JP4833955B2 - Pneumatic shock absorber - Google Patents

Description

  The present invention relates to a pneumatic shock absorber.

  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, a damping valve is arranged at each of the expansion side port and the compression side port provided on the piston, and the damping valve exhibits the damping force on both sides of the expansion. In this pneumatic shock absorber, in particular, the sliding portion between the rod outer periphery and the seal member is lubricated in order to be applicable to a place where vibration input is frequently performed such as between the vehicle body and the axle of the vehicle. I have to. Therefore, the pneumatic shock absorber is provided with a passage that circulates the lubricating oil that has fallen into the piston side chamber due to continuous use over a long period of time to the oil storage chamber disposed above, so that the passage gives resistance to the passing fluid. In the compression stroke of the pneumatic shock absorber, the passage also serves as a damping force generating element. (For example, refer to Patent Document 1).
JP 2006-349138 A

  In the conventional pneumatic shock absorber as described above, once the gas is sealed in the pneumatic shock absorber, the damping valve provided in the piston cannot be tuned, and the damping characteristic (piston of the pneumatic shock absorber) The nature of the generated damping force with respect to speed) cannot be adjusted from the outside.

  In order to make it possible to adjust the damping characteristic from the outside, it is necessary to adjust the damping valve provided on the piston from the outside, and the rod must be made hollow, which increases the processing cost. There is a risk that the rod strength will be reduced, so that the rod diameter increases to ensure strength, and as a result, the pneumatic shock absorber may increase in size.

 Accordingly, the present invention has been developed to improve the above-described problems, and the object of the present invention is to provide a pneumatic buffer that can change the damping characteristics without incurring economic disadvantage and increase in size. Is to provide a vessel.

  In order to achieve the above object, a pneumatic shock absorber in the problem solving means of the present invention includes a cylinder and a piston that is slidably inserted into the cylinder and separates two pressure chambers in the cylinder. In the pneumatic shock absorber, a passage that communicates the two pressure chambers outside the cylinder, a partition member that is provided in the middle of the passage and includes an expansion side port and a pressure side port, and is stacked on the partition member to form the expansion side port. An extension side leaf valve that opens and closes, a pressure side leaf valve that is stacked on the partition member to open and close the pressure side port, an extension side biasing member that biases the extension side leaf valve in a direction to close the extension side port, and a pressure side port A pressure-side biasing member that biases the pressure-side leaf valve in the closing direction, an extension-side adjusting means that adjusts the biasing force of the extension-side biasing member from the outside, and a pressure-side adjustment that adjusts the biasing force of the pressure-side biasing member from the outside Provided with means And features.

  According to the pneumatic shock absorber of the present invention, the partition member having the expansion side port and the pressure side port is provided in the middle of the passage communicating the two pressure chambers outside the cylinder, and the expansion side port is stacked on the partition member. An extension side leaf valve that opens and closes, a pressure side leaf valve that is stacked on the partition member to open and close the pressure side port, an extension side biasing member that biases the extension side leaf valve in a direction to close the extension side port, and a pressure side port A pressure side urging member for urging the pressure side leaf valve in a direction to close the pressure, an expansion side adjusting means for adjusting the urging force of the expansion side urging member from the outside, and a pressure side for adjusting the urging force of the pressure side urging member from the outside Since the adjusting means is provided, the damping characteristics can be adjusted from the outside without performing processing that increases costs, for example, processing that requires the piston rod to be hollow, and the damping characteristics can be reduced at low cost. Make adjustments As becomes, it becomes economically advantageous, it without causing a decrease in strength of the piston rod, there is no fear that air pressure shock absorber becomes large.

  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 according to an embodiment. FIG. 2 is an enlarged longitudinal sectional view of the damping characteristic adjusting unit of the pneumatic shock absorber according to the embodiment. FIG. 3 is an enlarged vertical cross-sectional view of the damping characteristic adjusting unit of the pneumatic shock absorber according to a modification of the embodiment. FIG. 4 is an enlarged longitudinal sectional view of a damping characteristic adjusting unit of the pneumatic shock absorber according to another modification of the embodiment.

As shown in FIG. 1, the pneumatic shock absorber D in one embodiment includes a cylinder 1 and a piston that is slidably inserted into the cylinder 1 and that separates two pressure chambers R <b> 1 and R <b> 2 into the cylinder 1. 2, a passage 3 communicating with the two pressure chambers R 1 and R 2 outside the cylinder 1, a partition member 4 provided in the middle of the passage 3 and having an extension side port 4 a and a pressure side port 4 b, The extension side leaf valve 5 which opens and closes the extension side port 4a, the pressure side leaf valve 6 which is stacked on the partition member 4 and opens and closes the compression side port 4b, and the extension side leaf valve 5 in the direction of closing the extension side port 4a. An extension side urging member 7 that urges the compression side, a pressure side urging member 8 that urges the pressure side leaf valve 6 in a direction to close the pressure side port 4b, and an extension that adjusts the urging force of the extension side urging member 7 from the outside. The biasing force of the side adjusting means 9 and the pressure side biasing member 8 Is constituted by a pressure side adjusting means 10 for adjusting the parts.

  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 pressure chamber R1 and a lower pressure chamber R2 in FIG. 1, and a piston rod 11 is connected to the upper end of the piston 2 in FIG.

  Further, an annular head member 12 is fitted to the upper end of the cylinder 1 in FIG. 1, and the head member 12 pivotally supports the piston rod 11 through a bearing 13 fixed to the inner periphery. ing. Further, a cylindrical valve housing 14 is fitted to the lower end of the cylinder 1, and a damping characteristic adjusting portion including the partition member 4 is accommodated in the valve housing 14.

  In the case of this pneumatic shock absorber D, an outer cylinder 15 covering the cylinder 1 is provided, and the lower end of the outer cylinder 15 is coupled to the outer periphery of the valve housing 14 fitted to the lower end of the cylinder 1 by welding or the like. ing. Further, the head member 12 fitted to the upper end of the cylinder 1 is accommodated in the outer cylinder 15 and is stacked on the upper side in FIG. 1 to seal between the outer periphery of the piston rod 11 and the outer cylinder 15. At the same time, it is fixed to the outer cylinder 15 by crimping the upper end opening end of the outer cylinder 15. With this configuration, the cylinder 1 is sandwiched between the head member 12 and the valve housing 14 and is fixed to the outer cylinder 15 in a state of being positioned in the radial direction and the axial direction.

  The valve housing 14 has a cylindrical shape as shown in FIGS. 1 and 2, and has a small-diameter small-diameter portion 14 a fitted into the cylinder 1 on the upper end side in FIG. A fitting portion 14b having a larger diameter than the fitting small diameter portion 14a and a large diameter portion 14c on the lower end side in FIG. 2 are provided, and on the inner periphery, a large inner diameter portion 14d on the upper end side in FIG. A small inner diameter portion 14e is provided, and a screw portion 14f is formed on the lower end side of the small inner diameter portion 14e.

  Further, the valve housing 14 includes a hole 14h that communicates a large-diameter portion 14d, a small-diameter portion 14a facing a gap between the cylinder 1 and the outer cylinder 15, and a stepped portion 14g between the fitting portions 14b.

  Further, the head member 12 includes a flow path 12b that communicates from the lower end in FIG. 1 facing the pressure chamber R1 to a stepped portion 12a facing the gap between the cylinder 1 and the outer cylinder 15. Therefore, the pressure chamber R1 and the pressure chamber R2 communicate with each other through the inside of the valve housing 14 described above, the hole 14h, the gap between the cylinder 1 and the outer cylinder 15, and the flow path 12b of the head member 12. Thus, a passage 3 is formed which communicates the pressure chamber R1 and the pressure chamber R2 outside the cylinder 1. It should be noted that a space as a lubricating oil reservoir may be provided between the head member 12 and the seal member 16, and the sliding portion between the seal member 16 and the piston rod 11 may be lubricated. R1 is communicated with the pressure chamber R2 through the space filled with the lubricating oil, and the lubricating oil is circulated between the pressure chamber R1 and the pressure chamber R2 as in the conventional shock absorber described in the background section. Also good.

  Subsequently, the partition member 4 fixed to the shaft member 17 screwed into the screw portion 14 f of the valve housing 14 is inserted into the large inner diameter portion 14 d of the valve housing 14. Specifically, the partition member 4 is located in the large inner diameter portion 14d and is disposed closer to the pressure chamber R2 than the hole 14h. The partition member 4 partitions the valve housing 14 into the pressure chamber R1 side and the pressure chamber R2 side. It has been. The seal ring 4c attached to the outer periphery of the partition member 4 is in close contact with the inner periphery of the large inner diameter portion 14d so that gas does not flow through the outer periphery of the partition member 4.

  Further, the shaft member 17 has a cylindrical shape, a large-diameter base end portion 17a at the lower side in FIG. 2, an intermediate portion 17b having a smaller diameter than the base end portion 17a, and an intermediate portion at the upper side in FIG. A small-diameter portion 17c that is set to a smaller diameter, and a screw portion 17d that is screwed into a screw portion 14f provided in the small-diameter portion 14e of the valve housing 14 is provided on the outer periphery of the lower end of the base end portion 17a. A screw portion 17e is also provided on the outer periphery of the upper end of the small diameter portion 17c, and a screw portion 17f is also provided on the inner periphery of the base end portion 17a.

  And the cylindrical spacer 18, the pressure side leaf valve 6, the partitioning member 4, the extension side leaf valve 5, and the cylindrical spacer 19 are assembled to the small diameter portion 17c of the shaft member 17 in order from the bottom in FIG. The members assembled to these small diameter portions 17c are sandwiched between a step portion at the boundary between the intermediate portion 17b and the small diameter portion 17c and a nut 20 screwed to the screw portion 17e and fixed to the small diameter portion 17c of the shaft member 17. Is done.

  In this case, the extension side leaf valve 5 is configured as a laminated leaf valve formed by laminating a plurality of annular leaves, and is laminated on the upper end of the partition member 4 in FIG. 1 to open and close the outlet end of the extension side port 4a. A resistance is given to the flow of gas from the pressure chamber R1 to the pressure chamber R2 via the passage 3, and the expansion side port 4a is against the gas flow from the pressure chamber R2 to the pressure chamber R1. Closes and functions as a check valve.

  On the other hand, the pressure side leaf valve 7 is also configured as a laminated leaf valve formed by laminating a plurality of annular leaves, and is laminated at the lower end in FIG. 1 of the partition member 4 to open and close the outlet end of the pressure side port 4b. It provides resistance to the gas flow from the pressure chamber R2 to the pressure chamber R1 via the passage 3, and closes the pressure side port 4b against the gas flow from the pressure chamber R1 to the pressure chamber R2. It also functions as a valve.

  A spring receiver 21 that is annular and contacts the outer peripheral side of the pressure side leaf valve 6 is slidably mounted on the outer periphery of the spacer 18, and is also annular and similar to the outer periphery of the spacer 19. A spring receiver 22 that contacts the outer peripheral side is slidably mounted.

  Further, a washer-shaped pressure side receiving member 23 is attached to the outer periphery of the intermediate portion 17b of the shaft member 17 so as to be movable in the axial direction, and between the pressure side receiving member 23 and the spring receiver 21, a pressure side urging force is provided. A coil spring as the member 8 is interposed.

  Further, the inner diameter of the pressure side receiving member 23 is smaller than the outer diameter of the base end portion 17a of the shaft member 17, and the pressure side receiving member 23 is located with respect to the shaft member 17 by the upper end of the base end portion 17a in FIG. Further downward movement is restricted.

  Further, the outer diameter of the pressure side receiving member 23 is larger than the inner diameter of the small inner diameter portion 14e of the valve housing 14, and when the shaft member 17 moves in the direction of coming out of the cylinder from the valve housing 14, the pressure side receiving member No. 23 abuts on the upper end of the small inner diameter portion 14e in FIG. 2 so that the outward movement of the cylinder is restricted.

  Accordingly, when the shaft member 17 is rotated and the shaft member 17 is moved downward in FIG. 2, which is outside the cylinder, with respect to the valve housing 14 in the manner of the feed screw mechanism, the pressure side receiving member 23 is moved to the small inner diameter portion 14 e. In the case of abutting on the upper end, the shaft member 17 is left without following the downward movement, the distance from the spring receiver 21 is reduced, and the compression side urging member 8 is compressed. The urging force for urging the compression side leaf valve 6 can be increased. On the other hand, when the shaft member 17 is moved inward of the cylinder with respect to the valve housing 14, the pressure side receiving member 23 is within the range where the pressure side receiving member 23 and the upper end of the small inner diameter portion 14e are in contact with each other. Since the movement of 17 does not follow, the distance between the pressure side receiving member 23 and the spring receiver 21 is extended, and the urging force for urging the pressure side leaf valve 6 of the pressure side urging member 8 can be reduced.

  In other words, in the case of this embodiment, the pressure side adjusting means 10 is constituted by the pressure side receiving member 23 that is restricted from moving outward from the cylinder with respect to the valve housing 14 and the shaft member 17 that holds the partition member 4. Has been.

  In the case of the pressure side adjusting means 10, when the shaft member 17 moves upward in FIG. 2 with respect to the valve housing 14 and the pressure side receiving member 23 moves away from the upper end of the small inner diameter portion 14 e of the valve housing 14, Since the urging member 8 does not extend any more, the lower limit of the urging force of the pressure side urging member 8 can be set, and the pressure side urging member 8 is not able to urge the pressure side leaf valve 6. There is no worry of getting out. In this embodiment, since the pressure side receiving member 23 is a washer that abuts on the upper end of the small inner diameter portion 14e of the valve housing 14 as described above, the lower limit of the urging force of the pressure side urging member 8 as described above. However, if this is not necessary, the pressure side biasing member is directly supported by the upper end of the small inner diameter portion 14e with the small inner diameter portion 14e of the valve housing 14 as the pressure side receiving member. You may do it.

  Although the spring receiver 21 can be omitted, by providing the spring receiver 21, even if a coil spring whose end rotates in the circumferential direction by expansion and contraction is adopted as the compression-side biasing member 8, the compression-side leaf valve 6 will not be damaged.

  Subsequently, a rod 24 is inserted into the shaft member 17, and the rod 24 includes a large-diameter base end 24a and a small-diameter shaft portion 24b rising from the base end 24a. A screw portion 24 c provided on the outer periphery of the shaft member 17 is screwed into a screw portion 17 f provided on the inner periphery of the base end portion 17 a of the shaft member 17.

  Further, the tip that is the upper end in FIG. 2 of the shaft portion 24b of the rod 24 is set to a length that protrudes from the upper end of the shaft member 17, and an annular extending side receiving member 25 is rotatable at the tip. It is installed. In addition, a coil spring as the extension side urging member 7 is interposed between the extension side receiving member 25 and the spring receiver 22 attached to the outer periphery of the spacer 19.

  When the rod 24 is rotated with respect to the shaft member 17, the rod 24 can be advanced and retracted in the axial direction with respect to the shaft member 17 in the manner of the feed screw mechanism. The distance between the extension side receiving member 25 and the spring receiver 22 can be changed by advancing and retracting the shaft member 17, so that the extension side leaf valve 5 of the extension side biasing member 7 can be changed in the same manner as the compression side adjusting means 10. The energizing force to be energized can be adjusted.

  That is, in the case of this embodiment, the extension side adjusting means 9 is held at the tip of the rod 24 and the rod 24 inserted into the shaft member 17 and the base end 24a screwed into the inner periphery of the shaft member 17. The extended side receiving member 25 is configured. The extension side receiving member 25 is rotatable about the shaft member in the circumferential direction, and the extension side urging member 7 employing a coil spring allows rotation of the end portion due to expansion and contraction. When adjusting the urging force, the extension side receiving member 25 moves smoothly, and even if the spring receiver 22 is omitted, the extension side leaf valve 5 is not damaged.

  In this embodiment, the inner periphery of the compression-side leaf valve 6 is fixed by the spacer 18 and the inner periphery of the expansion-side leaf valve 5 is fixed by the spacer 19, but the compression-side leaf valve 6 and the expansion-side leaf valve are fixed. The inner periphery of the pressure side leaf valve 6 and the extension side leaf valve 5 can be lifted by the extension side biasing member 7 and the pressure side biasing member 8, respectively. A configuration may be employed in which the urging is biased toward the partition member 4 side. In this case, the inner periphery of the compression side leaf valve 6 and the extension side leaf valve 5 can be lifted, and therefore, particularly exhibits a damping characteristic such that the damping force when the pneumatic shock absorber D expands and contracts at high speed reaches a peak. Can do.

  A seal ring 26 is interposed between the valve housing 14 and the shaft member 17, and a seal ring 27 is also interposed between the shaft member 17 and the rod 24. 17, the rod 24, the partition member 4, and the damping force adjusting portion constituted by the above-described members assembled thereto prevent gas from leaking.

  In this embodiment, the feed screw mechanism is employed when the shaft member 17 advances and retracts with respect to the valve housing 14 and when the rod 24 advances and retracts with respect to the shaft member 17, so that the flow passage area can be finely adjusted. However, although there is no problem that the shaft member 17 and the rod 24 are advanced and retracted by the action of the cylinder internal pressure, the shaft member 17 and the rod 24 may be advanced and retracted using other mechanisms.

  When the piston 2 moves upward in FIG. 1 and extends, the pneumatic shock absorber D configured in this way moves from the pressure chamber R1 in which the gas is compressed to the pressure chamber R2 that expands through the passage 3. Moving. Then, resistance is given to the gas flow by the extension side leaf valve 5, and the pneumatic shock absorber D generates the extension side damping force.

  In this pneumatic shock absorber D, the rod 24 is rotated by an external operation to advance and retract in the axial direction with respect to the shaft member 17, and the extension side biasing member 7 that biases the extension side leaf valve 5. The urging force can be adjusted, and the damping characteristic on the extension side can be changed from the outside by the adjustment.

  On the other hand, when the piston 2 moves downward in FIG. 1 and contracts, it moves from the pressure chamber R2 in which the gas is compressed to the pressure chamber R1 that expands through the passage 3. Then, resistance is given to the gas flow by the pressure side leaf valve 6, and the pneumatic shock absorber D generates a pressure side damping force.

  Further, even when the pneumatic shock absorber D contracts, the shaft member 17 is rotated by an external operation to advance and retract in the axial direction with respect to the valve housing 14, and the pressure side bias that biases the pressure side leaf valve 6. The biasing force of the member 8 can be adjusted, and the damping characteristic on the compression side can be changed from the outside by the adjustment.

  Therefore, according to this pneumatic shock absorber D, the partition member 4 provided with the expansion side port 4a and the pressure side port 4b is provided in the middle of the passage 3 communicating the two pressure chambers R1, R2 outside the cylinder 1, The extension side leaf valve 5 stacked on the partition member 4 to open and close the extension side port 4a, the pressure side leaf valve 6 stacked on the partition member 4 to open and close the pressure side port 4b, and the extension side port 4a are extended in the closing direction. The expansion side urging member 7 for urging the side leaf valve 5, the pressure side urging member 8 for urging the pressure side leaf valve 6 in the direction to close the pressure side port 4b, and the urging force of the expansion side urging member 7 are externally applied. And a pressure side adjusting means 10 for adjusting the urging force of the pressure side urging member 8 from the outside, and the damping characteristics on both sides of the pressure expansion are adjusted outside the cylinder 1. So that the processing is expensive, For example, since it is not necessary to process the piston rod 11 to be hollow, the damping characteristic can be adjusted at a low cost, which is economically advantageous and causes a decrease in the strength of the piston rod 11. There is no fear that the pneumatic shock absorber D will become large.

  Furthermore, according to the pneumatic shock absorber D in this embodiment, the valve housing 14 is provided at the end of the cylinder 1 so as to accommodate each member that adjusts the damping characteristics, so that the strength of the cylinder 1 is reduced. Is not invited.

  Next, the pneumatic shock absorber D1 according to a modification of the embodiment will be described. In the pneumatic shock absorber D1 in this modification, as shown in FIG. 3, the configuration of the valve housing 28 is changed. The valve housing 28 in this embodiment includes a cylindrical portion 28a fitted or screwed to the inner periphery of the cylinder 1 and a flange 28b provided on the outer periphery of the lower end of the cylindrical portion 28a. It is blocked by the ridge 28b. In the case of this embodiment, the compression side receiving member 23 abuts on the upper end of the cylindrical portion 28a, and the shaft member 17 is screwed to the inner periphery of the cylindrical portion 28a.

  Then, the partition member 4 is fitted to the inner periphery of the cylinder 1 and is drilled at a position where the room A below the partition member 4 in FIG. 3 is the lower end side portion of the cylinder 1 and is not blocked by the cylindrical portion 28a. The passage 3 is formed in the gap between the outer cylinder 15 and the cylinder 1 through the hole 1a.

  The other configuration is the same as that of the pneumatic shock absorber D of the embodiment, and even in this pneumatic shock absorber D1, it is possible to adjust the damping characteristics on both sides of the pressure expansion from the outside.

  Further, in the pneumatic shock absorber D1 in this modification, the partition member 4 is directly fitted into the cylinder 1, so that the valve housing 28 can be reduced in weight and size, and the pneumatic shock absorber The weight of D1 can be reduced.

  Finally, the pneumatic shock absorber D2 in another modification of the embodiment will be described. As shown in FIG. 4, the pneumatic shock absorber D <b> 2 in the other modification is obtained by changing the configuration of the valve housing 29. The valve housing 29 in this embodiment is provided with a valve hole 29a that closes the ends of the cylinder 1 and the outer cylinder 15 and opens from the side. The partition member 4 and the shaft member 17 are provided in the valve hole 29a. Each member necessary for adjusting the damping characteristics such as the rod 24 is accommodated.

  Then, the inside of the valve hole 29a is partitioned into two chambers B and C by the partition member 4. Like the pneumatic shock absorbers D and D1, one chamber B includes a through hole 29b provided in the valve housing 29 and a cylinder. The other chamber C communicates with the pressure chamber R <b> 2 through a through hole 29 c provided in the valve housing 29, and communicates with the pressure chamber R <b> 1 through a gap between the first cylinder 15 and the outer cylinder 15. That is, the valve hole 29a forms a part of the passage 3, and if the damping characteristic adjusting portion in the pneumatic shock absorbers D and D1 in each of the above embodiments is a so-called vertical type, the other In the pneumatic shock absorber D2 in the modified example, the damping characteristic adjusting unit is set to be a horizontal type.

  Therefore, even in the pneumatic shock absorber D2 in this other modified example, it is possible to adjust the damping characteristics on both sides of the pressure expansion from the outside as in the pneumatic shock absorber D of the embodiment.

  Further, in the pneumatic shock absorber D2 in this other modification, the damping characteristic adjusting unit is set to a horizontal type, and the shaft member 17 and the rod 24 are rotated from the side of the pneumatic shock absorber D2. Therefore, the damping characteristic can be adjusted while the pneumatic shock absorber D2 is interposed between the vehicle body and the axle of the vehicle.

  In the above-described embodiment, the pressure chamber R1 and the pressure chamber R2 are communicated with the piston 2 and a flow path that provides resistance to the passing gas is not provided. However, such a flow path may be provided. .

  Further, in the above description, the extension side urging member 7 and the compression side urging member 8 are coil springs, but elastic bodies such as rubber and other springs may be used.

  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 the pneumatic shock absorber in one embodiment. It is an expansion longitudinal cross-sectional view in the damping characteristic adjustment part of the pneumatic shock absorber of one embodiment. It is an expansion longitudinal cross-sectional view of the damping characteristic adjustment part of the pneumatic shock absorber in one modification of one embodiment. It is an expansion longitudinal cross-sectional view of the damping characteristic adjustment part of the pneumatic shock absorber in the other modification of one Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Passage 4 Partition member 4a Expansion side port 4b Pressure side port 4c, 26, 27 Seal ring 5 Extension side leaf valve 6 Pressure side leaf valve 7 Extension side biasing member 8 Pressure side biasing member 9 Extension side adjustment means 10 Pressure side Adjusting means 11 Piston rod 12 Head member 12a Step 12b in head member Flow path 13 in head member Bearing 14, 28, 29 Valve housing 14a Small diameter portion 14b in valve housing Fitting portion 14c in valve housing Large diameter portion 14d in valve housing Large inner diameter portion 14e in the valve housing Small inner diameter portion 14f in the valve housing Screw portion 14g in the valve housing Step 14h in the valve housing Hole 15 in the valve housing Outer cylinder 16 Seal member 17 Shaft member 17a Shaft Base end portion 17b in the shaft Intermediate portion 17c in the shaft member Small diameter portions 17d, 17e, 17f in the shaft member Screw portions 18, 19 in the shaft member Spacer 20 Nut 21, 22 Spring bearing 23 Pressure receiving member 24 Rod 24a Base end 24b in the rod Shaft portion 24a of rod Screw portion 25 of rod 25 Extension side receiving member 28a Tube portion 28b of valve housing 鍔 29a of valve housing Valve holes 29b and 29c of valve housing A, B, C Chambers D, D1, D2 Pneumatic buffer R1, R2 Pressure chamber

Claims (2)

In a pneumatic shock absorber comprising a cylinder and a piston slidably inserted into the cylinder and separating the two pressure chambers in the cylinder, a passage communicating the two pressure chambers outside the cylinder, A partition member provided on the way and having an extension side port and a pressure side port, an extension side leaf valve stacked on the partition member to open and close the extension side port, and a pressure side leaf stacked on the partition member to open and close the pressure side port A valve, an extension side biasing member that biases the extension side leaf valve in a direction to close the extension side port, a pressure side biasing member that biases the pressure side leaf valve in a direction to close the pressure side port, and an extension side biasing A pneumatic shock absorber comprising: an extension side adjusting means for adjusting the urging force of the member from the outside; and a pressure side adjusting means for adjusting the urging force of the pressure side urging member from the outside. A hollow valve housing that is provided at the end of the cylinder and that communicates with the inside of the cylinder is provided, and the partition member is annular and is fixed to a cylindrical shaft member that is screwed into the end of the valve housing. The inside is divided into one pressure chamber side and the other pressure chamber side, and the expansion side adjusting means is inserted into the shaft member and the base end is screwed to the inner periphery of the shaft member, and the tip of the rod An extension side receiving member to be held, and the rod is rotated from the outside to advance and retract with respect to the shaft member, thereby adjusting the distance between the extension side leaf valve and the extension side receiving member. The urging force of the extension side urging member interposed between the side leaf valve and the extension side receiving member can be adjusted, and the pressure side adjustment means is restricted from moving outward from the cylinder relative to the valve housing. Pressure side receiving member and shaft member outside The pressure-side biasing member interposed between the pressure-side leaf valve and the pressure-side receiving member by adjusting the distance between the pressure-side leaf valve and the pressure-side receiving member. The pneumatic shock absorber according to claim 1, wherein the biasing force is adjustable.

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