JP2019113124A - Friction damper - Google Patents

Abstract

To provide a friction damper which can preferably inhibit entry of foreign objects into a frictional surface.SOLUTION: A friction damper 1 includes a cylinder 10, a rod 20, a fixing part 30, a movable part 40, and multiple granules 50. The rod 20 is provided in a manner that one end side is inserted into the cylindrical cylinder 10 and the other end side protrudes from the cylinder 10. The rod 20 is provided so as to be movable in an axial direction relative to the cylinder 10. The fixing part 30 is fixed to the rod 20 so as to be movable with the rod 20. The movable part 40 is inserted into the rod 20 while slidably contacting with an inner peripheral surface of the cylinder 10 and is provided so that a distance D between itself and the fixing part 30 can be changed in a predetermined range. The multiple granules 50 have predetermined elasticity and fill a filling space S between the fixing part 30 and the movable part 40. In the friction damper 1, the distance D between the movable part 40 and the fixing part 30 changes in conjunction with axial relative movement of the rod 20 relative to the cylinder 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a friction damper.

  Patent Document 1 discloses a conventional friction damper. The friction damper comprises a first member and a second member. The first member has a friction material. The second member has a sliding portion which is movable relative to the friction material in a state of being in pressure contact with the friction material. With such a configuration, the friction damper of Patent Document 1 can generate a frictional force by relative movement of the first member and the second member in the axial direction to generate a damping force. In addition, such a friction damper always generates a constant damping force regardless of the amount of expansion or contraction or the direction of expansion or contraction.

Unexamined-Japanese-Patent No. 2015-31385

  The friction damper of Patent Document 1 always generates a constant damping force regardless of the amount of expansion or contraction or the direction of expansion or contraction. On the other hand, in the case of a fluid damper that generates a damping force by the resistance of a working fluid, it is known that the damping force characteristics differ depending on expansion and contraction such as so-called pressure and elongation, and those whose damping force characteristics change depending on the expansion amount. ing. The development of friction dampers having various damping force characteristics has been desired.

  The present invention has been made in view of the above-described conventional circumstances, and it is to be solved to provide a friction damper that can change damping force characteristics according to the form of expansion and contraction while having a simple configuration. It is an issue.

  The friction damper of the first invention comprises a cylinder, a rod, a fixed portion, a movable portion, and a plurality of particles. The cylinder is cylindrical. One end of the rod is inserted into the cylinder, and the other end is provided so as to protrude from the cylinder. Further, the rod is provided so as to be movable relative to the cylinder in the axial direction. The fixing portion is disposed in the cylinder and is movably fixed to the rod together with the rod. The movable portion is inserted through the rod while slidably in contact with the inner circumferential surface of the cylinder. In addition, the movable portion is provided so as to be able to change the distance between the movable portion and the fixed portion within a predetermined range. The plurality of particles have a predetermined elasticity and are filled in the filling space between the fixed part and the movable part. Then, in the friction damper, the distance between the movable portion and the fixed portion changes with the relative movement of the rod in the axial direction with respect to the cylinder.

  According to such a configuration, in the friction damper of the present invention, the plurality of particles in the filling space slide on the inner circumferential surface of the cylinder during expansion and contraction. The friction damper can cause the plurality of granules to function as a friction member, and generate a frictional force due to the sliding between the plurality of granules and the inner peripheral surface of the cylinder during expansion and contraction. In addition, since the movable part is inserted through the rod while being in sliding contact with the inner peripheral surface of the cylinder, the movable part and the rod move relative to each other due to the relative movement of the cylinder and the rod during expansion and contraction. The distance between and the fixed part changes. As a result, the volume of the filling space changes, and the filling rate of the particles in the filling space changes. That is, in the friction damper of the present invention, since the distance between the movable part and the fixed part is different between extension and contraction, and the volume of the filling space is different, the filling factor of the granular material changes. Thus, the force with which the plurality of particles are pressed against the inner circumferential surface of the cylinder changes, so that the magnitude of the frictional force generated at the time of extension and at the time of contraction can be changed.

  The friction damper of the second invention comprises a cylinder, a rod, a first fixing portion, a second fixing portion, and a plurality of particles. The cylinder is cylindrical. One end of the rod is inserted into the cylinder, and the other end is provided so as to protrude from the cylinder. Further, the rod is provided so as to be movable relative to the cylinder in the axial direction. The first fixing portion is disposed in the cylinder, and is movably fixed to the rod together with the rod. The second fixing portion is disposed in the cylinder in a manner such that the second fixing portion is arranged at a predetermined distance in the axial direction of the rod with respect to the first fixing portion. The second fixing portion is fixed to the rod so as to be movable together with the rod. The plurality of particles have a predetermined elasticity and are filled in the filling space between the first fixing portion and the second fixing portion. And a cylinder has the cross-sectional area change part formed in the form which the cross-sectional area of inner space changes with a predetermined ratio as it goes to the one end side of an axial direction.

  According to such a configuration, in the friction damper of the present invention, the plurality of particles in the filling space slide on the inner circumferential surface of the cylinder during expansion and contraction. The friction damper can cause the plurality of granules to function as a friction member, and generate a frictional force due to the sliding between the plurality of granules and the inner peripheral surface of the cylinder during expansion and contraction. In addition, since the cylinder has a cross-sectional area changing portion, the volume of the filling space changes according to the relative position of the first fixing portion and the second fixing portion in the axial direction to the cylinder, and the filling factor of the particles in the filling space Changes. That is, the filling rate of the granular material changes in accordance with the amount of expansion and contraction of the friction damper. As a result, the force with which the plurality of particles are pressed against the inner circumferential surface of the cylinder changes, so that the magnitude of the frictional force generated can be changed according to the amount of expansion and contraction.

  Therefore, the friction dampers of the first and second inventions can change the damping force characteristics according to the form of expansion and contraction while having a simple configuration.

  In the friction damper according to the first aspect of the invention, the cylinder may have a cross-sectional area change portion formed in such a manner that the cross-sectional area of the inner space changes at a predetermined rate toward one end in the axial direction. In this case, since the cylinder has the cross-sectional area changing portion, the volume of the filling space changes according to the relative position of the fixed part and the movable part in the axial direction to the cylinder, and the filling factor of the particles in the filling space changes. . That is, the filling rate of the granular material changes in accordance with the amount of expansion and contraction of the friction damper. As a result, the force with which the plurality of particles are pressed against the inner circumferential surface of the cylinder changes, so that the magnitude of the frictional force generated can be changed according to the amount of expansion and contraction.

  In the friction damper of the first aspect of the invention, the rod may have a restricting portion. The restricting portion is provided on the opposite side of the fixed portion of the movable portion in the axial direction of the rod, and abuts on the opposite surface of the fixed portion side of the movable portion to move the movable portion away from the fixed portion Regulate to move. In this case, the movement of the movable portion is restricted by the restricting portion, whereby the maximum distance between the movable portion and the fixed portion is defined. As a result, since the maximum volume of the filling space which changes due to the movement of the movable part is defined, the minimum filling factor of the particles in the filling space is defined. As a result, the minimum value of the frictional force generated according to the amount of expansion and contraction can be defined.

  In the friction damper of the first aspect of the invention, the rod may have a reduced diameter portion and a stepped portion. The reduced diameter portion is formed to be smaller in diameter than the other portions of the rod. The stepped portion is formed in the shape of a step at the boundary between the reduced diameter portion and the other portion. The movable portion is inserted into the reduced diameter portion, and the stepped portion functions as the restricting portion. In this case, the movement restriction of the movable part by the restriction part can be realized with a simple configuration.

  In the friction damper according to the first aspect of the invention, the movable portion can generate a frictional force when sliding with the inner circumferential surface of the cylinder. In this case, a larger damping force can be generated in combination with the frictional force by the granular material.

FIG. 2 is a side cross-sectional view schematically showing the friction damper of the first embodiment. It is a principal part expanded sectional view for demonstrating the effect | action of Embodiment 1, and shows the state at the time of (A) shrinkage | contraction, and (B) expansion | extension, respectively. FIG. 6 is a side cross-sectional view schematically showing the friction damper of the second embodiment. It is the IV-IV sectional view taken on the line of FIG. It is a principal part expanded sectional view for demonstrating the effect | action of Embodiment 2, and shows the state at the time of (A) contraction | contraction, and (B) expansion | extension, respectively. It is a side sectional view showing a friction damper of Embodiment 3 typically. It is the VII-VII sectional view taken on the line of FIG. It is a principal part expanded sectional view for explaining the operation of Embodiment 1, (A) State where distance between movable part and fixed part is the largest, (B) Distance between movable part and fixed part is The states closer to each other than the state of (A) are shown.

  Embodiments 1 to 3 in which the friction damper of the present invention is embodied will be described with reference to the drawings. In addition, the friction damper in the following embodiment is suitable for applications, such as state holding | maintenance of the flip-up-type door of a vehicle rear part, operation assistance, etc., for example.

First Embodiment
The friction damper 1 of Embodiment 1 is provided with the cylinder 10, the rod 20, the fixing | fixed part 30, the movable part 40, and the some granular material 50, as shown in FIG.
The cylinder 10 is formed in a bottomed cylindrical shape whose one end is open. A cylindrical rod guide 11 is fitted to the open end 10A of the cylinder 10. In the cylindrical rod guide 11, an insertion hole 11A penetrating in the axial direction is formed. A rod 20 described later is inserted into the rod guide 11. A cylinder side joint portion 12 is provided at the other end 10 B of the cylinder 10. The cylinder side joint portion 12, together with the rod side joint portion 21 described later, serves as a connecting portion between the door and one of the two members, such as the main body, which move relative to each other when the friction damper 1 is incorporated into a vehicle or the like.

  One end 20B of the rod 20 is inserted into the cylinder 10, and the other end 20A is provided so as to protrude from the cylinder 10. The rod 20 is provided so as to be movable relative to the cylinder 10 in the axial direction. The rod 20 has a cylindrical shape. The rod side joint portion 21 is fixed to the end 20A of the rod 20. The rod side joint part 21 becomes a connection site | part with the other of two members to move relatively with the above-mentioned cylinder side joint part 12. As shown in FIG. Further, a reduced diameter portion 22 is formed at the end 20B of the rod 20. The diameter reducing portion 22 is formed by reducing the diameter of a portion on the end portion 20B side of the rod 20 more than other portions. On the base end side of the reduced diameter portion 22 (the end 20A side of the rod 20), a stepped difference portion 22A (a restricting portion according to the present invention) which becomes a boundary between the reduced diameter portion 22 and other portions of the rod 20 Exemplifies as (1).

  The fixing portion 30 is disposed in the cylinder 10 and fixed to the rod 20 so as to be movable together with the rod 20. The fixing portion 30 has a disk shape having an outer diameter slightly smaller than the inner diameter of the cylinder 10. The center of the fixed portion 30 is disposed coaxially with the rod 20 and is fixed to the tip of the reduced diameter portion 22 (the tip on the end 20B side of the rod 20).

  The movable portion 40 is inserted into the rod 20 while in contact with the inner peripheral surface of the cylinder 10. The movable portion 40 is provided so as to be able to change the distance D with the fixed portion 30 within a predetermined range. The movable portion 40 has a disk shape. In addition, an insertion hole 40A having an inner diameter larger than the outer diameter of the reduced diameter portion 22 and smaller than the outer diameter of the portion closer to the end 20A than the reduced diameter portion 22 of the rod 20 is formed at the center of the movable portion 40. It is done. An outer peripheral surface of the movable portion 40 having such a configuration slidably contacts the inner peripheral surface of the cylinder 10 with a predetermined pressing force, and the fixed portion 30 at the end of the rod 20 on the end 20B side and the step portion The rod 22 is inserted into the reduced diameter portion 22 of the rod 20 so as to be movable between 22A and 22A. That is, in the present embodiment, the movable portion 40 generates a frictional force when sliding with the inner peripheral surface of the cylinder 10. In the movable portion 40, a maximum distance D between the movable portion 40 and the fixed portion 30 is defined by bringing the opposite surface 40B of the surface on the fixed portion 30 side into contact with the step 22A. In other words, the movable portion 40 is inserted into the reduced diameter portion 22 so as to be movable along the axial direction in a range in which the distance D between the movable portion 40 and the fixed portion 30 is maximized when the surface 40B contacts the step 22A. It is done.

  The plurality of granular bodies 50 have a predetermined elasticity. The granular body 50 is made of an elastomer and is formed in a spherical shape having substantially the same particle diameter. The plurality of particles 50 are filled in the filling space S between the fixed portion 30 and the movable portion 40. In the filling space S, the plurality of granular bodies 50 are in contact with the inner peripheral surface of the cylinder 10, and function as a friction member generating a frictional force by relative movement of the rod 20 in the axial direction with respect to the cylinder 10. . The inside of the cylinder 10 is divided into three spaces of the filling space S and rod side chambers 10C and opposite rod side chambers 10D on both sides of the filling space S. In other words, in the cylinder 10, the rod side chamber 10C and the filling space S are partitioned by the movable portion 40, and the opposite rod side chamber 10D and the filling space S are partitioned by the fixed portion 30.

  As described above, the movable portion 40 is fixed with the range between the fixed portion 30 fixed to the tip of the reduced diameter portion 22 and the step portion 22A at the base end of the reduced diameter portion 22 as a predetermined range. The distance D between the movable portion 40 and the portion 30 is changeable, but the plurality of granular bodies 50 are filled between the movable portion 40 and the fixed portion 30. For this reason, the movable range to the fixed part 30 side of movable part 40 turns into a range which can compress a plurality of granular objects 50.

  In the friction damper 1, the distance D between the movable portion 40 and the fixed portion 30 changes in accordance with the relative movement of the rod 20 in the axial direction with respect to the cylinder 10. In the case of the present embodiment, the movable portion 40 moves to the base end side (step portion 22A side) of the reduced diameter portion 22 when the friction damper 1 is contracted, and the distance D between the movable portion 40 and the fixed portion 30 increases. On the other hand, when the friction damper 1 is extended, the movable portion 40 moves toward the tip end side of the reduced diameter portion 22, that is, in the direction approaching the fixed portion 30, and the distance D decreases.

  The friction damper 1 according to the present embodiment includes a compression coil spring 60. The compression coil spring 60 is disposed in the opposite rod side chamber 10D of the cylinder 10 in such a manner that both ends abut on the bottom wall of the cylinder 10 and the fixing portion 30 respectively. The compression coil spring 60 exerts an elastic force in the extending direction of the friction damper 1. That is, the friction damper 1 is a so-called spring damper in which the elastic force of the compression coil spring 60 acts in the direction in which the projection length of the rod 20 from the cylinder 10 becomes longer (the extension direction of the friction damper 1).

Next, the effect of the friction damper 1 of the said structure is demonstrated.
When the friction damper 1 receives an external force and contracts, or the external force is removed and expanded by the elastic force of the compression coil spring 60, the rod 20 relatively moves in the axial direction relative to the cylinder 10. At this time, the fixed portion 30 and the movable portion 40 also move with the movement of the rod 20. Further, the plurality of granular bodies 50 filled in the filling space S formed between the fixed portion 30 and the movable portion 40 also move with the movement of the fixed portion 30 and the movable portion 40. Thereby, the plurality of granular bodies 50 and the inner circumferential surface of the cylinder 10 slide to generate a frictional force. Then, this frictional force acts against the expansion and contraction of the friction damper 1 to function as a damping force that attenuates the movement of contraction or expansion.

  In addition, when the friction damper 1 is expanded and contracted, the fixing portion 30 is fixed to the rod 20 and thus moves along with the rod 20. On the other hand, the movable portion 40 moves axially relative to the rod 20 until it receives a force larger than the friction force with the inner circumferential surface of the cylinder 10 directly or indirectly from the rod 20, and fixed. The magnitude of the distance D to the part 30 is changed. The movable portion 40 moves relative to the cylinder 10 along with the rod 20 when a force larger than the frictional force with the inner circumferential surface of the cylinder 10 is axially received from the rod 20.

Specifically, when the friction damper 1 is contracted, as shown in FIG. 2A, the movable portion 40 moves to the stepped portion 22A side (the end 20A side of the rod 20) and between the fixed portion 30 and the fixed portion 30. The distance D between the two is separated. As a result, the volume of the filling space S increases, and the filling rate of the particles 50 decreases. In this state, in the granular material 50 in the filling space S, the force pressed against the inner peripheral surface of the cylinder 10 is relatively weak. Therefore, the generated frictional force is relatively small, and the damping force is also small. On the other hand, in the friction damper 1 at the time of extension, as shown in FIG. 2 (B), the movable portion 40 moves to the fixed portion 30 side (the end 20B side of the rod 20) and the distance D between the movable portion 40 and the fixed portion 30 Become close to each other. As a result, the volume of the filling space S is reduced, and the filling rate of the granular material 50 is increased. In this state, the granular material 50 in the filling space S is compressed more strongly in the axial direction between the movable portion 40 and the fixed portion 30 and is pressed by a stronger force on the inner circumferential surface of the cylinder 10. Therefore, at the time of extension, the friction damper 1 generates a larger frictional force than at the time of contraction, and a larger damping force is generated. That is, the friction damper 1 functions as a so-called extension damper.
Thus, the friction damper 1 has different damping force characteristics at the time of contraction and at the time of extension.

  The plurality of granular bodies 50 filled in the filling space S slide on the inner circumferential surface of the cylinder 10 and move in the filling space S due to the relative movement of the rod 20 with respect to the cylinder 10. As the granular material 50 flows in the filling space S in this manner, the granular material 50 sliding in contact with the inner circumferential surface of the cylinder 10 is replaced. For this reason, the wear of the plurality of particles 50 is made uniform, and the durability can be improved.

  Further, by employing the plurality of granular bodies 50 as the friction member and filling the filling space S, ventilation between the rod side chamber 10C and the opposite rod side chamber 10D is secured by the gap between the granular bodies 50. Therefore, it is possible to cope with the volume change of the rod side chamber 10C and the opposite rod side chamber 10D when the friction damper 1 expands and contracts, without separately forming a communication hole or the like for ventilation.

  Further, in the friction damper 1, the fixed portion 30 is disposed on the end 20 B of the rod 20, and the movable portion 40 is disposed on the end 20 A of the rod 20 relative to the fixed portion 30. Therefore, at the time of extension of the friction damper 1, the movable portion 40 moves relative to the rod 20 toward the fixed portion 30. As a result, the distance D between the movable portion 40 and the fixed portion 30 is closer than when the friction damper 1 is contracted, and the filling rate of the granular material 50 is increased. As a result, the friction damper 1 functions as an extension damper that generates a larger damping force than at the time of contraction.

  The friction damper 1 also includes a compression coil spring 60. The compression coil spring 60 is disposed in the opposite rod side chamber 10D, and applies an elastic force in a direction in which the rod 20 protrudes from the cylinder 10, that is, in the extension direction of the friction damper 1. Thus, the friction damper 1 functions as a spring damper to which an elastic force is applied in the extension direction.

  As described above, the friction damper 1 includes the cylinder 10, the rod 20, the fixed portion 30, the movable portion 40, and the plurality of granular bodies 50. The cylinder 10 is cylindrical. The rod 20 has one end 20 B inserted into the cylinder 10 and the other end 20 A protruding from the cylinder 10. Also, the rod 20 is provided so as to be movable relative to the cylinder 10 in the axial direction. The fixing portion 30 is disposed in the cylinder 10 and fixed to the rod 20 so as to be movable together with the rod 20. The movable portion 40 is inserted into the rod 20 while slidably contacting the inner peripheral surface of the cylinder 10. Moreover, the movable part 40 is provided so that the distance D between the fixed parts 30 can be changed in a predetermined range. The plurality of granular bodies 50 have predetermined elasticity, and are filled in the filling space S between the fixed portion 30 and the movable portion 40. Then, in the friction damper 1, the distance between the movable portion 40 and the fixed portion 30 changes in accordance with the relative movement of the rod 20 in the axial direction with respect to the cylinder 10.

  With such a configuration, when the friction damper 1 is expanded and contracted, the plurality of granules 50 in the filling space S slide on the inner circumferential surface of the cylinder 10. The friction damper 1 can cause the plurality of granules 50 to function as a friction member, and generate a frictional force due to the sliding between the plurality of granules 50 and the inner circumferential surface of the cylinder 10 during expansion and contraction. Further, since the movable portion 40 is inserted in the rod 20 while slidably contacting the inner peripheral surface of the cylinder 10, the movable portion 40 and the rod 20 can be moved by the relative movement between the cylinder 10 and the rod 20 during expansion and contraction. Moves relative to each other, and the distance D between the movable portion 40 and the fixed portion 30 changes. Thereby, the volume of the filling space S changes, and the filling rate of the granular material 50 in the filling space S changes. That is, in the friction damper 1, the distance D between the movable portion 40 and the fixed portion 30 is different between the time of expansion and the time of contraction, and the volume of the filling space S is different. As a result, the force with which the plurality of particles 50 are pressed against the inner peripheral surface of the cylinder 10 changes, so the magnitude of the frictional force generated at the time of extension and at the time of contraction can be changed.

  Therefore, the friction damper 1 of the first embodiment can change the damping force characteristic according to the form of expansion and contraction while having a simple configuration.

  Moreover, the rod 20 has the level | step-difference part 22A as a control part. The stepped portion 22A is provided on the opposite side of the fixed portion 30 of the movable portion 40 in the axial direction of the rod 20 and abuts on the opposite surface 40B of the surface of the movable portion 40 on the fixed portion 30 side to fix the movable portion 40. It restricts movement in a direction further away from the part 30. As described above, the movement of the movable portion 40 is restricted by the step portion 22A as the restricting portion, whereby the maximum distance D between the movable portion 40 and the fixed portion 30 is defined. Thereby, since the maximum volume of the filling space S which changes with the movement of the movable portion 40 is defined, the minimum filling factor of the granular material 50 in the filling space S is defined. As a result, the minimum value of the frictional force generated according to the amount of expansion and contraction can be defined.

  Further, the rod 20 has a diameter reducing portion 22 and a step portion 22A as a regulating portion. The diameter reducing portion 22 is formed to be smaller in diameter than other portions of the rod 20. The stepped portion 22A is formed in the shape of a step at the boundary between the reduced diameter portion 22 and the other portion. The movable portion 40 is inserted into the reduced diameter portion 22. Thereby, the movement restriction of the movable part by the restriction part can be realized with a simple configuration.

  Further, the movable portion 40 generates a frictional force when sliding with the inner peripheral surface of the cylinder 10. For this reason, together with the frictional force by the granular material 50, a larger damping force can be generated.

Second Embodiment
Next, the second embodiment will be described with reference to FIGS.
The friction damper 201 of the second embodiment shown in FIG. 3 is different from the friction damper 1 of the first embodiment in that the second fixing portion 270 is provided and the shape of the cylinder 210. In the other parts, parts having substantially the same configuration and function as in the first embodiment are given the same reference numerals as in the first embodiment, and detailed description will be omitted.

  As shown in FIG. 3, the friction damper 201 of the second embodiment includes a cylinder 210 and a second fixing portion 270. Further, the friction damper 201 includes the rod 20, the fixing portion 30 (exemplified as a first fixing portion according to the present invention) similar to the first embodiment, and a plurality of granular bodies 50. The cylinder 210 has a groove 213. The grooved portion 213 is formed by recessing a part of the peripheral wall of the cylinder 210 from the inner peripheral side to the outer peripheral side. The grooved portion 213 is formed in such a manner that the amount of protrusion changes in the axial direction of the cylinder 210. The groove-shaped portion 213 is formed in such a manner that the cross-sectional area of the inner space of the cylinder 210 changes at a predetermined ratio as it goes to one end side in the axial direction of the cylinder 210. In the case of the present embodiment, the groove-shaped portion 213 is formed in a tapered shape so as to be recessed in the outer peripheral direction toward the end 10 B side (bottom wall side) of the cylinder 210. In the cylinder 210, the cross-sectional area of the inner space changes at a predetermined rate in the region where the groove-like portion 213 is formed in the peripheral wall. That is, the portion of the cylinder 210 in which the groove-like portion 213 is formed functions as a cross-sectional area changing portion according to the present invention. In the case of the present embodiment, as shown in FIG. 4, a plurality of (four in FIG. 4) groove portions 213 are formed around the central axis of the cylinder 210.

  The second fixed portion 270 is provided instead of the movable portion 40 of the first embodiment. The second fixing portions 270 are arranged at predetermined intervals in the axial direction of the rod 20 with respect to the fixing portion 30. The second fixing portion 270 is movably fixed to the rod 20 together with the rod 20. That is, the distance D between the second fixing portion 270 and the fixing portion 30 is unchanged. The second fixed portion 270 forms a filling space S with the fixed portion 30. The second fixing portion 270 is formed in substantially the same shape as the fixing portion 30, and has a disk shape having an outer diameter slightly smaller than the inner diameter of the cylinder 10. The center of the second fixed portion 270 is coaxially disposed with the rod 20 and fixed to the proximal end of the reduced diameter portion 22.

Next, the operation of the friction damper 201 configured as described above will be described.
When the friction damper 201 is expanded or contracted, it is contracted by receiving an external force, or when the external force is removed and expanded by the elastic force of the compression coil spring 60, the rod 20 is axially oriented with respect to the cylinder 210. Move relative to At this time, the plurality of granular bodies 50 filled in the filling space S between the fixed portion 30 and the second fixed portion 270 slide on the outer peripheral surface of the cylinder 210 to generate a frictional force. Then, this frictional force acts against the expansion and contraction of the friction damper 201, thereby acting as a damping force that attenuates the motion of contraction or expansion.

  When the friction damper 201 expands and contracts, the filling space S formed between the fixed portion 30 and the second fixed portion 270 axially moves in the cylinder 210. At this time, the filling space S moves in the region where the groove-like portion 213 in the cylinder 210 is formed. By providing the groove-shaped portion 213, the cylinder 210 is configured such that the cross-sectional area of the inner space changes at a predetermined rate as it goes to one end side in the axial direction. For this reason, the volume of the filling space S changes in accordance with the relative position of the fixed portion 30 fixed to the rod 20 and the second fixed portion 270 with respect to the cylinder 210 in the axial direction. That is, the volume of the filling space S changes according to the amount of expansion and contraction of the friction damper 201, and the filling rate of the granular material 50 also changes according to the amount of expansion and contraction.

Specifically, as shown in FIG. 5A, the amount of contraction of the friction damper 201 is relatively large, and the filling space S between the fixed portion 30 and the second fixed portion 270 is the end of the cylinder 210. When positioned closer to the portion 210B (closer to the end portion on the bottom wall side), each groove-shaped portion 213 is formed to be tapered in the outer peripheral direction toward the end portion 10B side, so that The cross-sectional area of the inner space of the cylinder 210 is increased, and the size of the filling space S is increased. For this reason, the filling rate of the granular material 50 is reduced, and the magnitude of the generated frictional force is reduced. On the other hand, as shown in FIG. 5B, the amount of contraction of the friction damper 201 is relatively small, and the filling space S between the fixed portion 30 and the second fixed portion 270 is closer to the end 210A of the cylinder 210. When positioned at the end portion of the bottom wall side, the cross-sectional area of the inner space of the cylinder 210 at the portion becomes smaller than the state shown in FIG. The size of S decreases. For this reason, the filling rate of the granular material 50 is increased, and the magnitude of the frictional force generated by being strongly pressed by the inner circumferential surface of the cylinder 210 becomes larger.
Thus, the friction damper 201 generates a larger damping force when the expansion amount is larger (the contraction amount is smaller) during expansion and contraction. That is, the friction damper 201 has different damping force characteristics according to the amount of expansion and contraction.

  In the friction damper 201, the granular material 50 slides on the inner circumferential surface of the cylinder 210, whereby the flow of the granular material 50 occurs in the filling space S. Thereby, the granular material 50 sliding in contact with the inner circumferential surface of the cylinder 210 is replaced. For this reason, the wear of the plurality of particles 50 is made uniform, and the durability can be improved.

  Further, by employing the plurality of granular bodies 50 as the friction members and filling the filling space S, ventilation between the rod side chamber 210C and the opposite rod side chamber 210D is secured by the gap between the granular bodies 50. For this reason, it is possible to cope with the volume change of the rod side chamber 210C and the opposite rod side chamber 210D when the friction damper 201 expands and contracts, without separately forming a communication hole or the like for ventilation.

  As mentioned above, the friction damper 201 is provided with the cylinder 210, the rod 20, the fixing | fixed part 30 as a 1st fixing | fixed part, the 2nd fixing | fixed part 270, and the some granular material 50. As shown in FIG. The cylinder 210 is cylindrical. The rod 20 has one end 20 B inserted into the cylinder 210 and the other end 20 A protruding from the cylinder 210. Also, the rod 20 is provided so as to be movable relative to the cylinder 210 in the axial direction. The fixing portion 30 as the first fixing portion is disposed in the cylinder 210 and fixed to the rod 20 so as to be movable together with the rod 20. The second fixing portion 270 is disposed in the cylinder 210 in a manner to be aligned with the fixing portion 30 in the axial direction of the rod 20 at a predetermined interval. In addition, the second fixing portion 270 is fixed to the rod 20 so as to be movable together with the rod 20. The plurality of granular bodies 50 have a predetermined elasticity, and are filled in the filling space S between the fixing portion 30 and the second fixing portion 270. The cylinder 210 is formed to have a groove-like portion 213 so that the cross-sectional area of the inner space changes at a predetermined rate toward the one end side in the axial direction.

  With such a configuration, the friction damper 201 generates a frictional force between the plurality of granular members 50 as the friction member and the inner peripheral surface of the cylinder 210 by expansion and contraction. Further, since the cylinder 210 has the groove-like portion 213, when the filling space S passes through the portion where the groove-like portion 213 is formed at the time of relative movement of the rod 20 with respect to the cylinder 210, the volume of the filling space S changes. The packing ratio of the particles in the space changes. That is, the filling rate of the granular material changes in accordance with the amount of expansion and contraction of the friction damper. As a result, the force with which the plurality of particles are pressed against the inner circumferential surface of the cylinder changes, so that the magnitude of the frictional force generated can be changed according to the amount of expansion and contraction.

  Therefore, the friction damper 201 can change the damping force characteristic according to the form of expansion and contraction while having a simple configuration.

Embodiment 3
Next, the third embodiment will be described with reference to FIGS.
The friction damper 301 of the third embodiment shown in FIG. 6 differs from the friction damper 1 of the first embodiment in that it has the same cylinder 210 as the second embodiment and the shape of the movable portion 340. In the other parts, parts having substantially the same configuration and function as in the first embodiment are given the same reference numerals as in the first embodiment, and detailed description will be omitted.

  As shown in FIG. 6, the friction damper 301 of the third embodiment includes the movable portion 340, the cylinder 210 similar to that of the second embodiment, the rod 20 similar to that of the first embodiment, the fixed portion 30, and a plurality of particles 50. And a compression coil spring 60. As shown in FIG. 7, the cylinder 210 is formed in a tapered shape so that the four groove-shaped parts 213 are recessed in the outer peripheral direction toward the end 10 B of the cylinder 210, whereby the inner space of the cylinder 210 is formed. The cross-sectional area of changes at a predetermined rate.

  The movable portion 340 is inserted through the rod 20 while being in contact with the inner peripheral surface of the cylinder 210, like the movable portion 40 of the first embodiment. Specifically, the movable portion 340 is provided so that the distance D between the movable portion 340 and the fixed portion 30 can be changed in a predetermined range by inserting the insertion hole 40A into the reduced diameter portion 22. Further, unlike the first embodiment, the movable portion 340 has a disk shape slightly smaller than the inner diameter of the cylinder 210. Furthermore, the movable portion 340 has a convex portion 341. As shown in FIG. 7, a plurality of (four in FIG. 7) convex portions 341 are provided on the outer periphery of the movable portion 340 and are provided so as to protrude in the outer peripheral direction. The plurality of convex portions 341 are provided corresponding to the grooved portion 213 of the cylinder 210, and slidably abut on the grooved inner surface of the grooved portion 213 as the inner peripheral surface of the cylinder 210. . Specifically, as shown in FIG. 7, in the convex portion 341, the tip end surface 341A slidably contacts the bottom wall surface 213A of the groove-shaped portion 213, and the side surface 341B is a side wall surface 213B of the groove-shaped portion 213. And is inserted into the groove-like portion 213 in the form of forming a gap therebetween. The movable portion 340 is in a form in which each of the plurality of convex portions 341 is inserted into the groove-shaped portion 213 forming the groove shape of the cylinder 210, and slidably contacts the inner peripheral surface of the cylinder 210 with a predetermined pressing force. There is.

Next, the operation of the friction damper 301 configured as described above will be described.
When the friction damper 301 expands and contracts, the plurality of granular bodies 50 filled in the filling space S between the fixed portion 30 and the movable portion 340 slide on the outer peripheral surface of the cylinder 210 to generate a frictional force. And when this frictional force acts against the expansion and contraction of the friction damper 301, it becomes a damping force which attenuates the movement of contraction or expansion.

  Further, in the friction damper 301, as in the first embodiment, at the time of contraction, the movable portion 340 moves to the side of the step portion 22A and the distance D between the movable portion 340 and the fixed portion 30 separates, and the volume of the filling space S increases. The filling rate of the granular material 50 is reduced. As a result, the generated frictional force is reduced and the damping force is also reduced. On the other hand, at the time of extension, in the friction damper 301, the movable portion 340 moves to the fixed portion 30 side, the distance D between the movable portion 340 and the fixed portion 30 approaches, and the volume of the filling space S decreases. Is increased. As a result, the generated frictional force increases and the damping force also increases.

  Further, in the friction damper 301, the cylinder 210 has a groove-like portion 213 formed to be tapered in the outer peripheral direction toward the end 10B side, and the movable portion 340 protrudes in the outer peripheral direction. By providing the convex portion 341 which is provided and inserted into the groove-like portion 213, the pressure of the movable portion 340 pressed against the inner peripheral surface of the cylinder 210 due to the difference in relative position between the cylinder 210 and the rod 20 is The size changes.

Specifically, in the friction damper 301, the magnitude of the frictional force generated between the tip end surface 341A of the convex portion 341 and the bottom wall surface 213A of the groove-like portion 213 as the movable portion 340 moves toward the end 210A of the cylinder 210. Becomes bigger. Therefore, in order to move the movable portion 340 axially relative to the cylinder 210, it is necessary to apply a larger axial force. Therefore, as shown in FIGS. 8A and 8B, when the friction damper 301 is stretched, the movable portion 340 is fixed against the elastic force of the granular material 50 when the amount of stretching is larger. Can be made closer. That is, the distance D between the movable portion 340 and the fixed portion 30 becomes smaller in the state where the amount of expansion is larger, the volume of the filling space S becomes smaller, and a larger frictional force is generated. For this reason, the friction damper 301 generates a larger damping force as the amount of extension increases.
Thus, at the time of extension, the friction damper 301 generates a larger damping force when the amount of extension is larger. That is, at the time of extension, the friction damper 301 has different damping force characteristics according to the amount of extension.

As described above, the friction damper 301 exhibits the same effects as the first and second embodiments.
Further, in the friction damper 301, the cylinder 210 has the groove-like portion 213, so that the cylinder 210 is formed in such a manner that the cross-sectional area changes at a predetermined rate as the inner space goes to one end in the axial direction. Further, the movable portion 340 is formed so as to protrude in the outer peripheral direction, and has a convex portion 341 inserted into the groove-like portion 213. The groove-shaped portion 213 is formed in a tapered shape so as to be recessed in the outer circumferential direction toward the end portion 10B of the cylinder 210. The convex portion 341 is slidably in contact with the bottom wall surface 213 </ b> A tapered in the axial direction among the inner peripheral surfaces of the groove-shaped portion 213. For this reason, when the friction damper 301 is expanded, the magnitude of the distance D between the movable portion 340 and the fixed portion 30 can be further reduced against the elastic repulsive force of the granular material 50 as the amount of expansion increases. it can. Thereby, the size of the filling space S can be made smaller according to the size of the amount of expansion at the time of expansion, and the filling rate of the granular material can be made larger. As a result, the friction damper 301 can generate a larger damping force as the amount of extension increases.

The present invention is not limited to the first to third embodiments described above with reference to 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 friction damper includes the compression coil spring that exerts an elastic force in the extension direction. However, it is not essential to exert the elastic force. Moreover, you may employ | adopt other forms, such as sealing compressed gas, as a form which makes elastic force act. When an elastic force is applied, it may be applied not only in the extension direction but also in the contraction direction.
(2) In the first to third embodiments, as the plurality of particles, elastomer particles are used, but this is not essential. The materials and the like of the plurality of particles are not particularly limited as long as they have predetermined elasticity.
(3) In the first to third embodiments, the form in which the particle diameters of a plurality of particles are substantially the same is exemplified, but a plurality of types of particles having different particle diameters may be used.
(4) In the first to third embodiments, a mode in which the diameter reducing portion is formed in the rod is exemplified, but it is not essential to form the diameter reducing portion. For example, the movable portion may be inserted without forming the diameter-reduced portion, and the diameter-increased portion may be formed at a portion corresponding to the step portion as the restricting portion to abut the movable portion.
(5) In the first and third embodiments, the fixed portion is disposed near the bottom wall of the cylinder and the movable portion is disposed near the opening of the cylinder in the cylinder so that the friction damper is extended. Although the form which generate | occur | produces large damping force was illustrated, you may make it generate larger damping force at the time of shrinkage | contraction by exchanging the position of a fixed part and a movable part.
(6) In the second and third embodiments, the cylinder is illustrated to have a groove-like portion, but the form in which the cross-sectional area of the inner space changes at a predetermined rate as the cylinder goes to one end in the axial direction is not limited thereto. . Moreover, when a cylinder has a groove-shaped part, the number, a shape, etc. are not limited to the form of the said embodiment.
(7) In the second and third embodiments, although the groove-shaped portion is formed in a tapered shape so as to be recessed in the outer peripheral direction toward the bottom wall side of the cylinder, this is not essential. For example, the groove-shaped portion may be configured to be depressed in the outer circumferential direction toward the opening of the cylinder. In this case, it is possible to realize a friction damper that generates a larger damping force as the amount of extension decreases.
(8) In the configuration of the second embodiment, the portion between the fixing portion and the second fixing portion of the rod may be formed in a conical shape that expands in diameter toward one end. In this case, when the rod moves in the direction of the other end, the particles in the filling space are pressed by the surface of the conical rod and pressed strongly by the inner circumferential surface of the cylinder. Such a configuration also makes it possible to change the magnitude of the frictional force generated at the time of expansion and contraction.
(9) In the third embodiment, the movable portion abuts on the inner peripheral surface of the cylinder at the tip end surface of the convex portion. However, in addition to this, the cylinder is also formed on the outer peripheral surface of the movable portion forming a circumferential surface. It is good also as a form contact | abutted to the internal peripheral surface of. In this case, since a larger frictional force can be easily generated between the movable portion and the inner circumferential surface of the cylinder as compared with the case where only the convex portion abuts, the frictional force generated upon extension and contraction is generated. The size of can be changed more greatly.

  1, 201, 301: friction damper, 10, 210: cylinder, 10A, 10B, 210A, 210B: end of cylinder, 10C: rod side chamber, 10D: opposite rod side chamber, 11: rod guide, 11A: insertion hole, 12 ... Cylinder side joint part, 20 ... Rod, 20A, 20B ... End part of rod, 21 ... Rod side joint part, 22 ... Reduced diameter part, 22A ... Step part (regulation part), 30 ... Fixing part, 40, 340 ... Movable part, 40A: insertion hole, 50: granular material, 213: grooved part (cross sectional area changing part), 213A: bottom wall surface, 213B: side wall surface, 270: second fixing part, 341: convex portion, 341A: tip Surface, 341B ... side surface, D ... distance between movable part and fixed part, S ... filling space

Claims (6)

A cylindrical cylinder,
A rod having one end inserted into the cylinder and the other end protruding from the cylinder, and a rod axially movable relative to the cylinder;
A fixing portion disposed in the cylinder and movably fixed to the rod together with the rod;
A movable portion which is slidably inserted into the rod while being slidably in contact with the inner circumferential surface of the cylinder, and in which the distance between the fixed portion and the fixed portion is changeable within a predetermined range;
And a plurality of particles filled in a filling space between the fixed part and the movable part, having a predetermined elasticity.
The distance when the rod moves relative to the cylinder relative to one side in the axial direction is different from the distance when the rod moves relative to the other side relative to the cylinder relative to the cylinder. And friction damper. A cylindrical cylinder,
A rod having one end inserted into the cylinder and the other end protruding from the cylinder, and a rod axially movable relative to the cylinder;
A first fixing portion disposed in the cylinder and movably fixed to the rod together with the rod;
A second fixing portion arranged in the cylinder at a predetermined interval in the axial direction of the rod with respect to the first fixing portion, and fixed to the rod movably together with the rod;
A plurality of particles having a predetermined elasticity and filled in a filling space between the first fixed portion and the second fixed portion;
A friction damper characterized in that the cylinder has a cross-sectional area change portion formed in such a manner that the cross-sectional area of the inner space changes at a predetermined rate toward the one end side in the axial direction.   The friction damper according to claim 1, wherein the cylinder has a cross-sectional area changing portion formed in such a manner that the cross-sectional area of the inner space changes at a predetermined rate toward the one end side in the axial direction.   The rod is provided on the opposite side of the fixed portion of the movable portion in the axial direction and abuts on the opposite surface of the surface of the movable portion on the fixed portion side, whereby the movable portion is further extended from the fixed portion The friction damper according to claim 1 or 3, further comprising a restricting portion that restricts movement in the direction of separating. The rod has a diameter-reduced portion formed to have a diameter smaller than that of the other portion, and a step-shaped step portion formed at the boundary between the diameter-reduced portion and the other portion,
The friction damper according to claim 4, wherein the movable portion is inserted into the reduced diameter portion, and the stepped portion is the restricting portion.   The friction damper according to any one of claims 1 and 3, wherein the movable portion generates a frictional force when sliding with the inner circumferential surface of the cylinder.

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