The Izhevsk Machine-Building Plant has produced many units, tools and equipment throughout its history. The IZH 250 lathe has become one of the most popular units, the demand for which continues to this day. Several modifications of this equipment have been produced, which are often used in both large and small enterprises.
With the IZH 250 you can perform many types of turning tasks in a collet, centers or chuck. The metal lathe IZH can produce metric, inch and modular threads.
Purpose of IZH 250
The metal lathe IZH 250 ensures high-quality execution of final operations. To perform turning, which does not require great precision and places significant loads on the machine, it is worth choosing another modification of the equipment - 250 ITP. To meet demand, Izhmash released several modernized versions of the IZH 250:
- IZH 250 ITVM.03 has a larger distance between centers, which makes it easy to process parts of non-standard shape.
- IZH 250 ITVMF1 is a unit with a digital indicator, which increases convenience, accuracy and efficiency.
- IZH 250 ITPM is used for low-precision turning operations.
Operating rules
Basic safety rules and general requirements for personnel when operating machines of the IZH family (briefly):
- Personnel without appropriate professional qualifications and clearance are not allowed to perform operations;
- Before starting work, the integrity of the power cable and the condition of the network are checked;
- the equipment must be connected through a circuit breaker duplicating the main protection system;
- the staff uses a full set of workwear, including, in addition to trousers and overalls with long sleeves, tightly fastened cuffs, safety glasses and a beret;
- Before starting work, you should check the functionality of the machine by starting it at idle speed;
- Preventive inspections must be carried out to check for debris getting into the gear shift system, drive lubricant replacement, and assessment of the condition of the pulleys.
After turning operations are completed, all working surfaces are cleaned of chips, dirt, and waste.
The machines of the IZH 250 family have operating features.
- The switching system with 12 adjustment positions is robotic.
- A mnemonic type of control is used, which ensures quick adaptation. However, personnel must read the documentation and undergo training before starting work.
- The condition of the fingers and gears of the switching unit must be checked periodically.
In addition to the intricacies of working with the gearbox, the features of the machine include blocking the feed in two directions simultaneously, which may require some getting used to by busy personnel.
Advantages of 250 ITVMF1
The 250 ITVMF1 is most in demand in modern conditions due to the additional digital indicator. It guarantees high productivity without loss of quality. The indicator allows you to speed up the measurement of the geometry of the workpiece and perform an approximate pass.
The dimensional accuracy ranges from 0.1 to 100 microns. And also, the operator does not need to remember the number of dial revolutions; independently, and sometimes manually, determine the characteristics and parameters. The machine automatically compensates for minor problems with the interaction of its own parts and wear of the cutting parts.
To count lateral movements with high accuracy – up to 0.005 mm/rev – the machine is equipped with a vernier mechanism. The lead screw connects directly to the guitar without the need for a gearbox.
ITV modifications comply with GOST 8-82 accuracy class B, ITP machines - P.
Structure of IZH 250ITVMF1
Screw-cutting lathe
The universal high-precision screw-cutting lathe 1I611P replaced its predecessor IZH-250 in the early sixties and was replaced by the 250ITVM machine of various modifications.
The production of machine tools at the arms factory affected the quality of the equipment. The use of high-quality steels, high-precision equipment for production, advanced technologies for the manufacture of parts and assemblies has made this brand a reliable, accurate and sought-after unit of the tool group.
Purpose and scope of application
The machine is designed to perform finishing and semi-finishing work in single or small-scale production. In the manufacture of parts from non-ferrous and ferrous metals it is possible
Use jaw chucks, collet chucks and centers. The relatively light weight and low level of power consumption allows operation in a PARM, on a ship, or in a multi-story building.
Performance Features and Benefits
The operational characteristics of the device allow processing of parts with the following diameters:
- above the bed up to 250 mm;
- above the caliper up to 125 mm;
- the longest workpiece length that can be processed is 500 mm;
- spindle rotation speed varies from 20 to 2000 rpm;
- longitudinal feed range from 0.01 to 1.8;
- cross feed range from 0.005 to 0.9;
- number of electric motors – three;
- power - three kW.
The design features of the machine allow you to:
- Turning works: turning; cutting metric, modular and inch threads; production of conical parts.
- Milling (using a four-jaw chuck, milling device on a caliper).
- Grinding (internal processing in the chuck and centers).
- Machining with end fixtures mounted in a drill chuck.
Specifics of the machine design
The largest diameter of a part that can be processed by the unit above the bed is 240 mm. The workpiece processed above the support can have a diameter of up to 168 mm. The longest workpiece length is 0.5 m.
The direct rotation frequency of the spindle has a wide range - from 63 to 3150 rpm. The spindle can be rotated in reverse at the same speed. Metric thread pitch ranges from 0.2 to 24 mm.
And also the screw-cutting lathe works with the following nuances:
- Automatic lubrication of the lead screw when cutting threads.
- Large range of adjustment of spindle speed and feed.
- The machine apron is equipped with a stop that can protect against overloads and, thanks to which turning can be carried out against a rigid stop.
- There are no gaps when attaching the cutter, which increases the rigidity and accuracy of its position during operation.
- The presence of preselective control, which allows you to select the spindle speed and prepare the machine for the next operation.
- The convenient structure of the spindle unit allows you to quickly and easily change drive belts, without disassembling the unit itself.
- The universal gearbox allows you to cut any type of thread without changing the gears on the guitar.
- The frame is made of cast iron with additions of chromium and nickel, the guides are very smooth and hardened with high frequency currents.
- The mnemonic principle of feed is carried out by a lever, the movement of which coincides with the direction of movement of the cutter.
Operation of the IZH 250 machine
Initial start-up of the machine
Before starting the machine for the first time, you must:
1) Check the presence of oil in the gearbox, the left pedestal reservoir, the feed box, and the apron.
2) Check the grounding of the machine; If the machine is not grounded, ground it.
3) After connecting to the network, the machine must be turned on at the minimum number of spindle revolutions, warm it up for 10..15 minutes, then check the operation of the machine mechanisms and oil pumps at idle speed and begin setting up the machine for its operation.
Control Features
The equipment drive has an electric motor with a power of 3 kW, a gearbox with 12 speed modes, and a system of V-belts and poly-V-belts. To change the operating mode, the turner turns the flywheel, which creates a combination of holes into which the fingers of the levers fit to engage the gear blocks. The gears stop their movement by pulling the lever, which allows you to change the speed of the machine.
The IZH 250 screw-cutting lathe is equipped with a closed apron that provides transverse and longitudinal feeds of the caliper manually and mechanically, and thread cutting using a lead screw. The locking device does not allow the lead shaft and lead screw to be turned on together.
The unit requires three phases, a voltage of 380 V with a current frequency of 50 Hz and 36 V for local lighting. Connection to the electrical network is made using a package switch.
In some embodiments of the IZH 250, a change in the spindle rotation speed occurs due to a change in the rotation speed of the engine drive shaft without the participation of a gearbox. For such models, electric motors with a power of 5.5 kW are used.
Electric motors with a power of 5.5 kW. for lathe
conclusions
IZH 250 is a legendary machine from IZHMASH, which for several decades has still remained in demand at any production enterprises. It was released in both the basic version and three upgraded versions. The design is optimized for turning small metal parts. Power units are characterized by increased performance and good service life.
The design has good protection against potential failure. The 12-speed gearbox makes it possible to optimize processing time while guaranteeing energy savings. When making a purchase, you should definitely pay attention to the general visual condition, operation of the engine and gearbox, and also make sure that there is no abrasive on the drive belts.
If all the requirements set out by the manufacturer are met, the IZH-250 lathe will ensure trouble-free processing of metal products for several decades.
Operational problems and safety rules
Problems when operating a lathe can arise if the equipment is not properly maintained or handled incorrectly.
Factors that influence the quality of turning are:
- incorrect sharpening of machine cutting parts;
- incorrect selection of operating mode;
- discrepancy between the axes of the centers during work in the centers due to the deviation of the tailstock during transverse movement;
- weak fixation of the incisor;
- poor spindle mounting.
Turning operations with metal workpieces can be accompanied by dangerous phenomena and factors:
- electricity;
- shavings and pieces of metal;
- heating of processed workpieces and equipment;
- moving parts and mechanisms;
- insufficient lighting of the work area;
- the appearance of reflections.
To ensure safety, the machine has protective covers and guards for the working area, guitar, and rotating parts. When performing turning operations, it is prohibited to remove the protective guards. It is important to keep the work area and equipment clean. And also be sure to wear special clothing - a suit that covers the body from possible metal penetration, and safety glasses.
Before starting work, be sure to check the cleanliness of the work area, put on protective clothing and protective accessories, check the presence of machine safety devices, lubrication of parts and serviceability of the equipment. Including adjusting the lighting.
Electrical diagram of the machine
Advantages and technical characteristics of the TV 7m lathe
The electrical circuit of the machine is given in the operating manual (passport). The life of the machine is ensured by three asynchronous electric motors: one motor drives the main mechanisms associated with the direct purpose of the machine, and the other two motors ensure the operation of the lubrication and cooling system.
Electrical circuit of the machine 1I611
To operate the main drive, one mains voltage is used, which is agreed upon with the customer during the machine ordering process. As for auxiliary electrical components, they are powered by the following voltage classes: 36 V is used for local lighting; for control circuits 127 V, and for braking circuits 60 V.
The electrical circuit provides protection of electric motors from technological violations, in particular from overload and short circuit. On machines of early models, motor protection from short circuits is carried out by fuses, and on new models - by automatic switches with built-in electronic protection units.
Electric motors are protected from overloads by thermal relays that respond to an increase in the stator circuit current.
https://youtube.com/watch?v=GbuH7ypauAY
Overview of operational requirements for electrical equipment:
- Motor bearings must be inspected and lubricated at least twice a year. To flush the bearings, before changing the lubricant, you should use only gasoline, preferably aviation grade;
- Electric motors and starting equipment should be cleaned of dust and dirt according to a schedule. Do not allow oil or other corrosive liquids to come into contact with the insulation of electrical equipment. This may lead to its destruction;
- at least once every 10 days, the reliability of all contact connections of the electrical circuit should be checked;
- periodically clean the cores of electrical equipment from corrosion. The presence of corrosion on them leads to a strong buzzing of these devices;
- If the machine is turned off by the protection systems, it can be turned on again only when the reason for the shutdown has been established.
How used is the model today?
Despite the rather “ancient” year of launch into mass production, the IZH 250ITVM passport is still of the old USSR type, but its performance is equal to modern modifications of similar equipment. Today it is supplied to private workshops, school classrooms and secondary construction education institutions without major differences from the original model.
Comparing the design of the machine with alternative multifunctional units, the old IZH 250 loses in many respects, but even such competition cannot completely suppress the demand for these models. The 250ITVM passport does not have superior characteristics, but the accuracy of work on this device can amaze even an experienced modern master of parts processing.
The model lags behind its competitors in terms of ergonomics, number of manufactured parts, lack of computer control and other indicators. But every review of devices capable of thread cutting cannot do without this basic representative of the class.
List of machine controls 250.01, 250F1
- Spindle speed selection handwheel
- Spindle speed switch
- Handles for selecting feed rates and thread pitch
- Handles for selecting feed rates and thread pitch
- Handles for selecting feed rates and thread pitch
- Shift knob
- Switching handle for bit and pitch increase link
- Cooling pump switch
- Input switch
- Main switch locking lock
- Digital display for machine 250 F1
- Lubrication station switch
- Button for general stop and emergency shutdown of the machine
- Manual longitudinal feed handwheel
- Manual cross feed handle
- Tool holder fastening handle
- Lead screw nut on/off handle
- Flywheel for moving the upper slide
- Light switch
- Quill clamp handle
- Handle for securing the tailstock on the machine
- Quill movement flywheel
- Nut for securing the tailstock to the bed
- Feed reverse handle
- 3Start and stop handle
- Safety mechanism adjustment screw
List of components of the machine 250.01, 250F1
- Bed 10.000 (03.10.000]
- Gearbox 17.000
- Feed box 30.000
- Guitar 25.000
- Front headstock 21.000
- Electrical equipment 90.000
- DRO layout F1.94.000
- Guard (cartridge) 86.000
- Apron 50.000
- Four-position tool holder 61.000
- Guard (support) 89.000
- Caliper 60.000
- Cooling 70.000
- Tailstock 40.000
- Fencing 10.02.000
- Grease 74.000
Features and capabilities
Analyzing the drawings of the 250ITVM, you can notice a lot of docking points for additional modules. The passport of the improved model is characterized by superior technical parameters, which allows for work with maximum loads. The accuracy of this model is ensured by a special digital indicator, thanks to which there is no need to spend a lot of time for manual measurement of workpiece parameters, and the need for trial runs is also eliminated.
Machine appearance
The Izhevsk plant has provided the ability to connect highly efficient modules even to basic standard equipment; this feature is used during modernization.
The 250ITVM installation is equipped with a function for fixing the head of the cutting tool without clearance. By carving using this technology, maximum rigidity, stability and accuracy are maintained throughout the operation. During thread cutting, the main lead screw is automatically lubricated. Thanks to the unique design of the spindle module, instantaneous change of drive belts is possible, and disassembly of the hub unit is not required.
