JP2009162324A - Pneumatic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic shock absorber, capable of preventing lubricant from running out, easily recovering lubricant, and simplifying structure. <P>SOLUTION: The pneumatic shock absorber D is provided with a cylinder 1, a piston 2 to part the inside of the cylinder 1 to a rod side chamber R1 and a piston side chamber R2, a rod 3 movably inserted into the cylinder 1 through the piston 2, a circular rod guide 4 axially supporting the rod 3, and a seal member 5 laminated on the rod guide 4 to seal the outer circumference of the rod 3. It is also provided with an oil storage chamber T facing slide parts of the rod 3 and the seal member 5 to store lubricant, an external passage 4d to connect the oil storage chamber T to the external, a connecting passage 11 to connect the oil storage chamber T into the cylinder 1, and a tap 15 capable of opening/closing the connecting passage 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  Conventionally, a pneumatic shock absorber includes a cylinder, a piston that is slidably inserted into the cylinder, and a rod that is movably inserted into the cylinder via the piston, and the working fluid is gas. It has been known.

  In this pneumatic shock absorber, the outer periphery of the rod is sealed with a sealing member fixed to the end of the cylinder in order to prevent leakage of the working gas filled in the cylinder to the outside.

In such a pneumatic shock absorber, since the rod enters and exits the cylinder and the working fluid is a gas, the seal member is liable to deteriorate unless care is taken. Therefore, the rod outer periphery and the seal are supported on the rod guide that supports the rod. An oil storage chamber facing the sliding part with the member is provided, a small amount of lubricating oil is filled in the oil storage chamber, and an oil film is formed on the outer periphery of the rod with the lubricating oil to prevent deterioration of the seal member. By doing so, the pneumatic shock absorber can be applied to places where vibration input is frequently performed, for example, between the vehicle body and the axle of the vehicle (see, for example, Patent Document 1).
JP 2006-349138 A

  The pneumatic shock absorber as described above is a useful technique in terms of ensuring good sealing performance, but there is a possibility that the following problems may be pointed out.

  In other words, conventional pneumatic shock absorbers use a small amount of lubricating oil in addition to gas. Therefore, when disposing of the pneumatic shock absorber, the lubricating oil must be recovered to prevent environmental contamination. However, the conventional pneumatic shock absorber structure cannot recover the lubricating oil unless it is decomposed, and the recovery operation becomes very troublesome.

  In addition, the lubricating oil in the oil storage chamber gradually falls from the oil storage chamber to the piston side chamber through the rod side chamber due to long-term use, and the lubricating oil is exhausted in the oil storage chamber. In addition to forming the oil storage chamber, a mechanism is required to feed the lubricating oil that has fallen into the cylinder from the piston side chamber to the oil storage chamber, which complicates the structure of the pneumatic shock absorber, increases its weight, and increases the number of parts. .

 Therefore, the present invention was devised to improve the above-described problems, and the object of the present invention is to prevent the lubricating oil from being depleted, to easily collect the lubricating oil, and to have a simple structure. Is to provide a pneumatic shock absorber.

  In order to achieve the above object, the problem-solving means of the present invention includes a cylinder, a piston that divides the cylinder into a rod-side chamber and a piston-side chamber, a rod that is movably inserted into the cylinder via the piston, In a pneumatic shock absorber comprising an annular rod guide that closes one end of a cylinder and pivotally supports a rod, and a seal member that is stacked on the rod guide and seals the outer periphery of the rod, sliding between the rod and the seal member An oil storage chamber that stores the lubricating oil facing the section, an external passage that communicates the oil storage chamber with the outside, a communication passage that communicates the oil storage chamber and the inside of the cylinder, and a plug that can open and close the communication passage are provided.

  According to the pneumatic shock absorber of the present invention, the lubricating oil can be easily refilled into the oil storage chamber facing the sliding portion between the rod and the seal member without disassembling the pneumatic shock absorber, so that the refilling operation is easy. In addition, it is possible to prevent depletion of the lubricating oil in the oil storage chamber without requiring that the pneumatic shock absorber be provided with a pump mechanism that causes an increase in weight and a complicated structure. Further, when the pneumatic shock absorber is discarded, the air pressure in the cylinder can be applied to the oil storage chamber via the communication path, so that the lubricating oil can be quickly and easily recovered from the oil storage chamber.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a schematic longitudinal sectional view of a pneumatic shock absorber. FIG. 2 is a perspective view of the rod guide.

  As shown in FIG. 1, the pneumatic shock absorber D in one embodiment basically includes a cylinder 1, a piston 2 that partitions the cylinder 1 into a rod side chamber R <b> 1 and a piston side chamber R <b> 2, and a piston 2. A rod 3 that is movably inserted into the cylinder 1, an annular rod guide 4 that pivotally supports the rod 3, and a seal member 5 that is stacked on the rod guide 4 and seals the outer periphery of the rod 3. It is configured.

  In the following, the cylinder 1 is formed in a cylindrical shape, and a piston 2 is slidably inserted therein. The piston 2 divides the inside of the cylinder 1 into an upper rod side chamber R1 and a lower piston side chamber R2 in FIG. 1, and a rod 3 is connected to the upper end of the piston 2 in FIG.

  The pneumatic shock absorber D includes an outer cylinder 6 that covers the cylinder 1, and an annular rod guide 4 is fitted to the upper end of the cylinder 1 and the upper end of the outer cylinder 6. The upper end of the cylinder 1 and the outer cylinder 6 is closed, and the rod 3 is slidably supported via a bearing 7 fixed to the inner periphery.

  As shown in FIGS. 1 and 2, the rod guide 4 includes a small-diameter holding portion 4a for holding the bearing 7 and the seal ring 8 from below on the inner periphery, an intermediate portion 4b having an inner diameter larger than the holding portion 4a, A large-diameter portion 4c having an inner diameter larger than that of the intermediate portion 4b, an external passage 4d that leads from the lower side of the intermediate portion 4b to the upper end of the rod guide 4, a vertical hole 4e that leads from the upper end to the lower end of the rod guide 4, and the intermediate portion 4b A lateral hole 4f that communicates with the longitudinal hole 4e from above, and a flow path 4g that communicates a gap between the rod side chamber R1, the cylinder 1, and the outer cylinder 6. In FIG. 2, the illustration of the bearing 7 and the seal ring 8 is omitted because the drawing becomes complicated.

  The lower ends of the cylinder 1 and the outer cylinder 6 are closed by a bottom member 9, and the bottom member 9 includes a through hole 9 a that communicates the piston side chamber R 2 with a gap between the cylinder 1 and the outer cylinder 6, And a damping force generating element 9b such as a throttle valve provided in the middle of the through hole 9a.

  Therefore, in the case of the pneumatic shock absorber D in this embodiment, the rod side chamber R1 and the piston side chamber R2 are provided in the flow path 4g provided in the rod guide 4, the gap between the cylinder 1 and the outer cylinder 6, and the bottom member 9. The passage 10 is communicated via a passage 10 formed by the provided through hole 9a. The passage 10 bypasses the inside of the cylinder 1 and communicates the rod side chamber R1 and the piston side chamber R2.

  The damping force generation element 9b may be any element that provides resistance to the gas flow, and other types of valves such as a leaf valve and a poppet valve can be used in addition to the throttle valve.

  Further, in the case of this pneumatic shock absorber D, a seal member 5 is provided which is disposed in the large-diameter portion 4c of the rod guide 4 and is laminated on the upper side of the rod guide 4 in FIG. The outer periphery of the rod 3 and the rod guide 4 are sealed, and the upper end opening end of the outer cylinder 6 is crimped together with the rod guide 4 to be fixed to the outer cylinder 6. With this configuration, the cylinder 1 is sandwiched between the rod guide 4 and the bottom member 9 and fixed to the outer cylinder 6 in a state of being positioned in the radial direction and the axial direction.

  In this embodiment, an annular spacer is provided between the open end of the outer cylinder 6 and the seal member 5 so that the seal member 5 and the rod guide 4 can be fixed by caulking the open end of the outer cylinder 6. The seal member 5 is pressed downward in FIG. Further, instead of caulking the opening end of the outer cylinder 6, a configuration that covers the opening end of the outer cylinder 6 by, for example, screwing a cap allowing the insertion of the rod 3 to the upper end of the outer cylinder 6 is adopted, The spacer 19 may be pressed with the cap.

  Returning, the seal member 5 is an annular plate-shaped insert metal 5a, a lip 5b held on the inner periphery of the insert metal 5a and slidably in contact with the outer periphery of the rod 3, and a lower surface of the insert metal 5a. 4 is provided with a seal portion 5c that tightly seals a step portion formed at the boundary between the intermediate portion 4b and the large diameter portion 4c, and the rod guide 4 and the rod 3 are maintained in an airtight state. Yes.

  Further, a seal ring 12 is interposed between the rod guide 4 and the outer cylinder 6, and together with the seal member 5, the cylinder 1 and the outer cylinder 6 are maintained in an airtight state.

  The rod guide 4 described above forms an oil storage chamber T with an annular gap between the intermediate portion 4 b and the rod 3. The oil storage chamber T faces the sliding portion S between the lip 5b and the rod 3 in the seal member 5 described above, and the oil storage chamber T is filled with the lubricating oil J1, and the lower end of the lip 5b is immersed in the oil. Thus, the sliding portion S can be lubricated.

  The oil storage chamber T is communicated to the outside of the pneumatic shock absorber D by the external passage 4d formed in the rod guide 4 as described above, and the rod that is inside the cylinder 1 through the vertical hole 4e and the horizontal hole 4f. The side chamber R1 is also communicated. In this case, the communication passage 11 is formed by the vertical hole 4e and the horizontal hole 4f.

  A plug 14 is screwed into the external passage 4d, and a plug 15 is screwed into the vertical hole 4e. The plug 14 includes a shaft portion 14a in which a screw groove that is screwed into the external passage 4d is formed, and a head portion 14b provided at the upper end of the shaft portion 14a in FIG. 1, and rotates the head portion 14b. Thus, it can be attached to and detached from the external passage 4d. Further, when the plug 14 is screwed to the outer passage 4d to the deepest depth, a seal ring 14c mounted on the outer periphery of the upper end of the shaft portion 14a is compressed and sandwiched between the head 14b of the plug 14 and the rod guide 4, and the plug 14 14 and the external passage 4d are sealed, and communication with the outside through the external passage 4d of the oil storage chamber T is tightly cut off.

  Further, the plug 15 includes a shaft portion 15a having a screw groove that is screwed into the vertical hole 4e, and a head portion 15b provided at the upper end of the shaft portion 15a in FIG. By doing so, it can be attached to and detached from the vertical hole 4e.

  Then, when the stopper 15 is screwed to the deepest depth with respect to the vertical hole 4e, a tip 15c having a tapered surface of the shaft portion 15a is provided below the connecting portion of the vertical hole 4e to the horizontal hole 4f in FIG. The vertical hole 4e can be closed by close contact with the inner edge of the stepped portion 4h to cut off the communication between the oil storage chamber T and the rod side chamber R1, and a seal ring 15d mounted on the outer periphery of the upper end of the shaft portion 15a It is compressed and clamped between the head portion 15b and the rod guide 4, the gap between the stopper 15 and the vertical hole 4e is sealed, and communication with the outside through the vertical hole 4e of the oil storage chamber T is tightly cut off. It is like that. That is, in this case, an opening / closing valve is constituted by the tip of the stopper 15 and the step portion 4h in the vertical hole 4e, and the communication passage 11 can be opened and closed by rotating the stopper 15.

  That is, the external passage 4d and the communication passage 11 that connect the oil storage chamber T to the outside and the rod side chamber R1 in the cylinder 1 are closed by the plug 14 and the plug 15, respectively, so that the lubricating oil filled in the oil storage chamber T is filled. The oil J1 is prevented from leaking outside and into the cylinder 1 through these passages 4d and 11. Further, since the vertical hole 4e is tightly closed by the plug 15, the sealed gas is prevented from leaking from the inside of the cylinder 1, and the inside of the cylinder 1 is maintained in an airtight state.

  In this embodiment, a through hole (not shown) is provided in the caulked portion of the outer cylinder 6 so that the plug 14 and the plug 15 screwed to the rod guide 4 can be externally operated. ing.

  In the case of this pneumatic shock absorber D, there is no flow path connecting the oil storage chamber T to the rod side chamber R1, and the lubricant oil J1 leaks from the oil storage chamber T to the rod side chamber R1 between the rod 3 and the seal ring 8. Therefore, if the lubricating oil J1 is filled in the oil storage chamber T in this way, the sliding portion S between the rod 3 and the seal member 5 is formed over a long period of time. Can be lubricated.

  In this embodiment, the rod side chamber R1 is filled with lubricating oil J2 so that the sliding portion between the inner periphery of the cylinder 1 and the outer periphery of the piston 2 can be lubricated. In the case of this pneumatic shock absorber D, the passage 10 bypasses the inside of the cylinder 1, and the piston 2 does not have a flow path that connects the rod side chamber R1 and the piston side chamber R2, and the lubricating oil J2 enters the piston side chamber R2. Since leakage occurs only through a narrow sliding gap between the cylinder 1 and the piston 2, if the lubricating oil J2 is filled in the rod-side chamber R1 in this way, the cylinder 1 and the piston over a long period of time. 2 can be lubricated.

  In the pneumatic shock absorber D configured in this manner, when the piston 2 moves upward in FIG. 1 and extends, gas is transferred from the rod side chamber R1 to be compressed to the piston side chamber R2 that is expanded through the passage 10. Moving. A resistance is applied to the gas flow by a damping force generating element 9b provided on the bottom member 9, and the pneumatic shock absorber D generates an extension side damping force.

  On the other hand, when the piston 2 moves downward in FIG. 1 and contracts, the gas moves from the compressed piston side chamber R2 to the rod side chamber R1 that expands through the passage 10. A resistance is applied to the gas flow by a damping force generating element 9b provided in the bottom member 9, and the pneumatic shock absorber D generates a compression side damping force.

  Although the pneumatic shock absorber D operates as described above, the lubricating oil J1 eventually falls into the cylinder 1 as a result of continuous use for a long period of time, and the lubricating oil J1 in the oil storage chamber T is depleted. Will go.

  If a sufficient amount of the lubricating oil J1 does not exist in the oil storage chamber T, the sealing member 5 may be worn out and the sealing performance may be deteriorated. However, in the pneumatic shock absorber D of this embodiment, the oil storage Since the external passage 4d that communicates the chamber T with the outside is provided, the plug 14 can be removed by operating from the outside of the pneumatic shock absorber D, and the lubricating oil J1 can be replenished to the oil storage chamber T via the external passage 4d. it can.

  As described above, in the pneumatic shock absorber D of the present embodiment, the lubricating oil J1 can be easily obtained without disassembling the pneumatic shock absorber D into the oil storage chamber facing the sliding portion S between the rod 3 and the seal member 5. Therefore, the lubricating oil in the oil storage chamber T can be easily replenished, and it is not necessary to provide the pneumatic shock absorber D with a pump mechanism that increases the weight or complicates the structure. J1 depletion can be prevented.

  Further, when the pneumatic shock absorber D is discarded, the lubricating oil J1 can be easily recovered from the oil storage chamber T via the external passage 4d. At the time of recovery of the lubricating oil J1, the pressure of the gas in the cylinder 1 can be applied to the oil storage chamber T by loosening the stopper 15 and separating the tip 15c from the inner edge of the step 4h of the vertical hole 4e. Lubricating oil J1 can be quickly discharged from the oil storage chamber T through the passage 4d, which can greatly contribute to reducing the burden and shortening the time for the lubricating oil recovery work.

  Further, as shown in FIG. 2, the connection portion a of the lateral hole 4 f constituting the communication passage 11 to the oil storage chamber T is disposed above the connection portion b of the external passage 4 d to the oil storage chamber T. Therefore, when the lubricating oil J1 is discharged, the lubricating oil J1 can be discharged preferentially and reliably by supplying gas from the cylinder 1 into the oil storage chamber T via the communication path 11, which is very convenient.

  Further, since the communication passage 11 communicates with the outside via the oil storage chamber T and the external passage 4d, the lubricant oil J2 left in the rod side chamber R1 can be recovered, and the lubricant oil J2 is depleted in the rod side chamber R1. In this case, the lubricating oil J2 can be replenished into the cylinder 1. In order to recover the lubricating oil J2 in the rod side chamber R1, the pneumatic shock absorber D is turned upside down from the posture shown in FIG. 1, and the lubricating oil J2 is collected around the vertical hole 4e, so that the cylinder 1 The lubricating oil J2 can be discharged preferentially by the pressure of the gas inside. Therefore, in this case, the lubricating oil J2 necessary for lubricating the sliding portion between the cylinder 1 and the piston 2 can be replenished, so that the pneumatic shock absorber D can be used for a longer period of time. At the same time, smooth expansion and contraction can be realized over a longer period, and the reliability and practicality of the pneumatic shock absorber D are improved.

  Further, since the inside of the cylinder 1 is communicated with the outside, gas can be supplied into the cylinder 1 and gas can be discharged from the cylinder 1, so that the pressure in the cylinder 1 can be tuned.

  In the case of this embodiment, the vertical hole 4e passes through the top and bottom of the rod guide 4 and can directly communicate with the outside through the cylinder 1. Therefore, the lubricating oil J2 is not connected to the oil storage chamber T. It is also possible to perform the supply and discharge, and the work can be completed quickly.

  Furthermore, in the case of this embodiment, since the external passage 4d and the communication passage 11 are provided in the rod guide 4, the configuration relating to the supply and discharge of the lubricating oil J1 can be integrated into the rod guide 4, and the rod guide There is an advantage that various functions and effects can be enjoyed with only four replacements.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a schematic longitudinal cross-sectional view of a pneumatic shock absorber. It is a perspective view of the rod guide of a pneumatic shock absorber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Rod 4 Rod guide 4a Holding part 4b in a rod guide Intermediate part 4c in a rod guide Large diameter part 4d in a rod guide External passage 4e in a rod guide Vertical hole 4f in a rod guide Horizontal hole 4g in a rod guide In a rod guide Channel 4h Step 5 in the vertical hole of the rod guide 5 Seal member 5a Insert metal 5b in the seal member Lip 5c in the seal member Seal portion 6 in the seal member Outer cylinder 7 Bearing 8, 12 Seal ring 9 Bottom member 9a Through hole 9b Damping force Generating element 10 Passage 11 Communication passage 14 Plug 14a Plug shaft 14b Plug head 14c Plug seal ring 15 Plug 15a Plug shaft 15b Plug head 15c Plug tip 15 Seal ring a in plug, b connecting section D pneumatic shock absorber J1, J2 lubricant R1 rod side chamber R2 piston side chamber S sliding portion T oil storage chamber

Claims (3)

A cylinder, a piston that divides the inside of the cylinder into a rod side chamber and a piston side chamber, a rod that is movably inserted into the cylinder via the piston, and an annular rod guide that closes one end of the cylinder and pivotally supports the rod And a pneumatic shock absorber provided with a seal member that is stacked on the rod guide and seals the outer periphery of the rod, an oil storage chamber that stores lubricating oil facing a sliding portion between the rod and the seal member, and the oil storage chamber An pneumatic shock absorber comprising an external passage communicating with the outside, a communication passage communicating between the oil storage chamber and the cylinder, and a plug capable of opening and closing the communication passage. The pneumatic shock absorber according to claim 1, wherein the external passage and the communication passage are formed in a rod guide. The pneumatic shock absorber according to claim 1 or 2, wherein the connecting portion of the communication passage to the oil storage chamber is disposed above the connecting portion of the external passage to the oil storage chamber.

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