Specialized lathes - design of technological processes. GC TechnoSpetsSnab: sale of industrial and construction equipment There are several types of specialized machines
Special machines are created to process specific parts or even to perform only certain operations and are mainly used in mass and large-scale production. When designing a special machine it is necessary:
a) reduce the main technological time to a minimum, which is achieved by using the most advantageous cutting tool designs, optimal cutting conditions, and multi-tool processing;
b) reduce auxiliary time to a minimum - achieved by complete automation of machine control;
c) reduce to a minimum the time spent on adjustment, which is achieved by using quick-change interchangeable tools and automation of adjustment.
Adjustment and adjustment of special machines is carried out using replaceable gears, replaceable cams or copiers, which simplifies the design of the drive compared to a universal machine.
Special machines are manufactured in one copy or in a small series, so the designer, in relation to single and small-scale production, can more widely use welded structures instead of cast ones, processing of machine parts according to markings, etc.
Since special machines are used to process specific parts, we must strive to create them that can be reconfigured using already mastered machine tools in their design.
Specialized machines occupy an intermediate position between universal and special machines. These machines, with the help of replaceable devices and devices, can be switched over in a relatively short time to process another part of the same name, but with different dimensions. Therefore, specialized machines are special machines that can be reconfigured;
they can also be classified as universal machines of a simplified design.
When designing a specialized machine, it is necessary to take into account the design features of both universal and special machines. Specialized machines should be created on the basis of normal series of general-purpose machines with maximum unification of the main components and parts IN The requirements for the accuracy and quality of surface parts of most modern machines and devices have sharply increased. Such high requirements can only be met when parts are manufactured on high-quality precision machines. Increasing the accuracy of machine tools is achieved by improving the designs of individual elements and assemblies, increasing rigidity and vibration resistance, reducing thermal deformations, increasing the accuracy of manufacturing parts and the assembly quality of machine tools.
To increase the rigidity of machine tools, you should:
a) create closed frame structures of machine tools;
b) use solid cast frames that have a box-like shape with internal partitions and diagonal ribs;
c) reduce the number of joints and improve the quality of their processing;
d) correctly design components from the point of view of rational distribution of loads in machines;
e) apply preload (tension) in joints and supports (especially spindle supports);
f) use rolling guides with a preliminary linkage:
g) increase the diameter of the spindle, reduce the length of its console;
h) use ball and hydrostatic screw pairs in the feed supply;
i) reduce the number of links in kinematic chains;
j) increase the rigidity of tool fastening;
k) use reliable securing of moving units during processing.
To increase the vibration resistance of machine tools, you should:
a) improve their static and dynamic characteristics;
b) carry out insulation of machines in order to control the influence of external disturbances transmitted through the base;
c) use various damping devices;
d) remove sources of vibration from the machine - electric motors; pumps for hydraulic systems, lubrication and cooling systems, etc.;
e) use an adjustable electric drive to reduce the number of gears that can be sources of disturbances; especially good results!.!
gives a thyristor drive with a low noise level;
f) use a split drive;
g) use high-precision bearings in spindle supports;
h) use helical gears instead of straight teeth; i) increase the accuracy of manufacturing gears and belt pulleys; use endless belts in belt drives;
High Quality
j) choose rational processing modes and tool geometry;
k) carry out balancing of fast-rotating parts of the machine and electric motor;
To reduce thermal deformations of machines, the following measures are carried out:
a) create thermosymmetric designs of machine components;
b) use structures that provide compensation for temperature deformations;
c) remove heat sources from the flock (electrical equipment, hydraulic system tanks, emulsions and lubricants);
d) intensive cooling of built-in drives is used;
e) reduce friction losses in drives;
f) select materials with similar or identical linear expansion coefficients for mating, and also use materials with low linear expansion coefficients;
g) place the hydraulic cylinder of the table drive (or other unit) next to the machine, and not under the table;
h) install devices for cooling the hydraulic system oil;
i) artificially equalize the temperature floor of the stack by heating or cooling its individual parts, etc.
The accuracy and quality of the machine’s operation are also ensured by:
a) choosing a rational layout of the machine;
b) the correct choice of materials and heat treatment for critical parts of the stack;
c) the use of rolling guides and hydrostatic guides;
d) the use of gears with a device for selecting gaps in feed chains and other assemblies;
e) the use of devices for the protection of steam regulators;
c) the use of devices for fine purification of coolant in order to improve the purity of processing;
g) the use of suction devices to remove dust from the grinding and wheel dressing zone;
h) the use of wheel wear compensation mechanisms;
i) the use of digital size indication devices;
j) the use of means of automatic control of the dimensions of parts during processing with automatic adjustment of the size;
k) high-quality aging of the basic parts of the machine;
m) hardening and grinding of guides;
m) the use of more advanced methods of fine chabrepey guides;
o) improving the general production culture.
The accuracy and roughness of surfaces machined on precision machines largely depends on the accuracy of the spindle supports. In spindle assemblies of precision machine tools, multi-load bearings are used.
Rice. 90. Methods for creating preload (dashed lines show angular contact ball bearings)
oil wedges (see Fig. 77 and 78), hydro- and aerostatic bearings and special rolling bearings.
Rolling bearings. To eliminate gaps between the rolling elements and bearing rings and increase the rigidity of the supports, reactive tension is also used. For this bearing - I ^
A metal-cutting machine (or more generally, a machine tool) is a technological machine on which, by removing chips from a workpiece, a part with specified dimensions, shape, relative position and surface roughness is obtained. The machines process workpieces not only made of metal, but also of other materials, so the term “metal-cutting machines” is becoming outdated and conventional. A workpiece is an object of labor from which a part is made by changing the shape, size and surface properties. The latter is a product of labor - a product intended for sale (in main production) or the enterprise's own needs (in auxiliary production).
Machines can be classified according to various criteria, the main ones of which are discussed below.
According to the degree of versatility, universal, specialized and special machines are distinguished.
Universal machines(or machines general purpose) are used for processing parts of a wide range, limited only by maximum dimensions, set of tools and technological operations.
Specialized machines used for processing similar parts (pipes, couplings, crankshafts and fasteners) in a certain range of sizes.
Special machines used to process one specific part, or less often - several parts of the same type.
Specialized and special machines are used mainly in large-scale and mass production.
According to the degree of processing accuracy, machines are divided into five classes:
- normal accuracy(H); Most universal machines belong to this class;
- increased accuracy(P); in the manufacture of machines of this class based on normal precision machines, increased demands are placed on the accuracy of processing of critical parts, the quality of assembly and adjustment of the machine;
- high precision(B), achieved through the special design of individual components, high requirements for the precision of manufacturing parts, assembly quality and adjustment of the machine as a whole;
- especially high precision(A), during the manufacture of which even more strict requirements than in the manufacture of class B machines;
- especially accurate(C) machines, or master machines.
To ensure the accuracy of operation of machines of classes B, A and C, it is necessary to maintain production premises constant, automatically adjusted temperature and humidity values.
Based on the degree of automation, a distinction is made between mechanized and automated machines (automatic and semi-automatic).
Mechanized machine has one automated operation, such as workpiece clamping or tool feeding.
Machine, while carrying out processing, makes all the working and auxiliary movements of the technological operation cycle and repeats them without the participation of a worker who only observes the operation of the machine, controls the quality of processing and, if necessary, adjusts the machine, i.e. adjusts it to restore the accuracy achieved during adjustment the relative position of the tool and the workpiece, the quality of the workpiece. (A cycle is understood as the period of time from the beginning to the end of a periodically repeating technological operation, regardless of the number of simultaneously manufactured parts.)
Semi-automatic- a machine operating with an automatic cycle, the repetition of which requires the intervention of a worker. For example, a worker must remove a part and install a new workpiece, and then turn on the machine to automatic operation in the next cycle.
Based on the location of the spindle, machines are divided into horizontal, vertical, inclined and combined.
Depending on the weight, there are light (up to 1 t), medium (up to 10 t) and heavy (over 10 t) machines, among which particularly heavy or unique ones (over 100 t) can be distinguished.
The totality of all types and sizes of manufactured machines is called a type. To designate the model of a mass-produced machine, a classification developed by the Experimental Research Institute of Metal-Cutting Machine Tools (ENIMS) has been adopted, according to which all machines are divided into nine groups. Each group, in turn, is divided into nine types, characterizing the purpose of the machine, its layout and other features.
The machine model is indicated by three or four numbers with the addition of letters in some cases. Thus, the designation of a screw-cutting lathe model 16K20P should be deciphered as follows: screw cutting lathe(first two digits) with the height of the centers (half largest diameter processing) 200 mm, increased precision P and the next modification K. When designating machines with numerical control (CNC), additional letters and numbers are added, for example 16K20PFZ (FZ - numerical control of three coordinate movements).
To designate special and specialized machines, each machine tool plant is assigned an index of one or two letters, followed by the registration number of the machine. For example, the Moscow machine tool OJSC “Krasny Proletary” has the MK index.
Control questions
- What is a metal cutting machine?
- How are metal-cutting machines classified according to the degree of versatility, accuracy, and automation?
- Tell us how the machine model is designated?
This equipment category includes: , . Aging of wood is carried out by brushing various wood blanks. The machines are designed for processing wooden board, linings, parquet board, window frames in order to highlight the structure of the wood.
Specialized machines are most often used in furniture production. With their help, you can highlight the structure of wood for the production of parquet, lining, wooden boards or window frames. Devices of this category also allow for high-quality metal processing of copper, steel and aluminum profiles.
A specialized machine is suitable for processing any wood-based materials. Moreover, it can also be used to work with certain types of plastics.
There are several types of specialized machines:
- Equipment for wood aging. The operating principle of this type of device is quite simple - artificial aging the massif occurs as a result of processing its surface with abrasive brushes. Depending on the model, the machine can be equipped with 1-4 working heads for fine/coarse processing of products.
- Laser copying equipment. A 3D laser scanner is used to obtain three-dimensional models by scanning the prototype with a laser beam. Moreover, the prototype can be made from different materials, including wood, metal, plasticine, clay, plaster and foam. This type of equipment can be used to create copies of products self made or details of interior items designed according to an individual sketch. Laser copying machines work by reading information coming from a reflected laser beam. The resulting code allows you to create a three-dimensional model, an exact copy of the original.
- Defect cutting and optimization machines are commonly used in wood sawmills. Specialized machines are designed for cross-cutting, trimming and sampling of defects found on splice lines. Such installations are characterized by a lot of advantages, the main of which can be called high performance, affordable price and modern design. The improved design of the clamp of a specialized machine prevents the formation of chips on the workpiece.
Specialized machines from NEVASTANKOMASH
The NEVASTANKOMASH company offers specialized machines in a wide range. We offer high-quality woodworking equipment from the world's best manufacturers.
Buy specialized machines from NEVASTANKOMASH to effectively modernize your production.
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- R2/300 - Machine for aging wood (GRIGGIO, Italy) (Width and processing height, 300 mm)
- The remaining 13
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This is a technological machine that is designed for processing materials by cutting. The purpose of the machine is to produce parts of a given shape and size (with the required accuracy and quality of the machined surface). The machines process workpieces not only from metal, but also from other materials, so the term “metal-cutting machine” is conditional.
According to the type of work performed, metal-cutting machines are divided into groups, each of which is divided into types, united by common technological characteristics and design features.
Models of mass-produced machines are assigned a digital or alphanumeric designation. As a rule, the designation consists of three to four numbers and one or two letters. The first digit is the number of the group to which the machine belongs, the second is the number of the machine type, the third and fourth characterize one of the main parameters of the machine or the part processed on it (for example, the height of the centers, the diameter of the rod, the dimensions of the table, etc.).
The letter after the first or second digit indicates that the machine has been modernized, the letter after the digits indicates a modification (modification) of the basic model of the machine. If the letter appears at the end of the model designation, then it indicates the accuracy class of the machine.
According to the degree of versatility, machines are divided into universal, specialized and special.
Universal machines designed for processing parts of a wide range in individual and small-scale production. These machines are characterized by a wide range of speed and feed control. TO universal machines relate turning , turning-screw-cutting, turning-turret, drilling , milling, planing, etc. (both manually controlled and CNC).
Specialized machines are used to process parts of one type, but different sizes. These include machines for processing pipes, couplings, crankshafts, as well as gear and thread processing, turning and backing, etc.
Specialized machines are characterized by rapid readjustment of replaceable devices and devices; They are used in serial and large-scale production.
Special machines are used to process parts of the same name and size; They are used in large-scale and mass production.
In the designation of specialized and special machines, the manufacturer's index of one or two letters is entered before the model number.
According to the degree of processing accuracy, machines are divided into five classes:
N - normal accuracy; Most universal machines belong to this class;
P - increased accuracy; machines of this class are manufactured on the basis of machines of normal accuracy, but the requirements for the accuracy of processing of critical parts of the machine, the quality of assembly and regulation are much higher;
B - high precision, achieved through the use of a special design of individual components, high requirements for the accuracy of manufacturing parts, quality of assembly and regulation of the machine as a whole;
A - especially high accuracy; these machines have even more stringent requirements than class B machines;
C - especially precise, they are used to produce parts for machines of accuracy classes B and A.
Machines of accuracy classes A, B and C are called precision (from the French precision - accuracy). It is better to operate these machines in temperature-controlled workshops, where the temperature and humidity are automatically regulated.
