Sleeve-type roll and rolling method

Abstract

The objective is to provide a sleeve-type roll that can prevent insufficient gripping force of the sleeve on the arbor and extend the outer diameter control range, as well as a rolling method using this sleeve-type roll. [Solution] The sleeve-type roll 100 comprises an arbor 10 and a sleeve 20, and is divided into a body BR located in the axial center of the arbor 10, a first shaft AR1 coaxially connected to one end edge of the body BR along the axial direction, and a second shaft AR2 coaxially connected to the other end edge of the body BR along the axial direction, and a hydraulic chamber 11b leading to an oil passage 11a is formed between the arbor 10 and the sleeve 20. In this sleeve-type roll 100, one end edge of the sleeve 20 along the axial direction extends beyond the boundary between the body BR and the first shaft AR1 toward the first shaft AR1 side, and the other end edge of the sleeve 20 along the axial direction extends beyond the boundary between the body BR and the second shaft AR2 toward the second shaft AR2 side.

Description

[Technical Field]

[0001] The present invention relates to a sleeve-type roll and a rolling method. [Background Art]

[0002] Conventionally, as a pressure roll used for pressure bonding of dissimilar materials, rolling of a rolled material, and the like, a sleeve-type roll having an arbor and a sleeve with a hydraulic chamber formed between the arbor and the sleeve is known (see, for example, Patent Document 1 below). According to this sleeve-type roll, by supplying hydraulic pressure to the hydraulic chamber to adjust the expansion of the sleeve, it is possible to adjust the outer diameter of the sleeve that directly presses the material. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 51-92770 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] An example of a conventional sleeve-type roll is shown in Fig. 7. Here, Fig. 7(a) is a longitudinal sectional view of the conventional sleeve-type roll 1, and Fig. 7(b) is an explanatory diagram schematically showing the outer diameter distribution of the outer peripheral surface when hydraulic pressure is applied to the hydraulic chamber of the conventional sleeve-type roll 1 to expand the body portion br. As shown in Fig. 7(a), the conventional sleeve-type roll 1 includes an arbor 2 and a sleeve 3. The sleeve-type roll 1 is divided into a plurality of regions along its central axis CL. That is, the sleeve-type roll 1 is divided into: a body portion br that applies a pressing force to a material directly or indirectly via another roll; a first shaft portion ar1 connected to one side of the body portion br; and a second shaft portion ar2 connected to the other side of the body portion br.

[0005] Arbor 2 is a metal shaft with an oil passage (not shown) formed inside, and is longer than the total length of sleeve 3. Therefore, the first shaft portion ar1 and the second shaft portion ar2 of arbor 2, which are supported by bearings B1 and B2, are not covered by sleeve 3 and are exposed. Thus, both ends of arbor 2 at the first shaft portion ar1 and the second shaft portion ar2 are directly supported by bearings B1 and B2. The sleeve 3 is a metal cylinder coaxially fixed around the arbor 2 and is fixed to the arbor 2 by shrink-fitting at the first shrink-fit portion 3a and the second shrink-fit portion 3b. A cylindrical gap space is formed as a hydraulic chamber between the central portion of the inner circumferential surface 3c of the sleeve 3 and the central portion of the outer circumferential surface 2b of the arbor 2. This hydraulic chamber is connected to the oil passage and receives hydraulic pressure from a hydraulic source (not shown) via the oil passage, pressurizing the sleeve 3 from the inside. As shown in Figure 7(b), the pressurized sleeve 3 deforms into a V-shape, with its outer diameter being largest at the center of the hydraulic chamber in the longitudinal direction.

[0006] When applying pressure to a material using a conventional sleeve-type roll 1 having the configuration described above, if the lengths of the first shrink-fit portion 3a and the second shrink-fit portion 3b are short, the gripping force at these two locations may be insufficient, causing the sleeve 3 to shift axially relative to the arbor 2. In that case, the load applied to the material will fluctuate with each rotation of the sleeve-type roll 1, which may cause defects in the product shape. Therefore, in order to prevent slippage, it is necessary to ensure that the lengths of the first shrink-fit portion 3a and the second shrink-fit portion 3b are long enough. However, extending the lengths of the first shrink-fit portion 3a and the second shrink-fit portion 3b leads to a reduction in the length of the hydraulic chamber formed between them. As a result, as shown in Figure 7(b), the range in which the outer diameter of the sleeve 3 can be controlled becomes narrower relative to the total length of the body portion br. Therefore, it may not be possible to provide an appropriate rolling effect to the total width of the material being processed.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a sleeve-type roll that can prevent insufficient gripping force of the sleeve on the arbor and extend the outer diameter control range, and a rolling method using this sleeve-type roll. [Means for solving the problem]

[0008] This invention was made in view of the above circumstances, and adopts the following embodiments. (1) That is, a sleeve-type roll according to one aspect of the present invention is It comprises an arbor with a pressurized fluid channel formed inside, and a sleeve coaxially fixed to the outer circumference of the arbor, The arbor is divided into a body portion located in the axial center, a first shaft portion coaxially connected to one end of the body portion along the axial direction, and a second shaft portion coaxially connected to the other end of the body portion along the axial direction. A pressurized chamber leading to the pressurized fluid passage is formed between the arbor and the sleeve. It is a sleeve-type roll, One end edge of the sleeve along the axial direction extends beyond the boundary between the body and the first shaft portion toward the first shaft portion, The other end of the sleeve along the axial direction extends beyond the boundary between the body portion and the second shaft portion toward the second shaft portion.

[0009] According to the sleeve-type roll described in (1) above, by extending one end of the sleeve toward the first shaft and extending the other end of the sleeve toward the second shaft, a longer fixing range of the sleeve to the arbor can be secured. Therefore, insufficient gripping force of the sleeve on the arbor can be prevented. Furthermore, since the fixing range is secured by extending toward the first and second shafts, it is possible to secure a longer pressurizing chamber without shortening its length. Thus, it is possible to achieve both prevention of insufficient gripping force of the sleeve on the arbor and an extension of the outer diameter control range.

[0010] (2) The sleeve-type roll described in (1) above may be configured as follows: The position of one end edge of the sleeve exceeds the position of the end edge of the bearing surface of the first shaft portion. The position of the other end edge of the sleeve exceeds the position of the end edge of the bearing surface of the second shaft portion. In the case of the sleeve-type roll described in (2) above, at least the entire length of the bearing surface in the first shaft and the entire length of the bearing surface in the second shaft can be used to fix the sleeve, thus more reliably preventing insufficient gripping force and making it possible to increase the length of the pressurizing chamber. Here, the bearing surface refers to the annular surface that is supported by the bearing in the sleeve-type roll.

[0011] (3) In the sleeve-type roll described in (1) or (2) above, A concave surface that partitions the pressurizing chamber may be formed on the inner circumferential surface of the sleeve. In the case of the sleeve-type roll described in (3) above, the area within the sleeve where the pressurized chamber is located can be made to expand more easily, allowing for more flexible control of the outer diameter of the body.

[0012] (4) In the sleeve-type roll described in (3) above, The concave surface may be formed in a V-shape such that the thickness of the sleeve, as viewed in a cross-section including the central axis of the sleeve, is thinnest at the central position in the axial direction of the body. In the case of the sleeve-type roll described in (4) above, the axial central position of the body can be made to bulge more easily, allowing for more flexible control of the outer diameter of the body.

[0013] (5) A rolling method according to one aspect of the present invention is A method of rolling a workpiece by sandwiching it between a pair of rolls, One or both of the pair of rolls may be sleeve-type rolls as described in any one of items (1) to (4) above. According to the rolling method described in (5) above, rolling can be performed using a sleeve-type roll in which the length of the pressure chamber along the axial direction is longer than that of the conventional art, so pressing force distribution control can be performed over a wide range along the width direction of the workpiece (the sheet width direction in a cross section perpendicular to the rolling direction). In addition, since rolling is performed using a sleeve-type roll in which the gripping force of the sleeve with respect to the arbor is sufficiently maintained, the risk of occurrence of load fluctuation acting on the workpiece accompanying axial displacement of the sleeve can be reduced. This makes it possible to suppress the occurrence of product defects. [Effects of the Invention]

[0014] According to the sleeve-type roll and the rolling method of each of the above aspects, it is possible to achieve both prevention of insufficient gripping force of the sleeve with respect to the arbor and elongation of the outer diameter control range. [Brief Description of the Drawings]

[0015] [Figure 1] It is a diagram showing a first embodiment of the present invention, in which (a) is a longitudinal sectional view of a VC roll system provided with a sleeve-type roll. (b) is an explanatory diagram schematically showing the outer diameter distribution of the outer circumferential surface of the body portion when hydraulic pressure is applied to the hydraulic chamber of the sleeve-type roll to inflate the body portion, in comparison with a conventional one. That is, in (b), the two-dot chain line shows the outer diameter distribution of a conventional sleeve-type roll, and the solid line shows the outer diameter distribution of the sleeve-type roll of the first embodiment. [Figure 2] It is a diagram showing a main part of the sleeve-type roll, in which (a) is an enlarged view of part A in Fig. 1, and (b) is an enlarged view of part D in Fig. 2(a). [Figure 3] It is a diagram showing another main part of the sleeve-type roll, in which (a) is a B-B sectional view of Fig. 1, and (b) is a C-C sectional view of Fig. 1. [Figure 4] It is a diagram showing a modified example of the sleeve-type roll, and is a longitudinal sectional view of a portion corresponding to part A in Fig. 1. [Figure 5] It is a longitudinal sectional view showing a sleeve-type roll according to a second embodiment of the present invention. [Figure 6]It is a diagram showing one embodiment of the rolling method of the present invention, wherein (a) shows the rolling step, and (b) shows the outer diameter distribution of a sleeve-type roll in the rolling step. That is, in the graph of (b), the horizontal axis represents the position in the sheet width direction of the workpiece, and the vertical axis represents the outer diameter at the same position. [Figure 7] It is a diagram showing a conventional sleeve-type roll, wherein (a) is a longitudinal sectional view, and (b) is an explanatory diagram schematically showing the outer diameter distribution of the outer peripheral surface when the body portion is expanded by applying hydraulic pressure to the hydraulic chamber. MODE FOR CARRYING OUT THE INVENTION

[0016] Embodiments and modified examples of the sleeve-type roll and the rolling method of the present invention will be described below based on the drawings. First, a first embodiment of the sleeve-type roll and modified examples thereof will be described with reference to FIGS. 1 to 4. Subsequently, a second embodiment of the sleeve-type roll will be described with reference to FIG. 5. Furthermore, one embodiment of the rolling method will be described with reference to FIG. 6.

[0017] [First Embodiment] In FIG. 1, (a) shows a longitudinal sectional view of a VC roll system provided with a sleeve-type roll 100. Also, (b) shows a diagram comparing the outer diameter distribution of the outer peripheral surface 21 in the body portion BR when hydraulic pressure is applied to the hydraulic chamber (pressurization chamber) 11b of the sleeve-type roll 100 with that of a conventional one. That is, in (b), the two-dot chain line shows the outer diameter distribution of the conventional sleeve-type roll 1 shown in FIG. 7(b), and the solid line shows the outer diameter distribution of the sleeve-type roll 100 of the present embodiment. In the following description, when the sleeve-type roll 100 is viewed along the central axis CL in FIG. 1, the side where a first shrink-fitting portion 23 described later is located may be referred to as "one side", and the side where a second shrink-fitting portion 24 described later is located may be referred to as "the other side". In addition, the extending direction of the central axis CL may be referred to as "axial direction" or "longitudinal direction".

[0018] The VC roll system of this embodiment is suitably used in a two-stage rolling mill equipped with a pair of work rolls that directly contact the front and back surfaces of a pair of metal strip materials that are to be processed. In this rolling mill, a sleeve-type roll 100 can be used as one or both of the pair of work rolls. Here, if the sleeve-type roll 100 is applied to only one of the pair of work rolls, a normal roll without an outer diameter control function may be used as the other work roll. In this case, a normal roll (not shown) may be placed parallel to the sleeve-type roll 100 directly below it, and the metal strip material may be sandwiched between them and pressed. Alternatively, if the sleeve-type roll 100 is applied to both of the pair of work rolls, a pair of sleeve-type rolls 100 may be placed parallel to each other vertically, and the metal strip material may be sandwiched between them and pressed.

[0019] In the following explanation, we will illustrate the case where a pair of sleeve-type rolls 100 are applied to a rolling mill that presses a pair of metal strip materials together. When viewing the configuration of this rolling mill from top to bottom in the vertical direction, the sleeve-type roll 100 shown in Figure 1(a) is first positioned at the top as the upper work roll, the metal strip material to be processed is placed directly below the sleeve-type roll 100, and another sleeve-type roll 100 (not shown) is placed directly below the metal strip material as the lower work roll.

[0020] As shown in Figure 1(a), the sleeve-type roll 100 in this embodiment is a VC (Variable Crown) roll that, in combination with a hydraulic device 200, constitutes a VC roll system, and is a work roll that directly contacts and applies pressure to the workpiece. The sleeve-type roll 100 comprises an arbor 10, a sleeve 20, a rotary joint 30, and a quick joint (not shown). The sleeve-type roll 100 is divided into three main parts along its central axis CL. Specifically, the sleeve-type roll 100 is divided into a body section BR that directly contacts the material to be pressed and applies pressure, a first shaft section AR1 connected to one side of the body section BR, and a second shaft section AR2 connected to the other side of the body section BR. Of these, the body section BR has the largest outer diameter, and a step is formed at the boundary between the body section BR and the first shaft section AR1. Similarly, a step is formed at the boundary between the body section BR and the second shaft section AR2. On the other hand, the first shaft section AR1 and the second shaft section AR2 have equal outer diameters.

[0021] The arbor 10 is a metal (e.g., made of chromium steel) shaft with an oil passage (pressurized fluid passage) 11a formed inside, and the outer diameter of the central portion along the central axis CL is smaller than the outer diameters of the adjacent portions. That is, when viewed from one side to the other, the arbor 10 has a first large-diameter portion located at the position of one bearing B1, a small-diameter portion having a smaller outer diameter than this first large-diameter portion, and a second large-diameter portion located at the position of the other bearing B2 and having the same outer diameter as the first large-diameter portion. Thus, the outer circumferential surface 11c of the arbor 10 is broadly divided into three parts: a small-diameter portion at the central position in the longitudinal direction, and large-diameter portions at one end and the other end in the longitudinal direction.

[0022] The first large-diameter portion has a constant outer diameter at each position in the axial direction, and one side of the inner circumferential surface 22 of the sleeve 20 is fixed to its outer circumferential surface by shrink-fitting to form the first shrink-fit portion 23. The second large-diameter portion has a constant outer diameter at each position in the axial direction, and the other side of the inner circumferential surface 22 of the sleeve 20 is fixed to its outer circumferential surface by shrink-fitting to form the second shrink-fit portion 24.

[0023] The small-diameter portion has a constant outer diameter at each axial position, forming a gap space of a constant size between it and the inner circumferential surface 22 of the sleeve 20. This gap space forms a cylindrical space and constitutes a hydraulic chamber (pressure chamber) 11b that pressurizes the inner circumferential surface 22 of the sleeve 20 from the inside out, i.e., radially outward with respect to the central axis CL. The hydraulic chamber 11b is a closed space partitioned by the outer circumferential surface of the small-diameter portion, the inner circumferential surface 22 of the sleeve 20, the stepped surface between the first large-diameter portion and the small-diameter portion, and the stepped surface between the second large-diameter portion and the small-diameter portion. At the positions of the first shrink-fit portion 23 and the second shrink-fit portion 24 at both ends of the hydraulic chamber 11b, the outer circumferential surface 11c of the arbor 10 and the inner circumferential surface 22 of the sleeve 20 are liquid-tightly joined, thus sealing the hydraulic chamber 11b to prevent oil leakage to the outside.

[0024] An oil passage 11a is formed inside the arbor 10, coaxial with the central axis CL. As illustrated in this embodiment, the oil passage 11a bends at a right angle at one end of the longitudinal direction, as shown on one side of Figure 1(a), and then branches in three directions to communicate with the hydraulic chamber 11b, as shown in Figure 3(a). Furthermore, as shown on the other side of Figure 1(a), the oil passage 11a bends at a right angle at an intermediate position in the longitudinal direction, and then branches in three directions to communicate with the hydraulic chamber 11b, as shown in Figure 3(b). As shown in Figures 3(a) and 3(b), the position of the oil passage 11a that branches at the BB cross-section in Figure 1 and the position of the oil passage 11a that branches at the CC cross-section are offset in the circumferential direction with respect to the central axis CL. Also, as shown in Figure 1(a), the hydraulic pressure is supplied to the hydraulic chamber 11b at two locations in the longitudinal direction along the central axis CL. Therefore, hydraulic pressure is supplied immediately and evenly to each position in the hydraulic chamber 11b. The shape of the oil passage 11a shown here is just one example. In this embodiment, Figures 3(a) and 3(b) illustrate a case where the oil passage branches in three directions. However, the configuration is not limited to this, and it is also possible to use a single direction without branching, or to branch in two or four or more directions.

[0025] As shown in Figure 1(a), a recess coaxial with the central axis CL is formed at the end of the second large-diameter portion of the arbor 10, and the rotary joint 30 is coaxially connected to this recess. The rotary joint 30 is rotatably connected to the arbor 10 around the central axis CL. Therefore, while the arbor 10 and sleeve 20 rotate together around the central axis CL, the rotary joint 30 remains stationary without rotating. The rotary joint 30 is connected to the hydraulic piping 60 of the hydraulic system 200 and receives hydraulic pressure from the hydraulic power source 50. The rotary joint 30 and the hydraulic piping 60 are detachably connected by a quick joint (not shown). A flow path is also connected between the rotary joint 30 and the oil passage 11a to allow for the supply of hydraulic pressure.

[0026] The sleeve 20 is a metal (e.g., made of chromium steel) cylinder coaxially fixed around the arbor 10, and is fixed to the arbor 10 by shrink-fitting at the first shrink-fit portion 23 and the second shrink-fit portion 24. Specifically, after manufacturing the arbor 10 and the sleeve 20, the sleeve 20 is heated first to cause thermal expansion. This thermal expansion causes the inner diameter of the sleeve 20 to become slightly larger than the inner diameter at room temperature, so the arbor 10 is inserted coaxially into the heated sleeve 20. Then, when the temperature of the sleeve 20 returns to room temperature, the inner diameter of the sleeve 20 shrinks back to its original size, and the first and second large-diameter portions are joined to the outer circumferential surface 11c of the arbor 10. In this way, the first shrink-fit portion 23 and the second shrink-fit portion 24 are formed. Meanwhile, the hydraulic chamber 11b is formed in the small-diameter portion.

[0027] Unlike the conventional sleeve 3 shown in Figure 7, the sleeve 20, as shown in Figure 1(a), has a length that covers the entire length of the arbor 10 from one end edge to the other. In other words, the total length of the sleeve 20 is the same as the total length of the arbor 10. Therefore, in the sleeve-type roll 100 of this embodiment, the sleeve 20, rather than the arbor 10, is directly supported by the bearings B1 and B2. In other words, both ends of the arbor 10 are indirectly supported by the bearings B1 and B2 via the sleeve 20. The outer diameter of the sleeve 20 is constant at each position along the central axis CL in the body BR. However, in the first shaft portion AR1 and the second shaft portion AR2 supported by bearings B1 and B2, the outer diameter of the sleeve 20 is smaller than the outer diameter at the body BR, and is the same size as the sleeve 20. Therefore, a step is formed between the first shaft portion AR1 and the body BR. Similarly, a step is also formed between the second shaft portion AR2 and the body BR.

[0028] The first shaft portion AR1 is coaxially and rotatably supported by the bearing B1 on its bearing surface bs1. The bearing surface bs1 is an annular surface of the outer circumferential surface of the first shaft portion AR1, centered on the central axis CL, that is supported by the bearing B1. The second shaft portion AR2 is also coaxially and rotatably supported by the bearing B2 at its bearing surface bs2. The bearing surface bs2 is an annular surface of the outer circumferential surface of the second shaft portion AR2, centered on the central axis CL, that is supported by the bearing B2. In this way, the bearing surface bs1 is supported by bearing B1, and the bearing surface bs2 is supported by bearing B2, so that the sleeve-type roll 100 is rotatably supported about the central axis CL by the pair of stationary bearings B1 and B2.

[0029] As shown in Figure 1(a), the hydraulic system 200 includes a hydraulic power source 50, hydraulic piping 60, and a hydraulic pump and valves (not shown). The hydraulic power source 50 is a container for storing oil to be supplied to the hydraulic chamber 11b. The hydraulic piping 60 is a pipe that connects the hydraulic power source 50 and the quick joint. The hydraulic pump is a pump that supplies oil from the hydraulic source 50 to the sleeve-type roll 100 and is connected to the hydraulic piping 60. Similarly, the valve is also connected to the hydraulic piping 60 and is capable of controlling the amount of oil sent to the hydraulic chamber 11b, controlling the amount of oil removed from the hydraulic chamber 11b, and blocking the backflow of oil from the hydraulic chamber 11b through the hydraulic piping 60.

[0030] When pressing a pair of metal strips together using a rolling mill equipped with a sleeve-type roll 100 having the configuration described above, first, the pair of metal strips are sandwiched between the sleeve-type roll 100 shown in Figure 1(a) and another sleeve-type roll 100 (not shown) positioned parallel to it directly below it. Then, while feeding the pair of metal strips along their longitudinal directions, the sleeve-type roll 100 shown in Figure 1(a), which is relatively above it, is lowered while maintaining a parallel position toward the other sleeve-type roll 100 directly below it, thereby applying pressure. This pressure causes the pair of metal strips to be pressed together and integrated, then fed out and wound into a coil to form the final product.

[0031] Here, the crimping process of the metal strip material is performed simultaneously with an inspection of the crimping state on the downstream side in the feeding direction. If the inspection results in an adjustment of the pressure distribution in the width direction of the metal strip material, hydraulic pressure is supplied from the hydraulic source 50 to the hydraulic chamber 11b via the hydraulic piping 60. This increases the internal pressure of the hydraulic chamber 11b, pressurizing the sleeve 20 from the inside. As shown by reference numeral 21 in Figure 1(b), the pressurized sleeve 20 is adjusted to have a shape with a V-shaped height distribution, where the outer surface 21 is highest at the center in the longitudinal direction along the central axis CL, and the height gradually decreases towards one side and the other side from this center position. As a result, the adjusted sleeve-type roll 100 has the largest outer diameter at the center in the longitudinal direction along the central axis CL, and the outer diameter gradually decreases towards one side and the other side from this center position. By using a sleeve-type roll 100 with an adjusted outer diameter in this manner to compress a metal strip, the pressure distribution in the width direction of the metal strip can be adjusted, and the compression strength distribution in the width direction of the metal strip can be made uniform.

[0032] Furthermore, according to the sleeve-type roll 100 of this embodiment, as shown in Figure 1(b), it is possible to make the V-shaped bulge area formed on the outer peripheral surface 21 wider and gentler than that of a conventional sleeve-type roll indicated by reference numeral 3d. This will be explained using Figures 2(a) and 7.

[0033] In the conventional sleeve-type roll 1 described above, as shown in Figure 7, both the first shrink-fit portion 3a and the second shrink-fit portion 3b were located within the range of the body portion br when viewed along the longitudinal direction. If the dimensions of these first shrink-fit portions 3a and 2 shrink-fit portions 3b along the central axis CL are too short, the gripping force of the sleeve 3 by shrink-fitting onto the arbor 2 will be insufficient, and the sleeve 3 may be misaligned axially with respect to the arbor 2. Therefore, the first shrink-fit portion 3a and 2 shrink-fit portion 3b needed to have a certain length. Consequently, it was necessary to secure a certain range for the first shrink-fit portion 3a and 2 shrink-fit portion 3b within the total length of the body portion br, which inevitably narrowed the range in which the outer diameter could be controlled, and as shown in Figure 7(b), there was a limitation in the range in which the outer diameter could be controlled.

[0034] In contrast, in the sleeve-type roll 100 of this embodiment, as shown in Figure 2(a), the position of the second shrink-fit portion 24 when viewed along the central axis CL extends beyond the boundary between the body portion BR and the second shaft portion AR2, into the range of the second shaft portion AR2. More specifically, as shown in Figure 2(a), the length dimension of the second shrink-fit portion 24 along the central axis CL is the same as the length dimension of the conventional second shrink-fit portion 3b, but its position is shifted to the other end of the arbor 10 (the end edge position). By moving the position of the second shrink-fit portion 24 to the right end of the arbor 10 in this way, the position of the other end of the hydraulic chamber 11b is moved further to the other side than in the conventional structure. The first shrink-fit portion 23 shown in Figure 1(a) is similar, but its position extends beyond the boundary between the body portion BR and the first shaft portion AR1 to the extent of the first shaft portion AR1. More specifically, as shown in Figure 1, the length dimension of the first shrink-fit portion 23 along the central axis CL is the same as the length dimension of the conventional first shrink-fit portion 3a, but its position is shifted to the position of one end of the arbor 10 (the end edge position). By moving the position of the first shrink-fit portion 23 to the left end position of the arbor 10 in this way, the position of one end of the hydraulic chamber 11b is moved to one side compared to the conventional structure.

[0035] In this way, by utilizing the ranges of the first shaft portion AR1 and the second shaft portion AR2 for shrink fitting, the length of the hydraulic chamber 11b is increased without narrowing the length dimensions of the first shrink-fit portion 23 and the second shrink-fit portion 24. As a result, as shown by reference numeral 21 in Figure 1(b), it is possible to control the outer diameter of the outer circumferential surface 21 over a wider range than in the conventional method. Furthermore, the position of one end edge of the sleeve 20 may be extended beyond the end edge position of the bearing surface bs1 of the first shaft portion AR1, or it may be configured to extend to just before the position of one end edge of the arbor 10. Similarly, the position of the other end edge of the sleeve 20 may be extended beyond the end edge position of the bearing surface bs2 of the second shaft portion AR2, or it may be configured to extend to just before the position of the other end edge of the arbor 10. This will be explained using Figures 2(a) and (b). In the above embodiment, in order to secure the range of the first shrink-fit portion 23, as shown in Figure 2(a), the position of the other end edge of the sleeve 20 is extended beyond the end edge position of the bearing surface bs2 of the second shaft portion AR2 to a position equal to the position of the other end edge of the arbor 10. However, the position of the other end edge of the sleeve 20 may be extended beyond the end edge position of the bearing surface bs2 of the second shaft portion AR2, or it may be configured to extend to just before the position of the other end edge of the arbor 10, as shown in Figure 2(b).

[0036] The main points of this embodiment, as described above, are summarized below. (1) That is to say, the sleeve-type roll 100 according to this embodiment is The system comprises an arbor 10 with an oil passage 11a formed inside, and a sleeve 20 coaxially fixed to the outer circumference of the arbor 10. The arbor 10 is divided into a body BR located in the axial center, a first shaft portion AR1 coaxially connected to one end edge of the body BR along the axial direction, and a second shaft portion AR2 coaxially connected to the other end edge of the body BR along the axial direction. A hydraulic chamber 11b leading to an oil passage 11a is formed between the arbor 10 and the sleeve 20. The position of one end edge of the sleeve 20 along the axial direction extends beyond the boundary between the body portion BR and the first shaft portion AR1 toward the first shaft portion AR1, The other end edge of the sleeve 20, along its axial direction, extends beyond the boundary between the body BR and the second shaft portion AR2 toward the second shaft portion AR2.

[0037] According to the sleeve-type roll 100 described in (1) above, by extending one end of the sleeve 20 toward the first shaft portion AR1 and extending the other end of the sleeve 20 toward the second shaft portion AR2, the fixing range of the sleeve 20 with respect to the arbor 10 can be made longer. Therefore, insufficient gripping force of the sleeve 20 with respect to the arbor 10 can be prevented. Furthermore, since the fixing range is made longer toward the first shaft portion AR1 and the second shaft portion AR2, it is possible to make the length of the hydraulic chamber 11b longer without shortening it. Therefore, it is possible to prevent insufficient gripping force of the sleeve 20 with respect to the arbor 10 and to expand the outer diameter control range length at the same time.

[0038] (2) In the sleeve-type roll 100 described in (1) above, the following configuration may be adopted as illustrated in Figures 2(a) and (b): The position of one end edge of the sleeve 20 exceeds the position of the end edge of the bearing surface bs1 of the first shaft portion AR1. The position of the other end edge of the sleeve 20 exceeds the position of the end edge of the bearing surface bs2 of the second shaft portion AR2. In the case of the sleeve-type roll 100 described in (2) above, at least the entire length of the bearing surface bs1 in the first shaft portion AR1 and the entire length of the bearing surface bs2 in the second shaft portion AR2 can be used to fix the sleeve 20, thereby more reliably preventing insufficient gripping force and making it possible to increase the length of the hydraulic chamber 11b. Here, bearing surface bs1 refers to the annular surface of the sleeve-type roll 100 that is supported by bearing B1. Similarly, bearing surface bs2 refers to the annular surface of the sleeve-type roll 100 that is supported by bearing B2.

[0039] Furthermore, as a modified example of the first embodiment described above, the configuration shown in Figure 4 may be adopted. Figure 4 is a diagram showing a modified example of the sleeve-type roll 100, and is a longitudinal cross-sectional view of the portion corresponding to part A in Figure 1. In this modified example, a sealing structure using an O-ring 11e as shown in Figure 4 is employed instead of the second shrink-fit portion 24 shown in Figure 2(a). Specifically, in this modified example, the arbor 10 has a groove 11d formed within the range corresponding to the position of the second shrink-fit portion 24. This groove 11d is an annular groove formed circumferentially on the outer surface 11c with the central axis CL as the center. The O-ring 11e is a sealing member installed in the groove 11d, and seals the hydraulic pressure in the hydraulic chamber 11b. In addition, this modified example employs a sealing structure using an O-ring 11e instead of the first shrink-fit portion 23 described above. This sealing structure is the same as the combination of groove 11d and O-ring 11e shown in Figure 4. Therefore, in this modified example, the hydraulic chamber 11b located between the pair of O-rings 11e is sealed.

[0040] Since the hydraulic chamber 11b is sealed by a pair of O-rings 11e, the arbor 10 and sleeve 20 may be fixed by mechanical fastening (not shown), or shrink fitting may be applied as in the first embodiment described above. Aside from the structure described above, the configuration of this modified example is the same as that of the first embodiment described above. According to this modified example, the length of the hydraulic chamber 11b can be made wider, similar to the first embodiment described above. In addition, the hydraulic chamber 11b can be sealed by the pair of O-rings 11e even if the shrink-fitting gripping force is reduced or shrink-fitting is not performed at all.

[0041] Furthermore, as another variation of the first embodiment described above, the sleeve-type roll 100 may be used as a backup roll in a roll system with four or more stages. The sleeve-type roll 100 of this embodiment is most preferably used as a work roll that directly contacts and applies pressure to the workpiece, and is therefore best suited for a two-stage roll system. However, even if used as a backup roll, it can still prevent insufficient gripping force of the sleeve 20 on the arbor 10, making it applicable to roll systems with four or more stages as well. Furthermore, as another modification of the first embodiment described above, the sleeve-type roll 100 may be applied not only to the crimping of metal strip materials, but also to a work roll or backup roll for rolling steel materials.

[0042] [Second Embodiment] A second embodiment of the present invention is shown in Figure 5. Figure 5 is a longitudinal cross-sectional view of the sleeve-type roll 100A of this embodiment, viewed in a section including its central axis CL. The sleeve-type roll 100A of this embodiment differs from the sleeve-type roll 100 of the first embodiment in that it is equipped with a sleeve 20A instead of sleeve 20. However, the other configurations are the same as those of the first embodiment, so a redundant explanation will be omitted here.

[0043] Unlike the sleeve 20 of the first embodiment described above, the sleeve 20A of this embodiment has an inner diameter that changes along the central axis CL. Specifically, the sleeve 20A has its largest inner diameter at its longitudinal center, and the inner diameter gradually decreases as it moves from this center toward one side and the other, forming a concave surface 22A on its inner circumferential surface. That is, as shown in Figure 5, when the hydraulic chamber 11bA is viewed in a longitudinal section including the central axis CL, the vertical height is highest at the central position, and the height gradually decreases as it moves toward one end or the other end of the sleeve 20A.

[0044] Here, since the outer diameter of the sleeve 20A is constant at each position along its longitudinal direction, the wall thickness of the sleeve 20A is formed to be thinnest at the center position in the longitudinal direction and gradually increase in thickness towards one or the other end of the sleeve 20A. In other words, the wall thickness of the sleeve 20A gradually decreases from one or the other end toward the center position, and is thinnest at the center position. With this configuration, when hydraulic pressure is supplied to the hydraulic chamber 11bA, the wall thickness of the sleeve 20A gradually decreases toward the center position, making it easier to deform the sleeve 20A around the center position and allowing for more flexible control of the outer diameter. In this embodiment, when viewed in the cross-section shown in Figure 5, concave surfaces are formed on both the outer circumferential surface 11c of the arbor 10 and the inner circumferential surface (concave surface 22A) of the sleeve 20A. However, the configuration is not limited to this; a concave surface 22A may be formed on the sleeve 20A, but a concave surface may not be formed on the outer circumferential surface 11c of the arbor 10. In this case, the outer diameter of the small diameter portion of the arbor 10 will be the same as the outer diameter of the large diameter portion described above.

[0045] The main points of this embodiment described above are summarized below. (3) Like the sleeve-type roll 100A constructed based on the sleeve-type roll 100 described in (1) or (2) above, A concave surface 22A that demarcates the hydraulic chamber 11bA may be formed on the inner circumferential surface of the sleeve 20A. In the case of the sleeve-type roll 100A described in (3) above, the area within the hydraulic chamber 11bA in the sleeve 20A can be made more flexible in controlling the outer diameter of the body BR.

[0046] (4) In the sleeve-type roll 100A described in (3) above, The concave surface 22A may be formed in a V-shape such that the thickness of the sleeve 20A, as viewed in a cross-section including the central axis CL, is thinnest at the axial center of the body BR. In the case of the sleeve-type roll 100A described in (4) above, the axial central position of the body BR can be made to bulge more easily, which allows for more flexible control of the outer diameter of the body BR.

[0047] [Embodiment of Rolling Method] Referring to Figure 6, an embodiment of the rolling method of the present invention will be described. Here, Figure 6(a) shows the rolling process of the rolling method, and (b) shows the outer diameter distribution of the sleeve-type roll 100 in the same rolling process. That is, in the graph of (b), the horizontal axis shows the position in the width direction of the workpiece, and the vertical axis shows the outer diameter at the same position. In this embodiment of the rolling method, a rolling mill is constructed by arranging a pair of sleeve-type rolls 100, as described in the first embodiment above, in parallel vertically, and a workpiece W, which is a strip of steel sheet, is sandwiched between them and rolled. Although not shown in Figure 6(a), a hydraulic device 200 is connected to each of the pair of sleeve-type rolls 100.

[0048] This rolling method comprises a feeding step of passing the workpiece W between a pair of sleeve-type rolls 100, a rolling step of applying pressure to the workpiece W from above and below in the vertical direction in the thickness direction while passing it through, and a winding step of winding the rolled workpiece W into a coil to form a product. In the rolling process, as shown in Figure 6(a), the workpiece W is sandwiched between a pair of upper and lower sleeve-type rolls 100 and passed through, while the relatively upper sleeve-type roll 100 is lowered to roll the workpiece W. Then, depending on the rolled state of the workpiece W, if it becomes necessary to control the pressure distribution in the width direction of the sheet, the outer diameter of the outer surface 21 shown in Figure 1(b) is controlled. By appropriately controlling the outer diameter during the rolling process, it becomes possible to obtain a more uniform product shape along the width direction of the sheet.

[0049] The main points of this embodiment described above are summarized below. (5) A rolling method according to one embodiment of the present invention is This method involves sandwiching the workpiece W between a pair of rolls and rolling it, For both of the pair of rolls, a sleeve-type roll 100 as described in any one of items (1) to (4) above is used. According to the rolling method described in (5) above, rolling can be performed using a sleeve-type roll 100 in which the length of the hydraulic chamber 11b along the axial direction is longer than in conventional methods, so that the applied pressure distribution can be controlled over a wide range along the width direction of the workpiece W (the width direction of the plate in a cross section perpendicular to the rolling direction). In addition, since rolling is performed using a sleeve-type roll 100 in which the gripping force of the sleeve 20 on the arbor 10 is sufficiently maintained, the risk of load fluctuations acting on the workpiece W due to axial misalignment of the sleeve 20 can be reduced. This can suppress the occurrence of product defects. Alternatively, the sleeve-type roll 100A shown in Figure 5 may be used instead of the sleeve-type roll 100. Furthermore, one of the pair of rolls may be a standard roll without outer diameter control. [Explanation of symbols]

[0050] 10 Arbor 11a Oil passage (pressurized fluid passage) 11b Hydraulic chamber (pressurized chamber) 11c Outer surface of the arbor 20 sleeves 22 Inner surface of the sleeve 22A concave 100, 100A Sleeve-type roll AR1 First shaft section AR2 Second shaft section BR Torso CL center axis W Work material

Claims

1. It comprises an arbor with a pressurized fluid channel formed inside, and a sleeve coaxially fixed to the outer circumference of the arbor, The arbor is divided into a body portion located in the axial center, a first shaft portion coaxially connected to one end of the body portion along the axial direction, and a second shaft portion coaxially connected to the other end of the body portion along the axial direction. A pressurized chamber leading to the pressurized fluid passage is formed between the arbor and the sleeve. It is a sleeve-type roll, One end edge of the sleeve along the axial direction extends beyond the boundary between the body portion and the first shaft portion toward the first shaft portion, The other end of the sleeve along the axial direction extends beyond the boundary between the body portion and the second shaft portion toward the second shaft portion. A sleeve-type roll characterized by the following features.

2. The position of one end edge of the sleeve exceeds the position of the end edge of the bearing surface of the first shaft portion. The position of the other end edge of the sleeve exceeds the position of the end edge of the bearing surface of the second shaft portion. The sleeve-type roll according to feature 1.

3. The sleeve-type roll according to claim 1, characterized in that a concave surface is formed on the inner circumferential surface of the sleeve to partition the pressurizing chamber.

4. The concave surface is formed in a V-shape such that the thickness of the sleeve, as viewed in a cross-section including the central axis of the sleeve, is thinnest at the central position in the axial direction of the body. The sleeve-type roll according to feature 3.

5. A rolling method in which a workpiece is sandwiched between a pair of rolls and rolled, One or both of the pair of rolls are sleeve-type rolls as described in any one of claims 1 to 4. A rolling method characterized by the following features.

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