Device and method for operating a mandrel rod in a pipe mill
By combining a pusher and a holding device, the mandrel and the tube blank move synchronously, solving the problem of the mandrel's axial stroke limiting productivity and improving the efficiency and temperature control of the seamless tube rolling facility.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SMS GROUP GMBH
- Filing Date
- 2021-06-30
- Publication Date
- 2026-05-19
AI Technical Summary
In existing seamless tube rolling facilities, the axial travel of the mandrel limits the increase in the rolling line's productivity, and the long contact time between the mandrel and the rolled product leads to temperature loss.
A combination of a pusher and a holding device is used. The pusher moves the mandrel along the rolling direction and is temporarily fixed at the point of action of the mandrel by a fixing unit. This shortens the working stroke of the fixing unit, reduces the movement time of the mandrel on the rolling line, and achieves synchronous movement between the mandrel and the billet.
It improves the productivity of rolled seamless tubes, reduces processing cycle time, lowers drive power and dynamic load, and reduces temperature loss and the number of mandrels.
Smart Images
Figure CN116056812B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an apparatus for operating a mandrel in a rolling mill for rolling seamless tubes. The invention also relates to a rolling mill for rolling seamless tubes and a method for rolling seamless tubes. Background Technology
[0002] In the manufacture of seamless tubes, a stretching mill is used, in which a tube blank is rolled on a long cylindrical mandrel. For this purpose, before the actual rolling process, the mandrel is inserted into the tube blank and travels with it through a mill with multiple mill stands arranged sequentially, thereby reducing the wall thickness and thus lengthening the tube blank on the mandrel. After the tube blank has passed through the mill stands, it is now rolled into the desired tube or semi-finished product, and the mandrel is pulled back against the rolling direction and removed from the mill stand assembly by means of a mandrel holding device.
[0003] It is known that the billet to be rolled is loaded into the rolling line via a transverse conveyor system, so that the billet is coaxial with the rolling axis and positioned flush with the mill. The mandrels required for forming the rolled product are also loaded into the rolling line via the transverse conveyor system. The lubricated mandrels are pushed into the billet by a pusher, and if necessary, by a mandrel holding device.
[0004] Such a mechanism with a mandrel holding device is described, for example, in document DE 27 42 288 C2. Alternatively, solutions are known to install a pre-inserted mandrel along with the rolled product in the rolling line.
[0005] If the mandrel is inserted into the billet during the rolling line, the required axial travel of the mandrel holding device is derived from the length of the rolled product and the mandrel length. The mandrel holding device must enter the rolled product during the majority of the processing cycle, which hinders higher clock frequencies and thus limits facility productivity. Solutions that pre-insert the mandrel alongside the rolling line have technical drawbacks, such as temperature loss in the rolled product due to prolonged contact time with the mandrel. Summary of the Invention
[0006] One object of the present invention is to improve the rolling of seamless tubes, and in particular to increase the productivity of rolling facilities used for rolling seamless tubes.
[0007] This objective is achieved by an apparatus according to the invention, a rolling mill according to the invention, and a method according to the invention. Advantageous improvements are derived from the dependent claims, the following description of the invention, and the description of preferred embodiments.
[0008] The apparatus is used to operate a mandrel in a rolling mill for rolling seamless tubes. The rolling mill includes a rolling mill, typically having multiple mill stands arranged sequentially along the rolling direction, configured to roll a tube blank on such a mandrel into a tube, wherein the tube blank is also referred to herein as a “rolled piece,” “rolled product,” or “workpiece.” The tube may be made, for example, of steel or a non-ferrous metal.
[0009] The device includes a pusher that moves or feeds a mandrel arranged in the rolling line along the rolling direction, thereby pushing or inserting the mandrel into the tube blank arranged along the rolling direction before the mandrel. The state in which the mandrel and the tube blank are arranged sequentially on the rolling line, i.e., the state in which the mandrel is neither fully nor partially pushed into the tube blank, is referred to herein as the basic state.
[0010] The device also includes a holding device with a fixing unit that can move along the rolling line. The holding device temporarily fixes the mandrel at a point of action in the region at the rear end of the mandrel and performs a working stroke from the starting position along the rolling direction and against the rolling direction, thereby allowing the mandrel to move into the mill along the rolling direction and to be pulled out of the mill against the rolling direction by the holding device.
[0011] In other words, the primary purpose of the holding device is to intercept the mandrel after the billet has been fed through the mill and pull it out of the mill against the rolling direction. The holding device may also at least partially engage in or participate in feeding the mandrel into the mill. For this purpose, the holding device has a fixing unit for temporarily holding or fixing, for example, clamping the mandrel at the point of action. In this document, the terms "holding" or "fixing" do not mean that the feeding of the mandrel along the rolling line is stopped, but rather that there is a temporary fixed connection between the mandrel and the fixing unit, so that the mandrel and the fixing unit do not move relative to each other along the rolling line in a fixed state. In its simplest case, the mechanism for fixing and releasing the mandrel may include a stop, alternatively implemented as a clamp, by a clip, or in other suitable manner.
[0012] It should be noted that spatial terms such as “rear,” “front,” “rear,” and “forward” refer to the rolling direction and are therefore clearly defined.
[0013] According to the invention, the retaining device is configured such that, in the base state, the initial position of the fixing unit is located between the two ends of the mandrel.
[0014] In other words, the working stroke of the fixing unit during the processing cycle is no longer composed of the lengths of the billet and the mandrel, but is relatively shortened, thereby reducing the main time of the processing cycle. The starting position is typically located in the region at the rear end of the mandrel in the base position, but according to the innovation described herein, the starting position is moved forward along the rolling direction, located between the front and rear ends of the mandrel. Preferably, the fixing unit does not return to the starting position at any time during a conventional rolling cycle. The shortening of the working stroke of the holding device, more precisely, its fixing unit, corresponds, for example, approximately to the length of the billet.
[0015] By shortening the working stroke in this way, the mandrel can be pre-inserted into the tube blank during a minor part of the processing cycle, thereby shortening the cycle time and increasing production.
[0016] The shortened working stroke of the retaining device further allows the mass of the motion to be minimized, thereby reducing drive power and dynamic load.
[0017] The fixed unit can be positioned and adjusted simply and flexibly according to the size of the tube blank. In this way, for shorter tube blanks, the system can be pre-positioned without problems, so as to further shorten the cycle time.
[0018] The processes of loading the mandrel into the rolling line and loading the billet into the rolling line can be performed simultaneously or concurrently, thereby further shortening the cycle time. Removing the pulled-back mandrel and loading the new billet can be performed sequentially along the shortest possible route. For this purpose, transfer devices can be pre-positioned at the shortest possible intervals.
[0019] By inserting the mandrel into the billet during the rolling line, potential temperature losses in the rolled product can be minimized. Simultaneously, the mandrel is heated only slightly, thereby further minimizing the number of mandrels in transit.
[0020] Preferably, the holding device is further configured such that the working stroke of the fixing unit is less than the total axial length of the mandrel and the tube blank. The working stroke can be reduced substantially to the length of the tube blank, thereby minimizing the cycle time of the processing cycle.
[0021] Preferably, the point of action of the mandrel is configured as a pivot portion, which includes, for example, a partial pivot portion, a thickened portion, a recessed portion, or a machined portion (hereinafter collectively referred to as the "pivot portion"). Thus, the mandrel has a section with a generally reduced diameter at the point of action, in which the fixing unit engages. In this way, temporary fixation between the mandrel and the fixing unit can be achieved simply and reliably in mechanical engineering. The fixing unit can be actively engaged in the pivot portion, for example, by clamping, or passively connected and / or stopped in the pivot portion.
[0022] Preferably, the holding device is configured such that the fixing unit is detached from the mandrel in the base state, allowing the mandrel, which has been fed along the rolling direction by the pusher from the base state, to move or travel relative to the fixing unit. In this case, the mandrel thus travels a certain distance along the rolling direction from the base state until its point of action reaches the fixing unit. Here, the fixing unit can guide the mandrel until the two are fixed relative to each other.
[0023] However, the stationary unit does not need to remain stationary as the mandrel is fed relative to the stationary unit in the rolling direction. More precisely, the holding device is preferably configured such that the stationary unit moves or accelerates (also in the rolling direction) at a lower speed (relative to the mandrel) during the feed of the pusher in the rolling direction, in order to at least partially compensate for the speed of the stationary unit and the speed of the mandrel. This speed compensation, or motion synchronization, can help to further shorten the cycle time of the machining process and reduce the mechanical load on the involved components. During the feed of the mandrel, the stationary unit can first remain in the initial position for a certain period before accelerating in the rolling direction.
[0024] Preferably, the holding device is configured such that when the point of action of the central shaft reaches the position of the fixing unit by means of the feeder, the fixing unit automatically engages with the point of action, i.e., the tapered portion. This engagement position can be the starting position of the fixing unit, or, if speed compensation is applied, it can be located downstream of it along the rolling direction.
[0025] Preferably, the retaining device has a slider that can move parallel to the rolling line, on which the fixing unit is arranged. The retaining device may also have an electric motor with a pinion / rack mechanism, by which the slider is driven. The slider and the rack are preferably located beside the rolling line. In this case, the retaining device is configured such that the mounting space on the rolling line remains accessible, allowing the mandrel to be inserted into and removed from the rolling line without retracting the fixing unit for securing the mandrel from its rear end.
[0026] Preferably, a connecting device is provided, which is configured to secure the mandrel to the feeder in a force-transmitting manner during forward travel until the mandrel is transferred to the holding device, wherein the connecting device is preferably mounted on the feeder. In this way, safe and reliable transfer of the mandrel can be achieved even at high processing speeds.
[0027] Preferably, the retaining device and the mandrel are configured such that they are connected to each other in a form-connected manner after the transfer occurs and are mechanically disengaged in discretely or continuously adjustable end positions of the retaining device.
[0028] The above objective will also be achieved by a rolling facility having a rolling mill having one or more mill stands for rolling seamless tubes and a device for operating a mandrel according to one of the above-described variant embodiments.
[0029] The mill is designed as a longitudinal mill, having, for example, three to eight mill stands, preferably five to six mill stands, and each stand having two to four work rolls, preferably three work rolls, wherein at least one roll is driven, preferably all rolls are driven. The term "longitudinal mill" includes all types of stretching mills, such as continuous mills, multi-stand automatic tube mills (MPMs), and tube jacking mills.
[0030] The features, technical effects, advantages, and embodiments already described with respect to the device for operating the mandrel are similarly applicable to the rolling mill.
[0031] The above objective is also achieved by a method for rolling seamless tubes using rolling mills, wherein the method includes: inserting a tube blank and a mandrel into a rolling line such that, viewed along the rolling direction, the mandrel is positioned before a pusher, the tube blank is positioned before the mandrel, and the first mill stand of the rolling mill is positioned before the tube blank, thereby placing the mandrel in a base state; positioning a retaining unit at a starting position between the two ends of the mandrel, wherein the retaining unit is detached from the mandrel, thereby allowing the mandrel to move along the rolling line relative to the retaining unit. The unit moves; the pusher moves along the rolling direction, thereby pushing the mandrel forward and into the billet, wherein relative displacement occurs between the fixed unit and the mandrel; when the point of action of the mandrel reaches the position of the fixed unit, the mandrel is fixed by the fixed unit, so that no more relative movement occurs between the fixed unit and the mandrel; the billet with the mandrel pushed in is conveyed through the rolling mill, so that the billet is rolled into a tube on the mandrel; and then the mandrel is withdrawn from the rolling mill in the opposite rolling direction by a holding device.
[0032] The listing of methods and steps does not necessarily specify the order or chronological sequence. For example, the billet and mandrel can be inserted into the rolling line and the positioning and fixing unit can be done successively, simultaneously, or overlappingly in time.
[0033] The features, technical effects, advantages, and embodiments already described with respect to the apparatus for operating the mandrel and the rolling mill are similarly applicable to the method.
[0034] Preferably, during the forward movement, the pusher dynamically transfers the spindle to the holding device, wherein the speeds of the two devices are synchronized with each other during the transfer.
[0035] Preferably, the billet and / or mandrel are inserted into the rolling line transversely to the rolling direction, i.e. transversely to the axial direction of the billet / mandrel, thereby allowing the rolling line to be loaded as quickly as possible. The same applies to removing the mandrel used during the rolling cycle from the rolling line.
[0036] Preferably, for the reasons stated above, during the feeding of the mandrel by the pusher in the rolling direction, the stationary unit moves or accelerates at a lower speed (relative to the mandrel) to at least partially compensate for the speed of the stationary unit in the rolling direction and the speed of the mandrel in the rolling direction. During the feeding of the mandrel by the pusher, the stationary unit may first remain at the initial position for a certain period of time before accelerating in the rolling direction.
[0037] Preferably, for the reasons mentioned above, the fixing unit secures the mandrel by engaging or abutting in the tapered portion at the point of action of the mandrel.
[0038] Preferably, after the mandrel is withdrawn from the rolling mill, it is transferred by releasing the fastener between the fixing unit and the mandrel and withdrawing the mandrel transversely to the rolling line, wherein this withdrawal preferably occurs at a location different from its base state. The mandrel is typically withdrawn closer to the rolling mill than its base state position.
[0039] Preferably, the billet is driven into the rolling mill by a separate driven roll, also known as a "pinch roll".
[0040] Further advantages and features of the invention will become apparent from the following description of preferred embodiments. The described features may be implemented individually or in combination with one or more of the features explained above, provided that these features do not contradict each other. Preferred embodiments are described below with reference to the accompanying drawings. Attached Figure Description
[0041] Preferred embodiments of the invention are further illustrated by the following description of the accompanying drawings. Wherein:
[0042] Figure 1A schematic plan view of a rolling facility for rolling seamless tubes is shown, the rolling facility having a device for operating a mandrel and a rolling mill;
[0043] Figure 2 shows the results according to Figure 1 The sequence of states of the rolling mill during the processing cycle; and
[0044] Figure 3 A connecting device mounted on a pusher is shown, which secures the mandrel to the pusher during forward travel until the mandrel is transferred to a holding device. Detailed Implementation
[0045] Preferred embodiments are described below with reference to the accompanying drawings. Here, identical, similar, or functionally equivalent elements are given the same reference numerals in the drawings, and repeated descriptions of these elements are omitted in part to avoid redundancy.
[0046] Figure 1 This is a schematic top view of a rolling facility 1 for rolling a tube blank 2, also referred to herein as a “rolled piece,” “rolled product,” or “workpiece,” into a tube 2’ (see Figure 2h), wherein the rolling facility 1 includes a device 10 for operating a mandrel 3 and a rolling mill 20.
[0047] The rolling mill 20 has multiple rolling mill stands 21 arranged sequentially along the rolling direction R. The tube blank 2 and the inserted mandrel 3 are transported together along the rolling line L through the rolling mill stands 21 and plastically deformed by rolling the tube blank 2 into a tube 2' on the mandrel 3.
[0048] The rolling mill 20 is preferably designed as a longitudinal rolling mill, for example having three to eight mill stands 21, preferably five to six mill stands, and each stand having two to four work rolls, preferably three work rolls, wherein at least one roll is driven, preferably all rolls are driven. The term "longitudinal rolling mill" includes all types of stretching mills, such as continuous rolling mills, multi-stand automatic tube mills (MPM), and tube jacking mills. The mill stand 21 includes the aforementioned work rolls, the structure of which is not further shown in the figure, and the work rolls perform the desired shaping of the workpiece. The longitudinal feed of the workpiece 2 is caused by two to four work rolls, preferably three work rolls, evenly arranged around the workpiece or rolling center.
[0049] exist Figure 1In this process stage, the tube blank 2 and mandrel 3 are already positioned before the mill 20 in the rolling line L. The tube blank 2 and mandrel 3 have been positioned accordingly by a transverse conveying system. The tube blank 2 is positioned directly before the first mill stand 21, preferably on a flush line before the mill 20. The mandrel 3 is coaxially positioned after the tube blank 2. The mandrel 3 includes a rounded or slightly conical tool head at its front end 3a to facilitate insertion of the mandrel 3 into the tube blank 2. The mandrel 3 has an actuation point 3c in the region of its rear end 3b for fixation by the holding device 12 described below. According to this embodiment, the actuation point 3c is constructed as a tapered portion, but the actuation point is not limited to this.
[0050] The device 10 for operating the mandrel 3 includes a pusher 11, also arranged in the rolling line L after the mandrel 3, and a device (not shown) for actively feeding the pusher 11 along the rolling direction R. Figure 1 In the basic state, there may be a small safety distance between the mandrel 3 and the pusher 11 to avoid hindering the transverse transport of the mandrel 3 into the rolling line L.
[0051] The device 10 also includes a holding device 12, the purpose of which is primarily to intercept the mandrel 3 after the billet 2 has been conveyed through the rolling mill 20 and pull the mandrel out of the rolling mill 20 in the opposite rolling direction R. The holding device 12 may also at least partially participate in or be involved in feeding the mandrel 3 into the rolling mill 20.
[0052] For this purpose, the retaining device 12 has a fixing unit 12a, which is configured to temporarily fix the mandrel 3, for example, clamp it at the point of action 3c. In its simplest case, the mechanism for fixing and releasing the mandrel 3 may include a stop, alternatively implemented as a clamp, by means of a clip, or in other suitable manner. The fixing unit 12a is configured to be movable along the rolling line L by means of a slider 12b. The slider 12b is preferably driven by an electric motor having a pinion / rack mechanism, the rack 12c of which is schematically shown in the figure. However, the actuator for moving the slider 12b is not limited to an electric pinion / rack mechanism. The retaining device 12 may alternatively be actuated, for example, hydraulically or by means of a linear motor.
[0053] Another embodiment of the retaining device 12 having a connecting device 40 mounted on the pusher 11 is in Figure 3 As shown in the diagram, the spindle 3 is fixed to the pusher 11 in a force-transmitting manner during forward travel by means of the connecting device 40, until the spindle is transferred to the holding device 12.
[0054] The process flow of rolling mill 1 for one processing cycle is described below with reference to Figure 2. Here, Figure 2 is divided into parts a) to n), which show a state of rolling mill 1 in chronological order during the processing cycle. For clarity, some reference numerals are omitted in Figure 2.
[0055] The starting point is the basic state shown in Figure 2a) (and Figure 1 (The basic state is consistent with that in the previous section), in which the billet 2 and mandrel 3 are placed into the rolling line L before the mill 20 by means of transverse conveying (not shown in the figure), also referred to herein as the mandrel transfer stroke. The fixing unit 12a is located in the starting position x in a loose state relative to the mandrel 3. A Thus, the mandrel 3 can move freely relative to the fixed unit 12a along the rolling direction R. In the basic state shown in Figure 2a), the initial position x A It is located between the two ends of the mandrel 3, preferably in the front half of the mandrel 3.
[0056] Starting from the basic state shown in Figure 2a), the pusher 11 moves along the rolling direction R, thereby feeding the mandrel 3 and inserting it into the tube blank 2 (see Figure 2b). The fixing unit 12a opens to allow the pusher 11 and the mandrel 3 to be fed.
[0057] During the feeding of the spindle 3, the stationary unit 12a first stops at the starting position x. A The spindle is then accelerated along the rolling direction R to achieve speed balance between the spindle 3 and the fixed unit 12a, as shown in Figure 2c). This stroke is also referred to herein as the spindle synchronization stroke. Therefore, relative motion occurs between the spindle 3 and the fixed unit 12a during the spindle synchronization stroke, and the point of action 3c is not yet directly located at the position of the fixed unit 12a. Here, complete or partial speed balance can be pursued.
[0058] When the point of action 3c of the mandrel 3 reaches the position of the fixing unit 12a, the fixing unit 12a engages or closes with the point of action 3c along the clamping stroke of the mandrel, as shown in Figure 2d). At the same time, the mandrel 3 completely penetrates the billet 2 and enters the rolling mill 20 at the head end 3a.
[0059] After the mandrel clamping stroke is completed, the synchronous movement between the pusher 11 and the mandrel 3 is cancelled. The further feed of the mandrel 3 along the rolling direction R, referred to herein as the mandrel feed stroke, is taken over by the holding device 12 and / or the mill 20. The pusher 11 stops, thereby separating the mandrel 3 and the pusher 11 from each other (see Figure 2e). At the same time, the billet 2 accelerates toward the first mill stand 21 during the billet acceleration stroke, wherein the mandrel 3 has completely penetrated the billet 2 and entered the mill 20 at the front end 3a.
[0060] Figure 2f) shows the rolling start stroke. The billet 2 enters the first mill stand 21 of the rolling mill 20. At the same time, the pusher 11 returns to its starting position, thus preparing the pusher for the next processing cycle.
[0061] Figure 2g) shows the state during the rolling of the tube blank 2, in which the tube blank 2 has been fed to the last mill stand 21 of the rolling mill, and Figure 2h) shows the state in which the tube blank 2 has left the last mill stand 21 of the rolling mill 20 and has been fully rolled into tube 2' on the mandrel 3. The mandrel 3 has completed a full stroke, which is also referred to here as mandrel stroke - end of rolling.
[0062] Then the mandrel 3 is removed from the mill 20 against the rolling direction R by the retaining device 12 and returns to the exit position (see Figure 2i).
[0063] Then, the mandrel transfer stroke is performed, during which the fixing of the central mandrel 3 is released or loosened by the fixing unit 12a (see Figure 2k), and then it is withdrawn laterally from the rolling line L (see Figure 2l). Afterward, a new tube blank 2 and a new mandrel 3 are placed into the rolling line L (see Figures 2m) and 2n). Within the scope of the mandrel transfer stroke, the placement of the tube blank 2 and the mandrel 3 can be performed sequentially, simultaneously, or overlappingly in time.
[0064] The above process can be executed by controller 30, which in... Figure 1 The diagram is shown schematically. For clarity, the communication paths with the corresponding actuators, sensors, etc., are not shown.
[0065] The controller 30 can form a separate electronic unit that communicates with machine controllers, facility controllers, etc., or is a component of them. Communication between electronic components can be analog or digital, wired or wireless. The controller 30 can be a component of internet-based and / or cloud-based applications, or can be implemented in other ways, and can also access databases if needed.
[0066] The device 12 is designed such that the installation space within the rolling line L remains accessible, allowing the mandrel 3 to be inserted into and removed from the rolling line L without retracting the fixing unit 12a from the mandrel's rear end 3. In other words, the working stroke of the fixing unit 12a during the processing cycle is no longer composed of the length of the billet 2 and the length of the mandrel 3, but is relatively shortened, thereby reducing the main processing cycle time. Starting position x A Typically, the initial position is located in the region 3b at the rear end of the spindle rod 3 in the base position, but according to the innovation proposed in this paper, the initial position xA The mandrel 3 moves forward along the rolling direction R, with its initial position located between the front end 3a and the rear end 3b of the mandrel 3. The reduction in the working stroke of the retaining device 12, or more precisely, its fixing unit 12a, roughly corresponds to, for example, the length of the tube blank 2.
[0067] By shortening the working stroke in this way, the mandrel 3 can be pre-inserted into the tube blank 2 during a minor part of the processing cycle, thereby reducing cycle time and increasing production.
[0068] Shortening the working stroke of the holding device 12 further allows for the minimization of the mass moved, thereby reducing drive power and dynamic load. The connection between the holding device 12 and the mandrel 3 during the synchronous stroke of the mandrel helps to further shorten the cycle time of the processing cycle. Positioning and adjusting the fixing unit 12a according to the size of the tube blank 2 can be performed easily and flexibly. Thus, the system can be pre-positioned without problems even with shorter tube blanks 2, further reducing cycle time. The process steps of placing the mandrel 3 into the rolling line L and placing the tube blank 2 into the rolling line can be performed simultaneously, thereby further shortening the cycle time of the processing cycle. The removal of the pulled-back mandrel 3 and the insertion of the new tube blank 2 can be performed directly and sequentially along the shortest possible path. For this purpose, a transfer device can be pre-positioned and installed at the shortest possible distance.
[0069] By inserting the mandrel 3 into the billet 2 in the rolling line L, any temperature loss in the rolled product can be minimized. At the same time, less heating of the mandrel 3 allows for minimizing the number of mandrels 3 in circulation.
[0070] Where applicable, all individual features presented in the embodiments may be combined and / or interchanged with each other without departing from the scope of the invention.
[0071] List of reference numerals
[0072] 1 Rolling facilities
[0073] 2. Tube blank
[0074] 2' Rolled tubing
[0075] 3. Spindle rod
[0076] 3a Spindle front end
[0077] 3b Spindle rear end
[0078] 3c point of action
[0079] 10. Device for operating the spindle rod
[0080] 11. Feeder
[0081] 12. Maintain equipment
[0082] 12a Fixed Unit
[0083] 12b Slider
[0084] 12c rack
[0085] 20 rolling mill
[0086] 21 Rolling Mill Stand
[0087] 30 Controllers
[0088] 40 Connecting devices
[0089] L rolling line
[0090] R Conveying direction / Rolling direction
[0091] x A Starting position.
Claims
1. An apparatus (10) for operating a mandrel (3) in a rolling mill (1), said rolling mill having a rolling mill (20) for rolling seamless tubes (2'), wherein, The device (10) has: A pusher (11) is configured to move a mandrel (3) arranged in the rolling line (L) along the rolling direction (R) so that the mandrel (3) can be moved from the basic state into the tube blank (2) arranged in front of the mandrel (3) along the rolling direction (R); Holding device (12), the holding device having a fixing unit (12a) movable along the rolling line (L), the holding device being configured to temporarily fix the mandrel (3) at a point of action (3c) in the region of the rear end (3b) of the mandrel (3) and from the starting position (x A The mandrel (3) begins its working stroke along the rolling direction (R) and against the rolling direction (R), thereby allowing the mandrel (3) to enter the mill (20) along the rolling direction (R) and to be pulled out of the mill (20) against the rolling direction (R) by the holding device (12). Its features are, The retaining device (12) is configured such that, in the basic state, the starting position (x) of the fixing unit (12a) is... A It is located between the two ends (3a, 3b) of the spindle rod (3).
2. The device (10) according to claim 1, characterized in that, The holding device (12) is configured such that the working stroke of the fixing unit (12a) is less than the total axial length of the mandrel (3) and the tube blank (2).
3. The device (10) according to claim 2, characterized in that, The holding device (12) is configured such that the working stroke of the fixing unit (12a) corresponds to the length of the tube blank (2).
4. The apparatus (10) according to any one of claims 1 to 3, characterized in that, The point of action (3c) of the spindle (3) is configured as a pivot portion, and the fixing unit (12a) is configured to engage with the pivot portion and / or stop at the pivot portion.
5. The apparatus (10) according to claim 4, characterized in that, The pivot portion includes a locally thickened portion, a recessed portion, and / or a machined portion.
6. The apparatus (10) according to any one of claims 1 to 3, characterized in that, The holding device (12) is configured such that in the base state, the fixing unit (12a) is disengaged from the mandrel (3), so that the mandrel (3) to be fed by the pusher (11) from the base state along the rolling direction (R) can move relative to the fixing unit (12a).
7. The apparatus (10) according to claim 6, characterized in that, The holding device (12) is configured such that during the feeding of the pusher (11) in the rolling direction (R), the fixing unit (12a) is fed or accelerated at a lower speed relative to the mandrel (3) in order to at least partially compensate for the speed of the fixing unit (12a) in the rolling direction and the speed of the mandrel (3) in the rolling direction (R), thereby achieving speed balance between the mandrel (3) and the fixing unit (12a).
8. The apparatus (10) according to any one of claims 1 to 3, characterized in that, The holding device (12) is configured such that when the point of action (3c) of the spindle (3) reaches the position of the fixing unit (12a) by means of the feeder (11), the fixing unit (12a) engages with the point of action (3c).
9. The apparatus (10) according to any one of claims 1 to 3, characterized in that, The holding device (12) has a slider (12b) that can move parallel to the rolling line (L), and the fixing unit (12a) is arranged on the slider.
10. The apparatus (10) according to claim 9, characterized in that, The holding device (12) has an electric motor with a pinion and rack mechanism (12c), and the slider (12b) is driven by the electric motor.
11. The apparatus (10) according to any one of claims 1 to 3, characterized in that, The device is provided with a connecting device (40) configured to fix the mandrel (3) to the pusher (11) in a force-transmitting manner during forward travel until the mandrel is transferred to the holding device (12).
12. The apparatus (10) according to claim 11, characterized in that, The connecting device (40) is mounted on the pusher (11).
13. The apparatus (10) according to claim 11, characterized in that, The retaining device (12) and the spindle (3) are configured such that they are connected to each other in a form-fitting manner after the transfer occurs, and can be mechanically disengaged in discrete or continuous adjustable end positions of the retaining device (12).
14. A rolling mill (1) comprising a mill (20) for rolling seamless tubes (2') including one or more mill stands (21) and a device (10) for operating a mandrel (3) according to any one of the preceding claims, wherein, The rolling mill (20) is configured as a longitudinal rolling mill.
15. The rolling facility (1) according to claim 14, characterized in that, The mill (20) is configured as a longitudinal mill having three to eight mill stands (21) and each mill stand (21) having two to four work rolls, wherein at least one of the work rolls is driven.
16. The rolling facility (1) according to claim 15, characterized in that, All the working rolls in the working rolls are driven.
17. The rolling mill (1) according to any one of claims 14 to 16, characterized in that, The longitudinal mill has five to six mill stands (21).
18. The rolling mill (1) according to any one of claims 14 to 16, characterized in that, Each mill stand (21) has three work rolls.
19. A method for rolling a seamless tube (2') using a rolling facility (1) according to claim 14 or 18, wherein, The method has the following characteristics: The tube blank (2) and mandrel (3) are loaded into the rolling line (L) such that, along the rolling direction (R), the mandrel (3) is positioned in front of the pusher (11), the tube blank (2) is positioned in front of the mandrel (3), and the first mill stand (21) of the mill (20) is positioned in front of the tube blank (2), thereby placing the mandrel (3) in a basic state; Position the fixing unit (12a) of the holding device (12) at the starting position (x) between the two ends (3a, 3b) of the mandrel (3). A At the location where the fixing unit (12a) is detached from the mandrel (3), the mandrel (3) is able to move relative to the fixing unit (12a) along the rolling line (L); The pusher (11) is moved along the rolling direction (R), thereby pushing the mandrel (3) forward and into the tube blank (2), wherein relative movement occurs between the fixed unit (12a) and the mandrel (3); When the point of action (3c) of the mandrel (3) reaches the position of the fixing unit (12a), the mandrel (3) is fixed by the fixing unit (12a), so that no relative movement occurs between the fixing unit (12a) and the mandrel (3) thereafter; A tube blank (2) with an inserted mandrel (3) is fed through the rolling mill (20), whereby the tube blank (2) is rolled into a tube (2') on the mandrel (3); and Then, the mandrel (3) is pulled out of the mill (20) in the opposite direction of the rolling (R) by the holding device (12).
20. The method according to claim 19, characterized in that, During the forward movement, the pusher (11) dynamically transfers the mandrel (3) to the holding device (12), wherein the speeds of the mandrel (3) and the holding device (12) are synchronized with each other during the transfer.
21. The method according to claim 19 or 20, characterized in that, The tube blank (2) and / or the mandrel (3) are inserted into the rolling line (L) transversely to the rolling direction (R).
22. The method according to claim 19 or 20, characterized in that, During the feeding of the mandrel (3) along the rolling direction (R) by the pusher (11), the fixing unit (12a) is fed or accelerated at a lower speed relative to the mandrel (3) in order to partially or completely compensate for the speed of the fixing unit (12a) along the rolling direction and the speed of the mandrel (3) along the rolling direction (R).
23. The method according to claim 22, characterized in that, During the feeding of the mandrel (3) along the rolling direction (R) by the pusher (11), the stationary unit (12a) first stops at the starting position (x) before accelerating along the rolling direction (R). A ).
24. The method according to claim 19 or 20, characterized in that, The fixing unit (12a) secures the mandrel (3) by engaging or stopping the fixing unit (12a) in the tapered portion at the point of action (3c) of the mandrel (3).
25. The method according to claim 19 or 20, characterized in that, After the mandrel (3) is withdrawn from the mill (20), the mandrel (3) is transferred by disengaging the fastener between the fixing unit (12a) and the mandrel (3) and exiting the mandrel (3) transversely to the rolling line (L).
26. The method according to claim 25, characterized in that, The exit occurs at a location different from the base state.
27. The method according to claim 19 or 20, characterized in that, The tube blank (2) is driven into the rolling mill (20) by a separate driven roll.