JP2018028338A - Torque converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a temperature rise of a torque converter.SOLUTION: A turbine 3 has a turbine shell 31 which is movable in an axial direction. A lockup part 4 is formed in an outer periphery of an outer shell constituted by a front cover 1 and an impeller shell 21. A piston 5 is integrally moved with the turbine 3 in the axial direction. The piston 5 is engaged with the lockup part 4 by movement to the front cover 1 side. A one-way valve 10 allows the flow of a fluid from a first space S1 between the front cover 1 and the piston 5 to a second space S2 between the piston 5 and the impeller shell 21.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a torque converter.

  The torque converter has an impeller and a turbine, and transmits torque from the impeller to the turbine via internal hydraulic oil. The impeller is fixed to a front cover to which torque from the engine is input. The turbine is disposed opposite the impeller in the fluid chamber. When the impeller rotates, hydraulic oil flows from the impeller to the turbine, and torque is output by rotating the turbine.

  The torque converter has a lockup mechanism. The lockup mechanism has a piston, and when the lockup mechanism is turned on, the piston engages with the front cover. As a result, torque from the front cover is directly input to the piston.

  For example, in the torque converter described in Patent Document 1, the outer peripheral end of the turbine shell forms a piston. The lock-up mechanism is turned on when the piston engages with a lock-up portion extending radially inward from the outer peripheral wall portion of the outer shell of the torque converter.

US Pat. No. 9,297,448

  In the torque converter configured as described above, the flow of the hydraulic oil is obstructed by the piston and the lock-up portion, and the circulation of the hydraulic oil is stagnated inside the torque converter. As a result, the torque converter becomes hot. Arise.

  The subject of this invention is suppressing the high temperature of a torque converter.

  A torque converter according to an aspect of the present invention includes a front cover, an impeller, a turbine, a lockup portion, a piston, and a one-way valve. Torque is input to the front cover. The impeller has an impeller shell fixed to the front cover, and an impeller blade attached to the impeller shell. The turbine has a turbine shell that is axially movable and a turbine blade attached to the turbine shell. The lock-up portion is formed on the outer peripheral wall portion of the outer shell constituted by the front cover and the impeller shell. The piston is configured to move integrally with the turbine in the axial direction. The piston is configured to engage with the lockup portion by moving to the front cover side. The one-way valve is configured to allow fluid flow from the space between the front cover and the piston to the space between the piston and the impeller shell.

  According to this configuration, the hydraulic oil can flow from the space between the front cover and the piston to the space between the piston and the impeller shell by the one-way valve. For this reason, hydraulic fluid can be circulated within the torque converter, and as a result, high temperature of the torque converter can be suppressed.

  Preferably, the piston is formed by a member separate from the turbine shell. The piston and the turbine shell are coupled to each other. According to this configuration, the material of the piston and the turbine shell and the construction method such as heat treatment can be made different from each other.

  Preferably, the one-way valve is disposed radially inward of the engaging portion between the piston and the lockup portion and radially outward of the coupling portion between the piston and the turbine shell. Preferably, the one-way valve is formed on a piston. According to this configuration, the hydraulic oil flowing through the one-way valve can flow between the turbine shell and the impeller shell after flowing the gap between the piston and the turbine shell radially outward. Moreover, it can prevent that the dimension of radial direction becomes large by forming a one-way valve inside radial direction rather than the said engaging part.

  Preferably, the lockup portion extends radially inward from the outer peripheral wall portion.

  The one-way valve may be disposed radially outside the engaging portion between the piston and the lockup portion. Further, the one-way valve may be formed in the lock-up portion.

  The lockup part may be comprised by the outer peripheral wall part.

  Preferably, the piston contacts the lockup portion in a state where the engagement with the lockup portion is released. According to this structure, the responsiveness of lockup can be improved.

  In a state where the engagement between the piston and the lockup portion is released, the gap between the piston and the outer peripheral wall portion or the gap between the piston and the lockup portion may be within 0.1 mm. According to this configuration, by setting the gap to within 0.1 mm, it is possible to suppress the flow of hydraulic oil through the gap and improve the responsiveness of lockup.

  Preferably, the one-way valve is a reed valve.

  One of the piston and the lockup portion may have a lip seal that extends to the other of the piston and the lockup portion.

  Preferably, the torque converter further includes an output hub that outputs torque. One of the piston and the turbine shell slides axially on the output hub. One of the piston and the turbine shell sliding on the output hub preferably has an orifice hole radially inward from the torus of the torque converter. According to this configuration, the hydraulic oil can circulate in the torque converter through the orifice hole in the locked-up state.

  Preferably, the piston has a cylindrical portion extending in the axial direction at the outer peripheral end portion. According to this configuration, the rigidity of the piston can be increased.

  Preferably, the piston is formed of a material different from that of the turbine shell.

  Preferably, the torque converter further includes a damper device and a driven plate. The damper device has an elastic member and is disposed between the front cover and the piston. The driven plate is engaged with the elastic member. The driven plate is attached to the piston or turbine shell.

  According to the present invention, an increase in the temperature of the torque converter can be suppressed.

Sectional drawing of a torque converter. The expanded sectional view of a lockup part. Sectional drawing of the torque converter which concerns on a modification. The expanded sectional view of the torque converter which concerns on a modification. The expanded sectional view of the torque converter which concerns on a modification.

  Hereinafter, embodiments of a torque converter according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a torque converter. In the following description, “axial direction” means a direction in which the rotation axis O of the torque converter 100 extends. Further, the radial direction means a radial direction of a circle around the rotation axis O. Further, the circumferential direction means a circumferential direction of a circle around the rotation axis O. Specifically, the axial direction indicates the left-right direction in FIG. Although not shown, an engine is arranged on the left side of FIG. 1, and a transmission is arranged on the right side of FIG.

  As shown in FIG. 1, the torque converter 100 can rotate around the rotation axis O. The torque converter 100 includes a front cover 1, an impeller 2, a turbine 3, a lockup unit 4, a piston 5, and a one-way valve 10. The torque converter 100 further includes a stator 6, a damper device 7, an output hub 8, and the like.

[front cover]
The front cover 1 receives torque from the engine. The front cover 1 has a disc part 11 and a cylindrical first cylindrical part 12. The first cylindrical portion 12 extends in the axial direction from the outer peripheral end of the disc portion 11 to the impeller 2 side.

[Impeller]
The impeller 2 includes an impeller shell 21, a plurality of impeller blades 22, and an impeller core 23. The impeller shell 21 is fixed to the front cover 1. For example, the impeller shell 21 is welded to the front cover 1.

  The front cover 1 and the impeller shell 21 constitute an outer shell of the torque converter 100. The first cylindrical portion 12 of the front cover 1 corresponds to the outer peripheral wall portion of the outer shell. An outer peripheral end portion of the impeller shell 21 is fixed to the first cylindrical portion 12. For example, the impeller shell 21 and the front cover 1 are welded to each other.

  The impeller blade 22 is attached to the impeller shell 21. Specifically, the impeller blade 22 is fixed to the inner surface of the impeller shell 21.

  The impeller core 23 is formed in an annular shape. The impeller core 23 supports the end portion of each impeller blade 22 on the turbine 3 side.

[Turbine]
The turbine 3 is disposed to face the impeller 2. The turbine 3 includes a turbine shell 31, a plurality of turbine blades 32, and a turbine core 33. The turbine shell 31 is fixed to the piston 5 with rivets 101. The turbine shell 31 may be fixed to the piston 5 by welding instead of the rivet 101. The turbine shell 31 is movable in the axial direction together with the piston 5.

  The turbine blade 32 is attached to the turbine shell 31. Specifically, the turbine blade 32 is fixed to the inner surface of the turbine shell 31 by brazing.

  The turbine core 33 is formed in an annular shape. The turbine core 33 supports the end portion of each turbine blade 32 on the impeller 2 side.

[Stator]
The stator 6 is configured to rectify the hydraulic oil that returns from the turbine 3 to the impeller 2. The stator 6 can rotate around the rotation axis O. Specifically, the stator 6 is supported on a fixed shaft (not shown) via a one-way clutch 64. The stator 6 is disposed between the impeller 2 and the turbine 3. The stator 6 includes a disk-shaped stator carrier 61, a plurality of stator blades 62 attached to the outer peripheral surface thereof, and a stator core 63 attached to the outer peripheral end portion of each stator blade 62.

[Lock-up part]
The lockup portion 4 is formed on the outer peripheral wall portion of the outer shell of the torque converter 100, that is, the first cylindrical portion 12. Specifically, the lockup portion 4 extends radially inward from the first cylindrical portion 12. The lockup part 4 is formed in an annular shape.

  The lockup portion 4 is attached to the first cylindrical portion 12 so as not to rotate. That is, the lockup portion 4 rotates integrally with the first cylindrical portion 12. The term “unrotatable” is a concept that includes not only a complete rotation but also a movement in the circumferential direction corresponding to the clearance. Specifically, the lockup portion 4 and the first cylindrical portion 12 are spline-fitted with each other. The lock-up portion 4 faces the outer peripheral end portion 511 of the piston 5 in the axial direction. When viewed in the radial direction, at least a part of the lockup portion 4 overlaps the turbine 3.

  As shown in FIG. 2, the lockup portion 4 includes a lockup main body portion 41 and an extending portion 42. The lockup main body portion 41 is an annular plate and extends radially inward from the first cylindrical portion 12. Spline grooves are formed on the outer peripheral surface of the lockup main body 41.

  The extending part 42 is formed in an annular shape. The extending portion 42 extends in the axial direction from the lockup main body portion 41 toward the engine side. The outer diameter of the extending part 42 is smaller than the outer diameter of the lockup main body part 41. In the first cylindrical portion 12, the inner peripheral surface on the engine side has a smaller inner diameter than the inner peripheral surface on the transmission side. When the lockup main body portion 41 abuts against the stepped portion due to the difference in the inner diameter, the axial movement of the lockup portion 4 toward the engine is restricted.

  An annular groove 43 extending in the circumferential direction is formed on the outer peripheral surface of the extending portion 42. An O-ring 44 is accommodated in the annular groove 43. Thereby, it is possible to prevent the hydraulic oil from flowing through between the lock-up portion 4 and the first cylindrical portion 12.

[piston]
As shown in FIG. 1, the piston 5 is disposed between the front cover 1 and the turbine 3. Specifically, the piston 5 is disposed between the turbine 3 and the damper device 7. The piston 5 is formed by a member separate from the turbine shell 31. The piston 5 basically has a shape along the turbine shell 31. The turbine shell 31 and the piston 5 are coupled to each other. Specifically, the turbine shell 31 is coupled to the piston 5. For this reason, the piston 5 moves in the axial direction integrally with the turbine 3. The piston 5 slides on the output hub 8 in the axial direction.

  The piston 5 includes a piston plate 51 and a friction material 52. The piston plate 51 is a substantially disk-shaped plate. An opening is formed at the center of the piston plate 51. The piston plate 51 can be formed of a material different from that of the turbine shell 31. For example, the piston plate 51 may be made of iron, and the turbine shell 31 may be made of aluminum.

  The outer peripheral end of the piston plate 51 is disposed on the radially outer side than the outer peripheral end of the turbine shell 31. That is, the outer diameter of the piston 5 is larger than the outer diameter of the turbine 3. The piston plate 51 and the turbine shell 31 are arranged with a gap therebetween.

  The plate thickness of the piston plate 51 is thicker than the plate thickness of the turbine shell 31. The piston plate 51 is subjected to heat treatment in order to improve its strength.

  A friction material 52 is attached to the outer peripheral end 511 of the piston plate 51. The friction material 52 extends in an annular shape. The outer peripheral end portion 511 faces the lockup portion 4 with the friction material 52 interposed therebetween. When the piston 5 moves to the front cover 1 side, the piston 5 engages with the lockup portion 4. That is, the piston 5 is frictionally engaged with the lockup portion 4 by the friction material 52. As a result, the piston 5 and the front cover 1 rotate integrally.

  In a state where the engagement between the piston 5 and the lockup portion 4 is released, the friction material 52 and the lockup portion 4 are in contact with each other. The friction material 52 may be attached to the lockup unit 4. In this case, the friction material 52 and the piston 5 are in contact with each other in a state where the engagement between the piston 5 and the lockup portion 4 is released.

  The outer peripheral end 511 of the piston plate 51 overlaps with the turbine 3 when viewed in the radial direction. The outer peripheral end 511 extends so as to be substantially perpendicular to the axial direction. That is, the outer peripheral end 511 extends substantially parallel to the radial direction.

  The piston 5 further includes a second cylindrical portion 53 (an example of the cylindrical portion of the present invention) and a boss portion 54. The second cylindrical portion 53 extends in the axial direction from the outer peripheral end portion of the piston plate 51. Specifically, the second cylindrical portion 53 extends in the axial direction toward the transmission side.

  The boss portion 54 extends in the axial direction from the inner peripheral end portion of the piston plate 51. Specifically, the boss portion 54 extends in the axial direction toward the engine side. The inner peripheral surface of the boss portion 54 is in contact with the outer peripheral surface of the output hub 8. The boss portion 54 and the output hub 8 are sealed. Specifically, an annular groove is formed on the outer peripheral surface of the output hub 8, and an O-ring 81 is accommodated in the annular groove. The O-ring 81 seals between the piston 5 and the output hub 8.

  The piston 5 further has an orifice hole 56. The orifice hole 56 is formed so as to penetrate the piston plate 51. The orifice hole 56 is disposed radially inward of the torus. The torus is an annular space surrounded by the impeller core 23, the turbine core 33, and the stator core 63.

[Driven plate]
The driven plate 9 is attached to the piston 5. Specifically, the driven plate 9 is attached to the piston plate 51 by a rivet 101. The driven plate 9 may be fixed to the piston plate 51 by welding instead of the rivet 101.

  The driven plate 9 extends from the piston plate 51 to each outer peripheral side torsion spring 71 of the damper device 7, and engages with each outer peripheral side torsion spring 71. Specifically, each driven plate 9 is in contact with the end face of each outer peripheral torsion spring 71 in the circumferential direction. The driven plates 9 are arranged at intervals in the circumferential direction.

[Damper device]
The damper device 7 is disposed between the front cover 1 and the piston 5 in the axial direction. Torque is transmitted from the piston 5 to the damper device 7. Specifically, the damper device 7 elastically connects the piston 5 and the output hub 8. The damper device 7 includes an outer peripheral side torsion spring 71, an intermediate plate 72, an inner peripheral side torsion spring 73, and an output plate 74. The output plate 74 is formed integrally with the output hub 8.

  Torque from the driven plate 9 is transmitted to the intermediate plate 72 via the outer peripheral torsion spring 71. The torque transmitted to the intermediate plate 72 is transmitted to the output plate 74 via the inner peripheral side torsion spring 73. Since the output plate 74 is formed integrally with the output hub 8, it rotates integrally with the output hub 8. The output hub 8 outputs torque to the transmission side.

[One-way valve]
The one-way valve 10 is configured to restrict the flow of hydraulic oil in the torque converter 100. Specifically, the one-way valve 10 allows hydraulic oil to flow from the first space S1 between the front cover 1 and the piston 5 to the second space S2 between the piston 5 and the impeller shell 21. It is configured as follows. The one-way valve 10 is configured to restrict the flow of hydraulic oil from the second space S2 to the first space S1.

  The one-way valve 10 is attached to the piston 5. The one-way valve 10 is disposed radially inward of the engagement portion between the piston 5 and the lockup portion 4. In addition, the one-way valve 10 is disposed at a radially outer side than the coupling portion between the piston 5 and the turbine shell 31, that is, the rivet 101.

  The one-way valve 10 is attached so as to cover a through hole 55 formed in the piston plate 51. Further, when the driven plate 9 is arranged so as to cover the through hole 55 of the piston plate 51 as in the present embodiment, the driven plate 9 is located at a position facing the through hole 55 of the piston plate 51. have. The one-way valve 10 allows the flow of hydraulic oil from the first space S1 to the second space S2 through the through holes 55 and 91 and the flow of hydraulic oil from the second space S2 to the first space S1. To regulate. The one-way valve 10 is, for example, a reed valve. The one-way valve 10 is attached to the surface of the piston plate 51 that faces the turbine shell 31 side.

[Torque converter operation]
Next, the operation at the time of lock-up of the torque converter 100 will be described. First, in a state where the lockup is not performed, the friction material 52 of the piston 5 is not engaged with the lockup portion 4. That is, the friction material 52 of the piston 5 and the lockup portion 4 are not frictionally engaged, and the piston 5 and the front cover 1 can be rotated relative to each other. In this state, the friction material 52 and the lockup portion 4 are in contact with each other.

  When the torque converter 100 is locked up, hydraulic fluid is supplied to the second space S2. Thereby, the hydraulic pressure of the hydraulic oil in the second space S2 increases. Since the piston 5 and the lockup portion 4 are in contact with each other, the hydraulic oil rise timing in the second space S2 is fast.

  When the hydraulic pressure of the hydraulic oil in the second space S2 rises, the turbine shell 31 moves together with the piston 5 in a direction away from the impeller shell 21, that is, toward the front cover 1 side. As a result, the friction material 52 of the piston 5 frictionally engages with the lock-up portion 4, and the front cover 1 and the piston 5 rotate integrally. That is, the torque from the front cover 1 is transmitted to the piston 5 without passing through the hydraulic oil. In this locked-up state, the hydraulic oil in the second space S <b> 2 passes through the orifice hole 56 of the piston 5 so that the hydraulic pressure of the hydraulic oil in the second space S <b> 2 does not decrease. It can flow into the space S1. As a result, the hydraulic oil in the torque converter 100 can be lubricated to prevent the torque converter 100 from becoming hot.

  When releasing the lock-up of the torque converter 100, hydraulic oil is supplied to the first space S1 to increase the hydraulic pressure of the hydraulic oil in the first space S1. Then, the piston 5 moves in a direction away from the front cover 1, and as a result, the frictional engagement between the friction material 52 of the piston 5 and the lockup portion 4 is released. As a result, the torque from the front cover 1 is transmitted to the turbine 3 via the impeller 2 and the hydraulic oil, and then transmitted to the output hub 8. The friction material 52 of the piston 5 is not in frictional engagement with the lockup portion 4 but is in contact therewith.

  In a state where the lock-up is released, the hydraulic oil in the first space S1 flows to the second space S2 via the one-way valve 10. Specifically, the hydraulic oil in the first space S1 flows into the gap between the piston 5 and the turbine shell 31 via the one-way valve 10, flows in the gap radially outward, and then from the radially outer side. Then, it flows into the space between the turbine shell 31 and the impeller shell 21.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

Modification 1
In the said embodiment, although the piston 5 is formed with the turbine shell 31 and another member, the structure of the piston 5 is not limited to this. For example, the piston 5 may be formed by the turbine shell 31 and one member. For example, the outer peripheral end of the turbine shell 31 may constitute a piston.

Modification 2
In the said embodiment, although the lockup part 4 is comprised by the member extended in the radial inside from the 1st cylindrical part 12, the structure of the lockup part 4 is not limited to this. For example, as shown in FIG. 3, the lockup part 4 may be comprised by a part of 1st cylindrical part 12 which is an outer peripheral wall part. The engagement surface of the lockup portion 4 constituted by a part of the first cylindrical portion 12 faces the impeller 2 side in the axial direction. Specifically, the engagement surface of the lockup portion 4 is inclined so as to face the radially inner side. The outer peripheral end of the piston 5 extends substantially parallel to the lockup portion 4.

Modification 3
In the said embodiment, although the one-way valve 10 is formed in the piston 5, the structure of the one-way valve 10 is not limited to this. For example, as shown in FIG. 4, the one-way valve 10 may be formed in the lock-up portion 4. The one-way valve 10 closes a through hole 45 formed in the lockup portion 4. In this case, the one-way valve 10 is disposed radially outside the engaging portion between the piston 5 and the lockup portion 4.

Modification 4
In the above embodiment, the piston 5 and the lockup portion 4 are in contact with each other in a state where the engagement between the piston 5 and the lockup portion 4 is released. However, the piston 5 and the lockup portion 4 are not in contact with each other. There may be. In this case, it is preferable that the clearance between the first cylindrical portion 12 and the second cylindrical portion 53 of the piston 5 be within 0.1 mm. As a result, the responsiveness of lockup can be improved.

Modification 5
As shown in FIG. 5, the piston 5 may have a lip seal 57. The lip seal 57 extends from the piston plate 51 toward the lockup portion 4. The tip of the lip seal 57 is in contact with the lockup portion 4. The lip seal 57 is disposed on the radially outer side of the friction material 52. The lip seal 57 is configured to prevent the hydraulic oil in the second space S2 from flowing into the first space S1 and to allow the hydraulic oil to flow in the reverse direction. The lip seal 57 may be disposed on the radially inner side of the friction material 52. Further, the piston 5 may not have the lip seal 57, but the lock-up portion 4 may have the lip seal 57. In this case, the lip seal 57 extends toward the piston 5, and the tip of the lip seal 57 is in contact with the piston 5.

Modification 6
In the above embodiment, the piston 5 is configured to slide on the output hub 8, and the turbine shell 31 is attached to the piston 5. However, the present invention is not limited to this configuration. For example, the turbine shell 31 may be configured to slide on the output hub 8, and the piston 5 may be attached to the turbine shell 31.

Modification 7
In the above embodiment, the outer peripheral wall portion of the outer shell of the torque converter 100 is configured by the first cylindrical portion 12 of the front cover 1, but the configuration of the outer peripheral wall portion is not limited thereto. For example, the impeller shell 21 has a cylindrical portion, and the outer peripheral wall portion may be constituted by the cylindrical portion of the impeller shell 21 and the first cylindrical portion 12 of the front cover 1. Or you may comprise an outer peripheral wall part only with the cylindrical part of the impeller shell 21. FIG.

1: Front cover 2: Impeller 21: Impeller shell 22: Impeller blade 3: Turbine 31: Turbine shell 32: Turbine blade 4: Lock-up part 5: Piston 56: Orifice hole 57: Lip seal 7: Damper device 8: Output hub 9: Driven plate 10: One-way valve 100: Torque converter

Claims (14)

A front cover to which torque is input;
An impeller having an impeller shell fixed to the front cover, and an impeller blade attached to the impeller shell;
A turbine having an axially movable turbine shell, and a turbine blade attached to the turbine shell;
A lockup portion formed on an outer peripheral wall portion of an outer shell constituted by the front cover and the impeller shell;
A piston configured to move integrally with the turbine in the axial direction and engage with the lockup portion by moving toward the front cover;
A one-way valve that allows a fluid flow from a space between the front cover and the piston to a space between the piston and the impeller shell;
A torque converter.
The piston is formed by a member separate from the turbine shell,
The piston and the turbine shell are coupled to each other;
The torque converter according to claim 1.
The one-way valve is disposed radially inward of an engagement portion between the piston and the lockup portion and radially outward of a coupling portion between the piston and the turbine shell, and is formed in the piston. To be
The torque converter according to claim 2.
The lock-up portion extends radially inward from the outer peripheral wall portion.
The torque converter in any one of Claim 1 to 3.
The one-way valve is disposed radially outside the engaging portion between the piston and the lockup portion, and is formed in the lockup portion.
The torque converter according to claim 4.
The lockup portion is configured by the outer peripheral wall portion.
The torque converter in any one of Claim 1 to 3.
The piston is in contact with the lockup portion in a state where the engagement with the lockup portion is released;
The torque converter according to any one of claims 1 to 6.
In a state where the engagement between the piston and the lock-up portion is released, a gap between the piston and the outer peripheral wall portion, or a gap between the piston and the lock-up portion is within 0.1 mm.
The torque converter according to any one of claims 1 to 6.
The one-way valve is a reed valve;
The torque converter in any one of Claim 1 to 8.
One of the piston and the lockup portion has a lip seal extending to the other of the piston and the lockup portion,
The torque converter in any one of Claim 1 to 9.
It further includes an output hub that outputs torque,
One of the piston and the turbine shell slides axially on the output hub;
One of the piston and the turbine shell sliding on the output hub has an orifice hole radially inward from the torus of the torque converter,
A torque converter according to any one of claims 1 to 10.
The piston has a cylindrical portion extending in an axial direction at an outer peripheral end portion,
The torque converter according to any one of claims 1 to 11.
The piston is formed of a material different from that of the turbine shell.
The torque converter according to any one of claims 1 to 12.
A damper device having an elastic member and disposed between the front cover and the piston;
A driven plate engaged with the elastic member;
Further comprising
The driven plate is attached to the piston or the turbine shell,
The torque converter according to any one of claims 1 to 13.

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