DAMPER DEVICE

Abstract

A damper device includes a first rotary member to which a power of an engine is inputted. The second rotary member is disposed to be rotatable relatively to the first rotary member. The plurality of elastic members elastically couple the first rotary member and the second rotary member in a rotational direction. The seat member is disposed between at least one of the first and second rotary members and one of the plurality of elastic members, and is movable in the rotational direction in accordance with compression and extension of the one of the plurality of elastic members. The auxiliary compression mechanism changes a posture of the seat member so as to compress the one of the plurality of elastic members by a predetermined amount in transmitting the power between the first rotary member and the second rotary member.

Claims

1. A damper device comprising: a first rotary member to which a power of an engine is inputted; a second rotary member disposed to be rotatable relatively to the first rotary member; a plurality of elastic members for elastically coupling the first rotary member and the second rotary member in a rotational direction; a seat member disposed between at least one of the first and second rotary members and one of the plurality of elastic members, the seat member movable in the rotational direction in accordance with compression and extension of the one of the plurality of elastic members; and an auxiliary compression mechanism for changing a posture of the seat member so as to compress the one of the plurality of elastic members by a predetermined amount in transmitting the power between the first rotary member and the second rotary member.

2. The damper device according to claim 1, wherein the auxiliary compression mechanism changes the posture of the seat member so as to compress the one of the plurality of elastic members by causing the first or second rotary member to make contact with the seat member.

3. The damper device according to claim 2, wherein the seat member includes a first contact surface and a second contact surface, one of the first and second contact surfaces capable of selectively making contact with part of the first or second rotary member, and the auxiliary compression mechanism changes the posture of the seat member so as to compress the one of the plurality of elastic members by causing one of the first and second contact surfaces of the seat member to make contact with the first or second rotary member.

4. The damper device according to claim 2, wherein the seat member includes a support surface for supporting an end surface of the one of the plurality of elastic members, and the auxiliary compression mechanism changes a posture of the support surface so as to compress the one of the plurality of elastic members.

5. The damper device according to claim 3, wherein the seat member includes a first engaging portion on a surface thereof for making contact with the first or second rotary member, and the first or second rotary member includes a second engaging portion, the second engaging portion for being engaged with the first engaging portion of the seat member, the second engaging portion for changing the posture of the seat member when engaged with the first engaging portion.

6. The damper device according to claim 5, wherein the first engaging portion is a recess recessed in the rotational direction, and the second engaging portion is a protrusion protruding in the rotational direction, the protrusion for being engaged with the recess.

7. The damper device according to claim 3, wherein the first rotary member includes an accommodation portion having an annular shape, the accommodation portion recessed in an axial direction, the accommodation portion including an outer peripheral side inner wall surface, the plurality of elastic members and the seat member are accommodated in the accommodation portion of the first rotary member, the seat member includes an outer peripheral side support portion for restricting a rotation directional end of the one of the plurality of elastic members from moving to an outer peripheral side, the first and second contact surfaces of the seat member are provided on an outer peripheral surface of the outer peripheral side support portion, one of the first and second contact surfaces capable of selectively making contact with the outer peripheral side inner wall surface of the accommodation portion, and the seat member is capable of taking a first posture and a second posture, the first posture for causing the first contact surface to make contact with the outer peripheral side inner wall surface, the second posture for causing the second contact surface to make contact with the outer peripheral side inner wall surface.

8. The damper device according to claim 7, wherein the seat member includes a support surface for supporting an end surface of the one of the plurality of elastic members, the support surface changes in posture depending on which of the first and second postures the seat member takes, and the one of the plurality of elastic members is compressed by the predetermined amount when the seat member changes in posture from the first posture to the second posture.

9. The damper device according to claim 7, wherein the seat member makes contact with the outer peripheral side inner wall surface of the first rotary member in an entirety of a rotation directional actuation region thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Referring now to the attached drawings which form a part of this original disclosure:

[0033] FIG. 1 is a cross-sectional front view of a flywheel assembly according to a preferred embodiment of the present disclosure;

[0034] FIG. 2 is a cross-sectional side view of the flywheel assembly shown in FIG. 1;

[0035] FIG. 3A is a diagram showing a first spring seat taking a first posture;

[0036] FIG. 3B is a diagram showing the first spring seat taking a second posture; and

[0037] FIG. 4 is a torsional characteristic diagram of the flywheel assembly for explaining advantageous effects of the preferred embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0038] FIGS. 1 to 3 show a flywheel assembly according to a preferred embodiment of the present disclosure. It should be noted that the flywheel assembly is an exemplary damper device. FIG. 1 is a cross-sectional front view of the flywheel assembly in which illustration of some components of the flywheel assembly such as a second flywheel is omitted. FIG. 2 is a cross-sectional side view of the flywheel assembly, whereas FIGS. 3A and 3B show part of FIG. 1 in enlarged representation.

Entire Configuration

[0039] A flywheel assembly 1 is a device for transmitting power generated in an engine to a transmission through a clutch device (not shown in the drawings). As shown in FIGS. 1 and 2, the flywheel assembly 1 includes a first flywheel 2 (an exemplary first rotary member), a second flywheel 3 and a damper mechanism 4.

First Flywheel 2

[0040] The first flywheel 2 is a member to which the power generated in the engine is inputted. The first flywheel 2 is fixed to a crankshaft (not shown in the drawings) of the engine. As shown in FIGS. 1 and 2, the first flywheel 2 includes a first plate 21, a second plate 22 and a support member 23.

[0041] The first plate 21 includes a first plate body 21a having a disc shape, two first lateral portions 21b, and a tubular portion 21c axially extending from the outer peripheral part of the first plate body 21a and that of each first lateral portion 21b. Additionally, each first lateral portion 21b includes outer peripheral portions 21e on the rotation directional ends thereof. Each first lateral portion 21b is a portion bulging toward the engine than the first plate body 21a, and is shaped by, for instance, stamping. The two first lateral portions 21b are disposed at equal pitches in the rotational direction.

[0042] A second plate 22 is an annular member fixed to the tubular portion 21c, and includes a second plate body 22a having a disc shape, two second lateral portions 22b and an inner tubular portion 22c.

[0043] The outer peripheral end of the second plate body 22a is fixed to the distal end of the tubular portion 21c of the first plate 21 by welding. Additionally, outer peripheral portions 22e are provided on the rotation directional ends of each second lateral portion 22b. Each second lateral portion 22b is a portion bulging toward the transmission than the second plate body 22a, and is shaped by, for instance, stamping. The two second lateral portions 22b are disposed at equal pitches in the rotational direction. The inner tubular portion 22c is a tubular portion extending toward the engine from the inner peripheral part of the second plate body 22a, and makes contact at the inner peripheral surface thereof with a seal member 38.

[0044] Two relatively wide accommodation spaces S (see FIG. 2) are formed for accommodating the damper mechanism 4 by disposing the second lateral portions 22b in opposition to the first lateral portions 21b in the outer peripheral part of the first flywheel 2.

[0045] The support member 23 is fixed to the first plate 21 by, for instance, rivets 27.

Second Flywheel 3

[0046] The second flywheel 3 is disposed to be rotatable with respect to the first flywheel 2. The second flywheel 3 includes a second flywheel body 31 and an output plate 33 (an exemplary second rotary member). The output plate 33 is fixed to the second flywheel body 31 by rivets 32. The second flywheel 3 is supported by a bearing 39 while being rotatable with respect to the first flywheel 2.

[0047] The second flywheel body 31 is an annular member disposed on the transmission side of the second plate 22. An inner peripheral portion 31a of the second flywheel body 31 is rotatably supported by the support member 23 through the bearing 39.

[0048] The output plate 33 is fixed to the second flywheel body 31, while being disposed within the accommodation spaces S produced axially between the first plate body 21a and the second plate body 22a. As shown in FIG. 1, the output plate 33 includes a body 33a having an annular shape and two transmission portions 33b provided on the outer peripheral part of the body 33a. The inner peripheral part of the body 33a is fixed to the inner peripheral portion 31a of the second flywheel body 31 by the rivets 32.

[0049] The transmission portions 33b protrude further radially outward from the outer peripheral part of the body 33a. Each transmission portion 33b is provided with engaging protrusions 33c (second engaging portions) protruding from the outer peripheral end thereof to both sides in the rotational direction.

Damper Mechanism 4

[0050] The damper mechanism 4 is a mechanism elastically coupling the first flywheel 2 and the second flywheel 3 in the rotational direction. The damper mechanism 4 includes four first torsion springs 41, four second torsion springs 42, four first spring seats 45 (exemplary seat members) and six second spring seats 46. The first and second torsion springs 41 and 42 are exemplary elastic members. These torsion springs 41 and 42 and spring seats 45 and 46 compose two units. Only one of the units is shown in FIG. 1.

[0051] Specifically, each unit is composed of two first spring seats 45, two pairs of the first and second torsion springs 41 and 42 disposed to be interposed between these first spring seats 45 in the rotational direction, and three second spring seats 46, each of which is disposed between each adjacent pair of the torsion springs 41 and 42. Each unit is disposed within each accommodation space S.

[0052] Additionally, the damper mechanism 4 is provided with auxiliary compression mechanisms for compressing each first torsion spring 41 by a predetermined amount by changing the posture of each first spring seat 45 without moving each first spring seat 45 in the rotational direction when compression of the first and second torsion springs 41 and 42 is started.

First and Second Torsion Springs 41 and 42

[0053] As shown in FIG. 1, two first torsion springs 41 and two second torsion springs 42 are disposed to act in series between the first flywheel 2 and the second flywheel 3. Each first torsion spring 41 is a torsion spring with relatively low stiffness, whereas each second torsion spring 42 is a torsion spring with relatively high stiffness. Moreover, the first and second torsion springs 41 and 42 are arranged such that two second torsion springs 42 are interposed between two first torsion springs 41 in the rotational direction.

First Spring Seats 45 and Auxiliary Compression Mechanisms

[0054] The first spring seats 45 are disposed in the rotation directional ends of each accommodation space S. In other words, the first spring seats 45 are contactable to the outer peripheral portions 21e and 22e, which are the ends of the first and second lateral portions 21b and 22b, and are also contactable to the transmission portions 33b of the output plate 33.

[0055] Each first spring seat 45 is disposed between each first torsion spring 41 and each transmission portion 33b of the output plate 33 in the rotational direction, and supports one end of each first torsion spring 41. Each first spring seat 45 is made of resin and has a block shape. As shown close-up in FIG. 3A, a recess 45a, to which one end of each first torsion spring 41 is inserted, is provided on one rotation directional side (the first torsion spring 41 side) of each first spring seat 45. A bottom surface 45b of the recess 45a functions as a support surface that supports one end surface of each first torsion spring 41. A surface 45c is provided on the other rotation directional side (the transmission portion 33b side) of each first spring seat 45, and functions as a contact surface that makes contact with each transmission portion 33b of the output plate 33. The contact surface 45c is provided with an engaging recess 45d (a first engaging portion) that enables one of the engaging protrusions 33c of each transmission portion 33b to be engaged therewith. The engaging recess 45d is provided on part of the outer peripheral part of each first spring seat 45, and has a shape opened to the output plate 33 side and the outer peripheral side.

[0056] As shown in FIGS. 3A and 3B, a first contact surface 451 and a second contact surface 452 are provided on the outer peripheral surface of each first spring seat 45 so as to be contactable to an inner peripheral surface 21d (an outer peripheral side inner wall surface) of the tubular portion 21c of the first plate 21. The first contact surface 451 is provided on a side close to the output plate 33, whereas the second contact surface 452 is provided on a side remote from the output plate 33. One of the first and second contact surfaces 451 and 452 is selectively contactable to the inner peripheral surface 21d of the tubular portion 21c. In other words, the first and second contact surfaces 451 and 452 have an equal curvature (equal to the curvature of the inner peripheral surface 21d), but have different centers of curvature. Therefore, the second contact surface 452 does not make contact with the inner peripheral surface 21d of the tubular portion 21c in a state that the first contact surface 451 makes contact therewith. Contrarily, the first contact surface 451 does not make contact with the inner peripheral surface 22d of the tubular portion 21c in a state that the second contact surface 452 makes contact therewith.

[0057] In such a configuration, as shown in FIG. 3A, the first contact surface 451 of each first spring seat 45 makes contact with the inner peripheral surface 21d of the tubular portion 21c in a state that one of the engaging protrusions 33c of each transmission portion 33b is not engaged with the engaging recess 45d of each first spring seat 45 (the posture of each first spring seat 45 in this state is defined as a first posture). By contrast, as shown in FIG. 3B, when one of the engaging protrusions 33c of each transmission portion 33b is engaged with the engaging recess 45d of each first spring seat 45, each first spring seat 45 rotates on the spot (without moving in the rotational direction) due to this engagement as depicted with arrow in FIG. 3B, and the second contact surface 452 of each first spring seat 45 makes contact with the inner peripheral surface 21d of the tubular portion 21c (the posture of each first spring seat 45 in this state is defined as a second posture).

[0058] Then, when the posture of each first spring seat 45 is changed from the first posture shown in FIG. 3A into the second posture shown in FIG. 3B, the support surface 45b of each first spring seat 45 is changed in posture such that the inner peripheral side thereof is moved toward each first torsion spring 41. Therefore, each first torsion spring 41 is configured to be compressed by a predetermined amount even though each first spring seat 45 is not moved in the rotational direction.

[0059] As described above, one of the engaging protrusions 33c of each transmission portion 33b and the engaging recess 45d of each first spring seat 45 compose each auxiliary compression mechanism that changes the posture of each first spring seat 45 between the first posture and the second posture whereby each first torsion spring 41 is compressed by the predetermined amount.

Second Spring Seats 46

[0060] The second spring seats 46 support the other ends of the first torsion springs 41 and both ends of the second torsion springs 42 in both the radial direction and the axial direction. Specifically, the second spring seats 46 are disposed between the other end of each first torsion spring 41 and one end of each second torsion spring 42 adjacent to each first torsion spring 41 and between two second torsion springs 42, respectively. Each second spring seat 46 is made of resin and has a block shape. Each second spring seat 46 is provided with recesses on both rotation directional sides thereof so as to support the ends of the first and second torsion springs 41 and 42 adjacent to each other or the ends of two second torsion springs 42.

[0061] It should be noted that two second spring seats 46, each of which is disposed between each pair of the first and second torsion springs 41 and 42 adjacent to each other, and one second spring seat 46 disposed between two second torsion springs 42 are different in shape, but detailed explanation thereof will be herein omitted.

Actions

[0062] As described above, the damper mechanism 4 is composed of two units, but one of the units will be hereinafter focused and explained for easy explanation.

[0063] In a state that power is not being transmitted from the engine to a clutch disc assembly through the flywheel assembly 1, each transmission portion 33b of the output plate 33 and each first spring seat 45 are not press-contacted to each other. Therefore, one of the engaging protrusions 33c of each transmission portion 33b is not engaged with the engaging recess 45d of each first spring seat 45, and each first spring seat 45 takes the first posture as shown in FIG. 3A.

[0064] When this state transitions to a state that the clutch disc assembly is pressed onto the second flywheel 3, power is transmitted from the engine to the transmission through the flywheel assembly 1 and the clutch disc assembly.

[0065] In such a power transmission activated state, each transmission portion 33b of the output plate 33 presses the contact surface 45c of each first spring seat 45. Accordingly, one of the engaging protrusions 33c of each transmission portion 33b is engaged with the engaging recess 45d of each first spring seat 45, and the posture of each first spring seat 45 transitions from the first posture to the second posture as shown in FIG. 3B. As explained above in detail, each first torsion spring 41 is compressed by the predetermined amount due to this change in posture of each first spring seat 45. In other words, each first spring seat 45 changes in posture without moving in the rotational direction, whereby each first torsion spring 41 is compressed by the predetermined amount. Because of this, a torsional characteristic, exerted as the torsional characteristic of the flywheel assembly 1 when power transmission is started, is not a torsional characteristic including stiffnesses of the first spring seats 45a and the output plate 33 but that attributed to approximately only stiffnesses of the first torsion springs 41. Therefore, it is possible to prevent erroneous misfiring detection attributed to an attached state of each first spring seat in the well-known device.

[0066] It should be noted that after each auxiliary compression mechanism operates as described above, each first spring seat 45 is moved in the rotational direction while keeping the second posture. In other words, each first spring seat 45 is moved in the rotational direction in accordance with compression and extension of each first torsion spring 41, while the second contact surface 452 keeps making contact with the inner peripheral surface 21d of the tubular portion 21c.

[0067] FIG. 4 shows difference in torsional characteristics between the present preferred embodiment described above and the well-known device. It should be noted that in FIG. 4, the torsional characteristics are schematically shown without based on actual measurement.

[0068] In FIG. 4, broken line indicates torsional characteristics of the well-known device, whereas solid line indicates those of the present preferred embodiment. Characteristic C1 indicates a torsional characteristic attributed to the first spring seats and the output plate, whereas characteristic C2 indicates that attributed to only the first torsion springs. On the other hand, characteristic C3 indicates a torsional characteristic where each first torsion spring 41 is compressed by change in posture of each first spring seat 45.

[0069] As is obvious from FIG. 4, when power transmission is started, the stiffness in the torsional characteristic is lower in the present preferred embodiment than in the well-known device. Therefore, it is possible to prevent erroneous misfiring detection that has occurred in the well-known device.

Other Preferred Embodiments

[0070] The present advancement is not limited to the aforementioned preferred embodiment, and a variety of changes and modifications can be made without departing from the scope of the present disclosure.

[0071] (1) The number, arrangement, stiffness and so forth of the first torsion springs and those of the second torsion springs are not limited to those in the aforementioned preferred embodiment.

[0072] (2) In the aforementioned preferred embodiment, the first spring seats 45 are configured to support one circumferential-side end of one of the two first torsion springs 41 composing one unit and the other circumferential-side end of the other of the two first torsion springs 41. However, one first spring seat can be provided on the end of only one of the two first torsion springs in one unit.

[0073] (3) In the aforementioned preferred embodiment, the output plate 33 is provided with the engaging protrusions 33c. However, engaging protrusions can be provided on part of the outer peripheral portions 21e and 22e of the first and second lateral portions 21b and 22b of the first flywheel 2, and can be configured to be engaged with the engaging recesses 45d of the first spring seats 45.

[0074] (4) The aforementioned preferred embodiment has explained that the present disclosure is applied to the flywheel assembly. However, the present disclosure is also applicable to other types of damper device.