JP2005188634A - Rotary damper and seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size of a rotary damper with a damper mechanism and a click mechanism combined. <P>SOLUTION: The rotary damper comprises a vane 14 rockingly provided in a fluid chamber 17 filled with viscose fluid, the vane 14 being partially elastically deformable, and an engagement part 16 with which an elastically deformable portion thereof engages, provided in the fluid chamber 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a seat provided with a rotary damper provided with a vane provided so as to be able to swing in a fluid chamber filled with a viscous fluid, an armrest that rotates, and a rotary damper that controls the rotation of the armrest. It is.

  Conventionally, as shown in FIG. 7, a fluid chamber 27 filled with viscous fluid is formed by partitioning a space formed between the housing 21 and the rotor 22 accommodated therein by a partition wall 23, A rotary damper in which a vane 24 is swingably disposed in the fluid chamber 27 is known.

  This type of rotary damper has a rotational force of the rotor due to the resistance generated when the viscous fluid compressed by the oscillation of the vane moves through a slight gap formed between the vane and the fluid chamber inner surface. Can be attenuated, and the rotational movement of the controlled object can be made slow.

  Incidentally, as described above, the conventional rotary damper is configured to include a mechanism that exhibits a buffering function (hereinafter referred to as “damper mechanism”), but this stops the rotation of the rotor at a predetermined position, When adding a mechanism for holding the rotor in a stopped state (hereinafter referred to as “click mechanism”) at a load below a predetermined level, a click mechanism is not provided inside the damper mechanism, but is provided outside the damper mechanism. (See, for example, JP-A-8-182635).

  Therefore, the rotary damper itself becomes larger, and the parts that make up the click mechanism are required in addition to the parts that make up the damper mechanism. There is a problem that the cost of manufacturing a finished product having both of these is high.

  Further, some conventional rotary dampers have a check valve and can make a difference in the braking force exhibited by the vane swinging direction. For example, in the rotary damper shown in FIGS. 7 to 11, the fluid chamber 27 is divided into two chambers (first and second chambers) 27a and 27b by the vane 24, and the vane 24 communicates with the first chamber 27a. A fluid passage 28 having a large diameter portion 28a and a small diameter portion 28b having a smaller diameter than the large diameter portion 28a and communicating with the second chamber 27b is formed in the axial direction, and the large diameter portion 28a of the fluid passage 28 is formed. Is provided with a spherical valve body 29 having a diameter larger than that of the small diameter portion 28b.

  The valve element 29 functioning as a check valve is shown in FIG. 10 when the vane 24 moves in one direction (counterclockwise in FIG. 7) and compresses the viscous fluid in the first chamber 28a by one surface. As described above, the boundary between the large diameter portion 28a and the small diameter portion 28b is closed to prevent the viscous fluid from passing through the fluid passage 28. As a result, the resistance of the viscous fluid is increased, and the braking force exerted by the rotary damper is also increased. On the other hand, when the vane 24 moves in the reverse direction (clockwise in FIG. 7) and compresses the viscous fluid in the second chamber 28b by the other surface, the valve element 29 has a large diameter as shown in FIG. The boundary between the portion 28a and the small diameter portion 28b is opened to allow the viscous fluid to pass through the fluid passage 28. As a result, the resistance of the viscous fluid is small, and the braking force exerted by the rotary damper is also small.

  However, the valve body 29 constituting such a check valve is also formed separately from the vane 24 and then incorporated into the vane 24, which increases the number of parts and thereby increases the manufacturing cost. There's a problem.

  On the other hand, some seats are configured to include armrests that rotate. For example, an automobile seat can be stowed upright in a position that does not protrude from the front of the seat back, and when used, an armrest that is in a use position can be pulled out from the stowed position and rotated to the use position. Is provided.

  However, the armrest provided on the seat of the automobile has a structure in which the storage state is maintained by the frictional resistance generated between the seatback and the seatback and the armrest, for example, like a seat made of leather. If the frictional resistance generated between the two is small, if an impact is applied to the seat, it will not be able to hold the stowed state when the seat back is popped out of the stowed position or lifted forward and left behind. There was a problem of becoming.

JP-A-8-182635

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the size of a rotary damper having both a damper mechanism and a click mechanism. It is another object of the present invention to provide a seat provided with an armrest that can maintain the stored state even when the frictional resistance generated between the seatback and the seatback is small.

In order to solve the above problems, the present invention provides the following rotary damper and seat.
(1) A rotary damper provided with a vane that is swingably provided in a fluid chamber filled with a viscous fluid, wherein at least a part of the vane is elastically deformable, A rotary damper characterized in that an engaged portion to which an elastically deformable portion of a vane is engaged is provided.
(2) The rotary damper according to (1), wherein the engaged portion is formed integrally with the housing as a part of the housing forming the peripheral wall of the fluid chamber.
(3) The engaged portion is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface is a portion other than a portion near the one surface engaging the engaged portion. However, it can be elastically deformed by forming a slope that is inclined so that the distance from the peripheral surface of the fluid chamber increases toward the other surface side, and a recess that opens to one surface side is provided near the tip of the vane. The rotary damper according to (1) or (2) above, wherein
(4) The rotary damper according to (3), wherein the vane has a length in a radial direction in which a part near one surface existing at a tip of the vane is in pressure contact with a peripheral surface of the fluid chamber.
(5) The rotary damper according to (3) or (4), wherein the vane is configured by a single member.
(6) A seat including an armrest that rotates and a rotary damper that controls the rotation of the armrest, wherein the rotary damper is provided in a fluid chamber filled with a viscous fluid so as to be swingable. And at least a part of the vane is elastically deformable, and the fluid chamber has an engaged portion with which the elastically deformable portion of the vane engages.
(7) The engaged portion constituting the rotary damper is integrally formed with the housing as a part of the housing forming the peripheral wall of the fluid chamber. Sheet.
(8) The engaged portion constituting the rotary damper is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface is closer to the one surface engaged with the engaged portion. A portion other than a portion is inclined so that the distance from the peripheral surface of the fluid chamber increases toward the other surface side, and a recess opening on one surface side is provided near the tip of the vane. The sheet according to (6) or (7), wherein the sheet is elastically deformable.
(9) The vane constituting the rotary damper has a length in a radial direction in which a part near one surface existing at a tip thereof is in pressure contact with a peripheral surface of the fluid chamber. Sheet.
(10) The sheet according to (8) or (9), wherein the vane constituting the rotary damper is constituted by a single member.

According to the present invention described in (1), since the elastically deformable portion of the vane can be engaged with the engaged portion provided in the fluid chamber, the movement of the vane can be prevented. A rotary damper having both a damper mechanism and a click mechanism can be reduced in size.
According to the present invention described in (2), since the engaged portion is formed integrally with the housing as a part of the housing forming the peripheral wall of the fluid chamber, the damper mechanism is configured. The click mechanism can be configured without requiring a member other than the members. Therefore, it is possible to reduce the number of parts as compared with the conventional case and to reduce the manufacturing cost.
According to the present invention described in (3) above, the engaged portion is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface is engaged with the engaged portion. A portion other than a portion close to one surface is an inclined surface that is inclined so that the distance from the circumferential surface of the fluid chamber increases toward the other surface side, and opens to the one surface side near the tip of the vane. Since the depression is provided, it can be elastically deformed, so that it is possible to make a difference in the braking force exhibited by the vane swinging direction. That is, when the viscous fluid is compressed by one surface of the vane, the pressure of the viscous fluid existing in the inside of the depression increases, so that the tip of the vane is deformed, and the portion between the surface and the peripheral surface of the fluid chamber is deformed. Therefore, the braking force exerted can be increased. Conversely, when the viscous fluid is compressed by the other surface of the vane, the pressure of the viscous fluid existing in the recess is reduced, and the slope formed at the tip of the vane (a portion other than a portion near the one surface) is viscous. By receiving the pressure of the fluid, the tip of the vane is deformed, and a gap between a part near the one surface and the peripheral surface of the fluid chamber is increased, so that the braking force exerted can be reduced.
According to the present invention described in (4) above, since the vane has a radial length in which a portion near one surface existing at the tip thereof is pressed against the peripheral surface of the fluid chamber, the vane is more viscous to one surface of the vane. The sealing performance when compressing the fluid can be improved, and a greater braking force can be exhibited.
According to the present invention described in (5) above, since the vane is composed of a single member, a click mechanism can be configured without requiring a member other than the members configuring the damper mechanism. Further, it is possible to make a difference in the braking force that is formed separately from the vane and does not require a member that is assembled to the vane, depending on the swinging direction of the vane.
According to the present invention described in (6) above, the rotary damper that controls the rotation operation of the armrest includes the vane that is swingably provided in the fluid chamber filled with the viscous fluid, and at least one of the vanes. Even if the friction resistance generated between the armrest and the seat back is small, the portion is made elastically deformable and the fluid chamber has an engaged portion to which the elastically deformable portion of the vane is engaged. Thus, it is possible to maintain the stored state of the armrest. In addition, there is an advantage that the installation space for the rotary damper is small.
According to the present invention described in (7) above, the engaged portion constituting the rotary damper is formed integrally with the housing as a part of the housing forming the peripheral wall of the fluid chamber. The number of parts constituting the damper can be reduced, and the manufacturing cost of the rotary damper can be reduced. As a result, the manufacturing cost of the sheet can also be reduced.
According to the present invention as described in (8) above, the engaged portion constituting the rotary damper is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface is A portion other than a portion closer to one surface that engages with the engaging portion is an inclined surface that is inclined so that the distance from the peripheral surface of the fluid chamber increases toward the other surface side, and in the vicinity of the tip of the vane, By providing a recess opening on one surface side, it is possible to be elastically deformed. Therefore, the rotary damper can make a difference in the braking force exerted depending on the swinging direction of the vane. Therefore, when the armrest is rotated in one direction, the movement is slow, and when the armrest is rotated in the opposite direction, the armrest can be freely operated.
According to the present invention described in (9) above, the vane that constitutes the rotary damper has a radial length in which a portion near one surface existing at the tip thereof is in pressure contact with the peripheral surface of the fluid chamber. The rotary damper can exert a greater braking force. Therefore, even when the weight of the armrest itself is heavy, it is possible to appropriately control the rotation operation.
According to the present invention described in (10) above, since the vane constituting the rotary damper is composed of a single member, the number of parts constituting the rotary damper is reduced and the manufacturing cost of the rotary damper is reduced. As a result, the manufacturing cost of the sheet can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to examples shown in the drawings.

  1 to 3 are views showing a rotary damper according to an embodiment of the present invention, FIG. 1 is a view showing an internal structure, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. FIG. 2 is a cross-sectional view taken along a line BB in FIG. 1. As shown in these drawings, the rotary damper according to this embodiment includes a housing 11, a rotor 12, a partition wall 13, a vane 14, and a plug 15.

  The housing 11 has a substantially circular inner wall having a smaller diameter than the peripheral wall 11a, in addition to a peripheral wall 11a having a substantially circular cross section existing on the outer periphery of the housing 11 and a bottom wall 11b closing one end of the housing 11. 11c. The inner wall 11c serves to support a rotor 12 described later. Further, by providing the inner wall 11c, there is an advantage that it is possible to create an arrangement space for the seal member that prevents the leakage of the viscous fluid. 2 and 3, reference numeral 18 denotes an O-ring as a seal member.

  The rotor 12 is formed to have a substantially circular cross section having an axial length shorter than the axial length of the housing 11, and has a substantially square hole 12 a penetrating along the axial center. . The rotor 12 is rotatably accommodated in the housing 11 in a state where the inner wall 11c of the housing 11 is inserted into a groove 12b formed on an end surface facing the inner surface of the bottom wall 11b of the housing 11.

  The partition wall 13 is formed integrally with the housing 11 so as to protrude from the peripheral wall 11a of the housing 11 toward the axial center. The partition wall 13 is formed such that the tip surface thereof is in sliding contact with the outer peripheral surface of the rotor 12. By partitioning the space formed between the rotor 12 and the housing 11 by the partition wall 13, a fluid chamber 17 filled with a viscous fluid such as silicon oil is formed in the housing 11.

  The vane 14 is formed integrally with the rotor 12 so as to protrude from the outer peripheral surface of the rotor 12 toward the peripheral surface of the fluid chamber 17 (inner peripheral surface of the housing 11) 17a. By arranging the vane 14 in the fluid chamber 17, the fluid chamber 17 is divided into two chambers (hereinafter referred to as "first chamber" and "second chamber") 17a and 17b, respectively.

  The tip of the vane 14 that faces the peripheral surface 17c of the fluid chamber 17 is such that the portion 14d other than the portion 14c near the one surface 14a becomes closer to the peripheral surface 17c of the fluid chamber 17 as it goes toward the other surface 14b. A substantially U-shaped depression 14e that opens to the one surface 14a side is provided near the tip of the vane 14 as an inclined slope, so that it can be elastically deformed.

  Further, the vane 14 has a length in the radial direction in which a part 14 c near the one surface 14 a existing at the tip thereof is pressed against the peripheral surface 17 c of the fluid chamber 17. That is, the radial length of the vane 14 is set to be larger than the distance from the outer peripheral surface of the rotor 12 to the peripheral surface 17c of the fluid chamber 17 before being accommodated in the housing 11. When the vane 14 is disposed in the fluid chamber 17, a part 14 c near the one surface 14 a existing at the tip of the vane 14 is in pressure contact with the peripheral surface 17 c of the fluid chamber 17.

  Further, as shown in FIG. 1, the vane 14 is configured as a single member, and is configured without any member that is formed separately from the vane 14 and then assembled to the vane 14. ing.

  An engaged portion 16 protruding from the peripheral surface 17c is provided on the peripheral surface 17c of the fluid chamber 17 in which the vane 14 is disposed. The engaged portion 16 is formed of a small protrusion protruding along the axial direction at a predetermined position on the peripheral surface 17c of the fluid chamber 17, and as shown in FIG. 1, a housing forming the peripheral wall 17a of the fluid chamber 17 11 is formed integrally with the housing 11.

  The opening of the housing 11 is closed by a plug 15 after the rotor 12 and the vane 14 are disposed in the housing 11 and filled with a viscous fluid. A part of the plug 15 is fitted into a groove 12c formed on the upper end surface side of the rotor 12, and the peripheral edge thereof is joined to the housing 11 by caulking.

  According to the rotary damper configured as described above, as shown in FIG. 4, a part 14 c near the one surface 14 a existing at the tip of the vane 14 is engaged with the peripheral surface 17 c of the fluid chamber 17. By engaging the portion 16, the vane 14 can be prevented from moving in the counterclockwise direction.

  Here, since the tip of the vane 14 is configured to be elastically deformable, when engaging the engaged portion 16, first, a part 14 c near the one surface 14 a rides on the engaged portion 16. After that, the portion 14c near the one surface 14a gets over the engaged portion 16, so that the portion 14c near the one surface 14a is deformed so as to be in pressure contact with the peripheral surface 17c of the fluid chamber 17 again.

  The portion 14d other than the portion 14c near the one surface 14a existing at the tip of the vane 14 is inclined so that the distance from the peripheral surface 17c of the fluid chamber 17 increases toward the other surface 14b side. A portion 14 c closer to 14 a is easily engaged with the engaged portion 16.

  If the vane 14 is engaged with the engaged portion 16, the engaged portion 16 becomes an obstacle that prevents the vane 14 from moving in the counterclockwise direction, and a predetermined load or more is applied to the rotary damper. As long as there is not, rotation of the rotor 12 can be made into a stop state.

  On the other hand, when a predetermined load or more is applied to the rotary damper, the tip of the vane 14 is deformed, and the engagement state between the vane 14 and the engaged portion 16 is released. As a result, the vane 14 can move in the counterclockwise direction, the stopped state of the rotor is released, and the rotor can be rotated.

  When the engagement state between the vane 14 and the engaged portion 16 is released, when the rotor 12 rotates counterclockwise (braking force exerting direction) as shown in FIG. The viscous fluid in the first chamber 17a is compressed, and the viscous fluid in the first chamber 17a tends to move to the second chamber 17b through a gap formed between the vane 14 and the inner surface of the fluid chamber 17. At this time, the pressure of the viscous fluid existing in the recess 14e provided in the vane 14 increases and increases, so that a gap between the portion 14c near the one surface 14a and the peripheral surface 17c of the fluid chamber 17 is obtained. The tip of the vane 14 is deformed so that the portion 14 c near the one surface 14 a is strongly pressed against the peripheral surface 17 c of the fluid chamber 17. As a result, the degree of close contact between the portion 14c near the one surface 14a of the vane 14 and the peripheral surface 17c of the fluid chamber 17 is further increased, so that the viscous fluid generated when moving from the first chamber 17a to the second chamber 17b is increased. The resistance becomes large, and the rotational force of the rotor can be greatly attenuated.

  On the other hand, as shown in FIG. 6, when the rotor 12 rotates in the clockwise direction (the direction in which the braking force is not exerted), the viscous fluid in the second chamber 17b is compressed by the vane 14, and the second chamber 17b. The viscous fluid tends to move to the first chamber 17 a through a gap formed between the vane 14 and the inner surface of the fluid chamber 17. At this time, the pressure of the viscous fluid existing in the recess 14e provided in the vane 14 decreases and decreases, and in addition to this, a slope formed at the tip of the vane 14 (other than the part 14c near the one surface 14a). Since the portion 14d) receives the pressure of the viscous fluid, the tip of the vane 14 is deformed so that the portion 14c near the one surface 14a of the vane 14 and the peripheral surface 17c of the fluid chamber 17 are separated from each other. A large gap is formed between the portion 14 c and the peripheral surface 17 c of the fluid chamber 17. As a result, the viscous fluid can move in a large amount through a gap formed between a portion 14c near the one surface 14a existing at the tip of the vane 14 and the peripheral surface 17c of the fluid chamber 17, so that the second fluid 17b The resistance of the viscous fluid generated when moving to the first chamber 17a is very small. As a result, the rotor 12 can rotate with almost no damping force.

  As described above, according to the rotary damper according to the present embodiment, the elastically deformable portion of the vane 14 is in the engaged portion 16 provided in the fluid chamber 17 in the fluid chamber 17 in which the damper mechanism is inherent. Since the movement of the vane 14 can be prevented by the engagement, the rotary damper having both the damper mechanism and the click mechanism can be downsized.

  In addition, the engaged portion 16 is formed integrally with the housing 11 as a part of the housing 11 that forms the peripheral wall of the fluid chamber 17, and an elastically deformable portion that engages with the engaged portion 16. Since the vane 14 has a single member, the click mechanism can be configured without requiring a member other than the members configuring the damper mechanism. Therefore, it is possible to reduce the number of parts as compared with the conventional case and to reduce the manufacturing cost.

  Further, the distance between the tip of the vane 14 and the peripheral surface 17c of the fluid chamber 17 increases as the portion 14d other than the portion 14c near the one surface 14a engaged with the engaged portion 16 moves toward the other surface 14b. Since the recess 14e that opens toward the one surface 14a is provided near the tip of the vane 14 in the vicinity of the tip of the vane 14, the braking force exerted depending on the swinging direction of the vane 14 is provided. It is possible to make a difference.

  Further, the vane 14 has a portion 14c near the one surface 14a existing at the tip of the vane 14 having a radial length in pressure contact with the peripheral surface 17c of the fluid chamber 17, so that braking superior to that of a conventional rotary damper is achieved. It becomes possible to exhibit the characteristics. That is, when an experiment was performed using the rotary damper (example) according to this example and the conventional rotary damper (comparative example) shown in FIGS. 7 to 11, the rotary damper according to this example was excellent. It has been confirmed that it has braking characteristics.

  In the experiment, the rotary damper housings 11 and 21 are fixed at predetermined positions, and the rotors 12 and 22 are connected to a shaft that rotates together with the arm (object to be controlled), and 2.5 N · m and 5 N · Each of the m loads was applied to rotate the arm. The rotation angle of the arm is 0 ° in the horizontal state, the arm is rotated from the + 80 ° point, and the −30 ° point (a point 30 ° above the horizontal state) from the + 30 ° point (30 ° below the horizontal state) The operation time until the point) was measured.

  The experiment is performed when the rotary damper is installed so that the rotors 12 and 22 rotate in the braking force exerting direction and when the rotary damper is installed so that the rotors 12 and 22 rotate in the braking force non-exhibiting direction, respectively. It was done 3 times.

  As a result of the experiment, the average operation time when the rotary damper is installed so that the rotors 12 and 22 rotate in the braking force exerting direction is 8.8 seconds for the comparative example when the load is 2.5 N · m. On the other hand, in the example, it was 12.1 seconds, and when the load was 5 N · m, the comparative example was 1.7 seconds, whereas the example was Was 2.0 seconds (see FIG. 12).

  The average operation time when the rotary damper is installed so that the rotors 12 and 22 rotate in the direction in which the braking force is not exerted is 0.80 second for the comparative example when the load is 2.5 N · m. In contrast to the example, the example was 0.58 seconds, and when the load was 5 N · m, the comparative example was 0.29 seconds, whereas the example was It was 0.25 seconds (see FIG. 13).

  From the results of this experiment, in the example, the rotational force of the rotor 12 can be attenuated when the rotor 12 rotates in the direction of exerting the braking force, compared to the comparative example. It has been confirmed that when rotating in the non-demonstration direction, it has excellent braking characteristics that the rotational force can be prevented from being attenuated.

  14 and 15 are diagrams illustrating an example in which the rotary damper according to the present embodiment is applied to a vehicle seat. The seat 30 includes an armrest 31 that rotates. In the rotary damper 10 according to the present embodiment, the housing 11 is fixed to the frame of the armrest 31 in order to control the rotation operation of the armrest 31, and the rotor 12 is connected to the support shaft 32 of the armrest 31.

  According to the seat 30, the vane 14 constituting the rotary damper 10 is engaged with the engaged portion 16 when the armrest 31 is stored in a standing posture at a position that does not protrude from the front surface of the seat back 33. By installing the rotary damper 10 so as to be in a state, even when the frictional resistance generated between the armrest 31 and the seat back 33 is small, the armrest 31 is stored without causing the armrest 31 to jump out or leave behind. Can be held. Moreover, since the rotary damper 10 can be configured in a small size, there is an advantage that the installation space for the rotary damper 10 can be reduced.

  Further, according to the seat 30, when the armrest 31 is rotated downward from the stored state to be used, the rotation operation of the armrest 31 is made slow by the braking force exerted by the rotary damper 10. Can do.

  On the other hand, when the armrest 31 is rotated upward from the use state to the retracted state, the braking force exerted by the rotary damper 10 is very small. Therefore, the armrest 31 can be freely rotated with a small force. it can.

It is a figure which shows the internal structure of the rotary damper which concerns on one Example of this invention. It is an AA section sectional view in FIG. It is a BB section sectional view in FIG. It is a figure which shows the engagement state of a vane and a to-be-engaged part. It is a figure which shows a state when a rotor rotates in the braking force display direction. It is a figure which shows a state when a rotor rotates in the braking non-demonstration direction. It is a figure which shows the internal structure of the conventional rotary damper (comparative example). It is an AA section sectional view in FIG. It is a BB section sectional view in FIG. FIG. 8 is a cross-sectional view taken along a line CC in FIG. 7 and shows a state of the valve body when the rotor rotates in the braking force exerting direction. FIG. 8 is a cross-sectional view taken along the line CC in FIG. 7, illustrating a state of the valve body when the rotor rotates in the braking force non-demonstration direction. It is a graph which shows a braking characteristic when a rotor rotates in the braking force display direction. It is a graph which shows a braking characteristic when a rotor rotates to a braking force non-development direction. It is a perspective view of a sheet. It is a figure which shows the state which attached the rotary damper to the armrest.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Rotary damper 11,21 Housing 12,22 Rotor 13,23 Partition 14,24 Vane 15,25 Plug 16,26 Engagement part 17,27 Fluid chamber 17a, 27a 1st chamber 17b, 27b 2nd chamber 18 O-ring 28 Fluid passage 28a Large diameter portion 28b Small diameter portion 29 Valve body 30 Seat 31 Armrest 32 Support shaft 33 Seat back

Claims (10)

  A rotary damper provided with a vane provided in a fluid chamber filled with a viscous fluid so as to be swingable, wherein at least a part of the vane is elastically deformable, and the elasticity of the vane is provided in the fluid chamber. A rotary damper having an engaged portion with which a deformable portion is engaged.   The rotary damper according to claim 1, wherein the engaged portion is formed integrally with the housing as a part of a housing forming a peripheral wall of the fluid chamber.   The engaged portion is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface has a portion other than a portion near the one surface engaging the engaged portion, An inclined surface that is inclined so that the distance from the peripheral surface of the fluid chamber increases toward the surface side, and a recess that opens to the one surface side is provided in the vicinity of the tip of the vane, thereby enabling elastic deformation. The rotary damper according to claim 1 or 2, wherein the rotary damper is provided.   4. The rotary damper according to claim 3, wherein the vane has a length in a radial direction in which a portion near one surface existing at a tip of the vane is in pressure contact with a peripheral surface of the fluid chamber.   The rotary damper according to claim 3 or 4, wherein the vane is composed of a single member.   A seat having a rotating armrest and a rotary damper for controlling the rotating operation of the armrest, wherein the rotary damper includes a vane that is swingably provided in a fluid chamber filled with a viscous fluid. The seat is characterized in that at least a part of the vane is elastically deformable, and the fluid chamber has an engaged portion with which the elastically deformable portion of the vane engages.   The seat according to claim 6, wherein the engaged portion constituting the rotary damper is formed integrally with the housing as a part of the housing forming the peripheral wall of the fluid chamber.   The engaged portion constituting the rotary damper is provided on the peripheral surface of the fluid chamber, and the tip of the vane facing the peripheral surface is other than a portion near the one surface engaging the engaged portion. This portion is an inclined surface that is inclined so that the interval with the peripheral surface of the fluid chamber increases toward the other surface side, and a recess that opens to one surface side is provided in the vicinity of the tip of the vane. The sheet according to claim 6 or 7, wherein the sheet is deformable.   The sheet according to claim 8, wherein a portion of the vane that constitutes the rotary damper has a length in a radial direction in which a part near one surface existing at the tip thereof is pressed against the peripheral surface of the fluid chamber.   The sheet according to claim 8 or 9, wherein the vane constituting the rotary damper is constituted by a single member.

Images