The quality of engineering production depends on the quality of the parts produced, which is mainly determined by the manufacturing industry, as well as for vital parts, by forging or hot stamping. Hot forging was developed in the mass and large-scale industry, which consumes more than 60% of stamped forgings.
In the manufacture of high-precision forgings, a crank-forging press (CHFP) plays an important role, which has a steady tendency to increase power. Voronezh Plant for the Production of Heavy Mechanical Presses produces high-frequency physical parts of various nominal capacities. In recent years, various studies have been carried out for the design and production of powerful crank-stamping presses of hot nominal capacity equal to 80 and 125 MN.
The volume of industrial realization of the crank-forming press of the new generation produced by JSC Tyazhmekhpress is described by statistical data on the volumes, structure and geography of supplies on these machines made in the period 1985–2006. Comparison of these data with data on CHFP provided by foreign manufacturers suggests that during this period TMP has become the undisputed leading supplier of these hot forging presses. The volumes of supplied vehicles are on average the following:
TMP in the period 1985-2006. — about 750 items, 50% were exported;
The German company SMS Eumuco — about 500 items over the past 40 years;
Japanese company Sumitomo Heavy Industries — about 100 titles over the past 35 years;
The American company National Machinery — about 500 items from 1950 to the end of the 80s, when the company was forced to abandon the production of CHFP;
The German company Hasenclever — about 200 names from 1950 to 1995.
The advantage of TMP in the field of heavy crank-forging presses (40MN and more) is more obvious, since its productivity in quantitative production is 1.5-2 times higher. Moreover, TMP as a manufacturer of unique equipment (with a capacity of more than 80 million tons) has no competitors.
It is indicative that about 87% of exported CHFP is made up of machines supplied to industrialized countries. In these countries, the forging industries with the most stringent requirements for technology and equipment are most developed.
The design and modernization of these presses required exploration and development work in the following main areas:
1. better durability of the main parts;
2. achieving the required rigidity of the mold system;
3. dynamic stability of the press;
4. Rational manufacturing technology of huge main parts of the press.
Currently, TMP is seeking to develop a 160 MN crank-forging press and automatic lines for the manufacture of crankshafts and front axle beams based on it. With a maximum bearing weight of 200 kg, over 2300 mm in length and technological performance up to 2800 kJ.
The main design features of the private business enterprise OAO Tyazhmekhpress are the following:
— 10, 16 and 25 MN presses are produced without medium shafts (gears).
— The eccentric shafts of all presses do not have the weight of the flywheel. Flywheels are mounted on special plugs attached to the press frame.
— Double-piston calipers and press rigidity at the level of modern samples help to obtain high-precision forgings.
— Press slides orthogonal, frame construction with two counterweights.
— Ensuring the necessary tightening of the press frame and exit from the stop is carried out by special hydraulic nuts mounted on the tie rods in the upper part of the press.
— The eccentric mechanism for adjusting the height of the shutter is moved to the slider, has an electric drive or hydraulic motor with a reading accuracy of 0.1 mm.
— All drive bearings and the actuator are constantly lubricated with oil using the TRABON centralized single-line lubrication system. This system guarantees metered lubrication at every lubrication point.
— Enabled two-stage engagement of an unstressed clutch.
— Stamping capacity indicator with digital readings or computer processing and signal storage.
— The presses are equipped with a continuous monitoring system that provides effective control of the temperature of the bearings, the operation of the lubrication system, the load of the electric motor, stamping performance, etc.
Currently, all the forges of the world have about 17 CHFP with a nominal capacity of 110, 120, 125 and 160 MN and 27 CHFP with a capacity of 80 MN. The manufacture of such heavy presses was carried out mainly in countries with highly developed mechanical engineering (USA, Japan, Germany, Russia) in factories with sufficient technological and production potential.
Heavy chfp are used for the manufacture of heavy forgings weighing 50-150 kg. For example, these may be engine crankshafts, truck front axle beams and pipeline flanges.
Since the manipulation of such heavy forgings by hand is quite difficult, presses are usually basic.