Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B35/00—Drives for metal-rolling mills, e.g. hydraulic drives
  • B21B35/12—Toothed-wheel gearings specially adapted for metal-rolling mills; Housings or mountings therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21B—ROLLING OF METAL
  • B21B21/00—Pilgrim-step tube-rolling, i.e. pilger mills
  • B21B21/005—Pilgrim-step tube-rolling, i.e. pilger mills with reciprocating stand, e.g. driving the stand
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S388/00—Electricity: motor control systems
  • Y10S388/923—Specific feedback condition or device
  • Y10S388/93—Load or torque

Definitions

• the invention relates to a method for torque compensation on the drive of a rolling stand of a vocational step rolling mill, which is linearly reciprocated via a crank drive, in particular a cold pilger rolling mill.
• German patent DE-C-10 64 461 to supplement the crank mechanism that generates the movement of the roll stand with a similar crank mechanism that is operated out of phase by 90 degrees. In this way, there is a constant exchange of kinetic energy between the two crank mechanisms.
• this method has the advantage that the crank speeds and the crank torque, and thus also the engine speed and engine torque, are almost constant over a movement cycle, it has the disadvantage that the mechanical engineering expenditure is very great. This also applies to the space requirement, because deep foundations are generally required. Finally, higher order inertial forces are difficult to balance.
• Another way to solve the problem provides torque compensation by interposing unevenly geared gears. If you accelerate a crank drive that moves a roll stand to a certain speed and then decouple it from the drive, the speed of the crankshaft will change periodically. In the case of freedom from friction, this statement will apply for any length of time. If you now place an unevenly geared transmission between the drive and the crankshaft, which at the constant drive speed on the output side has exactly the speed curve that the crank drive in non-driven state, the crank mechanism can also be driven at a constant engine speed and constant engine torque. The intermediate gear must convert the constant speed into a variable speed, which corresponds to the free speed curve of the crank drive. Since the speed fluctuations of the crank mechanism depend on the respective speed, the transmission behavior of the intermediate gear must be variable.
• An intermediate gear that is actually used for torque compensation is the universal joint, which can be adapted to the speed fluctuations by changing the articulation angle in the joint (DE-A-20 30 995).
• the last-mentioned method also has the disadvantage that a great deal of design effort is required to enable the torque compensation to be set to a specific speed.
• the engine returns to generator mode if the torque compensation is not automatically adjusted.
• the influence of the load on the torque compensation cannot be taken into account.
• the speed curve of the crank drive calculated from the kinematic dimensions, the moving masses and the external loads, is specified as the target speed curve for the drive motor.
• the invention has recognized that an optimal torque compensation can be realized if the target speed of the motor does not become lower than the current actual speed. Generator operation is safely avoided if the target speed of the drive motor always corresponds to the speed to which it is being accelerated or decelerated by the load. To ensure this, it is necessary to know the speed curve that is set. This can be calculated precisely if the kinematic dimensions, the moving masses and the external loads are known. The calculated speed curve, which a friction-free crank drive would have in the state driven with constant torque, is given to the drive motor as the desired speed curve.
• the invention means that acceleration or braking torques no longer have to be applied by the engine.
• the engine In the stationary area, the engine only works against friction losses and external loads. If there is no external load, the engine only works against the almost constant friction losses, the engine torque is then approximately constant.
• the proposed system is operated with a fast computer, which calculates the crank speed depending on the respective crank position and communicates it to the drive system.
• Systems of this type which meet the necessary control speed and control accuracy are state of the art.
• This reduced engine torque is only a calculation variable, it should not be confused with the actual engine torque.
• the actual engine torque will differ from the " reduced engine torque" at least by the proportion for overcoming frictional losses.
• the starting value ⁇ 0 on the basis of which the prediction of the angular velocity curve ⁇ ( ⁇ ) is based, must be determined iteratively. To do this, change ⁇ 0 until the condition With n is met with sufficient accuracy as the predetermined speed average.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
• Control Of Metal Rolling (AREA)
• Transmission Devices (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6431946

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (15)

• 1991
  • 1991-05-15 DE DE4116307A patent/DE4116307C1/de not_active Expired - Fee Related
• 1992
  • 1992-04-30 KR KR1019920007378A patent/KR920021231A/ko not_active Ceased
  • 1992-05-13 EP EP92250121A patent/EP0513954B1/de not_active Expired - Lifetime
  • 1992-05-13 DE DE59201439T patent/DE59201439D1/de not_active Expired - Fee Related
  • 1992-05-14 RU SU925011633A patent/RU2054339C1/ru active
  • 1992-05-15 JP JP4148470A patent/JPH05154511A/ja active Pending
  • 1992-05-15 US US07/883,089 patent/US5291108A/en not_active Expired - Fee Related

Also Published As

Similar Documents

Legal Events