JP7504237B2 - Bracket fixing member, shock absorber, and method of manufacturing shock absorber - Google Patents

Description

The present invention relates to a bracket fixing member, a shock absorber, and a method for manufacturing a shock absorber.
This application claims priority based on Japanese Patent Application No. 2021-014842, filed on February 2, 2021, the contents of which are incorporated herein by reference.

There are shock absorbers with brackets attached (see, for example, Patent Documents 1 and 2).

JP 2001-182772 A JP 2002-283993 A

In some cases, brackets are attached to a base member by resistance welding. It is desirable to prevent deterioration of welding quality in such attachment structures.

The present invention provides a bracket fixing member, a shock absorber, and a method for manufacturing a shock absorber that can suppress deterioration in welding quality.

According to a first aspect of the present invention, the bracket fixing member comprises a cylindrical or arc-shaped base member, and a bracket having a plurality of fixing portions arranged in the circumferential direction of the base member, the fixing portions being arranged so as to overlap with the outer periphery of the base member and fixed to the base member by resistance welding, the bracket having an arc-shaped portion formed so that the curvature of the circumferential outer portion is wider in the outer diameter direction than the curvature between at least the plurality of the fixing portions.

According to a second aspect of the present invention, the shock absorber includes a cylindrical cylinder. The shock absorber includes a first bracket and a second bracket that are formed by molding a plate material to cover at least a portion of the outer periphery of the cylinder and are fixed to the cylinder. The second bracket includes a holding portion that holds a separate member, and an arc-shaped portion that has a plurality of fixing portions in the circumferential direction of a base member that is the cylinder or the first bracket, is arranged to overlap with the outer periphery of the base member, and is fixed to the base member by resistance welding, and is formed so that the curvature of the outer circumferential portion is wider in the outer diameter direction than the curvature between at least the plurality of fixing portions.

According to a third aspect of the present invention, a method for manufacturing a shock absorber having a cylindrical cylinder includes the steps of preparing a first bracket, at least a portion of which is formed in an arc shape, and a second bracket, the second bracket having a first arc-shaped portion at least a portion of which is formed in an arc shape and having a plurality of protrusions protruding from the inner periphery of the first arc-shaped portion and a second arc-shaped portion that is circumferentially outward of the first arc-shaped portion and is formed to extend radially outward beyond the first arc-shaped portion; fixing the first bracket to the cylinder; positioning the second bracket such that the protrusions abut against the outer periphery of a base member formed of the cylinder or the first bracket; and resistance welding by passing an electric current between the base member and the protrusions.

The above-mentioned shock absorber and shock absorber manufacturing method make it possible to suppress deterioration in welding quality.

1 is a cross-sectional view showing a shock absorber according to a first embodiment of the present invention. 1 is a side view showing a main part of a shock absorber according to a first embodiment of the present invention; 3 is a cross-sectional view taken along the line III-III in FIG. 2, showing a main portion of the shock absorber according to the first embodiment of the present invention. 4 is a cross-sectional view showing a main portion of the shock absorber according to the first embodiment of the present invention after a second bracket arrangement step and before a second bracket welding step. FIG. FIG. 6 is a cross-sectional view showing a main part of a shock absorber according to a second embodiment of the present invention. FIG. 11 is a cross-sectional view showing a main part of a shock absorber according to a third embodiment of the present invention. 10 is a cross-sectional view showing a main part of a modified example of the shock absorber according to the first embodiment of the present invention. FIG.

[First embodiment]
A first embodiment of the present invention will be described below with reference to FIGS.

Figure 1 shows a shock absorber 11 (bracket fixing member) of the first embodiment. The shock absorber 11 is used in suspension devices for vehicles such as automobiles and railroad cars. Specifically, it is a shock absorber used in strut-type suspensions for automobiles. The shock absorber 11 has a cylindrical inner tube 12, a cylindrical outer tube 14 with a bottom, a first bracket 15 (base member), and a second bracket 16 (bracket) attached by welding to the outer periphery of the first bracket 15 as shown in Figure 2. The outer tube 14 has a larger diameter than the inner tube 12. The outer tube 14 is provided on the outer periphery of the inner tube 12 to form a reservoir chamber 13 between the inner tube 12 and the outer tube 14. The first bracket 15 is attached by welding to the outer periphery of the outer tube 14. The inner tube 12 and the outer tube 14 shown in Figure 1 form a cylindrical cylinder 17.

The outer cylinder 14 is a one-piece molded product made of a single piece of metal. The outer cylinder 14 has a cylindrical side wall 21, a bottom 22 that closes one axial end of the side wall 21, and an opening 23 on the side of the side wall 21 opposite the bottom 22.

The shock absorber 11 has an annular body member 30 attached to one axial end of the inner cylinder 12, and an annular rod guide 31 attached to the other axial end of the inner cylinder 12. The inner cylinder 12 fits into the bottom 22 of the outer cylinder 14 via the body member 30. The inner cylinder 12 also fits into the opening 23 of the side wall 21 of the outer cylinder 14 via the rod guide 31. In this state, the inner cylinder 12 is positioned radially and axially relative to the outer cylinder 14.

The shock absorber 11 has an annular seal member 33 on the opposite side of the rod guide 31 from the bottom 22. This seal member 33 is fitted into the inner periphery of the opening 23 side of the side wall 21. A locking portion 34 is formed on the end of the side wall 21 opposite the bottom 22. The locking portion 34 is formed by plastically deforming radially inward by curling. The seal member 33 is sandwiched between the locking portion 34 and the rod guide 31.

The shock absorber 11 has a piston 35 slidably fitted in the inner cylinder 12. The piston 35 defines a first chamber 38 and a second chamber 39 in the inner cylinder 12. The first chamber 38 is provided between the piston 35 and the rod guide 31 in the inner cylinder 12. The second chamber 39 is provided between the piston 35 and the body member 30 in the inner cylinder 12. The second chamber 39 in the inner cylinder 12 is defined as a reservoir chamber 13 by the body member 30. The first chamber 38 and the second chamber 39 in the inner cylinder 12 are filled with oil liquid, which is a working fluid. The reservoir chamber 13 between the inner cylinder 12 and the outer cylinder 14 is filled with gas and oil liquid, which are working fluids.

The shock absorber 11 has a piston rod 41. One side of the piston rod 41 is connected to the piston 35. The other side of the piston rod 41 extends from the outer cylinder 14 to the outside through the opening 23. The piston 35 is connected to the piston rod 41 by a nut 43. The piston rod 41 extends from the inner cylinder 12 and the outer cylinder 14 to the outside through the rod guide 31 and the seal member 33. The part of the piston rod 41 that extends from the outer cylinder 14 to the outside is connected to the vehicle body side. The piston rod 41 is guided by the rod guide 31 and moves axially together with the piston 35 relative to the inner cylinder 12 and the outer cylinder 14. The seal member 33 closes the gap between the outer cylinder 14 and the piston rod 41 to restrict the oil in the inner cylinder 12 and the gas and oil in the reservoir chamber 13 from leaking out to the outside.

The piston 35 is formed with passages 44 and 45 that penetrate in the axial direction. The passages 44 and 45 can connect the first chamber 38 and the second chamber 39. The shock absorber 11 has an annular disc valve 46 on the side opposite the bottom 22 of the piston 35 in the axial direction. The disc valve 46 can close the passage 44 by abutting against the piston 35. The shock absorber 11 also has an annular disc valve 47 on the side of the bottom 22 of the piston 35 in the axial direction. The disc valve 47 can close the passage 45 by abutting against the piston 35.

The disc valve 46 is a damping valve on the compression side. That is, when the piston rod 41 moves to the compression side to increase the amount of penetration into the inner cylinder 12 and the outer cylinder 14, and the piston 35 moves in a direction to narrow the second chamber 39, and the pressure in the second chamber 39 becomes higher than the pressure in the first chamber 38 by a predetermined value or more, the disc valve 46 opens the passage 44. When the disc valve 46 opens the passage 44, a damping force is generated. At least one of the piston 35 and the disc valve 46 has a fixed orifice (not shown) that communicates between the first chamber 38 and the second chamber 39 through the passage 44 even when the disc valve 46 is in the state where the passage 44 is most blocked.

The disc valve 47 is an extension damping valve. That is, when the piston rod 41 moves to the extension side to increase the amount of protrusion from the inner cylinder 12 and the outer cylinder 14, and the piston 35 moves in a direction narrowing the first chamber 38, and the pressure in the first chamber 38 becomes higher than the pressure in the second chamber 39 by a predetermined value or more, the disc valve 47 opens the passage 45. When the disc valve 47 opens the passage 45, a damping force is generated. At least one of the piston 35 and the disc valve 47 has a fixed orifice (not shown) that communicates the first chamber 38 and the second chamber 39 through the passage 45 even when the disc valve 47 is in the most closed state of the passage 45.

Passages 52 and 53 are formed in the body member 30, which penetrate in the axial direction. Passages 52, 53 can connect the second chamber 39 and the reservoir chamber 13. An annular disk valve 55 is provided on the bottom 22 side of the body member 30 in the axial direction. An annular disk valve 56 is provided on the side of the body member 30 opposite the bottom 22 in the axial direction. The disk valve 55 can close the passage 52 by abutting against the body member 30. The disk valve 56 can close the passage 53 by abutting against the body member 30.

The disc valve 55 is a damping valve on the compression side. That is, when the piston rod 41 moves to the compression side, the piston 35 moves in a direction narrowing the second chamber 39, and the pressure in the second chamber 39 becomes higher than the pressure in the reservoir chamber 13 by a predetermined value or more, the disc valve 55 opens the passage 52. When the disc valve 55 opens the passage 52, a damping force is generated. The disc valve 56 is a suction valve. That is, when the piston rod 41 moves to the extension side, the piston 35 moves to the first chamber 38 side, and the pressure in the second chamber 39 becomes lower than the pressure in the reservoir chamber 13, the disc valve 56 opens the passage 53. At that time, the disc valve 56 allows the hydraulic fluid to flow from the reservoir chamber 13 into the second chamber 39 without generating a substantial damping force.

The first bracket 15 is made of metal. The first bracket 15 is fitted to the side wall 21 on the bottom 22 side of the axial center position of the outer cylinder 14, and welded and fixed. As shown in Figs. 2 and 3, the first bracket 15 has a fitting portion 60 that is shaped like a part of a cylinder and fits into the outer periphery of the side wall 21, and a pair of substantially flat first and second extension portions 61 and 62 that extend from the fitting portion 60 in the same direction radially outward from the fitting portion 60 in approximately parallel relation to each other. The fitting portion 60, which is at least a part of the first bracket 15, is formed in an arc shape. The first and second extension portions 61 and 62 each have two mounting holes 63. The first bracket 15 is connected to the wheel side by fasteners (not shown) inserted into these mounting holes 63.

A hole 65 is formed in the fitting portion 60 on the opposite side of the fitting portion 60 in the circumferential direction from the pair of first extension portion 61 and second extension portion 62. The hole 65 is formed in the middle of the fitting portion 60 in the axial direction, as shown in FIG.

The fitting portion 60 has an arc-shaped first main fitting portion 71 on the side opposite the bottom portion 22 from the punching hole 65 in the axial direction of the cylinder 17. The first main fitting portion 71 continuously covers the outer peripheral surface 21a of the side wall portion 21 of the outer tube 14 for more than half the circumference. In addition, the fitting portion 60 has an arc-shaped second main fitting portion 72 on the side opposite the bottom portion 22 from the punching hole 65 in the axial direction of the cylinder 17. The second main fitting portion 72 continuously covers the outer peripheral surface 21a of the side wall portion 21 of the outer tube 14 for more than half the circumference.

In addition, the fitting portion 60 has a pair of arc-shaped first and second clamping portions 75 and 76 between the first main fitting portion 71 and the second main fitting portion 72 in the axial direction of the cylinder 17, as shown in FIG. 3. The first clamping portion 75 is an arc-shaped portion that continuously covers the outer peripheral surface 21a of the side wall portion 21 of the outer cylinder 14 over a range less than half the circumference. The second clamping portion 76 is also an arc-shaped portion that continuously covers the outer peripheral surface 21a of the side wall portion 21 of the outer cylinder 14 over a range less than half the circumference. The first main fitting portion 71 and the second main fitting portion 72 shown in FIG. 2 and the first clamping portion 75 and the second clamping portion 76 shown in FIG. 3 each form a part of the same cylinder.

The first main fitting portion 71 and the second main fitting portion 72 each fit into the outer periphery of the side wall portion 21 of the outer tube 14, and the first clamping portion 75 and the second clamping portion 76 clamp the outer periphery of the side wall portion 21 of the outer tube 14 from opposite radial sides.

2, the first extension portion 61 extends radially outward from the edge of the first clamping portion 75 opposite the hole 65 and from the edge of the first main fitting portion 71 and the edge of the second main fitting portion 72 adjacent to both sides of the edge of the first clamping portion 75. The first extension portion 61 extends parallel to the central axis of the fitting portion 60.

3 extends radially outward from the edge of the second clamping portion 76 opposite the hole 65 and from the edge of the first main fitting portion 71 and the edge of the second main fitting portion 72 adjacent to both sides of the edge of the second clamping portion 76 radially outward from the first main fitting portion 71 and the second main fitting portion 72. The second extension portion 62 extends parallel to the central axis of the fitting portion 60.

The first bracket 15 is formed into the above shape by pressing a single flat plate material. The second main fitting portion 72 is fitted into the side wall portion 21 on the bottom 22 side in the axial direction of the cylinder 17. The first main fitting portion 71 is fitted into the side wall portion 21 on the opposite side of the bottom 22 in the axial direction of the cylinder 17 from the second main fitting portion 72. The first clamping portion 75 and the second clamping portion 76 are in a state of clamping the side wall portion 21.

In this state, the first bracket 15 is fixed to the outer tube 14 by welding. Then, the first bracket 15 covers the outer peripheral surface 21a of the side wall portion 21 of the outer tube 14, i.e., the outer peripheral surface 21a of the cylinder 17, at the fitting portion 60, and a pair of substantially flat first extension portions 61 and second extension portions 62 extend radially outward from the fitting portion 60 in parallel with each other from the outer tube 14, i.e., the cylinder 17. Thus, the first bracket 15 is formed by molding a plate material so as to cover at least a portion of the outer peripheral side of the cylinder 17, and is fixed to the cylinder 17.

3, depending on the finish of the first bracket 15, a protrusion 81 that protrudes radially outward from the outer peripheral surface 75a of the first clamping portion 75 may be formed on the outer peripheral side, which is the radially outer side (curved convex side) of the first clamping portion 75, at the edge portion on the side of the punching hole 65. This protrusion 81 is a burr or burr that occurs when forming the punching hole 65 by press working. If a burr or burr protrudes radially inward from the inner peripheral surface 75b of the radially inner side of the first clamping portion 75, which is the radially inner side (curved concave side) of the first clamping portion 75, this protruding portion will interfere when fitting into the outer tube 14. For this reason, the plate material that is the material of the first bracket 15 is in a flat state, and the punching direction of the press processing for the hole 65 is aligned with this, and then the formation of the fitting portion 60 by bending processing is performed so that even if a protrusion 81 is generated, this protrusion 81 protrudes radially outward from the outer circumferential surface 75a.

The first bracket 15 has a pair of first extensions 61 and second extensions 62 that are connected to a knuckle (not shown) on the wheel side. In other words, the first bracket 15 is a knuckle bracket that is connected to the knuckle.

The second bracket 16 has an arc-shaped portion 91 that is generally arc-shaped and is fixed to the first bracket 15, and a retaining portion 92 that extends from the arc-shaped portion 91 and retains a separate component.

The arc-shaped portion 91 has a first arc-shaped portion 101 having a shape of a part of a cylinder, a second arc-shaped portion 102 having a shape of a part of a cylinder, and a flat connecting portion 103 connecting the first arc-shaped portion 101 and the second arc-shaped portion 102. The connecting portion 103 extends from one circumferential end edge of the first arc-shaped portion 101 in a direction substantially extending the first arc-shaped portion 101. The second arc-shaped portion 102 extends from an end edge of the connecting portion 103 opposite the first arc-shaped portion 101 in a direction substantially extending the connecting portion 103. The arc-shaped portion 91 is fixed to the outer peripheral surface 75a of the first clamping portion 75 of the first bracket 15 at the first arc-shaped portion 101.

As shown in Fig. 4, before being attached to the first bracket 15, the second bracket 16 has a plurality of protrusions 111, specifically two protrusions, which protrude radially inward from the inner circumferential surface 101a on the radially inner side (curved concave side) of the first arc-shaped portion 101 at intervals in the circumferential direction of the first arc-shaped portion 101. The plurality of protrusions 111 are aligned in the axial direction of the first arc-shaped portion 101.

In the first arc-shaped portion 101, recesses 112 are formed so as to align with the protrusions 111 in the axial and circumferential positions of the first arc-shaped portion 101. The recesses 112 are recessed radially inward from the outer peripheral surface 101b on the radially outer side (the curved convex side). The recesses 112 are secondarily formed in order to form the protrusions 111 by plastic deformation in the plate-shaped material. Thus, the second bracket 16 has a plurality of recesses 112, specifically two, spaced apart in the circumferential direction of the first arc-shaped portion 101, the same number as the protrusions 111.

The second arc-shaped portion 102 is formed so as to be located circumferentially outside the first arc-shaped portion 101 on which the multiple protrusions 111 are formed, and to be wider in the outer diameter direction than the first arc-shaped portion 101. The second arc-shaped portion 102 has a radial thickness equivalent to that of the first arc-shaped portion 101. The second arc-shaped portion 102 is coaxial with the first arc-shaped portion 101, has a larger outer diameter than the first arc-shaped portion 101, and also has a larger inner diameter. In other words, the inner circumferential surface 102a on the radially inner side (curved concave side) of the second arc-shaped portion 102 is larger in diameter than the inner circumferential surface 101a of the first arc-shaped portion 101. The outer circumferential surface 102b on the radially outer side (curved convex side) of the second arc-shaped portion 102 is larger in diameter than the outer circumferential surface 101b of the first arc-shaped portion 101.

The connecting portion 103 extends from the edge of the first arc-shaped portion 101 on the second arc-shaped portion 102 side in the circumferential direction toward the second arc-shaped portion 102 and connects to the edge of the second arc-shaped portion 102 on the first arc-shaped portion 101 side in the circumferential direction. The connecting portion 103 has a connecting surface 103a and a connecting surface 103b. The connecting surface 103a connects the inner peripheral surface 101a of the first arc-shaped portion 101 and the inner peripheral surface 102a of the second arc-shaped portion 102. The connecting surface 103b connects the outer peripheral surface 101b of the first arc-shaped portion 101 and the outer peripheral surface 102b of the second arc-shaped portion 102. The connecting portion 103 extends in the circumferential direction of the first arc-shaped portion 101 and the second arc-shaped portion 102 so as to be positioned more outward in the radial direction of the first arc-shaped portion 101 and the second arc-shaped portion 102 as it approaches the second arc-shaped portion 102 from the first arc-shaped portion 101. The arc-shaped portion 91, which has the first arc-shaped portion 101, the connecting portion 103, and the second arc-shaped portion 102, is a stepped arc.

The second bracket 16 is formed into the above-mentioned shape from a single plate material by pressing. The first arc-shaped portion 101 of the second bracket 16 is arranged to cover the outer peripheral surface 75a of the first clamping portion 75 of the first bracket 15, and the multiple protrusions 111 abut against the outer peripheral surface 75a of the first clamping portion 75. At that time, the inner peripheral surface 101a and the outer peripheral surface 101b of the first arc-shaped portion 101 and the inner peripheral surface 101a and the outer peripheral surface 102b of the second arc-shaped portion 102 are arranged approximately coaxially with the outer peripheral surface 75a of the first clamping portion 75, and the multiple protrusions 111 are arranged so as to align the position in the axial direction of the first clamping portion 75 and to be spaced apart in the circumferential direction of the first clamping portion 75.

At this time, the second bracket 16 has a plurality of protruding portions 111 and a second arc-shaped portion 102. At least a portion of the protruding portions 111 is the first arc-shaped portion 101 formed in an arc shape. The plurality of protruding portions 111 protrude toward the inner periphery of the first arc-shaped portion 101. The second arc-shaped portion 102 is disposed circumferentially outside the first arc-shaped portion 101. The second arc-shaped portion 102 is formed to extend radially outward beyond the first arc-shaped portion 101.

In this state, the multiple protrusions 111 are fixed to the first clamping portion 75 by resistance welding such as projection welding. Then, the multiple protrusions 111 of the second bracket 16 and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111 are melted and integrated, respectively, to become the multiple fixing portions 121 shown in FIG. 3. The multiple fixing portions 121 are all provided from the first arc-shaped portion 101 to the first clamping portion 75, and join the first arc-shaped portion 101 to the first clamping portion 75. In this state, the inner peripheral surface 101a and the outer peripheral surface 101b of the first arc-shaped portion 101 and the inner peripheral surface 102a and the outer peripheral surface 102b of the second arc-shaped portion 102 of the second bracket 16 are arranged closer to the outer peripheral surface 75a of the first clamping portion 75 than before welding, and are arranged approximately coaxially with the outer peripheral surface 75a.

In this manner, the second bracket 16 fixed to the first bracket 15 has a circular arc-shaped portion 91 having a plurality of fixing portions 121 provided in the circumferential direction of the first bracket 15, and is arranged so as to overlap with the outer periphery of the first bracket 15. The fixing portions 121 of the second bracket 16 are fixed to the first bracket 15 by resistance welding. In this state, the circular arc-shaped portion 91 is formed so that the curvature of the second circular arc-shaped portion 102, which is the outer circumferential portion, is wider in the outer diameter direction than at least the curvature between the fixing portions 121 of the first circular arc-shaped portion 101. In addition, the first circular arc-shaped portion 101 of the circular arc-shaped portion 91 is joined to the first bracket 15, while the portion of the connecting portion 103 on the second circular arc-shaped portion 102 side and the second circular arc-shaped portion 102 are separated from the first bracket 15.

The arc-shaped portion 91 is spaced from the edge of the first clamping portion 75 on the side of the hole 65 of the first clamping portion 75 to the outside in the radial direction of the first clamping portion 75, where the portion of the second arc-shaped portion 102 of the connecting portion 103 and the second arc-shaped portion 102 are spaced from the edge of the first clamping portion 75 on the side of the hole 65 of the first clamping portion 75. Here, as described above, depending on the construction of the first bracket 15, a protrusion 81 that protrudes radially outward from the outer circumferential surface 75a of the first clamping portion 75 may be formed. The arc-shaped portion 91 is a portion of the connecting portion 103 on the side of the second arc-shaped portion 102 or the second arc-shaped portion 102 that overlaps the protrusion 81 with the circumferential position of the first clamping portion 75. In addition, the arc-shaped portion 91 is spaced apart from the protruding portion 81 to the outside in the radial direction of the first clamping portion 75, at the portion of the connecting portion 103 on the second arc-shaped portion 102 side and the second arc-shaped portion 102. The second bracket 16 does not come into contact with the protruding portion 81 of the first bracket 15 at all, and is completely spaced apart from the protruding portion 81.

After welding to the first bracket 15, the periphery of the fixed portion 121 of the first arc-shaped portion 101 of the second bracket 16 may abut against the first clamping portion 75 of the first bracket 15. However, even if the first clamping portion 75 has a protruding portion 81, the second bracket 16 will not abut against the protruding portion 81. In other words, the second bracket 16 is structured to ensure clearance with the first bracket 15 in the portion other than the protruding portion 111 while suppressing a reduction in the seating area of the protruding portion 111 that abuts against the first bracket 15, which is the mating part to be assembled.

The holding portion 92 extends in the opposite direction to the connecting portion 103 from the edge of the second arc-shaped portion 102 on the opposite side of the circumferential direction from the connecting portion 103. The holding portion 92 is formed to extend further in the outer diameter direction of the second arc-shaped portion 102 than the second arc-shaped portion 102. When hoses are held in the holding portion 92, the second bracket 16 becomes a hose bracket. When harnesses are held in the holding portion 92, the second bracket 16 becomes a harness bracket.

The manufacturing method of the shock absorber 11 of the first embodiment includes a first bracket preparation process for preparing a first bracket 15, at least a part of which, the fitting portion 60, is formed in an arc shape.

The manufacturing method of the shock absorber 11 of the first embodiment includes a second bracket preparation process for preparing a second bracket 16 having a plurality of protrusions 111 and a second arc-shaped portion 102. At least a portion of the protrusion 111 is the first arc-shaped portion 101 formed in an arc shape. The protrusion 111 protrudes toward the inner periphery of the first arc-shaped portion 101. The second arc-shaped portion 102 is disposed circumferentially outside the first arc-shaped portion 101. The second arc-shaped portion 102 is formed to extend radially outward beyond the first arc-shaped portion 101.

The manufacturing method of the shock absorber 11 of the first embodiment includes a first bracket welding process for fixing the first bracket 15 prepared in the first bracket preparation process to the cylinder 17. In this first bracket welding process, the first bracket 15 is in a state in which the second main fitting portion 72 fits into the outer peripheral surface 21a of the side wall portion 21 on the bottom 22 side in the axial direction of the cylinder 17, the first main fitting portion 71 fits into the outer peripheral surface 21a of the side wall portion 21 on the opposite side of the bottom 22 in the axial direction of the cylinder 17 from the second main fitting portion 72, and the first clamping portion 75 and the second clamping portion 76 abut against the outer peripheral surface 21a of the side wall portion 21. Then, in the first bracket welding process, the first bracket 15 is fixed to the outer tube 14 of the cylinder 17 by welding in this state.

The manufacturing method of the shock absorber 11 of the first embodiment includes a second bracket arrangement process in which the second bracket 16 prepared in the second bracket preparation process is arranged so that the protruding portion 111 abuts against the outer periphery of the first bracket 15. In this second bracket arrangement process, the second bracket 16 is arranged so that the first arc-shaped portion 101 covers the outer periphery 75a of the first clamping portion 75 of the first bracket 15, and the multiple protruding portions 111 abut against the outer periphery 75a of the first clamping portion 75. At that time, the second bracket 16 is arranged so that the central axis of the first arc-shaped portion 101 and the central axis of the second arc-shaped portion 102 are parallel to the central axis of the first clamping portion 75, and the multiple protruding portions 111 are arranged so that they are spaced apart in the circumferential direction of the first clamping portion 75 with their positions in the axial direction of the first clamping portion 75 aligned. In the second bracket arrangement step, the second bracket 16 abuts against the first bracket 15 only at the two protruding portions 111. Even if the first bracket 15 has a protruding portion 81, the second bracket 16 will not abut against the protruding portion 81.

The manufacturing method of the shock absorber 11 of the first embodiment includes a second bracket welding process in which a current is passed between the first bracket 15 and the multiple protrusions 111 of the second bracket 16 arranged in the second bracket arrangement process so as to abut against the outer periphery of the first bracket 15 at the multiple protrusions 111. This second bracket welding process melts and integrates the two protrusions 111 of the second bracket 16 and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111 to form two fixed portions 121. In the second bracket welding process, the two protrusions 111 melt and the arc-shaped portion 91 approaches the first clamping portion 75, but even if the first bracket 15 has a protrusion 81, the second bracket 16 does not abut against the protrusion 81.

Although the second bracket welding process will be performed after the second bracket placement process, the first bracket welding process may be performed before the second bracket placement process or after the second bracket welding process.

Patent Documents 1 and 2 disclose attaching a bracket to a shock absorber. The bracket may be attached to a base member by resistance welding, and it is desirable to suppress deterioration in welding quality in such an attachment structure. One cause of deterioration in welding quality in resistance welding is the occurrence of shunt current, which causes current to flow to areas other than the object to be welded.

In contrast, the shock absorber 11 of the first embodiment has a first bracket 15 which is an arc-shaped base member, and a second bracket 16 which includes a plurality of fixing portions 121 provided in the circumferential direction of the first bracket 15, and an arc-shaped portion 91. The fixing portions 121 are arranged so as to overlap with the outer periphery of the first bracket 15. The fixing portions 121 are fixed to the first bracket 15 by resistance welding. The arc-shaped portion 91 is formed so that the curvature of the second arc-shaped portion 102, which is the outer circumferential portion relative to the first arc-shaped portion 101 between the fixing portions 121 and 121, is wider in the outer diameter direction than the curvature of at least the first arc-shaped portion 101 between the fixing portions 121 and 121.

More specifically, the shock absorber 11 of the first embodiment has a first bracket 15 formed by molding a plate material so as to cover at least a part of the outer periphery of the cylinder 17 and fixed to the cylinder 17. The shock absorber 11 also has a second bracket 16 including a holding portion 92 for holding a separate member, a plurality of fixing portions 121 in the circumferential direction of the first bracket 15, and an arc-shaped portion 91. The fixing portions 121 are arranged so as to overlap with the outer periphery of the first bracket 15. The fixing portions 121 are fixed to the first bracket 15 by resistance welding. The arc-shaped portion 91 is formed so that the curvature of the second arc-shaped portion 102, which is the outer circumferential portion relative to the first arc-shaped portion 101 between the fixing portions 121 and 121, is wider in the outer diameter direction than the curvature of the first arc-shaped portion 101 between the fixing portions 121 and 121.

The manufacturing method of the shock absorber 11 of the first embodiment includes a first bracket preparation process and a second bracket process. In the first bracket preparation process, a first bracket 15 is prepared, in which at least a portion of the fitting portion 60 is formed in an arc shape. In the second bracket preparation process, a second bracket 16 is prepared, in which a first arc-shaped portion 101 is formed at least in a portion in an arc shape, and the second bracket 16 has a plurality of protruding portions 111 protruding on the inner circumferential side of the first arc-shaped portion 101, and a second arc-shaped portion 102 that is located circumferentially outside the first arc-shaped portion 101 and is formed to expand in the outer radial direction more than the first arc-shaped portion 101.

The manufacturing method of the shock absorber 11 of the first embodiment includes a first bracket welding process for fixing the first bracket 15 prepared in the first bracket preparation process to the cylinder 17, a second bracket arrangement process for arranging the second bracket 16 prepared in the second bracket preparation process so that the protrusion 111 abuts against the outer periphery of the first bracket 15, and a second bracket welding process for passing an electric current between the first bracket 15 and the multiple protrusions 111 to perform resistance welding.

According to the first embodiment described above, in welding the second bracket 16 to the first bracket 15, it is possible to suppress the shunting of current flowing to parts other than the multiple protrusions 111 to be welded. This makes it possible to suppress the deterioration of welding quality. In addition, it is possible to reduce the precision of the second bracket 16 and the first bracket 15, which required high precision to prevent shunting, and to improve productivity. In addition, even if the second bracket 16 is slightly tilted when radial pressure is applied when welding the second bracket 16 to the first bracket 15, it is possible to suppress shunting. In addition, it is possible to increase the degree of freedom in the layout of the second bracket 16 and the first bracket 15, which had limitations on the layout due to shunting. In addition, it is possible to relax design and process restrictions for shunting countermeasures, and to increase the degree of freedom in design and process.

In particular, depending on the finish, the first bracket 15 may have a protruding portion 81 formed at the edge of the first clamping portion 75 on the side of the punch hole 65, which protrudes radially outward from the outer circumferential surface 75a of the first clamping portion 75. For this reason, if the arc-shaped portion 91 of the second bracket 16 has a certain curved shape, the portion of the arc-shaped portion 91 that faces the protruding portion 81, which is a portion other than the multiple protruding portions 111 to be welded, may come close to the protruding portion 81 and cause a branching flow. In contrast, in the first embodiment, the arc-shaped portion 91 has a second arc-shaped portion 102 that is formed to be wider in the outer diameter direction than the first arc-shaped portion 101, so that it is shaped to be separated from the protruding portion 81. Therefore, it is possible to prevent the portion of the arc-shaped portion 91 that faces the protruding portion 81, which is a portion other than the multiple protruding portions 111 to be welded, from coming close to the protruding portion 81 and causing a branching flow. This makes it possible to prevent current from flowing to other parts than the projections 111 that are the welding targets, thereby making it possible to prevent deterioration in welding quality.

In addition, the second bracket 16 has a second arc-shaped portion 102, which is a circumferentially outer portion of the first arc-shaped portion 101 between the fixing portions 121, spaced apart from the first bracket 15, which is the base member. This further reduces current shunting to portions other than the multiple protrusions 111 to be welded, thereby further reducing deterioration in welding quality.

[Second embodiment]
A second embodiment of the present invention will be described with a focus on differences from the first embodiment, mainly based on Fig. 5. Note that parts common to the first embodiment will be designated by the same names and reference numerals.

In the second embodiment, the shock absorber 11A (bracket fixing member) is provided with a second bracket 16A instead of the second bracket 16 in the first embodiment.

The second bracket 16A has an arc-shaped portion 91A that is partially different from the arc-shaped portion 91, and a retaining portion 92 similar to that of the first embodiment. The arc-shaped portion 91A also has an overall arc shape. The second bracket 16A is fixed to the first bracket 15 at the arc-shaped portion 91A.

The arc-shaped portion 91A has a first arc-shaped portion 101 similar to that of the first embodiment, and a second arc-shaped portion 102A that is partially different from the second arc-shaped portion 102. The second arc-shaped portion 102A extends from one circumferential end edge of the first arc-shaped portion 101 in a direction extending the first arc-shaped portion 101. The arc-shaped portion 91A is fixed to the outer peripheral surface 75a of the first clamping portion 75 of the first bracket 15 at the first arc-shaped portion 101.

The second arc-shaped portion 102A has an outer peripheral surface 102Ab on the radially outer side (convex curved side) arranged on the same cylindrical surface as the outer peripheral surface 101b of the first arc-shaped portion 101. In other words, the outer peripheral surface 101b of the first arc-shaped portion 101 and the outer peripheral surface 102Ab of the second arc-shaped portion 102A are continuous with each other coaxially and with the same diameter. The second arc-shaped portion 102A has an inner peripheral surface 102Aa on the radially inner side (concave curved side) that is recessed radially outward from the inner peripheral surface 101a of the first arc-shaped portion 101. As a result, the second arc-shaped portion 102A is formed so that its inner peripheral surface 102Aa is located circumferentially outside the inner peripheral surface 101a of the first arc-shaped portion 101 and is wider in the outer radial direction than the inner peripheral surface 101a of the first arc-shaped portion 101. The inner circumferential surface 102Aa of the second arc-shaped portion 102A is a curved surface. The second arc-shaped portion 102A has a radial thickness that becomes thinner toward a circumferential middle portion, and the thickness of the second arc-shaped portion 102A at its thickest radial portion is equal to the thickness of the first arc-shaped portion 101.

The second bracket 16A is formed into the above-mentioned shape from a single plate material by pressing. The first arc-shaped portion 101 of the second bracket 16A is arranged to cover the outer peripheral surface 75a of the first clamping portion 75 of the first bracket 15, and the multiple protrusions 111 (see FIG. 4) abut against the outer peripheral surface 75a of the first clamping portion 75. At that time, the inner peripheral surface 101a and the outer peripheral surface 101b of the first arc-shaped portion 101 and the outer peripheral surface 102Ab of the second arc-shaped portion 102A of the second bracket 16A are arranged approximately coaxially with the first clamping portion 75, and the multiple protrusions 111 (see FIG. 4) are arranged so as to align the position in the axial direction of the first clamping portion 75 and to be spaced apart in the circumferential direction of the first clamping portion 75.

At this time, the second bracket 16A has a plurality of protruding portions 111 (see FIG. 4) and a second arc-shaped portion 102A. At least a portion of the protruding portions 111 is the first arc-shaped portion 101 formed in an arc shape. The protruding portions 111 protrude toward the inner circumference of the first arc-shaped portion 101. The second arc-shaped portion 102A is disposed circumferentially outward from the inner circumference surface 101a of the first arc-shaped portion 101. The second arc-shaped portion 102A has an inner circumference surface 102Aa formed to expand in the outer diameter direction more than the inner circumference surface 101a of the first arc-shaped portion 101.

In this state, the multiple protrusions 111 (see FIG. 4) are fixed to the first clamping portion 75 by resistance welding such as projection welding. Then, the multiple protrusions 111 (see FIG. 4) of the second bracket 16A and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111 (see FIG. 4) are melted and integrated to form multiple fixed portions 121. In this state, the inner peripheral surface 101a and the outer peripheral surface 101b of the first arc-shaped portion 101 and the outer peripheral surface 102Ab of the second arc-shaped portion 102A of the second bracket 16A are disposed closer to the outer peripheral surface 75a of the first clamping portion 75 than before welding, and are arranged substantially coaxially with the outer peripheral surface 75a.

In this manner, the second bracket 16A fixed to the first bracket 15 has a circular arc portion 91A having a plurality of fixing portions 121 arranged in the circumferential direction of the first bracket 15, and is arranged so as to overlap with the outer periphery of the first bracket 15, and the fixing portions 121 are fixed to the first bracket 15 by resistance welding. In this state, the circular arc portion 91A is formed so that the curvature of the inner circumferential surface 102Aa of the second circular arc portion 102A, which is the outer circumferential portion, is wider in the outer diameter direction than at least the curvature between the fixing portions 121 of the inner circumferential surface 101a of the first circular arc portion 101. In addition, the first circular arc portion 101 of the circular arc portion 91A abuts against the first bracket 15, while the second circular arc portion 102A is separated from the first bracket 15.

In this state, the inner peripheral surface 102Aa of the second arc-shaped portion 102A of the arc-shaped portion 91A is spaced from the edge of the first clamping portion 75 on the side of the punching hole 65 to the outside in the radial direction of the first clamping portion 75. Here, as described above, depending on the construction of the first bracket 15, a protrusion 81 that protrudes radially outward from the outer peripheral surface 75a of the first clamping portion 75 may be formed on the edge of the first clamping portion 75 on the side of the punching hole 65. The arc-shaped portion 91A overlaps the protrusion 81 and the second arc-shaped portion 102A in the circumferential direction of the first clamping portion 75. The second arc-shaped portion 102A of the arc-shaped portion 91A is spaced from the protrusion 81 to the outside in the radial direction of the first clamping portion 75 due to the concave shape of the inner peripheral surface 102Aa. The second bracket 16A does not come into contact with the protruding portion 81 of the first bracket 15 at all, and is completely separated from the protruding portion 81.

After welding to the first bracket 15, the periphery of the fixed portion 121 of the first arc-shaped portion 101 of the second bracket 16A may abut against the first bracket 15. However, even if the first clamping portion 75 has a protrusion 81, the second bracket 16A will not abut against the protrusion 81. In other words, the second bracket 16A is structured to ensure clearance with the first bracket 15 in the portion other than the protrusion 111 (see FIG. 4), while suppressing a reduction in the seating area of the protrusion 111 (see FIG. 4) that abuts against the first bracket 15, which is the mating part to be assembled.

The retaining portion 92 extends from an edge of the second arc-shaped portion 102A on the opposite side of the first arc-shaped portion 101 in the circumferential direction of the second arc-shaped portion 102A in the opposite direction to the first arc-shaped portion 101. The retaining portion 92 is formed to extend in the outer diameter direction of the second arc-shaped portion 102A further than the second arc-shaped portion 102A.

The manufacturing method of the shock absorber 11A of the second embodiment includes a first bracket preparation process for preparing a first bracket 15, a second bracket preparation process for preparing a second bracket 16A, and a first bracket welding process similar to that of the first embodiment.

The manufacturing method of the shock absorber 11A of the second embodiment also includes a second bracket arrangement process in which the second bracket 16A prepared in the second bracket preparation process is arranged so that the protrusions 111 (see FIG. 4) abut against the outer periphery of the first bracket 15. In this second bracket arrangement process, the second bracket 16A abuts against the first bracket 15 only at the two protrusions 111 (see FIG. 4). Even if the first bracket 15 has a protrusion 81, the second bracket 16A will not abut against the protrusion 81.

The manufacturing method of the shock absorber 11A of the second embodiment also includes a second bracket welding process in which a current is passed between the first bracket 15 and the multiple protrusions 111 (see FIG. 4) of the second bracket 16A arranged so as to abut the outer periphery of the first bracket 15 at the multiple protrusions 111 (see FIG. 4) in the second bracket arrangement process. The second bracket welding process melts and integrates the two protrusions 111 (see FIG. 4) of the second bracket 16A and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111 (see FIG. 4) to form two fixed portions 121. Even if the first bracket 15 has a protrusion 81, the second bracket 16A does not abut against the protrusion 81 in the second bracket welding process.

In addition, in the manufacturing method of the shock absorber 11A of the second embodiment, the first bracket welding process may be performed before the second bracket placement process or after the second bracket welding process.

The shock absorber 11A of the second embodiment has a first bracket 15 which is an arc-shaped base member, and a second bracket 16A which includes a plurality of fixing portions 121 provided in the circumferential direction of the first bracket 15, and an arc-shaped portion 91A. The fixing portions 121 are arranged so as to overlap with the outer circumferential side of the first bracket 15. The fixing portions 121 are fixed to the first bracket 15 by resistance welding. The arc-shaped portion 91A is formed so that the curvature of the inner circumferential surface 102Aa of the second arc-shaped portion 102A, which is the outer circumferential portion relative to the first arc-shaped portion 101 between the fixing portions 121 and 121, is wider in the outer diameter direction than the curvature of the inner circumferential surface 101a of the first arc-shaped portion 101 between the fixing portions 121 and 121.

More specifically, the shock absorber 11A of the second embodiment has a first bracket 15 formed by molding a plate material so as to cover at least a portion of the outer periphery of the cylinder 17 and fixed to the cylinder 17. The shock absorber 11A also has a second bracket 16A including a holding portion 92 that holds a separate member, a plurality of fixing portions 121 in the circumferential direction of the first bracket 15, and an arc-shaped portion 91A. The arc-shaped portion 91A is disposed so as to overlap the outer periphery of the first bracket 15, and the fixing portion 121 is fixed to the first bracket 15 by resistance welding. The arc-shaped portion 91A is formed so that the curvature of the inner surface 102Aa of the second arc-shaped portion 102A, which is the circumferentially outer portion relative to the first arc-shaped portion 101 between the fixed portions 121 and 121, is wider in the outward diameter direction than the curvature of the inner surface 101a of the first arc-shaped portion 101 between the fixed portions 121 and 121.

The manufacturing method of the shock absorber 11A of the second embodiment includes a first bracket preparation step of preparing a first bracket 15 in which at least a part of the fitting portion 60 is formed in an arc shape. The manufacturing method of the shock absorber 11A of the second embodiment also includes a second bracket preparation step. In the second bracket preparation step, a second bracket 16A is prepared. The second bracket 16A has a plurality of protrusions 111 (see FIG. 4) and a second arc-shaped portion 102A. The protrusions 111 are the first arc-shaped portion 101, at least a part of which is formed in an arc shape, and protrude toward the inner periphery of the first arc-shaped portion 101. The arc-shaped portion 102A is located circumferentially outside the first arc-shaped portion 101 and has an inner periphery 102Aa formed to expand in the outer diameter direction more than the inner periphery 101a of the first arc-shaped portion 101. In addition, the manufacturing method of the shock absorber 11A of the second embodiment includes a first bracket welding process of fixing the first bracket 15 prepared in the first bracket preparation process to the cylinder 17, a second bracket positioning process of positioning the second bracket 16A prepared in the second bracket preparation process so that the protrusion 111 (see Figure 4) abuts the outer periphery of the first bracket 15, and a second bracket welding process of passing an electric current between the first bracket 15 and the multiple protrusions 111 (see Figure 4) to perform resistance welding.

According to the second embodiment described above, as in the first embodiment, when welding the second bracket 16A to the first bracket 15, it is possible to suppress current shunting to areas other than the multiple protrusions 111 (see FIG. 4) that are the welding targets. This makes it possible to suppress deterioration of welding quality.

[Third embodiment]
A third embodiment of the present invention will be described with a focus on differences from the first embodiment, mainly with reference to Fig. 6. Note that parts common to the first embodiment will be designated by the same names and reference numerals.

In the shock absorber 11B (bracket fixing member) of the third embodiment, an insulating material 131 is provided between the first bracket 15 and the second bracket 16. The insulating material 131 is provided in the entire range where the second bracket 16 covers the first clamping portion 75 of the first bracket 15, excluding the multiple protrusions 111. The insulating material 131 is formed in a sheet shape with holes 132 at the positions of the multiple protrusions 111. The insulating material 131 is attached to the outer peripheral surface 75a of the first clamping portion 75. Note that the insulating material 131 may be formed by applying an insulating liquid agent to the outer peripheral surface 75a of the first clamping portion 75 except for the positions where the multiple protrusions 111 abut, and then curing it.

The second bracket 16 has multiple protrusions 111 that pass through corresponding holes 132 in the insulating material 131 and abut against the outer circumferential surface 75a of the first clamping portion 75 of the first bracket 15. In this state, the multiple protrusions 111 are fixed to the first clamping portion 75 by resistance welding such as projection welding. Then, the two protrusions 111 of the second bracket 16 and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111 are melted and integrated to form the fixed portion 121B.

The manufacturing method of the shock absorber 11B of the third embodiment includes a first bracket preparation step of preparing the first bracket 15, a second bracket preparation step of preparing the second bracket 16A, and a first bracket welding step similar to the first embodiment. The first bracket preparation step includes a step of arranging an insulating material 131 on the outer peripheral surface 75a of the first clamping portion 75 of the first bracket 15.

The manufacturing method of the shock absorber 11B of the third embodiment also includes a second bracket arrangement process in which the second bracket 16 prepared in the second bracket preparation process is arranged so that the protrusions 111 abut against the outer periphery of the first bracket 15. In this second bracket arrangement process, the two protrusions 111 of the second bracket 16 abut against the outer periphery 75a of the first clamping portion 75 through the corresponding holes 132 of the insulating material 131. In the second bracket arrangement process, the second bracket 16 abuts against the first bracket 15 only at these two protrusions 111. Even if the first bracket 15 has a protrusion 81, the second bracket 16 does not abut against the protrusion 81.

The manufacturing method of the shock absorber 11B of the third embodiment also includes a second bracket welding process in which current is passed between the first bracket 15 and the multiple protrusions 111 of the second bracket 16, which are arranged in the second bracket arrangement process so that the multiple protrusions 111 abut against the outer periphery of the first bracket 15, and the multiple protrusions 111. This second bracket welding process melts and integrates the two protrusions 111 of the second bracket 16 and the abutting portions of the first clamping portion 75 of the first bracket 15 against the respective protrusions 111, to form two fixed portions 121B. Even if the first bracket 15 has a protrusion 81, the second bracket 16 does not abut against the protrusion 81 in the second bracket welding process.

In addition, in the manufacturing method of the shock absorber 11B of the third embodiment, the first bracket welding process may be performed before the second bracket placement process or after the second bracket welding process.

In the shock absorber 11B of the third embodiment, an insulating material 131 is provided at a position other than the protrusion 111 between the first bracket 15 and the second bracket 16. Therefore, when welding the second bracket 16 to the first bracket 15, it is possible to further suppress the shunting of current flowing to areas other than the multiple protrusions 111 that are the welding targets. This makes it possible to further suppress the deterioration of welding quality.

In the above-described first to third embodiments, the second bracket 16, 16A is welded to the first bracket 15 as an arc-shaped base member, but the present invention can also be applied to a case where the second bracket 16, 16A is directly welded to the cylindrical cylinder 17 instead of the first bracket 15, such as by modifying the first embodiment and directly welding the multiple protrusions 111 of the second bracket 16 to the side wall portion 21 of the outer tube 14 of the cylindrical cylinder 17, as in the shock absorber 11C (bracket fixing member) shown in FIG. 7. When modifying the third embodiment, the insulating material 131 is provided in the portion covered by the first arc-shaped portion 101 of the side wall portion 21 of the outer tube 14.

In addition, in the shock absorbers 11, 11A to 11C, the second bracket 16, 16A is attached to the first bracket 15 or cylinder 17 by welding, but the present invention can also be applied to cases where a bracket is attached to a base member by welding in a device other than a shock absorber. That is, when welding a bracket to a cylindrical or arc-shaped base member, the bracket can be structured so that it has multiple fixing parts provided in the circumferential direction of the base member, is arranged so as to overlap with the outer periphery of the base member, and the fixing parts are fixed to the base member by resistance welding, and has an arc-shaped part formed so that the curvature of the outer circumferential portion is wider in the outer diameter direction than the curvature between at least the multiple fixing parts.

The bracket fixing member of the first aspect of the embodiment described above has a cylindrical or arc-shaped base member, and a bracket having a plurality of fixing parts provided in the circumferential direction of the base member, which are arranged so as to overlap with the outer periphery of the base member and are fixed to the base member by resistance welding, and which has an arc-shaped part formed so that the curvature of the outer circumferential portion is wider in the outer diameter direction than the curvature between at least the plurality of fixing parts. This makes it possible to suppress deterioration of welding quality.

The bracket fixing member of the second aspect of the embodiment is the bracket fixing member of the first aspect, wherein the circumferential outer portion of the bracket is spaced apart from the base member.

The shock absorber of the third aspect of the embodiment is a shock absorber equipped with a cylindrical cylinder, and has a first bracket and a second bracket. The first bracket is formed by molding a plate material so as to cover at least a part of the outer periphery of the cylinder. The first bracket is fixed to the cylinder. The second bracket has a holding portion, a plurality of fixing portions, and an arc-shaped portion. The holding portion holds a separate member. The fixing portion is provided in the circumferential direction of a base member consisting of the cylinder or the first bracket. The fixing portion is disposed so as to overlap with the outer periphery of the base member and is fixed to the base member by resistance welding. The arc-shaped portion is formed so that the curvature of the circumferential outer portion is wider in the outer diameter direction than the curvature between at least the plurality of the fixing portions. This makes it possible to suppress a deterioration in welding quality.

A shock absorber in a fourth aspect of the embodiment is the shock absorber in the third aspect, wherein the second bracket has an outer circumferential portion spaced apart from the base member.

The manufacturing method of a shock absorber according to the fifth aspect of the embodiment is a manufacturing method of a shock absorber having a cylindrical cylinder, and includes the steps of preparing a first bracket having at least a portion formed in an arc shape, and a second bracket having a first arc-shaped portion having at least a portion formed in an arc shape, a plurality of protrusions protruding from the inner circumferential side of the first arc-shaped portion, and a second arc-shaped portion that is located circumferentially outside the first arc-shaped portion and is formed in an arc shape so as to expand in the outer radial direction more than the first arc-shaped portion, a step of fixing the first bracket to the cylinder, a step of arranging the second bracket so that the protrusions abut against the outer periphery of a base member made of the cylinder or the first bracket, and a step of resistance welding by passing an electric current between the base member and the protrusions. This makes it possible to suppress deterioration of welding quality.

The above-mentioned shock absorber and shock absorber manufacturing method make it possible to suppress deterioration in welding quality.

11, 11A, 11B, 11C Shock absorber (bracket fixing member)
15 First bracket (base member)
16, 16A Second bracket (bracket)
17 Cylinder (base member)
91, 91A: Arc-shaped portion 92: Holding portion 101: First arc-shaped portion 102, 102A: Second arc-shaped portion (outer portion in the circumferential direction)
111 Protruding portion 121 Fixing portion

Claims (5)

A cylindrical or arc-shaped base member;
A bracket including a fixing portion and an arc-shaped portion;
Equipped with
the fixing portion is provided in a plurality of parts in a circumferential direction of the base member, the fixing portion is arranged so as to overlap with an outer circumferential side of the base member, and the fixing portion is fixed to the base member by resistance welding;
A bracket fixing member in which the arc-shaped portion includes a first arc-shaped portion formed between a plurality of the fixing portions, a second arc-shaped portion having a larger diameter than the first arc-shaped portion and positioned circumferentially outward, and a connecting portion connecting the first arc-shaped portion and the second arc-shaped portion . The bracket fixing member according to claim 1,
The bracket fixing member, wherein the second arcuate portion of the bracket is spaced apart from the base member. A shock absorber having a cylindrical cylinder,
a first bracket formed by molding a plate material so as to cover at least a portion of an outer circumferential side of the cylinder and fixed to the cylinder;
A second bracket;
having
The second bracket is
A holding portion for holding a separate member;
A plurality of fixing portions in a circumferential direction of a base member formed of the cylinder or the first bracket;
a first arc-shaped portion between at least a plurality of the fixing portions, a second arc-shaped portion having a larger diameter than the first arc-shaped portion and disposed circumferentially outward, and a connecting portion that connects the first arc-shaped portion and the second arc-shaped portion is formed in the arc-shaped portion;
the fixing portion is disposed so as to overlap an outer circumferential side of the base member and is fixed to the base member by resistance welding. The shock absorber according to claim 3,
The second bracket has a second arcuate portion spaced apart from the base member. A method for manufacturing a shock absorber having a cylindrical cylinder, comprising the steps of:
A first bracket having at least a portion formed in an arc shape;
a second bracket having a first arc-shaped portion at least a portion of which is formed in an arc shape, the second bracket having a plurality of protrusions protruding toward an inner circumferential side of the first arc-shaped portion, a second arc-shaped portion located circumferentially outside the first arc-shaped portion, the second arc-shaped portion having a larger diameter than the first arc-shaped portion and formed in an arc shape so as to expand in an outer diametrical direction , and a connecting portion connecting the first arc-shaped portion and the second arc-shaped portion ;
and preparing
fixing the first bracket to the cylinder;
a step of disposing the second bracket so that the protrusion abuts against an outer periphery of a base member formed of the cylinder or the first bracket;
A step of passing an electric current between the base member and the protrusion to perform resistance welding;
A method for manufacturing a shock absorber comprising the steps of:

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