Organization of maintenance and repair of electrical equipment of radial drilling machine 2K522

Introduction

Drilling machines are a large group of metal cutting machines designed to obtain through and blind holes in a continuous material, for finishing (countersinking, unfolding) holes formed in a blank in some other way, for cutting internal threads, for countersinking end surfaces.

Using special tools and accessories, on drilling machines you can spread holes, cut holes of large diameter in sheet material, lap accurate holes, etc.

The electrical equipment of ‏metallorezhushchikh machines is constantly being improved due to the use of boleye‏ new electric control devices, protection, pre‏obrazovate‏le‏y, semiconductor devices and elements.

The theme of this diploma project is the Design of Electrical Equipment of the Radial Drilling Machine 2K522.

Purpose: Study of electrical equipment of radial drilling machine, its purpose and operation principle;

Tasks:

. Study of requirements for electrical equipment of radial drilling machine 2K522.

. Analysis of the electric drive system and control diagram;

. Analysis of failures of electrical equipment of radial drilling machine 2K522;

.Provide the graphic part: electrical schematic diagram of control of EP of radial drilling machine.

Section 1. common part

1.1. Purpose and technical data of the machine

Moving around the table plane of large and heavy parts causes great inconvenience and loss of time. Therefore, in the treatment of a large number of holes in such parts, radial drilling machines are used. When working on them, the part remains stationary, and the spindle with a drill moves relative to the part and is installed in the required position.

The Model 2K522 radial drilling machine is designed to process holes in small, medium, and mainly hard-to-reach locations of large parts. The machine is used in auxiliary and small-scale production.

You can drill, expand, thread in different planes and at any angle on the machine.

Technical specifications:

Largest nominal drilling diameter, mm, in steel 32

Largest diameter of cut thread in steel M16

Spindle departure (max/min), mm 800/300

Distance from spindle end to plate (max/min), mm 1000/220 (220 below plate plane)

Distance from spindle axis to floor at its horizontal position (max/min), mm 1470/550

Spindle Stroke 250

Total angle of hose rotation, deg 360

Total turning angle of drill head, deg 360

Morse spindle cone 4

Dimensions of the working surface of the plate, mm 800x630

Dimensions of T-shaped slots, mm 18

Number of spindle speed stages 12

Spindle speed, min-1 45-63-90 125180250 355-500-710 1000-1400-2000

Number of feeds 4

Feed value, mm/v 0.056; 0,1; 0,18; 0,32

Main motion drive power, kW 1.5

Cooling device capacity, l/min, minimum 2.5

Hose lifting drive by column electromechanical, manual

Size of detachable box table, mm 500x360x400

Overall dimensions of the machine (LxBxH), mm, not more than 1480x940x1990

Machine weight, kg, not more than 950

Overall dimensions of package (LxBxH), mm 2040x1060x2290

1.2. Arrangement and interaction of machine units

The radial drilling machine 2K522 consists of the following main units: base, column, housing, hose, carriage, drill head, column clamping mechanism, coolant supply system and electrical equipment.

A column with a body and a hose is installed on the base, and a coolant tank is attached to it at the end.

The column is a steel pipe installed in the base on two bearings. Part of electrical equipment and mechanism of column clamping are located in the base.

The body is a rigid cast iron and is a basic part for assembling a speed box, a mechanism for moving the body along the column of the mechanism for clamping the body on the column.

Electrical equipment is installed in the housing niche.

On the front side of the housing there are control handles of the speed box, a mechanism for moving the spindle head along the column and a control panel.

The hose is attached to the housing with four grips. Carriage with drilling head secured on it moves along guides of hose. Sleeve is turned about its axis by handle through worm gear.

The drill head is a cast iron casting in which a spindle, a feed box and a steering device are mounted.

The spindle of the machine has a wide range of speed control and can be spatially oriented by turning the sleeve and drill head.

Machine 2K522 is equipped with a device for processing holes to a given depth and devices that protect against overloads in torque and axial force. When processing large-sized parts outside the working surface of the plate, the machine is set up using screw supports. It is recommended to process small parts on a box table installed on the table plate.

A distinctive feature of the machine of this type is the presence of a rotary column and the installation of the drill head carriage on the hose guides in rolling bearings, which significantly increases the usability of the machine.

The machine is manufactured for use in temperate climates, on order for operation in tropical climates, as well as for processing parts in an inch measurement system.

The electrical equipment of the machine can be made for the current of the supply network with a frequency of 50 and 60 Hz and voltages of 220, 380, 400, 415, 440, 600 V.

1.3. Process requirements for the drive

Three asynchronous short-circuited motors are installed on the machine: a main drive motor, a hose drive motor for moving the hose along the column, and a coolant pump motor. All motors are powered by 220/380V.

Automatic setting of spindle rotation speed and feed values depending on turret position is performed by switching of electromagnetic couplings of feed and magnetic starters of two-speed asynchronous motor of main drive.

The main drive of the drilling machines is carried out from asynchronous short-circuited motors. The spindle speed is controlled by switching gears of the gearbox. To reduce the number of intermediate transmissions, multi-speed asynchronous motors can be used in some cases.

Based on the above data, the main drive uses a short-circuited asynchronous motor for the 2K522 radial drilling machine.

The machine also has auxiliary drives. Auxiliary drives serve to facilitate performance of the specified task. Auxiliary drives include hose drive and cooling pump.

Consider the rated operating modes of the motors. Operating modes of electric drives are characterized by great diversity both in nature and in cycle duration, load values, and cooling conditions.

Based on the analysis, a special mode class is selected. In accordance with GOST 18374 "Electric rotating machines. General Specification "eight rated operating modes of electrical machines have been established, which have the symbols S1S8.

In the machine, the main drive operates in S1 mode.

Mode S1 provides for constant load operation until the temperature of all engine parts reaches the steady state value.

Auxiliary drive motors operate in mode S2. S2 - short-term mode in which the period of constant load alternates with periodic engine shutdown. At the same time, the load periods are insufficient so that the excess of the motor temperature can reach steady values, the stop periods are sufficient to cool the engine to ambient temperature.

Consider protection of motors against environmental conditions according to GOST 1425496 "Degrees of protection provided by shells (IP code)." IP letters and the following two digits are used to indicate the degree of protection. The first digit indicates the degree of protection of personnel from contact with moving parts or approaching them and from contact with moving parts located inside the shell, as well as the degree of protection of the product from ingress of solid foreign bodies. The second digit indicates the degree of protection of the product from ingress of water.

In practice, two degrees of protection IP23 and IP44 are used to protect engines. The first of them characterizes machines in the so-called protected version, the second in closed.

Based on this information to protect motors from environmental conditions, the degree of machine protection is IP23.

To eliminate incorrect operations and abnormal operation modes of electrical equipment in the electrical circuit diagram of the machine:

control of correct switching by means of the command set is performed by limit switches of the latter.

elimination of possibility of simultaneous actuation of coupling of reduction gear box and coupling of lower revolutions of reduction gear boxes at reverse by corresponding actuation of chains containing contacts of operation mode switch and magnetic starter in the circuit.

electric motors are protected from overload by thermal relays.

electric equipment of the machine is protected against short circuits by fuses. Zero protection is provided by disconnecting magnetic starters when the mains voltage decreases below 0.85 nominal.

to improve operating conditions of contacts of limit switches parallel to coils of electromagnetic couplings for anti-EMF closures, chains consisting of discharge resistors and diodes are included.

Section 2. electrical part

2.1. Control diagram and its elements

The diagram is presented in Annex 2.

M1 Cooling pump motor

M2 Main drive motor

M3 Motor of hose movement drive by column

EL Luminaire

HL Signal lamp

KK1, KK2, KKZ Thermal relays RTT5-10

KM1-KM6 Magnetic starters

QF1, QF2, QF3 Automatic switches

QS Disconnector Switch (Electrical Cabinet Mechanical Interlock)

SA2, SA3 Handle switch, with lock

SB1, SB2 Push-button switches "Emergency stop," "Stop"

SB3-SB5 Push buttons

SQ1-SQ6 Limit switches (track)

SQ8 Approach sensor

TV Voltage transformer down

2.2. Analysis of electric drive system and control diagram

Work on the machine should be started in the following order:

set the spindle actuation handle to neutral position;

turn QS switch-disconnector lever to actuate it. In this case, the signal lamp HL lights up;

circuit breakers QF1 (power circuit protection), QF2 (control circuit protection) and QF3 (lamp circuit protection) must be ON;

press the pushbutton SB3 to turn on the machine electric control circuit. Keep in mind that the machine is activated only when the "spindle on" handle is in the neutral position. At that, KM1 starter operates and prepares electrical circuit for operation with its normally open contact. This starter provides "zero" protection of the machine, i.e. in case of sudden voltage loss the starter KM1shuts down and the machine stops operating. When restoring the voltage supply, the machine can only be switched on when the SB3 button is pressed again;

by turning the reverse mechanism handle to one of the extreme positions in which it is fixed, the KMZ or KM4 starter is actuated through normally open contacts of SQ1.2 or SQ2.2 limit switches.

The KMZ or KM4 starters start the main motor M2 hourly or counterclockwise, respectively. Spindle rotation stops when handle returns to neutral position; the hose moves up or down when push buttons SB4 or SB5 are pressed; actuation of electric pump is performed by SA3 selector switch; the local lighting illuminator is switched on by the SA2 switch.

For emergency stop of the machine press the red mushroom-shaped pusher of SB1, SB2 "Emergency stop" - "Stop" button or turn off QS disconnector switch. At the same time, restoration of the emergency stop circuit is possible only after the pushbuttons of buttons SB1 and SB2 are set to the initial position manually.

Electrical equipment protection system:

Power circuits of electric motors and transformer are protected against short-circuit currents by QF1 circuit breaker,

protection of control and lighting circuits by QF2 and QF3 circuit breakers.

Protection of electric motors against long-term overloads is carried out by thermal relays KK1, KK2, KKZ.

The voltage in the machine is signaled by the HL lamp.

Locking devices:

The following emergency prevention measures are provided in the electrical circuit of the machine, ensuring safety of operation in case of incorrect actions of the operator, failure of individual elements of the machine, power outage:

"zero" protection is provided to prevent machine mechanisms self-starting after unexpected power supply interruption;

when the hose is manually moved up or down, the lifting handle presses SQ3 track switch pusher, when the housing is clamped, SQ4 track switch pusher is pressed. These switches open the switching circuit of the motor M3 of the hose movement drive;

limitation of hose movement in the upper and lower extreme position is performed by SQ5 and SQ6 track switches;

SQ1 and SQ2 track switches are interlocked, which prohibits the initial activation of the machine, if the spindle actuation handle is in the operating position;

SQ8 approach sensor is installed in front of the tool in the machine, when the lever is pressed, the KM1 starter will be immediately disconnected and open contact of all other starters through it normally with power supply disconnection from all engines.

2.6. Electrical equipment arrangement and connection diagram and

connections

The connection diagrams are based on the schematic electrical diagram, and the sketch of the location of the electrical equipment of all elements on the machine. All elements are connected using electrical wiring. When compiling a connection diagram, the same designations are used as on the schematic diagram.

The connection diagram shows in general form; push-button station, main and auxiliary control room, lighting, terminal boxes with terminal numbers and grounding points of electric motors, interlocking contacts of protections, tees, etc. (Annex 1)

The equipment located in the cabinet is surrounded by a common frame, the bundles of wires running in the same direction are depicted in a common diagram with one bold line. All ends of the wires connecting the clamps of individual devices are marked in accordance with the numbering of the connections available on the diagrams and the principle.

The common connection points of several elements in the diagram have the same number. Connection circuits are used for actuation during manufacture of electric drive unit and during its operation.

2.7. Installation of electrical equipment

Before installation of the machine, the insulation resistance shall be measured with megohmmeter a voltage of 500 V. The insulation resistance of the stator windings on the housing and between phases shall be not less than 0.5 MOhm.

A motor having a winding insulation resistance below 0.5 MOhm must be dried by a short-circuit current, including a motor with a stalled rotor and a reduced voltage (10% of the nominal).

During drying the winding temperature shall rise smoothly, not exceeding 100 ° С. Drying is considered complete if the insulation resistance has reached 0.5 MOhm, and then does not increase within 2... 3 hours.

Before installation, the engine should be cleaned of dust and anti-corrosion grease. Remove grease with rags wetted in kerosene or gasoline. During the installation of the engine, a mount must be made that provides normal rotation transmission conditions, as well as the necessary protection against shocks and vibrations.

During installation of the engine, free inflow of cooling air into the fan casing and its free withdrawal shall be provided.

The fan casing shall be at least 20 mm from the wall. It is allowed to connect the engine to the drive mechanism using an elastic coupling, belt or V-belt transmission.

When the motors are rigidly coupled to the drive mechanism by means of a coupling, the shafts shall be strictly demolished and parallel. If this requirement is not met, additional bearing forces, increased vibration and rapid engine failure may occur. This is not recommended for these reasons. If the flange panel engine is attached directly to a mechanism having an oil bath, seals shall be provided or other measures shall be taken to prevent oil from entering the engine through the shaft line. At belt drive belt tension shall be ensured by means of tension roller or sled with which the engine is mounted. The motor axis shall be perpendicular to the belt direction. Do not use stitched straps. belts need to be stretched like this. Excessive tension results in rapid failure of the belt and bearing.

In any method of rotation, it is necessary to perform dynamic balancing of parts mounted on the shaft: pulley, clutch, gear, etc. At the same time, it should be borne in mind that the engine rotor is balanced without a key. The part to be fitted must be balanced with the standard key. The mandrel on which the balancing is performed must have a key slot and be balanced without a key. In case of improper balancing of rotating parts of the transmission during the engine operation of emerging vibrations, which lead to premature wear of bearings, violation of the drive accuracy, to engine failure. To avoid damage to the bearings, the transmission elements must be fitted to the shaft in the heated state of application of forces and impacts. Before packing the transmission elements, it is necessary to remove the anti-corrosion coating from the projecting end of the shaft, and then slightly lubricate the end of the shaft with grease. After the final installation, manually check whether the rotor of the engine rotates freely.

When installing electrical devices, observe the following rules:

First of all, devices are placed, the location of which in the cabinet is predetermined by their purpose and use; for example, the insertion switch or circuit breaker is set so that its handle is in a convenient position at a level of 1.51.7 m from the floor; main fuses are located below or near the input switch, heavy contactors and starters are located on the lower part of the panel.

In the places most convenient for maintenance, there are units and sets of devices of the main control units: amplifying and regulating devices, measuring devices, etc.

3. Fuses for individual power circuits are placed above and thermal relays below the respective contactors.

When placing devices on panels with front mounting, it is necessary to provide places for laying bundles of inter-equipment and inter-panel wires, horizontal paths and vertical gaps between the devices, places for sets of clamps and plug connectors.

Electrical connections during the circuit breaker installation are performed according to the technical documentation for the circuit breaker (depending on the circuit breaker design). The terminals of the fixed contacts of the main circuit of the switch are connected to the voltage source, the movable contacts - to the load.

Switches of stationary version are installed on vertical plane by leads of fixed contacts upwards with possibility of turning in specified plane by 90 ° to both sides, of sliding version - by 90 ° to the left (by leads of fixed contacts to the left). It is allowed to deviate up to 5 ° from the working position in any direction.

Section 3. economic part

3.1. Modernization proposals and their economic justification

Modernization of in-service equipment means bringing its condition into line with modern requirements by making partial changes and improvements to the design of machines or refinement of machines related to the improvement of production technology.

The technical orientation and scope of modernization works required in the conditions of this enterprise are determined primarily by specific production requirements. At the same time, in accordance with the prospect of a specific production by modernization, the task of improving the overall technical level of the existing fleet of technological equipment should be solved.

Depending on the technical orientation, it is necessary to distinguish between general technical and technological (target) modernization.

In conditions of single and small-scale production, characterized by a wide range of products, a comprehensive general technical modernization should prevail, ensuring the improvement of a number of technical and operational characteristics of the existing equipment.

In conditions of mass production with a limited range of products, when it is required to improve only individual technical and operational characteristics of the existing equipment, it is advisable to carry out partial general technical modernization, which ensures an increase in the technical performance of machines that limit this production.

As a result of general technical modernization, the technical and operational indicators of the existing equipment are approaching the indicators of modern drilling machines of a similar purpose.

In the conditions of large-scale and mass production with a narrow range of products and established technology, technological (target) modernization is most important, aimed at solving individual technological tasks of production, introducing progressive technological processes and automation of equipment.

Modernization should be combined with planned repairs. The main areas of modernization of the obsolete fleet of machine-building equipment of machine-building enterprises are modernization to bring machines to the level of modern safety requirements and improve their technical characteristics, increase drive power, expand the range of speeds and supplies. These works are accompanied by works related to increasing the stiffness and vibration resistance of the machine, which allows to increase processing modes and reduce machine time.

Equipping machines with mechanized loading devices, software control systems and other devices that automate the machine cycle, reduces auxiliary time and frees the operator, creates conditions for multi-stage maintenance.

One of the main areas of modernization is the improvement of the operational properties of the machine and the extension of its operability due to measures taken to increase the durability of the machine parts and assemblies. This work shall also be performed to restore the accuracy and performance of the drilling machines. The main area of ​ ​ work here is associated with a decrease in the intensity of wear of machine parts, especially guide base parts (frames, posts, crossarms, etc.), and a decrease in its effect on the workability of the machine.

Reduction of wear intensity of guide base parts is achieved, first of all, by improvement of lubrication methods providing liquid friction, use of oils with improved operational properties (anti-jump, anti-lock, etc.) and introduction of more advanced protective devices and seals preventing ingress of chips, abrasive, dust and dirt. Wear of guide hardening and application of overlay guides are significantly reduced. In the latter case, it is possible to change the design of the rails to stabilize the amount of wear on all faces. Reduction of roughness of working surfaces due to their stacking and fine construction changes lubrication mode and increases bearing capacity and rigidity of guides.

The choice of optimal combinations of materials and heat treatment of rubbing pairs in the manufacture and repair of worn out parts is also one of the main directions of reducing their wear. It should be borne in mind here that together with the increase in the content of chromium, nickel, molybdenum, tungsten, the wear resistance of the parts increases. This is greatly facilitated by quenching, cementation, nitriding, coating of the surface of the parts with chromium, nickel (electroplating).

The use of more wear resistant materials is particularly relevant in the manufacture of gears. It is known that the wear resistance of cemented and hardened gears is about 1.5 times higher than those made of 40X steel, followed by hardening with high frequency currents. It also improves their operation by introducing barrel-shaped rounding of tooth ends and refining the speed switching system in order to reduce impact loads during switching.

The systematic and purposeful improvement of the technological operation and maintenance of machines is also a significant reserve for improving their durability.

No less important direction of modernization to reduce the impact of wear on the workability of machines is associated with compensation of wear by adjustment (adjustment of clearance in guides, screw-nut connections, elimination of clearance and creation of pre-tension in bearings, etc.) and automatic compensation of wear (triangular guides, etc.), as well as elimination of the effect of wear of parts on the operability of others.

Rational use of surface plastic deformation (PPD) treatment in the manufacture of parts of drilling machines creates negative stresses in the surface layer, which leads to a significant increase in fatigue strength. The introduction of this treatment in the process of manufacturing spare parts to machines is especially relevant for heavy cycle load parts. The wide use of PPD processing in combination with work on reducing dynamic loads due to balancing, the introduction of elastic links, dampers into the design of machine drives, and the use of motors with increased sliding in some cases significantly increases the fatigue strength of parts of metal cutting machine drives. However, it should be noted here that by the last GOST for labor protection, the braking mode of drives of certain types of machine tools has been significantly tightened. This leads to an increase in loads in the drive of the machine during braking, which does not exclude the possibility of its breakdowns.

Modernization of the drives of the main movement of the drilling machines in order to increase their power and speed in order to realize the capabilities of a modern cutting tool on them is carried out with a simultaneous increase in stiffness and vibration resistance of the supporting system of the machine. The scope of work during such modernization largely depends on the design of the drive, the reserves of strength and accuracy of the manufacture of its parts and the terms of reference for the modernization of the machine.

In some cases, the machines are equipped with a turret head, multi-spindle nozzles and other devices that allow for multi-tool and multi-position processing of parts, which dramatically reduces machine and piece processing times.

Modernization of drilling machines in order to reduce auxiliary time is carried out by equipping the machines with various loading and clamping devices, active size control devices, reading devices, automating the working cycle of the machine, etc. The greatest effect of modernization can be obtained if it is carried out systematically on the basis of complex automation and mechanization, excluding manual monotone operations from the production process.

Ultimately, the feasibility of modernization is determined by its cost-effectiveness. This does not apply to the modernization of drilling machines related to the improvement of working conditions and safety, which, of course, must be carried out.

Section 4. operation of electrical equipment

4.1. Maintenance of machine electrical equipment

On radial-drilling machines operations are performed for processing of unit technological holes or their groups, on blanks with large mass and significant dimensions. Correct operation and service life depends on timely repair of machines and compliance with maintenance regulations.

Mandatory maintenance work is divided into daily, weekly, quarterly and shift end. The following types of work shall be carried out every day:

Check the appearance of the unit - make sure that there are no mechanical damages, cracks, scratches on the machine parts. Remove dust, chips and dirt from the machine surface using a metal brush and oiled rags. Cleaning of chips by hands is not permitted.

Clean or change the filter - it is necessary to monitor the purity of the oil.

Lubricate and clean the spindle cone before each tool installation.

Weekly maintenance activities include the following mandatory checks:

Screw pair of housing lifting - presence of lubrication and analysis of mechanism condition in order to detect mechanical damages, burrs, scratches, etc. Check presence of lubrication.

Machine columns - the absence of mechanical damages is checked, the unit is cleaned of dirt and treated with liquid lubricant. If scratches, burrs are detected, check the upper gland. It must be replaced if its integrity is violated. Scratches are cleaned.

Console Guides-Analyzes the ease of movement of the drill head. With difficult movement of the unit, dust and dirt are removed, liquid lubricant is treated. If necessary, the movement of the drill head is adjusted.

Motors - check the condition of the unit, cables and grounding, as well as evaluate the appearance of the engine, the housing is cleaned of dust, dirt and oil stains.

Once a quarter, machine maintenance is carried out with checking the quality of operation of individual units and the entire unit, with corrective settings:

Clamping of the housing on the column and presence of spindle withdrawal during clamping - for this purpose the hose on the column is clamped. With a force of 900H at the end of the sleeve, turning it around the column. The clamp shall hold the applied load. In case of clamp loosening, as well as spindle withdrawal at clamp more than 0.35 mm, adjustment is performed.

Radial run-out of spindle hole - checked at the end and at a distance of 300 mm.

Carriage clamping on the sleeve - for this purpose, the carriage is fixed on the sleeve, with an axial force of 2500 N. The clip must hold the applied load. If clamp is loosened, correction is performed.

Fixation of machine parts - check the reliability of fixation of units, machine blocks, terminals of electrical equipment.

Perpendicular axis of spindle to working surface of foundation slab (stiffness) in longitudinal and transverse plane.

Parallelism of drilling head travel path along the surface sleeve of foundation slab.

If the tool is stuck in the workpiece or if it is rotated on the table with the tool, the machine must be stopped immediately.

When moving the spindle head along the cross-arm of the radial drilling machine, it should not be accelerated much. Do not tilt close to the rotating spindle to monitor the processing progress. When operating, when possible, do not use cartridges and accessories with projecting parts. If they are, then it is necessary to protect them.

After removing the machined part or accessory from the machine, remove all bolts from the slots of the table and remove them to the installed place. When removing the tool, it should be knocked out only by a wedge specially designed for this purpose and corresponding in size to the cone. For knocking out, it is necessary to use brass, copper or non-hot steel hammers to prevent the formation of fragments that can cause injury to the worker.

When transporting blanks and processed parts, slings should be placed taking into account the position of the center of gravity of blanks.

When using a sling, pay attention to the ring located at one of its ends, which indicates the date until which the sling strength is guaranteed. It is forbidden to use damaged slings, as well as wire or ropes for transportation.

It is only necessary to remove chips from the machined hole after stopping the spindle and retracting the tool. Special magnetic chip removal devices should be used to remove fine chips from blind holes and hollow blanks. Use of compressed air for chip blowing is prohibited.

After adjustment of the radial drilling machine, it is necessary to securely fix its crossbeam in the required position.

Installation of tools should be carried out only when the machine is completely stopped, avoiding cutting of hands against cutting edges. It is necessary to constantly monitor the reliability and strength of its attachment, as well as alignment. Changing the tool without stopping the machine can be done only if there is a special quick-change cartridge.

It is always necessary to rigidly and firmly attach the cutting and auxiliary tools. Ensure that the shanks of tools and mandrels are carefully fitted to the spindle cone. Before installing the tool, it is necessary to inspect and wipe the mounting surfaces, nicks on these surfaces are not allowed.

When the tool is fixed in the drill cartridge, the end of its shank must rest against the bottom of the cartridge seat.

When cutting threads with throwers, especially in blind holes, it is necessary to attach the tool in the safety cartridge.

Installation of blanks and clamps:

1. Before installing the workpiece on the machine, check the condition of the base surfaces. Securely attach the workpiece to the machine regardless of its size and weight, use only a serviceable tool when fixing.

2. When installing the workpiece on a set of dimensional liners, use as few of them as possible in height.

3. Attach the workpiece in places with solid supports; such attachment eliminates the possibility of deformation and breakage of the workpiece during processing.

4. As fasteners it is necessary to use high nuts, the support surface of which is hardened. Do not use nuts with crushed surfaces.

Methods of operation at drilling machine:

1. Before stopping the machine, it is mandatory to remove the tool from the workpiece.

2. When drilling holes, cut-in feed must be carried out manually, and mechanical feed must be switched on after full entry into the material of the cutting edges of the drill.

3. When the tool is blunted, broken, and the edges of the hard-alloy cutting inserts are painted, stop the machine and replace the tool.

4. Drill deep holes in two receptacles: first drill the hole to a depth of 5-6 diameters with a conventional drill, then to a given depth - with an elongated one.

5. During processing of deep holes, periodically remove the cutting tool from the hole and clean it with brush or brush from chips and supply LPG.

6. When drilling hollow blanks or blanks, in which the surface at the drill outlet is located at an angle to the axis of its rotation, use automatic feeding and use shaped liners.

7. When machining holes in thin plates and strips, they must be fixed in special devices.

When adjusting the drilling operation, it is necessary to pay attention to the state of the cutting tool, its reliable attachment, timely change, etc.

Zenkering is used mainly for the semi-finished treatment of drilled, cast and forged holes, occasionally for finishing. The accuracy achieved in this case corresponds to 9-12th square meters, and the surface roughness is 3.2-6.3 microns.

The sankers work like a drill when the hole is drilled. Therefore, many failure causes are similar to drilling failures.

Deployment is used for final treatment of holes with low roughness and high accuracy, it is carried out after preliminary treatment with drill, zenker or boring cutter.

The roughness of the holes after deployment is 0.63-2.5 microns, and the accuracy reaches 7-8th square meters.

In order to obtain improved processing accuracy, allowance is removed sequentially by several scans.

The causes of the problems, as a rule, are violations of processing technology, unsatisfactory adjustment of the machine, incorrect operation of the tool, etc.

4.2. Types and causes of wear of electrical machines

Electrical machines are most often damaged due to unacceptable long-term work without repair (wear and tear), due to poor storage and maintenance, due to disruption of the mode of operation for which they are designed.

All failures can be divided into two categories (due to the reason that caused the failure) - electrical, mechanical.

Electrical failures include failures due to breakdown of insulation on the housing and between phases, breakage of conductors in the winding, closure between winding turns, violation of contacts and connections (soldered and welded), unacceptable reduction of insulation resistance due to its aging or excessive wetting, violation of inter-sheet insulation of magnetic conductors, excessive sparking in collector machines.

Mechanical failures include failures due to smelting of babbit in sliding bearings, destruction of separator, balls or rollers in rolling bearings, deformation of rotor shaft, formation of deep tracks on surface of collector or contact rings, weakening of attachment of pole cores and stators to bed, breaking of bands or their sliding, weakening of core pressing, deterioration of machine cooling due to clogging of cooling channels.

Faults and damage to electrical machines causing a failure cannot always be detected by external inspection, since some of them (mainly electric) are hidden and can only be detected after the corresponding tests and disassembly of the machine. The work on pre-repair detection of faults and damages of electrical machines is called defect.

Consider the typical causes of electrical machine failure.

Breaking the insulation of the rotor winding onto the housing leads to a slow increase in rotation speed during the start of the asynchronous motor. The rotor is highly heated even at low load. Failure of insulation between contact rings and rotor shaft leads to the same phenomena.

Breakdown of insulation between phases leads to short circuit in the winding. When the stator winding is short-circuited, strong vibrations of the AC motor are observed, which stop after disconnecting it from the network, strong humming, asymmetry of currents in the phases, rapid heating of individual sections of the winding. In case of short circuit of phase rotor winding, the same effect is observed as in case of failure of insulation between contact rings and shaft.

Breaking the conductors of the stator winding of the asynchronous motor causes current asymmetry and rapid heating of one of the phases (in the extreme mode - phase break, the rotor does not rotate or its speed is small, there is strong noise and rapid heating of the engine).

Breakage of the short-circuited rotor winding rod leads to increased vibrations, reduction of rotation speed under load, pulsations of stator current sequentially in all phases. Winding short circuit of stator or rotor winding results in excessive heating of electric machine at rated load.

Disruption of contacts, solder or welded joints in asynchronous motors is equivalent in manifestation to a break in turns, rods of short-circuited windings or winding phase depending on the location of this connection.

Disruption of contact in the brush chain leads to increased sparking between the contact rings and the brushes.

Unacceptable reduction of insulation resistance can be due to severe contamination of insulation, humidification and partial destruction caused by aging insulation.

Violation of the inter-sheet insulation of the cores of magnetic conductors leads to an unacceptable increase in the temperature of individual sections of the magnetic conductor and the entire magnetic conductor as a whole, increased heating of the windings, burnout of part of the magnetic conductor (fire in steel).

Butterfly smelting in sliding bearings and excessive wear of rolling bearings lead to violation of alignment of shafts of electric machine and mechanism, to appearance of rotor eccentricity. The smelting of the babbit causes an increase in the vibrations of the electric machine, which do not disappear after it is disconnected from the network.

Wear of rolling bearings leads to the appearance of large single-sided attraction forces, as a result of which the engine does not develop a nominal speed, and its operation is accompanied by strong humming. Increased vibrations may also result from imbalance of rotating parts (rotor, half-couplings or pulley). Deformation of the rotor shaft leads to the appearance of eccentricity of the rotor and large forces of one-sided attraction.

Weakening the attachment of poles and stator cores leads to increased vibrations that disappear after the machine is disconnected from the network.

The loosening of the magnetic core sheets causes noise and increased engine vibrations.

Clogging of cooling (ventilation) channels leads to unacceptable heating of the electric machine or its individual parts.

The production of the manifold and contact rings leads to deterioration of switching, rapid wear of the brushes and increased heating of the contact rings and the manifold.

The same effects can be caused by different causes. This often does not make it possible to unambiguously name the malfunction of the electric machine by its external appearance, but forces to limit itself to a list of possible malfunctions that will be specified during the defect with a view to their subsequent elimination.

Conclusion

The following issues were considered and analyzed in this thesis:

main requirements for the electrical equipment of the radial drilling machine.

studied the electrical equipment required for the operation of the radial drilling machine, analyzed the operation of the schematic diagram.

calculation and selection of electric motor power of radial drilling machine. Check calculation of power circuit elements was performed, protection and control equipment was selected.

analysis of malfunctions occurring during operation of the radial drilling machine, the causes of their occurrence and methods of troubleshooting.

In the graphic part of the project there is an electrical schematic diagram of control of the electric drive of the radial drilling machine. The principle of operation of the selected electrical equipment and the entire control circuit of the machine is described.

Work on the diploma project allowed me to systematize and consolidate the knowledge of the device and the principle of operation of electrical and electromechanical equipment, as well as consolidate the skills in calculating the main parameters of electrical equipment.

Схема принципиальная.cdw

Общий вид.cdw