US-12618447-B2 - Method of manufacturing shock absorber

Abstract

A damping unit and an actuating unit of a damping force adjustment mechanism are inserted into a case provided to a side portion of an outer tube (outer cylinder). After the damping unit and the actuating unit are fastened together, a shock absorber main body with an upper end (another end) of a piston rod facing down is placed in a spring seat fixing jig, and a spring seat is fixed (press-fitted) over the shock absorber main body. A spring seat support portion of the spring seat fixing jig is not arranged between the damping force adjustment mechanism or a bracket and the spring seat. Thus, the spring seat can be fixed (press-fitted) over the shock absorber main body (outer cylinder) without being restricted by an arrangement of the damping force adjustment mechanism or the bracket.

Inventors

• Wataru Takagi

Assignees

• HITACHI ASTEMO, LTD.

Dates

Publication Date

20260505

Application Date

20220909

Priority Date

20211022

Claims (5)

1. 1 . A method of manufacturing a shock absorber, the shock absorber comprising: an inner cylinder; an outer cylinder having a bottomed tubular shape, which defines, in combination with the inner cylinder, a reservoir; a piston inserted into the inner cylinder; a piston rod having one end coupled to the piston and another end extending to an outside through an opening of the outer cylinder; a damping force adjustment mechanism provided to a side portion of the outer cylinder, the damping force adjustment mechanism including a damping unit capable of adjusting a damping force and an actuating unit capable of actuating the damping unit; and a spring seat, which is fixed to the outer cylinder and is configured to receive a suspension spring, the method comprising: a fastening step of fastening the damping unit and the actuating unit together, which are provided to the side portion of the outer cylinder; and a spring-seat fixing step of fixing the spring seat to the outer cylinder after the fastening step, wherein the spring-seat fixing step comprises a pushing step of pushing a bottom portion of a shock absorber main body under a state in which the another end of the piston rod is facing down.
2. 2 . The method of manufacturing a shock absorber according to claim 1 , wherein a distance between the damping force adjustment mechanism and the spring seat is set to 30 mm or less.
3. 3 . The method of manufacturing a shock absorber according to claim 1 , wherein, in the fastening step, a jig is pushed in a radial direction of the damping force adjustment mechanism.
4. 4 . The method of manufacturing a shock absorber according to claim 1 , wherein, in the fastening step, a jig is pushed in an axial direction of the damping force adjustment mechanism.
5. 5 . The method of manufacturing a shock absorber according to claim 1 , further comprising, after the fastening step, a bracket fixing step of fixing a bracket to the outer cylinder so that the bracket is located at a position closer to a bottom portion of the outer cylinder than the spring seat.

Description

TECHNICAL FIELD The present invention relates to a method of manufacturing a damping force adjustable shock absorber that adjusts a damping force by controlling a flow of a working fluid caused along with a stroke of a piston rod. BACKGROUND ART In Patent Literature 1, there is described a damping force adjustable hydraulic shock absorber of control-valve side-mounting type (hereinafter referred to as “control-valve side-mounting type shock absorber”). In the control-valve side-mounting type shock absorber, a side wall of a case 25 is crimped toward an annular groove 60 formed in an outer periphery of a solenoid case 42 to form a crimped portion 61 in the side wall of the case 25. In this manner, the solenoid case 42 is fixed to the case 25. CITATION LIST Patent Literature PTL 1: JP 2015-197126 A SUMMARY OF INVENTION Technical Problem In general, a shape and an arrangement of a spring seat or a bracket, each to be fixed to a shock absorber main body (outer cylinder), differ for each vehicle model. In the control-valve side-mounting type shock absorber, an arrangement of a control valve (damping force adjustment mechanism) or the spring seat is determined in accordance with a vehicle layout. In the control-valve side-mounting type shock absorber described above, after the spring seat is fixed to the outer cylinder, a damping unit (valve mechanism unit) and an actuating unit (actuator) of the damping force adjustment mechanism that is provided to a side portion of the outer cylinder are fastened together with a fastening jig. When a distance between the control valve (damping force adjustment mechanism) and the spring seat in an axial direction is short (for example, 30 mm or less), however, the fastening jig cannot be brought closer to a case accommodating the damping force adjustment mechanism, which is to be joined to the side portion of the outer cylinder. Thus, after the damping unit and the actuating unit of the damping force adjustment mechanism are fastened together with the fastening jig, the spring seat is press-fitted over the shock absorber main body (outer cylinder). In this case, the spring seat is required to be restricted from rotating in a direction about an axis (is required to be positioned) with respect to the shock absorber main body. However, there arises a problem in that a rotation restricting jig for the spring seat may interfere with the control valve or the bracket. The present invention has an object to provide a method of manufacturing a shock absorber, which enables press-fitting of a spring seat over a shock absorber main body without being restricted by an arrangement of a damping force adjustment mechanism or a bracket. Solution to Problem According to the present invention, there is provided a method of manufacturing a shock absorber, the shock absorber including: an inner cylinder; an outer cylinder having a bottomed tubular shape, which defines, in combination with the inner cylinder, a reservoir; a piston inserted into the inner cylinder; a piston rod having one end coupled to the piston and another end extending to an outside through an opening of the outer cylinder; a damping force adjustment mechanism provided to a side portion of the outer cylinder, the damping force adjustment mechanism including a damping unit capable of adjusting a damping force and an actuating unit capable of actuating the damping unit; and a spring seat, which is fixed to the outer cylinder and is configured to receive a suspension spring, the method including: a fastening step of fastening the damping unit and the actuating unit together, which are provided to the side portion of the outer cylinder; and a spring-seat fixing step of fixing the spring seat to the outer cylinder after the fastening step. The method of manufacturing a shock absorber according to one embodiment of the present invention enables press-fitting of a spring seat over a shock absorber main body without being restricted by an arrangement of a damping force adjustment mechanism or a bracket. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a sectional view of a shock absorber according to an embodiment. FIG. 2 is an enlarged view of a damping force adjustment mechanism of FIG. 1. FIG. 3 is a view of the shock absorber according to the embodiment when viewed from a bottom portion side. FIG. 4 is a conceptual diagram of a spring seat fixing jig to be used for a method of manufacturing a shock absorber according to the embodiment. FIG. 5 is an explanatory view for illustrating a shock absorber main body that is placed in the spring seat fixing jig. DESCRIPTION OF EMBODIMENTS One embodiment of the present invention is described with reference to the accompanying drawings. A shock absorber 1 illustrated in FIG. 1 is a damping force adjustable hydraulic shock absorber of a so-called control-valve side-mounting type in which a damping force adjustment mechanism 31 is horizontally mounted to a side portion of an outer tube 3 (outer cylinder)