A kind of uncoiler device with controllable thickness periodic fluctuation in cold rolling process

Abstract

In the technical field of rolling mill equipment, the application provides a cold rolling process thickness periodic fluctuation controllable uncoiling device, which comprises a first roller assembly, a second roller assembly, a power device and a base; the first roller assembly and the second roller assembly are installed on the base along the axial direction of the base; the power device is arranged on one end side wall of the base, the power device drives the first roller assembly and the second roller assembly to rotate at the same speed in the same direction, the first roller and the second roller are the same in structure, the application limits the shaft spacing of the two rollers, solves the temperature gradient generated by the continuous contact of the hot-rolled steel coil and the roller at the same position, improves the uniformity of the microstructure of the hot-rolled steel coil in the rolling direction, and solves the problem of the thickness periodic fluctuation of the strip steel in the cold rolling process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rolling mill equipment, in particular to a coil unloading device capable of controlling thickness periodic fluctuation in cold rolling process. BACKGROUND

[0002] Micro-alloyed high-strength steel will produce thickness fluctuation problem in cold rolling process, which is caused by the uneven microstructure of the cold rolling base along the rolling direction. Hot-rolled micro-alloyed steel is the cold rolling base of cold-rolled micro-alloyed high-strength steel. After the completion of laminar cooling, the coil unloading and transportation process is completed by using the hot continuous rolling production line coil support roller device and saddle trolley. However, in this process, the hot-rolled micro-alloyed steel has uneven thermal contact with each device, which leads to excessive cooling rate at the contact position, and further causes uneven distribution of the microstructure of the hot-rolled micro-alloyed steel along the rolling direction, which seriously affects the cold rolling production of micro-alloyed high-strength steel.

[0003] In view of the problem of hot-rolled strip coiling and transportation, a series of new equipment has been designed by steel enterprises and scholars in the industry. The utility model patent with application number 95230970.X discloses a roller type steel coil unloading trolley; the utility model patent with application number 201520753328.0 discloses a solid coiler. The above utility model patents provide beneficial designs for simplifying the process and improving the efficiency of hot-rolled strip coiling and transportation, but they are not effective in solving the problem of uneven microstructure of hot-rolled strip along the rolling direction. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art to some extent. The present application provides a coil unloading device capable of controlling thickness periodic fluctuation in cold rolling process, and the technical solution is as follows:

[0005] A coil unloading device capable of controlling thickness periodic fluctuation in cold rolling process, comprising:

[0006] a first roller assembly, a second roller assembly, a power device and a base;

[0007] The first roller assembly and the second roller assembly are installed on the base along the axial direction of the base;

[0008] A power device is arranged on one end side wall of the base, the power device drives the first roller assembly and the second roller assembly to rotate at the same speed in the same direction, and the first roller and the second roller have the same structure;

[0009] The distance between the roller axis of the first roller assembly and the roller axis of the second roller assembly is the roller axis spacing, and the value of the roller axis spacing satisfies formula (1):

[0010]

[0011] wherein L is the distance between the axes of the idlers, R is the outer diameter of the hot coil, R' is the inner diameter of the hot coil, μ is the friction coefficient between the hot coil and the idlers, g is the acceleration of gravity, r is the radius of the idlers in the first idler assembly, V is the linear speed of the hot coil, which is the winding speed, and T is the time from the end of winding to the stopping of the rotation of the hot coil when it is transported to the horse.

[0012] Preferably, the base comprises two vertical plates and a bottom plate, the upper surfaces of the two ends of the bottom plate are respectively provided with two vertical plates, and the two vertical plates are vertically arranged with the bottom plate.

[0013] Two bearing seats are respectively arranged on each vertical plate.

[0014] Preferably, the first idler assembly comprises an idler, a bearing and a driven gear.

[0015] Two bearings are respectively arranged at the two ends of the idler, and a driven gear is arranged at one end of the idler.

[0016] The two bearings of the first idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates, and the two bearings of the second idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates.

[0017] Preferably, the power device comprises a hydraulic motor and a driving gear.

[0018] The output end of the hydraulic motor is provided with the driving gear.

[0019] The driving gear is engaged with the driven gears of the first idler assembly and the second idler assembly at the same time.

[0020] The driving gear supports the driven gears of the first idler assembly and the second idler assembly to rotate in the same direction and at the same speed at the same time.

[0021] Preferably, the idlers of the first idler assembly and the second idler assembly are uniformly decelerated.

[0022] Preferably, the angular acceleration of the idlers of the first idler assembly and the second idler assembly is α, and the absolute value of the formula of the α is formula (2):

[0023]

[0024] Wherein, α = - |α|.

[0025] Preferably, the α = 1.67 s -1 , L = 750 mm.

[0026] Preferably, the hot coil is a steel coil.

[0027] The beneficial effects of the technical solutions provided by the embodiments of the present invention include at least the following:

[0028] The embodiments of the present invention use a hydraulic motor to drive two idler rollers to rotate in the same direction at equal speeds, so that the outermost layer of the hot-rolled steel coil is in uniform contact with the idler rollers. This solves the problem of uneven cooling rates at different positions caused by uneven thermal contact between the idler rollers and the hot-rolled steel coil, thereby making the longitudinal structure and mechanical properties of the steel coil uniformly distributed, and solving the problem of thickness periodic fluctuations caused by the subsequent cold rolling process.

[0029] The idler rollers are connected to the base using self-aligning roller bearings, which can withstand the radial heavy load from the weight of the steel coil and the smaller axial load generated during the start-stop process of the steel coil being unloaded onto the saddle. A hydraulic motor is used to provide power; hydraulic motors are characterized by high torque, good stability, high reliability, strong load capacity, and strong adaptability, thus enabling stable operation under the harsh working conditions of the coiling process section.

[0030] Compared with existing technologies, this device solves the temperature gradient caused by the continuous contact between hot-rolled steel coils and idler rolls at the same position. This device improves the uniformity of the microstructure in the rolling direction of hot-rolled steel coils. This device solves the problem of periodic fluctuations in strip thickness during cold rolling. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Fig. 1 This is a schematic diagram of the structure of the device provided by the present invention;

[0033] Fig. 2 A schematic diagram of the meshing structure of the driving gear and two driven gears provided by the present invention;

[0034] Fig. 3 The circumferential temperature of the steel coil when it is unloaded onto the saddle provided by this invention;

[0035] Fig. 4 Phase volume fraction statistically derived from metallographic experiments in embodiments of the present invention;

[0036] Fig. 5 Phase volume fractions statistically analyzed in metallographic experiments for comparative examples provided in this invention;

[0037] Fig. 6 The thickness data of DP780 during the cold rolling process provided by this invention.

[0038] Marking description:

[0039] 1. Hydraulic motor; 2. Driving gear; 3. Driven gear; 4. Roller; 5. Base; 6. Hot coil. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0041] Unless otherwise defined, technical terms or scientific terms used in the present application shall be understood as having the usual meaning as understood by those of ordinary skill in the art to which the present application belongs. The terms "first", "second" and similar words used in the present application do not represent any order, number or importance, but are only used to distinguish different components. Similarly, "one", "an" or "the" and similar words do not represent a quantity limitation, but represent the existence of at least one. The terms "including" or "containing" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The terms "connected" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.

[0042] It should be noted that "up", "down", "left", "right", "front", "back" and the like used in the present application are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationships may also change accordingly.

[0043] As shown in Figs. 1-2 , the hot-rolled strip based on the prior art has the problem of uneven heating in the rolling direction, and an embodiment of the present application provides a coil unloading device with controllable thickness periodic fluctuation in the cold rolling process, comprising: a first roller assembly, a second roller assembly, a power device and a base 5; the first roller assembly and the second roller assembly are installed on the base 5 along the axial direction of the base 5; a power device is arranged on one end side wall of the base 5, the power device drives the first roller assembly and the second roller assembly to rotate at the same speed in the same direction, the first roller and the second roller have the same structure;

[0044] Wherein, the distance between the roller axis of the first roller assembly and the roller axis of the second roller assembly is the roller axis spacing, the value of the roller axis spacing satisfies formula (1):

[0045]

[0046] Where L is the distance between the roller axes, R is the outer diameter of hot coil 6, R' is the inner diameter of hot coil 6, μ is the friction coefficient between hot coil 6 and the roller, g is the acceleration due to gravity, r is the radius of the roller in the first roller assembly, V is the linear velocity of hot coil 6 and the winding speed, and T is the time from the end of winding to the time when it is transported to the saddle and stops rotating.

[0047] Hot coil 6 is the conveying component on this device. The main principle of this device is to solve the problem of uneven cooling rate at various positions caused by uneven thermal contact between idler roller 4 and hot-rolled steel coil, thereby making the longitudinal structure and mechanical properties of the steel coil uniform and solving the problem of thickness periodic fluctuation caused by the subsequent cold rolling process.

[0048] This device specifically includes a base 5, with two bearing seats on each side of the base 5. The bearing seats are used to mount idler rollers 4. A first idler roller assembly and a second idler roller assembly are included, and the structures and connections of the first and second idler roller assemblies are identical. The idler rollers 4 in both idler roller assemblies are mounted within the bearing seats of the base 5. The idler rollers 4 in the first and second idler roller assemblies are parallel to each other, and are arranged parallel to the axis of the base 5. The bearing seats are used to mount self-aligning roller bearings, and bearings, which are self-aligning roller bearings, are installed at both ends of the idler rollers 4 in the two idler roller assemblies.

[0049] In one specific embodiment, the base 5 includes two upright plates and a bottom plate. Two upright plates are respectively provided on the upper surfaces of both ends of the bottom plate, and the two upright plates are perpendicular to the bottom plate. Two bearing seats are respectively provided on each upright plate.

[0050] In one specific embodiment, the first idler assembly includes: an idler 4, bearings, and a driven gear 3; two bearings are respectively disposed at both ends of the idler 4, and a driven gear 3 is disposed at one end of the idler 4; the two bearings of the first idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates, and the two bearings of the second idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates.

[0051] In one specific embodiment, the power device includes: a hydraulic motor 1 and a drive gear 2; the output end of the hydraulic motor 1 is equipped with the drive gear 2; the drive gear 2 meshes with both the driven gear 3 of the first idler assembly and the driven gear 3 of the second idler assembly; the drive gear 2 supports simultaneously driving the driven gear 3 of the first idler assembly and the driven gear 3 of the second idler assembly to rotate in the same direction and at the same speed.

[0052] In one specific implementation, the rotation of the idler roller 4 is a uniformly decelerated motion, the initial rotational speed of the idler roller 4 is equal to the winding speed, and the angular acceleration of the idler roller 4 of the first idler roller assembly and the idler roller 4 of the second idler roller assembly is α. The absolute value of α is calculated by formula (2):

[0053]

[0054] Where α = -|α|, r is the radius of the idler roller in the first idler roller assembly, V is the linear velocity of the hot roll 6 (winding speed), and T is the time from the end of winding to the time it is transported to the saddle and stops rotating.

[0055] To ensure safety during deceleration, there must be no sliding friction between the hot coil 6 and the idler roller 4. Therefore, the distance L between the axes of the two idler rollers should satisfy formula (1). The hot coil 6 is a steel coil.

[0056] The embodiments and comparative examples involved in this invention are all based on the prior art microalloyed duplex steel DP780. The microalloyed duplex steel DP780 supports the unwinding device proposed in this invention, while the comparative examples use a normal unwinding device.

[0057] Under the constraints of formulas (1) and (2), the parameters in this embodiment are: where α = 1.67s -1 L = 750mm. Under these parameters, the uncoiling device uses a thermal imager to collect circumferential temperature data during the steel coil cooling process. After coiling, the outermost ring of the steel coil is taken for metallographic analysis to statistically analyze its microstructure composition. Specific temperature data and microstructure composition statistics are as follows: Fig. 3 , Fig. 4 and Fig. 5 As shown.

[0058] After implementation, the cold rolling process was continued for the examples and control examples. The cold rolling thickness data of the examples and control examples were obtained using the cold continuous rolling production line data acquisition system. The specific cold rolling thickness data is as follows: Fig. 6 As shown in the figure. It can be seen that the device proposed in this invention has achieved good results.

[0059] Based on the comparison results between this embodiment and the control example, it can be seen that:

[0060] In the embodiment of the present invention, a hydraulic motor 1 drives two idler rollers 4 to rotate in the same direction at equal speeds, so that the outermost layer of the hot-rolled steel coil (hot coil) is in uniform contact with the idler rollers 4. This solves the problem of uneven cooling rate at different positions caused by uneven thermal contact between the idler rollers and the hot-rolled steel coil, thereby making the longitudinal structure and mechanical properties of the steel coil uniformly distributed, so as to solve the problem of thickness periodic fluctuation caused by the subsequent cold rolling process.

[0061] The idler roller and the base 5 are connected by a self-aligning roller bearing, which can withstand the radial heavy load caused by the weight of the steel coil and the small axial load generated during the start and stop of the steel coil unwinding to the saddle; a hydraulic motor 1 is used to provide power. The hydraulic motor 1 has the characteristics of high torque, good stability, high reliability, strong load capacity and strong adaptability, so it can operate stably under the harsh working conditions of the coiling process section.

[0062] Compared with existing technologies, this device solves the temperature gradient caused by the continuous contact between hot-rolled steel coils and idler rolls at the same position. This device improves the uniformity of the microstructure in the rolling direction of hot-rolled steel coils. This device solves the problem of periodic fluctuations in strip thickness during cold rolling.

[0063] In summary, the present invention is feasible in principle, simple in design, stable in process, technically feasible, efficient in preparation, scalable, and highly designable, and can effectively achieve the batch stable and efficient preparation of thermoplastic resin micro-debonding test samples.

[0064] The following points need to be explained:

[0065] (1) The accompanying drawings of the embodiments of the present invention only involve the structures involved in the embodiments of the present invention. Other structures can refer to the general design.

[0066] (2) For clarity, the thickness of layers or regions is enlarged or reduced in the drawings used to describe embodiments of the present invention; that is, these drawings are not drawn to actual scale. It is understood that when an element such as a layer, film, region, or substrate is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be intermediate elements.

[0067] (3) Where there is no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0068] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A coil unloading device with controllable thickness periodic fluctuations during cold rolling, characterized in that, include: First idler assembly, second idler assembly, power unit and base; The first idler roller assembly and the second idler roller assembly are mounted on the base along the axial direction of the base; A power device is provided on one side wall of the base, and the power device drives the first idler assembly and the second idler assembly to rotate in the same direction and at the same speed. The first idler assembly and the second idler assembly have the same structure. Wherein, the distance between the roller axis of the first idler assembly and the roller axis of the second idler assembly is the roller axis spacing, and the value of the roller axis spacing satisfies formula (1): Where L is the distance between the idler roller axes, R is the outer diameter of the hot roll, R' is the inner diameter of the hot roll, μ is the friction coefficient between the hot roll and the idler roller, g is the acceleration due to gravity, r is the radius of the idler roller in the first idler roller assembly, V is the linear velocity of the hot roll and the winding speed, and T is the time from the end of winding to the time when the roll is transported to the saddle and stops rotating.

2. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 1, characterized in that, The base includes two upright plates and a bottom plate. An upright plate is respectively provided on the upper surface of each end of the bottom plate, and the two upright plates are arranged perpendicular to the bottom plate. Two bearing seats are installed on each upright plate.

3. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 2, characterized in that, The first idler assembly includes: an idler, a bearing, and a driven gear; The two bearings are respectively disposed at both ends of the idler roller, and a driven gear is disposed at one end of the idler roller; The two bearings of the first idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates, and the two bearings of the second idler assembly are respectively installed in the corresponding bearing seats of the two vertical plates.

4. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 3, characterized in that, The power unit includes: a hydraulic motor and a drive gear; The drive gear is installed at the output end of the hydraulic motor; The driving gear meshes simultaneously with the driven gear of the first idler assembly and the driven gear of the second idler assembly; The driving gear can simultaneously drive the driven gears of the first idler assembly and the second idler assembly to rotate in the same direction and at the same speed.

5. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 1, characterized in that, The idlers of the first idler assembly and the idlers of the second idler assembly undergo uniformly decelerated motion.

6. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 1, characterized in that, The angular acceleration of the idler rollers of the first idler roller assembly and the idler rollers of the second idler roller assembly is α, and the absolute value of α is calculated by formula (2): Where α = -|α|.

7. The uncoiling device with controllable thickness periodic fluctuation during cold rolling process according to claim 6, characterized in that, The hot-rolled coil is a steel coil.

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