JP2008064144A - Gas filling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas filling device which reliably prevents any gas leakage and also prevents application of any excessive pressure to a cylinder. <P>SOLUTION: The gas filling device comprises: a gas filling head 10 movable in the axial direction of a hydraulic buffer D in which an opening end side of an outer cylinder 31 is inserted therein, and an outer circumference of the opening end of the outer cylinder 31 is kept in a gastight manner; a caulking roller 20 which is rotatably provided in the gas filling head 10 around the circumferential direction of the hydraulic buffer D to caulk the opening end of the outer cylinder 31 inwardly; and a push-rod 23 which is provided in the gas filling head 10 movably in the axial direction of the hydraulic buffer D to push an insert metal 35 to a rod guide 34 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a gas sealing device.

  In general, a multi-cylinder type hydraulic shock absorber includes a rod guide that closes the opening end of the cylinder and the opening end of the outer cylinder covering the cylinder and supports a rod that is movably inserted into the cylinder. The rod guide is laminated with an annular insert metal having a seal member on each of the inner periphery and the outer periphery to keep the hydraulic shock absorber oil-tight.

  In the reservoir chamber formed between the cylinder and the outer cylinder of such a double cylinder type hydraulic shock absorber, it is necessary to enclose a gas in addition to the hydraulic oil, and the gas encapsulating the gas in the reservoir chamber Examples of the device include a vacuum head capable of sucking and pressing the insert metal, a gas-filled head that holds the open end of the outer cylinder through an O-ring and supplies gas, and an open end of the outer cylinder And a caulking roller for caulking (see, for example, Patent Document 1).

  According to this gas sealing device, the hydraulic shock absorber being assembled is mounted in advance with a rod guide that slidably holds the piston rod on the cylinder opening end and the inner periphery of the opening end of the outer cylinder. An annular insert metal provided with a seal that seals the outer cylinder and cylinder is temporarily assembled above, and a gas-filled head is put on the open end of the outer cylinder of the hydraulic shock absorber in this state. One end of the insert metal is sucked, and the gas is supplied into the gas filling head in a state where the insert metal is floated from the rod guide to fill the reservoir chamber with the gas.

After that, after gas of a predetermined pressure is sealed in the reservoir chamber, the vacuum head is moved closer to the cylinder side to press the insert metal toward the rod guide side, and this cylinder and the outer cylinder are provided with this seal. While keeping the sealed state with the inserted metal, the gas enclosure head is moved upward, the outer cylinder is withdrawn from the inside of the gas enclosure head, and the open end of the outer cylinder is exposed to the outside at atmospheric pressure, and the outside exposed to the outside The caulking roller is brought close to the opening end of the cylinder and the opening end is caulked inward, and the insert metal and the rod guide are fixed to the outer cylinder and the cylinder to finish the gas filling process of the hydraulic shock absorber. .
JP 2000-120754 (paragraph numbers 0028 to 0040, FIGS. 4 to 6)

  However, there is a possibility that it is pointed out that the gas sealing apparatus as described above has the following problems.

  As described above, in the conventional gas sealing apparatus, after the gas is sealed, the gas sealing head is detached from the outer cylinder in order to crimp the open end of the outer cylinder. At this time, the insert metal is pressed against the rod guide by the vacuum head. However, if the dimensional control between the seal member on the outer periphery of the insert metal and the inner diameter of the outer cylinder is not strictly performed, a gap is generated in the portion, and the reservoir chamber Gas may leak outside.

  In addition, since it is necessary to prevent gas leakage from the reservoir chamber by pressing the insert metal with the vacuum head before the caulking process, an excessive large pressing force of the vacuum head directly acts on the cylinder. This is not preferable.

  Therefore, the present invention was devised in order to improve the above-described problems, and the object of the present invention is to reliably prevent gas leakage and to prevent an excessive pressing force from acting on the cylinder. It is to provide a gas filling device.

  In order to solve the above-described object, the problem solving means in the present invention includes a reservoir chamber between the cylinder and the outer cylinder covering the cylinder, and slides the piston rod on the cylinder opening end and the inner periphery of the opening end of the outer cylinder. A gas that fills a reservoir chamber in a hydraulic shock absorber in which a rod guide that is freely held is mounted and an annular insert metal having a seal that seals the outer cylinder and the cylinder is temporarily assembled above the rod guide. In the sealing device, a hollow gas-filled head in which the opening end side of the outer cylinder is inserted inside and the outer periphery of the outer-end of the outer cylinder is kept airtight and movable in the axial direction of the hydraulic shock absorber, And a caulking roller that is rotatably provided around the circumferential direction of the hydraulic shock absorber and caulks the open end of the outer cylinder inward, and moves in the axial direction of the hydraulic shock absorber in the gas filling head. And a depressible push rod insert metal to the rod guide side provided.

  According to another aspect of the present invention, a rod is provided with a reservoir chamber between a cylinder and an outer cylinder covering the cylinder, and the piston rod is slidably held on the cylinder opening end and the inner periphery of the opening end of the outer cylinder. In a gas sealing method in which gas is sealed in a reservoir chamber in a hydraulic shock absorber in a state where a guide is mounted and an annular insert metal having a seal for sealing the outer cylinder and the cylinder is temporarily assembled above the rod guide, A step of sealing the gas into the reservoir chamber while inserting the opening end side of the outer cylinder into a hollow gas-filled head capable of holding the outer periphery of the outer end of the shock absorber in an airtight state; A caulking roller provided in the gas filling head is brought close to the opening end of the outer cylinder and the opening end of the outer cylinder is caulked while maintaining the airtight state of the opening.

  According to the gas sealing apparatus of the present invention, all steps necessary for gas sealing processing from gas sealing to the process of caulking the open end of the outer cylinder are inserted into the gas sealing head and a hydraulic shock absorber is maintained in an airtight state. Since it can be performed, there is no possibility that the gas supplied into the reservoir chamber leaks during the gas filling process, so that a gas having a predetermined gas pressure can be reliably sealed in the reservoir chamber.

  Also, when crimping the open end of the outer cylinder, the insert metal is pressed with a push rod, but the gas does not leak from the reservoir chamber during the gas filling process, so the pressing force of the push rod is It can be made smaller than the conventional device, and there is no problem that an excessively large pressing force is applied to the cylinder.

  Further, since the rotating members of the caulking roller and the pressing roller are accommodated in the gas sealing head, the safety of the gas sealing device is improved.

  Hereinafter, the gas filling apparatus of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a gas sealing apparatus according to an embodiment. FIG. 2 is a cross-sectional view of the gas filling head of the gas filling device according to the embodiment. FIG. 3 is a cross-sectional view of the gas filling head of the gas filling device according to the embodiment. FIG. 4 is a longitudinal sectional view of the hydraulic shock absorber. FIG. 5 is a view showing a state where one end of the hydraulic shock absorber is inserted into the gas-filled head.

 As shown in FIG. 1, a gas sealing apparatus 1 according to an embodiment includes a base 2, a chuck 3 that is attached to the base 2 and holds a hydraulic shock absorber D, and a gas sealing head that is provided on the base 2. A frame 4 that supports 10 and is movable in the vertical direction with respect to the base 2, and a holding member 22 that is provided on the frame 4 and that holds the caulking roller 20 and the pressing roller 21 provided in the gas-filled head 10 are rotated. The motor 5 is a rotational driving means for driving, and a gas supply source 8 for supplying gas into the gas filling head 10.

 Hereinafter, each part will be described in detail. The base 2 is provided with an elevating means 6. A frame 4 is attached to the upper end of the elevating means 6, and the frame 4 is attached to the base 2 by the elevating means 6. On the other hand, it can be moved in the vertical direction in FIG. The lifting means 6 only needs to be able to move the chuck 3 up and down in FIG. 1 as described above. For example, a hydraulic cylinder can be used, and the motor is driven by a motor and a motor. A feed screw mechanism including a screw shaft and a nut screwed onto the screw shaft may be employed.

 Further, a gas sealing head 10 is fixedly supported above the frame 4, and the gas sealing head 10 is positioned above the chuck 3.

  As shown in FIG. 2, the gas-filled head 10 includes a small-diameter portion 10a, a large-diameter portion 10b having a larger diameter than the small-diameter portion 10a, and an annular cap 10c connected to the opening of the large-diameter portion 10b. A communication hole 10f is formed in the step portion 10d formed at the boundary between the small diameter portion 10a and the large diameter portion 10b so that gas can be introduced into the inside. An annular seal member 10e is provided on the inner periphery of the cap 10c. When a later-described hydraulic shock absorber D is inserted into the inner periphery of the cap 10c, the later-described hydraulic shock absorber will be described. The inside of the gas filled head 10 is maintained in an airtight state by sliding contact with the outer periphery of the outer cylinder 31 of D. A gas introduction pipe 14 connected to the gas supply source 8 is fixed to the communication hole 10f. The cap 10c is connected to the large-diameter portion 10b by bolting or the like and is detachable. When replacing the caulking roller 20 and the pressing roller 21 accommodated in the gas filled head 10, the cap 10c is removed. It can be removed from the large diameter portion 10b.

 Further, a holding member 22 is rotatably accommodated in the gas-filled head 10 via ball bearings 25, 26, and 27. The holding member 22 is connected to the cylindrical portion 22a and the lower end of the cylindrical portion 22a. The upper end of the cylindrical portion 22a protrudes upward from the inside of the small-diameter portion 10a of the gas-filled head 10 and is on the outer periphery of a portion protruding outward from the small-diameter portion 10a of the cylindrical portion 22a. A sprocket 22c is attached.

 Subsequently, as shown in FIGS. 2 and 3, three pressing rollers 21 are rotatably attached to the lower end of the flange portion 22b of the holding member 22 at equal intervals in the circumferential direction of the flange portion 22b. Each pressing roller 21 includes a shaft 21a that is vertically attached to the flange portion 22b, and a cylindrical roller portion 21b that is rotatably attached to the outer periphery of the shaft 21a via a ball bearing (not shown). The hydraulic shock absorber D can be positioned by bringing the roller portion 21b of each pressing roller 21 into contact with the outer periphery of the outer cylinder 31 of the hydraulic shock absorber D described later.

  Further, as shown in FIGS. 2 and 3, caulking rollers 20 are arranged and attached to the lower end of the flange portion 22b of the holding member 22 at three positions between the pressing rollers 21, respectively. The caulking roller 20 is inserted into the lower end of the flange portion 22b of the holding member 22 with a cylindrical body 20a attached to the center of the holding member 22 and a ball bearing (not shown) rotatably. And a roller head 20b attached thereto. That is, the caulking roller 20 is rotatable around an imaginary line V perpendicular to the axis of the hydraulic shock absorber D positioned at the center of the gas filled head 10 by the pressing roller 21.

  A head portion 20c having a curved surface is provided at the tip of the roller head 20b. By pressing the head portion 20c against the opening end of the outer cylinder 31 of the hydraulic shock absorber D from above, the outer cylinder 31 is provided. It is possible to crimp the open end of the head so as to be plastically deformed following the curved surface of the head portion 20c.

 From the above, since the holding member 22 is rotatable with respect to the gas-filled head 10 via ball bearings 25, 26, 27, the motor 5 fixed to the frame 4 is used. When the sprocket 22c is driven to rotate, the holding member 22 rotates with respect to the gas-filled head 10, and both the caulking roller 20 and the pressing roller 21 are rotated around the axis of the gas-filled head 10 in the gas-filled head 10. Can be done.

 Incidentally, the cylindrical portion 22a and the flange portion 22b of the holding member 22 can be separated by being coupled by bolt coupling or the like, and depending on the outer diameter of the hydraulic shock absorber D, the caulking roller 20 and the pressing member 20 can be separated. The roller 21 can be exchanged.

 Further, a push rod 23 is accommodated in the holding member 22 described above so as to be movable in the vertical direction in FIG. 2, which is the axial direction of the holding member 22. Specifically, the push rod 23 includes a hollow hole 23a that opens from the lower end and is formed along the axis thereof. A piston rod 33 of a hydraulic shock absorber D described later can be inserted into the hollow hole 23a. It is like that.

 In addition, cylindrical slide bearings 28 and 29 are interposed between the outer periphery of the push rod 23 and the inner periphery of the holding member 22, respectively. The holding member 22 and the gas filling head 10 can be moved up and down smoothly.

Further, the upper end of the push rod 23 is connected to an elevating means 7 fixed to the frame 4 so that the push rod 23 can be moved up and down relative to the holding member 22 and the gas-filled head 10 by the elevating means 7. It has become. The lifting means 7 only needs to be able to move the push rod 23 up and down in FIG. 1. For example, a hydraulic cylinder can be used as well as the lifting means 6. It is also possible to employ a feed screw mechanism comprising a screw shaft that is driven by and a nut that is screwed onto the screw shaft, and between the gas-filled head 10 and the holding member 22, and between the holding member 22 and the push rod 23. Between the two, annular seal rings 15 and 16 are interposed, respectively, so that the gas is not leaked from the upper side in FIG. Has been.

 On the other hand, as shown in FIG. 4, the hydraulic shock absorber D attached to the chuck 3 of the gas sealing apparatus 1 configured as described above is slidable within the cylinder 30, the outer cylinder 31 covering the cylinder, and the cylinder 30. 4, a piston rod 33 movably inserted into the cylinder 30 and connected at one end to the piston 32, an upper end in FIG. 4 that is the opening end of the cylinder 30, and an opening end of the outer cylinder 31. An annular insert metal 35 having a rod guide 34 mounted on the inner periphery of the middle upper end and slidably holding the piston rod 33, and seals S1 and S2 for sealing the outer cylinder 31 and the cylinder 30 above the rod guide 34. And a base valve member 36 fitted to the lower end of the cylinder 30 and a lower cap 37 for sealing the lower end of the outer cylinder 31 to form a so-called multi-cylinder shock absorber. The upper chamber R1 and the lower chamber R2 configured by the piston 32 in the cylinder 30 are filled with hydraulic oil, and the hydraulic oil is also placed in the reservoir chamber R formed between the cylinder 30 and the outer cylinder 31. Fixed amount filling.

 Further, the annular insert metal 35 is provided with a seal S1 composed of an oil seal and a dust lip slidably contacting the outer periphery of the piston rod 33 on the inner peripheral side, and provided on the shoulder of the rod guide 34 on the outer peripheral side. A seal S <b> 2 is provided which is inserted into the notch 34 a and seals between the rod guide 34 and the outer cylinder 31.

  In the hydraulic shock absorber D that is transported to the gas sealing device 1 and fixed to the chuck 3, the insert metal 35 of the above configuration has the upper end portion of the outer cylinder 31 inward as shown in FIG. 5. In the state where it is not crimped and not fixed, it is temporarily assembled above the rod guide 34 and conveyed to the gas sealing device 1. As described above, when the insert metal 35 is in a temporarily assembled state, a gap is formed between the seal S2 provided on the outer peripheral side and the inner periphery of the opening end of the outer cylinder 31, and this gap is reduced. It is possible to supply gas into the reservoir chamber R via The filling of the working oil into the upper chamber R1, the lower chamber R2, and the reservoir chamber R has been completed.

  In this state, the hydraulic shock absorber D conveyed to the gas sealing device 1 is gripped by the chuck 3 at the lower end of the outer cylinder 31, and the hydraulic shock absorber D is fixed to the gas sealing device 1. Then, after fixing the hydraulic shock absorber D in this manner, the frame 4 is moved downward in FIG. 1 by the elevating means 6 so that the upper end side of the hydraulic shock absorber D is positioned right above the chuck 3. It is inserted into the cap 10c of the sealing head 10.

  Then, as described above, as shown in FIG. 5, the seal member 10e of the cap 10c is slidably contacted with the outer periphery of the open end of the outer cylinder 31 of the hydraulic shock absorber D, and the inside of the gas-filled head 10 is brought into an airtight state. The piston rod 33 protruding upward in FIG. 5 from 30 is inserted into the hollow hole 23 a of the push rod 23. In this state, the descent of the frame 4 is stopped and the state is maintained so that the caulking roller 20 does not contact the opening end of the outer cylinder 31 that is the upper end in FIG.

  Further, when the upper end serving as one end of the hydraulic shock absorber D is inserted into the gas filling head 10, each of the roller portions 21 b of the three pressing rollers 21 comes into contact with the outer periphery of the open end of the outer cylinder 31, and the hydraulic shock absorber D Can be positioned so as to be concentric with the gas-filled head 10, and it is possible to reliably prevent a gap from being formed between the seal member 10e that seals around the outer cylinder 31 and the outer periphery of the outer cylinder 31, Further, the tension force can be applied uniformly over the entire circumference of the seal member 10e, and the inside of the gas filled head 10 can be reliably maintained in an airtight state.

  Subsequently, with the upper end serving as one end of the hydraulic shock absorber D being inserted into the gas filling head 10, the gas is supplied from the gas supply source 8 through the gas introduction pipe 14 fixed to the communication hole 10 f into the gas filling head 10. And the gas supplied into the gas-filled head 10 is contained in the reservoir chamber R via a gap between the seal S2 on the outer peripheral side of the temporarily assembled insert metal 35 and the inner periphery of the outer cylinder 31 described above. To be introduced.

  Then, when the pressure of the gas supplied into the reservoir chamber R in this way reaches a predetermined pressure, this time, the lift means 7 is driven and the push rod 23 is moved to the lower side in FIG. The insert metal 35 is pressed toward the rod guide 34.

  After that, the frame 4 is lowered, and the opening end of the outer cylinder 31 is brought into contact with the head portion 20c of the caulking roller 20 as shown by a broken line in FIG. Then, the open end of the outer cylinder 31 is crimped inward.

  Specifically, by rotating the holding member 22, the caulking roller 20 is rotated around the circumferential direction of the hydraulic shock absorber D, the frame 4 is lowered, and the head portion 20 c of the caulking roller 20 is moved to the open end of the outer cylinder 31. Then, the head portion 20c is gradually moved downward as the caulking progresses. At this time, the push rod 23 is driven by the elevating means 7 to press the insert metal 35 against the rod guide 34 with a predetermined pressing force. Although not specifically shown, the elevating means 7 A load sensor for detecting a pressing force is provided, and the pressing force detected by the load sensor by the lifting means 7 is controlled by feedback or feedforward. The pressing force with which the rod 23 presses the insert metal 35 can be maintained at a predetermined value.

  The descending distance of the frame 4 per rotation of the holding member 22 is set so as to be optimal for caulking the outer cylinder 31 with the caulking roller 20. When the hydraulic shock absorber D is moved closer to the caulking roller 20 with the frame 4, the hydraulic shock absorber D functions as a guide by the pressing roller 21, so that the outer cylinder 31 does not run out. It is possible to securely crimp the entire circumference of the open end of the outer cylinder 31.

  That is, the caulking roller 20 and the pressing roller 21 are rotated around the circumferential direction of the hydraulic shock absorber D in synchronization with each other, and the hydraulic shock absorber D is positioned at the center of the gas filled head 10 by the pressing roller 21. The caulking process of the opening end of the outer cylinder 31 is advanced by the caulking roller 20 while the outer cylinder 31 of the hydraulic shock absorber D is clamped while the 21 rotates and the shaft shock of the hydraulic shock absorber D is prevented. Therefore, it is possible to securely crimp the entire circumference of the open end of the outer cylinder 31.

  When this caulking process is completed, the temporarily assembled insert metal 35 is fixed by the caulking portion of the open end of the outer cylinder 31, and the seal S2 provided on the outer periphery of the insert metal 35 is pushed into the notch 34a of the rod guide 34. Then, the reservoir chamber R is pressed against the inner periphery of the outer cylinder 31 with an appropriate pressing force, and the reservoir chamber R is sealed by the seal S2. Further, since the space between the outer periphery of the piston rod 33 and the inner periphery of the insert metal 35 is sealed with the seal S1, the outer cylinder 31 and the cylinder 30 of the hydraulic shock absorber D are completely sealed.

  When the machining is completed up to such a state, the frame 4 is lowered, the hydraulic shock absorber D is taken out from the gas filled head 10, and the hydraulic buffer D is removed from the chuck 3. The hydraulic shock absorber D can be obtained.

  The above-described process is obtained and gas filling processing into the hydraulic shock absorber D by the gas filling device 1 is performed. In the gas filling device 1 according to the present embodiment, the opening end of the outer cylinder 31 from the gas filling. The gas supplied to the reservoir chamber R is performed by inserting the hydraulic shock absorber D into the gas sealing head 10 and maintaining the airtight state until all processes required for gas sealing until the process of crimping is performed. Since there is no possibility of leakage at the time of gas filling processing, a gas having a predetermined gas pressure can be reliably sealed in the reservoir chamber R.

  In addition, when the open end of the outer cylinder 31 is caulked, the insert metal 35 is pressed by the push rod 23. In the gas sealing apparatus 1 according to the present embodiment, the gas is supplied from the reservoir chamber R during the gas sealing process. Therefore, the pressing force of the push rod 23 can be made smaller than that of the conventional device, and there is no problem that an excessively large pressing force is applied to the cylinder 30.

  Furthermore, when caulking the open end of the outer cylinder 31 with the caulking roller 20, it is not necessary to drive the caulking roller 20 from the outer peripheral side to the inner peripheral side of the outer cylinder 31, and simply the hydraulic shock absorber D. Can be pushed inward of the gas filling head 10, and the number of drive sources such as a motor and a hydraulic cylinder that need to be mounted in the gas filling device 1 can be reduced.

  Further, since the rotating objects of the caulking roller 20 and the pressing roller 21 are accommodated in the gas sealing head 10, the safety of the gas sealing device 1 is improved.

 Further, since all processes necessary for gas sealing processing from gas sealing to the process of caulking the open end of the outer cylinder 31 can be performed with a single gas sealing device, facilities can be consolidated and costs can be reduced. It is also possible to cope with cell production.

 In addition, in the place mentioned above, the raising / lowering means 6 raises / lowers the flame | frame 4, The hydraulic buffer D is inserted in the gas enclosure head 10 by this raising / lowering means 6, and the above-mentioned series of processes are performed. However, instead of moving the frame 4 up and down by the lifting / lowering means 6, instead of moving the chuck 3 up and down, the hydraulic buffer D in the gas-filled head 10 can be used. Can be inserted and the above processing can be performed.

 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 front view of the gas sealing apparatus in one embodiment. It is sectional drawing of the gas enclosure head of the gas enclosure apparatus in one embodiment. It is a transverse cross section of the gas enclosure head of the gas enclosure in one embodiment. It is a longitudinal cross-sectional view of a hydraulic shock absorber. It is a figure which shows the state which inserted the end of the hydraulic buffer into the gas enclosure head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas filling apparatus 2 Base 3 Chuck 4 Frame 5 Motors 6, 7 Lifting means 8 Gas supply source 10 Gas filling head 10a Small diameter part 10b Large diameter part 10c Cap 10d Step part 10e Seal member 10f Communication hole 14 Gas introduction pipe 15, 16 Seal ring 20 Caulking roller 20a Tube body 20b Roller head 20c Head portion 21 Pressing roller 21a Shaft 21b Roller portion 22 Holding member 22a Tube portion 22b Hook portion 22c Sprocket 23 Push rod 23a Hollow holes 25, 26, 27 Ball bearings 28, 29 Slide bearing 30 Cylinder 31 Outer cylinder 32 Piston 33 Piston rod 34 Rod guide 34a Notch 35 Insert metal 36 Base valve member 37 Lower cap D Hydraulic shock absorbers S1, S2 Seal R Reservoir chamber R1 Upper chamber R2 Lower chamber

Claims (5)

A reservoir chamber is provided between the cylinder and the outer cylinder that covers the cylinder, and a rod guide that slidably holds the piston rod is mounted on the cylinder open end and the inner periphery of the open end of the outer cylinder. In a gas sealing device for sealing a gas in a reservoir chamber in a hydraulic shock absorber in a state where an annular insert metal having a seal for sealing a cylinder and a cylinder is temporarily assembled, an opening end side of the outer cylinder is inserted inside A hollow gas-filled head that holds the outer periphery of the open end of the outer cylinder in an airtight state and is movable in the axial direction of the hydraulic shock absorber, and an outer cylinder that is rotatably provided in the gas-filled head around the circumferential direction of the hydraulic shock absorber. A caulking roller that caulks the open end of the metal inward, and a pusher that is provided in the gas-filled head so as to be movable in the axial direction of the hydraulic shock absorber and can press the insert metal toward the rod guide. Gas filled device being characterized in that a Shuroddo. Located in the gas-filled head at equal intervals around the outer cylinder, contacts the outer circumference of the outer cylinder to position the hydraulic shock absorber in place, and rotates in the circumferential direction in synchronization with the caulking roller The gas sealing device according to claim 1, comprising at least three possible pressing rollers. The gas filling device according to claim 1 or 2, wherein the caulking roller is rotatable around a virtual line perpendicular to the axis of the hydraulic shock absorber. A reservoir chamber is provided between the cylinder and the outer cylinder that covers the cylinder, and a rod guide that slidably holds the piston rod is mounted on the cylinder open end and the inner periphery of the open end of the outer cylinder. In a gas sealing method in which gas is sealed in a reservoir chamber in a hydraulic shock absorber in a state where an annular insert metal having a seal for sealing the cylinder and the cylinder is temporarily assembled, the outer periphery of the opening end of the outer cylinder of the hydraulic shock absorber is airtight A process of sealing the gas inside the reservoir chamber while inserting the open end side of the outer cylinder into a hollow gas-filled head that can be held in the chamber, and maintaining the air-tight state by holding the open end of the outer cylinder with the gas-filled head And a step of caulking the open end of the outer cylinder by bringing a caulking roller provided in the gas enclosure head close to the open end of the outer cylinder. In the step of caulking the open end of the outer cylinder, the insert metal of the hydraulic shock absorber is pressed toward the rod guide by a push rod provided in the gas filled head so as to be movable in the axial direction of the hydraulic shock absorber. Item 5. A gas sealing method according to Item 4.

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