JP2017227263A - Shock absorber and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock absorber improved in assembly property in manufacturing, and to provide a method for manufacturing the shock absorber.SOLUTION: A shock absorber includes a positioning plate 41 attached to a cylinder 2 for coaxially positioning the cylinder 2 relative to an external cylinder 3 when the cylinder 2 is assembled to the external cylinder 3. Accordingly, when a rod guide 8 is assembled thereafter, the rod guide 8 can be readily fitted to the cylinder 2 and the external cylinder 3 because the cylinder 2 is coaxially positioned (fixed) relative to the external cylinder 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shock absorber and a method for manufacturing the same.

  2. Description of the Related Art As a shock absorber incorporated in a vehicle suspension device, a double-cylinder hydraulic shock absorber (hereinafter referred to as “buffer”) is known. In the shock absorber, since the axial length of the cylinder is shorter than the axial length (full length) of the outer cylinder, it is complicated to fit the rod guide into both the outer cylinder and the cylinder. On the other hand, in the damping force adjustment type shock absorber of the control valve lateral type (for example, refer to “Patent Document 1”), the cylinder swings with respect to the axis of the outer cylinder when the rod guide is assembled, and the joint (connection pipe) is the separator tube. It is a problem that it comes off from the branch pipe.

Japanese Patent Laid-Open No. 2014-199078

  Then, this invention was made | formed in view of the said situation, and it was made as a subject to provide the buffer which improved the assembly | attachment property at the time of manufacture, and the manufacturing method of the said buffer.

  In order to solve the above-described problems, a shock absorber according to the present invention is a shock absorber attached between two members that are relatively movable, a cylinder in which a working fluid is sealed, a piston inserted into the cylinder, and one end. Is connected to the piston, the other end extending to the outside of the cylinder, an outer cylinder provided on the outer periphery of the cylinder, and formed between the cylinder and the outer cylinder, and working fluid and gas Is mounted on the cylinder and the outer cylinder, and is mounted on the outer surface of the cylinder or the inner surface of the outer cylinder. The cylinder is attached to the outer cylinder. And an annular positioning plate that is positioned coaxially with respect to each other.

  In order to solve the above problems, a shock absorber manufacturing method of the present invention includes a cylinder in which a working fluid is sealed, a piston inserted into the cylinder, one end connected to the piston, and the other end of the cylinder. A piston rod extending to the outside, an outer cylinder provided on the outer periphery of the cylinder, a reservoir formed between the cylinder and the outer cylinder and enclosing a working fluid and gas, the cylinder and the outer cylinder And a rod guide for guiding the piston rod, and a step of mounting an annular positioning plate on the outer surface of the cylinder or the inner surface of the outer cylinder, Inserting a cylinder into the outer cylinder, and positioning the cylinder coaxially with respect to the outer cylinder by the positioning plate in the insertion process; While the small diameter portion of the serial rod guide is fitted to an end portion of the cylinder, and having the steps of: fitting an end portion of the outer cylinder diameter portion of the rod guide.

  ADVANTAGE OF THE INVENTION According to this invention, the buffer which improved the assembly | attachment property at the time of manufacture, and the manufacturing method of the said buffer can be provided.

It is sectional drawing by the axial plane of the buffer of this embodiment. It is an enlarged view of the principal part in FIG. It is AA arrow sectional drawing in FIG.

An embodiment of the present invention will be described with reference to the accompanying drawings.
A shock absorber 1 according to this embodiment shown in FIG. 1 is a control valve laterally mounted damping force adjusting hydraulic shock absorber provided with a damping force generating mechanism 25 described later. For convenience, the vertical direction in FIG. 1 is defined as the vertical direction in the shock absorber 1.

  The shock absorber 1 has a double cylinder structure in which an outer cylinder 3 is provided on the outer periphery of a cylinder 2, and an annular reservoir 4 is formed between the cylinder 2 and the outer cylinder 3. A piston 5 is slidably fitted into the cylinder 2, and the piston 5 divides the inside of the cylinder 2 into two chambers, a cylinder upper chamber 2A and a cylinder lower chamber 2B. One end of a piston rod 6 is connected to the piston 5 by a nut 7. The other end side (the upper side in FIG. 1) of the piston rod 6 passes through the cylinder upper chamber 2A and is inserted into the rod guide 8 and the oil seal 9 mounted on the upper ends of the cylinder 2 and the outer cylinder 3, and the cylinder 2 To the outside. A base valve 10 that separates the cylinder lower chamber 2 </ b> B and the reservoir 4 is provided at the lower end of the cylinder 2.

  The piston 5 is provided with passages 11 and 12 for communicating the cylinder upper chamber 2A and the cylinder lower chamber 2B. The passage 12 is provided with a check valve 13 that allows only working fluid to flow from the cylinder lower chamber 2B to the cylinder upper chamber 2A. On the other hand, the passage 11 is opened when the pressure of the working fluid in the cylinder upper chamber 2A reaches a constant pressure (set pressure), and the working fluid (pressure) in the cylinder upper chamber 2A is supplied to the cylinder lower chamber 2B. A disc valve 14 is provided for relief.

  On the other hand, the base valve 10 is provided with passages 15 and 16 for communicating between the cylinder lower chamber 2B and the reservoir 4. The passage 15 is provided with a check valve 17 that allows only working fluid to flow from the reservoir 4 to the cylinder lower chamber 2B. On the other hand, the passage 16 is opened when the pressure of the working fluid in the cylinder lower chamber 2B reaches a certain pressure (set pressure), and the working fluid (pressure) in the cylinder lower chamber 2B is relieved to the reservoir 4. A disc valve 18 is provided. The cylinder 2 is filled with an oil liquid as a working fluid, and the reservoir 4 is filled with an oil liquid and a gas.

  A separator tube 20 that forms an annular passage 21 between the cylinder 2 and the cylinder 2 is attached to the cylinder 2. Both end portions of the separator tube 20 are fitted (fixed) to the outer surface of the cylinder 2 via seal rings 19 each mounted in an annular seal groove. The annular passage 21 communicates with the cylinder upper chamber 2 </ b> A through a passage 22 formed in the upper end side wall of the cylinder 2. In addition, a branch pipe 34 serving as a passage communicating with the annular passage 21 projects from the lower side wall of the separator tube 20. An inflow port 24 having a large diameter with respect to the branch pipe 34 and positioned coaxially is opened on the side wall of the outer cylinder 3, and a damping force generation mechanism 25 is attached to the inflow port 24. The cylinder 2 has a shorter axial length (full length) than the outer cylinder 3. In other words, the outer cylinder 3 extends upward beyond the upper end of the cylinder 2.

(Damping force generation mechanism)
The damping force generation mechanism 25 is accommodated in a cylindrical case 26 attached to the inlet 24 of the outer cylinder 3. The damping force generation mechanism 25 includes a pilot type (back pressure type) main valve 27, a pilot valve 28 that is a solenoid-driven pressure control valve that controls the valve opening pressure of the main valve 27, and a downstream side of the pilot valve 28. A fail valve 29 that is provided and operates at the time of failure is provided. On the other hand, a connecting pipe 30 that forms an inlet passage is fitted into the branch pipe 34 in a liquid-tight manner. Here, the oil liquid as the working fluid is introduced from the annular passage 21 to the connecting pipe 30 connected to the branch pipe 34, passes through the main valve 27, the pilot valve 28, and the fail valve 29, and is further surrounded by the case 26. Flow into the chamber 26A. The oil in the chamber 26 </ b> A flows into the reservoir 4 through the passage 31 at the end of the case 26 and the inlet 24 of the outer cylinder 3.

  Here, before the main valve 27 is opened, a damping force is generated by controlling the flow of the oil liquid by the pilot valve 28. On the other hand, when the main valve 27 is opened, a damping force is mainly generated by the main valve 27. A part of the oil fluid upstream of the pilot valve 28 is introduced into a back pressure chamber 32 formed at the back of the main valve 27, and the internal pressure of the back pressure chamber 32 acts in the valve closing direction of the main valve 27. . At this time, the damping force is adjusted by adjusting the control pressure of the pilot valve 28, and the control pressure of the pilot valve 28 is adjusted by a control current supplied to the solenoid 35 through the lead wire 36. Thereby, the internal pressure of the back pressure chamber 32 changes, and the valve opening pressure and the opening degree of the main valve 27 are adjusted.

  The fail valve 29 is closed when the vehicle is stopped waiting for a signal, or when the solenoid 35 is de-energized, and the oil valve 29 is replaced with the oil valve instead of the normally open pilot valve 27. Limit the flow. Thereby, the excessive fall of damping force is prevented and moderate damping force is maintained. On the other hand, a baffle plate 33 is provided in the reservoir 4 to restrict the flow of oil that flows from the damping force generation mechanism 25 through the passage 31 and the inlet 24 of the outer cylinder 3 into the reservoir 4. The baffle plate 33 prevents the gas in the reservoir 4 from dissolving into the oil liquid by preventing the generation of vortices and bubbles near the liquid surface due to the jet of the oil liquid flowing into the reservoir 4 from the inlet 24. As a result, generation of aeration and cavitation is suppressed, and a stable damping force can be obtained.

(Positioning plate)
As shown in FIGS. 2 and 3, the shock absorber 1 has a positioning plate 41 that positions (fixes) the cylinder 2 coaxially with respect to the outer cylinder 3. The positioning plate 41 includes a cylindrical sleeve portion 42 and a flange portion 43 formed on the periphery of one end of the sleeve portion 42. The sleeve portion 42 is fitted to the outer surface of the upper end portion of the cylinder 2, that is, the outer surface of the portion protruding from the upper end of the separator tube 20. The positioning plate 41 is slidably brought into contact with the inner side surface 3 </ b> A of the outer cylinder 3 at the outer peripheral edge 43 </ b> A (outer end) of the flange portion 43 with the sleeve portion 42 attached to the cylinder 2. Thereby, the cylinder 2 and the separator tube 20 fixed to the cylinder 2 are positioned coaxially with respect to the outer cylinder 3.

  The positioning plate 41 is positioned in the vertical direction (axial direction) with respect to the cylinder 2 by having one end (lower end in FIG. 2) abutted against the upper end of the separator tube 20. Here, the reservoir 4 is vertically divided by the flange portion 43 of the positioning plate 41. For this reason, the positioning plate 41 allows the upper space 4A and the lower space 4B of the reservoir 4 to communicate with each other, that is, allows the fluid to flow between the upper space 4A and the lower space 4B of the reservoir 4. A plurality of (in this embodiment, “3”) passages 44 are provided.

  Each passage 44 is formed by cutting out the outer peripheral edge 43A of the flange portion 43, and has a constant width in the radial direction and extends in an arc shape along the outer peripheral edge 43A, as shown in FIG. In other words, the positioning plate 41 brings the cylinder 2 and the separator tube 20 into contact with the outer cylinder 3 by bringing the three abutting portions 45 formed between the adjacent passages 44 into contact with the inner surface 3A of the outer cylinder 3. Is positioned (fixed) on the same axis. That is, the cylinder 2 is supported at three points on the outer cylinder 3 through the positioning plate 41. The positioning plate 41 can be manufactured by resin molding, press molding, or the like.

(Production method)
Next, a method for manufacturing the shock absorber 1 of the present embodiment will be described. Note that, for the purpose of simplifying the description of the specification, the description of the steps that are the same as the known manufacturing method is omitted.
First, the positioning plate 41 is attached (fixed) to the outer surface of the upper end portion of the cylinder 2. The separator tube 20 is mounted (fixed) on the outer surface of the cylinder 2, and the positioning plate 41 is in contact with the upper end of the separator tube 20 in the vertical direction (axial direction) with respect to the cylinder 2. Positioned.

  Next, the cylinder 2 is inserted into the outer cylinder 3 from the upper end opening of the outer cylinder 3, and the lower end of the cylinder 2 is fitted to the base valve 10. At this time, the outer peripheral edge 43 </ b> A of the flange portion 43 of the positioning plate 41 attached to the cylinder 2, in other words, each contact portion 45 is slidably brought into contact with the inner side surface 3 </ b> A of the outer cylinder 3. Thereby, the cylinder 2 and the separator tube 20 are aligned and positioned coaxially with respect to the outer cylinder 3, and at the same time, the cylinder 2 is supported by the outer cylinder 3 through the positioning plate 41. A bottom cap 37 that supports the base valve 10 is attached to the lower end of the outer cylinder 3.

  Next, the damping force generation mechanism 25 is assembled in the case 26 joined to the outer surface of the outer cylinder 3. At the time of the assembly, the connecting pipe 30 is fitted into the branch pipe 34 of the separator tube 20. Here, the cylinder 2 has a lower end supported by the base valve 10 and an upper end supported by the outer cylinder 3 via the positioning plate 41. In other words, the cylinder 2 is supported by the positioning plate 41 with respect to the outer cylinder 3. Since it is positioned (fixed) coaxially, the cylinder 2 and the separator tube 20 are prevented from swinging with respect to the outer cylinder 3. As a result, after the connecting pipe 30 is fitted into the branch pipe 34, the connecting pipe 30 is prevented from being detached from the branch pipe 30.

  After the damping force generating mechanism 25 is assembled, the piston 5 fixed to the lower end of the piston rod 6 is inserted into the cylinder 2, and the small-diameter portion 8A of the rod guide 8 that is slidably fitted to the piston rod 6 is inserted into the cylinder. 2 and the large-diameter portion 8 </ b> B of the rod guide 8 is fitted inside the upper end of the outer cylinder 3. Also here, the cylinder 2 is positioned (fixed) coaxially with respect to the outer cylinder 3 by the positioning plate 41, so that the rod guide 6 can be easily fitted to both the cylinder 2 and the outer cylinder 3. .

  The rod guide 8 has a stepped portion 8C formed between the small-diameter portion 8A and the large-diameter portion 8B in contact with the upper end of the cylinder 2 so that the rod guide 8 can move vertically with respect to the cylinder 2 and the outer cylinder 3. Positioned in the axial direction. In this state, it is possible to generate an axial force on the cylinder 2 through the rod guide 8 by caulking the upper end of the outer cylinder 3 inward.

(effect)
According to the present embodiment, by assembling the cylinder 2 to the outer cylinder 3, the cylinder 2 is positioned (fixed) coaxially with respect to the outer cylinder 3. In other words, it is possible to suppress the shake (rattle) of the separator tube 20 attached (fixed) to the cylinder 2 with respect to the outer cylinder 3.
Accordingly, the connecting pipe 30 fitted into the branch pipe 34 of the separator tube 20 after the cylinder 2 is assembled to the outer cylinder 3 does not come off (disengage) from the branch pipe 34 of the separator tube 20, and the damping force is poor. Generation | occurrence | production can be prevented and the reliability of the buffer 1 can be improved by extension.
In addition, since the cylinder 2 is positioned (fixed) coaxially with respect to the outer cylinder 3 when the connecting pipe 30 and the rod guide 8 are assembled, the assembling property of the connecting pipe 30 and the rod guide 8 is improved. The manufacturing process can be streamlined.

  Conventionally, when the connecting pipe 30 is fitted into the branch pipe 34 of the separator tube 20 or when the rod guide 8 is fitted into the cylinder 2 and the outer cylinder 3, the outer surface of the cylinder 2 and the inner side surface 3A of the outer cylinder 3 are used. Contamination due to scratches caused by contact with the working fluid may be mixed into the working fluid and cause problems. However, in this embodiment, the cylinder 2 is already outside when the connecting pipe 30 and the rod guide 8 are assembled. Since it is positioned (fixed) coaxially with respect to the cylinder 3, the cylinder 2 and the outer cylinder 3 do not come into contact with each other at the time of assembly, so that the occurrence of contamination as described above can be prevented and extended. Can improve the reliability of the shock absorber 1.

(Modification)
In the above-described embodiment, the cylinder 2 is positioned (fixed) coaxially with respect to the outer cylinder 3 by bringing the positioning plate 41 mounted on the outer surface of the cylinder 2 into contact with the inner surface 3A of the outer cylinder 3. Configured.
On the other hand, a positioning plate (not shown) corresponding to the positioning plate 41 of the present embodiment is mounted on the outer surface of the separator tube 20, and the positioning plate is brought into contact with the inner surface 3A of the outer cylinder 3, thereby separating the separator. The tube 20 (cylinder 2) can be configured to be positioned (fixed) coaxially with respect to the outer cylinder 3.
On the other hand, a positioning plate (not shown) corresponding to the positioning plate 41 of the present embodiment is mounted on the inner surface 3A of the outer cylinder 3, and the positioning plate is brought into contact with the outer surface of the cylinder 2 or the separator tube 20, The cylinder 2 and the separator tube 20 may be configured to be positioned (fixed) coaxially with respect to the outer cylinder 3. Here, when the part (branch pipe 34) which protrudes outside is formed in the positioning object like the separator tube 20 of the present embodiment, the protruding part when the cylinder 2 is assembled to the outer cylinder 3 A notch corresponding to the passage 44 is formed in the positioning plate so as not to hit the positioning plate.

1 shock absorber, 2 cylinder, 3 outer cylinder, 4 reservoir, 5 piston, 6 piston rod, 8 rod guide, 41 positioning plate

Claims (6)

A shock absorber mounted between two relatively movable members,
A cylinder filled with a working fluid; a piston inserted into the cylinder; a piston rod having one end connected to the piston and the other end extending to the outside of the cylinder; and an outside provided on the outer periphery of the cylinder A cylinder, a reservoir formed between the cylinder and the outer cylinder, in which a working fluid and a gas are sealed, a rod guide mounted on the cylinder and the outer cylinder and guiding the piston rod, and the cylinder A shock absorber comprising: an annular positioning plate mounted on an outer side surface or an inner side surface of the outer cylinder and positioning the cylinder coaxially with respect to the outer cylinder. The separator tube is provided between the cylinder and the outer cylinder, and both ends are fitted to the outer surface of the cylinder, and the positioning plate includes an outer surface of the separator tube, an outer surface of the cylinder, or the The shock absorber according to claim 1, wherein the shock absorber is attached to an inner surface of the outer cylinder. The shock absorber according to claim 1 or 2, wherein the positioning plate has a passage for circulating the working fluid sealed in the reservoir. A cylinder filled with a working fluid; a piston inserted into the cylinder; a piston rod having one end connected to the piston and the other end extending to the outside of the cylinder; and an outside provided on the outer periphery of the cylinder A buffer provided with a cylinder, a reservoir formed between the cylinder and the outer cylinder, in which a working fluid and a gas are sealed, and a rod guide mounted on the cylinder and the outer cylinder and guiding the piston rod. A method of manufacturing a vessel,
Mounting an annular positioning plate on the outer surface of the cylinder or the inner surface of the outer cylinder;
Inserting the cylinder into the outer cylinder, and positioning the cylinder coaxially with respect to the outer cylinder by the positioning plate in the insertion process;
Fitting the large diameter portion of the rod guide to the end portion of the outer cylinder while fitting the small diameter portion of the rod guide to the end portion of the cylinder;
A method of manufacturing a shock absorber, comprising: In the step of mounting the positioning plate, the positioning plate is mounted on the outer surface of the separator tube whose both ends are fitted to the outer surface of the cylinder, the outer surface of the cylinder, or the inner surface of the outer cylinder. The manufacturing method of the shock absorber according to claim 4 characterized by things. A step of fitting a connecting pipe approached from the outside of the outer cylinder to a branch pipe of the separator tube while the cylinder is positioned coaxially with respect to the outer cylinder by the positioning plate; The manufacturing method of the buffer according to claim 5.

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