DE1602195A1 - Strip thickness measuring device for rolling mills and similar devices - Google Patents

Description

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PATENT ENGINEERS F. W. HEMMERICH. GE R D MÖLLER- D. GROSSE - jS 1 - DÜSSELDORF 1, BERLINER ALLEE 34-36

United Engineering and Foundry Comp., Pittsburgh, PA 15222 / U3A

Tape thickness measuring device for roller gauges and similar devices

The invention relates to a tape thickness measuring device for measuring the thickness of the material as it passes between a Pair of thick reducing parts, e.g. Rolling a! Talzwerk or calender.

More particularly, the invention relates to a material processing device, consisting of at least one pair of roller units, a device between the roller units is arranged and which constantly presses said roller units apart, whereby an initial distance between the folds and which device is responsive to changes in the spacing between the rollers. The device, which puts the said roller unit under pressure, consists of a device for continuous Measuring and generating a signal indicative of a change in the distance between a pair of roller units, a device that picks up said signal and produces a deviation signal for the material thickness, that is indicative of the difference between the real ones Distance and the original distance between said pair of rollers.

In one form, the invention provides a first piston-cylinder unit in a rolling mill, through which a pressure in opposite direction to the rolling pressure applied between the pair of reducing rolls of the rolling mill developed, the said pressure being equal to the rolling pressure at all times. and is bigger. than this, a second

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Piston-cylinder unit which is arranged between the lialzv / erksvalzeii and which press the vials apart against the gcnanuicn? Ii-ucll and which includes a device by which the railing of the piston of the second piston-cylinder unit is measured and a ui ^ al is generated which is characteristic of the said displacement, a control system for recording the said signal and for comparing this signal with a signal which is characteristic of the desired distance between the rolling mill rolls, said system in FIG La ;; e is to generate a signal which is characteristic of the difference between the two signals mentioned and a change in the pressure of the said first piston cylinder unit, carried out in such a way that the position of the rollers with respect to one another is changed, so that the difference between the two the above-mentioned signals in. -. essentially reduced to zero.

When producing tape-like material, e.g. Apparent strip in a rolling mill, it has hitherto been extremely difficult to obtain a match in the thickness of the material in To get longitudinal direction. While a number of methods and devices have been proposed for compensating for the elastic elongation of the mill, all of these ideas have suffered serious shortcomings. For example, the invention of US Pat. No. 2.6S0.978, issued June 15, 1954, entitled "Production of Sheet Metal and Strip" can be disadvantageous in that there is a substantial delay in the time the correction signal is produced occurs until the correction is made. This delay is primarily attributable to the inertia of the pitch, which creates a substantially non-dimensional product. British Patent No. 955,164 to

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April 15th lir.il under the title "Improvements in and on Rolling Mills "is a recent attempt to solve the problem. However, the proposal is disadvantageous in that the correction signal only a small part of the Wnlzweri: sdehnun ;; compensated and therefore a really exact dimensional accuracy of the Material cannot be reached.

! i> he vorlio; s "e ilriindung schaxit a Jlechanisiv.us actually through which the distance between the processed salt of a" iearbeitunjrsvorriektunir such as a calender or a rolling mill, gei "will eat in such a way öit'Z the use of this mechanism is only conditional to a very small degree in the construction of the device.

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A JOrη? the invention is illustrated in the following Drawings.

Fl'-ζ. 1 is a schematic view of a four-high rolling mill incorporating the features of the invention.

J ¹ IiJ. Figure 2 is a schematic illustration of two work roll balancing cylinders in conjunction with the calibration control system for operating the rolling mill.

3 is an enlarged fragmentary elevational view of the piston-cylinder unit and that shown in FIG Strip thickness measuring device.

/ ig. 4 is a second embodiment of a tape thickness measuring device for a balancing cylinder.

Fig. 5 is a comparison of the suspension curves of a conventional one "i / alzwerk and a rolling mill that accordingly of the invention is built.

In Fig. 1 is shown one of the columns Io of a four-high rolling mill, which has a window 11 in which back-up roll chocks 12 for the rotatable reception of the back-up rolls 13 with the backup roll chocks having openings 15 on their adjacent sides for receiving the work roll chocks 16 are provided which support the work rolls 17 rotatably. The rollers 17 are constituted by a pair of piston-cylinder units 18 for each pair of chocks pushed apart, i.e. one pair for each end of the roll, with the constructive Details will be explained in more detail later.

Between the backup roll chocks are the normal backup roll balancing cylinders 19, which separate the backup roll chocks and ensure that the upper Chocks are held against the adjustment screw 20,

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which is guided in a nut 21 which is fastened in the stand 10. The screw is rotated in the usual way by a worm gear motor unit, not shown. In the lower part of the rolling mill, the lower backup roll chock 12 is gripped by the piston of the piston-cylinder unit 22. As in Jj ¹ Xg. 2 shows, the piston of the piston-cylinder unit 22 is in connection with a servo valve 23, the hydraulic side of the valve in turn being connected to a pump 24 which is driven by an electric motor 25. It should be noted that the parts of the other rolling mill stand are identical to that just described, so that a description of these parts is not deemed necessary.

Reference is made to FIG. 3, which is an enlarged drawing of one of the balancing cylinder assemblies provided between a pair of work roll chocks 16 of the rolling mill shown in FIG. The upper work roll assembly 16 is separated from the lower 16 by a plunger 26 of one of the four balancing cylinders 18. ',' He shown, the lower work roll chock 16 is provided in the usual manner with a recess 27 in which the cylinder 28 of one of the balancing cylinder units 18 is accommodated.

The plunger 26 of the cylinder is actuated by a lower Pressurized liquid, which comes from the passage 31 from a unit, not shown. The plunger 28 is hollow formed and in its center there is an electrical one Displacement measuring device 32. The outer part of the device consists of an armature winding 33 in which a back and forth Her movable armature 34 lies, wherein the upper part of the armature is in communication with the upper part of the plunger 26 and itself moved with this »The armature winding 33 receives current from the electrical lines Ll and L2. The change in tension

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caused by the movement of the anchor is <; e— To eat by a nut Vorrichcuiig to be described. With this one Construction is the protruding part of the plunger 20 Marks for the gap between the Arneics rollersl7 trending material that is in an exact proportional electrical signal is converted by the displacement of the stapler 52.

One embodiment for the shift display device is shown in / ig. 1, where the balancing cylinder 37 is made of magnetic material, while the cylinder plunjer 38 is preferably made of a non-magnetic material such as brass or the like. A transformer coil 39 is wound in cylinder 37 to generate a magnetic field through which plunger 3H passes, producing an electrical signal which changes depending on the particular position of the plunger relative to winding 39, l'fie noted above, the plunger identifies the desired gap distance between the work rolls 17 which, for all practical purposes, represents the flick of the material to the engagement of the rolls.

Referring now to the control system illustrated in Figure 2, for simplicity only the displacement indicators are 32 of two interacting balancing cylinder units 18 illustrated. The displacement indicators 32 are arranged in rows and form a combined yes Resistance 42a in a web of a Wheat st one's see Bridge circuit 41, which is connected in a conventional manner to a not shown Stroinaggregat by lines L3 and L4 is. By mounting a pair of indicators 32 in series in a land, any tendency of the work roll chocks is eliminated 16 compensated for rotation or tilting. Resistors 42b, 42c and 42d, one of which is because of the rolling mill conditions is selectively variable are combined

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rii '■ "" - ""iidersinud' IIa and form the other \> ^f th e of BrürkeiT ^ Roises, "Jer one iloannungsfühlvorrichtimg 42e besitxl.. from which the voltage is supplied to an amplifier and then through line L5 to the servo valve 23. The operation of the pressure circuit is such that the resistor 42a becomes variable since it represents the sum of the resistances of the devices 32, as previously said. These changes create an unbalanced state that acts on the displacement of the cinema pieces IG and characterizes a dimensional condition. The unbalanced condition, which may be plus or minus, is compensated for by using the output voltage of the device 12e as a signal for actuating the servo control unit 2L, which causes the operation of the piston-cylinder unit 22, thereby changing its pressure in dependence on the signal will. This causes a change in the gap until the plunger ZG of the cylinder 2S has been moved sufficiently to be balanced in the bridge circle.

In a certain construction, the plunger dos Ausba-Ianciex-ungs; -ylinder eiae Bewecun.t of four inches, being the device i> 2 or coil 39 atix a change in the bei; in the range of G, OOO1 inches.

It should be noted that one of the advantages of this from which Srxindehmen derives, lies in the fact that the devices Ii2 easily into the chocks of an existing Vfalzwerk can be built in, resulting in very low initial costs develop. A second significant advantage is that the invention provides displacement indicators which installed inside the balancing cylinder units 18 can be, whereby the devices are protected against the external UiHgebungsbedingungen of the rolling mill.

It can be seen that although a hydraulic forci the Adjustment dex rolls has been shown, various other designs for changing the position of the work rolls

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can be used, the main idea being that the change be as simultaneous as possible at the time occurs at which the deviation in the displacement of the balancing cylinder the balancing cylinder extensiveness is detected.

An illustration of the effectiveness of the invention is given in Fig. 5, where a comparison is made of the mill elongation curves of a conventional mill with a mill incorporating the features of the invention. As shown in Fig. 5, the mill ^{strain curve for the conventional mill forms a substantial angle with respect to point o and o f} and the lines drawn perpendicular to the base line t. In the conventional rolling mill, t2, that is, the change in the material thickness due to the elastic expansion of the rolling mill resulting from a change in the rolling pressure P, is essential. For example, a change in the thickness of an incoming strip of 0.0050 inches, ie where tf - t ^ = t ^, gives a change in the elastic elongation of the mill of

t2> which in turn leads to a change in the thickness of the expiring 0.0040 inch ribbon.

The same symbols have been used in the elongation curve of a rolling mill incorporating the features of the invention, with the effective rolling mill module 500 10 ⁶ lbs / ins. is 10 ^ lbs / ins compared to 20 χ. in a conventional rolling mill. This substantial improvement in the rolling mill module can be seen in the bevel of the rolling mill elasticity curve in FIG. In the improved rolling mill, the curve is essentially vertical to the base line t and the difference between point o and point o ¹ on the rolling mill elasticity curve is very small. Thus, for a variation in incoming strip thickness of 0.0050 inches, the variation in exit thickness is 0.002 inches in terms of the change in thickness resulting from mill elongation. The change is thus reduced to only 5 % of what normally occurs and is equivalent to an improvement of 95%. 009813/0931

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According to the provisions of the patent statutes, the Principle and mode of operation of the invention explained and explained and described what the best form of training is held. It should be noted, however, that within the scope of the appended claims, the invention in other Manner as specifically illustrated and described here.

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Claims (1)

Claims 1. In a device for processing elongated material consisting of a stand, first and second parallel arranged cooperating rollers that form a stitch opening into which the material to be processed with the ends of said rollers rotatable in bearing chock units in said stator are stored, a device for adjusting said first rollers relative to the second roller for Change of the roll gap, a pressure-exerting device including a sliding plunger, which between the opposite bearing chock units of said rollers are arranged, and that said rollers continuously pushing away from each other before machining begins, creating an original roll gap between the mentioned rollers, the improvement arises characterized, that a device is associated with said pressure-exerting device, which is responsive to a change in the displacement said plunger of said pressure device is responsive in a direction which permits the separation of the rollers and corresponds to a change in the roll gap, a device associated with the plunger displacement measuring device, which produces a signal which is indicative of the extent of the displacement of said plunger and for a Change in the roll gap mentioned. bath 009813/0931 - A 2 - 21 209 July 20, 1967 rE.se 11 - ^{A 2} - 2. An apparatus according to claim 1, in which said The pressure-exerting device consists of a first pair of piston cylinder units and the said plungers represent the plungers of these units, thereby g e k e η η ζ e i c h net, that said device for adjusting said first \ ialze from a second pair of piston-cylinder units exists, which are arranged in the said otänder and to exercise a jolt in a poem, the separation of the said rollers counteracts said pressure of said second piston-cylinder units between the called "ialzenpaar" developed rolling pressure is the same or larger than this, a device for receiving said Signal and to compare said signal with a: second üignal is present, which is indicative for the desired distance between said rollers, a device for generating a third signal is present, which is characteristic of the difference between said first and second signals, a device picks up said third signal and the pressure in said second piston-cylinder unit changes so that said first tialze against said second Tialze and move away from it until the difference between said first and second signals substantially Is zero. 3. An apparatus according to claim 1,
characterized, that an electrically driven adjusting screw is available which lies in said stand and which adjusts said second roller relative to said first roller and thus initially produces the desired roll gap. 009813/0931 -A3- July 20, 1967 rm.se 4. An apparatus according to claim 1, wherein each work- _; . roll is provided with a back-up roll, back-up roll chocks for said back-up rolls are in said stand, said pressure-exerting device consists of a pair of piston-cylinder units for each pair of opposing bearing chock units of said work rolls, characterized, that said device for generating a signal, this is indicative of the extent of the displacement of said plungers, a signal of the sum of the displacement the plunger generates, for each pair of said piston-cylinder units, a device that picks up said signal and comparing said signal with a second signal indicative of the desired distance between said rollers, a device generates a third signal which is indicative of the difference between said first and second signal, a device receives said third signal and the pressure changed in said piston-cylinder units so that said first roller against said second roller and is moved away from it, the difference between said first and second signals is substantial Is zero. 5. An apparatus according to claim 1,
characterized , that said pressurizing device consists of piston cylinder j the units in which the named plungers as ο
ο Pistons of the named units act, the named plungers have hollow inner parts, an armature with the plungers - ^{i is} in connection and with these relative to the named ones · **. Cylinders is movable, the said anchors are in anchor to move windings attached to said cylinders ^ T are and a device supplying electric current to the said Supplies armature windings, BATHROOM ÖK - A 4 - 21 209 July 20, 1967 rm.se ή-χ - A 4 - A device according to claim 1, in which said pressurizing device consists of piston-cylinder units, characterized , that the said cylinders consist of the said units consist of metallic material, said plungers form the pistons of said units and of non-metallic Material consist, transformer coils are wound in the named cylinders to generate a magnetic field, through which the said plungers go, creating an electrical signal that deals with the particular The position of the plunger changed relative to the transformer coil. • -End - 009813/0931. >. BATH