TW201837337A - Friction damper - Google Patents

Abstract

Provided is a friction damper capable of suitably suppressing entry of foreign matter into a friction surface. A friction damper (1) is provided with a cylinder (10), a rod (20), a friction member (30), an elastic member (40), and a seal member (50). The cylinder (10) is formed like a tube. The rod (20) is capable of freely reciprocating in an axial direction and is partially housed in the cylinder (10). The friction member (30) is arranged inside the cylinder (10) to generate a damping force based on a frictional force generated between the friction member (30) and an outer circumferential surface (20C) of the rod (20) as a result of relative movement between the cylinder (10) and the rod (20). The elastic member (40) applies an elastic force in a direction in which the length of projection of the rod (20) on one end (20A) side from the cylinder (10) increases. The elastic force of the elastic member (40) is applied to the seal member (50). The seal member (50) is held by the elastic member (40) to seal a clearance (CP) through which the outside and the inside of the cylinder (10) communicate with each other.

Description

 Friction damper  

The present invention relates to a friction damper.

Patent Document 1 discloses a conventional damper. The friction damper is provided with an outer housing, a rod, an inner damping member, and a spring. The outer casing is formed in a cylindrical shape. The rod is provided to protrude from one end of the outer casing. Further, the rod is reciprocally inserted into the outer casing along the axial direction. The inner damping member is slidably attached to the rod on the inner circumferential surface of the outer casing. The internal attenuating member generates a damping force by utilizing the frictional force generated between the outer casing and the inner peripheral surface of the outer casing by the relative movement of the outer casing and the rod. The spring acts toward the spring between the outer casing and the rod to impart a resilient force to the front end of the rod away from the outer casing. Thereby, the friction damper of Patent Document 1 can absorb vibration and impact between the outer casing and the rod.

 [Previous Technical Literature]    [Patent Literature]  

Patent Document 1: Japanese Patent Laid-Open Publication No. 2006-507460

However, in the friction damper, if a foreign matter such as water or a contaminating material intrudes into the friction surface, the appropriate attenuation performance cannot be exerted. Therefore, in the friction damper of Patent Document 1, a dust cap is attached to both ends of the outer casing to prevent entry of foreign matter. However, in the case of a seal member such as a dust cover of Patent Document 1, there is a possibility that it may fall off due to vibration and impact.

The present invention has been made in view of the above-described conventional circumstances, and provides a friction damper that can appropriately suppress entry of foreign matter into a friction surface as a problem to be solved.

The friction damper of the present invention is provided with a cylinder, a rod, a friction member, an elastic member, and a sealing member. The cylinder system is formed in a cylindrical shape. The rod reciprocates freely along the axial direction, and a part is housed in the cylinder. The friction member is disposed inside the cylinder, and generates a damping force by a frictional force generated between at least one of an inner circumferential surface of the cylinder or an outer circumferential surface of the cylinder by relative movement between the cylinder and the rod. The elastic member imparts an elastic force in a direction in which the length of the elastic member protrudes from the cylinder toward the end side of the rod. The sealing member is biased by the elastic member to be held by the elastic member to close the gap between the outside and the inside of the communicating cylinder.

The friction damper of the present invention may be provided with an outer tube. The outer tube is formed in a bottomed cylindrical shape, and one end of the rod is connected to the bottom portion, and one end of the cylinder is inserted into the cylindrical portion, and a gap is formed between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the cylinder. Further, the elastic member is disposed on the outer circumference of the cylinder, and can provide an elastic force toward the end surface on the opening side of the outer tube. Further, the sealing member is disposed on the outer circumference of the cylinder, and the gap can be closed by the elastic member abutting against the end surface on the opening side of the outer tube and the outer circumferential surface of the cylinder.

In the friction damper of the present invention, the groove portion can be formed in the outer tube. The groove portion is formed at an end portion on the inner circumferential surface side of the end surface on the opening side of the outer tube, and is open toward the end surface side and the inner circumferential surface side on the opening side of the outer tube. Moreover, the sealing member may be disposed in the groove portion.

The friction damper of the present invention may be provided with an outer tube. The outer tube is formed in a bottomed cylindrical shape, and one end of the rod is connected to the bottom portion, and one end portion of the cylinder is inserted into the cylindrical portion, and a gap is formed between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the cylinder. The elastic member is disposed between one end of the cylinder and the bottom of the outer tube, and can impart an elastic force toward the end surface on one end side of the cylinder. Further, the sealing member is disposed on the inner circumference of the outer tube, and the gap can be closed by the elastic member abutting against the end surface on one end side of the cylinder and the inner circumferential surface of the outer tube.

The friction damper of the present invention may be provided with a rod guide. The rod guide closes the opening portion on one end side of the cylinder, and is formed with an insertion hole through which the rod is reciprocally inserted in the axial direction, and is formed between the insertion hole and the outer peripheral surface of the rod. There is a gap. The elastic member is disposed on the outer circumference of the rod protruding from the cylinder, and can impart an elastic force toward the end surface on the outer side of the rod guide. Further, the sealing member is disposed on the outer circumference of the rod protruding outward from the rod guide, and the gap can be closed by the elastic member abutting against the end surface on the outer side of the rod guide and the outer circumferential surface of the rod.

In the friction damper of the present invention, the sealing member is abuttable and disposed on an inclined surface that is inclined with respect to a direction orthogonal to the axial direction.

In the friction damper of the present invention, the elastic member may be a coil spring. Further, a washer disposed between the coil spring and the sealing member may be provided.

1,201, 301‧‧‧ friction damper

10, 510‧ ‧ cylinder

One end of the 10A‧‧ ‧ cylinder

10B‧‧‧The other end of the cylinder

10C‧‧‧Expanding Department

10D‧‧‧Reducing section

10E‧‧‧ outer circumference of the other end of the cylinder

10F‧‧‧ one end of the cylinder

10G‧‧‧Steps Department

End face of one end of 10H, 510H‧‧ ‧ cylinder

11, 611‧‧‧ rod guides

11A‧‧‧ inserted through hole

11B, 611B‧‧‧ end face of the outer side of the rod guide

12‧‧‧Cylinder side joint

12A‧‧‧through hole

20‧‧‧ pole

One end of 20A‧‧‧ rod

20B‧‧‧The other end of the pole

20C‧‧‧ outside the pole

21‧‧‧Piston Department

21A‧‧‧The outer surface of the piston

22‧‧‧ bolt

23‧‧‧Washers

30‧‧‧ Friction members

30A‧‧‧The inner circumference of the friction member

40, 240, 340, 840, 1340‧‧‧ elastic members

41, 42, 242, 342, 442, 542, 642 ‧ ‧ washers

42A, 242A, 342A‧‧‧ sloped surface

50, 250, 350, 1250, 1350 ‧ ‧ sealing components

60, 460‧‧‧ outside management

61‧‧‧Bottom of the outer tube

62‧‧‧The tube of the outer tube

62A‧‧‧End of the open side of the outer tube

62B, 462B‧‧‧ end face of the open side of the outer tube

62C‧‧‧The inner circumference of the outer tube

63‧‧‧ rod side joint

63A‧‧‧through hole

63B‧‧‧ Screw Department

70, 71‧‧‧ bushing

CP‧‧‧ clearance (CP1: gap between rod guide and rod, CP2: space inside outer tube, CP3: gap between outer surface of cylinder and inner circumference of outer tube)

ES‧‧‧Space outside the cylinder

G1~G11‧‧‧Ditch Department

The space inside the IS‧‧‧ cylinder

Fig. 1 is a side sectional view schematically showing a friction damper of a first embodiment.

Fig. 2 is an enlarged view of a main part of Fig. 1.

Fig. 3 is a side sectional view schematically showing the friction damper of the second embodiment.

Fig. 4 is an enlarged view of a main part of Fig. 3.

Fig. 5 is a side sectional view schematically showing the friction damper of the third embodiment.

Fig. 6 is an enlarged view of a main part of Fig. 5.

Fig. 7 is a partially enlarged cross-sectional view showing the friction damper of another embodiment, and is a view showing another form of the groove portion (part 1).

Fig. 8 is a partially enlarged cross-sectional view schematically showing a friction damper according to another embodiment, and is a view showing another form of the groove portion (Part 2).

Fig. 9 is a partially enlarged cross-sectional view schematically showing a friction damper according to another embodiment, and is a view showing another form of the groove portion (part 3).

Fig. 10 is a partially enlarged cross-sectional view schematically showing a friction damper according to another embodiment, and is a view showing another form of the groove portion (fourth).

Fig. 11 is a partially enlarged cross-sectional view schematically showing a friction damper according to another embodiment, and is a view showing another form of the groove portion (fifth).

12(A) to 12(C) are schematic cross-sectional views showing main parts of a friction damper according to another embodiment, and showing another form of the groove portion (the sixth).

Fig. 13 is a cross-sectional view showing an essential part of a friction damper according to another embodiment, and schematically showing another embodiment of the sealing member (part 1).

Fig. 14 is a partially enlarged cross-sectional view schematically showing a friction damper according to another embodiment, and schematically showing another embodiment of the sealing member (Part 2).

Embodiments 1 to 3 in which the friction damper of the present invention is embodied will be described with reference to the drawings. Further, in the following embodiments, a friction damper used for a caster such as a wheelchair or a baby buggy or a transporting trolley is exemplified. The friction damper can be formed, for example, by a mechanism portion such as a link mechanism provided between a bracket and a wheel of the caster, and can be formed in a bump or the like of a guide block or the like. The vibration of the stepped road is attenuated or the shock is moderated.

 <Embodiment 1>  

As shown in FIGS. 1 and 2, the friction damper 1 of the first embodiment includes a cylinder 10, a rod 20, a friction member 30, an elastic member 40, and a sealing member 50. Further, the friction damper 1 is provided with an outer tube 60.

The cylinder 10 is formed in a cylindrical shape with both ends open. At one end portion 10A of the cylinder 10, a cylindrical rod guide 11 is fitted by screwing, so that the opening portion on the end portion 10A side is closed. The cylindrical rod guide 11 is formed with an insertion hole 11A penetrating in the axial direction. The rod guide 11 presses the friction member 30 to be described later in the axial direction. A cylinder side joint portion 12 is provided at the other end portion 10B of the cylinder 10. The cylinder side joint portion 12 is a joint portion with another member when the rod side joint portion 63 described later is incorporated into the mechanism portion. A through hole 12A through which a pin or the like is inserted is formed in the cylinder side joint portion 12. An enlarged diameter portion 10C which is expanded in diameter from the other portion is formed in the vicinity of the end portion 10A of the cylinder 10. The friction member 30 is housed in the enlarged diameter portion 10C and the rod 20 is inserted. A reduced diameter portion 10D disposed adjacent to the enlarged diameter portion 10C is formed inside the cylinder 10 near the end portion 10B. Further, the outer peripheral surface 10E of the end portion 10B side of the cylinder 10 is formed to have a larger diameter than the outer peripheral surface 10F of the end portion 10A side. As described above, the stepped portion 10G is formed on the outer peripheral surface of the cylinder 10 by expanding the outer peripheral surface of the end portion 10B side. The step portion 10G is provided with a washer 41 that supports an end portion of the elastic member 40 to be described later.

The rod 20 is reciprocally movable in the axial direction, and a part thereof is accommodated in the cylinder 10. The rod 20 is formed in a cylindrical shape, and is disposed in a state in which the one end portion 20A protrudes from the end portion 10A of the cylinder 10. Further, the rod 20 has one end portion 20A side supported by the insertion hole 11A of the rod guide 11 and the other end portion 20B side supported by the reduced diameter portion 10D of the cylinder 10. Specifically, the rod 20 is slidably inserted into the cylindrical bushes 70 and 71 which are respectively provided in the reduced diameter portion 10D of the cylinder 10 and the insertion hole 11A of the rod guide 11 through the cylindrical bushes 70 and 71. The two bushings 70, 71 are supported by the reduced diameter portion 10D of the cylinder 10 and the rod guide 11.

A piston portion 21 is provided in the middle of the axial direction of the rod 20. The piston portion 21 is formed to have an outer diameter that is larger than the outer diameter of the other portion of the rod 20. The rod 20 arranges the piston portion 21 in the enlarged diameter portion 10C of the cylinder 10. A bolt 22 is attached to the other end 20B of the rod 20. The bolt 22 is attached to the end portion 20B of the rod 20 with a washer 23 having an outer diameter larger than the inner diameter of the reduced diameter portion 10D of the cylinder 10. The washer 23 abuts against the outer end surface of the reduced diameter portion 10D, thereby functioning as a retaining portion for preventing the rod 20 from coming off the rod guide 11 side, and functions as a metal seal for preventing foreign matter from entering the inside of the cylinder 10. And play the function.

The friction member 30 is disposed inside the cylinder 10. Specifically, the friction member 30 is disposed in the enlarged diameter portion 10C of the inside of the cylinder 10 . The friction member 30 is urged in the axial direction by the rod guide 11. The friction member 30 is a member formed of a cylindrical shape and composed of a urethane rubber having a hardness of 70°. The friction member 30 is formed such that the outer diameter and the axial length thereof correspond to the inner diameter and the axial length of the enlarged diameter portion 10C, and are disposed in the cylinder 10 so as to be embedded in the enlarged diameter portion 10C. The outer peripheral surface 21A of the piston portion 21 is slidably abutted against the inner peripheral surface 30A of the friction member 30. Specifically, the friction member 30 is formed such that the diameter of the inner peripheral surface 30A is smaller than the diameter of the outer peripheral surface 21A of the piston portion 21, and the surface of the outer peripheral surface 21A of the piston portion 21 is abutted while being elastically deformed.

The friction member 30 generates a damping force by utilizing the frictional force generated between the outer circumferential surface of the rod 20 by the relative movement between the cylinder 10 and the rod 20. In the case of the present embodiment, the friction member 30 is relatively moved in the axial direction with respect to the cylinder 10 by the rod 20, and between the inner circumferential surface 30A and the outer circumferential surface 21A of the piston portion 21 in the outer circumferential surface of the rod 20. Produces friction. In the friction damper 1 of the first embodiment, the friction surface refers to the inner circumferential surface 30A of the friction member 30 and the outer circumferential surface 21A of the piston portion 21. Further, the frictional force generated by the sliding of the friction surfaces acts as a damping force for suppressing the movement of the rod 20 in the axial direction. Further, a through hole (not shown) that penetrates both end faces in the axial direction is formed in the piston portion 21. The through hole ensures the ventilation between the spaces IS inside the cylinder 10 partitioned by the piston portion 21, and corresponds to the volume change of the space IS when the piston portion 21 moves while the friction damper 1 expands and contracts. .

The elastic member 40 imparts an elastic force in a direction in which the length of the end portion 20A of the rod 20 protrudes from the cylinder 10 (the horizontal direction in FIG. 1). In other words, the elastic member 40 imparts an elastic force in a direction in which the friction damper 1 is elongated. In the present embodiment, the elastic member 40 is disposed on the outer circumference of the cylinder 10, and is biased toward the end surface 62B on the opening side of the pipe 60 to be described later. Specifically, the elastic member 40 of the present embodiment is a compression coil spring, and is disposed on the outer circumference of the cylinder 10 such that the cylinder 10 is inserted into the inner circumference from the end portion 10A side. A washer 41 that abuts against the step portion 10G of the cylinder 10 is provided at one end of the elastic member 40. The other end portion of the elastic member 40 is provided with a gasket 42 that abuts against the end surface 62B of the opening side of the pipe 60 to be described later. The washers 41, 42 are biased toward the mutually away from each other by the elastic force of the elastic member 40, which is transmitted to the cylinder 10 and the outer tube 60 of the support washers 41, 42.

Moreover, as shown in FIG. 2, the gasket 42 is formed with the inclined surface 42A. The inclined surface 42A is formed to be open to the end surface and the inner circumferential surface of the gasket 42 in the axially outer side (the left direction in FIG. 2). That is, the inclined surface 42A is formed so as to be inclined with respect to the direction orthogonal to the axial direction, that is, the radial direction of the gasket 42, and faces the axially outer side and the inner circumferential direction of the gasket 42. The inclined surface 42A is formed over the entire circumference of the gasket 42, and has a tapered shape which is reduced in diameter from the axially outer end surface toward the other end. The inclined surface 42A forms a groove portion G1 which is a space surrounded by the outer circumferential surface 10F of the cylinder 10 and the end surface 62B of the opening side of the outer tube 60. The groove portion G1 has a triangular cross section.

The sealing member 50 is given an elastic force of the elastic member 40, and is held by the elastic member 40 to close the gap CP between the outside and the inside of the communication cylinder 10. The gap CP is a passage connecting the space ES outside the cylinder 10 and the internal space IS. In the case of the present embodiment, the gap CP is the gap CP1 between the insertion hole 11A of the rod guide 11 and the outer circumferential surface 20C of the rod 20 (between the bushing 71 and the rod 20), and the inner side of the outer tube 60. The space CP2 and the gap CP3 between the outer circumferential surface 10F of the cylinder 10 and the inner circumferential surface 62C of the cylindrical portion 62 of the outer tube 60 are formed. Further, a space CP2 inside the outer tube 60 is connected to an air passage (not shown) corresponding to a volume change caused by the expansion and contraction of the friction damper 1.

In the present embodiment, the sealing member 50 is disposed on the outer circumference of the cylinder 10, and the elastic member 40 abuts against the end surface 62B of the opening side of the outer tube 60 and the outer circumferential surface 10F of the cylinder 10 to close the gap CP. Moreover, the sealing member 50 is arrange|positioned in the groove part G1. The sealing member 50 is an O-ring. The sealing member 50 abuts against the inclined surface 42A which is the inner wall of the groove portion G1 having a triangular cross section, and receives the elastic force of the elastic member 40 via the inclined surface 42A. Further, in a state in which the sealing member 50 is pressed by the elastic force of the elastic member 40, the sealing member 50 abuts against the axial contact surface, that is, the end surface 62B of the opening side of the outer tube 60, and the cylinder which is abutting surface in the radial direction. The outer peripheral surface 10F is 10, and the gap CP is closed. The sealing member 50 of the present embodiment is disposed at a position which is a boundary between the gap CP and the external space ES, and can be considered to close the outermost side of the gap CP. The sealing member 50 as an o-ring is pressed, for example, by a compression allowance prescribed by the Japanese Industrial Standard (JIS).

The outer tube 60 is formed in a bottomed cylindrical shape with one end open. The outer tube 60 has a bottom portion 61 and a tubular portion 62. A rod side joint portion 63 is provided on the outer side of the bottom portion 61 of the outer tube 60. The rod side joint portion 63 is provided as a joint portion with other members together with the cylinder side joint portion 12. A through hole 63A through which the pin or the like is inserted is formed in the rod side joint portion 63. The rod side joint portion 63 is attached to the rod 20 by being inserted through the bottom portion 61 of the outer tube 60 and screwed to the screw portion 63B of the end portion 20A of the rod 20. That is, the outer tube 60 is connected to the bottom portion 61 with an end portion 20A which is one end of the rod 20. The outer tube 60 is attached to the end portion 20A of the rod 20 in such a manner that the end portion 62A on the opening side of the tubular portion 62 covers the outer peripheral surface 10F of the end portion 10A of the cylinder 10. In other words, one end portion 10A of the cylinder 10 is inserted into the tubular portion 62 of the outer tube 60.

Next, the action and effect of the friction damper 1 of the first embodiment will be described. When the friction damper 1 is contracted by an external force, or the external force is removed and is elongated by the elastic force of the elastic member 40, the outer peripheral surface 21A of the piston portion 21 of the rod 20 slides on the inner peripheral surface 30A of the friction member 30 to generate frictional force. . This frictional force acts against the expansion and contraction, and functions as a damping force that attenuates the contraction or elongation motion.

When the friction damper 1 expands and contracts, the sealing member 50 disposed in the groove portion G1 relatively moves with respect to the cylinder 10. That is, the sealing member 50 slides in the axial direction on the outer peripheral surface 10F of the cylinder 10 when the friction damper 1 expands and contracts. The sealing member 50 is sandwiched between the inclined surface 42A and the end surface 62B of the opening side of the outer tube 60 by the elastic force of the elastic member 40. Therefore, the sealing member 50 is stably held without falling off, thereby reliably preventing the intrusion of foreign matter.

In addition, the sealing member 50 is disposed on the outer circumference of the cylinder 10, and is biased toward the end surface 62B of the opening side of the outer tube 60 by the elastic force of the elastic member 40, and is pressed against the end surface 62B and the outer circumferential surface 10F of the cylinder 10 while being pressed. The gap CP is closed. Therefore, the gap CP is stably closed, and the intrusion of foreign matter toward the gap CP is prevented. Further, the sealing member 50 closes the gap CP at the position closest to the space ES of the outer side of the gap CP, and maximizes the distance to the space IS inside the cylinder 10. Therefore, even if the foreign matter enters the gap CP beyond the sealing member 50, it can be suppressed from reaching the friction surface in the cylinder 10.

As described above, the friction damper 1 of the first embodiment includes the cylinder 10, the rod 20, the friction member 30, the elastic member 40, and the sealing member 50. The cylinder 10 is formed in a cylindrical shape. The rod 20 is reciprocally movable in the axial direction, and a part thereof is accommodated in the cylinder 10. The friction member 30 is disposed inside the cylinder 10, and generates a damping force by frictional force generated between the outer peripheral surface 21A of the rod 20 by the relative movement between the cylinder 10 and the rod 20. The elastic member 40 imparts an elastic force in a direction in which the length of the one end portion 20A of the rod 20 protrudes from the cylinder 10 becomes longer. The sealing member 50 is biased by the elastic force of the elastic member 40, and is held by the elastic member 40 to close the gap CP between the outside and the inside of the communication cylinder 10.

According to this configuration, the friction damper 1 has the sealing member 50 subjected to the elastic force of the elastic member 40, and the sealing member 50 is held in a state to which the elastic force is imparted. Therefore, it is possible to surely prevent the sealing member 50 from coming off due to impact or vibration. As a result, the state sealed by the sealing member 50 can be surely maintained.

Therefore, the friction damper 1 can appropriately suppress the intrusion of foreign matter toward the friction surface.

Further, the friction damper 1 is provided with an outer tube 60. The outer tube 60 is formed in a bottomed cylindrical shape, and one end portion 20A of the rod 20 is connected to the bottom portion 61, and one end portion 10A of the cylinder 10 is inserted into the cylindrical portion 62, and the inner circumferential surface of the cylindrical portion 62 and the cylinder 10 are A gap CP (CP3) is formed between the outer peripheral faces 10F. Further, the elastic member 40 is disposed on the outer circumference of the cylinder 10, and is biased toward the end surface 62B of the opening side of the outer tube 60. Further, the sealing member 50 is disposed on the outer circumference of the cylinder 10, and the elastic member 40 abuts against the end surface 62B of the opening side of the outer tube 60 and the outer circumferential surface 10F of the cylinder 10 to close the gap CP. Therefore, for example, the length of the gap CP which is an intrusion path of the foreign matter can be further extended as compared with the case where the sealing member is disposed on the inner circumference of the cylinder. Thereby, it is possible to suppress the foreign matter that has passed through the sealing member 50 from reaching the frictional surface in the cylinder 10, that is, the inner circumferential surface of the friction member 30 and the outer circumferential surface 21A of the piston portion 21 of the rod 20.

Further, the sealing member 50 is disposed to abut against the inclined surface 42A that is inclined with respect to the direction orthogonal to the axial direction. Therefore, in addition to the axial direction, the elastic force of the elastic member 40 can be appropriately converted into a force that presses the sealing member 50 in the radial direction. As a result, the sealing member 50 can be appropriately pressed against the axial end surface, that is, the end surface 62B of the outer tube 60 on the opening side, and the radial abutting surface, that is, the outer circumferential surface 10F of the cylinder 10.

Further, the elastic member 40 is a coil spring. Further, a gasket 42 disposed between the elastic member 40 as a coil spring and the sealing member 50 is provided. Therefore, the elastic force can be appropriately given as compared with the case where the sealing member 50 is directly biased by the elastic member 40.

 <Embodiment 2>  

Next, the second embodiment will be described with reference to Figs. 3 and 4 and the like. The friction damper 201 of the second embodiment shown in Figs. 3 and 4 is different from the friction damper 1 of the first embodiment in the arrangement of the elastic member 240 and the sealing member 250. In the other portions, the components having the same configurations and functions as those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the detailed description thereof will be omitted.

As shown in FIGS. 3 and 4, in the friction damper 201 of the second embodiment, the elastic member 240 is a compression coil spring. The elastic member 240 is disposed such that the rod 20 is inserted into the inner circumference from the end portion 20A side and the outer circumference thereof is covered by the tubular portion 62 of the outer tube 60. One end of the elastic member 240 abuts against the bottom 61 of the outer tube 60. At the other end of the elastic member 240, a washer 242 that abuts against the end face 10H on the end 10A side of the cylinder 10 is provided. The washer 242 is biased toward the bottom 61 of the outer tube 60 to impart an elastic force to the elastic member 40, which is transmitted to the cylinder 10 of the support washer 242.

Moreover, as shown in FIG. 4, the gasket 242 is formed with the inclined surface 242A. The inclined surface 242A is formed to be open to the end surface and the outer peripheral surface of the gasket 242 in the axially inner side (the right direction in FIG. 4). That is, the inclined surface 242A is formed to be inclined with respect to the direction orthogonal to the axial direction, that is, the radial direction of the washer 242, and faces the axial inner side and the outer circumferential direction of the washer 242. The inclined surface 242A is formed over the entire circumference of the gasket 242, and has a tapered shape which is expanded in the axial direction from the axially inner end surface toward the other end. The inclined surface 242A forms a groove portion G2 which is a space surrounded by the end surface 10H on the end portion 10A side of the cylinder 10 and the inner circumferential surface 62C of the tubular portion 62 of the outer tube 60. The groove portion G2 has a triangular cross section in the same manner as the groove portion G1 of the first embodiment.

The sealing member 250 is imparted with an elastic force of the elastic member 240. The sealing member 250 is held by the elastic member 240 to close the gap CP. The sealing member 250 is disposed on the inner circumference of the tubular portion 62 of the outer tube 60, and the elastic force of the elastic member 240 is imparted to the end surface 10H on the end portion 10A side of the cylinder 10. More specifically, the sealing member 250 is disposed in the groove portion G2. The sealing member 250 is an O-ring similarly to the sealing member 50 of the first embodiment. The sealing member 250 abuts against the inclined surface 242A which is the inner wall of the groove portion G2 having a triangular cross section, and receives the elastic force of the elastic member 240 via the inclined surface 242A. In addition, the sealing member 250 is pressed against the axial contact surface, that is, the end surface 10H on the end portion 10A side of the cylinder 10, and the radial contact surface, that is, the elastic force of the elastic member 240 is received by the inclined surface 242A. The inner peripheral surface 62C of the tubular portion 62 of the tube 60 closes the gap CP.

Next, the effect of the friction damper 201 of the second embodiment will be described. When the friction damper 201 is contracted by an external force or the external force is removed and is extended by the elastic force of the elastic member 240, the outer peripheral surface 21A of the piston portion 21 of the rod 20 is in the inner circumference of the friction member 30 as in the first embodiment. The face 30A slides to generate friction. This frictional force acts against the expansion and contraction, and functions as a damping force that attenuates the contraction or elongation motion.

When the friction damper 201 expands and contracts, the sealing member 250 disposed in the groove portion G2 relatively moves with respect to the outer tube 60. That is, the sealing member 250 slides in the axial direction on the inner circumferential surface 62C of the cylindrical portion 62 of the outer tube 60 when the friction damper 201 expands and contracts. The sealing member 250 is sandwiched between the inclined surface 242A and the end surface 10H on the end portion 10A side of the cylinder 10 by the elastic force of the elastic member 240. Therefore, the sealing member 250 is stably held without falling off, thereby reliably preventing the intrusion of foreign matter.

Further, the sealing member 250 is disposed on the inner circumference of the tubular portion 62 of the outer tube 60, and is provided with an elastic force to the elastic member 240 toward the end surface 10H on the end portion 10A side of the cylinder 10, and is abutted against the outer tube 60 while being pressed. The inner peripheral surface 62C of the tubular portion 62 and the end surface 10H on the end portion 10A side of the cylinder 10 close the gap CP. Therefore, the gap CP is stably closed, and the intrusion of foreign matter toward the gap CP is prevented.

In the friction damper 201 thus constructed, the sealing member 250 receives the elastic force of the elastic member 240, and the sealing member 250 is held in a state of being subjected to the elastic force. Therefore, it is possible to surely prevent the sealing member 250 from coming off due to impact or vibration. As a result, the state sealed by the sealing member 250 can be surely maintained. Therefore, similarly to the friction damper 1 of the first embodiment, the friction damper 201 can appropriately suppress the intrusion of foreign matter toward the friction surface.

Further, the friction damper 201 has the elastic member 240 disposed between the end portion 10A of the cylinder 10 and the bottom portion 61 of the outer tube 60, and imparts an elastic force toward the end surface 10H on the one end portion 10A side of the cylinder 10. Further, the sealing member 250 is disposed on the inner circumference of the outer tube 60, and the elastic member 240 abuts against the end surface 10H on the end portion 10A side of the cylinder 10 and the inner circumferential surface of the outer tube 60 to close the gap CP. Therefore, the gap CP can be appropriately closed by the sealing member 250. Further, since the elastic members 240 are arranged side by side in the axial direction of the cylinder 10, the radial direction of the friction damper can be reduced as compared with the case where the elastic members are disposed on the outer circumference of the cylinder.

Further, the sealing member 250 is disposed to abut against the inclined surface 242A that is inclined with respect to the direction orthogonal to the axial direction. Therefore, in addition to the axial direction, the elastic force of the elastic member 240 can be appropriately converted into a force that presses the sealing member 250 in the radial direction. As a result, the sealing member 250 can be appropriately pressed against the axial end surface, that is, the end surface 10H on the end portion 10A side of the cylinder 10, and the radial abutting surface, that is, the inner circumference of the cylindrical portion 62 of the outer tube 60. Face 62C.

Further, the elastic member 240 is a coil spring. Further, a washer 242 disposed between the elastic member 240 as a coil spring and the sealing member 250 is provided. Therefore, the elastic force can be appropriately given as compared with the case where the sealing member 250 is directly biased by the elastic member 240.

 <Embodiment 3>  

Next, a third embodiment will be described with reference to Figs. 5 and 6 and the like. The friction damper 301 of the third embodiment shown in Figs. 5 and 6 is different from the friction damper 1 of the first embodiment in the arrangement of the elastic member 340 and the sealing member 350. In the other portions, the components having the same configurations and functions as those in the first embodiment are denoted by the same reference numerals as in the first embodiment, and the detailed description thereof will be omitted.

As shown in Fig. 5 and Fig. 6, in the friction damper 301 of the third embodiment, the elastic member 340 is a compression coil spring, and similarly to the elastic member 240 of the second embodiment, the rod 20 is inserted from the end portion 20A side. The inner circumference and the outer circumference thereof are arranged to be covered by the tubular portion 62 of the outer tube 60. One end of the elastic member 340 abuts against the bottom 61 of the outer tube 60, and the other end is provided with a washer 342 that abuts against the end face 10H on the end 10A side of the cylinder 10. The washer 342 is biased toward the bottom 61 of the outer tube 60 to impart an elastic force to the elastic member 40, which is transmitted to the cylinder 10 supporting the washer 342.

Moreover, as shown in FIG. 6, the inclined surface 342A is formed in the gasket 342. The inclined surface 342A is formed to be open to the end surface and the inner circumferential surface of the gasket 342 in the axially inner side (the right direction in FIG. 6). That is, the inclined surface 342A is formed to be inclined with respect to the direction orthogonal to the axial direction, that is, the radial direction of the washer 342, and faces the axial inner side and the inner circumferential direction of the washer 242. The inclined surface 342A is formed over the entire circumference of the gasket 342, and has a tapered shape which is reduced in diameter from the axially inner end surface toward the other end in the axial direction. The inclined surface 342A forms a space G3 which is a space surrounded by the end surface 11B on the outer side of the rod guide 11 and the outer peripheral surface of the rod 20. The groove portion G3 has a triangular cross section in the same manner as the groove portions G1 and G2 of the first and second embodiments.

The sealing member 350 is imparted with an elastic force of the elastic member 340. The sealing member 350 is held by the elastic member 340 to close the gap CP. The sealing member 350 is disposed on the outer circumference of the rod 20, and the elastic force of the elastic member 240 is imparted to the end surface 11B on the outer side of the rod guide 11. More specifically, the sealing member 350 is disposed in the groove portion G3. The sealing member 350 is an O-ring similarly to the sealing members 50 and 250 of the first and second embodiments. The sealing member 350 abuts against the inclined surface 342A which is the inner wall of the groove portion G3 having a triangular cross section, and receives the elastic force of the elastic member 340 via the inclined surface 342A. Further, the sealing member 350 is pressed against the axial abutting surface, that is, the end surface 11B on the outer side of the rod guide 11 and the abutting surface in the radial direction, by the elastic force of the elastic member 340 via the inclined surface 342A. The outer peripheral surface 20C of 20 is closed while closing the gap CP.

Next, the effect of the friction damper 301 of the third embodiment will be described. When the friction damper 301 is contracted by an external force or the external force is removed and is extended by the elastic force of the elastic member 340, the outer peripheral surface 21A of the piston portion 21 of the rod 20 is in the inner circumference of the friction member 30 as in the first embodiment. The face 30A slides to generate friction. This frictional force acts against the expansion and contraction, and functions as a damping force that attenuates the contraction or elongation motion.

When the friction damper 301 expands and contracts, the sealing member 350 disposed in the groove portion G3 relatively moves with respect to the rod 20. That is, the sealing member 350 slides in the axial direction on the outer circumferential surface of the rod 20 when the friction damper 301 expands and contracts. The sealing member 350 is sandwiched between the inclined surface 342A and the end surface 11B on the outer side of the rod guide 11 by the elastic force of the elastic member 340. Therefore, the sealing member 350 does not fall off and is stably held, thereby reliably preventing the intrusion of foreign matter.

Further, the sealing member 350 is disposed on the outer circumference of the rod 20, and the elastic force of the elastic member 340 is applied to the end surface 11B on the outer side of the rod guide 11, and is pressed against the outer peripheral surface of the rod 20 and the rod guide while being pressed. The end face 11B on the outer side of 11 is closed to close the gap CP. Therefore, the gap CP is stably closed, and the intrusion of foreign matter toward the gap CP is prevented.

According to the above, in the friction damper 301 of the third embodiment, the sealing member 350 receives the elastic force of the elastic member 340, and the sealing member 350 is held in a state in which the elastic force is imparted. Therefore, it is possible to surely prevent the sealing member 350 from coming off due to impact or vibration. As a result, the state sealed by the sealing member 350 can be surely maintained. Therefore, similarly to the friction dampers 1 and 201 of the first and second embodiments, the friction damper 301 can appropriately suppress the intrusion of foreign matter toward the friction surface.

Further, the friction damper 301 is provided with a rod guide 11 that closes the opening portion on the end portion 10A side of the cylinder 10, and is formed to allow the rod 20 to be reciprocally inserted in the axial direction. The through hole 11A is inserted, and a gap CP1 is formed between the insertion hole 11A and the outer peripheral surface 20C of the rod 20. The elastic member 340 is disposed on the outer circumference of the rod 20 protruding from the cylinder 10, and imparts an elastic force toward the end surface 11B on the outer side of the rod guide 11. Further, the sealing member 350 is disposed on the outer circumference of the rod 20 that protrudes outward from the rod guide 11, and is abutted against the end surface 11B on the outer side of the rod guide 11 and the outer peripheral surface 20C of the rod 20 by the elastic member 340. The gap CP is closed. As described above, since the elastic members 340 are arranged side by side in the axial direction of the cylinder 10, the radial direction of the friction damper can be reduced as compared with the case where the elastic members 340 are disposed on the outer circumference of the cylinder 10.

The present invention is not limited to the first to third embodiments described by the above description and the drawings. For example, the following embodiments are also included in the technical scope of the present invention.

(1) In the first to third embodiments, the O-ring is exemplified as the sealing member, but the invention is not limited thereto, and other sealing members may be employed. Further, it is not limited to a sealing member having a circular cross section like an O-ring, and a sealing member having another cross-sectional shape such as a cross-sectional elliptical shape, a cross-sectional half-moon shape, a cross-sectional rectangular shape, and a cross-sectional U-shape may be used.

(2) In the first to third embodiments, the groove portion is formed in the form of a gasket, but the configuration is not essential. The groove portion may be formed on the member side that receives the elastic force of the elastic member via the gasket. For example, as shown in FIG. 7 , the groove portion G4 formed on the end surface 462B of the tube 460 that receives the elastic force of the elastic member 40 via the gasket 442 may be used. Further, as shown in FIGS. 8 and 9, the end surface 510H of the cylinder 510 which is formed by the elastic force of the elastic members 240 and 340 via the washers 542 and 642, and the groove portion of the end surface 611B of the rod guide 611 may be formed. G5, G6. Further, as shown in FIG. 10, the groove portion formed by the two members may be formed across the groove portion G7 formed by both the gasket 42 and the outer tube 460. Further, as shown in FIG. 11, the groove portion may be formed directly on the elastic member as in the groove portion G8 formed at the end portion of the elastic member 840. Similarly to the groove portions of the first to third embodiments, the groove portions have a triangular cross section, and an inclined surface for abutting the sealing member can be formed.

(3) In the first to third embodiments, the form in which the groove portion having the triangular cross-section is formed is exemplified, but the configuration is not essential. The cross-sectional shape of the groove portion is not limited to a triangular shape. For example, a groove portion G9 having a rectangular cross section as shown in Fig. 12(A) or a groove portion G10 having a sectional fan shape as shown in Fig. 12(B) may be used, and Fig. 12 (C) A groove portion of another cross-sectional shape such as a groove portion G11 having a cross-sectional shape in which a rectangular cross-section and an inclined surface are combined.

(4) In the first to third embodiments, the sealing member is disposed in the form of the groove portion, but the configuration is not essential. For example, as shown in FIG. 13, the annular sealing member 1250 similar to the gasket or the resin disposed as the material of the sealing member as shown in FIG. 14 may be coated with the elastic member 1340. In the sealing member 1350 or the like, the sealing member is disposed without providing the groove portion.

(5) In the first to third embodiments, the space connection inside the outer tube is exemplified in the form of an air passage (not shown) corresponding to the volume change caused by the expansion and contraction of the friction damper. Not a necessity. When the air passage is provided, for example, in order to suppress the intrusion of foreign matter, a vent hole that is connected to the other end side of the rod to ensure a distance from the outside, or a crank or a cylinder portion of the outer tube may be used. Various types of vent holes, such as vent holes formed by bending.

(6) In the first to third embodiments, the gasket is attached to the other end portion of the rod, and the metal seal is prevented from entering the cylinder by the metal seal. However, this configuration is not essential. In the case where a seal is provided at the other end of the rod, the gasket is not limited thereto, and a sealing member of another shape such as an O-ring may be provided.

(7) In the first to third embodiments, the gasket supporting the end surface of the elastic member or the gasket attached to the other end portion of the rod is exemplified, but a spacer or the like may be used instead of the gasket. The gasket has a member of thickness in the axial direction.

(8) In the first to third embodiments, the friction member is exemplified by a frictional force generated between the outer circumferential surface of the rod to generate a damping force, but may be set to the inner circumference of the cylinder. A form in which a frictional force is generated, that is, a form in which the friction member is attached to the rod or a frictional force is generated between the inner circumferential surface of the cylinder and the outer circumferential surface of the rod, that is, the friction member is set to It slides freely with both the cylinder and the rod.

(9) In the third embodiment, the friction damper is provided with a tube having a bottom portion and a cylindrical portion and having one end portion of the rod connected to the bottom portion, and an elastic member disposed on the outer circumference of the rod. And through the bottom of the outer tube, the elastic force of the elastic member is imparted to the direction in which the length of one end of the rod protrudes from the cylinder becomes longer; however, in this case, the tubular portion of the outer tube is not essential. In other words, in the form of an outer tube, for example, a member having a disk-shaped member that receives one end of the connecting rod and receives the elastic force of the elastic member, or one end of the rod may be expanded. The diameter directly depends on the shape of the elastic member.

(10) In the first to third embodiments, the rod guide is provided as an example. However, the rod guide does not necessarily have to have a function of guiding the rod. In other words, the rod guide member can close the opening portion on one end side of the cylinder, and is formed with an insertion hole through which the rod can be reciprocally inserted in the axial direction, and the insertion hole and the outer circumference of the rod A gap is formed between the faces, and the form thereof is not particularly limited. For example, the rod guide may be in a form in which the end portion of the cylinder is bent inwardly. In such a rod guide, the sealing member may also be interposed between the rod and the rod.

(11) In the first to third embodiments, the sealing member provided with the elastic force imparted to the elastic member is exemplified, but it may be provided in the rod guide in addition to the configuration. A form of another sealing member between the inner circumferential surface of the insertion hole of the lead member and the outer circumferential surface of the rod, or between the inner circumferential surface of the reduced diameter portion of the cylinder and the outer circumferential surface of the rod.

(12) In the first to third embodiments, the form of the coil spring as the elastic member is exemplified, but the configuration is not essential. Further, when a coil spring is provided, it is preferable to provide a gasket disposed between the coil spring and the sealing member as described in the above embodiments. For example, the open end, the closed end, or the presence or absence of grinding, there are several types of ends of the coil spring. When the end portions are directly brought into contact with the sealing member, unevenness or the like is generated in the non-contact portion, and the elastic force is unevenly distributed in the radial direction of the sealing member. However, the reason is that the sealing member can be imparted with an equal elastic force by the gasket by interposing the gasket.

Claims (8)

 A friction damper comprising: a cylindrical cylinder; a rod reciprocally movable along an axial direction, and a part of which is housed in the cylinder; and a friction member disposed inside the cylinder A damping force is generated by a frictional force generated between the inner circumferential surface of the cylinder or the outer circumferential surface of the rod by relative movement between the cylinder and the rod; an elastic member facing the rod One end side is provided with an elastic force from a direction in which the length of the cylinder protrudes longer; and a sealing member is provided with an elastic force of the elastic member, and is held by the elastic member to communicate a gap between the outside and the inside of the cylinder. Closed.    The friction damper of claim 1, wherein the outer tube is provided with a bottomed cylindrical outer tube, and the end of the rod is connected to one end of the rod at the bottom, and one end of the cylinder is inserted into the tube portion. The gap is formed between the inner circumferential surface of the tubular portion and the outer circumferential surface of the cylinder, and the elastic member is disposed on the outer circumference of the cylinder, and an elastic force is applied to an end surface of the opening of the outer tube, and the sealing is performed. The member is disposed on the outer circumference of the cylinder, and the gap is closed by the elastic member abutting against the end surface on the opening side of the outer tube and the outer circumferential surface of the cylinder.    The friction damper according to claim 2, wherein the outer tube is formed with a groove portion, and the end portion of the groove portion on the inner circumferential surface side of the end surface on the opening side opens toward the end surface side and the inner circumferential surface side of the opening side, and The above sealing member is disposed.    A friction damper according to claim 1, wherein the bottom of the cylinder is provided with a bottomed cylindrical outer tube, and the end of the rod is connected to one end of the rod at the bottom, and one end of the cylinder is inserted into the tubular portion. The gap is formed between the inner circumferential surface of the tubular portion and the outer circumferential surface of the cylinder, and the elastic member is disposed between one end of the cylinder and the bottom of the outer tube toward the end surface of one end of the cylinder. The elastic member is provided, and the sealing member is disposed on the inner circumference of the outer tube, and the gap is closed by the elastic member abutting against an end surface on one end side of the cylinder and an inner circumferential surface of the outer tube.    A friction damper according to claim 1, wherein the rod damper is provided with a rod guide that closes an opening portion on one end side of the cylinder and is formed to freely move the rod along the axial direction Inserting a through hole, and forming the gap between the insertion hole and the outer circumferential surface of the rod, wherein the elastic member is disposed on an outer circumference of the rod protruding from the cylinder toward the rod guide The outer end surface is provided with an elastic force, and the sealing member is disposed on the outer circumference of the rod protruding outward from the rod guide, and the end surface of the outer side of the rod guide and the rod are abutted by the elastic member The gap is closed on the outer peripheral surface.    The friction damper according to any one of claims 1 to 5, wherein the sealing member abuts and is disposed on an inclined surface that is inclined with respect to a direction orthogonal to the axial direction.    The friction damper according to any one of claims 1 to 5, wherein the elastic member is a coil spring and includes a gasket disposed between the coil spring and the sealing member.    The friction damper according to claim 6, wherein the elastic member is a coil spring and includes a gasket disposed between the coil spring and the sealing member.