Damping device

Abstract

This invention relates to a vibration damping device. The torsional characteristics of the vibration damping device are diversified through a simple structure. The vibration damping device (1) includes an input side plate (30), a hub flange (40), and an elastic connecting part (50). The elastic connecting part (50) has four coil springs (51) pre-compressed in a neutral state where there is no relative rotation between the input side plate (30) and the hub flange (40). Two of the coil springs (51) are further compressed from a compressed state to a free state when the input side plate (30) twists relative to the hub flange (40) from a neutral state to one side (R1). Additionally, the other two coil springs (51) are further compressed from a compressed state to a free state when the input side plate (30) twists relative to the hub flange (40) from a neutral state to the other side (R2). Furthermore, during compression, the two end faces of each coil spring (51) change from a single-sided contact state to a double-sided contact state.

Description

Technical Field

[0001] This invention relates to vibration damping devices. Background Technology

[0002] Vehicle noises and vibrations typically occur during idling, while driving, and during sudden braking or acceleration (low-frequency vibrations). Vibration damping devices are installed to suppress these noises and vibrations.

[0003] Regarding abnormal noises at idle speed, which are related to the low torsional angle region of the damping device's torsional characteristics, low torsional stiffness is preferable in this region. On the other hand, for sudden braking or acceleration, the torsional characteristics need to be as stiff as possible.

[0004] Here, as shown in Patent Documents 1 and 2, a vibration damping device is provided that offers multiple levels of torsional characteristics. In the devices shown in these documents, abnormal noise at idle speed is suppressed by lowering the torsional stiffness of the first level of the torsional characteristics (low torsional angle region). In addition, the torsional stiffness of the second level of the torsional characteristics (high torsional angle region) is set higher to attenuate vibrations during sudden braking or sudden acceleration.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2001-304341

[0006] Patent Document 2: Japanese Patent Application Publication No. 2005-106143

[0007] In the vibration damping device shown in the above patent documents, the splined hub, which is the output side component, is separated into a cylindrical hub and a flange provided on the outer periphery of the hub, and a secondary vibration damping unit is provided between the separated hub and the flange.

[0008] In such conventional multi-stage vibration damping devices, the number of components increases, and miniaturization of the device is hindered. Summary of the Invention

[0009] The objective of this invention is to enable multiple torsional characteristics of a vibration damping device through a simple structure.

[0010] (1) The vibration damping device according to the present invention includes: a first rotating body and a second rotating body that rotate about a rotation axis respectively; and an elastic connecting part. The second rotating body is configured to rotate relative to the first rotating body. The elastic connecting part has a first elastic member and a second elastic member that are pre-compressed in a neutral state where there is no torsion caused by the relative rotation between the first rotating body and the second rotating body, and elastically connects the first rotating body and the second rotating body along the rotation direction.

[0011] When the first elastic member twists relative to the second rotating body from a neutral state to a first side in the direction of rotation, it is further compressed from a compressed state to a free state. Similarly, when the first rotating body twists relative to the second rotating body from a neutral state to a second side in the direction of rotation, it is further compressed from a compressed state to a free state. Furthermore, during compression, one or both end faces of the first and second elastic members in the circumferential direction change from a single-sided contact state to a double-sided contact state.

[0012] Furthermore, the term "free state" here refers to the state where each elastic member is at its free length without compression or elongation. Additionally, "single-sided contact state" refers to the state where one or both end faces of the elastic member in the circumferential direction are in contact with only one radially inner or outer side relative to the first rotating body and / or the second rotating body; "double-sided contact state" refers to the state where one or both end faces of the elastic member in the circumferential direction are in contact with both the radially inner and outer sides relative to the first rotating body and / or the second rotating body.

[0013] In this vibration damping device, in the neutral state, due to the first elastic member and the second elastic part being configured in a compressed state, the first rotating body and the second rotating body are subjected to torsional torque in either the first side or the second side of the rotation direction. That is, the torsional torques of the first elastic member and the second elastic member in the neutral state are opposite. Therefore, the torsional characteristics of each elastic member are shifted in the longitudinal direction (torque direction) of the characteristic diagram.

[0014] Furthermore, during compression, the two end faces of the first and second elastic members change from a single-sided contact state to a double-sided contact state. Therefore, when each elastic member is compressed in a single-sided contact state, its rigidity is relatively low; if it changes from a single-sided contact state to a double-sided contact state, its rigidity increases from low to high. Therefore, by staggering the timing of the transition from a single-sided contact state to a double-sided contact state in the elastic members, the bending point of the torsional characteristic (the point where the torsional rigidity changes) is shifted in the lateral direction (torsional angle direction) of the characteristic diagram.

[0015] By appropriately setting the torque direction and torsional angle direction shifts of the torsional characteristics of the first and second elastic members as described above, the combined torsional characteristics of the first and second elastic members can be made to have two or three levels. Therefore, multiple levels of torsional characteristics can be achieved with a simple structure.

[0016] Furthermore, in this vibration damping device, in the neutral state, the first and second rotating bodies are subjected to torsional torque in either the first or second side of the rotation direction due to the compression of the first elastic member and the second elastic part. Therefore, even if a torque variation less than the torsional torque generated by the compressed elastic member is input, the torsional angle (relative rotation) between the first and second rotating bodies can be suppressed to a small extent. Thus, collision noise between the components caused by torque variation can be suppressed within a specified torsional angle range.

[0017] (2) Preferably, the first elastic member is further compressed from the compressed state when the first rotating body is twisted relative to the second rotating body from the neutral state to the second side of the rotation direction. In addition, the second elastic member is further compressed from the compressed state when the first rotating body is twisted relative to the second rotating body from the neutral state to the first side of the rotation direction.

[0018] (3) Preferably, the first elastic member and the second elastic member have the same rigidity.

[0019] (4) Preferably, the first rotating body has a first support portion and a second support portion. The second rotating body also has a first receiving portion and a second receiving portion. The first receiving portion is offset to a first side in the rotational direction such that it partially overlaps with the first support portion when viewed axially. The second receiving portion is offset to a second side in the rotational direction such that it partially overlaps with the second support portion when viewed axially. Furthermore, in this case, a first elastic member is disposed on the first support portion and the first receiving portion. Additionally, a second elastic member is disposed on the second support portion and the second receiving portion, and operates in parallel with the first elastic member.

[0020] (5) Preferably, the first support portion and the second support portion each have a first support surface at their ends on a first side of the rotation direction and a second support surface at their ends on a second side of the rotation direction. Additionally, the first receiving portion and the second receiving portion each have a first receiving surface at their ends on the first side of the rotation direction and a second receiving surface at their ends on the second side of the rotation direction. In this case, the first elastic member is compressed between the first support surface and the second receiving surface, and the second elastic member is compressed between the first receiving surface and the second support surface. Furthermore, it is preferable that at least one of the first support surface and the first receiving surface is inclined to at least one of the second support surface and the second receiving surface in a manner that opens radially outward.

[0021] By tilting at least one of the support surface and the receiving surface where each elastic member is disposed in a radially outward manner, it is possible to change each elastic member from a single-sided contact state to a double-sided contact state when each elastic member is compressed.

[0022] (6) Preferably, the elastic connecting portion further includes a third elastic member and a fourth elastic member. The third elastic member and the fourth elastic member are pre-compressed and configured in a neutral state. Furthermore, when the first rotating body twists relative to the second rotating body from a neutral state to a first side in the rotational direction, the third elastic member is further compressed from a compressed state to a free state. When the first rotating body twists relative to the second rotating body from a neutral state to a second side in the rotational direction, the fourth elastic member is further compressed from a compressed state to a free state. Moreover, during compression, the end faces of the third and fourth elastic members on one or both sides change from a single-sided contact state to a double-sided contact state.

[0023] (7) Preferably, the first rotating body further includes a third support portion and a fourth support portion. The third support portion is disposed opposite to the first support portion across the rotation axis. The fourth support portion is disposed opposite to the second support portion across the rotation axis. Furthermore, preferably, the second rotating body also includes a third receiving portion and a fourth receiving portion. The third receiving portion is disposed opposite to the first receiving portion across the rotation axis. The fourth receiving portion is disposed opposite to the second receiving portion across the rotation axis. Moreover, the third receiving portion is offset towards a first side in the rotational direction such that it partially overlaps with the third support portion when viewed axially. The fourth receiving portion is offset towards a second side in the rotational direction such that it partially overlaps with the fourth support portion when viewed axially.

[0024] Furthermore, in this configuration, the third elastic member is disposed in both the third support portion and the third receiving portion. Additionally, the fourth elastic member is disposed in both the fourth support portion and the fourth receiving portion, and operates in parallel with the third elastic member.

[0025] (8) Preferably, the third support portion and the fourth support portion each have a third support surface at their ends on the first side of the rotation direction and a fourth support surface at their ends on the second side of the rotation direction. Additionally, the third receiving portion and the fourth receiving portion each have a third receiving surface at their ends on the first side of the rotation direction and a fourth receiving surface at their ends on the second side of the rotation direction. In this case, the third elastic member is compressed between the third support surface and the fourth receiving surface. Furthermore, the fourth elastic member is compressed between the third receiving surface and the fourth support surface. Moreover, at least one of the third support surface and the third receiving surface is inclined to at least one of the fourth support surface and the fourth receiving surface in a manner that opens radially outward.

[0026] (9) Preferably, the first receiving portion is disposed at a predetermined angle offset from a first side of the first support portion in the rotational direction, and the second receiving portion is disposed at a predetermined angle offset from a second side of the second support portion in the rotational direction. In this case, in the first torsion angle region, the first elastic member and the second elastic member are in unilateral contact. Furthermore, in the second torsion angle region, which is larger than the first torsion angle region, the first elastic member is in unilateral contact, and the second elastic member is in unilateral contact. Moreover, in the third torsion angle region, which exceeds the second torsion angle region, the first elastic member and the second elastic member are in unilateral contact.

[0027] (10) Preferably, the first receiving portion is disposed at a predetermined angle offset from a first side of the first support portion in the rotational direction, and the second receiving portion is disposed at a predetermined angle offset from a second side of the second support portion in the rotational direction. In this case, in the first torsion angle region, the first elastic member is in a one-sided contact state, and the second elastic member is in a two-sided contact state. Furthermore, in the second torsion angle region beyond the first torsion angle region, both the first elastic member and the second elastic member are in a two-sided contact state.

[0028] (11) Preferably, the first receiving portion is disposed at a predetermined angle offset from a first side of the first support portion in the rotational direction, and the second receiving portion is disposed at a predetermined angle offset from a second side of the second support portion in the rotational direction. In this case, in the first torsion angle region, the first elastic member and the second elastic member are in contact on both sides. Furthermore, in the second torsion angle region, which is larger than the first torsion angle region, the first elastic member is in contact on one side, and the second elastic member is in contact on both sides. And, in the third torsion angle region, which exceeds the second torsion angle region, the first elastic member and the second elastic member are in contact on both sides.

[0029] In the present invention described above, the torsional characteristics of the vibration damping device can be diversified through a simple structure. Attached Figure Description

[0030] Figure 1 This is a cross-sectional view of a vibration damping device according to an embodiment of the present invention.

[0031] Figure 2 yes Figure 1 Front view of the vibration damping device.

[0032] Figure 3A This is a schematic diagram showing the relationship between the input side plate and the hub flange.

[0033] Figure 3B This is a schematic diagram showing the relative rotation angle between the input side plate and the hub flange as θ1.

[0034] Figure 3C This is a schematic diagram showing the relative rotation angle between the input side plate and the hub flange as θ2.

[0035] Figure 4 This is an enlarged schematic diagram of the support section (storage section).

[0036] Figure 5 This is a diagram showing the torsional characteristics of single-sided and double-sided contact states.

[0037] Figure 6 This is a diagram illustrating the torsional characteristics of the first embodiment of the present invention.

[0038] Figure 7 This is a diagram illustrating the torsional characteristics of the second embodiment of the present invention.

[0039] Figure 8 This is a diagram illustrating the torsional characteristics of the third embodiment of the present invention. Detailed Implementation

[0040] -First Implementation Method-

[0041] [Overall Structure]

[0042] Figure 1 This is a cross-sectional view of a vibration damping device 1 with a torque limiter according to an embodiment of the present invention (hereinafter referred to simply as "vibration damping device"). Additionally, Figure 2 This is a front view of the vibration damping device 1, showing a portion of it with its constituent components removed. Figure 1 In the middle, an engine (not shown) is arranged on the left side of the vibration damping device 1, and a drive unit (not shown) including an electric motor, a transmission device, etc. is arranged on the right side.

[0043] Furthermore, in the following description, the axial direction is the direction in which the rotation axis O of the vibration damping device 1 extends. Additionally, the circumferential direction is the circumferential direction of the circle centered on the rotation axis O, and the radial direction is the radial direction of the circle centered on the rotation axis O. Furthermore, the circumferential direction does not need to be perfectly aligned with the circumferential direction of the circle centered on the rotation axis O. Also, the radial direction does not need to be perfectly aligned with the diametrical direction of the circle centered on the rotation axis O.

[0044] The vibration damping device 1 is disposed between the flywheel (not shown) and the input shaft of the drive unit, and is used to limit the torque transmitted between the engine and the drive unit, and to attenuate rotational fluctuations. The vibration damping device 1 has a torque limiting unit 10 and a vibration damping unit 20.

[0045] [Torque Limiting Unit 10]

[0046] The torque limiting unit 10 is disposed on the outer periphery 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 disc 13, a pressure plate 14, and a conical spring 15.

[0047] The cover plate 11 and the support plate 12 are arranged axially at a predetermined interval, and the outer periphery of the two plates 11 and 12 is fixed to the flywheel by a plurality of bolts 16.

[0048] The friction disc 13, pressure plate 14, and conical spring 15 are axially positioned between the cover plate 11 and the support plate 12.

[0049] The friction disc 13 has a core plate and a pair of friction members fixed to both sides of the core plate. Furthermore, the inner periphery of the friction disc 13 is fixed to the vibration damping unit 20 by a plurality of rivets 17. A pressure plate 14 and a conical spring 15 are disposed between the friction disc 13 and the support plate 12.

[0050] The pressure plate 14 is formed in a ring shape and is disposed on the support plate 12 side of the friction disc 13. In addition, a plurality of claws 14a are formed on the outer periphery of the pressure plate 14, which engage with a plurality of engaging holes 12a formed on the support plate 12.

[0051] A conical spring 15 is disposed between the pressure plate 14 and the support plate 12. The conical spring 15 presses the friction disc 13 against the cover plate 11 via the pressure plate 14.

[0052] [Vibration Damping Unit 20]

[0053] The vibration damping unit 20 has an input side plate 30 (an example of a first rotating body), a hub flange 40 (an example of a second rotating body), an elastic connection 50, and a hysteresis generation mechanism 60.

[0054] <Input Side Panel 30>

[0055] 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 as circular plates with a hole in their center, and are spaced apart from each other axially. The first plate 31 has four stop portions 31a and four fixing portions 31b on its outer periphery. Additionally, 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. The first support portions 301 and the second support portions 302 are formed at the same positions in both the first plate 31 and the second plate 32. Furthermore, an assembly hole 32a is formed in the first plate 31 at a position corresponding to the rivet 17.

[0056] The stop portion 31a is formed by bending the outer periphery of the first plate 31 toward the second plate 32 and extends axially. The fixing portion 31b is formed by bending the front end of the stop portion 31a radially outward. The fixing portion 31b is fixed to the outer periphery of the second plate 32 by a plurality of rivets 33. Therefore, the first plate 31 and the second plate 32 cannot rotate relative to each other and cannot move axially relative to each other.

[0057] A pair of first support portions 301 are arranged opposite each other across a rotation axis O. Additionally, a pair of second support portions 302 are arranged opposite each other across a 90° interval from the first support portions and also across the rotation axis O. Each support portion 301, 302 has an axially penetrating hole and raised edges cut out from the inner and outer peripheries of the hole.

[0058] As shown in Figure 3 ( Figures 3A-3C As schematically shown, each support portion 301, 302 has an R1 support surface 301a, 302a at its end on the first rotation direction side (hereinafter referred to only as the "R1 side"), and an R2 support surface 301b, 302b at its end on the second rotation direction side (hereinafter referred to only as the "R2 side"). The width of the hole in each support portion 301, 302 (the distance between the R1 support surface and the R2 support surface) is L. Each support surface 301a, 301b, 302a, 302b is inclined in a manner that opens radially outward, as will be described later in detail.

[0059] Furthermore, in Figure 3, the first support portion 301 and the second support portion 302 are shown by solid lines, and the first receiving portion 401 and the second receiving portion 402 of the hub flange 40 (described later) are shown by dashed lines. Additionally, Figure 3 is a schematic diagram, and... Figure 2 The actual shape shown is different.

[0060] <Hub flange 40>

[0061] like Figure 1 as well as Figure 2 As shown, the hub flange 40 has a hub 41 and a flange 42. The hub flange 40 is rotatable relative to the input side plate 30 within a specified angular range. The hub 41 is formed in a cylindrical shape and has a spline hole 41a formed in its center. In addition, the hub 41 has a hole that passes through the center of the first plate 31 and the second plate 32. The flange 42 is formed as a circular plate with a hole in its center and is disposed radially outward of the hub 41. The flange 42 is axially disposed between the first plate 31 and the second plate 32.

[0062] like Figure 2As shown, a plurality of external teeth 41b are formed on the outer peripheral surface of the hub 41, and a plurality of internal teeth 42a are formed on the inner peripheral surface of the flange 42, which mesh with the external teeth 41b of the hub 41. Therefore, the hub 41 and the flange 42 rotate integrally. Furthermore, in this embodiment, the hub 41 and the flange 42 are constructed independently, but they can also be constructed from a single component.

[0063] The flange 42 has four stop protrusions 42b, a pair of first storage portions 401 and second storage portions 402, and four cutouts 403.

[0064] Four stop protrusions 42b are formed by protruding radially outward from the outer periphery of the flange 42. The position where each stop protrusion 42b is formed is radially outward from the center of the circumferential direction of each receiving portion 401, 402. Moreover, when the input side plate 30 and the hub flange 40 rotate relative to each other, the stop protrusions 42b abut against the stop portion 31a of the first plate 31, thereby preventing the relative rotation of the input side plate 30 and the hub flange 40.

[0065] like Figure 3A As shown, a pair of first storage portions 401 are positioned corresponding to a pair of first support portions 301. Additionally, a pair of second storage portions 402 are positioned corresponding to a pair of second support portions 302. More specifically, in a neutral state where the relative rotation angle between the input side plate 30 and the hub flange 40 is 0° and there is no twisting (twist angle 0°), the pair of first storage portions 401 are offset by an angle θ1 (e.g., 2°) towards the R1 side, partially overlapping the first support portions 301 when viewed axially. Furthermore, the second storage portions 402 are offset by an angle θ1 towards the R2 side, partially overlapping the second support portions 302 when viewed axially.

[0066] Each storage section 401 and 402 is an almost rectangular hole with an arc-shaped outer perimeter. For example... Figure 3A As shown, each storage portion 401, 402 has an R1 storage surface 401a, 402a at its R1 side end and an R2 storage surface 401b, 402b at its R2 side end. The width of the hole in each storage portion 401, 402 (the distance between the R1 storage surfaces 401a, 402a and the R2 storage surfaces 401b, 402b) is set to L, the same as the width of the hole in each support portion 301, 302. Each storage surface 401a, 401b, 402a, 402b is inclined in a manner that opens radially outward, as will be described in detail later.

[0067] 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.

[0068] <Elastic Connector 50>

[0069] 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.

[0070] Furthermore, the free length Sf of all four helical springs 51 is the same. The free length Sf of the helical spring 51 is the same as the width L of each support portion 301, 302 and each storage portion 401, 402. In addition, the four helical springs 51 have the same rigidity, and the four resin components 52 have the same rigidity.

[0071] <Storage state of coil spring 51>

[0072] 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".

[0073] 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.

[0074] Specifically, such as Figure 3AAs shown, in the neutral state, in a pair of first window groups w1, the R1 side end face of the coil spring 51 abuts against the R1 support surface 301a, and the R2 side end face abuts against the R2 receiving surface 401b. On the other hand, in a pair of second window groups w2, the R1 side end face of the coil spring 51 abuts against the R1 receiving surface 402a, and the R2 side end face abuts against the R2 support surface 302b.

[0075] <Single-sided and double-sided contact of helical spring 51>

[0076] Here, Figure 4 Enlarged views of the support portions 301 and 302 are provided. Furthermore, Figure 4 For illustrative purposes only, the actual shape and dimensions differ. As shown, the support surfaces 301a, 301b, 302a, and 302b of each support portion 301 and 302 are inclined at δ° (e.g., 3°) in a manner that opens from the radially inward side to the outward side. Therefore, when the helical spring 51 is arranged without gaps in the rotational direction in each support portion 301 and 302, in the uncompressed state, only a portion of the radially inward side of the two end faces of the helical spring 51 abuts against each support surface 301a, 301b, 302a, and 302b (this state is described as "one-sided contact state"). Moreover, if the helical spring 51 is compressed by a predetermined amount, then thereafter, both the radially inward and outer sides of the helical spring 51 abut against each support surface 301a, 301b, 302a, and 302b (this state is described as "two-sided contact state").

[0077] Although not shown in the figure, the storage surfaces 401a, 401b, 402a, and 402b of each storage section 401 and 402 are tilted at the same angle δ°.

[0078] As described above, by tilting each support surface 301a, 301b, 302a, 302b and each receiving surface 401a, 401b, 402a, 402b in a radially outward opening manner, the torsional characteristics of the helical springs 51 arranged in each support portion 301, 302 and each receiving portion 401, 402 become Figure 5 As shown. That is, the coil spring 51 has low stiffness in the torsional angle region A where it is compressed in a unilateral contact state, and high stiffness in the torsional angle region B where it is compressed in a unilateral contact state.

[0079] In addition, Figure 5 The diagram shows the torsional characteristics without causing the support portions 301, 302 and the storage portions 401, 402 to shift in the direction of rotation.

[0080] <Hysteresis Generating Mechanism 60>

[0081] like Figure 1As shown, the hysteresis generating mechanism 60 includes a first bushing 61, a second bushing 62, and a conical spring 63. The first bushing 61 is axially disposed between a first plate 31 and a flange 42. A friction member is fixed to the friction surface between the first bushing 61 and the first plate 31. The second bushing 62 is axially disposed between a second plate 32 and a flange 42. A friction member is fixed to the friction surface between the second bushing 62 and the flange 42. Furthermore, a plurality of axially protruding engaging protrusions 62a are formed on the second plate 32 side surface of the second bushing 62, which engage with engaging holes 32b in the second plate 32. The conical spring 63 is axially compressed and disposed between the second bushing 62 and the second plate 32.

[0082] Based on the above structure, the first bushing 61 is pressed by the first plate 31, and the second bushing 62 is pressed by the flange 42. Therefore, when relative rotation occurs between the input side plate 30 and the hub flange 40, a hysteresis torque is generated between them.

[0083] [action]

[0084] Furthermore, in the following descriptions of the action and the diagrams illustrating the torsional characteristics, hysteresis torque is omitted. Additionally, the description of the torsional characteristics only pertains to the torsional characteristics from the neutral state towards the positive side.

[0085] As described above, in this embodiment, the support surfaces of each support portion 301, 302 and the receiving surfaces of each receiving portion 401, 402 are formed to open radially outward. Therefore, in each window group w1, w2, during the compression of the helical spring 51, the contact state changes from a single-sided contact state to a double-sided contact state. Hereinafter, in the first window group w1 and the second window group w2, the torsional stiffness of the single-sided contact state is set to k1, and the torsional stiffness of the double-sided contact state is set to k2. Furthermore, the case with an offset of 2° will be described as an example.

[0086] <Neutral State>

[0087] In a neutral state where the input side plate 30 and the hub flange 40 do not rotate relative to each other, such as Figure 3A As shown, the helical spring 51 of the first window group w1 is disposed between the R1 support surface 301a and the R2 receiving surface 401b. The gap G0 between the R1 support surface 301a and the R2 receiving surface 401b is narrower than the width L (equal to the free length Sf of the helical spring) of each support portion 301, 302 and each receiving portion 401, 402. Therefore, in the first window group w1, the helical spring 51 is disposed in a compressed state. Therefore, as Figure 6 As shown by the dashed line, in the first window group w1, a torsional torque -t is generated due to the compression of the helical spring 51.

[0088] Furthermore, also in a neutral state, the helical spring 51 of the second window group w2 is positioned between the R1 receiving surface 402a and the R2 support surface 302b. The interval between the R1 receiving surface 402a and the R2 support surface 302b is G0, which is narrower than the width L (equal to the free length Sf of the helical spring) of each support portion 301, 302 and each receiving portion 401, 402. Therefore, in the second window group w2, the helical spring 51 is positioned in a compressed state. Therefore, as Figure 6 As shown by the double-dotted line, in the second window group w2, a torsional torque +t is generated due to the compressed helical spring 51.

[0089] <Work of the first window group w1>

[0090] With an offset of 2°, in the first window group w1, as follows Figure 6 As shown by the dashed line, in the region of torsion angle 0 to θ1 to θ2 (compression → free length → compression), the helical spring 51 operates in a single-sided contact state (rigidity k1). If the angle exceeds θ2, it is compressed in a double-sided contact state (rigidity k2). The operation of the first window group w1 will be explained in more detail below.

[0091] Figure 3B This illustrates the state where, with a torque variation input to the damping unit 20, the hub flange 40 is twisted by an angle θ1 relative to the input side plate 30 from a neutral state towards the R2 side. Here, in the first window group w1, the gap G1 between the R1 support surface 301a, where the end face of the coil spring 51 abuts on the R1 side, and the R2 receiving surface 401b, where the end face of the coil spring 51 abuts on the R2 side, is larger than the gap G0. This gap G1 is the same as the free length Sf of the coil spring. That is, when the twist angle between the input side plate 30 and the hub flange 40 is +θ1, in the first window group w1, the coil spring 51 becomes the free length Sf, as shown... Figure 6 As shown, the torsional torque generated by the helical spring 51 is "0".

[0092] As described above, in the first window group w1, in the region of torsion angle 0 to θ1, the helical spring 51 changes from a compressed state to its free length and operates in a one-sided contact state. Therefore, the torsional stiffness becomes k1.

[0093] Next, if the hub flange 40 twists relative to the input side plate 30 by more than an angle θ1, then as Figure 3C As shown ( Figure 3CThe diagram shows the case where the torsion angle is θ2 (>θ1). The end face of the coil spring 51 on the R1 side of the first window group w1 abuts against the R1 receiving surface 401a, and the end face on the R2 side abuts against the R2 supporting surface 301b. Furthermore, at this torsion angle θ2, the coil spring 51 is in a double-sided contact state. Here, the gap G2 between the R1 receiving surface 401a and the R2 supporting surface 301b is narrower than the free length Sf of the coil spring 51. That is, if the torsion angle between the input side plate 30 and the hub flange 40 exceeds θ1, the coil spring 51 is compressed from its free length Sf, as... Figure 6 As shown by the dashed line, the torsional torque gradually increases.

[0094] As described above, in the first window group w1, in the region exceeding the torsion angle θ1, the helical spring 51 is compressed from its free length, and if the torsion angle becomes θ2, it is compressed in a double-sided contact state. Therefore, the torsional stiffness becomes k2.

[0095] <Working with the second window group w2>

[0096] With an offset of 2°, in the second window group w2, as follows Figure 6 As shown by the double-dotted line, in the region of torsion angle -θ2 to -θ1 to 0 (compression → free length → compression), the helical spring 51 operates in a one-sided contact state (rigidity k1). If the torsion angle exceeds 0 (compression → compression), it is compressed in a two-sided contact state (rigidity k2). The operation of the second window group w2 will be explained in more detail below.

[0097] In the second window group w2, when the hub flange 40 twists relative to the input side plate 30 from a neutral state towards the R2 side, the coil spring 51 is always compressed between the R1 receiving surface 402a and the R2 supporting surface 302b. That is, in the second window group w2, as... Figure 6 As shown by the double-dotted line, the torsional torque increases as the torsion angle increases.

[0098] Here, the helical spring 51 is further compressed from the compressed state and is compressed in a double-sided contact state, and the torsional stiffness becomes k2.

[0099] <Characteristics of Synthesis>

[0100] As is clearly understood above, the torsional characteristics resulting from the combination of the first window group w1 and the second window group w2 become Figure 6 The solid line represents the characteristic. That is, the stiffness in each torsional angle region becomes...

[0101] Twist angle 0~θ2: k1+k2

[0102] θ2~:2k2.

[0103] As described above, each support portion 301, 302 is offset from its corresponding receiving portion 401, 402, and each support surface 301a, 301b, 302a, 302b and each receiving surface 401a, 401b, 402a, 402b is formed in a manner that opens radially outward, thereby easily obtaining a level 2 torsional characteristic.

[0104] Here, in the overall torsional characteristics of the damping unit, the apparent torsional torque in the neutral state is "0". However, the components on the input and output sides experience positive and negative torsional torques respectively. Therefore, when the torque variation is within the range of +t to -t, the torsional angle between the input side plate 30 and the hub flange 40 is reduced to the range of -θ1 to +θ1, and the end faces of the coil springs 51 of the first window group w1 do not contact the R1 receiving surface 401a and the R2 support surface 301b respectively. In addition, the end faces of the coil springs 51 of the second window group w2 do not contact the R2 receiving surface 402b and the R1 support surface 302a respectively. Therefore, it is possible to suppress the collision noise between the components caused by torque variation within the range of +t to -t.

[0105] In addition, when the torsion angle is ±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.

[0106] Furthermore, if the torsion angle increases further, the resin components 52 of each window group w1 and w2 are compressed, and the torsion characteristics become higher than k2. Moreover, if the torsion angle increases further, the stop protrusion 42b of the flange 42 abuts against the stop portion 31a of the first plate 31, preventing the relative rotation between the input side plate 30 and the hub flange 40.

[0107] -Second Implementation Method-

[0108] Figure 7 The torsional characteristics are shown when the offset between each support portion 301, 302 and the corresponding storage portion 401, 402 is 1° (a smaller example than the offset in the first embodiment).

[0109] Here, the offset is smaller than in the first embodiment; therefore, compared to the first embodiment, the characteristics of the first window group w1 are shifted to the negative side. That is, as... Figure 7 As shown by the dotted line, in the region of torsion angle -θ3 to θ4 (compression → free length → compression), the helical spring 51 operates in a one-sided contact state (rigidity k1). If the angle exceeds θ4 (compression → compression), it is compressed in a two-sided contact state (rigidity k2).

[0110] Furthermore, the characteristics of the second window group w2 are opposite to those of the first window group w1, and are shifted to the positive side compared to the first embodiment. That is, as... Figure 7 As shown by the double-dotted line, in the region of torsion angle -θ4 to θ3 (compression → free length → compression), the helical spring 51 is compressed in a one-sided contact state (rigidity k1), and if it exceeds the angle θ3 (compression → compression), it is compressed in a two-sided contact state (rigidity k2).

[0111] As is clearly understood from the above, the operation of each helical spring 51 is basically the same as that of the first embodiment, except for the timing of the transition from free length to compression.

[0112] The synthetic characteristics of this second embodiment become Figure 7 The solid line represents the characteristic. That is, the stiffness of each torsional angle region becomes...

[0113] Twist angle 0~θ3: 2k1

[0114] θ3~θ4:k1+k2

[0115] θ4~:2k2.

[0116] Therefore, in this second embodiment, level 3 torsional characteristics can be easily obtained.

[0117] -Third Implementation Method-

[0118] Figure 8 The torsional characteristics are shown when the offset between each support portion 301, 302 and the corresponding storage portion 401, 402 is 3° (a larger offset than in the first embodiment).

[0119] Here, the offset is larger than in the first embodiment; therefore, compared to the first embodiment, the characteristics of the first window group w1 are shifted to the positive side. That is, as... Figure 8 As shown by the dotted line, in the region of torsion angle 0 to θ5 (compression), the helical spring 51 is compressed in a double-sided contact state (rigidity k2), in the region of torsion angle θ5 to θ6 (compression → free length → compression), it operates in a single-sided contact state (rigidity k1), and if the angle exceeds θ6, it is compressed in a double-sided contact state (rigidity k2).

[0120] Furthermore, the characteristics of the second window group w2 are opposite to those of the first window group w1, shifting negatively compared to the first embodiment. That is, as... Figure 8 As shown by the double-dotted line, in the region of torsion angle -θ6 to -θ5 (compression → free length → compression), the helical spring 51 operates in a one-sided contact state (rigidity k1). If the angle exceeds -θ5 (compression → compression), it is compressed in a two-sided contact state (rigidity k2).

[0121] As is clearly understood from the above, for the compression action of each helical spring 51, only the timing of the transition from free length to compression differs; otherwise, it is essentially the same as the first embodiment.

[0122] The synthetic characteristics of this third embodiment become Figure 8 The solid line represents the characteristic. That is, the stiffness in each torsional angle region becomes...

[0123] Twist angle 0~θ5: 2k2

[0124] θ5~θ6:k1+k2

[0125] θ6~:2k2.

[0126] Therefore, in this third embodiment, the same as in the second embodiment, level 3 torsional characteristics can be easily obtained.

[0127] [Other Implementation Methods]

[0128] The present invention is not limited to the embodiments described above, and various modifications or variations can be made without departing from the scope of the present invention.

[0129] (a) The relationship between the width of each support portion 301, 302 and each storage portion 401, 402 and the free length of the helical spring 51 is not limited to the above embodiment.

[0130] (b) In the above embodiments, all helical springs are made to have the same stiffness, but helical springs with different stiffnesses can also be used.

[0131] (c) The number of the storage part, the support part and the helical spring is just one example and is not limited to the above embodiment.

[0132] (d) In the above embodiments, each support surface and each receiving surface are inclined in a way that opens outward in a radial direction, but it is also possible to incline only one side of the surface.

[0133] Explanation of reference numerals in the attached figures

[0134] 1... Vibration damping device; 30... Input side plate (first rotating body); 301... First support part; 302... Second support part; 301a, 302a... R1 support surface; 301b, 302b... R2 support surface; 40... Hub flange (second rotating body); 401... First storage part; 402... Second storage part; 401a, 402a... R1 storage surface; 401b, 402b... R2 storage surface; 50... Elastic connection part; 51... Helical spring (first elastic member, second elastic member).

Claims

1. A vibration damping device, comprising: The first rotating body rotates about its axis of rotation; A second rotating body, rotating about the rotation axis, and configured to rotate relative to the first rotating body; and The elastic connection includes a first elastic member and a second elastic member pre-compressed in a neutral state where there is no torsion caused by the relative rotation between the first and second rotating bodies. The elastic connection elastically connects the first and second rotating bodies in the rotational direction. When the first elastic member twists relative to the second rotating body from the neutral state to a first side in the rotational direction, it is further compressed from a compressed state via a free state. When the first rotating body twists relative to the second rotating body from the neutral state to a second side in the rotational direction, the second elastic member is further compressed from a compressed state via a free state. During compression, the end faces of the first elastic member and the second elastic member change from a single-sided contact state to a double-sided contact state on one or both sides in the circumferential direction.

2. The vibration damping device according to claim 1, wherein, The first elastic member is further compressed from the compressed state when the first rotating body twists relative to the second rotating body from the neutral state to a second side in the rotation direction. The second elastic member is further compressed from the compressed state when the first rotating body twists relative to the second rotating body from the neutral state to the first side of the rotation direction.

3. The vibration damping device according to claim 1 or 2, wherein, The first elastic member and the second elastic member have the same rigidity.

4. The vibration damping device according to claim 1 or 2, wherein, The first rotating body has a first support portion and a second support portion. The second rotating body has: a first receiving portion disposed offset to a first side in the rotational direction such that it partially overlaps with the first support portion when viewed axially; and a second receiving portion disposed offset to a second side in the rotational direction such that it partially overlaps with the second support portion when viewed axially. The first elastic member is disposed in the first support portion and the first receiving portion. The second elastic member is disposed on the second support portion and the second receiving portion, and the second elastic member operates in parallel with the first elastic member.

5. The vibration damping device according to claim 4, wherein, The first support portion and the second support portion each have a first support surface at their ends on a first side of the rotation direction and a second support surface at their ends on a second side of the rotation direction. The first storage portion and the second storage portion have a first storage surface at their ends on the first side of the rotation direction, and a second storage surface at their ends on the second side of the rotation direction. The first elastic member is compressed and disposed between the first supporting surface and the second receiving surface. The second elastic member is compressed and disposed between the first receiving surface and the second supporting surface. At least one of the first support surface and the first receiving surface is inclined to the second support surface and the second receiving surface in a manner that opens radially outward.

6. The vibration damping device according to claim 4, wherein, The elastic connecting part also has a third elastic member and a fourth elastic member that are pre-compressed in the neutral state. The third elastic member is further compressed from a compressed state to a free state when the first rotating body twists relative to the second rotating body from the neutral state to a first side in the rotational direction. The fourth elastic member is further compressed from a compressed state to a free state when the first rotating body twists relative to the second rotating body from the neutral state to a second side in the rotational direction. During compression, the end faces of the third and fourth elastic members change from a single-sided contact state to a double-sided contact state on one or both sides in the circumferential direction.

7. The vibration damping device according to claim 6, wherein, The first rotating body further comprises: a third support portion disposed opposite to the first support portion across the rotation axis; and a fourth support portion disposed opposite to the second support portion across the rotation axis. The second rotating body further comprises: a third storage portion disposed opposite to the first storage portion across the rotation axis; and a fourth storage portion disposed opposite to the second storage portion across the rotation axis. The third storage portion is offset toward a first side in the direction of rotation such that it partially overlaps with the third support portion when viewed in the axial direction. The fourth storage portion is offset toward a second side in the direction of rotation such that it partially overlaps with the fourth support portion when viewed in the axial direction. The third elastic member is disposed in the third support portion and the third receiving portion. The fourth elastic member is disposed on the fourth support portion and the fourth storage portion, and the fourth elastic member operates in parallel with the third elastic member.

8. The vibration damping device according to claim 7, wherein, The third support portion and the fourth support portion each have a third support surface at their ends on the first side of the rotation direction and a fourth support surface at their ends on the second side of the rotation direction. The third and fourth storage portions have a third storage surface at their ends on the first side of the rotation direction and a fourth storage surface at their ends on the second side of the rotation direction. The third elastic member is compressed and disposed between the third support surface and the fourth receiving surface. The fourth elastic member is compressed and disposed between the third receiving surface and the fourth supporting surface. At least one of the third support surface and the third receiving surface is inclined to the fourth support surface and the fourth receiving surface in a manner that opens radially outward.

9. The vibration damping device according to claim 4, wherein, The first storage portion is offset at a predetermined angle relative to a first side of the first support portion in the rotational direction, and the second storage portion is offset at the same predetermined angle relative to a second side of the second support portion in the rotational direction. In the first torsion angle region, both the first elastic member and the second elastic member are in contact on one side. In a second torsion angle region that is larger than the first torsion angle region, the first elastic member is in a unilateral contact state, and the second elastic member is in a unilateral contact state. In the third torsion angle region, which exceeds the second torsion angle region, the first elastic member and the second elastic member are in a state of double-sided contact.

10. The vibration damping device according to claim 4, wherein, The first storage portion is offset at a predetermined angle relative to a first side of the first support portion in the rotational direction, and the second storage portion is offset at the same predetermined angle relative to a second side of the second support portion in the rotational direction. In the first torsion angle region, the first elastic member is in a unilateral contact state, and the second elastic member is in a unilateral contact state. In a second torsion angle region that exceeds the first torsion angle region, the first elastic member and the second elastic member are in a state of double-sided contact.

11. The vibration damping device according to claim 4, wherein, The first storage portion is offset at a predetermined angle relative to a first side of the first support portion in the rotational direction, and the second storage portion is offset at the same predetermined angle relative to a second side of the second support portion in the rotational direction. In the first torsion angle region, the first elastic member and the second elastic member are in contact on both sides. In a second torsion angle region greater than the first torsion angle region, the first elastic member is in a unilateral contact state, and the second elastic member is in a unilateral contact state. In the third torsion angle region, which exceeds the second torsion angle region, the first elastic member and the second elastic member are in a state of double-sided contact.

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