JP2007313523A - Cylindrical object manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical object-manufacturing method capable of manufacturing a cylindrical object consisting of a combined plate in a short time at low cost. <P>SOLUTION: The cylindrical object manufacturing method includes a material preparation step of preparing a rectangular flat base steel plate 3 and a rectangular flat mating plate 4, an overlapping step of overlapping the mating plate 4 on the base steel plate 3, a forming step of forming a combined steel plate 5 by joining the mating plate 4 with the base steel plate 3 by welding only a side along the direction forming the circumferential direction when a cylindrical shape is formed in future out of peripheral edges out of the overlapped mating plate 4, a curving step of curving the combined steel plate 5 in a cylindrical shape so that the mating plate 4 forms the inner circumferential side, a butting step of butting two sides of the combined steel plates 5 facing each other when the cylindrical shape is formed, and a cylindrical object forming step of forming the cylindrical object by welding the two butted sides to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a cylindrical object. More specifically, the present invention relates to a method for manufacturing a cylindrical object in which at least a part of the inner peripheral surface is lined with a material different from the cylindrical base material.

  Conventionally, a composite steel sheet in which steel sheets of different materials are overlapped and joined is known. A typical example of this composite steel sheet is a rolled stainless clad steel sheet. The rolled stainless steel clad steel plate is manufactured by joining a carbon steel plate and a stainless steel plate in a state of being superposed by a hot rolling method. On the other hand, this rolled stainless clad steel sheet may be formed into a cylindrical shape and used. For example, a housing for a side thruster of a ship or the like. Side thrusters are used to move the hull laterally, such as when a ship is berthing. Accordingly, the side thrusters are attached sideways so that the axial direction thereof is perpendicular to the longitudinal direction of the hull.

  FIG. 10 shows an example of a side thruster. This side thruster 51 is formed of a low carbon steel in a cylindrical shape, and a propeller 53 for propulsion is provided in a housing 52. Of the inner peripheral surface of the housing 52, the radially outer region 54 of the propeller 53 is susceptible to cavitation due to water flow, and the rust preventive coating on the inner peripheral surface of the housing 52 is damaged and directly exposed to a corrosive environment. There is a risk that. For this reason, the said range 54 of the inner peripheral surface of the housing 52 is required to protect the inner peripheral surface of the housing 52 from corrosion even if the anticorrosive coating film is damaged by cavitation. For this purpose, it is common to apply a low-carbon stainless steel lining to the range 54, and the rolled stainless steel clad steel sheet is used for this purpose. In the housing 52, a cylinder made of a rolled stainless steel clad steel plate is used in a range 54 radially outward of the propeller 53, and a cylinder made of a low carbon steel plate is used in the other range 55.

  FIG. 11 schematically shows an example of a method for manufacturing the housing 52 using a rolled stainless clad steel plate.

  As shown in FIG. 11 (a), a rectangular carbon steel plate 56 and a rectangular rolled stainless clad steel plate (simply referred to as a clad steel plate) 57 dimensioned to form a housing of a desired size when formed into a cylindrical shape are obtained. Prepared. Each of the steel plates 56 and 57 has a thickness of about 25 to 50 mm, and a length (a circumferential length when it becomes a cylinder) is about 6.5 to 10.5 m. Further, the width (length in the axial direction when it becomes a cylinder) is about 1.0 to 2.6 m for the carbon steel plate 56 and about 0.3 to 1.0 m for the clad steel plate 57. A groove for welding is applied to the sides 56A and 57A of the steel plates 56 and 57 that face each other when they are curved in a cylindrical shape. In addition, after the cylindrical shape is formed in the future, the sides 56B and 57B to be joined and welded are also subjected to groove processing for welding. The groove processing is cut by a dedicated groove processing machine. In particular, since the clad steel plate is bonded to the stainless steel plate, it is difficult to perform groove processing by gas cutting, and the plate thickness is limited by the ability of the plasma cutting machine.

  As shown in FIG. 11 (b), the carbon steel plate 56 and the clad steel plate 57 are each individually bent into a cylindrical shape, and the opposed two sides 56A and 57A are welded together to form a cylindrical object. Of course, the clad steel plate 57 is curved so that the stainless steel plate side becomes the inner peripheral surface.

  Next, as shown in FIG. 11 (c), after adjusting and aligning the groove portions of the opposed opposite sides 56B and 57B, the two sides 56B and 57B are welded together. To form a cylindrical object. And the finishing process of a welding part etc. is performed, antirust coating etc. are given, and the housing 52 is formed.

  Thus, when a clad steel plate is used, in order to weld-bond the carbon steel plate 56 and the clad steel plate 57, it is necessary to perform groove processing by a dedicated groove processing machine on both. Even more difficult is the process of butt welding the thick plates 56 and 57 together. Moreover, the process of making it curved and cylindrical is required for each of the carbon steel plate 56 and the clad steel plate 57. As described above, since many processes are required, a long period of time and high cost are forced. In addition, since the material of the housing for the side thruster needs to comply with the ship classification standard, when purchased from a steel manufacturer, the delivery time is extremely long and the price is high.

  As a technique related to the cylindrical manufacturing method described above, for example, Patent Document 1 discloses a cladding pipe manufacturing method. The clad pipe is composed of a cylindrical outer layer made of plain steel or low alloy steel and a nickel-based alloy coating layer formed on the inner peripheral surface of the outer layer. The nickel-based alloy coating layer is formed by overlay welding. Therefore, this method is not suitable for large-diameter cylindrical objects such as side thruster housings.

  Patent Document 2 discloses a method for manufacturing a can body. In this manufacturing method, a steel plate to which chrome plating or the like is applied is rolled into a cylindrical shape, and two parallel sides facing each other are overlapped and welded. The thickness of the plated steel sheet is 1 mm or less, which is not suitable as a method for producing a thick and large-diameter cylindrical object such as a side thruster housing.

  Patent Document 3 discloses a method of coating a stainless steel plate on a base plate formed of carbon steel installed in a nuclear reactor containment vessel. In this method, an annular stainless steel thin plate is placed on the upper surface of an annular base plate formed of carbon steel, and the periphery thereof is fixed to the base plate by welding. Patent Document 3 does not disclose a method of manufacturing a cylindrical object.

Patent Document 4 discloses a method for manufacturing a steel container. In this manufacturing method, a hot-rolled steel sheet is formed into a cylindrical shape by using a forming apparatus, and then the facing edges are welded together by a non-welding machine. However, this Patent Document 4 does not disclose a method for producing a cylindrical article with a lining.
JP 2005-248321 A JP-A-6-7948 JP 2003-177191 A JP 62-2554938 A

  The present invention has been made to solve the above-mentioned problems, and by avoiding restrictions on processing equipment and processing procedures due to the use of clad steel plates as in the prior art, the number of manufacturing steps can be greatly reduced. An object of the present invention is to provide a method of manufacturing a cylindrical object that can also reduce the manufacturing cost.

According to the present invention, a method for producing a cylindrical object in which at least a part of the inner peripheral surface is lined is:
A material preparation step of preparing a rectangular flat base metal plate and a flat laminated metal plate;
A superposition process of superimposing a metal plate on the base material steel plate;
By welding at least a part of the periphery of the laminated laminated metal plate, a combined steel sheet forming step of joining the laminated metal plate to the base steel sheet to form a composite steel sheet;
A bending step of bending the composite steel sheet into a cylindrical shape so that the laminated metal plate is on the inner peripheral side;
A butting process of butting two opposing sides of a cylindrical composite steel sheet;
A cylindrical object forming step of forming a cylindrical object by joining the abutted two sides by welding.

  According to this manufacturing method, since the laminated metal plate is joined to the base material steel plate to form a composite steel plate, there is no need to bend both the rolled clad steel plate and the carbon steel plate as in the conventional example. There is no need to butt weld a cylindrical object made of a steel plate and a cylindrical object made of a carbon steel plate. Furthermore, the great work of groove processing on the rolled clad steel sheet can be omitted.

  In the superimposing step, the mating metal plates are aligned to positions where the opposing two ends of the mating metal plates are slightly retracted from the positions of the opposing two sides of the base steel plate to be matched in the future in the cylindrical shape. be able to. In this way, when bending into a cylindrical shape, a circumferential compressive force is applied to the laminated metal plate due to the difference in curvature, but at this time, an extension allowance for the base steel plate of the laminated metal plate is ensured. The problem that the plates are in contact with each other can be prevented.

  In the superimposing step, a plurality of laminated metal plates are arranged in series along a circumferential direction when the cylindrical shape is formed in the future, and a gap is formed between opposing sides of the adjacent laminated metal plates. Can do. By doing so, when the metal plate is welded and bonded to the base steel plate, and thereafter, the allowance for expansion of the metal plate when it is bent into a cylindrical shape is ensured, the same advantages as described above can be obtained. .

  In the composite plate forming step, of the four sides of the laminated metal plate, only the side along the circumferential direction when it becomes a cylindrical shape in the future can be welded to the base steel plate. By doing so, when the metal plate is welded and joined to the base material steel plate, and then bent into a cylindrical shape, the margin of elongation in the circumferential direction with respect to the base material steel plate of the matched metal plate is ensured. The same advantages can be obtained.

  In the bending step, the end of the composite steel sheet can be bent in an arc shape in advance by a press device having a curved press die, and then the entire composite steel plate can be bent in a cylindrical shape by a bending roller device.

  In the butting step, the two opposite sides are butted by applying tensile force to each other in the diametrical direction at two axially opposite ends of the cylindrically curved composite steel sheet by a pulling device. Time alignment can be performed.

  In the cylindrical object forming step, the two sides that are abutted are temporarily joined by tack welding, and then the force that opens the two opposing ends at the axial end of the cylindrical object radially is expanded by the expansion device. By adding, the roundness of the cylindrical object can be adjusted.

  In the cylindrical object forming step, after welding the two butted sides, a cover plate made of the same material as the laminated metal plate can be bonded to the surface of the weld joint by welding. By carrying out like this, the range which makes a base material steel plate the composite steel plate can be covered with the material of a metal plate without fail.

  In the material preparation step, a carbon steel plate can be selected as the base steel plate, and a stainless steel plate can be selected as the laminated metal plate.

  According to the method of manufacturing a cylindrical object of the present invention, it is not necessary to purchase a clad steel plate with a long delivery date, and restrictions on processing equipment and processing procedures due to the use of the clad steel plate can be avoided. Manufacturing costs are greatly reduced.

  An embodiment of a method for manufacturing a cylindrical object according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view illustrating a housing for a side thruster such as a ship as a cylindrical object that can be manufactured by the manufacturing method of the present invention. The housing 1 has a cylindrical shape, and a propeller (not shown) is accommodated therein. The housing 1 is made of low carbon steel, but the range 2 corresponding to the outer side of the propeller in the radial direction is low as a countermeasure against corrosion caused by damage to the rust-preventing coating film due to cavitation. A carbon stainless steel plate is lined. Hereinafter, this range is referred to as a lining range 2.

  FIG. 2 shows a processing procedure for a steel plate used as the material of the housing 1. FIG. 2 (a) shows a rectangular low carbon steel plate (hereinafter referred to as a carbon steel plate or a base steel plate) 3 as a base steel plate, and the housing 1 shown in FIG. 1 when curved in a cylindrical shape. It is formed in the dimension used as the shape. Grooves are applied to the opposing two short sides 3A that are to be curved and butt welded in the future. Since the base steel plate 3 is a carbon steel plate and before the stainless steel plate is attached, the cutting means and the processing means can be selected almost without being limited by the plate thickness. Therefore, the groove can be processed by so-called gas cutting, which is convenient. The groove is processed so that a groove surface is formed on the inner peripheral side when the base steel plate 3 is bent into a cylindrical shape.

  FIG. 2 (b) shows a range 2 in which a laminated metal plate (hereinafter referred to as a laminated plate) 4 is pasted on the surface that becomes the inner peripheral surface when the base steel plate becomes a cylindrical shape in the future, that is, as described above. The lining range 2 corresponding to the radially outward direction of the propeller is shown. In this embodiment, although the said laminated board is formed from the low carbon stainless steel (for example, JIS SUS316L), it does not specifically limit to a material. Of the periphery of this range 2 in the base steel plate 3, the oxidized portion (so-called black skin) on the surface of the portion W to be welded in the future is ground and removed.

  As shown in FIGS. 2 (b) and 2 (c), two laminated plates 4 are prepared and both have a rectangular shape. The short sides 4A and 4B are approximately 1/3 of the short side 3A of the base steel plate 3, but are not limited to this size. The ratio is determined by the axial length of the housing 1 and the size of the propeller. Further, the number of sheets is not limited to two, and may be one or three or more. However, it is preferable to use a plurality of sheets for the reason described later. The lining range 2 is occupied by arranging these two sheets in series along the long side direction of each other. A gap D1 having a predetermined dimension (about 15 to 20 mm in the present embodiment) is formed between the opposing short sides 4A of the two laminated plates 4. A plurality of the laminated plates 4 are provided with a gap D1 between them when welding and joining to the base steel plate 3 and thereafter when being bent into a cylindrical shape, the adjacent short sides of the adjacent laminated plates 4 are opposed to each other. This is to prevent the two from pressing each other and floating from the base steel plate 3.

  In other words, due to the difference in curvature between the base steel plate 3 and the mating plate 4 when it is curved in a cylindrical shape, a compressive force is applied to the mating plate 4 on the inner surface side of the cylinder in the circumferential direction. For this reason, the laminated plate 4 tends to float from the base steel plate 3, but it is necessary to prevent this lifting by securing an extension allowance of the laminated plate 4 with respect to the base steel plate 3. For this purpose, the position of the other short side 4B of each laminated plate 4 is formed in a shape that is slightly retracted from the groove portion of the short side 3A of the base steel plate 3. That is, a gap D <b> 2 is formed between the end portion of the laminated plate 4 and the groove portion of the base material steel plate 3. With such an arrangement, the laminated plate 4 is positioned on the base material steel plate 3 and fixed to the base material steel plate 3 by a clamp.

  Next, as shown in FIG. 2 (d), the long side 4C of the laminated plate 4 is welded and joined to the base material steel plate 3. In advance, tack welding with a welding length of about 50 mm and a welding pitch of about 200 mm is performed. . These dimensions are examples and are not limited. In order to prevent the laminated plate 4 from floating from the surface of the base steel plate 3, the welded portion is struck by a so-called white hammer for each tack welding. Further, the short sides 4A and 4B of the laminated plate 4 are not welded until the final stage of processing so that the displacement in the longitudinal direction of the laminated plate 4 during welding or bending can be absorbed. It is preferable to affix a tape to a portion where welding is not performed so that foreign matter does not enter between the base steel plate 3 and the laminated plate 4. The long side 4C of the laminated plate 4 is subjected to main welding to the base steel plate 3. In the present embodiment, the above welding is fillet welding, and the leg length is approximately the same as the thickness of the laminated plate 4. Through the above series of steps, the mating plate 4 is bonded to the base material steel plate 3, and the composite steel plate 5 is completed. As the above welding, arc welding is generally adopted.

  3 and 4 show a process of bending the composite steel plate 5 into a cylindrical shape. FIG. 3 shows a step of bending both ends of the composite steel plate 5 in advance by the press device 6. In the case of a composite steel sheet having a length of about 6000 to 10000 mm, a range of about 500 mm at each end is curved by the press device 6. 3A is a diagram in which the right end portion of the composite steel plate 5 is curved, and FIG. 3B is a diagram in which the left end portion of the same composite steel plate 5 is curved. Finally, the composite steel sheet 5 is formed into a cylindrical shape by a feed bending process using the bending roller device 7 of FIG. As the pre-process, the vicinity of both ends in the long side direction of the composite steel plate 5 is curved in an arc shape by the press device 6. This is because the bending roller device 7 cannot apply pressure to the vicinity of both ends in the long side direction of the composite steel plate 5. This pressing device 6 has a male die 6A having a cylindrical convex surface and a female die 6B having a cylindrical concave surface. When the plate thickness is thick as in the housing 1 of the side thruster, it is preferable to perform a preliminary bending process by the press device 6, but a pressing force is also applied to the end of the steel plate, such as a four-roller. As long as the apparatus is capable of being bent, it may be bent into a cylindrical shape directly by the bending roller device 7 without being pre-processed and in a flat plate shape.

  FIG. 4 shows a bending roller device 7 for bending the composite steel plate 5 having both ends bent into a cylindrical shape. 4A is a front view thereof, FIG. 4B is a side view thereof, and FIG. 4C is a schematic side view showing a state in which the composite steel plate 5 is bent into a cylindrical shape. The apparatus 7 includes a pressure roller 8 that presses a plate to be processed from above to below, a pair of feed rollers 9 that feed the plate while supporting the plate from below, and a backup roller that supports the feed roller 9 from below. 10 and a pressure cylinder 11 that urges both ends of the pressure roller 8 in the axial direction downward. The pair of feed rollers 9 are arranged apart from each other in the plate feed direction, and the pressure roller 8 is disposed between the feed rollers 9 in plan view. As shown in FIG. 4 (c), the composite steel sheet 5 to be processed is pressed and curved between the pair of feed rollers 9 from above by the pressure roller 8 while being fed by the rotation of the feed roller 9. It is done. The composite steel plate 5 is made to be cylindrical by repeating this pressing while being reciprocated.

  Moreover, it is also possible to form a plate material into a cylindrical shape without using the bending roller device 7 by continuously performing the bending process by the press device 6 along the longitudinal direction of the target plate material. However, it is preferable to use the bending roller device 7 in consideration of processing efficiency and the like.

  Each of the pressure cylinders 11 is configured to be able to adjust the stroke of the pressure rod 12 independently. On the other hand, since the composite steel plate 5 has the laminated plate 4 lined on a part thereof, the plate thickness is not uniform on the left and right in the width direction. As a result, the strokes required for the pressure rods 12 of the left and right pressure cylinders 11 shown in FIG. Therefore, by making the pressure strokes of the left and right pressure cylinders 11 different, a uniform pressure is applied from the pressure roller 8 in the width direction of the composite steel plate 5. Such pressurization control makes it possible to form a cylindrical object with high roundness. During the bending process, a bending gauge is applied to the inner diameter side of the cylinder, the roundness of the arc-shaped portion is confirmed, and the operation of the bending roller device 7 is controlled.

  FIG. 5 shows the composite steel plate 5 before being welded, which is formed into a cylindrical shape by the bending process described above. The cylindrical composite steel plate 5 needs to be accurately aligned in order to weld and join the groove portions formed on the two short sides 3A of the base steel plate 3 facing each other. For this purpose, the axial ends of the cylindrical composite steel plate 5 are deformed by applying a force inward in the diametrical direction so that the groove portions are accurately opposed to each other. In order to apply force in the diametrical direction, as shown in the figure, a pair of clamps 14, a chain 15 that couples the clamps 14, and a lever block 16 that is disposed in the middle of the chain 15 and winds up the chain 15, A pull-in device 13 is used.

  The drawing device 13 is attached to each of both ends of the cylindrical composite steel plate 5 in the axial direction. First, the pair of clamps 14 are respectively attached at two locations facing each other in the diameter direction at the end of the cylindrical composite steel plate 5. Next, by winding the chain 15 with the lever block 16, a force is applied in a direction in which the two opposite positions to which the clamps 14 are attached are brought close to each other, and the deformed direction is reduced. Of course, at this time, the diameter is slightly increased in the direction perpendicular to the diameter reducing direction. If necessary, the above operation is repeated by attaching to a plurality of different diameter directions. With this operation, the groove portions are aligned with each other within a range necessary for welding and joining.

  The retracting device is not limited to the lever block, and any other suitable jacks can be employed. Further, a bar may be used in place of the chain 15. The clamp 14 is attached to one end of each of the two bars, and a jack like a turn buckle is prepared to make the two bars approach each other instead of the lever block. The other ends of the two bars are connected by this jack. The clamps are respectively attached at two locations facing the diameter direction at the end of the cylindrical composite steel plate 5. Next, the jack is operated so that the two bars are brought close to each other, and the cylindrical composite steel sheet 5 is reduced in diameter in the diameter direction. Even with such a device, an effect equivalent to that of the above-described retracting device 13 can be obtained.

  Next, as shown in FIG. 6, the cylindrical composite steel plate 5 is laid down so that the groove portion becomes the bottom, and tack welding is performed. The tack welding has a welding length of about 50 mm and a welding pitch of about 200 mm, but is not limited to these dimensions. After tack welding, various dimensional accuracy is confirmed and corrected. In particular, the roundness is corrected as follows.

  7 and 8 show a process of correcting the roundness of the cylindrical composite steel plate 5. FIG. The roundness is corrected by expanding the cylindrical composite steel sheet 5 by applying a force radially to each of both ends in the axial direction. In order to apply a force radially, an expansion device 17 as shown is used. FIG. 8 is a view taken along line VIII-VIII in FIG. The expansion device 17 has a plurality of support columns 18 extending radially at equal angular intervals. The plurality of struts 18 are fixed to each other at their central portions, and have an overall star shape. A jack 19 is detachably attached in the vicinity of the end of each column 18. Each jack 19 can expand and contract its pressing rod 19A in the radial direction (outward). A stopper 20 for receiving and supporting the reaction force of the jack 19 is detachably attached to each column 18 inside each jack 19.

  First, the expansion device 17 is disposed at each end of the cylindrical composite steel plate 5. At this time, as shown in FIG. 8, the state in which all the jacks 19 are arranged inside the cylindrical composite steel plate 5 so that the pressing rod 19 </ b> A of each jack 19 can act on the inner peripheral surface of the cylindrical composite steel plate 5. To. And the support | pillar 18 is made to contact | abut to the edge part of the cylindrical composite steel plate 5. FIG. Next, the jack 19 in the necessary direction is operated to apply a force for expanding the cylindrical composite steel plate 5 outward in the diametrical direction. In this way, the roundness of the cylindrical composite steel sheet 5 is corrected. Next, the main welding is performed while the cylindrical composite steel plate 5 is laid sideways (see FIG. 6) so that the groove portion becomes the bottom.

  Next, finishing after welding will be described with reference to FIG. First, the surplus portion R of the weld bead B is removed by a grinder or the like (FIG. 9A) and finished so as to be flush with the periphery thereof. Further, a portion of the outer peripheral surface of the cylindrical composite steel plate 5 corresponding to the weld line (back side of the weld bead) M is removed by arc air gouging to form a groove. This groove is finished by overlay welding.

  The vicinity of the weld joint portion on the inner peripheral surface side finished in this way is not covered with the laminated plate 4. This exposed range includes the aforementioned gap D2 with the weld joint portion as the center. The plate material 21 for covering this range is overlapped (FIG. 9B), and overlay welding is applied to a gap of about 10 mm between the plate material 21 and the laminated plate 4, and the plate material 21 is applied to the base steel plate 3. Adhere (FIG. 9C). In this way, the aforementioned exposure range is completely covered. As the plate material 21 and the welding material for build-up welding, a material equivalent to the laminated plate 4 is selected. This is because the weld metal that welds and joins the base steel plates 3 is made of the same material as the base steel plate 3, and this portion needs to be covered with a material having corrosion resistance equivalent to that of the laminated plate 4.

  Next, the gap D1 (FIG. 9 (d)) between the opposing short sides 4A of the two laminated plates 4 described above is build-up welded with a welding material equivalent to the laminated plate 4, and thereafter a grinder or the like. To finish the surface (FIG. 9E). In addition, when the dimension of the said clearance gap D1 is comparatively large, it weld-bonds, after inserting the board | plate material of the material equivalent to the laminated board 4 in the clearance gap D1 similarly to the covering of the welding joint part mentioned above.

  As described above, by using the plate material 21 made of the same material as the laminated plate 4 and the welding material made of the same material as the laminated plate 4, the entire lining range 2 on the inner peripheral surface of the cylindrical composite steel plate 5 is subjected to corrosion resistance treatment. The cylindrical composite steel plate 5 is completed through the above steps to form the housing 1. Finally, a rust-proof coating is applied.

  According to the manufacturing method of the above cylindrical object, a bending process is not required for each of the carbon steel plate and the clad steel plate as in the prior art using the rolled clad steel plate. The bending process may be performed only on the composite steel sheet 5. Moreover, the groove processing apparatus only for a rolled clad steel plate in a prior art is not required. Furthermore, the butt welding of difficult large diameter cylindrical objects in a prior art becomes unnecessary. In addition, it is not necessary to purchase a long-priced and expensive rolled clad steel sheet.

  In the embodiment described above, the manufacture of the housing of the side thruster is illustrated, but the present invention is not limited to this. The present invention can also be applied to a cylindrical object such as a pipe having a smaller size (axial length, diameter, plate thickness) than this housing. Further, as long as a bending device such as a press device or a bending roller device can be applied, the present invention can also be applied to a cylindrical object such as a tank or casing having a larger size than the side thruster housing.

  Moreover, in the said embodiment, although it becomes the partial composite steel plate by which the laminated board was affixed only to some of the internal peripheral surfaces of a cylindrical object (housing 1), this cylinder is used as the object of a manufacturing method. The shape is not limited. The whole inner peripheral surface may be a composite steel plate. It can be easily understood that the manufacturing method described above can be applied even to this cylindrical object. At that time, if necessary, through holes may be formed at a plurality of locations on the laminated plate, and plug welding may be performed on the base material steel plate.

  Further, in the present embodiment, the laminated plate 4 is curved so as to be on the inner peripheral surface side of the cylinder, but may be curved so as to be on the outer peripheral surface side on the contrary as required by the user. That is, the manufacturing method can also be applied when manufacturing a cylindrical object having a corrosion-resistant laminated plate attached to the outer peripheral surface.

  The method for manufacturing a cylindrical object according to the present invention can manufacture a cylindrical object made of a composite plate at a low cost and in a short period of time. For example, a cylindrical object whose inner surface or outer surface is subjected to corrosion resistance is manufactured. It is useful to do.

It is a longitudinal cross-sectional view which illustrates the housing for side thrusters, such as a ship, as a cylindrical object which can be manufactured with the manufacturing method of this invention. It is a perspective view which shows roughly the manufacturing process of the composite steel plate used as the material of the housing of FIG. It is a front view which shows roughly the process of curving the both ends of the said composite steel plate before making the composite steel plate of FIG. 2 curve cylindrically. FIG. 4A is a partial cross-sectional view schematically showing an example of an apparatus for bending a composite steel sheet having both ends bent into a cylindrical shape, and FIG. 4B is a side view of FIG. FIG. 4 (c) is a side view schematically showing a state in which the composite steel sheet is bent by the apparatus of FIG. 4 (a). It is a perspective view which shows the state before welding of the cylindrical object formed cylindrically with the apparatus shown in FIG. It is a perspective view which shows the state which welds the cylindrical object formed in the cylindrical shape shown in FIG. It is a front view which shows an example of the apparatus for correcting the roundness of a cylindrical object. It is a VIII-VIII line arrow directional view of FIG. FIG. 9A to FIG. 9E are partial cross-sectional views showing a procedure for finishing a cylindrical object. It is a partially notched perspective view which shows an example of the side thruster with which a ship is equipped. 11 (a) to 11 (c) are perspective views schematically showing a manufacturing process of the side thruster housing shown in FIG.

Explanation of symbols

1 ... Housing
2 ... Lined range
3 ... Base steel plate
4 ... Laminated plate
5 .... Composite steel plate
6 ... Pressing device
7. Bending roller device
8 ... Pressure roller
9 ... Feeding roller
10 ... Backup roller
11 ... Pressure cylinder
12 ... Pressure rod
13... Retraction device
14 .... Clamp
15 ... Chain
16 .... Lever block
17 ... Expansion device
18 ... Stand
19 ... Jack
20 ... Stopper
21 ... Plate material
D1, D2 ... Gap

Claims (9)

A material preparation step of preparing a rectangular flat base metal plate and a flat laminated metal plate;
A superposition process of superimposing a metal plate on the base material steel plate;
By welding at least a part of the periphery of the laminated laminated metal plate, a combined steel sheet forming step of joining the laminated metal plate to the base steel sheet to form a composite steel sheet;
A bending step of bending the composite steel sheet into a cylindrical shape so that the laminated metal plate is on the inner peripheral side;
A butting step of butting two sides of the composite steel plate facing each other when made cylindrical;
A method of manufacturing a cylindrical object in which at least a part of an inner peripheral surface is lined, which includes a cylindrical object forming step of forming a cylindrical object by joining the butted two sides together by welding.   In the superposition step, the metal plates are aligned to positions where the two opposite sides of the metal sheet are slightly retracted from the positions of the two opposite sides of the base steel sheet that will be made cylindrical in the future. The method for producing a cylindrical object according to claim 1.   In the superimposing step, a plurality of laminated metal plates are arranged in series along a direction that becomes a circumferential direction when it becomes a cylindrical shape in the future, and a gap is formed between opposing sides of adjacent laminated metal plates. Item 2. A method for producing a cylindrical article according to Item 1.   2. The method for manufacturing a cylindrical object according to claim 1, wherein, in the composite plate forming step, only the side along the circumferential direction of the four sides of the laminated metal plate in the circumferential direction is welded to the base steel plate. .   2. The cylindrical object according to claim 1, wherein in the bending step, an end of the composite steel sheet is curved in an arc shape in advance by a press device having a curved press die, and then the entire composite steel sheet is curved in a cylindrical shape by a bending roller device. Manufacturing method.   In the butting step, the two opposite sides are butted by applying tensile force to each other in the diametrical direction at two axially opposite ends of the cylindrically curved composite steel sheet by a pulling device. The method for manufacturing a cylindrical object according to claim 1, wherein time alignment is performed.   In the cylindrical object forming step, the two sides that are abutted are temporarily joined by tack welding, and then the force that opens the two opposing ends at the axial end of the cylindrical object radially is expanded by the expansion device. The manufacturing method of the cylindrical object of Claim 1 which adjusts the roundness of a cylindrical object by adding.   2. The cylindrical article manufacturing method according to claim 1, wherein, in the cylindrical article forming step, after welding the two butted sides, a cover plate made of the same material as the laminated metal plate is bonded to the surface of the welded joint by welding. Method. The manufacturing method of the cylindrical object of Claims 1-8 which selects a carbon steel plate as a base material steel plate in the said material preparation process, and selects a stainless steel plate as a laminated metal plate.

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