Rolling status observation device, rolling status observation method, rolling processing device, and rolling processing method

Abstract

Provided are: a rolling observation technology that tracks moment-to-moment changes in the rolling situation at one specific point (a material point) on a sheet material that passes through a roll bite from before rolling until after rolling and makes it possible to easily observe the changes in situ; and a rolling technology that is based on observation results from the rolling observation technology. According to the present invention, a rolling situation observation device that observes a rolling situation during the rolling of a workpiece by passage of the workpiece through a roll gap provided between a pair of rolls that rotate in opposite directions comprises a rolling unit that rolls the workpiece by passing the workpiece through the roll gap while moving the axial centers of the pair of rolls at a prescribed speed toward the upstream side of the workpiece but keeping one point on the workpiece at a fixed position and a rolling situation observation unit that observes the rolling situation of the workpiece at a roll bite from the outside in the axial direction of the pair of rolls toward the workpiece.

Description

[Technical Field]

[0001] The present invention relates to a rolling state observation device, a rolling state observation method, a rolling processing device, and a rolling processing method. [Background technology]

[0002] Rolling is a plastic processing method in which the workpiece is passed between a pair of rolls that rotate in opposite directions, thereby reducing its thickness and stretching it, thereby increasing its length. The structure and mechanical properties of metal materials are greatly improved by undergoing plastic processing, i.e., by the forging effect. Therefore, on an industrial scale, most basic metal materials such as plates, foils, bars, wires, and pipes are manufactured by rolling.

[0003] In recent years, the behavior of deformation and load during rolling of metallic materials has become predictable with high accuracy thanks to the development of rolling theory based on elementary analysis methods and numerical analysis methods such as the finite element method.In addition, it has become possible to investigate microstructural changes during deformation using image correlation methods and high-intensity X-rays during material testing.

[0004] However, there are still many rolling phenomena that have not been fully elucidated. For example, the occurrence of surface defects and changes in surface properties such as roughness that occur during rolling, the mechanism by which lubricant is drawn into the rolling interface (the interface between the sheet material being processed and the roll) and the microscopic formation of oil pits, the process by which rolling processing structures such as shear bands are formed in the roll bite (the area where the surface of the sheet material comes into contact with the roll and undergoes plastic deformation), and the pulsation phenomenon in which the material speed periodically fluctuates have not yet been fully elucidated.

[0005] To elucidate these phenomena, it is thought that it would be effective to directly observe the workpiece as it is deforming in the roll bite and observe the changes that occur during rolling in situ. However, because the workpiece deforms rapidly under the high load of the rolls rotating at high speed, it is extremely difficult to observe the rolling conditions in situ in the roll bite. At present, we are limited to estimating the changes that occur during rolling by observing the state before and after rolling.

[0006] For example, currently, changes during rolling are estimated by measuring the roughness before and after rolling and evaluating the transfer rate of roll roughness, or formation models are discussed by measuring the structure and texture before and after rolling. However, these methods do not track and observe the same location in the material before and after rolling, but merely observe changes in statistical quantities such as the average and standard deviation of surface roughness and grain size, and do not completely elucidate the phenomena occurring during rolling.

[0007] For this reason, it is difficult to further improve the accuracy of the model. For example, it is possible to estimate the average roughness value after rolling from the average roughness value before rolling, but it is not possible to completely predict the roughness profile after rolling from the roughness profile before rolling. In other words, predictions have traditionally been made based on a probabilistic approach, and a deterministic approach has not been used, so that elucidation of many phenomena has relied heavily on experience.

[0008] This is thought to be due to the complexity of the rolling phenomenon, such as the fact that deformation during the roll bite is not uniform in the thickness direction, the speed of the plate increases nonlinearly, and the direction of the frictional shear stress acting on the plate from the roll reverses at the neutral point.

[0009] Therefore, the inventors have proposed a rolling method (also called the "geocentric rolling method") in which rolling is performed by rotating one roll around another roll that is fixed in space without rotating. With this method, the relative geometric relationship between the roll and the workpiece is exactly the same as in normal rolling, but because the fixed roll does not rotate, if a transparent fixed roll is used, it becomes possible to directly observe the state of the interface between the sheet material and the roll from inside the fixed roll, and to directly observe the behavior of the lubricant at the interface during rolling, and the phenomenon of lubricant capture and seepage in recesses on the sheet material surface (Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0010] [Non-Patent Document 1] “In-situ observation of rolling interface using a geocentric rolling mill”, Yutaka Utsunomiya, Yoshimitsu Terada, Yuji Iseya, Ryo Matsumoto: Proceedings of the 2021 Spring Symposium on the Technology of Plasticity, (2021), 49. [Non-patent document 2] “In-situ observation of lubricant oil at the rolling interface”, Yutaka Utsunomiya, Yoshimitsu Terada, Ryo Matsumoto, CAMP-ISIJ, 34(2021), 278. Summary of the Invention [Problem to be solved by the invention]

[0011] However, the above-mentioned techniques only observe the rolling status of the plate material passing through the roll bite at a single point, and do not track the moment-to-moment changes in the rolling status at a specific point (material point) of the plate material from before rolling to after rolling. Therefore, they are not necessarily suitable as a method for elucidating the situation that changes moment-to-moment from before rolling to after rolling, such as internal deformation and structural changes in the plate material during rolling.

[0012] Therefore, an object of the present invention is to provide a rolling observation technique that can easily observe on-site the moment-by-moment changes in the rolling situation at a specific point (material point) of a plate material passing through a roll bite, while tracking the changes from before rolling to after rolling, and further to provide a rolling processing technique based on the observation results.

[0013] The present inventors have conducted extensive research into solving the above problems and have found that the above problems can be solved by the invention described below, thereby completing the present invention.

[0014] The invention described in claim 1 is A rolling status observation device for observing a rolling status when a workpiece is rolled by passing the workpiece through a roll gap provided between a pair of rolls rotating in opposite directions, comprising: a rolling section that rolls the workpiece while moving the axial centers of the pair of rolls in the upstream direction of the workpiece at a predetermined speed and passing the workpiece through the roll gap, with one point of the workpiece remaining stationary at a fixed position; and a rolling status observation unit that observes the rolling status of the workpiece during roll bite from the axial outside of the pair of rolls toward the workpiece.

[0015] The invention described in claim 2 is 2. The rolling status observation device according to claim 1, wherein the roll is a disk-shaped roll and is supported by a cantilever.

[0016] The invention described in claim 3 is The rolling status observation device according to claim 2, characterized in that the disk-shaped roll is installed upright, the lower side is supported by a cantilever, and the roll diameter is formed in a tapered shape with a smaller diameter at the lower side and a larger diameter at the upper side.

[0017] The invention described in claim 4 is a roll gap adjustment mechanism for adjusting the roll gap is provided in the rolling processing section, The rolling status observation device according to any one of claims 1 to 3, characterized in that the roll gap adjustment mechanism is a roll gap adjustment mechanism that adjusts the roll gap by inserting shim plates of a predetermined thickness between opposing surfaces of roll support mechanisms that support each of the pair of rolls.

[0018] The invention described in claim 5 is 5. The rolling state observing device according to claim 1, wherein the means for observing the rolling state is an optical microscope or an electron microscope.

[0019] The invention described in claim 6 is The rolling status observation device according to any one of claims 1 to 5 is characterized in that the rolling process of the workpiece is carried out while the workpiece is kept stationary in a fixed position by controlling the rotation speed of the roll and / or the movement speed of the axis of the roll.

[0020] The invention described in claim 7 is 7. The rolling status observing device according to claim 6, wherein the rotation speed of the roll and / or the moving speed of the axis of the roll is controlled so as to satisfy the following formula: v t (x)={Rh1 / (Rh1+x 2 )}·v R (1+f s ) x: Position in the rolling direction of the plate in the local coordinate system with the center of plate thickness at the minimum roll gap position as the origin (mm) v t (x): Roll speed when the material point is at x in the local coordinate system (mm s -1 ) R: Roll radius (mm) h1: thickness after rolling (mm) v R : Roll peripheral speed (mm s -1 ) f s :Advanced rate

[0021] The invention described in claim 8 is 8. The rolling status observing device according to claim 1, wherein the rotation of the roll and the movement of the axis of the roll are performed by one drive motor.

[0022] The invention described in claim 9 is The rolling status observation device according to any one of claims 1 to 8, characterized in that the rolling processing section is equipped with an upstream tensioning mechanism that is connected to the upstream end of the workpiece and applies upstream tension to the workpiece, and a downstream tensioning mechanism that is connected to the downstream end of the workpiece and applies downstream tension to the workpiece.

[0023] The invention described in claim 10 is Using the rolling status observation device according to any one of claims 1 to 9, This is a rolling status observation method, characterized in that the central axes of the pair of rolls are moved at a predetermined speed in the upstream direction of the workpiece, the workpiece is passed through the roll gap, and the rolling status of the workpiece during the roll bite is observed while rolling the workpiece while keeping the workpiece stationary at a fixed position.

[0024] The invention described in claim 11 is Using the rolling status observation device according to claim 9, a state in which upstream tension is applied to the workpiece by the upstream tension applying mechanism, and a state in which downstream tension is applied to the workpiece by the downstream tension applying mechanism, or both of these states are set; This is a rolling status observation method, characterized in that the central axes of the pair of rolls are moved at a predetermined speed in the upstream direction of the workpiece, the workpiece is passed through the roll gap, and the rolling status of the workpiece during the roll bite is observed while rolling the workpiece while keeping the workpiece stationary at a fixed position.

[0025] The invention described in claim 12 is A rolling method for rolling a workpiece by passing the workpiece through a roll gap provided between a pair of rolls rotating in opposite directions, comprising: This is a rolling method characterized in that the observation results obtained using the rolling status observation method described in claim 10 are reflected in the rolling conditions of the workpiece, and the workpiece is rolled. [Effects of the Invention]

[0031] According to the present invention, it is possible to provide a rolling observation technique that can easily observe on-site the moment-by-moment changes in the rolling situation at a specific point (material point) of a plate material passing through a roll bite while tracking them from before rolling to after rolling, and further to provide a rolling processing technique based on the observation results. [Brief explanation of the drawings]

[0032] [Figure 1] 1A is a schematic cross-sectional view comparing the positional relationship between the roll and the material point in a conventional rolling method and the positional relationship between the roll and the material point in the rolling method of the present embodiment. FIG. [Figure 2] FIG. 2 is a schematic plan view of an example of a rolling processing portion in one embodiment of the present invention. [Figure 3] FIG. 2 is a schematic perspective view of an example of a rolling processing section in one embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing the configuration of the back side of the first stage and second stage in one embodiment of the present invention. [Figure 5] 1 is a diagram illustrating a main equipment configuration of a rolling status observation device according to an embodiment of the present invention.

[0023] FIG. [Figure 6] 1 is a schematic plan view illustrating a rolling status observation method according to an embodiment of the present invention. FIG. [Figure 7] 1 is a diagram illustrating the behavior of a workpiece in a conventional rolling method. FIG. [Figure 8] 1A and 1B are diagrams illustrating (a) the change in plate thickness and (b) the change in speed in the roll contact area near the roll bite during conventional rolling. [Figure 9] FIG. 1 is a diagram illustrating the change over time in the position of a material point in conventional rolling. [Figure 10] 1A and 1B are diagrams illustrating an observation field obtained in an embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating the X coordinate of each material point obtained in one embodiment of the present invention. [Figure 12]FIG. 10 is a diagram showing the results of converting the coordinates of each material point obtained in an embodiment of the present invention from global coordinates (X, Y) to local coordinates (x, y). [Figure 13] FIG. 10 is a diagram showing the correlation between the predicted and measured values of the movement amount of each material point obtained in one embodiment of the present invention. [Figure 14] 1 is an image illustrating the rolling state in one embodiment of the present invention (reduction rate: 17.0%). [Figure 15] 10 is an image illustrating the rolling state in one embodiment of the present invention (reduction rate: 33.6%). [Figure 16] 1 is an image illustrating the rolling state in one embodiment of the present invention (reduction rate: 60.0%). [Figure 17] FIG. 1 is a diagram illustrating the moving speed of the material point in an embodiment of the present invention (reduction rate: 17.0%). [Figure 18] FIG. 10 is a diagram illustrating the moving speed of the material point in one embodiment of the present invention (reduction rate: 33.6%). [Figure 19] FIG. 1 is a diagram illustrating the moving speed of the material point in one embodiment of the present invention (reduction rate: 60.0%). [Figure 20] The results calculated from equation (5) are superimposed on FIG. [Figure 21] The results calculated from equation (5) are superimposed on FIG. [Figure 22] The results calculated from equation (5) are superimposed on FIG. [Figure 23] 1 is a diagram illustrating the behavior of a workpiece in a conventional rolling method. FIG. [Figure 24] FIG. 10 is a schematic plan view of an example of a rolling processing portion in another embodiment of the present invention. [Figure 25] 25 is a schematic side view showing an example of a tension applying mechanism of the rolling processing section shown in FIG. 24. [Figure 26] FIG. 2 is an enlarged side view (photograph of the surface portion) of the workpiece used in the examples. [Figure 27] FIG. 1 is a diagram showing the speed of a workpiece in the roll contact area near the roll bite during rolling in an example. DETAILED DESCRIPTION OF THE INVENTION

[0033] [1] Basic concept of the present invention Before describing specific embodiments of the present invention, the basic concept of the present invention will be described.

[0034] In-situ observation of the rolling status by tracking moment-to-moment changes at a specific point (material point) of a plate material passing through the roll bite from before rolling to after rolling requires a camera or other observation device to be moved a long distance parallel to the moving material point. However, with conventional rolling methods, the speed change of the plate material in the roll bite is not linear, and the amount of movement of the plate material during rolling is also large. Therefore, tracking the changes in the material point during rolling from before rolling to after rolling and observing the rolling status in-situ requires highly accurate control of the position and speed of the plate material, which is not easy. In addition, the camera vibrates, causing so-called camera shake, which can make it difficult to capture clear images, making this method unrealistic.

[0035] As a result of extensive research, the inventors of the present invention came up with the idea that if the material point could be fixed in space by reversing the concept of the conventional rolling method, the observation means could also be fixed, and in-situ observation of the rolling situation could be easily performed.

[0036] That is, instead of the conventional rolling method in which the material point of the workpiece is moved, the inventors came up with the idea of fixing the workpiece at a fixed position in space and keeping it stationary, while moving the axial center of the roll in the upstream direction while rotating. However, in this case, it is necessary to ensure that the relative relationship between the workpiece and the roll near the roll contact area (roll gap) is the same as that in the conventional rolling method. In this way, the material point is fixed at a single point in space from before rolling to after rolling, so that the rolling situation at the material point passing through the roll bite can be easily observed in situ while tracking the moment-to-moment changes from before rolling to after rolling, while maintaining the rolling situation essentially the same as in the conventional method.

[0037] Therefore, in order to make the relative relationship between the plate material and the rolls in the vicinity of the roll contact area (roll gap) equivalent to that in the conventional rolling method, the present inventors considered making the relative moving speed of the material point with respect to the rolls from before rolling to after rolling the same as in the conventional method, and conducted extensive research into specific methods for achieving this.

[0038] 23A and 23B are diagrams illustrating the behavior of a workpiece in a conventional rolling method. As shown in FIG. 23A, in the conventional rolling method, a pair of rolls rotates around their respective axes at a peripheral speed v R They rotate in opposite directions. Meanwhile, the plate material being processed passes through the gap (roll bite) between the two rotating rolls, reducing its thickness from h0 to h1.

[0039] If we take a coordinate system (hereinafter also referred to as the "global coordinate system") fixed in space with the center of thickness at the minimum roll gap position as the origin, the rolling direction as the X axis, and the thickness direction as the Y axis, the plate material before rolling approaches the rolls at a constant speed v0, and when it comes into contact with the rolls it is pulled into the roll bite by frictional force, and while the plate thickness gradually decreases as the processing progresses, it gains speed as it enters the minimum roll gap, and after passing through the minimum roll gap it moves away from the rolls at a constant speed v1.

[0040] When rolling thin plate material, the change in plate width, i.e., the expansion of the width, is generally so small that it can be ignored, and so the volume of the plate material during rolling can be considered to be constant (constant mass flow law). That is, the following (Equation 1) holds between the inlet plate thickness h0 and speed v0, between the outlet plate thickness h1 and speed v1, and between the plate thickness h(X) at coordinate X in the rolling direction and speed v(X). h0v0=h1v1=h(X)v(X) (Formula 1)

[0041] Here, the frictional force acting between the roll and the plate acts in the opposite direction to the relative speed of the plate to the roll. Therefore, at the entrance of the roll bite, the speed of the plate inevitably becomes equal to the roll peripheral speed v RIt enters at a speed v0 slower than [speed]. However, within the roll bite, as the sheet thickness decreases from h0 to h1, the speed of the sheet material increases. And at the roll bite exit, it is discharged at a speed v1 faster than the roll peripheral speed v R That is, between v0, v R , and v1, the relationship of the following (Equation 2) holds. v0 < v R < v1 ··············· (Equation 2)

[0042] From (Equation 2), as shown in Fig. 23(b), during rolling, within the roll bite, there is a neutral point N where the speed v(X) of the sheet material coincides with the roll peripheral speed v R and the relative speed becomes zero. It can be seen that with this neutral point N as the boundary, the direction of the relative speed of the sheet material with respect to the roll peripheral speed changes, and the direction of the frictional shear stress acting on the rolling interface between the roll and the sheet material also changes. And by defining the ratio (v1 / v R - 1) of the discharge speed v1 of the sheet material with respect to the roll peripheral speed v as the advancement rate f R , the discharge speed v1 of the sheet material can be obtained from the following (Equation 3). s That is, the discharge speed v1 of the sheet material can be obtained from the following (Equation 3). v1 = v R (1 + f s ) ············ (Equation 3)

[0043] Here, assuming that the length (projection contact length) in the rolling direction of the roll bite is sufficiently small with respect to the roll diameter, the thickness h(X) of the sheet material located at the rolling direction coordinate X in the roll bite can be approximated by the following (Equation 4) as a quadratic function of X. Note that R is the roll radius (half of the roll diameter D). h(X) = h1 + X 2 / R ··········· (Equation 4)

[0044] And the inventor found that the moving speed v(X) of the sheet material located at the rolling direction coordinate X in the roll bite can be defined by deriving the following (Equation 5) from the above (Equation 1), (Equation 3), and (Equation 4). v(X) = {Rh1 / (Rh1 + X 2)}·v1 ={Rh1 / (Rh1+X 2 )}·v R (1+f s )...(Formula 5)

[0045] As described above, when the plate material is kept stationary at a fixed position while the rolls are rotated and their axes are moved upstream, if the relative moving speed of the material point with respect to the rolls from before rolling to after rolling is kept the same as in the conventional method, the relative relationship between the plate material and the rolls in the vicinity of the roll contact area (roll gap) can be made equivalent to the relationship in the conventional rolling method.

[0046] Therefore, by controlling the moving speed v(X) of the plate material located at the rolling direction coordinate X during the roll bite with sufficiently high precision based on the newly derived (Equation 5) above, the material point of the plate material before rolling to after rolling can be fixed in space, and the observation means can also be fixed, making it possible to observe the rolling situation in situ.

[0047] In the rolling industry, the preconceived notion and preconception that rolling is performed with fixed rolls has long been the norm, and so the idea of fixing the workpiece, i.e., the plate material, and moving the rolls, as in the present invention, has not been conceived. Even if the idea had been conceived, it would be difficult to figure out how to achieve this specifically. The present inventor attempted to change the way of thinking as described above and gave careful consideration to how the relative relationship between the plate material and the rolls could be made equivalent to that in conventional rolling methods. As a result, the inventor succeeded in in-situ observation of the moment-by-moment changes in the rolling status at the material point of the plate material passing through the roll bite, tracking them from before rolling to after rolling.

[0048] [2] Rolling status observation technology in this embodiment 1. Differences from conventional technology Figure 1 is a schematic cross-sectional view comparing (a) the positional relationship between the roll and the material point in a conventional rolling method and (b) the positional relationship between the roll and the material point in the rolling method of this embodiment. Here, the motion between the roll and the material point is made relatively the same.

[0049] As shown in Figure 1(a), in the conventional rolling method, the material point P, which was located at the X coordinate a0 at the start of rolling (t=0), is moved to the X coordinate a0 after the sheet material passes through the roll bite (t=t s ) moves to the X coordinate a1, while the roll axis is fixed in space, so after the plate material passes through the roll bite (t = t s ) is also located at the same X coordinate b0 (b1=b0) as when rolling started (t=0).

[0050] In contrast, in the rolling of this embodiment, as shown in FIG. 1(b), the roll axis, which was located at the X coordinate b0 at the start of rolling (t=0), moves to the X coordinate b0 after the plate material passes through the roll bite (t=t s ) moves to the X coordinate b1, while the material point P is fixed in space, so after the plate material passes through the roll bite (t=t s ) is also located at the same X coordinate a0 (a1 = a0) as when rolling started (t = 0).

[0051] That is, in the rolling of this embodiment, the rolls are moved while the plate is kept stationary, so that the relative relationship between the plate and the rolls in the vicinity of the roll contact area (roll gap) is made equivalent to that in the conventional rolling method. Specifically, in the coordinates (local coordinates) determined from the relative relationship between the rolling direction in the roll bite and the material point, the speed v(X) of the plate located at the local coordinate X in the rolling direction in the roll bite is set to the upstream moving speed v of the roll axis so that it satisfies the above (Equation 5). t By controlling the above, the relative relationship between the sheet material and the rolls in the vicinity of the roll contact area (roll gap) is maintained the same as in the conventional method.

[0052] In this way, by changing from the conventional rolling method in which the plate material is moved to a rolling method in which the rolls are moved (called the "fixed material point rolling method"), the material point can be fixed in space during the rolling process. Therefore, by observing this material point with a fixed observation means, it becomes possible to observe on the spot, tracking the moment-to-moment changes in the rolling situation at the material point from before rolling to after rolling.

[0053] As can be seen from the above (Equation 5), the moving speed of the material point during the roll bite changes nonlinearly and is not constant. Therefore, in order to make the material point completely stationary, the peripheral speed of the roll v R The upstream moving speed of the roll axis v t It is necessary to control these independently. The specific control amount depends not only on the rolling conditions but also on the initial coordinates of the material point to be observed. To perform such control accurately, two drive motors must be used: one to rotate the rolls and one to move the roll axis. However, the use of two drive motors inevitably makes the equipment complex and large.

[0054] Therefore, the inventors further investigated ways to miniaturize the device by controlling the rotation and movement of the rolls with a single motor, and succeeded in creating a rolling processing device that can essentially keep the material point completely still, although it is not possible to completely fix the material point in space.

[0055] Here, "substantially keeping the material point completely still" means that by setting the rolling conditions so that the movement distance is sufficiently short, even if not zero, and making it possible to mount it on the sample stage of the optical microscope, and by auxiliary movement of the sample stage of the microscope in addition to the movement of the roll axis during rolling as necessary, the movement of the material point due to rolling can be kept within the field of view of the microscope, and the rolling situation can be observed in a state similar to that in which the material point is completely still.

[0056] 2. Rolling status observation device according to this embodiment (1) Rolling Processing Section 2 and 3 are a schematic plan view and a schematic perspective view of an example of the rolling section of the rolling status observation device according to the present embodiment, which was fabricated based on the above-described concept. Note that FIG. 3 shows the rolling section with the side guide 8 removed. In FIGS. 2 and 3, 1 denotes the rolling section, 2 denotes the rolling unit, 3a denotes the first roll, 3b denotes the second roll, 4a denotes the first stage, 4b denotes the second stage, 5a denotes the first pinion support, 5b denotes the second pinion support, 6a denotes the first shim plate, 6b denotes the second shim plate, 7 denotes the housing, 8 denotes the side guide, 9 denotes the shaft, 10 denotes the rack, 11 denotes the free roller, 12 denotes the motor, 13 denotes the gear head, 14 denotes the intermediate gear unit, and 14a denotes the intermediate gear. Finally, S denotes the workpiece (plate material).

[0057] 4 is a diagram showing the configuration of the back side of the first stage 4a and the second stage 4b. In FIG. 4, 15a is a first pinion, 15b is a second pinion, 16a is a first gear, and 16b is a second gear. The first pinion 15a is rotatably supported at the bottom of the first pinion support portion 5a (the back side of the first stage 4a). Similarly, the second pinion 15b is rotatably supported at the bottom of the second pinion support portion 5b (the back side of the second stage 4b).

[0058] 2 to 4, the first pinion 15a and the second pinion 15b are meshed with a rack 10 provided on the inner surface of the housing 7 along the movement direction of the first stage 4a and the second stage 4b. The first pinion 15a and the second pinion 15b are also meshed with a first gear 16a and a second gear 16b. As a result, during rolling, the first pinion 15a, the second pinion 15b, the first gear 16a, and the second gear 16b are rotated in conjunction with the movement of the first stage 4a and the second stage 4b, and the first roll 3a and the second roll 3b can be rotated in the direction of the arrow.

[0059] The rolling unit 2 comprises a first stage 4a and a second stage 4b, and a first roll 3a, a second roll 3b and a side guide 8 are arranged on the upper surface of each stage. The first roll 3a and the second roll 3b are rotatably supported on the first stage 4a and the second stage 4b, respectively.

[0060] Here, the first roll 3a and the second roll 3b may be arranged vertically, but this is not preferable because it requires observation of the rolling state from a horizontal direction, and when combined with a rolling state observation unit to form a rolling state observation device, it results in an increase in the installation area.As shown in Figures 2 and 3, if they are arranged horizontally, the rolling state can be observed from a vertical direction, which is preferable because it reduces the installation area and allows for the miniaturization of the rolling state observation device.

[0061] It is more preferable that the first roll 3a and the second roll 3b are supported in a cantilevered state with the rotation shafts projecting from the underside of the rolls and the upper side of the stage being free. This allows for closer access to the workpiece in the roll bite from the side where no bearings are provided, making it possible to continue to directly observe the side of the workpiece deforming in the roll bite, and also makes it easy to install an observation means for the rolling status observation section, such as a microscope, since it does not interfere with the roll bearings.

[0062] In this embodiment, the first roll 3a and the second roll 3b are preferably disk-shaped rolls, which makes it possible to make the entire device thinner and to more easily install the observation means.

[0063] If the disk-shaped rolls are arranged in a cantilevered state, the parallelism of the rolls may decrease due to the force applied to each roll during rolling, which may cause the workpiece to bend laterally. Therefore, in anticipation of the decrease in parallelism of the rolls, it is preferable that the roll diameter of the disk-shaped roll is formed in advance into a tapered truncated cone shape with a smaller diameter at the bottom and a larger diameter at the top. It is also preferable to arrange a backup roll near the disk-shaped roll to suppress elastic deformation of the disk-shaped roll.

[0064] The two side guides 8 are arranged at a distance corresponding to the thickness h0 of the workpiece S, with their opposing surfaces parallel to the X-axis, and support the workpiece S placed on the stage from both sides.

[0065] The rolling unit 2 is housed in a housing 7 and supported so as to be movable in the X-axis direction. A motor 12 is installed on one side of the housing 7, and the driving force of the motor 12 is transmitted to an intermediate gear unit 14 via a gear head 13. A shaft 9 installed along the X-axis direction is inserted into an intermediate gear 14a that constitutes the intermediate gear unit 14.

[0066] The shaft 9 has a male thread cut at a predetermined pitch that is engaged with a female thread on the inner surface of a hole in the center of the intermediate gear 14a. By rotating in accordance with the rotation of the intermediate gear 14a, the rotational power from the motor is converted into two-dimensional movement, and the rolling unit 2 connected to the tip of the shaft 9 can be moved.

[0067] At this time, it is preferable that free rollers 11 be provided on the sides of the first stage 4a and the second stage 4b facing the housing 7 so that the rolling unit 2 can move smoothly relative to the housing 7.

[0068] The first roll 3a and the second roll 3b are provided on the first stage 4a and the second stage 4b, respectively, and the roll gap can be adjusted by adjusting the distance between the first stage 4a and the second stage 4b. The adjustment method is not particularly limited, but from the viewpoint of simplifying the structure, it is preferable to adjust the roll gap by inserting a first shim plate 6a having a thickness corresponding to the roll gap between the first stage 4a and the second stage 4b.

[0069] At this time, each component is housed in the housing 7 on the assumption that the rolling unit 2 can move even when the roll gap is at its maximum. Therefore, if the thickness of the inserted first shim plate 6a is thinner than the thickness corresponding to the maximum roll gap, a gap will be created in the housing 7, which may cause the rolls to wobble and move, which is not desirable.

[0070] Therefore, in this embodiment, it is preferable to insert a second shim plate 6b having a thickness corresponding to the difference between the thickness of the inserted first shim plate 6a and the thickness corresponding to the maximum roll gap into the lower frame (motor 12 side) of the housing 7. In other words, it is preferable to keep the sum of the thicknesses of the first shim plate 6a and the second shim plate 6b constant.

[0071] As a result, even when the roll gap is adjusted, no gap is generated in the housing 7, the rolls can be moved stably, and the rolling status can be stably observed. The reason why the second shim plate 6b is inserted into the lower frame (motor 12 side) of the housing 7 is to keep the position of the observation means arranged on the upper frame side of the housing 7 constant.

[0072] A controller is connected to the motor 12, and the rotation speed of the motor 12 is adjusted to an appropriate speed by the controller, thereby adjusting the moving speed of the rolling unit (=moving speed of the rolling rolls) v t The peripheral speed v of the rolling rolls 3a and 3b can be adjusted. RBy adjusting the ratio of the circumferential lengths of the first pinion 15a and the second pinion 15b, and the first gear 16a and the second gear 16b, a desired speed, specifically, for example, v R :v t It can be adjusted to be 1:1.

[0073] (2) Rolling status observation device Fig. 5 is a diagram illustrating the main equipment configuration of the rolling status observation device according to this embodiment. As shown in Fig. 5, the rolling status observation device according to this embodiment comprises a rolling processing section main body equipped with a rolling unit, rolls, pinions, and racks, a control mechanism equipped with a gearbox, motor, and controller for controlling the movement of the rolling processing section, an observation mechanism equipped with an optical microscope and capture board for observing the rolling status, and a control / recording computer for controlling the observation of the rolling status and recording the observation results.

[0074] The control mechanism includes a DC servo motor, a gearbox equipped with a gear head and gear unit, and a motor, specifically a controller equipped with an H-Bridge circuit and a USB-DAC that drives the DC servo motor. The observation mechanism includes, for example, an optical microscope and a capture board as observation means. The control mechanism and observation mechanism are each connected to a control and recording computer. The computer is equipped with LabVIEW and is programmed to control the relative movement speed of the plate material in the rolling processing section based on the above-mentioned (Equation 5).

[0075] The control mechanism controls the movement of the rolling processing unit body under instructions from a computer. Image data observed by the observation mechanism is recorded by a computer as appropriate and played back on a monitor as a video or still image.

[0076] If necessary, the rolling processing part may be mounted on an XY sample stage (not shown) of an optical microscope of the observation mechanism, and by controlling the central axis of the rolling roll, i.e., the relative position of the rolling part with respect to the microscope in accordance with the progress of rolling, it is possible to observe the rolling status with the material point kept completely still. Note that the observation means of the observation mechanism may be an electron microscope in addition to the optical microscope described above.

[0077] (3) Rolling status observation method Observation of the rolling status using the rolling status observation device is performed by installing the observation means of the observation mechanism (an optical microscope in Figure 5) outside the axial direction of the roll, i.e., above the width of the workpiece (transverse direction of the rolling surface) TD (Transversal Direction), and the results are displayed or recorded on a computer. At this time, the observation means is positioned so that the optical axis is located directly above the material point.

[0078] Specifically, first, a test rolling is performed using a sample with material points marked, and the roll moving speed (v t ) and rotation speed (v R ) is observed to confirm that it is in accordance with the command value. Then, it is confirmed that the material point is stationary. After that, the workpiece to be observed is rolled and the rolling motion is observed.

[0079] Fig. 6 is a schematic plan view illustrating a rolling status observation method according to this embodiment. As shown in Fig. 6, the workpiece S is held stationary at a predetermined position on the stage by a side guide 8 along the direction of roll movement. Next, a pair of rolls 3a, 3b set at a predetermined roll gap are moved at a peripheral speed v R while rotating in the opposite directions in synchronization for a given time t s , in the opposite direction to RD, with a predetermined moving speed v t This allows the rolling situation to be observed with the material point passing through the roll bite fixed at one point in space.

[0080] In the above, the "predetermined moving speed" means a speed controlled to comply with a separately determined rule, and may be constant or may change over time.

[0081] Based on the obtained observation results, it becomes possible to predict with high accuracy the behavior of deformation, load, etc. during rolling, and by reflecting (feeding back) the results in on-site rolling work, higher quality rolling can be performed. Furthermore, when a rolling machine for actual work is manufactured based on the above-mentioned rolling section, it can be a rolling machine with a smaller installation area than conventional rolling machines.

[0082] 3. Adding tension When a backward tension is applied to a plate material to be processed, the speed at which the plate material moves slows down. This can be explained theoretically.

[0083] If the rear tension is further increased, the speed of the strip material will slow down even further, and it will eventually emerge slower than the roll speed. However, this phenomenon could not be predicted by conventional theory, because conventional theory determines the point where the roll peripheral speed and the strip speed are the same, i.e., the neutral point, and then calculates the strip inlet and outlet speeds. It has been pointed out that strip materials emerge at a speed slower than the roll peripheral speed in actual rolling processes, on rare occasions, but the cause was unknown.

[0084] The rolling process of a plate material is usually divided into multiple stages and performed by passing the plate material through multiple rolling mills in succession. However, if the plate material comes out at a speed slower than the peripheral speed of the rolls as described above, it becomes difficult to predict the speed of the plate material, making it impossible to appropriately set the rotational speed of the rolls of each rolling mill, and operation becomes difficult. In particular, it is known that this phenomenon is likely to occur in high-strength steel plates, the production volume of which has recently increased, and this has become a major concern.

[0085] For this reason, it is important to clarify the reason why the strip emerges at a speed slower than the roll peripheral speed. The first step in clarifying this reason is to understand how the speed changes in the roll bite when tension is applied. However, until now, there has been no technology that can accurately measure the speed change of the strip in the roll bite in such cases.

[0086] Under these circumstances, the inventors have invented the rolling status observation device described above. Therefore, they have repeatedly conducted experiments and studies to see whether it is possible to accurately measure the change in speed of a plate material due to the application of tension by using this rolling status observation device.

[0087] Specifically, an upstream tensioning mechanism that applies tension to the plate material in the upstream direction and is connected to the rolling processing unit 1 shown in Figure 2 is provided, and a downstream tensioning mechanism that applies tension to the plate material in the downstream direction and is connected to the downstream end of the plate material. By applying tension in the upstream and downstream directions as appropriate, an experiment was conducted to see if it is possible to accurately measure changes in the speed of the plate material.

[0088] As a result, it was found that by using the above-mentioned rolling status observation device, it is possible to accurately measure the change in the speed of the strip material due to the application of tension. In particular, it was found that it is possible to accurately measure the phenomenon in which the strip material comes out at a speed slower than the roll peripheral speed by applying rear tension until the strip material becomes slower than the roll peripheral speed.

[0089] From the viewpoint of the rolling state observation device, this can be said to have a great effect in that the rolling state observation device can accurately measure the change in the speed of the strip material due to the application of tension, and in particular can accurately measure the phenomenon in which the strip material comes out at a speed slower than the roll peripheral speed by applying rear tension until the strip material becomes slower than the roll peripheral speed.

[0090] Furthermore, the fact that it was possible to accurately measure the phenomenon in which the plate material comes out at a speed slower than the roll peripheral speed by applying a large rear tension in this way can be said to be of great academic significance in elucidating the cause of the plate material coming out at a speed slower than the roll peripheral speed. [Example]

[0091] Next, the following specific experiments will be carried out, and the usefulness of the present invention will be explained based on the results thereof.

[0092] 1. Experiment 1 First, a confirmation experiment was carried out on the behavior of the workpiece in the conventional rolling method.

[0093] Specifically, rolling was performed on a Pb-Sn plate material with a thickness of 0.50 mm and a width of 5.0 mm under the conditions shown in Table 1, according to the rolling method shown in Figure 7. In Figure 7, A, B, and C are material points assigned prior to the start of rolling (t = 0 s), and are assigned to positions X = 0 mm, -5.3 mm, and -10.8 mm, respectively, on the X coordinate system with the center of the roll as the origin.

[0094] [Table 1]

[0095] Based on the above rolling conditions, the sheet metal ejection speed v1 from the roll bite is 0.282 mm s -1 (=0.266×(1+0.06)), and the entry speed v0 of the plate material into the roll bite is 0.226 mm s -1 We can see that this is (=0.282×0.400 / 0.500).

[0096] Then, (a) the change in thickness and (b) the change in speed of the strip in the roll contact area near the roll bite during rolling were calculated based on the above-mentioned (Equations 1) to (5). The results are shown in Figure 8. In Figures 8(a) and (b), the horizontal axis is the X coordinate with the roll axis as the origin, and the vertical axis is (a) the strip thickness and (b) the strip speed, respectively.

[0097] From Figure 8(a), it can be seen that the plate material that enters the roll bite with a plate thickness of h0 = 0.500 mm decreases in thickness along the roll arc, and is discharged from the roll bite after reaching h1 = 0.400 mm.

[0098] And from Figure 8(b), the speed is 0.226 mm·s -1 The plate material entered the roll bite at X = -0.3 mm and its speed increased during the roll bite. The roll peripheral speed reached 0.266 mm s -1 That is, it reaches the neutral point, and then it becomes 0.282 mm s -1 The plate is discharged from the rolling mill at this speed, and it can be seen that the change in plate speed during the roll bite is not linear.

[0099] Next, the time changes in the positions of material points A, B, and C were calculated by integrating the velocity changes shown in Figure 8(b). The results are shown in Figure 9. In Figure 9, the vertical axis represents the elapsed time t from the start of rolling, and the horizontal axis represents the coordinate X (mm).

[0100] From Fig. 9, material point A is located near the minimum roll gap point at the start of rolling (t = 0 s), and is immediately ejected from the roll bite. After that, the material moves at a constant speed v1 = -0.282 mm s -1 It can be seen that the position in the rolling direction changes almost linearly with the rolling time.

[0101] It can be seen that stock point B is located 5.3 mm upstream from the roll bite entrance at the start of rolling (t = 0 s), enters the roll bite at t = 21 s, is discharged from the roll bite at t = 26 s, and then moves away from the rolling mill at the same speed as stock point A. As mentioned above, the sheet metal elongates as it passes through the roll bite, and the moving speed changes from v0 to v1, so the gradient at stock point B in Figure 9 is larger after rolling than before rolling. It can also be seen that the amount of movement of point B between the start of rolling (t = 0 s) and t = 60 s reaches approximately 15 mm.

[0102] Furthermore, since material point C is located 10.8 mm upstream from the roll bite entrance at the start of rolling (t = 0 s), it finally reaches the roll bite entrance at around t = 44 s, and after that, although there is a time lag, it shows the same changes as material points A and B.

[0103] The above results show that in conventional industrial rolling methods in which rolling is performed while moving a long workpiece, the amount of movement of the plate material becomes very large before and after passing through the roll bite.

[0104] 2. Experiment 2 Next, using the rolling status observation device according to this embodiment, which is configured as shown in FIG. 5 by incorporating the rolling processing section shown in FIGS. 2 and 3, the same plate material as above (Pb—Sn plate material with a thickness of 0.50 mm and a width of 5.0 mm) was rolled under the same rolling conditions (see Table 1).

[0105] (1) Rolling Processing Section Specifically, assuming that a rolling processing section with a total length of 200 mm and a total width of 150 mm is to be observed using an upright optical microscope, the working distance between the objective lens and the side of the plate material is within the focal length of the microscope, and the motor 12 is positioned at the front, with an asymmetrical configuration in which the top (opposite the motor) is short and the bottom (on the motor side) is long, so that the working distance between the objective lens and the side of the plate material falls within the focal length of the microscope and the sample stage can be mounted on it.

[0106] The diameter (roll diameter) D of the rolls 3a and 3b was 20 mm, and the maximum length that could be rolled of the plate material S was 100 mm. Three shim plates with thicknesses of 0.1 mm, 0.2 mm, and 0.5 mm were prepared, and were appropriately selected and combined to form the first shim plate 6a, while the remaining shim plate was used as the second shim plate 6b. By inserting each of these, the roll gap could be changed from 0 mm to 8 mm in 0.1 mm increments, and the overall thickness of the shim plates was fixed at 0.8 mm.

[0107] The rotation and movement of the rolls 3a and 3b are driven by precisely controlled serial servo motors. Specifically, a Faulhaber 4490H028BS two-pole servo motor (rated voltage: 48V, maximum rotation speed: 16,000 rpm, starting torque: 1,724 mNm, rated power: 282 W, angular tolerance: ±0.1°) is used as the motor 12. A Faulhaber 42GPT 178:1 planetary gearhead (gear ratio: 178:1, maximum torque: 34 Nm, backlash tolerance: ±0.4°, maximum rotation speed: 10,000 rpm) is incorporated to reduce the speed. The reduced power is then transmitted to the shaft 9 connected to the rolling unit 2 via an intermediate gear unit 14 consisting of three intermediate gears (all with a 1:1 gear ratio). The rotation of the motor 12 was controlled accurately based on the above formula (5) by receiving commands from a personal computer via a control unit "MC5010S RS" manufactured by the same company.

[0108] The shaft 9 is threaded with a male screw at a 1.5 mm pitch, and the rotational power is converted into two-dimensional movement in the left and right directions, enabling the rolling unit 2 to move. A pair of steel rolls (first roll 3a and second roll 3b) are attached to the rolling unit 2, and each roll is connected to a pinion at the bottom of the rolling unit 2 via an intermediate gear (gear ratio 1:1) 14a.

[0109] (2) Roll peripheral speed v R and unit movement speed v t Relationship First, using the above-mentioned rolling section, the roll peripheral speed v R and unit movement speed v t We investigated the relationship between these two factors.

[0110] Specifically, the motor speed is fixed at 2,000 rpm, and the time it takes for the roll to make one revolution under no load is measured along with the distance traveled by the unit in the global coordinate system, thereby determining the roll peripheral speed v R and unit movement speed v t As a result, when the motor rotation speed is 2,000 rpm, the roll peripheral speed vR is 0.266 mm·s -1 , unit movement speed v t is 0.282 mm·s -1 and the roll peripheral speed v R and unit movement speed v t It was found that the relationship between these is expressed by the following formula (6). v R :v t =266:281=1.000:1.056 (Formula 6)

[0111] From this result, originally, the unit movement speed v t is the roll peripheral speed v R Although it is preferable that the unit movement speed v t is the roll peripheral speed v R It was found that the rolling speed was approximately 6% faster than in the previous study. This difference is thought to be due to the meshing position of the rack and pinion, but if it is only to this extent, it is sufficient to keep the movement of the material point due to rolling within the field of view of the microscope by auxiliary movement of the sample stage of the optical microscope as necessary, and therefore the rolling status can be observed in the same state as if the material point were completely stationary.

[0112] (3) Observation of material point movement Next, the plate material was rolled using the above-mentioned rolling status observation device, and the movement of the material point was observed (rolling time: 56 seconds).

[0113] Specifically, a Casio digital single-lens reflex camera, "Exilim EX-F1" (frame size: 640 × 480 pixels, frame rate: 300 fps), was placed with the lens facing downwards on a close-up table installed above the rolling section of the rolling observation device, so as to obtain the observation field shown in Figure 10. The roll and plate movement during the rolling process were recorded at three material points A (X = -1.3 mm), B (X = -6.3 mm), and C (X = -11.3 mm) that had been indented into the plate at intervals of approximately 5 mm. The lens used was a standard lens for the camera (focal length of 36 to 432 mm at 12x magnification). In Figure 10, RD (Rolling Direction) is the direction of roll movement, and ND is the normal direction.

[0114] Then, still images were captured from the filmed video every 2 seconds, and the X coordinate of each material point was measured in the global coordinate system (a coordinate system fixed in space). Specifically, images were captured from the video using the video editing software that comes standard with Windows 10, and then the coordinates were read from the images using LeafcounterPlus.

[0115] The results for rolling with a reduction ratio of 20% are shown in Figure 11. In Figure 11, the vertical axis represents time (s), and the horizontal axis represents the rolling direction position X (mm) of the material point in the global coordinate system. The open symbols (○, △, □) indicate that the material point is not in the roll bite, while the filled symbols (●, ▲, ■) indicate that the material point is located in the roll bite. The × symbol indicates the position of the roll axis, and the dashed line indicates the position of the roll bite entrance calculated from the position of the roll axis (×) and the geometrically determined contact length. In this experiment, the contact length was set to 1.00 mm.

[0116] From Figure 11, it can be seen that material point A is located near the minimum roll gap point in the roll bite at the start of rolling (t = 0), but is ejected from the roll bite at t = 4 s, and thereafter there is almost no change in the coordinates.

[0117] On the other hand, material point B reaches the roll bite at t = approximately 23 s after the start of rolling, and material point C at t = approximately 45 s, and it can be seen that the slope (speed) of the coordinates of material points A, B, and C changes at the point of contact with the movement distance of the roll axis, that is, after passing the roll bite, but the positions change very little. As an example, looking at the coordinates of material point B, it can be seen that it moved 1.05 mm in the direction opposite to the rolling direction between t = 0 s and t = 22 s, before rolling, and that there was almost no movement between passing the minimum roll gap and t = 56 s, when rolling ended.

[0118] From this result, it can be seen that when the rolling status observation device according to the present embodiment is used, the material point can be successfully made stationary after rolling. On the other hand, before rolling, when the speed v0 of the plate material is greater than the roll peripheral speed v R Since the rolling speed is slower than that of the material point C, a slight movement in the opposite direction to the rolling direction is observed, and the amount of movement increases the longer the time before rolling, i.e., the further upstream the point is. However, even at material point C, which is further upstream, the amount of movement is only about 2 mm at most, and considering that it is quite possible to keep the movement of the material point within the field of view of the microscope by auxiliary movement of the sample stage of the optical microscope, there is no problem in thinking that the material point is essentially kept completely still.

[0119] (4) Expansion of material point movement into local coordinates Next, the movement of the material point in the global coordinate system obtained above was expanded into local coordinate system (coordinate system determined from the relative relationship between the rolling direction during the roll bite and the material point). Here, the global coordinate system (X, Y) and the local coordinate system (x, y) have the relationship shown in the following (Equation 7). In Equation 7, (X0, Y0) indicate the coordinates in the global coordinate system of the origin of the local coordinate system at the start of rolling (t = 0).

[0120]

number

[0121] Specifically, the coordinates of the roll axis were read in advance in the same way as for the material point, and converted from global coordinates (X, Y) to local coordinates (x, y) using equation (7). The results are shown in Figure 12, which are almost the same as the movement of the material point in the conventional rolling method shown in Figure 9. It can be seen that even when this method is adopted, the relative relationship between the plate material and the roll is the same as in the conventional rolling method, and the same rolling situation as in the conventional method is expressed.

[0122] (5) Velocity change of material points Next, from the gradients of each material point in Figures 11 and 12, the entry speeds v0 and V0 of the plate material into the roll bite area, and the exit speeds v1 and V1 of the plate material from the roll bite area in the local coordinate system and global coordinate system were calculated. The results are shown in Table 2. Table 2 also shows the moving speed v of the rolling unit. t , roll peripheral speed v R are also shown, and the units are mm·s -1 is.

[0123] [Table 2]

[0124] From Table 2, the exit strip speed v1 in the local coordinate system of material point B is equal to the rolling unit moving speed v t It can be seen that it is almost equal to

[0125] (6) Material point movement (a) Prediction of movement in the local coordinate system Next, using FIG. 12, the predicted value of the movement amount in the local coordinate system was obtained.

[0126] Specifically, first, the coordinate X of each material point at the start of rolling in FIG. 12 is divided by the entry speed v0 to calculate the time from the start of rolling to passing through the minimum roll gap (time before rolling t' a Then, the total rolling time of 56 seconds was subtracted from the time before rolling, t' a Subtract the time after rolling, t' bIn addition, the time after rolling t' b By multiplying this by the delivery speed v1, the movement amount after rolling u' is b Furthermore, the displacement after rolling, u', was calculated. b The X coordinate u' at the start of rolling a The total movement amount u' was calculated by adding the absolute value of v0 (corresponding to the movement amount before rolling) and used as the predicted value of the movement amount in the local coordinate system. Note that nonlinear speed changes in the roll bite are ignored here, and it is assumed that the plate moves in the roll bite at the same speed as the speed before rolling. The measured values for point B in Figure 12 were used for v0 and v1. The results are shown in Table 3.

[0127] [Table 3]

[0128] (b) Comparison of predicted and measured displacements Next, the predicted values of the movement amounts obtained above were compared with the measured values. The results are shown in Table 4. Here, the movement amount X during the total rolling time of the rolling unit, 56 seconds, was calculated from the movement amount in the local coordinate system. t The amount of movement in the global coordinate system obtained by subtracting

[0129] [Table 4]

[0130] From Table 4, it can be seen that for all material points A, B, and C, the actual amount of movement in the local coordinate system is large at 13 mm or more, but the amount of movement in the global coordinate system is kept to a small value of 2 mm or less, meaning that each material point can be kept almost stationary in space.

[0131] FIG. 13 shows the correlation between the predicted and measured values of the movement amount obtained above, where (a) shows the result of a comparison in the global coordinate system, and (b) shows the result of a comparison in the local coordinate system.

[0132] Figure 13 shows that there is a fair degree of agreement between the measured and predicted values in both (a) the global coordinate system and (b) the local coordinate system. In both cases, the predicted values are overestimated compared to the measured values, but the difference between the measured and predicted values is less than 1.5 mm, making it possible to predict the movement of the material point with sufficient accuracy.

[0133] 3. Experiment 3 As a result of the above experiment, it was found that by moving the roll axis while rotating it with the plate material fixed in space, it is possible to observe the rolling status with a large amount of spatial movement in the local coordinate system, while all material points remain substantially stationary in the global coordinate system from before rolling to after rolling.

[0134] Therefore, in this experiment, rolling was performed at different reduction rates using a rolling status observation device in which the rolling processing section was mounted on the sample stage of an optical microscope, and the rolling status was observed from just before the roll bite until the end of the roll bite, and changes in the moving speed were determined from changes in the coordinates of the material point.

[0135] Specifically, a Mitutoyo micro-Vickers hardness tester was used to make an indentation with a diagonal length of 0.167 mm at the center of the thickness of the side of a plate material (a Pb-Sn plate with a thickness of 0.50 mm and a width of 5.0 mm) to define a material point.

[0136] And the roll peripheral speed v R =0.266 mm·s -1 , unit movement speed v t =0.282 mm·s -1 Under lubricated rolling conditions, the roll gap was changed to three levels: (a) 0.3 mm, (b) 0.2 mm, and (c) 0.1 mm by adjusting the shim plate, and rolling was performed. The reduction ratios were (a) 17.0%, (b) 33.6%, and (c) 60.0%.

[0137] The optical microscope used was a Keyence VH-Z500, with a magnification of 100x. The video signal output from the optical microscope was recorded on a PC via a commercially available capture board, AMR-VGAA1-G1117. The input video signal was recorded using OBS (Open Broadcaster Software) (resolution: 640 x 480 pix, frame rate: 30 fps).

[0138] Images were extracted every three frames from the recorded images using VLC media player (VideoLAN project) and its add-on software. The coordinates of the indentation were measured from the extracted frame images using pixel measurement software. The measurement point for the indentation was the center of the indentation, and the reference point was the right edge of the captured image. In addition, the number of pixels on the micron bar (scale) of the optical microscope at the same magnification was measured in advance, and the magnification ratio was determined and used as the reference.

[0139] Figure 14 shows excerpts from images taken from just before the roll bite to after it ends at a reduction ratio of 17.0%. From Figure 14, it can be seen that, over time, the indentation, i.e., the material point, enters the roll bite, decreases in the thickness direction, and extends in the rolling direction. It can also be seen that after passing the minimum roll gap point (X = 0), there is almost no movement, and it can be seen that the speed of the plate after rolling is almost equal to the moving speed of the unit.

[0140] Figure 15 shows excerpts from images taken from just before the roll bite to after it ends at a reduction ratio of 33.6%. From Figure 15, it can be seen that the material point appears to move upstream (retreat) until it enters the roll bite, and then appears to be almost stationary after passing through the minimum roll gap. Note that even in this case, the indentation was within the field of view.

[0141] Figure 16 shows excerpts from images taken at a reduction rate of 60.0%, from just before the roll bite to after it ended. From Figure 16, it can be seen that the retreat rate of the material point before rolling is higher than at a low reduction rate (33.6%), but that the retreat rate decreases during the roll bite, and after passing the roll bite, it appears to be almost stationary, just as with the low reduction rate. Furthermore, because the reduction rate was high, significant deformation of the indentation was observed, especially immediately after entering the roll bite. In this case, the roll gap was narrow and the images were dark, so image data with increased brightness was used for the subsequent measurement of the gauge point coordinates.

[0142] Next, the change in the moving speed was calculated from the change in coordinates of the measured material point. Specifically, the forward movement ratio was calculated from the delivery speed after passing through the minimum roll gap, and it was found to be 0.056 at a reduction ratio of (a) 17.0%, 0.060 at (b) 33.6%, and 0.067 at (c) 60.0%.

[0143] The moving speed of the material point was calculated by dividing the moving distance in the local coordinate system by the time. For smoothing purposes, the average of five points, including two points before and two points after, was taken as the measured value.

[0144] The results for a reduction ratio of 17.0% are shown in Fig. 17. As shown in Fig. 17, the material point was moving at a speed slower than the roll peripheral speed (0.24 mm s -1 ), the speed increases to the roll peripheral speed (0.266 mm s -1 ), and after passing through the minimum roll gap, the speed is constant (0.28 mm s -1 ) is emitted.

[0145] The results for a reduction ratio of 33.6% are shown in Fig. 18. As shown in Fig. 18, the speed was slower (0.19 mm s ) than for a reduction ratio of 17.0%. -1 ), it accelerates in the roll bite and reaches a maximum value (0.30 mm s -1 ), and then the speed is almost the same as that of the reduction rate of 17.0% (0.28 mm s -1 ) is emitted.

[0146] The results for a reduction ratio of 60.0% are shown in Fig. 19. As shown in Fig. 19, the entry speed was even slower (0.11 mm s ) than for reduction ratios of 17.0% and 33.6%. -1 ), and after monotonically accelerating, the exit speed (0.28 mm s) was almost the same as that for the reduction ratios of 17.0% and 33.6%. -1 ) is emitted.

[0147] Next, we investigated the relationship between the moving speed of the material point obtained above and the speed of the plate calculated using the above-mentioned (Equation 5) as a speed prediction formula. s was assumed to be constant (0.06) regardless of the rolling reduction rate.

[0148] 17 to 19, the results calculated from equation (5) are added and shown in Figs. 20 to 22. As shown in Figs. 20 to 22, when the material point speed obtained by actual measurement is compared with the material point speed obtained from the speed prediction equation (equation 5), they show a tendency to be almost the same, but at low reduction rates, the measured value is slightly faster. This is because the forward rate f s It is thought that the forward slip ratio was slightly overestimated because the roll gap was assumed to be constant at 0.06, resulting in the actual measured travel speed being slightly faster. Furthermore, when the reduction ratio is 60.0% (Fig. 22), although there is a slight deviation near the roll bite entrance, the overall trend is in good agreement, and the deviation becomes smaller as the minimum roll gap is approached. This variation in speed near the roll bite entrance is thought to be caused by the elastic deformation of the rolls, the existence of an elastic wedge in the workpiece at the center of thickness all the way to the downstream end, and deformation of the indentation mark (the gauge mark).

[0149] From the above results, it was confirmed that in the rolling method of this embodiment, in which rolling is performed by fixing the plate material as the workpiece and moving the rolls, when considering the speed change during the roll bite, (Equation 5) can be used as a speed prediction equation, and the speed change during the roll bite can be controlled based on (Equation 5).

[0150] 4. Experiment 4 In Experiment 4, a rolling observation device equipped with a tension applying mechanism was used to examine the change in speed of the workpiece S when tension was applied to the workpiece S and the workpiece was rolled.

[0151] Figure 24 shows a schematic plan view of the rolling section of the rolling status observation device used in this experiment. This rolling status observation device is equipped with an upstream tensioning mechanism connected to the upstream end of the workpiece S to apply tension in the upstream direction (rearward direction) to the workpiece S, and a downstream tensioning mechanism connected to the downstream end of the workpiece S to apply tension in the downstream direction (forward direction) to the workpiece S, in addition to the rolling section shown in Figure 2. The upstream tensioning mechanism and downstream tensioning mechanism are each fixed to the rolling section 1 via fixing members 19.

[0152] 25(a) and 25(b) are schematic side views showing the configuration of an upstream tension applying mechanism and a downstream tension applying mechanism, respectively. Each tension applying mechanism comprises a wire 17, a pulley 18, and loads (weights) 20a and 20b. The wire 17 is suspended from the pulley 18, with one end connected to an end of the workpiece S and weights 20a and 20b hanging from the other end. As a result, a tension (rear tension) σ corresponding to the mass of the weight 20a in the upstream direction is applied to the upstream end of the workpiece S. b A tension (forward tension) σ corresponding to the mass of the weight 20b is applied to the downstream end of the workpiece S in the downstream direction. f By changing the mass of the weights 20a and 20b, σ b and σ f The size of the image can be set to a desired size.

[0153] In this experiment, a Pb-Sn plate with a thickness of 0.5 mm, width of 5.0 mm, and length of 80 mm was used as the workpiece S. In addition, to measure the moving speed of the plate, a Vickers hardness indentation with a diagonal length of 125 μm was made on the side of the plate. Figure 26 shows a side view (photograph of the surface) of the workpiece S used.

[0154] The rolling was carried out at a reduction rate of r: 15% and a roll peripheral speed of v R :0.281mm / s, unit movement speed v t The load and tension were set in four ways as shown in Table 5.

[0155] [Table 5]

[0156] The experimental results are shown in Figure 27. In the figure, the horizontal axis is the X coordinate with the center of the roll axis as the origin. The vertical axis is the strip speed on the left and the equation {Strip speed (v) - Roll peripheral speed (v)} on the right. R )} / roll peripheral speed (v R The forward slip ratio of the plate was calculated from the results shown in Figure 27. The calculated forward slip ratio is shown in Table 6.

[0157] [Table 6]

[0158] As shown in the above experimental results, the phenomenon of the forward rate becoming negative was reproduced, and it was found that this phenomenon occurs when only rearward tension is applied.

[0159] As described above, it has been confirmed that by using the rolling status observation device of the present invention, it is possible to investigate the change in speed of a workpiece when rolling is performed with tension applied.

[0160] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments. Various modifications can be made to the above-described embodiments within the scope of the same or equivalent to the present invention. [Explanation of symbols]

[0161] 1. Rolling Processing Department 2 Rolling Unit 3a Roll 1 3b 2nd Roll 4a 1st Stage 4b Second Stage 5a First pinion support 5b Second pinion support part 6a First shim plate 6b Second shim plate 7. Housing 8 Side guide 9 Shaft 10 racks 11 Free Roller 12 motors 13 Gearhead 14 Intermediate gear unit 14a intermediate gear 15a 1st pinion 15b Second pinion 16a 1st gear 16b 2nd gear 17 Wire 18 Pulley 19 Fixing member 20a, 20b Load A, B, C, P material points h0, h1 plate thickness N neutral point S Work material (plate material) v0, v1 Plank movement speed v R Roll peripheral speed

Claims

1. A rolling status observation device for observing a rolling status when a workpiece is rolled by passing the workpiece through a roll gap provided between a pair of rolls rotating in opposite directions, comprising: a rolling section that rolls the workpiece while moving the axial centers of the pair of rolls in the upstream direction of the workpiece at a predetermined speed and passing the workpiece through the roll gap, with one point in the workpiece remaining stationary at a fixed position; a rolling status observation unit that observes the rolling status of the workpiece during roll bite from the axial outside of the pair of rolls toward the workpiece.

2. 2. The rolling condition observation device according to claim 1, wherein the roll is a disk-shaped roll and is supported by a cantilever.

3. 3. The rolling status observation device according to claim 2, wherein the disk-shaped roll is set upright, the lower side is supported by a cantilever, and the roll diameter is formed in a tapered shape with a smaller diameter at the lower side and a larger diameter at the upper side.

4. a roll gap adjustment mechanism for adjusting the roll gap is provided in the rolling processing section, 4. The rolling status observation device according to claim 1, wherein the roll gap adjustment mechanism adjusts the roll gap by inserting shim plates of a predetermined thickness between opposing surfaces of roll support mechanisms that support each of the pair of rolls.

5. 5. The rolling state observation device according to claim 1, wherein the means for observing the rolling state is an optical microscope or an electron microscope.

6. 6. The rolling status observation device according to claim 1, wherein the rolling of the workpiece is performed while the workpiece is kept stationary at a fixed position by controlling the rotation speed of the roll and / or the moving speed of the axis of the roll.

7. 7. The rolling status observing device according to claim 6, wherein the rotation speed of the roll and / or the moving speed of the axis of the roll are controlled so as to satisfy the following formula: v ｔ (x)={Rh １ / (Rh １ +x ２ )}・v Ｒ (1+f ｓ ) x: The thickness of the plate in the local coordinate system with the center of the plate thickness at the minimum roll gap position as the origin Position in rolling direction (mm) v ｔ (x): Roll movement speed (mm) when the material point is at x in the local coordinate system ・s －１ ) R: Roll radius (mm) h １ : Plate thickness after rolling (mm) v Ｒ : Roll peripheral speed (mm s －１ ) f ｓ : Advanced rate

8. 8. The rolling status observation device according to claim 1, wherein the rotation of the rolls and the movement of the axial centers of the rolls are performed by a single drive motor.

9. 9. The rolling status observation device according to claim 1, wherein the rolling processing section is provided with an upstream tensioning mechanism that is connected to an upstream end of the workpiece and applies tension in the upstream direction to the workpiece, and a downstream tensioning mechanism that is connected to a downstream end of the workpiece and applies tension in the downstream direction to the workpiece.

10. Using the rolling status observation device according to any one of claims 1 to 9, a method for observing a rolling state, the method comprising: moving the central axes of the pair of rolls in the upstream direction of the workpiece at a predetermined speed, passing the workpiece through the roll gap, and rolling the workpiece while keeping the workpiece stationary at a fixed position, while observing the rolling state of the workpiece during the roll bite.

11. Using the rolling status observation device according to claim 9, a state in which upstream tension is applied to the workpiece by the upstream tension applying mechanism, and a state in which downstream tension is applied to the workpiece by the downstream tension applying mechanism, or both of these states are set; a method for observing a rolling state, the method comprising: moving the central axes of the pair of rolls in the upstream direction of the workpiece at a predetermined speed, passing the workpiece through the roll gap, and rolling the workpiece while keeping the workpiece stationary at a fixed position, while observing the rolling state of the workpiece during the roll bite.

12. A rolling method for rolling a workpiece by passing the workpiece through a roll gap provided between a pair of rolls rotating in opposite directions, comprising:

11. A rolling method, characterized in that the results of observation obtained using the rolling state observation method according to claim 10 are reflected in the rolling conditions of the workpiece, and the workpiece is rolled.

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