JP2005054863A - Hydraulic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic damper having a large stroke of a piston rod and large capacity of a gas chamber and improved in installation into a car body. <P>SOLUTION: This hydraulic damper 10 is formed by inserting the piston rod 12 into a damper tube 11, slidably housing a piston 14 provided in the piston rod 12 in oil chambers 41A and 41B inside the damper tube 11, and providing the gas chamber 43A, which compensates a volume change of the oil chambers 41A and 41B inside the damper tube 11 corresponding to a volume change inside the piston rod 12 moving forward/backward inside the damper tube 11, in the damper tube 11. A gas tank 60 to be connected to the gas chamber 43A provided in the damper tube 11 is provided outside the damper tube 11. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydraulic shock absorber suitable for use in a vehicle.

  As an inverted hydraulic shock absorber, as disclosed in Patent Document 1, a piston rod is inserted into a damper tube, a piston provided on the piston rod is slidably accommodated in an oil chamber in the damper tube, and is advanced and retracted into the damper tube. Some gas chambers that compensate for the volume change of the oil chamber in the damper tube corresponding to the volume change of the piston rod are separated from the oil chamber in the damper tube by a partition wall.

As another hydraulic shock absorber, as described in Patent Document 2, a gas chamber and an oil chamber are provided in a sub tank provided outside the damper tube so as to be separated by a partition wall, and this oil chamber is connected to the oil chamber in the damper tube. However, there is a gas chamber that compensates for the volume change of the oil chamber in the damper tube corresponding to the volume change of the piston rod that advances and retreats to and from the damper tube.
JP-A-8-210412 JP-A-8-184341

  In the hydraulic shock absorber of Patent Document 1, an oil chamber and a gas chamber are provided in a single damper tube. Therefore, if the stroke of the piston rod is increased, the capacity of the gas chamber decreases, and the capacity of the gas chamber If you try to take a large, you will not be able to take the stroke required for the piston rod.

  In the hydraulic shock absorber of Patent Document 2, the oil chamber in the subtank and the oil chamber in the damper tube are connected directly or via a pipe. In order to avoid oil leakage during mounting on the vehicle body, It is necessary to install without separating it from the damper tube, and the mounting workability is poor.

  SUMMARY OF THE INVENTION An object of the present invention is to increase the stroke of a piston rod and the capacity of a gas chamber in a hydraulic shock absorber and to improve the attachment to a vehicle body.

  The invention according to claim 1 corresponds to the volume change of the piston rod that is inserted into the damper tube, the piston provided on the piston rod is slidably accommodated in the oil chamber in the damper tube, and advances and retracts into the damper tube. In a hydraulic shock absorber provided with a gas chamber in the damper tube to compensate for the volume change of the oil chamber in the damper tube, a gas tank connected to the gas chamber provided in the damper tube is provided outside the damper tube. It is.

  According to a second aspect of the present invention, in the first aspect of the present invention, the gas tank is further connected to a gas chamber through a communication hole provided in a mount mounting bolt on the upper portion of the damper tube.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the gas tank further includes a gas sealing plug.

  According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the gas tank is a gas filled tank.

(Claim 1)
(1) By connecting a gas tank to the internal gas chamber in the damper tube, the capacity of the gas chamber can be increased without increasing the damper tube even if the stroke of the piston rod is increased.

  (2) At the time of mounting on the vehicle body, the damper tube with the gas tank separated may be mounted on the vehicle body, and then the gas tank may be connected to the damper tube.

(Claim 2)
(3) By connecting the gas tank to the internal gas chamber in the damper tube through the communication hole provided in the mount mounting bolt on the upper part of the damper tube, it is possible to connect the gas tank without changing the shape of the damper tube. Can be facilitated.

(Claim 3)
(4) By providing the gas tank with the gas sealing plug, the gas can be easily sealed after the gas tank is connected to the damper tube, and the gas pressure can be adjusted.

(Claim 4)
(5) Since the gas tank is a gas filled tank, it is not necessary to fill the gas after the gas tank is connected to the damper tube, and it can be used easily.

  1 is an overall cross-sectional view showing a hydraulic shock absorber, FIG. 2 is a lower cross-sectional view of the hydraulic shock absorber, and FIG. 3 is an upper cross-sectional view of the hydraulic shock absorber.

  The hydraulic shock absorber 10 for a vehicle inserts a piston rod 12 into a damper tube 11, fixes a piston 14 to a piston bolt 13 provided at an insertion end of the piston rod 12, and slides the piston 14 into the damper tube 11. An inverted type damper is configured in which the damper tube 11 is mounted on the vehicle body side and the piston rod 12 is mounted on the wheel side. The damper tube 11 is fixed to the vehicle body side by mounting bolts 16A provided in a vehicle body mounting mount 16 described later.

  The damper tube 11 has a mount mounting bolt 15 fixed in a liquid-tight manner at its upper end, and a vehicle body mounting mount 16 is fixedly attached to the mount mounting bolt 15 with a nut 17.

  The damper tube 11 has a rod guide 18 inserted into a lower end portion thereof, and the rod guide 18 is fixed in a liquid-tight manner together with an oil seal 19 and a washer 20, and the piston rod 12 is slidably supported on the rod guide 18.

  In the hydraulic shock absorber 10, an end plate 22 welded to a lower end portion of a reinforcing tube 21 is fixed to a protruding end of the piston rod 12 with respect to the damper tube 11 with a nut 23. The reinforcing tube 21 is loaded on the outer periphery of the damper tube 11, and an oil seal 24 </ b> A, a guide bush 25 </ b> A, a collar 26, a guide bush 25 </ b> B, and an oil seal 24 </ b> B are assembled in that order from the upper end opening of the reinforcing tube 21. These built-in members are fixed to the inner periphery of the reinforcing tube 21 by the stopper ring 27 engaged with the inner peripheral groove. The oil seals 24A and 24B are in sliding contact with the outer periphery of the damper tube 11, and seal a lubricant such as oil and grease filled between the guide bushes 25A and 25B. The reinforcing tube 21 is slidably supported on the outer periphery of the damper tube 11 via the guide bushes 25A and 25B, and functions as a strength member that supports the load between the vehicle body side and the wheel side together with the piston rod 12.

  The hydraulic shock absorber 10 is screwed onto the outer periphery of the reinforcing tube 21 and fixed with a lock nut 31A, and an upper spring seat supported on the lower surface of the vehicle body mounting mount 16 via a thrust bearing 32A. A suspension spring 30 is interposed between the suspension spring 30 and the suspension spring 30. The suspension spring 30 absorbs the impact that the vehicle receives from the road surface.

  The hydraulic shock absorber 10 includes a piston 14 slidably accommodated in the damper tube 11, and a piston rod side oil chamber 41 </ b> A that accommodates the piston rod 12 inside the damper tube 11, and a piston side that does not accommodate the piston rod 12. The oil chamber 41B is partitioned. The hydraulic oil is sealed in the piston rod side oil chamber 41A and the piston side oil chamber 41B.

  The hydraulic shock absorber 10 slidably accommodates a free piston 42 as a gas-liquid separation partition immediately above the piston-side oil chamber 41B in the damper tube 11, and the piston 10 is disposed in the damper tube 11 and in a gas tank 60 described later. It has a gas chamber 43 partitioned with respect to the side oil chamber 41B. The gas chamber 43 is filled with a pressurized gas such as nitrogen gas or air, and compensates for the total volume change of the oil chambers 41 </ b> A and 41 </ b> B in the damper tube 11 corresponding to the volume change of the piston rod 12 that moves forward and backward to the damper tube 11. To do.

  The hydraulic shock absorber 10 includes a piston valve device 50, and the damping force generated by the piston valve device 50 dampens the expansion and contraction vibration of the piston rod 12 accompanying the absorption of the impact force by the suspension spring 30.

  In the piston valve device 50, a compression side plate valve 51, a piston 14, an extension side plate valve 52, and a valve stopper 53 are inserted into a piston bolt 13 provided on the piston rod 12, and these are fixed by nuts 54.

  In the compression process of the hydraulic shock absorber 10, the hydraulic oil in the piston side oil chamber 41 </ b> B pushes and opens the pressure side plate valve 51 through the pressure side flow path 51 </ b> A of the piston 14, and the pressure side plate valve 51 is formed between the lower surface of the piston 14. From the gap to the piston rod side oil chamber 41A, and a damping force is generated due to the flow resistance of the gap. At this time, the volume change of the oil chambers 41 </ b> A and 41 </ b> B corresponding to the entry volume of the piston rod 12 entering the damper tube 11 is compensated by the displacement (rise) of the free piston 42 pressurized by the gas chamber 43. .

  In the extension step of the hydraulic shock absorber 10, the hydraulic oil in the piston rod side oil chamber 41 </ b> A pushes and opens the extension side plate valve 52 through the extension side flow passage 52 </ b> A (not shown) of the piston 14, and the extension side plate valve 52 is connected to the piston 14. It flows into the piston side oil chamber 41B from the gap formed between the upper surface and a damping force due to the flow resistance of the gap. At this time, the volume change of the oil chambers 41A and 41B (the total volume change of the oil chamber 41A and the oil chamber 41B) corresponding to the retraction volume of the piston rod 12 retreating from the damper tube 11 is pressurized by the gas chamber 43. It is compensated by the displacement (lowering) of the free piston 42.

  In the hydraulic shock absorber 10, a bump stopper cap 28 that restricts the maximum compression stroke is fixedly attached to the upper end portion of the reinforcing tube 21. The bump stopper cap 28 is affixed to a bump rubber (not shown) that is affixed to the outer periphery of the upper end side of the damper tube 11 and backed up on the lower surface of the vehicle body mounting mount 16 and regulates the maximum compression stroke. A rebound rubber 29 for restricting the maximum extension stroke is inserted into the outer periphery of the piston rod 12 inserted into the damper tube 11.

  However, in the hydraulic shock absorber 10, the gas chamber 43 is separated from the piston-side oil chamber 41 </ b> B by the free piston 42 in the damper tube 11, and the damper tube 11 is provided by the gas tank 60. The external gas chamber 43B is formed outside.

  The gas tank 60 is connected to the internal gas chamber 43 </ b> A in the damper tube 11 by a pipe 70. The pipe 70 has joint bolts 71 and 72 at both ends, and the joint bolt 71 is screwed to the upper end female thread portion 15B of the communication hole 15A drilled on the central axis of the mount mounting bolt 15, and the joint bolt 72 is connected to the gas tank. In order to pierce the cap 61 of 60, it is screwed to the screw portion 61A. The internal gas chamber 43 </ b> A and the external gas chamber 43 </ b> B are communicated via the communication hole 15 </ b> A of the mount mounting bolt 15, the hollow passages of the joint bolts 71 and 72, and the pipe 70.

  The gas tank 60 may be a can or the like to which the pipe 70 can be connected. The cap 61 is fitted to one end of the cylindrical body and the bottom plate 62 is fitted and fixed to the other end, and the joint bolt 72 of the pipe 70 is fixed to the cap 61 as described above. The bottom plate 62 is provided with a gas sealing plug 63. The gas sealing plug 63 can be connected by tire filling or the like. The gas pressure in the gas tank 60 can be adjusted by supplying and discharging with the gas filling plug 63, the feeling of the hydraulic shock absorber 10 can be changed, and the gas pressure can be set in the gas tank 60 according to preference.

  The assembly of the hydraulic shock absorber 10 and the attachment work to the vehicle body can be performed as follows.

  (1) The tip of the positioning rod is inserted into the damper tube 11 from the communication hole 15A of the mount mounting bolt 15 provided in the damper tube 11, and the bolt provided at the base end of the positioning rod is screwed to the female thread portion 15B. To do. A free piston 42 is inserted into the damper tube 11 from the lower end opening of the damper tube 11, and the free piston 42 is supported and positioned by the tip of the positioning rod.

  (2) After inserting the piston rod 12 and the piston 14 into the inside of the damper tube 11 from the lower end opening of the damper tube 11 of the above (1) and filling the inside of the damper tube 11 with hydraulic oil, the lower end opening of the damper tube 11 Insert the rod guide 18 or the like into the part and caulk the lower end of the damper tube 11.

  (3) Attach the damper tube 11 of (2) above to the vehicle body.

  (4) The positioning rod (1) is pulled out from the communication hole 15A of the mount mounting bolt 15 of the damper tube 11 (3). The joint bolt 71 of the pipe 70 connected to the gas tank 60 is screwed to the female thread portion 15B of the communication hole 15A of the mount mounting bolt 15. Thereby, the external gas chamber 43B of the gas tank 60 is connected to the internal gas chamber 43A of the damper tube 11, and a large-capacity gas chamber 43 is formed.

  (5) Gas can be sealed in the external gas chamber 43B to the internal gas chamber 43A by using the gas sealing plug 63 of the gas tank 60, and a desired gas pressure can be loaded in the entire large-capacity gas chamber 43.

According to the present embodiment, the following operational effects can be obtained.
(1) By connecting the gas tank 60 to the internal gas chamber 43A in the damper tube 11, the capacity of the gas chamber 43 can be increased without increasing the damper tube 11 even if the stroke of the piston rod 12 is increased. it can.

  (2) When attaching to the vehicle body, the damper tube 11 with the gas tank 60 separated may be attached to the vehicle body, and then the gas tank 60 may be connected to the damper tube 11 to improve the workability.

  (3) The configuration of the damper tube 11 is remarkably changed by connecting the gas tank 60 to the internal gas chamber 43A in the damper tube 11 through the communication hole 15A provided in the mount mounting bolt 15 at the upper part of the damper tube 11. Without this, the connection of the gas tank 60 (attachment of the pipe 70) can be facilitated.

  (4) Since the gas tank 60 includes the gas sealing plug 63, the gas can be easily sealed after the gas tank 60 is connected to the damper tube 11, and the gas pressure can be adjusted.

  The gas tank 60 may be a gas filled tank. At this time, the gas sealing plug 63 can be deleted. According to this gas tank 60 which has been filled with gas, it is not necessary to fill the gas after the gas tank 60 is connected to the damper tube 11 and can be used easily. If a plurality of types of gas tanks 60 with different gas pressure settings are prepared without adjusting the gas pressure or the like, it is possible to select and use the gas pressure tanks 60 according to preference.

The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. Included in the invention. For example, the gas tank may be directly connected to the damper tube without piping.
Alternatively, a fixed partition member may be provided in the piston-side oil chamber of the damper tube, and a compression-side damping force generator may be provided on the fixed partition member.

FIG. 1 is an overall cross-sectional view showing a hydraulic shock absorber. FIG. 2 is a lower sectional view of the hydraulic shock absorber. FIG. 3 is a top sectional view of the hydraulic shock absorber.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hydraulic buffer 11 Damper tube 12 Piston rod 14 Piston 15 Mount mounting bolt 15A Communication hole 41A, 41B Oil chamber 43 Gas chamber 43A Internal gas chamber 43B External gas chamber 60 Gas tank 63 Gas filled plug

Claims (4)

The piston rod is inserted into the damper tube, the piston provided on the piston rod is slidably accommodated in the oil chamber in the damper tube, and the oil chamber in the damper tube corresponding to the volume change of the piston rod moving forward and backward to the damper tube In a hydraulic shock absorber provided with a gas chamber in the damper tube to compensate for the volume change of
A hydraulic shock absorber characterized in that a gas tank connected to the gas chamber provided in the damper tube is provided outside the damper tube.   2. The hydraulic shock absorber according to claim 1, wherein the gas tank is connected to the gas chamber through a communication hole provided in a mount mounting bolt at an upper portion of the damper tube.   The hydraulic shock absorber according to claim 1 or 2, wherein the gas tank includes a gas sealing plug.   The hydraulic shock absorber according to claim 1 or 2, wherein the gas tank is a gas filled tank.

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