JP4999439B2 - shock absorber - Google Patents

Description

  The present invention relates to a shock absorber.

  As a conventional shock absorber, there is one as shown in FIG. The shock absorber 101 includes a piston 105 in a resin tube 103.

  In the tube 103, viscous oil is sealed as a working liquid. A guide member 107 is attached to the tube 103, and the guide member 107 can be fitted to the piston rod 109 and guided.

  A resin lid member 111 is attached to the end of the tube 103 by caulking the resin, and a seal member 113 is interposed between the guide member 107, the lid member 111, and the piston / rod 109.

  When the piston rod 109 extends and contracts, the piston 105 reciprocates in the tube 103, and the input to the piston rod can be attenuated by the drag of the viscous oil.

  However, when there is a large input to the piston rod 109, it is easy to break, particularly on the extension stroke side, starting from the lid member 111, etc., and it is necessary to increase the resin thickness to a certain level or to form the whole with metal. There were problems such as increase and enlargement.

  On the other hand, when a member that simply reinforces the tube 103 is provided, there is a problem that the number of parts increases correspondingly, and parts management and assembly become complicated.

JP-A-10-227326

  The problem to be solved is that there is a risk of an increase in weight and an increase in size. If a member that simply reinforces the tube is provided, the number of parts increases correspondingly, and parts management and assembly become complicated. Is a point.

The present invention makes it possible to reduce the size and weight without increasing the number of parts. Therefore, a piston rod that can be expanded and contracted in a tube enclosing a working liquid, and a reciprocating movement within the tube attached to the piston rod. A piston that can be provided, and a seal member that seals between the tube and the piston / rod; and a reinforcing cover that covers the outer surface of the tube and that has a higher strength than the tube is provided. The seal member is fitted between the end edge of the tube and the piston rod, and partially protrudes outward with respect to the end edge of the tube. Engage with the protruding portion of the seal member with respect to the edge of the tube, and the other end is a stepped portion or end surface on the other end side with respect to the edge of the tube Combined with, the most important feature that is fixed to the tube.

  The shock absorber of the present invention includes a piston rod that can be stretched and contracted in a tube filled with a working liquid, a piston that is attached to the piston rod and is capable of reciprocating in the tube, the tube, A sealing member that seals between the piston and the rod, covers the outer surface of the tube, provides a reinforcing cover that is stronger than the tube, and the sealing member is supported by the reinforcing cover, so that the reinforcing cover covers the tube. Therefore, the overall size and weight can be reduced. Moreover, since the sealing member is provided on the reinforcing cover, the number of parts does not increase, and parts management and assembly can be facilitated.

Small, was realized without increasing the number of parts and weight.

[Shock absorber structure]
FIG. 1 is a cross-sectional view showing the structure of a shock absorber according to an embodiment of the present invention.

  As shown in FIG. 1, the shock absorber 1 includes a piston 5 in a tube 3.

The tube 3 is formed in a cylindrical shape with resin, and a stopper 9 is attached to one end via an O-ring 7. A seal member 11 is attached to the opening 10 at the other end of the tube 3. Sealing member 11 is formed by a rubber, it is formed integrally by molding a metal reinforcement cover 13, and has a supported configurations in the reinforcing cover 13.

The inner periphery of the tube 3 is composed of a large inner diameter portion 15 and a small inner diameter portion 17, and viscous oil is enclosed as a working liquid.
The reinforcing cover 13 is formed in a cylindrical shape corresponding to the tube 3, and the sealing member 11 is formed on the end wall 19. The end wall 19 is in contact with the end edge portion 23 of the tube 3 via the outer edge portion 21 of the seal member 11. The other end 25 of the reinforcing cover 13 is crimped to the end surface 27 of the tube 3.

  Accordingly, the reinforcing cover 13 reinforces the tube 3 by covering the entire outer surface closely.

  The piston 5 is provided integrally with a piston rod 29 that can be expanded and contracted with respect to the tube 3, and is provided so as to be capable of reciprocating at a small inner diameter portion 17 in the tube 3. The piston rod 29 extends out of the tube 3 through the seal member 11. That is, the seal member 11 seals between the tube 3 and the piston / rod 29.

  The piston 5 is provided with a plurality of orifices 31 as flow passages. The orifice 31 is formed penetrating in the moving direction of the piston 5, and allows the viscous oil to pass from the front to the rear in the moving direction of the piston 5 by moving the piston 5.

  The piston rod 29 is provided with a sliding shaft portion 33 having a relatively small diameter at the tip. A locking head 35 having a diameter larger than that of the sliding shaft 33 is formed at the tip of the sliding shaft 33.

A valve body 36 is supported on the sliding shaft portion 33 so as to be relatively movable in the axial direction.
The large inner diameter portion 15 of the tube 3, the guide member 37 is attached, and a piston fitted in the rod 17 and this piston rod 17 and can guide.

  The guide member 37 is provided with a circular accumulator recess 39, and the accumulator recess 39 communicates with the small inner diameter portion 17 via an accumulator orifice 41. An accumulator 43 is accommodated in the accumulator recess 39.

  The intermediate portion 47 of the seal member 11 is in close contact with the end outer edge 45 of the guide member 37.

[Action of shock absorber]
When the piston rod 29 contracts with respect to the tube 3 and the piston 5 moves with respect to the tube 3, the valve body 36 receives the pressure of the viscous oil on the compression side ahead of the moving direction of the piston 5, and the valve body 36 slides 33. Relative movement along. The orifice 31 is closed by the relative movement of the valve body 36, and a drag force corresponding to the speed of the piston 5 rises. By the rise of this drag, it is possible to achieve a reliable damping action during the contraction stroke.

  When the piston rod 29 extends with respect to the tube 3 and the piston 5 moves in the opposite direction with respect to the tube 3, the relative movement of the valve body 36 returns, and the valve body 36 is locked as shown in FIG. It is biased toward the 35 side. The orifice 31 is opened by the deviation of the valve body 36. By this opening, the viscous oil on the compression side passes through the orifice 31 and flows into the non-compression side. The piston 5 can exert a relatively light damping force against an external force only by the drag force of the viscous fluid passing through the orifice 25.

During the extension stroke, the compression-side viscous oil flows from the accumulator orifice 41 into the accumulator recess 39 while compressing the accumulator 43. Therefore, the extension stroke of the piston rod 29 can be performed without difficulty.
The viscous oil in the accumulator recess 39 flows backward in the moving direction of the piston 5 when the piston rod 29 undergoes a contraction stroke.

[Effect of Example 1]
The shock absorber 1 according to the first embodiment of the present invention includes a piston rod 29 provided in a tube 3 filled with viscous oil so as to be able to expand and contract, and a reciprocating movement within the tube 3 attached to the piston rod 29. A piston 5 that can be provided, and a seal member 11 that seals between the tube 3 and the piston rod 29, a metal reinforcing cover 13 that covers the outer surface of the tube 3 is provided, and the seal member 11 is Since the reinforcing cover 13 supports the tube 3, the tube 3 can be reinforced by the metal reinforcing cover 13, and the overall size and weight can be reduced. In addition, since the sealing member 11 is provided integrally with the reinforcing cover 13, there is no increase in the number of parts, and parts management and assembly can be facilitated.

  Since the sealing member 11 is molded integrally with the reinforcing cover 13, the sealing member 11 can be easily formed on the reinforcing cover 13.

  FIG. 2 is a cross-sectional view of a shock absorber according to the second embodiment of the present invention. The basic configuration is the same as that of the first embodiment, and the same or corresponding components will be described with the same reference numerals or the same reference numerals marked with A.

  In the shock absorber 1A of this embodiment, a stepped portion 47 is provided on the end surface 27 side of the tube 3A, and the claw portion 49 of the reinforcing cover 13A is click-engaged with the stepped portion 47. The reinforcing cover 13 </ b> A is fitted from the end edge 23 side of the tube 3.

  Therefore, in this embodiment, in addition to the same effects as in the first embodiment, at the time of assembly, the claw portion 49 is click-engaged with the stepped portion 47 by fitting and inserting the reinforcing cover 13A from the piston rod 29 side. Thus, the reinforcing cover 13A can be easily assembled.

  FIG. 3 is a cross-sectional view of a shock absorber according to a third embodiment of the present invention. The basic configuration is the same as that of the first embodiment, and the same or corresponding components will be described with the same reference numerals or B added to the same reference numerals.

  In the shock absorber 1B of this embodiment, a stepped portion 47B is provided in the vicinity of the boundary between the large and small inner diameter portions 15 and 17 of the tube 3B, and the other end 25B of the reinforcing cover 13B is caulked and joined to the stepped portion 47B. is there. For this reason, the reinforcing cover 13B is formed to be short so as to reinforce the large inner diameter portion 15 side of the tube 3B, and is provided on the end portion side of the piston rod 29 in the extension stroke direction. It is also possible to provide a configuration in which a claw portion as in Example 2 of the reinforcing cover 13B is provided and this claw portion is click-engaged with the stepped portion 47B.

In the present embodiment, in addition to the same effects as in the first embodiment, the reinforcing cover 13B is short, and an increase in cost due to the provision of the reinforcing cover 13B can be suppressed.
[Others]
The reinforcing cover is not limited to metal, and can be formed of a resin having a higher strength than the tube 3. When the reinforcing cover is made of resin, the reinforcing cover and the seal member 11 can be formed by two-color molding.

(Example 1) which is sectional drawing of a shock absorber. (Example 2) which is sectional drawing of a shock absorber. (Example 3) which is sectional drawing of a shock absorber. It is sectional drawing of a shock absorber (conventional example).

Explanation of symbols

1,1A, 1B Shock absorber
3 Tube 5 Piston 11 Seal member 13, 13A, 13B Reinforcement cover 29 Piston rod

Claims (4)

A piston rod that can be expanded and contracted in a tube filled with working fluid;
A piston attached to the piston rod and provided so as to reciprocate within the tube;
A seal member for sealing between the tube and the piston rod;
Covering the outer surface of the tube and providing a reinforcing cover with higher strength than the tube,
Supporting the sealing member on the reinforcing cover ;
The seal member is fitted between the end edge of the tube and the piston rod and partially protrudes outward with respect to the end edge of the tube.
The reinforcing cover has one end engaged with a protruding portion of the seal member with respect to the end edge portion of the tube, and the other end engaged with a stepped portion or an end surface on the other end side with respect to the end edge portion of the tube, Fixed to the tube,
Shock absorber characterized by that. The shock absorber according to claim 1,
The reinforcing cover is made of metal or resin.
Shock absorber characterized by that. The shock absorber according to claim 1 or 2,
The shock absorber is characterized in that the seal member is molded integrally with the reinforcing cover. The shock absorber according to any one of claims 1 to 3,
The reinforcing cover is provided on the end side in the extension stroke direction of the piston rod.
Shock absorber characterized by that.

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