JP2017177110A - Cylindrical body manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylindrical body manufacturing method that is capable of reducing manufacturing cost.SOLUTION: This cylindrical body manufacturing method includes: a plate-like body arrangement step of arranging a plate-like body 51 having a pair of sides 52 longer than the peripheral length of a molding unit that bends the press-molded type plate-like body in a cylindrical shape; a press step of forming the plate-like body 51 cylindrical by pressing a press mold so as to form a projected part 71 that projects more outside in the extending direction of both end edges 54 than the other parts of both end edges 54 by butting together both end edges 54 of the plate-like body 51; and a welding step of welding both end edges 54 for form a joined part.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a method for manufacturing a cylindrical body.

  There is a technique in which a tab plate is welded in advance to a plate-like body before being rounded when the plate-like body is welded after being rounded (see, for example, Patent Document 1).

JP 2006-281253 A

  If the tab plate is welded to the plate-like body, the manufacturing cost increases.

  Therefore, an object of this invention is to provide the manufacturing method of the cylinder which can reduce manufacturing cost.

  In order to achieve the above object, according to the present invention, a plate-like body having a pair of sides longer than the length in the circumferential direction of a molding portion for bending the plate-like body of a press mold into a cylindrical shape is disposed in the press mold. The plate-like body arranging step and the both end edges of the plate-like body are butted in the circumferential direction so as to form a protruding portion that protrudes outward in the extending direction of the both end edges from the other ends. A pressing step of pressing the press mold to form the plate-like body into a cylindrical shape, and a welding step of welding the both end edges to form a joint.

  According to the present invention, the manufacturing cost of a 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 used with the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a sectional side view showing the 1st metallic mold, core metal, the 2nd metallic mold, and both jigs used with the manufacturing method of the cylinder concerning one embodiment of the present invention. It is a front view after the plate-shaped object 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 which concerns on one Embodiment of this invention. It is a front view before the 2nd press process of the manufacturing method of the cylinder which concerns on one Embodiment of this invention. It is a front view in the 2nd press process of the manufacturing method of the cylinder which concerns on one Embodiment of this invention. FIG. 7 is a front sectional view of the state after FIG. 6 during the second pressing step of the method for manufacturing a cylindrical body according to the 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 escape portion at the time shown in FIG. 6. It is the elements on larger scale which show the relationship between the plate-shaped body and escape part at the time shown in FIG. It is a partial enlarged plan view which shows the relationship between the plate-shaped body and escape part at the time shown in FIG. 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 concerning one embodiment of the present invention. It is a front sectional view showing an example of a cylinder device using a cylinder manufactured by a cylinder manufacturing method according to an embodiment of the present invention. It is a front sectional view showing another example of a cylinder device using a cylinder manufactured by a cylinder manufacturing method according to an embodiment of the present invention.

  A method for manufacturing a cylinder according to an embodiment of the present invention will be described below with reference to the drawings.

  The cylindrical body manufacturing method according to the present embodiment is a so-called single pipe tube manufacturing method, and includes a first mold 11, a core metal 12, a second mold 13 and a pair of jigs 14 (FIG. 1) 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 protruding from the mating surface 11 a that can contact the second mold 13, and a forming groove 22 recessed from the protrusion tip of the protrusion 21. The mating surface 11 a, the protrusion 21, and the molding groove 22 extend linearly along the length direction of the first mold 11. The ridge portion 21 has a pair of inclined surfaces 21a whose intervals are narrower toward the protruding tip side. The forming groove 22 has a semi-cylindrical groove surface 22a, and the width and depth are constant regardless of the position in the length direction. Each end face 11b on both sides in the length direction of the first mold 11 is a flat surface that extends so as to be orthogonal to the length direction.

  The cored bar 12 has a columnar shape, and the outer diameter portion 32 on the outer side in the radial direction has a constant outer diameter, and the outer peripheral surface 32a is cylindrical. In the core metal 12, the radius of the outer peripheral surface 32 a of the outer diameter portion 32 is smaller than the radius of the groove surface 22 a of the molding groove 22 of the first mold 11. The metal core 12 is a flat surface in which both end surfaces 12a on both sides in the length direction, that is, both axial sides, spread so as to be orthogonal to the length direction. The length of the cored bar 12 is equal to the length of the first mold 11.

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

  The jig 14 has a short columnar shape having a cylindrical outer peripheral surface 14 a, and as shown in FIG. 2, the end surface 44 a of the end 44 on one side in the axial direction is in relation to the central axis of the jig 14. It is a flat surface that spreads out orthogonally. In the jig 14, a relief portion 45 is formed in the end portion 44, which is recessed in the axial direction of the jig 14 from the end surface 44 a and recessed inward in the radial direction of the jig 14 from the outer peripheral surface 14 a. The relief portions 45 are parallel to each other and extend from the both ends of the bottom surface 45a of the jig 14 in the radial direction to the outer peripheral surface 14a in the radial direction. 1 and a back wall surface 45c parallel to the end surface 44a that connects the end surface 44a opposite to the end surface 44a of the bottom surface 45a and both side wall surfaces 45b.

  The outer diameter of the jig 14, that is, the diameter of the outer peripheral surface 14 a is larger than the outer diameter of the core metal 12, that is, the diameter of the outer peripheral surface 32 a, and the radius of the outer peripheral surface 14 a is the molding groove of the first mold 11. 22 is larger than the radius of the groove surface 22 a and the radius of the groove surface 42 a of the molding groove 42 of the second mold 13. A bottom surface 45 a of the escape portion 45 shown in FIG. 2 is curved in a cylindrical shape whose distance from the center of the jig 14 is the same as the radius of the cored bar 12. That is, the outer peripheral surface 32a of the cored bar 12 and the bottom surface 45a of the relief part 45 are arranged on the same cylindrical surface with the jig 14 and the cored bar 12 aligned with the central axis.

  In the press device, the cored bar 12 is arranged in parallel with the molding groove 22 in the longitudinal direction, vertically above the molding groove 22 of the first mold 11 arranged horizontally. One jig 14 is brought into contact with one end surface 12a in the axial direction of the cored bar 12 at the end surface 44a. At this time, this one jig | tool 14 will be in the state which arrange | positioned the escape part 45 in the upper end part, and made the metal core 12 and the center axis line correspond. In this state, the outer peripheral surface 32a of the core metal 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 12a in the axial direction of the cored bar 12 at the end face 44a. At this time, the other jig 14 is in a state in which the relief portion 45 is disposed at the upper end portion thereof and the core metal 12 and the central axis line are made coincident with each other. In this state, the outer peripheral surface 32a of the core metal 12 and the bottom surface 45a of the escape portion 45 of the other jig 14 are continuous. The cored bar 12 and the pair of jigs 14 may be integrally formed so as to be in the above state. In addition, the pair of jigs 14 may be in the above-described state with respect to the cored bar 12 in a second pressing step described later.

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

  As shown in FIGS. 3 to 4, the manufacturing method of the present embodiment is configured so that the core metal 12 and the pair of jigs 14 (only one is shown in FIGS. 3 and 4) are integrated vertically downward after the plate-like body arranging step. A first pressing step of lowering the core metal 12 into the molding groove 22 while keeping the position in the longitudinal direction aligned with the first mold 11 and pressing the plate-like body 51 to plastically deform it. Contains. In the first pressing step, a plastic deformation portion is formed in the middle portion of the plate-like body 51 by the groove surface 22a of the molding groove 22 of the first die 11 and the outer peripheral surface 32a of the outer diameter portion 32 of the core metal 12. 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 plate thickness direction is bent in the same shape as the groove surface 22a, and the surface on the other side in the plate thickness direction is bent in the same shape as the outer peripheral surface 32a. 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 are not bent and extend from both ends in the circumferential direction of the semi-cylindrical portion 56 in a direction away from the first mold 11. Part 57. That is, the first metal mold 11 and the core metal 12 bend the plate-like body 51 into a U shape. In this first pressing step, one jig 14 shown in FIG. 2 comes into contact with one end face 11b of the first mold 11 at its end face 44a, and the other jig 14 comes into contact with the first mold 11 at its end face 44a. In contact with the other end face 11b.

  In the press device, as shown in FIG. 5, the second mold 13 is parallel to the molding groove 42 facing the cored bar 12 and aligned vertically with the cored bar 12 in the longitudinal direction. Arrange as you make. And the manufacturing method of the cylinder of this embodiment lowers the 2nd metal mold | die 13 which is a press molding die to the perpendicular downward direction, The state with which the position of the length direction with the core metal 12 was match | combined A second pressing step is included in which the metal core 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 are guided to the groove surface 42 a side by the pair of inclined surfaces 42 b of the molding groove 42 of the second mold 13. Next, as shown in the order of FIGS. 6 to 7 and FIGS. 7 to 8, the pair of flat plate portions 57 of the plate-like body 51 are arranged on the outer periphery of the groove surface 42 a of the forming groove 42 and the outer diameter portion 32 of the cored bar 12. The pair of curved plate portions 58 are plastically deformed by the surface 32a as shown in FIG. The pair of curved plate portions 58 has a cylindrical shape in which the surface on one side in the plate thickness direction is bent in the same shape as the groove surface 42a, and the surface on the other side in the plate thickness direction is bent in the same shape as the outer peripheral surface 32a. Eggplant.

  Thus, by the first pressing step and the second pressing step, the plate-like body 51 is bent into a shape having the semi-cylindrical portion 56 and the pair of curved plate portions 58 to be O-shaped, that is, 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. The surface comes into contact with the inclined surface 21a. Further, in the second pressing step, one jig 14 shown in FIG. 2 comes into contact with one end face 13b of the second mold 13 at the end face 44a, and the other jig 14 comes into contact with the second mold at the end face 44a. 13 is in contact with the other end face 13b.

  All of the first mold 11, the core metal 12, the second mold 13 and the pair of jigs 14 constituting the press mold include a molding groove 22, an outer diameter portion 32, a molding groove 42 and a pair of end portions 44. Then, the plate-like body 51 is pressed to form a molded portion 61 that is bent into a cylindrical shape, specifically, a cylindrical shape.

  And in the manufacturing method of this embodiment, what has a pair of edge | side 52 longer than the circumferential direction length of the shaping | molding part 61 in the state which pressed this as the plate-shaped object 51, and the above-mentioned 1st press process and 1st Press molding in two pressing steps. That is, in the plate-like body arranging step shown in FIG. 3, the plate-like body 51 having a pair of sides 52 longer than the circumferential length of the molding portion 61 shown in FIG. 11 and the metal core 12.

  As a result, when the pair of flat plate portions 57 of the plate-like body 51 shown in FIG. 5 is replaced with the pair of curved plate portions 58 shown in FIG. As shown in FIG. 7 to FIG. 8, the first mold 11 further presses each other in the circumferential direction as the pair of curved plate portions 58 are curved after contacting each other and abutting in the circumferential direction. , Added from the core 12 and the second mold 13.

  At this time, the intermediate part 55 between the edge parts 54 of the plate-like body 51 is formed by the molding groove 22 of the first mold 11, the outer diameter part 32 of the core metal 12, and the molding groove 42 of the second mold 13. Since the increase in the plate thickness is restricted by pressing, both edge portions 54 are strongly pressed against each other in the circumferential direction.

  On the other hand, both edge portions 54 of the plate-like body 51 are provided on one jig 14 that contacts the one end surface 12a of the core metal 12 and the one end surface 13b of the second mold 13 shown in FIG. An escape portion 45 that can escape to the outside in the extending direction of the both end edge portions 54 is provided, and contacts the other end surface 12a of the core metal 12 and the other end surface 13b of the second die 13 at the end surface 44a. The other jig 14 is also provided with an escape portion 45 that allows the both end edge portions 54 of the plate-like body 51 to escape outward in the extending direction of the both end edge portions 54. Further, the portions excluding the escape portions 45 of the pair of end portions 44 of the pair of jigs 14 regulate the escape of the intermediate portion 55 of the plate-like body 51 in the same direction.

  Therefore, the both end edge portions 54 are plastically deformed so as to enter the pair of relief portions 45 arranged on both outer sides in the respective extending directions. That is, both edge portions 54 do not enter the escape portion 45 as shown in FIG. 9 at the time of starting the butting in FIG. 6 in the second pressing step, but then absorb the extra circumferential length. The plastic deformation occurs on both sides of the extending direction while entering both the escape portions 45.

  That is, as shown in FIG. 10, both end edges 54 extend into one of the relief portions 45 so as to protrude outward in one of the extending directions as shown in FIG. When the second pressing step shown in FIG. 8 is completed, the protruding portion 71 is extended so as to further protrude outwardly in one extending direction 45 in one escape portion 45 as shown in FIG. . Similarly, the both edge portions 54 extend into the other escape direction 45 so as to protrude outwardly in the extending direction, thereby forming the protruding portion 71.

  In other words, the plate-like body 51 is plastically deformed into a cylindrical shape, and at that time, both end edges 54 are plastically deformed and extend from the side 52 to both outer sides in the extending direction of the both end edges 54 to form the protrusions 71. Form. By the first and second pressing processes, the plate-like body 51 is formed of a pair of projecting portions 71 projecting on both outer sides of one end edge portion 54 and a pair of projecting portions projecting on both outer sides of the other end edge portion 54 71 and a main body 72 between them. That is, by the first and second pressing processes, both end edge portions 54 of the plate-like body 51 are plastically deformed so that both end edge portions 54 extend beyond the main portion 72 that is the other portion of the plate-like body 51. The length in the current direction becomes large. Note that both end edges 54 partially enter each other during plastic deformation, and as a result, a temporary joined state is maintained in which the butted state is maintained. In addition, about said arrangement | positioning which makes a pair of jig | tool 14 contact | abut to the 1st metal mold | die 11, the core metal 12, and the 2nd metal mold | die 23, the both-ends edge part 54 is abutted by the 2nd press process at the latest ( The state shown in FIG. 6 and FIG.

  As described above, in the first and second pressing processes, both end edges 54 of the plate-like body 51 are butted in the circumferential direction, and both end edges 54 protrude outward in the extending direction from the main part 72 which is the other part. The first mold 11, the core metal 12, the second mold 13, and the pair of jigs 14 constituting the press mold are pressed so as to form the portion 71, and the plate-like body 51 is formed into a cylindrical shape, specifically To make it cylindrical. In the first and second pressing processes, both edge portions 54 are provided on the first die 11, the core metal 12, the second die 13, and the molding part 61 of the pair of jigs 14 constituting the press mold. Projecting portions 71 are formed at both end edge portions 54 by the relief portions 45 for projecting in the extending direction.

  In the manufacturing method of the present embodiment, next, a welding process is performed to weld the both end edges 54 in the temporarily joined state as described above to the joined portion 63 shown in FIG. 12 in which the joined state is permanently maintained. . In this welding process, both edge portions 54 shown in FIG. 11 are continuously welded from both projecting portions 71 at one end in the extending direction to both projecting portions 71 at the other end through the intermediate main body portion 72. It will be. By performing this welding process, the plate-like body 51 becomes a cylindrical body 51A having a main body 72 and a protrusion 71 shown in FIG. Here, in a welding process, the both-ends edge part 54 is welded with the welding method with high energy density. The welding method with high energy density includes laser welding, plasma welding (a type that does not use a welding rod), electron beam welding, and the like. By performing the welding process, both end edges 54 are melted and welded in the vicinity of the abutted portions to form the joints 63.

  Here, both protrusions 71 at one end in the extending direction of both end edge portions 54 where welding is started and both protrusions 71 at the other end in the extending direction of both end edge portions 54 where welding ends are melted down. There is a possibility that the welding quality is not stable, for example, 75 occurs. That is, the joint 63 extends continuously in the axial direction of the cylinder 51A in the main body 72 excluding the two protrusions 71 at one end and the two protrusions 71 at the other end, and the cylinder 51A is connected to the inner peripheral surface thereof. Is formed so as to continuously traverse in the radial direction, which is a direction connecting the outer peripheral surface and the both projecting portions 71 at one end and both projecting portions 71 at the other end, a melt-off 75 occurs. It may not be formed in this way.

  For this reason, in the manufacturing method of this embodiment, the removal process which cuts and removes these protrusion parts 71 is performed after a welding process. As shown in FIG. 13, the cylindrical body 51A after the removal step includes only the main body 72, and the joint portion 63 continuously extends over the entire length in the axial direction of the cylindrical body 51A. It is formed so as to continuously traverse in the radial direction, which is the direction connecting the outer peripheral surface. Thereby, the cylindrical body 51A after the removal step becomes a cylindrical tubular body that is hermetically sealed over the entire circumference. The cylinder body 51A is an open pipe that opens on both sides in the axial direction.

  In Patent Document 1, when a cylindrical body is manufactured by rounding a plate-like body, tab plates are welded in advance to the four corners of the plate-like body before rounding, and these tab plates are removed after welding. Thus, a technique for preventing welding defects is disclosed. Thus, welding the tab plate to the plate-like body increases the number of manufacturing steps and increases the manufacturing cost.

  On the other hand, in the manufacturing method of the present embodiment, the pair of sides 52 longer than the circumferential length of the first mold 11, the core metal 12, the second mold 13, and the molding portion 61 of the pair of jigs 14. A plate-like body arrangement step of arranging a plate-like body 51 having a thickness between the first die 11 and the core metal 12 in the press mold, and both end edges 54 of the plate-like body 51 are butted in the circumferential direction. The plate-shaped body 51 is formed into a cylindrical shape by pressing the press mold so that the protruding portion 71 that protrudes outward in the extending direction of the edge portions 54 is formed on the edge portion 54 by the plastic deformation. The first and second pressing steps and the welding step of welding the both edge portions 54 to form the joint portion 63 are included. This eliminates the need to weld the tab plate to the plate-like body, or to form the protrusions in a pressing process different from the pressing process for making the plate-like body cylindrical, thereby reducing the manufacturing process. it can. Therefore, the manufacturing cost of the cylinder 51A can be reduced.

  In addition, if the tab plate is welded to the plate-like body, the tab plate may drop off from the plate-like body during conveyance, etc., but the both end edges 54 are located at both end edges rather than the main portion 72 in the first and second pressing processes. Since the protruding portion 71 protruding outward in the extending direction of the portion 54 is formed, the possibility of component dropout can be suppressed low.

  Further, in the first and second pressing processes, the first metal mold 11, the core metal 12, the second metal mold 13, and the molding part 61 of the pair of jigs 14 are provided so that both end edges 54 extend in the extending direction. Since the relief portion 45 for projecting outward is pressed so as to form the projections 71 at both end edges 54, the projections 71 can be formed well and easily by inducing plastic deformation. Therefore, the manufacturing cost can be further reduced.

  Moreover, the quality improvement of 51 A of cylinders can be aimed at by performing the removal process which removes the protrusion part 71 of 51 A of cylinders after a welding process. That is, even if there is a portion where the welding quality is not stable at the start and end of welding where the welding quality of the joint portion 63 is difficult to stabilize, by disposing these on the protruding portion 71, these can be removed and lost. Therefore, the quality of the cylinder 51A can be improved. Note that the removal step may be omitted when the sliding component does not directly contact the protrusion 71 or when the seal member does not directly contact.

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

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

  A piston 117 is slidably provided inside the cylinder 112. The piston 117 defines an upper chamber 118 and a lower chamber 119 in the cylinder 112. The upper chamber 118 and the lower chamber 119 are filled with working fluid as working fluid, and the reservoir chamber 114 is filled with working fluid and gas as working fluid. 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 of the piston rod 122 in the axial direction 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.

  Although not shown in the figure, 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, the pressure in the upper chamber 118 rises. An extension side damping force generation mechanism is provided that generates a damping force by restricting the flow of the working fluid from the lower chamber 119 to the lower chamber 119. Further, when the piston rod 122 moves to the contraction side to reduce 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 piston 117 moves from the lower chamber 119 to the upper chamber. A contraction force generation mechanism on the contraction side that generates a damping force by restricting the flow of the hydraulic fluid while supplying the hydraulic fluid to 118 is provided.

  The outer cylinder 113 includes a rod guide 125 that guides the piston rod 122 in a cylindrical shape at an end on the side from which the piston rod 122 protrudes, and a seal member 126 that is an oil seal that forms an annular shape and seals the working fluid. And are provided. As for the rod guide 125 and the seal member 126, the seal member 126 is provided on the protruding side of the piston rod 122 in the axial direction of the outer cylinder 113, that is, outside the rod guide 125. 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. A base valve 128 is provided in the outer cylinder 113 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 protruding side of the piston rod 122 to form the body member 130. And a bottom cover member 131 for closing the end portion of the base plate. The body member 130 is provided with a caulking portion 133 that protrudes radially inward from the cylindrical body main body portion 134 from the position of the opening portion 132 on the protruding side of the piston rod 122.

  The caulking portion 133 has a cylindrical shape that continues to the body main 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 part is bent radially inward by caulking and plastically deformed to form a caulking part 133.

  The cylinder 112 is formed of a cylindrical body, and one end side in the axial direction is supported in a fitted state on a base valve 128 placed inside the bottom cover member 131 of the outer cylinder 113. Further, the cylinder 112 is supported in a fitted state by a rod guide 125 in which the other end side 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. A large-diameter outer peripheral portion 144 is formed opposite to the bottom lid member 131, and a small-diameter outer periphery having a smaller diameter than the large-diameter outer peripheral portion 144 is formed on the bottom lid member 131 side. A portion 145 is formed. The rod guide 125 has a large-diameter outer peripheral portion 144 fitted into the inner peripheral portion of the trunk main body portion 134 of the outer cylinder 113, and a small-diameter outer peripheral portion 145 fitted into the inner peripheral portion of the cylinder 112.

  The seal member 126 seals the inner periphery of the outer cylinder 113 by contacting the inner periphery of the body main body 134 of the outer cylinder 113 and the rod guide 125 at the outer periphery thereof. Further, the seal member 126 seals the outer periphery of the piston rod 122 with the inner periphery thereof contacting the outer periphery of the piston rod 122. Accordingly, the seal member 126 closes the space between the outer cylinder 113 and the piston rod 122 and restricts the hydraulic fluid in the cylinder 112 and the high-pressure gas and hydraulic fluid in the reservoir chamber 114 from leaking to the outside. The seal member 126 is sandwiched between the caulking portion 133 of the outer cylinder 113 and the rod guide 125. The seal member 126 is an integrally molded product in which a metal annular member 162 is embedded in a rubber elastic member 161.

  And the parts before forming the crimp part 133 of the above-mentioned trunk | drum member 130 are manufactured with the manufacturing method of the cylinder of this embodiment. That is, the cylindrical body 51 </ b> A is a part before forming the caulking 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 where the piston 117 of the cylinder device 111 does not slide and constitutes a part of the body member 130.

  Further, the cylindrical body 51A manufactured in the present embodiment is a component of the cylinder device 211 shown in FIG. 15, for example. The cylinder device 211 includes a cylindrical cylinder 212 in which a liquid or gas as a fluid is sealed, and the cylinder device 211 is disposed on the central axis of the cylinder 212 and from an opening (not shown) at one end in the axial direction of the cylinder 212 to the outside. It has a projecting piston rod 213 and a covered cylindrical dust cover 214 which is fixed to an external projecting portion of the piston rod 213 and covers 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 projects from the cylinder 212. The piston 215 is slidably provided on 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 fluid flow resistance generated at that time. Specifically, the cylinder device 211 is a shock absorber that constitutes a suspension device of the vehicle. When the vehicle body side and the wheel side of the vehicle relatively vibrate, the piston rod 213 has a protrusion 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. To generate damping force.

  A cylindrical mounting eye 221 is fixed to the end of the piston rod 213 on the protruding tip side by welding, and a cylindrical mounting eye 223 is also fixed to the end of the cylinder 212 opposite to the protruding 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.

  In the cylinder device 211, for example, the piston rod 213 is attached to the vehicle body side via a mounting member (not shown) inserted into the rubber bush 222 in the mounting eye 221 fixed to the piston rod 213. It is attached to the wheel side through 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. 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 includes an effective disk-shaped lid member 231 fixed to the piston rod 213, and a cylindrical cover body 232 that is fitted to the outer peripheral portion of the lid member 231 and fixed by welding or the like. Yes.

  And the cover main body 232 of the dust cover 214 is manufactured with the manufacturing method of the cylinder of this embodiment. That is, the cylindrical body 51 </ b> A becomes the cover main body 232. As a result, the cylinder 51 </ b> A is used for a dust cover 214 that is a non-sliding portion to which the piston 215 of the cylinder device 211 does not slide, and constitutes a part of the cover body 232.

  In the above-described embodiment, a plate body having a pair of sides is bent into a cylinder shape so that the pair of sides are in the circumferential direction, and both end edges connecting the pair of sides are welded to form a cylinder body The plate-like body in which the plate-like body having the pair of sides longer than the circumferential length of the molding portion for bending the plate-like body of the press molding die into a cylindrical shape is disposed in the press molding die. The press molding so as to form a projecting portion that protrudes outward in the extending direction of the both end edge portions from the other end edge portions by abutting the both end edge portions of the plate-like body in the circumferential direction. A pressing step of pressing the mold to form the plate-like body into a cylindrical shape, and a welding step of welding the both end edges to form a joint. This eliminates the need to weld the tab plate to the plate-like body, or to form the protrusions in a pressing process different from the pressing process for making the plate-like body cylindrical, thereby reducing the manufacturing process. it can. Therefore, the manufacturing cost of a cylinder can be reduced.

  In the pressing step, the protruding portions are provided at the both edge portions by a relief portion provided in the molding portion of the press mold so that the both edge portions protrude outward in the extending direction of the both edge portions. Since it presses to form, a plastic deformation can be induced | guided | derived favorably and easily, and a protrusion part can be formed. Therefore, the manufacturing cost can be further reduced.

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

11 First mold (press mold)
12 Core metal (press mold)
13 Second mold (press mold)
14 Jig (press mold)
45 Escape part 51 Plate-like body 51A Cylindrical body 52 Side 54 Both-ends edge part 61 Molding part 63 Joint part 71 Projection part 72 Main part (other part)

Claims (3)

A method of manufacturing a cylindrical body having a plate-like body having a pair of sides bent into a cylindrical shape so that the pair of sides is in the circumferential direction, and welding both end edges connecting the pair of sides. ,
A plate-like body arranging step of placing the plate-like body having the pair of sides longer than the length in the circumferential direction of the molding portion for bending the plate-like body of the press-molding die into the cylindrical shape;
The press mold is pressed so that the both end edges of the plate-like body are butted in the circumferential direction to form a protruding portion that protrudes outward in the extending direction of the both end edges from the other ends. Pressing the plate-like body into a cylindrical shape,
A welding step of welding the both end edges to form a joint;
The manufacturing method of the cylinder characterized by including.   In the pressing step, the protruding portions are provided at the both edge portions by a relief portion provided in the molding portion of the press mold so that the both edge portions protrude outward in the extending direction of the both edge portions. The method for manufacturing a cylinder according to claim 1, wherein pressing is performed to form the cylinder.   The method for manufacturing a cylindrical body according to claim 1, further comprising a removing step of removing the protruding portion after the welding step.

Images