Grinding machine - for metal, wood and other materials
A grinder is a device, used for processing workpieces of different materials with abrasive tools and is able to provide surface roughness from 0,02 to 1,25 micron. Grinding machines, which may have different design, allow to solve problems effectively, related to the surface treatment of parts, made of different materials.
One of the many types of grinding machines
Application of grinding machines
A number of technological operations can be performed with the help of a grinding machine:
- grinding of internal and external surfaces of details, having different shape and purpose;
- sharpening tools for various purposes;
- peeling, grinding, as well as pieces of metal castings, products with a complex profile;
- processing of gear parts, as well as threaded parts;
- formation of keyways of spline and spiral type on steel bars.
The grinding machine is practically irreplaceable when working with details, made of ceramic and magnetic materials and are difficult to process and high fragility. in addition, grinding machines, capable of performing technological operations of grinding and peeling at high speeds, which makes such equipment efficient and productive. On these machines, you can remove a large amount of metal from the surface of the workpiece in a short period of time during processing.
The video below shows the operation of a circular grinder with CNC:
All grinders work on the same principle: metal processing is carried out by simultaneous rotation of the abrasive wheel and movement or rotation of the workpiece. The work surface is the periphery or end of the abrasive wheel, and the workpiece moves relative to it with a straight or arc trajectory. Any grinder contains several kinematic chains in its design, which provide:
- moving the desktop in the longitudinal and transverse directions, which is possible due to the hydraulic drive;
- rotation of the working tool - grinding wheel, carried out at the expense of the individual drive of the working tool;
- feeding the workpiece or tool in the transverse direction due to the hydraulic or electromechanical drive;
- circle dressing, which can be performed manually by using an electromechanical or hydraulic system;
- rotation of the workpiece or desktop;
- feeding the working tool to the depth, which can be performed by hydraulic, mechanical drive.
Classification of grinding equipment
Depending on the field of application, grinding machines are divided into a number of types.
Circular grinding
This equipment is designed for grinding cylindrical (THE 25-600 mm) and conical workpieces. Such machines have a spindle in their design, rotating in the horizontal plane, which can move on special slides. Detail, which needs processing, can be clamped in the chuck or between the centers of the rear and front headstock.
Circular grinding machine
Universal circular grinders
Such machines are used for grinding the outer cylindrical and end surfaces of the workpieces (THE 25-300 mm), as well as conical parts. To perform the workpiece can be fixed in the centers or in the chuck.
Universal circular grinder
Mortise circular grinders
Grinding machines of this type are used for processing cylindrical (THE 150-400 mm), conical and profile blanks, which are fixed in the equipment centers. Processing is carried out at the expense of cross movement (incision) abrasive wheel.
The circular grinding machine is mortise
Centerless rounds
Processing on such equipment can be performed according to two schemes: on the aisle (cylindrical surfaces (THE 25-300 mm) and the method of incision (cylindrical, conical and profile surfaces). A distinctive feature of grinding machines of this type is that, that in their design there are no centers for fixing the workpieces.
Centerless circular grinder
Waltz grinders
These include machines for grinding cylindrical rollers, conical and profile configuration. Fixing of workpieces on machines of this type is carried out with the help of equipment centers.
Waltz grinding machine
For grinding crankshaft necks
On such machines, working by the method of cutting, perform simultaneous or sequential grinding of the connecting rod necks of the crankshafts.
The machine for grinding of necks of cranked shafts
Internal grinding
These devices allow you to process cylindrical and conical holes in a wide range of sizes (diameter 1-10 cm, on a table grinder and to 100 cm - in production).
Internal grinding machine
Surface grinding
Machining on such equipment is performed by the end face or periphery of the abrasive wheel. Grinding machines of this type can be equipped with additional devices, that gives the chance to carry out on them processing of preparations from metal of a difficult configuration. Depending on the location of the spindle, surface grinders can be horizontal or vertical. One or two columns may also be provided in the design of such devices.
Surface grinding machine
Bilateral surface grinders
On this equipment it is possible to carry out processing of two flat surfaces at the same time, which significantly increases its productivity. Such grinders, on which the processed details are fixed on the special giving device, can be vertical or horizontal type.
Double-sided surface grinder
For grinding guides
Maximum length of guides, which can be machined with these grinders, is 1000-5000 mm Guides of such types are equipped with beds, desktops, sledges and other components of equipment for various purposes.
Universal sharpeners
Such grinders are used for sharpening various tools with a maximum diameter 100-300 mm (taps, sweeps, countersinks, cutters, etc.). Technical possibilities of the equipment of this type allow to equip it with additional devices for processing of cylindrical preparations, as well as for internal and end grinding.
Universal sharpening machine
Peeling and grinding
This grinding equipment is used for peeling and cleaning the surface of the workpieces by grinding. Such machines use abrasive wheels with a diameter 100-800 mm.
Peeling and grinding machine
Flat grinding
This grinding equipment is used for grinding workpieces with flat and cylindrical surfaces. Diameter of abrasive disks, which are installed on such machines, is 200-800 mm
Flat grinding machine
Round grinding
Calibration and measuring instruments are ground on this equipment, made of metal. Maximum diameter of calibers and tools, which can be processed on machines of this type, – 50-200 mm
Grinding and grinding
With the help of such equipment perform grinding holes, the maximum diameter of which is 100-300 mm
Grinding and grinding machine
Grinding and finishing
These are machines, designed to perform finishing (grinding) operations. Various metal products are processed on such devices: crankshafts with the maximum diameter 100-200 mm, spindle equipment, pistons, etc..
Polishing
Such machines are used to polish metal parts. On this universal equipment it is possible to carry out polishing of flat, cylindrical, conical, internal surfaces, as well as blanks of complex configuration. An endless belt width can be used as a working tool on these machines 100-200 mm or soft polishing wheel with a diameter 100-200 mm
Grinding and polishing machine
Honing
There are also honing machines, which are used to perform fine grinding (0,04-0.08 mm in diameter).
Honing machine
We make the simplest grinding machine with our own hands
Given that fact, that serial grinding equipment is not cheap, it makes sense to think about it, to make such a machine with your own hands. Even the simplest homemade machine, which is quite easy to do, will allow you to grind workpieces of various configurations with high efficiency and quality.
The bearing element of the self-made machine for performance of grinding works is a bed, on which two drums and the electric motor are fixed. You can use a thick steel sheet to make the frame, from which the platform of the necessary size is cut out.
Everything is much easier with the engine: it can be removed from an old washing machine, which has already served its term. Drums can be made typesetting, for this purpose it is convenient to use a chipboard plate, from which disks of necessary diameter are cut out.
A simple homemade machine from improvised means
As an example, consider the sequence of steps for the manufacture of homemade grinding machine, the bed which has the sizes of 50х18 see. In the first place, from a steel sheet cut out a bed, as well as a desktop, on which the electric motor will be fixed. The dimensions of such a table will be approximately 18x16 cm.
Importantly, to the ends of the frame and the desktop, to be connected, were trimmed as evenly as possible. Thick sheet metal, from which you will make a bed and a desktop, difficult to cut by hand, therefore it is better to perform such a procedure on a milling machine. Three holes must be drilled in the frame and on the workbench and securely fastened with bolts.. Only then is the engine installed and securely connected to the desktop surface in this way, so that the base of the engine fits snugly to the surface of the site.
Another homemade machine, gathered "on his knees"
Choosing an electric motor for your homemade grinding equipment, it is important to pay attention to power: it must not be lower 2,5 kw, and the rotational speed is close 1500 rpm. If you use a drive with more modest characteristics, then the machine will have low efficiency. You can avoid the need to use a gearbox, if you correctly choose the diameters of the drive and tension drum.
The diameters of the drums should be chosen depending on, how fast the abrasive tape will move. So, if the speed of the tape should be approx 20 m / sec, then it is necessary to make drums with a diameter 20 cm. A fixed axle is used to install the tension drum, and the master is fixed directly on the motor shaft. To make the rotation of the tension drum easier, the bearing unit is used. Ground, on which the tension drum is established, best done with some bevel, this will ensure smooth contact of the abrasive tape with the workpiece.
The homemade version is a bit more complicated
It will not be particularly difficult to make drums for a homemade grinder. For this purpose it is necessary to cut from a chipboard square preparations in the size 20 on 20 cm, in the center of each of which a hole is drilled. These blanks are then assembled into a thick package 24 cm, which is drilled to form a cylindrical drum with a diameter 20 cm.
That the abrasive tape did not slip on drums, wide rubber rings can be stretched on their surface, which are usually cut from the camera of a bicycle or moped. Abrasive tape width, which you can make yourself, should be approximately 20 div.
Belts for belt grinding machines
As in production, grinding machines are often used at home as well, working tools which have a textile tape with a layer of abrasive powder. The basis of such tapes is a dense material (calico, sarja) or special paper, and the abrasive layer on them is fixed by means of glue structure.
The effectiveness of such tape depends on a number of parameters: the density of the abrasive powder and the composition of its grains. Ribbons are more efficient, powder on which takes no more 70% their area. This is due to the fact, that the processed material is not clogged between the abrasive grains of such tape. As an abrasive powder, applied to the working surface of the tape, can be used as natural, and artificial materials, but they must all have high hardness.
One of the types of belt-grinding machine
Tapes are classified, mounted on a grinder, behind the number, denoting the size of abrasive grains, expressed in hundredths of a millimeter. The reliability and effectiveness of such tape also depends on the type of adhesive, which is used to fix abrasive grains. To date, two types of such glue are used: carnelian and synthetic resin.
Usually, belt grinders are used in woodworking enterprises. The tape on such machines can be attached to the reels, that allows to carry them to the category of circular grinding equipment. But in most cases, these machines are universal, They can be used to process wooden parts with the help of tape, and with the use of grinding wheels.
