Roll stand

Abstract

The invention relates to a roll stand (1) for rolling a metal stock to be rolled, comprising a first roll housing (3), which is arranged on the drive side; a second roll housing (5), which is arranged on the operating side, each roll housing (3, 5) having at least one receiving opening (6, 7) for an installation piece (8, 9) for rotatably supporting a roll (10) which is provided with roll journals and which is not axially movable; and at least two locking plates (11, 12, 13, 14) for locking the installation pieces (8, 9), each locking plate (11, 12, 13, 14) being arranged on the respective roll housing (3, 5) end face remote from the roll and being connected to said housing via at least one axial load measuring bolt (15, 16, 17, 18) at least in a formfitting manner such that each of the locking plates (11, 12, 13, 14) overlaps with at least one part of the respective receiving opening (8, 9) such that an axial force which is produced during the rolling process and which is transmitted to at least one of the axial load measuring bolts (15, 16, 17, 18) via the roll journal, the installation piece (8, 9), and the locking plate (11, 12, 13, 14) can be detected by the respective axial load measuring bolt (15, 16, 17, 18).

Description

[0001] The present invention relates to a rolling stand for rolling a metallic rolling stock in a hot rolling or cold rolling process.

[0002] Roll stands for rolling metallic stock are generally known from the prior art. In roll stands that comprise non-axially movable rolls, each work roll is rotatably supported and axially backlash-free via two roll necks in a chock, also called a bearing housing. Ideally, therefore, only forces that extend transversely to the longitudinal axis of the work rolls should occur during the rolling process.

[0003] However, this ideal situation is hardly achievable in practice, as the work rolls are exposed to various disturbances during the rolling process. For example, asymmetries within the rolling stock cause significant disruptions in the rolling process. These disturbances lead to a compensating axial movement or force in the rolls. Because the work rolls are mounted without axial play, this adversely affects the rolling quality of the rolling stock and the bearings installed in the chocks.

[0004] CN 102327902 A discloses an operator-side roll stand with a work roll rotatably mounted in a chock. The chock located in the operator-side roll stand is locked against axial displacement by locking plates. The locking plates are bolted to the operator-side roll stand by preloaded screws. The extended screws incorporate a strain gauge, which can be used to measure the axial force of the work roll extending only in the direction of the operator-side roll stand.

[0005] Another device for measuring the axial force in an operator-side roll stand is also known from CN 205413924 U. The device comprises a bolt having a strain gauge, which is arranged in the operator-side roll stand and screwed to it in a pre-tensioned manner.

[0006] Against this background, the object of the present invention is to provide a rolling stand with which an improved product quality can be achieved in the rolled rolling stock and which requires less maintenance. Description of the invention

[0007] According to the invention, the object is achieved by a rolling stand having the features of patent claim 1.

[0008] The roll stand according to the invention is intended for rolling a metallic rolling stock and comprises a first roll stand arranged on a drive side and a second roll stand arranged on an operating side. Each of the roll stands has at least one receiving opening for a chock for the rotatable mounting of an axially immovable roll provided with a roll neck. The roll stand further comprises at least two locking plates for locking the chocks—and the rolls mounted therein—against axial displacement outward of the roll stand. At least one locking plate is arranged on an end face of the respective roll stand remote from the roll. Furthermore, the roll stand comprises at least two axial force measuring bolts.During rolling operation, each of the at least two locking plates is in an advanced position in which it covers at least part of the respective receiving opening to lock the chocks located therein—with the rolls rotatably mounted therein—against axial displacement. In this advanced position, the locking plates are each connected at least positively to the roll stand via at least one axial force measuring pin, so that an axial force generated during a rolling process and transmitted via the roll neck, the chock, and the locking plate to at least one of the axial force measuring pins can be detected by the respective axial force measuring pin.

[0009] The present invention is based on the fundamental finding that by detecting the axial forces of the work rolls not only in one but in both axial directions, i.e., toward the operating and drive sides of the rolling stand, process- and / or system-related disturbances occurring during the process can be better detected and thus quantitatively corrected. This has a particularly beneficial effect on the product quality of the rolled stock and wear, which leads to reduced maintenance requirements for the rolling stand.

[0010] According to the invention, this is achieved in that the two roll stands are designed essentially identically, so that the axial force generated during a rolling process, regardless of the axial direction in which it acts, can be transmitted via the roll neck, the chock and the locking plate to at least one of the axial force measuring bolts and can thus be detected.

[0011] The detected process- and / or system-related disturbances can be corrected manually by a worker, for example. However, it is advantageous to have them corrected automatically. For this purpose, the rolling stand preferably has a control loop comprising RAC (Roll Alignment Control) programming and / or TFC (Thrust Force Control) programming, which acts on the hydraulic actuators of the rolling stand depending on the values ​​determined by the axial force measuring pin.

[0012] Further advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technologically expedient manner and can define further embodiments of the invention. The features specified in the claims are further specified and explained in the description below, with further preferred embodiments of the invention being presented.

[0013] In a first advantageous embodiment, each of the at least two locking plates is positively connected to the roll stand via the at least one axial force measuring pin in such a way that each of the axial force measuring pins is not preloaded. It has been shown that this non-preloading of the axial force measuring pins leads to particularly high measurement resolution, since the entire introduced axial force can be measured. In this context, it has proven particularly advantageous if each of the axial force measuring pins is positively and materially connected to the roll stand. Typically, the axial force measuring pin has a threaded section at each of its two ends. The axial force measuring pin is screwed to the roll stand in a positive-locking manner via a first threaded section. The locking plate is fixed via a measuring pin nut, preferably with an air gap, via a second threaded section.To ensure that there is no play in the two threads, they are additionally bonded using a thread adhesive, for example.

[0014] In a further preferred embodiment, the at least one locking plate arranged on the drive side is fixed and the at least one locking plate arranged on the operator side is designed to be movable. The horizontally movable locking plate makes changing rolls particularly easy. The locking plates, which normally secure a chock in the roll stand against axial displacement, are moved laterally outwards for a roll change and then release the respective chock for removal towards the operator side of the roll stand. This embodiment is particularly advantageous if the axial force measuring pin is not clamped to the locking plate and the plate can then be moved freely horizontally, because this eliminates the time-consuming process of removing the axial force measuring pins to replace the rolls.In this context, it is particularly preferred that the at least one locking plate arranged on the operator side comprises an actuator by means of which it can be displaced, so that the roller change can be carried out semi-automatically or fully automatically.

[0015] The actuator can, for example, be designed in the form of a hydraulic cylinder or in the form of a threaded drive.

[0016] In a further preferred embodiment, the axial force measuring pin arranged on the operator side has a larger overall diameter than the axial force measuring pin arranged on the drive side. The larger diameter compensates for the unfavorable lever arm on the at least one locking plate arranged on the operator side.

[0017] In the context of the present invention, the term "total diameter" means a diameter averaged over the entire length of the axial force measuring bolt.

[0018] It is particularly preferred that the rolling stand comprises at least two, preferably four or eight locking plates, so that each of the chocks can be locked via at least two or even four locking plates.

[0019] In order to produce a symmetrical lever on the respective locking plates, it is advantageously provided that each of the locking plates is connected to the respective roller stand via at least two axial force measuring bolts at least in a form-fitting manner, particularly preferably in a form-fitting and material-fitting manner.

[0020] Preferably, each of the axial force measuring bolts has a substantially cylindrical base body with a first threaded portion arranged at a first distal end and a second threaded portion arranged at a second distal end and a central portion arranged between the first and the second threaded portion with at least one radial transverse bore which opens into a central longitudinal bore of the axial force measuring bolt and at least one strain gauge arranged on its outer circumferential surface and at a distance from the transverse bore.

[0021] Due to the transverse bore required for the electrical connection of the strain gauge, the axial force measuring bolt, and in particular the central section, is subjected to asymmetrical loading by the introduced axial force. The area directly around the transverse bore is exposed to particularly high loads. Surprisingly, it has been shown that arranging the strain gauge axially spaced from the transverse bore has a particularly beneficial effect on the quality of the measurement results. In this context, it is particularly preferred if the strain gauge has a minimum distance from the transverse bore and if the minimum distance corresponds to at least 1.5 times the diameter, more preferably at least 2 times the diameter, and most preferably 3 to 5 times the diameter of the transverse bore. The distance refers to the center point of the transverse bore to the center point of the strain gauge.With regard to the positioning, the at least one strain gauge with the transverse bore can be arranged on a common surface line, on a common circular line, and / or on different surface and circular lines. When determining the positioning, care must be taken to ensure that the strain gauge is positioned on the surface of the axial force measuring bolt in such a way that it can detect the axial strains occurring. The strain or deformation changes the resistance of the strain gauge, which can then be converted into an axial force.

[0022] In a particularly preferred embodiment, the central section has at least one pressure relief groove extending transversely to the longitudinal axis of the axial force measuring pin on its surface in the region of the at least one transverse bore. In this context, it is advantageously provided that the at least one pressure relief groove has a minimum length and this corresponds to at least 2 / 10 of the diameter of the central section, more preferably at least 3 / 10 of the diameter of the central section, and particularly preferably at least 4 / 10 to a maximum of 6 / 10 of the diameter of the central section. The at least one pressure relief groove arranged in the region of the transverse bore further reduces the loads occurring as a result of the introduced axial forces and improves the quality of the measurement results.

[0023] Furthermore, it is advantageously provided that the first threaded section has a larger diameter than the second threaded section. The axial force measuring pin is connected to the roll stand of the rolling mill via the first threaded section in a form-fitting manner, preferably a form-fitting and material-fitting manner. The axial force measuring pin can be fixed via the second threaded section by means of a measuring pin nut in a form-fitting and / or material-fitting manner, preferably a form-fitting and material-fitting manner. The first threaded section can be designed to be sufficiently long to enable optimal force introduction. If necessary, the first threaded section could be arranged in the roll stand via a separate threaded bushing. Character description

[0024] The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description and / or figures. In particular, it should be noted that the figures and in particular the illustrated proportions are only schematic. The same reference numerals denote the same objects, so that explanations from other figures can be used as a supplement if necessary. They show: Fig. 1 shows an embodiment of a rolling stand according to the invention in a schematic horizontal cross-sectional view, Fig. 2 shows an embodiment of the Figure 1shown axial force measuring bolt in a representation with sleeve and measuring bolt nut, and Fig. 3 a partial sectional view of the axial force measuring bolt arranged in the rolling stand according to the above embodiment.

[0025] In Figure 1 A variant of the rolling stand 1 according to the invention is shown, which is intended for rolling a metallic rolling stock. The rolling stand 1 comprises a first roll stand 3 arranged on a drive side 2 and a second roll stand 5 arranged on an operating side 4. Each of the roll stands 3, 5 has at least one receiving opening 6, 7 for a respective chock 8, 9. The chocks 8, 9 serve to rotatably support an axially non-displaceable roll 10 provided with roll necks 8.1, 9.1.

[0026] The Figure 1The roll stand 1 shown comprises, in the embodiment variant shown here, four locking plates 11, 12, 13, 14 for locking the chocks 8, 9 - and thus the rolls - against axial displacement. To install and remove the rolls from the roll stand, the rolls together with the chocks are pushed axially through the receiving opening of the roll stand. For this purpose, the receiving opening is released by moving the locking plates 11-14 transversely to the axial direction. Preferably, two locking plates 11, 12, 13, 14 are arranged on an end face of the respective roll stand 3, 5 remote from the rolls, at the level of the chocks 8, 9. In the embodiment variant shown here, each of the locking plates 11, 12, 13, 14 is connected to the roller stand 1 via at least one axial force measuring bolt 15, 16, 17, 18.Preferably, two axial force measuring pins arranged vertically relative to one another can be provided per locking plate. Due to the horizontal cross-section, in the present . Figure 1 However, only one axial force measuring pin 15, 16, 17, 18 per locking plate 11, 12, 13, 14 is visible.

[0027] In the embodiment variant shown here, each of the axial force measuring pins 15, 16, 17, 18 is positively and preferably also materially connected to the respective roll stand 3, 5 in such a way that each of the locking plates 11, 12, 13, 14 covers at least part of the receiving opening 6, 7 of the respective roll stand 3, 5, so that an axial force caused during a rolling process and transmitted via the roll neck, the chock 8, 9 and the locking plate 11, 12, 13, 14 to at least one of the axial force measuring pins 15, 16, 17, 18 can be detected by the respective axial force measuring pin 15, 16, 17, 18. In the embodiment variant shown here, the axial force measuring bolts 17, 18 arranged on the operator side have a larger overall diameter than the axial force measuring bolts 15, 16 arranged on the drive side.

[0028] The two locking plates 11, 12 arranged on the drive side are preferably fixedly connected to the roll stand, whereas the two locking plates 13, 14 arranged on the operator side are designed to be movable. This design variant is particularly advantageous when the axial force measuring pins 13, 14 are not preloaded relative to the locking plates, since the time-consuming process of loosening the axial force measuring pins or the locking plates to replace the roll 10 can be avoided. For this purpose, the two locking plates 13, 14 arranged on the operator side have an actuator (not shown) via which the two locking plates 13, 14 arranged on the operator side can be moved fully automatically.

[0029] In order to achieve a particularly high measurement resolution, the eight axial force measuring bolts 15, 16, 17, 18 arranged in the roll stand 1 are connected in such a form-fitting and material-locking manner that they are not preloaded. This is achieved in the present case by setting an air gap 35 between a measuring bolt nut 19 of the axial force measuring bolt 15, 16, 17, 18 and the respective locking plate 11, 12, 13, 14 ( Fig. 3 ). This non-preloading of the axial force measuring pins 15, 16, 17, 18 achieves a particularly high measurement resolution, since the entire introduced axial force can be measured. This is supported by the fact that the axial force measuring pins 15, 16, 17, 18 are fixed to the roll stand 3, 5 on one side with a positive and preferably also material fit, and on the other side with the measuring pin nut 19 with a positive and preferably also material fit. In this case, the material fit is achieved by an adhesive bond.

[0030] By detecting the axial forces in both axial directions of the roll 10, i.e., toward the operating and drive sides 2 and 4 of the rolling stand 1, numerous process- and / or system-related disturbances occurring during the process are identified, allowing them to be quantitatively corrected. This has a particularly beneficial effect on the product quality of the rolled stock and wear, which leads to reduced maintenance requirements for the rolling stand 1.

[0031] In Figure 2 is a variant of one of the Figure 1 The axial force measuring pin 17 shown is shown in a representation with sleeve 20 and measuring pin nut 19. The axial force measuring pin 17 is made of chromium-nickel steel 30CrNiMo8, for example, and is tempered for a load of 1300 N / mm 2<.

[0032] The axial force measuring bolt 17 has a substantially cylindrical base body 21 with a first threaded portion 22 arranged at a first distal end and a second threaded portion 23 arranged at a second distal end and a central portion 24 arranged between the first and second threaded portions 22, 23.

[0033] Again Figure 3 partially removable, the axial force measuring pin 17 has two radially oppositely arranged transverse bores 25, which open into a central longitudinal bore 26 of the axial force measuring pin 17, as well as two strain gauges 27 arranged radially opposite one another on its outer surface and spaced from the transverse bores 25. As is particularly evident from the Figure 2 As can be seen, the strain gauge 27 and the transverse bore 25 are arranged on a common surface line in the embodiment shown here.

[0034] Furthermore, the axial force measuring pin 17 in the presently illustrated embodiment has two pressure relief grooves 28, 29 extending transversely to the longitudinal axis of the axial force measuring pin 17 at each of the two transverse bores 25. The pressure relief grooves 28, 29 arranged in the region of the transverse bores 25 further reduce the loads resulting from the introduced axial forces, improving the quality of the measurement results.

[0035] The central section 24 has a raised, circumferentially extending sealing seat surface 30, 31 for the sleeve 20, arranged in the area of ​​the first and second threaded sections 22, 23, so that the central section 24 and the two strain gauges 27 arranged on the outer surface between the two sealing seat surfaces 30, 31 are hermetically encapsulated. The sleeve 20 effectively protects the strain gauges 27 from all environmental influences. In order to optimally adjust the air gap 35, the sleeve 20 has an axial extension that is smaller than the thickness of the locking plate 11, 12, 13, 14.

[0036] In Figure 3is a partial sectional view of the axial force measuring bolt 17 arranged in the rolling stand 1 in a longitudinal section. The electrical connections 32 of the respective strain gauges 27 can be seen here, which run through the transverse bores 25 and the central longitudinal bore 26. Furthermore, it can be seen from the present illustration that the first threaded section 22, which is positively and materially connected to the rolling stand 5, has a larger diameter than the second threaded section 23. Furthermore, Figure 3 It can be seen that the sleeve 20 has two radially extending grooves 33, 34 into which O-rings are inserted (not shown). List of reference symbols

[0037] 1 Roll stand 2 Drive side 3 First roll housing 4 Operating side 5 Second roll housing 6 Mounting opening 7 Mounting opening 8 Chock 8.1 Roll neck 9 Chock 9.1 Roll neck 10 Roll 11 Locking plate 12 Locking plate 13 Locking plate 14 Locking plate 15 Axial force measuring pin 16 Axial force measuring pin 17 Axial force measuring pin 18 Axial force measuring pin 19 Measuring pin nut 20 Sleeve 21 Cylindrical body 22 First threaded section 23 Second threaded section 24 Middle section 25 Cross bore 26 Longitudinal bore 27 Strain gauge 28 Pressure relief groove 29 Pressure relief groove 30 Sealing seat surface 31Sealing surface 32Electrical connections 33Grooves 34Grooves 35Air clearance

Claims

1. Roll stand (1) for rolling a metallic rolling material, comprising a first roll housing (3) arranged on a drive side and a second roll housing (5) arranged on a control side, wherein each of the roll housings (3, 5) has at least one receiving opening (6, 7) for a chock (8, 9) for rotatable mounting of an axially non-displaceable roll (10) provided with roll journals, at least two locking plates (11, 12, 13, 14) for locking the chocks (8, 9), wherein a respective one of the locking plates (11, 12, 13, 14) is so arranged at the end of the respective roll housing (3, 5) remote from the roll that the plate (11, 12, 13, 14) covers at least a part of the receiving opening (8,9) thereof and is at least mechanically positively connected with the roll housing by way of at least one axial force measuring pin (15, 16, 17, 18) that an axial force, which is produced during a rolling process and which is transmitted by way of the roll journal, the chock (8, 9) and the locking plate (11, 12, 13, 14) to at least one of the axial force measuring pins (15, 16, 17, 18), is detectable by the respective axial force measuring pin (15, 16, 17, 18).

2. Roll stand (1) according to claim 1, wherein each of the at least two locking plates (11, 12, 13, 14) is mechanically positively connected by way of the at least one axial force measuring pin (15, 16, 17, 18) with the roll housing (3, 5) in such a way that each of the axial force measuring pins (15, 16, 17, 18) is not biased.

3. Roll stand (1) according to claim 1 or 2, wherein the at least one locking plate (11, 12) arranged at the drive side is configured to be non-displaceable with the drive-side roll housing and the at least one locking plate (13, 14) arranged at the control side is configured to be displaceable.

4. Roll stand (1) according to claim 3, wherein associated with the at least one locking plate (13, 14) arranged at the control side is an actuator by way of which the at least one locking plate (13, 14) is displaceable.

5. Roll stand (1) according to any one of the preceding claims, wherein the axial force measuring pin (17, 18) arranged at the control side has a greater overall diameter by comparison with the axial force measuring pin (15, 16) arranged at the drive side.

6. Roll stand (1) according to any one of the preceding claims, comprising at least four locking plates (11, 12, 13, 14) so that each of the chocks (8, 9) is lockable by way of at least two locking plates (11, 12, 13, 14).

7. Roll stand (1) according to any one of the preceding claims, wherein at least one of the locking plates (11, 12, 13, 14) is at least mechanically positively connected with the respective roll housing (3, 5) by way of two or even more axial force measuring pins (15, 16, 17, 18).

8. Roll stand (1) according to any one of the preceding claims, wherein each of the axial force measuring pins (15, 16, 17, 18) has a substantially cylindrically formed base body (21) with a first threaded section (22) arranged at a first distal end, with a second threaded section (23) arranged at a second distal end and with a middle section (24) arranged between the first and the second threaded sections (22, 23), wherein the middle section is provided with at least one radial transverse bore (25), which opens into a central longitudinal bore (26) of the axial force measuring pin (15, 16, 17, 18), and at least one strain gauge arranged on its outer circumferential surface and at a spacing from the at least one transverse bore (25).

9. Roll stand (1) according to claim 8, wherein the at least one strain gauge (27) has a respective minimum spacing from the at least one transverse bore (25) and the minimum spacing corresponds with at least 1.5 times the diameter of the transverse bore (25).

10. Roll stand (1) according to one of the preceding claims 8 and 9, wherein the at least one strain gauge (27) is arranged with the at least one transverse bore (25) on a common circumferential line, on a common circular line and / or on different circumferential and circular lines.

11. Roll stand (1) according to any one of the preceding claims 8 to 10, wherein the middle section (24) has in the region of the at least one transverse bore (25) a pressure relief groove (28, 29) extending transversely to the longitudinal axis.

12. Roll stand (1) according to claim 11, wherein the pressure relieve groove (28, 29) has a minimum length and this corresponds with at least 2 / 10 of the diameter of the middle section.

13. Roll stand (1) according to any one of the preceding claims 8 to 12, wherein the axial force measuring pin (15, 16, 17, 18) comprises a sleeve (20) which is arranged on two mutually spaced apart and circumferentially extending sealing seat surfaces (30, 31) so that the at least one strain gauge (27) arranged on the outer circumferential surface between the i two sealing seat surfaces (30, 31) is hermetically encapsulated.

14. Roll stand (1) according to any one of the preceding claims 8 to 13, wherein the axial force measuring pin (15, 16, 17, 18) is formed from a chromium-nickel steel.

15. Roll stand (1) according to any one of the preceding claims 8 to 14, wherein the first threaded section (22) has a larger diameter than the second threaded section (23).

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