Design of vertical milling machine 6P13F3

Introduction

The development of machine tools determines the level of all machine-building production, since metal-cutting machines with their high productivity, accuracy and versatility are the main type of technological equipment for the dimensional processing of parts.

The need for improvement - modernization of machines is primarily associated with the development of R&D, in a word, modernization is driven by progress. The main provisions characterizing the technical level of the machine-building production fleet include the study of consumer properties of metal-cutting machines, their technical characteristics and areas of use, peculiarities of kinematics and structural design, automation capabilities provided by various control systems.

Machines occupy a special place among such machines as textiles, light industry machines, printing machines, etc., that is, for the production of means of production. Therefore, machine tool engineering is called the core of mechanical engineering.

Modern metal cutting machines are highly developed machines that consist of a large number of mechanisms and use mechanical, electrical, electronic, hydraulic, pneumatic and other methods of movement and cycle control. Behind the design and purpose, it is difficult to find more diverse machines than metal cutting machines.

Modern metal cutting machines are characterized by a very high technical level compared to other technological machines.

The main factors affecting the development of machine tool building include:

  increase of cutting speed to the level, maximum permissible from the point of view of machine operation safety; according to European standards, such speeds exceed 1000 m/adin (currently up to 100,000 m/min), and the process is called "ultra-high speed processing";

 treatment with a laser beam used as a tool;

 treatment without the use of lubricating cooling process means (SOTS), which are one of the main sources of environmental pollution;

  precise processing of parts from hardened steels on lathes, which makes it possible to exclude expensive and environmentally dirty grinding process.

Process system - machine consists of several functional subsystems:

The manipulation subsystem ensures delivery of the workpieces to the processing site, their clamping in a given position, removal of the finished part from the working zone;

The control subsystem, based on the input external information to the additional internal information, ensures the correct functioning of all other subsystems in accordance with the task.

The machine is divided into several main units.

The main drive of the machine drives the tool or workpiece to carry out the cutting process at a certain speed. The feed drive is required to move the tool relative to the workpiece to form the surface to be treated. The main motion drive shall provide constant cutting power during cutting and the supply drive shall provide constant torque Mkr.

Specification for Special Machine Design

Design a vertical NC milling machine with detailed development of the main motion drive.

The machine is designed to perform a variety of milling operations in single and serial production.

Technical characteristics

Spindle speed range, rpm: 700-1200

Main motion drive: Electromechanical

Feed control range, mm/min

- Longitudinal feed: 5-150

- Cross feed: 100-200

-Vertical feed: 150-1500

Feed Drive: Electromechanical

Workpiece Material: Carbon Steel

Machine Layout and Design

3.1. Analysis of structures of existing machines

Machine layout is a system of arrangement of machine units and guides characterized by structure, proportions and properties.

The process diagram of the machine construction, in which, in accordance with the process task, the composition of working and installation movements, the number of necessary spindles, the processing scheme, the number of different positions and dimensions are determined, is called the process layout.

Milling machines are mainly equipped with rectangular and contoured ECU.

With rectangular control, the machine table moves in a direction parallel to one of the coordinate axes, which makes it impossible to process complex surfaces. Rectangular control machines are used for milling planes, bevels, slots, equally high bosses and other similar surfaces.

With contour control, the path of the table movement is more complex. Contour-controlled machines are used for milling various cams, dies, molds and other similar surfaces. The number of controlled coordinates is usually three, and in some cases four and five. At contour control the shaping movement is performed on at least two coordinate axes simultaneously.

In CNC milling machines, asynchronous motors (in these cases there is a speed box) or DC motors are used as the main motion drive. On small milling machines with a rectangular CNC, a single-wire DC electric motor and a gearbox with automatically shiftable electromagnetic couplings are used, and on heavy machines with

contour control every controlled coordinate displacement is performed from independent DC electric drive.

CNC milling machine feed drives have short kinematic chains that transmit movements from the motor directly to the actuator.

3.2. Select and describe the proposed layout and

machine structure

The NC milling machine is cantilever, that is, its table has working movements in the horizontal plane (along the x and y coordinates) and (together with the cantilever) installation movements in the vertical direction (along the w coordinate); working movement along z coordinate has slider with milling head installed on it.

The machine is designed for processing of flat or spatial articles of complex profile made of steel, cast iron, hard-to-process and non-ferrous metals, mainly with end and end cutters, drills in single and serial production of metalworking industries.

The machine is equipped with a numerical software control device of H332M type, which allows to process products in the software control mode simultaneously by three coordinates.

Pulse-phase tracking system of program control with input of information on perforated tape is used in machine.

The layout of a NC vertical-milling cantilever is not much different from that of a traditional NC-free machine. Machine units and mechanisms are mounted on the bed. Frame front has guides closed by casing, along which cantilever moves. On horizontal

rails are mounted along longitudinal rails

of which the table moves. Fixed on welding plane of bed

milling head, along vertical guides of which slider with spindle moves. In accordance with safety requirements, the slider has a protective shield. Behind the machine there is a cabinet with electrical equipment and ECU.

Machine lubrication system [12]

The lubrication system shall ensure reliable lubrication of all the main friction joints of the machine. Due to this, wear of the mechanisms is reduced, noise during the operation of the machine is reduced and its efficiency increases.

The choice of lubricant for machine tools is complicated by the fact that they have a variety of friction pairs operating at different speeds and loads. The use of different lubricants would unduly complicate the design of the lubricating system and make it difficult to operate such a machine. The most advanced centralized lubrication system provides sufficient reliable lubrication of all main units.

Lubrication of bearings and gears of rotary head of designed overtikalfshared machine is performed from bed pump, and lubrication of bearings of spindle and mechanism of sleeve movement is performed by syringing.

Lubrication of the speed box is carried out from a plunger pump driven by an eccentric. The pump capacity is about 2 l/min. Oil is supplied to the pump through the filter. Oil is supplied from the pump to the oil distributor, from which it is diverted through the pipe to the eye of pump operation monitoring and through a flexible hose to the rotary head. The speed box elements are lubricated by spraying oil coming from the holes of the oil distributor tube located above the speed box.

Lubrication of the switchgear is performed from the speed gearbox lubrication system by oil spraying. The absence of oil rain can cause unacceptable heating of the cheeks of the switching forks and lead to jamming of the forks, their deformation or breakdown.

Lubrication of the supply box is performed by spraying of oil supplied from the console lubrication system. In addition, in the lower part of the cantilever plate there is a hole (drilling into the delivery cavity of the lubrication pump) through which lubricant is supplied to the oil distributor of the supply box.

Two pipes are removed from the oil distributor: on the eye of pump operation control and for lubrication of bearings of the II axis. Oil is supplied directly through oil distributor for lubrication of friction clutch bearings.

Proposed system comprises plunger pump, spool distributor, oil distributor and tubes extending therefrom to feed oil to bearings, gear wheels, transverse and vertical displacement screws. Plunger lubrication pump of the cantilever, feed box, mechanisms of the "tabletop" unit sucks oil through the filter mesh from the oil bath and supplies it through the tube to the spool distributor. Pipes are removed from the spool distributor: for lubrication of vertical guides of the cantilever, to the connector of flexible hose of lubrication of the "tabletop" unit and to the oil distributor of the cantilever. The pump capacity is about 1 l/min.

Machine Design Control System [13]

7.1 Numerical Software Control Device

The machine of model 6RF337 is equipped with the ECC of model N332M. In the upper part of the panel there is a strip 8 of light numerical information, on which the frame numbers of control program VII, tool numbers and three-bit correction numbers are displayed using special lamps. Light annunciator 1 informs about the progress of SR execution. In case of any problems, the inscriptions 2 (Machine Failure) or 3 (NC Failure) are displayed. During normal operation the inscription 4 ("Automatic") and indicators informing the operator about the place (address) of command execution are displayed.

Keys 5 ("Drive"), 6 ("NC") and 7 ("Process shutdown") are used to confirm UP commands recorded on the punch tape. The same keys are used in Manual Input mode.

Under the name "Address" there are keys indicated by letter symbols of the code and serve to address various types of commands introduced into ECC during operation in "Manual input" mode.

During adjustment from ECC, correction is carried out from the process panel 9 located below the main ECC panel. 18 decadal switches 10 are arranged on the panel 9, on which four-digit numbers can be dialed. Below the process panel is placed a photo reader "Consul 3376," coming from a reader 11 reading the head 12, two reels 14; the latter are used for winding and winding of tapes with UP recording. On panel 9 there are also control keys: 16 (start); 17 (direction of the tape to the left); 18 (direction of the tape to the right); 19 (turning off the photo reader).

7.2 Main technical characteristics of ECU of "N33-2M" type

Interpolation is linear and circular.

How to specify geometric information in the program in increments.

The discrete setting of geometric dimensions is 0.01 mm. Interpolation accuracy ± 1 is discrete without error accumulation.

The number of program-controlled coordinates is 3, of which simultaneously controlled during linear interpolation 3, during circular interpolation 2.

The device allows the development of line segments specified in one frame with a value for each coordinate up to ± 999999 units of discreteness, circular arcs - with a radius of up to 999999 units of discreteness.

Machine accuracy control diagram [6]

The geometric and kinematic accuracy of the machine characterizes the accuracy of movement of its forming units without power and thermal effects. Therefore, these characteristics are mainly related to the accuracy of manufacturing and assembly of the machine, that is, to technological factors. High requirements for the accuracy of modern machines determine strict tolerances for the accuracy of movement and position of working elements related to the geometry of the machine, as with its initial characteristic.

By accuracy, machines are divided into five classes:

Class H - machines of normal accuracy, provide processing of parts according to approximately 8-7 accuracy standards.

Class P - machines of increased accuracy, are made mainly on the basis of machines of class H, but with higher requirements for the accuracy of basic parts (spindle and its supports, filling, etc.).

Class B - machines of high accuracy, which are provided due to the special design of individual elements, higher quality of their manufacture and operation in special conditions.

Class A - machines of particularly high accuracy, manufactured with stricter tolerances than machines of class B.

Class C - ultra-precision machines - special masters - machines designed for the manufacture of precision parts of machines, machines and devices, the accuracy of which depends on obtaining the required characteristics of the product (dividing and reference wheels, measuring screws, etc.).

Permissible deviations for standard-regulated accuracy indicators of machine tools during the transition from class to class make up geometric progression with denominator A = 1.6.

The standards "Standards of accuracy" also include a check of accuracy and roughness of the sample product, the configuration and material of which

are set by the standard. Sample is treated at finishing modes. The results obtained cannot serve as a sufficiently complete characteristic of the accuracy of the machine, and for this purpose special tests are required that take into account the entire range of power and heat loads and the characteristic of the range of processed parts.

The list of accuracy checks and the relevant standards specified in the standards reflect the specifics of the machines of this type and the processing method used. By the nature of the check, you can divide into the following groups.

1. Accuracy of movement: radial and axial run-out of the spindle, end and axial run-out of the faceplate (table); straightforward movement of caliper (table); constant angular position of the table working surface during its movement; precision of discrete movements.

2. Accuracy of mutual position and movement; parallelism of spindle axis caliper motion, perpendicular to spindle axis to table surface; the alignment or parallelism of the two spindles; mutual perpendicular of longitudinal and transverse movement of table.

3. Positioning accuracy (setting): accuracy of table (caliper) movement to the specified position; accuracy of angular position fixation at turning of the turret (spindle unit), accuracy of manual setting of linear (angular) positions of the working tool by measuring scales.

4. Kinematic accuracy: accuracy of the spindle-lead screw ratio (turning-screw machines); accuracy of longitudinal and transverse movement of the cross table (processing of shaped profiles); accuracy of mutual movement (rotation) of spindle and table (tooth-cutting machines.)

5. Precision of workpiece and tool position surfaces: table working surface flatness, T-o accuracy

different slots of the table and their parallelism; accuracy of spindle conical hole position; end and radial run-out of spindle base surfaces (flange end).

6. Precision of guide surfaces: flatness of slide guides, flattness of guides.

For normal precision machines, as a rule, not all errors are measured, but only those that most affect processing accuracy (for example, table positioning accuracy; radial and axial run-out of the spindle). The higher the accuracy requirements of the machine (higher its accuracy class), the more parameters characterizing the position and movement of the unit are measured.

Various metrological means and equipment are used to determine geometric and kinematic accuracy of the machine. If during the main checks (groups 1 - 4) characterizing the output parameters of the machine, the applied measurement method allows to evaluate these parameters not only during the movement of units without loads, but also during the working modes of the machine (during processing), up to the obtained results will fully characterize the accuracy of the machine taking into account its power and thermal deformations. For this purpose, contact measuring devices, often used to check the geometric accuracy of the machine, are usually not suitable.

Table 9 shows examples of schemes for measuring the geometric and kinematic accuracy of stakes using contact methods used in standard checks and modern methods; allows to evaluate parameters of machine mass units trajectories. Diagrams of the following accuracy checks are given:

and a ) measuring the radial and axial run-out of the spindle.

b) measuring the radial and axial run-out of the spindle and the path of movement of the spindle axis,

c) measurement of deviation from perpendicular of spindle axis

relative to the table surface;

d) measuring the deviation from the perpendicular of two movements (table and spindle head) using a calibrated laser source;

e) measurement of table positioning accuracy;

f) measurement of table positioning accuracy using a laser interferometer;

g) measuring the accuracy of the spindle-caliper ratio "using a reference lead screw;

and h ) measuring the accuracy of the spindle-caliper ratio using a laser interferometer.

Operation of the machine [3]

Machine maintenance. Check the ease of moving the machine table in all directions with manual feeds, if necessary loosen the locking devices and set the table in a position convenient for setting the cutter.

If vibrations occur, stop the machine and take measures to eliminate them, check the condition and attachment of the cutter, reliability of the workpiece and accessory attachment, selected cutting modes.

Install and change the mill. Before installing the cutter on the machine, check:

Sharpening quality - cutting edges must not have decorations, cracks and burns;

The reliability and strength of the cutting teeth in the cutter body, as well as the degree of their wear, provided that the cutter was in operation; If the cutting edges of the cutter are blunted or crumbled, the cutter must be replaced;

The mounting surfaces of the cutter, mandrel, adapter bushings, collet and spindle, as well as the end faces of the mounting rings, so that they do not leave dirt and fibers from wiping material.

When installing and removing the cutters, guard against hand wounds to the cutting edges. To do this, it is necessary to use sleeves or pre-put casings covering its cutting teeth on the cutter.

When fixing the shank of the mandrel or cutter in the spindle of the machine, make sure that it sits tightly, without play. Locking is performed by turning on the speed box to avoid spindle turning.

After fixing the cutter, check the beating of its cutting edges. Set the speed and feed boxes to the specified modes, as well as install and attach the stops of automatic shutdown of feed.

To remove the cutter or mandrel from the table, use a special puncture, having previously placed a wooden tray on the machine table, preventing damage to both the tool and the machine table.

Installation of blanks and clamps. Before placing the blanks on the machine table or in the accessory, clean them from contamination; Pay special attention to the state of the base surfaces if there are burrs, grates and other irregularities on the base surfaces, remove them with a locksmith tool.

The workpiece attachment points should be selected as close to the surface to be treated as possible. Special attention should be paid to the state of the table surface.

Before placing the workpiece on the machine table, it must be thoroughly cleaned of dirt and chips. If the workpiece is attached to untreated surfaces, notched grips shall be used.

If processing is performed in the appliance, the following works shall be performed:

Before installation of the accessory wipe the table and seats of the accessory;

When raising the position of the accessory on the machine table, use only hammers with inserts made of soft material (copper, brass);

If the blank is attached to untreated surfaces, it is necessary to equip the clamps with clamping jaws with a notch;

By securing the workpieces in the clutches to the treated surfaces, they must be equipped with soft metal loaders;

When fixing cylindrical blanks in the cartridge of the dividing head, split sleeves made of soft metal should be used and foil should be laid.

Remove chips from the table after removing each processed part using capron, hair or bristle brushes.

.

Install and remove heavy blanks and accessories (with weight more than 20 kg) using lifting devices only; It is allowed to release the workpiece from suspension only after its installation and reliable fixation on the machine.

Milling Machine Techniques:

The workpiece is fed to the cutter only after turning on the spindle rotation, while the mechanical feed is turned on until the cutter contacts the workpiece;

Before stopping the machine, it is necessary to first turn off the feed, then remove the mill from the machined part and turn off the rotation of the spindle;

Remove the cutter to a safe distance so as not to damage the hands on its cutting edges when removing the machined part or measuring it on the machine;

Adjust correctness of LPG supply to cutting zone;

Avoid placing cutting, auxiliary and measuring tools, as well as other workpieces and previously machined parts on the machine table.

Conclusion

During the course project, a special vertical milling machine with CNC was developed, skills were gained in the design of drives of the main movement and feed movement, and in the selection of motors for these drives.

During the course design, a kinematic calculation of the main movement drive was carried out.

In the process of working on a course project, the obtained theoretical knowledge was better applied.

List of literature used

1. Handbook of Technology and Machine Builder/Ed. A.G. Kosilova and R.K. Meshcheryakova. M.: Mechanical Engineering, 1985. T.1. 656 pages, T.2. 496 pages.

2. Eremin A.N. Methodological foundations of course design of metal cutting machines. Tomsk, Publishing House of TSU, 1973. – 250 pages.

3. Cherpakov B.I. metal cutting machines: a textbook for beginning professional. education - M.: Ed. Academy, 2003. – 368 pages.

4. Charisomenov I.V., Charisomenov G.I. Electrical equipment of machine tools and automatic lines. M.: Engineering, 1987. – 224 pages.

5. Chernov N.N. Metal cutting machines. M.: Engineering, 1978. – 389 pages.

6. Designing Metal Cutting Machines and Machine Tools: Tutorial. Under the commonly. Ed. A.S. Pronikova. - M.: Publishing House of Bauman Moscow State Technical University: Mechanical Engineering, T.1., 1994. -444s, T.2.1., 1995-371s., T.2.2., 1995-320s.

7. Course design of machine parts/Ed. A.S. Chernavsky. M.: Engineering, 1988. – 416 pages.

8. Scheinblit A.E. Course design of machine parts. M.: Higher School, 1991. – 432 pages.

9. Tepinkichiev V.K.. Metal cutting machines. M.: Mechanical Engineering, 1973.- 472 s.

10. Tarzimanov G.A. Designing metal cutting machines. - M.: Engineering, 1980. – 288 pages.

11. Machine tools for automated production. Textbook under. ed. V.V. Bushueva. In two volumes. M.: Stankin, 1994.

12. Sukhinina L.A. et al. Design and calculation of a metal cutting machine. Methodological guidelines. Almetyevsk, AGNI, 2009. – 128 pages.

13. Holofteev S.A. Laboratory workshop on the course "Metal cutting machines." - M.: Higher School, 1991. – 240 pages.

Material Inventory

1. Calculation and explanatory note:

Pages 59;

Figures 7;

Tables 11;

2. Graphic Material:

1.2. General view of the machine in 2 projections - A1

2.2. Kinematic scheme of the machine - A1

3.2. Development and convolution of speed box - A1

4.2. Shpindelny knot - A1

3. Application:

1 Machine Specification

2. Speed box specification

3. Spindle Assembly Specification