US2523553A

US2523553A - Adjusting device for rolling mills

Info

Publication number: US2523553A
Application number: US689361A
Authority: US
Inventors: Blain Paul
Original assignee: Acieries Et Forges Firminy
Current assignee: ACIERIES ET FORGES DE FIRMINY SA; Acieries Et Forges Firminy
Priority date: 1946-01-29
Filing date: 1946-08-09
Publication date: 1950-09-26
Anticipated expiration: 1967-09-26
Also published as: DE852388C; FR920775A; BE470806A; GB629623A

Description

2 Sheets-Sheet 1 P. BLAIN ADJUSTING DEVICE FOR ROLLING MILLS Sept. 26, 1950 Filed Aug. 9, 1946 Sept. 26, 1950 P. BLAlN 2,523,553

ADJUSTING DEVICE FOR ROLLING MILLS Filed Aug. 9, 1946 2 Sheets-Sheet 2 5 L M I 7040A BLA/N Patented Sept. 20, 1950 ADJUSTING DEVICE FOR ROLLING MILLS Paul Blaln, Paris, France, assignor to Soclete Anonyme des Aoieries et Forges de Firminy, Paris, France, a body corporate or France Application August 9,1948, Serial No. 889,861

In France January 29, 1946 My invention is concerned with a method of controlling the pressure acting upon the rolls of a rolling mill for the purpose of performing a given duty. for instance providing for uniformity in the thickness of the rolled material. This result is obtained primarily by means comprising a source or pressure fluid and a hydraulic squeezer-controlling relay so associated with the supply and the discharge that practically it cannot be cut oil simultaneously from both. Thus,- the pressure within the squeezing jacks oi the rolling mill is at all times either increasing or decreasing and each of these phases in the operation oi the mill is quite briei' since it is almost immediately brought to an end by the very excess in the pressure change occurring in the desired direction, which excess initiates a change in the opposite direction. In this manner, without resorting to any special means apart from the provision of a suitable connection of the relay with the supply and the discharge respectively, the squeezing jack is connected alternatingly and /1 Claim. (Ci. 80-58? at very small time intervals with the supply and the discharge.

Am embodiment of the invention will now be described for the purpose of exempliflcation and by no means of limitation in which the duty of the arrangement is to provide for uniformity in the thickness of the material worked upon; in the description reference will be had to'the appended in which- Figure l is a diagrammatical section taken on the axis of the relay.

Figure 2 is a diagram showing the application of the method to the uniio o i w oi the rolling pre.

his. 3 shows the whole arrangement incorporating this improved distributor.

Returning to Fig. 1, showing a conventional hydraulic irelay, II is the body of the relay and t the piston. The body of the relay contains three pipe channels, one pipe t connected to the adlusting lack, one pipe t connected to the water mains, and finally a thin one 5 connected to the discharge. In line with the relative position of the piston and the body oi the relay, the adjusting jack is placed incommunication with the high-pressure water mains or with the discharge, the pipe leading to the jack being theoretically closed when the piston is in the position shown in Fig. i.

In fact, outside the periods of sharp change of load of the mill during which the adjusting Jack is put in open connection with the highpressure mains or with the exhaust, the piston only changes its position imperceptibly from the position shown by the figure; the pressure in the Jack that is enforced by the working conditions of the mill is regulated by the relay in the following way: a slight escape exists between the space i in connection with the high-pressure mains and the space 8 connected to the Jack; in the same way a slight escape exists between the space it and the space 8 connected to the exhaust. An exceedingly small change of the position oi the piston 2 in the body I of the relay modifies the load losses suflered by the fluid in the traverse through one or the other or these throttlings, one of the load losses increasing when the other lessens. The pressure in the adjusting jack, comprised between that of the highepressure mains and that Of the exhaust, is thus defined by the position of the piston 2 in the body i; a very slight modification of this position around the mean position shown on the figure can during normal operation cause the pressure of the jack to vary between that of the highpressure mains and that of the exhaust:

It is possible to get the varying pressure that it is necessary to initiate in the adjusting jacks of the mill, in order that the degree of adjusting may correspond with the regulation called for, in a difierent way that, for certain forms of operation, will prove of greater interest than the one just described.

The means for feeding the jacks, that is the object of my invention, consists in placing the jack, alternatively and at very short intervals, in communication with the high-pressure mains and with the exhaust. These alternatives of feeding and discharge cause slight fluctuations of pressure in the Jacks, that, provided they are sumciently slight which is so if the frequency of the feed and discharge intervals is large enough, cannot prove a hindranc to the rolling, with the mean pressure standing at a figure that depends only on the relative importance of the intervals of feed and discharge, it the pressure of the mains remains steady.

Fig. 2 illustrates, as an example with no binding limits, 9, way of applying this method for regulating the pressure of the rolling. it designates the body of the distributor in which a piston II is adapted to move. The body of the distributor contains thre tubular channels of which one i2 connected to the adjusting jack, another it connected to the high-pressure mains and finally a third marked HI that is connected to the exhaust. The piston takes up two end positions in the distributor body, that shown in accuse illustrated. the jack communicates with the highpressure mains. In the other position, the jack connects with the exhaust. when working, the piston goes without stop from one of the positions to the other in step with the impulses that are given by the electromagnet,- the coil of which is closed or opened by a contact placed tor instance on a contrivance for measuring the thick'- ness of the band, and this contact closes the circuit oi the electromagnet when the thickness goes beyond the set value and opens the circuit in the opposite case.

In the example that has been given of an application of the method for the regulation of the rolling pressure, that is the obiect of my invention, the adjusting jack is fed directly with high-pressure liquid by the distributor. It is possible, still keeping within the sphere of my invention, to act on the adjusting jack with the help 01' a hydraulic multiplicator, while the distributor in this case supplies liquid at medium pressure to the big cylinder of'the multiplicator, with the jack connected to the small cylinder.

Fig. 3 illustrates what is the arrangement in this case 01' the control members of the adjusting mechanism. In this figure, 20 designates a roll stand furnished with hydraulic adjusting jacks 2|. These Jacks are fed directly by the highpressure end of a multiplicator 22 whose low pressure end is connected alternatively with mains with medium pressure 24 and with the exhaust by a distributor 23. The piston oi the distributor is actuated by the electromagnet 25 in antagonism with the spring 20, and the contact that closes or opens the circuit of the electromagnet is controlled by a contrivance for measuring thicknesses 21.

This contrivance closes the circuit, thus starting a flow of liquid under pressure to the adjusting jack when the thickness of the band goes over the set value. In the opposite case, the circuit is open. thus exhausting the jack.

What I claim as my invention and desire to secure by Letters Patent is:

In a rolling mill having opposed rolls adjustable toward and away from one another, a control system for maintaining the thickness 01' the rolled material substantially uniform comprising a source of pressure fluid, hydraulic means tor. tightening the rolls, a control valve comprising a casing having spaced ports connected respectively to the source of pressure fluid, the roll tightening means and an exhaust, a valve member freely reciprocable in said casing between a position in which the roll tightening means is connected with the source of pressure fluid and a position in which the roll tightening means is connected with the exhaust, an electromagnet for holding the valve member in one of said positions when energized, means responsive to the thickness 01 the rolled material for energizing said electromagnet upon predetermined variation 01 thickness or the rolled material, and spring means for moving said valve member to the other of said positions when the electromagnet is deenergized and for holding it at said other position until the electromagnet is reenergized.

PAUL BLAIN.

REFERENCES CITED The following references are of record in the UNITED STATES PATENTS Number Name Date 1,969,536 Winne Aug. 7, 1934 2,040,755 Meyer May 12, 1936 2,267,380 Tyler Dec. 31, 1940