Damping device

Abstract

In a vibration damper, hysteresis torque in a low torsion angle region is reduced by a simple structure, and sufficient hysteresis torque is obtained in a high torsion angle region, and slight vibrations are effectively damped. The device has an input side plate (30), a hub flange (40), a coil spring (51), and a hysteresis generation mechanism (60). The hysteresis generation mechanism (60) has a friction member, and generates hysteresis torque. The friction member is not in frictional contact with the input side plate (30) in a low torsion angle region, is in frictional contact with the input side plate (30) to generate hysteresis torque in a high torsion angle region, and is not in frictional contact with the input side plate (30) in a prescribed slight torsion angle range in the high torsion angle region. Further, the friction member is positioned at a neutral position by the operation of the coil spring (51) in a neutral state.

Description

TECHNICAL FIELD

[0001] The present application relates to a vibration damper. BACKGROUND

[0002] Generally, abnormal noise and vibration of a vehicle exist in the abnormal noise at idling, the abnormal noise during running, and the sudden braking or the sudden start (low frequency vibration). A vibration damper is provided in order to suppress these abnormal noises and vibrations.

[0003] With respect to the abnormal noise at idling, it is preferable that the torsional rigidity be low in a low torsional angle region of the torsional characteristics of the vibration damper. On the other hand, with respect to the sudden braking or the sudden start, it is necessary to make the torsional characteristics as high as possible in a high torsional angle region. Also, it is necessary to make the slight vibration attenuate by making the hysteresis torque in a slight angle range small when slight vibration is input due to the combustion variation of the engine, for example, in the high torsional angle region.

[0004] Therefore, a vibration damper as shown in Patent Document 1 is provided. This device has two-stage torsional characteristics, has low rigidity and low hysteresis torque in a low torsional angle region, and has high rigidity and high hysteresis torque in a high torsional angle region. Also, in the high torsional angle region, the hysteresis torque is not made to act in a slight torsional angle range.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-372101

[0006] In the vibration damper shown in Patent Document 1, in order to obtain the two-stage torsional characteristics, and in order to prevent the hysteresis torque from being generated in the slight torsional angle range in the high torsional angle region, it is necessary to separate the hub flange, which is a member on the output side, into a cylindrical hub and a flange or the like provided on the outer peripheral side of the hub, and the structure of the device is very complicated. SUMMARY

[0007] The present application relates to a vibration damper.

[0008] (1) A vibration damper according to the present application includes a first rotating body and a second rotating body that rotate around a rotation axis, an elastic link, and a hysteresis generation mechanism. The second rotating body is capable of relative rotation with respect to the first rotating body. The elastic link has a first elastic member and a second elastic member, and elastically links the first rotating body and the second rotating body in the rotation direction. The hysteresis generation mechanism has a friction member that is disposed so as to be capable of frictional contact with the first rotating body or the second rotating body, and generates a hysteresis torque when the second rotating body is twisted by relative rotation with respect to the first rotating body.

[0009] The friction member of the hysteresis generation mechanism does not come into frictional contact with either the first rotating body or the second rotating body in a low-torque-angle region from a neutral state in which there is no torque between the first rotating body and the second rotating body to a first torque angle. In addition, the friction member comes into frictional contact with either the first rotating body or the second rotating body to generate a hysteresis torque in a high-torque-angle region beyond the first torque angle, and does not come into frictional contact with either the first rotating body or the second rotating body in a prescribed small torque-angle range in the high-torque-angle region. Further, the friction member is positioned in the neutral position by the operation of the first elastic member and the second elastic member in the neutral state.

[0010] Further, the "neutral position" of the friction member is the position of the friction member in the rotational direction in the neutral state in which there is no torque between the first rotating body and the second rotating body.

[0011] Here, in a low-torque-angle region from the neutral state in which the torque is 0° to the first torque angle, the friction member does not come into frictional contact with either the first rotating body or the second rotating body. Therefore, in this case, no hysteresis torque based on the friction member is generated, and it is possible to make the hysteresis torque of the entire device in the low-torque-angle region small. In addition, in a high-torque-angle region in which the torque exceeds the first torque angle, the friction member comes into frictional contact with either the first rotating body or the second rotating body to generate a hysteresis torque. Also, in this high-torque-angle region, in a prescribed small torque-angle range, the friction member does not come into frictional contact with either the first rotating body or the second rotating body, and therefore, no hysteresis torque based on the friction member is generated.

[0012] Further, when the first rotating body and the second rotating body return from the state of being twisted to the neutral state, the friction member is positioned in the neutral position by the operation of the first elastic member and the second elastic member. That is, in the neutral state, the friction member is always maintained in the neutral position.

[0013] As described above, in the neutral state, it is possible to position the friction member in the neutral position always using the elastic member that is always used in the vibration damper. Also, it is possible to make the friction member not work in the low-torque-angle region and work in the high-torque-angle region, and in a small torque-angle range in the high-torque-angle region, the friction member does not work. Therefore, by a simple structure, it is possible to make the hysteresis torque in the low-torque-angle region small, and it is possible to obtain a sufficient hysteresis torque in the high-torque-angle region, and it is possible to effectively attenuate small vibrations during running.

[0014] (2) Preferably, the first rotating body has a first support portion and a second support portion. In addition, the second rotating body has a first receiving portion and a second receiving portion. The first receiving portion is disposed so as to be offset to a first side in the rotation direction by an amount in which a portion overlaps the first support portion when viewed in the axial direction. The second receiving portion is disposed so as to be offset to a second side in the rotation direction by an amount in which a portion overlaps the second support portion when viewed in the axial direction. In this case, the first elastic member is disposed in a pre-compressed state in the first support portion and the first receiving portion. In addition, the second elastic member is disposed in a pre-compressed state in the second support portion and the second receiving portion, and works in parallel with the first elastic member.

[0015] Here, the support portions and the receiving portions are each disposed so as to be offset in the reverse direction, and the elastic members are disposed in a compressed state in these support portions and receiving portions. Therefore, a gap exists in the rotation direction between the elastic members and the friction members working thereby, and the end surfaces of the support portions or the receiving portions in which the elastic members are disposed. Therefore, due to a twist angle corresponding to this gap, the friction members do not come into frictional contact with the first rotating body and the second rotating body.

[0016] Furthermore, if the relative rotation of the second rotating body with respect to the first rotating body continues, the gap between the elastic members and the end surfaces of the support portions or the receiving portions disappears, and the rotation of the friction members stops, but the first rotating body or the second rotating body rotates, and therefore the friction members come into frictional contact with the first rotating body or the second rotating body, and a hysteresis torque is generated.

[0017] (3) Preferably, the offset amount of the first support portion and the first receiving portion is the same as the offset amount of the second support portion and the second receiving portion, and the first twist angle is larger than a twist angle corresponding to the offset amount. In this case, the friction members do not come into frictional contact with either the first rotating body or the second rotating body when the twist angle of the first rotating body and the second rotating body from the neutral state is toward an angle corresponding to the offset amount, and when the twist angle from the neutral state is toward the first twist angle. In addition, the friction members come into frictional contact with either the first rotating body or the second rotating body when the twist angle of the first rotating body and the second rotating body exceeds the angle corresponding to the offset amount, and do not come into frictional contact with either the first rotating body or the second rotating body in a range of angles that is the difference between the first twist angle and the twist angle corresponding to the offset amount.

[0018] (4) Preferably, the friction members are relatively rotatable with respect to the first rotating body or the second rotating body in a range of twist angles corresponding to the offset amount and a range of twist angles of the first twist angle.

[0019] (5) Preferably, the friction members have a first abutting portion and a second abutting portion. The first abutting portion abuts against an end surface on a first side in the rotation direction of the first elastic member. The second abutting portion abuts against an end surface on a second side in the rotation direction of the second elastic member.

[0020] Here, the friction member abuts against one end surface of the first elastic member and the other end surface of the second elastic member. In addition, the first elastic member and the second elastic member are arranged in opposite directions while being compressed in advance. Therefore, in the neutral state, the friction member is always positioned at the neutral position by the first elastic member and the second elastic member.

[0021] (6) Preferably, the first elastic member is further compressed from the compressed state via the free state when the first rotary body is twisted from the neutral state to the first side of the rotation direction with respect to the second rotary body, and is further compressed from the compressed state when the first rotary body is twisted from the neutral state to the second side of the rotation direction with respect to the second rotary body.

[0022] In addition, in this case, the second elastic member is further compressed from the compressed state via the free state when the first rotary body is twisted from the neutral state to the second side of the rotation direction with respect to the second rotary body, and is further compressed from the compressed state when the first rotary body is twisted from the neutral state to the first side of the rotation direction with respect to the second rotary body.

[0023] Further, the "free state" here is a state in which each elastic member has no compression or extension of the free length.

[0024] In this vibration damping device, in the neutral state, the first rotary body and the second rotary body are subjected to a torsional torque in either direction of the first side of the rotation direction and the second side of the rotation direction by the first elastic member and the second elastic member arranged in the compressed state. Therefore, even if a torque variation below the torsional torque generated by the compressed elastic member is input, the first rotary body and the second rotary body do not rotate with respect to each other. Therefore, it is possible to suppress the collision sound between each member due to the torque variation within a prescribed torsional angle range.

[0025] (7) Preferably, the first support portion and the second support portion each have a first support surface at an end portion of the first side of the rotation direction and a second support surface at an end portion of the second side of the rotation direction. In addition, the first housing portion and the second housing portion have a first housing surface at an end portion of the first side of the rotation direction and a second housing surface at an end portion of the second side of the rotation direction. In this case, the first elastic member is arranged in compression between the first support surface and the second housing surface, and the second elastic member is arranged in compression between the first housing surface and the second support surface.

[0026] (8) Preferably, the first elastic member and the second elastic member have the same rigidity.

[0027] (9) Preferably, the elastic link portion further has a third elastic member and a fourth elastic member. The third elastic member and the fourth elastic member are arranged in a pre-compressed state in the neutral state. In addition, the third elastic member is further compressed from the compressed state to the free state when the first rotating body is twisted to the first side of the rotating direction from the neutral state with respect to the second rotating body. The fourth elastic member is further compressed from the compressed state to the free state when the first rotating body is twisted to the second side of the rotating direction from the neutral state with respect to the second rotating body.

[0028] (10) Preferably, the first rotating body has a third support portion and a fourth support portion. The third support portion is arranged opposite to the first support portion across the rotation axis. The fourth support portion is arranged opposite to the second support portion across the rotation axis. In addition, the second rotating body has a third receiving portion and a fourth receiving portion. The third receiving portion is arranged opposite to the first receiving portion across the rotation axis. The fourth receiving portion is arranged opposite to the second receiving portion across the rotation axis.

[0029] In this case, the third receiving portion is arranged offset to the first side of the rotating direction with a part overlapping the third support portion when viewed in the axial direction. In addition, the fourth receiving portion is arranged offset to the second side of the rotating direction with a part overlapping the fourth support portion when viewed in the axial direction. Further, the third elastic member is arranged in a pre-compressed state in the third support portion and the third receiving portion. In addition, the fourth elastic member is arranged in a pre-compressed state in the fourth support portion and the fourth receiving portion, and works in parallel with the third elastic member.

[0030] In the present application as described above, in the vibration damping device, it is possible to make the hysteresis torque in the low torsion angle region small with a simple structure, and to obtain sufficient hysteresis torque in the high torsion angle region and to effectively damp a slight vibration. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a sectional view of a vibration damping device of an embodiment of the present application.

[0032] Figure 2 is a front view of the vibration damping device of Figure 1

[0033] Figure 3A is a schematic view showing the relationship between the input side plate and the hub flange.

[0034] Figure 3B is a schematic view in the case where the relative rotation angle of the input side plate and the hub flange is θ1.

[0035] Figure 3C is a schematic view in the case where the relative rotation angle of the input side plate and the hub flange is θ2.

[0036] ​Figure 4 is an enlarged view of the hysteresis generation mechanism.

[0037] Figure 5 is an enlarged view of the hysteresis generation mechanism.

[0038] Figure 6 is an enlarged view of Figure 2 .

[0039] Figure 7 is a graph showing the torsion characteristics.

[0040] Figure 8 is an explanatory view showing the neutral state.

[0041] Figure 9 is an explanatory view showing the state of transition from the neutral to a torsion angle of 2°.

[0042] Figure 10 is an explanatory view showing the state of transition of the torsion angle from 2° to 4°.

[0043] Figure 11 is an explanatory view showing the state of transition of the torsion angle from 4° to 7°.

[0044] Figure 12 is an explanatory view showing the state of transition of the torsion angle from 7° to 5°.

[0045] Figure 13 is an explanatory view showing the state of transition of the torsion angle from 5° to 3°.

[0046] Figure 14 is an explanatory view showing the state of transition of the torsion angle from 3° to 2°.

[0047] Figure 15 is an explanatory view showing the state of transition of the torsion angle from 2° to 1.5°.

[0048] Figure 16 is an explanatory view showing the state of transition of the torsion angle from 1.5° to 1°.

[0049] Figure 17 is an explanatory view showing the state of transition of the torsion angle from 1° to the neutral state. DETAILED DESCRIPTION

[0050] [Overall Structure]

[0051] Figure 1 is a sectional view of a vibration damper 1 with a torque limiter (hereinafter, only referred to as "vibration damper") of an embodiment of the present application. In addition, Figure 2 is a front view of the vibration damper 1, a part of which is removed to show the components. Figure 1In the present embodiment, an engine (not shown) is disposed on the left side of the vibration damper 1, and a drive unit (not shown) including a motor, a transmission, and the like is disposed on the right side.

[0052] Further, in the following description, the axial direction is the direction in which the rotation axis O of the vibration damper 1 extends. In addition, the circumferential direction is the circumferential direction of a circle centered on the rotation axis O, and the radial direction is the radial direction of the circle centered on the rotation axis O. Further, the circumferential direction need not necessarily coincide with the circumferential direction of the circle centered on the rotation axis O. In addition, the radial direction need not necessarily coincide with the diameter direction of the circle centered on the rotation axis O.

[0053] The vibration damper 1 is a device that is disposed between a flywheel (not shown) and an input shaft of a drive unit, limits the torque transmitted between the engine and the drive unit, and attenuates rotational fluctuations. The vibration damper 1 has a torque limiting unit 10 and a vibration damping unit 20.

[0054] [Torque limiting unit 10]

[0055] The torque limiting unit 10 is disposed on the outer circumferential side of the vibration damping unit 20. The torque limiting unit 10 limits the torque transmitted between the flywheel and the vibration damping unit 20. The torque limiting unit 10 has a cover plate 11, a support plate 12, a friction plate 13, a pressure plate 14, and a coned disc spring 15.

[0056] The cover plate 11 and the support plate 12 are disposed at a prescribed interval in the axial direction, and the outer circumferential portions of the two plates 11, 12 are fixed to the flywheel by a plurality of bolts 16.

[0057] The friction plate 13, the pressure plate 14, and the coned disc spring 15 are disposed between the cover plate 11 and the support plate 12 in the axial direction.

[0058] The friction plate 13 has a core plate and a pair of friction members fixed to the both side surfaces of the core plate. Further, the inner circumferential portion of the friction plate 13 is fixed to the vibration damping unit 20 by a plurality of rivets 17. The pressure plate 14 and the coned disc spring 15 are disposed between the friction plate 13 and the support plate 12.

[0059] The pressure plate 14 is formed in a ring shape, and is disposed on the support plate 12 side of the friction plate 13. Further, a plurality of claws 14a are formed in the outer circumferential portion of the pressure plate 14, and the claws 14a engage with a plurality of engagement holes 12a formed in the support plate 12.

[0060] The coned disc spring 15 is disposed between the pressure plate 14 and the support plate 12. The coned disc spring 15 presses the friction plate 13 toward the cover plate 11 via the pressure plate 14.

[0061] [Vibration damping unit 20]

[0062] The vibration reduction unit 20 has an input-side plate 30 (one example of the first rotating body), a hub flange 40 (one example of the second rotating body), an elastic link 50, and a hysteresis generation mechanism 60.

[0063] <INPUT-SIDE PLATE 30>

[0064] The input-side plate 30 has a first plate 31 and a second plate 32. The first plate 31 and the second plate 32 are formed in a circular plate shape having a hole in a center portion, and are arranged apart from each other in the axial direction. The first plate 31 has four stop portions 31a and fixing portions 31b at outer peripheral portions, respectively. In addition, the first plate 31 and the second plate 32 each have a pair of first support portions 301 and a pair of second support portions 302. In the first plate 31 and the second plate 32, the first support portions 301 and the second support portions 302 are formed at the same positions. In addition, a hole 32a for assembly is formed in the first plate 31 at a position corresponding to the rivet 17.

[0065] The stop portion 31a is formed by bending the outer peripheral portion of the first plate 31 toward the second plate 32, and extends in the axial direction. The fixing portion 31b is formed by bending the front end of the stop portion 31a toward the radial direction outside. This fixing portion 31b is fixed to the outer peripheral end portion of the second plate 32 by a plurality of rivets 33. Thus, the first plate 31 and the second plate 32 cannot rotate with respect to each other, and cannot move in the axial direction with respect to each other.

[0066] The pair of first support portions 301 are arranged opposite each other across the rotation axis O. In addition, the pair of second support portions 302 are arranged opposite each other across the rotation axis O at an interval of 90° from the first support portions. Each support portion 301, 302 has a hole that penetrates in the axial direction, and a rim portion that is cut out standing at the inner peripheral edge and the outer peripheral edge of the hole.

[0067] As schematically shown in FIG. 3( Figures 3A-3C ), each support portion 301, 302 has an Rl support surface 301a, 302a at the end portion on the first rotation direction side (hereinafter, only referred to as "Rl side"), and an R2 support surface 301b, 302b at the end portion on the second rotation direction side (hereinafter, only referred to as "R2 side"). The width of the hole of each support portion 301, 302 (the distance between the Rl support surface and the R2 support surface) is L.

[0068] In addition, in FIG. 3, the first support portion 301 and the second support portion 302 are shown by a solid line, and the first receiving portion 401 and the second receiving portion 402 of the hub flange 40 described later are shown by a single-dot chain line. In addition, FIG. 3 is a schematic view, and differs from the actual specific shape shown in FIG. 2. Figure 2

[0069] < HUB FLANGE 40 >

[0070] As​Figure 1 and Figure 2 As shown in FIG. 1, the hub flange 40 has a hub 41 and a flange 42 formed integrally. The hub flange 40 is relatively rotatable with respect to the input-side plate 30 within a prescribed angular range. The hub 41 is formed in a cylindrical shape, and a spline hole 41a is formed in the center portion thereof. In addition, the hub 41 penetrates the holes of the center portions of the first plate 31 and the second plate 32. The flange 42 is formed in a circular plate shape, and extends from the outer peripheral surface of the hub 41 to the radially outer side. The flange 42 is disposed between the first plate 31 and the second plate 32 in the axial direction.

[0071] The flange 42 has four stopper protrusions 42b, a pair of first receiving portions 401 and a pair of second receiving portions 402, and four notches 403.

[0072] The four stopper protrusions 42b are formed so as to protrude from the outer peripheral surface of the flange 42 to the radially outer side. The positions at which the stopper protrusions 42b are formed are radially outside the central portions in the circumferential direction of the receiving portions 401 and 402. Furthermore, when the input-side plate 30 and the hub flange 40 are relatively rotated with respect to each other, the stopper protrusions 42b come into abutment with the stopper portions 31a of the first plate 31, thereby inhibiting the relative rotation of the input-side plate 30 and the hub flange 40.

[0073] As shown in FIG. 3, the pair of first receiving portions 401 are disposed at positions corresponding to the pair of first support portions 301. In addition, the pair of second receiving portions 402 are disposed at positions corresponding to the pair of second support portions 302. In more detail, in a neutral state (twist angle 0°) in which the relative rotation angle between the input-side plate 30 and the hub flange 40 is 0° and the two are not twisted, as shown in FIG. 4, the pair of first receiving portions 401 are disposed so as to be offset by an angle θ1 (for example, a twist angle of 2°) to the R1 side in such a manner that a part thereof overlaps the first support portions 301 when viewed in the axial direction. In addition, the second receiving portions 402 are disposed so as to be offset by the same angle θ1 to the R2 side in such a manner that a part thereof overlaps the second support portions 302 when viewed in the axial direction. Figure 3A

[0074] Each of the receiving portions 401 and 402 is a substantially rectangular hole in which the outer peripheral portion is formed in a circular arc shape. As shown in FIG. 5, each of the receiving portions 401 and 402 has an R1 receiving surface 401a, 402a at the end portion on the R1 side and an R2 receiving surface 401b, 402b at the end portion on the R2 side. The width of the hole of each of the receiving portions 401 and 402 (the distance between the R1 receiving surface 401a, 402a and the R2 receiving surface 401b, 402b) is set to be L, which is the same as the width of the hole of each of the support portions 301 and 302. Figure 3A

[0075] ​​Four cutouts 403 are formed radially inward from the outer periphery of the flange 42 to a predetermined depth between adjacent circumferentially adjacent receiving portions 401 and 402. The positions of each cutout 403 correspond to the positions of the rivets 17 that connect the friction disc 13 of the torque limiting unit 10 and the first plate 31. Therefore, the torque limiting unit 10 and the vibration damping unit 20, which are assembled in different processes, can be fixed by using the assembly hole 32a of the second plate 32 and the cutouts 403 of the flange 42 and by using the rivets 17.

[0076] <Elastic Connector 50>

[0077] The elastic connection 50 has four helical springs 51 (an example of a first elastic member and a second elastic member) and four resin members 52. Each helical spring 51 has an outer spring and an inner spring. The four helical springs 51 are housed in the respective housing portions 401, 402 of the flange 42 and are supported radially and axially by the respective support portions 301, 302 of the input side plate 30. These helical springs 51 operate in parallel.

[0078] Furthermore, the free lengths of all four helical springs 51 are identical. The free length of each helical spring 51 is the same as the width L of each support portion 301, 302 and each receiving portion 401, 402. Additionally, the four helical springs 51 have the same rigidity, and the four resin components 52 have the same rigidity.

[0079] <Storage state of coil spring 51>

[0080] Here, the arrangement of each support portion 301, 302 and each storage portion 401, 402 in the neutral state, as well as the storage state of each coil spring 51, will be described in detail below. Furthermore, in the following description, the first support portion 301 and the first storage portion 401 will sometimes be referred to as "first window group w1", and the second support portion 302 and the second storage portion 402 will sometimes be referred to as "second window group w2".

[0081] As mentioned above, in a neutral state, such as Figure 3A As shown, a pair of first storage portions 401 are offset by an angle θ1 relative to the corresponding first support portion 301 towards the R1 side. On the other hand, a pair of second storage portions 402 are offset by an angle θ1 relative to the second support portion 302 towards the R2 side. Furthermore, a coil spring 51 is fitted in a compressed state at the opening (a hole extending through the axis) of the axially overlapping portion of each storage portion 401, 402 corresponding to each support portion 301, 302.

[0082] Specifically, such as Figure 3AAs shown, in the neutral state, in the pair of first window groups wl, the end surface of the Rl side of the coil spring 51 abuts against the Rl support surface 301a, and the end surface of the R2 side abuts against the R2 receiving surface 401b. On the other hand, in the pair of second window groups w2, the end surface of the Rl side of the coil spring 51 abuts against the Rl receiving surface 402a, and the end surface of the R2 side abuts against the R2 support surface 302b.

[0083] <Delay generation mechanism 60>

[0084] As shown in Figure 1 and Figure 4 , the delay generation mechanism 60 has a first bush 61, a second bush 62, a conical spring 63, and a friction plate 64. Furthermore, Figure 4 is Figure 1 a partial enlarged view.

[0085] The first bush 61 is disposed in the axial direction between the first plate 31 and the flange 42. A friction member is fixed to the side of the first bush 61 on the first plate 31 side. The second bush 62 is disposed in the axial direction between the second plate 32 and the flange 42. A friction member is fixed to the side of the second bush 62 on the flange 42 side. In addition, a plurality of engagement protrusions 62a (refer to Figure 2 ) protruding in the axial direction are formed on the side of the second bush 62 on the second plate 32 side, and engage with the engagement holes 32b of the second plate 32. Thus, the second bush 62 rotates integrally with the second plate 32. The conical spring 63 is disposed in a compressed state in the axial direction between the second bush 62 and the second plate 32. The friction plate 64 is disposed in the axial direction between the second bush 62 and the flange 42.

[0086] The first bush 61, the second bush 62, and the friction plate 64 are independent members, but function integrally with each other as the friction member of the delay generation mechanism 60. In more detail, as shown in Figure 4 , the first bush 61 has a plurality of (two in this example) restriction protrusions 61a and engagement protrusions 61b.

[0087] The restriction protrusions 61a are formed protruding in the axial direction on the side of the first bush 61 on the flange 42 side. As shown in Figure 5 , the restriction protrusions 61a are formed through long holes 42c formed in the flange 42 that are long in the circumferential direction. Furthermore, in the neutral state, a gap corresponding to a torsion angle of 2·θ1 (one example of a first torsion angle) is formed between the restriction protrusions 61a and the end surface of the long holes 42c in the circumferential direction on the Rl side, and a gap corresponding to a torsion angle of θ1 is formed on the R2 side (the position of the first bush 61 and the friction plate 64 in this neutral state is referred to as the "neutral position"). In addition, the engagement protrusions 61b engage with the engagement holes 64a formed in the friction plate 64.

[0088] Therefore, the first bush 61 and the friction plate 64 cannot relatively rotate with respect to each other and rotate integrally. In addition, as described above, the second bush 62 rotates integrally with the second plate 32.

[0089] According to the above structure, the first bush 61 and the friction plate 64 can relatively rotate by an angle of 2-θ1 to the R1 side and by an angle of θ1 to the R2 side with respect to the hub flange 40. Therefore, within the above range of the torsion angle, there is substantially no frictional contact between the first bush 61 and the first plate 31, and no hysteresis torque is generated therebetween. In addition, likewise, within the above range of the torsion angle, the friction plate 64 rotates in synchronization with the first plate 31, and therefore, there is no frictional contact between the second bush 62 and the friction plate 64, and no hysteresis torque is generated therebetween.

[0090] On the other hand, within a range exceeding the above range of the torsion angle, the first bush 61 and the friction plate 64 are prohibited from relatively rotating with respect to the flange 42. Therefore, frictional contact occurs between the first bush 61 and the first plate 31 and between the second bush 62 and the friction plate 64, and hysteresis torques are generated therebetween.

[0091] Here, as Figure 2 and as Figure 2 a partial enlarged view of Figure 6 indicated, the friction plate 64 is substantially rectangular in shape. In addition, on the outer peripheral surface of the friction plate 64, two protruding portions 641 protruding to the radially outer side are formed at opposite positions across the rotation axis O. The protruding portions 641 are located in the circumferential direction between the first window group wl and the second window group w2. Furthermore, the end surface (one example of the second abutting surface) 641a of each protruding portion 641 on the R1 side abuts against the end surface on the R2 side of the coil spring 51 compressedly arranged in the second window group w2. In addition, the end surface (one example of the first abutting surface) 641b of each protruding portion 641 on the R2 side abuts against the end surface on the R1 side of the coil spring 51 compressedly arranged in the first window group wl.

[0092] As described above, each protruding portion 641 of the friction plate 64 is pressed in opposite directions by a pair of coil springs 51 in compression. Therefore, the friction plate 64 and the first bush 61 rotating in synchronization therewith are always positioned at the neutral position in the neutral state.

[0093] [Torsion characteristics: absence of hysteresis torque]

[0094] Here, in order to easily explain the operation, first, the torsion characteristics based on the four coil springs 51 in the absence of hysteresis torque will be described. In Figure 7In this case, the dashed line indicates the torsional characteristics of the coil spring 51 based on the first window group wl, the double-dot chain line indicates the torsional characteristics of the coil spring 51 based on the second window group w2, and the solid line indicates the torsional characteristics wo after the torsional characteristics are synthesized.

[0095] <First window group wl>

[0096] In a neutral state in which the input-side plate 30 and the hub flange 40 do not have relative rotation, as shown in FIG. 6A, the coil spring 51 of the first window group wl is arranged in compression between the Rl support surface 301a and the R2 receiving surface 401b. The interval Go between the Rl support surface 301a and the R2 receiving surface 401b is narrower than the width L (equal to the free length of the coil spring) of each support portion 301, 302 and each receiving portion 401, 402. Therefore, in the first window group wl, as shown by the dashed line in FIG. 6B, a torsional torque -t based on the compressed coil spring 51 is generated. Figure 3A Figure 7

[0097] Figure 3B A state is shown in which a torque is input to the damping unit 20, and the hub flange 40 is twisted by an angle θl relative to the input-side plate 30 on the R2 side (positive side of the torsional characteristics) from the neutral state. In this state, the offset of the first support portion 301 and the first receiving portion 401 is "0".

[0098] Here, in the first window group wl, the interval Gl between the Rl support surface 301a, which the end surface on the Rl side of the coil spring 51 abuts against, and the R2 receiving surface 401b, which the end surface on the R2 side of the coil spring 51 abuts against, is greater than the interval Go. This interval Gl is the same as the free length of the coil spring. That is, in the case where the torsion angle of the input-side plate 30 and the hub flange 40 is +θl, in the first window group wl, the coil spring 51 becomes the free length, as shown in FIG. 6C, and the torsional torque becomes "0". Figure 7

[0099] In addition, if the hub flange 40 is twisted beyond the angle θl relative to the input-side plate 30, as shown in FIG. 6D (a case where the torsion angle is θ2 (> θl) is shown), the end surface on the Rl side of the coil spring 51 of the first window group wl abuts against the Rl receiving surface 401a, and the end surface on the R2 side abuts against the R2 support surface 301b. Here, the interval G2 between the Rl receiving surface 401a and the R2 support surface 301b is narrower than the free length of the coil spring 51. That is, if the torsion angle of the input-side plate 30 and the hub flange 40 exceeds θl, the coil spring 51 is compressed from the free length, as shown in FIG. 6E, and the torsional torque gradually increases. Figure 3C Figure 3C Figure 7

[0100] ​​​​​​On the other hand, in a case where the hub flange 40 is twisted from the neutral state to the Rl side (negative side of the torsional characteristics) with respect to the input-side plate 30, the coil springs 51 of the first window group w1 are always compressed between the Rl support surface 301a and the R2 housing surface 401b. That is, in the first window group w1, as shown in FIG. 6, in the negative side of the torsional region, as the torsional angle becomes larger, the torsional torque also becomes larger toward the negative side. Figure 7

[0101] <Second Window Group w2>

[0102] In the neutral state, the coil springs 51 of the second window group w2 are compressed and arranged between the Rl housing surface 402a and the R2 support surface 302b. The interval between the Rl housing surface 402a and the R2 support surface 302b is G0, which is narrower than the width L (equal to the free length of the coil spring) of each support portion 301, 302 and each housing portion 401, 402. Therefore, as shown in FIG. 8, in the neutral state, in the second window group w2, the torsional torque based on the compressed coil springs 51 is generated +t. Figure 7

[0103] In a case where the hub flange 40 is twisted from the neutral state to the R2 side (positive side of the torsional characteristics) with respect to the input-side plate 30, the coil springs 51 of the second window group w2 are always compressed between the Rl housing surface 402a and the R2 support surface 302b. That is, in the second window group w2, as shown in FIG. 9, in the positive side of the torsional region, as the torsional angle becomes larger, the torsional torque also becomes larger. Figure 7

[0104] On the other hand, in a case where the hub flange 40 is twisted from the neutral state to the Rl side (negative side) by an angle θl with respect to the input-side plate 30, in the second window group w2, the interval between the Rl housing surface 402a, against which the Rl side end surface of the coil spring 51 abuts, and the R2 support surface 302b, against which the R2 side end surface of the coil spring 51 abuts, is larger than the interval G0. The interval in this case is the same as the free length of the coil spring 51. That is, in a case where the torsional angle of the input-side plate 30 and the hub flange 40 is -θl, in the second window group w2, as shown in FIG. 10, the torsional torque is "0". Figure 7

[0105] Further, if the hub flange 40 is twisted to the Rl side beyond the angle θl with respect to the input-side plate 30, the Rl side end surface of the coil spring 51 of the second window group w2 abuts against the Rl support surface 302a, and the R2 side end surface abuts against the R2 housing surface 402b. Moreover, if the torsional angle further becomes larger, the coil spring 51 is compressed from the free length, and as shown in FIG. 11, the torsional torque gradually becomes larger toward the negative side. Figure 7

[0106] <Synthesized Torsional Characteristics>​​​​​

[0107] As a whole vibration damping unit, the composite Figure 7 The characteristic w1 shown by the dashed line and the characteristic w2 shown by the double-dotted line become the torsional characteristic w0 shown by the solid line. That is, in the neutral state, the torsional torque is "0", and as the torsional angle increases towards the positive and negative sides, the torsional torque also increases towards the positive and negative sides.

[0108] Here, in the overall torsional characteristics of the damping unit, the apparent torsional torque in the neutral state is "0". However, as mentioned above, the components on the input and output sides exert positive and negative torsional torques respectively. Therefore, for the torsional angle range of -θ1 to +θ1, the components on the input and output sides do not rotate relative to each other. Thus, collision noise between components caused by torque variations can be suppressed within this torsional angle range.

[0109] In addition, when the torsion angle exceeds ±θ1, the helical springs 51 of the first window group w1 or the second window group w2 become free length, but compared with the structure in which all helical springs 51 are set to free length, it is able to suppress the collision noise between components.

[0110] [Action: Hysteresis exists]

[0111] Next, use Figure 8 The following diagrams illustrate the torsional characteristics taking into account hysteresis torque. In the diagrams, "IP" represents the input side plate 30, and "HF" represents the hub flange 40. The first bushing 61 and friction plate 64 are also described as "friction members FP". Furthermore, the diagrams show the input side plate 30 rotating relative to the hub flange 40 towards the R1 side (the positive side in this example). However, the torsional characteristics on the negative side (rotating to the opposite side) are the same except for a portion of the high torsional angle region; therefore, the torsional characteristics on the negative side are omitted here. Additionally, in the following description, the aforementioned angle θ1 is described as "2°", but this angle is only an example.

[0112] <Neutral State>

[0113] Figure 8 The neutral state is shown. In this neutral state, the coil springs 51 of each window group w1, w2 are compressed. Furthermore, as described above, the end faces of the protrusions 641 of the friction plate 64, i.e., the abutment surfaces 641a, 641b, abut against the end faces of the corresponding coil springs 51, thus positioning them in the neutral position. Therefore, a 4° gap is ensured between the limiting protrusion 61a of the first bushing 61 and the end face of the elongated hole 42c of the flange 42, on the R1 side and a 2° gap is ensured on the R2 side.

[0114] <Neutral state -> Twist angle 2°>

[0115] Figure 9 A case where the input-side plate IP is twisted by 2° to the Rl side with respect to the hub flange HF from the neutral state is shown. Here, the coil springs 51 of the first window group wl are from compression elongation to free length, and the coil springs 51 of the second window group w2 are further compressed from the compressed state in the neutral state.

[0116] In addition, the end surfaces of the coil springs 51 of each window group wl, w2 move in the rotation direction, and thus the friction member FP also rotates. However, in this twist angle region (neutral -> 2°), the restriction protrusion 61a of the first bush 61 does not abut on the end surface of the long hole 42c of the flange 42. Thus, the friction member FP (the first bush 61 and the friction plate 64) rotates in synchronization with the first plate 31, and no hysteresis torque is generated between the first bush 61 and the input-side plate IP (the first plate 31). In addition, the second bush 62 rotates with the input-side plate IP (the second plate 32), and thus no hysteresis torque is generated between the second bush 62 and the friction plate 64.

[0117] < Twist angle 2° -> 4° >

[0118] Figure 10 A case where the input-side plate IP is twisted by 4° to the Rl side with respect to the hub flange HF is shown. Here, the coil springs 51 of the first window group wl are compressed from free length, and the coil springs 51 of the second window group w2 are further developed in the compressed state.

[0119] Until the twist angle is 4°, the restriction protrusion 61a of the first bush 61 does not abut on the end surface of the long hole 42c of the flange 42. Thus, as described above, no hysteresis torque is generated.

[0120] < Twist angle 4° -> 7° >

[0121] Figure 11 A case where the input-side plate IP is twisted by 7° to the Rl side with respect to the hub flange HF is shown. Here, the coil springs 51 of the first window group wl and the second window group w2 are further developed in the compressed state.

[0122] If the torsion angle is 4° or more, the limiting protrusion 61a of the first bushing 61 abuts against the end face of the elongated hole 42c of the flange 42. Therefore, movement (i.e., rotation) of the friction member FP towards the R1 side is prohibited. Thus, if the input side plate IP rotates at a torsion angle of 4° or more relative to the hub flange HF, rotation of the friction member FP is prohibited, resulting in frictional contact between the first bushing 61 and the input side plate IP (first plate 31), generating a hysteresis torque between them. Furthermore, the second bushing 62 rotates together with the input side plate IP (second plate 32), thus also generating a hysteresis torque between the second bushing 62 and the friction plate 64.

[0123] In addition, such as Figure 10 As shown, during the period when the torsion angle changes from 2° to 4°, the contact surfaces 641a and 641b of the friction plate 64 move away from the end face of the helical spring 51 of the corresponding first window group w1. If the torsion angle is 4°, the gap between them is 2° (an example of a small torsion angle). Moreover, if the torsion angle is 4° or more, this gap is always maintained at 2°. This gap of 2° is obtained by subtracting the offset equivalent to the torsion angle (2°) from the gap (4°) between the limiting protrusion 61a and the R1 side of the hole 42c. Therefore, in the high torsion angle region where the torsion angle is 4° or more, within the aforementioned angle range of 2° (relative torsion angle), the friction member FP can work with the input side plate IP. That is, within the angle range of 2° relative torsion angle, no hysteresis torque is generated. Furthermore, such a small torsion angle in the high torsion angle region that does not generate hysteresis torque does not exist in the torsion characteristics on the negative side.

[0124] Therefore, in the high torsion angle region with a torsion angle of 4° or more (absolute angle), a relatively large hysteresis torque can be obtained, and within a certain torsion angle of 4° or more, no hysteresis torque is generated within a range of 2° between the input side plate IP and the hub flange HF. Therefore, for torsional characteristics, small torque fluctuations can be effectively attenuated in the driving region, which is a high torsion angle region.

[0125] <Return to neutral state: Twist angle 7° → 5°>

[0126] Figure 12The case where the input-side plate IP returns from the state where it is twisted 7° to the Rl side from the hub flange HF to a twisted angle of 5° is shown. If the twisted angle is returned by 2° (i.e., a small twisted angle) as such, the abutment surface of the friction member FP abuts against the end surface of the coil spring 51 of the first window group wl. Therefore, as described above, no hysteresis torque is generated in the range of the twisted angle of 7° to 5°, but if the twisted angle is further returned from 5°, the input-side plate IP rotates, but the movement (rotation) of the friction member FP is prohibited. Therefore, if the twisted angle is returned by 2°, a hysteresis torque is further generated.

[0127] < Return to neutral state: twisted angle 5° → 3° >

[0128] Figure 13 The case where the input-side plate IP returns from the state where it is twisted 7° to the Rl side from the hub flange HF to a twisted angle of 5° is shown. If the twisted angle is returned by 2° (i.e., a small twisted angle) as such, the abutment surface of the friction member FP abuts against the end surface of the coil spring 51 of the first window group wl. Therefore, as described above, no hysteresis torque is generated in the range of the twisted angle of 7° to 5°, but if the twisted angle is further returned from 5°, the input-side plate IP rotates, but the movement (rotation) of the friction member FP is prohibited. Therefore, if the twisted angle is returned by 2°, a hysteresis torque is further generated.

[0129] Here, in the twisted region on the Rl side, the compression amount of the coil spring 51 of the first window group wl is smaller than that of the coil spring 51 of the second window group w2. Also, in the region where the twisted angle exceeds 4°, a hysteresis torque is generated. Therefore, when returning to the neutral state from a state where the twisted angle is large, if the twisted angle is 3° (one example), the torque based on the coil spring 51 of the first window group wl and the hysteresis torque based on the hysteresis generation mechanism 60 are balanced with each other. Therefore, the coil spring 51 of the first window group wl is not further elongated due to the hysteresis torque. That is, if the twisted angle is 3° or less when returning to the neutral state, the coil spring 51 of the first window group wl does not work until the prescribed twisted angle, and the torsional rigidity of the entire device is only the rigidity (specifically, the rigidity of 1 / 2 of the combined characteristics) of the coil spring 51 of the second window group w2.

[0130] Also, the end surface on the Rl side of the coil spring 51 of the first window group wl, in the state where it abuts against the hub flange HF, is not further rotated. Also, the abutment surface 641b of the friction plate 64 abuts against the end surface of the coil spring 51 of the first window group wl, and therefore, the friction member FP also does not work (rotate). On the other hand, the input-side plate IP rotates, and therefore, a hysteresis torque is generated from the twisted angle of 5° to 3°.

[0131] < Return to neutral state: twisted angle 5° → 3° >

[0132] Figure 14The diagram shows the state where the torsion angle changes from 3° to 2°. In this case, the torque of the helical spring 51 based on the first window group w1 further decreases. Therefore, in this torsion angle region (3°→2°), as described above, the helical spring 51 of the first window group w1 does not operate (elongate), and the overall torsional stiffness of the device is only the stiffness of the helical spring 51 of the second window group w2. Furthermore, in the region where the torsion angle is from 3° to 2°, the friction member FP and the input side plate IP rotate in conjunction with the hysteresis torque, therefore, no hysteresis torque is generated.

[0133] <From a torsion angle of 2° to a neutral state>

[0134] Figure 15 This indicates a change in the torsion angle from 2° to 1.5°. Figure 14 In the state shown with a torsion angle of 2°, the end face of the coil spring 51 of the first window group w1 on the R2 side abuts against the end faces of the input side plate IP and the hub flange HF on the R2 side. Furthermore, if the torsion angle is smaller than 2°, the end face of the coil spring 51 of the first window group w1 abuts against the end face of the hub flange HF on the R2 side. Therefore, in the region where the torsion angle is smaller than 2°, the friction member FP is repelled by the coil spring 51 of the first window group w1 and cannot rotate in conjunction with the input side plate IP. Thus, a hysteresis torque is generated corresponding to the force (torque) of the coil spring 51 of the first window group w1 being compressed.

[0135] Figure 16 This indicates the state where the torsion angle changes from 1.5° to 1°. If the torsion angle becomes 1°, the end face of the R1 side of the helical spring 51 of the first window group w1 abuts against the end face of the input side plate IP. Therefore, during the period from the torsion angle from 1° to the neutral state, the helical springs 51 of the first window group w1 and the second window group w2 are working, resulting in the combined rigidity of the helical springs 51 of the two window groups w1 and w2. In addition, at this moment, the friction member FP (first bushing 61 and friction plate 64) is positioned in the neutral position.

[0136] Figure 17 This illustrates the state transitioning from a torsional angle of 1° to a neutral state. Here, the input side plate IP returns to the neutral state together with the friction member FP, and no hysteresis torque is generated between them.

[0137] As described above, in this embodiment, a small hysteresis torque can be obtained in the low torsion angle region where the torsion angle is small. Furthermore, in the high torsion angle region where the torsion angle is 4° or more, sufficient hysteresis torque can be obtained, and even when the input side plate 30 and the hub flange 40 twist within a small torsion angle range due to minute torque variations, the torque variation can be effectively attenuated. Moreover, these characteristics can be achieved through an integral hub flange.

[0138] Further, in this embodiment, in the case of a twist from the neutral state toward the Rl side, a hysteresis torque is not generated until the twist angle is 4°, but in the case of a twist from 4° back to the neutral state, a hysteresis torque is generated within a prescribed angle range. However, in the case of returning to the neutral state, in the case of a twist from an angle smaller than 4° toward 4° in the opposite direction, a hysteresis torque is not generated. Therefore, in the low twist angle region, a smaller hysteresis torque can be obtained.

[0139] [Other Embodiments]

[0140] The present application is not limited to the above embodiments, and various modifications or changes can be made without departing from the scope of the present application.

[0141] (a) In the above embodiment, as the friction member that is a hysteresis generation mechanism, the first bush 61 and the friction plate 64 are provided, but the friction plate can be omitted by providing the function of the friction plate to the first bush.

[0142] (b) The specific numerical values of the widths of the respective support portions 301, 302 and the respective housing portions 401, 402, the length of the coil spring 51, or the twist angle are one example, and are not limited to these numerical values.

[0143] (c) In the above embodiment, the rigidity of all of the coil springs is made the same, but coil springs of different rigidity can also be used.

[0144] (d) The number of housing portions, support portions, and coil springs is one example, and is not limited to the above embodiment.

[0145] Explanation of Reference Numerals

[0146] 1...damping device; 30...input side plate (first rotating body); 301...first support portion; 302...second support portion; 301a, 302a...Rl support surface; 301b, 302b...R2 support surface; 40...hub flange (second rotating body); 401...first housing portion; 402...second housing portion; 401a, 402a...Rl housing surface; 401b, 402b...R2 housing surface; 50...elastic link portion; 51...coil spring (first elastic member, second elastic member); 61...first bush; 62...second bush; 64...friction plate; 641...protruding portion; 641a, 641b...abutment surface.

Claims

1. A vibration damping device comprising: a first rotating body that rotates around a rotating axis; a second rotating body that rotates around the rotating axis and is configured to be able to relatively rotate with the first rotating body; and a hysteresis generating mechanism that has a friction member configured to be able to frictionally contact with the first rotating body or the second rotating body, the hysteresis generating mechanism generating a hysteresis torque when the second rotating body is twisted relative to the first rotating body by the relative rotation, wherein the friction member of the hysteresis generating mechanism is not in frictional contact with either the first rotating body or the second rotating body in a neutral state in which there is no twist between the first rotating body and the second rotating body and in a low twist angle region up to a first twist angle, the friction member generates friction by sliding relative to the first rotating body or the second rotating body to generate a hysteresis torque in a high twist angle region exceeding the first twist angle, and is not in frictional contact with either the first rotating body or the second rotating body in a prescribed small twist angle range in the high twist angle region, the friction member is positioned in a neutral position by operation of the first elastic member and the second elastic member in the neutral state, the first rotating body includes a first support portion having a width along a circumferential direction of the first rotating body and a second support portion having a width along the circumferential direction of the first rotating body, the second rotating body includes a first receiving portion having a width along a circumferential direction of the second rotating body and a second receiving portion having a width along the circumferential direction of the second rotating body, the width of the first receiving portion is the same as the width of the first support portion, and the width of the second receiving portion is the same as the width of the second support portion, the first receiving portion is disposed to partially overlap the first support portion and to be angularly offset from the first support portion in a first rotational direction when the first rotating body and the second rotating body are in the neutral state, and the second receiving portion is disposed to partially overlap the second support portion and to be angularly offset from the second support portion in a second rotational direction when the first rotating body and the second rotating body are in the neutral state, the first elastic member is compressed in the first support portion and the first receiving portion when the first rotating body and the second rotating body are in the neutral state, and the second elastic member is compressed in the second support portion and the second receiving portion when the first rotating body and the second rotating body are in the neutral state, the second elastic member is actuated in parallel with the first elastic member and expansion forces of the first elastic member and the second elastic member cancel each other out to hold the first rotating body and the second rotating body in the neutral state and hold the friction member in the neutral position when the first rotating body and the second rotating body are in the neutral state.

2. The vibration damping device according to claim 1, wherein the offset amount of the first support portion and the first receiving portion is the same as the offset amount of the second support portion and the second receiving portion, the first twist angle is larger than a twist angle corresponding to the offset amount, and the friction member is disposed to be in frictional contact with the first rotating body and the second rotating body in a high twist angle region exceeding the first twist angle. ​ The elastic connecting part has a first elastic member and a second elastic member, and the elastic connecting part elastically connects the first rotating body and the second rotating body in the rotation direction; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ the frictional member is in frictional contact with either of the first and second rotating bodies if the torsion angle of the first and second rotating bodies exceeds the angle corresponding to the offset amount, and the frictional member is not in frictional contact with either of the first and second rotating bodies in a range of angles from the first torsion angle to the difference between the first torsion angle and the torsion angle corresponding to the offset amount.

3. The vibration-damping device according to claim 2, wherein the frictional member is relatively rotatable with respect to the first or second rotating body in a range of torsion angles corresponding to the offset amount and the first torsion angle range.

4. The vibration-damping device according to claim 1, wherein the frictional member has a first abutting portion that abuts against an end surface on a first side in a direction of rotation of the first elastic member, and a second abutting portion that abuts against an end surface on a second side in the direction of rotation of the second elastic member.

5. The vibration-damping device according to claim 1, wherein the length of the first elastic member in an uncompressed free state is the same as the width of the first support portion and the first receiving portion in a circumferential direction of the first and second rotating bodies, and the length of the second elastic member in an uncompressed free state is the same as the width of the second support portion and the second receiving portion in the circumferential direction of the first and second rotating bodies, the angular offset of the first receiving portion with respect to the first support portion causes (1) the first elastic member to transition from an initial compressed state to an uncompressed free state, and then be re-compressed as the first rotating body rotates in the first rotational direction with respect to the second rotating body from the neutral state, and (2) the first elastic member to be further compressed from its initial compressed state as the first rotating body rotates in the second rotational direction with respect to the second rotating body from the neutral state, the angular offset of the second receiving portion with respect to the second support portion causes (1) the second elastic member to transition from an initial compressed state to an uncompressed free state, and then be re-compressed as the first rotating body rotates in the second rotational direction with respect to the second rotating body from the neutral state, and (2) the second elastic member to be further compressed from its initial compressed state as the first rotating body rotates in the second rotational direction with respect to the second rotating body from the neutral state.

6. The vibration-damping device according to claim 5, wherein the first and second support portions each have a first support surface at an end on a first side in the direction of rotation, and a second support surface at an end on a second side in the direction of rotation, the first and second receiving portions each have a first receiving surface at an end on the first side in the direction of rotation, and a second receiving surface at an end on the second side in the direction of rotation, the first elastic member is compressed between the first support surface and the second receiving surface, the second elastic member is compressed between the second support surface and the first receiving surface. The second elastic member is arranged in compression between the first receiving surface and the second support surface.

7. The vibration-damping device according to claim 1, wherein The first elastic member and the second elastic member have the same rigidity.

8. The vibration-damping device according to claim 1, wherein The elastic link further has a third elastic member and a fourth elastic member arranged in advance in compression in the neutral state, The third elastic member is further compressed from a compressed state via a free state when the first rotating body is twisted from the neutral state to a first side in the rotational direction with respect to the second rotating body, The fourth elastic member is further compressed from a compressed state via a free state when the first rotating body is twisted from the neutral state to a second side in the rotational direction with respect to the second rotating body.

9. The vibration-damping device according to claim 8, wherein The first rotating body further has a third support portion arranged opposite the first support portion across the rotation axis, and a fourth support portion arranged opposite the second support portion across the rotation axis, The second rotating body further has a third receiving portion arranged opposite the first receiving portion across the rotation axis, and a fourth receiving portion arranged opposite the second receiving portion across the rotation axis, The third receiving portion is arranged offset to a first side in the rotational direction with a portion overlapping the third support portion in an axial view, The fourth receiving portion is arranged offset to a second side in the rotational direction with a portion overlapping the fourth support portion in an axial view, The third elastic member is arranged in advance in compression between the third support portion and the third receiving portion, The fourth elastic member is arranged in advance in compression between the fourth support portion and the fourth receiving portion, and works in parallel with the third elastic member.

Images