Milling machine and its components. Modern metal milling machines - types, features, purpose. Milling machines and work performed on them

This is equipment for processing shaped and flat metal workpieces with screw and straight generatrices. Using machines, you can make grooves, grooves, holes, apply internal and external threads, as well as produce a number of other technological operations. Depending on the direction of movement of the working body, horizontal and milling machines are distinguished. The main components and mechanisms in both types of equipment are the same, except for the support and trunk, which are not present in the vertical modifications.

Base

The base is made of solid cast iron. When installing the equipment, one side of the part fits tightly to the floor, and the other side is bolted to the frame.

The base also has a special trough into which coolant is collected, and an electric pump for supplying coolant to the tool.

bed All the main components and mechanisms of the milling machine are attached to the part. Spindle, gearbox

, the engines are hidden inside the structure, and the remaining units are mounted on external surfaces. In the upper part of the frame there can be horizontal guides for moving the trunk, on the front wall - vertical guides for the console or spindle head. The part is reinforced from the inside with stiffening ribs. The frame can be cast or welded. The first option is considered more reliable and durable, but welding produces more complex structures.

Trunk (creeper) This unit is available on horizontal and horizontal milling machines. universal type and is rarely found on CNC machines. The main purpose of the trunk is correct installation and reliable support of the mandrel

. The mechanism is mounted on horizontal guides of the frame and allows for changes in reach, that is, the distance to the mirrors. When processing massive parts, when chips of a large cross-section are obtained, special supports are used for additional fixation of the workpiece, which form a connection between the trunk and the console.

Console The operation of the equipment largely depends on the rigidity of the console and the accuracy of its guides. Supports are attached to the element using two bolts, which ensure the stability of the entire system during operation. On non-cantilever machines, vertical movement is organized by the spindle head along vertical guides

Sled

Purpose of the mechanism- ensuring the relationship between the X and Y axes. The upper guides of the slide are used to move the table in the longitudinal direction, and the lower ones are used to move the slide itself along the console guides.

Table

The main working element of a milling machine, which moves on a slide. On the surface of the table there are clamping and other fixing devices for firmly securing workpieces. For this purpose, the part has longitudinal grooves. The joint operation of the table, console and slide ensures the supply of the workpiece to the cutter. Movement in longitudinal, vertical and transverse directions is possible. Typical equipment usually has manual and mechanical feed. The use of one method or another depends on the tasks:

• For idle runs and installation movements of the table, a manual, mechanical method is used
• For working feed, mechanized feed is most often used.

Additionally, the possibility of rapid movement of the table is provided, the so-called rapid movement in all three directions. The movement is carried out at a constant speed ( most of machines are equipped with an additional clutch or high-speed motor), while the working feeds have a multi-stage shift box. The operator independently selects the mode depending on the material of the workpiece and cutter, as well as the type of processing.

Spindle

One of the main mechanisms of standard equipment, the purpose of which is to transmit torque from the gearbox to the cutting tool. The part is made rigid, durable, with high accuracy sizes, since the correctness and quality of operation of the mandrel with the mounted cutter depends on its parameters. The spindle is made of alloy steel and undergoes thermal hardening, grinding, and balancing.

Electric motors

Main movement - rotates the spindle, located in the spindle headstock or column.

Working feeds, rapid movements - fixed to the feed box

Moving the console - mounted on the console, if available

Coolant supply. Located in a tray or chip collector. Other auxiliary equipment- located in places chosen by the manufacturer.

Gearbox

By rotating the gears and switching them, the force from the electric motor is transmitted to the spindle. The mechanism also allows you to adjust the speed cutting tool.

Gearbox

The purpose of the unit is to change the table feed speed in all three directions.

Conclusion

In general, we can say that typical milling machines of various types and purposes consist of three main parts:

• motor (electric motor, gearbox and spindle);
• transmission (a set of devices that transmit rotation from engines to executive bodies);
• executive (table, support, spindle, cutting tool).

Control systems are also present in almost all models of modern standard equipment. There are many CNC options, each of them has its own advantages and disadvantages.

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Milling machines designed for processing external and internal flat, shaped surfaces, ledges, grooves, straight and helical grooves, splines on shafts, cutting gears, etc.

The designs of milling machines are varied. They produce universal, specialized and special milling machines. The main shaping movements are the rotation of the cutter (the main movement) and the feed movement, which is imparted to the workpiece or cutter. The main movement and feed drives are operated separately. Auxiliary movements associated with the supply and removal of the workpiece to the tool are mechanized and carried out by a drive of accelerated movements. The main elements of machine mechanisms are unified. The main parameter characterizing milling machines general purpose, is the size of the working surface of the table.

IN general case milling machines can be divided into two main groups: 1) general purpose or universal (vertical milling, horizontal milling, longitudinal milling); 2) specialized and special (slot-milling, key-milling, rotary-milling, copy-milling, etc.). Based on their design features, these machines are divided into

Rice. 119. Milling machines:

A - universal cantilever horizontal-milling, b - wide-universal cantilever horizontal-milling, c - wide-universal cantilever-less milling, d cantilever vertical-milling, e - non-cantilever vertical-milling, f - non-cantilever horizontal-milling, g - longitudinal milling, h - rotary-milling, and - drum-milling

On console (the table is located on a lifting bracket-console), non-cantilever (the table moves on a fixed frame in the longitudinal and transverse directions) and continuous action (carousel and drum).

In single, small- and medium-scale production, cantilever milling machines are the most common. Universal con-

A solo horizontal milling machine (Fig. 119, a) has a horizontal spindle 2 and a retractable trunk 7, on which an earring J is installed, supporting a mandrel with a cutter; the console 4 moves along the guide of the rack 5. The console contains a slide 6 and a table 7.

A widely universal cantilever horizontal milling machine (Fig. 119; b), in addition to a horizontal spindle, has a spindle head 7, which can be rotated on the trunk in two mutually perpendicular directions, due to which the spindle with the cutter can be installed at any angle to the table plane and to the workpiece being processed . On head 1, an overhead head 2 is mounted, intended for drilling, reaming, countersinking, boring and milling.

A cantilever vertical milling machine (Fig. 119, d) has a vertical spindle J, which is located in a rotating spindle head 2 mounted on a rack 7. Non-cantilever vertical and horizontal milling machines (Fig. 119, e, f), used for processing workpieces of large-sized parts, have a slide 2 and a table 3, which move along the guides of the frame 7. The spindle head 5 moves along the guides of the rack 6. The spindle 4 has axial movements when installing the cutter.

Longitudinal milling machines (Fig. 119, g) are designed for processing blanks of large-sized parts. On the frame there are installed two vertical posts 6, connected by a cross member 7. Milling heads J with horizontal spindles and a traverse (cross member) 4 are mounted on the guide posts. Milling heads 5 with vertical spindles are mounted on the latter. Table 2 moves along the guides of racks 4.

Rotary milling machines (Fig. 119, h), designed for processing surfaces with end mills, have one or more J spindles for finishing and roughing. The spindle head 2 moves along the guides of the rack 1. The table 4, rotating continuously, imparts feed rotation to the workpieces installed on it. The table with slide 5 has an installation movement along the guides of the frame 6. Drum-milling machines (Fig. 119, i) are used in large-scale and mass production. The workpieces are installed on a rotating drum 2, which has a feed movement. Milling heads 3 (for roughing) and 1 (for finishing) move along the guides of the racks 4.

Widely versatile cantilever horizontal milling machine mod. 6Р82Ш. The machine is used to perform various milling operations, as well as drilling and simple boring work in workpieces made of cast iron, steel, and non-ferrous metals. The machine can operate in semi-automatic and automatic modes, which makes it possible to operate multiple machines. In Fig. 120, 121, 122 shown

Respectively general form, main components and kinematic diagram of this machine.

Technical characteristics of the machine. The size of the working surface of the table (length x width) 1250 x 320 mm; maximum table movement: longitudinal - 800 mm, transverse - 240 mm, vertical - 360 mm; number of spindle speed steps 18; spindle speed limits 31.5-1600 min"1; number of table feeds 18; longitudinal and transverse feed limits 25-1250 mm/min, vertical - 416.6 mm/min; machine dimensions 2305 x 1950 x 1680 mm; weight 2830 kg.

Kinematics of the machine. The drive of the horizontal spindle (main movement) is carried out by an electric motor Ml through gears - 208

Redachi. The number of speed stages is equal to the number of transmission ratio options from the electric motor to the spindle, i.e. 3 x 3 x 2 = = 18. Minimum rotation speed n^ = 1460 [ (27/53) x (60/38) x x (17 /46) x (19/69) = 31.5 min"1; maximum bird = 1460 x (27/53) x x (22/32) x (38/26) x (82/38) = 1600 min1.

The spindle of the rotating head is driven into rotation by the M2 electric motor through gears. Number of rotation stages 2x3x2=12; lp1i11 = 1430 x (28/72) x (34/66) x (21/59) x (28/28) x (19/19) = = 1600 min"1.

The drive of the table feeds in the transverse and longitudinal directions is carried out through gears from the MZ electric motor. Minimum table feed fc in the indicated directions = 1430 x x (26/50) x (26/57) x (18/36) x (18/40) x (13/45) x (18/40) x (28/ 35) x (18/33) x x (33/37) x (18/16) x (18/18) x 6 = 25 mm/min, L^x = 1430 x (26/50) x (26/ 57)x x (36/18) x (24/24) x (40/40) x (28/35) x (18/33) x (33/37) x (18/16) x (18/18) ) x cotton = 1250 mm/min.

Accelerated table feed in longitudinal and transverse directions 5U = 1430 x (26/33) x (28/35) x (18/33) x (33/37) x (18/16) x (18/18) x 6 = =3000 mm/min.

Maximum table feed in vertical direction<5вшах =1430 х (26/50) х (26/57) х (36/18) х (24/34) х (40/40) х (28/35) х (18/33) х х(22/33) х (23/46) х 6 = 1000 мм/мин.

The gearbox of the spindle drive of the rotating head 6 moves along the guides of the frame 1 (Fig. 121) by rotating the flywheel 75 (Fig. 120) with the clamp 39 released.

The horizontal spindle gearbox is located in the frame and connected to the electric motor shaft by an elastic coupling. Spindle 11 of the machine (Fig. 123) is mounted on bearings 4, 2, 12. The axial clearance in the spindle is adjusted by grinding rings 9,10. Increased clearance in bearing 4 is eliminated by grinding half rings 5 ​​and nut 1 as follows. Remove cover 3 (or side cover), flange 6, spring ring 7, rings 8 and take out half rings 5. Using nut 1, select the gap so that during operation the heating of the bearings does not exceed 60 ° C. Measure the size of the gap between the bearing and the spindle collar and Accordingly, the half rings 5 ​​are polished. Then the half rings are installed and parts 6, 8, 7, 3 are mounted.

The gearbox (Fig. 124) allows you to select the required speed without sequentially passing through intermediate stages. Rack 1 (Fig. 124, a), moving by means of a handle through gear sector 2 and fork 10 (Fig. 124, b), moves the main roller 3 with shift disc 9 in the axial direction using gear 2 and bushing 4. On the disc There are several rows of holes located opposite pins 8 of racks 5 and 7, connected in pairs to wheel 6. A shift fork is attached to one of each pair of racks. The slats move when the disk is pressed on the pins. At the end of the disk stroke, the forks occupy a position corresponding to the engagement of certain pairs of gears. When selecting speeds, the dial is fixed by ball 1 (Fig. 124, b), which falls into the grooves of sprocket 11. Handle 5 (Fig. 124, a) is fixed when turned on by ball 3 and spring 4; in this case, the handle tenon fits into the groove of the flange.

The rotating head (Fig. 125) is mounted on the trunk through the intermediate plate using bolts inserted into the annular T-shaped groove and centered in the annular recess. The spindle 8, mounted in a sliding sleeve 9, receives rotation from the gearbox through a cam clutch 1 and conical wheels 4, 2 and 5, 4. Wheels 7 and 3 are used to adjust the axial clearance in the bearings and spindle, and half rings 2 and nut 6 - for eliminating the gap in the front bearing. The sleeve is advanced using a handwheel.

The overhead head (Fig. 126) is mounted on the rotary head with bolts entering the T-shaped groove and firmly fixed. Spindle 5 receives rotation from spindle 1 of the rotary head through bevel gears 3, 4. Use a nut to adjust the clearance in the spindle bearings.

The feed box (Fig. 127, a) provides working feeds and installation movements of the table, slide and console by switching 2-Y

Blocks of gear wheels and transmission of rotation to input shaft B through a ball safety clutch, cam clutch 4 and bushing 3, connected by a key to clutch 4 and shaft B. Stopper 1 rigidly fixes the position of nut 15. When the feed mechanism is overloaded, the balls in contact with the hole of the clutch 2, the springs compress and come out of contact. In this case, wheel 14 slips relative to clutch 2, and the working feed stops.

Rapid rotation is transmitted from the electric motor (bypassing the gearbox) to gear C, which is installed on the shank of the friction clutch housing 9 and has a constant rotation speed. Nut 10 must be tightened. Housing 9 rotates freely. The friction disks are connected (one through another) to the housing 9 and the sleeve 12 connected to shaft B. When clutch 4 is pressed to the end

Bushings 5 ​​and then disks 7 and 8 onto nut 11 are connected and transmit rapid rotation to shaft B and gear A. Compression force of the disks

7 and is adjusted using pin 6. The movement from shaft B to the driven shaft is carried out through the cam clutch 13.

The feed switching mechanism (Fig. 127, b) is included in the feed box assembly. The principle of operation of the mechanism is similar to the operation of a gearbox. When turned on, roller 1 is locked by balls 6 and bushing 2, which prevents disk 9 from moving in the axial direction. When you press the ^ button, the balls fall into the annular groove

Roller 3 and roller 7 are released from fixation. Shift disk 9 is secured against rotation by ball 8 through bushing 5, connected by a key to ball 7. Screw 7 adjusts the spring tension.

The console (Fig. 128) combines the nodes of the machine feed chain. It contains shafts and gears that transmit movement from the feed box in three directions (to the longitudinal, transverse and vertical feed screws); mechanism for switching on transverse and vertical feeds. Gear 8 rotates from wheel A (Fig. 127, a) and transmits movement to gears 7, 4, 2, 1 (Fig. 128, a). Wheel 8 can transmit movement to the shaft only through cam coupling 6. Then, through cylindrical and bevel gears, the movement is transmitted to screw 16 (Fig. 128, b). The engagement of the pair 16 and 10 is adjusted by compensators 14, 15 and fixed with a screw inserted into pin 13. The sleeve 77 is not dismantled; the vertical movement nut is fixed in the column. Wheel 2 rotates shaft IX of the longitudinal chain through a key and splines. The cross-feed screw X rotates from wheel 2 and wheel 7, which is freely seated on the shaft, when the cross-feed clutch is engaged. Shafts XII and XIII are dismantled when removing the stoppers at wheels 8, 9.

The slide is dismantled after removing the shaft Ш, for which you need to remove the upper shield on the console guides, knock out pin 3 and remove shaft IX. The mechanism for activating the installation movements (Fig. 129) turns on the clutch and compresses the friction clutch discs. Lever 7 is pinned on axis 4. The latter is pressed in the direction of the frame mirror by spring 6. The right nuts 2 serve to adjust the spring force, the left nuts J, resting against the end of the sleeve 5, regulate and limit the stroke of the axis. The shoulder of the lever 7 rests on the cam 7. When the cam 7 is turned, the lever 7 moves, compressing the spring 6. The second end of the axis 8 has a fine tooth, which ensures the installation of the lever 9, which connects the axis 8 with the rod of the electromagnet at a slight angle. The latter is connected through a rod and a hinge to a fork, from which, through a nut and a spring, the force is transmitted to lever 9. Thus, regardless of the force of the electromagnet, the force on the lever is determined by the degree of compression of the spring.

The mechanism for switching on the transverse and vertical feeds (Fig. 130) controls the switching on and off of the cam clutches of the transverse and vertical feeds from the feed electric motor. Made in a separate building. When the handle 5 moves up, down, left, right, the drum 7 associated with it makes the corresponding movements and, with its bevels, through the lever system controls the inclusion of cam clutches, and through the pins - the limit switches intended for reversing the feed motor. The drum is connected by rod 2 with a backup handle. When turning the transverse stroke on and off, the rod moves translationally, and when turned on

Rice. 128. Console: a - development, b - section

Vertical stroke - turns. Screw 4 and nut 3 are used to eliminate gaps in the system.

The lead screw 1 (Fig. 131) of the table receives rotation through the sliding key of the sleeve 9, located in the bushings 5, 7. The sleeve 9 rotates from the cam coupling 6 through the splines when it engages with the cams of the sleeve 5, connected to the bevel gear 4. On the sleeve 5 there is a gear ring, which is in mesh with the gear wheel of the round table drive. Clutch 6 has a toothed ring for rotating the longitudinal feed screw from the handwheel. The slide is clamped to the guide console by faceplate 8. Wheel 9 (Fig. 132) is spring-loaded in case of tooth contact with tooth. Engagement of the wheels is only possible when coupling 6 and bushing 5 are disconnected. This blocks the flywheel during mechanical feeds. Nuts 2 and 3 of the lead screw (Fig. 131) are located on the left side of the slide. The gap in the console and slide guides is selected using wedges.

The mechanism for turning on the longitudinal feed (Fig. 132) turns on the longitudinal stroke clutch, turns on and reverses the feed motor. Handle 4 is fixedly connected to axis 2 by turning lever 7, along the curved surface of which roller 75 rolls when switching (Fig. 132). In the neutral position of the lever 10, the roller is located in the middle cavity; when it is turned on, it is in one of the side depressions. The movement of roller 15 through lever 16 is transmitted to rod 5 through wheel 7, rack 6 and fork 8, driving clutch 6 (Fig. 131). Spring 2 (Fig. 132) constantly presses on rod 5. Spring 4 ensures that the handle is turned on when a tooth hits the tooth of coupling 6. Spring 4 is adjusted by screw 3 through the hole in plug 7.

On the same axis with the lever 16 there is a lever 18, which serves to engage the clutch 6 with a cam 19 attached to the rod 20 connecting the main longitudinal stroke handle with the backup one. The limit switch 7 7 turns on and reverses the feed motor. It is turned off after clutch 6 is turned off. On the hub 5 (Fig. 133) of the longitudinal stroke handle there are protrusions that are acted upon by the longitudinal stroke limiting cams or (in automatic cycles) the longitudinal stroke control cams. The operation of the limit switches is checked with cover 14 removed (Fig. 132).

The automatic cycle mechanism is designed to control the table movements from the cams. On the axis of the longitudinal stroke handle, two sprockets are installed, directly connected to sprockets 6у 5 (Fig. 133) for switching on high speed when the machine is operating in an automatic cycle. Sprocket 6 rotates from a return spring cam located on the front side of the table in a T-shaped groove. Sprocket 3 has different depths of depressions, which means that when it is rotated 218

Rice. 134. Clutch locking mechanism

At 45° it provides a different amount of stroke for rod 2 (Fig. 134), which, acting on the limit switch, turns on the high-speed electromagnet.

The clutch locking mechanism (Fig. 134) is designed to prepare the machine for operation in the automatic cycle. When you press pinion shaft 2, rack 3 disengages from gear 4 and engages with pinion shaft 2. When shaft 2 rotates, the cam clutch moves and engages with the cam gear. From this moment on, the longitudinal stroke handle cannot be turned on. The clutch can only be locked with the handle in the middle (neutral) position. This is provided by a T-shaped slot in wheel 4 and a pin J installed in the slide body. When you press the gear shaft 2 with cone 1 and finger 13 (Fig. 132), the contacts of the limit switch are opened, blocking the circuit for switching on the transverse and vertical feed. This eliminates the inclusion of two movements at the same time when the cam clutch is locked: the table and the slide or the table and the console.

Dividing heads. The technological capabilities of milling machines are expanded by dividing heads. They serve for periodic rotation of the workpiece around an axis (when processing teeth, splines, grooves, etc.) at equal or unequal angles, as well as for continuous rotation of the workpiece, coordinated with the longitudinal feed of the machine table when cutting helical grooves. There are heads for direct division; multi-spindle; universal; optical. Dividing heads are equipped with accessories: spindle rollers; front center with leash; jack; clamps; center mandrels and cantilever mandrels for installing the workpiece; universal pads; tailstock; guitars with replaceable gears; three-jaw chucks.

When processing using a dividing universal head, the workpiece 1 (Fig. 135, a, b) is installed on a mandrel in the centers of the spindle 6 of the head 2 and the tailstock 8. The modular disk cutter 7 receives rotation, and the machine table receives a working longitudinal feed. After each periodic rotation of the gear blank, the cavity between adjacent teeth is machined. After processing the cavity, the table quickly moves to its original position. The cycle of movements is repeated until all the teeth of the wheel are completely processed.

The working position of the workpiece is set and fixed when the spindle 6 is rotated by handle 3 along the dividing disk 4 with a dial. A spring device fixes handle 3 when it enters the corresponding hole of the dividing disk. On the latter, eleven circles with numbers of holes 25, 28, 30, 34, 37, 38, 39, 41, 42, 43, 44, 47, 49, 51, 53, 54, 57, 58, 59 are concentrically located on both sides , 62, 66.

Universal dividing heads are divided into limb (Fig. 136, a, bc) and limbless (Fig. 136, d). The rotation of the handle 7 relative to the dial 2 is transmitted through gears 5, 6 and a worm gear 7, 8 to the spindle. The heads are configured for direct, simple and differential division.

Direct division. It is ensured by installing a dividing disk with 30 evenly spaced holes on the spindle. The disk is turned with a handle and the circle is divided

In 2, 3, 4, 5, 6, 15 and 30 parts. By using a special dividing disk, you can divide into unequal parts.

Simple division (Fig. 136, a) into Z equal parts is performed by rotating the handle relative to a stationary disk according to the following kinematic chain: 1/Z= Wp(Z5/2^) x (D/D), where (D/2$) x x(Zn/Zz) = /N pr - number of handle revolutions; N - head characteristic (usually N = 40). Then 1/Z= pr x (1/N), from where yar - N/Z= A/B, where B is the number of holes through which the handle needs to be turned. The sliding sector J (Fig. 135, a), consisting of two radial rulers, is moved apart by an angle corresponding to the number A of holes, and the rulers are fastened. If the left ruler rests against the handle lock, then the right one is aligned with the hole into which you need to insert the lock the next time you turn it.

Example. Set up the dividing head for milling the teeth of a cylindrical wheel with Z= 100. Characteristics of the head N- 40; Yar = N/Z= A/B = 40/100 = 4/10 = 2/5 = 12/30, i.e. A = 12 and B = 30. Thus, use the circumference of the dividing disk with the number of holes B = 30, and the sliding sector is adjusted to the number of holes A = 24. 222

Differential division is used when it is impossible to select a dividing disk with the required number of holes. If the disk does not have the required number of holes for the number Z, take a number close to Z, for which there is a corresponding number of holes. The difference (1/Z- is compensated by additional rotation

Spindle head for this difference. It can be positive (additional rotation of the spindle is directed in the same direction as the main one) or negative (additional rotation is negative). This is ensured by additional rotation of the dividing disk relative to the handle, i.e., if during a simple movement the handle is rotated relative to a stationary disk, then with differential division the handle is rotated relative to a slowly rotating disk in the same or opposite direction. Rotation of the disk is transmitted from the head spindle through replaceable wheels a - ly c - d (Fig. 136, b), a conical pair 9 and 10 and gears J and 4. The amount of additional rotation of the handle pr £ = N(/Z- l/Ztj, ) = (1/Z) x x(a/b) x (c/d) x (Z,/Z10) x (Z3/Z4).

We accept (2^/Z10)(Z3/^) = = C (usually C = 1). Then (a/b)(c/d) =N/C[(Zt> -

Example. Set up the dividing head for milling the teeth of a cylindrical wheel with Z = 99. It is known that N - 40 and C = 1. The number of handle revolutions for simple division pf = 40/99. Considering that the dividing disk does not have a circle with the number of holes 99, we take Z - 100 and the number of handle revolutions Pf = 40/100 = = 2/5 = 12/30, i.e. we take a disk with the number of holes around the circle B - 30 and when dividing, turn the handle into 12 holes (A = 12). The gear ratio of replacement wheels is determined by the equation: (d/6) x (c/rf) = 7V/C= [(2^, - Z)/2^] = =(40/1) [ (100-99)/ 100] = 40/100.

Limless dividing heads (Fig. 136, d) do not have dividing disks. The handle is turned one turn and fixed on a fixed disk 2. With simple division into equal parts, the kinematic chain has the form: /(a2/b2) x (c2/d2) x (Z3/Z4) = 1/Z.

Considering that Z3/Z4 = /V, we obtain (a2/b2) x (c2/d2) = N/Z.

Optical dividing heads (Fig. 137) provide division with increased accuracy and consist of a housing 7, a glass disk 2 having 360 precise degree divisions visible through a microscope 3. The optical system has 60 divisions for counting arc minutes. The heads are secured in the spindle and rotated to the required angle with a reading through the microscope eyepiece on the scale of disk 2.

Milling of helical grooves, evenly spaced around the circumference (see Fig. 135, b), is performed when installing the workpiece in the centers. The table is rotated to the angle of inclination of the helix of the groove so that the disk cutter 7 is aligned with the direction of the groove. The workpiece receives continuous rotation from the longitudinal feed lead screw, and the table receives longitudinal feed in the direction of the groove. Equation of the kinematic chain from the dividing head spindle to the longitudinal feed screw (see Fig. 136, c): (Z%/Zn)(Zb/Z$) x x(Z4/Z3) x (Zw/Z))(d/ a)(b/dx)pb = p, where ръ is the lead screw pitch. Considering that (Z%/Z1)(Zb/Zs)(ZA/Zz)(ZXo/Z)) = 1/7V(see Fig. 134, c), we obtain (ax/bx)(cx/dx) = N(nD/tga>)/Pb.

LABORATORY WORK No. 6

Kinematic calculation and construction of the structural mesh of the gearbox of a horizontal milling machine mod. 6Р82.Design features

Features of the main components and mechanisms of the machine

Goal of the work:

1. Familiarize yourself with the layout and main components horizontal - milling

Machine tool mod. 6Р82.

2. Learn to perform kinematic calculation and construction structural

mesh speed boxes for horizontal milling machine mod. 6Р82.

Work order:

Read the description of the “Laboratory work”.

Milling represents a type of cutting using a tool called a milling cutter. Milling cutter is a cutting tool with several teeth, each of which is a simple cutter. When rotating, the cutter cuts its teeth into the workpiece approaching it and with each tooth cuts chips from its surface. After completing the pass, the cutter removes the treated surface workpiece layer of metal. The surface obtained after passing the cutter is called treated surface . The surface formed on the workpiece directly by the cutting edge of the cutter is called cutting surface.

Depending on the location of the cutter axis relative to the machined surface, milling is distinguished cylindrical cutter and end cutter. The rotational movement of the cutter is called main movement , and the forward movement of the workpiece is feed motion . Both of these movements must be carried out by a milling machine. The main movement, i.e. the rotation of the cutter, is determined by the number of revolutions of the machine spindle per minute, the feed is determined by the amount of minute movement of the machine table with the workpiece fixed on it relative to the cutter.

Processing schemes blanks on machines milling group (Fig. 1) include processing of both planes and shaped surfaces.

1. Horizontal planes milled on horizontal milling machines with cylindrical cutters (Fig. 1, A) and on vertical milling machines with end mills (Fig. 1, b). It is advisable to use cylindrical cutters to process horizontal planes up to 120 mm wide. In most cases, it is more convenient to process planes with end mills due to the greater rigidity of their fastening in the spindle and smoother operation, since the number of simultaneous working teeth of an end mill is greater than the number of teeth of a cylindrical cutter.

2. Vertical planes milled on horizontal milling machines with end mills (Fig. 1, V) and face milling heads, and on vertical milling machines with end mills (Fig. 1, G).

3. Inclined planes end milling (Fig. 1, d) and end mills on vertical milling machines, in which the milling head with spindle rotates in a vertical plane. Inclined planes of small width are milled on a horizontal milling machine using a single-angle disk cutter (Fig. 1, e).

4. Combined surfaces milled with a set of cutters (Fig. 1, and) on horizontal milling machines. The accuracy of the relative position of the machined surfaces depends on the rigidity of the cutter attachment along the length of the mandrel. For this purpose, additional supports (suspensions) are used, and the use of cutters that are disproportionate in diameter is avoided (the recommended ratio of cutter diameters is no more than 1.5).

Rice. 1. Schemes for processing workpieces on milling machines

Rice. 2. Horizontal milling machine mod. 6P82:

1-base; 2 - bed: 3 - console; 4-sled 5-table;

Spindle: 7 - trunk

Rice. 3. Kinematic diagram of a horizontal milling machine mod. 6Р82

5. Shoulders and rectangular grooves end milling (Fig. 1, h) and disk (Fig. 1, And) cutters on vertical and horizontal milling machines. It is more advisable to mill shoulders and grooves with disk cutters, since they have a larger number of teeth and allow working with high cutting speeds.

6. Shaped grooves milled with a shaped disk cutter (Fig. 1, To), corner grooves – single-angled and double-angled (Fig. 1, l) cutters on horizontal milling machines.

7. Wedge groove milled on a vertical milling machine in 2 passes: rectangular groove end mill, then groove bevels - single-angle cutter (Fig. 1, m).

8. T-slots(Fig. 1, n), which are widely used in mechanical engineering as machine grooves, for example, on milling machine tables, are milled in 2 passes: first the groove rectangular profile - with an end mill, then the lower part of the groove - with a milling cutter T-slots .

9. Keyways milled with end or key milling (Fig. 1, O) cutters on vertical milling machines. The accuracy of obtaining a keyway is an important condition when milling, since the nature of the fit of the parts mating to the shaft on the key depends on it. Milling with a key cutter ensures a more precise groove; When regrinding along the end teeth, the diameter of the key cutter practically does not change.

10. Shaped surfaces of an open contour with a curved generatrix and a straight guide are milled on horizontal and vertical milling machines with shaped cutters of the appropriate profile (Fig. 1, P). The use of shaped cutters is effective when processing narrow and long shaped surfaces. Wide profiles processed with a set of shaped cutters.

11. Horizontal, vertical, inclined planes and grooves simultaneously processed on longitudinal milling double-column machines with face and end mills with the movement of the longitudinal feed of the table on which the body workpiece is fixed in the fixture (Fig. 1, R).

12. Horizontal planes using the continuous milling method, they are processed on rotary milling machines with end mills (Fig. 1, With). The workpieces are installed in fixtures evenly spaced around the circumference of the table, and a circular feed motion is imparted to them. The workpiece first undergoes rough processing (size H 1 ), and then the cutter installed in the second spindle is processed finally (size N g ).

13. Spatially complex surfaces processed on semi-automatic copy-milling machines (Fig. 1, T). Processing is carried out with a special end mill. Milling is carried out along 3 coordinates: x, y, z (volumetric milling).

Study the purpose of the main components of a horizontal milling machine mod. 6Р82

(Fig. 2). Execute layout sketch machine, indicating the main components.

3. Develop technological adjustments processing of parts on horizontal milling

machines (according to Fig. 1).

4. Build kinematic diagram speed boxes (Fig. 3) of the machine mod. 6Р82

(the width of the gears is at least 5 mm, the minimum gear width is at least 15 mm).

5. Build structural mesh machine speed boxes mod. 6Р82 (width and

height not less than 120 mm).

Horizontal milling machines

In Fig. Figure 20 shows the main components of a horizontal milling machine type 6M82G produced by the Gorky Milling Machine Plant. The machine belongs to the second size range, but in terms of design it is similar to the 6M83G horizontal milling machine, which belongs to the third size range. The production of M series machines was mastered in 1960; they are often found in the workshops of our factories. Good knowledge of the 6M82G machine makes it possible to quickly master work on other types of horizontal milling machines, since their main components differ little from the components of this machine.
All components and parts of the machine are interchangeable with the exception of wedges and some guides, which are scraped down.
The 6M82G machine externally differs from the previously produced 6N82G model only in the presence of a longitudinal feed handwheel on the front side of the table; it has a slightly different range of spindle rotation speeds and table feeds.

The base of the machine is cast from gray cast iron and is precisely cut on both sides. On one side of the base, the machine frame is installed and bolted; the other side is adjacent to the workshop floor. At the base there is a trough for coolant, which flows through tubes from the table. An electric pump is mounted on the base to supply coolant from the trough to the tool.
The bed is used to fasten all components and mechanisms of the machine. Some machine components (gearbox, spindle, electric motor with belt drive, motion transmission mechanism to the feedbox) are located inside the frame and are not visible. Other components of the machine (console, feed box, trunk, table, pump for supplying coolant) are located on the outer surfaces of the bed.
The bed is box-shaped and reinforced inside with ribs; on its front wall there are vertical guides (made in the form of a dovetail) for the console, and at the top there are horizontal guides for the trunk.
The trunk is available on horizontal and universal milling machines and is used for correct installation and milling mandrel support. The trunk is installed in horizontal guides on the top of the frame and can be fixed at any distance from its mirror, i.e., with different overhang (see Fig. 10). To increase rigidity when processing heavy parts and large sections of chips, supports are used that connect the trunk to the console.
The console is a rigid cast iron casting mounted on the vertical guides of the frame. The console moves along the vertical guides of the frame and carries horizontal guides for the slide. It is supported by a stand which has a telescopic screw for raising and lowering the console. The rigidity of the console structure and the accuracy of its guides are of paramount importance. machine operation. The console has two bolts that secure supports connecting the machine table with the trunk for better stability under heavy loads.
The slide is an intermediate link between the console and the machine table. The table moves along the upper guides of the slide in the longitudinal direction, and the lower part of the slide moves in the transverse direction along the upper guides of the console.
The table is mounted on the guide rails and moves in the longitudinal direction. Workpieces, clamping and other devices are secured on the table, for which the working surface of the table has longitudinal T-shaped grooves.
The movements of the table, slide and console impart longitudinal, transverse and vertical feeds to the workpiece in relation to the cutter.
Cantilever milling machines usually have both manual and mechanical feed of the table, slide and console.
For installation movements during adjustment and for idle runs of the table, manual or mechanical feed is used, and for working feeds - only mechanical feed.
In addition to working feeds, the table usually has high speed (accelerated movement) in all three directions - for bringing the workpiece to the cutter, as well as for reverse movement.
The high speed is carried out at one constant speed, and the working feeds have several stages, which can be set using the feed box depending on the processing, the material of the cutter and the workpiece.
Spindle. To rotate the cutting tool, a spindle is used, which receives movement from the gearbox. The accuracy of rotation of the mandrel with the cutter on depends on the precision of the spindle, its strength and rigidity. Milling machine spindles are made of 40Xi alloy steel and subjected to heat treatment.

In Fig. Figure 21 shows the spindle of the 6M82G machine. The spindle has three roller and ball bearings. The front end of the spindle and the conical socket for mounting and fastening the tool and mandrel are machined very precisely.
The front end of the spindle of the 6M82G milling machine is shown in Fig. 22. The inner cone 2, into which the milling mandrel is inserted, is made very steep. The rotation of the milling mandrel is carried out by drivers 3, which are inserted into grooves in the end of the spindle and screwed on with screws. The milling heads are secured with screws screwed into holes 4 and centered by the front part 1 of the spindle. Sometimes a special mandrel is used for centering, one end of which fits into the conical socket 2 of the spindle, and a milling head is mounted on the other.

Domestic milling machines have a standard front end of the spindle (Fig. 22).
The spindle rotates from an electric motor located in the machine frame, through a pulley, a belt drive and then through a gearbox. The engine is located inside the frame, which increases operational safety and reduces the area occupied by the machine.
Gearbox designed to transmit rotation from the pulley to the spindle and to change the number of its revolutions by switching gears.
The table feeds are driven by an electric motor located in the machine console through a feed box.
The feed box is used to change table feeds in the vertical, longitudinal and transverse directions.
Cantilever milling machines of modern design, like the 6M82G machine, have separate electric motors to drive the gearbox and feedbox.
In Fig. Figure 23 shows a 6N81G horizontal milling machine produced by the Dmitrov Milling Machine Plant. It belongs to the first size range. All its main components and mechanisms (base, bed, trunk, console, table) are similar to those discussed above. The only difference is that the rotation of the spindle is transmitted through a belt drive from the gearbox pulley, rigidly connected to the electric motor of the main movement drive. In addition, the spindle is equipped with a gear drive, allowing high and low spindle speeds.

Vertical milling machines

A vertical milling machine differs from a horizontal one only in the location of the spindle, therefore everything stated above about a horizontal milling machine applies to a vertical milling machine, with the exception of those parts and assemblies that the latter does not have (trunk, supports).
In Fig. Figure 24 shows the main components of a vertical milling machine type 6M12P produced by the Gorky Milling Machine Plant.

Machines of this model, together with the horizontal milling machine 6M82G (see Fig. 7) or the universal milling machine 6M82 (see Fig. 8) form a range of cantilever milling machines of the 2nd size.
All machines in the 2nd size range have 18 spindle speeds in the range of 31.5-1600 rpm and 18 feed levels ranging from 25 to 1250 mm/min for longitudinal and transverse movements of the table and from 8.3 to 400 mm/min- for vertical. The table speed in the longitudinal and transverse directions is 3000 mm/min, and for vertical - 1000 mm/min. Machines in the 3rd size range have the same speeds, working feeds and high speeds.
The working surface of the table for size 2 machines is 320X1500 mm mm):

The working surface of the table for size 3 machines is 400X2000 mm. The table has the following maximum mechanical movements (in mm):

In Fig. Figure 25 shows the main components of the 6N11 vertical milling machine produced by the Dmitrov Milling Machine Plant. Machines of this model, together with horizontal milling machines 6N81G (see Fig. 23) and similar universal milling machines 6N81 form a range of cantilever milling machines of the 1st size.
All machines in the first size range have 16 spindle speeds ranging from 65 to 1800 rpm and 16 table feed levels ranging from 35 to 980 mm/min for longitudinal movement, from 25 to 765 mm/min for transverse and from 12 to 830 mm/min for vertical; high speed - 2900, 2300 and 1150, respectively mm/min.
The working surface of the table for machines of the first size, as indicated earlier, is 250X1000 mm. The table has the following maximum mechanical movements (in mm):

Goal of the work: Study the structure and operation of the NO-800 universal milling machine, become familiar with the equipment used to secure the tool, the drives of the main movement, feed movements and auxiliary movements.

Tools and accessories

1. Universal milling machine mod. H0-800

2. Cutting and auxiliary tools

3. Blank

4. Operational sketch

5. Microscope BMI-1 with a set of measuring heads

Basic information

Classification of milling machines

Milling machines constitute the sixth group of machine tools. They are widely used in the manufacture of various machine parts. Using various cutters, machines can process flat and shaped surfaces, grooves, surfaces of rotating bodies, cut gears using the copying method, and perform other milling operations.

Depending on production conditions and for processing workpieces different types Various milling machines can be used. They can be divided into general purpose and special purpose machines.

General purpose machines include: cantilever milling machines, vertical milling machines, horizontal milling machines, universal and widely universal machines, non-cantilever milling machines with a fixed or rotating spindle head, with a round table, with a copying device; longitudinal milling single-column horizontal or vertical; two-post with two or more spindles; rotary milling machines with one or more spindles.

Special machines include copy-milling, spline and key-milling, drum-milling, CNC milling machines, etc.

Among general purpose machines, there are several types of machines:

1.Vertical milling machines designed to perform various milling operations.

A distinctive feature of these machines is the vertical position of the spindle axis and the presence of a movable console on which the slide and table are located. The workpiece being processed is fixed on the table; it moves longitudinally along the guides of the console, which, in turn, moves in three mutually perpendicular directions. The feed box is mounted on the console.

On vertical milling machines, almost all types of cutters, milling heads, end, modular and other cutters are used, depending on the operations performed.

The tool is mounted either on mandrels with a conical shank, fixed in the spindle, or in collet chucks. On vertical milling machines, up-milling is performed, and if there is a device that compensates for the gap between the screw and the nut of the longitudinal feed mechanism, down-milling is also possible.

2. Horizontal milling machines designed for milling various surfaces: horizontal, inclined and shaped, as well as ledges, grooves, etc. The spindle axis of machines of this type is horizontal. The feed movements are the same as the feed movements of workpieces on a vertical milling machine.

Universal machines of this type have the following distinctive feature: their table can be rotated about the vertical axis by. This makes it possible to machine helical grooves on cylindrical surfaces using a dividing head

3. Widely versatile milling machines have various options for installing the spindle: in horizontal, vertical and inclined positions in two mutually perpendicular planes. Milling cutters can be used on widely versatile milling machines various types(cylindrical, disk, face, milling heads, etc.) for processing medium-sized workpieces under single and small-scale production. These machines are equipped with a large set of devices: round tables, dividing heads, special devices.

Auxiliary tool and devices used on milling machines

To secure the cutting tool on milling machines, various auxiliary tools are used. It allows you to mount on machines both a cantilever tool (shank, end mills, milling heads, etc.) and a tool mounted on mandrels, one end of which is installed in the spindle, the other in the shackle bushing (disc, cutting, modular cutters, etc. .).

The design of the auxiliary tool depends on the mounting and connecting part of the cutter and the design features of the spindle. For example, cutters with a conical shank - directly in the spindle or through an adapter conical bushing. The end of the holes of spindles of milling machines has a Morse taper No. 3,4,5. Torque is transmitted to the tool from the spindle through crackers attached to the spindle, which fit into grooves on the end part of the bushing or mandrel.

Attachment cutters (disc cutters, cut-off cutters, etc.) are based along the hole on a mandrel that has a key for transmitting torque.

A mandrel with a cutter or a set of cutters is attached at one end to the spindle, and the other to the earring or pendant. In the case of cantilever fastening, the mandrel is installed only in the mounting hole of the spindle. Face milling cutters are secured with four bolts on a spindle or on a mandrel, centered with a collar on the spindle or on the mandrel. Torque is also transmitted by two end keys.

Main components of cantilever milling machines

Base – serves as a support for the machines.

bed – the basic unit of the machine, in the internal cavity of which the gearbox is located , spindle, main movement electric motor.

The console is moved along the vertical guides of the frame. A trunk is installed in the upper guide groove.

Spindle – a rigid hollow shaft, at the front end of which cutters are installed and secured. The conical section of the spindle hole (7:24) is intended for installing cutters using mandrels or adapter bushings.

Trunk – in machines with a horizontal spindle, it is designed to support the free end of the milling mandrel with a shackle. The extension of the trunk is adjustable and fixed in the desired position.

Console – a box-shaped cast iron that houses the feed drive electric motor, feed box and its switching mechanism. The console is connected to the frame by a vertical dovetail groove.

Sled – an intermediate unit between the console and the machine table. The lower groove of the slide is installed on the horizontal guides of the console in the transverse direction. The top groove of the dovetail slide serves as a guide for the table.

Table – located on a slide and moves along it in the longitudinal direction. The workpiece to be processed or devices for fastening the workpiece are installed and secured on the table.

Design of a universal console horizontal milling machine model 6M82

Horizontal milling machines have a spindle, the axis of which is horizontal, and the work table moves in the longitudinal, transverse and vertical directions. They are divided into simple and universal, the latter are no different in appearance from simple ones, but have a table rotating around a vertical axis. This allows you to machine helical grooves, cut helical gears, etc. The main movement is the rotation of the cutter, and the feed movement is the longitudinal, transverse or vertical movement of the table. In Fig. 5.1 shows the layout, main components and movements of the universal console horizontal milling machine mod. 6M82.

Rice. 5.1. Universal horizontal milling machine mod. 6M82

On the base plate 1 there is a frame 2, inside which there is a main movement mechanism driven by an electric motor 3 and a gearbox 4. A console 5 is mounted in the vertical guides of the frame, which can move vertically along these guides. On the horizontal guides of the console there are transverse slides 6, a rotary plate 7, and on the guides of the latter there is a longitudinal (working) table 8. Thus, a part mounted directly on the table, in a vice or fixture, can receive feed in three directions. The presence of a rotating plate allows, if necessary, to rotate the desktop in a horizontal plane and set it to the required angle. Some horizontal milling machines do not have a rotary platen; in this case they are called simple in contrast to universal. The table feed drive is located inside the console 5 and consists of an electric motor 9, a feed box 10 and other mechanisms.

Milling chucks and short mandrels are inserted directly into the conical seat of the spindle. The trunk 12 is located in the upper part of the frame 2 . A suspension 13 with a center (on the left) or with a bearing (on the right) is installed in its guides. Two supports 14 can also be attached to the trunk, the lower ends of which are connected to the console. The supports serve to stiffen the console.

In Fig. 5.2 shows the kinematic diagram of a universal horizontal milling machine mod. 6M82.

Rice. 5.2. Kinematic diagram of a universal horizontal milling machine mod. 6M82

The drive of the main movement starts from the electric motor 69 and is carried out by an 18-speed gearbox. Rotation from shaft I is transmitted to shaft II using gears 1-2, and then through one of three pairs of wheels (3-4, 5-6 or 7-8) to shaft III. From here, one of the gears 9-10, 11-12 or 4-13 communicates movement to shaft IV, and the last one along the chain of wheels 14-15 or 16-17 - to spindle V. The change in speed is achieved by switching wheels 3-5-7,10-13 -12 and 14-16.

The feed mechanism drive is located inside the console. Electric motor 63, using gears 18-19, 20-21, rotates shaft VIII. Then, through gears 22-23, 24-25 or 26-27, rotation is transmitted to shaft IX. From shaft IX through gears 27-28, 29-30 or 31-32, rotation is transmitted to shaft X. From here, movement to shaft XI can be transmitted through a pair of wheels 33-34 (wheel 33 moves to the right to engage clutch M), or through a search consisting of wheels 35-36, 37-33 and 33-34 (in this case, wheel 33 occupies the position shown in the diagram). The wide wheel 34 is freely mounted on the shaft and transmits rotation to it when the clutch 64 is engaged. When the functional disk clutch M is engaged, shaft XI can receive the rapid rotation necessary for rapid movements. The fast rotation chain consists of a group of gears 18-19, 19-52 and 52-53. Clutches 67 and 64 are interlocked and have one control element: when one clutch is turned on, the second is turned off and vice versa. Table feeds are carried out using screw mechanisms: longitudinal - in pairs 54-55; transverse 56-57 and vertical 58-59. Nut 55 is fixed in upper skid, 57 – in the console, 59 – in cabinet 66.

The longitudinal feed chain connects shaft XI with lead screw 54. It consists of gears 38-39, 40-42, 43-44, 45-46 (in the diagram, screw 54 is rotated 90° relative to the axis of wheels 44 and 45; its axis is perpendicular to the plane of the drawing).

The cross feed chain consists of gears 38-39, 40-42-47.

The vertical feed chain includes gears 38-39, 40-41, 48-49 and 50-51. To turn the feeds on and off, clutches 62, 65, 70 are used.

Technical characteristics of the machine mod. 6M82

Dimensions of the working surface of the table, mm 320 x 1250

Maximum table movement:

longitudinal, mm 800

transverse, mm 250

vertical, mm 420

Distance from the axis of the horizontal spindle to

Table surfaces, mm 30-450

Number of spindle speeds 18

Spindle rotation speed, rpm. 31.5-1600

Number of working feeds of the table 18

Table feed, mm/min:

Longitudinal 25-125

Transverse 25-125

Vertical 8.3-416.6

Drive motor power

Main movement, kW 7.5

dimensions, mm:

width 195

height 1680

Weight, kg 2900

Design and principle of operation of the machine mod. NO-800

The universal milling machine model NO-800 is designed to perform milling operations technological processes for the production of instrument parts. The machine is intended for use as part of the technological equipment of instrument-making industry enterprises.

Milling machines used in precision instrument making usually operate with small-diameter cutters, and therefore economically feasible cutting speeds can be achieved by increasing the spindle speed (up to 4000 rpm).

A feature of most of these machines is the lack of automatic feed. Manual feeding is carried out primarily by a system of elementary mechanisms (lever or lever, wheel and rack), and the removal of small-section chips necessitates the use of short milling mandrels when assembling machines, dispensing with the use of a trunk, etc.

Milling machines for precision instrumentation, depending on the location of the spindle, are divided into vertical and horizontal. There are also combined machines in which the spindle can be installed horizontally or vertically, which is determined by the nature of the work performed. Basically, these milling machines are small-sized and installed on tables or workbenches. Some vertical milling machines have swivel heads, the spindle of which can be set at an angle of ± 40°.

Technical characteristics of the machine mod. NO-800

Technical data, main parameters and characteristics:

1. Distance from the spindle axis to the bed guides, mm 90

2. Distance from the spindle axis to the side slide, mm 80

3. Maximum movement of the spindle head in the horizontal and vertical planes, 50

4. Diameter of the working surface of the table, mm 100

5.Maximum longitudinal movement of the table, mm 100

6. Maximum vertical travel of the table, mm 50

7. Price for dividing the table movement dial, mm 0.01

8. Table tilt angle in the vertical plane ±300

9. Headstock tilt angle ±300

10. Headstock motor:

power, kW 0.25

rotation speed, min -1 3000

11. Special cone in the spindle for the collet, 290

13. Machining accuracy during milling, mm 0.02

14. Spindle rotation frequency, min –1 5300

15. Overall dimensions, mm 650 x 610 x 670

Parts can be processed in a special device that is attached to the table.

1. Spindle.

2. Three-stage belt drive pulleys.

3. Console.

4. Table rotation lever.

5. Flywheel for transverse movement of the table.

6. Desk.

7. Spindle adjustment device in vertical position.

8. Tension roller.

9. Stand.

10. Flywheel for longitudinal movement of the rack.

11. Lever for vertical movement of the table.

12. Electric motor.

13. Housing.

14. Launch equipment.

Rice. 4.3. Sketch of the machine mod. NO-800

The general view of the machine is shown in Fig. 4.3. The machine consists of a housing (bed) 13, in which the drive and starting equipment 14 are built. The rotation of the spindle 1 is carried out from the electric motor 12 through a three-stage belt drive that goes around the tension roller 8. The spindle hole is designed for the use of a collet or mandrel for cutters. The base of the rack 9, which carries the spindle 1, is fixed to the prismatic guides 15 of the frame using two eccentrics. The longitudinal movement of the rack 9 is limited by the thrust screws 16 and is carried out by a micrometric screw 10 with a division value of 0.01 mm. The gap in the guides is adjusted using a wedge.

Console 3, carrying a round table 6, moves in the vertical direction along prismatic guides using a rack and pinion pair from the handle 11, fixed to the rack and pinion axis. The rotation of the table 6 around its axis is carried out using a lever 4, and the transverse movement of the table is carried out by rotating the flywheel 5 of the micrometer screw. All screw movements are limited by stop screws.

The tilt of the console and spindle head is fixed with clamping bolts. The gaps in the guides are adjusted using wedges.

The machine spindle rotates in two bronze bushings. One bushing is solid with an internal conical hole, and the second is split. Radial and axial play are adjusted using nuts.

Safety requirements when performing laboratory work

1. Persons who have undergone safety training and have studied these instructions are allowed to work on the universal milling machine mod HO-800.

2. It is prohibited to carry out any type of work on the machine without the permission of the teacher or engineer.

3. When installing the machine, it must be reliably grounded common system grounding.

The electrical resistance measured between the grounding clamp located at the input to the machine and any metal part of the machine that may be energized at 42 V or higher must not exceed 0.1 Ohm.

4. When repairing, the machine must be disconnected from the power supply by the input switch.

5. While the machine is operating, it is prohibited to make handmade in the part processing area.

Work order

1. Familiarize yourself with the purpose, layout and technical characteristics milling machine mod. HO-800.

2. Study the purpose of the main components of the machine.

3. Identify the main movement, feed movements and auxiliary movements.

4. Using the sketch provided by the teacher, set up the machine for processing and, using a BMI-1 microscope, determine the accuracy of the obtained dimensions and compare them with the specified value.

1. Name and purpose of the work.

2. Tools, equipment and accessories for work.

3. Layout of the machine mod. NO-800 indicating all types of movements (main movement, feed movement, auxiliary movements).

2. Sketch of the part.

3. Measuring scheme and setting up the machine.

4. Conclusions and recommendations.

Test questions for laboratory work

1. Classification of milling group machines.

2. Purpose and types of work performed on milling machines.

3. An auxiliary tool used on milling machines.

4. Design, layout and kinematic diagram of the machine mod. 6M82.

5. Name the main components and movements necessary to carry out the cutting process on a mod. HO-800.