Joined body, method of manufacturing joined body, and shock absorber
A first annular groove is filled with a material of a solenoid case and a first joined portion is formed after a second annular groove is filled with the material of the solenoid case and a second joined portion is formed. This allows a load applied to a piston rod when the material of the solenoid case flows into the first annular groove to be partially received by the second joined portion, thereby contributing to reducing a reaction force received by the piston rod and thus preventing the deformation of an upper-end portion of the piston rod due to the reaction force received by the piston rod.
1 . A joined body of two members, the joined body comprising:
a rod-like member; and
a counterpart member,
wherein the rod-like member and the counterpart member are joined by fitting a one-end portion of the rod-like member into a fitted hole of the counterpart member and pressing a material of the counterpart member to thus cause the material to plastically flow into a groove provided on a circumferential surface of the rod-like member,
wherein the groove includes a first groove provided on a one-end side of the rod-like member and a second groove provided so as to be axially spaced apart from the first groove, and
wherein a depth of the first groove is greater than a depth of the second groove.
2 . The joined body according to claim 1 , wherein the first groove includes two grooves and the second groove includes one groove.
3 . A joined body of two members, the joined body comprising:
a rod-like member; and
a counterpart member,
wherein the rod-like member and the counterpart member are joined by fitting a one-end portion of the rod-like member into a fitted hole of the counterpart member and pressing a material of the counterpart member to thus cause the material to plastically flow into a groove provided on a circumferential surface of the rod-like member,
wherein the groove includes a plurality of first grooves provided on a one-end side of the rod-like member and a second groove provided so as to be axially spaced apart from the first grooves, the number of second groove(s) is smaller than the number of first grooves,
wherein the counterpart member includes a first recessed portion formed near the first grooves by pressing a surface on one axial side, and a second recessed portion formed near the second groove by pressing a surface on an opposite axial side, and
wherein a volume of the first recessed portion is greater than a volume of the second recessed portion.
4 . The joined body according to claim 3 , wherein an axial depth of the first recessed portion is greater than an axial depth of the second recessed portion.
5 . A method of manufacturing a joined body of two members,
the joined body including a rod-like member and a counterpart member,
the rod-like member and the counterpart member being joined by fitting a one-end portion of the rod-like member into a fitted hole of the counterpart member and pressing a material of the counterpart member to thus cause the material to plastically flow into a groove provided on a circumferential surface of the rod-like member,
the method of manufacturing the joined body comprising:
a first plastic flow step of causing the material of the counterpart member to plastically flow into a second groove provided at a position spaced apart from one end of the rod-like member; and
a second plastic flow step of causing the material of the counterpart member to plastically flow into a first groove including a groove deeper than the second groove provided on a one-end side of the rod-like member.
6 . A shock absorber comprising:
a cylinder sealingly containing hydraulic fluid therein;
a piston mechanism partitioning an inside of the cylinder into two chambers;
a piston rod having a one-end portion joined with the piston mechanism and an opposite-end portion extending out of the cylinder; and
a joined portion formed by fitting the one-end portion of the piston rod into a fitted hole of the piston mechanism and pressing a material of the piston mechanism to thus cause the material to plastically flow into a groove provided on a circumferential surface of the piston rod,
wherein the groove includes a first groove provided on a one-end side of the piston rod and a second groove provided so as to be axially spaced apart from the first groove, and
wherein a depth of the first groove is greater than a depth of the second groove.