JP2011143754A - Drive device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive device for a hybrid vehicle capable of suppressing a shock generated in the drive device when rotating an output member to a prescribed direction and when changing over a drive mode. <P>SOLUTION: The drive device 2 mounted in the hybrid vehicle 1 includes: a differential mechanism 9 which is configured as a mutually differentially rotatable single pinion type planetary gear mechanism where an engine 3 and a first MG 5 are connected to a ring gear R through a clutch 10 allowing the intermittence of power transmission where a second MG 6 is connected to a sun gear S, and an output gear 8 for outputting power to drive wheels 7 of the vehicle 1 is connected to a carrier Cr positioned in the center when arranging respective rotation elements on a collinear diagram; a brake 11 capable of changing over the ring gear R between a braking state that the ring gear R cannot be rotated and a brake release state of releasing the braking state; and a controller 20 performing control so that the drive mode of the drive device 2 is changed over between a series drive mode and a series parallel drive mode according to the travel state of the vehicle 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a drive device for a hybrid vehicle that has an internal combustion engine and a motor generator and can be switched to a plurality of drive modes.

  A planetary gear mechanism having a sun gear, a ring gear and a carrier that can rotate differentially with each other, a second motor generator is connected to the sun gear, and an output member for outputting power to the drive wheels of the vehicle to the ring gear The carrier is provided with a differential mechanism to which the engine and the first motor generator are connected via a clutch and a brake capable of interrupting power transmission. The brake can be switched between a braking state in which the carrier is braked in a non-rotatable state and a braking release state in which the braking is released. In addition, a control unit that controls operations of the engine, the first motor generator, the second motor generator, the clutch, and the brake is provided. As a result, the clutch is in an engaged state in which power is transmitted between the engine and the first motor generator and the carrier, and the brake is in a braking state, and the engine and the first motor generator are stopped so as to stop the second motor generator. In the driving mode for driving the output member, the clutch is in the released state in which the power transmission between the engine and the first motor generator and the carrier is blocked, the brake is in the braking state, and the output member in the second motor generator The series drive mode in which the first motor generator is rotated by the engine and power is generated by the engine, the clutch is in the engaged state and the brake is in the brake released state, and the engine and the first motor generator output the output member. Drive and engine and first motor generator A hybrid that can be controlled by the control unit so as to be selectively switched to any one of a parallel drive mode in which the second motor generator is driven to rotate to generate power, and the vehicle can travel in each drive mode A vehicle drive device is known (see Patent Document 1).

JP 2000-209706 A

  In the hybrid vehicle drive device disclosed in Patent Document 1, when the output member is rotated in a predetermined direction, the rotation direction of the second motor generator is, for example, the opposite direction to the output member in the series drive mode, but in the parallel drive mode. The same direction as the output member. Therefore, when the series drive mode is switched to the parallel drive mode, the rotation direction of the second motor generator is reversed. Therefore, when the output member is rotated in a predetermined direction and when the drive mode is switched, there is a possibility that an impact may occur in the drive device.

  Accordingly, an object of the present invention is to provide a drive device for a hybrid vehicle that can suppress an impact generated in the drive device when the output member is rotated in a predetermined direction and the drive mode is switched.

  A drive device for a hybrid vehicle according to the present invention is a drive device mounted on a hybrid vehicle, and includes a first rotating element, a second rotating element, and a third rotating element that are differentially rotatable with respect to each other. The rotating elements are combined such that the third rotating element is located between the first rotating element and the second rotating element when the elements are arranged on a collinear diagram, and the first rotating element Is connected to an internal combustion engine and a first motor generator through clutch means capable of intermittently transmitting and receiving power, a second motor generator is connected to the second rotating element, and a driving wheel of the vehicle is connected to the third rotating element. A differential mechanism to which an output member for outputting power is connected, and a brake switchable between a braking state in which the first rotating element is braked in a non-rotatable state and a braking release state in which the braking is released And the driving mode of the driving device according to the traveling state of the vehicle, the clutch means being in an engaged state in which power is transmitted between the internal combustion engine and the first motor generator and the first rotating element. And the brake means is in the brake released state, and the output member is driven by the internal combustion engine and the second motor generator, and the first motor generator is rotationally driven by the internal combustion engine to generate electric power. 1 driving mode, the clutch means is in a released state in which power transmission between the internal combustion engine and the first motor generator and the first rotating element is blocked, and the brake means is in the braking state, and The output member is driven by the second motor generator, and the first motor generator is rotationally driven by the internal combustion engine. And a control means for controlling the operations of the internal combustion engine, the first motor generator, the second motor generator, the clutch means, and the brake means so as to be switched to (Claim 1).

  In the hybrid vehicle drive device of the present invention, when the output member is rotated in a predetermined direction, the rotation direction of the second motor generator is the same direction as the output member in the first drive mode, and the output is also output in the second drive mode. It is in the same direction as the member. Note that the rotation direction of the internal combustion engine in the first drive mode is also the same direction as the output member. Thus, the rotation direction of the second motor generator in each drive mode when the output member is rotated in a predetermined direction is the same. Therefore, even if the drive mode is switched, the rotation direction of the second motor generator is not reversed. Thereby, when rotating an output member to a predetermined direction and switching a drive mode, the impact which generate | occur | produces in a drive device can be suppressed.

  In one aspect of the hybrid vehicle drive device of the present invention, the differential mechanism is a single pinion type planetary gear mechanism having a sun gear, a ring gear, and a carrier, and the first rotating element is the ring gear. The second rotating element may be the sun gear, and the third rotating element may be the carrier. According to this embodiment, three rotating elements that are differentially rotated with each other are realized, and the above-described problems can be solved.

  In one aspect of the hybrid vehicle drive device of the present invention, the differential mechanism is a double pinion planetary gear mechanism having a sun gear, a ring gear, and a carrier, and the first rotating element is the carrier. The second rotating element may be the sun gear, and the third rotating element may be the ring gear. According to this embodiment, three rotating elements that are differentially rotated with each other are realized, and the above-described problems can be solved.

  As described above, in the hybrid vehicle drive device of the present invention, when the output member is rotated in a predetermined direction, the rotation direction of the second motor generator is the same direction as the output member in the first drive mode, Even in the second drive mode, the direction is the same as that of the output member. Note that the rotation direction of the internal combustion engine in the first drive mode is also the same direction as the output member. Thus, the rotation direction of the second motor generator in each drive mode when the output member is rotated in a predetermined direction is the same. Therefore, even if the drive mode is switched, the rotation direction of the second motor generator is not reversed. Thereby, when rotating an output member to a predetermined direction and switching a drive mode, the impact which generate | occur | produces in a drive device can be suppressed.

The figure which shows schematically the whole structure of the vehicle by which the drive device which concerns on one form of this invention is mounted. The figure which shows an example of the alignment chart of the drive device of the hybrid vehicle provided with the differential mechanism in which a vehicle is drive | working forward in series parallel drive mode. The figure which shows an example of the collinear diagram of the drive device of the hybrid vehicle provided with the differential mechanism in which the vehicle is moving ahead in series drive mode or EV drive mode. The figure which shows the relationship between the gear ratio in a series parallel drive mode, and theoretical transmission efficiency.

  FIG. 1 schematically shows the overall configuration of a vehicle on which a drive apparatus according to an embodiment of the present invention is mounted. As shown in this figure, the vehicle 1 is configured as a so-called hybrid vehicle. The vehicle 1 is provided with a driving device 2 for traveling. The drive device 2 includes an internal combustion engine (hereinafter sometimes referred to as an engine) 3 and a first motor generator (hereinafter simply referred to as a first MG) connected to a transmission shaft 4 that transmits power of the internal combustion engine 3. 5), a second motor generator 6 (hereinafter sometimes abbreviated as "second MG"), an output gear 8 as an output member for outputting power to the drive wheels 7 of the vehicle 1, and A differential mechanism 9 configured as a single pinion type planetary gear mechanism having a sun gear S, a ring gear R and a carrier Cr as three rotational elements capable of differential rotation, and a clutch as clutch means capable of intermittently transmitting and receiving power 10 and a brake 11 as a brake means. The transmission shaft 4 is connected to the oil pump 12.

  The internal combustion engine 3 is configured as a spark ignition type multi-cylinder internal combustion engine. The first MG 5 and the second MG 6 have the same configuration, and have both a function as an electric motor and a function as a generator. A battery (not shown) is electrically connected to the first MG 5 and the second MG 6 via an inverter (not shown). The first MG 5 includes a stator 5a fixed to a case 13 which is a fixing member, and a rotor 5b arranged coaxially on the inner peripheral side of the stator 5a. Similarly, the second MG 6 includes a stator 6a fixed to the case 13 and a rotor 6b arranged coaxially on the inner peripheral side of the stator 6a.

  As shown in FIG. 1, the output gear 8 is connected to a differential mechanism 9. In the power transmission path from the differential mechanism 9 to the drive wheel 7, a counter shaft 17 provided so that the counter gear 15 and the drive gear 16 rotate integrally, and a differential mechanism that transmits the rotation of the drive gear 16. 18 and a drive shaft 19 are provided. The counter shaft 17 is provided so that the counter gear 15 meshes with the output gear 8. Therefore, the power output from the differential mechanism 9 is transmitted to the differential mechanism 18 via the output gear 8, the counter gear 15, the counter shaft 17, and the drive gear 16. The power transmitted to the differential mechanism 18 is then transmitted to the drive wheel 7 via the drive shaft 19.

  As described above, the differential mechanism 9 has three rotating elements that are differentially rotatable with respect to each other. The differential mechanism 9 rotates and rotates a sun gear S that is an external gear, a ring gear R that is an internal gear disposed coaxially with the sun gear S, and a pinion P that meshes with these gears S and R. And a carrier Cr which is held so as to be freely revolved. In this embodiment, as shown in FIG. 1, the second gear MG6 is connected to the sun gear S, the internal combustion engine 3 and the first MG5 are connected to the ring gear R via the clutch 9, and the output gear 8 is connected to the carrier Cr. Has been. The illustrated sun gear S corresponds to the second rotating element of the present invention, the ring gear R corresponds to the first rotating element of the present invention, and the carrier Cr corresponds to the third rotating element of the present invention.

  The clutch 10 is provided between the engine 3 and the first MG 5 and the ring gear R, and power transmission is interrupted therebetween. That is, the clutch 10 is switched between an engaged state where the engine 3 and the first MG 5 and the ring gear R are connected and power is transmitted, and a released state where the connection is released and power transmission is blocked.

  The brake 11 is fixed to the case 13 and is provided between the case 13 and the ring gear R. The brake 11 is switched between a braking state in which the ring gear R is braked so as not to rotate and a braking release state in which the braking is released.

  The operation of the driving device 2 is controlled by the control device 20. The control device 20 is configured as a computer for appropriately controlling the operation of the hybrid vehicle 1, and outputs signals corresponding to the engine 3, the first MG 5, the second MG 6, the clutch 10, the brake 11, and the vehicle speed of the vehicle 1. A vehicle speed sensor 21 and an accelerator opening sensor 22 that outputs a signal corresponding to the accelerator opening are connected. In addition to this, peripheral devices such as various sensors are connected to the control device 20, but these are not shown.

  The control device 20 determines that the drive mode of the drive device 2 is the series / parallel drive mode as the first drive mode, the second drive mode, in accordance with the traveling state of the vehicle 1, that is, the numerical values acquired from various sensors such as the vehicle speed sensor 21. The operation of the engine 3, the first MG5, the second MG6, the clutch 10, the brake 11 and the like are respectively switched so as to be selectively switched to any one of the series drive mode as the first drive mode and the EV drive mode as the third drive mode. Control.

  First, when the vehicle 1 is driven in the series / parallel drive mode, the control device 20 controls the clutch 10 to the engaged state and the brake 11 to the brake released state, respectively, and the engine 3, the first MG 5 and the electric motor as the generator are controlled. The second MG 6 is controlled so as to operate. The power of the engine 3 is transmitted to the ring gear R because the clutch 10 is in the engaged state and the brake 11 is in the brake released state. Further, the ring gear R can be rotated because the brake 11 is in a brake released state. Therefore, the power of the engine 3 is transmitted to the carrier Cr that drives the output gear 8 via the ring gear R. The power of the second MG 6 that operates as an electric motor is transmitted via the sun gear S to the carrier Cr that drives the output gear 8. Therefore, the vehicle 1 can be driven by the power of the engine 3 and the second MG 6. At this time, the first MG 5 connected to the transmission shaft 4 is rotationally driven by the power of the engine 3 to generate electric power, that is, operate as a generator. The electric power generated by the generator is supplied to the second MG 6 via an inverter (not shown) and a battery (not shown). With this electric power, the second MG 6 operates as an electric motor. The generated power may be supplied to the second MG 6 via an inverter (not shown) instead of a battery (not shown).

  Next, when the vehicle 1 is driven in the series drive mode, the control device 20 controls the clutch 10 to the disengaged state and the brake 11 to the braking state, respectively, and the engine 3, the first MG 5 as the generator and the second MG 6 as the motor. Are controlled to operate. The power of the engine 3 is not transmitted to the ring gear R because the clutch 10 is in the released state. The ring gear R is fixed so as not to rotate by the brake 11 in a braking state. Therefore, the power of the second MG 6 that operates as an electric motor is transmitted to the carrier Cr that drives the output gear 8 via the sun gear S. As a result, the vehicle 1 can be driven by the power of the second MG 6. At this time, the first MG 5 connected to the transmission shaft 4 is rotationally driven by the power of the engine 3 to generate electric power, that is, operate as a generator. The electric power generated by the generator is supplied to the second MG 6 via an inverter (not shown) and a battery (not shown). With this electric power, the second MG 6 operates as an electric motor. The generated power may be supplied to the second MG 6 via an inverter (not shown) instead of a battery (not shown).

  Subsequently, when the vehicle 1 is driven in the EV drive mode, the control device 20 controls the clutch 10 to be in an engaged state and the brake 11 to be in a braking state, and controls the second MG 6 to operate as an electric motor. . Since the clutch 10 is in the engaged state, the engine 3 and the first MG 5 are controlled by the control device 20 so that they operate. However, since the brake 11 is in the braking state, the operation thereof is stopped. The ring gear R is fixed so as not to rotate by the brake 11 in a braking state. Therefore, the power of the second MG 6 that operates as an electric motor is transmitted via the sun gear S to the carrier Cr that drives the output gear 8. As a result, the vehicle 1 can be driven by the power of the second MG 6. As described above, the control device 20 functions as the control means of the present invention.

  2 and 3 show an example of a collinear diagram of the differential mechanism 9. As is well known, the collinear diagram is a well-known that the rotational speed of each rotating element can be represented by a straight line when the rotating elements of a differential mechanism such as a planetary gear mechanism are arranged at intervals based on the gear ratio (speed ratio). Is. As shown in FIGS. 2 and 3, when the three rotating elements of the single pinion type planetary gear mechanism 9 as the differential mechanism 9 are arranged on the collinear diagram, the order of the sun gear S, the carrier Cr, and the ring gear R is as follows. To arrange these elements. That is, the rotating elements are combined such that the carrier Cr as the third rotating element is positioned between the ring gear R as the first rotating element and the sun gear S as the second rotating element. As described above, referring to FIGS. 1 to 3, the second MG 6 is connected to the sun gear S, the output gear 8 is connected to the carrier Cr, and the internal combustion engine 3 and the first MG 5 are connected to the clutch 9 from the ring gear R. Connected through.

  FIG. 2 shows an example of a collinear diagram of a hybrid vehicle drive device having a differential mechanism in which the vehicle is traveling forward in the series / parallel drive mode. In this drive mode, since the vehicle 1 is traveling forward, the rotation direction of the output gear 8 is the forward rotation direction. Further, since the clutch 10 is controlled to the engaged state and the brake 11 is controlled to the brake released state, the forward rotation torque output from the engine 3 is transmitted to the carrier Cr via the ring gear R. At this time, the reverse torque is applied to the sun gear S by the output torque transmitted from the ring gear R to the carrier Cr. However, since the torque in the forward rotation direction is output from the second MG 6 so that the sun gear S does not rotate in the reverse rotation direction, neither the sun gear S nor the second MG 6 rotates in the reverse rotation direction. Therefore, the rotational speed of the second MG 6 is 0 on the alignment chart of FIG. By increasing the output torque of the second MG 6, the second MG 6 rotates in the forward rotation direction on the alignment chart.

  FIG. 3 shows an example of a collinear diagram of the differential mechanism in which the vehicle is traveling forward in the series drive mode or the EV drive mode. In these drive modes, since the vehicle 1 is traveling forward, the rotation direction of the output gear 8 is the forward rotation direction. Further, the rotation speed of the ring gear R is fixed to 0 by the brake 11 being controlled to be in a braking state. Thereby, the torque output from the second MG 6 is transmitted to the carrier Cr. As shown in FIG. 3, the second MG 6 rotates in the forward rotation direction.

  According to the above configuration, when the control device 20 functions as the control means of the present invention, the drive mode of the drive device 2 is set to the series / parallel drive mode, the series drive mode, and the EV according to the traveling state of the vehicle 1. It is possible to selectively switch to any one of the drive modes, and the vehicle 1 can travel in these three drive modes. Further, the sun gear S, the ring gear R, and the carrier Cr function as the three rotating elements of the present invention, so that three rotating elements that are differentially rotated with each other can be realized. Furthermore, the rotation direction of the second MG 6 in each drive mode during forward traveling is the normal rotation direction (the same direction). Therefore, even if the drive mode is switched, the rotation direction of the second MG 6 is not reversed. Thereby, the impact which generate | occur | produces in the drive device 2 at the time of forward driving | running | working (when rotating an output member to a predetermined direction) and switching a drive mode can be suppressed.

  FIG. 4 shows the relationship between the gear ratio and the theoretical transmission efficiency in the series / parallel running mode. In this figure, the present invention is indicated by a solid line L1, and a comparative example is indicated by a one-dot chain line L2 for comparison with the present invention. An alternate long and short dash line L2 is configured as a planetary gear mechanism having a sun gear, a ring gear, and a carrier that can be differentially rotated with each other, and the second MG is connected to the sun gear, and the ring gear outputs power to the drive wheels of the vehicle. The output member is connected, and the carrier is provided with a differential mechanism to which the engine and the first MG are connected via a clutch capable of interrupting power transmission. The brake is connected to the case and can be switched between a braking state in which the carrier is braked so as not to rotate and a braking release state in which the braking is released. Further, a control device is provided for controlling the operations of the engine, the first MG, the second MG, the clutch, and the brake so as to be selectively switched to any one of the three drive modes. The clutch is in an engaged state in which power is transmitted between the engine and the first MG and the carrier, the brake is in a brake released state, and the output gear is driven by the engine and the second MG, and the first MG is driven by the engine. A hybrid vehicle drive device in which the vehicle travels in the series / parallel drive mode of the three drive modes by being controlled so as to generate electric power by being rotationally driven.

  As illustrated, the theoretical transmission efficiencies of the solid line L1 and the alternate long and short dash line L2 change with respect to the gear ratio. When the first MG is 0, the point where the theoretical transmission efficiency is 1 is a mechanical point, and the left side of FIG. 4 is the high speed side and the right side of FIG. 4 is the low speed side. In contrast to the alternate long and short dash line L2, in the solid line L1 of the present invention, the mechanical point can be set to the low speed side by the above-described configuration. Therefore, the solid line L1 can suppress deterioration in fuel consumption as compared with the alternate long and short dash line L2 even when the low-frequency side traveling frequency is high.

  The present invention is not limited to the above-described form and can be implemented in various forms. The EV drive mode as the third drive mode described above is not limited to the control described above. For example, when the vehicle 1 is driven in the EV drive mode, the control device 20 controls the clutch 10 to be in the disengaged state and the brake 11 to be in the braking state, respectively, and controls the second MG 6 to operate as an electric motor. Control is performed by the control device 20 so that the operations of the engine 3 and the first MG 5 are stopped. The ring gear R is fixed so as not to rotate by the brake 11 in a braking state. Therefore, the power of the second MG 6 that operates as an electric motor is transmitted via the sun gear S to the carrier Cr that drives the output gear 8. As a result, the vehicle 1 can be driven by the power of the second MG 6. That is, in the series drive mode described above, the EV drive mode in this case is set by being controlled by the control device 20 so that the operations of the engine 3 and the first MG 5 are stopped. In this case, in the EV drive mode, the rotation speed of the ring gear R is fixed to 0 by the brake 11 that is controlled in the braking state. Thereby, the torque output from the second MG 6 is transmitted to the carrier Cr. Further, the operations of the engine 3 and the first MG 5 are stopped. Therefore, an example of a collinear diagram of the differential mechanism in which the vehicle is traveling forward in the EV drive mode in this case is the same as FIG. As shown in FIG. 3, even in the EV drive mode in this case, the second MG 6 rotates in the forward rotation direction. In the EV drive mode in this case, since the vehicle 1 is traveling forward, the rotation direction of the output gear 8 is the normal rotation direction. Therefore, even if the EV drive mode as the third drive mode described above is changed to the EV drive mode in this case, the above-described effects can be obtained.

  In the embodiment described above, a single pinion type planetary gear mechanism is applied as the differential mechanism 9, but a double pinion type planetary gear mechanism having a sun gear S, a ring gear R, and a carrier Cr may be applied. In this case, the first rotating element may be the carrier Cr, the second rotating element may be the sun gear S, and the third rotating element may be the ring gear R.

  In the embodiment described above, the planetary gear mechanism is applied as the differential mechanism 9, but a planetary roller mechanism having a sun roller, a ring roller, and a carrier may be applied.

  In the above-described embodiment, the switching of the three drive modes as the drive mode of the drive device 2 has been described. However, the control device 20 determines the drive device according to the traveling state of the vehicle 1, that is, the numerical values acquired from various sensors such as the vehicle speed sensor 21. 2, the engine 3, the first MG 5, the second MG 6, the clutch 10, and the brake so that the drive mode can be switched between a series / parallel drive mode as the first drive mode and a series drive mode as the second drive mode. Each of the operations such as 11 may be controlled.

  When the vehicle 1 is decelerated, the first MG 5 and the second MG 6 are controlled by the control device 20 so as to operate as generators, and the generated power may be regenerated to a battery (not shown) via an inverter (not shown). .

2 Drive device 3 Internal combustion engine (engine)
4 Transmission shaft 5 First motor generator (first MG, electric motor, generator)
6 Second motor generator (second MG, electric motor, generator)
8 Output gear (output member)
9 Differential mechanism (planetary gear mechanism, single pinion type planetary gear mechanism, double pinion type planetary gear mechanism, planetary roller mechanism)
10 Clutch (clutch means)
11 Brake (brake means)
13 Case 20 Control device (control means)
S Sun Gear R Ring Gear P Pinion Cr Carrier

Claims (3)

A drive device mounted on a hybrid vehicle,
The first rotating element and the second rotating element have a first rotating element, a second rotating element, and a third rotating element that are differentially rotatable with each other, and the rotating elements are arranged on a collinear diagram. The rotary elements are combined so that the third rotary element is positioned between the internal combustion engine and the first motor generator via clutch means capable of interrupting power transmission. A differential mechanism in which a second motor generator is connected to the second rotating element, and an output member for outputting power to driving wheels of the vehicle is connected to the third rotating element;
Brake means switchable between a braking state in which the first rotation element is braked in a non-rotatable manner and a braking release state in which the braking is released;
The drive mode of the drive device is in an engaged state in which power is transmitted between the internal combustion engine, the first motor generator, and the first rotating element according to the traveling state of the vehicle. A first drive mode in which the brake means is in the brake released state, and the internal combustion engine and the second motor generator drive the output member and the internal combustion engine rotationally drives the first motor generator to generate electric power. The clutch means is in a released state in which power transmission between the internal combustion engine and the first motor generator and the first rotating element is blocked, and the brake means is in the braking state, and the second The motor generator drives the output member and the internal combustion engine drives the first motor generator to generate power. Second driving mode and, the internal combustion engine to be switched on to carry out, and the first motor generator, the second motor-generator, the clutch means, and control means for respectively controlling operation of said brake means,
A drive device for a hybrid vehicle comprising: The differential mechanism is a single pinion type planetary gear mechanism having a sun gear, a ring gear, and a carrier,
2. The drive device for a hybrid vehicle according to claim 1, wherein the first rotation element is the ring gear, the second rotation element is the sun gear, and the third rotation element is the carrier. The differential mechanism is a double pinion type planetary gear mechanism having a sun gear, a ring gear, and a carrier,
2. The drive device for a hybrid vehicle according to claim 1, wherein the first rotating element is the carrier, the second rotating element is the sun gear, and the third rotating element is the ring gear.

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