US2736217A

US2736217A - Blain

Info

Publication number: US2736217A
Authority: US
Priority date: 1952-09-16
Publication date: 1956-02-28
Anticipated expiration: 1973-02-28
Also published as: FR1063351A; GB743233A; DE944846C

Description

Feb. '28, 1956 P. BLAlN 2,736,217

ADJUSTING DEVICE IN ROLLING MILLS Filed Oct. 18, 1952 5 Sheets-Sheet 1 Fyiz fiqfz 2 12 0 6 2 In van/"0r du/ 5/0/77 Feb. 28, 1956 P. BLAIN 2,736,217

ADJUSTING DEVICE :N ROLLING MILLS Filed Oct. 18, 1952 5 Sheets-Sheet 2 In ven for; Pau/ B/a/ Feb. 28, 1956 P. BLAIN 2,736,217

ADJUSTING DEVICE IN ROLLING MILLS Filed Oct. 18, 1952 5 Sheets-Sheet a In venfor Paul fi/a/n /2,' 7

flff'orng/ Feb. 28, 1956 P. BLAIN ADJUSTING DEVICE IN ROLLING MILLS 5 Sheets-Sheet 4 Filed Oct. 18, 1952 Feb. 28, 1956' P. BLAlN 2,736,217

ADJUSTING DEVICE IN ROLLING MILLS Filed Oct. 18, 1952 5 Sheets-Sheet 5 lllllhlll I H van 7%) Pau/ 5/4/77 United States Patent ADJUSTING DEVICE IN ROLLING MILLS Paul Blain, Firminy, France, assignor to Societe Anonyme des Acieries et Forges de Firminy, Paris, France Application October 18, 1952, Serial No. 315,482 Claims priority, application France September 16, 1952 3 Claims. (Cl. 80-56) In rolling mills of conventional design the gap between the rolls is adjusted with the aid of screws or occasionally of wedges arranged in the standards and acting through the medium of chocks upon the trunnions of said rollers. The force exerted by the rolls upon the product in the course of the rolling process results from the elastic deformation of the whole system comprising the standards and the various parts subjected to the force. Such an elastic deformation, known as the yield, is far from being negligible. Of course, it is dependent on the force exerted upon the product during the rolling process, which explains why, with a definite set of the screws and wedges, such a rolling mill can only deliver a finished product of uniform thickness on condition that beforehand the material to be subjected to the rolling process is uniform in thickness and hardness, a requirement which is scarcely satisfied. The yield, in addition to its detrimental effect upon the uniformity of thickness of the rolling product, is also the cause of difficulties where fiat products are rolled on plain rolls.

Effectively, with the band material carefully presented parallel with the axis of the rolling mill and the rolls set exactly parallel with one another, if the band happens to creep sidewise towards one of the standards, an increased force is exerted upon the latter while the stress upon the opposite standard is decreased correspondingly. As a consequence of the yield the rolls can no longer remain parallel; instead, they will move apart from one another at that end of the rolls towards which the band started creeping and towards one another at the opposite end. In these conditions the transversal displacement of the band together with the inclination of the rolls relative to each other become more and more considerable and the band drifts sidewise as far as the trunnions.

These few considerations show how desirable would be a device capable of keeping the rolls parallel with and at a constant distance from one another irrespective of the force exerted thereupon during the rolling process.

My invention relates to an adjusting device in rolling mills by which the problem just set forth is resolved. It consists of various combinations and arrangements of parts to be described hereinafter, which notably include a pair of measuring devices adapted very accurately tomeasure the distances between trunnions provided for that purpose at either end of the companion rolls and consequently the distances between the rolls themselves at either end of the pair, together with means controlled automatically by said measuring devices and adapted in each standard to move the trunnions towards or away from one another depending on whether the distance measured is larger or smaller than the desired distance; in a preferred embodiment of my invention the said measuring devices are metrological pneumatically operating apparatus adapted to set electric or electronic and hydraulic relays into action which regulate the squeezing action of the rolling mill.

A preferred embodiment of my invention will be de- Figure 5 is a cross sectional view of the standards' and shows the hand-operated mechanism for the adjustment of the rolls according to line VV of Fig. 4.

Figure 6 diagrammatically shows the pneumatic, elec-,

trio and hydraulic circuits controlling the operation of the regulating device.

Figure 7 takes up the same diagram again in the form of an automatically controlled system.

The rolling mill illustrated is of the two-high type,

it being understood that my new adjusting deviceis also applicable to rolling mills of any other kind, notably of the four-high type. The apparatus adaptedto ascertain the relative positions of the cylinders engage bearing surfaces providing coaxial extensions of the working cylinder trunnions and include pneumatic feelers, it being understood that the feelers may be caused to act through other, e. g. hydraulical, electrical, magnetical or like transmission fluids. i

In the rolling mill diagrammatically shown in Fig. l,

the two

companion rolls

1 and 2 are provided with

trunnions

3, 5 and 4, 6 respectively which are mounted in chocks retained in the standards.

Cylindricalbearing surfaces

7, 8, 9 and 10 provide coaxial extensions of the trunnions, of which the

ones

7 and 8 are located on the service side of the mill while the

others

9 and 10 are located on the opposite side between the

trunnions

5, 6 and the

couplings

11, 12. I

The said bearing surfaces are designed to cooperate with apparatus adapted to keep the distances 13 and 14 constant irrespective of the rolling pressure, said apparatus providing the discriminator in the power relay of my adjusting device.

As shown more particularly in Fig. 2 the apparatus includes a frame 15 formed in its lower portion with four

abutments

16, 17, 18, 19 designed to engage the bearing surface providing the extension of the lower trunnion and in its upper portion with one single abutment 20 designed to rest on the corresponding bearing surface providing the extension of the upper trunnion. Thus, the apparatus is designed to rest on said bearingsurfaces at five points which are so located that it is only able to i move parallel with the axes of the rolls. In fact, the way in which the apparatus is rested on the bearing surfaces practically confers a well defined position upon it, as will be explained later on; anyway, a slight displacement of the apparatus parallel with the axes of the-rolls is of no consequence upon the result of the measurement since the rolls are parallel. Vertically guided in the frame of the apparatus is a slide 21 which carries. a feeler- 22 which normally engages the underside of the upper bearing surface, whereby the relative position of the companion rolls is ascertained. The said slide can be moved up and down by means of a mechanism including a Cardan joint 27, a pair of bevel gear wheels 25, 26 and a worm spindle 24, the whole of which provides the roll adjusting means.

In order that the apparatus may function dependably it is necessary that the slide should occupy a well defined 1 position relative to the frame. With this end in view, as shown in Fig. 3, the frame carries a perforate hardened steel plate 28 the ground surface of which has a vertical V-seetioned groove. 29 cut. therein. The slide is provided with three

rest studs

30, 31, 32 with ball shaped ends.

Two of them 3%), 3-1. engage the bottom of the said V-sectioned groove while the third one 32 engages the plane ground surface of the. plate. A spring 23 anchored to. the slide at about. the centre of the circle inscribed inthe base triangle keeps the slide: in engagement with the plate and at the same time with the apex of the worm spindle 24,.

' Eachv stud 3.1,. 30 engages the said V-sectioned groove at two points while the third stud 32 rests onv the plate at one single point. On the other hand, the slide avails of a further rest on the frame through the medium of the worm spindle 24, so. that to any given position in which the. worm, spindle is set there corresponds a well defined position of the slide relative to the frame.

With. the apparatus set in position on the bearing surfaces, as Shown in Fig. 4 it is kept in engagement therewith by the tension of a coil spring 33 anchored at its one end to the frame of the apparatus at 35 and at its opposite end to one of the uprights of the standard at 34. The pull exerted by the spring 33 upon the whole apparatus is so directed that all of the five abutments- 16, 17, 18, 19, 20 are. kept in engagement with the related bearing surfaces. Although as already stated the apparatus with its five abutments resting on the cylindrical bearing surfaces it will nevertheless assume a position of equilibrium which is symmetric with respect to the plane normal to the axes of the rolls through the point 34 at which the spring 33' is anchored to the. standard upright.

A pair of operating handwheels 36 and 42' illustrated in Figs. 4 and are provided which are adapted through the medium of the mechanism including the Cardan

joints

37 and 27, bevel gear wheels 26 and 25 and the worm spindle 24 to adjust the apparatus at either side of the rolling mill and also through the medium of a mechanism to be' described hereinafter, to set the two rolls parallel and then to'regulate the distance therebetween.

Apparatus secured to a rolling mill in the manner just described can be fixed and removed quite readily, so that the removal of the rolls is not delayed materially. In taking away the apparatus it is only necessary to detach the spring 33, to disengage a telescopic coupling (not shown) provided: between the Cardan

joints

27 and 37 and to hook the apparatus on a bracket provided at a point on the standard upright where it will not interfere with aneasy dismounting of the rolls. The same procedure is followed in setting the apparatus back to operative position, forwhich just as little time isrequired.

The mechanism shown in Fig. 5 and designed to adjust the distance between the mill rolls includes ashaft 38 extending through the rolling mill and adapted through the medium of the bevel gear wheels 39, 40 to act upon the Cardan shaft 41 assigned to the apparatus arranged at the back side of the mill. The hand-wheel 42 designed to. adjust the apparatus arranged at the front side of the mill is. keyed on a hollow shaft 43 and is adapted through the medium of the bevel gear wheels 44, 45 to act upon the Cardan shaft assigned to the apparatus located on said front side. Each hand-wheel can be manipulated separatelyr for the purpose of settingthe two rolls parallel with each. other, upon which they can be locked together and thence manipulated. as one single unit for the purpose of adjusting. the distance between the two rolls.

Such a hand-operated adjusting device is quite simple in. design, and it obviously remains within the scope of this invention to replace it by more elaborate means involvingthe use of electric. control motors. and reduction gears.

The pneumatic circuit 47 illustrated in Fig. 6 consists of a well known system commonly used in machining shops. toe-heck the. dimensions of parts and to ensure that said dimensions remain within predetermined limits. The

circuit is supplied with air at a pressure of 6 atm. from the plant main through a pipe 48. The air can flow in two directions through a T-union 4%. included in each branch pipe leading from said T-union is a head nozzle 50, 51 respectively and a tail nozzle.

The one 52 of said tail nozzles has a fixed section which is controlled by means of a needle valve. The other tail nozzle 22 consists of a feeler and its section is variable in dependency on the longitudinal position of the feeler. A diaphragm manometer 54 provided with a contact 55 through which an electric circuit is opened or closed is responsive to the difference in the pressures prevailing in the pipes between the corresponding head and tail nozzles. Even an extremely slight displacement of the feeler will result in a sign change in the said pressure diflerence and consequently in the opening or the ciosin g of the electric circuit.

The electric circuit 56 includes a voltage source 57, contact 55 arranged in the aforementioned manometer 54 and the coil 58' of a hydraulic electro-valve 59. The said circuit has been simplified designedly for the sake of simpleness, it being understood that it may include auxiliary electromagnetic of electronic relays so that the contact in, manometer 54 may not be loaded too heavily.

The hydraulic circuit is similar to the one described in the U. S. Patent No. 2,523,553 dated September 26, 1950; and granted to Paul Blain. The source 60' or" lowpressure fluid comprises a pump 61 and a by-pass 62 controlling the pressure. The aforementioned hydraulic electro-valve 59 sets the low-pressure side 63 of an intensifier with either the source of pressure or with the discharge depending on Whether the coil is energized or not. The. high-pressure side 6.4 of the intensifier is connected with one of the jacks controlling the distance between the mill rolls.

It is. to be understood that what has just been described corresponds to the adjusting means assigned to one of the standards of the rolling mill. The other standard is equipped with similar means which however are completely independent of the former.

The operation of the adjusting means is as follows:

The contact 55 in the manometer 54 closes when the feeler indicates that the distance between the axes of the rolls on the side considered exceeds the value set with the aid of the operating handwheel. With the said contact thus closed the coil 58 of the hydraulic electro-valve 59 is energized and a communication is established through said valve between the source of pressure 60 and the low-pressure side 63 of the hydraulic intensifier. Thereby,, oil is caused to flow from the intensifier 64 towards the adjusting jack 65 assigned to the standard, with the result that, the. force exerted by said jack is increased. The trunnions are moved towards each other until the distance between. their axes as ascertained by the feeler 22 becomes. less than the distance set, whereby the circuit is opened at the contact 55 of manometer 54. The coil 58 of the hydraulic electrovalve 59 is thus de-energized, so that the latter sets the low pressure side of the intensifier 63 into communication with the discharge pipe 66. The oil flows are thus reversed and the force exerted by the jack 65 assigned to the cage is decreased.

The result, is that. the: trunnions are now moved away from each. other until their interaxial distance is signaled by the feeler 22 tobe in excess of the prescribed value, when the contact 55 in manometer 54 will close once more. The cyclev just described is repeated over and over again. Consequently, the force exerted by the jack assigned to the standard is continually subjected to variations of small amplitude to either side of a mean value which is precisely the one by which the desired interaxial distance as set with the aid of the hand-wheel is obtained.

The working of this adjusting mechanism will now be described more specifically, some technical terms being 5 used which are well known in the art of automatic control mechanisms.

As shown in Fig. 7, the arrangement conforms with the diagram of principle of automatic control systems: the feeler 22 constitutes the discriminator of the system and compares the input magnitude as which is set by the manipulation of the adjusting hand-wheel 36 with the output magnitude Y which is the distance between the trunnions, i. e. between the working generatrices of the rolls. The pneumatical device 47, the electric circuit 56 and the electro-valve 59 as a whole constitute a relay with no neutral position adapted depending on the sign of the difference to set up a flow of definite value in either of two directions through the hydraulic circuits constituting the intensifier. The adjusting jack 65 is the prime mover in the automatic control mechanism. The whole plant constitutes the direct chain of the automatic control mechanism, the reaction chain of whichrepresented by the line 67 in the diagramimpresses the magnitude y upon the discriminator. The said automatic control mechanism belongs to the class of self-oscillating systems with impulse modulation. The frequency of self-oscillation may be influenced by known means with a view to bringing it to a value consistent with the accuracy aimed at. When no difference is signalled the volumes of oil that flow into and out of the adjusting jack in the course of a cycle are equal. The difference signal is eifective to create a difference between the said volumes by modulating the impulses.

What I claim is:

1. A device for maintaining the initial parallel setting and reference spacing of a pair of rotary rolls mounted in bearings supported by a pair of uprights, said pair of rolls having extensions on either side of said bearings in the form of ground cylindrical journals, the device comprising a pair of reference units each comprising a frame having four lower abutments, an upper abutment and a hook member, a slide vertically adjustable in guide means provided in said frame and a feeler member rigidly mounted on said slide, a pair of springs each having one end anchored on an upright and the other end engaged on the hook member of the frame of one of the reference units so as to urge said frame in such a direction that said four lower abutments of said frame will engage one journal of said lower roll and the upper abutment of the same frame will engage one journal of said upper roll, said feeler shifting position in response to the shifting of said upper roll.

2. A device for maintaining the initial parallel setting and reference spacing of a pair of rotary rolls mounted in bearings supported by a pair of uprights, said pair of rolls having extensions on either side of said hearings in the form of ground cylindrical journals, said device comprising a pair of reference units each comprising a frame having four lower abutments, an upper abutment, a slide vertically adjustable in guide means provided in said frame, and a feeler member rigidly mounted on said slide, spring means having one end anchored on an upright and the other end connected to the frame of one of the reference units so as to urge said frame in such a direction that said four lower abutments of said frame will engage one journal of said lower roll and the upper abutment of the same frame will engage one journal of said upper roll, said feeler shifting in response to the shifting of said upper roll.

3. A device as defined in claim 1, wherein said four lower abutments are arranged in pairs disposed at right angles to one another and wherein said top abutment is parallel to one of said pairs of lower abutments.

References Cited in the file of this patent UNITED STATES PATENTS 762,010 Uncapher June 7, 1904 1,507,930 McDonough Sept. 9, 1924 2,332,289 Zeitlin Oct. 19, 1943 2,369,598 Misset Feb. 13, 1945 2,523,553 Blain Sept. 26, 1950 2,684,001 Wilson July 20, 1954 FOREIGN PATENTS 644,957 Germany Nov. 1, 1934