US3733870A - Rolling mill employing non-variable prestressing - Google Patents

Rolling mill employing non-variable prestressing Download PDF

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Publication number
US3733870A
US3733870A US00193355A US3733870DA US3733870A US 3733870 A US3733870 A US 3733870A US 00193355 A US00193355 A US 00193355A US 3733870D A US3733870D A US 3733870DA US 3733870 A US3733870 A US 3733870A
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United States
Prior art keywords
prestressing
jack
jacks
conduit means
pressure chamber
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US00193355A
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English (en)
Inventor
L Diolot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Societe Nouvelle Spidem
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Societe Nouvelle Spidem
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Publication of US3733870A publication Critical patent/US3733870A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B31/00—Rolling stand structures; Mounting, adjusting, or interchanging rolls, roll mountings, or stand frames
    • B21B31/02—Rolling stand frames or housings; Roll mountings ; Roll chocks
    • B21B31/028—Prestressing of rolls or roll mountings in stand frames
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
    • B21B37/58—Roll-force control; Roll-gap control
    • B21B37/64—Mill spring or roll spring compensation systems, e.g. control of prestressed mill stands

Definitions

  • ABSTRACT pp 193,355 In a rolling mill in each upright there is provided a first hydraulic jack forming part of a hydromechanical 3 F i n ti 1 D clamping system and a pair of second hydraulic jacks 0] ore App ca on Pr on y am forming part of a prestressing device.
  • One side of a Oct. 28, 1970 France ..7038962 cylindcr of a plunger piston jack also forming part Of the hydromechanical clamping system communicates [52] US. Cl ..72/245 with the pressure chamber of the first hydraulic jack, [51] Int. Cl.
  • the present invention relates to a rolling mill equipped with a hydromechanical clamping system, with which a prestressing device is very closely associated for the purpose of maintaining the force exerted by such prestressing at a substantially constant and furthermore optimum value.
  • the rolling mill according to the present invention has the same fundamental elements as those of the rolling mill disclosed in U.S. Pat. No. 3,578,766.
  • a main clamping jack associated with a plunger jack of small section and long stroke, in such manner as to maintain captive a constant quantity of fluid within the volume constituted by the pressure chamber of the clamping jack, the working chamber of the plunger jack and the conduit system interconnecting these two chambers;
  • the rolling mill comprises, in each stand, a system of prestressing jacks constituted, for example, by two identical jacks disposed between the backing-up chocks.
  • a first modification introduced into the machine thus defined consists in interconnecting the two pressure chambers of the prestressing jacks associated with one and the same upright.
  • the common space thus obtained is connected, by means of a conduit system of suitable section, to the pressure chamber of the plunger jack associated with the same upright.
  • an external pressure source which may be isolated at will from the conduit with the aid of blocking means.
  • the invention makes it possible to define a relationship between the sections of the pistons of the various jacks involved in the regulation of the rolling mill, in such manner as to optimize and, at the same time, render constant the prestressing force to be exerted.
  • FIGURE schematically shows one of the machine uprights and the clamping means associated therewith.
  • Reference numeral 1 designates the machine upright (or stand) containing the rolls 2 and 3 and also their chocks 4 and 5; 6 designates the main clamping jack, 7 and 8 the prestressing jacks.
  • Reference numeral 9 designates the plunger piston jack, which is of small section and has a long travel and which is associated through a first conduit means 13 with the clamping jack 6.
  • the jack 9 is subjected, as known, to the action of a regulating device, for example, an electromechanical device (not shown).
  • the pressure chambers of the jacks 7 and 8 are hydraulically interconnected by a second conduit means 14 and are connected with the cylinder of the jack 9 by a third conduit means 15.
  • a source of external pressure 10 communicates with the conduit means 15 through a fourth conduit means 16. The said source may, however, be isolated from the conduit means 15 with the aid of a blocking means 11 disposed in the conduit means 16.
  • the FIGURE also shows three elastic chains in the upright representing three force paths, as explained in detail in the aforenoted U.S. Pat. No. 3,673,843.
  • the long chain I extends from the, points A and B and passes successively through a portion of the upper chock 4, a fixed wedge 12, the upper horizontal beam of the stand 1, the vertical part of the stand 1, the lower horizontal beam of the stand 1, the clamping jack 6 and finally, a portion of the lower chock 5.
  • the short chain II extends only through the two chocks 4 and 5 and the associated prestressing jacks 7. It is noted that for both chains 1 and II symmetrical traces (not shown) pass through the opposite half of the same components l-8 and 12. With regard to the chain III, it is rectilinear and extends through the rolls 2, 3 and the metal undergoing treatment.
  • K1 is the yielding coefficient of the long chain 1
  • K2 is the yielding coefficient of the short chain ll
  • K3 is the yielding coefficient of the rolls and metal chain Ill
  • h is the distance between the points A and B common to the three chains
  • AL is the momentary displacement of the plunger jack 9
  • s1 is the total section of the working chamber at one side of the piston in the jack 9, i.e., of a first compartment of the said jack which is permanently associated with the pressure chamber of the jack 6,
  • Z1 is the section of the latter chamber
  • s2 is the section of the working chamber at the other side of the piston in the jack 9, i.e., of a second compartment of jack 9 and is equal to sl reduced by the section of the rod of said piston; said second compartment is permanently associated with the pressure chambers of jacks 7 and 8,
  • Z2 is the section of the assembly of the two pistons of the prestressing jacks located in the same upright and interconnected in parallel and connected to that side of the pressure chamber of the jack 9 in which the active section of the piston is s2,
  • rl (s1/Zl) is the ratio of the hydraulic reduction between the hydromechanical regulation and the clamping
  • r2 (s2/Z2) is the ratio of hydraulic reduction between the hydromechanical regulation and the prestressing.
  • the invention will refer more particularly to the last two, i.e., to the ratios rl and r2; according to the invention, it is required to make these two ratios equal to each other. This will make it possible to determine one of the sections of the pistons involved, if the three others are known.
  • the two coefficients K1 and K2 may be considered as being of the same order of magnitude; thus, their ratio may be considered to be I. It thus follows that a given variation AFl causes a variation AF2, the magnitude of which is inversely proportionate to the yielding coefficient K3 of the chain III.
  • a further important advantage of the invention is that it thereby becomes possible to control, by a single manipulation, i.e., by manipuiation of the control rod of the plunger jack piston 9, the entire regulation of the machine.
  • control is obtained of the closure of the blocking means 11 isolating the pressure source 10 from the connecting conduit between the prestressing jacks 7, 8 and the plunger jack 9; on the other hand, as known from French Pat. No. 1,213,820, which relates to hydromechanical clamping, single and adequate manipulation for simultaneously controlling regulation of the two rolling mill uprights is achieved.
  • the said single manipulation also suffices in the case of the improved rolling mill according to the present invention.
  • the prestressing force F2 is exerted on the upstream face of the piston of the jack 9, in the same direction as the force normally exerted on this same face due to the regulating manipulation.
  • it thereby becomes possible to reduce the force required by the said manipulation, i.e., to reduce the power of the associated control motors by the magnitude corresponding to the prestressing force F2.
  • a rolling mill employing hydromechanical clamping and prestressing and being of the known type that has (a) a plurality of stands, (b) at least two rolls, (c) a chock held in each stand to support each end of each roll, (d) a main clamping jack incorporated in each stand for urging said rolls towards one another and including a pressure chamber, (e) a piston plunger jack of small section and large stroke and including a hydraulic cylinder and a piston movable therein, (f) first conduit means for maintaining communication between said cylinder and the pressure chamber of said main clamping jack, (g) hydraulic fluid of constant quantity maintained captive between said jacks, (h) at least two prestressing jacks incorporated in each stand between the chocks held therein to exert a separating force thereto, each prestressing jack including a pressure chamber, (i) means supplying hydraulic fluid under pressure to the pressure chamber of each prestressing jack, (j) blocking means for arbitrarily isolating said means supplying hydraulic fluid, the

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Metal Rolling (AREA)
  • Control Of Metal Rolling (AREA)
  • Actuator (AREA)
US00193355A 1970-10-28 1971-10-28 Rolling mill employing non-variable prestressing Expired - Lifetime US3733870A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7038962A FR2110734A5 (enrdf_load_stackoverflow) 1970-10-28 1970-10-28

Publications (1)

Publication Number Publication Date
US3733870A true US3733870A (en) 1973-05-22

Family

ID=9063433

Family Applications (1)

Application Number Title Priority Date Filing Date
US00193355A Expired - Lifetime US3733870A (en) 1970-10-28 1971-10-28 Rolling mill employing non-variable prestressing

Country Status (5)

Country Link
US (1) US3733870A (enrdf_load_stackoverflow)
DE (1) DE2152747A1 (enrdf_load_stackoverflow)
ES (1) ES396356A1 (enrdf_load_stackoverflow)
FR (1) FR2110734A5 (enrdf_load_stackoverflow)
GB (1) GB1372257A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4087999A (en) * 1976-11-24 1978-05-09 Vydrin Vladimir Nikolaevich Device for automatic adjustment of roll gap in mill stand
US4095448A (en) * 1976-02-20 1978-06-20 Schloeman-Siemag Aktiengesellschaft Roll housing of divided construction with removable housing cap
US4973001A (en) * 1988-05-03 1990-11-27 Krupp Polysius Ag Material bed roller mill

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4095448A (en) * 1976-02-20 1978-06-20 Schloeman-Siemag Aktiengesellschaft Roll housing of divided construction with removable housing cap
US4087999A (en) * 1976-11-24 1978-05-09 Vydrin Vladimir Nikolaevich Device for automatic adjustment of roll gap in mill stand
DE2654891A1 (de) * 1976-11-24 1978-06-08 Tscheljabinskij Politekhn I Im Vorrichtung zur automatischen regelung des walzspaltes im walzgeruest
US4973001A (en) * 1988-05-03 1990-11-27 Krupp Polysius Ag Material bed roller mill

Also Published As

Publication number Publication date
ES396356A1 (es) 1974-05-01
GB1372257A (en) 1974-10-30
FR2110734A5 (enrdf_load_stackoverflow) 1972-06-02
DE2152747A1 (de) 1972-05-04

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