Setting chastotnik lathe cl 1201. Frequency converter for a lathe. Budget chastotnik for a lathe

The use of frequency converters to control the speed of the lathe spindle, regulate the rotation speed of the main drive of the grinding machine, regulate the speed by the traction body of the drawing line, control the line of longitudinal and transverse cutting of sheet metal.

Job: The frequency converter 1 regulates the speed of rotation of the asynchronous motor 2 of the main drive of the spindle 3. The system operates in a closed circuit with feedback on the rotation speed. The rotation speed is measured by a pulse sensor 6. The operating mode of the variable frequency drive is set from the control panel 5. The cutter 4 moves smoothly from right to left along the rotating part.

Prior to the introduction of variable frequency drive, the speed of the motor was fixed and the speed of the spindle could only be changed discretely by means of a gearbox.

Equipping machine tools with a frequency-controlled electric drive makes it possible to meet the most stringent and contradictory requirements imposed by the technology of processing various materials. The use of a frequency-controlled drive makes it easier to control the machine due to the possibility of smoothly changing the speed of the spindle without stopping it, and to expand the range of speed. The use of a gearbox and a variable frequency drive allows you to optimally set the spindle speed and get maximum torque at low speeds.

Increasing the spindle speed control range to 1:100 or more and expanding the machine's capabilities for processing parts from various materials due to this.

improving the quality of detail processing and reducing the number of breakages of the cutting tool due to the precise maintenance of the spindle speed,

reducing the number of equipment breakdowns by reducing shock loads on the electric drive and mechanical transmission during start-up and stop.

Task to be solved: direct regulation of the rotation speed of the grinding wheel to ensure the required quality of grinding of various materials.

Options: wheel speed rpm, discrepancy between the wheel speed leads to a violation of the quality of grinding. For example, grinding soft materials at high speed leads to "burning" of the surface, and the plastic melts.

Adjusting the speed of rotation of the circle using a frequency converter allows you to:

expand the capabilities of the machine for processing various raw materials,

choose the optimal speed of rotation of the circle to improve the quality of processing of each material.

Machine diagram. The workpiece 1 is fixed horizontally on the work table 2. The work table is moved relative to the rotating wheel using handles 3 and 4. The grinding wheel 8 is rotated by a high-speed electric motor 5 at the speed required for a given material. Rotation speed control is achieved using a frequency converter 6. The specified required speed is set from the control panel 7.

For the production of bar metal, wire, pipes and other metal products of a constant section, drawing is widely used. This is a continuous process of metal deformation by pulling workpieces through one or more calibrated holes (drawing dies) on drawing benches.

Job: The original coil of wire is located on the uncoiler 1. Through the rotating rollers 2, called the scale breaker, the wire is fed into the lubricator 3. Next, the wire is pulled through the draw bar 4 with a tapering section (shown below in the arrow).

Three or four turns of wire are laid on the drive drum of the drawing machine 7. The drum is driven by an asynchronous motor 6, which is controlled by a frequency converter 8. The wire tension force (torque on the drum shaft) is measured by a tension sensor 5. The feedback signal from the tension sensor is fed to the input of the frequency converter. Thus, a closed circuit for controlling the moment on the pull drum shaft is built.

The specified moment on the shaft is set on the front panel of the control cabinet 9. In this case, in the steady state of the drawing mill, the linear speed of the wire at the exit from the die is maintained constant. From the output of the drawing machine, through the stacker 14, the wire will be fed to the take-up spool 12 of the winding machine. The stacker makes reciprocating movements, and ensures uniform laying of the wire.

The speed of rotation of the winding coil drive motor 13 is controlled by the frequency converter 10 so that the speed decreases as the winding diameter increases. The winding diameter is determined by the feedback sensor 11. The feedback sensor is a variable resistor, the resistance of which changes in proportion to the angle of rotation of the pressure roller.

The main purpose of the frequency converter application: expanding the capabilities of the drawing mill for processing metal of various strengths (hard and low-plasticity, difficult to deform, low-strength) and a wide range of cross sections. This is achieved by smooth control of the drawing speed in the range of 1:1000 or more.

The use of a frequency-controlled drive, in addition, provides:

automation of drawing mill operation under variable load due to coordinated regulation of drive motors,

exclusion of wire breaks due to smooth start-up and braking of the drawing machine drum,

improving the quality of finished products by accurately maintaining the drawing speed.

The use of automated cutting lines becomes necessary almost always when working with sheet metal: the manufacture of metal structures, metal profiles, body parts, etc. Frequency converters are part of the control systems of such lines.

Several converters can be installed in a typical cutting line: one of them 1 controls the electric drive 11 of the unwinder 10, the other 2 - the electric drive 6 of the sheet broaching, the third 3 - the electric drive 4 of the winder 5. General control is carried out from the panel of the control cabinet 9. For metal cutting disk shears 8 and cross cut shears 7 are used.

In slitting lines, an electric drive with a frequency converter provides strip traction, smooth start/brake. The speed of the strip is maintained automatically by changing the loop in the loophole 12 using speed sensors.

In the transverse cutting lines (there is no winding device and converter 3, a receiving table 13 is installed in the place of the loop pit), an electric drive with a frequency converter and a pulse sensor provides strip traction, smooth start-up, braking and precise stop of the strip at the moment of cutting.

The main purpose of using a frequency converter is to precisely stop the strip at the moment of cutting in the cut-to-length lines and to maintain the specified strip speed in the slitting lines.

The use of a frequency-controlled drive also provides:

ensures high productivity of metal cutting lines.

reducing labor costs and reducing metal waste.

The cutting process is controlled centrally from the control cabinet. The operator on the control panel sets the number and length of strips and sheets to be produced.

We will show you our acquisition to solve an important issue. A year ago we bought a Chinese lathe. It had the following problem. It is not possible to smoothly change the spindle speed. We decided to make changes to the design of the lathe.

Frequency converter instead of gearbox

For this purpose, a frequency converter was purchased. It allows you to change the frequency of the current supplied to the electric motor of the lathe. The device operates from a single-phase network with a voltage of 220 volts, and gives out to an electric motor. This device has many control buttons. How does a frequency converter work? The device allows using the control panel with four switches in a row to reverse, turn the machine on and off, change the speed of rotation of the engine.

Why so many switches? Simplified can be done as follows. The device allows you to make multi-stage speeds. This device has five outputs, for different types of engine on and off, for different rotational speeds.

Adjusting the frequency converter

1. In the first setting, we can do a simple turn on of the desktop lathe motor. The start occurs at a frequency of 10 hertz. Using a variable resistor, you can change the speed of rotation of the motor by increasing the frequency of the current up to 400 hertz.
2. If we need to change the direction of rotation of the lathe engine using a frequency converter, then first turn off the device. Turn on the toggle switch for changing the rotation of the engine torque. As a result, the engine began to rotate in the opposite direction. The frequency converter can also change the direction of rotation of the motor.
3. Now consider the possibility of changing the rotation of the engine of a desktop lathe using toggle switches, without using a rheostat. To do this, we use only the inclusion and deactivation of the corresponding speeds. To do this, we translate the frequency converter into the “on” position, the device produces 10 hertz. The toggle switches are configured so that when they are turned on, the frequency of the current increases by 5 hertz. As a result, we can control the speed of the lathe spindle with a frequency converter without a mechanical gearbox.

Operating conditions of the chastotnik for a lathe

1. The frequency converter operates in a wide temperature range from +35 to -20 degrees. However, it must be borne in mind that it is necessary to choose a frequency converter based not on power, but on the motor current. You can not count on any frequency of engine operation. Not every engine can operate at a frequency of 100 hertz, although the frequency converter produces them without problems. For example, a 0.55 kW motor at 2800 rpm may stop at 75 hertz and run fine at 65 hertz. In theory, the engine can operate normally with small deviations from 50 hertz.
2. At low spindle speeds, additional cooling must be installed on the motor, since the native fan will not cope. To maintain sufficient torque at low speeds, vector acceleration is applied. Vector acceleration must be supported by the frequency converter.
3. You need to put an encoder on the motor, make the adjustment in closed loop, always maintain the torque. Sometimes, at the factory, synchronous motors with an encoder are installed on lathes. Chinese frequency manufacturers.

For the spindle, the frequency control of the stator flux clutch is sufficient. This is called sensorless vector flow control. You always need to know how to set up the frequency converter, do a minimum of parameterization and start automatic adaptation. You can use the company's software to set up the controllers, as well as your own controller tuning programs.

Electronic filling of the frequency converter

Chinese manufacturers already know how to make motors and software. For the factory version, this is normal, but in everyday life it is expensive.

Modern asynchronous motors have a relatively complex control. Starting a powerful asynchronous motor is associated with large current overloads. High torque can damage bearings and engine mounts. An abrupt shutdown of the engine leads to overvoltage and to accidents in the electrical installation. Therefore, today frequency converters are good control systems for electric motors.

The output stages of such devices must be powerful. This problem is solved by insulated gate transistors. The converter consists of a clock generator, the frequency of which can be controlled. It is assembled on simple logical elements. In order to obtain a three-phase system, ten pulses were divided into a sequence of six pulses.

We will show you a purchase that will help solve an important issue. A year earlier, a lathe made in China was purchased. He had some problem. It was not possible to adjust the spindle speed. Therefore, adjustments were made to the design of the machine.

Bought for this frequency converter. With it, you can change the frequency of the current sent to the propulsion system of the machine. The device operates from a single-phase type network with a voltage of 220 volts, and supplies three phases of 220 volts to the engine. 220 volt converter has a large number of control keys. How does a frequency converter work? It is capable of using the remote control and switches to reverse, start and turn off the installation, adjust the speed of the engine unit.

Adjusting the frequency converter

1. Having carried out the first setting, we have the possibility of simply starting the propulsion system of a lathe in a desktop version. The launch is carried out at a frequency of 10 hertz. Using a variable transistor, it is possible to change the speed of the propulsion system by increasing the frequency of the current to 400 hertz.
2. To change the direction of rotation of the lathe motor device using the converter, you must turn on the device. We turn on the toggle switch that changes the rotation of the torque of the propulsion system. At the same time, the engine began to rotate in the opposite direction.
3. Now let's start considering the possibility of turning the engine of a lathe in a desktop version due to toggle switches, without using a rheostat. For this purpose, only the necessary speeds are turned on and off. When the chastotnik is switched to the “on” mode, the device generates 10 hertz. The toggle switches are configured in such a way that when they are started, the current frequency increases by 5 hertz. As a result, we are able to adjust the speed of the machine spindle due to the frequency converter without a mechanical transmission.

Working Conditions of Converter for Lathe

1. The converter is able to operate in wide temperature ranges from +35 to -20 degrees. But, it should be borne in mind that the selection of the converter is carried out not by power, but in accordance with the current of the propulsion system.
2. If the spindle is running at low speeds, then additional cooling elements should be mounted on the engine, because the standard fan will not handle the load. To maintain the required torque at low speeds, vector-type acceleration is used.
3. An encoder is installed on the electric motor, adjustment is made in a closed circuit, and the torque is stably maintained. From time to time, at the enterprise, asynchronous devices with an encoder are installed on lathes.

Electronic components of the frequency converter

Chinese manufacturers already have the technology for the production of propulsion units and software. For the factory version, this is acceptable, but for domestic conditions it is too expensive.

New models of asynchronous type motor units have complicated control. When starting high power asynchronous motors, high current overloads occur. Significant torque can lead to the destruction of bearings and supports of the propulsion system. If the engine is suddenly turned off, overvoltage and accidents in the electrical installation can occur. Therefore, when controlling electric motors, frequency converters are used.

Information about the manufacturer of the Universal-3 (TSh3) lathe

The manufacturer of the Universal-3 desktop lathe is a factory founded in 1932.

Starting from 1964, the plant began to manufacture erosion machines using electrophysical and chemical processing methods. Almost all tool shops of various enterprises use electroerosive machines and, in particular, models MA96, LF96F3, SK96F3, 4732F3M, 4733F3 and modern models SKE200F2, SKE200F3, SKE250F2, SKE250F3, SKE250F5.

Benchtop lathes of the Universal series

The first model of a desktop lathe station wagon with two round guides was developed by the organization ENIMS(Experimental Research Institute of Metal Cutting Machines). The machine was taken as a basis Unimat SL Austrian company EMCO (over 600 thousand machines of this model have been sold over 40 years).

The Universal lathe was mass-produced at the enterprise Moscow Machine Tool Plant StankoKonstruktsiya.

Since 1968, the StankoKonstruktsia plant began to produce a desktop screw-cutting lathe. Universal-2- Significantly improved Universal machine.

In the second half of the 80s, the design of the machine was significantly revised: starting from the model Universal-3 instead of two round guides, one of a larger diameter appeared in the middle of the bed and the headstock was no longer disconnected from the bed. The machine began to be mass-produced at once by several factories:

• Plant StankoConstruction: Station wagon, Station wagon-2, Station wagon-3 (TSh3), Station wagon-3m, mini current(SKT100-01, SKT100-02, SKT100-03).
• Votkinsk Machine-Building Plant: Universal-V (TSh3-01)
• Vladimir Plant of Precision Equipment : Universal-2
• Michurinsky Plant Progress: TN-1 , TN-1m
• Orion SKTB Nizhny Novgorod: TN-1m
• Penza Instrument-Making Plant(FSUE FSPC "PO "Start" named after M.V. Protsenko"), Penza: TD-180, TN-150

Station wagon-3 (TSh3) desktop multifunctional screw-cutting lathe. Purpose, scope

Machine Universal-3 replaced the previously produced Universal-2. The design of the latter was completely redesigned: two round guide beds were replaced by one more powerful one, the design of the headstock was completely changed, etc.

This machine is a hobby class machine and is intended for individual (domestic) use, i.e., in terms of its design features and technical characteristics, the machine is not intended for use in production.

The Universal-3 metal lathe is designed for processing workpieces made of metal, wood, and all types of plastic by turning.

The Universal-3 machine is a desktop lathe and is intended for all kinds of turning work:

• turning and boring of external and internal cylindrical, shaped and conical surfaces
• drilling holes, chamfering
• hole boring
• segment
• metric thread cutting

The spindle of the Universal-3 lathe is a hollow steel part, with an inner hole of 15 mm for processing bar material, mounted on 2 roller bearings in the front and rear supports of the headstock.

The spindle receives 9 rotation speeds from a 370 W electric motor through a pulley drive.

On the threaded end of the spindle, you can also install a collet with various internal holes.

Unlike the Universal-2 machine, the spindle cannot move along its axis.

The caliper with the cutter mounted on it moves along the longitudinal guides by 215 mm and along the transverse guides by 90 mm.

A distinctive feature of the machine is its wide versatility and the possibility of readjustment using devices that allow you to perform the following work:

• drilling holes
• milling of planes, recesses, grooves, etc.
• grinding and polishing
• sharpening of various roaring and household tools
• sawing sheet material, battens, boards with a circular saw
• contour sawing with a jigsaw
• planing of the planes of laths, bars and boards using a planer
• winding of springs
• threading with dies and taps with manual rotation of the spindle to other

With the help of simple devices made on the machine by the amateur himself, other work can be done.

The traditional visual layout of the machine, combined with a proven kinematic scheme, allows you to confidently provide turning with an accuracy class "H" for a long service life.

In comparison with the small-sized machines offered on the market, it is easy to operate, reliable and durable.

Due to the wide possibilities of the machine, its use at home is of great interest, and when mastering labor skills, working on it will be a great pleasure.

The machine can also be widely used in school circles, clubs, pioneer palaces, pioneer camps, etc. for the manufacture of radio components, models of aircraft and ships, small original household items and decorations, individual toys, parts, games, etc.

The machine works from a single-phase AC mains with a voltage of 220 V and a frequency of 50 Hz.

The cast bed, rigid hardened guides and the main body parts of the machine are made of high-quality modified cast iron with aging carried out and ensure high precision of the workpiece.

In the Universal-3 machine, a device is installed that provides a change in the direction of movement of the caliper without changing the direction of rotation of the spindle and stopping it.

Accuracy standards for turning operations:

• Out-of-roundness of the processed sample-product with dimensions Ø30 x 125mm, no more than - 20
• Taper of the processed sample-product with dimensions Ø30 x 125mm, no more than - 30
• Roughness of the machined surface Ra, microns - 1.25 (for finishing modes)

The technological capabilities of the Universal-3 machine can satisfy both a professional with the most diverse interests and an amateur.

Machine tool manufacturer Universal-3 - factory StankoConstruction Moscow city.

• for drilling work - drills 2300-0181 (GOST 10902-77)
• during milling work - end mills 2220-0037 (GOST 17025-71): Cutting speed is not more than 15 m/min.
• Surface grinding device: The cup grinding wheel 18 (see Fig. 4) is fastened to the mandrel 15 with the help of a screw 19 and a washer 20. Gaskets 21 made of cardboard are placed under the wheel and under the washer. The mandrel with the circle installed on it is screwed onto the front end of the machine spindle. Then, a protective ring 17 is put on the casing 14, located above the spindle, and it is fixed on it with screws 16 with washers through the grooves designed to adjust the position of the protective ring relative to the grinding wheel.

Standard scope of delivery

The standard delivery set of the Universal-3 desktop machine includes:

Accessories:

1. Three-jaw chuck 7100-0001 with flange and ring assy
2. Reverse jaw set and key for three-jaw chuck 7100-0001
3. Drill chuck with key 6-B10 or 10-B16 GOST 8522
4. Shank for drill chuck
5. Tool holder is movable
6. Fixed tool holder
7. Center rotating
8. Center thrust 2 pcs.
9. Driver chuck
10. Mandrel with screws and clamp assembly (for boring work)
11. Collet F6
12. Collet F8
13. Surface grinding device
14. Vise
15. Sharpening device
16. Circular saw device
17. Leash for woodworking
18. handcuff
19. Jigsaw device
20. Screen
21. Chuck housing
22. Polyethylene oiler

Tool:

1. open-end wrench
2. Socket keys GOST11737
3. 7812-0373 40HFA H12x1 S=4
4. 7812-0374 40HFA H12x1 S=5
5. 7812-0375 40HFA H12x1 S=6
6. Chisel
7. Square key S8
8. Socket wrench S10x13
9. Key handle S10x13
10. Square key S7
11. Straight cutter right (high-speed steel)
12. Cutter through right with a plate of hard alloy
13. Scoring cutter (high-speed steel)
14. Boring cutter (high speed steel)
15. Cutting cutter (high-speed steel) 2 pcs.
16. External threaded cutter (high-speed steel)
17. Internal threaded cutter (high-speed steel)
18. Circular saw 3420-0356 GOST 980-80
19. Jigsaw file L=125 mm. TU 205.07.359-81 5 pcs.
20. Twist drill Ø6.0 GOST 10902
21. End mill with cylindrical shank Ø6.0 GOST 17025

Dimensions of the working space of the Universal-3 lathe. Caliper sketch

Dimensions of the working space of the Universal-3 machine. Caliper sketch

Spindle drawing of a screw-cutting lathe Universal-3

Photo of the spindle end of the Universal-3 lathe

List of components of the Universal-3 machine in turning version

1. drive unit
2. bed
3. headstock
4. caliper
5. tailstock
6. electrical box

The list of controls for the screw-cutting lathe Universal-3

1. feed motion control handle (turning on the mechanical longitudinal feed of the caliper to the left, right and turning it off)
2. main movement control handle (turning on the forward rotation of the spindle, stopping and turning on the reverse rotation)
3. caliper transverse handwheel
4. tool post travel handwheel
5. quill clamp handle
6. quill travel handwheel
7. handwheel for longitudinal movement of the caliper
8. machine power off button (red)
9. power button for the electrical equipment of the machine (black)

The device and operation of the lathe Universal-3

A hollow cylindrical guide is fixed on the machine bed. It is a common base for the main components of the machine: headstock, caliper, tailstock. Another common base for these assemblies is the flat bed rail.

In the front part of the bed under the casing there is a lead screw for the longitudinal movement of the caliper.

A bracket is installed on the left wall of the headstock. It has a machine drive motor attached to it.

Under the cover covering the bracket, there are spindle rotation drive pulleys and a feed drive mechanism.

Additional accessories to the multifunctional lathe Universal-3. Setting up the machine for different types of processing

The machine is supplied in a lathe version. Additional accessories included in the delivery set (see Table 7) are used to carry out other machine versions with the help of simple changeovers: milling and drilling, grinding, jointing, etc.

The accessories are described below and how to adjust for various types of processing.

Tool holders

The scope of delivery includes two tool holders: movable and fixed.

With the help of a movable tool post mounted on a carriage, conical surfaces can be machined. The fixed tool post is attached to the slide of the caliper with a screw and a cracker, which is included in one of the T-slots of the slide. There are two screws in the carriage, which, using the same crackers, fasten the carriage to the caliper slider.

In general, the carriage can be installed in any of the grooves of the caliper slider in accordance with the setup requirements.

For processing tapered surfaces, the carriage should be installed on the slider so that the initial zero stroke of the carriage scale coincides with the risk on the left end of the slider. Such installation is carried out with the help of one screw in the bases of the carriage, which is screwed into a threaded hole specially provided for this purpose, located on the upper plane of the slider between two T-shaped grooves. The price of division of the carriage scale is 1°.

ATTENTION! After turning the carriage to the required angle, it is necessary, in order to avoid an accident, to securely fix it with the fixing screw, as described above.

Collet clamp

The clamp consists of a collet, a nut and a ring, the collet is inserted into the taper hole of the spindle, and the nut is screwed onto the spindle along the thread. With the help of this nut, a workpiece or a cutting tool inserted into its inner cylindrical hole is clamped in a collet moving along its axis.

Milling and drilling device

The device (Fig. 4) is a rack 3, along the guides of which the table 4 moves. The movement is carried out by rotation of the handwheel I, rigidly connected to the lead screw 2. The workpiece is attached to the table with clamps 11 using studs 10, nuts 9, screws 8 and crackers 7 included in the T-slots of the table. In order to adjust the machine for milling or drilling work, it is necessary to fix the stand on the machine support with the help of strips 6 and screws 5, as shown in Fig. 4.

The end mill or drill is fixed in a collet clamp or in a special drill chuck 12 included in the delivery.

Chuck 12 is connected to the spindle using a special shank 13, also included in the delivery.

In addition to clamps, a vice can be used to fix the workpiece, which are attached to the table of the milling and drilling device with screws using crackers. The fixed jaw of the vise has two prismatic grooves that allow you to conveniently fix cylindrical parts.

Kinematic diagram of the lathe Universal-3

Description of the kinematic diagram of the screw-cutting lathe Universal-3

Main drive chain

In this circuit, the rotation of the spindle is carried out from the electric motor 3 through a V-belt transmission (see Fig. 3). 9 operating speeds of rotation of a spindle are provided.

Two steps (200 and 300 rpm) can be obtained if the pulley 13, which is rigidly seated on the motor shaft, is connected with a belt to the intermediate pulley 1, and that, in turn, along the "a" stream, to the pulley 2, freely rotating relative to the motor shaft . From pulley 2, along one of two free streams - "in" or "c" - the rotation is transmitted directly to pulley 9, which is rigidly connected to the spindle.

One stage (650 rpm) is obtained by transferring rotation from pulley 13 directly to pulley 9, bypassing intermediate pulleys 1 and 2.

Two more steps (525 and 1000 rpm) can be obtained by putting a replaceable pulley 12 on the pulley 13 so that the end on which there are cams is turned outward. From pulley 12, as in the first case, the rotation is transmitted to the intermediate pulley 1, and from it along the stream "b" - to the pulley 2, which transmits the rotation of the pulley 9 along the streams "a" or "c".

The remaining four steps (1200, 1700, 2800 and 3200 rpm) are obtained if the motor shaft is connected to pulley 2 through pulley 12 using cams located on one of the ends of the latter. Now, along any of the four streams, rotation can be transferred to pulley 9.

Note: The 1200 rpm stage can also be obtained without connecting the motor shaft to pulley 2.

Feed drive chain

The movement of the caliper to the right and left is carried out by the lead screw 14.

Rotation to the lead screw is transmitted directly from the spindle by a gear II rigidly fixed on it.

Through the gear wheel 10, the rotation is transmitted to the gear wheels 8 and A, then to the intermediate roller 5. There are two options for transmitting rotation to this roller: the first option (indicated by the number I in the diagram) - through the block of gear wheels B-C and the wheel D and the second (indicated by the number II in the diagram) - through gear wheels B and C.

The first option is used for feed during normal turning, the second - for threading. A gear wheel 6 is rigidly connected to the roller 5. From this wheel to the wheel 7, fixed at the left end of the lead screw, rotation can be transmitted either through a pair of gear wheels 15 and 16 - and then the caliper will move to the left, or through the gear wheel 17, which will provide move the caliper to the right. All three wheels (15, 16 and 17) are mounted on the rotary device 4 (see D-D) and are in constant engagement with the gear wheel 6 (central). Thus, it is possible to carry out the movement of the caliper both to the right and to the left with the same direction of rotation of the spindle.

It is also possible to turn off the caliper feed without stopping the spindle rotation. This is ensured by disengaging gears II and 10 using the same rotary device 4 and spring 18.

ATTENTION! To avoid breakage of the gear wheels of the feed drive chain, the inclusion and switching of the direction of movement of the caliper should be performed with the spindle not rotating.

The movement of the tailstock quill and the transverse movement of the caliper are carried out by handwheels through the corresponding screw pairs, as shown in the kinematic diagram.

Electrical equipment of the lathe Universal-3. General information

According to the method of protection against electric shock, the electrical equipment of the machine belongs to class I, i.e. has a working insulation, an element for grounding and a wire with a grounding conductor for connection to a power source and grounding.

The circuit diagram of the machine is shown in Fig. 14, the list of electrical equipment elements is in Table 4. Electrical equipment is located in a separate box (see Fig.1, pos.6). The box is closed with a lid. The cover is attached with two screws, one screw is located in the center of the cover under the rubber mat, the other fixes the cover to the frame, providing grounding of the cover.

Description of the operation of the electrical circuit of the Universal-3 lathe

The electrical equipment is powered from a single-phase alternating current network with a voltage of 220 V, a frequency of 50 Hz.

The start and stop of the electric motor is carried out using the KV relay (see Fig. 14), which is controlled by the SB2 (start) and SB1 (stop) buttons. When starting, the KV relay turns on and becomes self-powered, connecting the electric motor to the network with its contacts and providing zero protection, i.e. shutdown of the electric motor in the absence of voltage in the network. The overload protection of the electric motor is carried out by the starting relay A, which breaks the starting circuit, which turns off the KV relay. Restart is possible only after 15-50 s, i.e. after the return of the thermal protection elements of the start-up relay A to their original position.

When starting the motor, an increase in its starting torque occurs due to the connection of the contacts of the start-up relay A of the starting capacitor C1 in parallel with the working capacitor C2. After the motor accelerates and the starting current decreases, the capacitor C1 is turned off.

Reversing the electric motor is carried out using the switch SA, which, with the middle (vertical) position of the handle, ensures that the electric motor is turned off, i.e. stop it even if the KV relay is on. Handle should be left in neutral position

Screw-cutting desktop machine Universal-3. Video

The Universal-3 machine is shown in which the block of capacitors and the starting relay are replaced by a frequency converter.

Of the benefits, smooth speed control (from hundreds to about 4000).

Of the minuses low torque at low speeds.

Technical characteristics of the Universal-3 machine