Lenofilament machine for metal

Contents

Introduction

1. Main part

1.1 Purpose of the article

1.2 Technical Specifications

1.3 Semi-automatic line arrangement

1.4 Safety measures during semi-automatic line operation

1.5 Principle of semi-automatic line operation

1.6 Safety measures during repair and maintenance of automatic line

1.7 Safety requirements for repair and maintenance of electrical equipment

1.8 Operation and maintenance of equipment - lubrication, organization, routine maintenance

1.8.1 Essence and content of the ToR system

1.8.2. Equipment Maintenance

1.8.3. Types of repairs

1.8.4. Frequency, duration and labor intensity of repairs

1.8.5 Repair methods

2. Design part

2.1 Design Input

2.2 Calculation of geometrical parameters of saw teeth and cutting force

2.3 Kinematic calculation of saw belt drive

2.4 Gearing Calculation

2.4.1 Selection of materials and heat treatment

2.4.2 Determining the number of gear and gear teeth

2.4.3 Definition of allowable contact stresses

2.4.4 Definition of allowable bending stresses

2.4.5 Determination of inter-axial distances

2.4.6 Module Definition

2.4.7 Sizing gear wheels

2.4.9 Determination of design loads in gear engagement

2.4.9 Test calculation for contact strength

2.4.10 Check calculation for bending endurance

2.5 Calculation of tensile force of saw blade

and tensioner screw thread selection

2.6 Calculation of pulley axis

2.7 Calculation of bearings

Introduction

LP metal machines are designed to cut all commonly used materials, from aluminum and its alloys, non-ferrous metals, to highly solid steel. LP machines are characterized by rigidity of design and high productivity, subject to small size and mobility. A cooling system can be used for large machines.

The pioneers among Russian metallurgists in the field of the use of LP machines, of course, are iron and steel enterprises. Non-ferrous metal processing plants are more cautious about switching to a new cutting technology. The reduction of cost, the increase in competitiveness of Russian metallurgy is directly related to the introduction of new saving technologies. In the field of metal cutting for Russian metallurgists, the use of LP machines has become new. Tape sawing is one of the most easy-to-integrate and fast-to-pay technologies.

They are used by machine builders and metallurgists, including those who are engaged in the production of such difficult-to-process materials as titanium and nickel alloys.

In terms of functionality, therefore, in the field of application, the entire wide range of LP machines can be divided into several classes. First class LP are designed for high-performance cutting of almost all metals used in modern mechanical engineering: non-ferrous alloys, structural and high-alloy steels, nickel and titanium alloys. They are capable of cutting at high speed both solid rolled and forged large diameter, as well as pipes and thin-walled profile. Equipment of this class can be used in the main industries of metallurgical plants, in the procurement areas of high-tech enterprises using difficult-to-process materials, as well as in workshops with a need for high productivity per unit of equipment.

The rapid growth in our country of the fleet of LP machines has led to a multiple increase in the supply of cut-off equipment on the market. Lenofuel technologies have already proved that they have a future in the field of simple productive cutting equipment. Now in our country to one degree or another there are a lot of manufacturers of LP machines and tape saws. And this is not the limit, since only in Europe there are dozens of manufacturers of LP machines producing hundreds of different models and sizes.

In this regard, most plants face the difficult problem of correctly choosing the necessary equipment. Errors in the decision to purchase a machine often lead to the equipment either simply failing to meet the task, the performance of the equipment does not meet the necessary requirements, or the cost of one cut exceeds all economically justified standards. The vast majority of technical specialists of enterprises do not have much practical experience in the operation of modern LP machines, and therefore the criteria for their evaluation. In this situation, the correctness of the choice depends very much on the technical literacy of the seller, as well as on his integrity and decency. But today in Russia, specialists of several companies with at least four to five years of sales and service experience can really provide qualified assistance. Often, the seller's desire to sell the equipment at any cost turns into simply discarded money for the enterprise, and for the person who decided, at least, confirmation of his incompetence. In fact, there is a simple methodology based on a number of parameters: technical, financial, organizational, service, which allows you to determine the buyer with the purchase of optimal cut-off equipment.

The technical parameters of the machine are determined based on the task due to the range of sizes of the workpieces to be processed, the grade of the material and its physical properties, the required capacity and load factor of the equipment. In terms of functionality, and therefore in the field of application, the entire wide range of LP machines can be divided into four classes. The main task of the buyer is to correctly determine which class he needs to solve production problems, and classify the machines offered on the market as accurately as possible.

Classification of LP machines.

Grade I LP are designed for high-performance cutting of almost all metals used in modern mechanical engineering. These are non-ferrous alloys, structural and highly alloyed steels, nickel and titanium alloys. They are capable of cutting at high speed both solid rolled and forged large diameter, as well as pipes and thin-walled profile. Hence the areas of application: the main production of metallurgical plants, procurement areas of high-tech enterprises using difficult-to-process materials, as well as workshops, with the need for high productivity per unit of equipment. This is due to the fact that only first class machines can successfully work with both bimetallic and hard alloy saws.

According to the design of horizontal machines, only gantry (in which the saw frame moves along the movable portal) and two rack (in which the saw frame drops along the vertical posts) belong to the first class. At the same time, the main criterion of a two-post machine, according to which it can be attributed to machines of the first class, is the design of guides along which the saw frame moves during the working stroke. Guides must be designed for ultra-high loads that occur when cutting large diameter forgings from hard-to-process materials. During cutting, forces appear that tend to deform the saw frame, guide posts and the bed. This results in microdeformations of the saw frame which can be transmitted to the remaining bearing parts of the machine structure. In first class machines, this problem is solved by either using prismatic guides with linear bearings that compensate for deformations, or by developing the diameter of cylindrical guides that have sufficient rigidity to handle all forces. The relative stiffness factor of the struts must be at least 0.28 (the relative stiffness factor is equal to the ratio of the diameter of the guide saw frame to the maximum diameter of the workpiece). By the degree of automation, the machines of this group are automatic and semi-automatic. Mandatory attributes include: a powerful electric drive with a wide range of speeds, control and feed speed and pressure, a web tension control device, a relatively wide saw that withstands colossal alternating loads, a saw cleaning mechanism, etc. Most often, the options used are CNC control, which tracks a number of parameters, control of saw deflection, installation of a blank by laser, a system of periodic automatic lubrication of units and friction pairs. That is, low-fuel class I can be attributed to special cut-off equipment. At the same time, they are characterized by the highest resistance of the cutting tool and, accordingly, by the low cost of one cut. The most common are second and third class machines.

Grade II LP machines can be used in all procurement industries (except those where first class machines are needed). They are capable of cutting non-ferrous metals, alloyed and stainless steels, part of heat-resistant steels and easily processed titanium alloys, that is, those materials that can be treated with bimetallic strip saws (with a cutting edge made of fast-cutting steel).

In terms of design, these are double-strut (with a relative stiffness factor of the struts less than 0.28), single-strut and cantilever (with a saw frame fixed on a hinge). Most of these machines allow you to cut the workpiece at various angles to its axis. Therefore, they refer to universal equipment. But the lower rigidity of the design, the lower power of the electric drive and the simplified design limit practical application. The second class is used for pipe size cutting, profile cutting, and solid rolling. At the same time, the diameter of the solid rolled stock should be limited to about 7080% of the maximum allowable size for a given machine (since productivity is very significantly reduced, and most importantly the equipment life). The mandatory features of the cantilever machines of this group are the forced lowering of the saw frame by a hydraulic drive (unlike third-class machines where the saw frame is lowered under its own weight, held by a hydraulic cylinder), an electric drive with a smoothly changing speed range, control of the feed speed/pressure, a device for visual control of the tension of the web, a saw cleaning mechanism, the need to adjust the inclination of the axes of the pulleys of the saw drive. According to the degree of automation of the machine of this group, automatic and semi-automatic are manufactured. On automatic machines, the billet is fed into the cutting zone by hydraulic clutches, which makes it possible to have an accuracy in the length of the billet of about 0.1 mm. On the above-mentioned workpieces, class II machines have high resistance of the cutting tool, and the shortest payback period among all LP machines. This just influenced the mass popularity of their use at the procurement industries of machine-building plants, bridge-building enterprises, and companies manufacturing metal structures.

Low fuel III class

Basically, these are machines with a cantilever arrangement of the saw frame (but sometimes there are also simplified two-post ones). They are made in automatic, semi-automatic and manual versions. The main disadvantages of cantilever machines of the third class are lowering the saw frame under its own weight or due to the muscular force of the worker, the frequent absence of saw cleaning mechanisms and visual control of saw tension, the need to periodically adjust the inclination of the axes of the saw drive pulleys, the lack of control and adjustment of the saw pressure on the workpiece (the valve on the supporting cylinder allows you to adjust only the supply speed, and even then in a very narrow range), a non-rigid bed with a heavy saw frame, etc. This group is very capricious in operation, due to the use of cheaper components and components, the equipment is unreliable, requires high qualification of maintenance personnel and frequent routine work. Therefore, in the world of such a class machine is used in small industries that do not require high productivity, for cutting mainly pipes and profile rolled stock into size. The length of solid rental takes too long. So, even compared to second-class machines, the performance at a continuous rental can be lower by one and a half to two times. Lowering the saw frame under its own weight often causes vibration of the web during cutting and a sharp decrease in the life of the saw. But due to the fact that manufacturers still have very little experience in operating LP machines, and the cost of a piece of equipment of the third class is relatively small, they are imported to Russia in very large quantities. They are trying to use them even in the procurement workshops of large plants. Of course, compared to disc saws or mechanical legs, even they are a significant step forward, but economically and technically this is the wrong solution to the problem. Since at a relatively low price (10-40% lower than class II), high operating costs and low resource lead to the fact that the payback period is extended for almost the entire life of the equipment. This has already been felt by those enterprises that have been operating LP machines for more than three to four years, and they focus their repeated purchases of cut-off equipment mainly on second and first class machines.

Class IV LP machines include all household and table machines. It is categorically not recommended to use them in any production, since the resource of this equipment cannot withstand any criticism at a relatively high cost.

Ribbon webs

For modern tape-making metal processing technologies, the market today offers carbon steel tape webs and bimetallic webs - with a spring base and teeth made of fast-cutting steel or hard alloy. The variety of design parameters of tape webs in combination with the application of optimal cutting modes allows to ensure high productivity and reduce the cost of the processing process on LP machines compared to other methods of separating cutting blanks.

Types of ribbons

Tape webs made from high-quality high-carbon tool steel are designed for economical cutting of a wide range of alloyed and non-alloyed steels with a tensile strength of up to 80 kPa/mm square meters. but in terms of their technical and operational characteristics they are inferior to bimetallic tape webs.

Bimetallic tape webs, especially with a tooth made of fast-cutting steel, have become the most widespread in modern tape technology. The cutting part of the teeth is made of fast-cutting steel M42 (analogue 11P2M10K8). This steel, highly alloyed with molybdenum and cobalt, has high hardness (up to 950 HV) and redness resistance. The specially selected spring steel of the base of the ribbon web provides it with strength and durability, and a reliable electron beam welded joint with cutting teeth allows you to use these saws in the most difficult production conditions. Saws of the new design with combined pitch are most used for cutting pipes, profiles and blanks of variable section. Variable pitch of saw tooth makes it possible to significantly reduce vibration, increase stability and efficiency of cutting process of blanks of variable cross section.

Tape webs with a hard alloy tooth are used for the most difficult cutting conditions. They are used on high-performance and rigid double-column LP machines for cutting such difficult-to-process materials as cast iron, non-ferromagnetic alloys, rare earth metals and alloys such as Monel, Inconel, Hastela, etc., with a high content of nickel and titanium, and at the same time significantly reduce the cost of separation cutting. The design of the seat for placing the solid alloy plate guarantees the strength of its connection to the saw blade. The teeth of the saws have a wiring that provides the necessary clearance when sawing shavings. These saws are used for cutting only solid sections with a diameter of 60 mm. The maximum effect of their use is achieved when they are used on LP machines manufactured by the Turkish group of companies UZAY, equipment specially designed for cutting difficult-to-process materials.

Tape Sheet Specifications

In order to achieve optimal conditions when working with certain groups of materials and the shape of the blanks, it is necessary to accurately select the parameters of the ribbon web: pitch, shape and dressing, as well as the operation modes of the LP machine - speed and feed of the ribbon web.

Determining the Feed Rate of the Ribbon Web

For optimal cutting, it is necessary that each tooth of the ribbon web cuts chips of a certain thickness. Almost the feed is selected according to the recommendations of equipment manufacturers or according to the type of chips that are obtained during cutting. In the case of fine or dusty chips, it is necessary to increase the feed speed of the web or reduce the cutting speed. Weakly curled chips indicate the correct sawing mode. The chips are thick or with a blue cast indicates an excessive feed speed or increase the cutting speed.

After determining the technical parameters of the machine, the financial issues of the cost of equipment, the form of payment, deferral of payments, discounts, etc. come to the second place. This is followed by organizational issues, which are closely related to logistics and commissioning, which go into service maintenance and training of maintenance personnel (mechanics, technologists, workers). An important parameter is a service that depends on the manufacturer (availability of direct contact with technical specialists and the logistics service) and the supplier (availability of a service service, a regional network of representative offices with warehouses of tape saws, consumables and spare parts). The preliminary criterion for evaluating the service provided may be the number of enterprises with two or more machines of this company. Since even in the presence of a significant number of equipment in the country, if the service is unsatisfactory and the quality of the machines leaves much to be desired, the buyer is unlikely to make a repeated purchase of equipment from this seller. To summarize the above, we can say that the choice of any equipment, and especially little known, is a complex and painstaking process, so you need to try to make it carefully and consciously.

In this thesis, we will calculate the drive of the tape of the LP machine, which will allow us to manufacture our own LP machine. Firstly, this will allow us to save money, since a machine manufactured by our own plant is cheaper than one purchased from contractors. Secondly, the installation of the machine should have an economic effect.

Purpose of the product

Semi-automatic line for treatment of rod ends is intended for cutting round rolled stock by a certain length for preparation of radial forging machine blank.

Semi-automatic line arrangement

The semiautomatic line consists of loading stacks and trolleys, receiving stacks and trolleys, feeding stacks with pre-cylinders for supplying a part, movable frames (left and right), belt-and-saw machines installed on movable frames, part clamping device, saw lifting mechanisms, pneumatic equipment, electrical equipment, lubricating and cooling device.

Principle of semi-automatic line operation

The semi-automatic line is designed to cut off rolled stock by a certain size. First, round stock blanks are placed on the receiving rack with a crane. After that, the machine tool rolls one blank into the clamping device and triggers the clamping mesanism with the button.

After making sure that the workpiece is clamped by the tool button, the saw belt drive mechanism starts to move at the sawing speed.

At the same time, the pneumatic system is automatically started, which lowers the sawing mechanism at the feed speed. Also, a lubricant cooling system is automatically turned on, which supplies LPG to the sawing zone and cools the cutting tool. Moreover, the right and left mechanisms work simultaneously.

After sawing, the pneumatic system automatically raises the sawing mechanism, the clamping mechanism is automatically expanded, and the blank is fed into the storage rack by the release mechanism.

Types of repairs

Maintenance of equipment in operable condition is provided by its maintenance and scheduled repairs.

Scheduled repairs of two types are provided by the M&R system at ferrous metallurgy enterprises: current and capital.

The main type of repair aimed at restoring the operability of the equipment is ongoing repair. In the period between the current repairs, the operability of units and machines is supported by their technical maintenance, which also includes minor repairs.

The current repair is carried out to ensure or restore the operability of the equipment and consists in replacing or restoring rapidly wearing parts or assemblies, reconciling individual units, elements of metal structures, pipelines, etc., changing oil in capacitive (cartor) lubrication systems, checking fasteners and replacing failed fasteners, replacing the headset, and water-cooled valves and other elements of furnace units.

Depending on the nature and scope of work performed during equipment stops for current repairs, and on the duration of such stops, current repairs are divided into the first current repair (T1), the second current repair (T2), the third current repair (T3) and the fourth repair (T4). At the same time for the same type of the equipment the amount of works of everyone of a type of repair previous (one after another) is included into the volume of the subsequent, i.e. maintenance of T2 completely includes also the works performed at maintenance of T maintenance of Tz - the works performed at repair of T2, etc.

Maintenance costs are charged to operating costs.

Overhaul is performed to restore serviceability and complete or close to complete restoration of equipment life with replacement or restoration of any parts of it, including basic ones. The overhaul work also includes work on the modernization of equipment and the introduction of new equipment, carried out according to previously developed and approved projects.

Large-volume works carried out to improve the main technological parameters of the unit (increase in the volume of blast furnace or capacity of open-hearth mills, increase in the productivity of rolling mills, aglomeration and roasting machines, etc.), in which, as a rule, the foundation is strengthened or replaced, the power of drives, heating devices, etc., are related to reconstructions.

Overhaul of equipment with a frequency of at least one year is considered to be overhaul, at which, as a rule, all worn-out parts, assemblies and other structural elements (including non-thrust lining) are completely disassembled, replaced or restored, basic parts and foundations are repaired, equipment is assembled, reconciled, adjusted and tested idle and under load.

Capital repairs are financed by depreciation charges.

Equipment reconstruction is carried out due to credit for capital construction or at the expense of loans of the State Bank with a corresponding change in the book value of the reconstructed object.

For blast furnaces and air heaters, overhauls of the first, second and third are increased

discharges, and for firing machines OK306 and OK520 - capital repairs of the first and second discharges.

Frequency, duration and labor intensity of repairs

The standards are developed on the basis of summarizing the advanced experience of enterprises in the field of organization and repair of equipment, taking into account the practice of developing local (factory) repair standards.

At enterprises where more progressive indicators have been achieved compared to those given in Annexes 5-19, the periodicity and duration of equipment repairs, planning and repair should be carried out according to the indicators achieved.

The frequency of equipment stops for current and overhaul repairs is determined by the service life of the parts and the technical condition of the units and mechanisms of the unit, and the duration of stops is determined by the time required to perform the most labor-intensive (of the planned for this repair) work.

The frequency of repairs is established based on the three-shift operation of the equipment with a continuous schedule.

For equipment operating one or two 8-hour shifts per day, the periodicity standards for current and capital repairs should be applied with a coefficient equal to 1.4, respectively.

The normative duration of repairs determines not the calendar downtime, but the actual overall duration of the repair work itself.

The normative duration of equipment stops for all types of scheduled repairs also includes the time for preparing the workplace for repair, cleaning and cleaning machine units, testing and adjustment of equipment after repair, and for process furnaces and heating devices - also the time required for their preliminary cooling before repair and subsequent heating at its completion.

The normative duration of equipment repairs is established based on continuous repair work during the day (three-shift). If repairs are carried out in one or two shifts during each day, the duration of equipment downtime in the repair should be adjusted, that is, increased responsibly by 2.8 or 1.4 times.

During equipment reconstruction, as well as during overhaul with reconstruction of individual units, the duration of its downtime is established taking into account the volume of work related to reconstruction.

Repair methods

The restoration of the operability of the equipment, which was destroyed during its operation, must be carried out by wide implementation:

Methods of dispersed capital repairs of equipment.

Methods of aggregate replacement.

The essence of the dispersed method of overhaul consists in the performance of overhaul of equipment, where it is technically possible and reforestation, in parts on the days of scheduled stops for its ongoing repairs. This allows either to reduce the duration of equipment downtime during overhaul, or to completely exclude the latter.

When implementing a dispersed method of capital repair, the following conditions must be observed:

To perform repairs in parts, such works should be performed, which are technically possible and comprehensive, regardless of the total scope of work provided for by the defect list.

The minimum scope of work on the overhaul of equipment, intended for execution when it is suspended for ongoing repair (in case of dispersed repair), should include the full scope of work on the overhaul of individual, included in the complex of the machine, mechanism or unit.

If the specified minimum scope of work cannot be performed within the time stipulated by the plan for one stop of the unit for ongoing repair, some increase in the duration of this stop is allowed.

According to Position 0 of MR and R for screw mechanism:

T1 current repair of 8 hours with alternation in 30 days.

T2current repair 24 hours with variability in 90 days.

K-overhaul of 120 hours with variability in 5 years.