JP2015001301A - Vehicle power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lubricate a toroidal gear change mechanism of a vehicle power transmission device and power transmission gears with suitable oil.SOLUTION: The inside of a transmission case 11 is partitioned into a first chamber 15 for accommodating a toroidal gear change mechanism 22 and a second chamber 16 for accommodating a first gear 32 and a second gear 38, the toroidal gear change mechanism 22 in the first chamber 15 is lubricated with first oil, the first gear 32 and the second gear 38 in the second chamber 16 are lubricated with second oil, thereby a temperature and the viscosity of the first oil which is desired to be maintained at a relatively-low temperature and high viscosity and a temperature and the viscosity of the second oil which is desired to be maintained at a relatively-high temperature and low viscosity can be independently managed, the traction performance of the toroidal gear change mechanism 22 can be improved, and the reduction of the agitation resistance of the second oil caused by the first and second gears 32, 38 and the reduction of drive loads of oil pumps 42, 46 for supplying the second oil can be achieved.

Description

  The present invention provides a first gear disposed on the input shaft after the input shaft and the output shaft are disposed in parallel inside the transmission case and the engine driving force is shifted by a toroidal transmission mechanism disposed on the input shaft. The present invention also relates to a vehicle power transmission device that outputs to a differential gear via a second gear disposed on the output shaft.

  In a hybrid vehicle including both an internal combustion engine and an electric motor as a driving source for traveling, the first cooling water circulation passage includes a first cooling water circulation passage for cooling the internal combustion engine and a second cooling water circulation passage for cooling the electric motor. Further, it is known from Patent Document 1 and Patent Document 2 below that the radiator of the second cooling water circulation passage is integrally configured.

JP-A-10-266855 Japanese Patent Laid-Open No. 10-259721

  By the way, inside a transmission case of a continuously variable transmission equipped with a toroidal transmission mechanism, a toroidal transmission mechanism and other power transmission mechanisms such as a gear and a wet multi-plate clutch are housed. The other power transmission mechanisms were lubricated with the common oil stored in the mission case. However, it is desirable that the oil that lubricates the toroidal transmission mechanism is a relatively high viscosity oil to prevent the input and output disks from slipping against the power roller, while the gear and wet The oil for lubricating other power transmission mechanisms such as a multi-plate clutch is desirably an oil having a relatively low viscosity in order to reduce the stirring resistance and the driving load of the oil pump.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to lubricate a toroidal transmission mechanism of a power transmission device for a vehicle and a gear for power transmission with appropriate oils.

  In order to achieve the above object, according to the first aspect of the present invention, a toroidal transmission in which an input shaft and an output shaft are arranged in parallel inside a mission case and the driving force of the engine is arranged on the input shaft. A power transmission device for a vehicle that outputs to a differential gear via a first gear arranged on the input shaft and a second gear arranged on the output shaft after shifting by a mechanism, wherein the inside of the transmission case is Partitioning into a first chamber housing the toroidal transmission mechanism and a second chamber housing the first gear and the second gear, lubricating the toroidal transmission mechanism in the first chamber with a first oil, A vehicle power transmission device is proposed in which the first gear and the second gear in a second chamber are lubricated with a second oil.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, an electric motor capable of transmitting a driving force to the differential gear without using the toroidal speed change mechanism is provided, and the engine is a first engine. Cooled by a cooling medium, the electric motor is cooled by a second cooling medium, the first oil exchanges heat with only the second cooling medium, and the second oil is in an operating state of the engine and the electric motor. Accordingly, there is proposed a vehicle power transmission device that performs heat exchange with the first cooling medium or the second cooling medium that is selectively supplied by a cooling medium switching mechanism.

  According to the invention described in claim 3, in addition to the configuration of claim 2, the cooling medium switching mechanism is configured such that the temperature of the second cooling medium is higher than the temperature of the first cooling medium. Heat exchange of the second cooling medium with the second oil, and heat exchange of the first cooling medium with the second oil when the temperature of the first cooling medium is higher than the temperature of the second cooling medium. A vehicle power transmission device is proposed.

  In addition, the 1st cooling water of embodiment respond | corresponds to the 1st cooling medium of this invention, and the 2nd cooling water of embodiment corresponds to the 2nd cooling medium of this invention.

  According to the configuration of the first aspect of the present invention, the vehicle power transmission device is configured such that the input shaft and the output shaft are arranged in parallel inside the transmission case, and the engine driving force is shifted by the toroidal transmission mechanism disposed on the input shaft. Then, it outputs to the differential gear via the first gear arranged on the input shaft and the second gear arranged on the output shaft. The interior of the transmission case is partitioned into a first chamber that houses the toroidal transmission mechanism and a second chamber that houses the first gear and the second gear, and the toroidal transmission mechanism in the first chamber is lubricated with the first oil, Since the first gear and the second gear in the two chambers are lubricated with the second oil, it is desirable to maintain the viscosity and the viscosity of the first oil at a relatively low temperature, and to maintain the viscosity at a relatively high temperature and a low viscosity. It is desirable to control the temperature and viscosity of the second oil separately, improve the traction performance of the toroidal transmission mechanism, reduce the stirring resistance of the second oil by the first and second gears, and reduce the second oil The drive load of the oil pump to be supplied can be reduced.

  According to the second aspect of the invention, the electric motor capable of transmitting the driving force to the differential gear without using the toroidal transmission mechanism is provided, the engine is cooled by the first cooling medium, and the electric motor is cooled by the second cooling medium. Is done. Since the first oil exchanges heat only with the second cooling medium, the first oil can be kept at a low temperature by heat exchange with the relatively low-temperature second cooling medium that has cooled the electric motor. Further, since the second oil exchanges heat with the first cooling medium or the second cooling medium selectively supplied by the cooling medium switching mechanism according to the operating state of the engine and the electric motor, the first cooling medium or the second cooling medium is exchanged. An advantageous one of the cooling media can be used to maintain the second oil at a high temperature.

  According to the configuration of claim 3, the cooling medium switching mechanism causes the second cooling medium to exchange heat with the second oil when the temperature of the second cooling medium is higher than the temperature of the first cooling medium. When the temperature of the cooling medium is higher than the temperature of the second cooling medium, the first cooling medium is exchanged with the second oil, so that one of the higher temperatures of the first and second cooling mediums is effectively used. By utilizing this, the temperature of the second oil can be raised to the maximum.

Sectional drawing of the power transmission device for vehicles (1-1 sectional view taken on the line of FIG. 3). Sectional drawing of the motive power transmission device for vehicles (2-2 sectional view taken on the line of FIG. 3). FIG. 3 is a three-direction arrow view of FIG. 1. The circuit diagram of the heat exchange system of 1st, 2nd cooling water and 1st, 2nd oil. The time chart explaining the effect | action of the heat exchange of the oil of a continuously variable transmission.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the transmission case 11 of the continuously variable transmission T for a hybrid vehicle includes a first case 12, a second case 13 coupled to the first case 12, and a second case 13. And a third case 14 to be joined. Partitions 12 a and 13 a are formed in the first case 12 and the second case 13, respectively. A first chamber 15 is defined between the partition walls 13 a of the third case 14 and the second case 13. A second chamber 16 is defined between the partition wall 12a of the first case 12 and the third chamber 17 on the left side of the partition wall 12a of the first case 12 in the figure.

  An input shaft 18 is supported so as to straddle the first case 12, the second case 13, and the third case 14, and the left end portion of the input shaft 18 extending into the third chamber 17 has a damper 19 and a generator 20. To the crankshaft 21 of the engine E.

  A toroidal transmission mechanism 22 having a known structure is provided at the right end of the input shaft 18 extending into the first chamber 15. The single cavity type toroidal speed change mechanism 22 includes a substantially cone-shaped input disk 23 supported on the input shaft 18 so as not to rotate relative to the input shaft and slidable in the axial direction, and rotatable relative to the input shaft 18 and slidable in the axial direction. A pair of crank-shaped pivots having one end rotatably supported by a substantially cone-shaped output disk 24 supported and opposed to the input disk 23, and a pair of trunnions (not shown) arranged so as to sandwich the input shaft 18 therebetween. The shafts 25 and 25, a pair of power rollers 26 and 26 which are rotatably supported by the other ends of the pivot shafts 25 and 25 and abut against the input disk 23 and the output disk 24, and the input disk 23 is hydraulically connected to the output disk 24 side. And a hydraulic loader 27 that suppresses the slippage of the power rollers 26 and 26.

  Opposing surfaces of the input disk 23 and the output disk 24 are formed of toroidal curved surfaces. When the pair of trunnions move in the opposite directions along the trunnion shafts 28, 28, the pair of power rollers 26, 26 are moved to the trunnion shaft 28. , 28 and the contact points of the power rollers 26, 26 with respect to the input disk 23 and the output disk 24 change, so that the gear ratio between the input disk 23 and the output disk 24 changes steplessly.

  A first oil pump 29 is disposed inside the first chamber 15, and the drive gear 30 fixed to the input disk 23 is engaged with the driven gear 31 fixed to the pump shaft, so that the input shaft 18 is rotated. In conjunction with this, the first oil pump 29 is driven. The first oil pump 29 pumps up the first oil stored in the bottom of the first chamber 15 and supplies it to the hydraulic loader 27 as hydraulic oil and supplies it to the toroidal transmission mechanism 22 as lubricating oil.

  When the pair of trunnions are driven in opposite directions along the trunnion shafts 28 and 28 by the hydraulic pressure generated by the first oil pump 29, the power rollers 26 and 26 are tilted in one direction around the trunnion shafts 28 and 28, Since the contact point with the input disk 23 moves radially outward with respect to the input shaft 18, and the contact point with the output disk 24 moves radially inward with respect to the input shaft 18, the rotation of the input disk 23 rotates. The speed is increased and transmitted to the output disk 24, and the gear ratio of the toroidal transmission mechanism 22 is continuously reduced.

  On the other hand, when the pair of trunnions are driven along the trunnion shafts 28, 28 in the opposite direction, the power rollers 26, 26 are tilted around the trunnion shafts 28, 28 in the other direction and contact points with the input disk 23. Moves radially inward with respect to the input shaft 18, and the contact point with the output disk 24 moves radially outward with respect to the input shaft 18, so that the rotation of the input disk 23 is decelerated to the output disk 24. The transmission ratio of the toroidal transmission mechanism 22 is continuously increased.

  In the second chamber 16, a first gear 32 is supported on the outer periphery of the input shaft 18 so as to be relatively rotatable, and the first gear 32 is attached to the output disk 24 of the toroidal transmission mechanism 22 with a wet multi-plate hydraulic clutch 33. Can be coupled through. A drive gear 34 is fixed to the input shaft 18 through a nut 48 so as not to be relatively rotatable and axially movable. Two thrust bearings 35 and 36 are disposed between the drive gear 34 and the first gear 32. The

  Accordingly, the load that the hydraulic loader 27 of the toroidal transmission mechanism 22 presses the input disk 23 leftward in FIG. 1 is the path of the power rollers 26, 26 → the output disk 24 → the hydraulic clutch 33 → the thrust bearing 35, and the second case 13 It is transmitted to and supported by the support member 13b fixed to the head. Further, the load by which the hydraulic loader 27 of the toroidal transmission mechanism 22 presses the input shaft 18 to the right in FIG. 1 is transmitted to and supported by the support member 13b through the path of nut 48 → thrust bearing 36.

  An output shaft 37 parallel to the input shaft 18 is supported inside the second chamber 16, and a second gear 38 that meshes with the first gear 32 and a final drive gear 39 are fixed to the output shaft 37. Is done. A differential gear D is disposed inside the second chamber 16, and a final driven gear 40 fixed to the casing meshes with the final drive gear 39.

  A pair of axles 41, 41 extends from the differential gear D to the left and right through the first case 12 and the second case 13.

  Further, a second oil pump 42 is disposed inside the second chamber 16, and the drive gear 34 fixed to the input shaft 18 is engaged with the driven gear 43 fixed to the pump shaft, so that the input shaft 18 The second oil pump 42 is driven in conjunction with the rotation. The second oil pump 42 pumps up the second oil stored in the bottom of the second chamber 16 and supplies it as hydraulic oil to the hydraulic clutch 33, and also includes the first gear 32, the second gear 38, the differential gear D, and the hydraulic clutch. 33 is supplied as lubricating oil.

  An electric motor M is supported on the right side surface of the second case 13, and a motor output gear 45 fixed to the motor shaft 44 protruding into the second chamber 16 is connected to a second gear 38 fixed to the output shaft 37. Mesh. A third oil pump 46 is disposed inside the second chamber 16, and a driven gear 47 fixed to the pump shaft meshes with the final driven gear 40.

  Next, a circuit diagram of the heat exchange system for the first and second cooling water and the first and second oils will be described with reference to FIG.

  The cooling system of the engine E includes a first cooling water pump 51 driven by the engine E, a first radiator 52 that cools the first cooling water whose temperature has been increased by exchanging heat with the engine E, and a warming temperature of the engine E. It is comprised with the thermostat 53 which blocks | prevents circulation of the 1st cooling water temporarily at the time of an incomplete machine.

  The cooling system of the electric motor M includes a second cooling water pump 54 driven by the electric motor M, a second radiator 55 that cools the second cooling water whose temperature has been increased by heat exchange with the electric motor M, and a toroidal The second heat exchanger 56 is configured to exchange heat with the first oil in the first chamber 15 that houses the speed change mechanism 22. In addition to the electric motor M, the second cooling water cools a PDU (power drive unit) 57 that converts a direct current of a battery (not shown) into a three-layer alternating current.

  Further, a portion other than the toroidal transmission mechanism 22 of the continuously variable transmission T, that is, a power transmission mechanism such as the first gear 32, the second gear 38, the differential gear D, and the hydraulic clutch 33 housed in the second chamber 16 is lubricated. The second oil is cooled by the first heat exchanger 58. The cooling medium that exchanges heat with the second oil by the first heat exchanger 58 is switched by the cooling medium switching mechanism 59. That is, the cooling medium switching mechanism 59 supplies the first cooling water that cools the engine E and the second cooling water that cools the electric motor M and the like to the first heat exchanger 58.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  The vehicle according to the present embodiment includes an engine E and an electric motor M as a driving source for traveling. When the remaining capacity of the battery is sufficient, the vehicle travels with the driving force of the electric motor M without using the engine E. To do. That is, when the electric motor M is driven in a state where the hydraulic clutch 33 is disengaged, the driving force is the axle 41 in the path of the motor output gear 45 → second gear 38 → final drive gear 39 → final driven gear 40 → differential gear D. , 41, the vehicle travels forward or backward depending on the direction of rotation of the electric motor M.

  When the remaining capacity of the battery becomes a predetermined value or less, the traveling by the electric motor M is switched to the traveling by the engine E. That is, when the engine E is driven with the hydraulic clutch 33 engaged, the driving force thereof is the input shaft 18 → toroidal transmission mechanism 22 → hydraulic clutch 33 → first gear 32 → second gear 38 → final drive gear 39 → final. The vehicle is transmitted to the axles 41 and 41 through a path of the driven gear 40 → the differential gear D, and the vehicle travels forward with the driving force of the engine E. At this time, the gear ratio can be arbitrarily changed by driving the trunnion of the toroidal transmission mechanism 22 to change the tilt angle of the power rollers 26 and 26.

Further, the electric motor M can be driven when the vehicle starts, and both the engine E and the electric motor M can be driven when traveling uphill, and the electric power for driving the electric motor M at that time is the electric motor M by the engine E. Can be obtained by driving as a generator,
By the way, the first oil that lubricates the toroidal transmission mechanism 22 in the first chamber 15 is relatively high in order to ensure the frictional force of the contact portion between the input disk 23 and the output disk 24 and the power rollers 26 and 26. Viscosity is necessary, and for this reason it is necessary to keep the temperature of the first oil relatively low. On the other hand, the second oil that lubricates the first gear 32, the second gear 38, the differential gear D, the hydraulic clutch 33, and the like in the second chamber 16 desirably has a low viscosity in order to reduce the agitation resistance. In addition, it is necessary to keep the temperature of the second oil relatively high.

  If the first oil in the first chamber 15 and the second oil in the second chamber are shared, the above two requirements cannot be satisfied. However, according to the present embodiment, the interior of the mission case 11 is By partitioning into the 1st chamber 15 holding 1 oil, and the 2nd chamber 16 holding the 2nd oil, the temperature and the viscosity of the 1st oil and the 2nd oil can be managed separately.

  Hereinafter, the operation of the temperature management of the first oil and the second oil will be described with reference to the time chart of FIG.

  Mode 1 in the time chart of FIG. 5 is an EV travel mode in which the vehicle travels only by the driving force of the electric motor M without using the engine E when the remaining capacity of the battery is sufficient. When the remaining battery capacity is reduced by the EV driving mode, the driving force of the engine E is basically used by driving the driving force of the engine E, and the electric motor M is auxiliaryly used by the driving force of the engine E. This is an HEV traveling mode in which the battery is charged by operating as a generator. Further, mode 2 of the HEV traveling mode is a mode when the temperature of the first cooling water (cooling water of the engine E) is low, and mode 3 of the HEV traveling mode is when the temperature of the first cooling water is high. Mode.

  In mode 1, the engine E is stopped and the electric motor M is driven, so that the driving force of the electric motor M is the path of the motor output gear 45 → second gear 38 → final drive gear 39 → final driven gear 40 → differential gear D. Therefore, the third oil pump 46 connected via the driven gear 47 is operated by the final driven gear 40 to supply the second oil in the second chamber 16 to the first heat exchanger 58. . At this time, since the hydraulic clutch 33 is disengaged, even if the first gear 32 meshed with the second gear 38 rotates, the rotation of the first gear 32 is transmitted to the toroidal transmission mechanism 22 and the input shaft 18. Instead, the first oil pump 29 and the second oil pump 42 are stopped. When the first oil pump 29 is stopped, the first oil is not supplied to the second heat exchanger 56.

  In this mode 1, the cooling medium switching mechanism 59 supplies the second cooling water (cooling water for the electric motor M and the PDU 57) to the first heat exchanger 58 and exchanges heat with the second oil in the second chamber 16. To do. The second oil that lubricates the first gear 32 and the second gear 38 preferably has a relatively high temperature in order to reduce its viscosity and reduce the stirring resistance and the driving load of the third oil pump 46. By cooling the electric motor M and the PDU 57 and exchanging heat with the second cooling water whose temperature has risen, the temperature of the second oil can be raised quickly.

  At this time, since the engine E is stopped, the first cooling water that is the cooling water of the engine E is lower in temperature than the second cooling water, and the heat is temporarily exchanged between the first cooling water and the second oil. In this case, it is difficult to raise the temperature of the second oil early.

  When the remaining capacity of the battery falls below a predetermined value, the mode shifts to the HEV mode, basically travels with the driving force of the engine E, uses the driving force of the electric motor M as an auxiliary, and generates electric power with the driving force of the engine E. To charge the battery. Mode 2 of the HEV modes is a mode immediately after the operation of the engine E is started, and the temperature of the first cooling water is not sufficiently increased. Therefore, as in the mode 1, the second oil and the second cooling are performed. Exchange heat with water. Further, mode 3 of the HEV mode is a mode when the temperature of the first cooling water exceeds the temperature of the second cooling water, and the cooling medium switching mechanism 59 is replaced with the high-temperature first cooling water instead of the low-temperature second cooling water. By supplying 1 cooling water to the first heat exchanger 58 and exchanging heat with the second oil in the second chamber 16, the temperature of the second oil can be further increased to further reduce the viscosity. .

  Further, since the engine E is driven in the HEV mode, the first oil pump 29 and the second oil pump 42 that operate in conjunction with the rotation of the input shaft 18 operate. The second oil pump 42 cooperates with the third oil pump 46 to supply the second oil in the second chamber 16 to the first heat exchanger 58. The first oil pump 29 supplies the first oil in the first chamber 15 to the second heat exchanger 56.

  The first oil that lubricates the toroidal transmission mechanism 22 is desirably relatively low temperature and high viscosity in order to prevent slipping between the input disk 23, the output disk 24, and the power rollers 26, 26. In the entire period of the HEV mode in which the mechanism 22 operates, the temperature of the first oil can be kept low by exchanging heat between the first oil and the relatively low-temperature second cooling water.

  While driving in the HEV mode, the battery is charged by operating the electric motor M as a generator with the driving force of the engine E, and when the remaining capacity of the battery is restored, the frequency of use of the engine E decreases and the electric motor M is used. Since the frequency increases, the temperature of the first cooling water gradually decreases and the temperature of the second cooling water gradually increases. As a result, when the temperature of the second cooling water exceeds the temperature of the first cooling water, the mode 3 is switched to mode 2 again, and the second oil is subjected to heat exchange with the high-temperature second cooling water. The temperature can be kept high.

  When the remaining capacity of the battery further recovers, the EV mode (mode 1) is entered again, the engine E is stopped, and the vehicle runs only with the driving force of the electric motor M. In this mode 1, since the temperature of the first cooling water is lower than the temperature of the second cooling water, the second oil exchanges heat with the second cooling water having a higher temperature.

  As described above, the first chamber 15 that houses the toroidal transmission mechanism 22 inside the transmission case 11, and the second chamber 16 that houses the first gear 32, the second gear 38, the differential gear D, the hydraulic clutch 33, and the like. The toroidal transmission mechanism 22 in the first chamber 15 is lubricated with the first oil, and the first gear 32, the second gear 38, the differential gear D, the hydraulic clutch 33, etc. in the second chamber 16 are lubricated with the second oil. Since it is lubricated, the temperature and viscosity of the first oil, which is desirably maintained at a relatively low temperature and high viscosity, and the temperature and viscosity of the second oil, which is desirably maintained at a relatively high temperature and low viscosity, are separately provided. To improve the traction performance of the toroidal transmission mechanism 22, reduce the stirring resistance of the second oil by the first and second gears 32, 38, and supply the second oil 3 can be reduced drive load of the oil pump 42, 46.

  In addition, since the first oil, which is desirably maintained at a low temperature, exchanges heat with only the relatively low-temperature second cooling water, the traction performance of the toroidal transmission mechanism 22 can be ensured by keeping the temperature of the first oil low. it can. In addition, since the second oil, which is desirably maintained at a relatively high temperature, exchanges heat with one of the first cooling water and the second cooling water, the temperature of the second oil is increased to the maximum. Thus, the viscosity can be reduced, the stirring resistance can be reduced, and the driving loads of the second and third oil pumps 42 and 46 for supplying the second oil can be reduced.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the toroidal transmission mechanism 22 of the embodiment is of a single cavity type, but may be of a double cavity type.

11 Transmission case 15 First chamber 16 Second chamber 18 Input shaft 22 Toroidal transmission mechanism 32 First gear 37 Output shaft 38 Second gear 59 Cooling medium switching mechanism D Differential gear E Engine M Electric motor

Claims (3)

A toroidal transmission mechanism (22) in which an input shaft (18) and an output shaft (37) are arranged in parallel inside the mission case (11) and the driving force of the engine (E) is arranged on the input shaft (18). For a vehicle that outputs to a differential gear (D) via a first gear (32) disposed on the input shaft (18) and a second gear (38) disposed on the output shaft (37) after shifting. A power transmission device,
Inside the transmission case (11), a first chamber (15) that houses the toroidal transmission mechanism (22), and a second chamber that houses the first gear (32) and the second gear (38) ( 16), the toroidal transmission mechanism (22) in the first chamber (15) is lubricated with the first oil, and the first gear (32) and the second gear in the second chamber (16) are lubricated. A power transmission device for a vehicle, wherein the gear (38) is lubricated with a second oil. An electric motor (M) capable of transmitting a driving force to the differential gear (D) without passing through the toroidal transmission mechanism (22), the engine (E) is cooled by a first cooling medium, and the electric motor ( M) is cooled by the second cooling medium,
The first oil exchanges heat only with the second cooling medium;
The first oil or the second cooling medium is selectively supplied by the cooling medium switching mechanism (59) according to the operating state of the engine (E) and the electric motor (M). The vehicle power transmission device according to claim 1, wherein heat exchange with the vehicle is performed.   The cooling medium switching mechanism (59) causes the second cooling medium to exchange heat with the second oil when the temperature of the second cooling medium is higher than the temperature of the first cooling medium, and the first cooling medium 3. The vehicle power transmission device according to claim 2, wherein when the temperature of the first cooling medium is higher than the temperature of the second cooling medium, the first cooling medium exchanges heat with the second oil.

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