JP2007024158A - Pneumatic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic shock absorber causing no delay in generating damping force while securing a basic length. <P>SOLUTION: The pneumatic shock absorber K comprises a cylinder 1, a piston 2 slidably inserted in the cylinder 1 to partition a working chamber A formed in the cylinder 1, into one chamber R1 and the other chamber R2, and a rod 3 inserted in the cylinder 1 movably through the piston 2. One or both of the one chamber R1 and the other chamber R2 are provided with a pair of partition wall bodies 41, 42 coming in sliding contact with the inner periphery of the cylinder 1 to form a space 43 isolated from the working chamber A, and the rod 3 is provided with a passage 41 by-passing the isolated space 43. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shock absorber mounted on a vehicle or the like, and more particularly to an improvement of a pneumatic shock absorber that can be used as a suspension of a vehicle or the like.

  2. Description of the Related Art 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 (for example, Patent Documents 1 and 2).

In this pneumatic shock absorber, a working chamber formed in a cylinder is divided into one chamber and the other chamber by a piston, gas is sealed as a working fluid in this working chamber, and when a damping force is generated, a hydraulic shock absorber and Similarly, one of the chambers or the other chamber is compressed with a piston so as to cause a difference between the one indoor pressure and the other indoor pressure.
JP 2004-132429 A JP 2004-132428 A

  Now, the pneumatic shock absorber as described above is a useful technique in that the weight of the shock absorber is reduced by using a gas as the working fluid, but there are the following problems.

  That is, when using a conventional pneumatic shock absorber as a vehicle suspension, it is necessary to secure a mounting length equivalent to that of a vehicle hydraulic shock absorber. It will be the same level.

  Then, as described above, the pneumatic shock absorber uses the working fluid as a gas, and the gas is rich in compressibility and has a small bulk elastic modulus. Therefore, the pneumatic shock absorber expands and contracts compared to a hydraulic shock absorber that uses working oil as the working fluid. The pressure increase in the one chamber or the other chamber to be compressed is delayed with respect to the volume change of the one chamber or the other chamber to be compressed at the time of operation.

  Therefore, the conventional pneumatic shock absorber has a problem that the generation of the required damping force is delayed as compared with the hydraulic shock absorber.

  Therefore, the present invention was devised to improve the above-described problems, and an object of the present invention is to provide a pneumatic shock absorber that does not delay the generation of damping force while ensuring the basic length. That is.

  The problem-solving means of the present invention includes a cylinder, a piston that is slidably inserted into the cylinder and that defines a working chamber formed in the cylinder into one chamber and the other chamber, and is movable into the cylinder via the piston. A pair of pneumatic shock absorbers that are coupled to the rod in one or both of the one chamber and the other chamber and that are in sliding contact with the inner periphery of the cylinder to form a space isolated from the working chamber. A partition wall is provided, and a flow path that bypasses the isolated space is provided in the rod.

  According to the pneumatic shock absorber of the present invention, the volume formed by the partition body and the partition body can reduce the volume in the working chamber. The generation of force will not be delayed.

  Further, in this pneumatic shock absorber, the basic length is secured and the generation delay of the damping force is avoided by accommodating the partition wall in the working chamber. Since it is not necessary to shorten the vertical length and further increase the vertical length of the rod, there is no need to design and manufacture a cylinder or rod as a special product for pneumatic shock absorbers. Since the rod can be used as it is, the cost of developing and manufacturing a pneumatic shock absorber can be reduced. Furthermore, the structure is simple and the weight of the pneumatic shock absorber is extremely increased. There is no practical.

  Therefore, in this pneumatic shock absorber, it is possible to secure the mountability in the vehicle and the riding comfort in the vehicle while reducing the cost.

  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 schematic longitudinal sectional view of a pneumatic shock absorber according to a modification of the embodiment. FIG. 3 is a schematic longitudinal sectional view of a pneumatic shock absorber according to another embodiment.

  As shown in FIG. 1, the pneumatic shock absorber K in one embodiment is divided into a cylinder 1 and a working chamber A formed in the cylinder 1 into a rod side chamber R1 that is one chamber and a piston side chamber R2 that is the other chamber. A piston 2 that is movably inserted into the cylinder 1 via the piston 2, and a rod side chamber R1 that is coupled to the rod 3 and slidably contacts the inner periphery of the cylinder 1 and is isolated from the working chamber A. And a pair of partition walls 41 and 42 that form a space 43 and a flow path 31 that is provided in the rod 3 and bypasses the space 43.

  In the following, the cylinder 1 is formed in a cylindrical shape, and the upper and lower ends thereof are closed by the head member 5 and the bottom member 6, respectively, whereby the working chamber A is separated in the cylinder 1. Furthermore, the working chamber A is divided into a rod side chamber R1 and a piston side chamber R2 by a piston 2 slidably inserted into the cylinder 1.

  The piston 2 is connected to the rod 3 and is provided with passages 21 and 22 for communicating the rod-side chamber R1 and the piston-side chamber R2, and damping force generating elements 23 and 24 are provided in the middle of the passages 21 and 22. Is provided.

  Further, a check valve 25 that allows only a flow from the rod side chamber R1 to the piston side chamber R2 is provided in the middle of the passage 21, and only a flow from the piston side chamber R2 to the rod side chamber R1 is provided in the middle of the passage 22. Is provided. Therefore, in the passage 21, the pneumatic shock absorber K is extended, that is, the passage of the fluid is allowed only when the rod 3 protrudes from the cylinder 1, and in the other passage 22, The fluid is allowed to pass only when the pneumatic shock absorber K is contracted, that is, when the rod 3 is moved into the cylinder 1.

  The damping force generating elements 23 and 24 are variable throttle valves as shown in the figure, and change the resistance applied to the fluid flow according to the expansion / contraction frequency and expansion / contraction speed of the pneumatic shock absorber K. Can be done. Note that the damping force generating elements 23 and 24 may be fixed throttle valves, leaf valves, or the like in addition to the variable throttle valves as long as they are suitable for a vehicle on which the pneumatic shock absorber K is mounted.

  Subsequently, the partition wall body 41 is formed into an annular shape, and the inner peripheral side thereof is coupled to the rod 3 with a predetermined distance from the piston 2, and the outer peripheral side thereof is in sliding contact with the inner periphery of the cylinder 1.

  Further, the partition body 42 is also formed in an annular shape like the partition body 41, and the inner peripheral side thereof is coupled to the rod 3 with a predetermined distance from the partition body 41, and the outer peripheral side is slidably contacted with the inner periphery of the cylinder 1. It is.

  Therefore, the space 43 between the partition walls 41 and 42 is isolated from the working chamber A. Due to the presence of the partition walls 41 and 42 and the space 43, the volume in the working chamber A in the cylinder 1 is reduced. The partition walls 41 and 42 partition the rod side chamber R1 into two chambers R1a and R1b on the rod side and piston side in the drawing. The space 43 is filled with a predetermined amount of oil.

  Further, the rod 3 is provided with a flow path 31 that avoids the space 43. The flow path 31 bypasses the space 43 and separates the two rooms R1a and R1b separated by the partition walls 41 and 42. In communication, both the rooms R1a and R1b function as the rod side chamber R1.

  In turn, the head member 5 is formed in an annular shape, and on the inner peripheral side thereof is provided with a bearing 51 that pivotally supports the rod 3 and is provided with a recess 52 that opens from the upper end side.

  And the above-mentioned cylinder 1 is covered with the bottomed cylindrical outer cylinder 10 arrange | positioned on the outer side of the cylinder 1, The bottom member 6 is fitted by the bottom part of this outer cylinder 10, A sealing member 11 that holds an annular seal S on the inner peripheral side is fixed to the head member 5 at an opening end that is the upper end of the outer cylinder 10 in the figure.

  In the sealing member 11 described above, the axial length that is the vertical length in FIG. 1 is set shorter than the axial length that is the vertical length of the annular seal S, and the annular seal S is sealed. The stopper member 11 is held by the sealing member 11 so as to protrude from the lower end of the stopper member 11 toward the inside of the cylinder 1. In the above description, the sealing member 11 holds the annular seal S. However, the annular seal S may be welded to the sealing member 11 so as not to be separated.

  The lower end of the annular seal S protruding from the sealing member 11 is disposed in the recess 52 of the head member 5, and the oil storage chamber T is separated by the recess 52 and the sealing member 11.

  A rod 3 that protrudes from the cylinder 1 and is slidably inserted into the bearing 51 of the head member 5 is inserted on the inner peripheral side of the annular seal S. The annular seal S is inserted into the rod 3 with a predetermined compression force. It is press-contacted to the outer periphery.

  Therefore, the rod 3 passes through the oil storage chamber T, and this oil storage chamber T faces the sliding contact portion between the rod 3 and the annular seal S.

  Further, the oil storage chamber T is communicated with the rod side chamber R <b> 1 by a passage 53 provided in the head member 5, and is communicated with a gap B between the cylinder 1 and the outer cylinder 10 by a passage 54.

  Here, the end 53a of the passage 53 on the oil storage chamber T side opens from the side wall 52a of the recess 52, and the end 53a is positioned at least above the lowermost end of the annular seal S in the drawing. Is set to Further, a check valve 55 that allows only the flow of fluid from the oil storage chamber T to the rod side chamber R1 is provided in the middle of the passage 53.

  On the other hand, the bottom member 6 is provided with a passage 61 that connects the piston-side chamber R2 and the gap B. In the middle of the passage 61, a check that allows only the flow of fluid from the piston-side chamber R2 toward the gap B is provided. A valve 62 is provided.

  Therefore, the oil storage chamber T is communicated with the piston side chamber R2 via the passage 54, the gap B, and the passage 61 described above.

  The cylinder 1 is filled with working gas, the oil storage chamber T is filled with oil, and the oil level O of the oil in the oil storage chamber T is below the lowermost end of the annular seal S. In consideration of the fact that the oil does not fall down, the gap B is filled with a sufficient amount of oil.

  In the rod-side chamber R1, a small amount of oil is also filled in the rod-side chamber R1a, the piston-side chamber R1b, and the piston-side chamber R2, but the oil filled in the rod-side chamber R1a is pneumatic. This is to lubricate the space between the cylinder 1 and the partition body 42 when the shock absorber performs expansion and contraction. The oil filled in the piston-side chamber R1b is used when the pneumatic shock absorber performs expansion and contraction. This is to lubricate between the cylinder 1 and the piston 2, and the oil in the piston side chamber R2 prevents the oil level O in the oil storage chamber T from dropping when the pneumatic shock absorber contracts.

  Here, the outlet end of the flow path 31 in the rod-side room R1a facing the partition wall 42 may be positioned above the upper surface of the partition wall 42. By doing so, it is possible to store oil above the partition body 42 to some extent, so that it is possible to reliably lubricate the partition body 42 and the cylinder 1.

  Next, the operation of the pneumatic shock absorber K configured as described above will be described. First, when the pneumatic shock absorber K is extended, the rod side chamber R1 composed of the chambers R1a and R1b is compressed and the piston side chamber R2 is expanded, so that the gas in the rod side chamber R1 passes through the passage 21. It moves into the piston side chamber R2. During this movement, the gas passes through the damping force generating element 23, so that a pressure loss occurs and a damping force corresponding to the pressure difference between the rod side chamber R1 and the piston side chamber R2 is generated.

  At this time, the volume in the working chamber A is reduced by the partition wall bodies 41 and 42 and the space 43 formed by the partition wall bodies 41 and 42, and the pressure change in the working chamber A when the pneumatic shock absorber is extended is Since it is inversely proportional to the volume of the working chamber A, the pressure in the rod-side chamber R1 rises more rapidly and the pressure in the piston-side chamber R2 decreases more quickly than the pneumatic buffer without the partition walls 41, 42. It will be.

  That is, even if the length of the cylinder 1 or the rod 3 is equivalent to that of the hydraulic shock absorber, the pressure rise in the rod side chamber R1 and the piston side chamber are formed by the partition walls 41, 42 and the space 43 formed by the partition bodies 41, 42. Since the pressure drop in R2 becomes faster, the generation of damping force is similarly faster than that of the conventional pneumatic shock absorber.

  Furthermore, since the partition wall bodies 41 and 42 form a space 43 that is isolated from the working chamber A, compared with the case where a solid member is provided in the working chamber A and the volume of the working chamber A is reduced, that amount. The pneumatic shock absorber K is lightweight, and it is possible to reduce the weight of the pneumatic shock absorber K.

  Further, since the oil in the rod side chamber R1 is heavier than the gas and accumulated in the opening of the passage 21, the oil also moves into the piston side chamber R2 together with the gas.

  The oil in the rod side chamber R1 has a role of lubricating between the cylinder 1 and the piston 2 as described above, but passes through the damping force generating element 23 ahead of the gas, so the rod side chamber R1. This will prompt a rapid increase in pressure.

  Subsequently, when the pneumatic shock absorber K is contracted, the piston side chamber R2 is compressed and the rod side chamber R1 is expanded, so that the gas in the piston side chamber R2 moves into the rod side chamber R1 via the passage 22. . During this movement, since the gas passes through the damping force generating element 24, a pressure loss occurs and a damping force corresponding to the pressure difference between the rod side chamber R1 and the piston side chamber R2 is generated.

  Further, the gas in the piston side chamber R <b> 2 flows into the oil storage chamber T through the passage 54, the gap B and the passage 61 due to the pressure increase in the piston side chamber R <b> 2.

  At this time, the volume in the working chamber A is reduced by the partition wall bodies 41, 42 and the space 43 formed by the partition wall bodies 41, 42, and the pressure change in the working chamber A when the pneumatic shock absorber contracts is Since it is inversely proportional to the volume of the working chamber A, the pressure in the piston side chamber R2 rises more rapidly and the pressure in the rod side chamber R1 decreases more quickly than in the state without the partition walls 41 and 42.

  Accordingly, even during this contraction operation, even if the length of the cylinder 1 or the rod 3 is equivalent to that of the hydraulic shock absorber, the rod side chamber R1 is formed by the partition wall bodies 41 and 42 and the space 43 formed by the partition wall bodies 41 and 42. Since the internal pressure drop and the pressure rise in the piston side chamber R2 are accelerated, the generation of the damping force is similarly accelerated as compared with the conventional pneumatic shock absorber.

  That is, in this pneumatic shock absorber K, the volume in the working chamber A can be reduced by the partition wall bodies 41 and 42 and the space 43 formed by the partition wall bodies 41 and 42, so that the basic length can be mounted on the vehicle. Even if it is secured to the extent, the generation of damping force is not delayed.

  Further, in the present pneumatic shock absorber K, since the partition walls 41 and 42 are accommodated in the working chamber A, the basic length is ensured and the generation delay of the damping force is avoided. Therefore, it is not necessary to shorten the vertical length of the cylinder 1 in the drawing and further increase the vertical length of the rod 3 in the drawing. Therefore, the cylinder 1 and the rod 3 are newly added as special products for the pneumatic shock absorber. Therefore, it is possible to reduce the cost of development and production of the pneumatic shock absorber because it is possible to use the cylinder and rod for the hydraulic shock absorber as they are.

  As described above, by providing the partition walls 41 and 42 to a general pneumatic shock absorber having only the piston 2, the above-described effects can be obtained, so that the structure is simple and the pneumatic shock absorber is provided. It is practical without causing an extreme weight increase of the vessel K.

  When the pneumatic shock absorber K is contracted, the oil in the piston-side chamber R2 passes through the passage 61 ahead of the gas because the oil is heavier than the gas and accumulates in the opening of the passage 61. Therefore, a rapid pressure increase in the piston side chamber R2 is urged.

  Since the oil storage chamber T is pressurized in the same manner as the piston side chamber R2, the oil level O of the oil in the oil storage chamber T rises, and the oil level O rises and the pressure in the oil storage chamber T rises. Accordingly, the oil in the oil storage chamber T passes through the passage 53 and flows into the rod side chamber R1 together with the gas. Here, since the opening position of the end portion 53a of the passage 53 is located above the lowermost end of the annular seal S, the oil storage chamber T even if the oil moves from the oil storage chamber T into the rod side chamber R1 as described above. The oil level O of the inner oil is always located above the lowermost end of the annular seal S, and the oil in the oil storage chamber T continues to maintain the lubrication of the sliding contact portion between the rod 3 and the annular seal S. .

  Therefore, even if the pneumatic shock absorber K repeatedly expands and contracts, the oil in the oil storage chamber T continues to maintain the lubrication of the sliding contact portion between the rod 3 and the annular seal S, and is formed upright. The sliding portion of the rod 3 of the pneumatic shock absorber K is surely lubricated.

  Further, by providing an oil storage chamber facing the sliding contact portion of the rod 3 and positioning the oil surface above the lowermost end of the sliding contact portion, the sliding portion can be reliably lubricated, so that the structure is complicated. Therefore, the pneumatic shock absorber can be made upright without significant cost increase.

  When the pneumatic shock absorber K continues to expand and contract, the oil in the pneumatic shock absorber K circulates through the rod side chamber R1, the piston side chamber R2, and the oil storage chamber T, and the sliding portion of the pneumatic shock absorber K, that is, The sliding portion between the cylinder 1 and the piston 2 and the sliding portion of the rod 3 and the annular seal S are continuously lubricated.

  In addition to this, in the pneumatic shock absorber K in the present embodiment, oil is also filled in the space 43 between the partition walls 41, 42. Therefore, even when the partition wall body 41 slides relative to the cylinder 1, the sliding portion between the partition wall body 41 and the cylinder 1 is lubricated by the oil in the space 43. The relative movement between the cylinder 41 and the cylinder 1 can be kept smooth.

  That is, in the pneumatic shock absorber K, the oil circulation can prevent the oil in the rod-side chamber R1a and the piston-side chamber R1b in the rod-side chamber R1 from being lost. T, each sliding portion of the pneumatic shock absorber K can be lubricated by the oil in the rod-side chamber R1a and the piston-side chamber R1b in the rod-side chamber R1, and the pneumatic shock absorber K can be smoothly expanded and contracted. Operation is realized, manual resistance can be reduced, riding comfort in the vehicle can be improved, and durability of the pneumatic shock absorber K can be improved.

  In the above description, the partition walls 41 and 42 are provided in the rod-side chamber R1 which is one chamber. However, like the pneumatic shock absorber K1 in the modification of the embodiment shown in FIG. The partition bodies 44 and 45 may be provided in the piston side chamber R2.

  In the pneumatic shock absorber K1 in this modification, the piston 2 is not fixed to the lower end of the rod 3, but is fixed to an intermediate portion, and the lower end in FIG. 2 of the rod 3 is protruded into the piston side chamber R2.

  And the partition body 44 and 45 which forms the space 46 isolated from the working chamber A is couple | bonded with the part which protrudes in piston side chamber R2 of this rod 3. As shown in FIG.

  The partition body 44 is annular, and its inner peripheral side is coupled to the rod 3 at a predetermined interval from the piston 2, and its outer peripheral side is in sliding contact with the inner periphery of the cylinder 1.

  Further, the partition body 45 is also formed in an annular shape like the partition body 44, and its inner peripheral side is coupled to the rod 3 at a predetermined interval from the partition body 44, and its outer peripheral side is slidably contacted with the inner periphery of the cylinder 1. It is.

  Therefore, the space 46 between the partition walls 44 and 45 is isolated from the working chamber A, and the presence of the partition bodies 44 and 45 and the space 46 reduces the volume of the working chamber A in the cylinder 1. The partition walls 44 and 45 partition the piston-side chamber R2 into two chambers R2a and R2b on the piston side and the bottom member side in the figure, and the space 46 is filled with a predetermined amount of oil. ing.

  Further, the rod 3 is provided with a flow path 32 that avoids the space 46, and the flow path 32 bypasses the space 46 and separates the two rooms R 2 a and R 2 b separated by the partition walls 44 and 45. In communication, both the rooms R2a and R2b function as the piston side chamber R1.

  Even in this modification, a small amount of oil is filled in the piston side chamber R2a and the bottom member side chamber R2b in the rod side chamber R1 and the piston side chamber R2, but the oil filled in the rod side chamber R1. This is to lubricate between the cylinder 1 and the piston 2 when the pneumatic shock absorber performs expansion / contraction operation, and the oil filled in the piston-side chamber R2a is used when the pneumatic shock absorber performs expansion / contraction operation. In order to lubricate between the cylinder 1 and the partition wall 44, the oil in the chamber R2b on the bottom member side prevents the oil level O in the oil storage chamber T from descending when the pneumatic shock absorber contracts. It is.

  Here, the outlet end of the flow path 32 in the piston-side room R <b> 2 a facing the partition wall body 44 may be positioned above the upper surface of the partition wall body 44. By doing so, it is possible to store oil above the partition wall body 44 to some extent, so that it is possible to reliably lubricate the partition wall body 44 and the cylinder 1.

  The difference between the pneumatic shock absorber K1 and the pneumatic shock absorber K is that the partition body 44, 45 is provided in the piston side chamber R2 as the other chamber to form a space 46, and the inside of the piston side chamber R2 The other positions of the pneumatic shock absorber K1 in the modification are the same as those of the pneumatic shock absorber K in the above-described embodiment.

  As described above, even if the partition wall bodies 44 and 45 are provided in the piston side chamber R2 which is the other chamber to form the space 46, the inside of the working chamber A is similar to the pneumatic shock absorber K in the above-described embodiment. Since the volume can be reduced, the structure is simple, the extreme weight of the pneumatic shock absorber K1 is not increased, and the basic length can be secured and the damping force can be quickly generated.

  Further, like the pneumatic shock absorber K2 in the other embodiment shown in FIG. 3, the partition wall bodies 41 and 42 similar to those in the embodiment are provided in the rod side chamber R1 as one chamber to form the space 43. In addition, a flow path 31 that bypasses the space 43 is provided in the rod 3, and partition walls 44 and 45 similar to those of the modification of the embodiment are provided in the piston side chamber R2 that is the other chamber to form a space 46. A flow path 32 that bypasses the space 46 is provided in the rod 3, and the other configuration is the same as that of the pneumatic shock absorber K of the embodiment.

  As described above, in the pneumatic shock absorber K2 in the other embodiment, the partition walls 41, 42, 44, and 45 are provided in the rod side chamber R1 that is one chamber and the piston side chamber R2 that is the other chamber, respectively. By forming 43 and 46, the volume of the working chamber A is reduced.

  Then, even in the pneumatic shock absorber K2 in this other embodiment, the space 43 formed by the partition walls 41, 42, 44, 45 and the partition walls 41, 42, 44, 45 is used as the volume of the working chamber A. , 46, so that the structure is simple as in the pneumatic shock absorber K in the above-described embodiment, without causing an extreme weight increase of the pneumatic shock absorber K2. The basic length can be secured and the damping force can be generated quickly.

  The pneumatic shock absorbers K, K1, and K2 described above are configured as so-called single rod type shock absorbers, but may be configured as double rod type shock absorbers. The effects of securing the length and generating the damping force quickly are not lost. Further, in the pneumatic shock absorbers K, K1, and K2 of the present embodiment, a small amount of oil is circulated to the one chamber, the other chamber, and the oil storage chamber in consideration of the lubrication of the sliding portion particularly when it is configured upright. However, the present invention can also be embodied in a pneumatic shock absorber employing an inverted structure, and the structure of the pneumatic shock absorbers K, K1, K2 is not limited to this.

  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 schematic longitudinal cross-sectional view of the pneumatic shock absorber in the modification of one embodiment. It is a schematic longitudinal cross-sectional view of the pneumatic shock absorber in other embodiment.

Explanation of symbols

1 Cylinder 2 Piston 21, 22, 53, 54, 61 Passage 23, 24 Damping force generating element 25, 26 Check valve 3 Rod 31, 32 Flow path 41, 42, 44, 45 Partition body 43, 46 Space 5 Head member 51 Bearing 52 Recess 53, 54, 61 Passage 53a End 55, 62 in the passage Check valve 6 Bottom member 10 Outer cylinder A Working chamber B Clearance K, K1, K2 Pneumatic shock absorber O Oil level R1 in the oil storage chamber Rod side chamber R1a rod side chamber R1b Rod side chamber piston side chamber R2 Rod side chamber piston side chamber R2a Piston side chamber piston side chamber R2b Piston side chamber bottom member side chamber S Ring seal member T Oil storage Room

Claims (2)

A cylinder, a piston that is slidably inserted into the cylinder and divides a working chamber formed in the cylinder into one chamber and the other chamber, and a rod that is slidably inserted into the cylinder via the piston. In the pneumatic shock absorber provided, the rod is provided with a pair of partition walls that are coupled to the rod in one or both of the one chamber and the other chamber and that are in sliding contact with the inner periphery of the cylinder to form a space isolated from the working chamber. A pneumatic shock absorber provided with a flow path that bypasses a space to be isolated. 2. The pneumatic shock absorber according to claim 1, wherein the space to be isolated is filled with oil.

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