Damper device

Abstract

The present invention comprises a damper part in which is disposed a plurality of buffering units that cause a driving-side member and a driven-side member to relatively displace about a rotation axis center in conjunction with increases in load torque. Each buffering unit comprises a guide member having a spring and a pair of seats that engage a driving-side engagement part and a driven-side engagement part. A guide extension part extending in a direction opposite to the driven-side engagement part is formed on an outer peripheral part of each seat, and when the seat moves, the seat contacts the guide extension part, thereby allowing operation along a guide region centered on the rotation axis center.

Description

Damper Device

[0001] The present disclosure relates to a damper device.

[0002] As a damper for absorbing fluctuations in load torque in a transmission system that transmits the rotational driving force of an internal combustion engine to a traveling device, Patent Document 1 discloses a configuration in which a pair of seats (21) are arranged between a driving side member (disc plate 12 in the document) to which the rotational driving force of the internal combustion engine is transmitted and a driven side member (flanged hub 11 in the document) that transmits the rotational driving force to the traveling device, and an elastic member 14 using a compression coil spring is arranged between the pair of seats.

[0003] In this patent document 1, a window (12W) is formed in the driving side member (disc plate 12), notches (11W) are formed in the driven side member (flanged hub 11), and a seat (12) is arranged between the inner end surface of the window (12W) in the circumferential direction and the pair of notches (11W).

[0004] The damper device of Patent Document 1 has two convex surfaces (21a1 and 21a2 in the document) formed on both circumferential ends of a seat 21 that protrude in the disk circumferential direction. Also, a concave surface (12a in the document) is formed in a portion of a window 12W of a drive-side member (disc plate 12) that faces one of the convex surfaces of the seat 21, and a concave surface 11a is formed in a portion of a cutout 11W that faces the other convex surface of the seat 21.

[0005] In this damper device, when centrifugal force due to rotation is applied, the convex surface 21a1 of the seat 12 is fitted into and held in the concave surface 12a of the window 12W. In contrast, when there is no twist between the driving side member (disc plate) and the driven side member (flanged hub), the outer diameter side portion of the convex surface (21a2 in the literature) of the seat 21 comes into contact with the concave surface 11a of the flange 11F.

[0006] In this configuration, when twisting occurs between the driving-side member (disc plate 12) and the driven-side member (flanged hub), the outer diameter side portion of the convex surface (21a2 in the literature) of the seat (21) comes into contact with the concave surface (11a) of the flange (11F), forming a gap (31) between them. This prevents repeated contact and sliding between the convex surface (21a2 in the literature) and the concave surface (11a).

[0007] Furthermore, Patent Document 2 discloses a damper device of a similar configuration, which has a driving side member (disc plate 100 in the document) and a driven side member (clutch hub 200 in the document), with a pair of seats (400) supported between the driving side member (disc plate 100) and the driven side member (clutch hub 200), and a coil spring (500) disposed between the pair of seats (400).

[0008] In Patent Document 2, an engaging portion (208a1) having a convex portion is formed on the driving side member (disc plate 100), and an engaging portion (208a2) having a convex portion is formed on the driven side member (clutch hub 200).

[0009] In the damper of Patent Document 2, the convex portion of one engagement portion (208a1) engages with the corresponding concave portion of the seat (400), and the convex portion of the other engagement portion (208a2) engages with the corresponding concave portion of the seat (400). With this engagement structure, when centrifugal force acts when the damper device rotates and a rotational moment acts on the seat (400), the convex portion of the engagement portion comes into contact with the inner surface of the concave portion, thereby restricting the rotation of the seat (400).

[0010] JP 2017-172692 A JP 2019-157964 A

[0011] As described in Patent Documents 1 and 2, etc., a damper device is known that has a configuration in which a pair of seats are fitted into windows formed in a drive-side member, a spring is placed between these seats, and the driven-side member (such as a clutch hub) is displaced relative to the drive-side member (displacement that causes a twisted state) as the load torque varies, thereby operating the seats to reduce the gap between the pair of seats.

[0012] In such damper devices, as the rotation speed increases, centrifugal force can cause the seat to come into strong contact with the edge of the window opening. In such a situation of strong contact, frictional resistance (frictional force) increases when the seat moves, making it difficult for the seat to operate smoothly even when the load torque fluctuates, and it may not be possible to operate quickly in response to torque fluctuations.

[0013] If the seat cannot operate quickly in this way, the damper device will begin buffering at a torque value that far exceeds the load torque value assumed when the damper device was designed, which could lead to the inconvenience of applying a torque that exceeds the expected value to the drive system.

[0014] In particular, in those equipped with a compression coil spring between a pair of seats, the centrifugal force acting on the spring acts in a direction that lifts the end of the pair of seats that contacts the coil spring (away from the rotation axis), changing the posture of the seats when viewed in the direction along the rotation axis and further increasing the frictional resistance (frictional force) when the seats move.

[0015] Therefore, as described in Patent Documents 1 and 2, it is conceivable to form a convex or other guide portion on the driving member or the driven member, and form a concave or other guided portion on the sheet that is guided by this guide portion.

[0016] However, the configurations that have a structure for guiding a seat as described in Patent Documents 1 and 2 are a structure that guides the vicinity of one end of the seat, and therefore cannot control the posture of the seat as it moves.

[0017] For these reasons, there is a demand for a damper device that allows the seat to operate smoothly and provides appropriate cushioning when the load torque fluctuates.

[0018] A characteristic configuration of the damper device according to the present disclosure includes a drive-side member that rotates about a rotation axis by the rotational driving force of an internal combustion engine, a driven-side member that rotates about the rotation axis by the rotational driving force transmitted from the drive-side member and transmits the rotational driving force to a travel transmission device, and a damper section in which the drive-side member and the driven-side member are relatively displaced about the rotation axis as the load torque increases, and a plurality of buffer units are arranged along the same circumferential area centered on the rotation axis, and the buffer units are coupled to the drive-side engagement of the drive-side member. a pair of seats that engage with the driven-side engaging portion of the driving-side member and the driven-side engaging portion of the driven-side member, and a spring that applies a biasing force in a direction that moves the pair of seats apart, and a guide extension portion is formed on the outer periphery of the seat that extends in the opposite direction to the abutment portion with the driven-side engaging portion that the seat abuts, and when the seat moves in conjunction with the relative displacement between the driving-side member and the driven-side member, the guide member comes into contact with the guide extension portion, thereby enabling the seat to operate along a circumferential guide area centered on the rotation axis.

[0019] According to this configuration, even when the load torque acting between the drive-side member and the driven-side member fluctuates, causing the pair of seats sandwiched between the drive-side engagement portion and the driven-side engagement portion to move relative to each other so that the distance between them decreases, and a rotational moment acts on the seats due to the action of centrifugal force, the guide member contacts the guide extension portion. As a result, the seats can move along a circumferential guide area centered on the rotation axis while suppressing changes in the seat position due to the rotational moment. Furthermore, because the guide member can be made of a string-like material, suppressing the seat position from becoming too large can avoid the need for increased size. Thus, a damper device has been configured that allows the seats to move smoothly and provide appropriate cushioning when the load torque fluctuates.

[0020] 1 is a longitudinal sectional side view of a damper device; 2 is an enlarged cross-sectional view of the outer periphery of the damper device; 3 is a front view with a portion of the damper device cut away; 4 is a front view of the damper device showing an enlarged view of the damper section; 5 is a front view showing the positional relationship of a pair of seats with respect to a damper opening; 6 is a front view showing the positional relationship of a pair of seats with respect to a flange body; 7 is a longitudinal sectional side view of the seats; 8 is a front view of the damper device showing the buffer unit; 9 is a graph showing the relationship between torsion angle and torque; 10 is a longitudinal sectional side view of a seat of another embodiment (a); 11 is a longitudinal sectional side view of a seat of another embodiment (b); 12 is a longitudinal sectional side view of a seat of another embodiment (c); 13 is a longitudinal sectional front view showing the shape of a guide member of another embodiment (d); 14 is a longitudinal sectional front view showing the shape of a guide member of another embodiment (e); 15 is a longitudinal sectional side view of a seat and a pair of guide members of another embodiment (f). 1 is a longitudinal sectional front view of a first guide member of another embodiment (f). FIG. 2 is a longitudinal sectional front view of a second guide member of another embodiment (f). FIG. 3 is a longitudinal sectional front view showing the relationship with the first guide member when one sheet is displaced in another embodiment (f). FIG. 4 is a longitudinal sectional front view showing the relationship with the second guide member when one sheet is displaced in another embodiment (f). FIG. 5 is a longitudinal sectional front view showing the relationship with the first guide member when the other sheet is displaced in another embodiment (f). FIG. 6 is a longitudinal sectional front view showing the relationship with the first guide member when the other sheet is displaced in another embodiment (f).

[0021] An embodiment of a damper device A according to the present disclosure will be described below with reference to the drawings. In this embodiment, as an example of a damper device A, a configuration in which a limiter section T and a damper section D are arranged as shown in FIG. 1 is described. However, the configuration and positional relationship thereof are not limited to the following embodiment, and various modifications are possible within the scope of the gist thereof.

[0022] 1 to 3, the damper device A is disposed in a transmission path that transmits the driving force of a flywheel 1 that rotates integrally with the crankshaft of a vehicle engine E (internal combustion engine) to an input shaft 2 of a drive transmission device TM such as a transmission for the vehicle. This damper device A is not limited to being configured to transmit driving force from the flywheel 1, but may also be configured to transmit driving force from a fly mass. The engine may be one that uses gasoline, hydrogen gas, or the like as fuel.

[0023] The damper device A functions to protect the driving transmission device TM by limiting the transmission of load torque when a high load torque acts on the driving transmission device TM from the engine E, such as immediately after starting the engine E. The damper device A also functions to protect the driving transmission device TM by limiting the transmission of load torque when a high load torque acts on the driving transmission device TM from the wheels, such as when the vehicle is traveling on a rough road.

[0024] The damper device A can be installed not only in hybrid vehicles (HVs) that transmit the driving force of the engine and the driving force of the traction motor to the driving transmission device TM, but also in non-hybrid vehicles that do not use a traction motor.

[0025] The specific configuration of the damper device A is as described below. When describing the directions and positional relationships of the various parts of this damper device A, the direction extending radially from the rotation axis X as a reference will be referred to as the radial direction, the direction along the circumference centered on the rotation axis X will be referred to as the circumferential direction, and the direction along the rotation axis X will be referred to as the axial direction.

[0026] The damper device A functions to suppress the effects of load torque acting in a positive direction (e.g., the same direction as the rotation of the flywheel 1) and load torque acting in a negative direction (e.g., the opposite direction to the rotation of the flywheel 1), but in the following explanation, positive load torque and negative load torque will simply be referred to as load torque.

[0027] 1 to 3, the damper device A has a hub 3 into which the input shaft 2 of the travel transmission device TM is fitted (spline-coupled). The damper device A has side plates P (an example of a drive-side member) consisting of a first side plate 11 and a second side plate 12 that are arranged separately in a direction along a rotation axis X (which coincides with the axis of the input shaft 2) that serves as the rotation center of the hub 3.

[0028] The side plate P (drive-side member) rotates around the rotation axis X by the driving force of the engine E. The damper device A is provided with a hub 3 having a hole formed around the rotation axis X. Of the pair of side plates P, the one positioned closest to the flywheel 1 in the axial direction is referred to as a first side plate 11, and the one positioned closest to the travel transmission device TM is referred to as a second side plate 12.

[0029] The damper device A has a limiter portion T arranged on the outer periphery of the side plate P, a damper portion D arranged at a position closer to the rotation axis X than the limiter portion T, and a hysteresis portion H arranged on the outer periphery of the hub 3, on the inner periphery side of the damper portion D.

[0030] The damper section D has a plurality of (four in this embodiment) buffer units Da arranged in the same circumferential region centered on the rotation axis X. The details of the buffer units Da will be described later.

[0031] Furthermore, the damper device A has contact portions C formed at multiple locations (four locations in this embodiment) that bring the first side plate 11 and the second side plate 12 into contact with each other in the radial direction between the limiter portion T and the damper portion D.

[0032] The first side plate 11 is formed with a first bulging wall 11c that bulges toward the second side plate 12. Similarly, the second side plate 12 is formed with a second bulging wall 12c that bulges toward the first side plate 11 (see FIG. 2).

[0033] Rivets 6 are inserted through a plurality of through holes 13 formed in each of the first bulging wall 11 c and the second bulging wall 12 c, and the pair of side plates P are connected together with the first bulging wall 11 c and the second bulging wall 12 c in contact at a plurality of locations by the rivets 6. The first bulging wall 11 c and the second bulging wall 12 c connected in this manner form contact portions C.

[0034] The hub 3 has a flange body 4 (an example of a driven member) that rotates integrally with the hub 3. As shown in Fig. 4, the contact portion C (the first bulging wall 11c and the second bulging wall 12c) is disposed at a position where it can come into contact with a restricting protrusion 4a formed on the flange body 4 (the driven member).

[0035] As a result, when an increase in load torque causes the flange body 4 (driven-side member) and the side plate P (driving-side member) to reach a load acting posture in which they are displaced about the rotation axis X, the restricting protrusion 4a comes into contact with the contact portion C (see FIG. 4). In this way, the contact portion C functions as a stopper that determines the limit of relative displacement (displacement that results in a twisted state) between the flange body 4 and the side plate P.

[0036] [Limiter Section] As shown in Figures 1 and 2, the limiter section T is accommodated in an outer peripheral space S1 formed between the first side plate 11 and the second side plate 12, on the outer peripheral side of the first side plate 11 and the second side plate 12.

[0037] The limiter section T includes a lining plate 14 made of an annular plate material fixed to the flywheel 1, a first friction material 15 arranged at positions sandwiching the lining plate 14, and a second friction material 19. A pressure plate 17 engages with the first friction material 15, and contact pressure is applied to the pressure plate 17 from a disc spring 18, and a first side plate 11 is arranged outside the disc spring 18 (on the opposite side of the lining plate 14).

[0038] The second friction material 19 is supported in an engaged state by the second side plate 12. The lining plate 14 is connected and fixed to the flywheel 1 by connecting bolts 16 with a contact surface 14S of a plate-shaped connecting portion 14P integrally formed on the outer periphery of the lining plate 14 in contact with the flywheel 1.

[0039] The disc spring 18 is formed of an annular spring plate material centered on the rotation axis X, and the entire outer circumference or a partial circumferential area thereof abuts against the inner surface of the first side plate 11, and the entire inner circumference or a partial circumferential area thereof abuts against the pressure plate 17.

[0040] As shown in FIG. 1, a portion of the pressure plate 17 engages with the second side plate 12, and the engaging protrusion 17a engages with a hole in the second side plate 12, thereby preventing the first friction material 15 from rotating and positioning it radially.

[0041] 2, the first friction material 15 is prevented from rotating and positioned in the radial direction by a protrusion 17T formed on the pressure plate 17 engaging with a hole in the first friction material 15. Furthermore, the second friction material 19 is prevented from rotating and positioned in the radial direction by a protrusion 12T formed on the second side plate 12 engaging with a hole in the second friction material 19.

[0042] When the load torque is less than a threshold value, the limiter portion T maintains the first friction material 15 and the lining plate 14 in a pressed state, and also maintains the second friction material 19 and the lining plate 14 in a pressed state, thereby enabling the flywheel 1 and the pair of side plates P to rotate together.

[0043] In response to this, the limiter section T generates slippage between the first friction material 15 and the lining plate 14 when the load torque exceeds a threshold value, and also generates slippage between the second friction material 19 and the lining plate 14, thereby limiting the increase in the load torque and eliminating the inconvenience of excessive load torque acting between the flywheel 1 and the travel transmission device TM.

[0044] 1 and 2, the hysteresis portion H applies an appropriate frictional force between the pair of side plates P and the flange body 4 when the pair of side plates P and the flange body 4 are displaced relative to each other about the rotation axis X as the load torque increases. The hysteresis portion H also functions to apply an appropriate frictional force between the pair of side plates P and the flange body 4 when the load torque decreases and the pair of side plates P and the flange body 4 return to the neutral position shown in FIG. 3 due to the biasing force of the damper springs 21 (an example of a spring) of the damper portion D.

[0045] 1 to 3, the flange body 4 is fitted into a gear-shaped fitting portion on the outer periphery of the hub 3 and rotates integrally with the hub 3. The hysteresis portion H includes a first cylindrical portion 25, a first friction ring 26, a second cylindrical portion 27, a second friction ring 28, and an annular spring 29.

[0046] The first cylindrical portion 25 is rotatably fitted onto the outer periphery of the hub 3 on the side where the first side plate 11 is arranged, and the inner periphery of the first side plate 11 comes into contact with this outer periphery.

[0047] The first friction ring 26 is disposed between the flange body 4 and the first side plate 11. The first friction ring 26 has a plurality of first engagement protrusions 26a on its outer surface that engage with engagement portions of the first side plate 11, and the friction surface of the first friction ring 26 contacts the flange body 4.

[0048] The second cylindrical portion 27 is rotatably fitted onto the outer periphery of the hub 3 on the side where the second side plate 12 is arranged, and the inner periphery of the second side plate 12 comes into contact with this outer periphery.

[0049] The second friction ring 28 is disposed between the flange body 4 and the second side plate 12. The second friction ring 28 has a plurality of second engagement protrusions 28a on its outer surface that engage with engagement portions of the second side plate 12, and the friction surface of the second friction ring 28 contacts the flange body 4.

[0050] The annular spring 29 is configured as an annular disc spring centered on the rotation axis X, and is disposed at a position sandwiched between the second side plate 12 and the second friction ring 28 .

[0051] As a result, when the damper section D allows relative displacement in the rotational direction (displacement that results in a twisted state) between the pair of side plates P and the flange body 4 as the load torque increases, the hysteresis section H applies a frictional force from the first friction ring 26 and the second friction ring 28 to the flange body 4.

[0052] Thereafter, when the load torque decreases, the frictional force is maintained, and the biasing force of the damper spring 21 of the damper portion D allows relative rotation to return the relative position between the pair of side plates P and the flange body 4 to the neutral position shown in Figure 3.

[0053] 1 to 5, the damper section D includes a plurality of (four in this embodiment) buffer units Da arranged in the same circumferential region centered on the rotation axis X. As shown in FIGS. 5 and 6, each of the plurality of buffer units Da includes a pair of seats 22 arranged opposite each other and functioning as spring seats, a damper spring 21 (spring) sandwiched between the seats 22, and a cushion material 23.

[0054] The multiple buffer units Da and the multiple contact portions C are arranged at a position where they overlap with an imaginary line (not shown) extending radially so as to divide the rotation axis X into multiple parts circumferentially around the rotation axis X, with the buffer units Da positioned closer to the rotation axis X than the contact portions C.

[0055] Each of the first side plate 11 and the second side plate 12 has a plurality of (four in this embodiment) damper openings PW (an example of a drive-side engaging portion) formed therein.

[0056] 3 and 4, the flange body 4 has a driven-side engaging portion 4W formed by cutting out a portion of the outer periphery thereof. The restricting protrusion 4a is disposed at a position protruding radially outward from the driven-side engaging portion 4W.

[0057] As shown in FIGS. 4 and 5, the buffer unit Da has a pair of seats 22 fitted into the damper openings PW of the first side plate 11 and the second side plate 12 and into the driven side engaging portion 4W of the flange body 4.

[0058] The buffer unit Da sandwiches a damper spring 21 (spring) between a pair of seats 22 in a state where the damper spring 21 is engaged with a spring holding portion 22 d, and inserts a cushion material 23 into the internal space of the damper spring 21 .

[0059] 4 to 6, the seat 22 is integrally formed of a resin material and includes a seat body 22a, an engaging protrusion 22b formed on the outer surface of the seat body 22a, an extending portion 22c, a spring holding portion 22d, and an engaging recess 22e. The extending portion 22c is disposed on the outer periphery of the side plate P of the seat 22 and has a shape that extends toward the opposing seat 22.

[0060] Furthermore, a pair of guide extensions 22G are formed in a groove shape on the outer peripheral surface of the extension 22c, which is on the outside in the radial direction, as shown in Figures 6 and 7. As shown in Figures 5 to 7, the guide extensions 22G are formed in a region of the damper opening PW where the seat 22 abuts, and in a region of the driven-side engagement portion 4W that extends in the opposite direction from the region where the seat 22 abuts.

[0061] 5, the damper opening PW has engagement recesses PWa at both ends in the circumferential direction (left and right direction in FIG. 5) so as to engage with the engagement protrusions 22b of the seat 22. The damper opening PW forms contact surfaces PWd that come into close contact with the seat 22 near both ends in the circumferential direction, and forms a curved separation surface PWe at the circumferential center that bulges outward in the radial direction toward the outer periphery on the opposite side from the rotation axis X.

[0062] The flange body 4 forms an engagement protrusion 4Wt by protruding a portion of the driven side engagement portion 4W toward the seat 22, and when the load torque is small, the engagement protrusion 4Wt engages with the engagement recess portion 22e of the seat 22, stabilizing the posture of the seat 22.

[0063] When the damper device A rotates, the extension portion 22c is pressed against the inner surface of the outer periphery of the damper opening PW (the inner surface opposite to the rotation axis X) due to the rotation moment caused by the centrifugal force acting on the seat 22.

[0064] Furthermore, when the damper device A rotates, the centrifugal force acting on the damper spring 21 acts in a direction that lifts the end side of the pair of sheets 22 that contacts the damper spring 21 (in a direction away from the rotation axis), which similarly lifts the extension portion 22c and promotes a change in the posture of the sheet 22.

[0065] 5 has a shape in which the right end of the extension 22c protrudes toward the center of the damper opening PW. Therefore, for example, if the damper opening PW does not form the separation surface PWe, when the damper device A rotates, the position of the seat 22 changes due to the action of rotational moment caused by centrifugal force, and the protruding end of the extension 22c comes into strong contact with the inner surface on the outer periphery of the damper opening PW, increasing frictional resistance acting on the seat 22 and potentially impairing smooth operation of the damper section D.

[0066] To eliminate such inconveniences, the damper section D forms a separation surface PWe at the damper opening PW, and as described above, forms a pair of guide extension sections 22G on the outer peripheral surface of the sheet 22, and is provided with a pair of annular string-like guide members 32 that individually fit into each of the pair of guide extension sections 22G.

[0067] As shown in Fig. 8, the guide member 32 is configured as an annular body made of a flexibly deformable material such as a resin material or a metal wire, with the ends connected together. The guide member 32 that engages with the guide extension 22G is sized to slacken slightly so as to form an initial gap G (an example of a gap) between the guide extension 22G and the sheet 22 in a zero-torque state where no load torque is applied, as shown in Fig. 6. Furthermore, the resin material that forms the sheet 22 and the guide member 32 have high slidability (a small coefficient of friction).

[0068] With this configuration, as the load torque fluctuates, the side plate P (driving member) and the flange body 4 (driven member) undergo relative displacement (displacement resulting in a twisted state) about the rotation axis X, and when the loaded position is reached, the four seats 22, on which a pressing force acts due to the abutment of the flange body 4, move circumferentially as shown in Figure 4, and even in a situation where a rotational moment acts, the guide member 32 contacts these four seats 22 to suppress the change in position. Note that when the guide member 32 suppresses the change in position of the four seats 22 in this way, a gap is maintained between the guide member 32 and the four seats 22 on which the pressing force of the flange body 4 does not act (on which the flange body 4 does not abut).

[0069] As described above, the circumferential length of the guide member 32 is set so that, in a zero-torque state where no load torque is applied, the guide member 32 is slightly loosened to form an initial gap G (gap) in the radial direction between the guide member 32 and the guide extension 22G as shown in Figure 6. In order to suppress changes in the posture of the sheet 22, it is ideal for the guide member 32 to be in a state where tension is applied. To explain this, Figure 8 schematically shows a state where the load torque increases and the posture of one of the sheets 22 changes.

[0070] In other words, when the load torque increases and one of the sheets 22 begins to move circumferentially, the guide member 32 is loose at the beginning of this movement, and the engaging protrusion 22b of the sheet 22 engages with the engaging recess PWa of the damper opening PW, so the sheet 22 hardly changes its posture and begins to move quickly.

[0071] After this, the sheets 22 start to move, and after the engaging protrusion 22b moves away from the engaging recess PWa, the posture of the four sheets 22 changes slightly due to the action of the rotational moment, and the tension acting on the guide member 32 increases as a result of this posture change.

[0072] In particular, since the postures of the four sheets 22 change simultaneously, the shape of the guide member 32 changes to a substantially diamond shape when viewed in the direction along the rotation axis X, as shown in Figure 8. In this figure, the difference in posture among the four sheets 22 is slight.

[0073] Figures 9a and 9b show graphs showing the change in torque between a damper device A that uses a guide member 32 to regulate the position of the seat 22 and a damper device A that does not use a guide member 32, with the torsion angle on the horizontal axis and the torque acting on the transmission system that transmits the driving force on the vertical axis.

[0074] These graphs show the relationship between the torsion angle and torque, that is, the relationship with the reference torque Tm, when the damper device A rotates at a set rotation speed (number of rotations per unit time). When frictional resistance or the like acts on the movement of the seat 22, the relationship between the torsion angle and torque as shown in these graphs results in the actual positive torque value Ta when the torque increases and the actual negative torque value Tb when the torque decreases being significantly different from the reference torque Tm, as in the conventional example shown in Figure 9b.

[0075] In contrast, in the case of the device equipped with the guide extension portion 22G and the guide member 32, the seat 22 moves smoothly, and as shown in Figure 9a, the actual torque value Ta in the positive direction when the torque increases and the actual torque value Tb in the negative direction when the torque decreases do not differ significantly from the reference torque Tm, thereby realizing a rapid response.

[0076] 5, the damper device A forms a curved separation surface PWe that bulges outward in the radial direction at the damper opening PW, so that even when the position of the seat 22 changes due to a rotational moment, a center gap Ge (an example of a gap) is formed between the seat 22 and the extension portion 22c as shown by the two-dot chain line in the figure. This prevents the end of the seat 22 from coming into strong contact with the inner surface of the damper opening PW, significantly reduces the frictional resistance (frictional force) acting on the seat 22, and allows the seat to operate smoothly when the load torque fluctuates, enabling appropriate cushioning.

[0077] As a result, a damper device is configured that allows the seat 22 to move smoothly and provide appropriate cushioning when the load torque fluctuates, without increasing the size.

[0078] When the load torque acting between the pair of side plates P and the hub 3 is low, the damper portion D transmits the rotational driving force while maintaining the relative rotational phase between the pair of side plates P and the flange body 4 in the neutral phase shown in Figure 3 due to the biasing force of the damper spring 21.

[0079] In contrast, when the load torque exceeds a preset value or falls below a preset negative value, the damper section D compresses the damper spring 21, causing the flange body 4 and the pair of side plates P to displace relatively around the rotation axis X, thereby absorbing the fluctuations in the load torque, eliminating the inconvenience of excessive load torque acting between the pair of side plates and the hub 3, and protecting the travel transmission device TM.

[0080] [Effects of the embodiment] The damper device A is configured such that a limiter portion T is arranged on the outer periphery of a pair of side plates P (first side plate 11, second side plate 12), and a damper portion D is arranged closer to the center of the side plates P than this limiter portion T.

[0081] The damper section D is equipped with a plurality of buffer units Da, and when a rotational moment is applied to the seats 22 of the buffer units Da due to centrifugal force in association with fluctuations in load torque while the damper device A is rotating at high speed, the guide member 32 comes into contact with the four guide extensions 22G on which a pressing force acts due to the abutment of the flange body 4, thereby suppressing changes in the posture of these four seats 22. Note that a gap is maintained between the guide member 32 and the four seats 22 on which the pressing force of the flange body 4 does not act (the flange body 4 does not abut).

[0082] By suppressing the change in the position of the seat 22 in this way, the damper device A eliminates the inconvenience of a portion of the seat 22 being pressed against the inner surface of the outer periphery of the damper opening PW (the inner surface opposite the rotation axis X), which increases the frictional resistance when the seat 22 moves. Furthermore, the damper device A responsively operates the seat 22 when the load torque fluctuates, reliably reducing the effect of the load torque and reliably protecting the travel transmission device TM.

[0083] This damper device A is configured such that the guide member 32 is a ring-shaped body that can flexibly deform, and this guide member 32 comes into contact with the guide extension portion 22G on the radial outer surface of the sheet 22 centered on the rotation axis X, thereby applying tension to the guide member 32 and suppressing the effect of the rotational moment acting on the sheet 22.

[0084] Furthermore, since the guide member 32 contacts each of the four sheets 22 of the buffer unit Da, even though it has a simple configuration, when the load torque increases, the tension acting on the guide member 32 increases, thereby simultaneously suppressing the inconvenience of the four sheets 22 changing significantly.

[0085] Other Embodiments The present disclosure may be configured as follows in addition to the above-described embodiments (common numbers and symbols are used to denote components having the same functions as those in the embodiments).

[0086] (a) As shown in Figure 10a, a wide guide extension portion 22G is formed in the axial direction on the outer surface of the extension portion 22c of the sheet 22, and a belt-shaped guide member 32 is used so that it can be guided by fitting into the guide extension portion 22G.

[0087] (b) As shown in Figure 10b, groove-shaped guide extensions 22G are formed on both axial side surfaces of the sheet 22, and a pair of string-like guide members 32 are used that can be guided by fitting into the pair of guide extensions 22G.

[0088] (c) As shown in Figure 10c, a pair of guide extension portions 22G arranged parallel to the axial direction are formed on the outer surface of the extension portion 22c of the sheet 22, and a radially wide plate-shaped guide member 32 is used that can be guided by fitting into these guide extension portions 22G.

[0089] The guide member 32 shown in these alternative embodiments (a), (b), and (c) is configured as a ring-shaped body made by connecting materials such as resin material or metal wire in a circular ring shape, as in the above-mentioned embodiment, but for example, the guide member 32 may be divided into two parts in the circumferential direction (in the length direction).

[0090] (d) As in the alternative embodiment (a) described above, for example, as shown in Figure 10a, a guide extension portion 22G that is wide in the axial direction and has a groove-like shape is formed on the outer surface of the extension portion 22c of the sheet 22, and a belt-shaped guide member 32 is used so that it can be guided by fitting into the guide extension portion 22G.In this embodiment, as shown in Figure 10d, a shape-retaining annular body is used as the guide member 32, and a bulge portion 32Q that bulges outward the most radially is formed in the central portion that is midway in the circumferential direction of the pair of sheets 22 that make up the buffer unit Da.

[0091] In this alternative embodiment (d), restricting protrusions 32X are formed on the inner periphery of the guide member 32 at positions that sandwich each of the pair of sheets 22, thereby restricting the movement of the guide member 32 in the circumferential direction.

[0092] (e) This has a configuration that is basically the same as that of the alternative embodiment (d), but as shown in Figure 10e, the central portion of the bulging portion 32Q in the circumferential direction is formed in an arc shape that bulges outward in the radial direction around the rotation axis X. In this alternative embodiment (e), too, restricting protrusions 32X are formed on the inner periphery of the guide member 32 at positions that sandwich each of the pair of sheets 22, thereby restricting the movement of the guide member 32 in the circumferential direction.

[0093] In these alternative embodiments (d) and (e), even if the position of the seat 22 changes due to the action of a rotational moment caused by centrifugal force, causing the protruding end of the extension portion 22c to protrude radially outward, the protruding end makes strong contact with the guide member 32, suppressing the inconvenience of causing frictional resistance. In the configurations of these alternative embodiments (d) and (e), the guide member 32 may be configured to be held by the side plate P so as not to move relative to the side plate P. Also, in alternative embodiments (d) and (e), the guide member 32 is formed in an annular shape.

[0094] 11a, 11b, and 11c, a first guide member 32a is held by a first engagement portion 32at to one of a pair of opposing sheets 22 (the one on the left in FIG. 11b). Similarly, a second guide member 32b is held by a second engagement portion 32bt to the other of the pair of sheets 22 (the one on the right in FIG. 11c).

[0095] In this alternative embodiment (f), the first guide member 32 a and the second guide member 32 b are configured as annular bodies made of a material that is relatively rigid but allows some elastic deformation, such as resin or metal. As shown in Fig. 11 a, the first guide member 32 a and the second guide member 32 b are arranged at a predetermined distance in the axial direction.

[0096] In this alternative embodiment (f), as shown in Figures 11a, 11b, and 11c, a groove-shaped first guide extension portion 22Ga into which the first guide member 32a fits, and a groove-shaped second guide extension portion 22Gb into which the second guide member 32b fits, are formed in parallel on the radial outer surfaces of a pair of oppositely arranged sheets 22.

[0097] The first engaging portion 32at protrudes toward the inner periphery of the first guide member 32a and engages with a recess formed in the first guide extension portion 22Ga, thereby fixing the first guide member 32a fitted into the first guide extension portion 22Ga to the seat 22. Similarly, the second engaging portion 32bt protrudes toward the inner periphery of the second guide member 32b and engages with a recess formed in the second guide extension portion 22Gb, thereby fixing the second guide member 32b fitted into the second guide extension portion 22Gb to the seat 22.

[0098] In this alternative embodiment (f), the first guide extension 22Ga to which the first guide member 32a is fixed by the first engagement portion 32at is referred to as the fixed-side first guide extension 22Gat, and the second guide extension 22Gb to which the second guide member 32b is fixed by the second engagement portion 32bt is referred to as the fixed-side second guide extension 22Gbt.

[0099] The first guide member 32a has a fixed-side region S with a predetermined inner diameter and a guide-side region R with a larger inner diameter, with a first intermediate position Na being the boundary between the pair of circumferentially opposed sheets 22. Similarly, the second guide member 32b has a fixed-side region S with a predetermined inner diameter and a guide-side region R with a larger inner diameter, with a second intermediate position Nb being the boundary between the pair of circumferentially opposed sheets 22.

[0100] The first guide member 32a and the second guide member 32b have their fixed-side regions S fixed to the corresponding sheet 22. The first guide member 32a and the second guide member 32b are configured as annular bodies, so that four fixed-side regions S and four guide-side regions R are formed in the circumferential direction.

[0101] The inner diameter of the guide side region R of the first guide member 32a is a first expanded diameter portion 32ar whose radius is larger than the radius of the second guide extension portion 22Gb about the rotation axis X, thereby forming a radial gap GD in the radial direction between the first guide member 32a and the second guide extension portion 22Gb. Similarly, the inner diameter of the guide side region R of the second guide member 32b is a second expanded diameter portion 32br whose radius is larger than the radius of the first guide extension portion 22Ga about the rotation axis X, thereby forming a radial gap GD in the radial direction between the first guide extension portion 22Ga.

[0102] Figures 11b and 11c show only a pair of sheets 22 arranged opposite each other, but in this damper device A of another embodiment (f), for example, as shown in Figure 8, each sheet 22 of a plurality of buffer units Da is provided with a first guide member 32a and a second guide member 32b in a holding state.

[0103] In the damper device A of this alternative embodiment (f), when the load torque increases, one of a pair of opposing seats 22 moves toward the center, and as a result of this movement, a rotational moment that changes the posture of the seat 22 is applied due to the action of centrifugal force. Note that in the multiple buffer units Da that make up the damper section D, the seats 22 that are in similar positions also move toward the center, and a rotational moment is applied due to the action of centrifugal force.

[0104] For example, as shown in Figures 11d and 11e, when the side plate P is displaced counterclockwise relative to the flange body 4 (displacement resulting in a twisted state), the sheet 22 on the right side in these figures moves in a direction approaching the sheet 22 on the left side, and as a result of this movement, the sheet 22 on the right side separates from the engaging recess PWa (see Figure 5) of the damper opening PW, and a force that changes its posture is applied from the rotational moment acting on the sheet 22 on the right side due to the action of centrifugal force.

[0105] Even when the sheet 22 moves in this manner, the first guide member 32a is fixed at the fixed-side first guide extension portion 22Gat, and the fixed-side region S is in contact with the left-side sheet 22. In contrast, the guide-side region R of the first guide member 32a is positioned so as to be separated radially by a radial gap GD from the first guide extension portion 22Ga of the right-side sheet 22. Therefore, when one of the right-side sheets 22 moves toward the center, the first guide member 32a does not impart frictional resistance to the movement of the sheet 22.

[0106] 11e, the second guide member 32b is fixed to the fixed-side second guide extension 22Gbt of the right-side sheet 22, and the fixed-side region S is in contact with the right-side sheet 22. In contrast, the guide-side region R of the second guide member 32b is positioned so as to be separated radially by a radial gap GD from the second guide extension 22Gb of the left-side sheet 22. Therefore, when one of the right-side sheets 22 moves toward the center, the second guide member 32b does not change the position of the right-side sheet 22.

[0107] 11f and 11g, when the side plate P is displaced clockwise relative to the flange body 4 (displacement resulting in a twisted state), the left-side seat 22 moves toward the right-side seat 22. Even in such a movement, for the same reasons as those explained with reference to Figures 11d and 11e, the first guide member 32a and the second guide member 32b allow the seat 22 to move smoothly, and the position of the seat 22 is not changed.

[0108] In this way, when one seat 22 moves, tension acts on the first guide member 32a and the second guide member 32b, and these tensions are canceled out, so that the center of the annular shape of the first guide member 32a and the center of the annular shape of the second guide member 32b are maintained at positions that substantially coincide with the rotation axis X. As a result, the problem of the extension portion 22c of the seat 22 coming into contact with the opening edge of the damper opening PW is eliminated, allowing for smooth operation of the right seat 22, suppressing changes in the position of the seat 22, and enabling appropriate cushioning by the damper portion D.

[0109] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present disclosure are not limited to these, and can be modified as appropriate within the scope of not departing from the purpose of the present disclosure.

[0110] The above-described embodiment may be embodied as follows: (1) A drive-side member (side plate P) that rotates about the rotation axis X by the rotational driving force of an internal combustion engine (engine E), a driven-side member (flange body 4) that rotates about the rotation axis X by the rotational driving force transmitted from the drive-side member (side plate P) and transmits the rotational driving force to the travel transmission device TM, and a damper section D in which a plurality of buffer units Da are arranged along the same circumferential area centered on the rotation axis X so as to allow displacement to a load acting posture in which the drive-side member (side plate P) and the driven-side member (flange body 4) are relatively displaced about the rotation axis X as the load torque increases. a pair of seats 22 that engage with a drive-side engagement portion (damper opening PW) of the drive-side member (side plate P) and a driven-side engagement portion 4W of the driven-side member (flange body 4), and a spring (damper spring 21) that applies a biasing force in a direction that moves the pair of seats 22 apart, and a guide extension portion 22G that extends in the opposite direction to the driven-side engagement portion 4W is formed on the outer periphery of the seats 22, and a guide member 32 that comes into contact with the guide extension portion 22G when the seats 22 move in conjunction with relative displacement between the drive-side member (side plate P) and the driven-side member (flange body 4) thereby enabling operation along a circumferential guide area centered on the rotation axis X.

[0111] According to this, when the load torque acting between the driving-side member (side plate P) and the driven-side member (flange body 4) fluctuates and the pair of seats 22 sandwiched between the driving-side engagement portion (damper opening PW) and the driven-side engagement portion 4W move relatively so that the distance between them shortens, the guide member 32 contacts and guides the guide extension portion 22G. As a result, the seat 22 operates along a circumferential guide area centered on the rotation axis X, and even when a force is applied due to the action of centrifugal force that displaces the extension portion 22c outward, the guide member 32 suppresses changes in the position of the seat 22 and suppresses an increase in frictional resistance caused by a portion of the seat 22 contacting the inner surface of the damper opening PW, enabling appropriate cushioning.

[0112] (2) In the damper device A of (1), the guide member 32 is preferably configured as an annular body arranged on the outer periphery of the plurality of sheets 22, opposite the rotation axis X, and a gap is preferably formed between this annular body and the guide surface 31 of the sheet 22 when no load torque is acting.

[0113] According to this, when the sheets 22 start to move as the load torque increases, a gap exists between the guide member 32 and the guide surface 31, so the frictional resistance acting between the guide member 32 and the guide surface 31 is extremely small, enabling rapid operation of the sheets 22. Furthermore, because the guide member 32 is configured as an annular body that is arranged on the outer periphery of the sheets 22, opposite the rotation axis X, when the posture of the multiple sheets 22 changes as the load torque increases, the guide member 32 comes into contact with the guide surface 31 of each sheet 22, thereby suppressing the posture change of the sheets 22.

[0114] (3) In the damper device A of (1), it is preferable that the drive side engagement portion (damper opening PW) includes a contact surface PWd with which the outer peripheral surface of the sheet 22 opposite the rotation axis X is in close contact at zero torque when no load torque is acting, and a separation surface PWe that forms a gap with the outer peripheral surface when the sheet is displaced as the load torque increases.

[0115] According to this, at zero torque, the seat 22 is maintained in a stable position by contacting the contact surface PWd of the drive-side engagement portion (damper opening PW). In contrast, when the load torque increases, the seat 22 moves away from the contact surface PWd and reaches the region of the separation surface PWe. Even if the extension portion 22c is displaced away from the rotation axis X by centrifugal force as the position of the seat 22 changes, the extension portion 22c does not come into strong contact with the separation surface PWe, and therefore, an increase in frictional resistance does not occur.

[0116] (4) In the damper device A of (1), it is preferable that the guide member 32 has a shape in which the central region between the pair of sheets 22 bulges in a direction away from the rotation axis X.

[0117] As a result, even if the load torque increases and the extension portion 22c is displaced away from the rotation axis X due to centrifugal force as the posture of the seat 22 changes, the protruding end of the extension portion 22c does not come into strong contact with the central region of the guide member 32, and this does not result in an increase in frictional resistance.

[0118] (5) In the damper device A of (1), the guide member 32 preferably has a first guide member 32a held on one of the pair of sheets 22 and a second guide member 32b held on the other of the pair of sheets 22, and the extension portion 22c preferably has a first guide extension portion 22Ga that engages with the other of the pair of sheets 22 and a second guide extension portion 22Gb that engages with one of the pair of sheets 22.

[0119] According to this, when one of the seats 22 moves due to an increase in the load torque, the second guide member 32b held by the other seat 22 engages with the one of the seats 22, thereby suppressing the change in the position of the seat 22 at this engagement point. In this way, the suppression of the change in the position of the seat 22 is also performed when the other seat 22 moves.

[0120] (6) In the damper device A of (5), it is preferable that the first guide member 32a has a first enlarged diameter portion 32ar that forms a radial gap GD between it and the second guide extension portion 22Gb, and the second guide member 32b has a second enlarged diameter portion 32br that forms a radial gap GD between it and the first guide extension portion 22Ga.

[0121] As a result, a radial gap GD is formed between the first guide member 32a and the second guide extension 22Gb, and a radial gap GD is also formed between the second guide member 32b and the first guide extension 22Ga. Therefore, when one of the sheets 22 moves in accordance with an increase in load torque, the position of the sheet 22 does not change by more than the radial gap GD.

[0122] The present disclosure can be used in a damper device.

[0123] 4: driven-side member (flange body), 4W: driven-side engagement portion, 21: spring (dump spring), 22: seat, 22G: guide extension portion, 22Ga: first guide extension portion, 22Gb: second guide extension portion, 32: guide member, 32a: first guide member, 32ap: first enlarged diameter portion, 32b: second guide member, 32bp: second enlarged diameter portion, D: damper portion, Da: buffer unit, E: internal combustion engine, G: gap (initial gap), Ge: central gap (gap), GD: radial gap, GS: guide surface, P: drive-side member (side plate), PW: drive-side engagement portion, PWd: contact surface, PWe: separation surface, TM: travel transmission device, X: rotation axis

Claims

1. A damper device comprising: a driving-side member that rotates about a rotation axis center by the rotational driving force of an internal combustion engine; a driven-side member that rotates about the rotation axis center by the rotational driving force transmitted from the driving-side member and transmits the rotational driving force to a traveling transmission device; a damper portion in which a plurality of buffer units are arranged along the same circumferential region centered on the rotation axis center by relatively displacing the driving-side member and the driven-side member about the rotation axis center as the load torque increases; the buffer unit having a pair of sheets that engage with a driving-side engaging portion of the driving-side member and a driven-side engaging portion of the driven-side member, and a spring that applies a biasing force in a direction in which the pair of sheets are separated; a guide extending portion is formed on an outer peripheral portion of the sheet in a direction opposite to a contact portion with the driven-side engaging portion with which the sheet abuts, and a guide member is provided that enables the sheet to move along a circumferential guide region centered on the rotation axis center by contacting the guide extending portion when the sheet moves with the relative displacement between the driving-side member and the driven-side member.

2. The damper device according to claim 1, wherein the guide member is configured as an annular body disposed on an outer peripheral side opposite to the rotation axis center among the plurality of sheets, and a gap is formed between the annular body and a guide surface of the sheet in a state where the load torque does not act.

3. The damper device according to claim 1, wherein the driving-side engaging portion includes a close contact surface where an outer peripheral surface on the opposite side of the rotation axis center of the sheet is in close contact at zero torque where the load torque does not act, and a separation surface that forms a gap between the outer peripheral surface when the sheet is displaced as the load torque increases.

4. The damper device according to claim 1, wherein the guide member has a shape in which a central region between the pair of sheets bulges in a direction away from the rotation axis center.

5. The damper device according to claim 1, wherein the guide member has a first guide member held by one of the pair of sheets and a second guide member held by the other of the pair of sheets; the guide extending portion has a first guide extending portion that engages with the other of the pair of sheets and a second guide extending portion that engages with one of the pair of sheets.

6. The first guide member has a first diameter-expanded portion that forms a radial gap with the second guide extending portion, and the second guide member has a second diameter-expanded portion that forms a radial gap with the first guide extending portion. The damper device according to claim 5.