to control the reciprocating motion of the worktable, it should be adjusted accurately according to the grinding length of the work piece, and the stopper should be firmly tightened. When replacing the grinding wheel, you must first check the appearance to see if there is any trauma, and then tap it with a wooden hammer or wooden stick. The sound is required to be clear and no cracks. When installing the grinding wheel, it must be assembled according to the prescribed methods and requirements. After static balance debugging, it must be installed and tested. After everything is normal, it can be used. Workers should wear protective glasses during work, and trim the grinding wheel in a balanced manner to prevent impact. Measuring work pieces, adjusting or wiping the machine should be done after a shutdown. When using a magnetic chuck, clean the surface of the disk and the work piece, hold it tightly, and suck it firmly. If necessary, add a stopper to prevent the work piece from shifting or flying out. Pay attention to installing the grinding wheel protective cover or machine baffle, and the station should be over the front of the high-speed rotating grinding wheel.