Roll changing device and roll changing method for multi-rack housing universal rolling mill

Abstract

The invention belongs to the technical field of steel rolling equipment. The invention discloses a roll changing device and a roll changing method for a multi-rack housing universal rolling mill. The roll changing device comprises housing pull-out hydraulic cylinders, an upper layer track, a middle layer track, a roll system transverse moving trolley, a lower layer track and a chain type roll system conveying device, the roll system transverse moving trolleys are rigidly connected in series to form a group, are arranged on the lower-layer track and are provided with an upper-layer butt-joint track and a middle-layer butt-joint track; the upper-layer track, the middle-layer track and the lower-layer track are arranged in a crossed mode and are interrupted at the crossed position, and when the roller system transverse moving trolley is located at the crossed position, the butt-joint tracks form a continuous channel; the memorial archway pull-out hydraulic cylinder is arranged on the roller span and is used for pulling out or pushing the memorial archway and the machine core; the chain type roller system conveying device is installed on the roller span and used for transferring and finishing the old machine core. The roller replacing method comprises the steps of placing and replacing the machine core in advance, pulling out and disengaging, transversely moving and aligning, combining and reassembling, reversely aligning, conveying and finishing and the like, and simultaneous roller replacing or multi-time roller replacing is adopted. According to the invention, quick and accurate multi-rack batch roller replacement is realized, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of steel rolling equipment, and relates to a roll changing device and roll changing method for a multi-stand housing universal mill. BACKGROUND

[0002] At present, the production of profile steel generally adopts the universal rolling method, and the universal mill is the most important equipment for profile steel production. In the rolling process of the universal mill, the roll wears quickly, and the surface is prone to aging and cracking, so the old mill core needs to be replaced frequently. Therefore, the length of the roll changing operation time determines the production efficiency of the universal mill to a great extent. The traditional roll changing mode often relies on manual operation or simple mechanical assistance, resulting in a long time-consuming and low efficiency in the roll changing process, and inaccurate positioning, which may cause equipment damage or safety hazards. Especially in the multi-stand housing universal mill, the coordinated replacement of multiple stands further increases the complexity. If the old mill core cannot be quickly pulled out and accurately positioned, the continuity and yield of the entire production line will be directly affected.

[0003] Therefore, it is necessary to explore a roll changing device for a universal mill, which can quickly pull out and replace the mill core and accurately position it, so as to quickly load and unload the roll set into and out of the mill stand, reduce the difficulty of roll changing operation, reduce the roll changing time, make the mill quickly enter the working state, and improve the production efficiency of the universal mill. SUMMARY

[0004] Therefore, the present application aims to solve the above problems and provide a roll changing device and roll changing method for a multi-stand housing universal mill.

[0005] To achieve the above-mentioned purposes, the present application provides the following technical solutions: A roll changing device for a multi-stand housing universal mill, the universal mill is arranged on a main rolling span, one side of the main rolling span is a roll span, and the roll changing device comprises a housing pulling hydraulic cylinder, an upper layer track, a middle layer track, a roll system transverse moving trolley, a lower layer track and a chain type roll system conveying device. The upper layer track, the middle layer track and the lower layer track are distributed in layers. The lower layer track is installed on the civil foundation of the main rolling span, is parallel to the rolling line, and is located between the universal mill and the roll span. The roll system transverse moving trolleys are multiple and are rigidly connected in groups, are placed on the lower layer track, and are used for carrying the old mill core or the replacement mill core and transversely moving along the lower layer track. The roll system transverse moving trolley is provided with an upper layer butt joint track and a middle layer butt joint track. The upper layer track and the middle layer track are arranged in parallel and cross the lower layer track, and face the operating side housing of the universal mill. The upper layer track and the middle layer track are interrupted at the intersection with the lower layer track, and the upper layer butt joint track and the middle layer butt joint track butt joint with the upper layer track and the middle layer track respectively when the roller system transverse moving trolley is located at the intersection, the rolling mill core moves through the upper layer track, and the universal rolling mill operation side frame moves through the upper layer track and the middle layer track. The frame pulling hydraulic cylinder is arranged on the roll span, and the extending end is provided with a head trolley, the head trolley is slidably arranged on the middle layer track, and is used for pulling out or pushing the universal rolling mill operation side frame and the rolling mill core. The chain type roller system conveying device is installed on the roll span and butts joint with the upper layer track, and is used for pulling out the old rolling mill core from the roller system transverse moving trolley to the roll span.

[0006] Further, the tail end or the head of the roller system transverse moving trolley is provided with a roller system transverse moving trolley driving device, which is used for driving the transverse moving motion of the roller system transverse moving trolley.

[0007] Further, the driving element of the roller system transverse moving trolley driving device is a variable frequency speed regulation motor, and the variable frequency speed regulation motor is internally provided with a position detection encoder, which is used for detecting and feeding back the transverse moving position of the roller system transverse moving trolley. The head and the tail of the lower layer track are respectively left limit position and right limit position, and the left limit position and the right limit position are respectively provided with proximity switches installed on the civil engineering, which are used for limit position detection, so as to avoid the derailment of the roller system transverse moving trolley.

[0008] Further, the frame pulling hydraulic cylinder is arranged on the roll span, and the extending end is provided with a head trolley, the head trolley is slidably arranged on the middle layer track, and is used for pulling out or pushing the universal rolling mill operation side frame and the rolling mill core.

[0009] Further, the upper layer track and the middle layer track are provided with deceleration position, acceleration position, stop position and limit position, and the civil engineering at the deceleration position, the acceleration position, the stop position and the limit position is correspondingly provided with proximity switches, which are used for detecting the position of the frame pulling hydraulic cylinder in the pulling / pushing process, so as to control the moving process.

[0010] Further, the number of the roller system transverse moving trolleys is configured according to the number of the rolling mill stands, and the number of the roller system transverse moving trolleys is greater than the number of the rolling mill stands.

[0011] Further, when the number of the rolling mill stands is less than or equal to 4, the number of the roller system transverse moving trolleys is twice the number of the rolling mill stands.

[0012] Further, when the number of the rolling mill stands is 5, the number of the roller system transverse moving trolleys is 8; when the number of the rolling mill stands is 6, the number of the roller system transverse moving trolleys is 9; when the number of the rolling mill stands is 7, the number of the roller system transverse moving trolleys is 11; and when the number of the rolling mill stands is 8, the number of the roller system transverse moving trolleys is 12.

[0013] A roll changing method using the roll changing device, comprising the following steps: Step 1: According to the number of mill stands, place the same number of replacement mill cores as the old mill cores on the roll system transverse trolley in advance, and part of the roll system transverse trolley is empty; move the empty roll system transverse trolley to the intersection of the upper track and the lower track, and make the upper interface track and the middle interface track on the roll system transverse trolley respectively interface with the corresponding upper track and middle track; Step 2: Pull out the universal mill operating side canopy and the old mill core from the rolling position by the canopy pulling out hydraulic cylinder, the universal mill operating side canopy walks on the upper track and the middle track, and the old mill core walks on the upper track, and when pulled out to the roll system transverse trolley, the old mill core is placed on the roll system transverse trolley; Step 3: The canopy pulling out hydraulic cylinder continues to pull the universal mill operating side canopy to continue to retreat, separates the old mill core from the universal mill operating side canopy, and makes the universal mill operating side canopy separate from the roll system transverse trolley; Step 4: Transverse movement is performed by the roll system transverse trolley driving device to align the roll system transverse trolley on which the replacement mill core is placed with the mill row that needs to be replaced; Step 5: The universal mill operating side canopy is pushed forward by the canopy pulling out hydraulic cylinder to push the universal mill operating side canopy to the roll system transverse trolley, combine the universal mill operating side canopy with the replacement mill core, and after the combination is completed, the canopy pulling out hydraulic cylinder continues to push the universal mill operating side canopy and the replacement mill core until it is pushed back to the rolling position and is reloaded; Step 6: The roll system transverse trolley on which the old mill core is placed is realigned with the mill row by the roll system transverse trolley driving device in reverse; Step 7: The old mill core is pulled out from the roll system transverse trolley (4) to the roll gap by the chain type roll system conveying device for finishing.

[0014] Further, the roll changing method uses simultaneous roll changing or divided roll changing according to the number of mill stands; the simultaneous roll changing is that all old mill cores are replaced at the same time, that is, steps 1-7 are performed once; the divided roll changing is that all old mill cores are replaced in multiple times, that is, steps 2-7 are executed multiple times in cycles; When the number of mill stands is less than or equal to 4, the number of roll system transverse trolleys is twice the number of mill stands, and the simultaneous roll changing strategy is adopted; When the number of mill stands is 5, the number of roll system transverse trolleys is 8, the divided roll changing strategy is adopted, and the roll changing of 3 mill stands is first completed, and then the roll changing of the remaining 2 mill stands is completed; When the number of mill stands is 6, the number of roll system transverse trolleys is 9, the divided roll changing strategy is adopted, and the roll changing of 3 mill stands is first completed, and then the roll changing of the remaining 3 mill stands is completed; When the rolling mill stand is 7 stands, the roll system transverse trolley is 11, and the roll changing strategy is divided into two times, first, the roll changing of 3 stands is completed, and then the roll changing of the remaining 4 stands is completed. When the rolling mill stand is 8 stands, the roll system transverse trolley is 12, and the roll changing strategy is divided into two times, first, the roll changing of 4 stands is completed, and then the roll changing of the remaining 4 stands is completed.

[0015] The beneficial effects of the present application are: The roll changing device of the present application has simple and reasonable structure, is easy to install, can quickly form and release the support and positioning relationship between the frame and the machine core, and is accurate in positioning. Through the pulling out and pushing of the frame pulling out hydraulic cylinder, combined with the hierarchical distribution of the upper track, the middle track and the lower track, the stable walking of the operating side frame and the old rolling mill core in the pulling out process is ensured. The transverse movement function of the roll system transverse trolley is realized by a driving device installed at the end or head of the trolley. The device provides accurate position feedback through a variable frequency speed motor and a built-in encoder, so that the transverse movement is accurate and the deviation is reduced, and the roll changing reliability is improved. At the same time, the civil installation of the lower track and the rigid stringing group design of the roll system transverse trolley optimize the space occupation, especially in the multi-stand scene, when the number of stands is large, by reasonably configuring the number of trolleys (such as 6 for 3 stands and 8 for 5 stands in two times), the space occupation is avoided, and the maintainability is improved.

[0016] In addition, the present application introduces a position detection mechanism, including a pull wire sensor base fixed on the frame pulling out hydraulic cylinder base, an extended end fixed on the head trolley, and an absolute value encoder for real-time feedback of the moving position, to ensure the safety and accuracy of the pulling out and pushing process. The deceleration position, acceleration position, stop position and limit position of the upper track and the middle track correspond to the proximity switch on the civil engineering, which further controls the movement process to avoid collision. The built-in encoder of the roll system transverse trolley and the proximity switches of the left and right limit positions of the lower track prevent derailment and enhance the stability of the equipment. The functions of these detection elements are closely integrated in the device, making the overall operation more reliable and reducing the difficulty of roll changing. The chain type roll system conveying device is installed on the roll span, and the docking effect with the upper track realizes the smooth transfer of the old machine core from the main rolling span to the roll span, which is convenient for trimming and shortens the subsequent processing time.

[0017] Other advantages, objects and features of the present application will be in part apparent and in part pointed out hereinafter. Those skilled in the art will appreciate the teachings and purposes of the present application from the following specification and by practicing the application in its various embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the purpose, technical scheme and advantages of the present application clearer, the preferred detailed description of the present application will be made below in combination with the drawings, in which: Figure 1 is a top view of the roll changing device in the present application.

[0019] Figure 2 is a sectional view of the roll changing device in the present application.

[0020] Figure 3 is a schematic view of the roll changing method for 3 stands.

[0021] Figure 4 is a schematic view of the roll changing method for 4 stands.

[0022] Figure 5 is a schematic view of the roll changing method for 5 stands.

[0023] Figure 6 is a schematic view of the roll changing method for 6 stands.

[0024] Figure 7 is a schematic view of the roll changing method for 7 stands.

[0025] Figure 8 is a schematic view of the roll changing method for 8 stands.

[0026] Reference numerals: 1 - hydraulic cylinder for pulling out the housing; 2 - upper track; 3 - middle track; 4 - driving device for roll system transverse moving trolley; 5 - roll system transverse moving trolley; 6 - lower track; 7 - chain type roll system conveying device; 8 - operating side housing of universal rolling mill; 9 - old mill core; 10 - replaced mill core. DETAILED DESCRIPTION

[0027] The present application is described in greater detail by the specific working examples below, from which those skilled in the art will readily derive other advantages and embodiments of the present application. The present application can also be implemented or applied in other different specific embodiments, and the details in the present description can be modified or changed in various ways without departing from the spirit of the present application. It should be noted that the drawings provided in the following examples only schematically illustrate the basic concept of the present application, and the features in the following examples and embodiments can be combined with each other without conflict.

[0028] The drawings are only used for exemplary illustration, and the representation is only a schematic view, not a physical drawing, and should not be understood as a limitation of the present application; in order to better illustrate the embodiments of the present application, some components in the drawings can be omitted, enlarged or reduced, and do not represent the actual product size; it is understandable for those skilled in the art that some known structures and their descriptions in the drawings can be omitted.

[0029] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0030] Embodiment 1 As shown in Figure 1 and Figure 2 It is a roll changing device of a multi-stand housing universal rolling mill, the roll changing device is arranged on the main rolling span, one side of the main rolling span is the roll span, and the roll changing device comprises a housing pulling hydraulic cylinder 1, an upper layer track 2, a middle layer track 3, a roll system transverse moving trolley 4, a lower layer track 6 and a chain type roll system conveying device 7.

[0031] The upper layer track 2, the middle layer track 3 and the lower layer track 6 are distributed in layers; the lower layer track 6 is installed on the civil foundation of the main rolling span, is parallel to the rolling line, and is located between the universal rolling mill and the roll span; the roll system transverse moving trolley 4 is multiple and is rigidly connected in groups, is placed on the lower layer track 6, and is used for carrying an old rolling mill core 9 or a replacement rolling mill core 10 and moving transversely along the lower layer track 6; the roll system transverse moving trolley 4 is provided with an upper layer butt joint track and a middle layer butt joint track; the upper layer track 2 and the middle layer track 3 are arranged in parallel and are arranged in cross with the lower layer track 6, and are opposite to the universal rolling mill operation side housing 8, the upper layer track 2 and the middle layer track 3 are interrupted at the cross with the lower layer track 6, when the roll system transverse moving trolley 4 is located at the cross, the upper layer butt joint track and the middle layer butt joint track are respectively butt jointed with the upper layer track 2 and the middle layer track 3, the rolling mill core moves through the upper layer track 2, and the universal rolling mill operation side housing 8 is supported and moved by the upper layer track 2 and the middle layer track 3 in cooperation; the housing pulling hydraulic cylinder 1 is arranged on the roll span, and the extending end of the housing pulling hydraulic cylinder 1 is provided with a head trolley, the head trolley is slidably arranged on the middle layer track 3, and is used for pulling out or pushing the universal rolling mill operation side housing 8 and the rolling mill core; the chain type roll system conveying device 7 is installed on the roll span, is butt jointed with the upper layer track 2, and is used for pulling out the old rolling mill core 9 from the roll system transverse moving trolley 4 to the roll span.

[0032] The end or head of the roll system transverse moving trolley 4 is provided with a roll system transverse moving trolley driving device 5 for driving the transverse moving of the roll system transverse moving trolley 4, the driving element of the driving device 5 is a variable frequency speed regulation motor, and a position detection encoder is built in, for detecting and feeding back the transverse moving position of the roll system transverse moving trolley 4; the head and tail positions of the lower layer track 6 are respectively left limit position and right limit position, and the left limit position and the right limit position are respectively provided with proximity switches installed on the civil engineering, for limit position detection, to avoid the roll system transverse moving trolley 4 derailing.

[0033] The device also comprises a pull wire sensor, the base of the pull wire sensor is fixed on the base of the portal pulling-out hydraulic cylinder 1, the extending end is fixed on the head trolley of the portal pulling-out hydraulic cylinder 1, and the absolute value encoder in the base of the pull wire sensor is used for detecting the moving position of the operating side portal 8 of the universal rolling mill and the rolling mill core; the upper layer track 2 and the middle layer track 3 are provided with deceleration position, acceleration position, stop position and limit position, and the civil engineering at the deceleration position, acceleration position, stop position and limit position is correspondingly provided with proximity switches, for detecting the position of the portal pulling-out hydraulic cylinder 1 in the pulling / pushing process, to control the moving process.

[0034] The number of the roll system transverse moving trolley 4 is configured according to the number of the rolling mill stands, and the number of the roll system transverse moving trolley 4 is greater than the number of the rolling mill stands; when the number of the rolling mill stands is less than or equal to 4, the number of the roll system transverse moving trolley 4 is twice the number of the rolling mill stands; when the number of the rolling mill stands is 5, the number of the roll system transverse moving trolley 4 is 8; when the number of the rolling mill stands is 6, the number of the roll system transverse moving trolley 4 is 9; when the number of the rolling mill stands is 7, the number of the roll system transverse moving trolley 4 is 11; and when the number of the rolling mill stands is 8, the number of the roll system transverse moving trolley 4 is 12.

[0035] The roll changing method of the roll changing device in the embodiment comprises the following steps: Step 1: according to the number of the rolling mill stands, the number of the replacement rolling mill cores 10 equal to the number of the old rolling mill cores 9 is placed on the roll system transverse moving trolley 4 in advance, and part of the roll system transverse moving trolleys 4 are vacant; the vacant roll system transverse moving trolley 4 is moved to the intersection of the upper layer track 2 and the lower layer track 6, and the upper layer butt joint track and the middle layer butt joint track on the roll system transverse moving trolley 4 are respectively butt jointed with the corresponding upper layer track 2 and middle layer track 3; Step 2: the operating side portal 8 of the universal rolling mill and the old rolling mill core 9 are pulled out from the rolling position by the portal pulling-out hydraulic cylinder 1, the operating side portal 8 of the universal rolling mill walks on the upper layer track 2 and the middle layer track 3, the old rolling mill core 9 walks on the upper layer track 2, and when pulled out to the roll system transverse moving trolley 4, the old rolling mill core 9 is placed on the roll system transverse moving trolley 4; Step 3: the portal pulling-out hydraulic cylinder 1 continues to pull the operating side portal 8 of the universal rolling mill to continue to retreat, the old rolling mill core 9 is separated from the operating side portal 8 of the universal rolling mill, and the operating side portal 8 of the universal rolling mill is separated from the roll system transverse moving trolley 4; Step 4: The traverse movement is performed by the traverse movement trolley drive device 5, and the traverse movement trolley 4, which contains the replacement mill core 10, is aligned with the mill train that needs to be replaced. Step 5: Pull out the hydraulic cylinder 1 through the archway to push the universal mill operating side archway 8 forward, push the universal mill operating side archway 8 onto the roll system traverse trolley 4, combine the universal mill operating side archway 8 with the replacement mill core 10, after the combination is completed, pull out the hydraulic cylinder 1 through the archway to continue to push the universal mill operating side archway 8 and the replacement mill core 10 until they are pushed back to the rolling position and reinstalled; Step 6: Drive the roller system traverse trolley 4, which holds the old mill core 9, in reverse by the roller system traverse trolley drive device 5, and realign it with the mill train. Step 7: The old mill core 9 is pulled from the roll traverse trolley 4 to the roll space via the chain roller conveyor 7 for repair.

[0036] The roll changing method can be either simultaneous roll changing or multiple roll changing depending on the number of mill stands. Simultaneous roll changing means that all old mill cores 9 are replaced at the same time, that is, steps 1 to 7 are performed once. Multiple roll changing means that all old mill cores 9 are replaced in multiple cycles, that is, steps 2 to 7 are performed repeatedly. When the number of mill stands is ≤4, the number of roll system traverse trolleys (4) is twice the number of mill stands, and a simultaneous roll changing strategy is adopted, such as... Figure 3 , 4 The figures shown are schematic diagrams of the roll changing process for 3-stand and 4-stand mills, respectively. like Figure 5 The diagram shows the roll changing process for a 5-stand mill. When there are 5 stands in the mill, there are 8 roll traverse trolleys. A split roll changing strategy is adopted, first completing the roll changing for 3 stands, and then completing the roll changing for the remaining 2 stands. like Figure 6 The diagram shows the roll changing process for a 6-stand mill. When there are 6 stands in the mill, there are 9 roll traverse trolleys. A phased roll changing strategy is adopted, first completing the roll changing for 3 stands, and then completing the roll changing for the remaining 3 stands. like Figure 7 The diagram shows the roll changing process for a 7-stand mill. When there are 7 stands in the mill, there are 11 roll traverse trolleys. A phased roll changing strategy is adopted, first completing the roll changing for 3 stands, and then completing the roll changing for the remaining 4 stands. like Figure 8 The diagram shows the roll changing process for an 8-stand mill. When there are 8 stands in the mill, there are 12 roll traverse trolleys. A phased roll changing strategy is adopted, first completing the roll changing for 4 stands, and then completing the roll changing for the remaining 4 stands.

[0037] The embodiment can quickly load and unload the core into and from the mill stand, reduce the difficulty of roll changing operation, form assembly under the rolling line as a whole, save roll changing preparation time, make the rolling mill quickly enter the working state, and effectively improve the production efficiency of the universal rolling mill.

[0038] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, and they should be covered in the scope of the claims of the present application.

Claims

1. A roll changing device for a multi-stand universal rolling mill, wherein the universal rolling mill is located on the main rolling span, and one side of the main rolling span is the roll span, characterized in that, The roller changing device includes a hydraulic cylinder for pulling out the archway, an upper track, a middle track, a roller system traverse trolley, a lower track, and a chain roller system conveyor. The upper, middle, and lower tracks are distributed in layers. The lower track is installed on the civil engineering foundation of the main rolling span, parallel to the rolling line, and located between the universal rolling mill and the roll span. Multiple roll system traverse trolleys are rigidly connected in series and placed on the lower track to carry old or replacement mill cores and move them laterally along the lower track. The roll system traverse trolleys are equipped with upper and middle docking tracks. The upper and middle tracks are arranged parallel to each other and intersect with the lower track, facing the universal rolling mill's operating side archway. The upper and middle tracks are interrupted at their intersections with the lower track. When the roller system traverse trolley is located at the intersection, the upper docking track and the middle docking track are docked with the upper and middle tracks respectively. The mill core moves through the upper track, and the universal mill operating side archway moves in coordination with the upper and middle tracks. The hydraulic cylinder for pulling out the archway is located on the roll span, and its extended end is equipped with a head trolley. The head trolley is slidably located on the middle track and is used to pull out or push the universal mill operating side archway and the mill core. The chain roller conveyor is installed on the roll span and docks with the upper track to pull the old mill core from the roller traverse trolley to the roll span.

2. The roller changing device according to claim 1, characterized in that, The roller system traverse trolley is equipped with a roller system traverse trolley drive device at the end or the head, which is used to drive the traverse movement of the roller system traverse trolley.

3. The roller changing device according to claim 2, characterized in that, The driving element of the roller system traverse trolley driving device is a variable frequency speed control motor. The variable frequency speed control motor has a built-in position detection encoder, which is used to detect and provide feedback on the traverse position of the roller system traverse trolley. The head and tail positions of the lower track are the left and right limit positions, respectively. The left and right limit positions are equipped with proximity switches installed on the civil engineering structure for limit position detection to prevent the roller system traverse trolley from derailing.

4. The roller changing device according to claim 1, characterized in that, It also includes a pull wire sensor, the base of which is fixed on the base of the archway pull-out hydraulic cylinder, and the protruding end is fixed on the head carriage of the archway pull-out hydraulic cylinder. The movement position of the archway and the mill core on the universal mill operating side is detected by an absolute encoder inside the base of the pull wire sensor.

5. The roller changing device according to claim 4, characterized in that, The upper and middle tracks are equipped with deceleration positions, acceleration positions, stop positions, and limit positions. Proximity switches are installed on the civil works at the deceleration, acceleration, stop, and limit positions to detect the position of the hydraulic cylinder pulling out the archway during the pulling / pushing process, so as to control the movement process.

6. The roller changing device according to claim 1, characterized in that, The number of the roll system traverse trolleys is configured according to the number of mill stands, and the number of roll system traverse trolleys is greater than the number of mill stands.

7. The roller changing device according to claim 6, characterized in that, When the number of mill stands is ≤4, the number of traverse trolleys for the roll system is twice the number of mill stands.

8. The roller changing device according to claim 6, characterized in that, When there are 5 mill stands, there are 8 traverse carriages for the roll system; when there are 6 mill stands, there are 9 traverse carriages for the roll system; when there are 7 mill stands, there are 11 traverse carriages for the roll system; and when there are 8 mill stands, there are 12 traverse carriages for the roll system.

9. A method for changing rollers using the roller changing device according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Based on the number of mill stands, place replacement mill cores equal to the number of old mill cores on the roll system traverse trolley in advance, and leave some roll system traverse trolleys empty; move the empty roll system traverse trolleys to the intersection of the upper and lower tracks, and connect the upper docking track and the middle docking track on the roll system traverse trolley to the corresponding upper track and middle track respectively; Step 2: Pull out the universal mill operating side gate and the old mill core from the rolling position by pulling out the hydraulic cylinder through the gate. The universal mill operating side gate moves on the upper and middle tracks, and the old mill core moves on the upper track. When pulled out to the roll system traverse trolley, place the old mill core on the roll system traverse trolley. Step 3: Pull out the hydraulic cylinder to continue pulling the universal mill operating side panel backward, disengaging the old mill core from the universal mill operating side panel and causing the universal mill operating side panel to detach from the roll system traverse trolley. Step 4: The traverse is performed by the traverse trolley drive device, and the traverse trolley containing the replacement mill core is aligned with the mill train that needs to be replaced. Step 5: Push the universal mill operating side panel forward by pulling out the hydraulic cylinder through the panel, push the universal mill operating side panel onto the roll system traverse trolley, combine the universal mill operating side panel with the replacement mill core, after the combination is completed, pull out the hydraulic cylinder through the panel to continue pushing the universal mill operating side panel and the replacement mill core until they are pushed back to the rolling position and reinstalled; Step 6: Reverse drive the roller system traverse trolley drive device to realign the roller system traverse trolley containing the old mill core with the mill train. Step 7: The old mill core is pulled from the roll traverse trolley to the roll space via a chain roller conveyor for repair.

10. The roller changing method according to claim 9, characterized in that, The roll changing method is adopted according to the number of mill stands, either by simultaneous roll changing or by multiple roll changing; the simultaneous roll changing means that all old mill cores are replaced at the same time, that is, steps 1 to 7 are performed once; the multiple roll changing means that all old mill cores are replaced in multiple cycles, that is, steps 2 to 7 are performed repeatedly. When the number of mill stands is ≤4, the number of roll system traverse trolleys is twice the number of mill stands, and a simultaneous roll changing strategy is adopted. When there are 5 stands in the rolling mill, there are 8 traverse trolleys for the roll system. The roll changing strategy is adopted in stages. First, the roll changing of 3 stands is completed, and then the roll changing of the remaining 2 stands is completed. When there are 6 stands in the rolling mill, there are 9 traverse trolleys for the roll system. The roll changing strategy is adopted in stages. First, the roll changing of 3 stands is completed, and then the roll changing of the remaining 3 stands is completed. When there are 7 stands in the rolling mill, there are 11 traverse trolleys for the roll system. The roll changing strategy is adopted in stages. First, the roll changing of 3 stands is completed, and then the roll changing of the remaining 4 stands is completed. When the mill has 8 stands, there are 12 traverse trolleys for the roll system. A phased roll changing strategy is adopted, first completing the roll changing for 4 stands, and then completing the roll changing for the remaining 4 stands.

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