Method for on-machine mounting of a rolling device for a seamless steel tube cold rolling mill

Abstract

The application provides a method for installing a rolling device of a seamless steel pipe cold rolling mill, which comprises the following operation procedures: rolling roller preparation, cleaning the frame, installing the lower rolling roller, installing the butterfly spring assembly, installing the upper rolling roller, installing the T-shaped block and the wedge, installing and locking the frame bolt and the wedge bolt, pre-tightening and adjusting the roller gap of the upper and lower rolling rollers, and adjusting the meshing gap of the rolling roller gear and the frame transmission rack, wherein, the frame lining measurement procedure and the rolling device parameter measurement and correction procedure are arranged between the cleaning frame procedure and the lower rolling roller installation procedure.

Description

Technical Field

[0001] This invention relates to the field of cold rolling production technology for seamless steel pipes in the metallurgical and machinery industries, and in particular to a method for installing the roll assembly of a seamless steel pipe cold rolling mill. It is especially suitable for the precision installation of the roll assembly of a two-roll periodic seamless steel pipe cold rolling mill with a finished product specification of φ15mm or more, and is used for the precision installation of the roll assembly for cold rolling seamless steel pipes of high-strength steel grades such as nickel-based alloys, super austenitic and duplex stainless steel. Background Technology

[0002] Seamless steel pipes are common metallurgical products. Due to their high rolling precision, high speed, large production capacity, high yield, and ease of production organization and process technology adjustment, cold rolling technology for seamless steel pipes has become the main method for the production and processing of seamless steel pipes.

[0003] Seamless steel pipe cold rolling production equipment is classified into two-roll and multi-roll types according to the number of rolls. Among them, the two-roll periodic cold rolling mill is the most widely used seamless steel pipe cold rolling mill due to its compact structure, large rolling force, and high production capacity. The two-roll periodic cold rolling mill mainly consists of a rolling mechanism, a feed and rotation mechanism, a transmission mechanism, a mandrel chuck mechanism, a bed support mechanism, a feeding and blanking mechanism, a hydraulic system, a process lubrication system, an electrical automation control system, a pneumatic system, and auxiliary mechanisms. The function of the rolling mechanism is to perform room temperature cold deformation processing on the billet tube through a deformation tool composed of a mandrel (along with the mandrel) and a die.

[0004] The rolling mechanism consists of components such as a roll assembly, a base, a work frame, a slide plate assembly, and a transmission rack assembly. The base is mounted on a concrete foundation, with the work frame centrally and vertically installed inside the base. A slide plate assembly between the work frame and the base provides support, guidance, and protection, and is connected to the transmission mechanism via a horizontal connecting rod. The roll assembly comprises two relatively independent roll groups, upper and lower, each consisting of roll shafts, rolling bearings, square bearing seats, cylindrical gears (end gears), spacer rings, isolation rings, flat keys, end caps, through caps, positioning keys, ring holes, fasteners, and seals. These are installed in pairs within the work frame. Power is transmitted and the rolls rotate synchronously by the engagement of the cylindrical gears at the outer ends of the roll shafts with the transmission racks mounted on both sides of the base. Depending on the outer diameter of the finished seamless steel pipe, multiple finished product specifications can be rolled on a single mill by changing the ring holes and transmission gears on the roll assembly.

[0005] During seamless steel pipe rolling, the main motor drives the main transmission mechanism to transmit and output power through the main clutch. The work stand, under the action of the horizontal connecting rod, is driven by the transmission mechanism to perform reciprocating horizontal motion within the machine base. Meanwhile, the rolling mill assembly installed inside the work stand, relying on the meshing action of the cylindrical gear at the outer end of the roll shaft and the transmission rack of the machine base, converts the horizontal reciprocating motion of the work stand into the synchronous rotational motion of the rolling mill assembly (the opposing rotational motion of the upper and lower rolls). Through the annular rolling grooves installed in the middle of the roll shafts, which decrease in size from large to small, the billet is extruded and deformed, thus achieving cold rolling deformation processing of seamless steel pipes under normal temperature conditions. Therefore, for the rolling mechanism, and even the entire cold rolling mill, the rolling mill assembly is the most important component, and also the component with the highest daily usage and replacement frequency. On the one hand, during use, the relevant components of the rolling mill assembly will experience fatigue wear, especially the rolling bearings, transmission gears, and other moving parts, resulting in increased movement clearances. On the other hand, the annular rolling grooves, as the main deformation tool, will also experience diameter expansion wear due to wear. Meanwhile, roll assembly failures caused by equipment defects or rolling process issues are common, such as broken rolling bearings, ruptured annular bores, bent or broken roll shafts, and broken transmission gears.

[0006] Following the aforementioned equipment malfunctions, replacement of the roll assembly is necessary. Furthermore, due to lifespan limitations, irreparable component damage, and adjustments to rolling specifications, the roll assembly requires frequent disassembly and reassembly (on-machine) operations. Each reassembly must meet relevant technical requirements, satisfying both the roll assembly's own installation accuracy and the positioning and transmission accuracy of the roll assembly with the frame, base, drive rack, and other components. Particular emphasis must be placed on ensuring accuracy with the rolling centerline. The rolling centerline is a virtual straight line running through the entire cold rolling mill, serving as both the equipment installation reference and the reference for seamless steel pipe rolling. Regarding the rolling mill assembly, the rolling centerline must be located at the center point of the circular hole formed by the annular rolling grooves of the upper and lower rolls, with an error value not exceeding 0.5 to 2.0 mm (selected according to different rolling mill models). The vertical height and horizontal (four directions) error values ​​of the rolls must meet the standards; otherwise, it will cause rolling quality loss and abnormal damage to components such as rolls, stands, and transmission racks.

[0007] Currently, the requirements for installing the roll replacement device on the machine are: the machine base cover is open, the mandrel push rod has been withdrawn from the machine base area, the machine frame is stopped at the designated position inside the machine base (usually the rear limit point), the roll device inside the machine frame has been removed, the main power supply to the equipment is cut off, and the main clutch is in a disengaged state. The main procedures include: roll preparation (delivering the finished roll device to the machine side area) → cleaning the machine frame → installing the lower roll → installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the machine frame bolts and wedge bolts → pre-tightening and adjusting the roll gap between the upper and lower rolls → adjusting the meshing clearance between the roll gear and the machine base drive rack, etc., comprising nine steps. While the aforementioned installation method can complete the installation of the roll device on a seamless steel pipe cold rolling mill, it still has certain shortcomings in production practice, namely:

[0008] 1) Uncontrolled Accuracy of Height-Direction Roll Installation (On-Machine): The roll assembly itself cannot be directly calibrated with the rolling centerline. Accuracy is achieved through the height of the frame where the roll assembly is installed. Currently, there are no requirements for the compatibility between the frame and the roll assembly during installation. However, wear occurs at the contact surfaces between the frame and the lower rolls, and the bottom liner of the frame is not replaced synchronously with each off-machine roll. Therefore, the accuracy of the roll assembly relative to the rolling centerline after installation is like a blind box, only identifiable through post-installation measurement. This results in uncontrolled installation accuracy. Furthermore, if an error exceeding the rolling centerline is discovered, the time and labor-intensive process of removing the rolls and adjusting the frame is detrimental to orderly production. For large-scale cold rolling mills, a single roll assembly weighs over 2 tons, posing a high risk of lifting and installation, and the repetitive nature of the work poses a threat to occupational health and safety.

[0009] 2) Uncontrolled horizontal straightness accuracy of the roll installation: The horizontal straightness of the lower roll is directly related to the flatness of the bottom of the frame. The accuracy of the lower roll should not exceed tolerances when the frame is stable within the machine base. The upper roll is installed above the lower roll, and its straightness accuracy depends on eight sets of butterfly spring assemblies installed on top of the lower roll bearing housing. These spring assemblies support the upper roll and adjust the roll gap through pre-tension compression. However, the butterfly springs undergo plastic deformation under long-term pressure, and the amount of plastic deformation for each set is not necessarily the same. Therefore, the actual height of the eight sets of butterfly springs may not be the same, leading to horizontal skewness of the upper roll assembly after installation. This easily causes errors in the horizontal rolling centerline of the upper roll. Furthermore, the machining depth of the eight blind holes in the roll bearing housing where the butterfly springs are installed may not be completely consistent, and the blind holes after each replacement of the roll exhibit even greater differences. Therefore, skewness after upper roll installation is quite common, requiring disassembly and reassembly, resulting in a high rework rate.

[0010] 3) Frequent disassembly and assembly of rolling mill units, requiring high precision in one-time installation: With the recent industrialization of high-strength seamless steel pipes, such as those made from nickel-based alloys, duplex stainless steel, and super austenitic steel, the rolling forces and impact loads on rolling mill units during rolling deformation processes have increased significantly. This has led to a significantly shorter service life for rolling mill units compared to commonly used ordinary steel grades. Furthermore, the increasing variety of new steel grades and specifications results in a substantial increase in the amount of work required to reinstall (or put back on) rolling mill units after they have been offline, leading to high labor intensity. Therefore, ensuring the accuracy of rolling mill unit installation and minimizing rework is crucial to meeting production requirements.

[0011] The invention with patent number ZL 202010526891.X, entitled "An Online Roll Gap Detection Method for Roll Devices of Seamless Steel Pipe Cold Rolling Mills," is used to measure the roll gap during the use of roll devices in two-roll periodic seamless steel pipe cold rolling mills. It is used to determine whether the roll device can continue to be used or needs to be replaced. This is fundamentally different from the roll gap measurement in the pre-tightened state after the roll device is installed on the machine, which is involved in this invention. The purpose of measuring the roll gap in this invention is to correct the straightness of the roll in the horizontal direction.

[0012] The invention with application number 202110299937.3, entitled "A method for controlling the motion accuracy of the rolling mechanism of a seamless steel pipe cold rolling mill," mainly involves the accuracy measurement and adjustment of the working frame within the machine base, providing a carrier that meets the technical requirements for the subsequent installation of the rolling mill device, and is not related to the installation of the rolling mill device itself.

[0013] The utility model "Gear Meshing Gap Adjuster" with patent number ZL201220223935.2 is a device for adjusting the meshing gap between the roll gear and the machine base transmission gear. It provides a convenient tool for improving the installation accuracy of the roll assembly. It is not directly related to the on-machine installation operation of the roll assembly provided in this invention. The specific meshing gap accuracy is still selected according to the roll assembly of each model and specification.

[0014] In summary, while the current method of installing two-roll periodic seamless steel pipe rolling mills can meet existing production needs, it still has certain shortcomings in terms of installation accuracy and rolling centerline precision error. Summary of the Invention

[0015] The technical problem to be solved by this invention is to provide a method for installing the roll assembly of a seamless steel pipe cold rolling mill, which can ensure the accuracy of the roll assembly installation, meet the technical requirements of the rolling centerline, reduce rework rate, reduce repetitive labor intensity, reduce safety hazards in lifting operations, further meet the requirements of orderly production of high-strength steel seamless pipes, and promote the core competitiveness of enterprises in the market.

[0016] The technical problem it aims to solve can be addressed through the following technical solutions.

[0017] A method for installing a roll assembly on a seamless steel pipe cold rolling mill includes eleven steps (process steps): roll preparation → cleaning the mill frame → measuring the mill frame liner → measuring and correcting roll assembly parameters → installing the lower roll → measuring and installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the mill frame bolts and wedge bolts → pre-adjusting the roll gap → adjusting the meshing clearance between the roll gear and the mill base drive rack. In other words:

[0018] I. Roll Preparation

[0019] 1. Safety preparation: Informing the work project, providing safety technical instructions, implementing on-site safety precautions, and cleaning up the work site environment, etc.

[0020] 2. Personnel preparation: personnel organization (configuration of fitters, crane operators or crane operators), relevant qualification verification and certification for work, etc.

[0021] 3. Material preparation: According to the requirements of the roll changing work order, the warehouse will collect a set of roll assembly (finished components of upper and lower rolls), deliver it to the area next to the equipment for cleaning, wiping, and deburring, and verify and confirm the relevant technical parameters against the drawings;

[0022] 4. Equipment preparation: Prepare relevant tools and equipment according to the requirements of the work project, such as manual hydraulic pump, wrench, hammer, pry bar, measuring tools (including feeler gauge, depth gauge, vernier caliper, 90-degree angle ruler, straight ruler, etc.), work ladder, and special lifting tools and slings.

[0023] II. Cleaning the machine frame

[0024] 1. Working condition preparation: The working frame with the roll assembly removed is fixed at the rear limit position of the machine base;

[0025] 2. Safety preparation: Confirm that the equipment is in a state of main circuit power failure, main clutch is in disengagement, and main brake is in closed state (clamping the main clutch brake wheel), etc.

[0026] 3. Frame cleaning: Operators use a work ladder to enter the machine base, wipe the oil stains on the inner side and bottom of the U-shaped frame, remove burrs, and check the fastening bolts and lubrication lines, etc.

[0027] 4. T-block cleaning: Wipe all contact surfaces of the T-block and remove burrs, wipe and correct the outer circumference of the cylindrical pin, etc.

[0028] 5. Wedge cleaning: Wipe all contact surfaces of the wedge and remove burrs, and check the condition of the internal threaded post, etc.

[0029] III. Measurement of Frame Liner Plate

[0030] 1. Base plate measurement: Use a depth vernier caliper to measure the thickness of the base plate at two points on the left and right sides of the frame. Calculate the wear amount by comparing it with the standard thickness (drawing dimensions).

[0031] Wear amount of bottom liner S = standard thickness value - measured value;

[0032] The wear type of the top surface of the bottom liner was determined by measuring with a ruler, and it was identified as convex, concave, or wavy.

[0033] 2. Side Liner Measurement: Use a depth vernier caliper to measure the thickness of the four side lining plates on the left, right, front, and back of the frame. Calculate the wear amount by comparing the measurement with the standard thickness (drawing dimensions).

[0034] Side liner wear amount D = standard thickness value - measured value;

[0035] The wear type of the top surface of the side liner was measured using a ruler, and it was determined to be convex, concave, or wavy.

[0036] 3. Wear Determination: Based on the wear value calculated after actual measurement, determine whether the liner needs to be used or replaced.

[0037] The wear amount of the bottom liner plate S≥S1, and the range of S1 is set to a value between 0.5 and 2 mm, which is selected according to the rolling mill model. The set value of S1 is 2.0 mm for LG-220H / 180H, 1.5 mm for LG-150H / 110H, 1.0 mm for LG-60H / SKW-75 / KPW-50, and 0.5 mm for KPW-25 and LG-30H.

[0038] The wear amount of the side liner plate D≥D1, where D1 is a set value between 0.20 and 0.50 mm, selected according to the rolling mill model. The set value is 0.5 mm for LG-220H, 180H, and 150H, 0.3 mm for LG-110H, 60H, SKW-75, and KPW-50, and 0.2 mm for KPW-25 and LG-30H.

[0039] If the wear is not greater than the set value, it can continue to be used (with compensation and correction required); if the wear is greater than the set value, it needs to be replaced.

[0040] IV. Measurement and Correction of Rolling Mill Parameters

[0041] 1. Roll cleaning: Wipe the outer surface of the square bearing seat of the upper and lower rolls (assemblies) and the inner cylindrical surface of all blind holes respectively, and place the upper and lower rolls (assemblies) on a special working platform;

[0042] 2. Lower Roll Measurement: The width and height of the square bearing housing are measured using vernier calipers. The width and height wear amounts are calculated by referring to the drawings.

[0043] Wear amount L in the width direction of square bearing housing 下 =Standard value (drawing dimensions) - Measured value;

[0044] Wear amount H in the height direction of square bearing housing 下 =Standard value (drawing dimensions) - Measured value;

[0045] Using a depth vernier caliper, the depth B of the cylindrical blind holes used for mounting disc springs at eight locations on a square bearing housing was measured. 下 The actual depth of the eight blind holes should not deviate from the standard value on the drawing by more than 0.20 mm, and the difference between the deepest and shallowest of the eight blind holes should not deviate by more than 0.30 mm. Any deviations should be corrected.

[0046] The wear type of the bottom plane of the square bearing housing was measured using a ruler to determine whether it was convex, concave, or wavy.

[0047] 3. Determination of lower roll wear value: Wear amount L in the width direction of the square bearing housing 下 If the thickness is greater than 1.0 mm, the machine cannot continue to be used; if it is not greater than 1.0 mm, it can continue to be used, but correction and compensation are required (add a shim between the side plate of the frame and the frame).

[0048] Wear amount H in the height direction of square bearing housing 下 If the thickness is greater than 2.0mm, the machine cannot continue to be used. If it is not greater than 2.0mm, it can continue to be used, but it needs to be corrected and compensated (by adding a shim between the bottom liner of the frame and the U-shaped bottom plane of the frame).

[0049] 4. Upper Roll Measurement: Use vernier calipers to measure the width and height of the square bearing housing (since the top of the square bearing housing of the upper roll is a slope, measure the lowest and highest values ​​separately and then average them). Calculate the width wear and height wear by referring to the drawings.

[0050] Wear amount L in the width direction of square bearing housing 上 =Standard value (drawing dimensions) - Measured value;

[0051] Wear amount H in the height direction of square bearing housing 上 =Standard value (drawing dimensions) - Measured value;

[0052] Using a depth vernier caliper, the depth B of the cylindrical blind holes used for mounting disc springs at eight locations on a square bearing housing was measured. 上 The actual depth of the eight blind holes should not deviate from the standard value on the drawing by more than 0.20 mm, and the difference between the deepest and shallowest of the eight blind holes should not deviate by more than 0.30 mm. Any deviations should be corrected. The wear type of the top surface of the square bearing seat should be measured with a ruler to determine whether it is convex, concave, or wavy.

[0053] 5. Determination of upper roll wear value: Wear amount L in the width direction of the square bearing housing 上Wear greater than 1.0 mm means the machine cannot continue to be used; wear less than 1.0 mm means it can continue to be used, but requires correction and compensation (adding shims between the side liner and the frame); wear H in the height direction of the square bearing housing. 上 Greater than H 上1 H 上1 The range is set to 1–3.0 mm, depending on the specific rolling mill model. Specifically, LG-220H, 180H, and 150H use 3.0 mm; LG-110H, 60H, SKW-75, and KPW-50 use 2.0 mm; and KPW-25 and LG-30H use 1.0 mm. 上1 Setting value, H 上 Greater than H 上1 If the value is not greater than the above setting, it can continue to be used, but correction and compensation are required (add a shim between the wedge and the top inclined surface of the upper roll square bearing seat or directly rely on the horizontal displacement of the wedge on the inclined surface for correction).

[0054] 6. Correction for vertical (height) distance of the lower roll: Correction value A = Wear amount of bottom liner S + Wear amount of lower roll square bearing seat in the height direction H 下 ,

[0055] Furthermore, the sum of the corrected installation thickness of the bottom liner and the actual height of the square bearing seat should not exceed 1.0 mm from the original installation height of the equipment (or the standard value on the drawing); replace the bottom liner or mounting shim with one that meets the technical requirements according to the correction value A.

[0056] 7. Correction of vertical (height) distance of upper roll: After the top slope of the square bearing seat is superimposed with the wedge, the highest height value of the slope is greater than the top space distance Y after the upper roll is installed in the frame, and it is advisable to be Y+2mm. In other words, the wedge still has horizontal displacement space after being installed on the top slope of the upper roll (adjust the roll gap equivalent by pressing the upper roll below).

[0057] V. Install the lower roll

[0058] 1. Installation preparation: Use a special T-shaped lifting tool to hoist the lower roll (assembly). The lifting machinery will vertically lift the lower roll (assembly) to a height of 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, wipe the outer circumferential surface of the annular hole, the inner cylindrical surface of the eight blind holes, etc.

[0059] 2. Installation into the frame: Use cranes to lift the lower roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the lower roll with the side of the rack of the machine base and lower it at a uniform speed until the bottom plane of the square bearing seat of the lower roll is flat on the plane of the bottom liner of the frame.

[0060] 3. Lower roll positioning: Use a pry bar to adjust the gear at the end of the lower roll, align the ET section gear with the ET section tooth groove of the machine base drive rack, slightly pre-tighten the lower roll (assembly) with the lifting machinery, use a pry bar to pry at the other end (non-gear end) of the lower roll, horizontally move the lower roll (assembly), and finally align the gear at the end of the lower roll with the machine base drive rack in the horizontal direction;

[0061] 4. Lower roll calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the lower roll is flush with the inner end face of the U-shaped groove of the frame, in order to ensure the accuracy of the annular rolling groove installed on the lower roll and the rolling center line.

[0062] VI. Measurement and Installation of Disc Spring Assembly

[0063] 1. Inspection of butterfly spring assembly: Visually inspect the appearance of eight sets of butterfly springs. Use vernier calipers to measure the height of the butterfly spring assembly (i.e., the continuous length from the first to the last butterfly spring). The height error value of the eight sets of butterfly spring assemblies (between the highest and lowest) should not exceed 0.5mm. If the error value exceeds 0.5mm, the assembly needs to be replaced. Under normal operating conditions, all eight sets should be replaced at the same time (new parts and used assemblies cannot be mixed, as the height will definitely exceed the tolerance).

[0064] 2. Installation of butterfly spring assembly: Install the eight butterfly spring assemblies vertically and oriented as a whole in the eight cylindrical blind holes on the top plane of the square bearing seat of the lower roll;

[0065] 3. Calibration of butterfly spring assemblies: Use a depth vernier caliper to measure the height E of each of the eight butterfly spring assemblies protruding from the square bearing seat of the lower roll. The error value should not be greater than E1. The range of E1 is set between 0.5 and 1.0 mm, and is selected according to different rolling mill models. Specifically, the set value of E1 is 1.0 mm for LG-220H, 180H, and 150H, 0.8 mm for LG-110H, 60H, SKW-75, and KPW-50, and 0.5 mm for KPW-25 and LG-30H. If the actual measured error is greater than the set value, it is necessary to correct it by means of shims, etc.

[0066] VII. Install the upper rollers

[0067] 1. Installation preparation: Clean the top plane of the installed lower roll square bearing seat and the inner side of the frame U-shaped groove. Use a special T-shaped hoist to lift the upper roll (assembly). The hoisting machinery will vertically lift the upper roll (assembly) 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, and wipe the outer circumferential surface of the annular hole, blind holes, etc.

[0068] 2. Installation into the frame: Use cranes to lift the upper roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the upper roll with the inner vertical surface of the machine base and lower it at a uniform speed until the gear of the upper roll is 10-30mm above the transmission rack of the machine base, and the square bearing seat is oriented and embedded into the U-shaped groove of the frame. At the same time, the eight blind holes at the bottom of the square bearing seat are aligned with the eight butterfly springs.

[0069] 3. Upper Roll Positioning: Use a pry bar to make a small adjustment to the end gear of the upper roll, aligning the ET section gear with the ET section tooth groove of the machine base transmission rack. The crane descends at a constant speed until the end gear of the upper roll is fully embedded in the tooth groove of the transmission rack, and at the same time the square bearing seat and the butterfly spring are fully engaged (a small horizontal prying can be used to ensure the coaxiality of the blind hole and the butterfly spring).

[0070] 4. Upper Roll Calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the upper roll is flush with the inner end face of the U-shaped groove of the frame, so as to ensure the accuracy of the annular rolling groove installed on the upper roll and the rolling center line; when horizontal error occurs, adjust and lock it by adjusting the bolt on one side of the U-shaped groove of the frame.

[0071] 8. Install T-blocks and wedges

[0072] 1. T-block installation: Use a crane to lift a T-block to the upper side of the near end of the U-shaped groove of the frame, and lower it at a constant speed. When the bottom plane of the T-block is flush with the bottom plane of the inverted T-groove of the frame, manually push the T-block horizontally into the inverted T-groove; use the above method to install another T-block at the far end of the U-shaped groove of the frame.

[0073] 2. Install positioning pins: Use manual labor to install the four positioning pins into the cylindrical holes at the contact points between the T-block and the inverted T-groove of the frame. Install stop blocks on the outer sides of the two T-blocks. The stop blocks are embedded in the annular grooves of the positioning pins on both sides and fixed to the frame with bolts.

[0074] 3. Installing the wedge: Using lifting machinery or manual labor (selected according to the mill model and the weight of the wedge), one wedge is oriented and installed in the wedge groove between the square bearing seat of the upper roll at the near end and the T-block of the frame. Then, two adjusting bolts are screwed into the threaded posts at both ends of the wedge through the frame. The other wedge is installed in the wedge groove at the far end of the frame using the same method.

[0075] 9. Install and tighten the frame bolts and wedge bolts.

[0076] 1. Frame bolt installation: Use lifting machinery or manual labor (selected according to the mill model and bolt weight) to install one frame bolt in the round hole at the near end of the frame, and pass it through the T-block to protrude from the other end of the frame. Install and tighten the high-strength custom round nut, pre-tightening it to the position (preferably so that it cannot be tightened manually). Install the frame bolts at the far end of the frame in the same way.

[0077] 2. Pre-tightening and locking of frame bolts: Using lifting machinery or manual labor (selected according to the mill model and the weight of the hydraulic piston cylinder), the hydraulic piston cylinder is oriented and fixed on the high-strength custom round nut at the end of the frame bolt. Connect the manual hydraulic pump, and manually press the hydraulic pump to output pressure, causing the piston to move horizontally to press the frame and produce a slight elastic deformation in the horizontal length direction of the frame bolt until the set hydraulic value is reached (the hydraulic value is set according to different mill models, usually 12-25MPa is appropriate). At this time, immediately tighten the high-strength custom round nut at the end of the frame bolt until it can no longer be tightened manually. Depressurize the hydraulic pump, remove the hydraulic piston cylinder, and the pre-tightening and locking of the frame bolt is completed. Pre-tighten and lock the other end of the frame bolt in the same way, and the hydraulic values ​​at both ends should be consistent.

[0078] 3. Wedge pre-tightening adjustment: Use a wrench to tighten the adjusting bolt at one end of the frame, drag the wedge horizontally within the wedge groove until the wedge and the wedge groove are in a tight pre-tightened state; use the aforementioned method to pre-tighten the other wedge to ensure that the roll gap between the upper and lower rolls is in the initial state, and that the horizontality of the upper roll and the parallelism error with the rolling center line are not greater than 0.5mm.

[0079] 10. Pre-adjustment of roll gap

[0080] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the jog operation to position the frame in the middle of the machine base before disconnecting the main power supply;

[0081] 2. Measuring the initial roll gap: The operator enters the machine base and uses a feeler gauge to measure the roll gap between the upper and lower rolls, and determines the gap value between the square bearing seats on both sides of the roll and the gap value between the cylindrical surfaces on both sides of the annular rolling groove.

[0082] 3. Roll gap adjustment: Determine the working roll gap equivalent for the current rolling specification according to the technical requirements (set by the company's internal standards). Adjust the wedges installed in the frame separately, relying on the horizontal displacement of the wedges on the inclined surface at the top of the square bearing seat of the upper roll to press down or lift the roll gap until the roll gap equivalent meets the company's standards (production process sheet, technical notice), and the roll gap equivalents on both sides are consistent (error value not greater than 0.05~0.20mm, selected according to different rolling mill models), that is, the levelness of the upper and lower rolls and the parallelism with the rolling center line meet the standards.

[0083] 11. Adjust the meshing clearance between the roll gear and the machine base drive rack.

[0084] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the power-on jog operation to position the frame at the rear limit (rearmost end) of the machine base, then disconnect the main power supply;

[0085] 2. Measuring meshing clearance: Use a feeler gauge to measure the meshing clearance between the gear at the end of the lower roll and the rack of the machine base drive, and then measure the meshing clearance between the gear at the end of the upper roll and the rack of the machine base drive, and record the readings;

[0086] 3. Determine the meshing clearance value: Select the appropriate meshing clearance value according to different rolling mill models, preferably 0.05~0.15mm. Specifically, 0.10~0.15mm is suitable for LG-220H, 180H, and 150H; 0.08~0.12mm is suitable for LG-110H, 60H, SKW-75, and KPW-50; and 0.05~0.08mm is suitable for KPW-25 and LG-30H. If the actual measured meshing clearance is less than or greater than the set value, adjustment and correction are required.

[0087] 4. Adjusting the meshing clearance: Loosen the fixing bolts of the machine base drive rack, and use the gear clearance adjustment device on the outside of the machine base panel to horizontally move the machine base drive rack to achieve precise adjustment of the meshing clearance. When the measured meshing clearance is greater than the standard value, adjust the displacement of the machine base drive rack in the forward direction. When the measured meshing clearance is less than the standard value, adjust the displacement of the machine base drive rack in the reverse direction until the meshing clearance meets the standard. Then tighten the rack bolts.

[0088] 5. Verify and adjust the meshing clearance: After personnel have evacuated the machine base, inspect the relevant components, and use the jog operation to position the machine frame at the front limit (forwardmost) position of the machine base, then disconnect the main power supply; measure the meshing clearance between the lower roll end gear and the machine base drive rack again using a feeler gauge, and then measure the meshing clearance between the upper roll end gear and the machine base drive rack, recording the readings; when the measured value meets the standard requirement, the meshing clearance is up to standard; when the measured value exceeds the standard value, the meshing clearance needs to be adjusted again, i.e., loosen the machine base drive rack fixing bolts again, use the gear clearance adjustment device on the outside of the machine base panel to horizontally move the machine base drive rack, achieving precise adjustment of the meshing clearance; when the measured meshing clearance is > the standard value, adjust the machine base drive rack displacement in the forward direction; when the measured meshing clearance is < the standard value, adjust the machine base drive rack displacement in the reverse direction until the meshing clearance meets the standard, then tighten the rack bolts.

[0089] Following this, 6S practices are implemented on-site, including cleaning the work area and recycling tools and equipment, before handing them over to the production team. By following these steps, the method for installing roll assemblies on seamless steel pipe cold rolling mills, as provided by this invention, is completed. This method is applicable to the installation of roll assemblies for newly assembled products, as well as those for regenerated and repaired products. It is also suitable for installing roll assemblies on new work frames and repaired work frames. Roll assemblies installed using this method exhibit high installation accuracy, long service life, convenient subsequent adjustments, and good rolling stability. This enables efficient, fast, and precise installation of roll assemblies on seamless steel pipe cold rolling production lines, meeting the technical requirements for the installation and commissioning of roll assemblies on various models of two-roll periodic seamless steel pipe cold rolling mills.

[0090] The method described above has the following advantages and beneficial effects:

[0091] 1. The design is reasonable, the process is smooth, the steps are connected in an orderly manner, it is safe and reliable, saves labor and time, and is practical and efficient. It effectively ensures the accuracy and efficiency of the installation of the rolling mill device and meets the requirements of orderly production of the seamless steel pipe cold rolling production line.

[0092] 2. It meets the technical requirements of the rolling mechanism for the rolling centerline from the source, improves the one-time installation rate and accuracy of the roll device, reduces the rework rate, reduces the intensity of repetitive labor, and reduces safety hazards in lifting operations;

[0093] 3. The height correction compensation of the bottom liner plate of the frame ensures the compatibility between the lower roll and the frame, thereby ensuring the vertical accuracy of the roll assembly and the rolling center line;

[0094] 4. The synchronization accuracy of eight sets of butterfly springs ensures the support accuracy of the upper rolling mill device, and ensures the synchronization accuracy of the rolling mill device with the rolling center line.

[0095] 5. By compensating for the wear equivalent of the U-shaped groove side liner plate and the square bearing seat of the frame, the movement of the roll bearing seat inside the frame is reduced, thus reducing the accuracy error during tube deformation.

[0096] 6. No additional equipment, facilities, or special tools are required, resulting in low implementation costs, minimal investment, high cost-effectiveness, and ease of on-site implementation.

[0097] 7. The work methods are replicable, transferable, and standardized, reducing the requirements for the experience and skills of the workers and facilitating the organization of the supplier's human resources.

[0098] 8. The installation accuracy of the rolls on the rolling mill is controlled, and the rolling stability is good. This effectively ensures the service life of the rolling mechanism and roll device, meets the orderly production of the seamless steel pipe cold rolling production line, especially the technical requirements for the production of high-strength steel seamless steel pipes, and improves the core competitiveness of enterprises in the production of high-end seamless steel pipes.

[0099] 9. It has strong versatility and is applicable to all models and specifications of two-roll periodic seamless steel pipe cold rolling mills. It has broad application prospects and has certain reference and application value for improving the installation process of roll devices in similar two-roll periodic seamless steel pipe cold rolling mills. Attached Figure Description

[0100] Figure 1 This is a schematic diagram of the external structure of the rolling mill roll assembly of a seamless steel pipe cold rolling mill; among which, Figure 1 a, Figure 1 b and Figure 1 c illustrates the structure from different angles;

[0101] Figure 2 This is a schematic diagram of the internal structure of the rolling mill roll assembly of a seamless steel pipe cold rolling mill; among which, Figure 2 a is Figure 2 View AA in b;

[0102] Figure 3 This is a schematic diagram of the roll assembly structure of a seamless steel pipe cold rolling mill; among which, Figure 3 a and Figure 3 b illustrates the structure from different angles. Figure 3 c is Figure 3 b is a CC view;

[0103] Figure 4 A schematic diagram of the rolling mechanism frame structure of a seamless steel pipe cold rolling mill under operating conditions; among which... Figure 4 a and Figure 4 b illustrates the structure from different angles;

[0104] Figure 5 Schematic diagram of the working structure of the rolling mechanism base and frame of a seamless steel pipe cold rolling mill;

[0105] Figure 6 This is a flowchart of the installation process of the roll assembly of a seamless steel pipe cold rolling mill. Detailed Implementation

[0106] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0107] Reference Figures 1 to 6In the diagram, 10 and 20 are end gears, 11 and 13 are upper bearing seats, 12 is an upper ring hole type, 21 and 23 are lower bearing seats, 22 is a lower ring hole type, 31 and 32 are rear through covers, 33 is a front through cover, 41 is a positioning end cover, 42 is a roll shaft, 43 is a butterfly spring assembly, 44 is a bearing seat cover, 51 is a rolling bearing, 60 is a frame, 61 is an upper roll, 62 is a lower roll, 63 is a bottom liner plate, 64 is a side liner plate, 65 is an adjusting bolt, 66 is an adjusting bolt, 67 is a locking bolt, 68 is a T-block, 69 is a stop block, 70 is an adjusting wedge block, 71 is a positioning pin, 72 is a ring hole type, 80 is a working frame (front limit position), 81 is a machine base panel, 82 is a rear limit position of the roll gear, 83 is a tooth backlash adjuster, 84 is a transmission rack, and 85 is a rack bolt.

[0108] A steel pipe plant of a steel company in Shanghai uses the technology provided by this invention on imported SKW-75 and KPW-50 high-speed cold rolling mills, as well as two-roll periodic seamless steel pipe cold rolling mills of models LG-220H, LG-150H, LG-110H, and LG-60H, for the cold rolling production (deformation processing) of seamless pipes of high-strength steel grades such as nickel-based alloys, super austenitic and duplex stainless steel.

[0109] The following are specific examples.

[0110] Example 1

[0111] Taking the LG-220H two-roll periodic seamless steel pipe cold rolling mill with a rolled product specification of φ150~220mm as an example, the main processes consist of eleven steps: roll preparation → cleaning the mill frame → measuring the mill frame liner → measuring and correcting the roll assembly parameters → installing the lower roll → measuring and installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the mill frame bolts and wedge bolts → pre-adjusting the roll gap → adjusting the meshing clearance between the roll gear and the mill base drive rack. In other words:

[0112] I. Roll Preparation

[0113] 1. Safety preparation: Informing the work project, providing safety technical instructions, implementing on-site safety precautions, and cleaning up the work site environment, etc.

[0114] 2. Personnel preparation: personnel organization (configuration of fitters, crane operators or crane operators), relevant qualification verification and certification for work, etc.

[0115] 3. Material preparation: According to the requirements of the roll changing work order, the warehouse will collect a set of roll assembly (finished components of upper and lower rolls), deliver it to the area next to the equipment for cleaning, wiping, and deburring, and verify and confirm the relevant technical parameters against the drawings;

[0116] 4. Equipment preparation: Prepare relevant tools and equipment according to the requirements of the work project, such as manual hydraulic pump, wrench, hammer, pry bar, measuring tools (including feeler gauge, depth gauge, vernier caliper, 90-degree angle ruler, straight ruler, etc.), work ladder, and special lifting tools and slings.

[0117] II. Cleaning the machine frame

[0118] 1. Working condition preparation: The working frame with the roll assembly removed is fixed at the rear limit position of the machine base;

[0119] 2. Safety preparation: Confirm that the equipment is in a state of main circuit power failure, main clutch is in disengagement, and main brake is in closed state (clamping the main clutch brake wheel), etc.

[0120] 3. Frame cleaning: Operators use a work ladder to enter the machine base, wipe the oil stains on the inner side and bottom of the U-shaped frame, remove burrs, and check the fastening bolts and lubrication lines, etc.

[0121] 4. T-block cleaning: Wipe all contact surfaces of the T-block and remove burrs, wipe and correct the outer circumference of the cylindrical pin, etc.

[0122] 5. Wedge cleaning: Wipe all contact surfaces of the wedge and remove burrs, and check the condition of the internal threaded post, etc.

[0123] III. Measurement of Frame Liner Plate

[0124] 1. Measurement of the bottom liner: Use a depth vernier caliper to measure the thickness of the bottom liner at the left and right sides of the frame, and calculate the wear amount by referring to the standard thickness (drawing dimensions), that is, the wear amount of the bottom liner S = standard thickness value - measured value = 24 - 22.3 = 1.7mm; use a ruler to measure the wear type of the top plane of the bottom liner, and determine that it belongs to the convex type.

[0125] 2. Side Liner Measurement: Use a depth vernier caliper to measure the thickness of the four side liners on the left, right, front, and back of the frame. Calculate the wear amount by referring to the standard thickness (drawing dimensions), i.e., side liner wear amount D = standard thickness value - measured value = 12 - 11.8 = 0.2mm; use a ruler to measure the wear type of the top plane of the side liner to determine if it is a wavy pattern.

[0126] 3. Wear Determination: Based on the wear value calculated after actual measurement, determine whether the liner should be used or replaced. The wear of the bottom liner should be ≥2mm and the wear of the side liner should be ≥0.50mm. If the actual wear of the bottom liner is 1.7mm < 2.0mm, it can continue to be used (compensation and correction are required). If the wear of the side liner is 0.20mm < 0.5mm, it can continue to be used.

[0127] IV. Measurement and Correction of Rolling Mill Parameters

[0128] 1. Roll cleaning: Wipe the outer surface of the square bearing seat of the upper and lower rolls (assemblies) and the inner cylindrical surface of all blind holes respectively, and place the upper and lower rolls (assemblies) on a special working platform;

[0129] 2. Lower Roll Measurement: The width (799.8 mm) and height (759.8 mm at point) of the square bearing housing were measured using vernier calipers. The width and height wear amounts were calculated by referring to the drawings. The width wear amount L of the square bearing housing was also calculated. 下 =Standard value (drawing dimensions) - Measured value = 800 - 799.8 = 0.20mm, wear amount H in the height direction of the square bearing housing 下 =Standard value (drawing dimensions) - Measured value = 760 - 759.8 = 0.20mm; Use a depth vernier caliper to measure the depth B of the cylindrical blind holes for mounting the disc springs at eight locations on the square bearing housing. 下 =90±0.05mm, the actual depth of the eight blind holes =90±0.05mm and the error value of the standard value of 90.0mm on the drawing =0.05mm is not greater than 0.20mm, and the difference between the deepest and shallowest of the eight blind holes =0.10mm is not greater than 0.30mm, which meets the technical requirements; the wear type of the bottom plane of the square bearing seat was measured with a ruler and it was determined to be a convex center.

[0130] 3. Determination of lower roll wear value: Wear amount L in the width direction of the square bearing housing 下 =0.2mm or less than 1.0mm can continue to be used but requires correction and compensation (a shim is added between the side liner and the frame; considering the wear of the side liner, a shim made of 0.30mm stainless steel sheet is used for correction); the wear amount H in the height direction of the square bearing seat 下 =0.2mm and no more than 2.0mm can continue to be used, but correction and compensation are required (add a shim between the bottom liner of the frame and the U-shaped bottom plane of the frame; considering the wear of the bottom liner is 1.7mm, a 2.0mm thin plate is used to process the shim for compensation).

[0131] 4. Upper Roll Measurement: Use vernier calipers to measure the width of the square bearing housing (799.8mm) and its height (highest point 769.4mm, lowest point 720mm, average height in the middle 744.7mm). Calculate the wear amount L in the width direction of the square bearing housing by referring to the drawing. 上 Wear amount H in the height direction of square bearing housing 上 Among them, the width wear amount L 上 =Standard value (drawing dimensions) - Measured value = 800 - 799.8 = 0.20mm, Height wear H 上 =Standard value (drawing dimensions) - Measured value = 745 - 744.7 = 0.30mm; The depth B of the cylindrical blind holes for mounting the disc springs at eight locations on the square bearing housing was measured using a depth vernier caliper. 上=100±0.08mm, the actual depth of the eight blind holes has an error of 0.08mm from the standard value of 100.0mm on the drawing, which is no greater than 0.20mm, and the difference between the deepest and shallowest of the eight blind holes is 0.16mm, which is no greater than 0.30mm, which meets the technical requirements; the wear type of the top plane of the square bearing seat was measured with a ruler and it was determined to be a convex shape.

[0132] 5. Determination of upper roll wear value: Wear amount L in the width direction of the square bearing housing 上 =0.2mm or less than 1.0mm can continue to be used, but correction and compensation are required (a shim is added between the side liner and the frame; considering the wear of the side liner, a shim made of 0.30mm stainless steel sheet is used for correction); the wear amount H in the height direction of the square bearing seat 上 =0.3mm is not much, 3.0mm can still be used, through horizontal displacement compensation of the wedge.

[0133] 6. Correction for vertical (height) distance of the lower roll: Correction value A = Actual wear of the bottom liner S + Wear in the height direction of the square bearing seat of the lower roll H 下 =1.70+0.2=1.9mm, and the error value (or the standard value on the drawing) between the sum of the corrected bottom liner installation thickness and the actual height of the square bearing seat and the original installation height of the equipment 2.0 = 2.0-1.9=0.1mm is not greater than 1.0mm, which meets the technical requirements.

[0134] 7. Correction of vertical (height) distance of upper roll: After the top slope of the square bearing housing is superimposed with the wedge, the highest height value of the slope is greater than the top space distance Y = 115mm after the upper roll is installed in the frame, and Y + 2mm is preferred. The wedge height is 118mm, which meets the technical requirements.

[0135] V. Install the lower roll

[0136] 1. Installation preparation: Use a special T-shaped lifting tool to hoist the lower roll (assembly). The lifting machinery will vertically lift the lower roll (assembly) to a height of 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, wipe the outer circumferential surface of the annular hole, the inner cylindrical surface of the eight blind holes, etc.

[0137] 2. Installation into the frame: Use cranes to lift the lower roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the lower roll with the side of the rack of the machine base, and lower it at a uniform speed until the bottom plane of the square bearing seat of the lower roll is flat on the plane of the bottom liner of the frame.

[0138] 3. Lower roll positioning: Use a pry bar to adjust the gear at the end of the lower roll, align the ET section gear with the ET section tooth groove of the machine base drive rack, slightly pre-tighten the lower roll (assembly) with the lifting machinery, use a pry bar to pry at the other end (non-gear end) of the lower roll, horizontally move the lower roll (assembly), and finally align the gear at the end of the lower roll with the machine base drive rack in the horizontal direction;

[0139] 4. Lower roll calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the lower roll is flush with the inner end face of the U-shaped groove of the frame, in order to ensure the accuracy of the annular rolling groove installed on the lower roll and the rolling center line.

[0140] VI. Measurement and Installation of Disc Spring Assembly

[0141] 1. Inspection of butterfly spring assembly: Visually inspect the appearance of eight sets of butterfly springs, and use vernier calipers to measure the height of the butterfly spring assembly (i.e., the continuous length from the first to the last butterfly spring). The height error value of the eight sets of butterfly spring assemblies is 0.2mm (the highest is 206.2mm and the lowest is 206.5mm) and does not exceed 0.5mm, which meets the technical requirements.

[0142] 2. Installation of butterfly spring assembly: Install the eight butterfly spring assemblies vertically and oriented as a whole in the eight cylindrical blind holes on the top plane of the square bearing seat of the lower roll;

[0143] 3. Calibration of butterfly spring assembly: The height of each of the eight butterfly spring assemblies protruding from the square bearing seat of the lower roll was measured using a depth vernier caliper. The value E was 116.2-116.5mm, and the error value was 0.3mm, which was no more than 1.0mm, meeting the technical requirements.

[0144] VII. Install the upper rollers

[0145] 1. Installation preparation: Clean the top plane of the installed lower roll square bearing seat and the inner side of the frame U-shaped groove. Use a special T-shaped hoist to lift the upper roll (assembly). The hoisting machinery will vertically lift the upper roll (assembly) 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, and wipe the outer circumferential surface of the annular hole, blind holes, etc.

[0146] 2. Installation into the frame: Use cranes to lift the upper roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the upper roll with the inner vertical surface of the machine base and lower it at a uniform speed until the gear of the upper roll is 10-30mm above the transmission rack of the machine base, and the square bearing seat is oriented and embedded into the U-shaped groove of the frame. At the same time, the eight blind holes at the bottom of the square bearing seat are aligned with the eight butterfly springs.

[0147] 3. Upper Roll Positioning: Use a pry bar to make a small adjustment to the end gear of the upper roll, aligning the ET section gear with the ET section tooth groove of the machine base transmission rack. The crane descends at a constant speed until the end gear of the upper roll is fully embedded in the tooth groove of the transmission rack, and at the same time the square bearing seat and the butterfly spring are fully engaged (a small horizontal prying can be used to ensure the coaxiality of the blind hole and the butterfly spring).

[0148] 4. Upper Roll Calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the upper roll is flush with the inner end face of the U-shaped groove of the frame, so as to ensure the accuracy of the annular rolling groove installed on the upper roll and the rolling center line; adjust the axial position of the upper roll by pre-tightening the adjusting bolts to ensure that it is flush (the error value with the rolling center line meets the technical requirements) and then lock it.

[0149] 8. Install T-blocks and wedges

[0150] 1. T-block installation: Use a crane to lift a T-block to the upper side of the near end of the U-shaped groove of the frame, and lower it at a constant speed. When the bottom plane of the T-block is flush with the bottom plane of the inverted T-groove of the frame, manually push the T-block horizontally into the inverted T-groove; use the above method to install another T-block at the far end of the U-shaped groove of the frame.

[0151] 2. Install positioning pins: Use manual labor to install the four positioning pins into the cylindrical holes at the contact points between the T-block and the inverted T-groove of the frame. Install stop blocks on the outer sides of the two T-blocks. The stop blocks are embedded in the annular grooves of the positioning pins on both sides and fixed to the frame with bolts.

[0152] 3. Installing the wedge: Using a lifting machine, install one wedge in the wedge groove between the square bearing seat of the upper roll at the near end and the T-block of the frame. Then, screw two adjusting bolts through the two ends of the frame into the threaded posts at both ends of the wedge. Install the other wedge in the wedge groove at the far end of the frame using the same method.

[0153] 9. Install and tighten the frame bolts and wedge bolts.

[0154] 1. Frame bolt installation: Use lifting machinery to orient one frame bolt into the round hole at the near end of the frame, and pass it through the T-block to protrude from the other end of the frame. Install and tighten the high-strength custom round nut to the pre-tighten position (preferably so that it cannot be tightened manually). Install the frame bolts at the far end of the frame in the same way.

[0155] 2. Pre-tightening and locking of frame bolts: Use lifting machinery to orient and install the hydraulic piston cylinder onto the high-strength custom round nut at the end of the frame bolt and fix it. Connect the manual hydraulic pump and manually press the hydraulic pump to output pressure, causing the piston to move horizontally to press the frame and the frame bolt to produce a slight elastic deformation in the horizontal length direction until the set hydraulic value is 25MPa. At this time, immediately tighten the high-strength custom round nut at the end of the frame bolt until it cannot be tightened manually. Depressurize the hydraulic pump, remove the hydraulic piston cylinder, and the pre-tightening and locking of the frame bolts is completed. Pre-tighten and lock the other end of the frame bolt in the same way, and the hydraulic values ​​at both ends should be the same.

[0156] 3. Wedge pre-tightening adjustment: Use a wrench to tighten the adjusting bolt at one end of the frame, drag the wedge horizontally within the wedge groove until the wedge and the wedge groove are in a tight pre-tightened state; use the aforementioned method to pre-tighten the other end of the wedge to ensure that the roll gap between the upper and lower rolls is in its initial state, and that the horizontality of the upper roll and the parallelism error with the rolling center line are 0.3mm and not greater than 0.5mm, which meets the technical requirements.

[0157] 10. Pre-adjustment of roll gap

[0158] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the jog operation to position the frame in the middle of the machine base before disconnecting the main power supply;

[0159] 2. Measuring the initial roll gap: The operator enters the machine base and uses a feeler gauge to measure the roll gap between the upper and lower rolls, and determines the gap value between the square bearing seats on both sides of the roll and the gap value between the cylindrical surfaces on both sides of the annular rolling groove.

[0160] 3. Roll gap adjustment: Determine the working roll gap equivalent for the current rolling specification according to the technical requirements (set by the company's internal standards). Adjust the wedges installed in the frame separately, and rely on the horizontal displacement of the wedges on the top inclined surface of the square bearing seat of the upper roll to press down the roll gap until the roll gap equivalent is 4.0mm, and the roll gap equivalents on both sides are consistent (error value = 0.15mm, meeting the technical requirement of 0.05~0.20mm). That is, the levelness of the upper and lower rolls and the parallelism with the rolling center line meet the standards.

[0161] 11. Adjust the meshing clearance between the roll gear and the machine base drive rack.

[0162] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the power-on jog operation to position the frame at the rear limit (rearmost end) of the machine base, then disconnect the main power supply;

[0163] 2. Measuring meshing clearance: Use a feeler gauge to measure the meshing clearance between the lower roll end gear and the machine base drive rack, which is 0.25mm. Then measure the meshing clearance between the upper roll end gear and the machine base drive rack, which is 0.08mm. Record the readings.

[0164] 3. Determine the meshing clearance value: According to the enterprise standard, the standard value of the meshing clearance for this type of cold rolling mill should be 0.10 to 0.15 mm. The existing meshing clearance does not meet the technical requirements and needs to be corrected and adjusted.

[0165] 4. Adjusting the meshing clearance: Loosen the fixing bolts of the machine base drive rack, and use the gear clearance adjustment device on the outside of the machine base panel to horizontally move the machine base drive rack to achieve precise adjustment of the meshing clearance. The actual meshing clearance of the lower roll is 0.25mm, which is greater than the standard value of 0.10~0.15mm. Adjust the displacement of the machine base drive rack in the forward direction. The actual meshing clearance of the upper roll is 0.08mm, which is less than the standard value of 0.10~0.15mm. Adjust the displacement of the machine base drive rack in the reverse direction until the meshing clearance meets the standard of 0.10~0.15mm. Tighten the rack bolts.

[0166] 5. Check and adjust the meshing clearance: After personnel leave the machine base, check the relevant components, turn on the power and operate the jog to position the frame at the front limit (foremost position) of the machine base, and cut off the main power supply; measure the meshing clearance between the lower roll end gear and the machine base drive rack again with a feeler gauge = 0.10mm, and then measure the meshing clearance between the upper roll end gear and the machine base drive rack = 0.12mm. The adjusted meshing clearance meets the standard, and tighten the rack bolts.

[0167] Example (II)

[0168] Taking the LG-110H two-roll periodic seamless steel pipe cold rolling mill with a finished product specification of φ76~110mm as an example, the installation of a roll assembly (repaired part) with a finished product specification of φ90*5.5mm involves eleven main steps: roll preparation → cleaning the mill frame → measuring the mill frame liner → measuring and correcting the roll assembly parameters → installing the lower roll → measuring and installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the mill frame bolts and wedge bolts → pre-adjusting the roll gap → adjusting the meshing clearance between the roll gear and the mill base drive rack. In other words:

[0169] I. Roll Preparation

[0170] 1. Safety preparation: Informing the work project, providing safety technical instructions, implementing on-site safety precautions, and cleaning up the work site environment, etc.

[0171] 2. Personnel preparation: personnel organization (configuration of fitters, crane operators or crane operators), relevant qualification verification and certification for work, etc.

[0172] 3. Material preparation: According to the requirements of the roll changing work order, the warehouse will collect a set of roll assembly (finished components of upper and lower rolls), deliver it to the area next to the equipment for cleaning, wiping, and deburring, and verify and confirm the relevant technical parameters against the drawings;

[0173] 4. Equipment preparation: Prepare relevant tools and equipment according to the requirements of the work project, such as manual hydraulic pump, wrench, hammer, pry bar, measuring tools (including feeler gauge, depth gauge, vernier caliper, 90-degree angle ruler, straight ruler, etc.), work ladder, and special lifting tools and slings.

[0174] II. Cleaning the machine frame

[0175] 1. Working condition preparation: The working frame with the roll assembly removed is fixed at the rear limit position of the machine base;

[0176] 2. Safety preparation: Confirm that the equipment is in a state of main circuit power failure, main clutch is in disengagement, and main brake is in closed state (clamping the main clutch brake wheel), etc.

[0177] 3. Frame cleaning: Operators use a work ladder to enter the machine base, wipe the oil stains on the inner side and bottom of the U-shaped frame, remove burrs, and check the fastening bolts and lubrication lines, etc.

[0178] 4. T-block cleaning: Wipe all contact surfaces of the T-block and remove burrs, wipe and correct the outer circumference of the cylindrical pin, etc.

[0179] 5. Wedge cleaning: Wipe all contact surfaces of the wedge and remove burrs, and check the condition of the internal threaded post, etc.

[0180] III. Measurement of Frame Liner Plate

[0181] 1. Measurement of the bottom liner: Use a depth vernier caliper to measure the thickness of the bottom liner at the left and right sides of the frame, and calculate the wear amount by referring to the standard thickness (drawing dimensions), that is, the wear amount of the bottom liner S = standard thickness value - measured value = 20 - 19.6 = 0.4mm; use a ruler to measure the wear type of the top plane of the bottom liner and determine that it is concave.

[0182] 2. Side Liner Measurement: Use a depth vernier caliper to measure the thickness of the four side liners on the left, right, front, and back of the frame. Calculate the wear amount by referring to the standard thickness (drawing dimensions), i.e., side liner wear amount D = standard thickness value - measured value = 16 - 15.8 = 0.2mm; use a ruler to measure the wear type of the top plane of the side liner to determine if it is a wavy pattern.

[0183] 3. Wear Determination: Based on the wear value calculated after actual measurement, determine whether the liner plate needs to be used or replaced. The bottom liner plate with wear ≥1.5mm and the side liner plate with wear ≥0.30mm need to be replaced. The actual wear of the bottom liner plate and the side liner plate is 0.4mm and 0.2mm respectively, which meets the technical requirements and does not need to be replaced, but correction and compensation are required.

[0184] IV. Measurement and Correction of Rolling Mill Parameters

[0185] 1. Roll cleaning: Wipe the outer surface of the square bearing seat of the upper and lower rolls (assemblies) and the inner cylindrical surface of all blind holes respectively, and place the upper and lower rolls (assemblies) on a special working platform;

[0186] 2. Lower Roll Measurement: The width of the square bearing housing (500mm) and height (475mm) were measured using vernier calipers. The wear amount in width and height was calculated based on the drawings. The wear amount L in the width direction of the square bearing housing was determined. 下 =Standard value (drawing dimensions) - Measured value = 500 - 500 = 0, Wear amount H in the height direction of the square bearing housing 下 =Standard value (drawing dimensions) - Measured value = 475 - 475 = 0; Use a depth vernier caliper to measure the depth B of the cylindrical blind holes used for mounting the disc springs at eight locations on the square bearing housing. 下 =55±0.05mm, the error between the actual depth of the eight blind holes and the standard value on the drawing is 0.05mm, which is no greater than 0.20mm, and the difference between the deepest and shallowest of the eight blind holes is 0.10mm, which is no greater than 0.30mm, which meets the technical requirements and does not need to be corrected.

[0187] 3. Determination of wear value of lower roll: Since it is a new product assembly and has not been used, there is no wear. The aforementioned process measurement confirmed that there is no wear. Considering the wear between the bottom liner plate and the side liner plate, only a 0.30mm stainless steel shim is installed on the bottom liner plate for correction. The lateral wear of 0.20mm is not corrected.

[0188] 4. Upper Roll Measurement: Use vernier calipers to measure the width and height of the square bearing housing (500mm), height (highest point 482mm, lowest point 458mm, average height in the middle 475mm). Calculate the wear amount L in the width direction of the square bearing housing by referring to the drawings. 上 =500—500=0, wear amount H in the height direction of the square bearing housing 上 Among them, the width wear amount L 上 =Standard value (drawing dimensions) - Measured value = 500 - 500 = 0, Height wear H 上 =Standard value (drawing dimensions) - Measured value = 475 - 475 = 0; Use a depth vernier caliper to measure the depth B of the cylindrical blind holes used for mounting the disc springs at eight locations on the square bearing housing. 上 The actual depth of the eight blind holes, 45±0.05mm, has an error of no more than 0.5mm from the standard value of 45.0mm on the drawing. Furthermore, the difference between the deepest and shallowest of the eight blind holes, 0.10mm, is no more than 0.30mm, which meets the technical requirements.

[0189] 5. Upper roller wear value determination: Since it is a new product assembled and has not been used, there is no wear. Furthermore, the aforementioned process measurements have confirmed that there is no wear, so no correction is required.

[0190] 6. Correction for vertical (height) distance of the lower roll: Correction value A = Actual wear of the bottom liner S + Wear in the height direction of the square bearing seat of the lower roll H 下 =0.40+0=0.40mm. Considering practical application and procurement, a 0.30mm stainless steel strip is used as a shim for correction. The error between the sum of the corrected bottom liner installation thickness and the actual height of the square bearing seat and the original installation height of the equipment (or the standard value on the drawing) = 0.4-0.30=0.10mm is not greater than 1.0mm, which meets the technical requirements.

[0191] 7. Correction of vertical (height) distance of upper roll: After the top slope of the square bearing seat is superimposed with the wedge, the highest height value of the slope is greater than the top space distance Y = 102mm after the upper roll is installed in the frame, and Y + 2mm = 104mm is preferred. The actual value is 104.5mm, which meets the technical requirements.

[0192] V. Install the lower roll

[0193] 1. Installation preparation: Use a special T-shaped lifting tool to hoist the lower roll (assembly). The lifting machinery will vertically lift the lower roll (assembly) to a height of 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, wipe the outer circumferential surface of the annular hole, the inner cylindrical surface of the eight blind holes, etc.

[0194] 2. Installation into the frame: Use cranes to lift the lower roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the lower roll with the side of the rack of the machine base and lower it at a uniform speed until the bottom plane of the square bearing seat of the lower roll is flat on the plane of the bottom liner of the frame.

[0195] 3. Lower roll positioning: Use a pry bar to adjust the gear at the end of the lower roll, align the ET section gear with the ET section tooth groove of the machine base drive rack, slightly pre-tighten the lower roll (assembly) with the lifting machinery, use a pry bar to pry at the other end (non-gear end) of the lower roll, horizontally move the lower roll (assembly), and finally align the gear at the end of the lower roll with the machine base drive rack in the horizontal direction;

[0196] 4. Lower roll calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the lower roll is flush with the inner end face of the U-shaped groove of the frame, in order to ensure the accuracy of the annular rolling groove installed on the lower roll and the rolling center line.

[0197] VI. Measurement and Installation of Disc Spring Assembly

[0198] 1. Inspection of butterfly spring assembly: Visually inspect the appearance of eight sets of butterfly springs. Use vernier calipers to measure the height of the butterfly spring assembly (i.e., the continuous length from the first to the last butterfly spring). The height error value of the eight sets of butterfly spring assemblies (between the highest and lowest) should not exceed 0.5mm. If the error value exceeds 0.5mm, the assembly needs to be replaced. Under normal operating conditions, all eight sets should be replaced at the same time (new parts and used assemblies cannot be mixed, as the height will definitely exceed the tolerance).

[0199] 2. Installation of butterfly spring assembly: Install the eight butterfly spring assemblies vertically and oriented as a whole in the eight cylindrical blind holes on the top plane of the square bearing seat of the lower roll;

[0200] 3. Calibration of butterfly spring assembly: The height of each of the eight butterfly spring assemblies protruding from the square bearing seat of the lower roll is measured using a depth vernier caliper. The height is E = 52.5~53mm, and the error value meets the technical requirement of no more than 0.8mm.

[0201] VII. Install the upper rollers

[0202] 1. Installation preparation: Clean the top plane of the installed lower roll square bearing seat and the inner side of the frame U-shaped groove. Use a special T-shaped hoist to lift the upper roll (assembly). The hoisting machinery will vertically lift the upper roll (assembly) 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, and wipe the outer circumferential surface of the annular hole, blind holes, etc.

[0203] 2. Installation into the frame: Use cranes to lift the upper roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the upper roll with the inner vertical surface of the machine base and lower it at a uniform speed until the gear of the upper roll is 10-30mm above the transmission rack of the machine base, and the square bearing seat is oriented and embedded into the U-shaped groove of the frame. At the same time, the eight blind holes at the bottom of the square bearing seat are aligned with the eight butterfly springs.

[0204] 3. Upper Roll Positioning: Use a pry bar to make a small adjustment to the end gear of the upper roll, aligning the ET section gear with the ET section tooth groove of the machine base transmission rack. The crane descends at a constant speed until the end gear of the upper roll is fully embedded in the tooth groove of the transmission rack, and at the same time the square bearing seat and the butterfly spring are fully engaged (a small horizontal prying can be used to ensure the coaxiality of the blind hole and the butterfly spring).

[0205] 4. Upper Roll Calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the upper roll is flush with the inner end face of the U-shaped groove of the frame, so as to ensure the accuracy of the annular rolling groove installed on the upper roll and the rolling center line; adjust the axial position of the upper roll by pre-tightening the adjusting bolts to ensure that it is flush (the error value with the rolling center line meets the technical requirements) and then lock it.

[0206] 8. Install T-blocks and wedges

[0207] 1. T-block installation: Use a crane to lift a T-block to the upper side of the near end of the U-shaped groove of the frame, and lower it at a constant speed. When the bottom plane of the T-block is flush with the bottom plane of the inverted T-groove of the frame, manually push the T-block horizontally into the inverted T-groove; use the above method to install another T-block at the far end of the U-shaped groove of the frame.

[0208] 2. Install positioning pins: Use manual labor to install the four positioning pins into the cylindrical holes at the contact points between the T-block and the inverted T-groove of the frame. Install stop blocks on the outer sides of the two T-blocks. The stop blocks are embedded in the annular grooves of the positioning pins on both sides and fixed to the frame with bolts.

[0209] 3. Installing the wedge: Manually install one wedge into the wedge groove between the square bearing seat of the upper roll at the near end and the T-block of the frame. Then, screw two adjusting bolts through the two ends of the frame into the threaded posts at both ends of the wedge. Install the other wedge into the wedge groove at the far end of the frame using the same method.

[0210] 9. Install and tighten the frame bolts and wedge bolts.

[0211] 1. Frame bolt installation: Manually install one frame bolt into the round hole at the near end of the frame, and pass it through the T-block to protrude from the other end of the frame. Install and tighten the high-strength custom round nut to the pre-tightened position (preferably so that it cannot be tightened manually). Install the frame bolts at the far end of the frame in the same way.

[0212] 2. Pre-tightening and locking of frame bolts: Manually install and fix the hydraulic piston cylinder onto the high-strength custom-made round nut at the end of the frame bolt. Connect the manual hydraulic pump and manually press the hydraulic pump to output pressure, causing the piston to move horizontally to press the frame and produce a slight elastic deformation in the horizontal length direction of the frame bolt, until the set hydraulic value is 20MPa (preferably). Immediately at this point, tighten the high-strength custom-made round nut at the end of the frame bolt until it can no longer be tightened manually. Depressurize the hydraulic pump, remove the hydraulic piston cylinder, and the pre-tightening and locking of the frame bolts is completed. Pre-tighten and lock the other end of the frame bolt using the same method, and the hydraulic values ​​at both ends should be consistent.

[0213] 3. Wedge pre-tightening adjustment: Use a wrench to tighten the adjusting bolt at one end of the frame, drag the wedge horizontally within the wedge groove until the wedge and the wedge groove are in a tight pre-tightened state; use the aforementioned method to pre-tighten the other end of the wedge to ensure that the roll gap between the upper and lower rolls is in its initial state, and that the horizontality of the upper roll and the parallelism error with the rolling center line are 0.3mm and not greater than 0.5mm.

[0214] 10. Pre-adjustment of roll gap

[0215] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the jog operation to position the frame in the middle of the machine base before disconnecting the main power supply;

[0216] 2. Measuring the initial roll gap: The operator enters the machine base and uses a feeler gauge to measure the roll gap between the upper and lower rolls, and determines the gap value between the square bearing seats on both sides of the roll and the gap value between the cylindrical surfaces on both sides of the annular rolling groove.

[0217] 3. Roll gap adjustment: Determine the working roll gap equivalent for the current rolling specification according to the technical requirements (set by the company's internal standards). Adjust the wedges installed in the frame separately, and rely on the horizontal displacement of the wedges on the top inclined surface of the square bearing seat of the upper roll to press down the roll gap until the roll gap equivalent is 4.0mm, and the roll gap equivalents on both sides are consistent (error value = 0.15mm, meeting the technical requirement of 0.05~0.20mm). That is, the levelness of the upper and lower rolls and the parallelism with the rolling center line meet the standards.

[0218] 11. Adjust the meshing clearance between the roll gear and the machine base drive rack.

[0219] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the power-on jog operation to position the frame at the rear limit (rearmost end) of the machine base, then disconnect the main power supply;

[0220] 2. Measuring meshing clearance: Use a feeler gauge to measure the meshing clearance between the lower roll end gear and the machine base drive rack, which is 0.30 mm. Then measure the meshing clearance between the upper roll end gear and the machine base drive rack, which is 0.25 mm. Record the readings.

[0221] 3. Determine the meshing clearance value: According to the enterprise standard, the standard value of the meshing clearance for this type of cold rolling mill should be 0.08 to 0.12 mm. The existing meshing clearance does not meet the technical requirements and needs to be corrected and adjusted.

[0222] 4. Adjusting the meshing clearance: Loosen the fixing bolts of the machine base drive rack, and use the gear clearance adjustment device on the outside of the machine base panel to horizontally move the machine base drive rack to achieve precise adjustment of the meshing clearance. The actual meshing clearance of the lower roll is 0.30mm, which is greater than the standard value of 0.08~0.12mm. Adjust the displacement of the machine base drive rack in the positive direction. The actual meshing clearance of the upper roll is 0.258mm, which is greater than the standard value of 0.08~0.12mm. Adjust the displacement of the machine base drive rack in the positive direction until the meshing clearance meets the standard of 0.08~0.12mm. Tighten the rack bolts.

[0223] 5. Check and adjust the meshing clearance: After personnel leave the machine base, check the relevant components, turn on the power and operate the jog to position the frame at the front limit (foremost position) of the machine base, and cut off the main power supply; measure the meshing clearance between the lower roll end gear and the machine base drive rack again with a feeler gauge = 0.10mm, and then measure the meshing clearance between the upper roll end gear and the machine base drive rack = 0.10mm. The adjusted meshing clearance meets the standard, and tighten the rack bolts.

[0224] Example (3)

[0225] Taking the KPW-50 high-speed cold rolling mill for rolling seamless steel pipes with a finished product specification of φ15~42mm as an example, the main processes include: roll preparation → cleaning the mill stand → measuring the mill stand liner → measuring and correcting the roll assembly parameters → installing the lower roll → measuring and installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the mill stand bolts and wedge bolts → pre-adjusting the roll gap → adjusting the meshing clearance between the roll gear and the mill base drive rack, etc., consisting of eleven steps.

[0226] I. Roll Preparation

[0227] 1. Safety preparation: Informing the work project, providing safety technical instructions, implementing on-site safety precautions, and cleaning up the work site environment, etc.

[0228] 2. Personnel preparation: personnel organization (configuration of fitters, crane operators or crane operators), relevant qualification verification and certification for work, etc.

[0229] 3. Material preparation: According to the requirements of the roll changing work order, the warehouse will collect a set of roll assembly (finished components of upper and lower rolls), deliver it to the area next to the equipment for cleaning, wiping, and deburring, and verify and confirm the relevant technical parameters against the drawings;

[0230] 4. Equipment preparation: Prepare relevant tools and equipment according to the requirements of the work project, such as manual hydraulic pump, wrench, hammer, pry bar, measuring tools (including feeler gauge, depth gauge, vernier caliper, 90-degree angle ruler, straight ruler, etc.), work ladder, and special lifting tools and slings.

[0231] II. Cleaning the machine frame

[0232] 1. Working condition preparation: The working frame with the roll assembly removed is fixed at the rear limit position of the machine base;

[0233] 2. Safety preparation: Confirm that the equipment is in a state of main circuit power failure, main clutch is in disengagement, and main brake is in closed state (clamping the main clutch brake wheel), etc.

[0234] 3. Frame cleaning: Operators use a work ladder to enter the machine base, wipe the oil stains on the inner side and bottom of the U-shaped frame, remove burrs, and check the fastening bolts and lubrication lines, etc.

[0235] 4. T-block cleaning: Wipe all contact surfaces of the T-block and remove burrs, wipe and correct the outer circumference of the cylindrical pin, etc.

[0236] 5. Wedge cleaning: Wipe all contact surfaces of the wedge and remove burrs, and check the condition of the internal threaded post, etc.

[0237] III. Measurement of Frame Liner Plate

[0238] 1. Measurement of the bottom liner: Use a depth vernier caliper to measure the thickness of the bottom liner at the left and right sides of the frame, and calculate the wear amount by referring to the standard thickness (drawing dimensions), that is, the wear amount of the bottom liner S = standard thickness value - measured value = 16 - 14.8 = 1.2mm; use a ruler to measure the wear type of the top plane of the bottom liner to determine that it belongs to undulation.

[0239] 2. Side Liner Measurement: Use a depth vernier caliper to measure the thickness of the four side liners on the left, right, front, and back of the frame. Calculate the wear amount by referring to the standard thickness (drawing dimensions), i.e., side liner wear amount D = standard thickness value - measured value = 10 - 9.8 = 0.20 mm; use a ruler to measure the wear type of the top plane of the side liner to determine if it is a wavy pattern.

[0240] 3. Wear Determination: Based on the wear value calculated after actual measurement, determine whether the liner plate needs to be used or replaced. The bottom liner plate with wear ≥1.0mm and the side liner plate with wear ≥0.2mm need to be replaced. The actual wear of the bottom liner plate and the side liner plate is 1.2mm and 0.2mm respectively, which does not meet the technical requirements, and the bottom liner plate and the side liner plate need to be replaced.

[0241] IV. Measurement and Correction of Rolling Mill Parameters

[0242] 1. Roll cleaning: Wipe the outer surface of the square bearing seat of the upper and lower rolls (assemblies) and the inner cylindrical surface of all blind holes respectively, and place the upper and lower rolls (assemblies) on a special working platform;

[0243] 2. Lower Roll Measurement: The width of the square bearing housing is 380mm and the height is 355mm, measured using vernier calipers. The wear amount in width and height is calculated based on the drawings. The wear amount L in the width direction of the square bearing housing is... 下 =Standard value (drawing dimensions) - Measured value = 380 - 380 = 0, Wear amount H in the height direction of the square bearing housing 下 =Standard value (drawing dimension) - Measured value = 355 - 355 = 0; Use a depth vernier caliper to measure the depth B of the cylindrical blind holes used for mounting the disc springs at eight locations on the square bearing housing. 下 =35±0.05mm, the error between the actual depth of the eight blind holes and the standard value on the drawing is 0.05mm, not greater than 0.20mm, and the difference between the deepest and shallowest of the eight blind holes is 0.10mm, not greater than 0.30mm, which meets the technical requirements and does not need to be corrected.

[0244] 3. Determination of wear value of lower roll: Since it is a new product assembly and has not been used, there is no wear. The aforementioned process measurement confirmed that there is no wear. Considering that the bottom liner and side liner of the frame are worn and replaced with new products, no correction is made to the bottom liner and side liner.

[0245] 4. Upper Roll Measurement: Use vernier calipers to measure the width (380mm) and height (highest point 362mm, lowest point 388mm, average height in the middle 350mm) of the square bearing housing. Calculate the wear amount by referring to the drawings, where the width wear amount is L. 上 =Standard value (drawing dimensions) - Measured value = 500 - 500 = 0, Height wear H 上 =Standard value (drawing size) - Measured value = , 350 - 350 = 0; Use a depth vernier caliper to measure the depth B of the cylindrical blind holes used for mounting the disc springs at eight locations on the square bearing housing. 上 The actual depth of the eight blind holes (30±0.05mm) has an error of no more than 0.5mm from the standard value of 30.0mm on the drawing, and the difference between the deepest and shallowest of the eight blind holes (0.10mm) is no more than 0.30mm, which meets the technical requirements.

[0246] 5. Determination of wear value of upper roller: Since it is a new product assembled and has not been used, there is no wear. Furthermore, the aforementioned process has confirmed that there is no wear, so no correction is required.

[0247] 6. Correction for vertical (height) distance of the lower roll: Correction value A = Actual wear of the bottom liner S + Wear in the height direction of the square bearing seat of the lower roll H 下 Furthermore, the error between the sum of the corrected bottom liner installation thickness and the actual height of the square bearing seat and the original installation height of the equipment (or the standard value on the drawing) is no greater than 1.0mm; the actual rolls use new parts, the square bearing seats are not worn, and the bottom liner should be replaced with a new part if the wear exceeds the tolerance, so no further correction or compensation is required.

[0248] 7. Correction of vertical (height) distance of upper roll: After the top slope of the square bearing housing is superimposed with the wedge, the highest height value of the slope is greater than the top space distance Y = 84mm after the upper roll is installed in the frame, and Y + 2mm = 86mm is preferred. The actual value is 87.2mm, which meets the technical requirements.

[0249] V. Install the lower roll

[0250] 1. Installation preparation: Use a special T-shaped lifting tool to hoist the lower roll (assembly). The lifting machinery will vertically lift the lower roll (assembly) to a height of 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, wipe the outer circumferential surface of the annular hole, the inner cylindrical surface of the eight blind holes, etc.

[0251] 2. Installation into the frame: Use cranes to lift the lower roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the lower roll with the side of the rack of the machine base and lower it at a uniform speed until the bottom plane of the square bearing seat of the lower roll is flat on the plane of the bottom liner of the frame.

[0252] 3. Lower roll positioning: Use a pry bar to adjust the gear at the end of the lower roll, align the ET section gear with the ET section tooth groove of the machine base drive rack, slightly pre-tighten the lower roll (assembly) with the lifting machinery, use a pry bar to pry at the other end (non-gear end) of the lower roll, horizontally move the lower roll (assembly), and finally align the gear at the end of the lower roll with the machine base drive rack in the horizontal direction;

[0253] 4. Lower roll calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the lower roll is flush with the inner end face of the U-shaped groove of the frame, in order to ensure the accuracy of the annular rolling groove installed on the lower roll and the rolling center line.

[0254] VI. Measurement and Installation of Disc Spring Assembly

[0255] 1. Inspection of butterfly spring assembly: Visually inspect the appearance of eight sets of butterfly springs. Use vernier calipers to measure the height of the butterfly spring assembly (i.e., the continuous length from the first to the last butterfly spring). The height error value of the eight sets of butterfly spring assemblies (between the highest and lowest) should not exceed 0.5mm. If the error value exceeds 0.5mm, the assembly needs to be replaced. Under normal operating conditions, all eight sets should be replaced at the same time (new parts and used assemblies cannot be mixed, as the height will definitely exceed the tolerance).

[0256] 2. Installation of butterfly spring assembly: Install the eight butterfly spring assemblies vertically and oriented as a whole in the eight cylindrical blind holes on the top plane of the square bearing seat of the lower roll;

[0257] 3. Calibration of butterfly spring assembly: The height of each of the eight butterfly spring assemblies protruding from the square bearing seat of the lower roll was measured using a depth vernier caliper. The value E was 41.8 to 42.3 mm, and the error value met the technical requirement of not more than 0.8 mm.

[0258] VII. Install the upper rollers

[0259] 1. Installation preparation: Clean the top plane of the installed lower roll square bearing seat and the inner side of the frame U-shaped groove. Use a special T-shaped hoist to lift the upper roll (assembly). The hoisting machinery will vertically lift the upper roll (assembly) 1 to 1.2 meters above the ground. Wipe the two sides, top and bottom surfaces of the square bearing seat, and wipe the outer circumferential surface of the annular hole, blind holes, etc.

[0260] 2. Installation into the frame: Use cranes to lift the upper roll (assembly) to the position directly above the U-shaped groove of the frame. Align the end face of the gear at the end of the upper roll with the inner vertical surface of the machine base and lower it at a uniform speed until the gear of the upper roll is 10-30mm above the transmission rack of the machine base, and the square bearing seat is oriented and embedded into the U-shaped groove of the frame. At the same time, the eight blind holes at the bottom of the square bearing seat are aligned with the eight butterfly springs.

[0261] 3. Upper Roll Positioning: Use a pry bar to make a small adjustment to the end gear of the upper roll, aligning the ET section gear with the ET section tooth groove of the machine base transmission rack. The crane descends at a constant speed until the end gear of the upper roll is fully embedded in the tooth groove of the transmission rack, and at the same time the square bearing seat and the butterfly spring are fully engaged (a small horizontal prying can be used to ensure the coaxiality of the blind hole and the butterfly spring).

[0262] 4. Upper Roll Calibration: Use a ruler and a 90-degree angle ruler to measure that the inner end face of the square bearing seat on both sides of the upper roll is flush with the inner end face of the U-shaped groove of the frame, so as to ensure the accuracy of the annular rolling groove installed on the upper roll and the rolling center line; adjust the axial position of the upper roll by pre-tightening the adjusting bolts to ensure that it is flush (the error value with the rolling center line meets the technical requirements) and then lock it.

[0263] 8. Install T-blocks and wedges

[0264] 1. T-block installation: Use a crane to lift a T-block to the upper side of the near end of the U-shaped groove of the frame, and lower it at a constant speed. When the bottom plane of the T-block is flush with the bottom plane of the inverted T-groove of the frame, manually push the T-block horizontally into the inverted T-groove; use the above method to install another T-block at the far end of the U-shaped groove of the frame.

[0265] 2. Install positioning pins: Use manual labor to install the four positioning pins into the cylindrical holes at the contact points between the T-block and the inverted T-groove of the frame. Install stop blocks on the outer sides of the two T-blocks. The stop blocks are embedded in the annular grooves of the positioning pins on both sides and fixed to the frame with bolts.

[0266] 3. Installing the wedge: Manually install one wedge into the wedge groove between the square bearing seat of the upper roll at the near end and the T-block of the frame. Then, screw two adjusting bolts through the two ends of the frame into the threaded posts at both ends of the wedge. Install the other wedge into the wedge groove at the far end of the frame using the same method.

[0267] 9. Install and tighten the frame bolts and wedge bolts.

[0268] 1. Frame bolt installation: Manually install one frame bolt into the round hole at the near end of the frame, and pass it through the T-block to protrude from the other end of the frame. Install and tighten the high-strength custom round nut to the pre-tightened position (preferably so that it cannot be tightened manually). Install the frame bolts at the far end of the frame in the same way.

[0269] 2. Pre-tightening and locking of frame bolts: The hydraulic piston cylinder is manually installed and fixed onto the high-strength custom-made round nut at the end of the frame bolt. A manual hydraulic pump is connected, and the hydraulic pump is manually pressed to output pressure, causing the piston to move horizontally and press against the frame. This causes a slight elastic deformation in the horizontal length direction of the frame bolt until the set hydraulic pressure value is reached (the hydraulic pressure value is set according to different rolling mill models, usually 15-16 MPa is appropriate). At this point, the high-strength custom-made round nut at the end of the frame bolt is immediately tightened until it cannot be tightened manually. The hydraulic pump is then depressurized, the hydraulic piston cylinder is removed, and the pre-tightening and locking of the frame bolt is completed. The other end of the frame bolt is pre-tightened and locked in the same way. The hydraulic pressure values ​​at both ends should be consistent.

[0270] 3. Wedge pre-tightening adjustment: Use a wrench to tighten the adjusting bolt at one end of the frame, drag the wedge horizontally within the wedge groove until the wedge and the wedge groove are in a tight pre-tightened state; use the aforementioned method to pre-tighten the other end of the wedge to ensure that the roll gap between the upper and lower rolls is in the initial state, and that the horizontality of the upper roll and the parallelism error with the rolling center line are 0.2mm and not greater than 0.5mm.

[0271] 10. Pre-adjustment of roll gap

[0272] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the jog operation to position the frame in the middle of the machine base before disconnecting the main power supply;

[0273] 2. Measuring the initial roll gap: The operator enters the machine base and uses a feeler gauge to measure the roll gap between the upper and lower rolls, and determines the gap value between the square bearing seats on both sides of the roll and the gap value between the cylindrical surfaces on both sides of the annular rolling groove.

[0274] 3. Roll gap adjustment: Determine the working roll gap equivalent for the current rolling specification according to the technical requirements (set by the company's internal standards). Adjust the wedges installed in the frame separately, relying on the horizontal displacement of the wedges on the inclined surface at the top of the square bearing seat of the upper roll to press down the roll gap until the roll gap equivalent is 3.0mm, until the roll gap equivalent meets the company's standards (production process sheet, technical notice), and the roll gap equivalents on both sides are consistent (error value = 0.15mm, error value not greater than 0.05~0.20mm), that is, the levelness of the upper and lower rolls and the parallelism with the rolling center line meet the standards.

[0275] 11. Adjust the meshing clearance between the roll gear and the machine base drive rack.

[0276] 1. Frame positioning: Personnel evacuate the machine base, inspect relevant components, and use the power-on jog operation to position the frame at the rear limit (rearmost end) of the machine base, then disconnect the main power supply;

[0277] 2. Measuring meshing clearance: Use a feeler gauge to measure the meshing clearance between the lower roll end gear and the machine base drive rack, which is 0.05mm. Then measure the meshing clearance between the upper roll end gear and the machine base drive rack, which is 0.20mm. Record the readings.

[0278] 3. Determine the meshing clearance value: According to the enterprise standard, the standard value of the meshing clearance for this type of cold rolling mill should be 0.08 to 0.12 mm. The existing meshing clearance does not meet the technical requirements and needs to be corrected and adjusted.

[0279] 4. Adjusting the meshing clearance: Loosen the fixing bolts of the machine base drive rack, and use the gear clearance adjustment device on the outside of the machine base panel to horizontally move the machine base drive rack to achieve precise adjustment of the meshing clearance; the measured meshing clearance of the lower roll is 0.05mm, which is less than the standard value of 0.08~0.12mm, and the displacement of the machine base drive rack needs to be adjusted in the reverse direction; the measured meshing clearance of the upper roll is 0.20mm, which is greater than the standard value of 0.08~0.12mm, and the displacement of the machine base drive rack needs to be adjusted in the forward direction until the meshing clearance meets the standard, and then tighten the rack bolts.

[0280] 5. Check and adjust the meshing clearance: After personnel leave the machine base, check the relevant components, turn on the power and operate the jog to position the frame at the front limit (foremost position) of the machine base, and cut off the main power supply; measure the meshing clearance between the lower roll end gear and the machine base drive rack again with a feeler gauge = 0.08mm, and then measure the meshing clearance between the upper roll end gear and the machine base drive rack = 0.10mm. The adjusted meshing clearance meets the standard, and tighten the rack bolts.

Claims

1. A method for installing a roll assembly on a seamless steel pipe cold rolling mill, comprising the following steps: roll preparation → cleaning the mill frame → installing the lower roll → installing the disc spring assembly → installing the upper roll → installing the T-block and wedge → installing and locking the mill frame bolts and wedge bolts → pre-tightening and adjusting the roll gap between the upper and lower rolls → adjusting the meshing clearance between the roll gear and the mill base drive rack, characterized in that, Between the cleaning of the frame and the installation of the lower roll, there is also a frame liner measurement process and a roll device parameter measurement and correction process. The parameter measurement and correction process for the rolling mill assembly includes the following steps: S31. Roll cleaning; S32. Measure the wear of the lower roll and determine the type of surface wear; S33. Determination of wear value of lower roll; Determine whether the device can continue to be used or requires repair and compensation based on the wear value; S34. Measure the wear of the upper roll and determine the type of surface wear; S35. Determination of wear value of upper roll; Determine whether the device can continue to be used or requires repair and compensation based on the wear value; S36, Correction of vertical distance between lower rolls; The decision to replace the bottom liner or install gaskets will be made based on the correction value. Correction value A = Wear amount S of bottom liner plate + Wear amount H of lower roll square bearing seat in the height direction, and the error between the sum of the corrected bottom liner plate installation thickness and the actual height of the square bearing seat and the original installation height of the equipment or the standard value on the drawing is not greater than 1.0mm; and replace the bottom liner plate or mounting shim that meets the technical requirements according to the correction value A. S37, Correction of vertical distance between upper rolls; Ensure that the wedge still has horizontal displacement space after it is installed on the inclined surface at the top of the upper roll; After the top inclined surface of the square bearing housing is superimposed with the wedge, the highest inclined height is greater than the top space distance Y after the upper roll is installed in the frame, so that the wedge still has horizontal displacement space after it is installed on the top inclined surface of the upper roll.

2. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 1, characterized in that, The frame liner measurement process includes the following steps: S21. Measure the wear of the bottom liner and determine the type of surface wear. S22. Measure the wear of the side liner and determine the type of surface wear. S23. Based on the wear value calculated after actual measurement, determine whether the liner should continue to be used or replaced.

3. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 1 or 2, characterized in that, The types of surface wear include convex, concave, or wavy.

4. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 2, characterized in that, In step S23, the liner is determined to continue to be used or to be replaced based on whether the wear amount of the bottom liner S≥S1 and the wear amount of the side liner D≥D1 are satisfied. S1 is set to a value between 0.5 and 2 mm, and D1 is set to a value between 0.20 and 0.50 mm, depending on the mill model. If the wear amount is not greater than the set value, it can continue to be used under compensation and correction. If the wear amount is greater than the set value, it needs to be replaced.

5. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 1, characterized in that, In step S33, Wear amount L in the width direction of the square bearing housing of the lower roll 下 If the difference is greater than 1.0 mm, it is determined that the device cannot continue to be used; if the difference is not greater than 1.0 mm, it is determined that the device can continue to be used, but compensation and correction are required. Wear amount H in the height direction of the square bearing housing of the lower roll 下 If the difference is greater than 2.0mm, it is determined that the device cannot continue to be used; if the difference is not greater than 2.0mm, it is determined that the device can continue to be used, but compensation and correction are required.

6. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 1, characterized in that, In step S35, Wear amount L in the width direction of the square bearing housing of the upper roll 上 If the difference is greater than 1.0 mm, it is determined that the device cannot continue to be used; if the difference is not greater than 1.0 mm, it is determined that the device can continue to be used, but compensation and correction are required. Wear amount H in the height direction of the square bearing housing of the upper roll 上 Greater than H 上1 When determined to be unusable, the value is no greater than H. 上1 It was determined that it could continue to be used, but compensation and correction were required; among them, H 上1 Select a setting value between 1 and 3.0 mm depending on the model of the rolling mill.

7. The method for installing the roll assembly of a seamless steel pipe cold rolling mill according to claim 4, 5, or 6, characterized in that, The compensation correction includes methods such as adding shims or directly relying on the displacement correction of the inclined wedge on the inclined surface.

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