JP6546871B2 - Method of manufacturing cylinder - Google Patents

Description

  The present invention relates to a method of manufacturing a cylinder.

  In the case of manufacturing a cylindrical body by rounding a plate-like body and then welding it, there is a technique in which a tab plate is welded in advance to the plate-like body before rounding (see, for example, Patent Document 1).

JP, 2006-281253, A

  Welding the tab plate to the plate increases the manufacturing cost.

  Therefore, this invention aims at provision of the manufacturing method of the cylinder which can reduce manufacturing cost.

  In order to achieve the above object, the present invention arranges a plate-like body having a pair of sides longer than the circumferential length of a forming portion which cylindrically bends a plate-like body of a press forming die into the press forming die. A step of arranging the plate-like body, and forming the projecting portion which abuts the both end edges of the plate-like body in the circumferential direction and protrudes in the both end edges outward in the extension direction of the both end edges more than other portions. The press process which presses a press mold and makes the said plate-like body cylindrical, The welding process which welds the said both-ends edge part and it is set as a junction part.

  According to the present invention, the manufacturing cost of the cylinder can be reduced.

It is a front view which shows the 1st metal mold | die, core metal, 2nd metal mold | die, and one jig | tool which are used by the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a sectional side view which shows the 1st metal mold | die, core metal, 2nd metal mold | die, and both jigs used with the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a front view after the plate-shaped body arrangement | positioning process of the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a front view after the 1st press process of the manufacturing method of the cylinder concerning one embodiment of the present invention. It is a front view before the 2nd press process of the manufacturing method of the cylinder concerning one embodiment of the present invention. It is a front view in the 2nd press process of the manufacturing method of the cylinder concerning one embodiment of the present invention. FIG. 7 is a front cross-sectional view of the state after FIG. 6 during the second pressing step of the method for producing a cylindrical body according to one embodiment of the present invention. It is a front sectional view after the 2nd press process of the manufacturing method of the cylinder concerning one embodiment of the present invention. FIG. 7 is a partially enlarged plan view showing the relationship between the plate-like body and the relief portion at the time shown in FIG. 6. FIG. 8 is a partially enlarged plan view showing the relationship between the plate-like body and the relief portion at the time shown in FIG. 7; FIG. 9 is a partially enlarged plan view showing the relationship between the plate-like body and the relief portion at the time shown in FIG. 8; It is a top view of the cylinder after the welding process of the manufacturing method of the cylinder concerning one embodiment of the present invention. It is a top view of the cylinder after the removal process of the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a front sectional view showing an example of a cylinder device using a cylinder manufactured with a manufacturing method of a cylinder concerning an embodiment of the present invention. It is a front sectional view showing another example of the cylinder device using the cylinder manufactured by the manufacturing method of the cylinder concerning one embodiment of the present invention.

  The manufacturing method of the cylinder which concerns on one Embodiment of this invention is demonstrated below with reference to drawings.

  The method of manufacturing the cylindrical body of the present embodiment is a so-called single-tube tube manufacturing method, and the first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14 shown in FIGS. 1 is performed using a press apparatus having a press mold including only one of them.

  The first mold 11 has a protrusion 21 projecting from the mating surface 11 a that can be in contact with the second mold 13 and a forming groove 22 recessed from the protruding tip of the protrusion 21. The mating surface 11 a, the protrusion 21 and the forming groove 22 extend linearly along the length direction of the first mold 11. The protruding portion 21 has a pair of inclined surfaces 21 a whose distance from each other becomes narrower toward the protruding tip side. The groove surface 22a of the forming groove 22 is semi-cylindrical, and the width and the depth are constant regardless of the longitudinal position. The first mold 11 is a flat surface which spreads so that both end surfaces 11b on both sides in the length direction are orthogonal to the length direction.

  The metal core 12 has a cylindrical shape, and the outer diameter portion 32 on the radially outer side has a constant outer diameter, and the outer peripheral surface 32 a has a cylindrical shape. The radius of the outer peripheral surface 32 a of the outer diameter portion 32 of the core metal 12 is smaller than the radius of the groove surface 22 a of the forming groove 22 of the first mold 11. The metal core 12 is a flat surface which extends on both sides in the length direction, that is, both end faces 12 a on both sides in the axial direction so as to be orthogonal to the length direction. The core 12 has a length equal to the length of the first mold 11.

  The second mold 13 has a forming groove 42 recessed from the mating surface 13 a that can be in contact with the mating surface 11 a of the first mold 11. The mating surface 13 a and the forming groove 42 extend linearly along the longitudinal direction of the second mold 13. The forming groove 42 has a pair of inclined surfaces 42b on the mating surface 13a side and a groove surface 42a on the opposite side to the mating surface 13a. The pair of inclined surfaces 42b is inclined such that the distance between the pair of inclined surfaces 42b decreases as the distance from the mating surface 13a increases. The groove surface 42a has a semi-cylindrical shape, and the width and the depth are constant regardless of the longitudinal position, and extend between the pair of inclined surfaces 42b. In the second mold 13, the radius of the groove surface 42 a of the forming groove 42 is equal to the radius of the groove surface 22 a of the forming groove 22 of the first mold 11. The second mold 13 is a flat surface which spreads so that both end surfaces 13b on both sides in the longitudinal direction are orthogonal to the longitudinal direction. The second mold 13 has a length equal to the length of the first mold 11 and the core metal 12.

  The jig 14 has a short cylindrical shape having a cylindrical outer peripheral surface 14 a, and as shown in FIG. 2, the end face 44 a of the end portion 44 on one axial side with respect to the central axis of the jig 14 It is a flat surface that spreads orthogonally. In the jig 14, a recess 45 is formed at the end 44 in the axial direction of the jig 14 from the end face 44 a and in the radial direction of the jig 14 from the outer circumferential surface 14 a. The relief portions 45 are parallel to each other and extend from the bottom surface 45a inward in the radial direction of the jig 14 and both end edges of the bottom surface 45a in the circumferential direction of the jig 14 radially outward to the outer peripheral surface 14a. A pair of side wall surfaces 45b shown in FIG. 1 and a back wall surface 45c that is parallel to the end surface 44a and connects end surfaces opposite to the bottom surface 45a and the end surfaces 44a of the both side wall surfaces 45b.

  The jig 14 has an outer diameter, i.e., a diameter of the outer peripheral surface 14 a, which is larger than the outer diameter of the core 12, i.e., a diameter of the outer peripheral surface 32 a, and a radius of the outer peripheral surface 14 a is a formed groove of the first mold 11. The diameter is larger than the radius of the groove surface 22 a 22 and the radius of the groove surface 42 a of the forming groove 42 of the second mold 13. The bottom surface 45 a of the relief portion 45 shown in FIG. 2 is curved in a cylindrical shape having a distance from the center of the jig 14 equal to the radius of the core 12. That is, the outer peripheral surface 32 a of the core metal 12 and the bottom surface 45 a of the relief portion 45 are disposed on the same cylindrical surface in a state in which the jig 14 and the core metal 12 match the central axes.

  In the pressing apparatus, the cored bar 12 is disposed in parallel with the forming groove 22 in alignment with the forming groove 22 vertically above the forming groove 22 of the horizontally disposed first mold 11. Further, one jig 14 is brought into contact with one end face 12 a of the core metal 12 in the axial direction at the end face 44 a thereof. At this time, the relief member 45 is disposed at the upper end portion of the one jig 14 so that the core metal 12 and the central axis line coincide with each other. In this state, the outer peripheral surface 32a of the core 12 and the bottom surface 45a of the relief portion 45 of one jig 14 are continuous. In addition, the other jig 14 is brought into contact with the other end face 12 a in the axial direction of the core 12 at the end face 44 a thereof. At this time, the relief member 45 is disposed at the upper end of the other jig 14 so that the core metal 12 and the central axis line coincide with each other. In this state, the outer peripheral surface 32 a of the core 12 and the bottom surface 45 a of the relief portion 45 of the other jig 14 are continuous. The core 12 and the pair of jigs 14 may be integrally formed so as to be in the above state. Further, the pair of jigs 14 may be in the above state with respect to the core metal 12 in the second pressing step described later.

  And the manufacturing method of the cylinder of this embodiment is plate-shaped which arrange | positions the plate-shaped plate-like body 51 in the position between the 1st metal mold 11 and the core metal 12 in a press molding type | mold, as shown in FIG. Includes body placement process. The plate-like body 51 is formed by cutting the hoop material into a predetermined shape and size. In the plate-like body arranging step, the plate-like body 51 is placed on the ridge 21 of the first mold 11. The plate-like body 51 has a square or rectangular shape, and a pair of parallel sides (only one is shown in the drawing) of the sides 52 are aligned along the radial direction of the core 12 and both edge portions 54 connecting the pair of sides 52 Are arranged along the axial direction of the core 12.

  In the manufacturing method of this embodiment, as shown in FIGS. 3 to 4, the core metal 12 and a pair of jigs 14 (only one is shown in FIGS. 3 and 4) are vertically vertically integrated after the plate-like body arranging step. By lowering the core metal 12 into the forming groove 22 with the first metal mold 11 aligned with the first mold 11 in the longitudinal direction, and pressing the plate-like body 51 to plastically deform the first pressing step It contains. In this first pressing step, a plastically deformed portion is formed by the groove surface 22a of the forming groove 22 of the first mold 11 and the outer peripheral surface 32a of the outer diameter portion 32 of the core 12 in the middle portion of the plate-like body 51. A semi-cylindrical portion 56 is formed. The semi-cylindrical portion 56 has a semi-cylindrical shape in which the surface on one side in the thickness direction is curved in the same shape as the groove surface 22 a and the surface on the other side in the thickness direction is curved to the same shape as the outer peripheral surface 32 a. The plate-like body 51 after the first pressing step is a pair of flat plates in which portions other than the semi-cylindrical portion 56 extend in the direction away from the first mold 11 from both ends in the circumferential direction of the semi-cylindrical portion 56 without bending. It becomes the part 57. That is, the first mold 11 and the core metal 12 bend the plate-like body 51 in a U-shape. In this first pressing step, one of the jigs 14 shown in FIG. 2 is in contact with one end face 11b of the first mold 11 at its end face 44a, and the other jig 14 is at the end face 44a. Contacts the other end face 11b of

  In the press, as shown in FIG. 5, the second mold 13 is oriented with its forming groove 42 facing the metal core 12 vertically aligned with the metal core 12 above the metal core 12 so as to be parallel. Arrange as you like. And the manufacturing method of the cylinder of this embodiment is the state which matched the position of the metal core 12 with the length direction by lowering the 2nd metal mold 13 which is a press molding type vertically downward, and its state A second pressing step is included in which the core metal 12 is inserted into the forming groove 42 and the plate-like body 51 is pressed and plastically deformed.

  In the second pressing step, first, the pair of flat plate portions 57 of the plate-like body 51 is guided toward the groove surface 42 a by the pair of inclined surfaces 42 b of the forming groove 42 of the second mold 13. Next, as shown in FIG. 6 to FIG. 7 and FIG. 7 to FIG. 8 in order of the pair of flat plate portions 57 of the plate-like body 51, the groove surface 42a of the forming groove 42 and the outer periphery of the outer diameter portion 32 of the core 12 It is plastically deformed by the surface 32a to form a pair of curved plate portions 58 as shown in FIG. The pair of curved plate portions 58 has a shape similar to that of the groove surface 42a, with the surface on one side in the thickness direction bent, and the surface on the other side in the thickness direction bent to the same shape as the outer peripheral surface 32a. It is eggplant.

  Thus, the plate-like body 51 is bent into a shape having the semi-cylindrical portion 56 and the pair of curved plate portions 58 by the first pressing step and the second pressing step, and becomes O-shaped or cylindrical. At this time, the plate-like body 51 is bent so that the pair of sides 52 described above is in the circumferential direction of the cylinder. In the second pressing step, the mating surface 13 a of the second mold 13 is in surface contact with the mating surface 11 a of the first mold 11, and the pair of inclined surfaces 42 b of the second mold 13 is a pair of the first mold 11. It will be in the state which carries out surface contact on slope 21a. Further, in the second pressing step, one of the jigs 14 shown in FIG. 2 is in contact with one end face 13b of the second mold 13 at its end face 44a, and the other jig 14 is at the end face 44a. Contact the other end face 13b of 13.

  The forming groove 22, the outer diameter portion 32, the forming groove 42 and the pair of end portions 44 of the first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14 constituting the press molding die are all The plate-like body 51 is pressed to form a formed portion 61 which is bent in a cylindrical shape, specifically, in a cylindrical shape.

  Then, in the manufacturing method of the present embodiment, a plate-like body 51 having a pair of sides 52 longer than the circumferential length of the forming portion 61 in the state of being pressed is the first pressing step and the first pressing step. Press molding in 2 press processes. That is, in the above-described plate-shaped body arranging step shown in FIG. 3, the plate-shaped body 51 having the pair of sides 52 longer than the circumferential length of the forming portion 61 shown in FIG. Place between 11 and core 12

  As a result, in making the pair of flat plate portions 57 of the plate-like body 51 shown in FIG. 5 into the pair of curved plate portions 58 shown in FIG. 8 by the second pressing step described above, As shown in FIGS. 7 to 8, as shown in FIGS. 7 to 8, as the pair of curved plate portions 58 bends, the forces that press each other in the circumferential direction become the first mold 11. , And from the core 12 and the second mold 13.

  At this time, an intermediate portion 55 between the end edges 54 of the plate-like member 51 is formed by the forming groove 22 of the first mold 11, the outer diameter portion 32 of the core 12 and the forming groove 42 of the second mold 13. Since the pressing is performed and the expansion of the plate thickness is restricted, the both end portions 54 are strongly pressed to each other in the circumferential direction.

  On the other hand, one of the jigs 14 in contact with the one end face 12a of the core metal 12 and the one end face 13b of the second mold 13 shown in FIG. A relief 45 capable of escaping outward in the extending direction of both end edges 54 is provided, and abuts the other end face 12a of the core 12 and the other end face 13b of the second mold 13 at the end face 44a. The other jig 14 is also provided with a relief 45 capable of escaping the both end edges 54 of the plate-like body 51 outward in the extending direction of the both end edges 54. Further, the portions of the pair of end portions 44 of the pair of jigs 14 excluding the relief portions 45 regulate the relief of the middle portion 55 of the plate-like body 51 in the same direction.

  Therefore, the end edges 54 are plastically deformed so as to enter the pair of relief portions 45 disposed on both outer sides in the respective extending directions. That is, although both end edges 54 do not enter the clearance portion 45 at the start of butting as shown in FIG. 9 in the second pressing step, they absorb the extra circumferential length after that. Plastically deform on both sides in the extending direction while entering both of the relief portions 45.

  That is, as shown in FIG. 10 at the time shown in FIG. 7, the both-ends edge 54 extends into one of the relief portions 45 and protrudes outwardly in one extension direction to enter the protrusion 71 as shown in FIG. At the end of the second pressing step shown in FIG. 8, as shown in FIG. 11, the protrusion 71 is extended so as to be further convex to the outside of one extending direction in the one relief 45. . Similarly, while both end edge portions 54 enter the other relief portion 45, they extend so as to be convex to the other outside in the extension direction to form a protrusion 71.

  In other words, the plate-like body 51 plastically deforms in a cylindrical shape, and at that time, the both-ends edge portion 54 plastically deforms and extends from the side 52 to both sides in the extension direction of the both-ends edge portion 54 Form. In the first and second pressing steps, the plate-like body 51 is provided with a pair of projecting portions 71 projecting to both outer sides of one end edge portion 54 and a pair of projecting portions projecting to both outer sides of the other end edge portion 54 It becomes a shape which has 71 and the main-body part 72 among these. That is, in the first and second pressing steps, both end edges 54 of the plate-like member 51 are plastically deformed and extend both end edges 54 more than the main portion 72 which is the other portion of the plate-like member 51. The length of the existing direction becomes large. In addition, the both-ends edge part 54 will mutually penetrate partially at the time of plastic deformation, As a result, it will be in the temporary joining state by which the butt state is maintained. In the above arrangement in which the pair of jigs 14 is brought into contact with the first mold 11, the core metal 12 and the second mold 13, both end edges 54 are butted in the second pressing step at the latest ( This can be done by the states shown in FIG. 6 and FIG.

  As described above, in the first and second pressing steps, the both end edges 54 of the plate-like body 51 are butted in the circumferential direction, and the both end edges 54 protrude outward in the extending direction than the main portion 72 which is the other portion. The first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14 constituting the press molding die are pressed to form the portion 71, and the plate-like body 51 is formed into a cylindrical shape, specifically To be cylindrical. Further, in the first and second pressing steps, the first mold 11, the core metal 12, the second mold 13 and the forming portion 61 of the pair of jigs 14 constituting the press mold are provided at both end edges 54. The projection part 71 is formed in the both-ends edge part 54 by the relief part 45 for becoming convex in these extension directions.

  In the manufacturing method of the present embodiment, next, the welding process is performed to form the joint portion 63 shown in FIG. 12 in which the both end edges 54 in the temporary joint state are welded as described above to permanently maintain the joint state. . In this welding process, both end edges 54 shown in FIG. 11 are continuously welded from the two projecting parts 71 at one end in the extending direction to the two projecting parts 71 at the other end via the intermediate main part 72. It will be. By performing this welding process, the plate-like body 51 becomes a cylindrical body 51A having a main portion 72 and a projecting portion 71 shown in FIG. Here, in the welding process, the end edges 54 are welded by a welding method with high energy density. The welding method with high energy density includes laser welding, plasma welding (type without using a welding rod), electron beam welding and the like. By performing the welding process, both end edges 54 are entirely melted and welded in the vicinity of the butted portions to form a joint portion 63.

  Here, the two projections 71 at one end in the extending direction of the both-ends edge 54 where welding is started and the two projections 71 at the other end in the extending direction of the both-ends 54 at which welding is completed The welding quality may not be stable, for example, 75 may occur. That is, in the main part 72 excluding the two protruding parts 71 at one end and the two protruding parts 71 at the other end, the joint part 63 continuously extends in the axial direction of the cylindrical body 51A, and the cylindrical body 51A Are formed so as to continuously cross in the radial direction, which is a direction connecting the two and the outer peripheral surface, but with regard to the two protrusions 71 at one end and the two protrusions 71 at the other It may not be formed this way.

  For this reason, in the manufacturing method of the present embodiment, after the welding step, a removal step of cutting and removing these projecting portions 71 is performed. The cylindrical body 51A after the removing step is only the main body portion 72 as shown in FIG. 13, and the joint portion 63 continuously extends over the entire length in the axial direction of the cylindrical body 51A, and the cylindrical body 51A and its inner circumferential surface It is formed to continuously cross in a radial direction which is a direction connecting the outer circumferential surface. As a result, the cylindrical body 51A after the removing step becomes a cylindrical tubular body sealed along the entire circumferential length. The cylindrical body 51A is an open pipe which is open at both axial ends.

  In patent document 1, when manufacturing a cylinder by rounding a plate-like body and manufacturing it, tab plates are welded in advance at the four corners of the plate-like body before rounding, and these tab plates are removed after welding. Discloses a technique for preventing welding defects. As described above, welding the tab plate to the plate-like body increases the number of manufacturing steps and increases the manufacturing cost.

  On the other hand, according to the manufacturing method of the present embodiment, a pair of sides 52 longer than the circumferential length of the molding portion 61 of the first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14 is provided. And disposing the plate-like body 51 having the above-described structure between the first mold 11 and the core metal 12 in the press-molding die, and abutting both end edges 54 of the plate-like body 51 in the circumferential direction The plate-shaped body 51 is formed into a cylindrical shape by pressing the press mold so as to form, by plastic deformation, the projecting portion 71 projecting outward in the extending direction of the both-ends edge 54 from the main portion 72 which is the other portion. The first and second pressing steps and the welding step of welding both end edges 54 to form a joint portion 63 are included. As a result, it is not necessary to weld the tab plate to the plate-like body or to form the projecting portion in a pressing step different from the pressing step of making the plate-like body into a tubular shape, thereby reducing the number of manufacturing steps. it can. Therefore, the manufacturing cost of the cylindrical body 51A can be reduced.

  In addition, welding the tab plate to the plate-like body may cause the tab plate to fall off from the plate-like body at the time of transportation etc. Since the projecting portion 71 that protrudes outward in the extending direction of the portion 54 is formed, the possibility of falling off of the component can be reduced.

  Further, in the first and second pressing steps, both end edge portions 54 are provided in the forming portions 61 of the first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14, and the extending direction thereof Since the projecting portions 71 are formed on the both end edge portions 54 by the relief portions 45 which are convex to the outer side, plastic deformation can be induced favorably and easily to form the projecting portions 71. Therefore, the manufacturing cost can be further reduced.

  Moreover, the quality improvement of cylinder 51A can be aimed at by performing the removal process which removes the protrusion part 71 of cylinder 51A after a welding process. That is, even if there are portions where the welding quality is not stable at the beginning and end of the weld where the welding quality of the joint portion 63 is difficult to stabilize, by arranging these in the projection 71, these can be removed and eliminated. Therefore, the quality of the cylindrical body 51A can be improved. In the case where the sliding component is not in direct contact with the projecting portion 71 or in the case where the sealing member is not in direct contact, the removing step may be omitted.

  In addition, since only the protrusion 71 formed by plastic deformation is removed, it is possible to improve the yield and reduce the material cost when manufacturing the cylindrical body 51A.

  The cylindrical body 51A manufactured in the present embodiment is, for example, a component of the cylinder device 111 shown in FIG. The cylinder device 111 is used, for example, as a suspension device for an automobile or a railway vehicle. The cylinder device 111 has a double cylindrical structure including a cylindrical cylinder 112 and an outer cylinder 113 having a diameter larger than that of the cylinder 112 and provided on the outer peripheral side of the cylinder 112. The cylinder 112 has a cylindrical shape with both axial ends open, and the outer cylinder 113 has a bottomed cylindrical shape with one end closed in the axial direction and the other open. The outer cylinder 113 forms an annular reservoir chamber 114 with the cylinder 112.

  Inside the cylinder 112, a piston 117 is slidably provided. The piston 117 defines an upper chamber 118 and a lower chamber 119 in the cylinder 112. A hydraulic fluid as a working fluid is sealed in the upper chamber 118 and the lower chamber 119, and a hydraulic fluid and gas as a working fluid are sealed in the reservoir chamber 114. That is, the cylinder device 111 is a double cylinder type hydraulic shock absorber.

  A piston rod 122 is connected to the piston 117. One end in the axial direction of the piston rod 122 is inserted into the cylinder 112 and attached to the piston 117, and the other end in the axial direction protrudes from the cylinder 112 to the outside. The piston 117 moves integrally with the piston rod 122 and slides in the cylinder 112.

  In the piston 117, although not shown, when the piston rod 122 moves to the extension side to increase the amount of protrusion from the cylinder 112 and the piston 117 moves to the upper chamber 118 side and the pressure in the upper chamber 118 rises, the upper chamber 118 An extension-side damping force generating mechanism is provided which generates a damping force by restricting the flow of hydraulic fluid from the lower chamber 119 to the lower chamber 119. In the piston 117, when the piston rod 122 moves to the compression side reducing the amount of protrusion from the cylinder 112 and the piston 117 moves to the lower chamber 119 side and the pressure in the lower chamber 119 rises, the lower chamber 119 to the upper chamber A contraction-side damping force generating mechanism is provided which flows the hydraulic fluid to the valve 118 and restricts its flow to generate a damping force.

  The outer cylinder 113 has a cylindrical rod guide 125 for guiding the piston rod 122 at the end where the piston rod 122 protrudes, and a seal member 126 which is an oil seal for sealing the working fluid in an annular shape. And are provided. The rod guide 125 and the seal member 126 are provided at the seal member 126 on the protruding side of the piston rod 122 in the axial direction of the outer cylinder 113 rather than the rod guide 125, that is, on the outer side. The piston rod 122 passes through the inner peripheral side of the rod guide 125 and the inner peripheral side of the seal member 126. In the outer cylinder 113, a base valve 128 is provided on the side opposite to the rod guide 125 and the seal member 126.

  The outer cylinder 113 has a bottomed cylindrical shape as described above, and is joined to the cylindrical body member 130 and the end of the body member 130 opposite to the projecting side of the piston rod 122 to form the body member 130. And a bottom cover member 131 closing the end of the cover. The body member 130 is provided with a caulking portion 133 which protrudes radially inward of the cylindrical body portion 134 from the position of the opening 132 on the projecting side of the piston rod 122.

  The caulking portion 133 has a cylindrical shape that is continuous with the body portion 134 until the base valve 128, the cylinder 112, the piston 117, the piston rod 122, the rod guide 125 and the seal member 126 are disposed in the outer cylinder 113. This portion is bent radially inward by caulking and plastically deformed to form a caulking portion 133.

  The cylinder 112 is formed of a cylindrical body, and one end side in the axial direction is supported in a fitted state by the base valve 128 placed inside the bottom cover member 131 of the outer cylinder 113. The cylinder 112 is supported in a fitted state by a rod guide 125 whose other end in the axial direction is fitted to the opening 132 side of the outer cylinder 113.

  The rod guide 125 has a substantially stepped annular shape, and a large diameter outer peripheral portion 144 is formed opposite to the bottom lid member 131, and a small diameter outer periphery smaller in diameter than the large diameter outer peripheral portion 144 on the bottom lid member 131 side. The part 145 is formed. The large diameter outer peripheral portion 144 of the rod guide 125 is fitted to the inner peripheral portion of the trunk body portion 134 of the outer cylinder 113, and the small diameter outer peripheral portion 145 is fitted to the inner peripheral portion of the cylinder 112.

  The outer peripheral portion of the seal member 126 contacts the inner peripheral portion of the barrel main body portion 134 of the outer cylinder 113 and the rod guide 125 to seal the inner peripheral portion of the outer cylinder 113. Further, the seal member 126 has its inner peripheral portion in contact with the outer peripheral portion of the piston rod 122 to seal the outer peripheral portion of the piston rod 122. Thus, the seal member 126 closes the gap between the outer cylinder 113 and the piston rod 122 to restrict the hydraulic fluid in the cylinder 112 and the high pressure gas and hydraulic fluid in the reservoir chamber 114 from leaking out. The seal member 126 is nipped by the crimped portion 133 of the outer cylinder 113 and the rod guide 125. The seal member 126 is an integrally molded article in which a metal ring member 162 is embedded in a rubber elastic member 161.

  And the component before forming the crimping part 133 of the above-mentioned trunk | drum 130 is manufactured with the manufacturing method of the cylinder of this embodiment. That is, the cylindrical body 51A is a component before forming the crimped portion 133 of the body member 130. As a result, the cylindrical body 51A is used for the outer cylinder 113 which is a non-sliding portion which is not in sliding contact with the piston 117 of the cylinder device 111, and constitutes a part of the body member 130.

  The cylindrical body 51A manufactured in the present embodiment is, for example, a component of the cylinder device 211 shown in FIG. The cylinder device 211 is disposed on the central axis of a cylindrical cylinder 212 in which liquid or gas as a fluid is sealed, and on the central axis of the cylinder 212, and from the opening at one end of the axial direction of the cylinder 212 to the outside. The piston rod 213 has a protruding piston rod 213 and a cylindrical dust cover 214 fixed to the outer projecting portion of the piston rod 213 and covering the piston rod 213 and the opening side of the cylinder 212 (not shown).

  A piston 215 is attached to one end of the piston rod 213 disposed in the cylinder 212. That is, one end of the piston rod 213 is attached to the piston 215, and the other end protrudes from the cylinder 212. The piston 215 is slidably provided in the cylinder 212 and divides the inside of the cylinder 212 into two chambers. The piston 215 slides inside the cylinder 212 integrally with the movement of the piston rod 213 to change the volume of the two chambers, and generates a damping force by the flow resistance of the fluid generated at that time. Specifically, this cylinder device 211 is a shock absorber that constitutes a suspension system of the vehicle, and when the vehicle body side and the wheel side of the vehicle vibrate relative to each other, the piston rod 213 has a protruding length with respect to the cylinder 212 As a result, the piston 215 fixed to the piston rod 213 slides inside the cylinder 212 to change the volume of the two chambers, and the flow resistance of the fluid generated at that time causes the above-mentioned vibration to the above-mentioned vibration. Generate a damping force.

  A cylindrical mounting eye 221 is fixed by welding to the end of the piston rod 213 on the projecting tip end side, and the cylindrical mounting eye 223 is also fixed to the end of the cylinder 212 opposite to the projecting side of the piston rod 213. Is fixed by welding. A rubber bush 222 is provided inside the mounting eye 221, and a rubber bush 224 is provided inside the mounting eye 223.

  For example, the cylinder device 211 is attached to the vehicle body side via a mounting member (not shown) through which the piston rod 213 is inserted into the rubber bush 222 in the mounting eye 221 fixed thereto, and the cylinder 212 is Is mounted on the wheel side via a mounting member (not shown) inserted through a rubber bush 224 in a mounting eye 223 fixed to the wheel. Thereby, the cylinder device 211 attenuates the stroke of the wheel with respect to the vehicle body. Note that, contrary to the above, the cylinder 212 may be attached to the vehicle body side, and the piston rod 213 may be attached to the wheel side. The mounting eyes 221 and 223 are provided on both the piston rod 213 and the cylinder 212, but may be provided on only one of them.

  The dust cover 214 has an effective disk-shaped lid member 231 fixed to the piston rod 213, and a cylindrical cover main body 232 fitted on the outer periphery of the lid member 231 and fixed by welding or the like. There is.

  And the cover main body 232 of the dust cover 214 is manufactured by the manufacturing method of the cylinder of this embodiment. That is, the cylindrical body 51A is the cover main body 232. As a result, the cylindrical body 51A is used for the dust cover 214 which is a non-sliding portion which is not in sliding contact with the piston 215 of the cylinder device 211, and constitutes a part of the cover main body 232.

  In the embodiment described above, a cylindrical body is formed by bending a plate-like body having a pair of sides in a cylindrical shape such that the pair of sides is in the circumferential direction and welding the end edges connecting the pair of sides into a cylinder A method of manufacturing a plate-shaped body according to claim 1, wherein the plate-shaped body having the pair of sides longer than the circumferential length of the forming portion for bending the plate-shaped body of the press forming die into a cylindrical shape is disposed in the press forming die. And the press-forming step, wherein the both end edges of the plate-like body are circumferentially butted so as to form a protruding portion at the both end edges which protrudes outward in the extending direction of the both end edges more than other portions. The press process which presses a type | mold and makes the said plate-like body cylindrical, The welding process which welds the said both-ends edge part and it is set as a junction part. As a result, it is not necessary to weld the tab plate to the plate-like body or to form the projecting portion in a pressing step different from the pressing step of making the plate-like body into a tubular shape, thereby reducing the number of manufacturing steps. it can. Therefore, the manufacturing cost of a cylinder can be reduced.

  In the pressing step, the protruding portions are provided on the both end edges by the relief portion provided in the forming portion of the press mold so that the both end edges become convex outward in the extending direction of the both end edges. Because it is pressed to form, plastic deformation can be successfully and easily induced to form protrusions. Therefore, the manufacturing cost can be further reduced.

  Since the removal step of removing the protruding portion is included after the welding step, even if there is a place where the welding quality is not stable in the protruding portion, these can be removed and eliminated, so the quality of the cylinder can be improved. Can be

11 1st mold (press mold)
12 core metal (press molding type)
13 Second mold (press molding)
14 Jig (Press Mold)
45 relief part 51 plate-like body 51A cylinder 52 side 54 both-ends edge part 61 formed part 63 joint part 71 projecting part 72 main part (other part)

Claims (3)

A method of manufacturing a cylindrical body, comprising: bending a plate-like body having a pair of sides in a cylindrical shape such that the pair of sides is in the circumferential direction, welding both end edges connecting the pair of sides to form a cylinder ,
A plate-shaped body arranging step of arranging the plate-shaped body having the pair of sides longer than the circumferential length of the forming portion for bending the plate-shaped body of the press-forming mold into a cylindrical shape in the press-forming mold;
The press mold is pressed so that the both end edges of the plate member are circumferentially butted to form a protruding portion at the both end edges that protrudes outward in the extending direction of the both end portions more than other portions. Pressing the plate-like body into a cylindrical shape;
A welding step of welding the end edges to form a joint;
A method of manufacturing a cylindrical body comprising:   In the pressing step, the protruding portions are provided on the both end edges by the relief portion provided in the forming portion of the press mold so that the both end edges become convex outward in the extending direction of the both end edges. A method of manufacturing a cylinder according to claim 1, characterized by pressing to form.   The manufacturing method of the cylinder according to claim 1 or 2 including the removal process of removing said projection after said welding process.

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