JP4684363B2 - Torque converter - Google Patents

Description

  The present invention relates to a torque converter, and more particularly to a torque converter in which a stator brake is provided on an inner peripheral portion of a stator.

  The torque converter has three types of impellers including an impeller, a turbine, and a stator, and is a device that transmits power by a fluid inside a torus formed by these. The impeller forms a fluid chamber filled with hydraulic oil, together with a front cover to which power is input from the engine. Further, the turbine is disposed in the fluid chamber so as to face the impeller in the axial direction. A turbine hub constituting the turbine is connected to an input shaft of the transmission. The stator rectifies the flow of hydraulic oil returning from the turbine to the impeller, and is disposed between the inner peripheral portion of the impeller and the inner peripheral portion of the turbine. The stator is connected to a fixed housing or the like via a one-way clutch.

Here, in place of the conventional one-way clutch mounted on the stator, a torque converter including a brake for braking the rotation of the stator is provided (see Patent Document 1). In the torque converter disclosed in Patent Document 1, a stator brake is provided on the inner peripheral side of the stator, and a lockup clutch is provided between the front cover and the turbine. The lock-up clutch and the stator brake are in accordance with a differential pressure between the hydraulic oil pressure for turning on (locking) the lock-up clutch and the hydraulic oil pressure for turning off (unlocking) the lock-up clutch. The engagement force between the front cover and impeller and the stator is changed.
JP 2006-300909 A

  In the torque converter described in Patent Document 1, the stator brake is disposed on the inner peripheral side of the stator. Therefore, when the diameter of the brake disc is increased in order to ensure a large brake capacity, the torus of the torque converter is reduced, and the torque converter performance is adversely affected. On the other hand, if the torus is enlarged to ensure the performance of the torque converter, the space for the stator brake becomes narrow and a sufficient brake capacity cannot be ensured.

  Further, if the number of plates of the brake disk portion is increased in order to sufficiently secure the brake capacity, the stator brake becomes longer in the axial direction, which hinders the reduction of the axial dimension of the entire torque converter.

  An object of the present invention is to enable the size of a stator brake to be reduced while maintaining the performance of a torque converter. Another object of the present invention is to make it possible to dispose a stator brake on the inner peripheral side of the stator without increasing the size in the axial direction.

  A torque converter according to a first aspect transmits torque from an engine to a transmission input shaft by a fluid, and includes a front cover, an impeller, a turbine, a stator, a stator brake, and a first slide. A member and a second sliding member. Torque from the engine is input to the front cover. The impeller is connected to the front cover and constitutes a fluid chamber together with the front cover. The turbine is disposed opposite to the impeller and can output torque to the transmission. The stator is disposed between the impeller and the inner periphery of the turbine, and rectifies the flow of fluid flowing from the turbine to the impeller. The stator brake is connected to the stator in a relatively non-rotatable manner and is arranged on the inner peripheral side of the stator, and the fixed side is arranged on the inner peripheral side of the stator side member and connected to the non-rotatable member. It consists of a member and a brake disc part arranged between the stator side member and the fixed side member, and brakes the rotation of the stator. The first sliding member is disposed between the impeller and the stator side member in the axial direction, and rotatably supports the impeller and the stator side member. The second sliding member is disposed closer to the engine side in the axial direction than the first sliding member between the impeller and the fixed side member, and rotatably supports the impeller and the fixed side member. Moreover, the stator side member has a disk-shaped vertical wall part, and the outer cylindrical part formed extending from the outer peripheral side of the vertical wall part to the transmission side. And the 1st sliding member is arrange | positioned between the inner wall surface of an impeller, and the transmission side end surface of the outer cylindrical part of a stator side member.

  In this torque converter, the power input to the front cover and the impeller is transmitted to the turbine via the fluid and then to the transmission. In addition, the fluid flows from the impeller into the turbine and is returned to the impeller through the stator. Further, the rotation of the stator is braked by the stator brake, and thereby the capacity of the torque converter is controlled.

  Here, the stator brake includes a stator side member that can rotate together with the stator, and a fixed side member that cannot rotate. These members are arranged close to the impeller and do not rotate in synchronization with the impeller. On the other hand, it is necessary to bring the stator brake and the impeller closer to reduce the axial dimension of the torque converter.

  Therefore, the first and second sliding members are disposed between the stator side member and the fixed side member constituting the stator brake and the impeller, and the stator brake is supported so as to be relatively rotatable with respect to the impeller. Therefore, it is not necessary to provide a useless space between the stator brake and the impeller, and the axial dimension can be shortened. And since the 2nd sliding member arrange | positioned more to the inner peripheral side is arrange | positioned in the engine side in the axial direction rather than the 1st sliding member, the axial direction dimension of a torque converter can be shortened more.

  A torque converter according to a second aspect is the torque converter according to the first aspect, wherein the second sliding member is disposed on the inner peripheral side of the stator side member so as to overlap the stator side member in the axial direction.

  Here, since the second sliding member is arranged so as to overlap with the stator side member in the axial direction, the axial dimension can be further shortened.

  A torque converter according to a third aspect is the torque converter according to the first or second aspect, wherein the impeller has a cylindrical portion extending in the axial direction along the input shaft of the transmission on the inner peripheral portion. The stationary side member of the stator brake has a disk-like vertical wall portion and an inner cylindrical portion formed in the inner peripheral portion of the vertical wall portion so as to extend in the axial direction toward the transmission side. And the inner cylindrical part of a stationary-side member is arrange | positioned so that it may overlap in an axial direction in the inner peripheral side of the cylindrical part of an impeller.

  In this case, since the inner cylindrical portion of the stationary member constituting the stator brake is arranged so as to overlap the cylindrical portion of the impeller in the axial direction, the axial dimension can be further shortened.

  A torque converter according to a fourth aspect of the present invention is the torque converter according to any one of the first to third aspects, wherein the inner / outer diameter ratio of the torus including the impeller, the turbine, and the stator is 0.55 or more, and the stator brake is an inner portion of the torus. It is arranged on the circumferential side.

  In this case, the necessary torque converter performance can be maintained without increasing the number of stator brake disks.

  According to the present invention, the dimensions of the stator brake can be reduced while maintaining the performance of the torque converter. Further, the axial dimension of the torque converter can be shortened.

[Overall configuration of torque converter]
FIG. 1 is a longitudinal sectional view of a torque converter 1 in which an embodiment of the present invention is adopted. The torque converter 1 is a device for transmitting torque from the crankshaft of the engine to the input shaft 2 of the transmission. An engine (not shown) is arranged on the left side of FIG. 1, and a transmission (not shown) is arranged on the right side of FIG. OO shown in FIG. 1 is a rotating shaft of the torque converter 1.

  The torque converter 1 mainly includes a front cover 4, three types of impellers (impeller 5, turbine 6 and stator 7), a stator brake 8, and a lockup clutch 10.

[front cover]
The front cover 4 is a disk-shaped member, and a center boss 14 is fixed to the inner peripheral end by welding. The center boss 14 is a cylindrical member extending in the axial direction, and is inserted into a center hole of a crankshaft (not shown).

  Although not shown, the front cover 4 is connected to a crankshaft of the engine via a flexible plate. That is, a plurality of nuts 15 are fixed at equal intervals in the circumferential direction on the outer peripheral side and the engine side surface of the front cover 4, and bolts screwed into the nuts 15 connect the outer peripheral part of the flexible plate to the front cover. 4 is fixed.

  An outer peripheral cylindrical portion 4 a extending toward the axial transmission side is formed on the outer peripheral portion of the front cover 4. The impeller 5 is fixed to the tip of the outer peripheral cylindrical portion 4a by welding. As a result, the front cover 4 and the impeller 5 form a fluid chamber that is filled with hydraulic oil.

[Imperor]
The impeller 5 mainly includes an impeller shell 18, a plurality of impeller blades 19 fixed inside the impeller shell 18, and an impeller hub 20 fixed to the inner peripheral portion of the impeller shell 18. And the front-end | tip part of the outer peripheral side of the impeller shell 18 is welded to the front cover 4 as mentioned above. Further, a cylindrical portion 20 a extending toward the transmission side is formed on the inner peripheral portion of the impeller hub 20.

[Turbine]
The turbine 6 is disposed in the fluid chamber so as to face the impeller 5 in the axial direction. The turbine 6 mainly includes a turbine shell 22, a plurality of turbine blades 23 fixed to the impeller side surface, and a turbine hub 24 fixed to the inner periphery of the turbine shell 22. The turbine shell 22 and the turbine hub 24 are fixed by a plurality of rivets (not shown).

  The turbine hub 24 includes a disc-like flange portion 24a to which the inner peripheral portion of the turbine shell 22 is fixed, an outer cylindrical portion 24b formed on the outer peripheral portion of the flange portion 24a so as to extend toward the axial direction engine side, and a flange. And an inner cylindrical portion 24c formed to extend in the axial direction at the inner peripheral portion of the portion 24a. A spline hole is formed in the inner peripheral portion of the inner cylindrical portion 24c and meshes with a spline shaft formed at the tip of the input shaft 2 of the transmission. A thrust washer 25 is disposed between the front end of the inner cylindrical portion 24c of the turbine hub 24 and the front cover 4 so as to support both of them in a relatively rotatable manner.

[Stator]
The stator 7 is a mechanism for rectifying the flow of hydraulic oil that is disposed between the inner peripheral portion of the impeller 5 and the inner peripheral portion of the turbine 6 and returns from the turbine 6 to the impeller 5. The stator 7 is integrally formed by casting with resin, aluminum alloy or the like. The stator 7 mainly has an annular stator shell 30 and a plurality of stator blades 31 provided on the outer peripheral surface of the stator shell 30. The stator shell 30 is supported by a cylindrical fixed shaft 33 via the stator brake 8. The fixed shaft 33 is disposed between the outer peripheral surface of the input shaft 2 and the inner peripheral surface of the cylindrical portion 20 a of the impeller hub 20.

  A torus-shaped fluid working chamber is formed in the fluid chamber by the shells 18, 22, and 30 of the impellers 5, 6, and 7 described above. Here, in this embodiment, the inner / outer diameter ratio (D1 / D2) of the torus is 0.63, and the inner / outer diameter ratio of the torus is taken into consideration when considering the performance of the torque converter, the brake capacity of the stator brake described later, and the axial dimension. Is preferably 0.55 or more. As shown in FIG. 1, the outer diameter D2 of the torus is the outer diameter of the impeller blade 19, and the inner diameter D1 is the outer diameter of the stator shell 30 (the inner diameter of the stator blade 31).

[Stator brake]
The stator brake 8 is disposed on the inner peripheral side of the stator 7 and serves to brake the rotation of the stator 7. The stator brake 8 is a hydraulically operated clutch brake, and as shown in detail in FIG. 2, a brake case (stator side member) 35 and a multi-plate brake disc disposed inside the brake case 35. A portion 37, a piston 37 that presses the brake disc portion 36, and a brake fixing member (fixed side member) 38 that is disposed on the inner peripheral side of the brake disc portion 36 and connected to the fixed shaft 33. .

<Brake case>
As shown in FIG. 2, the brake case 35 includes a disc-shaped vertical wall portion 35a, an outer cylindrical portion 35b formed extending from the outer peripheral portion of the vertical wall portion 35a to the transmission side, and a vertical wall portion 35a. An inner cylindrical portion 35c formed to extend from the inner peripheral portion to the transmission side. The vertical wall portion 35 a is disposed substantially parallel to the flange portion 24 a of the turbine hub 24.

  A first thrust bearing 40 is disposed between the outer peripheral portion of the vertical wall portion 35 a and the inner peripheral portion of the turbine shell 22. The first thrust bearing 40 is a bearing (sliding member) for rotatably supporting the brake case 35 of the stator brake 8 with respect to the turbine hub 24 (turbine shell 22).

  A plurality of teeth 35d and 35e extending in the axial direction are formed on the outer peripheral surface and the inner peripheral surface of the outer cylindrical portion 35b, and the teeth 35d formed on the outer peripheral surface are formed on the inner peripheral surface of the stator shell 30. Meshed with the plurality of teeth 30a extending in the axial direction. A pair of snap rings 41 and 42 are attached to both ends of the teeth 30a in the axial direction on the inner peripheral surface of the stator shell 30. As described above, the brake case 35 and the stator shell 30 cannot be rotated relative to each other and cannot be moved relative to each other in the axial direction.

  Further, a second thrust bearing 43 is disposed between the axial front end surface of the outer cylindrical portion 35 b and the impeller shell 18. The second thrust bearing 43 is a bearing (sliding member) for rotatably supporting the brake case 35 of the stator brake 8 with respect to the impeller shell 18.

  The inner cylindrical portion 35 c is supported on the outer peripheral portion of the inner cylindrical portion 24 c of the turbine hub 24 via a roller bearing 44 so as to be relatively rotatable. That is, the inner cylindrical portion 35 c of the brake case 35 is disposed so as to overlap with the inner cylindrical portion 24 c of the turbine hub 24 in the axial direction. A thrust washer 45 is disposed between the axial tip of the inner cylindrical portion 35c and the brake fixing member 38.

<Brake disc part>
The brake disk portion 36 has a plurality of driven plates 48 (four in this example) and disks 49 (three in this example), which are alternately arranged in the axial direction.

  The driven plate 48 is a ring-shaped member having a plurality of teeth formed on the outer peripheral portion, and the teeth formed on the outer peripheral portion mesh with the teeth 35e of the brake case 35 so as to be movable in the axial direction. Of the four driven plates 48, the driven plate arranged closest to the transmission side is formed thicker than the other three driven plates, and the other three plates have the same thickness. Is formed.

  The disk 49 is a ring-shaped member having a facing member as a friction member attached to both surfaces. A plurality of teeth are formed on the inner periphery of the disk 49.

<Piston>
The piston 37 has a pressing portion 37a for pressing the driven plate 48 and the disc 49 of the brake disc portion 36 on the outer peripheral portion. A plurality of grooves are formed in the pressing portion 37a along the radial direction. In addition, a cylindrical support portion 37 b extending toward the transmission side in the axial direction is formed on the inner peripheral portion of the piston 37. The support portion 37b is supported on the outer peripheral surface of the inner cylindrical portion 35c of the brake case 35 so as to be movable in the axial direction. The piston 37 and the brake case 35 are sealed by two seal members 51 and 52 provided on the outer peripheral portion of the piston and the outer peripheral portion of the inner cylindrical portion 35c of the brake case 35.

<Brake fixing member>
As shown in FIG. 2, the brake fixing member 38 includes a disc-shaped vertical wall portion 38a, an outer cylindrical portion 38b extending axially from the outer peripheral portion of the vertical wall portion 38a to the engine side, and And an inner cylindrical portion 38c extending in the axial direction from the inner peripheral portion to the transmission side.

  A plurality of axially extending teeth are formed on the outer peripheral surface of the outer cylindrical portion 38 b, and these teeth mesh with the teeth formed on the inner peripheral portion of the disk 49. A spline hole is formed on the inner peripheral surface of the inner cylindrical portion 38 c, and this spline hole meshes with a spline shaft formed on the outer peripheral surface of the fixed shaft 33. In addition, the inner cylindrical part 38c is arrange | positioned at the inner peripheral side of the cylindrical part 20a of the impeller hub 20, and both have overlapped in the axial direction.

  Further, a third thrust bearing 50 is disposed between the outer peripheral portion of the vertical wall portion 38 a and the impeller shell 18. The third thrust bearing 50 is a bearing (sliding member) for supporting the brake fixing member 38 fixed so as not to rotate so as to be relatively rotatable with respect to the rotating impeller hub 20.

  Here, the third thrust bearing 50 is disposed on the engine side in the axial direction from the second thrust bearing 43. In addition, the third thrust bearing 50 is disposed inside the brake case 35 of the stator brake 8 and overlaps with the outer cylindrical portion 35b of the brake case 35 in the axial direction.

[Lock-up clutch]
The lockup clutch 10 is disposed between the front cover 4 and the turbine 6 and directly transmits power from the front cover 4 to the turbine 6. As shown in FIG. 1, the lockup clutch 10 has a piston 55 and a damper portion 56. The damper portion 56 is disposed between the piston 55 and the turbine 6.

  The piston 55 includes a piston main body portion 55a having a friction member 57 fixed to the surface on the front cover 4 side, an outer cylindrical portion 55b formed on the outer peripheral side, and an inner cylindrical portion 55c formed on the inner peripheral side. ,have. The inner cylindrical portion 55c is supported by the outer cylindrical portion 24b of the turbine hub 24 so as to be movable in the axial direction. Note that a seal member 58 for sealing between the piston 55 and the piston 55 is provided on the outer cylindrical portion 24 b of the turbine hub 24.

  The damper portion 56 is disposed on the inner peripheral side of the outer cylindrical portion 55b of the piston 55. The damper portion 56 includes a plurality of input side members 60 fixed to the piston 55, an output side member 61 fixed to the turbine shell 22, and a plurality of members for elastically connecting the input side member 60 and the output side member 61. And a torsion spring 62.

[Stator brake operation circuit]
As shown in FIG. 2, the circuit for operating the stator brake 8 includes a through hole 65 formed in the inner cylindrical portion 24 c of the turbine hub 24 and a through hole formed in the inner cylindrical portion 35 c of the brake case 35. And the hole 66. That is, in order to turn on the stator brake 8 (press the disk), hydraulic oil is supplied between the brake case 35 and the piston 37 via the through holes 65 and 66, and the stator brake 8 is turned off (the disk is pressed). In order to release the hydraulic fluid, the hydraulic oil is discharged through the same path (through holes 65 and 66). In the inner cylindrical portion 24 c of the turbine hub 24, seal members 67 and 68 are provided on both sides in the axial direction of the through hole 65.

[Torque converter operation]
When the lockup clutch 10 is off (lockup release), torque transmission between the front cover 4 and the turbine 6 is performed by fluid transmission between the impeller 5 and the turbine 6. When the impeller 5 is rotated by the engine, the hydraulic oil flows from the impeller 5 to the turbine 6 by centrifugal force. The hydraulic oil that has flowed from the impeller 5 to the turbine 6 rotates the turbine 6 and then passes through the stator 7. When passing through the stator 7, the hydraulic oil that has collided with the stator blade 31 is redirected by the blade and returned to the impeller 5.

  When the lockup clutch 10 is turned on, the hydraulic oil between the piston 55 and the front cover 4 is discharged. As a result, the piston 55 moves toward the front cover 4 in the axial direction, and the friction member 57 fixed to the piston body 55a is pressed against the front cover 4.

  When the lockup clutch 10 is turned on as described above, the power transmitted from the engine to the front cover 4 is input to the damper portion 56 via the lockup clutch 10. The power is transmitted to the turbine 6 through the damper portion 56 and further transmitted to the input shaft 2 of the transmission through the turbine hub 24. In this way, power is transmitted directly to the transmission side.

  The stator brake 8 is generally turned on when the engine is idling, that is, stopped. In this case, hydraulic oil is supplied to the back surface of the piston 37 through the through hole 65 of the turbine hub 24 and the through hole 66 of the brake case 35. Thereby, the piston 37 moves to the transmission side in the axial direction, and the driven plate 48 and the disk 49 are pressed against each other. Thereby, the stator 7 is braked and cannot rotate. In a state where the stator 7 is braked, the capacity coefficient of the torque converter is a relatively small value, so that the engine load becomes small. For this reason, consumption of fuel can be suppressed.

  On the other hand, when the vehicle starts running, the stator brake 8 is shifted from on (braking state) to off (braking release state). As a result, the capacity coefficient increases and a capacity of the torque converter sufficient for traveling can be obtained. When the stator brake 8 is turned from on to off, the hydraulic oil is discharged through the through holes 65 and 66.

[Features of this embodiment]
(a) Thrust bearings 43 and 50 are disposed between the brake case 35 and the brake fixing member 38 of the stator brake 8 and the impeller 5 to support the stator brake 8 so as to be rotatable relative to the impeller 5. . Therefore, it is not necessary to provide a useless space between the stator brake 8 and the impeller 5, and the axial dimension can be shortened. Further, since the third thrust bearing 50 is disposed on the engine side in the axial direction than the second thrust bearing 43 and is housed in the brake case 35, the axial dimension of the torque converter can be further shortened.

  (b) Since the inner cylindrical portion 35c of the brake case 35 is supported on the outer peripheral surface of the inner cylindrical portion 24c of the turbine hub 24, the axial dimension can be further shortened. Furthermore, since the inner cylindrical portion 38c of the brake fixing member 38 is disposed so as to overlap the cylindrical portion 20a of the impeller hub 20 in the axial direction, the axial dimension can be further shortened.

  (c) Since the stator 7 and the stator brake 8 are coupled by a plurality of teeth formed on the inner and outer peripheral portions thereof, the dimensions on the stator brake side can be ensured larger than other coupling methods. Thus, the diameter of the disk constituting the stator brake can be increased. Therefore, the required brake capacity can be ensured with a small number of disks.

  (d) The inner / outer diameter ratio (D1 / D2) of the torus is 0.55 or more, and the stator brake 8 is disposed on the inner peripheral side of the torus. Therefore, similarly to the above, it is possible to ensure a larger dimension on the stator brake side and increase the diameter of the brake disk portion, and it is possible to ensure a necessary brake capacity with a small number of disks. Therefore, the necessary torque converter performance can be maintained without increasing the number of stator brake disks.

[Other Embodiments]
In the above-described embodiment, the case where the stator brake is configured by a plurality of disks has been described. However, the present invention can be similarly applied to a single-plate stator brake.

  Further, the specific configuration of the lockup clutch is not limited to the above embodiment, and each oil supply circuit is not limited to the above embodiment.

1 is a schematic vertical sectional view of a torque converter 1. FIG. FIG. 2 is an enlarged partial view of FIG. 1.

DESCRIPTION OF SYMBOLS 1 Torque converter 2 Transmission input shaft 4 Front cover 5 Impeller 6 Turbine 7 Stator 8 Stator brake 20 Impeller hub 20a Impeller hub cylindrical portion 24 Turbine hub 24a Flange portion 24b Outer cylindrical portion 24c Inner cylindrical portion 35 Brake case 35a Vertical wall portion 35b Outer cylindrical portion 35c Inner cylindrical portion 36 Brake disc portion 37 Piston 38 Brake fixing member 38c Inner cylindrical portions 40, 43, 50 Thrust bearing 55 Lock-up clutch

Claims (4)

A torque converter for transmitting torque from an engine to a transmission input shaft by fluid,
A front cover (4) to which torque from the engine is input;
An impeller (5) connected to the front cover (4) and forming a fluid chamber together with the front cover (4);
A turbine (6) disposed opposite the impeller (5) and capable of outputting torque to the transmission;
A stator (7) arranged between the impeller (5) and the inner periphery of the turbine (6), for rectifying the flow of fluid flowing from the turbine (6) to the impeller (5);
A stator side member (35) that is connected to the stator (7) so as not to rotate relative to the stator (7) and is disposed on the inner peripheral side of the stator (7), and is disposed on the inner peripheral side of the stator side member (35). And a stationary member (38) connected to a non-rotatable member (33), and a brake disk portion (36) disposed between the stator member (35) and the stationary member (38), A stator brake (8) for braking the rotation of the stator (7),
A first sliding member (43) disposed between the impeller (5) and the stator side member (35) in an axial direction and rotatably supporting the impeller (5) and the stator side member (35). When,
Between the axial direction of the impeller (5) and the fixed side member (38), the first sliding member (43) is arranged on the engine side in the axial direction. The impeller (5) and the fixed side member (38) A second sliding member (50) that rotatably supports
With
The stator side member (35) includes a disc-shaped vertical wall portion (35a) and an outer cylindrical portion (35b) formed to extend from the outer peripheral side of the vertical wall portion (35a) to the transmission side. Have
The first sliding member (43) is disposed between an inner wall surface of the impeller (5) and a transmission side end surface of the outer cylindrical portion (35b) of the stator side member (35).
Torque converter.   The torque according to claim 1, wherein the second sliding member (50) is disposed on the inner peripheral side of the stator side member (35) so as to overlap the stator side member (35) in the axial direction. converter. The impeller (5) has a cylindrical portion (20a) extending in the axial direction along the input shaft (2) of the transmission on the inner peripheral portion,
The stationary side member (38) of the stator brake (8) is formed to extend in the axial direction on the transmission side on the disc-shaped vertical wall portion (38a) and the inner peripheral portion of the vertical wall portion (38a). An inner cylindrical portion (38c),
The inner cylindrical portion (38c) of the fixed side member (38) is disposed so as to overlap in the axial direction on the inner peripheral side of the cylindrical portion (20a) of the impeller (5).
The torque converter according to claim 1 or 2. The inner / outer diameter ratio of the torus constituted by the impeller (5), turbine (6) and stator (7) is 0.55 or more,
The stator brake (8) is disposed on the inner peripheral side of the torus,
The torque converter in any one of Claim 1 to 3.

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